• http://www.pourlascience.fr/ewb_pages/a/actualite-l-amour-est-dans-le-poil-31304.php

    Messieurs, faut-il vous laisser pousser la barbe pour être plus séduisant ? Une étude américaine suggère que les femmes trouvent plus attirant un homme avec une bonne barbe de trois jours, mais pas une petite barbe de trois jours - plutôt un début de toison plus proche d’une semaine -, pensez à Ben Affleck dans Argo, récemment couronné aux Oscars.

    Certains pourront pousser l’expérience jusqu’à la vraie barbe, selon leurs objectifs : lorsqu’il s’agit d’un flirt, les femmes sont plus attirées par une barbe de trois jours, et pour une relation durable avec enfants à la clé, elles semblent favoriser une barbe de Mathusalem. Les barbus, apparemment, sont considérés comme de bons candidats à la paternité, et les femmes y sont plus sensibles, d’après l’étude, lorsqu’elles sont en période de fertilité maximale, au milieu de leur cycle. A chacun sa barbe, à chacun ses amours.

    http://www.ehbonline.org/article/S1090-5138%2813%2900022-6/abstract

    The role of facial hair in women's perceptions of men's attractiveness, health, masculinity and parenting abilities

    Facial hair strongly influences people's judgments of men's socio-sexual attributes. However, the nature of these judgments is often contradictory. The levels of intermediate facial hair growth presented to raters and the stage of female raters' menstrual cycles might have influenced past findings. We quantified men's and women's judgments of attractiveness, health, masculinity and parenting abilities for photographs of men who were clean-shaven, lightly or heavily stubbled and fully bearded. We also tested the effect of the menstrual cycle and hormonal contraceptive use on women's ratings. Women judged faces with heavy stubble as most attractive and heavy beards, light stubble and clean-shaven faces as similarly less attractive. In contrast, men rated full beards and heavy stubble as most attractive, followed closely by clean-shaven and light stubble as least attractive. Men and women rated full beards highest for parenting ability and healthiness. Masculinity ratings increased linearly as facial hair increased, and this effect was more pronounced in women in the fertile phase of the menstrual cycle, although attractiveness ratings did not differ according to fertility. Our findings confirm that beardedness affects judgments of male socio-sexual attributes and suggest that an intermediate level of beardedness is most attractive while full-bearded men may be perceived as better fathers who could protect and invest in offspring.


    votre commentaire
  • http://www.larecherche.fr/actualite/cerveau/frappe-clavier-entraine-difficultes-a-lire-01-04-2013-99516

    L'utilisation fréquente des claviers d'ordinateur et de smartphone perturbe l'acquisition de la lecture chez les enfants chinois.

    A l'âge des ordinateurs, des smartphones et des tablettes, nous écrivons de moins en moins à la main. La plupart du temps, nous utilisons un clavier. Plusieurs études, dont une menée récemment par des chercheurs de l'université de Hongkong, suggèrent que cela pourrait avoir des conséquences sur notre capacité à lire [1].

    « Notre cerveau comprend deux circuits de lecture bien distincts, explique Stanislas Dehaene, du Collège de France. L'un permet de reconnaître la forme des lettres et leurs combinaisons, l'autre les gestes de l'écriture. Or, des travaux menés en 2012 dans mon laboratoire ont révélé que le circuit de l'écriture manuscrite nous aide à lire. De plus, l'équipe d'Édouard Gentaz, de l'université de Grenoble, a montré qu'apprendre à tracer les lettres facilite l'apprentissage de la lecture chez l'enfant. » L'abandon progressif de l'écriture manuscrite pourrait ainsi entraver la lecture et son apprentissage.

