An occasional quote

As I'm reading I keep coming across interesting passages that I would like to share. Here's the first.

In the future, humans may well be able to engineer themselves, be it by better drugs or better genes, to live as long as they please, but the cost may be twenty year olds with all the vigour, appetites and charm of the middle aged.

Armand Marie Leroi, Mutants

This is based on the idea that there is in inseparable linkage between the vim & vigour of youth and life span. As life span increases, youthful vitality will be diminished. This hypothesis is born out by experiments with fruit flies that have been bred for longer life. They produced fewer offspring, and lived a much slower, almost sloth-like existence.

Nature abounds with other examples of a connection. In a species of marsupial mice in Australia, the life of an adult male is a playboy's fantasy, or so it might appear, culminating in a 2 week period of repeated 12 hour frenzies of copulation. But then the mouse dies at the end of that single breeding season, "spent" in every sense of the word.

Conversely, the British Royal family's geneological history (with meticulous records dating over many centuries) shows a correlation between the lifespan of its members and their fecundity - Those who died shortly after menopause had on average 2.4 children. Those who lived a substantially longer life (past 90) averaged 1.8 but nearly half of the nonagenarians had no children at all.

Not exactly a slam dunk case, but interesting to think about as I approach middle age territory and watch the wrinkles grow.

Well I thought it would be fun...

...to have the kids personalize the digestive system a little by photoshopping their own faces onto a diagram of the digestive system.

So I lined up the assignment and told everyone to get their head shots ready and brought in the laptops to the classroom...

...only to find the laptops don't have photoshop loaded. So much for planning ahead and checking the software availability FIRST!

Anyway, a couple of students also expressed some reservations about putting their pictures on a body like this, so I gave them the option of picking a celeb to attach...*

Who knew bush was in such good physical condition (or Mr. Gatton for that matter!).

*I also thought better of it and found a different diagram of the digestive system and manipulated it a little to make the "private parts" a little more private.

Image Source

Lamarckianism

I like to use the example of the blind cave fish to test whether my students still harbor Lamarckian notions about evolution or if they have really caught on to the idea of natural selection. It's a good example because the Lamarckian explanation is so tempting. It just seems so logical that the cave fish lost their eyes because in total darkness they just don't need them anymore.

I bring this topic up again after mentioning it last week regarding wisdom teeth. Then yesterday reading an excellent book called simply Mutants, about all the things that can go wrong in a developing human embryo, I stumbled across this line (italics mine):

...But delightful as it may be to look at, red hair is not good for anything at all (i.e., has no adaptive survival value in any environment in which humans live ). MC1R (for simplicity's sake, the gene that causes dark hair when it functions "properly," red hair when it doesn't) may simply be a gene that is decaying because it is no longer needed, rather as eyes decay in blind cave-fish.

Now, I'm reasonably certain that the author is a hundred times more knowledgeable about biology, genetics and evolution, than I am, and yet either through carelessness or brutal editing, has issued a Lamarckian explanation for an evolutionary phenomenon. It's an otherwise fabulous book.

I started doubting myself, maybe I don't know as much as I thought I did. Maybe decay is the answer and I just haven't thought it through thoroughly enough to see how it works. But alas, serendipitously, I found PZ Myers' article in Seed Magazine on the very topic of HOW THE CAVEFISH LOST ITS EYES.

The Mexican blind cavefish raises the challenging evolutionary question: Does disuse lead to degeneration or disappearance of a feature? Here, an answer Darwin would have loved.

I certainly can't do the article justice by summarizing, so I'll leave you to go and read it for yourself. It's relatively short and sweet. I'll give you a hint about the ending - it's not Lamarck.

That Wasn't So Bad

I really expected to be in the oral surgeon's office for a couple of hours of excruciating discomfort. All those horror stories about wisdom tooth extraction. Turned out that it was over in a matter of minutes.

The worst pain is of course the injections of Novocaine, 4 to be exact. The doctor said I seemed to handle the harder ones better than the easy ones. Maybe I just got used to it. Anyway, I sat there a few minutes expecting the whole side of my face to go numb like the last time I had tooth work done, but he explained that upper teeth are easier to numb and wouldn't be so bad. The most noticeable effect was a loss of feeling in the roof of the mouth - otherwise the cheek, eye, ear, lips, felt pretty normal (ALL those areas were numb when I had lower tooth work done). All-in-all a much more pleasant experience than having a crown which required two separate numbing experiences!

What was a little freaky was the sound of the cracking tooth being extracted. Even with the heads-up that I would hear it and not to worry about it, it's a little disconcerting.

