(PHOTO: Arahsae)

A Taiwanese study suggests that free-range eggs may contain many times the levels of toxins, such as the dioxins produced by burning trash, than regular eggs—and may therefore be unhealthier for us. The researchers’ explanation for this is that letting hens out of their cages gives them access to delicious soil, plants, worms, and insects that we have horribly polluted. What goes around comes around.

While this is interesting and important work, it’s a pity it’s been spun (at least in the press release, linked below) as a reason to be concerned about the safety of eating free-range eggs, rather than a story about how pervasive—and well traveled—these toxins are in urbanized Taiwan.

Here’s the press release, and here’s the full paper.

IMAGE: Darryl Cunningham

Get the full strip at Darryl’s blog.

PHOTO: Sonnet Ehlers.

According to Radio Netherlands, a South African doctor named Sonnet Ehlers is poised to distribute thousands of free anti-rape condoms to local women sometime in the next two months, before the start of the 2010 World Cup. The condom, which Ehlers calls Rape-aXe, can be inserted by a woman like a tampon; if she is then penetrated by an attacker, the condom attaches itself to his penis through “razor-sharp barbs” that don’t break the skin, but do cause excruciating pain if an attempt is made to remove the condom. The idea is that the would-be rapist will hurriedly extract himself and hie to the nearest hospital, where he will first be treated (since the barbs can only be detached by surgical means) and then arrested.

Talk about the myth of the toothed vagina coming to life. I’m all for anti-rape measures, but one has to wonder whether the safety of a woman is going to be enhanced by the act of enraging a rapist with tiny barbs sticking into his penis.

More on the Rape-aXe, which was first developed five years ago and looks almost too much like a medieval torture device to be real, here and here.

PHOTO: Mario D’Amore

An MIT neuroengineer has discovered a way to genetically modify neurons so that their activity can be temporarily silenced using specific colors of light. The technique, which so far has only been tried on mice, takes advantage of a protein (named Arch) which is expressed by the modified neurons when the animals are exposed to rays of yellow-green light. When the proteins are expressed, they pump protons across the cell membrane, alter the neuron’s voltage, and stop it from firing.

In theory, the discovery (which is strangely beautiful, even in the absence of practical applications) could someday be used to treat disorders, such as epilepsy, that are caused by the overactive firing of neurons in certain parts of the brain. It’s also an extraordinarily finely-tuned tool for safely and selectively turning off brain activity, so researchers can learn what different regions of the brain do.

For more, check out the MIT news release or the group’s website.

A new study of older adults and sex, released in the British Medical Journal, finds that men are more likely than women “to be sexually active, report a good quality sex life, and be interested in sex.” In addition, when it comes to being sexually active, women...don’t live as long.

When calculated from age 30, sexual life expectancy for men is nearly 35 years, while sexual life expectancy for women is closer to 31. Those numbers are fairly close, but there’s a key denominator difference - men, on average, die younger than women, leaving women with a greater percentage of their older years in a sexually inactive state.

But, most interestingly, long-term relationships tend to increase women’s sexual life expectancies.

...the gender gap of sexual activity virtually disappeared in those who were married or living with a partner. And in an endorsement of eating right and getting your exercise, health was strongly associated with sexuality in both midlife and later life (whether good health leads to sexuality or vice versa cannot be parsed from the data).

Thanks to the University of Chicago Medical Center’s blog, which I love, for the hat tip.

A new study of 19,567 Chinese subjects found that daily naps increased the risk of developing Type 2 diabetes from 13.5% (without naps) to 15.1% (with naps). In addition, there was some evidence that longer siestas raised the risk more than shorter snoozes.

According to the authors, napping in China is a social norm, which is practiced by all ages primarily as a habit started in childhood. In Western countries, napping is less common and is often unplanned and prompted by sleepiness likely caused by aging, deteriorating health status or nighttime complaints....The authors noted that the association between napping and diabetes was observed despite the fact that nappers had higher levels of physical activity, which has been shown to reduce the risk of diabetes.

