Selected readings 10 24 10

Interesting reading and news items.

Please leave some comments that indicate which articles you find most interesting or that identify topics you would like to read about, and I will try to include more articles of a similar nature in the future

These items are also bookmarked at my Diigo account.

The New Nu News!

There could be an extra, "sterile" neutrino out there, although cosmology places tight restrictions on that. There could be a fundamental difference between neutrinos and anti-neutrinos, which we dont (at present) understand at all. Or there could be some physics thats completely off the radar that explains this, but it looks like the good ol standard model (and the simplest modifications to it) is woefully inadequate to explain what were seeing. [Starts with a Bang, 9/27/10]

Primordial Magnetic Field May Permeate the Universe

Two physicists attempting to overcome some unexpected fuzziness in images of distant, supermassive black holes say they have found yet another potential big bang vestige: an extremely weak magnetic field that stretches across the universe. If scientists confirm the finding, it could help reveal the origins of magnetism in the cosmos. [ScienceNOW, 9/24/10]

The Itch of Curiosity

Curiosity is one of those personality traits that gets short scientific shrift. It strikes me as a really important mental habit - how many successful people are utterly incurious? - but its also extremely imprecise. What does it mean to be interested in seemingly irrelevant ideas? And how can we measure that interest? While weve analyzed raw intelligence to death - scientists are even beginning to unravel the anatomy of IQ - our curiosity about the world remains mostly a mystery. [Wired, 8/3/10]

The Personality Paradox

Theres an interesting new paper in Biological Psychiatry on the genetic variations underlying human personality. The study relied on a standard inventory of temperaments - novelty-seeking, harm avoidance, reward dependence and persistence - as measured in 5,117 Australian adults. What did the scientists find? Mostly nothing. The vast genetic search came up empty. [Wired, 8/9/10]

The Worm In Your Brain

So our cortex turns out to be a lot older than previously thought. The common ancestor of us and ragworms–a wormy creature that lived 600 million years ago–not only had a brain, but had an ur-cortex. And it probably used that ur-cortex to learn about its world–most likely learning about the odors it sniffed. That animal’s descendants diverged into different forms, and the ur-cortex changed along the way. Yet they still used many of the same genes their ancestor did long ago. [The Loom, 9/3/10]

Mapping the Brain on a Massive Scale

A massive new project to scan the brains of 1,200 volunteers could finally give scientists a picture of the neural architecture of the human brain and help them understand the causes of certain neurological and psychological diseases. The National Institutes of Health announced $40 million in funding this month for the five-year effort, dubbed the Human Connectome Project. Scientists will use new imaging technologies, some still under development, to create both structural and functional maps of the human brain. [Technology Review, 9/28/10]

Recipes For Limb Renewal

Bioengineers continue to refine prosthetic limbs, but they still can’t replicate the entire constellation of capabilities provided by flesh and blood. So a few determined scientists are pursuing a different solution: They are seeking the recipe for regrowing a missing limb. [Chemical & Engineering News, 8/2/10]

If low serotonin levels arent responsible for depression, what is?

While traditional antidepressants do increase neurogenesis and relieve depression symptoms in some animal models, others show that neurogenesis and antidepressant behaviours are unrelated. Much of this debate comes down to the fact that we dont yet have a real understanding of neurogenesis, how it works, and how it is controlled both in normal brains and in the presence of antidepressants. Until we know, finding a truly effective antidepressant may remain out of reach. So while the monoamine/serotonin hypothesis for depression may be out, neurogenesis needs to step it up a little to make it in. [guardian.co.uk, 9/28/10]

A New Way to Make Stem Cells

A Harvard researcher has developed a way to make pluripotent stem cells that solves several of the major impediments to using them to treat human diseases. Derrick Rossi, an assistant professor at Harvard Medical School, created pluripotent stem cells--which can turn into virtually any other type of cell in the body--from non-stem cells without using viruses to tinker with a cells genome, as conventional methods do. This means that Rossis method could be substantially safer for treating disease. [Technology Review, 10/1/10]

Alien World Tour: The Exoplanets Around Star Gliese 581

The announcement Wednesday (Sept. 29) of two newfound alien planets circling the star Gliese 581 adds to the nearby solar systems intrigue, further cementing its status as a top candidate to harbor extraterrestrial life. One of the two newly discovered planets, known as Gliese 581g, is a small, Earth-like world that likely lies within its stars habitable zone - the just-right range of distances that allow liquid water to exist. Astronomers have now detected six planets orbiting Gliese 581, the most known to circle any star beyond our own sun. [Space.com, 9/29/10]

If Theres Life on Alien Planet Gliese 581g, How Do We Find It?

