Fresh water from the nucleus

Inderscience: Embargoed for release: 20-Nov-2007 00:15 Eastern US

The discovery of an environmentally friendly way to take salt out of seawater would be a major breakthrough for the world. Fresh, clean drinking water wherever it is needed would save lives, promote good health and even prevent war.

More than 3.5 billion people will be living in areas of severe water shortage by 2025. Climate change, desertification and over-population are all reducing fresh water supplies. Fresh water could soon become a rare and expensive commodity.

India faces a rapidly increasing demand for fresh water. This is driven by a growing population and by agricultural and industrial expansion.

New solutions to the old problem of getting fresh water supplies were explored at the Trombay Symposium on desalination and Water Reuse. These have now been published in a special issue of the International journal of Nuclear Desalination (IJND).

The methods of desalination that are used now are expensive and inefficient. There are a number of alternatives.

Pradip Tewari (of the desalination Division at Bhabha Atomic Research Centre, Mumbai) suggests a holistic approach. This would include seawater desalination in coastal areas, brackish water desalination and rainwater harvesting. This last is particularly useful in the monsoon season.

"The contribution of seawater and brackish water desalination would play an important role in augmenting the freshwater needs of the country," Tewari says.

Meenakshi Jain (CDM & Environmental Services and Positive Climate Care Pvt Ltd in Jaipur) draws attention to the energy problem. "Desalination is an energy-intensive process," he says.

Fossil fuels are only a short-term answer. In the long term, "desalination with fossil energy sources would not be compatible with sustainable development."

Fossil fuel reserves are finite, he adds, and "must be conserved for other essential uses". But the demand for desalted water will continue to rise.

A sustainable solution to water shortages that does not cause pollution is essential, Jain points out. Renewable energy technologies such as wind, solar and wave power, could be used to a limited extent to generate electricity and desalinate seawater.

But nuclear energy is the most promising technology. "Nuclear energy seawater desalination has a tremendous potential for the production of freshwater," Jain says.

A floating nuclear plant is one of the most flexible approaches, says S.S. Verma (Department of Physics at SLIET in Punjab). Small floating plants could produce electrical energy with very little pollution or greenhouse gas emissions.

These plants could be placed offshore wherever there is dense population on the coast. They would provide cheap electricity and, at the same time, use their waste heat to run a desalination plant. "Companies are already in the process of developing a special desalination platform for attachment to floating nuclear power plants," Verma says.

Another approach is low temperature evaporation (LTE) desalination technology. This can produce very pure water from seawater using either warm water (as low as 50 Celsius) or low-pressure steam from a nuclear power plant.

LTE has already been shown to be safe, reliable and relatively cheap, says A. Raha (desalination Division of the Bhabha Atomic Research Centre (BARC),Trombay).

This Centre recently commissioned a 50 tonnes-per-day, low-temperature desalination plant, he points out.

Solar, wind and wave power might seem effective for desalination, says co-editor of the journal, B.M. Misra. He is a former head of BARC. But these methods can't be used for large-scale production of freshwater. And this is what an increasingly industrial and growing population needs.

India already has plans to expand its nuclear power industry. Misra suggests that large-scale desalination plants could easily be included in those plans.

"The development of advanced reactors providing heat for hydrogen production and large amounts of waste heat will catalyse the large-scale seawater desalination for economic production of fresh water."

###

International journal of Nuclear desalination, 2007, volume 2, issue 4

More help with words

atom

element

energy

environment

fossilised

nucleus

nuclear

population

What's it all about?

1. Can people drink seawater?
2. What can be done to seawater to make it drinkable?
3. The story mentions three reasons more people will struggle to find fresh drinking water in future. State two of them.
4. What was the Trombay Symposium all about?
5. What does desalination mean?
6. The article mentions a number of problems with existing methods of desalination (not all in the same place in the story). Find three of these problems.
7. Besides desalinating seawater what else does Tewari suggest?
8. What two words in the story tell you that desalination uses a lot of energy?
9. What are fossil fuels?
10. Give two reasons they shouldn't be used for large-scale production of fresh water.
11. What does Jain believe is the most promising technology for producing fresh water?
12. A small floating nuclear plant could do two jobs at the same time. What are they?
13. LTE desalination is existing technology, which currently works using warm water. What could be used from a nuclear power plant with an LTE?
14. Solar, wind and wave power might seem attractive for desalination. But they can't be used for "large-scale production of freshwater". Why not?
15. Think of one question about desalination raised but not answered by this story.
16. How could you find an answer to that question?

More science teaching resources for this story

Nuclear freshwater UK US

Topic for discussion, research or pupil presentations

As is evident from the previous activity this news story is not so much about new findings or developments, but about possible new applications of existing and cutting-edge technology. It is much more about issues and applications than the average science research story.

Here are some of these taken straight from the text:

1. Fresh, clean drinking water wherever it is needed would save lives, promote good health and even prevent war.
2. Climate change, desertification and over-population are all reducing fresh water supplies.
3. The contribution of seawater and brackish water desalination would play an important role in augmenting the freshwater needs of the country.
4. Fossil fuel reserves are finite, and "must be conserved for other essential uses". But the demand for desalted water will continue to rise.
5. Nuclear energy seawater desalination has a tremendous potential for the production of freshwater.
6. Small floating nuclear plants could produce electrical energy with very little pollution or greenhouse gas emissions.
7. Solar, wind and wave power might seem effective for desalination. But these methods can't be used for large-scale production of freshwater.

And here are some possible topics for group discussion, research or presentations arising directly from the above. Students should be encouraged to think of others themselves.

1. "Prevent war" – really? Working in groups, students should carry out a short research project on the Internet and present their findings to the class. They could start by searching for "water wars".
2. A number of solutions, particularly nuclear, are presented in this article to the problem of rising demand for fresh water. All these are aimed at increasing the supply. Would it be more practical to stop the demand rising further by tackling one or all of climate change, desertification and over-population? Research, discuss and present.
3. Research the numbers. What is the demand for fresh water? How fast is it growing? What will the situation be in 2020 if current trends continue? What sort of numbers look possible from seawater, brackish water and rainwater harvesting? Some of the statistics for this activity may have been obtained in Topic 1.
4. Fossil fuels are used in many ways, from transport and heating to pharmaceuticals and plastics. In the students' opinions what are the "essential uses" for fossil fuels?
5. Nuclear desalination has tremendous potential but any technology comes with risks. What are they? What is the downside of nuclear desalination? Draw up a column of these risks and another column with the risks of not using nuclear. Decide.
6. Some anti-nuclear campaigners deny that nuclear energy produces very little pollution or greenhouse gases. Who is right? Investigate. Find actual numbers in terms of tonnes of nuclear waste and tonnes of waste produced by other sources of energy.
7. What are the problems with using solar, wind and wave technologies for large-scale production of energy or desalination?

Tips for science class discussions and groupwork

No 64

What's the magic of stories? People love stories. Stories put learning into context. Lectures often don't do this. They are abstract with mountains of facts. … Even the redoubtable Richard Feynman spoke of his frustration with science education in the preface to his Lectures in Physics saying, "I think the system is a failure." He summarised, "The best teaching can be done only when there is a direct individual relationship between a student and a good teacher –a situation in which the student discusses the ideas, thinks about the things, and talks about the things. It is impossible to learn very much simply by sitting in lectures."

Herreid, C.F. (2007) Start with a Story: The Case Study Method of Teaching College Science. Arlington, Virginia: NSTA Press

Cinnamon genes

Cold Spring Harbor Laboratory: Embargoed for release: 31-Oct-2007 17:00 Eastern US Time

Cinnamon genes

The cat genome has been sequenced for the first time. Scientists used samples taken from a four-year-old Abyssinian cat called Cinnamon. The report appears in Genome Research (www.genome.org).

Cinnamon is one of several mammals now being studied using a new method called light genome sequencing. The research team started with Cinnamon’s raw sequence data. Then scientists at a number of centres worked together. They used information from the genomes of other mammals that had been sequenced, together with earlier studies of the cat.

Six other mammal genomes have recently been completed. They are the human, chimpanzee, mouse, rat, dog, and cow. The human genome was finally sequenced in February 2001.

Similarities between the cat genome and these six let the scientists identify 20,285 possible cat genes.

They found hundreds of rearrangements within the chromosomes. These took place among the different mammals since they evolved from their common ancestor. This ancestor roamed the earth among the dinosaurs around 100 million years ago.

This latest research is expected to lead to health benefits for domestic cats. Ninety million are owned by Americans alone, according to The Humane Society. But the domestic cat is also a good model for human disease. This is why the National Human Genome Research Institute authorised the cat genome project three years ago.

Domestic cats can suffer from over 250 hereditary diseases. Many of these are like genetic diseases in humans. Cinnamon has a mutation, for example, that causes retinitis pigmentosa. This is an eye disease that can lead to blindness. In humans, retinitis pigmentosa affects 1 in 3,500 Americans.

The cat is also a good model for human infectious diseases such as HIV/AIDS. Feline immunodeficiency virus (FIV) is a relative of human immunodeficiency virus (HIV), which causes AIDS.

Using the cat genome data, the researchers identified several hundred thousand variants in the genes (known as SNPs, DIPs, and STRs). These can be used to discover the genes that cause hereditary diseases in cats and humans.

The scientists have already used these variants to identify the gene that causes Cinnamon’s retinitis pigmentosa. They published a paper on this in the May/June, 2007 issue of the Journal of Heredity.

These gene variants will also be useful for parentage testing, forensic analysis and studies of evolution. They will shed light on how the cat was domesticated. They will provide information on the development of fancy breeds. They will tell scientists how the great roaring cats have adapted to their environment.

The researchers also analysed the cat genome for interesting features, such as fragments of genes that migrated to the chromosomes from the mitochondria.

They also looked at a sea of repeating patterns that don't seem to do much. These included scores of genomic stretches from historic retroviruses. Some of these have known links to cancer.

The Cat Genome Project is based at the National Cancer Institute (Frederick, Md.). Cinnamon lives in a cat colony at the University of Missouri-Columbia. The sequencing data were generated by Agencourt Bioscience Corporation (Beverly, Mass.)

More help with words

cell

conception

conference

DNA

environment

evolution

fertilisation

individual

inherit

journal

molecule

protein

RNA

species

sperm

structure

What's it all about?

1. What was the name of the cat used in this research?
2. What kind of cat was she?
3. This research is all about sequencing the cat ------.
4. The scientists used a new method called ----- genome sequencing.
5. This meant they did not need to do as much work on the cat genome because they used information other scientists already had. Information about what?
6. The genomes of six mammals have recently been sequenced. If you had one of each of these in a room, how many legs would you have altogether?
7. The human genome has around 30,000 genes. Does the cat have more, fewer or about the same number of genes?
8. None of the six mammals studied was around at the time of the dinosaurs. But a type of animal related to all of them was. What two words does the story use for that animal?
9. What does each of the two words mean?
10. This new understanding of cat genes should eventually lead to ways of treating some cat diseases. It might also lead to ways of treating diseases in another living thing. Which one?
11. What is a hereditary disease?
12. Which hereditary disease does Cinnamon suffer from?
13. What would be the purpose of studying FIV (other than trying to treat the disease in cats)?
14. Hereditary diseases are caused by variants in the genes. What does this mean?
15. By studying variants of genes, scientists can learn lots of things about cats, humans and other living things. State three of these.
16. Viruses that infect a person or animal can sometimes leave genes inside the chromosomes of their sperm and eggs, which can then be passed on to children and children's children, and so on. What type of disease can these genes sometimes make more likely?
17. If you were these scientists what would you like to do next?
18. What question would that be trying to answer?

More science teaching resources for this story

Cinnamon genes UK US 31-Oct-2007

Topic for discussion, research or pupil presentations

Here are a few of the issues, implications and applications extracted from the cat genome research story:

1. This new research will lead to health benefits for cats. But the cat is also a good model for human disease.
2. Domestic cats can suffer from over 250 hereditary diseases. Many of these are like genetic diseases in humans. Cinnamon has a mutation, that causes retinitis pigmentosa, an eye disease that also affects humans.
3. The cat is also a good model for human infectious diseases such as HIV/AIDS. Feline immunodeficiency virus is a relative of human immunodeficiency virus (HIV), which causes AIDS.
4. Using the new cat genome data, the researchers identified several hundred thousand variants in the genes. These can be used to discover the genes that cause hereditary diseases in cats and humans.
5. The gene variants discovered in the cat will be useful for parentage testing, forensic analysis and studies of evolution. They will shed light on how the cat was domesticated. They will provide information on the development of fancy breeds. They will tell scientists how the great roaring cats have adapted to their environment.

Here are a few of the group research and/or discussion topics arising from the above. No doubt you will be able to think of others yourself.

1. What does it mean to be "a good model for human disease". Find three other animal models for human disease. What is the basic reason that studying one animal can provide useful information about another?
2. Find as many other hereditary diseases as possible that both cats and humans can suffer from.
3. Find as many other infectious diseases that both cats and humans can catch as possible. What is the difference between a hereditary disease and an infectious disease?
4. Variants of genes do not always cause disease. Find two examples of genes that have variants that simply make people or cat bodies look or work differently.
5. Choose one of the possible applications in this final paragraph. Find out as much as possible about this application and prepare a presentation on it to the class.

Tips for science class discussions and groupwork

No 63

It is a shame that more scientists don't read the education literature, for they would be aware of the quiet revolution taking place in teaching....

Put students into small interactive groups of four or five, give them projects, problems, tests, or case studies to analyze, and they will learn more effectively. Unlike many fads in education, which are enthusiastically touted but poorly investigated, cooperative learning may be the most thoroughly studied educational technique ever utilized. ...

Cooperative learning promoted higher individual knowledge than did competitive and individualistic learning, whether the task required verbal, mathematical, or physical skills. Most important the retention of knowledge was greater. Cooperative learning has striking additional benefits..."

Herreid, C.F. (2007) Start with a Story: The Case Study Method of Teaching College Science. Arlington, Virginia: NSTA Press

Extra genes make mouth water

University of California - Santa Cruz: Embargoed for release: 9-Sep-2007 13:00 Eastern US Time

Humans took over the world because of what went on in their mouths, say scientists.

We humans have far more copies of the salivary amylase gene than any of our ape relatives, the study found. We use these copies to flood our mouths with amylase. This is an enzyme that digests starch.

The new findings, published online on 9 Sep in Nature Genetics, support the idea that starchy food, like the potatoes and carrots we eat today, was a very important addition to the diet of early humans.