    Une hypothèse que confirment aujourd'hui Wai Ting Sio et ses collègues de l'université de Hongkong. Ces derniers se sont intéressés à une méthode de frappe sur clavier très utilisée en Chine, la méthode pinyin. Comme la langue chinoise comporte plusieurs milliers de caractères, les sinogrammes, il est impossible de concevoir un clavier où chaque touche correspondrait à un caractère. La méthode pinyin permet d'entrer ces caractères en passant par les lettres de l'alphabet latin. Par exemple, lorsque l'utilisateur veut écrire le mot chinois qui se prononce « li » et veut dire « poire », il frappe sur les touches « l » et « i » de son clavier. Apparaît alors une fenêtre proposant les sinogrammes qui se prononcent « li » (il existe de nombreux homophones en chinois) ; l'utilisateur n'a plus qu'à choisir le sinogramme souhaité.

    460

    En CM1, environ 30 % des élèves de Pékin et de Canton apprenant à lire avec la méthode pinyin ont deux ans de retard par rapport au niveau de lecture moyen à cet âge. Un chiffre qui augmente en CM2. Dans la ville de Jining, le nombre d'élèves avec des difficultés est plus élevé encore.

    Retard d'apprentissage

    Afin de savoir si cette technique a un impact sur l'apprentissage de la lecture, les chercheurs ont testé plus de 5 000 enfants fréquentant des écoles primaires de Pékin, de Canton et de Jining. Ces enfants étaient dans des classes équivalentes au CP, CM1 et CM2. Lors des tests, il leur était demandé de lire une liste de sinogrammes à voix haute, de la manière la plus exacte et la plus rapide possible.

    Or, plus de 28 % d'entre eux ont présenté des difficultés de lecture sévères : ils avaient deux ans de retard dans l'apprentissage de la lecture par rapport au niveau moyen des enfants de leur âge. Un taux beaucoup plus élevé que ceux rapportés par les précédentes études menées sur le sujet en Chine.

    Les chercheurs ont ensuite demandé à environ 700 de ces enfants de remplir un questionnaire sur leur usage quotidien de l'ordinateur et du smartphone, leur utilisation de la méthode pinyin, le temps passé à lire et à écrire à la main.

    Résultat : plus l'élève passait du temps devant son ordinateur ou son smartphone en utilisant la méthode pinyin, moins ses scores de lecture étaient bons. « Même si la relation de cause à effet n'est pas établie, la corrélation observée entre utilisation du clavier et difficultés de lecture est forte, estime Stanislas Dehaene. Et s'il n'est pas certain que les effets soient aussi délétères chez des enfants français, pour lesquels le clavier et le système d'écriture correspondent étroitement, ces résultats sont tout de même très préoccupants. »

    Par Jacques Abadie

    votre commentaire

  • http://www.youtube.com/watch?feature=player_embedded&v=7yNelyLCoMk#t=1s

    Image Copyright: The John Innes Center

    Professor Enrico Coen from the John Innes Centre (an independent research facility specializing in plant science and microbiology) has been awarded €2.5M EU funding to explore the growth and evolution of carnivorous plants. In speaking with research assistant Karen Lee, I am excited to learn more about both the scientific endeavors of the group, but also their plans for communicating about it. In addition to their main website, the ‘Inner Worlds’ project has a YouTube Channel, a Facebook page and a Twitter account to present their science to a wider audience.

    One of their first communication projects is a short film that was created using ‘optical projection tomography’, a microscopic technique that allows the viewer to ‘dive’ into the cavities of a carnivorous plant. The technology is among the latest developed to reveal the inner structure of organisms. According to Lee, the 3D views provided using this technique are vital to capturing the plants’ developmental process. The video provides a look at the inner workings of four different, vessel-shaped carnivorous plants that have evolved independently. If you view it while trying to channel your inner insect victim, you will see them as formidable death traps!

    It’s always encouraging to see such a commitment to both research and communication in a major research center. Kudos to the entire Coen lab!

     


    votre commentaire
  • http://blogs.scientificamerican.com/beautiful-minds/2013/04/03/can-you-smell-personality/


     

    First impressions matter. This may not come as much of a surprise, but just how quickly we form impressions, and which cues we use to make such rapid judgments may very much surprise you.