After spending decades searching for alien planets capable of harboring life, astronomers may have found one. So how can they check to see if life actually exists on this alien world? ... One of the planets discoverers said in a briefing yesterday that "the chances of life on this planet are 100 percent." To determine if this is true, researchers will have to scrutinize Gliese 581g from afar, searching its atmosphere for certain telltale molecules. But it might be a while before they have the tools to do this properly. [Space.com, 9/30,10]

Astronomer Seeks ET Machines

If we ever do receive a message from outer space, we’ll want to know what kind of aliens sent it. SETI researcher Seth Shostak says we shouldn’t expect them to be anything like us – in fact, they might not be biological at all, but instead, extraterrestrial machines. [Astrobiology Magazine, 10/1/10]

The Gates of Immortality

Why do cells allow some mistakes to accumulate? If evolution is such a powerful process-one that finds solutions to all manner of problems-how could there be processes or problems that cant be fixed? [The Scientist, 10/1/10]

The One True Path?

Niswender and Galli are elucidating a molecular link between mental illness and problems with how the body processes sugars. That link is part of the complex series of events that make up the insulin-signaling pathway, a crucial mechanism by which the pancreatic hormone insulin directs the transport and storage of glucose in virtually every cell type in the body. This is only one of a recent rash of discoveries about how insulin is also intricately involved in many disease processes, including the growth of cancer cells and defects in bone mass regulation. [The Scientist, 10/1/10]

A new source of CP violation?

Abazov et al. report an unexpectedly large value of the same-sign dimuon charge asymmetry. This means that they see pairs of positive muons, μ+μ+, among the debris of their proton-antiproton collisions more often than they see pairs of negative muons, μ-μ-. The key point is that their measurement violates CP symmetry, which relates the behavior of matter and antimatter particles. [Physics, 8/16/10]

Hagfish Analysis Opens Major Gap in Tree of Life

Since the 1970s, many evolutionary biologists have considered an eel-like, deep-sea-dwelling creature called the hagfish to be the closest extant relative of a last common ancestor for all backboned creatures. That made the hagfish a stand-in for a transitional species between invertebrates and higher animals, spanning a leap as dramatic as any in evolutionary history. But a new family tree based on high-powered molecular analysis lumps hagfish together with lampreys, a jawless fish that’s primitive, but very much a vertebrate. [Wired, 10/19/10]

On a quest to map the brain’s hidden territory

On a recent morning, Wedeen pulled up images created with the new technology, in which the lakes of white were crisscrossed by colorful, ropy bundles of fibers, revealing an elegant, three-dimensional architecture. Looking more like art than anatomy, these strands form the connections in the brain — the “connectome.’’ They are neural highways crucial for brain function, including thoughts, movements, and sensations. [The Boston Globe, 10/11/10]

The origin of complex life – it was all about energy

According to a new hypothesis, put forward by Nick Lane and Bill Martin, we are all natural-born gas-guzzlers. Our very existence, and that of every animal, plant and fungus, depended on an ancient partnership, forged a few billion years ago, which gave our ancestors access to unparalleled supplies of energy and allowed them to escape from the shackles of simplicity. [Not Exactly Rocket Science, 10/20/10]

The Fuel Of Evolution

Within the cells of humans and all other modern creatures are lots of tiny mitochondria, which may have been the key to the evolution of complex multicellular life billions of years ago. [InsideScience.org, 10/22/10]

Geologists revisit the Great Oxygenation Event

Why did oxygen levels spike 2.5 billion years ago, and how much oxygen was there in the atmosphere really? Why are banded iron formations made of layers only a few centimeters thick, and why did they stop forming so abruptly? If the oceans were oxygenated 2.5 billion years ago, why did multicellular life delay its appearance for another 2 billion years? And did all these changes really take place at pretty much the same time everywhere on Earth? [Physorg.com, 8/19/10]