Extra copies of the same gene mean that more of the enzyme it produces will be made in the mouth, says Nathaniel Dominy, one of the paper's authors. He is assistant professor of anthropology at University of California, Santa Cruz.

This new ability to eat calorie-rich starches could have fed our large brains. It would have opened up new food supplies that fuelled our colonisation of the planet, Dominy says.

Other primates eat mainly ripe fruits. These contain very little starch. So they did not get the same boost to their brain-power.

In their research the scientists sampled saliva from 50 European-American students. They found as many as 15 copies of the amylase gene per person. By comparison, all 15 chimpanzees they sampled had exactly two copies each.

They found that people with more copies of the gene had more amylase in their saliva.

Next the team studied humans with different diets. They found the same connection between the amount of starch eaten and the number of amylase gene copies.

The diet of the Yakut of the Arctic is mainly fish. They were found to have fewer copies of the gene than the related Japanese, whose diet includes starchy foods like rice. The same thing was found in two Tanzanian tribes. They are the Datog, who raise livestock, and the Hadza, who mostly eat tubers and roots.

"Even though they're closely related genetically and live close to each other geographically, still there are big differences in the average number of copies in these populations," Dominy said.

The discovery could greatly improve our understanding of how humans began. Anthropologists have long been stumped by the sudden increase in human brain size, body size and the area they lived in. All these happened at more or less the same time.

Meanwhile other great apes were hardly changing. Early humans simply must have found some source of better food to make it all possible.

"That's the big mystery of palaeoanthropology," Dominy says. "What changed?"

Why did our earliest human ancestors gain an "incredibly large brain, which is very energetically expensive to maintain"?

And why did they become at the same time "a much more efficient bipedal organism"?

For years more meat was thought to be the answer, as early humans learned to hunt. But, Dominy points out, even in human hunter-gatherers today, meat is a small part of their diet.

"They cooperate with language. They use nets. They have poisoned arrows, even, and still it's not that easy to hunt meat."

To think that 2-4 million years ago, our ancestors without any of these things could have done much better "doesn't make a whole lot of sense."

So some anthropologists are starting to think that the new food was starch stored by plants as underground tubers and bulbs. These would have been wild versions of modern-day foods like carrots, potatoes, and onions.

Once early humans learned to recognise these plants, this theory goes, it opened up a whole new food source that was unknown to the other apes.

"It's kind of a goldmine," Dominy said. "All you have to do is dig it up."

Tubers could have been especially important for early humans known as Homo erectus. They may have been the first humans to cook with fire. Since this idea was proposed, researchers have been looking for evidence.

This is not easy for a theory about perishable food eaten two million years ago. But in work earlier this year, Dominy and his colleagues found some. They discovered that the 'isotopic signature' of animals that eat tubers and bulbs today matched that found in the fossil remains of early humans.

This new discovery about amylase genes is another piece of evidence that points to the importance of starch in human origins. When early humans learned the secret of fire, cooking starchy vegetables would have made them much easier to eat. At the same time it would have made extra amylase gene copies more useful.

"We eat French fries and baked potatoes," Dominy says. "When you cook, you can afford to eat less overall, because the food is easier to digest. Some marginal food resource that you might only eat in times of famine, now you can cook it and eat it.

"Now you can have population growth and expand into new territories."

More help with words

absorb

calorie

carbohydrate

cell

complex

conception

DNA

drought

energy

enzyme

fertilisation

hypothesis

inherit

molecule

origins

protein

sperm

tentative

What's it all about?

1. This story is all about an enzyme called -------.
2. Where in the human body is this enzyme found?
3. What does it do?
4. The new discovery is that we have far more copies of the gene that makes the enzyme
   than our nearest relatives. What are those relatives?
5. Name two starchy foods we eat today.
6. What are you able to do if you have extra copies of the gene that makes amylase?
7. Do apes eat food that contains much starch?
8. The scientists studied two different types of living thing in their research. What
   were they?
9. Which had most copies of the amylase gene?
10. What did the people who had more copies of the gene also have more of?
11. After comparing humans and chimps what did the scientists compare next?
12. They found that people who ate more ------ had more ------ of the gene for amylase.
13. This means they produce more amylase in their ------ so they can digest the starch.
14. We know from fossils that in quite a short period of time in the past humans spread
    out over a wide area and their brains got bigger. What is the mystery in this?
15. What did scientists used to think had changed in the human diet to make them big-brained
    and "much more efficient".
16. In one sentence why is this now thought to be not a very likely explanation?
17. What do scientists like Dominy and his team now think was the big change in the human
    diet?
18. A change in the human diet was needed because big brains use up a lot of ------.
19. This new discovery is another piece of evidence for the importance of starch in early
    humans. What other piece of evidence had Dominy and his team discovered earlier?
20. Why would extra amylase have been less useful if the early humans had not already
    discovered how to cook?
21. If you were a young member of Dominy's team could you think of a question you would
    like to answer about early humans and what they ate?
22. Can you think how you might try to find an answer to that question?

More science resources

Mouth-watering extra genes UK US

Topic for discussion, research or pupil presentations

A) In groups, students should go through the article to find three hypotheses. They should then find one piece of evidence, mentioned in the article, that either supports or helps to refute each of these hypotheses.

This is a valuable exercise to get at the nature of science and scientific thinking, and this particular story is a good one to use for the exercise, since it contains a plentiful number of hypotheses, new findings and statements of accepted fact, some of which shade into each other. This will stimulate instructive and educationally valuable differences of opinion among the students.

B) In groups, students should think about a large band of early humans, most of whom have just a couple of genes to make amylase, just like the other great apes.

It's a fertile part of Africa these people inhabit, and there are lots of wild tubers and bulbs growing there. These would be an excellent source of food, because that is precisely what a tuber is - food for the growing plant.

The people have discovered fire and often cook the food they eat. Sometimes they dig up tubers and roots and roast them on the campfire, but because they don't make much amylase in their saliva, they can't digest these tubers very thoroughly, even when they are cooked, so much of this good food tends to pass through their bodies without being absorbed.

There comes a time however when a baby is born in the group that, by a small mistake in the copying process that takes place when cells divide, has four copies of the amylase gene. As this baby grows up, the rest of the band notices that he seems to love eating cooked wild roots. Because these are plentiful, young grows big strong and healthy and in due time has many children of his own.

The question the student groups have to address, in a 5 minute presentation they prepare together, is this:

A few hundred years later most of the group has four copies of the amylase gene, and some of them even have eight.

How exactly has this come about?

Tips for science class discussions and groupwork

No 62

'A non-commercial source for this sort of activity can be found on the ENSI site at http://www.indiana.edu/~ensiweb/lessons/falsasum.html. It's called "False Assumptions Can Get You in Trouble," developed by OBTA winner and NABT's first Evolution Educator of the Year, Steve Randak. Here's the synopsis for that lesson:

Little deceptive problem stories are presented to the class, and students are challenged to solve each problem by asking only yes/no questions. The key is for students to recognize what the False Assumption is that makes the solution tricky, and that many common problems are difficult to solve because we tend to assume a particular paradigm.

Things are not always what they seem! Science is a way to work around or through those false assumptions.

Strategies for doing this, and a collection of those little "stories" (ready for showing on overhead) are freely provided with the lesson. Many of the stories are similar to those in the MindTrap game. Once this lesson is introduced, the stories make an excellent "sponge" activity that can be used when your class finishes a few minutes early, and you can refresh the reality of nature that things are not always what they seem, and build their critical thinking skills.

Contribution to an NSTA forum for science teachers by Larry Flammer

Ancient lean gene

University of Texas: 4-Sep-2007 12:00 Eastern US Time

Scientists have found a gene that seems to have been keeping creatures lean since ancient times.

The gene was first discovered in flies by another research team. But it also keeps worms and mice trim, according to a report in the September issue of Cell Metabolism.

If the gene works the same way in humans, the discovery could lead to a new weapon against our bulging waistlines.

The gene is called Adipose (Adp). Animals without a working copy of it become obese. Those with greater than normal Adp activity in their fat tissues become slimmer, the researchers found.

"Maybe if you could affect this gene, even just a little bit, you might have a beneficial effect on fat," said Jonathan Graff of the University of Texas Southwestern Medical Center. He points out that people often become overweight very gradually, adding just one or two pounds a year.

"After 30 years, that's a lot."

Worms and flies are routinely studied as models of human health and disease. But that has been less true in fat biology, Graff says.

That's because worms and flies store their fat in multi-functional cells. Mammals on the other hand have special-purpose fat cells, known as adipocytes. But that difference doesn't rule out the possibility that the animals might use similar genes to control fat storage, Graff says.

In the new study, his team found that worms lacking Adp activity got fat. They seemed otherwise quite healthy and fertile. The scientists searched the genetic database in search of related genes. They finally found one that was very similar in flies.

Indeed, another scientist Winifred Doane, had found a natural strain of plump flies in Nigeria almost 50 years ago. These fat flies carried a mutation in their Adp gene.

The flies lived in a climate marked by cycles of famine. This meant they probably benefited from being highly efficient at fat storage, Doane had suggested.

To explore Adp further, Graff and his colleagues produced a strain of mutant flies like those that Doane had found years earlier. They found that the mutant flies were fat and had trouble getting around.

Flies with only one copy of the Adp mutation fell somewhere in between the fat and normal flies. This was evidence that the gene's effects are 'dose-dependent'.

This is good news for possible treatments for human obesity, Graff says. "Because it's like a volume control instead of a light switch. It can be turned up or down, not just on or off. Eventually, of course, the idea is to develop drugs to target this system, but that's in the years to come."

Turning now to mammals - and mice in particular - the researchers found the same kind of patterns.

"We made mice that expressed Adp in fat-storing tissues, and lo and behold, what happened," Graff said. "They were skinny. They weighed less, with markedly less fat. And their fat cells were smaller."

Smaller fat cells usually means better metabolic function, he said, including better blood sugar control.

Storing fat is a good way to get through lean times but too much fat in times of plenty causes health problems.

The search for molecules in the body that cause weight gain and poor blood sugar control "has taken on additional urgency due to the recent dramatic increase in obesity and diabetes," Graff said.

But in the modern world where many people have more or less unlimited supplies of food, it's a wonder that even more people aren't overweight, he added. Perhaps Adp is the answer.

If the gene plays a similar role in humans "it may be that some people's Adp works very well."

More help with words

breed

cell

conception

DNA

fertilisation

inherit

protein

species

sperm

What's it all about?

1. The gene this story is about was first discovered in -----?
2. What does the gene do?
3. The scientists in the story have been studying the same gene in two different types of creature. Name one of them.
4. Do we know yet if the gene does the same thing in humans?
5. What happens to flies, mice and worms that do not have the Adipose gene?
6. What happens to flies, mice and worms that that have plenty of Adipose activity in their body fat?
7. Do people usually put weight on suddenly?
8. What word in the story gave you the answer to that last question?
9. Worms and flies are often studied to learn more about health and disease in the human body – but not usually by scientists interested in ---.
10. That’s because worms and flies on the one hand and humans on the other have quite --------- kinds of fat cells.
11. But scientists might be able to learn something about fat in humans by studying worms and mice. That’s because although the cells might be different the ----- might be similar.
12. Graff and his colleagues studied a gene that helped keep worms slim first. What did they do next?
13. What did they find?
14. The flies that Doane had studied were fat because their Adp gene did not work normally. What word is used in the story to say this?
15. Why would Doane’s flies have found it useful to be able to store fat well?
16. Genes almost always come in pairs. When Graff and his colleagues produced flies with just one Adp gene that worked normally and one that didn’t what were the flies like?
17. What was this evidence for?
18. In one sentence and your own words explain why we would want a “volume control instead of a light switch” in a treatment for human obesity.
19. The scientists found the same type of results in their experiments with mice. Thinking back to what we were told about fat cells in different animals near the start of the story, why did the scientists do experiments on mice as well as on flies?
20. Getting fat is a big problem for many of us. So why do our bodies store fat at all?
21. In countries like ours, in which many people can eat as much as they want, it is surprising that more people are not fat. What does Graff suggest is the reason for this?

More science teaching resources for this story

Lean gene UK US

Topic for discussion, research or pupil presentations

Have the students look at the fat mice created by scientists here and here. Then in groups get them to discuss if it is ethical to do this kind of thing to animals.

Ask the question in different ways with different groups without letting the other groups see the wording. For example:

"Is it ethical to inflict suffering and death on animals in the hope of helping people who stuff themselves?"

"Is it ethical to experiment on animals with the aim of finding a cure for people who eat too much?"

"Is it ethical to use animal models to find cures for humans diseases such as diabetes and obesity?"

Get each group to prepare a PowerPoint presentation to deliver in turn to the class.

Discuss the results as a whole class. What can we learn from this exercise?

Tips for science class discussions and groupwork

No 61

Ground rules for discussion

You, as the teacher, will need to establish rules or guidelines on appropriate and inappropriate modes of argument and self-expression. The goal is a general atmosphere of mutual respect and tolerance but is more readily stated than achieved.

In defining the rules or framework for discussion, attention should be paid to both cultural and religious sensitivity as well as maintaining a balance between objectivity and emotional engagement. Try not to allow students to personalise the issues under discussion as this may arouse feelings of guilt and a need for self-justification.

Multiple perspectives can arise from differences of culture, religion, social class, gender or academic discipline and when several students within the group share a perspective the discussion can break down into a contest between rival ‘factions’.

A clear framework suggested by Susan Illingworth for students in Higher Education can be helpful here. Teachers should ensure that:

* Every member of the group has an opportunity to speak.

* Views can be expressed without interruption.

* Criticisms are aimed at arguments and not individuals.

* There are mechanisms for defusing heated situations.

* Participants are encouraged to apply constructive criticism to their own beliefs

* Participants are encouraged to look for common ground between opposing views

* Teaching materials are selected for their accessibility to a range of viewpoints.

Students are used to being asked for the correct answer, it will take them a while to come to terms with the fact that when discussing bioethics there will not always be correct answer, this needs to be made clear to them.

Students should feel safe in the classroom environment. As private individuals they could refuse to participate in a debate if it distressed them either by remaining silent or by walking away but in school students are expected to remain in class.

From section on Working with discussion at BioEthics Education Project

Sunny waves

Boulder, Colorado: Embargoed for release: 30-Aug-2007 14:00 Eastern US Time

The sun is the most familiar object in the sky - at least it was until this summer. It is also one of the best understood. But there are still some deep mysteries about what happens there.

One of the most puzzling is the fact that the outer layers of the sun's atmosphere, which is called the corona, are far hotter than the surface of the sun. This is very hard to understand. Scientists have compared it to a kettle boiling merrily on top of a block of ice.

One possible explanation is that heat is carried upwards by a special kind of wave called an Alfvén wave. Now scientists for the first time have observed Alfvén waves in the corona.

The discovery gives them an insight into the behaviour of the sun and its magnetic field. It should also lead to a better understanding of how the sun affects the earth and the rest of the solar system.

The research was led by Steve Tomczyk of the National Center for Atmospheric Research (NCAR). It is published this week in Science.

"Alfvén waves can provide us with a window into processes that are fundamental to the workings of the sun," says Tomczyk.

Alfvén waves are fast-moving disturbances that carry energy. They move out from the sun along magnetic field lines. They have been detected in space well beyond the Sun. But they have never before been seen within the corona.

Alfvén waves are hard to detect. This is partly because, unlike other types of wave, they don't create large disturbances in the corona. Also the changes in velocity they cause are small and not easily noticed.

"Our observations allowed us to unambiguously identify these oscillations as Alfvén waves," says co-author Scott McIntosh. He is at the Southwest Research Institute in Boulder.

"The waves are visible all the time and they occur all over the corona.” This was a surprise to the researchers, he added.

By tracking the speed and direction of the waves, researchers should now be able to work out basic properties of the sun's atmosphere. These include its density and the direction of its magnetic fields.

The research may also help scientists to predict solar storms. These are extremely violent events that spew thousands of tons of matter into space in the form of energetic particles.

When these particles hit earth's atmosphere they cause the aurora borealis, the northern lights. They can also have much less appealing effects, by blocking radio signals, causing electrical blackouts and damaging satellites. In March 1989 a solar storm caused a complete blackout of the city of Quebec.

Learning more about solar storms might also help to protect astronauts from dangerous levels of radiation in space.

"If we want to go to the moon and Mars, people need to know what's going to happen on the sun," Tomczyk says.

To observe the waves, Tomczyk and his colleagues used an instrument developed at the National Center for Atmospheric Research over the last few years.

The coronal multichannel polarimeter (CoMP) is attached to a telescope at the National Solar Observatory in New Mexico. It is a special instrument designed to gather light from the corona. This is much dimmer than the sun itself so is difficult to see against its glare.

The CoMP then tracks magnetic activity around the entire edge of the sun. It works fast, making a measurement as often as once every 15 seconds.

With the help of this instrument the research team were able to capture intensity and velocity measurements and polarisation images of the solar corona, all at the same time.

Those measurements and images revealed waves that were moving in paths that lined up with magnetic fields, and travelled at almost 2,500 miles per second.

So can these newly-discovered waves explain why the corona is so very hot? Well maybe. The Alfvén waves the researchers actually observed were, they say, too weak to heat the corona.

But the possibility remains that other, stronger Alfvén waves carry enough energy to do so.

The mystery of why the kettle is boiling on the block of ice has not yet been completely solved.

More help with words

atmosphere

disturbances

orbit

orbits

plane

planet

vibration

What's it all about?

1. What is the most familiar object in the sky?
2. Do we know everything there is to know about this object?
3. What word near the start of the story gave you the answer to that last question?
4. The heat of the sun is created deep beneath its surface, so this surface is not nearly as hot as its centre. That also means that it should be cooler far out from the surface. Is it?
5. What have scientists compared this to?
6. One explanation of this mystery is that Alfvén waves carry heat outwards. Have these Alfvén waves been observed before in the corona?
7. The story mentions two areas where our understanding will improve through the Alfvén wave discovery. State one of them.
8. Give one reason for Alfvén waves being hard to detect.
9. Are the scientists certain that what their instruments detected are Alfvén waves?
10. What word in the story gave you the answer to the last question?
11. By tracking the Alfvén waves, scientists will now be able to learn more about the sun's magnetic ------.
12. The work might also help scientists to predict what?
13. Give two reasons that would be very useful.
14. Why did the scientists have to use a special instrument to study the corona, instead of just looking at photographs taken through a normal telescope?
15. Apart from enabling the scientists to take images of the corona what else can the CoMP do?
16. The writer mentions three pieces of information that the CoMP was able to obtain at lots of different places in the corona. State two of these.
17. Putting all this information together allowed the scientists see that waves were travelling through the corona at almost 2,500 miles per second. In what direction?
18. Explain in one sentence why this is not the whole answer to the puzzle of the corona's high temperature.
19. If you were these scientists what would you like to study next?
20. What question would that research be trying to answer?

More science teaching resources for this story

Sunny waves UK US

Topic for discussion, research or pupil presentations

Stanford University has an excellent collection of sun science investigations, activities and discussion topics.

These include retrieving solar images, understanding the solar scale and an interview with Mr Sol:

"Have you ever wondered what our star thinks about his (or her?) role up there in the sky? Have you considered what an awesome responsibility it must be, generating all that heat and light from fusion and having so many living beings depending upon you?

Sol really does light up our life. Imagine what he might say if you could interview him. Why don't you do a little research (this web site is a good place to start) and then you and a friend create your own interview with Mr. Sol!

If you come up with a good interview, send it to us and we'll publish it here on the web!"

Tips for science class discussions and groupwork

No 60

Your students may not have the reasoning skills, or may not have the requisite prior knowledge to solve the problem you have given them. In either case you need to develop interventions which will chunk the ideas smaller while still giving them space to learn for themselves.

Our inclination in this case, based on our own learning experiences as students, is to tell the students things they need to know to solve the problem. In so doing you take away, as you have pointed out, opportunities for them to learn. Perhaps you are telling too much and not instead developing a set of questions for the students to work on and discuss that will lead them to where you when you want them to be.

....

Sometimes it seems to me that my students have a little mental switch in their heads, and I have to ask the right question to get them to turn it on.

Often the question is "Explain your reasoning."

Extract from a contribution to an NSTA teachers' forum by Joseph J. Bellina, Professor of Physics at Saint Mary's College, Notre Dame, Indiana

Out of body in the lab

University College London: 23-Aug-2007

Scientists can now give healthy people an out-of-body experience. In a paper published today in Science, Henrik Ehrsson tells how it is done. The neuroscientist from University College London also talks about the implications of the new discovery.

An out-of-body experience is just what it says - the feeling that you have left your body. It is usually described as feeling very real, not like a dream. People often report looking down on their actual bodies. The experience is taken by some people to be evidence that we have souls.

Out-of-body experiences are often linked to some kind of damage to the brain. This includes stroke and epilepsy, as well as drug abuse. They have also been reported by some people following traumatic events such as car accidents.

Around one in ten people claim to have had an out-of-body experience at some time in their lives.

What happens during one of these is that a person seems to be seeing his or her own body from outside of it.

Out-of-body experiences have fascinated mankind for thousands of years, Ehrsson says. “Their existence has raised fundamental questions about the relationship between human consciousness and the body.”

The experiences have been talked about in articles on religion, philosophy and psychology, he goes on. “Although out-of-body experiences have been reported in a number of clinical conditions, the neuroscientific basis of this phenomenon remains unclear.”

Being able to produce the illusion in the lab is important, Ehrsson says. One reason is that this tells us a little about how we normally get the feeling of being inside our bodies. Scientists don’t know much about that.

“This represents a significant advance, because the experience of one’s own body as the centre of awareness is a fundamental aspect of self-consciousness,” Ehrsson says.

Discovering how to create an out-of-body experience could also have real applications, Ehrsson says. “This is essentially a means of projecting yourself, a form of teleportation.”

One possible application is computer games, Ehrsson suggests. We should now be able to put people into a virtual character. That would mean they would feel and respond just as if they were that character.

“The experience of playing video games could reach a whole new level. But it could go much beyond that. For example a surgeon could perform remote surgery, by controlling their virtual self from a different location.”

The way the scientists create the experience in the lab is like this. A person sits in a chair wearing a small screen over each eye. These are connected to two cameras behind the participant’s head.

The image from the left camera is sent to the left eye screen. The image from the right camera is sent to the right eye screen. The participant’s brains sees these separate images as one 3-D image. This is what happens normally when we use two eyes to look at something.

In this case, though, the participants see their own back as it would look to someone sitting behind them.

The researcher then stands beside the participant. He touches the participant’s actual chest with a rod. At the same time he seems to touch the chest of the image’s body. He does this by moving a second rod towards where that body would be, just below the camera’s view.

When this is done the participants feel they are sitting behind their own body and looking at it. “This was a bizarre, fascinating experience for the participants,” Ehrsson says.

“It felt absolutely real for them and was not scary. Many of them giggled and said ‘Wow, this is so weird!’”.

To test the illusion some more, Ehrsson did another experiment. He measured the response of the participant’s body. In particular he measured the amount of sweat on the skin. He did this when it looked like the imaginary body was being threatened.

The response showed strongly that the participant thought the threat was real.

This whole experiment came from an idea Ehrsson had as a medical student. He wondered what would happen to our feeling of self if we could move our eyes a few metres away. This would let us see ourselves from the outside.

Would the self follow the eyes or stay in the body, Ehrsson wondered. This experiment seems to have answered that question.

The illusion is different from anything published before, Ehrsson says. “It is the first to involve a change in the perceived location of the self, relative to the physical body.”

It is also different from any virtual reality set-up, he says. “There has been no way of inducing an out-of-body experience in healthy people before, apart from unsubstantiated reports in occult literature.”

This is a very exciting development, Ehrsson says. “It has implications for a range of disciplines from neuroscience to theology.”

More help with words

evidence

convulsions

seizure

More science teaching resources for this story

Out-of-body in the lab UK US

What's it all about?

1. Scientists can now give ------- people an out-of-body experience.
2. People who get out-of-body experiences usually have some kind of damage to their brain. The article lists three ways this can happen. State two of them.
3. It also mentions events like car accidents that create shock and fear that last, but not actual brain damage. What word does the writer use for this type of event?
4. What percentage of people say they have had an out-of-body experience at some time in their lives?
5. Out-of-body experiences make people wonder about the connection between themselves and their ------.
6. The writer says out-of-body experiences are talked about in articles about three different areas of study. Name two of them.
7. What does “clinical conditions” mean?
8. When Ehrsson says “the neuroscientific basis of this phenomenon remains unclear” he means that scientists don’t understand yet what makes out-of-body ----------- happen.
9. What else about our relationship to our bodies do scientists not yet know much about?
10. Apart from making a start on the science of people’s feelings of themselves and their bodies, state two other ways this research could be useful.
11. What equipment did the scientists use to do the experiment?
12. What did it feel like to the participants be outside their own body and looking at it?
13. Can you think why the scientists pointed the cameras at the back of the participant rather than the front?
14. In one sentence what was the point of the sweat test the scientists did?
15. What were the two possibilities Ehrsson thought of when he wondered, as a medical student, what it would feel like if your eyes could move away from your body?
16. Which one actually happens according to the results of this experiment?
17. Imagine you are a scientist in Ehrsson’s team. Think up one question about all this that you would like to find the answer to.
18. Try to outline in one sentence an experiment that might help to answer that question.

Topic for discussion, research or pupil presentations

There are countless stories about out-of-body experiences all over the Web. Actually that's not quite true - with the help of modern technology they can now be counted.

A search on "out of body experience" in Google yields no fewer than 145 millions hits, while Yahoo finds an even more whopping 195 million.

Here's a small sample of them:

Alice: The first thing I experienced was the reality of consciousness ....everywhere! On every level I saw it. I felt it and experienced the reality of a caterpillar, and I was shown that life on any and all levels is equal and the level of awareness in every creature is the same. ... and it was as though I poked my head through some layer of some kind and I could see that there were not just a few dimensions, but that the dimensions went on and on... that there was nothing but creation continuing, never ending.

Dorothy: I couldn't believe it, but I knew, that I was dying. I was on the NE corner of the ceiling and adjacent to me on the NW corner of the ceiling, was a male presence who was "pulling" me with some kind of rope or cord that was connected to me, and he was telling me, "It's time to go, it's time to leave this world" and I told him "No! I can't leave my Mom, my Dad, Melvin Calvin Pete Marylou and Dolores.

Michael: She was holding a bowl of fruit in one arm. ... Oya showed herself as a black woman who had the most amazing brilliant white, deep, "old" eyes that I have ever seen. She was absolutely HUGE and very, very tall. I could tell just by looking into her eyes that this was a very wise collection of not just one spirit, but many, many spirits, probably hundreds, who are fiercely powerful. She had on an orange robe and a white turban-type headdress.

So the questions for discussion today are these:

What is the difference between this type of account and the research reported in the news story?

What is it exactly that makes Ehrsson's work science while most of the hundreds of millions of out-of-body experiences that people have recorded on the web are .... Well what are they exactly?

Some are pure fantasy, but others are no doubt genuine attempts to recount exactly what one person experienced.

Can this kind of subjective experience be part of science? If so how do we separate it from fiction, illusion, delusion or just plain lies?

Is Ehrsson's work science because it was done in a lab using scientific equipment?

Is it science because it was done by people who call themselves scientists?

Is it science because the story appears on a website called Real Science?

What is it that makes something science?

Tips for science class discussions and groupwork

No 59

Teachers often do not appreciate how the process of argumentation can help pupils engage with and understand the conceptual basis of what is under discussion. By thinking about alternative theories and the nature of evidence that supports them, pupils can be helped to appreciate not only the reasons for established scientific views but also why alternative views are not accepted. Commitment to these epistemological aims is necessary for teachers to implement ‘ideas and evidence’ lessons successfully.

Simon, S. and Maloney, J. (2006) Learning to teach ‘ideas and evidence’ in science: a study of school mentors and trainee teachers. School Science Review, 87(321), pp 75-82

Smart crows

University of Auckland, New Zealand: Embargoed for release: 16-Aug-2007, 12:00 Eastern US Time

For a long time humans were believed to be the only living things that used tools. Animals weren't thought to be smart enough. But then scientists found chimps using rocks to crack nuts. They saw gorillas testing water depth with a stick before stepping in. They observed orangutans slipping twigs into fruit to get seeds.

Great apes might not put up shelves in the study or a fence in the garden. But they can make and use tools in hundreds of different ways - usually to get food.

This is not too surprising, really, since chimps, gorillas and orangutans are our closest living relatives. But birds are pretty bird-brained, aren't they? There is surely no chance that they can use tools.

Well as a matter of fact they do. Scientists have known for some time that New Caledonian crows don't just use complex tools to get food - they actually make them. Now these same birds have been observed doing some creative thinking to use one tool to get at another.