I also have learned that I do not savour the taste of blood. That oddly salty, almost sweet, raw steak quality is decidedly unpleasant. I would not make a good vampire. And a gaping hole in your mouth tends to take a while to stop bleeding, so every 30 minutes or so I change the gauze that I' m supposed to bite down on to apply pressure. SO I'm off now to change the dressing and get ready for bed. SO far not too much pain or discomfort. But I am taking pain killers prophylactically as advised.

Wisdom Teeth

I have a long history of tooth problems, dating back to early childhood. I grew up in the rural south with unfluorinated water and super sweet iced tea and soda and candy and a general lack of awareness concerning good oral hygiene. And I didn't inherit the best genes either - my father had a complete set of false teeth in his 30s and mom has had her share of tooth problems over the years. Needless to say, all my experiences with dentists have been of the painful variety, which in turn led me to avoid the dentists as much as possible which in turn again ensured that when I did visit it would be an unpleasant experience.

So about a year & a half ago I was compelled to visit the dentist to get a crown. He informed me at the time that I had a wisdom tooth that would need to come out soon. He expressed surprise that it had not already caused me trouble or pain, and said he would leave it for the time being - the tooth would let me know when it was time to go. This week the tooth started talking to me. It's scheduled to come out on the 8th. Meantime I have to take antibiotics and I have a prescription for pain killers to get me through. I am trying to avoid the pain killers as much as possible - it's just barely tolerable on ibuprofen, we'll see if it gets worse.

Of course this got me thinking about the whole concept of wisdom teeth and why we have them when they cause so much trouble - a rather "unintelligent" design flaw to say the least - and the irony of then calling them "wisdom" teeth is inescapable. Nothing wise about a set of teeth that your mouth doesn't have room for.

The obvious (not necessarily correct, just intuitively obvious) explanation is that in our evolutionary history the modern human mouth (the jaw, really) decreased in size but the number of teeth remained the same as our larger-jowled ancestors. Scientists debate why this event occured: Was it a change in diet and eating habits or the necessary by-product of an increase in brain size? In other words, did the change in diet and subsequent decrease in jaw size allow the development of a larger brain or did the development of the larger brain drive the decrease in size of the jaw? I don't see why these two alternatives are mutually exclusive and I can see how both forces could have been at work simultaneously. Although it's not obvious why a larger jaw for a third set of molars would in itself be disadvantageous for eating softer or cooked foods.

Whatever the ultimate driving force, it seems the wisdom tooth problem is a pretty nice argument for evolution and illustrates the way evolution works- and perhaps more importantly how it DOESN'T work. It produces characteristics that are not perfect, just "good enough" to allow for survival. Who knows, perhaps given more time and a more primitive technological world, the wisdom tooth would not be such a problem - either we would have settled for a larger jaw or the wisdom-toothless trait would have become the norm. As it is, the wisdom tooth is not a fatal (normally) condition and even then it usually causes trouble relatively late in life - thus there's really no evolutionary mechanism for eliminating it.

In cursory research of this topic, I stumbled across this article from the Columbia News Service. Columbia as in Columbia University. It's an article by a journalism student, so I'm more than willing to cut a little slack here, but I still expected to find a pretty accurate and intelligent story. Unfortunately the author completely botched the concept of evolution generally & natural selection in particular. Here's a quote:

Scientists agree the human race is advancing -- if very, very slowly -- along the evolutionary track by shedding unnecessary parts like the wisdom tooth, though there's debate about what is causing it to disappear.

I'll just mention without going into the details that the whole concept of evolution representing some sort of "advance" in any metaphysical or cosmic sense is pretty much a dead topic and a little jarring to see people still discussing it in those terms.

What strikes me more is the Lamarckian explanation for the way in which the wisdom tooth is supposedly disappearing, the idea that we are shedding wisdom teeth simply because we don't need them. I read the whole article looking for a clarification of this simplistic explanation, but there is none. It reminds me of those stories I heard when I was younger about how we are losing our little toes because we don't use them any more. I also looked elsewhere for data that support the idea that we, as a species or even a population in the US, are losing the wisdom teeth at all. I browsed a couple of studies from PubMed that looked at wisdom teeth in a sampling of students. Both put the number at around 10% showing no wisdom teeth (congenitally missing) but neither refer to any change in this percentage over time. So I'm not even sure the general statement is supported by the evidence and I can't think of any plausible explanation for how it would occur. In general, here's what would have to happen.

Assumption: Congenitally missing wisdom teeth is an inherited condition - it is not a result of pre-natal or post-natal nutrition or the texture of the food eaten in early childhood or adolescence. If this trait is becoming more prevalent, then one of the following conditions would have to be met (there may be others, but these are the obvious possibilities.)

