Monday, March 28, 2005

Could similar facial features suppress attraction?

At BBC News, I find a short article with the title "Same face builds trust, not lust". The scientific study cited let students rate faces for trustworthiness and attractivity. They were shown pairs of faces where one of the faces had been altered to look more like the student's own face.

It turned out that the majority of the students rated the individuals similar to themselves as more trustworthy, but less sexually attractive. This result is taken to mean that "people steer clear of those who look like family to avoid inbreeding".


Not that people really used to know what they looked like (mirrors are quite new in the scheme of things). Thus, they should not really be (or at least have been) able to subconsciously conclude "like me = family". Of course, they could look at their own family and rate likeness _that_ way, I suppose. (Now I want to see a study where all the students are adopted and see if they react to their own facial features or those of their adoptive family)

And it has been proven somewhere (don't remember exactly where) that people do only look at a few facial features when they "classify" faces. All people do not necessarily look at the same features - that could skew the results of this test quite a bit if the researchers altered features that the testperson disregards.

And I also wonder if the testpersons were all heterosexual, and if the features altered were also altered to look more male if transferred from a woman to a man and vice versa. Otherwise, the testperson could decide that the women looked "unfeminine" or the men "unmanly" - which is generally considered to be a turnoff (partly rational, since it is tied to hormonal levels and such).

Tuesday, March 22, 2005

What I Will Do If I Ever Become Unnecessarily Rich

... and thus have money to spend on copyright fees.

(Go read today's Dilbert)

Love at First... Smell

Yes, I nicked the title from EurekAlert. It's a good title: researchers have investigated the impact of Major Histocompatibility Complex (MHC) types on attraction via smell, and showed that by mimicking the "right" MHC type with perfume, they could make previously unattractive males into irresistible"superhunks", judged by the behaviour of the females. (having the right combination of MHC:s from mum and dad will get you a better immune system, thus increasing your chance of survival) The research was conducted on fish, but since the mechanisms are believed to be the same for most vertebrates, it might be applicable to humans as well.

I clearly remember this being investigated before, also in humans, but do not really want to track down the references. I'm not sure that this will be very relevant in a real-life situtation for humans anyway, since we a) shower/wash very often b) wear all kinds of synthetic perfumes to cover up remaining olfactory emanations and c) tend to choose partners based on lots of other input besides smell anyway (try to explain people meeting each other and falling in love say, over Internet, with that they like each other's smell, or consider the reasons people dress up before going out).

The reason perfume companies will not really be jumping up and down with glee even if this turned out to be the single big factor? Well, that everybody is bound to need a different kind of coctail of MHC-mimicing chemicals to impress on someone, of course. "Please attach DNA sample of your love interest. Your personalized Attraction In A Bottle will arrive within six weeks" is not really that feasible. But it does give an interesting spin on those fairytales where you have to collect three strands of hair from your beloved for the witch to be able to concot a love potion. And come to think of it, old "folk wisdom" as snaring your intended with an apple that you have carried in your armpit for at least 24 hours (iick!) actually carries some weight, in the light of this.

Friday, March 18, 2005

Sometimes The Reporting Is More Interesting Than The News ...

... and the reporting following the sequencing of the X chromosome and a study on the inhibition of it (two articles in the latest number of Nature) is definitely one such case. Of course, the reported facts are basically correct - facts not reported, and the "filler text" in between is what I find interesting and/or amusing.

Probably very few people reporting on this have read the actual Nature article on the sequencing - it is definitely not a light read, and the figures do not help if you are not a geneticist already. Most of them - the people writing about this - probably read the Nature News entry (free) or the Nature News and Views entry (subscription), so most of the reporting covers X gene inhibition. There are also several news releases out from Reuters and such.