The findings appear in the online Current Biology on August 16. The researchers who did the work are at the University of Auckland, New Zealand.

The birds' skills in the use of tools, say the researchers, rival those seen in the great apes. What's more, it seems that the birds may have solved their problem using something called analogical reasoning.

This is a much more advanced type of thinking than simple trial and error. A person using it - or a crow - has to be able to see a new situation as somehow the same as something they've met before.

Analogical reasoning is why humans are so inventive, right from their earliest use of stone tools. It is what drives human innovation. It is the "hallmark of human intelligence", says Russell Gray of the University of Auckland. (It is also a rich source of humour.)

Both the great apes and the New Caledonian crows may be using analogical reasoning, says Gray. This may explain why "out of all the crow species in the world, only these crows routinely make and use tools."

In the study, the researchers presented crows with meat in a hole. A stick was available but it wasn't long enough to reach the meat. The birds needed to get a long stick out of a "toolbox" to get the meat from the hole.

There was another catch. The long stick was also out of reach. The creative thing the crows did was to use the short stick to get the long one out of the box, said Alex Taylor, also of the University of Auckland.

"They could then use the long stick to get the meat."

In a second experiment, the researchers reversed the positions of the two sticks. The small stick was now inside the toolbox while the long stick was handy. The crows briefly probed the box containing the short stick using the long stick. But they quickly corrected their mistake and took the long stick straight to the hole to get the meat.

These were hard problems for the crows, especially the first one, Gray said. "It was surprising to find that these 'bird-brained' creatures performed at the same levels as the best performances by great apes."

Six out of seven crows tried to get the long stick with the short stick at their first try at solving the problem.

"To do this, they had to inhibit their normal response of trying to get the food directly with the short stick and realize that they could use the short stick to get the long stick."

So let's hear no more about birds being bird-brained.

###

Taylor et al.: "Spontaneous Metatool Use by New Caledonian Crows." Publishing in Current Biology 17, 1-4, September 4, 2007. DOI 10.1016/j.cub.2007.07.057. http://www.current-biology.com

More help with words

ancestor

breed

comparing

fertile

orangutans

particular

What's it all about?

1. Animals used to be thought to be not smart enough to do something. What was that?
2. Give one piece of evidence we now have that shows this was wrong.
3. Why is it not too surprising that great apes use tools?
4. What other living things use tools and make them?
5. What type of thinking have these been found to use?
6. In which country do the scientists work who have done the research reported in this story?
7. What word does the writer use to say that the crows are about as skilful as the great apes in their use of tools?
8. When people use analogical reasoning they borrow an idea from a situation they have --- before, to help them work out what to do in a new situation.
9. This seems to be what great apes do sometimes and what the New Caledonian crows did in this experiment. Are the scientists sure the crows used analogical reasoning?
10. Which word in the article gives you the answer to the last question? The word is used twice in the paragraph that begins "Both the great apes and the New Caledonian crows ..."
11. In the experiment the crows were trying to get meat out of a hole using a stick. But the stick they could use wasn't ---- enough to reach the meat.
12. What was the creative thing the crows did with this short stick?
13. Try to explain in one sentence what the scientists mean when they say that this was creative.
14. After the crows had learned to use the short stick to reach the long one, the scientists swapped the sticks around. Can you think why they did this second experiment?
15. In one sentence how does an animal or a person use trial and error to solve a problem?
16. In one sentence how does an animal or a person use analogical reasoning to solve a problem?
17. Why do the scientists believe the crows used analogical reasoning rather than trial and error to solve their problem?
18. Imagine you are these scientists. Can you think of a question you would still like to answer about these crows, and the way they solve problems?
19. How could you try to answer that question?

More science teaching resources for this story

Smart crows UK US

Topic for discussion, research or pupil presentations

Students should watch the 12-minute video of bird brain researcher Erich Jarvis This is educationally instructive and thought-provoking in many ways.

The following is simply one possible discussion topic. Teachers of science will be able to think of a host of others.

The video is accessible equally to committed science students and to those whose interest in science is more cursory or even non-existent.

This accessibility, as can be seen from the feedback, gives rise to strong criticism from a scientist who self-deprecatingly calls himself GrumpyOldGeek.

There is nothing self-deprecating about Grumpy’s criticisms, however, which include comments like:

“I'd *much* rather watch a segment about hard science than a fluff piece that would better be presented in "People" magazine. My time is valuable and I really don't care whether or not Mr. Jarvis knows ballet and thinks that birds' brain parts should have a different name.”

The exchanges between Grumpy and someone who calls himself Kaba are rather heated, quite entertaining and very instructive. Students should read as much or as little of this as they feel like. Then working in groups they should try to boil down into one sentence what each of the disputants is saying.

They should then, by discussion among themselves, try to reach consensus about which of the two positions they most agree with – and why.

Tips for science class discussions and groupwork

No 58

I am a recent convert of cooperative learning. I attended a 3-day workshop at SUNY Stony Brook that sold me on POGIL- Process Oriented Guided-Inquiry Learning. I had wanted to do this, but I didn´t know how to implement it. Now that I have gone to this workshop, I am going to do it each and every Friday, or last day of the week. POGIL will work if you do a couple of things:

1. YOU must set up the groups, not the students. If you don´t know your students very well, look at their past grade history and ensure that you mix them as much as possible. putting all the As with the As only ensures that they will perform best, or might fight over the lead role all the time.

2. Keep the groups consistent. I am doing my groups every week on Fridays as a way to get this going very strongly. Don´t change the people in the group unless it is absolutely sure that the group cannot work together.

3. Don´t look at it as something additional. Be ready to change your lecture. As you move on with groups, the idea will be that the students are doing better at understanding the concepts and you won´t need to lecture as much on the topics covered.

4. Don´t think you can do something else, while they are on the assignment. One thing becomes very clear, you need to be a real facilitator, we are talking about teenagers after all and you need to keep track of time and keep everyone on task.

If you want to know more, don´t hesitate to contact me. To find out more about POGIL specifically for Chemistry teachers, go to: http://www.pogil.org

Extract from a contribution to an online forum of the National Science Teachers Association, by James Smith, AP Chemistry and General Chemistry, Perth Amboy High School, USA

Orangutans play charades

University of St Andrews, Scotland: Embargoed for release: 2-Aug-2007

Orangutans play charades

When orangutans make gestures to get their point across, they are using the same methods that people do when they play charades. Captive orangutans deliberately change or repeat signals depending on whether their audience 'got it' the first time.

The research is published in 2 August issue of the journal Current Biology.

The St Andrews University scientists were surprised that the orangutans were so clearly working out whether their audience understood what they were 'saying', says Professor Richard Byrne. “Looking at the tapes of the animal’s responses, you can easily work out whether the orangutan thinks it has been fully, partially or not understood."

This means that the great apes are passing information back to their audience about how well they have understood them, Byrne says. "Hence our charades analogy."

In playing the game of charades, we humans try to get our meaning across without words, using only gestures. And we also try to help our own team with hints about how they are doing - just as the orangutans have now been found to do.

The experiment that showed this was set up by Erica Cartmill and Richard Byrne. Their aim was to find out if orangutans intend to communicate with people through gesture. This is a skill that has already been found in chimpanzees.

The scientists presented six captive orangutans with two different food items. One was tasty to them. The other wasn't. Both could only be reached with human help.

There was another catch. The scientists sometimes pretended not to understand the orangutans’ requests. So they would sometimes give them only half of the delicious treat. Or they would hand over the yuckier food instead.

When the human didn't get it right the orangutans kept trying to make them understand, the researchers report. When the humans seemed to partly understand, the animals narrowed down their range of signals.

They focused on gestures already used and they repeated them - just as humans do in charades. But when the humans seemed to completely misunderstand, the orangutans tried new gestures. They did not repeat the failed signals.

This showed that the orangutan intended a particular result, Cartmill says. "It anticipated getting it and kept trying until it got the result."

The orangutans made a clear distinction between total misunderstanding and partial misunderstanding, she says. In the first case they gave up on signals they'd used already. They tried new ones to get the message across. In the second case "they tended to repeat the signals that had already partially worked, keeping at it with vigour.

"The result is that understanding can be achieved more quickly.”

The charades strategy is one way to build a shared lexicon from learned signals, the researchers say.

So more study of how apes communicate could help us learn about how the earliest forms of human language began.

Cartmill et al.: “Orangutans Modify Their Gestural Signaling According to Their Audience’s Comprehension.” Publishing in Current Biology 17, 1–4, August 7, 2007 DOI 10.1016/j.cub.2007.06.069. www.current-biology.com

More help with words

variety

great apes

report

What's it all about?

1. What animal is this story about?
2. Have the scientists been studying the animal in the wild?
3. What word in the second sentence gave you the answer to the last question?
4. At which university do the scientists work?
5. Which country is this in?
6. In the game of charades people don’t use words. Instead they try to get a message across to other people using --------.
7. They also try to help their own team with ----- about how they are doing.
8. The aim of the experiment was to find out if orangutans ------ to get messages across to people using gestures.
9. This has already been found in another animal. Which one?
10. Six orangutans were used in the experiment and two types of food. What was the main difference between the two types of food?
11. Could the orangutans get the food by themselves?
12. Somehow the orangutans had to make the humans ---------- them.
13. Explain in one sentence why the humans pretended not to understand what the orangutans were trying to tell them.
14. Give an example from the article of the humans partly understanding what the orangutans were trying to tell them.
15. What did the orangutans do if the humans seemed to partly understand?
16. If the humans seemed not to understand at all what did the orangutans do?
17. Can humans tell the difference between being partly understood and not being understood at all?
18. Do you think cats could? Or goldfish or canaries?
19. What do you think this tells us about orangutans’ brains?
20. Why might you expect to find a skill in orangutans that had already been found in chimpanzees?
21. If you were these scientists can you think of one question you would still like to answer about how orangutans try to communicate?
22. How could you try to answer that question?

More science teaching resources

Orangutans play charades UK US

Topic for discussion, research or pupil presentations

The following is extracted and adapted from a Discovery School lesson

Ask students to describe how apes, such as orangutans, chimpanzees and gorillas, are usually portrayed on TV or in the movies. Do they think the media portray the great apes realistically?

Rather than being cute, comical or dangerous, apes are highly intelligent – as this latest research clearly shows. They have been seen to use tools in thoughtful ways, exhibit self-awareness and demonstrate an empathic understanding of what other apes or humans are thinking and feeling.

Invite your students to imagine that they are working with the scientists at St Andrews. What kinds of experiments would they design in order to assess the thinking abilities of an orangutan?

Help students with their their ideas by asking what signs of intelligence they would look for.

Ask student working in groups to design four experiments: one that will assess an orangutan’s memory, one that will assess an orangutan's creativity, one that will assess an orangutan's ability to communicate, and one that will assess a factor that the students determine themselves.

Before they begin, review with them the requirements for a well-designed experiment, including the idea of a control group.

For each experiment that their groups devise, individual students should write one paragraph explaining what hypothesis it is designed to test and what results they expect to get from it.

When their work is complete, the teacher can conduct “scientific peer-review sessions” in which students review and critique each other’s experimental ideas.

Discussion Questions

1. Researchers are trying to learn how closely ape and human learning and behaviour resemble each other. One way is by teaching apes sign language. Even though these experiments don’t harm the apes, some people still object to this because the apes don’t get to choose whether or not to participate in the experiments. Debate whether animal experimentation of this kind is ethical

2. Apes can't speak because their vocal cords are different from those of humans. Since the 1940s scientists have been testing if meaningful communication between humans and apes is possible using a symbolic language. Their results have often seemed promising. One famous gorilla called Koko seems to have learned how to “speak” with American Sign Language. But some scientists have hotly disputed the results. Ask your students to use magazines, news reports and the Internet to research Koko’s sign language communications – what the scientists involved with the project claim to have discovered, and the criticisms of their methods and results. (A good place to start is www.gorilla.org.)

When their research is complete, ask them to write a set of questions whose answers could determine if Koko can actually understand sign language. Then divide students into pairs to critique each other’s experimental methods. Conclude with a class discussion about the questions the students developed and the difficulties in assessing Koko’s ability to communicate.

Suggested Reading

The Great Apes: Our Face in Nature’s Mirror. Michael Leach. Sterling Publishing, Inc., 1996. “Our closest living relatives are slowly being driven to extinction. Why? What can be done about it? As you read this poignant book, you’ll learn about the true nature of these animals as they live and behave in their natural habitat.”

Tips for science class discussions and groupwork

No 57

Marzano, in "Classroom Instruction that Works" notes that each time you set up the group, you need to remind them of the parameters, roles, etc. I have found that this is very true and when I do - even daily and occasionally within the class - remind them about how to work well in groups; I get much better results.

I find the most effective strategies for me are: a) make sure that everyone rotates through roles (even at high school level) and b) the group members get a stake in the evaluation process. Group grades and individual grades are important - I tell kids that I expect them to be honest, because if there is group work going on, then I am watching - and I will know it's wrong if the group that fought constantly gave themselves all A's (a rubric with a point system is better for evaluations - I like the way the one that someone posted for notebooks on the biology list is set up: http://www.journeytoexcellence.org/practice/instruction/theories/miscideas/notebook_evaluation.phtml

By the way - some good rubric examples on this site too; very impressive resource.

For some additional thoughts - check out: http://www.netc.org/focus/strategies/coop.php among others (Google

"Marzano cooperative learning").

Extract from a contribution to an online forum of the National Science Teachers Association by Kathleen M. Gorski, Ph.D., Kathleen M. Gorski, Ph.D., Master Teacher, The Nativity School of Worcester.

Renewables fail

Rockefeller University, New York: 25-Jul-2007 01:00 Eastern US Time

Renewables fail environmental test

Renewable does not mean green. This is the surprising result of research done by Professor Jesse Ausubel of Rockefeller University, New York. We might be able to build enough wind farms to produce all the energy the world needs, he says. Or dam enough rivers. Or grow enough biomass.

But we will wreck the environment if we do.

Ausubel worked out the power each kind of renewable energy produces for a given area of land that it disturbs. In other words he calculated power per square metre.

He showed that renewable energy needs enormous areas of land. He compares the destruction of nature by renewables with the space needed by nuclear power.

Nuclear energy is green," he says. "Considered in watts per square metre, nuclear has astronomical advantages over its competitors." His research appears in Inderscience's International Journal of Nuclear Governance, Economy and Ecology*.

Economies of scale help technologies to succeed, Ausubel points out. But there are no economies of scale with renewables. Just the opposite. More power from renewables means more land is used up. In fact the area needed for each kilowatt of power most likely increases.