Mirror Mirror On The Wall

Every one of the four forces of Nature we know of - gravity, electromagnetism, the weak force, and the nuclear force - all originate from slight variations of this narrative. Gauge symmetries are the origins of all the forces of Nature. For example, gravity arises from a gauge symmetry in 3D: a sphere of a gauge with its hand pointing in any direction in the full three dimensional span of space. [Schrödingers Dog, 10/22/10]

Gravity Up Close

Scientists know how gravity works at big distances -- the inter-planetary or inter-stellar range -- but does it work the same way at the inter-atomic range? A variety of tabletop experiments are trying to explore this issue. Already some theorists say that a departure from conventional gravity behavior could hint at the existence of extra dimensions. [InsideScience.org, 10/13/10]

Cracks In The Universe

Physicists are hot on the trail of one of strangest theorized structures in the universe. A team of researchers have announced what they think are the first indirect observations of ancient cosmic strings, bizarre objects thought to have contributed to the arrangement of objects throughout the universe. [InsideScience.org, 10/11/10]

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Selected readings 2 19 10

Interesting reading and news items.

These items are also bookmarked at my Diigo account.

Searching ALL the Tevatron data for exotic physics

The majority of published particle physics papers involve looking for a very specific elementary particle process. They conclude by either showing that it exists or constraining limits on how often that process could possibly occur. But is there a way to take advantage of a collider’s whole data set and seeing if it is consistent with an expansive theoretical model, such as the Standard Model of particle physics? [Symmetry breaking, 2/13/10]

The Cosmological Constant and the Dark Sector

The dark sector refers to dark energy and dark matter, which are two distinct phenomena which seem to have no direct connection other than in name. In this post I am going to talk about the cosmological constant, dark energy, and look at some landmark literature on the subject. [The Astronomist, 2/7/10]

Physicists Solve Difficult Classical Problem with One Quantum Bit

Most research on quantum information systems has concentrated on models that use multiple quantum bits. In a new study, physicists have demonstrated how to solve a difficult classical problem that completely encapsulates a quantum model that requires only one quantum bit. The scientists, Gina Passante, et al., from the University of Waterloo in Ontario, Canada, have presented their experimental results for the quantum solution of the approximation of the Jones polynomial, which is a knot invariant. [Physorg.com, 1/8/10]

Quantum computer calculates exact energy of molecular hydrogen

In an important first for a promising new technology, scientists have used a quantum computer to calculate the precise energy of molecular hydrogen. This groundbreaking approach to molecular simulations could have profound implications not just for quantum chemistry, but also for a range of fields from cryptography to materials science. [Physorg.com, 1/10/10]

Warp-Speed Algebra: New Algorithm Does Algebra in a Snap

Quantum computers can do wondrous things: too bad they do not exist yet. That has not stopped physicists from devising new algorithms for the devices, which can calculate a lot faster than ordinary computers—in fact, exponentially faster, in quite a literal sense. Once quantum computers do become available, the algorithms could become a key part of applications that require number crunching, from engineering to video games. [Scientific American, 1/1/10]

Fermi telescope closes in on mystery of cosmic ray acceleration

The Large Area Telescope collaboration, led by KIPAC researchers Takaaki Tanaka, Uchiyama, and Hiroyasu Tajima, released the first image of a supernova remnant in the giga-electronvolt energy range (about 200 million times the energy of visible light). By revealing the spatial distribution of cosmic rays in the remnant, this result is a significant step toward definitively determining how cosmic rays are accelerated in supernova remnants. [Symmetry breaking, 1/7/10]

Do particle theorists have a blind spot?

Theorist Matthew Strassler from Rutgers University challenged particle theorists to not be too simple in their analyses. Most people would probably not claim that theoretical particle physics is too simple, but Strassler argued that nature is likely to be even more complicated than hpysicists expect. And if theorists only properly examine the simplest classes of models, where simple is a relative term, they might be led astray in interpreting future Large Hadron Collider data. [Symmetry breaking, 2/14/10]

How to Change A Skin Cell Into A Nerve Cell or Cellular Anarchy & The Great Leap Sideways

A team at Stanfords Institute for Stem Cell Biology & Regenerative Medicine, led by Marcus Wernig and graduate student Thomas Vierbuchen, recently announced that a combination of only three transcription factors that would change a skin cell into a nerve cell -- with no intermediate (undifferentiated) steps. [h+ Magazine, 2/7/10]

Imaging the Brain Better, Faster, Thinner

fMRIs a tool, an amazing one in a lot of ways, but like any tool it needs to be used well. Along with others, Ive criticized various aspects of recent fMRI practice, but only because its frustrating to see such a powerful tool not being used to its full potential. So I was very pleased by a recent paper by Sabatinelli et al, The Timing of Emotional Discrimination in Human Amygdala and Ventral Visual Cortex. The authors set out to test a hypothesis - that seeing an emotionally charged picture would activate the amygdala and the inferotemporal cortex (IT) before activating the extrastriate occipital cortex. [Neuroskeptic, 2/3/10]

Uncovering the Genetic Controls of Cellular Aging

A fascinating thing about DNA replication is that the actual process lacks the ability to replicate the very ends of chromosomes. That means chromosomes should get shorter with every round of cell division (DNA replication), but they remain more or less the same length, getting gradually shorter with aging. The natural shortening of chromosomes is refered to as cellular aging. So how do chromosomes maintain their ends if not by replication? [DNA Dude, 2/9/10]

Gods will and beliefs are your own, not gods

According to these results believers project their own values and beliefs on their god (or gods) to a great extent, which could certainly help explain not only the great diversity and variability of religious belief and expression, but also the ambiguous nature of religious interpretation. [Ego sum Daniel, 1/27/10]

Hunting Fossil Viruses in Human DNA

The borna virus is at once obscure and grotesque. It can infect mammals and birds, but scientists know little about its effects on its victims. ... The virus now turns out to have an intimate bond with every person on Earth. In the latest issue of Nature, a team of Japanese and American scientists report that the human genome contains borna virus genes. The virus infected our monkey-like ancestors 40 million years ago, and its genes have been passed down ever since. [New York Times, 1/11/10]

The Origin of the Future: Death by Mutation?

The evolutionary biologist Michael Lynch has published a provocative paper (to mark his inauguration into the National Academy of Sciences) in which he makes another kind of forecast. Our future evolution, he warns, is going to lead to a devastating decline in our health. [The Loom, 1/7/10]

Spiral Galaxies Exist — But Why?

Its a minor miracle (and a topic of considerable debate) how all the spirals we see today managed to endure all that mayhem unscathed. "The formation of spirals is a problem," admits Christopher Conselice, a galaxy specialist at the University of Nottingham. "We dont know how they formed, or how they survive all those mergers." [Sky & Telescope, 2/16/10]

WMAP Refines "Precision Cosmology"

Without much public notice, the team running the Wilkinson Microwave Anisotropy Probe (WMAP) recently released results from the satellites "seven-year data set," updating the five-year data released in 2008. ... The two more years of data have further beaten down the statistical uncertainties in the cosmic background map, allowing analysts to refine what it tells us about the cosmos as a whole. If the new, revised results didnt make much news, its because they show modern cosmology to be steady on course. The better data only firm up confidence in what we already thought we knew. [Sky & Telescope, 2/14/10]

Cell phone radiation may fight Alzheimers... in mice

The study examined the performance of mice that received a daily dose of radiation similar to that produced by cell phones, and found that, over a period of several months, their memory improved. When the same procedure was performed with mice engineered to be predisposed to Alzheimers pathology, it was actually able to reverse some of the cognitive decline. [Nobel Intent, 1/6/10]

Zinc Fingers Could Be Key to Reviving Gene Therapy

The technique, which depends on natural agents called zinc fingers, may revive the lagging fortunes of gene therapy because it overcomes the inability to insert new genes at a chosen site. Other researchers plan to use the zinc finger technique to provide genetic treatments for diseases like bubble-boy disease, hemophilia and sickle-cell anemia. [New York Times, 12/28/09]

Climate change: No hiding place?

The fact that no record high happened in the 2000s does not mean that there was no warming over the decade—trends at scales coarser than the annual continued to point upwards, and other authorities suggest there have been record years during the period. Nor was the length of time without an annual record exceptional. Models simulating centuries of warming normally have the occasional decade in which no rise in surface temperatures is observed. [The Economist, 1/7/10]

Induced Pluripotent Stem Cells Fall Short of Potential Found in Embryonic Version

The act of reprogramming cells to make them as capable as ones from embryos apparently can result in aberrant cells that age and die abnormally, suggesting there is a long way to go to prove such cells are really like embryonic stem cells and can find use in therapies. [Scientific American, 2/11/10]

Pop Goes the Pulsar

One of the challenges of astrophysics is interpreting what we observe. Here on Earth we can set up experiments to test phenomena, but when it comes to the cosmos all we can do is sit back and watch. Weve sent probes to the furthest regions of our solar system, but even that is just a tiny corner of the heavens. So how can we possibly know that there are galaxies light years away, or that the universe is billions of years old? The answer is that we take what we know about physics here and apply it to what we observe there. [Upon Reflection, 2/17/10]

Should Evolutionary Theory Evolve?

Some evolutionary biologists say that the body of knowledge concerning evolutionary processes has simply outgrown the confines of the Modern Synthesis, which was crafted before science had a strong grasp of genomics, molecular biology, developmental biology, and other, more recently derived disciplines, such as systems biology. [The Scientist, 1/1/10]

Violating Parity with Quarks and Gluons

Quarks and gluons interact in interesting ways, and in the many fluctuations that happen in these high-temperature collisions we can get “bubbles” that pick out a direction in space. In the presence of these bubbles, quarks treat left and right differently, even though they treat both directions exactly the same when they’re in empty space. [Cosmic Variance, 2/16/10]

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Selected reading 12 5 09

Interesting reading and news items.

These items are also bookmarked at my Diigo account.

Fuelling fears

There is an awesome amount of energy tied up in an atom of uranium. Because of that, projections of the price of nuclear power tend to focus on the cost of building the plant rather than that of fuelling it. But proponents of nuclear energy—who argue, correctly, that such plants emit little carbon dioxide—would do well to remember that, like coal and oil, uranium is a finite resource. [The Economist, 11/30/09]

The Coming Nuclear Crisis

The perception is that nuclear power is a carbon-free technology, that it breaks our reliance on oil and that it gives governments control over their own energy supply. That looks dangerously overoptimistic, says Michael Dittmar, from the Swiss Federal Institute of Technology in Zurich who publishes the final chapter of an impressive four-part analysis of the global nuclear industry on the arXiv today. [Technology Review: the physics asXiv blog, 11/17/09]

Henry Markram Calls the IBM Cat Scale Brain Simulation a Hoax

This is a mega public relations stunt - a clear case of scientific deception of the public. These simulations do not even come close to the complexity of an ant, let alone that of a cat. IBM allows Mohda to mislead the public into believing that they have simulated a brain with the complexity of a cat - sheer nonsense. [Next Big Future, 11/24/09]

I have a long post on the subject: here

Immune System vs. Cancer

The comeback of an old idea in immunology prompts a rethink of cancer progression and approaches to treatment. [The Scientist, 11/1/09]

There’s No Such Thing as a ‘Simple’ Organism

What may be the most thorough study ever of a single organism has produced a beta code for life’s essential subroutines, and shown that even the simplest creatures are more complex than scientists suspected. [Wired Science, 11/30/09]

Americans Eating Habits More Wasteful Than Ever

After their biggest meal of the year, Americans might reflect on the fate of those moldering Thanksgiving leftovers. Nearly 40% of the food supply in the United States goes to waste, according to a new study, and the problem has been getting worse. [ScienceNOW, 11/25/09]

A New Spin on Electronics

Some physicists aim to develop a whole new technology called "spintronics" that would encode information in the directions in which electrons spin as well. Those efforts could lead to ultra-low-power electronics and even futuristic quantum computers. Now, such technologies may be an important step closer to reality thanks to a group of researchers that has managed to polarize the spinning electrons in silicon, the most common commercial semiconductor. [ScienceNOW, 11/25/09]

First programmable quantum computer created

Using a few ultracold ions, intense lasers and some electrodes, researchers have built the first programmable quantum computer. The new system, described in a paper to be published in Nature Physics, flexed its versatility by performing 160 randomly chosen processing routines. [Science News, 11/23/09]

Membrane Awakening

The boundary of a living, metabolizing cell is surprisingly similar to that hedge. The cellular membrane, once thought to be an inert barrier, is one of the most dynamic parts of the cell. The membrane and the plethora of proteins that stud its surface direct the exchange of information between cells, tightly control the flow of materials from inside to outside the cell, and provide surfaces for some of lifes most vital chemical reactions. [HHMI Bulletin, 11/1/09]

Superior Super Earths

Astronomers have discovered hundreds of Jupiter-like planets in our galaxy. However, a handful of the planets found orbiting distant stars are more Earth-sized. This gives hope to astrobiologists, who think we are more likely to find life on rocky planets with liquid water. The rocky planets found so far are actually more massive than our own. Dimitar Sasselov, professor of astronomy at Harvard University, coined the term “Super-Earths” to reflect their mass rather than any superior qualities. But Sasselov says that these planets – which range from about 2 to 10 Earth masses – could be superior to the Earth when it comes to sustaining life. [Astrobiology Magazine, 11/30/09]

Nanoparticles for gene therapy improve

Nanoparticles, made of biodegradable polymers, offer a chance to overcome one of the biggest obstacles to realizing the promise of gene therapy: The viruses often used to carry genes into the body can endanger patients. Furthermore, the particles created at MIT now rival viruses’ efficiency at delivering their DNA payload. [MIT News, 11/6/09]

Cancer research gets into the groove

The out-of-control cell growth that defines cancer results from runaway growth genes activated by regulator proteins, known as transcription factors, that sit on DNA and turn genes on and off. Transcription factors are often mutated in cancer, but scientists have been largely unable to design or find drugs capable of blocking the proteins. A creative method of targeting these gene regulators has recently been applied to cancer by a multi-institutional collaboration of researchers. [Broad Institute, 11/12/09]

Building a second sun: Take $10 billion, add coconuts

The balmy south of France has always been a magnet for sun worshippers. So it is perhaps fitting that here, not far from the Côte dAzur, an international team of researchers is building a machine to recreate the sun. ... [An] eclectic mix of ingredients will be turned into ITER, the International Thermonuclear Experimental Reactor - the next big thing in nuclear fusion research. [New Scientist, 10/12/09]

Out of your head: Leaving the body behind

In the 15 years since that dramatic incident, Brugger and others have come a long way towards understanding out-of-body experiences. They have narrowed down the cause to malfunctions in a specific brain area and are now working out how these lead to the almost supernatural experience of leaving your own body and observing it from afar. They are also using out-of-body experiences to tackle a long-standing problem: how we create and maintain a sense of self. [New Scientist, 10/13/09]

Researchers unravel brains wiring to understand memory

These are a few of the cutting-edge experiments that neuroscientists are performing in the latest efforts to understand the mysteries of how the brain learns, remembers and forgets. The work is shedding new light on how the brain handles memory storage, loss, fear, addiction and aging. Some explore the role of sleep — even a brief nap — in consolidating long-term memories. Others are building colorful wiring diagrams, nicknamed "Brainbows," that use different shades to show which neurons connect with which. [McClatchy, 9/22/09]

Scientists seek to manage dopamines good and bad sides

Dopamine [is] a natural brain chemical thats linked to pleasure, addiction and disease. This little molecule -- it consists of only 22 atoms -- is essential to life but can be a curse sometimes. Too much or too little of it can lead to drug abuse, reckless thrill-seeking, obesity, the tremors of Parkinsons disease, even restless leg syndrome, an irresistible urge to move your legs. [McClatchy, 10/6/09]

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Selected readings 6 13 10

Interesting reading and news items.

Please leave some comments that indicate which articles you find most interesting or that identify topics you would like to read about, and I will try to include more articles of a similar nature in the future

These items are also bookmarked at my Diigo account.

Anticipating the first steps beyond the Standard Model

Physicists’ knowledge of elementary particles is encapsulated in the Standard Model of particle physics, which currently describes almost everything we’ve seen. Yet there is compelling evidence that the Standard Model cannot be the complete description of nature. For example, despite all of its successes, the Standard Model describes only 20 percent of the mass of the Universe. Eighty percent of the mass is known as “dark matter,” which we have never directly observed and know next to nothing about. [Symmetry Breaking, 6/3/10]

Could DZero result point to multiple Higgses?

What caused the DZero result’s large deviation from Standard Model predictions is just as earth-shaking a mystery. The answer could point to the completion of the Standard Model, missing only the theorized Higgs boson particle, or the creation of a new story line for a host of new particles in the saga of how matter in the universe behaves. In their quest for a full explanation, scientists debate whether they are simply missing a chapter in the Standard Model or if they need a sequel that goes beyond the model, potentially including extra dimensions or a theory called supersymmetry that would double the number of known particles. [Symmetry Breaking, 6/4/10]

What is a "law of physics," anyway?

Why should nature be governed by laws? Why should those laws be expressible in terms of mathematics? Why should they be formulated within space and time? These were the questions posed at a fascinating workshop two weeks ago at the Perimeter Institute, the sequel to a workshop held at Arizona State University in December 2008. ... The bottom line is that the organizers had better start planning on more sequels, because the questions seem as intractable as ever. [Scientific American, 6/4/10]

What a shoddy piece of work is man

The human body is certainly no masterpiece of intelligent planning. The eyes retina, for instance, is wired back to front so that the wiring has to pass back through the screen of light receptors, imposing a blind spot. Now John Avise, an evolutionary geneticist at the University of California at Irvine, has catalogued the array of clumsy flaws and inefficiencies at the fundamental level of the genome. His paper ... throws down the gauntlet to advocates of Intelligent design, the pseudo-scientific face of religious creationism. What Intelligent Designer, Avise asks, would make such a botch? [Nature News, 5/3/10]

Illuminating the brain

Now though, advances in a five-year-old field called optogenetics are convincing these scientists to crack open molecular-biology textbooks. Using a hybrid of genetics, virology and optics, the techniques involved enable researchers to instantaneously activate or silence specific groups of neurons within circuits with a precision that electrophysiology and other standard methods do not allow. Systems neuroscientists have longed for such an advance, which allows them their first real opportunity to pick apart the labyrinthine jumble of cell types in a circuit and test what each one does. [Nature News, 5/5/10]

The code within the code

95% of the human genome is alternatively spliced, and that changes in this process accompany many diseases. But no one knew how to predict which form of a particular gene would be expressed in a given tissue. "The splicing code is a problem that weve been bashing our heads against for years," says Burge. "Now we finally have the technologies we need." [Nature News, 5/5/10]

European and Asian genomes have traces of Neanderthal

The genomes of most modern humans are 1–4% Neanderthal — a result of interbreeding with the close relatives that went extinct 30,000 years ago, according to work by an international group of researchers. [Nature News, 5/6/10]

Linux vs. Genome in Network Challenge

A comparison of the networks formed by genetic code and the Linux operating system has given insight into the fundamental differences between biological and computational programming. The shapes are very dissimilar, reflecting the evolutionary parameters of each process. Biology is driven by random mutations and natural selection. Software is an act of intelligent design. [Wired, 5/5/10]

Complex Life Traced to Ancient Gene Parasites

Mysterious gene structures called introns that help make complex organisms possible are descended from DNA parasites that infested bacteria billions of years ago, according to a new study. ... The findings fit the notion that group II introns flourished in the early Earth’s heat, and were ultimately co-opted into their hosts’ genomes. [Wired, 6/9/10]

The Magical Mystery Tour

Cassini, the first spacecraft to orbit Saturn, has revealed intricate details of the gas giant planet and its moons -- but many mysteries remain. Six years ago, the Cassini spacecraft began orbiting Saturn and taking detailed images of its ring and many moons. While the Cassini-Huygens mission has helped answer questions about this planetary system, it also has revealed new mysteries for scientists to puzzle over. [Physorg.com, 5/5/10]

Peptides may hold missing link to life

Scientists have discovered that simple peptides can organize into bi-layer membranes. The finding suggests a "missing link" between the pre-biotic Earths chemical inventory and the organizational scaffolding essential to life. [Physorg.com, 5/6/10]

Physicists study how moral behaviour evolved

A statistical-physics-based model may shed light on the age-old question "how can morality take root in a world where everyone is out for themselves?" Computer simulations by an international team of scientists suggest that the answer lies in how people interact with their closest neighbours rather than with the population as a whole. [Physicsworld.com, 5/5/10]

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