1. People who inherit congenitally missing wisdom teeth have an advantage over people who are born with wisdom teeth. By advantage, I mean ONLY that they are able to survive longer and produce more offspring. In the modern world this seems a rather unlikely scenario. I could be wrong, but an article that asserts an increase in the number of people who do not have wisdom teeth (as a result of evolution) needs to address this issue - do a significant number of people die as a result of having wisdom teeth compared with those who do not? Do the wisdom-toothless live longer and thereby produce more offspring? Are they more attractive and therefore find mates more successfully? Again, none of these possible explanations seem plausible.

2. The second possibility is that congenitally missing wisdom teeth is bundled with some other trait that is advantageous - a stronger jaw line, which seems to be a particularly attractive male feature (if less so for females), for example. Again this seems rather implausible, and in fact the opposite would seem more intuitively correct - a stronger jaw line would be more likely to have room for the extra set of molars.

3. Genetic drift - by pure chance a slightly larger number of offspring are produced with the missing wisdom teeth, and over time we have drifted toward a decrease in the incidence of wisdom teeth in our population. Like tossing a coin and getting 7 heads and 3 tails out of ten, this possibility is more likely in small isolated populations (If a subset of a population is getting 7/10 heads, by chance, another subset is just as likely to get 7/10 tails - when they commingle the outcome is back to the expected 5/10 each). I'm not sure this is a plausible answer given the large population size we are dealing with and the constant influx of immigrants from around the world into the gene pool.

I have absolutely no data to support or refute any of these possibilities. I also realize there may be more complicated factors at work. I'm just wondering where the author got her data and arrived at her conclusions. I'm always interested in how people imagine evolution occurs, and Lamarckian "disuse" seems to be a particularly common conception.

PS- Alexbarnett gets the award for most catchy title relating to this topic: An Inconvenient Tooth

Books Update

Trip to the Museum of Natural History on Friday revealed indeed an extensive selection of children's science books. Unfortunately, again, quite dissatisfying. Shelf after shelf of "core dumping" titles on dinosaurs, plants, mammals, frogs, snakes, human body, technology, etc. I want stories! I don't mean fictional stories, I mean stories in the sense of the books produced by best science writers for adults - Carl Zimmer's books tell stories about how scientists work and along the way reveal a great deal of information about the products of science in addition to the process. They have a central focus - usually a mystery or a problem to be solved - around which all the details coalesce. One would think that the story format would be all the more appealing to children, raised on a diet of fiction most of their lives, and yet they are the rarest of science books. In the stores there is often a "Young Adult" section for upper-middle school to high school aged students, and there's a rather large selection of titles - all fiction.

It's also my hunch that many of the non-fiction titles that may be more interesting are geared almost exclusively toward libraries. Few are available in paperback and fewer still are available in bookstores - what do I know, maybe they just don't sell. So I'll be talking to our librarian about getting some new material into the school library. In addition to the NSTA recommendations I mentioned earlier, I also stumbled on the Young Adult Library Association's recommendations. They have a quite extensive list including a list for college bound older students. All lists are broken down by category (fiction/nonfiction or science, history, etc.) and many are annotated.

core dump
n.

A recapitulation of knowledge (compare bits, sense 1). Hence, spewing all one knows about a topic (syn. brain dump), esp. in a lecture or answer to an exam question. “Short, concise answers are better than core dumps” (from the instructions to an exam at Columbia).

Originally: A copy of the data stored in the core memory of a computer, usually used for debugging purposes.


Answers.com

This Is "Fit To Print?"

I started writing this earlier today but had to leave before finishing it.

Ghosts in the machine. What is this rot? Scientists discovered (more or less accidentally) a part of the brain that, when electrically stimulated, induces phantom visions. The obvious logical conclusion to be drawn is that all those reports of people seeing ghosts and other supernatural apparitions are nothing more than the result of chemical/electrical disturbances in the brain. In other words, illusions. Most reasonable, rational people long ago accepted that these phenomena are merely tricks of the brain, but here comes a study - hard evidence really -that demonstrates the possibility of inducing exactly the kind of visions people sometimes report as paranormal. Case closed.

Unless, of course, your life's work is based on peddling this supernatural nonsense. Don't get me wrong. I don't really have a problem with kids believing in Santa or superman or space aliens or otherwise engaging in fantasies of ghosts or demons or the Avatar. But when these beliefs persist into adulthood in a literal way, you've got to wonder about the sanity of the people holding onto them.