This is because land that is good for wind, hydro-electricity, biomass or solar power would get used up first.

Looking at each renewable in turn paints a grim picture of their impact on the environment.

Take hydro-electricity. Suppose the entire province of Ontario, Canada were flooded with all the rain that falls on it in a year. Then store all this behind a 60 metre dam.

This would still generate just 80% of the energy produced by Canada's existing nuclear power stations. Put another way, each square kilometre of dammed land would provide electricity for just 12 Canadians.

Biomass energy is also horribly inefficient and destructive of nature. Vast areas would have to be harvested each year to produce power for a large part of the USA. To get the same electricity from biomass as from one nuclear power plant would take 2500 square kilometres of prime Iowa land.

"Increased use of biomass fuel in any form is criminal," says Ausubel. "Humans must spare land for nature. Every automobile would require a pasture of 1-2 hectares."

What about wind? A wind farm is three to ten times smaller than a biomass farm, Ausubel says. But 770 square kilometres of land are still needed to produce as much energy as one nuclear plant (generating 1000 megawatts electrical).

To supply the electricity the US used in 2005 would have taken a wind farm the size of Texas. This would have been covered with structures to extract, store and transport the energy. Even this is wildly optimistic, since it assumes round-the-clock wind at just the right speed.

One hundred square metres is a good size for a Manhattan apartment. But a far greater area would be needed to extract wind energy to run its laundry, microwave oven, plasma TV and computer. New York City would need every square metre of Connecticut turned into wind farms to power its electrical equipment.

Solar power is not the answer either. You could build a solar cell plant that would produce the same electricity as a 1000 megawatts nuclear power plant. But you'd have to paint 150 square kilometres of land black to do it. And you would need more land for storage and retrieval of the energy.

Every form of renewable energy needs vast infrastructure - concrete, steel, roads, Ausubel says. "As a Green, one of my credos is 'no new structures'. But renewables all involve ten times or more stuff per kilowatt as natural gas or nuclear."

The full footprint of uranium mining adds just a few hundred square kilometres.

There are certainly concerns about waste storage, safety and security. But the dense heart of the atom offers by far the smallest footprint of any energy source. Economies of scale would mean that the nuclear industry could increase the amount of energy it produces while shrinking the size of its power plants, Ausubel says.

This is what has happened in the computer industry. With investment and research, computers have grown steadily smaller and much more powerful.

"If we want to minimise new structures and the rape of nature, nuclear energy is the best option," says Ausubel.

"Renewables may be renewable, but they are not green."

*"Renewable and nuclear heresies", International Journal of Nuclear Governance, Economy and Ecology, Vol. 1, No. 3, 2007 229-243.

More help with words

atom

benefit

element

energy

fossil fuels

fossilised

mass

nuclear reactor

nucleus

particle

power

preserved

What's it all about?

1. The first paragraph mentions three kinds of renewable energy. Name two of them.
2. What will happen if we use any of these sources of renewable energy to supply all the energy the world needs?
3. What kind of science is this story talking about? Did Ausubel do an experiment, or do a calculation or do something else?
4. Ausubel compared the effects of using renewable energy to produce electricity with another way of producing electricity. What is that other way?
5. "Watts per square meter" is the kind of shorthand that scientists use. Square meters are a way of measuring ----.
6. Watts are a way of measuring power. So "watts per square meter" tells you the ----- produced by different power stations for the same area of land used up.
7. The phrase "astronomical advantages" means that nuclear power stations produce much power in the form of ----------- than renewables.
8. There is another way of looking at this. A power station that uses solar energy , biomass or wind turbines to produce electricity takes up an enormous amount of ----.
9. The story gives examples taken from Ausubel's research on how much land you have to use up to get useful energy from renewables. It talks first about ----- -----------.
10. Suppose we shut down all 25 of Canada's nuclear power stations. Then try to replace them with hydro-electric power stations. Ausubel shows that you need a dam much bigger than the whole province of ------- to do this.
11. Ausubel looks next at -------.
12. He says we would need to use the trees or plants from ---- square kilometers of "prime Iowa land" to get the same energy as from one nuclear power station
13. What do you think this prime land is used for now?
14. Wind power uses up less land than biomass but far more than nuclear. What would you have to do to Texas to produce enough electricity from the wind for the whole USA?
15. Is solar power any better?
16. Besides the power stations themselves, renewables also need new roads, buildings, cables and storage systems. What one word does the writer use for all of this?
17. There are concerns about nuclear energy. State two of them.
18. People who study how things are made and sold often talk about economies of scale. This means that the more of something you make the ------- it is to make each one.
19. You get economies of scale with nuclear energy Ausubel says. But you don't get them with renewable energy. In one sentence and your own words explain why that is.
20. What is the main conclusion of Ausubel's work?
21. Imagine you are a scientist. Think up one question you would like to have answered about all this.
22. How would you go about answering that question?

More teaching resources for this story

Renewables fail UK US

Topic for discussion, research or pupil presentations

The science in this story is simple – if you're a scientist. Young people still at school have a lot of misconceptions about energy and power, which is not surprising since it took scientists themselves many centuries to get it right.

Research shows that children often believe energy is intimately linked with being alive; they confuse energy with force; they see it as a type of fuel or a kind of fluid. These different misconceptions can often be held by the same person in different situations.

To try to make things clearer to young people in school, "more time should be devoted to qualitative questions", according to researcher Reinders Duit*, and "students should be advised to explain the physical phenomena in their own words".

This story provides a good opportunity to do precisely that. Working in groups students should tackle any or all of the following questions, some of which require research.

1 Fuel can be used up but energy can't. Explain this.

2 Imagine a power cut that lasts a whole day. Make a list of the things you do each day that you could no longer do. What if the power cut lasted a week, a month, a year?

3 Do the What kind of science news? exercises above. These are likely to generate even more debate and discussion than usual.

4 Using the results from these exercises try to answer the following questions: 1) What science has Ausubel actually done? 2) Are there any new discoveries in the story? 3) So what kind of story is this?

5 Make a list of the steps (no more than half a dozen for each) in getting electricity from wind, dammed water, biomass and solar cells. Then do the same for nuclear. In what way are solar cells different to all the others?

6 Confusion about concepts is not helped by the use of many different units for energy and power. These include joules and calories, and for electricity a set of units that sounds like they should be power but are actually energy – kilowatt-hours and megawatt-hours. There is also the fact that the calorie in everyday use is a perfectly respectable unit of energy but not the same one physicists use. It's a thousand times as large, and physicists call it the kilocalorie.

Working in groups, students should create as many examples as they can that illustrate joules (lifting an apple a metre in the air, dropping a bag of sugar), kilocalories (heating a kilogram of water, converting chocolate to motion) and kilowatt-hours. They should then attempt to create some way of picturing the amount of energy that the US used in 2005. That figure, according to Ausubel, was 4 million megawatt-hours – which is a whole lot of chocolate bars.

7 In the paper itself Ausubel describes himself as a Green, and goes on to say: "I should mention that I am not naïve about nuclear. Privileged to work with Soviet colleagues who participated in the Chernobyl clean-up, I saw the Dead Zone in 1990 with my own eyes. I visited the concrete sarcophagus encasing the blasted reactor …".

In one sentence students should answer this question: What is a Green?

*Duit, R. (1983) Energy conceptions held by students and consequences for science teaching In: Helm, H. and Novak, J.D. (eds). Proceedings of the International Seminar: Misconceptions in Science and Mathematics, 20-22 June 1983, Cornell University, Ithaca, N.Y. pp 316-323

Tips for science class discussions and groupwork

No 56

The connection between science and literacy is the subject of much attention in the science education community. This attention comes in large part from three sources. One is the growing body of research in science teaching and learning that suggests that language is essential for effective science learning – for clarity of thought, description, discussion and argument, as well as for recording and presentation of results. In addition to engaging in direct investigation of scientific phenomena, students make meaning by writing science, talking science and reading science. At the root of deep understanding of science concepts and scientific processes is the ability to

Extract from Douglas, R. (ed.) et al. (2006) Linking Science & Literacy in the K-9 Classroom. Arlington: NSTA Press.

Water, water everywhere

University College London: 11-Jul-2007 13:00 Eastern US Time

Scientists have found water on the planet of another star. This is the first time this key substance for living things has been found on an extrasolar planet.

More than 200 extrasolar planets have been discovered so far. These are planets in orbit around a star, in the same way as our Earth is in orbit around the sun.

Extrasolar planets don't usually have interesting names like Venus or Pluto. This one is called HD 189733b. It orbits a star in the constellation of Vulpecula the Fox. It is 64 light years away from us.

HD 189733b is a "transiting planet". This means it passes in front of its star. As transiting planets do this they absorb light from their star.

Different substances absorb different colours of light. So scientists can study the light that comes through their telescopes and discover what the planet's atmosphere is made of.

The team of scientists who discovered water on HD 189733b was led by Dr Giovanna Tinetti. She is a scientist at the European Space Agency and University College, London. The findings will be published in this week's Nature (July 12).

This is the first time that astronomers have been sure there is water on an extrasolar planet. Unfortunately the water is not lying around in puddles in great lakes and oceans full of alien fish and seabirds. We know this because HD 189733b is very hot indeed. So water there is in the form of water vapour in the atmosphere of the planet.

HD 189733b is far from being habitable, says Dr Tinetti, who recently took up an Aurora Fellowship at UCL. In fact it is quite hostile to life. But the new discovery shows that water might be more common out there than scientists thought.

It also shows something very important for future work, she says. The same method Dr Tinetti and her colleagues used to detect water on HD 189733b "can be used in the future to study more 'life-friendly' environments."

NASA's Spitzer Earth-orbiting telescope was used to make the discovery. The scientists made measurements at a number of key wavelengths. These were in the infrared part of the spectrum. It is light at these wavelengths that water vapour absorbs.

The detection relied on Dr Tinetti's painstaking analysis. It also relied on calculation of very accurate water absorption parameters. Dr Bob Barber and Professor Jonathan Tennyson did this. They are in UCL's Department of Physics & Astronomy.

Dr Barber said: "The absorption parameters were calculated from our Barber-Tennyson list of water vapour spectral lines. This includes over 500 million individual absorption features."

Each of these is like a fingerprint, he added. They provide "vital clues to the amount of water present and the temperature of the atmosphere."

Parts of the atmosphere of HD 189733b are very hot - around 2000 degrees Celsius, said Professor Tennyson. He is head of UCL's Physics & Astronomy Department. "You need the millions of lines we calculated to simulate this."

HD 189733 is a star much like our own Sun, although a little cooler. But its planet is very unlike Earth. It is a gas giant like Saturn and Jupiter, the largest planet in our solar system. It is actually 15% bigger than Jupiter.

The main difference between our gas giants and HD 189733b is distance from their parent sun. Jupiter is over five times as far away from the Sun as Earth is. But HD 189733b is more than 30 times closer to its star than Earth is to the Sun. This is why HD 189733b is so much hotter than Jupiter.

The "holy grail" for planet-hunters is to find a planet like Earth that has water in its atmosphere, said Dr Tinetti. "When it happens, that discovery will provide real evidence that planets outside our Solar System might harbour life.

"Finding the existence of water on an extrasolar gas giant is a vital milestone along that road of discovery."

More help with words

electromagnetic waves

feature

identifies

microwaves

model

planet

universe

What's it all about?

1. What have the scientists discovered?
2. What is an extrasolar planet?
3. What is the name of the extrasolar planet that has water on it?
4. How far away from us is this planet?
5. What does a transiting planet do to light from its star?
6. So scientists can study this light to find out which colours are missing. This tells them what substances have -------- the light.
7. Is the water on this planet lying around as a liquid?
8. What form is it in?
9. Could people live on HD 189733b?
10. What phrase from the article gave you the answer to the last question?
11. This discovery does not show there could be life on HD 189733b. But it does show two things. State one of them.
12. Which part of the electromagnetic spectrum were the scientists particularly interested in?
13. In your own words and one sentence explain why.
14. There were two main parts to the work that led to this discovery. One was to collect light from the star using the ------- telescope.
15. Then the scientists had to study this light to see what "colours" or wavelengths it contained - more importantly which ones were missing because they had been absorbed. Was this second part easy or difficult?
16. Which word in the story helped you to answer the last question?
17. Dr Barber mentions two other things about the planet - apart from water vapour being there - that can be learned from the light. What are they?
18. In what way is HD 189733b like Jupiter?
19. In what way is HD 189733b unlike Jupiter?
20. HD 189733 and HD 189733b are names for two different things. Look at where these names are used in the story and explain what each of them means.
21. In one sentence explain why astronomers are so interested in finding water on other planets.
22. If you were these scientists what work would you like to do next?
23. What question would that research be trying to answer?

More activities for this story

Water everywhere UK US

Topic for discussion, research or pupil presentation

A) I chatted to Dr Tinetti about her research earlier this summer, when she first came to London looking for somewhere to live while working at University College. After explaining her approach to searching for life on exoplanets - in which she develops computer models of planetary atmospheres and compares them with observations - she tried to answer a harder question: "Do you think there is life out there on other planets?"

Working in groups, students should listen to the short audio extract of this part of our talk. During the rest of the interview, which lasted over an hour, Dr Tinetti talked confidently about the scientific methods she and her colleagues are using - analysis, modelling, making observations. But in this extract she suddenly starts using a particular phrase that makes her sound very hesitant.

Working in groups students should try to find that phrase, and count the number of times Dr Tinetti uses it or some variant of it. They should then try to decide why the scientist seems so unwilling to be definite when tackling this one question.

The clue, which the teacher might point groups to as necessary, comes right at the end of the recording.

B) More activities:

Teachers' Domain has an appealing set of interactive resources on the search for extraterrestrial life, the Spitzer Space Telescope and infrared astronomy, astronomy at different wavelengths and the importance of water to life. These are pulled together in a comprehensive lesson plan on what makes a habitable planet. A teacher or school needs to register to access this, but this is a simple process from here.

C) Centauri Dreams is probably the best place on the Web for news and informed opinion
on exploring the stars and the prospects of finding life on other planets.

