Science Tidbits for June 26, 2012

Two quick news items for today and one video.

First up, more information on the effect that the 2009 H1N1 pandemic virus had. The H1N1 “swine” flu inflicted a particularly severe toll based on an interesting application of a couple concepts from the world of epidemiology and public health.

There are multiple ways to describe the death rates of a disease, one of which is simply the number of people that die from the disease. This simple measurement of mortality doesn’t tell us everything. Influenza typically kills a mix of the very young and very old. The 2009 H1N1 pandemic flu killed far more young people than the seasonal flu normally does, which changes the effect on society.

The concept to stress here is that of patient or person years. Functionally, every person that lives one year lives a person year. If you have fifty people that live one year, you can express this as fifty person years. If they are patients, you would say that there were fifty patient years.

A good way to bring this to the classroom is to compare one young person and one older person. Let’s say that the young person can expect to live sixty more years, while the older person can expect to live twenty more years. If both people die from the same disease, at the same time, the young person lost more years than the older person. Sure, if either one of them had survived the disease, either could have been hit by a bus the very next day, but statistically, the death of the younger person was a greater loss of potential years of life. If we have a very large population, with perhaps tens of thousands of young people and old people falling into our patient group. For every young person that dies, three older people have to die to add up to the same number of patient years.

It sounds like a very cold and callous way to look at the lives and deaths of real people, but this system is used to determine what level of risk is acceptable for a medication. How many patient years are saved from the treatment and how many are lost from side effects? How severe was an outbreak? How useful was a new safety technology installed in automobiles? Many concepts in public health take an impersonal look at an issue because of the sheer number of people involved.

This can lead to a great discussion of the differences between patient and population centered medicine, if that is in the scope of the class you are teaching.

The second tidbit is a quick explanation of a piece that was in the news a couple of weeks ago. A woman eating parboiled squid bit into what appeared to be a tasty piece of meat, but was in reality a reproductive organ of the male meal. This can either be passed along to students asking if it was real, or be used in a zoology course when discussing the reproductive strategies of a variety of invertebrates.

Finally, a video that I have used in teaching about the process of mitosis.

I have shown the video as is to a course, muted it and described the steps in the video, pausing to point out specific features, and have included it as a link on a course website (both Moodle and Blackboard). However you approach the multimodal classroom, videos like this can be very useful in helping students understand how something like mitosis works, and can be used at multiple levels of difficulty, from simply learning the phases of mitosis in order to beginning to understand the function of spindle fibers.

Teach on.

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Science Tidbits for June 25, 2012

First things first, the Houston Museum of Natural History (@HMNS) is running a fundraiser, calling on donors to “adopt” a prehistoric pet. Depending on the donation, you can adopt a different animal and can receive a variety of thank you gifts including drawings or replicas of your pet, certificates, or tickets to the museum, but most importantly, the knowledge that you are helping a home of public learning and science advocacy. If I get the job I’m hoping for, I might just adopt a triceratops. I hope it stays small. I hear they can get rather big…

Now on with the Science!

For the last week, I have been posting “science tidbits” as my own take on teaching tidbits. The idea behind a “tidbit” is that you can drop it right into a lesson plan in order to enrich the lesson, make it more relevant to students, or to tie it into current events. I try to mix in ideas about how to use them in the classroom and if you have an idea, please share it in the comments.

When you think of sharks, you usually think of fast predators, moving just under the waves, carefully stalking its prey… The Greenland shark fits all of those ideas except for “fast.” Scientists knew that the greenland shark ate seals from examination of stomach contents, but figured that they scavenged dead seals. Seals are really fast, so a shark that swims at a speed slower than a mile per hour is an unlikely predator. There is a new hypothesis, though…

“Arctic seals sleep in water to avoid predation by polar bears (Ursus maritimus), which may leave them vulnerable to this cryptic slow-swimming predator,” wrote the authors of a recent study on Greenland sharks’ speed, published in the Journal of Experimental Marine Biology and Ecology.

Where does this fit into a lesson? Any discussion of a food web in the Arctic would include polar bears as an apex predator, and adding the greenland shark into the mix stresses the diversity of the environment and the importance of what happens beneath the ice. You could also describe the shark, where it is found, how fast (or slow) it is, and ask students to come up with ideas about what an animal like this would eat.