Deborah Blum won a Pulitzer prize for “Ghost Hunters: William James and the Scientific Search for Life After Death.” I haven't read it, but I assume it's a pretty objective account of a turn of the century thinker who holds onto some romantic notions of spirituality and tries to bring science to bear on his beliefs. Sounds not much different from the "Creation Science" movement a few decades ago or the intelligent design fraud that is waning today. But apparently the author isn't just interested in this stuff for historical reasons but actually holds onto this desperate need for some form of supernatural world out there beyond the limited imaginations of the stale scientists who dismiss it. Nineteenth century indeed. Her conclusion says it all:

I suspect that we’ll dwell forever in the haunted landscape of our beliefs. To many people it’s a world more interesting — bigger, stranger, more mysterious — than the one offered by science. Why choose instead to be creatures of chemical impulse and electrical twitch? We would rather gamble on even a tiny, electrical spark of a chance that we are something more.

I suspect that my 8 year old twins have a similar rationalization somewhere deep in the recesses of their brains regarding Santa Claus. On one level, they must know that it just doesn't make sense and I can see the beginnings of doubt and realization on their faces and in the questions they ask. On the other hand, to disbelieve outright is to lose something warm & comforting and to risk not getting presents anymore. But eventually they will have to face the facts and appreciate the reality behind the fantasy - that Santa, in his purest form, is a mythical figure who represents something real but abstract, the spirit of giving and of generosity and good will and yes, even love. That is part of the "something more" that we are and it's enough for me, cynical "scientist" that I am.

I Started a Blog...

...which nobody read.

Sprites 2006 album Modern Gameplay

AKA Friday Random 10 + 1

I was about to post my random 10 for today when this song started playing on my Yahoo radio station. Seriously, not making this up. Must be a message from the BlogGods.

But since I don't pay much attention to the gods anyway, here goes.

Artist - Title

1. Yo La Tengo - Sugarcube
2. Phoenix - North
3. Dismemberment Plan - Time Bomb
4. Franklin Bruno - Bulk Removal Truck
5. Cat Power - Say
6. Muse - Starlight
7. Placebo - Running Up That Hill
8. Joesf K - Endless Soul
9. Patty Griffin - One Big Love
10. Bloc Party - Plans
    

Naked Roach

Sounds like it ought to be a euphemism for something, but no...

Until they reach adult size the Madagascan hissing cockroaches molt every few weeks. This was one of the few and probably the first that I ever observed in this state. I actually took this picture back in September, and just now got around to uploading to my computer from the camera. Since then I've seen a few more, and even one that was in the process of emerging from its exoskeleton. Just to add to the ick factor, they usually eat the molted shell.

Nowhere to Browse

I spent about an hour in a bookstore looking for reading recommendations for my students. I wanted some titles that were written with young readers in mind, but the science section is hopeless - it is filled with books that are written, in principle, for the lay-reader, but they are mostly pretty heavy reading even for me, and certainly beyond the reading level of most of my students. Even the advanced readers would have a hard time with the science content of almost all of the books, including the Cartoon Guide to Genetics that I finally purchased.

So off I trudged to the children/young adult section. Waste of time. Their nonfiction selection is an abomination, and especially so for science. Most of the offerings are those Eyewitness or similar type books, which are almost mini-encyclopedias more than anything else - not exactly what I have in mind. Hardly any scientist biographies (Einstein, not much else), and no titles comparable to any of the selections in the adult section. I've been to a couple of the major bookstores in the city and they all look the same in this regard. I haven't tried Bank Street yet, maybe they will have a better variety. Then there's the Museum of Natural History gift shop that has a rather large book section as well. I'll check them out after the holiday.

I came home from my book hunt and remembered that the NSTA publishes an annual list of recommended trade books (non-textbooks with science content). I selected a few examples and searched Barnes & Noble online. Turns out they do in fact carry most of the books online. But online browsing just isn't the same. I want to see the book and flip through the pages and read a little to get a feel for it. Looks like that's a luxury I won't have.

Happy Holidays

This has been one of the nicest pre-holiday weeks I've ever experienced as a teacher. There's been warm feelings all around, our "office party" was well done, students have been excited, albeit reluctant to get much work done. I think I timed it so that this wasn't a problem and factored in some down-time this week to tie up some lose ends, such as finishing the (PBS) Evolution video and working on some extra credit assignments and the like.

My 8th graders had the luxury today of having laptops in the classroom so I had everyone set up their google account and post something on the class reading blog. I let them go a little crazy and post whatever they wanted (within reason) with the caveat that all would be deleted soon except for serious reading logs. I did have one student post her pre-reading entry on the book she chose, which was nice - otherwise it's a free-for-all, instant messaging, chat-room kinda atmosphere. Maybe I'll copy everything to a single post and leave it there- they can get pretty attached to their postings.

The English teacher (humanities in our school) approached me about the assignment and offered some much-appreciated ideas on modifying or augmenting the assignment somewhat to take into account the huge range of abilities and access to resources among our students. Some students have no problem getting to a public library or bookstore to find books, and no trouble picking a book that appeals to them, is at an appropriate reading level, and satisfies the requirements of the assignment. Others will be both unable to get the necessary materials and unwilling to ask for help. I will be at a bookstore this weekend looking for 5-10 titles at a range of reading levels to recommend and we will be offering to order copies for them from Barnes & Noble for a discounted price. Also the 200 page requirement may be a bit much for the 10 weeks I've given them to complete the assignment. So I'll probably reduce that to a 100-150 range for the book, and 10-15 for the articles.

In other news, I'm totally unprepared for the holidays. I am going to try to buy all gifts for next year during the after-Christmas sales this year in an effort to avoid this madness next year - although I think a lot of the after-Christmas sales are fraudulent and will have to be careful in terms of comparing prices. I'm going downtown early tomorrow morning for last-minute items, but there may not be an "early" in terms of beating the crowds.

Now the Good News

At the risk of being pre-mature, I've been informed that my student blogs got the nod from the "elves" at the DOE. That means I may be able to demonstrate how to post tomorrow and a few of the intrepid may even get started over the break or sooner with their book reviews or article summaries.

In other good news, and in a completely different vein, Pitchfork has posted their annual Top *** lists. I'll post the links here, but Pitchfork has a habit of moving things around so I'll try to keep checking to make sure they work. If they break, you can find the links pretty easily from Pitchfork's homepage. First, there's the Top 100 Tracks. Up from last years "Top 50 Singles" because they've expanded the field a bit to include any track, released as a single or not, including remakes and covers - basically anything released in 2006. Then there's the Top 50 Albums, which always take a while to wade through.

Finally, the one I have browsed a little already is the Guest List - a collection of recommendations from some of the bands/artists themselves. I already fell in with Juana Molina's Son, an "alternative Latin" sound that's mesmerizing - and I thought I didn't like Latin music.

So that'll more than fill any free moments I have over the break to sit back and record some new music.

Good Mood Dashed

A series of cold viruses had left me in a pretty dark mood these last 4 weeks or so, but today I felt well enough to bike in to work (the weather was unseasonably warm), and by the time I got set up for the day at school the endorphins were kicking in and I felt pretty good, excited even, about presenting the blog to my students this morning.

Turns out the DOE found something objectionable on my blogs and blocked them from the school's server - I don't know if it's the link to a NY Times article on !BREAST! cancer, or the article on whale !VOMIT! (ambergris, actually), or the reference to Eli Lily's !DRUG! problems, or Chile's policy on the morning after !PILL! Or maybe they just don't like blogspot because it might have !BLOGS!

Who knows. All I know is they need to get a clue. If the security filters are this lame, or if they are stupid enough to think blogs are bad, they may as well get rid of the whole idea of internet access in the schools as more and more content, commentary, and meaningful interactions are being conducted on blogs.

So there went my great day. I did speak to our tech person about getting the blogs allowed, we'll see what happens. Worst case scenario, I may have to host the blogs on my own website (like this one) for the time being.

A Tear for Baiji

(Cross posted to my student blogs)

"I consider myself a strong man," he said. "But when I saw that footage I cried for several minutes. It's just so terribly sad."

That was August Pfluger's response to watching a video of Qi Qi (pronounced "chee-chee"), the last known member of the now apparently extinct Chinese River Dolphin, or baiji. Qi Qi died in 2002 after over 20 years living in captivity. She was rescued after being caught in fish hooks and brought to the aquarium.

Pfluger lead a team along China's Yangtze river (the dolphin's only habitat) in a 6-week search for any remaining dolphins that might still be alive but their quest was fruitless and they have essentially declared the species extinct. Official recognition of the extinct status takes a lot longer to reach.

There are now only 5 remaining species of freshwater dolphins, and 4 of them are "critically endangered."

As usual, the culprit is human exploitation of the rivers. In the case of the baiji, industrial needs led to the dredging and deepening of the river, boats propellers may confuse the dolphin's sonar, and pollution reduces the dolphin's food supply, which consists of smaller fishes in the river.

Baiji is the first large species of (aquatic) mammal to become extinct since the Caribbean monk seal was driven to extinction by over hunting in the 1950s.