Let's begin with a list of links:
Nature News
Science Now
New Scientist
BBC News
MSNBC

Guardian Unlimited
FOX News
Washington Post
The Scientist
National Human Genome Research Institute

Most amusing so far was definitely Washington Post's Rick Weiss (probably not intentionally, or maybe he is so subtly ironic that I do not realize it) who found it important to cite David Page, interim director of the Whitehead Institute for Biomedical Research in Cambridge, Mass., who states that the X chromosome is not as "pink" as one might believe and that in fact, it can be considered rather "blue" since men also have one.

All men who have been afraid that they where tainted by "pinkness" may now take a collective deep breath in relief.

Weiss begins his article by stating that "She has been slow to reveal secrets, but the X chromosome has now bared it all". (What's with the reference to strip-tease?) Otherwise, it covers mostly the same ground as the other articles, with an interesting aside on how sex chromosomes first evolved in reptiles and gradually became X and Y.

Nature News' Erica Check focuses on the silencing of one of the two X chromosomes, a mechanism that ensures that women do not get "too much" of the expression of the genes found in X although they have double copies of it. The choice of which X to suppress is made, randomly, in the beginning of development. One of the two reports in Nature now shows that this suppression is not as effective as previous ly thought: at least 15% of the genes in the "inactive" X are expressed, in some women up to 25%. Thus, it is probable that women are more genetically varied than men, and that differences between women could be rather big due to this differential expression. (This is 200 to 300 genes we are talking about)

Genetically determined diseases on the X chromosome could thus have a different level of expression from woman to woman, but a binary expression in men. Science Now's Elizabeth Pennizi covers approximately the same issue, but in a much shorter text. New Scientist (David Bainbridge) has an excerpt of an article from their paper-version on the web that seems to mention the same things as well.

The Scientist's Stephen Pincock has written a surprisingly long article compared to how little of actual facts it contains, but is the only one so far I've seen citing Nature News and Views' (not to be confused with Nature News; subscription required) Chris Gunter (but then again, he cites rather many people in this piece).

If you want to read only one article, I recommend Nature News and Views (Chris Gunter), if you have a Nature subscription. It's detailed but accessibly written, covering both the X sequencing and X gene activation. She also mentiones something that I find especially intriguing: the amount of "escaping" genes is not static, but varies with age - more genes are expressed in the young than in the old.

If you want to read more about sequencing rather than X gene activation, Washington University has a nice news entry covering the problems, technical details and methods used in more detail.

Via Star Tribune I find something that I've been wondering but not yet bothered to calculate: the level of genetic difference between man and woman. It is 2%, according to Robert Lee Hotz, which would make it bigger than the often cited 1.6% difference between human and chimpanzee. Go figure. Duke University genetics expert Huntington Willard is cited as saying: "In essence, there is not one human genome, but two -- male and female."

And with a 200 to 300 genes possible difference between women, maybe you should not even talk about one female genome, but several. Given that many medicines are almost exclusively tested on men, this should be enough to give the medical companies gray hairs as they realise that in some cases, the right thing to do is having several test on women with differing genomes. Ouch, that would become expensive.

Thursday, March 17, 2005

What Price Authenticity?

This weeks Nature reports that Japanese delicacies may soon become more expensive, as officials as well as retailers are beginning to use genetic testing to ensure that products really are what their sellers claim. Just as with many European products, the area from which the product comes is considered important for the quality of the product and is often used in marketing. Testing of products such as crabs, seaweed and tofu is considered, according to the article.

Of course, this is only feasible if the difference really is genetic and not due to the local environment (for comparison, champagne is 'real champagne' because it comes from the right district, with a certain quality of soil, in France, the same kind of grapes may be grown in other places as well). To find genetic markers that indicate, with a very low level of doubt, that each product is "the real thing" can be come complicated, especially if accidental crossing or breeding has occurred previously. Personally, I would say that quality could depend at least as much on careful handling of your "product" as where it came from, but this will of course vary from case to case. If given the choice to eat of two genetically identical chickens, one reared with antibiotics and one without, would you say that the quality doesn't depend on the environment they were reared in?

