Links - June 2, 2011

A few orders of business:

1. My mitosis painting from artologica arrived this week! It is gorgeous and I can't wait to frame it and hang it in my new condo.
2. Add this blog on Facebook if you wanna.
3. I PASSED MY THESIS DEFENSE!!

I'll get back to posting soon. Now some links. Some of these are kind of old since I've been in the thesis defense cave. Sorry.

Physiology

Semen allergy suspected in rare post-orgasm illness. Some dudes are allergic to their own semen and become ill for weeks after ejaculating. On the plus side, hyposensitization therapy seems to work for some of these dudes.

Human skin cells turned into nerve cells. Epidermal cells from circumcised foreskin are being turned into nerve cells via a reprogramming called transdifferentiation, which is faster than converting adult cells into stem cells and then back into some other type of cell. Unfortunately the success rate is very low.

Anorexic brain responds to food anxiously. Instead of releasing dopamine in pleasure centers like most people, food causes anorexics to activate areas of their brain associated with anxiety. Considering my phobia and my own battle with my relationship with food, I can relate to that.

Blue lights show to give brain a boost! But is it better than coffee? Photoreceptors in the eye that detect blue wavelengths of light boost alertness and concentration. Blue wavelengths are specifically associated with reduced levels of melatonin (which makes you sleepy) in the brain. That's why I have f.lux installed on all my computers. It automatically turns up the 'warmth' of your computer screen after sunset. This way you minimize your exposure to blue light in the evening, causing less inhibition of melatonin release so you can fall asleep easier.

Other Science

Bats use carnivorous pitcher plant as living toilet. It seems that a certain species of bat and pitcher plant have evolved a nice symbiotic relationship. The bat gets a place to roost, and the plant gets fertilizer. Also I just love anything to do with poop, so this was right up my alley. Bats aren't alone; it seems that some shrews have a similar relationship with another species of pitcher plant.

23andMe DNA Test Review: It's right for me but is it right for you? This is a good read for anyone considering getting genotyped through 23andMe. It does a bit of explaining about the process and product, and what questions you should think about before deciding to buy. I'm happy with it, personally, but you need to consider what you want to get out of the product.

Mpemba's baffling discovery: can hot water freeze before cold? A great story about scientific inquiry and battling dogma.

Other Stuff

Calvin and Hobbes Fight Club. Someone did a mash-up of the Fight Club trailer with scenes from the Calvin and Hobbes comic strip. Watch the video!

I've gone and done it now: What it's like without the Muslim headscarf. Interesting read from a woman reconsidering her stance on the hijab.

The National Academies Press makes all PDF books free to download. The title says it all.

The man who wasn't there. There's been a lot of buzz lately in my meatspace life about the circumstances surrounding Jim Tressel's resignation as the Ohio State University football team's head coach. I've been finding it hard to care very much because football isn't as important or interesting to me as it was once upon a time. However I did like reading this post, which has an interesting take on his legacy.

Links - May 24, 2011

My thesis defense is in one week (whoa!), so I'm taking a break from blogging to go into hardcore study and preparation mode. I'll see you back here after June 1^st, hopefully with good news!

In the meantime, here are some links to hold you over. Also, I made a Facebook page for my blog the other day on a whim. It occurred to me that there are some blogs I follow through Facebook that aren't in my RSS reader, so I'd like to have that option available for people who maybe do the same. You can 'like' it if you like this blog and like 'liking' the things you like.

Physiology

Does sexual intercourse hinder subsequent athletic performance? Many athletes superstitiously abstain from sex the night before a big game, meet, or performance, but is there actual evidence to support this belief? Some say it reduces testosterone and energy the following day, but it seems that there aren't any studies that confirm this suggestion.

Seven Deadly Sins Sunday: Gluttony. The link is to part 5 of 5, use the links at the top of the post to read the earlier posts. A great discussion of the physiology of gluttony. This is becoming one of my new favorite blogs.

Gut bacteria linked to behavior: That anxiety may be in your gut, not in your head. The gut flora may be influencing brain chemistry and behavior.

Other Biology

A map of charismatic canid genomic variation. All that genetics PCA and structure (a program similar to ADMIXTURE) crap, but applied to dogs!

America's most poisonous pill. It's not what you think (although the title is more than a bit misleading). Klonopin, a benzodiazepine, is apparently the second most abused drug in America behind opioids like Oxycontin.

Sex, sleep, and the law: When nocturnal genitals pose a moral problem. If someone forcibly tries to have sex with you while they're sleepwalking, can they be prosecuted?

