Repelling Mosquitoes. Or Not.

So all those gadgets and candles you use for getting rid of mosquitoes? Mostly worthless, it seems.

A large number of different spray-on repellents and wearable repellent devices are commercially available. The efficacies of many repellents are unknown. This study focuses on the efficacy of eleven different repellents in reducing the number of Ae. aegypti female mosquitoes attracted to human bait. We performed attraction-inhibition assays using a taxis cage in a wind tunnel setting. One person was placed upwind of the taxis cage and the mosquito movement towards or away from the person was recorded. The person was treated with various spray-on repellents or equipped with different mosquito repellent devices.

The most effective repellent was a DEET-based product. And least effective were devices which use high-frequency sound to keep mosquitoes away. Link found via ScienceMag.

Women in Science – Dr. Maud L. Menten

To start my Women in Science series, I’ll present information on a scientist with whom I share a birthday – Dr. Maud L. Menten, Biochemist from Canada. Born in Port Lambton, Ontario in 1879, Dr. Menten graduated from the University of Toronto in 1913 (some sources say 1911). 330px-Michaelis_Menten_S_P_E_ES.svgLater in 1913, she was an author for the article “Die Kinetik der Invertinwirkung” which introduced the Michaelis-Menten equation, used to relate the reaction rate of an enzyme to the concentration of a substrate.

The reaction rate increases with increasing substrate concentration [S], asymptotically approaching its maximum rate V_\max, attained when all enzyme is bound to substrate. It also follows that V_\max = k_\mathrm{cat} [E]_0, where [E]_0 is the initial enzyme concentration. k_\mathrm{cat}, the turnover number, is the maximum number of substrate molecules converted to product per enzyme molecule per second.

Her contributions to science continued long after the Michaelis-Menten equation. She made additional discoveries/co-discoveries relating to hemoglobin, blood sugar, and kidney functions. Because women were not generally able to work in the medical field in Canada at the time, she ended up working mainly in the US with some time spent in Europe, as well.

Dr. Menten continues to be honored today by the Dr. Maud L. Menten Memorial Lecture Series.

The Dr. Maud L. Menten Memorial Lecture Series is held annually by the Department of Biochemistry. Two mini-symposia and at least eight lectures will be held each year. The speakers are expected to be active, high-profile scientists and are nominated by the Department of Biochemistry research community. Invitations are sent after selection of the speakers by the Dr. Maud L. Menten Memorial Lecture Series Committee.

On Getting More Women in to Science

No, alas, I don’t have the magical solution to the question here – Why are there still so few women in science? physics conference photoJust sharing this New York Times article that goes into some depth on a look at this question. When you start with this:

“Last summer, researchers at Yale published a study proving that physicists, chemists and biologists are likely to view a young male scientist more favorably than a woman with the same qualifications. Presented with identical summaries of the accomplishments of two imaginary applicants, professors at six major research institutions were significantly more willing to offer the man a job.”

you know you’ve got quite a bit of ground to cover. Or at least, that’s how I viewed the article, and why I read the complete story. Written by a woman who started out studying physics, the article paints a picture of an institution that might not be putting enough effort into encouraging women, no matter how capable, to pursue their interests.

Mostly, though, I didn’t go on in physics because not a single professor — not even the adviser who supervised my senior thesis — encouraged me to go to graduate school. Certain this meant I wasn’t talented enough to succeed in physics, I left the rough draft of my senior thesis outside my adviser’s door and slunk away in shame.

Notice in the above image, there is only one woman in the picture – Marie Curie. Things have certainly improved since 1927, but we as a nation still have far fewer women contributing to the sciences than one might expect. So what is behind this? Is it just a lack of encouragement? Well, no, but that certainly plays into the problem. There’s also the issue of women leaving the workforce when they have children, but even that doesn’t make up the full problem. One additional factor is that women typically get lower salaries, fewer research dollars, less lab space, and poorer equipment.

But broader studies show that the perception of discrimination is often accompanied by a very real difference in the allotment of resources. In February 2012, the American Institute of Physics published a survey of 15,000 male and female physicists across 130 countries. In almost all cultures, the female scientists received less financing, lab space, office support and grants for equipment and travel, even after the researchers controlled for differences other than sex.