National Geographic Article

Hello yeah it's been a while...

..not much, how `bout you?

Ahh, the 70s. I couldn't resist. I'm guessing England Dan & John Ford Coley - let me look it up. Hold on a second, wait for it... Yes! I was right. Kind of embarassing, really. I don't listen to radio and even if I did I doubt you'd hear that stuff anymore except on the cheesiest soft rock/easy listening stations. And another pet-peeve - I don't know when stations decided we don't really want to know who performs the music anyway, but when I do have the displeasure of listening to radio (my wife sometimes channel surfs when we are driving somwhere) they NEVER announce the artists. Drives me batty when I hear an old song and then we rack our brains for an hour trying to remember who did it, waiting patiently for the voice break and hoping this will be that one time in a thousand where the DJ will put our suffering to an end with the old, "and you just heard..."

So what brings me back to the blog. I decided last week to strike up the student blogging idea again. I got some nice tradebooks from the parents of my students at an annual Barnes & Noble fundraising event and wanted to get the students to start reading science that is way more interesting than what gets covered in the textbook and doesn't require me to copy newspaper articles every week. So the reading blog seemed a perfect fit.

I've created a basic assignment consisting of a choice between a heavy reading requirement ( a 200 page book, e.g.) with a limited written requirement (3 blog entries) or a limited reading requirement (25 newspaper/magazine articles) with a heavier written component (one blog entry per article). Students also have the option of turning in their logs in the traditional pen/paper fashion. I've posted links below, but the blog is just starting and no student entries yet. One separate blog per class. Only students and I will be allowed to post or comment.

The other nice thing I discovered is that Blogger has made it significantly easier to add outside content to the blog. So I've posted some site feeds from a number of science & health news providers to the sidebar, offering a source of reading selections to those students who want to take the articles path, right there on the blog itself. Check it out.

Science Readers (Blog)

Assignment

That Didn't Take Long

Do teachers ever stop complaining about getting sick? End of the second week in school and already I have my first cold, along with several colleagues and a good number of students in a pretty small school. Fortunately it is not serious, a relatively minor version (as of now, it could get worse) and if I really wanted to I could even do some exercise in spite of it, but I've been good lately so I can take a few days off without much guilt or worry.

What has me particularly annoyed, though, is what I've discovered about those gel-type hand "sanitizers" along the way. In August I bought a big economy bottle of the stuff hoping that using it liberally might cut down on some of the colds I get every year - I still average 5-6 per school year, some of them lingering for 2 or more weeks - "Kills 99.99% of germs and bacteria..." Sure. Umm, could you define "germ?"

Turns out that 0.01% of germs that don't have to worry about hand sanitizers includes the cold viruses, which are the number one problem among most people in the civilized world when it comes to pathogens that make us sick on a regular basis. I would give up just about any pleasureable, non-essential activity you can think of for freedom from these dreaded almost-living particles that exist for no other reason that to make me misreable.

So, when a colleague mentioned that those products don't work on viruses, I argued that they were all alcohol based and I thought alcohol killed everything? Not exactly. I came home and did a little research, and it turns out that alcohol is not effective against nonenveloped viruses, and wouldn't you know it, most of the viruses that cause the common cold are nonenveloped viruses - both the rhinoviruses and adenoviruses.

The other important point about hand sanitizers is that the jury seems to still be out as to whether cold viruses are more likely spread in the first place through hand-to-nose contact or through the air, in which case no hand sanitizer will help anyway, even one that might be effective at killing these viruses.

Bottom line, I'll still use it when I get off the subways and buses - no telling WHAT nasty bugs I might get on my hands there and better safe than sorry. But at school, I don't see much use in the products.

Sophmore Year

Wow, if I thought this second year was going to be a little easier, it isn't looking that way at the moment. I've not had time to post at all, so I'll skip the kwetching and go straight to the instruction.

I'm pretty happy with the way things are going at the moment. We just got into some nature of science stuff this week and will finish up the introductory material next week. I budgeted 2 full weeks (not counting this past one) and I may just meet the schedule for a change. This week we talked a little about magic - I did the "Science Never Sucks" (Word Doc) trick with the test tubes, penny, and soapy water. Worked in 2 classes but not a third. The penny is just a hair too big or doesn't sit just right on the lip of the test tube so it's a little inconsistent. Then I showed them a "gory" Crisangel video and we talked a little about the importance of observation and skepticism.