Other Stuff

Marketing food to kids with cartoon characters. Kids think that food tastes better when there are cartoon characters on the box, and this is true for foods from cereal to carrot sticks. This can be a good way to get kids to make healthier food choices, but chances are that for every healthy food option endorsed by Shrek or Nemo there are a handful of unhealthy ones endorsed by that lemur from Madagascar.

Forensics: The call of the crime lab. A good report on the state of the occupation. I wanted to be a forensic scientist for a long time, but I don't like chemistry enough to be very good at it.

Happy guys finish last, says new study on sexual attractiveness. "Women find happy guys significantly less sexually attractive than swaggering or brooding men." Guilty.

What they are really typing. A few studies attempt to quantify what students are really doing on their laptops during class.

Links - May 13, 2011

I'm sorry for not posting much lately. I have, as Gerty-Z joked on Twitter, reached the 'herding cats' portion of my graduate education. I'm busy wrapping up loose ends and trying to schedule and prepare for my thesis defense. Also most of my blogging energy is going to other things. I've been flexing my sociology muscles since I'm a little burnt out on science at the moment, mi dispiace. I'm sure you understand. But, hey, here's some stuff you can read! My commentary is a bit cursory today because, again, feeling a little burnt out. It's all good though, I promise.

Physiology

Sex on the brain: Orgasms unlock altered consciousness. I was mostly just amused by the woman's description of being instructed to masturbate while in an fMRI machine.

Just how dangerous is sitting all day? Spending long periods sitting down can be very harmful for you, even if you exercise regularly. See also: 7 Myths about Physical Activity.

Burning proteins to save water. Breaking down muscle for energy releases water, and certain long-distance migratory birds are taking advantage of this. I have the paper for this in my reading queue.

Is semen really an antidepressant? Wow, this topic seems to get people blogging like no other! Check out this one in Jezebel which includes a quote by our pal Kate Clancy.

How kissing can boost your mood instantly. Props to Sheryl for not naming this article "The neuroscience of kissing"!

Biology

Wildlife in the Star Wars Universe. Gorgeous photos of alien wildlife compared to earthly beings.

Other stuff

Mythbusting Bisexual Men. Apparently people believe that bisexual men are rarer than unicorns.

Brown man + white woman and Marriage and the intersection of gender and race. Razib and Sociological Images tackle the numbers behind actual rates of marriage outside of one's own race.

In other news, apparently Kedar is upset that I didn't remind the world that today is his birthday. So, HAPPY BIRTHDAY KEDAR! I got him a tie, a Wii Fit Plus, and a really skimpy dress for me.

The birthday monkey boy, circa 1987.

Links - May 5, 2011

Feliz Cinco de Mayo! Before I get to the links, here are some things that have been going on lately:

- My post not too long ago on the efficacy of cortisol supplement during exposure therapy for specific phobias was picked by Jason as one of his ResearchBlogging Editor's Selections last week.

- Razib and Zach have invited me to contribute at Brown Pundits. I'm not really sure what I'm going to talk about over there yet, but I accepted the offer.

- I already mentioned it, but I have a guest post at the LabSpaces guest blog Dangerous Experiments on caloric intake and hypoadiponectinemia. My last guest post was on circumcision and cervical cancer at the Scientific American guest blog.

Physiology

How peppermint may cool that irritable bowel syndrome. IBS is thought to be caused by permanent agitation of enteric nerves (nerves in the gastrointestinal tract) that become oversensitive to inflammation, often occurring after an infection such as a bout of gastroenteritis (caused by "stomach flu" or food poisoning). Menthol from peppermint and other "cooling" compounds may be able to soothe the bowels and alleviate some of the symptoms of IBS. I think I may have already known this on a subconscious level, since I tend to suck on peppermints when I'm feeling anxious (anxiety and stress are major triggers of IBS).

Superfetation: Pregnant while already pregnant. On the Scientific American Guest Blog, a discussion of the unlikely factors that must happen in concert for a woman to get pregnant again when she's already got a half-done bun in her oven.

Other Biology

How do you ID a dead Osama? Christie Wilcox explains the DNA analysis process that may have been used to confirm Bin Laden's identity. See also 23andMe's post on the topic.

Nature's Living Tape Recorders May Be Telling Us Secrets. Superb lyrebirds are superb mimics of any sound you can imagine. Be sure to watch the embedded video.

Other Stuff

How to Boost Interest in Space: Talk About Poop. Yeah, I mean, look. I've seen enough space movies to know that peeing in space has to be pretty tightly controlled, otherwise you've got a big ol' mess (and, actually, I've never heard anyone address the issue of women trying to urinate in space; that's gotta be more difficult). BUT WHAT ABOUT POOPING?!