Nature cites Yoshito Tsuya, an agricultural economist at Utsunomiya University, as saying that genetic testing may force up the price, but that customers will be prepared to pay more "to make sure they get the real thing". To what level of surety, one may ask? There is no such thing as 100% correctness in testing (especially if you put the testing in the hands of persons that may or may not be educated enough to perform it correctly), and would you be prepared to pay twice as much for something that has a, say, 10% chance to be generic despite its certificate?

But for someone who is not that scientifically literate, "approved by genetic testing" undoubtedly sounds impressive and reassuring. And it is bound to be great for marketing. Not to mention for the companies that develop and sell the testing kits.

If one must measure something as dodgy as "authenticity", why not use professional tasters or chemical analysis by something like mass spectroscopy (to measure the proportions of trace amounts of characteristic compounds)? Not that that may always work, either, if the similarities are too big. Which, of course leads to the question at the bottom of this: if something is, by all possible measurements, identical to something else - which one is the copy?

Tuesday, March 15, 2005

Fasting Reduces Risk Of Getting Cancer

It has been known for some time that having a calorie-restricted diet leads to a longer life. The down part used to be that the research that came up with this result advocated a restriction with as much as 33% of a total 'normal' diet - essentially a life of food deprivation. Now new research has shown that a reduction with as little as 5% may be almost as beneficial - if you eat intermittently (in this experiment, only three days a week). The key seems to be that the cells are made to replicate slower, which means that they get more time to repair damage to their DNA before they divide and that the likelihood to transfer damage to the next generation of cells thus is less.

But the thing that I find most interesting in this release is a chance remark by the author: " No doubt, one would be hard pressed to find people willing to embark on what amounts to a lifetime of food deprivation [...] ".

No, it would be rather easy. They are called fashion-conscious women and are often willing to go to rather extreme measures in order to ensure that they stay really, really thin - basically by eating less calories. It would be really interesting (not to mention ironic) if the crazed ideals of the fashion industry turned out to be efficient "medicine" against cancer.

But anyway, such extreme measures now seem not to be needed. A 5% reduction only amonts to 100 calories per day - equivalent to a slice of bread, or half of a candy bar. Maybe it will be easier to skip that late-night snack if you're not doing it for the beach season but for the increased chance of a healthy life without cancer.

The release, which I found through EurekAlert, is here.

Monday, March 14, 2005

One every 5.8 seconds

When "blogging" is mentioned in Italian Vogue - in an off-hand way, as if most readers can be expected to already know what is - you can definitely call it a wide-spread phenomenon. In fact, "blog" has been denoted word of the year for 2004, and according to a US think-tank a new blog is created every 5.8 seconds (according to BBC News, here).

Another side of the issue is that only 40% of all blogs are updated more than once every two months (I'd believe that once in a week is a minimum for keeping readers), and that some seem concerned that blog readers will only seek out blogs mirroring their own views. The first part is not really something I consider a problem, since there are so very many very good blogs in a variety of areas. Naturally, not every blogger-wannabe will be verbal enough or ego-centric enough to continue blogging when the first spate of enthusiasm wears off.

And all readers cannot be expected to want to continually challenge their worldview. The amount of scandalmongering newspapers and glossy magazines that flood the market should be proof of that, if nothing else. There is definitely already enough slanted reporting, enough that noone who wants to read unchallenging material will need to go dissapointed. (For an interesting parallel to this, I suggest you go and read "The Political Blogosphere and the 2004 U.S. Election: Divided They Blog" at http://www.blogpulse.com/papers/2005/AdamicGlanceBlogWWW.pdf . At least look at the nice illustration of linking patterns between liberal and conservative blogs, which is figure 1 in the paper)

What the blogosphere offers is something rather opposite: continuity. If you follow the blog of a normally prolific writer, you'll rather soon get to know their views on the subjects they cover. And if you know a person's views you can get a quite good feeling for when they manage to be objective and what they would leave out of an account. Just as you would be able to with a person you know in 'real life'. And, come to think of it, it's rather probable that you and you friends do not differ overly much in views on the things you consider important, so most of your input is biased anyway.