Lead author Neil Thomas, PhD, reader in epidemiology at the University of Birmingham, U.K., said that additional research is needed to determine if napping itself plays a causative role in the development of type 2 diabetes, or if other factors are involved.

You can read the study abstract here.

(PHOTO: Addrox Karpenkopf.)

Japanese computer scientists are awesome, aren’t they? I mean, really. They’ve gone and made a program that can tell new parents if their baby is crying because it’s in pain, or just because.

The team has employed sound pattern recognition approach that uses a statistical analysis of the frequency of cries and the power function of the audio spectrum to classify different types of crying. They were then able to correlate the different recorded audio spectra with a baby’s emotional state as confirmed by the child’s parents. In their tests recordings of crying babies with a painful genetic disorder, were used to make differentiating between the babies’ pained cries and other types of crying more obvious. They achieved 100% success rate in a validation to classify pained cries and “normal” cries.

No word on whether the program can translate complex sentences, such as “Stop pinching my cheeks or I’ll bite you, lady!”

Via Eureka News.

From Proto magazine comes a nice round-up of the latest advances in restoring vision, including artificial retinas (like hearing aids for your eyes), gene therapy, and stem-cell treatments that may be able to regrow damaged retina cells.

The piece has a great opening line: “How many electrodes can fit on the back of an eye?” (Answer: In about five years, hopefully 1,000.)

PHOTO: Alice Rosen

Okay, it’s clear that scents contribute to our experience of flavor—that’s the reason strong-smelling food is the only kind you can taste when you’re stuffed up—but can flavor contribute to our experience of smell? How weird would that be?

Weird enough to be true, I guess. Brandeis neuroscientists recently had rats sniff and eat a particular kind of food while their taste cortex was knocked out (I love that researchers can just knock shit out like that. I’d like them to knock out my procrastination cortex). Then they reactivated the taste cortex and gave the rats the same food to sniff--but this time the animals didn’t recognize it, and were less likely to eat it. So the scientists knocked out the taste cortex again, and the rats went for the food. In other words, the taste and olfactory systems each seem to contribute a piece of sensory information that is combined in the brain to produce a unique...um...food stamp.

My favorite part of this study is that it relies heavily on rats wanting to sniff each other’s breath--the mechanism the scientists used to introduce the food odors. Seems rats, unlike people, love the whiffs of old lunch their peers produce.

PHOTO: Dolphin stomach infested with parasites, by Jeremy Sternberg

Delusional parasitosis is a rare and uncomfortable condition in which people come to be convinced—quite falsely—that they have been infested by parasites. There’s no single cause of delusional parasitosis; sometimes it arises as a manifestation of some underlying psychiatric disorder, such as schizophrenia, but in other cases it emerges in otherwise seemingly healthy, rational people.

I’ve just come across a fascinating case study of eight patients with DP in Singapore, notable because it contains detailed descriptions of the beliefs and behaviors inspired by the condition. One 65-year-old housewife complained of “threadlike worms dropping from pigeon droppings, then becoming insects which fly off from her hair.” She said she heard the noises made by the insects as they bit her, a sound like “tuck, tuck, tuck.” She poured kerosene on her head to try to kill them. A 60-year-old fruit seller saw “small, black, thorny parasites with 8 legs crawling in his skin,” which he believed had been caused by black magic directed at him by another seller in the market where he worked. This man was so tormented by his condition that he tried to hang himself three times.

You can read the entire article here.

(One final note: Many doctors contend delusional parasitosis is behind the strange symptoms reported by people who believe they have a controversial disorder known as Morgellons Disease. So far Morgellons has not been widely accepted as a real diagnosis in the medical community, but so many patients have complained about their terrible suffering, which purportedly includes the discovery of bizarre and unidentifiable fibers lodged beneath their skin, that the CDC recently launched an epidemiological study of it.)