Mythbusting Princess Leia's Hair. As if you needed to be told that Leia's hair defied the laws of physics.

I Liked The Royal Wedding (And It's Okay If You Did Too). What kind of power does the monarchy really have?

Links - April 25, 2011

Physiology

AAPA symposium on Evolution through the Life Course: Why we shouldn't prescribe hormonal contraception to twelve year olds. Can the benefits of hormonal contraceptives seen in adult women be applied to girls as young as 11-12? Can the use of hormonal contraceptives influence the development of the hypothalamic-pituitary-gonadal endocrine pathways in pubescent girls? Oral contraceptives are often marketed as period regulators, especially to young girls who are more likely to experience irregular periods. However, period irregularity after menarche is due to the maturation process of the negative-feedback arc that regulates the endocrine pathway, and the effects of flooding this developing system with exogenous hormones aren't well understood.

Divided by language, united by gut bacteria – people have three common gut types and Bacterial Ecosystems Divide People Into 3 Groups, Scientists Say. The microbiome seems to be a pretty hot topic right now.

http://terriblepunyrightness.wordpress.com/2011/04/20/that-semen-antidepressant-study/. I'm glad someone finally took this to task. If you're not familiar, there's an oft-cited study on college-age women that claims that women who don't use condoms are less depressed than women who use condoms or are abstinent. The authors took this to mean that there are magical happy juices in semen that is absorbed through the vaginal wall and boosts women's mood. However, there are problems with this study that people often fail to address when discussing it.

Erection-inducing condoms may soon be available in Europe. The condoms use a topical vasodilator to prevent, um, deflation after putting it on.

The neuroscience of relationship breakups. Looking at a photo of an ex-significant other immediately after a breakup activates the same areas of the brain as when experiencing physical pain.

Other Biology

DNA Origami Gets Curves. Just look at the pictures!

Perseverating on Perseverative Error: What Does The "A-not-B Error" Really Tell Us About Infant Cognition? Baby talk may be an adaptive mechanism for learning generalizable information.

Nature in time-lapse: 10 awe-inspiring videos. They're all good, but this one is my favorite:



Other Stuff

Nervous nellies. Culture is probably to blame for the fact that girls seem to be plagued by anxiety more often than boys. A good companion piece to this: The secret lives of boys.

Reflections of Gotham: Why Do New Yorkers Wear So Much Black? A pretty cool summary of the history of dyes and textile trade, and how that may be influencing the color choices of New Yorkers.

Links - April 20, 2011

Physiology

Opinion: The decline of physiology. Medical schools in the UK are scaling back their basic physiology education in favor of more pathology and clinical courses which skim over the basic physiology needed to understand those situations. If you are a physiologist, the APS encourages you to participate in the comments discussion.

Sucked out of a plane? What are the physiological consequences of being sucked out of an airplane? This made me think of the airlock scenes in Battlestar Galactica. (CALLY NOOOOO!)

The neuroscience of the gut. I briefly mentioned the brain-gut axis earlier this week. It has been established that the gut flora can have an effect on things like obesity (although the exact nature of the relationship is still poorly understood), but it seems that the gut flora may also influence the brain and behavior in more ways than previously thought.

Remembering a time when blood did not flow right to left. A history lesson from Dr. Isis.

Genetics

Do genes modify the health impact of sedentary behavior? Travis at Obesity Panacea (which isn't a new blog by any means but is quickly becoming one of my new favorites) interviews Caren Smith, the lead author of a recent paper exploring how genetics may influence the impact of sedentary behavior. They found that women with the TT genotype at SNP rs6507931 were at a higher risk when engaging in sedentary behavior than women with other genotypes. 23andMe v3 includes this SNP, so you can look up your genotype here. I'm CT at rs6507931, does that mean I don't have to worry about sedentary behavior affecting my health? No, not at all. As Dr. Smith says in the interview, "With respect to worrying about genotype vs. worrying about sedentary behavior, at the moment we know more about the overwhelmingly beneficial effects of physical activity than we do about the effects of interactions with certain genotype.  While it is likely that some people derive greater benefits than others from exercise (or conversely, at put at higher risk through inactivity), the vast majority of people would benefit from increasing their overall physical activity."

"Coffee, I must have coffee..." At 23andMe's blog, they explore some recent papers that link one's genotype to the amounts of coffee and other caffeinated beverages that one consumes. Anecdotally, I have one of the caffeine-desirous genotypes, and I do drink about 3 cups of black tea a day. When I say cups, I mean my tea cup, which is much closer to 2 measuring cups.

Razib Khan's 23andMe v3 genotype. Razib has put his 23andMe data into the public domain.