And the blogosphere also offers something else: the insight that no matter your quirks or special interests, there are people just like you (altough they may live a continent or two away). I would have valued that very much when I was a teenager growing up in a small town.

Saving the best for last, I am now off to read about the 2005 bloggie awards. Especially the "How to Learn Swedish in 1000 Difficult Lessons " sound interesting, it is always rewarding to make fun of your mother language. And having memes as a category is an inspired idea, but my favourite meme is still "Friday Cat Blogging" (found at, for instance, the excellent "Mouse Words"). Must be my cat abstinence speaking.

Thursday, March 10, 2005

Getting Closer to a Breast Cancer Vaccine

Actually, I would wish that someone either came up with a better term than "cancer vaccine" or bothered to broaden the definition of "vaccine" a bit. As it stands, vaccine is defined as "a preparation of weakened or killed pathogen of of a portion of the pathogen's structure". Together with the common definition of pathogen as "agent that causes disease, especially a living microorganism such as a bacterium, virus or fungus" (both definitions from Dictionary.com, but they could just as well have been picked from my school books some years ago), I can easily think of situations where publicity around cancer vaccines will lead to a rather large number of people getting the idea that cancer is contagious. But since "vaccine" is a nice short word that people tend to know and have a generally positive view of, I can understand the will to use it for publicity and as a pedagogic tool. Ah, well, maybe I am too pessimistic about the level of calm, level-headed reasoning and extent of knowledge in natural sciences of my fellow human beings...

And anyhow, this post is supposed to be about a nice news release I found at EurekAlert about progress towards a vaccine to immunize high-risk people against breast cancer. The efforts of the research group in question seem to be focused on the protein mammaglobin-A expressed at high levels by many breast cancer tumours. It also present normally and involved in breast development (but supposedly not at such high levels). The mechanism is that vaccine-primed immune cells type T ("T cells") attack cells expressing mammaglobin-A antigens, which leads to shrinking tumours. Clinical trials are planned.

Wednesday, March 09, 2005

Anti Heart Disease #3: Laughter Almost As Beneficial As Workout

Nature News and New Scientist both report on a study showing that laughter may be almost as good for cardiovascular health as stress is bad. Measurements on people watching 15-minute film clips of either "harrowing" or "comical" nature showed that stress decreased blood flow by an average of 35%, while laughter increased blood flow by 22%. The effects were due to constriction and relaxation of artery walls, respectively. The effect of stress was expected, but not the magnitude of the effect of laughter.

And watching a comedy or reading a funny book is bound to have less side effects than medication.

Anti Heart Disease #2: First Gene Turned On By Fatty Food Has Been Found

Science Now reports that American and Swedish researchers have found the first gene that really is turned on by a high-fat diet. The gene is implicated in hardening of arteries - atherosclerosis - and subsequent heart disease. Expression of the gene increases the amount of fatty substances in arteries. Further investigation in humans showed that individuals that suffer from atherosclerosis have a slightly different variant of this gene than those who don't, something that would make it possible to screen people for the disease-inducing gene and treat them before the disease is developed.

Anti Heart Disease #1: Why Fish Oil Is Good For You, Especially Combined With Aspirin

Fish oil has been shown to be effective against several diseases. Many of these diseases have chronic inflammation in common, and fish oil seems effective in suppressing the inflammation. Until recently, it was not known how. Nature News reports that researchers now have found a bit of the mechanism behind its anti-inflammatory properties: Omega-3 fatty acids become converted to lipids that seem to counter inflammation. The conversion becomes more effective if aspirin is added. Focusing on one of the lipids, resolvin E1, the researchers found that it inhibited migration of some human immune cells and reduced skin inflammation in rabbits. Work to prove that resolvin E1 really counteracts disease is now in progress, as well as investigation of the other lipids.

