In today’s link roundup, Uncertain Chad points to a new digital library of mathematical function. As a huge, huge fan of Abramowitz & Stegun (which can now be downloaded as a PDF, if you would rather not have it sitting majestically on your shelf), I am thrilled.

Sometimes you’ll be happily calculating along, and wind up with an equation you wouldn’t want to meet at night in a dark alley. But, a quick flip through Abramowitz & Stegun frequently turns up your nemesis, along with handy tricks for disarming it. Additional satisfaction comes when you write the paper, and get to throw off lines like “The solutions to equation 4 are confluent hypergeometric functions (of the first kind)”.

However, it will be hard top my amusement when I once discovered that the solutions to my problem were closely related to Anger functions.

I can only hope that Dr. Hate and Professor Loathing someday derive equally useful function forms.

My newest column for Discover is about that strangest of the senses, smell. An odor can be an overwhelming experience, and yet it’s often impossible to put that experience into words. In fact, we’re terrible at naming smells, despite being exquisitely sensitive to the differences between them. I take a look at some recent research that may bring us closer to resolving this paradox, with the invention of the first yardstick for the nose–a simple measurement of odor molecules that reveals a lot about how pleasant or vile we find them. Not only might it help us understand our own noses, but it may even let us build electronic noses to sniff for things we don’t want to stick our own noses in. Check it out.

With smallpox largely eradicated around the world, health organizations phased out the smallpox vaccine between the 1950s and 1970s (the last natural case of the disease was seen in 1977, in Somalia). During that span, Raymond Weinstein says, the AIDS crisis broke out in force. And in a study in BMC Immunology, he argues those two events could be connected.

Supposing that smallpox vaccination could have some effect on a person’s susceptibility to HIV, researchers led by Weinstein tested the idea on cells in a lab. They took immune cells from 10 people recently vaccinated against smallpox and 10 people never vaccinated. HIV, they found, was five times less successful at replicating with the cells of vaccinated people.

Why?

The researchers believe vaccination may offer some protection against HIV by producing long-term alterations in the immune system, possibly including the expression of a receptor called CCR5 on the surface of white blood cells, which is exploited by the smallpox virus and HIV [BBC News].

Any finding that expands knowledge of how HIV replicates could be an important one. And while this small study can’t prove Weinstein’s assertion is correct, the argument is, at the very least, plausible. Says Weinstein:

“There have been several proposed explanations for the rapid spread of HIV in Africa, including wars, the reuse of unsterilised needles and the contamination of early batches of polio vaccine. However, all of these have been either disproved or do not sufficiently explain the behaviour of the HIV pandemic” [Press Association].

Related Content:
DISCOVER: Whatever Happened to… Smallpox?
DISCOVER: 20 Things You Didn’t Know About… Lab Accidents
DISCOVER: Killer Pox in the Congo
80beats: Researchers Track the HIV Virus to a Hideout in the Bone Marrow
80beats: S. African HIV Plan: Universal Testing & Treatment Could End the Epidemic

Image: CDC

To answer that question, don't go comparing their personality traits (the Newfie: famously loyal and sweet, Tiger Woods: um, no comment). Instead, look to the knees. Newfoundland dogs are prone to cruciate ligament disease, the same knee disorder that has troubled Woods and many other professional athletes--the disease makes dogs and humans more prone to ligament ruptures. Now, researchers at Liverpool University are asking Newfie owners to send in DNA samples from their pets so they can search for genetic factors that predispose dogs to the condition. According to lead researcher Arabella Baird, the study could have two benefits. If researchers determine which genes put dogs at risk of the condition, they can help breeders create healthier lines of dogs by preventing matings between dogs with the key genes. But the study may also help medical researchers find the comparable genes in humans, The Guardian reports:
Baird added: "The disease in humans tends to occur when stress is put on the ligament, but there have been some preliminary findings that suggest there is a genetic component that could predispose humans to the condition.... Our project will be looking at many genes and the results of our study in dogs will be comparative to ...

See here and here. The Union of Concerned Scientists has organized a statement from 800 researchers in Virginia defending Michael Mann and denouncing Ken Cuccinelli's tactics and investigation. Key quote: "In the interests of the people of Virginia, we urge you to halt this burdensome and entirely unwarranted investigation." Now if only the University of Virgina would lend its heft to the cause...