Beyond that, the greenland shark isn’t the best known or best studied of sharks, which can make it an interesting creature for an “internet” scavenger hunt, where students hunt for information about the slowest shark, or smallest deer or a venomous mammal, or a good topic for a short group presentation on lesser known organisms.

Making the tidbits again, a chance to talk about zoonotic diseases. Koala bears are one of the cutest animals on the planet. Who doesn’t love them?

Wild koala numbers started dropping last decade, and researchers asked the obvious question, why? (Brainstorm opportunity) It turns out that there are three different organisms attacking koalas, one of which is a retrovirus that is attacking their immune system. The other two are different strains of the Chlamydia, Chlamydia pecorum and Chlamydia pneumoniae, and at least the C. pneumoniae strain can infect humans.

Unfortunately, C. pneumoniae can be transmitted to humans. Koala’s incredible cuteness works on the disease’s behalf. People enjoy picking them up, but like many tree-dwelling animals, koalas don’t much care where they urinate. If an infected koala urinates on a person, they can possibly transmit the strain of chlamydia to the human.

It is frighteningly easy to pick up diseases from animals, wild or domestic, so being aware of these risks is a good idea. Another opportunity for discussion comes in with what people can do to help the koalas. There is a vaccine that appears to work for the retrovirus, but the only treatment for chlamydia sp. is antibiotics. This can quickly lead to a secondary discussion of antibiotic resistance, as there is nothing to prevent reinfection or to prevent resistance from arising. Since humans can be infected with C. pneumoniae, it would be a very bad thing to encourage the bacteria to develop resistance in the wild as it would limit which antibiotics could be used to treat infected humans. This closely mirrors discussions of the use of antibiotics in livestock.

The opportunities for dropping this topic into lessons about infectious diseases, antibiotic resistance, ecology… are endless. Its a good topic for high school on, with advanced undergraduate and any graduate student delving deeper, perhaps presenting short talks on the topic.

The concept of a “living fossil” is a messy one. It suggests that an organism is completely changeless over millions of years, which can be very misleading. Many so called living fossils closely resemble their ancient relatives, while others have undergone morphological changes. The coelacanth isn’t just a single species of lobe finned fish, but is a large group of both modern and extinct species with many morphological differences and falls into several species. Beyond that, they are no longer thought to be the group most likely to have given rise to land dwelling tetrapods.

This isn’t just a good discussion topic, but can be a good topic for small group discussions in high school and undergraduate courses. Give students a list of misconceptions about evolution (a very long list can be found here) and have them examine and present the science behind them. This has great risks and great rewards. Students teaching each other can be one of the most effective ways to learn, and breaking down bad ideas is an important step in the process of learning evidence based science. Remember what Chuck said,

False facts are highly injurious to the progress of science, for they often endure long; but false views, if supported by some evidence, do little harm, for every one takes a salutary pleasure in proving their falseness.

-Charles Darwin

Giving students the tools to replace false facts with true ones is vital in teaching topics that are controversial in culture, but not among scientists. The talk origins database is one of the best ones you can offer for evolution, with Skeptical Science a great one for climate change (from real skeptics, not ones using the title for PR purposes). However, if you get a student that wants to present personal beliefs instead of what the evidence says, or if you pick a topic that is too broad or too narrow, it can end up as a mess.

The other risk/landmine is that you absolutely should avoid discussing religion in a public school classroom, and if you are teaching at a religiously affiliated private college (or even a public institution), you need to be careful to make sure that your administration backs you up. Creationist organisations can put a tremendous amount of pressure on a college and the list of educators that have lost their positions due to the controversy that they can bring to bear is very long and grows longer every year. Be careful to stay within the boundaries of science. No matter what you think of NOMA personally, it is a good guideline for the classroom. If you limit discussion topics to things like living fossils, missing links, the existence of transitional fossils, or why gaps in the fossil record are not only expected but are not a problem for evolution, you should be fine. If you need advice, talk to the NCSE (link above).

If you are using the previous tidbit, or are sending students to use the internet for sources, this is a good read for you and for more advanced students. Lots of material on the internet is accurate, but lots of it is simply junk. If students are doing a presentation, go over their sources with them, and look to make sure that they are reliable.