    Take the face. Superstar social psychologist Nalini Ambady (**see below) and her colleagues found that judgements of traits relating to power (competence, dominance, and facial maturity) based on photos of the faces of managing partners of America’s 100 top law firms predicted the law firms’ financial success. What’s more, these judgements demonstrated significant cross-cultural agreement, and were consistent across much of the lifespan (significant predictions were found based on judgements of their undergraduate yearbook pictures taken before they started their law careers).

    What about other cues? Research suggests that human body odor signals quite a bit of information, including sex, age, genetic compatibility, and female fertility status. Which raises the obvious question: Can you smell someone’s personality?! Recent research suggests you actually can (at least for some traits). Agnieszka Sorokowska and colleagues gave 30 women and 30 men 100% cotton white T-shirts (after washing them all in the same washing powder) and asked them to wear them for three consecutive nights on a scheduled weekend. All participants were single and slept alone during the weekend. During the daytime, the T-shirts were left wrapped in their bed linen and after three days the experimenters collected the shirts, placed them in sealed plastic bags, and froze them. Within a week of collecting the T-shirts, 100 men and 100 women each rated three men’s and three women’s thawed samples in non-transparent plastic bags in a closed, well-ventilated room. What did they find?

    The strongest relationships between self-assessed personality and judgements based on body odor were found for extraversion, neuroticism, and dominance. To put their findings in perspective, judgements of extraversion and neuroticism based on smell were about as accurate (and in some cases more accurate) than ratings based on videotaped behavior in prior studies. Not bad. Interestingly, ratings of dominance based on smell were only accurate when people were rating the smell of the opposite sex. According to the researchers, this suggests that “judgements of dominance based on body odour might be especially important in a mating context.” No effects of smell on personality were found for agreeableness, conscientiousness, and openness to experience.

    What explains these effects? The authors suggest that extraversion, neuroticism, and dominance may be related to physiological processes (hormones, enzymes, and neurotransmitters) that directly or indirectly influence body odor more than other personality traits. It’s also noteworthy that all three of these traits are particularly emotional dimensions of personality. It’s possible that fear, stress, and positive emotions are each related to the production of specific substances that influence body odor. For instance, maybe neurotics sweat a lot, and sweat has a particular smell.

    But there are other possibilities. Maybe extraverts smell different as a consequence of their behaviors (e.g., specific diet). Maybe people just form general impressions of personality based on pleasantness of body odor and that drives all of their judgements. Maybe there was less of an effect of agreeableness, conscientiousness, and openness to experience because an accurate judgement of these traits takes longer to accurately assess since they are based on much more than physical appearance and odor. Who knows? Only future research will be able tease these possibilities apart.

    Nevertheless, the findings are certainly intriguing, and suggest that a person’s face and smell are important cues that influence first impressions of personality. But what happens when face and smell cues are combined? To find out, Sorokowska recently conducted a follow up study in which she mixed together both cues. When people only rated body odor, their assessments agreed with the T-shirt donors’ self-assesments of neuroticism and dominance. Judges also stated that they associated neuroticism with an unpleasant smell. These findings are consistent with the earlier study.

    When people only rated facial pictures, however, there was no longer an effect of dominance and the strongest effects were for extraversion and neuroticism. Same story when both facial and smell cues were presented together. Interestingly, the faces and body odor of people scoring higher in dominance were perceived as less attractive. Since this finding is consistent with judgements based on faces alone and contrary to the ratings based solely on body odor, this suggests that ratings of attractiveness are more influenced by facial cues than by body odor. Indeed, prior research conducted in a real world setting found that sight was a better predictor of attractiveness than smell when women judged the attractiveness of men.

    So where does that leave us? As the researchers note, first impressions are based on the integration of multiple cues, and they are not always accurate. Nevertheless, these results do suggest that the combination of different cues has an effect on the person’s first impression. In particular, it seems that while people can accurately judge a person’s level of neuroticism based on their smell and face, adding a face to a person’s smell increases the accuracy of judging the person’s level of extraversion but decreases the accuracy of accurately judging the person’s level of dominance.