Tuesday, March 08, 2005

Husbands' Career Decides If Couples Relocate For Jobs

Although single, college-educated men and women both tend to move to big cities to increase the opportunity of finding a job, married college-educated women tend to do the same only if their husbands also hold a degree. This is the result of a recent study performed by economists at Washington University in St. Louis. They found that if the husband has a college degree a couple are more likely to move to a big city, regardless of the wife's degree and that the educational level of the woman thus has little or no influence on a couple's decision to relocate for career advancement.

So, the best career investment for a woman still seems to be to choose the right husband (or no husband at all). Depressing.

They May Be Able To Play Chess, But...

they suck at arm-wrestling, those robots. New Scientist reports that arm-wrestling robots have been beaten by a teenaged girl, 17-year old Panna Felsen (who was chosen for being weak and untrained, apparently). The robots were developed by three different teams who had chosen slightly different varieties of "muscle" for the arms. As the competition was meant to show, there is clearly a need for develpoment of better robot muscles...

Beer is the new green tea?

In a speculative but amusing article, Science News reports that beer may be anti-carcinogenic. Researchers from Okyama University tested the effect of beer (minus the alcohol) on mice that also were fed HCA:s, cooked meat carcinogens. The mice that were fed beer extract were much less likely to develop cancer (or, rather, DNA mutations that are precursors to cancer) than mice who did not get the extract.

The same group reported two years ago that anti-oxidants found in green tea combat the effect of HCA:s.

Friday, March 04, 2005

A Symphony of Tastes

A really interesting piece in Nature News about a professional musician, ES, who has an unusual form of synesthesia - she experiences different tone intervals as tastes. The article can be found here, if you are a Nature subscriber, but the most interesting part is the table in the news entry, listing the tastes corresponding to different intervals:

Minor second: Sour
Major second: Bitter
Minor third: Salty
Major third: Sweet
Fourth: Mown grass
Tritone: Disgust
Fifth: Pure water
Minor sixth: Cream
Major sixth: Low-fat cream
Minor seventh: Bitter
Major seventh: Sour
Octave: No taste

As Nature also notes, the "pleasant" intervals seem to correspond to "pleasant" tastes. What they really mean by pleasant is a little bit shady here (an educated musician will have had a rather large amount of learning and thus is likely to have somewhat different preferences compared to someone uneducated), but generally it is assumed to mean foremost the intervals making up minor/major chords (minor/major third + fifth). Sweet is definitely considered as "pleasant" even to a newborn, but how one views "salty" varies a bit. Biologically speaking, both are pleasant tastes, while sour and bitter are considered unpleasant.

I would really like to know what happens when she hears tones combined into chords, with two or more tone intervals at the same time. If no cross-combination effects occur, a major chord (a "happy"-sounding chord) would taste sweet and a minor chord (a "sorrowful"-sounding chord) would taste salty.

Interesting is also, that an octave (experienced as the "same" note as the ground note but lower or higher) has no taste, and that a major seventh - which has similar apparent "feeling" as a minor second - also is percieved as bitter. And it is incredibly funny that tritonus (one of the two intervals in the table that did not evoke a taste, but rather an experience) is percieved as "disgusting". It is a horrible interval for intonation and most musicians really dislike the sound of it as well.

UPDATE: New Scientist News has an entry about this as well, and cite ES's description of Bach as "particularly creamy"

UPDATE 2: At Sean A Dave's Synesthesia site, there is an interesting list of different kinds of synesthesia. You can also listen to the song "Synesthesia" by The Bobs.

Wednesday, March 02, 2005

Yet Another Reason to Like Liquorice

Liquorice - or rather glycyrrhizic acid (GA), one of its key components - could become useful in treating virulent diseases. Researchers at New York University, New York City, have managed to kill cells experiencing latent herpes infection by applying GA. Apparently, GA suppresses expression of a gene that is essential for the ability of the cell to support the virus. Since latency mechanisms are similar, it might work for other latent viral infections as well. (Via Science Magazine News )

The nice thing is, that GA is the compund that gives liquorice its sweet taste. So medication based on this could taste good, as well.