And one for the teachers, when you are teaching a difficult concept, one that students typically respond to by saying that they will never use it… you need to respond immediately with real world uses, or defuse it before it starts. That can be easy for me. Not understanding evolution kills people via a bad understanding of antibiotic resistance, genetic and evolutionary causes of medical problems, etc. Students can grasp the importance of medicine, poisons, venoms, cancer. But not everything is so easy. Tidbits help a lot. That is the purpose of sharing them and always looking for new ones.

Teach on.

Science Tidbits for June 21 and 22, 2012

Good Morning, Tokyo. I promised tidbits by morning, and it is still morning on the other side of the planet.

Whenever I teach about the cell cycle, I discuss cancer, and when I discuss cancer and the cell cycle, I talk about how some anticancer drugs work in relation to the cell cycle. While my own dissertation work focuses on using cell cycle dependent drugs and making them more effective by tricking the cell into dividing with a second drug, all before it has repaired damage caused by first, I’m always looking for recent work that hits on this topic. This press release talks about using just such a “one two punch” to attack cancer cells. The full paper can be found here, but access is subscription limited. I suppose I’ll be hitting up the University library.

I love talking about flu as an example of… well, lots of things. Mutation rates, genes, viruses, zoonotic pathogens, genetic recombination, etc. One of the things I talk about is how close we are to an H5N1 pandemic. Right now, the H5N1 strains that are being monitored don’t pass from human to human very efficiently, which is one thing that keeps it from running rampant through the population. All it takes is a few small mutations and the virus can pick up the ability to pass from human to human, and it is only a matter of time before just such a mutant strain evolves. Hopefully, by that point in time, we will have universal influenza vaccines ready, or at least have methods approved for rapid vaccine production via cell culture. The chicken egg method is just too slow.

Do you know that the color you call blue is seen in precisely the same way as another person? A wavelength of 460 nm is a specific shade of blue. Do you see the same exact shade as another person? Does your brain interpret in precisely the same way?

We have no good way of knowing if my color blue is the same as yours, since every person has different eyes and different brains. Your brain, when you look around you, is receiving information from the surrounding world from your eyes, transferred along the occular nerves, and is decoding it. As it does this, it produces a simulation from that information. You can’t see some things that are there. You can’t see pigments that reflect in the ultraviolet range, but they are present, and many insects can see them. Illusions and mirages are excellent examples of errors in your interpretation of the world and how it is in reality.

This is especially true if you have certain genes for colorblindness. The “normal” person has three different types of cone cells in their eyes. They have trichromatic vision. These cones detect different ranges of color, and for each type of colorblindness, you lose one of those ranges. Your simulation is reduced pretty significantly for each malfunctioning cone cell type.

It turns out that there aren’t only people that have one fewer cone cell type, but some people have one extra type of cone cell, and are called tetrochromatic.

This is one of those little details that you can toss in to a lecture about vision or sex linked genes (some types of colorblindness are sex linked, and tetrochromatic vision definitely appears to be). I find that these kind of teaching tidbits can be a useful way of keeping students that are at the top of the curve right there, involved. They may already know a decent portion of the material, but if you toss in a few bits of trivia that they haven’t seen before, they pay attention for the new things that they didn’t already know about.

More fun Pollinator Week stuff from Bug Girl. Ignore the Burt’s Bees commercial part of the video, and enjoy the information about how bees are the true masters of interpretive dance, and how they are involved in pollination. Oh, did I mention that it is one of Isabella Rossellini’s wonderful videos about nature? Because it is.

Are you teaching a class about reproduction? Are you teaching a minimally mature class? Then fill them in on the oddities of animal penises (via Discovery News). The duck one is actually kind of useful if you are talking about prezygotic barriers to reproduction as a means of speciation. Ducks have penises and vaginas that can be species specific, which can prevent one species from being able to mate with another.

Ever have a student ask why you get brain freeze when you eat or drink something cold? Here is a nice video explanation.
Oh, and if you haven’t heard that Europe is working on increasing the involvement of girls in STEM (Science Technology Engineering Math) education, then you have missed out on one of the worst PR bungles ever. Why is it bad (other than being painful to watch)?

Sexist imagery decreases the performance of female students on tests in STEM subjects. Nicole (NoisyAstronomer) points out the problems in the campaign and also gives some good examples of what women doing science look like. (If you are on Google+, follow her for great astronomy news and information) Kylie Sturgess at Token Skeptic also has some great examples of women in science and a good takedown of the ad as well (Kylie’s podcast is pretty great, too).

