Americans more likely than Japanese to focus on the goal rather than the process of actions

27 junio, 2013 Deja un comentario

Research published this month in the scientific journal Personality and Social Psychology Bulletin has uncovered a cultural variation in the way American and Japanese people describe everyday actions.

In their study, Yuri Miyamoto of the University of Wisconsin at Madison and her colleagues said their research “provided the first evidence of cultural differences in attention to goal versus process identification of an action at the individual and collective levels.”…>>>more

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Categorías:Uncategorized

Efficiency in photosynthesis is due to quantum mechanism

23 junio, 2013 Deja un comentario

The initial steps of photosynthesis comprise the absorption of sunlight by pigment-protein antenna complexes followed by rapid and highly efficient funneling of excitation energy to a reaction center. In these transport processes, signatures of unexpectedly long-lived coherences have emerged in two-dimensional ensemble spectra of various light-harvesting complexes. Here, we demonstrate ultrafast quantum coherent energy transfer within individual antenna complexes of a purple bacterium under physiological conditions. We find that quantum coherences between electronically coupled energy eigenstates persist at least 400 femtoseconds and that distinct energy-transfer pathways that change with time can be identified in each complex. Our data suggest that long-lived quantum coherence renders energy transfer in photosynthetic systems robust in the presence of disorder, which is a prerequisite for efficient light harvesting…>>>more

Categorías:Ecology, Nature, Physics

The new Ikea of the Cars!!!

23 junio, 2013 Deja un comentario
Categorías:Human

Scientists discover key signaling pathway that makes young neurons connect

23 junio, 2013 Deja un comentario

An astonishing discover about how neurons grow up:

euroscientists at The Scripps Research Institute (TSRI) have filled in a significant gap in the scientific understanding of how neurons mature, pointing to a better understanding of some developmental brain disorders.

In the new study, the researchers identified a molecular program that controls an essential step in the fast-growing brains of young mammals. The researchers found that this signaling pathway spurs the growth of neuronal output connections by a mechanism called “mitochondrial capture,” which has never been described before…>>>more

Categorías:Animals Models, Brain, Genetics

Big Science vs. Little Science: How Scientific Impact Scales with Funding

22 junio, 2013 Deja un comentario

Agencies that fund scientific research must choose: is it more effective to give large grants to a few elite researchers, or small grants to many researchers? Large grants would be more effective only if scientific impact increases as an accelerating function of grant size. Here, we examine the scientific impact of individual university-based researchers in three disciplines funded by the Natural Sciences and Engineering Research Council of Canada (NSERC). We considered four indices of scientific impact: numbers of articles published, numbers of citations to those articles, the most cited article, and the number of highly cited articles, each measured over a four-year period. We related these to the amount of NSERC funding received. Impact is positively, but only weakly, related to funding. Researchers who received additional funds from a second federal granting council, the Canadian Institutes for Health Research, were not more productive than those who received only NSERC funding. Impact was generally a decelerating function of funding. Impact per dollar was therefore lower for large grant-holders. This is inconsistent with the hypothesis that larger grants lead to larger discoveries. Further, the impact of researchers who received increases in funding did not predictably increase. We conclude that scientific impact (as reflected by publications) is only weakly limited by funding. We suggest that funding strategies that target diversity, rather than “excellence”, are likely to prove to be more productive…>>>more

Categorías:Uncategorized

Relativity behind mercury’s liquidity

22 junio, 2013 Deja un comentario

Why is mercury a liquid at room temperature? If you ask that question in a school classroom you will probably be told that relativity affects the orbitals of heavy metals, contracting them and changing how they bond. However, the first evidence that this explanation is correct has only just been published.

An international team led by Peter Schwerdtfegerof Massey University Auckland in New Zealand used quantum mechanics to make calculations of the heat capacity of the metal either including or excluding relativistic effects. They showed that if they ignored relativity when making their calculations, the predicted melting point of mercury was 82°C. But if they included relativistic effects their answer closely matched the experimental value of -39°C.

Relativity states that objects get heavier the faster they move. In atoms, the velocity of the innermost electrons is related to the nuclear charge. The larger the nucleus gets the greater the electrostatic attraction and the faster the electrons have to move to avoid falling into it. So, as you go down the periodic table these 1s electrons get faster and faster, and therefore heavier, causing the radius of the atom to shrink. This stabilises some orbitals, which also have a relativistic nature of their own, while destabilising others. This interplay means that for heavy elements like mercury and gold, the outer electrons are stabilised. In mercury’s case, instead of forming bonds between neighbouring mercury atoms, the electrons stay associated with their own nuclei, and weaker interatomic forces such as van der Waals bonds hold the atoms together…>>>more

Categorías:Physics

Nanoparticles control blood vessel growth

22 junio, 2013 Deja un comentario

Peptide-coated gold nanoparticles can be used to deliberately activate or inhibit the growth of blood vessels. This is the new finding from researchers at the University of Southampton in the UK who say that their experiments could be important for developing better cancer therapies using these materials…>>>more

Categorías:Health, Nano-technology