We spent a little time on the "Tracks" activity that I can't link to for copyright issues. E-mail me and I'll send you the copy that I scanned. It's actually from BSCS (or that's where I got it) and involves exposing a "fossil bed" (picture) of animal tracks, one section at a time, and making observations/inferences, then revising those inferences as more information accumulates. I'm sure there are other versions of the activity, but a google search turned up nothing. It was interesting to me that students at the end wanted to know the "real" story. That lack of certainty is obviously a problem in science for a lot of people. We seem to crave an author, an authority, or an authoritarian to give us a definitive answer.

Next week we will be playing with the hissing cockroaches. They will begin a long term observation of the critters and I will start by asking them to compare the cockroaches to themselves in as much detail as possible. I don't have a formal lab write-up. Instead, they will be taking notes and keeping a log in their journals. For lab minutes I will have to supply some sort of worksheet to keep on file for them, but that will have to wait a few weeks. I also have the mealworms that I will work in at some point. I found an idea to conduct a controlled experiment on the effect of temperature on their development from pupa to adult. It's the only transition where there's a certain degree of control for the age variable, since you can actually know within a few hours when a mealworm turns into a pupa, then measure how long it takes to turn into a beetle. Unfortunately I think my adult beetles are engaging in a little cannibalism, and I may have to start a separate cage for the adults to keep this from continuing. Gotta get those student monitors lined up next week to help with some of the lab set up and live critter upkeep.

Sunscreens Cause Skin Cancer

Sunscreens Can Damage Skin, Researchers Find

Science Daily

This is straight out of Woody Allen's "Sleeper."

Researchers discovered that the active ingredients in sunscreen can penetrate the skin where they themselves do damage when exposed to UV radiation. The effect is negated if fresh sunscreen is applied (where it will remain for a period of time on the surface of the skin) to stop the UV rays from penetrating the lower layers of the skin. In other words, on the surface of the skin, the sunscreeen prevents UV rays from causing damage to your skin cells. However, when the chemicals in sunscreen penetrate to the lower layers of the skin they actually magnify the damaging effects of the sun's rays. This is, in a weird way, great news for the sunscreen industry, since the solution to the problem is to reapply sunscreen often. Long term, the solution is to find ways to keep the uv filters from being absorbed into the skin.

Tacks Along the Hudson

I was hoping this post would be about that warm fuzzy feeling that comes from doing good deeds to help your fellow human being, but it will quickly turn into a rant about ugly behavior. I've been thinking about this post for a while, ever since I saw an ad on TV for some insurance company that depicts a series of linked events where a person steps in/up to help someone else - perfect strangers. The recipient of that random act of kindness is depicted in the next scene helping another, and so on and so on. (I'll update when I see it again and record the details). I normally hate television in general and particularly commercials, but this one strikes a cord with the goody-goody in me, which I like to think all of have inside us on some level.
First the warm fuzzy. I got a flat tire on my bike yesterday and found a tack in my tire. I had one patch left, fixed the flat, started pumping it up and realized the tack had gone through both sides of the tube, so there were TWO holes in the tire and I had no more patches left. I only had the one patch left because I just got a flat tire two days earlier going the other direction on the same path, caused by - a tack. It was early evening on a cloudy day that looked like rain, so not a lot of traffic on the bike path. Nevertheless, I flagged down a couple of guys on bikes. Both stopped to chat briefly but neither had any patches with them. I was about to give up and start walking when a pair of cyclists rode by before I could even see them coming, and without waiting for me to ask, one called out, "Everything OK?" I called back "Got any patches?,", to which the guy stopped, turned around, came back and shuffled through his sack, pulled out a patch, gave me a second one just in case. Saved me from a long walk home. I'm eternally grateful to someone I'll most likely never see again.
Time to repay the debt. Today I went running along the same path. I got caught in the heavy rain that lasted over an hour. The rain began shortly after I started running, and of course, stopped shortly after I finished running. I just can't catch break these days. I was so distracted by the rain that when I saw a guy fixing a flat tire on his bike under an overpass, I didn't even make the connection with my own troubles. A little further on, however, I looked down and saw a whole cluster of those sharp tacks that are used for furniture upholstery.

So I actually stood there (or stooped to be precise) and picked up all those tacks. Now, there's an element of self-interest here, in that I ride this path all the time and I'm tired of patching tires, but I also patted myself on the back for saving a good number of other cyclists from getting flat tires. So, start running again and get about 10 yards when I see another cluster of tacks. OK, stop & pick them up. Start running again expecting to see another cluster, but it looks clean - for about 100 yards, then another cluster of shorter tacks. Yes, I stopped and picked them up. Then another. Yup, picked them up. Suddenly a few yards away a huge cluster of tack, just too many for me to pick up. I tried sweeping them aside with my foot, but they stuck in my shoe. I had to admit defeat.