Tips for science class discussions and groupwork

No 55

Science inquiry is typically a collaborative activity and as such involves teams of students in discussing, planning, and conducting investigations together and in sharing responsibilities for talking, reading, writing, and other kinds of presentations. Communication, therefore, plays a major role in science inquiry, and language is one of its central elements. In science inquiry, however, communication involves simultaneous use of other forms such as pictorial and numerical representations. Teams of science inquirers talk about and write their questions, their tentative explanations, their plans, their data, their conclusions, and their reasons and judgements about relationships between evidence and explanations, and about how they make public presentations and scientific arguments in behalf of their work. It is in the context of this kind of scientific activity that students' literacy of the spoken and written word develops along with literacy of the phenomenon. It is also in relation to direct experiences in scientific investigations that words acquire nuances or "negotiated meanings"; inevitably, those meanings differ from meanings conveyed by the same words in ordinary speech.

From Douglas, R. (ed.) et al. (2006) Linking Science & Literacy in the K-9 Classroom. Arlington: NSTA Press.

Ancient green land

Copenhagen University: 5-Jul-2007 14:00 Eastern US Time

The world's oldest DNA has shown that ancient Greenland was once covered in conifer forest and had a mild climate.

Eske Willerslev is an expert in extracting DNA from organisms buried in permafrost. He is a professor at Copenhagen University.

Willerslev has been analysing DNA from beneath Greenland's kilometre-thick icecap. The DNA is close to half a million years old. The results have just been published in the journal Science.

Ten percent of the Earth's surface has been covered with ice for thousands of years, hiding what lies beneath. But scientists have been drilling through the icecap to collect complete columns of ice from top to bottom.

This ice contains yearly layers and is a frozen archive of the world's climate.

Eske Willerslev began to wonder if there might also be DNA buried deeply. If so then perhaps he could reconstruct the living environment of ancient times.

Ice-core samples

The lower parts of the icecap are mixed with mud from the bottom, which is what Willerslev was interested in. So he obtained base layer samples from three drillings. The first two were DYE-3 from the south of Greenland and the GRIP drilling from the middle of the Greenland ice sheet.

The third core came from the John Evans glacier in Canada. This is only a few thousand years old. These samples were used to test the methods.

From the Canada samples Willerslev found DNA from three of the four most common plants that grow in the area. "That means that what one finds under the ice represents the local environment," he explains.

Greenland samples

In the sample from the GRIP drilling, the scientists found no DNA remains at all. Not from plants, mammals or insects. The explanation, says Willerslev, is that the ice in the middle of the ice sheet is over three kilometres thick.

"The greater pressure produces a higher temperature at the base, and so the DNA material, which cannot tolerate warmth, disintegrates."

But at the DYE-3 drilling site the ice is 'only' two kilometres thick. Here the scientists found DNA so well preserved that traces of a long list of plants and insects could be found. These included pine, spruce, alder and yew trees.

There were also remains of flies, butterflies and moths that once flew and fluttered among the Greenland woodland. Traces of beetles and spiders were also found.

These results prove for the first time that there were forests full of life in south Greenland

The genetic material is telling a story of a living environment completely different from what we see today, says Willerslev. "We have found grain, pine, yew and alder. These correspond to the landscapes we find in Eastern Canada and in the Swedish forests today."

The scientists can also tell what the climate was like at the time. This is because each tree species has its own temperature needs. "The yew trees reveal that the temperature during the winter could not have been lower than minus 17 degrees Celsius," says Willerslev

Traces of other trees show that the summer temperatures were at least 10 degrees Celsius.

Dating

The scientists used the genetic traces of butterflies, moths, flies and beetles, to analyse their mitochondria. These contain small pieces of DNA that change with time in a regular way. This means they can be used like a clock to date the DNA.

The team also analysed the insects' amino acids, which also change over time. Both dating methods suggest that the insects were at least 450,000 years old.

The dating of the samples remains uncertain. But the DNA has been preserved under ice for at least 130,000 years, and perhaps up to 1 million years, say the scientists.

More help with words

average

breed

cell

conception

fertile

fertilisation

genes

individual

inherit

molecule

permanent

sperm

subsoil

temperature

What's it all about?

1. Scientists have discovered that something once covered Greenland. What was that?
2. What have the scientists found out about the climate there?
3. What is special about the DNA they used to make these new discoveries?
4. How thick is Greenland's icecap?
5. How old is the DNA the scientists have found beneath the icecap?
6. What have scientists been doing to collect complete columns of ice?
7. Each year more snow falls, so each year a new layer is laid down on the icecap. What does the writer of the article call these layers?
8. The scientists studied samples from how many different drilling sites?
9. Where were these sites?
10. The Canada samples were used to test that DNA from drillings was actually DNA from the ----- environment.
11. The two sets of Greenland drillings gave very different results. What were they?
12. What reason do the scientists suggest for the result at the GRIP drilling site?
13. State six of the living things the scientists found traces of at the third drilling site.
14. What do these results prove for the first time?
15. The results are telling a story of a living ----------- on Greenland much different from the solid icecap that exists there today.
16. What else can the scientists tell about Greenland at the time the trees were alive?
17. In one sentence how can they do that?
18. When were the insects the scientists found traces of actually alive?
19. Willerslev wondered if there was ancient DNA under the ice. If there was he could use it to "reconstruct the living environment" of long ago. In one sentence and your own words what does "reconstruct the living environment" mean?
20. Find a sentence in the story that says what the aim of this work was.
21. Find a sentence or phrase in the story that is a hypothesis.
22. Find a sentence or phrase in the story that is evidence for a hypothesis.
23. If you were these scientists what question would you still have about any of this?
24. Can you think how you might try to answer that question?

More activities for this story

Ancient green land UK US

Topic for discussion, research or pupil presentations

A) In the popular film Ice Age the intrepid heroes meet a whole army of dodos, the flightless bird that went extinct in the 17th century (not during the Ice Age at all but who’s counting?).

These are portrayed as hilariously stupid, headstrong and clumsy birds, which manage to extinguish themselves at every opportunity by crashing into each other, falling off cliffs into diving into molten lava.

While this makes for entertaining episodes, it is very unfair on the poor old dodo and totally misrepresents why species do go extinct. For a start any animal as suicidally stupid as the dodos in this film wouldn’t have evolved and survived in the first place.

In Ice Age 2, Manny the mammoth believes himself to be the last of his kind - until he meets a female mammoth who thinks she’s a possum (don’t ask - you need to see it).

Working in groups, students should choose a bird or animal that is now extinct, such as the dodo, mammoth, sabre-toothed tiger, and explore the various possible reasons for their extinction. They should deliver a presentation on the subject to the class.

The class should then try to find the feature common to all extinctions.

B) An interesting twist on the above is an in-depth lesson from Discovery School, with extension activities and recommended websites. This lesson looks at why particular species, known as living fossils, have survived into the present, when their contemporaries have long gone the way of 99.9% of all species that ever walked, crawled, swam or flew. Extinction is normal.

A nice aspect of the lesson is the following activity that aims to make the scientific method explicit in kids’ minds:

Before beginning the research, have students develop a hypothesis about why their animal did not become extinct. They should write their hypothesis on Part A of the sheet ... Students should base their hypotheses on the facts discussed during step 5, as well as the discussion about why dinosaurs became extinct. Below is a sample hypothesis explaining why coyotes might survive if conditions on Earth changed dramatically and other species were killed off.

Tips for science class discussions and groupwork


No 54

Many of our students are poor readers ... if they do not understand what they read, then school and reading simply become a source of frustration. I am teaching and coordinating our summer school program, which is primarily web based (LA and Math).

There is a ton of reading that these kids must do and many of them simply cannot do it - which is probably much of the reason they are in summer school to begin with. Being able to work one on one with these students has been an eye opening experience. This new perspective, coupled with
what I am learning from the reading course [the Florida On line Reading Professional Development], is causing me to become passionate about the belief that we all (teachers) must accept the responsibility of helping all students become better readers, regardless of our particular content. Many of the students I have been working with this summer are also some of our biggest discipline problems, which may result from the overwhelming frustration they encounter every day.

Extract from an online forum of the National Science Teachers Association by Tina Annucci, Gamble Rogers Middle School, St Augustine, FL

Giant fossil penguins

Giant prehistoric penguins in Peru? It sounds more like something out of Hollywood than real science.

But a researcher from North Carolina State University, along with colleagues in other countries, has shown that two new penguin species reached equatorial regions tens of millions of years earlier than was thought possible. What's more, this was when the earth was much warmer than it is now.

Palaeontologist Dr. Julia Clarke is assistant professor of marine, earth and atmospheric sciences at NC State. She and her colleagues studied two newly discovered extinct species of penguins. Palaeontologists from Peru had found the new penguins' sites in 2005.

Both new species lived on the south coast of Peru. The first is called Icadyptes salasi. These penguins stood 5 feet tall and lived about 36 million years ago. The second new species, Perudyptes devriesi, lived about 42 million years ago. It was roughly the same size as a living King Penguin (2.5-3 feet tall). It represents a very early stage of penguin evolution.

These new penguin fossils are among the most complete yet recovered. They call into question earlier hypotheses about penguin evolution and how penguin species moved from one part of the world to another.

Scientists believed that penguins evolved in Antarctica and New Zealand. They later moved closer to the equator. This was thought to have happened about 10 million years ago - after the Earth had gone through a period of cooling (34 million years ago).

Nowadays we think of penguins as adapted to life in cold countries, Clarke says. "But the new fossils date back to one of the warmest periods in the last 65 million years of Earth's history. The evidence indicates that penguins reached low latitude regions more than 30 million years prior to our previous estimates."

These new species are the first fossils to show that penguins were already living near the equator when the Earth's climate changed dramatically. This happened when the extremely warm Palaeocene and Eocene epochs gave way to "icehouse" Earth and permanent polar icecaps.

Penguins reached equatorial regions during this earlier warm period, these new fossils show. They also thrived there at that time: More species are now known from the new Peruvian sites than live there today.

Clarke and her colleagues estimate that the two Peruvian species are the result of two different dispersal events. They reached this conclusion by comparing evolutionary relationships with the places other fossil penguins have been found.

This showed that the ancestors of Perudyptes seem to have lived in Antarctica. Those of Icadyptes may have started out near New Zealand, say the scientists.

The new penguin specimens are among the most complete yet discovered that show what early penguins looked like. Both have long narrow pointed beaks. This is thought to be an ancestral beak shape for all penguins.

Perudyptes devriesi has a slightly longer beak than some living penguins. But the giant Icadyptes salasi has a much longer beak, with features not known in any extinct or living species.

The beak is sharply pointed, almost spear-like. The bird's neck is robustly built with strong muscle attachment sites. Icadyptes salasi is among the largest species of penguin yet found.

These fossils seem to contradict some of what we thought we knew about the relationship between penguins and climate. But Clarke warns against jumping to conclusions.

We should not assume that because prehistoric penguins were not adapted to the cold, living penguins won't be affected by climate change.

"These Peruvian species are early branches off the penguin family tree, that are comparatively distant cousins of living penguins," Clarke says. "In addition, current global warming is occurring on a significantly shorter timescale.

"The data from these new fossil species cannot be used to argue that warming wouldn't negatively impact living penguins."

More help with words

breed

environment

evolution

fertile

fossil

individual

permanent

placental

species

tentative

tissue

typical

What's it all about?

1. Where have these penguin fossils been found?
2. How many new species have been found there?
3. Who has been studying them?
4. Who found the sites?
5. How tall was Icadyptes?
6. How long ago did it live in Peru?
7. How tall was Perudyptes?
8. Fossils are often simply small pieces of bone or faint impressions in rock. Are these new penguin fossils like that?
9. What word in the story gave you the answer to the last question?
10. These new fossils are forcing scientists to think again about what happened to penguins in the past. What five-word phrase does the writer use to say this?
11. Before this new discovery scientists thought penguins had first appeared on Earth how many millions of years ago?
12. In what countries did they think penguins had first appeared?
13. Were those countries warm or cold at that time?
14. So penguins were thought to always have been birds suited to life in ---- countries.
15. Does this new evidence support that belief or show it was wrong?
16. Climate is just average weather over a long time. So what was the climate like when these penguins were living near the equator?
17. What happened to Earth's climate a long time after the penguins were living in Peru?
18. So was it warmer or colder near the equator, when these penguins lived there, than it is now?
19. Did the penguins do well living near the equator?
20. What word in the story gives you the answer to the last question?
21. "Comparing evolutionary relationships" means studying fossils and different parts of fossils to figure out which ones came first. What did this work suggest to the scientists?
22. Are they sure about this?
23. Find three words in the story that help give you the answer to question. Look in the paragraph that begins "Clarke and her colleagues ..." and in the next paragraph.
24. Depending on your answer to question 15 complete one of these sentences: 1) These new fossils support the belief that penguins have always been suited to life in cold countries because ... Or 2) These new fossils show scientists were wrong to think penguins have always been suited to life in cold countries. The reason is ....
25. With as much detail as you can find, from the whole story, describe Icadyptes salasi.
26. The sentence that begins "We should not assume that ..." is a hard one to make sense of. In your own words what is this sentence trying to say?
27. The very last sentence is also hard to follow. Rewrite this sentence in your own words.
28. What two reasons does Clarke give for making her last statement?
29. If you were these scientists what research would you like to do next?
30. What question would that research be trying to answer?

Topic for discussion, research or pupil presentations

A) In the popular film Ice Age the intrepid heroes meet a whole army of dodos, the flightless bird that went extinct in the 17th century (not during the Ice Age at all but who's counting?).

These are portrayed as hilariously stupid, headstrong and clumsy birds, which manage to extinguish themselves at every opportunity by crashing into each other, falling off cliffs into diving into molten lava.

While this makes for entertaining episodes, it is very unfair on the poor old dodo and totally misrepresents why species do go extinct. For a start any animal as suicidally stupid as the dodos in this film wouldn't have evolved and survived in the first place.

In Ice Age 2, Manny the mammoth believes himself to be the last of his kind - until he meets a female mammoth who thinks she's a possum (don't ask - you need to watch it).

Working in groups, students should choose a bird or animal that is now extinct, such as the dodo, mammoth, sabre-toothed tiger, and explore the various possible reasons for their extinction. They should deliver a presentation on the subject to the class.

The class should then try to find the feature common to all extinctions.

B) An interesting twist on the above is an in-depth lesson from Discovery School, with extension activities and recommended websites. This lesson looks at why particular species, known as living fossils, have survived into the present, when their contemporaries have long gone the way of 99.9% of all species that ever walked, crawled, swam or flew. Extinction is normal.

A nice aspect of the lesson is the following activity that aims to make the scientific method explicit in kids' minds:

Before beginning the research, have students develop a hypothesis about why their animal did not become extinct. They should write their hypothesis on Part A of the sheet ... Students should base their hypotheses on the facts discussed during step 5, as well as the discussion about why dinosaurs became extinct. Below is a sample hypothesis explaining why coyotes might survive if conditions on Earth changed dramatically and other species were killed off.

