Is Psychometric g a Myth? - "As an online discussion about IQ or general intelligence grows longer, the probability of someone linking to statistician Cosma Shalizi's essay
g, a Statistical Myth approaches 1. Usually the link is accompanied by an assertion to the effect that Shalizi offers a definitive refutation of the concept of general mental ability, or psychometric
g."
[more inside]
posted by kliuless
on Apr 11, 2013 -
113 comments
Science & the City is the public gateway to the New York Academy of Sciences. We publish a comprehensive calendar of public science events in New York City, host events featuring top scientists in their fields, and produce a weekly podcast covering cutting-edge science. Meanwhile, the American Museum of Natural History presents over 200 public programs each year including workshops, seminars, lectures, cultural events, and performances. Museum lectures are presented by scientists, authors, and researchers at the forefront of their fields. These engaging sessions often reveal the findings of the Museum's own cutting-edge research in genomics, paleontology, astrophysics, biodiversity, and evolutionary biology and complement the science behind the Museum's world-famous cultural and scientific halls and special exhibitions. Now many are available in podcast form. [more inside]
posted by Blasdelb
on Mar 26, 2013 -
3 comments
What do 3D printing, jelly, liver transplants, chainmail, dental fillings, ferrofluids, and the Six Million Dollar man have to tell us about our future? Materials scientist and engineer Mark Miodownik lets us know in
this Royal Institution lecture.
posted by cthuljew
on Mar 22, 2013 -
8 comments
Group selection, which was once widely rejected as a significant evolutionary force, is now accepted by all who seriously study the subject. There is still widespread confusion about group selection, however, not only among students and the general public, but among professional evolutionists who do not directly study the subject. We list eight criticisms that are frequently invoked against group selection, which can be permanently laid to rest based upon current knowledge. Experts will always find something to critique about group selection, as for any important subject, but these eight criticisms are not among them. Laying them to rest will enable authors to openly use the term group selection without being handicapped during the review process. [HTML],
[PDF]
posted by Blasdelb
on Jan 15, 2013 -
41 comments
Why You Won’t Be the Person You Expect to Be (NYT): "When we remember our past selves, they seem quite different. We know how much our personalities and tastes have changed over the years. But when we look ahead, somehow we expect ourselves to stay the same... They called this phenomenon the “end of history illusion,” in which people tend to “underestimate how much they will change in the future.”"
(via exp.lore) [more inside]
posted by flex
on Jan 6, 2013 -
34 comments
The Norovirus: A Study in Puked Perfection, "Each norovirus carries just nine protein-coding genes (you have about 20,000). Even with that skimpy genetic toolkit, noroviruses can break the locks on our cells, slip in, and hack our own DNA to make new noroviruses. The details of this invasion are sketchy, alas, because scientists haven’t figured out a good way to rear noroviruses in human cells in their labs. It’s not even clear exactly which type of cell they invade once they reach the gut. Regardless of the type, they clearly know how to exploit their hosts. Noroviruses come roaring out of the infected cells in vast numbers. And then they come roaring out of the body. Within a day of infection, noroviruses have rewired our digestive system so that stuff comes flying out from both ends."
[more inside]
posted by Blasdelb
on Jan 3, 2013 -
120 comments
Association of Coffee Drinking with Total and Cause-Specific Mortality [FULL TEXT HTML]: "We used data from a very large study,
the National Institutes of Health (NIH)–AARP Diet and Health Study (
ClinicalTrials.gov number, NCT00340015), to determine whether coffee consumption is associated with total or cause-specific mortality. The current analysis, involving more than 400,000 participants and 52,000 deaths, had ample power to detect even modest associations and allowed for subgroup analyses according to important baseline factors, including the presence or absence of adiposity and diabetes, as well as cigarette-smoking status."
[more inside]
posted by Blasdelb
on Dec 25, 2012 -
85 comments
One of the many problems farmers of various kinds of legumes need to deal with is the
pea aphid. They reproduce incredibly fast and live by sucking the sap out of the plants,
an electron micrograph of one in action. However, while they are terrifying parasites of legumes, they have their own yet more horrific parasites, a
parasitoid wasp.