Their examples are what get people interested in science. Normal people doing interesting things. And the great thing about this is that when you show minority groups involved in science, it increases their involvement, and doesn’t discourage people in majority groups. Their functional privilege makes such differences invisible to them. Well, except for the ones that need their privilege reinforced, and require that all discussions be about them.

Have a nice weekend. I’ll be calling people to push poll on evolution.

Science Tidbits for June 20, 2012

How do plants communicate with each other? Most people have no idea that plants can communicate with other plants, and this can make for a fun active learning exercise during a botany lesson. Get students to brainstorm possible means of communications, either as a class or in small groups, and discuss how such signals would be detected. Changes in color? Plants don’t have any known means of detecting this. Smell? Well, plants don’t have noses, but many receptors exist inside cells and on the surface of cells. A volatile chemical can move through the air from one plant, be absorbed by another plant and cause changes in gene expression. You can make this as simple or complex as you like, including chemical names, genes expressed, or for primary school students, you can easily talk about one plant sending a message that it has been damaged by a grazer and another plant receiving the message and tasting bad to grazing animals.

That one has been known about for a while, but one that has just been discovered is communication by sound. Apparently, the roots of corn saplings (corn that has germinated and has begun to grow) both produce and detect a clicking noise…

And her intuition was right. She, along with fellow researchers Stefano Mancuso and Daniel Robert, used powerful acoustic instrumentation which allowed them to hear clicking sounds coming from the roots of corn saplings. They also found that when they suspended the young roots in water and played a continuous noise at 200 Hz – a similar frequency to the clicks – the plants grew towards the source of the sound.

Seriously? A sound influences root growth? Science is so cool! They have no idea how this works, but that is pretty cool in itself. This could make for a very interesting discussion as well, with students developing hypotheses as to how the plants are both making and detecting the sound. A great lesson to be had here is that there are always new things to discover, and not knowing the answer to a question means that there are still things to learn.

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Another fun discussion topic for any class can be about how strange beliefs spread through society. For instance, the claims that the world will end this year (2012), based on Mayan prophecy is a fun one. In fact, you can make this as simple or as complex as you like, asking students to look for articles that are both critical of or in support of these claims and discuss what makes for a good argument and what doesn’t. For a simple one, you can just talk about how the people that study Mayan history are completely annoyed by the 2012 hysteria. One easy visual is to show students a 2012 and a 2013 calender, pointing out that the world doesn’t end when you get to the end of one calender year.

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Of course, this tidbit and the previous one fit together neatly. How do you tell good information from bad? Apply your baloney detection toolkit, which is made easier with the careful use of the internet.

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Ever want to talk about exoplanets (planets orbiting other stars)? This is a good place to start… You can see all the planets that we have discovered so far (as of June 2012), with the knowledge that we are discovering more all the time. This can lead into a discussion of how we discover planets. Phil Plait gives a great video explanation, which makes for a good bit of media to add to the classroom.

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And how could I not mention that the REAL Skywalker ranch is getting some historic preservation attention. The set used in Episode IV of the Star Wars saga as the home of a Owen, Beru and a young Luke Skywalker is getting some well deserved maintenance and care. A trip to Tatooine… I mean Tunisia never sounded so good.

Teach on.

Science Tidbits June 19, 2012

Fast one today, as I spent a fair bit of time today at the Lexington Humane Society making friends with the cats and dogs. It’s June, which means that there are lots of adorable little kittens out there in need of homes, but don’t overlook the wonderful adult animals out there. We have three cats from LHS, two of which were adopted as adults. It is easier to place kittens into loving homes than adult cats who lack the tiny furball cuteness of the larval cat. With an adult cat, though, you have the knowledge of what the cat’s personality is and you know that you have brought home a special friend that may have spent several months in a small cage. If you can’t give a cat a good home right now, consider making a donation of food or money (call first and find out what they need).

On with the show.

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Top story, and for good reason, a Chicago woman has been cured of Sickle Cell Anemia! This isn’t a first ever, but is wonderful to see! Her bone marrow was killed via radiation and bone marrow carrying the gene for normal hemoglobin was transplanted. This is a pretty major intervention, as you can imagine, but it is great to see that some people are getting relief from this painful disease.

