Lots of people are talking about this latest paper on HIV. It is an “open access” paper in the PNAS, and you can get it here.Human immunodeficiency virus (HIV) is a retrovirus that can cause AIDS (acquired immunodeficiency syndrome). It is a member of a larger group of viruses (the Smian immunodeficiency viruses) which are generally thought to be of African origin. There are two types of HIV (HIV-1, and HIV-2), with HIV-1 being the more virulent and, in human populations, most widespread.There are several theories as to the origin of HIV. When I was in Zaire in the mid 1980s, people in the cities were insisting that several Zairois had been brought to the US and infected with “Sida” (AIDS) and sent back t Zaire unaware of their condition to spread the disease. It has been suggested that HIV was accidentally included in polio vaccine. These and other ideas are highly unlikely, as it turns out. Continue reading HIV: Congo to Haiti to Pandemic
You roll your head, hoping to loosen the knots in your neck, and shut your eyes. After rubbing them you settle back into staring, hunched inches away from the computer screen. Despite the brief reprise your vision remains cloudy, causing the words on the monitor to blur. At this point, you need to know: With each further click on the keyboard, video watched on YouTube, and e-mail sent–are you damaging your vision?
The answer? It depends. Go here to find out.Thanks, Scott, for the tip.
When discussing global warming (and more broadly, climate change), especially here in the Great White North, it is often quipped that a little global warming is not necessarily a bad thing. So what if cold regions get warmer? That would be good for growing more food, having a warmer winter, and so on. Also, when we note the very large “natural” climate changes and contrast this with what is happening now, some people conclude that human-induced global warming is small change and therefore unimportant.There are two reasons why this is wrong. Continue reading Why is global warming important?
How the brain works … what it does, how it does it, and how well it does it … is a matter of how neurons are arranged in relation to each other, in circuits. But that is only part of the story. These neurons also need to function properly, and the connections between them need to function properly. For instance, it is thought that Einstein’s brain (he was a smart-guy, we assume) was not especially large, but it is though the had a somewhat better than average setup for keeping his neurons happy.A protein called postsynaptic density-95 (PSD-95) acts as a structural element around which other components of the synapse … the “connection” between two nerurons” is built. The more PSD-95 available, the better the connection, according to MIT researchers with a recent paper in Nature.It was already known that mice with an altered PDD95 gene … to produce an ineffective protein … had trouble with memory and learning.The newly reported research describes the molecular processes associated with the function of this protein. There could be real-life applications of this work. According to Morgan H. Sheng, Menicon Professor of Neuroscience at MIT’s Picower Institute for Learning and Memory:
“Adding a phosphate group to a single amino acid allows PSD-95 to promote synapse size and strength, … Therefore, promoting this process could help improve cognitive function.”
This will be in the November 8th Nature and is reported here as well.
Giraffa camelopardalis .. the tallest of all land animals.It is said that giraffes evolved a long neck in order to feed off the top of trees, avoiding competition with other browsing mammals. However, most leaves are actually eaten by insects who can get to these leaves as well as any other. Personally, I think the long neck is an adaptation to having very long legs. The long neck allows the giraffe to reach water without having to get too far down on the ground or lay on its side.
I’m sure you’ ve heard, but in case not: Not one, not two, not even three, but TEN new genomes were just released, bringing the total for fruit fly genomes to twelve species.These fruit flies diverged several tens of millions of years ago, which in the large picture, is kinda recent. This will allow a useful meso-time scale comparative study across diverging genomes trapped in somewhat less divergent phenotypes.We are now starting to see patterning in the fundamental nature of selection For instance, it is now possible to begin to estimate the relative rate of genetic change at the base-pair level that is accounted for by different kinds of selective forces, such as sexual selection, selection on the immune system, and so on, and to place this in the broader context of neutral process.A good place to start reading about this is here, at Nature News.
Bell Museum of Natural History EventsIn addition to the regular menu of science and culture programs, this month the Bell Museum will be hosting the second annual
Summary: Will “BBC” stand for Bill’s British Cuckolds”?; US Computer Users are blissfully ignorant, it turns out; List of Ten Most Addictive Games is out. Continue reading Technology News
Ten years ago, thirteen lucky lemurs were taken from Duke’s primate center and the Hogle Zoo in Salt Lake City, and other facilities, and let loose in their native lands in Madagascar.These were black and white ruffed lemurs, Varecia variegata variegata. They are rain forest dwellers native to Madagascar.Several were almost instantly eaten by predators, which is not at all surprising because the Predator IQ is pretty much determined by environmental factors in primates (as is intelligence in general). Of the original 13, three survive today.Lemurs being lemurs, there was also romance, and in the end there are now six or more offspring born of five of the original animals. Most of the offspring that were born in the wild were also eaten by predators, more than would have happened if they were born of wild primates, most likely. This is not surprising, since the ability to do complex thing in primates is not inherited genetically, but rather, passed on through cultural processes, and none of the original lemurs were savvy about predators.Hopefully as generations go by, the survival rate will go up, and if that happens fast enough, this group will not go extinct.The story is detailed, with more pictures and even sound files you can listen to, here at Duke’s site.