Here is a really nice close up picture of one doing its thing,
a video of the act, and
here is a brain meltingly horrific video of a dissection of the mummified aftermath 8 days later. Essentially,
these wasps deposit their eggs in a pea aphid and the growing larva feeds on it, developing there for about a week, and then consuming the host from the inside out like a
Xenomorph. When it’s done, the wasp larva dries the aphid’s cuticle into a papery brittle shell and an adult wasp emerges from the aphid mummy. Legume farmers love them,
and you can even order their mummies online these days. However, farmers noticed that the wasps didn't work as effectively on all of the aphids, and so researchers went to work figuring out why. It turns out that all aphids have a
primary bacterial endosymbiont living inside their cells, in addition to and just like a mitochondria, and that many have some combination of five other secondary endosymbionts. Interestingly, two of those other five,
Hamiltonella defensa and
Serratia symbiotica have been shown to confer varying levels of resistance to the parasitoid wasp, allowing the aphid to survive infection. However, it turns out that there is yet one more layer to this story,
[more inside]
posted by Blasdelb
on Oct 22, 2012 -
50 comments
Mitigating Mutational Meltdown in Mammalian Mitochondria PLoS Biol 6(2): e35. [The PDF, where you can read the paper in its much prettier intended format.]Mitochondria are remarkable microorganisms. About two billion years ago, their distant free-living ancestors hooked up with a truly foreign lineage of archaebacteria and started a genomic merger that led to the most successful coevolved mutualism on the planet: the eukaryotic cell. Along the way, evolving mitochondria lost a lot of genomic baggage, entrusted their emerging hosts with their own replication, sorted out genomic conflicts by following maternal inheritance, and have mostly abstained from sex and recombination. What mitochondria did retain was a subset of genes that encode critical components of the electron transport chain and ATP synthesis enzymes that carry out oxidative phosphorylation. Because mitochondria house the biochemical machinery that requires us to breathe oxygen, it was first assumed that mitochondrial genes would show very slow rates of molecular evolution. So it was big news almost 30 years ago when mitochondrial DNA (mtDNA) evolution was observed to be quite rapid [1]. How could the genes for a highly conserved and critical function sustain the consequences of high mutation pressure and permit rapid rates of nucleotide substitution between species? Without the benefits of recombination, where offspring can carry fewer mutations than either parent, mutations should accumulate in mitochondrial genomes through the random loss of less-mutated genomes, a process referred to as Muller's ratchet [2,3]. How have mitochondria avoided a mutational meltdown, or at least significant declines in fitness?
Here is a jaw droppingly beautiful 3D animation of what Mitochindria look like in action.
[more inside]
posted by Blasdelb
on Oct 19, 2012 -
37 comments
Provirophages and transpovirons as the diverse mobilome of giant viruses Abstract: A distinct class of infectious agents, the virophages1 that infect giant viruses of the Mimiviridae family, has been recently described. Here we report the simultaneous discovery of a giant virus of Acanthamoeba polyphaga (Lentille virus) that contains an integrated genome2 of a virophage (Sputnik 2), and a member of a previously unknown class of mobile genetic elements3, the transpovirons4. The transpovirons are linear DNA elements of ∼7 kb [kilobases]5 that encompass six to eight protein-coding genes, two of which are homologous6 to virophage genes. Fluorescence7 in situ hybridization8 showed that the free form of the transpoviron replicates within the giant virus factory and accumulates in high copy numbers inside giant virus particles, Sputnik 2 particles, and amoeba cytoplasm. Analysis of deep-sequencing data showed that the virophage and the transpoviron can integrate9 in nearly any place in the chromosome of the giant virus host and that, although less frequently, the transpoviron can also be linked to the virophage chromosome. In addition, integrated fragments of transpoviron DNA were detected in several giant virus and Sputnik genomes. Analysis of 19 Mimivirus strains revealed three distinct transpovirons associated with three subgroups of Mimiviruses. The virophage, the transpoviron, and the previously identified self-splicing introns10 and inteins11 constitute the complex, interconnected mobilome12 of the giant viruses and are likely to substantially contribute to interviral gene transfer.
[
Full Text PDF] and
two explanations in English [more inside]
posted by Blasdelb
on Oct 16, 2012 -
28 comments
The drugs don't work : a modern medical scandal - "
The doctors prescribing the drugs don't know they don't do what they're meant to. Nor do their patients. The manufacturers know full well, but they're not telling."
posted by Gyan
on Sep 22, 2012 -
76 comments
Have you ever wondered what the water temperature off the Kamchatka Peninsula is? What about the wind speed in the Andaman Sea? Or maybe you’re losing sleep over the chlorophyll levels in the South Pacific. Fortunately, all of that information –- and 450 million other data points collected from oceanographic instruments around the world –- is freely and easily accessible thanks to the Marinexplore project. [more inside]
posted by Egg Shen
on Aug 28, 2012 -
3 comments
"
The Heretic: For decades, the U.S. government banned medical studies of the effects of LSD. But for one longtime, elite researcher, the promise of mind-blowing revelations was just too tempting."
[more inside]
posted by andoatnp
on Jul 30, 2012 -
113 comments
“[...] it took more than a dozen calls to work out the details of her zombie contagion. “After about the 17th time,” says McGuire, “I called and said, ‘If I did this, this, this, this, this, this and this, could I raise the dead?’ And got, ‘Don’t … don’t do that.’
And at that point, I knew I had a viable virus.”
posted by batmonkey
on Jun 27, 2012 -
70 comments
While
growth prospects
in the field are
incredibly high, recent trends, such as
"tools grow[ing] more advanced" (see
Adobe Flash Builder or
MS Visual Studio) have had people wondering over the past few years if computer science has much room for growth left.
Some question whether it is alive. Others,
such as Carnegie Mellon, say not so fast. In any case,
employment has been a bit iffy (
/.). There is the possibility that Computer Science
is simply growing up (PDF), then again
the U of Florida decided to say good bye to it this past week. But hey, if you are not going to that University, and still are shooting for computer science,
here are some tips.
posted by JoeXIII007
on Apr 23, 2012 -
57 comments
