Get flash to fully experience Pearltrees
Computer tracking of tagged ants demonstrated that workers divided into three specialized groups — but often switched groups as they aged. Alessandro Crespi Because all the workers in an ant colony look the same, tracking their movements and interactions by eye is fiendishly difficult. Instead, Danielle Mersch and her colleagues tagged every single worker in entire colonies and used a computer to track them, accumulating what they say is the largest-ever data set on ant interactions. The biologists, based at the University of Lausanne in Switzerland, have found that the workers fall into three social groups that perform different roles: nursing the queen and young; cleaning the colony; and foraging for food.
At what age do children develop a fascination with animals? A brand new paper by Vanessa LoBue et al investigates young children’s interest in live animals. A set of three studies looked at young children in a naturalistic play environment in which they could choose to interact with animals or toys. The animals were always in an enclosure, so the children could only look at them and not physically touch them. One obvious difference between animals and toys is that the animals move. It would be very difficult to control for this, so for the purposes of this research animals were chosen that did not move much.
Sifakas (singular "sifaka"; i / ʃ ɪ ˈ f ɑː k / ; Malagasy pronunciation: [ˈsifakə̥] ( listen ) ) are a genus ( Propithecus ) of lemur from the family Indriidae within the order Primates . Their name of the family is an onomatopoeia of their characteristic "shi-fak" alarm call. [ citation needed ] Like all lemurs , they are found only on the island of Madagascar . All species of sifakas are threatened , ranging from vulnerable to critically endangered . [ 2 ] Sifakas are medium sized indrids with a head and body length of 40 to 55 centimetres (16 to 22 in) and a weight of 3 to 6 kilograms (6.6 to 13 lb).
In 1953, Cambridge researchers Watson and Crick published a paper describing the interweaving 'double helix' DNA structure - the chemical code for all life. Now, in the year of that scientific landmark's 60th Anniversary, Cambridge researchers have published a paper proving that four-stranded 'quadruple helix' DNA structures - known as G-quadruplexes - also exist within the human genome. They form in regions of DNA that are rich in the building block guanine, usually abbreviated to 'G'. The findings mark the culmination of over 10 years investigation by scientists to show these complex structures in vivo - in living human cells - working from the hypothetical, through computational modelling to synthetic lab experiments and finally the identification in human cancer cells using fluorescent biomarkers.
Zoologger is our weekly column highlighting extraordinary animals – and occasionally other organisms – from around the world Species: Ambystoma maculatum Habitat: Throughout the eastern USA and parts of southern Canada , leaving other salamanders green with envy When you think about it, animals are weird.
Cabinet and the author regret that a previous version of this article omitted its sources. To readers who are interested in learning more about Calhoun's research, we highly recommend "Escaping the Laboratory: The Rodent Experiments of John B Calhoun and Their Cultural Influence" by Edmund Ramsden and Jon Adams, LSE Department of Economic History, 2008, to which this article is indebted. How do you design a utopia?
Aarathi Prasad: Scientists are making progress in techniques for reproducing life without sex Experiments show that sperm and eggs can be generated from male stem cells, she says People will have more choices about when and how to have children, Prasad says Prasad: Science could help free people from tough choices between work and family Editor's note: Aarathi Prasad is a London-based biologist and science writer and the author of " Like a Virgin: How Science is Redesigning the Rules of Sex". (CNN) -- Last year on the 50th anniversary of the creation of the contraceptive pill its inventor Carl Djerassi spoke of the coming dramatic changes to reproductive options -- of the technologies that will have just as big an impact on society in the 50 years to come.
As I have discussed in previous blog posts , a number of unusual sexual behaviors have been documented in human beings, from cutting a hole in one’s pants in order to masturbate easily in public to letting insects bite one’s genitals. However, humans aren’t the only ones with curious sexual proclivities—unusual behaviors also occur in the animal kingdom with some frequency. In this post, I’d like to share what is perhaps the most, um, interesting scientific study of animal sexuality I have ever come across. 1
The 7th amendment to the EU Cosmetics Directive prohibits to put animal-tested cosmetics on the market in Europe after 2013. In that context, the European Commission invited stakeholder bodies (industry, non-governmental organisations, EU Member States, and the Commission’s Scientific Committee on Consumer Safety) to identify scientific experts in five toxicological areas, i.e. toxicokinetics, repeated dose toxicity, carcinogenicity, skin sensitisation, and reproductive toxicity for which the Directive foresees that the 2013 deadline could be further extended in case alternative and validated methods would not be available in time. The selected experts were asked to analyse the status and prospects of alternative methods and to provide a scientifically sound estimate of the time necessary to achieve full replacement of animal testing.
About Fish That Change Sexes While most animals remain the same sex throughout their lifetimes, many types of fish can switch between sexes. These changes are usually... How to Tell the Gender of Clownfish What Animals Can Change Their Sex? How to Tell If a Python Is Male or Female; How to Tell the Difference Between...
__IMAGE_2 A parasite thought to be harmless and found in many people may actually be causing subtle changes in the brain, leading to suicide attempts. New research appearing in the August issue of The Journal of Clinical Psychiatry adds to the growing work linking an infection caused by the Toxoplasma gondii parasite to suicide attempts. Michigan State University's Lena Brundin was one of the lead researchers on the team. About 10-20 percent of people in the United States have Toxoplasma gondii , or T. gondii , in their bodies, but in most it was thought to lie dormant, said Brundin, an associate professor of experimental psychiatry in MSU's College of Human Medicine.
You can use the "Rendering Details" dialog box to change the settings for viewing this image. To change the color displayed for a channel, click on the color box at the right, which opens the "Choose Color" dialog box. You can choose the color using the interactive features at the top. Hex color codes can be input in the text box. Preset colors can be selected at the bottom.
The Green vine snake ( Ahaetulla nasuta ), is a slender green tree snake found in India , Sri Lanka , Bangladesh , Burma , Thailand , Cambodia and Vietnam . Not to be confused with Oxybelis fulgidus , which is found in Central and South America. [ edit ] Description The green vine snake is diurnal and mildly venomous . The reptile normally feeds on frogs and lizards using its binocular vision to hunt. They are slow moving, relying on camouflaging as a vine in foliage.
Sep 01 '04 (Updated Sep 10 '04) Write an essay on this topic. Popular Products in Books From $ 5 From $ 7
We present the first national DNA barcode resource that covers the native flowering plants and conifers for the nation of Wales (1143 species). Using the plant DNA barcode markers rbcL and matK , we have assembled 97.7% coverage for rbcL , 90.2% for matK , and a dual-locus barcode for 89.7% of the native Welsh flora. We have sampled multiple individuals for each species, resulting in 3304 rbcL and 2419 matK sequences. The majority of our samples (85%) are from DNA extracted from herbarium specimens. Recoverability of DNA barcodes is lower using herbarium specimens, compared to freshly collected material, mostly due to lower amplification success, but this is balanced by the increased efficiency of sampling species that have already been collected, identified, and verified by taxonomic experts.