    Who knows, maybe someday they’ll sell Chanel “personality perfume” that you can dab on yourself before you go out so you can smell more confident!

    © 2013 Scott Barry Kaufman, All Rights Reserved

    Image by Steve Dressler.


    votre commentaire
  •  

    Just saying, “the pox” out loud sends a microbial shiver down the spine, given the tremendous amount of death and disease the poxviruses have wreaked on mankind. The scourge of perhaps the most notorious member of the poxvirus family, variola virus, which causes smallpox, extended across human history from the ancient Egyptian dynasty to the late 20th century.

    This continued until the widespread implementation of an overwhelmingly successful vaccine developed through the efforts of a certain gentleman scientist, Edward Jenner. He famously observed that milkmaids who came into contact with cowpox virus (a close cousin of variola virus) experienced a mild skin infection that protected them against smallpox. After inoculating other people with material scraped from the milkmaids’ eruptions, Jenner noted that they, too, became immune to smallpox.

    Nowadays, in a pleasant refinement from pustule scrapings, the smallpox vaccine contains a live version of vaccinia virus, a related but much milder poxvirus that looks and behaves enough like variola virus to trick the immune system into developing “smallpox” immunity.

    So, poxviruses, like vaccinia virus, can be tamed and moulded from old villains into useful tools to avert or treat human disease. This is particularly true for cancer. Since the mid-1800′s, natural virus infections, such as influenza, have been reported to cure cancer patients of their disease. Such testimonials helped to drive the modern development of poxviruses as anti-cancer agents, harnessing their natural preference to search out, infect and kill cancer tissue while shunning normal, healthy areas.

    For a poxvirus focused on replicating to produce lots of tiny virus offspring, tumour tissue is a surefire location for success: the mutations that allow cancer cells to grow so quickly also render them defenceless to viral attack. Typically, viral replication in tumour cells pops them open, disgorging their contents and releasing newly-hatched viruses to spread throughout the tumour, before being mopped up, neutralised and contained by the immune system. This approach can have brilliant results for some cancer patients, and poxvirus-based cancer treatments are now into advanced stage clinical trials.

    Recently, poxviruses have also been applied to address a long-standing problem affecting cancer patients undergoing tumour removal surgery. Particularly after long and complicated procedures, cancer patients naturally enter a bodywide state of repair, where most energy is diverted into the healing process. Perversely, this temporary disturbance in the natural biological balance actually encourages any missed bits of tumour to spread, causing new patches of disease to spring up. While the reason for this is not entirely understood, suppression of the normal immune response, in particular a specific population of immune cells known as, ‘natural killer’ cells, is at least part of the problem.

    A team at the University of Ottawa, led by surgical oncologist Dr. Rebecca Auer, reasoned that applying an engineered poxvirus an hour before surgery, which would home to the tumour and deploy immune-stimulating payloads, could restore the balance of the immune system. As they report in the journal, Cancer Research, this happily proved to be true: the virus kicked the apathetic natural killer cells into upping their game, reinvigorated the surgically-stunned immune system and, in mice at least, prevented the surgery-induced spread of tumour material. Poxviruses were therefore blended seamlessly into a normal surgical regime with excellent results.

    Since poxviruses have been so widely applied to humans in the smallpox vaccine, there is a huge amount of safety data to recommend their use in the clinic, and in the treatment of over 500 cancer patients, there have been no serious complications. Incorporating a naturally-adapted cancer-loving microorganism like poxvirus into the available arsenal of anti-cancer treatments is plainly a splendidly progressive choice.

    Image: Pox, by Sanofi Pasteur on Flickr

    http://blogs.scientificamerican.com/guest-blog/2013/02/15/fighting-cancer-with-poxviruses/


    votre commentaire


    Suivre le flux RSS des articles de cette rubrique
    Suivre le flux RSS des commentaires de cette rubrique