Blue Jay

I got way too excited about seeing this little guy through my window today. I’ve lived in Columbus for 8 years, and somehow this is the first only the second time I’ve ever seen a Blue Jay here (I forgot about one time that I saw one 4 years ago). I wish the photos were better quality, but I had to use what I had on hand before he hopped away!

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Heat shock proteins keep mosquitoes fertile after they feed on you.

One of my committee members is an insect physiologist. I picked him for my committee because he’s an excellent physiologist who has experience with lipid chemistry. (He’s also an all around nice guy and a very successful scientist.) I took a photoperiodism seminar that he taught, and it was my favorite seminar class in graduate school. Despite all of this, my understanding of insect physiology is… almost nonexistent. I know a little bit about diapause from his seminar and a writing class that I took with one of his advisees, but that’s about it. I’d like to learn, and if I had another year or two of grad school ahead of me I’d probably take an insect physiology class. As a wise man once said, “If ‘if’s and ‘but’s were candies and nuts then we’d all have a Merry Christmas,” am I right?

Anyway, my point is that he has a paper in PNAS this week that I found really interesting, but you’ll have to forgive me if there are any physiological inaccuracies in this post. I claim responsibility for anything that’s wrong.


Aedes aegypti. Credit: Flickr user Sanofi Pasteur

It may not seem like it during this part of the year (in the northern hemisphere anyway), but most of the time, mosquitoes don’t drink blood. Males and females both drink nectar for their own survival; it is the propagation of the species that requires your blood. Female mosquitoes sometimes need to take a hot blood meal to get the required proteins and iron for making eggs. While necessary for reproduction, drinking mammalian blood has a lot of unique physiological challenges, not the least of which is the temperature difference.

At room temperature, the average human’s body temperature is about 15°C (almost 30°F) warmer than that of the average mosquito, and when a female takes a blood meal, her body temperature spikes 10°C in one minute! While ectotherms like mosquitoes are used to fluctuating body temperatures based on environmental conditions (such as the day/night cycle), these changes are usually gradual, allowing the mosquito ample time to alter their physiology. Hot blood meals impose the unique physiological problem of rapidly increasing body temperature without much time to adjust, which can cause enzymatic dysfunction and disrupt physiological pathways such as digestion, reproduction, and metabolism.

Obviously mosquitoes are not dying out because they are heat stressed and can’t reproduce (wouldn’t that be great?), so how are they getting around this problem? Heat shock proteins! Heat shock proteins can aid as enzymatic “chaperones”, making sure that the enzyme proteins stay folded in the proper conformation during times of physiological stress (not just heat but also extreme cold, lack of oxygen, infection, or exposure to toxins, among other things). Enzymes are a key player in digestion; they aid in the breakdown of proteins, fats, and carbohydrates, and the absorption of certain nutrients, so the mosquitoes definitely want to conserve their function right after taking a meal.

It turns out that female mosquitoes experience an 8-fold spike in heat shock protein expression in the midgut following a hot blood meal. When the mosquitoes were prevented from being able to express HSP70 (the heat shock protein active in these mosquitoes), the blood proteins from their meal stayed in the midgut longer, suggesting that digestion of blood proteins is somehow impaired. It is unclear whether this is due to a deficiency in breaking down the proteins or slower uptake of proteins and nutrients from the midgut, but the result is the same: the proteins are staying in the midgut longer instead of going into the body and aiding egg formation.

While heat shock proteins are not preferentially expressed in the ovaries after a hot blood meal, the mosquitoes prevented from expressing HSP70 also made fewer eggs than control mosquitoes, which provides further evidence that the delay of protein digestion and nutrient absorption is interfering with egg production. Since mosquitoes are vectors for many human diseases, research like this can be used towards initiatives to potentially limit the fecundity of mosquitoes (i.e. how rapidly they reproduce) and reduce human infection with diseases like yellow fever, malaria, and dengue fever.


ResearchBlogging.orgBenoit, J., Lopez-Martinez, G., Patrick, K., Phillips, Z., Krause, T., & Denlinger, D. (2011). Drinking a hot blood meal elicits a protective heat shock response in mosquitoes Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1105195108

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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.

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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?

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Total calorie intake is most influential in regulating adiponectin

Today I have a guest post over at the LabSpaces guest blog Dangerous Experiments. In that post I discuss a recent paper that examines the relative influence of total caloric intake, relative amount of dietary fat, and existing body fat on the circulating levels of an endocrine called adiponectin. Adiponectin is involved in energy homeostasis, specifically glucose uptake and the breakdown of fat, among other things. Hypoadiponectinemia (having too little adiponectin) is a risk factor for a lot of obesity-related diseases, like Type II Diabetes and metabolic syndrome.


ResearchBlogging.orgLiping Qiao, Bonggi Lee, Brice Kinney, Hyung sun Yoo, and Jianhua Shao (2011). Energy intake and adiponectin gene expression Am J Physiol Endocrinol Metab. DOI: 10.1152/ajpendo.00004.2011

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Ohio State University student body reacts to Osama Bin Laden’s death

Cross-posted at Brown Pundits.

Campus Parties After Bin Laden News” – NBC4 Columbus, OH [additional video coverage at link]

Within an hour of the announcement from President Obama that Osama Bin Laden had been killed, students and other young people began to gather at Mirror Lake on the OSU campus.

The traditional place for a rally prior to the annual Ohio State-Michigan football rivalry, Sunday night, it became a place of celebration.

Bin Laden is viewed as the planner behind the 9/11 attacks on the U.S. and a reason the U.S. has been fighting in Afghanistan for nearly 10 years.

Police gathered near the lake after the flag-waving group, estimated at 1,000, splashed in the water but were just a presence for safety rather than control, according to police.

The apparently spontaneous event continued after midnight.

More videos on YouTube here and here.

To be honest, I’ve never understood my students’ desire to celebrate things by jumping into Mirror Lake (really a man-made pond in the middle of campus). I didn’t even understand it when I was an undergrad here. I wonder how this kind of mass mob assembles spontaneously? I’m sure Facebook had a lot to do with it.

I don’t begrudge these students their catharsis. I doubt many of them know someone who died in the actual 9/11 attack, but I’m willing to bet that a good number of them have lost a friend or relative in the 10 years that followed. I lost an acquaintance from high school, and my youngest brother is in the Navy right now (he’s stationed at the same base as the Navy SEALs that carried out the operation).

However, watching several hundred (possibly a thousand) overwhelmingly white bodies assemble in a mob to celebrate the death of a brown man still leaves me a little uneasy, no matter how vile the individual was. I hope that in their celebration they were able to maintain some perspective and remember President Obama’s words, “We are not at war with Islam,” and the subtext beneath his words: we are not at war with brown-skinned people who have funny names. Like, you know, the President. Or my boyfriend. Or my future kids.

I like to believe the best in people and especially in my students. I hope my brown students were safe last night. I hope everyone was safe last night and in the times to come. That’s all.

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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.

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.

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