Other Biology

That's not a dinosaur! Our cultural consensus of what dinosaurs are "supposed" to look like is rapidly diverging from what scientists are discovering about dinosaur morphology. This sorta came home for me when I recently re-watched The Land Before Time and realized that the brontosaurus never existed! I also went off on a tangent about how stegosaurus and triceratops did not live during the same time period (which I actually knew even as a kid from reading Calvin and Hobbes). This prompted Kedar to implore me to just shut up and enjoy the movie, but how can I when I'm experiencing cognitive dissonance?!

Other Stuff

How to get academic papers for free. I had no idea about a lot of these. After reading this I logged in at my local public library's website using my library card, and was shocked to find that they had access to quite a few academic databases. Not as good as my university's library, but still pretty damn good.

Mis-illustrating abortion. 90% of abortions happen in the first trimester, so why do 90% of news articles about abortion show pictures of women in their third trimester?

How I, a married, middle-aged man, became an accidental spokesperson for gay rights overnight. "The real problem here is certainly not that Facebook is a homophobic company. It's that their terrible corporate policy on censorship needs to stop siding with the idiots, the complainers and the least-enlightened and evolved amongst us as a matter of business expediency!"

The real life models for classic pinup paintings. Okay, this is pure fluff. Pure, delicious fluff:

Source. You know, I've always thought those ankles looked like they were bent at an unnatural angle, but apparently they're true to life!

Pictures and video for a Sunday afternoon.

Source. A reader pointed me to a second composite image of a "global human." It is "a composite itself from four composite of Northwest European, South & West Asian, East Asian and African faces..."

As I said in the comments at Razib's blog: "My, that is one attractive fellow. He looks decidedly Hispanic to me, which I suppose shouldn't be surprising since Hispanics are already highly mixed people with Asian, African, and European ancestry. However, if you squint, he can look a bit Indian (or Italian, or mulatto, or hapa, or…)." I think the thought exercise here is less what the guy actually looks like, but more what we as individuals see in him.

Source. To correct [people's misinterpretations about the relative size of Africa due to maps using the Mercator projection], Kai Krause has created this map and associated information to show that Africa's total area is almost the same as that of the United States, China, India, Japan and all of Europe combined.

I learned about the faults of Mercator projections when I was pretty young, although I can't remember where I learned it. I think it was something I saw on television. My young brain couldn't quite wrap itself around the geometry involved, but I got the major point. Many maps use a system that, instead of staying true to the curvature of the earth, lay things out in such a way that the lines of latitude and longitude make rectangles instead of curved lines. This is mainly for ship navigation and the like, but it has the unfortunate effect of exaggerating land masses at the poles and diminishing land masses near the equator, such as central America, Africa, and India. In the Mercator projection, Africa looks to be only slightly larger than Greenland! If you've ever looked at a globe (I had a globe when I was a kid, which helped me with the geometry of this issue a bit), you know that's definitely not true. The original blog post has more detailed info on Mercator projections if you're interested.

Source. Myotonia congenita, or congenital myotonia is a skeletal muscle-locking disorder. In affected individuals, when the muscles contract, they do not immediately relax again: for a short period the affected muscles stiffen. If the individuals are standing up, they'll fall over, as the kittens in the video do.

I felt bad watching this video. Every time a kitten would fall down, my immediate instinct was to laugh, but then I wanted to cry. I had a very conflicting experience to say the least. The blog post accompanying this video has a really great explanation of the physiology involved in the disease; I suggest you check that out as well.

Neuromuscular Junction Cookie!

This is adorable. From here, found via this science cookie roundup post that I also highly recommend you visit, if you enjoy stuff like anatomical cakes and cookies that resemble T-4 macrophages.

Click to enlarge!

Links: comparative physiology, molbio carnival, autism.

There's a new comparative physiology blog in the science blogosphere! I recommend you go check out Life Lines. It is nice to know that I'm not the only one out there.

The debut edition of the MolBio blog carnival (the pet project of LabRat and Psi Wavefunction, among others) is posted, and includes a post from me! Go check that out as well.

I'm just about to head out to the office to clean out the last of our junk from the old office and move the last of the useable junk to the new office. Part of today's task will be recycling 3 giant file cabinets full of papers that have accumulated in the room from past graduate students. Thank whatever deity you like that we live in the age of digital documents, because I love not having to deal with that crap. Anyway, since I'm on my way out, I don't have time for a detailed discussion of this study that caught my eye: Relatives of individuals with autism tend to display abnormal eye movements. The investigators examined first-degree relatives (siblings and parents) of autistic individuals for sensorimotor impairments. From the press release:

When compared with controls, family members of individuals with autism tended to perform more slowly and less accurately on eye movement tasks, including those assessing saccades and smooth-pursuit eye movements. "The present findings document that first-degree relatives of individuals with autism demonstrate a unique pattern of oculomotor impairments similar to that previously reported in independent samples of individuals with autism, suggesting that these alterations within sensorimotor and cognitive brain circuitry may be familial traits," the authors write.

They also found that family members were more prone to obsessive and compulsive behaviors, but that this was unrelated to sensorimotor impairments. I've downloaded the paper and will probably blog about it tomorrow.

Housekeeping

The August edition of Scientiae is up, and one of my posts has been included! Go take a look, read around, and comment on all the contributors' blogs. Scientia Pro Publica #36 has also been posted, and two of my posts were included. Be sure to read that as well.

I've also been named runner-up for July's blog pick of the month on everyONE (PLoS ONE's community blog). I am quite flattered.

And finally, as you already know if you're reading this post, my blog has moved from WordPress to Field of Science! The move isn't completely finished yet. I'm not currently listed from the front page, and things may look a bit wonky until the overlord finds enough time in his very busy schedule to finish the coding. The site and feed are functional, though, so I decided to make the move official this morning.

For those of you who are reading for the first time, my name is Michelle, and I'm a second year master's student in ecophysiology. Ecophysiology is a lot like regular physiology, except it takes into account the ways that external environmental conditions put selective pressure on the structure and function of an organism's internal physiology. I suppose you could also call it evolutionary physiology or something of that sort, but I prefer ecophysiology because my work specifically deals with the way certain critters have adapted to life in the desert. My field is fascinating but the day-to-day of my actual research is pretty boring, which is why I write this blog. It gives me an outlet to read and talk about papers in other areas of physiology (and the wider world of science) that I find more interesting. I teach introductory human physiology at my university, and my physiology blogging is at about the same level as what I teach, I like to break things down and make them simple so that a layperson can understand what's going on.

You may want to check out the pages tabbed at the top of my blog, they'll tell you how to get in touch with me, my disclaimer and philosophy as to the content I post on this blog, and it'll help you out with the people and things I talk about because it may not be immediately apparent what I'm referring to. Thanks for coming!

Weekend links

Here are some links of things I found interesting this week:

From ScienceNews.org, Sadness response strengthens with age.

In a recent study, people in their sixties felt sadder than people in their twenties did after viewing an emotionally distressing scene from a movie. This heightened emotional response to sorrow may reflect a greater compassion for other people and may strengthen social bonds, researchers propose.

Janet at Adventures in Ethics and Science posts on Research methods and primary literature.

I think there's value for students in digging up, and digging through, the primary literature of the discipline in which they are learning to do research. Sure, you don't want the primary literature to seem more authoritative as a source of knowledge than the actual experimental system a student is studying. But neither, I think, does it make sense to just throw an experimental system at a student and say "Here, come up with a good research question and figure out how to answer it."

Christina at Oscillator posts about the mechanism and evolution of motion sickness:

What is going on in our guts and brains when we're in a moving vehicle that makes us throw up? Why can't we just deal with motion better? As it negatively affects so many, this nauseating (did you know: the word nausea itself comes from the Greek word for boat!) inconvenience associated with technologically-assisted travel by sea, land, air, or IMAX screens has been the focus of intense and sometimes wacky research for more than 100 years. Although a great deal of mechanistic evidence for how motion sickness happens has been described, the theories of why it happens are still controversial and fascinating.

From LabSpaces.net, Aging and longevity tied to a specific brain region in mice.

Researchers watched two groups of mice, both nearing the end of a two-day fast. One group was quietly huddled together, but the other group was active and alert. The difference? The second set of mice had been engineered so their brains produced more SIRT1, a protein known to play a role in aging and longevity. "This result surprised us," says the study's senior author Shin-ichiro Imai [...]. "It demonstrates that SIRT1 in the brain is tied into a mechanism that allows animals to survive when food is scarce. And this might be involved with the lifespan-increasing effect of low-calorie diets."

From EurekAlert, Unique means of animal locomotion reported for first time.

[T]he gut of the crawling tobacco hawkmoth caterpillar (Manduca sexta) moves forward independently of and in advance of the surrounding body wall and legs, rather than moving along with them. [...]"Understanding this novel motion system may help efforts to design soft-bodied robots," said the article's senior author, Barry Trimmer [...]. "It may also prompt re-examination of the potential role soft tissues play in biomechanical performance of humans and other animals."

Isis blogs about how physiology was cooler 40 years ago:

John Severinghaus is a big deal in physiology. If you have ever been in the hospital and had to have the O2 and CO2 in your blood measured to determine if your heart and lungs were working properly, you can thank John Severinghaus for the ability to have that test done. Dr. Severinghaus built the first blood gas machine and is credited for the first functioning CO2 and O2 electrodes.

Ethan at An Inordinate Fondness for Beetles blogs about recreational sex as a survival strategy:

There are plenty of studies out there on human sexuality that seem to assume that evolution hasn't quite caught up with all our modern sexual tinkering, seeing as how they start off assuming all sex, and all our sex drives, stem only from a fundamentally a reproductive urge [...]. There are points where this makes sense–genetically-driven instinct won't catch on to the advent of The Pill for a few millenia to come. But other purposes for sex, and forms of non-reproductively oriented sex, have been around for more than enough time.

Razib at Gene Expression blogs about The Anglo Revolutions:

The idea that whites, or at least "non-ethnic" whites, "have no culture," gets at the root of it. What is assumed, what is background, what is default, is not deemed worthy of history. When it comes to Anglo history and culture the commanding heights remain of interest, William Shakespeare, the King James Bible, the Magna Carta, etc. But much of the more mundane detail is of little general interest compared to the more salient identities of race, religion, and such. I believe this causes real pragmatic problems.

Photo: giant rats!

ScienceDaily reports on an archeological excavation of  eight rat species weighing over a kilogram. One of the rat species weighed over SIX kilograms.

Above is one partially intact skull compared to the skull of a normal black rat. This isn't even the biggest skull they found. Dude.

Doin' it capybara-style.

I didn't have time to write a post for this morning because I spent all day yesterday sulking around and being grumpy about various things, some pretty important and some rather petty and silly. I'm also a bit grumpy this morning because I have four hours of office hours to look forward to this afternoon because my students' final exam is tomorrow. I am in need of some serious rodent therapy.

They should call it capybara-style. Source.

Some other people have written some very great posts, though, and you should read them this morning once you've gotten your fill of capybara sex.

Dr. Zen at Neurodojo explores the difference between slit and round pupils in snake eyes.

Razib at Gene Expression: Knowledge is not value-free.

Darren at Tetrapod Zoology has two great posts up about American Pronghorns.

UPDATE: Scicurious posts about the sex and neurogenesis paper that I blogged about last week.

The last nail in the coffin of Sb? Perhaps.

I can't say that I was surprised to learn that Bora of A Blog Around The Clock was leaving ScienceBlogs, because I got a pingback a few days ago from his new hangout. I assumed that he'd been considering making a move for a while and wanted a backup plan in case he really did decide to leave, but man, I had no idea he was going to go out with such a big bang. His farewell post is a painful but necessary read for anyone who has ever spent a sizeable chunk of time reading or writing on Sb. I will continue to read his blog wherever he ends up.

Rodent Saturday!

Today's required rodent reading is this post on squirrels and cedar-mice by Christopher at Catalogue of Organisms. It includes a wonderful photo of an Indian giant squirrel eating what looks suspiciously like a fish biscuit.

Indian Giant Squirrel, Ratufa indica. Source.

Now, for my contribution to Saturday's rodent blog, I will tell you about a new mouse species of the South American Akodon genus that was described earlier this year by Braun and colleagues in New species of Akodon (Rodentia: Cricetidae: Sigmodontinae) from central Argentina.

Species of the genus Akodon are unique to South America and live mostly along the Andes from Venezuela to the southernmost parts of the continent in a very diverse variety of habitats. The species described in this paper, Akodon viridescens, is native to the Cuyo Region in northwestern Argentina, particularly the Córdoba Montane Savanna.

Location of specimen collection. The shaded area is the Córdoba Montane Savanna.

The namesake for this new species comes from an unusual characteristic: the fur of this mouse species actually has an iridescent green hue in natural sunlight! I am imagining something akin to an old soda bottle in the sunlight. Unfortunately I could not find any images of these critters on the interwebs, but here's a photo of another Akodon spp. From Peru:

Look how adorable! What a dear little creature. Source.

The authors were at least kind enough to include a photo of the critter's skull, for those of you who like bones:

Skull and teeth of A. viridescens. Click to enlarge.

---

Braun, J., Mares, M., Coyner, B., & Van Den Bussche, R. (2010). New species of Akodon (Rodentia: Cricetidae: Sigmodontinae) from central Argentina Journal of Mammalogy, 91 (2), 387-400 DOI: 10.1644/09-MAMM-A-048.1

It is probably in bad taste to use an 'in my pants' phrase when talking about the kidneys.

I think I may have jinxed myself (in a good way) because all of my students seemed to understand the hemoglobin saturation curve today! Talk about serendipity. For some reason it was just clicking with them today, so that's a pretty good sign. Tomorrow we get to start the <3 <3 renal system <3 <3! (I totally cream my pants over stuff like glomerular filtration rate and counter current multiplication.) Then a week from today the class will be over and I have sweet delicious freedom until the middle of September. Well, sweet delicious semi-freedom since Advisor has a project he wants me to work on, but at least I get to set my own schedule and I don't have to wake up at 7am every day if I don't want to. Small victories, right?

I'm feeling better today, but not any more productive than yesterday. Oh well, there's always the weekend. I feel like I write better on the weekend anyway.

Cool stuff from the interwebs:

- Isis teaches us that veins are squishy.
- Mo at Neurophilosophy tells us that by deleting a single gene, researchers can make female mice exhibit masculine behaviors and try to mate with other females. She adds a caveat that this probably has little to nothing to do with human sexuality.
- GrrlScientist alludes to changes that may be afoot regarding ScienceBlogs.

Random sick day crap. Also gas exchange.

Other people blog about stuff I've blogged about. Imagine that.

- Neuroskeptic tackles the issue of autism and wealth.
- Allison at Dormivigilia blogs about referee bias in soccer.

I also discovered a very useful blog today called Better Posters. It is all about how to make better scientific posters, and surprisingly active considering the subject. How much can there possibly be to say about how to make a poster? Apparently a lot.

I've been way too unproductive today. I took a sick day off work because I had a rough night last night and a rough morning this morning, so I've been sitting around all day eating soup, reading Calvin and Hobbes (mom got me the collector's edition for my birthday, holy crap), and napping. I have a general feeling of malaise but no real symptoms aside from a sore throat and meh stomach (not exactly nauseated, but upset in some way I can't articulate), so hopefully this is just a funk and it'll go away by tomorrow. I'm hoping it is just stress and anxiety (possibly related to the pressure to churn out my manuscript, perhaps?) and not any kind of actual illness.

I missed lecture today on one of my favorite subjects to think about but one of my least favorite subjects to try to explain to students: gas exchange.

Source.

No matter HOW many times I try to explain the oxyhemoglobin dissociation curve, most of my students just don't get it. It's a pretty abstract idea that can be hard to absorb for a lot of students, especially when they only have the minimum prerequisites of 5 credit hours of biology or chemistry in order to take this class. To put it very simply, hemoglobin binds to oxygen when the partial pressure of oxygen is high (such as in the lungs) and kicks off oxygen when the PP of oxygen is low (such as in tissues that are actively doing work). I don't know what makes this so hard to grasp. If I were a better teacher I'd probably be able to communicate it in a more intuitive way. Fortunately I don't aspire to be a teacher after grad school.

Weird things professors do.

I got my thesis proposal back from my advisor this morning, and I've spent most of the afternoon going over his comments and making revisions while K and his friend kill aliens on the couch next to me. Friend brought over his PS3, and K is enjoying his last week of freedom before he starts his first Real World Job. It is somewhat distracting, but I'm surprised at how much work I've actually gotten done.

Advisor doesn't think I need to change anything major, and that it is "almost ready for [my] committee". This is good news, but the best part about reading my advisor's manuscript revisions is the way he chooses to get his point across.

For example, in one sentence I was explaining that there was genetic divergence between populations of my study species in the USA and Desert Country. I figured that the reader would know that it was genetic divergence for the expression of 'protein channels', seeing as how that's what my whole thesis is about, but his comment was, "for what???? beak length??? what?" hahahahaha. Okay, I get his point, I should be clearer as to what I'm talking about.

In other news, this morning CB (the professor who teaches the human physio class I TA) was talking to the class about, I don't know, blood pressure or something, and my attention went off to space for a moment. When I came back to the present, CB had adopted an Arnold Schwarzenegger accent and was talking about how she couldn't touch her nose because of all of her muscles. I still have no idea what point she was illustrating with that, but man, that was fucking surreal.

Stuff I liked today:

- Afarensis has a nice post up explaining how the genus Homo and extinct hominids can be distinguished from other living apes AND how living primates (including humans) can be distinguished from extinct hominids by examining critical points on the proximal femur bone.

Vanity and links.

I received a very nice email today from an author on one of the papers I've blogged about this week. It was a bit shocking to me, though, as I had no idea that some authors actually take the time to look up the people who talk about their papers on the blogosphere. I suppose I should think of it as if it were me, in which case my vanity would certainly get the best of me.

My dear little blog is getting a disproportionate amount of hits today because of my post on differentiating between the use of 'sex' and 'gender' as terms in physiological studies. Probably not a lot of hits in the scheme of things, but oh man, you should see the disparity on my unique visitors graph.

Anyway, enough about me. Here are some things I enjoyed reading today:

- Scicurious posts on stress resilience in mice.
- Bora posted a graph comparing hits on seed.com and scienceblogs.com and includes a linkfest to all the posts on Sb about Pepsigate, an issue I've been following intently but have no very strong opinions on.
- I have discovered a wonderful new-to-me blog called Statistical Modeling, Causal Inference, and Social Science. It is no secret that I adore statistics, although I often feel like I'm in over my head with it. I will be following this blog closely, as it seems right up my alley.
- Anyone here from researchblogging.com who also happens to be a current or new grad student should think about checking out Samia's zomg grad skool!!!1 carnival.

Mediating burn-induced gastric impairment with insulin treatment

I'm trying to think my way through some of the results in Mechanisms of burn-induced impairment in gastric slow waves and emptying in rats by Sallam et al. This article (like almost all of the articles I talk about on this blog) is outside of my subfield in physiology, so I'm trying to apply the little that I know about gastro and immune physiology in order to get this to make sense.

It is established that severe skin burns result in decreased gut motility and clearance, likely due to sympathetic nervous system and immune system pathways. Flesh wounds typically activate the fight or flight response, which floods the blood with glucose for readily-available energy and also decreases gut motility in order to reduce the amount of energy being used by areas of the body not involved in immediate survival. The immune system has similar effects via different pathways. The end result is a rise in blood glucose (hyperglycemia) that I would assume is used for energy to repair or rebuild the injured tissue, which is an energetically expensive process. These effects are supplemented by the effects of stress endocrines, which also act to increase blood glucose levels, and possibly growth endocrines as well (I don't know enough about the inflammation response to know if growth endocrines are responsible for the rebuilding of injured tissues, but I would imagine that they are). Additionally, when the skin barrier has been compromised, it would make sense to me that the body would want to be in a post-absorptive state, so that areas of the body not involved in repairing the injury site will run off of ketones and reduce the fuel available for pathogens that may get in through the compromised barrier.

What I gather from this is that in response to a severe skin burn, a) the body shuts (or slows) down the gastrointestinal tract in order to conserve energy for repair and to force the body into a post-absorptive state and b) various systems in the body act to induce hyperglycemia so that energy is readily available at the repair site.

Among many, many other things, the authors of this paper found that administering insulin to burned rats stabilized gastric motility and increased clearance. Introducing insulin into the system would clear glucose out of the blood and put it back into storage in the body, reducing hyperglycemia in the rats. The authors theorize that insulin also acts to potentiate the effects of stronger vasodilators like nitric oxide, which would then increase the blood flow to the gastrointestinal tract.

What does this mean for the patient? As I've mentioned, rebuilding issue is metabolically expensive, and recovering patients have high energy demands that often can't be met because eating is ineffective due to the symptoms outlined above. Patients may experience uncomfortable GI side effects such as ulcerations, bleeding, vomiting, and distention. Increasing gut motility and clearance by treatment with insulin after a severe cutaneous burn may ameliorate some of these symptoms and provide the patient with more energy for the healing process than would be available via other routes of administration.

However, I can't help wondering what effect this may have on healing. Do the energetic benefits of enteral feeding outweigh the energetic costs of running the GI tract at normal speed? And by not forcing the body to run on ketones, would it be more likely that pathogens could enter the body at a time when the immune system is compromised because most of the body's resources are being shunted towards repair? Unfortunately this study doesn't answer any of those questions, since the rats had to be killed in order to measure gastric clearance. I would like to see a future study that examines the treatments administered here and their effects on the healing process.

EDIT: The more I think about this paper, the more I wonder how dehydration is factoring into the equation. After a serious burn, often the skin permeability barrier is compromised, and patients lose water via evaporation rapidly through the wound. As a result, burn patients can quickly become dehydrated. I searched the methods to see if the authors were accounting for this, and I saw no evidence that they were. All they mention is that "[B]lood glucose level was measured preburn, 6 h after burn and 30 min after meal, using a commercially available glucometer." If the authors are not counting for dehydration and possible loss in blood volume because of that, the blood glucose level could appear to be higher when in fact the animal had a normal total amount of glucose in their blood.

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Sallam, H., Oliveira, H., Liu, S., & Chen, J. (2010). Mechanisms of Burn-induced Impairment in Gastric Slow Waves and Emptying in Rats AJP: Regulatory, Integrative and Comparative Physiology DOI: 10.1152/ajpregu.00135.2010