Most courses on genetics use Sickle Cell as an example of a disease where people carrying one copy of the gene are protected against malaria, but people with two copies have a lethal disease unless the disease is treated. Even then, most patients have a much shorter lifespan and have to deal with a painful disorder and side effects from the treatment. This gives us hope that better treatments could be within reach… but will require a much improved donor database.

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Its National Pollinator Week, and Bug Girl has information on the importance of our pollinators. For a person who has kept honeybees, this is a week I can dance for. Insect collecting and photographing can be great projects for students from elementary school all the way up to undergraduate, with identification exercises, learning about habitat and ecological niches as needed. If some students are particularly interested, 4-H programs offer a chance for students to direct their own learning and to practice their public speaking skills.

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Class discussion topic for all ages and a chance to discuss the history of the exploration of space: Is it time to return to the moon?

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Following up on yesterday’s tidbit about mating strategies, the Giant Cuttlefish shows its colors.

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A fast Toxic Tuesday, a returning feature of this blog, a quick list of several incredibly deadly proteins, running the gamut from ricin, produced by a bean, to botulinum, produced by a bacteria.

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Finally, news on the textbook controversy in South Korea. Creationist groups had pressured publishers to remove evolution from textbooks without input from scientists. Scientists will now get their say, and hopefully this misadventure will end with science back in science texts.

Teach on.

Science tidbits June 18, 2012

Science tidbits for this, the 18th of June, 2012

You got your dolphin on my octopus! You got your octopus on my dolphin!

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1) Raw milk is not “safe” 2) Blogs are a great way for students to write about science for a broad audience.

– In the last seminar class I taught, I wanted to include a blog writing assignment, where students would write up a post on their seminar topic for popular consumption. I still would like to try it, perhaps for an honors class. Beyond that, this is an outstanding topic for discussion of personal risk and how public health decisions are made. While a single person may have very low risk from drinking raw milk, the probability that a single person or multiple people in a population will be affected becomes extremely likely. Blessed are the cheesemakers.

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“Wildlife rangers were forced to shoot dead the [lion] cubs’ mother after it was spotted in Nairobi’s Karen suburb” – I stayed for a week in Karen with family while my wife was gathering data for her dissertation, and photographed lions enjoying the remains of an antelope in the nature reserve with Nairobi’s skyline in the distance. Turns out, this isn’t an isolated experience. Lions sometimes find their way into Karen and get stuck in the compounds (think of a cul-de-sac, with tall fences around each home with a locked gate, and at the entry to the cul-de-sac is another locked gate, sometimes manned by a guard), which means that nobody can come or go until the lion leaves.

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Poor itty bitty spider got the fungal rot, down came the rain, washed the spores about. Cordyceps is a genus of sac fungi that parasitize arthropods. While parasites tend to give people the willies, as do spiders, Cordyceps is a fascinating group that challenges what students think about when they hear “fungus.”

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Via Jerry Coyne,  a good read about gill slits, and how they fit into vertebrate development. This can also help you answer questions from students about what a gill slit is and how it fits into the evidence for evolution from a common ancestor.

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Bonobos (the nice chimps) have now been sequenced! 1.3% diff from us, 0.4% diff from Pan troglodytes. I wouldn’t introduce the sexual habits of Bonobos to elementary or middle school students… and I would be hesitant to discuss it with high school students unless I knew that my administration had my back. For undergraduates, most can handle a discussion of the variety of sexual habits of animals, and it can lead to a better understanding that what they think is natural is not always reflected in reality.

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Gender roles in nature, with cartoons for those that need pictures. This is another good topic for advanced high school students and undergraduates, when discussing reproductive strategies, sexual selection and evolution. Try showing pictures of male and female birds and discussing how the bright colors of males are important for multiple reasons, including attracting a mate and perhaps even displaying the health of the bird (no parasites, good nutrition, etc). Then show them a picture of male and female seahorses and ask them which they think is which (males tend to be dull and females brightly colored). As you describe how the seahorses rear their young, see if you can start a discussion on how the individuals competing for the attention of a mate are the ones investing resources in their appearance, and that this is not always the male.

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Evolution as chemical warfare. Mouse eats seed. Plants that poison seeds selected for. Now for mice to evolve immunity. If you are looking for a way to introduce the Red Queen Hypothesis, this is perfect.