One Spring’s Month

A month in the spring can make a huge difference. Move your mouse over the image (or click the image) to see the difference between April and May on the Fulton School campus.

The full sized images can be seen here.

Note: To embed the image above use:

<iframe style=”overflow:hidden;” src=”http://earthsciweb.org/js/images/spring/spring.html” width=490 height=326 seamless />

Red-eared Slider

Rescued red-eared slider.

This little guy was rescued just down the road by one of our bicyclists. His under-shell, which is called the plastron, is beautifully decorated.

It’s in the fish tank with the tadpoles at the moment. Red-eared sliders grow to 12-25cm long, and they’re named after the red splotch that’s located just behind their eye.

It seems happy enough in the tank, but we’ll release him to the creek at the end of the semester in a couple weeks.

They’re native to Missouri, but according to the Missouri Department of Conservation’s nice little reference book, Show Me Herps, these have been the targets of illegal collection, and international trade. Ones released in Europe have become invasive species there.

The red “ears” aren’t really ears, just a patch of red behind the eye.

Embeddable DNA

Ravenclaw’s four genes on the DNA string annotated. Note that start and stop codons bracket each gene, and there is non-coding (junk) DNA between each gene.

Using English words like “blue eyes” to represent genes in DNA strings with the DNA Writer runs the risk that students start to wonder if actual genes are coded in English.

I’d say it was a small risk, but today I did have that question from a couple of students today.

Fortunately, it was quite easy to disabuse them of the impression: they didn’t actually believe it, but they just had to know for sure.

I did like one of the questions though, “Does that mean that Spanish people have DNA written in Spanish?”

Embedding the Tiles

With that caveat, since I, and a few of my students, like the pretty patterns the DNA Writer produces (see above), I created a way to embed the color sequences into other webpages like this blog.

By default, the embedded image links back to the DNA Writer website, but you can adjust it so that it does not. Instead, the nucleobase tiles will change color when you click on them. The color changing helps keep track of where you are if you’re trying to string the sequence in beads.

For academic purposes, you can also change the message you get when the mouse hovers over the tiles. By default it give the plain English translation, but you can make it say whatever you want, or even have it just show the base sequence.

The Genetics of Blondes

Photo by Graham Crumb (via Wikimedia Commons).

Hair color tends to come up pretty organically when talking about heredity and genetic traits. Blonde hair in people of European descent is a result of a the interactions of a combination of genes, but the blonde afros of Melanesians appears to be the result of a single mutation of a single gene.

Switching one “letter” of genetic code-replacing a “C” with a “T”-meant the difference between dark hair and blond hair.

— Loury (2012): The Origin of Blond Afros in Melanesia in Science

Basic JavaScript

One of my students couldn’t get VPython to install and run her computer. She was running Windows 8, and I have not used Windows, much less this version of it to figure out what the problem was. This is one of the challenges with a bring your own device policy. So, instead I gave the lesson on numerical integration using javascript.

To make things easier, I create a barebones template of a webpage build around javascript (using the jquery library to make interactivity easier).

If you open the webpage file (index.html) in your browser you should see nothing but the word “Hello”. The template is blank, but it’s ready so students can start with the javascript programming right away, which a few of my programming elective students have done.

For reference, this file (basic-jquery-numeric-int.zip) uses the template to create a program that does numerical integration. Someone using the webpage can enter the limits (a and b) and the number of trapezoids to use (n), and the program calculates calculates the area under the curve f(x) = -x2/4 + x + 4.

It’s a very bare template and doesn’t have any comments, so it’s not useful unless you’re at least a little familiar with html and javascript and just need a clean place to start.

A Movie in Atoms

A neat stop-motion movie made by manipulating individual atoms.

This is a great spark-the-imagination video because you can use it to talk about the physics of atoms and molecules, and what is temperature — they had to cool the atoms down to 4 Kelvin to keep them from moving too much.

How they did it:

More detail from Slate, and NPR: