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Science Sunday #10

Posted by Don McLenaghen on August 21, 2011

– and on the seventh day we learn.
Each week I hope to give a synopsis of the interesting science stories I have heard on my plethora of science podcasts I listen to each week plus anything I pick up scanning the inter-web. This week’s top stories:

Words of the Week:

Haptic – Pertaining to the sense of touch or the branch of psychology that investigates cutaneous sense data.

Apoptosis – a type of cell death in which the cell uses specialized cellular machinery to kill itself; a cell suicide mechanism that enables metazoans to control cell number and eliminate cells that threaten the animal’s survival.

Stories:

 Boys Reach Sexual Maturity Younger and Younger –

Graphing puberty

Study shows that since the 18th century boys have been reaching puberty younger and younger. This is a trend that has been long acknowledged in girls because of the ability to observe first menstruation. Lacking the obvious sign, figuring out when boys reach puberty has been difficult.  Joshua Goldstein, director of the Max Planck Institute for Demographic Research in Rostock (MPIDR), has used mortality data for a way to measure puberty in boys. One of the odd side-effects of puberty in boys is something called the “Accident Hump”. When male hormone production during puberty reaches a maximum level the probability of dying jumps up. This phenomenon, called the “accident hump,” exists in almost all societies and is statistically well documented.

The accident hump, which also exists among male apes, occurs because young men participate in particularly risky behaviour when the release of the hormone testosterone reaches its maximum. Dangerous and reckless shows of strength, negligence, and a high propensity to violence lead to an increased number of fatal accidents. The probability remains low, but the rate jumps up considerably. This behaviours is also linked to mate selection pressures.

Science Daily

 Introducing the  Cognitive Computer Chip –

The chip has demonstrated the ability to play the game Pong and can also read written numbers 0 to 9. IBM Research-Zurich

A microchip with about as much brain power as a garden worm might not seem very impressive, compared with the blindingly fast chips in modern personal computers. But a new microchip made by researchers at IBM represents a landmark. Unlike an ordinary chip, it mimics the functioning of a biological brain—a feat that could open new possibilities in computation.

The cognitive chips are massively parallel microprocessors that consume very little power. But they also have a fundamentally different design. The two prototype semiconductor cores each has 256 neuron-like nodes. One core is linked to 262,144 synapse-like memory modules, while the other is linked to 65,536 such memory synapses. These cores are called “neurosynaptic core”.

Still, cognitive computing is still years away from the marketplace, and it will more likely complement than replace conventional computers. Even its champions who freely use the brain analogy do so with a sense of humility.

“We’re not trying to build a brain,” Mr. Modha (an I.B.M. researcher who is the project leader) said. “We’re trying draw inspiration from the brain.”

NY Times

Zeit News

 Earth & Moon may be younger than thought – 

New research using a technique that measures the isotopes of lead and neodymium in lunar crustal rocks shows that the moon and Earth may be millions of years younger than originally thought. The common estimate of the moon’s age is as old as 4.5 billion years old (roughly the same age as the solar system.

However, Lawrence Livermore National Laboratory scientist Lars Borg and international collaborators have analyzed three isotopic systems (lead, samarium and neodymium) in ancient lunar rocks, and determined that the moon could be much younger than originally estimated. In fact, its age may be 4.36 billion years old.

This implies the Earth is similarly as young because current theories hold the Moon was formed largely from Earthly material in a cosmic collision.

“If our analysis represents the age of the moon, then the Earth must be fairly young as well,” said Borg, a chemist. “This is in stark contrast to a planet like Mars, which is argued to have formed around 4.53 billion years ago. If the age we report is from one of the first formed lunar rocks, then the moon is about 165 million years younger than Mars and about 200 million years younger than large asteroids.”

Science Daily

Nature

Space.com

New Scientist

Science

 Welcome to phase space –

Curved Momentum Space

Physicist Lee Smolin at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, Canada, doesn’t think so. He and a trio of colleagues are aiming to take relativity to a whole new level, and they have space-time in their sights. They say we need to forget about the home Einstein invented for us: we live instead in a place called phase space.

So what is phase space? It is a curious eight-dimensional world that merges our familiar four dimensions of space and time and a four-dimensional world called momentum space.

Cartesian view of Momentum Space

Just as space-time can be pictured as a coordinate system with time on one axis and space – its three dimensions condensed to one – on the other axis, the same is true of momentum space. In this case energy is on one axis and momentum – which, like space, has three components – is on the other

Science News

New Scientist

 Benefits of the Open Source Software Market Identified – 

A forthcoming paper in Marketing Scienceby Columbia Business School Class of 1967 Associate Professor of Business, Brett Gordon, in collaboration with Vineet Kumar, Assistant Professor of Business Administration at Harvard Business School, and Kannan Srinivasan, Heinz College Professor of Management, Marketing and Information Systems at the Tepper School of Business at Carnegie Mellon University, finds that commercial open source software (COSS) results in high-quality products, and that despite the free-riding that is inherent in the industry due to information-sharing, the market creates spillover benefits for both consumers and producers.

Science Daily

New York Times

 Retraction Watch

 Duration channels mediate human time perception – 

Testing perceptions of time

We are very sensitive to subtle differences in the timing of the sounds in speech or music, and in visual stimuli and yet we know very little about how the brain times such short durations. Is there some sort of ticking clock, a metronome of the mind? Dr James Heron of Bradford University reports in the Proceedings of the Royal Society, evidence for neural time channels, tuned to respond to specific durations.

The task of deciding how long sensory events seem to last is one that the human nervous system appears to perform rapidly and, for sub-second intervals, seemingly without conscious effort. That these estimates can be performed within and between multiple sensory and motor domains suggest time perception forms one of the core, fundamental processes of our perception of the world around us. Given this significance, the current paucity in our understanding of how this process operates is surprising.

One candidate mechanism for duration perception posits that duration may be mediated via a system of duration-selective ‘channels’, which are differentially activated depending on the match between afferent duration information and the channels’ ‘preferred’ duration. However, this model awaits experimental validation.

This current study uses the technique of sensory adaptation, and presents data that are well described by banks of duration channels that are limited in their bandwidth, sensory-specific, and appear to operate at a relatively early stage of visual and auditory sensory processing. The results suggest that many of the computational principles the nervous system applies to coding visual spatial and auditory spectral information are common to its processing of temporal extent.

Material World

Proceedings of the Royal Society B

 Broad-Spectrum Antiviral Therapeutics – 

Scientists in the US say they have developed a new treatment that attacks the genetic code of viruses. In experiments they say they have successfully treated 15 different types of virus with the same method and this could in time produce a new drug with the ability to tackle nearly all viruses.

Currently there are relatively few antiviral therapeutics, and most which do exist are highly pathogen-specific or have other disadvantages. Sceintist have developed a new broad-spectrum antiviral approach, dubbed Double-stranded RNA (dsRNA) Activated Caspase Oligomerizer (DRACO) that selectively induces apoptosis in cells containing viral dsRNA, rapidly killing infected cells without harming uninfected cells.

So far they have created DRACOs and shown that they are nontoxic in 11 mammalian cell types and effective against 15 different viruses, including dengue flavivirus, Amapari and Tacaribe arenaviruses, Guama bunyavirus, and H1N1 influenza.

However, this is still only preliminary testing on cell cultures and rats. Time will tell if the side-effects and efficacy in humans can be better surmounted by this ‘miracle cure’ than previous contenders.

PloS One

Popular Science

Science In Action

 Institutional racism in awarding research grants?  – 

An NIH-backed study, published in the journal Science, found a 10 percentage point difference in the number of grants awarded to black researchers compared with white researchers with similar credentials. Blacks make up 10.2 percent of the U.S. population, but only 1.2 percent of the principal investigators of biomedical research studies are black.

They commissioned a study led by University of Kansas economics professor Donna Ginther. Ginther and colleagues from Discovery Logic, a unit of Thomson Reuters, and the NIH analyzed data from 2000 to 2006.

The raw data showed a 13 percentage point gap in the success rates between black and white applicants. It also showed a 4 percentage point gap in the success rates of white over Asian applicants. There were no apparent differences in success rates among Hispanic and white applicants.

The team next spent more than two years looking for possible explanations for the differences. Among black applicants, differences in education, country of origin, training, employer characteristics, previous research awards, and publication record accounted for 3 percentage points of the difference. But that still left a 10 percentage point spread.

Ginther said the findings suggest one of two possibilities. Either black applicants had not been afforded the same types of “cumulative advantages” as whites — including education but also mentoring or serving on an NIH grant review panel — or there was bias in the NIH grant review system.

When applicants send proposals to the NIH, they identify their race, ethnicity and gender, but this information is removed from the application before the materials are sent to review. Collins said it is possible that reviewers are able to guess the race or ethnicity of an applicant by looking at names or where they trained.

The NIH plans to start a program in which promising young researchers from underserved groups are invited to serve on more grant review panels.

Science Mag

The Economist

Slate

Science News

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