And then, let us look at the protrayal of women in science:

Although two of the scientists on the show are women, one, Bernadette, speaks in a voice so shrill it could shatter a test tube. When she was working her way toward a Ph.D. in microbiology, rather than working in a lab, as any real doctoral student would do, she waitressed with Penny. Mayim Bialik, the actress who plays Amy, a neurobiologist who becomes semiromantically involved with the childlike but brilliant physicist Sheldon, really does have a Ph.D. in neuroscience and is in no way the hideously dumpy woman she is presented as on the show.

No, there is not a solution in the article, although the story is well worth reading. And as I already noted, I don’t know the answer. But it is a fascinating question, and one that has led me to look into the issue of women in science more. Watch Little Bits of Science in the near future for articles about famous and not-so-famous female scientists and more discussion on this topic.

Photo by iharsten

Weekends on the Couch Add to Weight

In news that shouldn’t surprise anyone, scientists find that sitting around doing nothing on the weekends contributes to fat buildup in the body. What might be surprising to some is that this sedentary time is apparently worse for the body than a normal 9-5 weekday desk job.

Exercise scientists reported that even a 20-minute reduction in sedentary time on Saturdays and Sundays added up to a loss of more than 2 pounds and 1.6 percent of body fat after a year. But the same association was not seen with sedentary time during the weekdays.

So do your body a favor and spend at least some of your weekend time getting out of the house and doing something active, whether it’s a full workout at the gym, a long walk with your dog, or pretty much anything that raises your heart rate.

Anxiety and Differences in Perceptions

The following study looked important to me, as I suffer from a general anxiety disorder:

In a study of anxiety sufferers, scientists have learned that people with anxiety likely perceive the world differently. By a series of tests involving sound and financial gaming, scientists examined the perceptions and reactions of people with and without generalized anxiety. There findings suggest that those with anxiety are less able to differentiate between new stimuli than those without. Verbosely (with reference notes removed here):

Recent studies have suggested that overgeneralization can underlie anxiety disorders. OL_p2_Fig1_v1.3In this account, following formation of association between a stimulus and an aversive outcome, stimuli that are only somewhat similar to the original stimulus would still elicit increased anxiety in affected individuals. In an unsafe environment full of complex stimuli where the original stimulus is still dangerous, this is an extreme but rational strategy.

In practical terms, what happened was sounds were played, and a certain sound resulted in increased financial standings in a fictionalized economy. A different sound resulted in decreased financial standings. A third sound was standing neutral, with no increase or decrease associated. Later, outside the game, similar sounds were used, and those with anxiety had greater reactions to the sounds similar to those which were used within the game.

New Zealander Nigel Latta Blows Stuff Up

For a little more fun in science, we head to New Zealand, where Nigel Latta blows stuff up. The Science Learning Hub provides links to TV New Zealand, where, with a little proxy magic, you can watch this science aficionado do exactly what the title says he will.

Latta confesses, in pre-show publicity, a love for science and a fascination for many of the big questions it poses. He has two science degrees – a Bachelor of Science in Zoology and a Master of Science in Marine Science – and in this new series, he provides a fun and engaging gateway into the sciences.

EDIT: In case you can’t find a proxy to support viewing the NZTV videos, here’s a YouTube video showing a sample of Nigel’s work:

Budget Problems Could Lead to Berkeley College of Chemistry Shutdown

While emphasizing there are no firm plans in place yet, there is talk at Berkeley of shutting down the College of Chemistry in order to help with budget problems the school is facing. berkeley chemistry photoThere is also a petition by the student body to not do this.

The College of Chemistry was established in 1872. In the 20th century, researchers in the college at the Lawrence Berkeley National Laboratory discovered nine elements now on the periodic table. Today, the college is known as a pioneer in traditional and emerging fields of chemistry.

By Thursday evening, Melville’s petition, which addresses Chancellor Nicholas Dirks, had gained more than 1,800 signatures — more than the College of Chemistry’s undergraduate population.

Photo by martinhfp

Soccer Star Brandi Chastain to Donate Brain to Science

Hoping to help scientists better understand the effects of repeated head trauma, US soccer star Brandi Chastain has stated she will donate her brain to science.

“Hopefully, what can be learned is, can doctors and scientists and neuroscientists look at the brain of someone like me, who has been playing soccer a majority of my life, and really dissect the brain and say, ‘Here’s where we see it beginning?’ Could we then use that information to help say that before the age of 14, it’s not a good idea to head the ball?'” Chastain told USA Today.