Tips for science class discussions and groupwork

No 54

Many of our students are poor readers ... if they do not understand what they read, then school and reading simply become a source of frustration. I am teaching and coordinating our summer school program, which is primarily web based (LA and Math).

There is a ton of reading that these kids must do and many of them simply cannot do it - which is probably much of the reason they are in summer school to begin with. Being able to work one on one with these students has been an eye opening experience. This new perspective, coupled with what I am learning from the reading course [the Florida On line Reading Professional Development], is causing me to become passionate about the belief that we all (teachers) must accept the responsibility of helping all students become better readers, regardless of our particular content. Many of the students I have been working with this summer are also some of our biggest discipline problems, which may result from the overwhelming frustration they encounter every day.

Extract from an online forum of the National Science Teachers Association by Tina Annucci, Gamble Rogers Middle School, St Augustine, FL

Bone-crunching wolves

University of California, Los Angeles: 21-Jun-2007 12:00 Eastern US Time

The icy expanses of Alaska were once the home of large, bone-crunching wolves. This was a unique type of wolf that died out, along with many other big animals, at the end of the Pleistocene.

These extinct Alaskan wolves had robust bodies, strong jaws and massive canine teeth. They regularly killed prey larger than themselves and ate their bones, according to research in today's online edition of Current Biology.

These results are surprising, says Blaire Van Valkenburgh of the University of California, Los Angeles. "The unique attributes of Alaskan Pleistocene wolves had not been previously recognised. They show that wolves suffered an extinction at the end of the Pleistocene."

This new research shows that if wolves had not survived in the Old World, there might not be any wolves in North America today.

"But the living gray wolf differs dramatically from that which roamed Alaska just 12,000 years ago."

The gray wolf is one of a few large predators that survived the mass extinction of the late Pleistocene. But this research shows that wolves did disappear at that time from northern North America

To study Alaska's ancient wolves, the researchers collected the remains of bones from the permafrost in eastern Beringia. They examined their chemistry and genes.

Remarkably they found that these late-Pleistocene wolves were distinct from modern wolves. They had different genes and different bodies.

None of the ancient wolves had exactly the same genes as modern wolves, the researchers report. Their skull shape and the way their teeth had worn down showed they were specialised hunters and scavengers. Chemical analysis of the wolf bones confirmed this.

The wolves fed on extinct megafauna, like the bison, mammoth and woodland muskox.

The ancient wolves had large teeth, broad skulls and short snouts, says Van Valkenburgh. This gave them very strong bites. Their teeth were often worn-down or broken. This strongly suggests "regular and frequent bone-cracking and bone-crunching behaviour."

All this came in very handy in ancient Alaska. Wolves there faced stiff competition for food from other fierce competitors. These included lions, short-faced bears and sabre-tooth cats.

When food is scarce modern wolves eat more of their prey, including the bones. They also eat faster which makes broken teeth more likely.

The extinction of this specialised wolf could be a sign of things to come for today's specialised predators, Van Valkenburgh says.

One example is a North American gray wolf that was discovered only recently. It is unusual because it is nomadic. Packs of these wolves migrate with the caribou across the North American tundra. All other wolves have their own territories and do not migrate.

"Global warming threatens to eliminate the tundra, and it is likely that this will mean the extinction of this important predator," says Van Valkenburgh.

More help with words

average

breed

cell

compounds

conception

elements

environment

fertile

fertilisation

herbivore

inherit

permanently

Pleistocene

species

sperm

subsoil

temperature

What's it all about?

1. Where in the world did these wolves live?
2. Is this type of wolf still alive today?
3. What happened to them?
4. Which one word near the start of the story tells what happened to them?
5. How often did these Alaskan wolves kill prey larger than themselves?
6. If wolves had not survived in Europe what might have happened in North America?
7. How long ago were these Alaskan wolves alive?
8. What parts of the wolves' bodies did the researchers study to learn about them?
9. These wolves were different from today's wolves in several different ways, the scientists found. State one of them.
10. Three different pieces of evidence showed that the wolves were specialised hunters and scavengers. State two of them.
11. What did the wolves eat?
12. How did the scientists work out that the wolves crunched bones?
13. In your own words what does "stiff competition" mean?
14. In what kind of conditions do modern wolves behave like these ancient wolves?
15. Are most wolves nomadic or territorial?
16. In one sentence what does this mean?
17. In one sentence why can being specialised sometimes be a problem?
18. If the weather or the supply of food changed, would an animal that was specialised be more or less likely to survive?
19. What change do you think happened that made these Alaskan wolves die out?
20. If you were these scientists what research would you like to do now?
21. What question would that research be trying to answer?

Topic for discussion, research or pupil presentations

Discovery School has a nice lesson on Ice Ages and extinctions. Its learning objectives include the following.

Students will:

• understand what causes ice ages;
• learn about plants and animals that lived during the Ice Age;
• understand why certain Ice Age animals became extinct.

Here is an extract:

Tell students that they are going to conduct some research about the Ice Age and the animals that lived during that period. Divide students into five groups. Each group will be working on the three questions listed below... Visit the Web sites provided with each question for essential background information. Brief answers are provided in italics.

...

Question 3. Why did many animals become extinct at the end of the Ice Age? (Although scientists do not know for sure, they suspect the causes are either hunting by people or environmental changes as a result of the warming of Earth. Some researchers think that overhunting by humans eliminated a major species, either the mammoth or the mastodon, which led to more general extinction. Other scientists think that rising temperatures, changing rainfall patterns, and the melting of the glaciers caused many changes to the ecosystem, resulting in the extinction of certain animals.)

...

Have each group share its findings. What have students learned about the relationship between the environment of the Ice Age and the animals that lived then? What is the relationship between the changing environment of the Ice Age and the animals that became extinct?

Have students complete the Take-Home Activity Sheet: Giving a Scientific Opinion. The purpose of the sheet is to see whether students can apply what they have learned about the Ice Age to modern times. If possible, have students share their ideas with their classmates.

(Note however that some of the links from the Discovery webpage no longer work.)

Tips for science class discussions and groupwork

No 53

Collaborative activities seem to provide less information to the teacher about an individual pupil's progress. This may appear to be a serious drawback for any assessment procedure. However, collaborative discussion, debate and argument are immensely valuable in terms of getting pupils to reflect carefully on their own ideas, to take alternative possibilities seriously and in this way to kick start the learning process.

Naylor, S. and Keogh, B. (2007) Active Assessment : thinking, learning and assessment in science. School Science Review, 88(325), pp 73-79

Martian wandering

University of California, Berkeley: 13-Jun-2007 13:00 Eastern US Time

There were once great oceans on Mars, say a team of scientists at the University of California, Berkeley.

A large plain at the planet's north pole looks very like an ocean basin, even from Earth. Images taken by the Viking spacecraft in the 1980s showed two possible ancient shorelines. Each of these was thousands of kilometres long, with features like those found in Earth's coastal regions.

These dried-up shorelines, as they seemed to be, were name Arabia and Deuteronilus. Scientists estimated the dates when they were filled with water at between 2 and 4 billion years ago.

But then in the 1990s Mars Global Surveyor measured the surface of Mars to a resolution of 300 metres. They found that the shorelines vary in height by several kilometres (more than a mile).

They rise and fall like waves, with several thousand kilometres from one peak to the next.

Here on Earth the height of any shoreline is pretty much the same everywhere. So experts began to reject the notion that Mars once had oceans.

But the UC Berkeley scientists have now found an explanation for the undulating Martian shorelines. The north and south poles of Mars have moved by nearly 3,000 kilometres along its surface. This happened within the past 2 or 3 billion years.

Spinning objects bulge at their equator. So this "true polar wander" could have caused the change in height of the shorelines that we now see on Mars, say the scientists.

"When the spin axis moves relative to the surface, the surface deforms," says study co-author Michael Manga. He is UC Berkeley professor of earth and planetary science. "That is recorded in the shoreline."

The paper will appear in this week's issue of Nature. The lead author is Taylor Perron, a former UC Berkeley graduate student, now a postdoctoral fellow at Harvard University.

Perron's calculations show that the response of Mars' elastic crust could create very large elevation differences for features like a shoreline. This is exactly what we see. The Arabia shoreline varies in elevation by about 2.5 kilometres. The Deuteronilus shoreline varies by about 0.7 kilometres.

"This is a beautiful result that Taylor got," says co-author Mark Richards. He is professor of earth and planetary science and dean of mathematical and physical sciences at UC Berkeley.

"The mere fact that you can explain a good fraction of the information about the shorelines with such a simple model is just amazing. It's something I never would have guessed at the outset.

"This really confirms that there was an ocean on Mars."

So now the question is: What caused Mars' spin axis to move?

A spinning planet is most stable when its mass is farthest from its spin axis. So any shift of mass on the planet could cause the spin axis to move. This might be a shift of mass within the mantle. It could be a mass shift between the mantle and the crust to form a volcano. It could even be an addition of mass caused by a meteorite hitting the planet.

Richards has modelled polar wander in Earth's past. This was generated by the upwelling of hot mantle. Some scientists believe this shifted Earth's spin axis 800 million years ago, by 90 degrees, tipping the planet on its side.

The UC team calculates that on Mars an initial shift of 50 degrees from today's pole would have been enough to disrupt the Arabia shoreline. This is equal to about 3,000 kilometres on the surface.

A shift of 20 degrees from today's pole, or 700 kilometres, would have changed the Deuteronilus shoreline.

Interestingly, today's pole and the two ancient poles lie in a line that is a constant distance from the planet's largest feature. This is the Tharsis rise, a huge bulge near the equator which contains Mars' most recent volcanic vent, Olympus Mons.

Tharsis is the largest volcano in the solar system. It formed about 4 billion years ago, not long after Mars solidified.

The positions in relation to each other of Tharsis and the path of the poles is exactly what scientists would expect if a mass had shifted that was smaller than the Tharsis rise. This is because the planet would then rotate so that the large mass of Tharsis stayed on the equator - as far away from the axis as possible.

"This alignment is unlikely to occur by coincidence," the team writes.

Manga has a hunch about the mass shift that led to the tilt of Mars' spin axis. If a flood of water had filled the Arabia ocean 3 billion years ago, to a depth of several kilometres, that might have been enough to shift it 50 degrees to the south.

When the water disappeared, the pole could have shifted back again. Then it could have shifted again by 20 degrees during the flood that created the Deuteronilus shoreline.

The unknown source of water must have produced a flood greater than any seen on Earth, Manga says. Huge canyons have been cut in the flanks of the Tharsis rise. Where has the water gone?

Well it might have evaporated. But there is another, more intriguing possibility. All that water might have sunk into underground dikes. These would be frozen near the surface.

But they could be liquid below.

More help with words

conference

core

depression

doctorate

erupt

journal

lava

orbit

planet

vapour

research

volcanic

What's it all about?

1. What is the main conclusion of this latest research?
2. Whereabouts on Mars is the large plain that looks like an ocean basin?
3. Roughly how long are the two possible shorelines photographed by the Viking spacecraft in the 1980s
4. What names were they given?
5. How old were they estimated to be?
6. For a while the plains were thought to be the remains of ancient oceans. Then new images started coming in during the 1990s. Which spacecraft took these images?
7. What kind of information about the surface of Mars did these new images show in much more detail than the Viking images?
8. What did this new information about the surface of Mars show about the edges of the large plains?
9. Shorelines on Earth are pretty much at the same height. So there was no obvious reason for shorelines on Mars to vary in height by as much as several ----------.
10. Scientists therefore began to think these were not ancient ----------.
11. But now the UC scientists have found a way to explain how a shoreline could end up with some parts much ------- than others.
12. It is all about what happens when things spin. What happens to the surface of spinning objects near their equators?
13. But the large plain that looks like an ocean basin is nowhere near the equator nowadays. Where is it?
14. For the scientists' new idea to work the large plain must have been much closer to the equator in the past than it is now. In just a few words what makes the equator move? (The article actually talks about the spin axis moving. But if the spin axis moves the equator must move. This is because the equator is an imaginary line around the planet half-way between the ends of the spin axis.)
15. If you stick a lump of wet putty or plasticine onto a spinning ball its spin axis will shift. Exactly the same thing happens if a big rock hits a planet from space. A big rock from space is called a ---------.
16. The spin axis will also shift if big masses of stuff move around the planet – from the inside to the surface or from the surface to its insides. Give one example, which we also see on Earth, of material from inside a planet getting to its surface.
17. So the scientists' idea is that a big mass of something moved on Mars. This made the spin axis shift so that what looks like shoreline was closer to the ------- than it is now.
18. Remember that the surface of a planet ------ near the equator. So parts of the shoreline closer to the equator would have ended up higher than other parts.
19. This is the scientists' idea for explaining why the shoreline is nothing like as level as shorelines here on -----.
20. Manga thinks the moving mass that made the spin axis shift was a flood of water into the ocean. Does he have any evidence for this?
21. Why do you think the possibility that there is liquid water under the surface of Mars is described as intriguing?
22. How sure do you think we can be that things happened just as these scientists say?
23. Make a list of the actual observations that are mentioned in the story, as distinct from ideas, suggestions and the results of calculations.
24. Do you think there might be another explanation for these observations?
25. If you were these scientists what would you like to do next?
26. What would be the aim of that research?

What kind of story is this?
Learning to do science is about learning to think. Experiments, direct teaching, group activities and discussions all have a part to play. So do science news stories.

Like other non-fiction texts, science stories contain different kinds of statements. To get at the science behind the words - and to make reading them an active experience - students should pull a text apart and explore the kinds of statement it contains.

We've met some of these in the later questions of the previous activity. Science news stories usually include the aims of the research or reasons for doing it. They often contain a hypothesis. Sometimes evidence for a hypothesis is given, or a hypothesis is used to make a prediction. Towards the end of a story the direction of future research the scientists are planning is often discussed, as well as outstanding questions the research will be designed to answer.

All these types of statement occur in some science stories. Virtually all science stories, however, will contain statements of the following four types:

• new findings or developments;
• the technology and methods the scientists used;
• previous or accepted knowledge, which may or may not be supported by the new findings;
• issues, implications and applications of the research.

So the next activity is designed to engage students with the latest science news by exploring the meaning and structure of a story as revealed by the content and balance of these four statement types:

Pulling it apart
In groups students should read through the story looking for new findings or developments. Once they have reached agreement, or at least consensus, and have underlined all the statements about what the scientists have just discovered or achieved, they can compare and discuss.