All the clusters I described above were along the newly-constructed pathway that runs along and below the Riverbank State Park between 135th and 145th streets (approximately). On the way back, I found more clusters north of the Park, and in the rain and scattered amongst the debris, who knows how many other clusters there are that I didn't spot? So it looks like I will have to find an alternative path temporarily.

OK, I'll skip the rant. I have to constantly remind myself of all the foolish things I did as a kid, and I hate to admit that this isn't that far different from some pranks that I did in fact pull when I was young & oblivious to the effects of my actions on others. I vented to a neighbor and I followed his advice to contact the parks department. Awaiting a response. In the meantime, if you're a cyclist, be very careful along the bike path from about 158th street to 133rd(?) street where the path ends - and always carry extra patches!

UPDATE (9-9-06)

The problem continues and is growing. I didn't ride along the path for a few days, both because of the beginning of the school year and because there were a couple of days where it rained. So when I finally rode to work on Friday I took a detour on the way in (no time for flats on the way to work) and then the usual route, slowly, on the way back. That's when I started passing by people again pushing their bikes with flat tires. I thought I had missed them, since I went slowly and didn't see any tacks, but a short distance from my home I noticed the tire getting a little flat, slowly, so I pulled over and sure enough there was another tack in the tire. I talked to a couple of other "riders" (pushers by now) and we cursed and speculated on what was going on. It's fresh tacks every day it seems. These are little steel nails that rust quickly and the ones we pull out of our tires are needle sharp and shiny. I'm slowly coming around to the idea of camera surveillance in the parks!

UPDATE II (1/14/07)

I meant to post this a few months ago but didn't have the time. Below is the text of an e-mail from the Parks Department and a contact e-mail for future problems. This is dated 10/27/06:

Mr. G -

Thank you for your note regarding the tacks strewn along the pathways in Riverside and Ft. Washington Park. We appreciate that you brought this matter to our attention. Your comments along with many others were quite helpful in identifying the problematic locations.

We've swept the entire length of the pathway and believe we've solved the problem though it remains a mystery why someone would do this.

If you should have any other questions regarding this or any other matter in Riverside Park, please feel free to reach out to me directly at kc.sahl@parks.nyc.gov or 212.408.0264.

Thank you,

KC

Haven't been out in a while but I expect the problem to be minimal in the winter months anyway.

Labs 2006

Lab List 2006-2007 - Part 1



This is taking a lot longer than I expected - Part 2 will follow...

I've divided them by topic according to my sequence for the year. A hodge-podge of labs from various sources, which I've linked to where possible. I hope to some day standardize the formats and customize them, but good lord that takes time and focus. Some labs are not available electronically. I've offered alternatives that are available or explanations of the labs that you can use as a starting point. I found all these labs by 1) creating my own from scratch or adapting existing labs, 2) browsing other science teachers' sites (click on the links in the sidebar), 3) browsing back issues of sciene teacher journals like American Biology Teacher or NSTA's Science Teacher, 4) googling key terms and seeing what comes up, 5) following leads that come in through various listservs.

Nature Of Science/Evolution

1. Black Box - Mental Models Lab

2. Natural Selection Game

3. Variation in Sunflower Seeds Worksheet. Adapted from Monaco Education Service

Organizations & Patterns

4. Chemical Reactions ( No write-up yet. I used my Experimental Design Worksheet and talked them through it. Students manipulate baking soda amount, measure magnitude of the reaction via balloon diameter. I'll try to write up something more substantial later on).

5. Mello Jello. Jello, detergents, enzymes. Controlled experiment on Enzyme Action. I have students fill out Experimental Design Worksheet in addition to answering the concept questions that come with the activity.

6. Making Cheese (Protein Denaturation) Just add sugar - yummy.

7. Egg 0smosis. Try the Exploratorium version of the "Naked Egg."

8. Diffusion Through a Membrane (Part 1) State Lab - No elecronic version available. Description: Red Onion Cells

9. Comparing Plant & Animal Cells (Mike Comet)

Homeostasis

10. Making Connections (Part 1) New York State - (Alternative)

11. Lung Capacity (Mike Comet)

12. Frog Dissection (Optional) - Here's an HTML version. Mine are not in electronic form.

Reproduction

13. Mealworm Life Cycle (Long Term Study, no write-up yet)

14. Zebra Fish Embryos Study (Still looking into this)

15. Flower Dissection. Mine is not available electronically. Try Access Excellence Version.

That's about half of the labs I have on tap. Next up - Genetics, Modern Evolution, Ecology Labs and a few additions to Homeostasis.