Monday, March 22, 2010

Arthropod Phylogeny

Arthropod relationships revealed by phylogenomic analysis of nuclear protein-coding sequences in Nature.
The evolutionary interrelationships of arthropods has long been a matter of dispute. A new phylogeny applies an arsenal of techniques to more than 41,000 base pairs of DNA from 75 arthropod species. The results support the idea that insects are land–living crustaceans, that crustaceans comprise a diverse assemblage of at last three distinct arthropod types, and that myriapods (millipedes and centipedes) comprise the closest relatives of this great 'pancrustacean' group

See also Surprising New Branches on Arthropod Family Tree
The the newly defined sister group to the Hexapoda (insects and related species) is the Xenocarida or strange shrimp some unusual recently discovered marine crustaceans. So insects are actually more closely related to some oddball marine crustaceans than other terrestrial arthropods such as spiders.

High Energy Cosmic Rays

Cosmic-ray theory unravels in Nature.
Astrophysicists ponder whether ultrahigh-energy particles really do come from the centre of galaxies

Could they be iron nuclei instead of protons?

Pregnant fathers selective abortion

Evolutionary biology: Pregnant fathers in charge in Nature.
Pipefish and related species provide rare examples of extreme male parental care. Controlled breeding experiments allow the resulting conflicts of interest between female, male and offspring to be explored

The Golden Ratio found in a magnet

Solid-state physics: Golden ratio seen in a magnet
The golden ratio — an exact 'magic' number often claimed to be observed when taking ratios of distances in ancient and modern architecture, sculpture and painting — has been spotted in a magnetic compound

Sterile Neutrinos

Hunt for the sterile neutrino heats up in Nature.
Neutrinos like to keep to themselves. These ghostly particles are so reluctant to interact with ordinary matter that billions zip harmlessly through each person every day, and it takes giant, specialized detectors to capture even a handful of them. Now astronomers are finding hints of an even more elusive type of neutrino, one so shy that it could never be detected directly: the sterile neutrino

Sunday, March 21, 2010

Fairness Behaviour Across Societies

Fairness in Modern Society in Science.
Experiments in psychology and economics have demonstrated that in industrialized societies all over the world, a substantial fraction of individuals will be fair in anonymous interactions and will punish unfairness (1, 2). However, it has not been clear whether this benevolent, prosocial behavior depends on innate human psychology or norms peculiar to industrialized societies. Henrich et al. explored the motivation for fairness in anonymous interactions across dramatically diverse societies and on page 1480 of this issue (3), they report that this behavior increases with the level of the society's market integration, measured as households' average percentage of calories that are purchased.

Controlling Turbulence

Controlling Turbulence in Science.
Pipes feature strongly in the infrastructure of everyday life, from domestic water pipes to oil and natural gas conduits. A primary consequence of the onset of turbulence in the fluid flowing through the pipes is the dramatically increased power required to pump stuff at the same rate. Thus, the incentives to understand and control the transition process are strong. However, more than 100 years after Osborne Reynolds's seminal experiments on the transition of flow through a pipe from a laminar (smooth) to a turbulent state, the exact physical mechanism that drives this phenomenon still vexes the fluid mechanics community. On page 1491 of this issue, Hof et al. (1) describe a mechanism that feeds energy into a turbulent flow system, allowing the onset of the transition to be manipulated and even the suppression of the turbulence

Is Depression Adaptive?

The bright side of being blue:
Depression as an adaptation for analyzing complex problems

by Paul W. Andrews and J. Anderson Thomson, Jr.
Depression ranks as the primary emotional condition for which help is sought. Depressed people often have severe, complex problems, and rumination is a common feature. Depressed people often believe that their ruminations give them insight into their problems, but clinicians often view depressive rumination as pathological because it is difficult to disrupt and interferes with the ability to concentrate on other things. Abundant evidence indicates that depressive rumination involves the analysis of episode-related problems. Because analysis is time consuming and requires sustained processing, disruption would interfere with problem-solving. The analytical rumination (AR) hypothesis proposes that depression is an adaptation that evolved as a response to complex problems and whose function is to minimize disruption of rumination and sustain analysis of complex problems. It accomplishes this by giving episode-related problems priority access to limited processing resources, by reducing the desire to engage in distracting activities (anhedonia), and by producing psychomotor changes that reduce exposure to distracting stimuli. Because processing resources are limited, the inability to concentrate on other things is a tradeoff that must be made to sustain analysis of the triggering problem. The analytical rumination hypothesis is supported by evidence from many levels, including genes, neurotransmitters and their receptors, neurophysiology, neuroanatomy, neuroenergetics, pharmacology, cognition and behavior, and the efficacy of treatments. In addition, we address and provide explanations for puzzling findings in the cognitive and behavioral genetics literatures on depression. In the process, we challenge the belief that serotonin transmission is low in depression. Finally, we discuss implications of the hypothesis for understanding and treating depression.

see also Depression’s Upside in the New York Times.

Friday, March 19, 2010

First Clay Mathematics Prize Awarded

The First Clay Mathematic Prize was awarded to Grigoriy Perelman for solving the Poincare Conjecture.


Too Big to Fail by Andrew Ross Sorkin a dense account of the 2008 financial crisis.
Drive by Daniel H. Pink, about research into human motivation.
Lanark by Alasdair Gray, a Kafkasque novel.
Empire of Illusion by Chris Hedges, a polemic against corporations and popular culture which I would not recommend.
Shop Class as Soulcraft: An Inquiry Into the Value of Work by Matthew B. Crawford a charming book celebrating manual work and craftsmanship.

Saturday, March 13, 2010

Happy Baby on the Silver Bank

photos by Mike Murphy

Dancers on the Silver Bank

photos by Mike Murphy
The humpback whale courtship display is one of the most spectacular in nature. The female is almost always the active one (the "dancer" or "valentine") while the male watches passively - a reversal of the usual norm in the animal kingdom. Occasionally the male begins to join in, which started to happen at the end of the this encounter on the Silver Bank two weeks ago, but I don't believe we got a picture of that part alas.