In groups they should go through the story again looking for the technology and methods the scientists used in their research. Once they have reached agreement or consensus, and have underlined the statements that talk about the methods and equipment the scientists used, they can compare and discuss.

They should repeat the activity for existing knowledge.

Any areas of disagreement in these activities - whether among the students or between teacher and students - should be regarded as opportunities for discussion rather than errors to be corrected.

Having fully engaged with the latest science news through the above activities, students will be far better able to talk and think about the science and its implications than someone who has simply read about it in a newspaper or watched a brief item on television.

Now it's time for them to get to grips with the issues raised by the research.

Young people have opinions. But school science traditionally allowed little scope for forming and expressing these - which is why it turned many of them off the subject for life.

Putting it together again

In groups, students should read through the latest story looking for issues, implications and applications. Once they have reached agreement, or at least consensus, and have underlined all the relevant statements in the story, they can compare and discuss.

Having done all this the students are well armed to explore the issues raised by the story. A suggested discussion topic specific to this new story is provided below.

Topic for discussion, research or pupil presentations

A simple demonstration of a spin axis shifting can be done with a football and a lump of something sticky, like wet mud or honey. If the football is set spinning on the floor with its axis straight up, and the sticky stuff dropped in the region of its "north pole" what happens next simulates how the spin axis of Mars has shifted, according to the UC scientists.

Two things to notice, the second not obvious from the story:

1) The sticky stuff ends up going around the equator.

2) It is not the spin axis that shifts, but the planet with respect to the axis. The orientation of the spin axis in space is fixed (apart from the effect of the small torque of the incoming mass), but the positions of the poles on the planet move.

Working in groups pupils should predict what will happen, do the experiment, then compare their predictions with what actually happened. They should then try to explain what they saw.

It takes a bit of teacher practice to get the spin rate and stickiness just right, so that big blobs of honey don't go flying around the room - although this is quite entertaining and isntructive.

A less messy approach would be to use the teaching aid movie on polar wander set up by Dave Stegman at Monash University

Teachers can find more activities, resources and lessons about Mars here

Tips for science class discussions and groupwork

No 52

"The 5-E model is designed to help kids construct their own understanding and then form questions to complete that understanding. Some teachers may find that some items do not lend themselves to the 5-E model, but I have found in my biology class that any subject can be taught with the 5-E model. Where most people turn from the 5-E model is because there is less planning involved and less "classroom confusion" (students may at times be actively moving around the room and creating noise in class). They also feel more in control by being the leader of the classroom instead of being an active part of the learning experience.

For myself, I find it exciting to develop lessons where I get to be creative and I can keep the creativity in my classroom. Personal opinion, but I think that as we move students through to graduation, we are being forced to take the creativity out of their learning experience. The 5-E lets me keep that creativity and excitement level in my class because I am actively involved in the learning. It also lets me use Multiple Intelligences to make learning the information relevant to each student. Sometimes, depending on how the students create their meaning, we are led down different paths than another group of students.

For those that like every class at the same point every day, this can be a hard item to deal with."

NSTA forum entry by teacher Bob Penrose (May 2007)

For more see 5E model and constructivism.

Wireless power

Massachusetts Institute of Technology: 7-Jun-2007

Imagine cell phones, household robots, MP3 players and laptop computers that can recharge their batteries without being plugged in. Some might not even need bulky batteries at all.

A team from MIT has just taken a step toward this vision of wireless power. The work will be reported in the June 7 issue of Science Express. This is the advance online version of the journal Science.

The story starts late one night a few years ago. Professor Marin Soljacic (pronounced Soul-ya-cheech) was standing in his pyjamas, staring at his cell phone on the kitchen counter. "It was probably the sixth time that month that I was wakened by my cell phone beeping to let me know I had forgotten to charge it.

"It occurred to me that it would be so great if the thing took care of its own charging."

Soljacic started thinking about physics and engineering that could make this happen. Several ways to send power without using wires have been known for centuries. The best known is electromagnetic radiation, such as radio waves.

These are great for sending information. But they are no use for sending power. Electromagnetic radiation spreads out in all directions, so most of the power would be wasted. It is possible to beam electromagnetic radiation in one direction. Lasers do it.

But this needs an uninterrupted line of sight between the source and the device. It also needs some kind of tracking device if the receiver is moving around. And it could be dangerous.

So the MIT team came up with a novel idea. They call it WiTricity. Using this they have now lit up a 60 watt light bulb from a power source over 2 metres away. There was no physical connection between source and appliance.

WiTricity is based on something called coupled resonance. Two objects that have the same resonant frequency exchange energy very efficiently. But very little energy will pass to other nearby objects.

Frequency is number of vibrations per second. Everything has a natural frequency, the frequency it vibrates at naturally. A child on a swing is a good example.

If given one big push this will swing back and forth at the natural frequency. A short swing will move faster than a long swing, so it will have a greater natural frequency.

Now suppose Mum pushes the swing any old time she feels like it. Sometimes she will speed the swing up. Sometimes she will slow it down. Overall very little energy will be given to the swing.

But suppose she times her pushes just right. The swings will get higher and higher. Energy is being transferred from the parent to the child on the swing. The reason is that Mum times it so she pushes at the natural frequency of the swing. This is resonance.

There are lots of examples of resonance. A wine glass vibrates at a certain frequency if it is tapped. Its natural frequency will be different depending on the amount of wine in the glass. So imagine a room with 100 wine glasses, each filled with wine to a different level.

If an opera singer produces a single note inside the room, the glass that vibrates naturally at the same frequency as the note gains energy from the sound waves. It might even gain enough to burst. The other glasses would not be affected because their resonant frequencies are all different from the frequency of the note.

These ideas apply to all kinds of resonances (for example acoustic, mechanical, electromagnetic). But the MIT team concentrated on one particular type, namely resonators that are coupled magnetically. The team explored a system of two electromagnetic resonators coupled mostly through their magnetic fields.

They found that the source and receiver were strongly coupled, even when the distance between them was several times larger than they were. This means power was being transferred efficiently.

Magnetic coupling is particularly good for everyday applications. This is because most common materials interact very little with magnetic fields. So power is not transferred to other objects in the room. "The fact that magnetic fields interact so weakly with biological organisms is also important for safety," Andre Kurs, a graduate physics student points out.

The design the team studied has two copper coils. Each is a resonant system. One of the coils, attached to the power source, is the sending unit. Instead of irradiating the environment with electromagnetic waves, this fills the space around it with a magnetic field. This oscillates at megahertz (millions of times a second) frequencies but does not send out any energy at first.

But when the receiving unit, which has the same resonant frequency, is brought into this field, energy is transferred. The coupled resonance means that the sending unit and receiving unit are strongly connected. But everything else around is not. Moffatt, an MIT undergraduate in physics, explains:

"The crucial advantage of using the non-radiative field lies in the fact that most of the power not picked up by the receiving coil remains bound to the vicinity of the sending unit, instead of being radiated into the environment and lost."

With such a design, power transfer has a limited range. The range is shorter for smaller-size receivers.

Even so, for a laptop-sized coil, power levels more than enough to run a laptop can be transferred over a distance the size of a room. This works well in pretty much all directions. It even works when there are objects between the source and the receiver.

Professor Peter Fisher says: "As long as the laptop is in a room equipped with a source of such wireless power, it would charge automatically, without having to be plugged in. In fact, it would not even need a battery to operate inside of such a room."

In the long run, this could reduce our need for batteries, which are heavy, expensive and harmful to the environment.

WiTricity is based on very well known laws of physics. So why has no one thought of it before? "In the past, there was no great demand for such a system, so people did not have a strong motivation to look into it," says Professor John Joannopoulos.

In recent years portable electronic devices, such as laptops, cell phones, iPods and even household robots have become much more common, he says. "All of these require batteries that need to be recharged often."

As for the future, Soljacic says, "Once, when my son was about three years old, we visited his grandparents' house. They had a 20-year-old phone and my son picked up the handset, asking, 'Dad, why is this phone attached with a cord to the wall?'

"That is the mindset of a child growing up in a wireless world. My best response was, 'It is strange and awkward, isn't it? Hopefully, we will be getting rid of some more wires and also batteries soon.'"

More help with words

cycles

device

electromagnetic

electron

energy

field

frequency

natural frequency

radiation

resonance

response

spirals

vibrate

vibration

What's it all about?

1. This story is about being able to recharge everyday things without having to plug them in to an electricity supply. This is called -------- power.
2. Why was Prof Soljacic in his pyjamas when the idea for this research first came to him?
3. How many times had he been wakened that month by his mobile phone beeping?
4. Why was it beeping?
5. One way to send energy without using wires is by electromagnetic radiation. Give one reason this is not likely to work well.
6. Why might it be dangerous?
7. What does MIT call their new method?
8. What electrical item did they use in their demonstration?
9. In your own words what does "no physical connection" mean?
10. What is a natural frequency?
11. Resonance is when energy gets transferred very effectively because it is supplied at the same -------- as the natural frequency of an object.
12. The writer gives a couple of examples of resonance to help explain what the scientists have been doing. Pick one of these and describe very briefly what happens at resonance.
13. Resonance can take place with all sorts of things, such as sounds or moving objects. What did the MIT scientists concentrate on in their work?
14. Resonance is all about the frequency of the energy supplied being the same as the ------- frequency of the thing receiving the energy.
15. Frequency is fairly easily understood when you can see something moving back and forth like a child on a swing. The frequency of a child on a swing is the ------ of times she swings back and forth in a certain time.
16. But frequency is a useful idea for anything that is moving or changing, even when it's too small or moving too fast to see. The frequency of a sound for instance is the number of pressure waves in the --- that hit your ear in a second.
17. The frequency of a magnetic field is the number of times it ------- direction in a second.
18. The frequency of the magnetic field the scientists used was several megahertz, the writer says. This means it changes direction -------- of times a second.
19. At first there is a coil in the room that is producing a rapidly changing magnetic field. But it is not sending out any ------.
20. Then when a second coil is brought fairly close to the first, energy passes. But only if the natural frequency of the second coil is the ---- as the natural frequency of the first.
21. Moffatt refers to a "non-radiative field". What does "non-radiative" mean?
22. A radiative field produces electromagnetic radiation. In question 5 you gave one reason for not using electromagnetic radiation for wireless energy. Now find as many reasons in the story as you can for not using electromagnetic radiation for wireless energy.
23. State one disadvantage of the method these scientists have developed.
24. If you were these scientists what would you like to do next?
25. Why?

What kind of story is this?
Learning to do science is about learning to think. Experiments, direct teaching, group activities and discussions all have a part to play. So do science news stories.

Like other non-fiction texts, science stories contain different kinds of statements. To get at the science behind the words - and to make reading them an active experience - students should pull a text apart and explore the kinds of statement it contains.

We've met some of these in the later questions of the previous activity. Science news stories usually include the aims of the research or reasons for doing it. They often contain a hypothesis. Sometimes evidence for a hypothesis is given, or a hypothesis is used to make a prediction. Towards the end of a story the direction of future research the scientists are planning is often discussed, as well as outstanding questions the research will be designed to answer.

All these types of statement occur in some science stories. Virtually all science stories, however, will contain statements of the following four types:

• new findings or developments;
• the technology and methods the scientists used;
• previous or accepted knowledge, which may or may not be supported by the new findings;
• issues, implications and applications of the research.

So the next activity is designed to engage students with the latest science news by exploring the meaning and structure of a story as revealed by the content and balance of these four statement types:

Pulling it apart
In groups students should read through the story looking for new findings or developments. Once they have reached agreement, or at least consensus, and have underlined all the statements about what the scientists have just discovered or achieved, they can compare and discuss.

In groups they should go through the story again looking for the technology and methods the scientists used in their research. Once they have reached agreement or consensus, and have underlined the statements that talk about the methods and equipment the scientists used, they can compare and discuss.

They should repeat the activity for existing knowledge.

Any areas of disagreement in these activities - whether among the students or between teacher and students - should be regarded as opportunities for discussion rather than errors to be corrected.

Having fully engaged with the latest science news through the above activities, students will be far better able to talk and think about the science and its implications than someone who has simply read about it in a newspaper or watched a brief item on television.

Now it's time for them to get to grips with the issues raised by the research.

Young people have opinions. But school science traditionally allowed little scope for forming and expressing these - which is why it turned many of them off the subject for life.

Putting it together again

In groups, students should read through the latest story looking for issues, implications and applications. Once they have reached agreement, or at least consensus, and have underlined all the relevant statements in the story, they can compare and discuss.

Having done all this the students are well armed to explore the issues raised by the story. A suggested discussion topic specific to this new story is provided below.

Topic for discussion, research or pupil presentations

This is a tough story for schoolkids. Resonance is university level science and engineering, and electromagnetic induction is upper high school. But the philosophy of this website, and the whole science in society movement, is that you don't need a PhD in nuclear physics to engage with the key ideas of modern science.

The key ideas in this story are resonance, natural frequency and the difference between WiTricity and electromagnetic radiation.

A) In groups students should research as many examples of resonance as they can find. They should then prepare a short presentation to explain how their favourites among these work, and the principle that is common to them all.

They may find the following websites useful starting points:

Earthquakes, bridges, seashells, all from Discovery Education

Vibrating strings from Nova

Musical instruments from the Physics Classroom

Guitars and rockets from NASA (podcast and transcript)

Tacoma Narrows collapse from Nova

B) In groups they should compile a list of similarities between WiTricity and electromagnetic radiation. They should then compile a list of differences. They should brainstorm these tasks at first, writing down every suggestion from the group, no matter how trivial or even frivolous they seem. Only when this is complete should they examine each item, retaining any that has a grain of truth.

Tips for science class discussions and groupwork

No 51

As part of their report they must submit 5 new words/terms they learned, summarize the article, give me a complete citation as for a bibliography (MLA format), 5 questions that they would like to ask the author, the subject, or anyone about the article. They must tell me how the illustrations helped or detracted from their understanding of the article; and give me 2 questions that refer to the illustrations.

"You might try magazine articles - I've done this with my older kids using 5 magazine articles from an 'approved magazine' typically, Smithsonian or National Geographic.

This has been great for pushing them to look at periodicals, and using another source for reading material. For my purposes, I don't restrict the topics, so it's fun to see the things they are interested in beyond what we cover in class. I take a day and try to answer their questions if I can, or point them to where they can find out more for themselves.

National Science Teachers Association (NSTA) forum entry by teacher Kathleen Gorski (May 2007)