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Updated: 2 weeks 4 days ago

First recordings of whole-brain neural activity of an unrestrained animal

27 January 2015

MIT Technology Review: Recording neural activity for an entire brain has only ever been done with animals that are held in place. Recordings of unrestrained animals have been limited to small sections of the brain. Now Jeffrey Nguyen of Princeton University and his colleagues have recorded whole-brain activity in swimming nematodes. To do that, they suspended a movable camera system above a petri dish holding a nematode and then used image recognition software to keep the camera focused on the animal's head. Combined with a standard imaging technique that causes neurons to fluoresce when they release calcium ions, which is considered a proxy for neural activity, the system allowed them to record five brain volumes per second.

Ocean warming increases frequency of severe El Niños and La Niñas

27 January 2015

New Scientist: Previous analysis of the El Niño Southern Oscillation has suggested that warming ocean temperatures are going to cause the number of extreme El Niño events to double in frequency in the 21st century. Now Wenju Cai of the Commonwealth Scientific and Industrial Research Organisation in Melbourne, Australia, and his colleagues have shown that the number of extreme La Niña events is also expected to double. In their analysis, 17 of 21 climate models showed a doubling in frequency, and the average increase across all models was 74%. Cai says it is the uneven heating of the Pacific Ocean that is driving the increasing severity of the two weather patterns. An especially severe El Niño discharges larger amounts of energy from equatorial waters, which allows larger areas of cold water to rise to the surface. The lower temperatures at the ocean surface drive La Niñas.

Large asteroid passes by Earth

27 January 2015
BBC: On Monday asteroid 2004 BL86 traveled past Earth at a comfortably safe distance of 1.2 million km, about three times as far away as the Moon. In its wake was its own small moon. At 325 m wide, the asteroid is a fairly large one. Although it could cause considerable damage, including mass extinctions, were it to hit Earth, an asteroid of that size doesn't pass by often. The next is not expected until 2027. Because of the risk, however, scientists have been working to identify and track all asteroids at least 1 km in size. Sky surveys indicate that more than 90% of them have probably been located. Smaller asteroids, of which there could be tens of thousands, pose much less risk because they tend to disintegrate high in Earth's atmosphere.

Why alkali metals explode in water

27 January 2015
Nature: Why a piece of sodium or potassium explodes when it comes in contact with water has never been precisely understood. Now, using high-speed cameras, Pavel Jungwirth of the Czech Academy of Sciences in Prague and his colleagues took a closer look at what occurs during the very first milliseconds of the process. Their experiment involved allowing a droplet of a sodium–potassium alloy, which is liquid at room temperature, to fall into a container of water. Within 0.3–0.5 ms, metal spikes shot out from the droplet’s surface and the water around the droplet turned blue. Using computer modeling, the researchers have determined that when the metal drop hits the water, each of the atoms on its surface loses an electron. The electrons become solvated in the water, and their ability to absorb light results in the transient blue color captured by the high-speed imaging. At the same time, the positively charged ions remaining in the metal droplet repel each other and fly apart in what is known as a Coulomb explosion. Hence, the researchers show that the runaway, explosive effect exhibited by alkali metals in water is initially caused by electrostatic forces rather than thermal ones.

UK committee calls for ban on fracking

26 January 2015
BBC: The UK Parliament’s Environmental Audit Committee has called for a national moratorium on hydraulic fracturing, or fracking, for shale gas. According to the committee members, fracking will add to carbon emissions and keep the UK from meeting its carbon targets. In addition, it could have adverse environmental impacts on local water supplies, air quality, and public health. The UK Department of Energy and Climate Change disagrees, however, saying environmental risks can be minimized by proper procedures and monitoring, and shale gas would serve as a reliable backup to renewable energy sources, such as solar and wind, which are intermittent. The debate is particularly pressing because of the UK’s participation in the upcoming international conference on climate change in Paris at the end of the year.

Report suggests cuts to NSF ocean sciences infrastructure

26 January 2015

Nature: On 23 January the US National Research Council released a report on NSF's ocean sciences division. In 2013 the division began spending more money on infrastructure than on basic science research, so NSF commissioned the report to seek outside advice. The report recommends that the division drastically reduce what it spends on infrastructure. The biggest target is the $386 million Ocean Observatories Initiative, whose operating budget could be slashed by 20%. The report also suggests a 10% cut to the scientific ocean-drilling program and a 5% cut in NSF's contribution to support its 20-vessel research fleet.

Planetary Society to launch solar-powered CubeSat in May

26 January 2015
New York Times: The Planetary Society, a nonprofit space advocacy group based in Pasadena, California, plans to launch the first of two solar-powered Lightsail spacecraft into Earth orbit on an Atlas V rocket in May. The craft is planned as a test run for a longer mission set for 2016. For the first flight, the tiny CubeSat will spend four weeks in low Earth orbit, during which all critical functions will be checked before its sails are deployed. Because of its low altitude, the craft will drop out of orbit within days of extending its sails. The second Lightsail will be placed in a higher orbit by a SpaceX Falcon Heavy rocket. Solar-sail technology is being explored as a way of reducing the cost of conducting space missions in the solar system. Ultimately, laser-driven craft might one day allow interstellar travel.

Adjusted ice-sheet models more closely match historical records

26 January 2015

Ars Technica: Historical records of sea levels during the past several million years show periods during which they were as much as 20 m higher than they are currently. However, when fed climate details from the periods of highest sea levels, current computer models do not match the historical record. To attempt to correct the models, David Pollard and Richard Alley of the Pennsylvania State University and Robert DeConto of the University of Massachussetts Amherst added two physical processes not currently included in the models—hydrofracturing and cliff failures. Hydrofracturing occurs when water fills crevasses in ice sheets to such depth that the pressure from the water breaks the ice sheet even further. Cliff failures occur when a cliff of ice becomes so tall that it collapses under its own weight. Both processes can increase the calving of icebergs from ice sheets. When that occurs near the grounding line, it can accelerate the loss of a glacier trapped behind the sheet. The adjusted model predicted a much quicker and more severe loss of ice sheets, which could account for much of the historical sea-level rise.

Directing electrons with molecular vibrations

26 January 2015
A targeted low-energy excitation can dramatically alter the course of charge transfer in a molecule.

Molecular self-assembly may allow for advancements in microchips

23 January 2015

MIT Technology Review: As microchips become smaller, photolithography, the current technique for producing them, is reaching its limits in terms of complexity and expense. A group of researchers at IBM has demonstrated a process of molecular directed self-assembly that may provide a method for making significantly smaller microchips. By carefully preparing a set of block copolymers, and guiding the molecules' positioning using existing photolithography methods, the team was able to create circuit features that were separated by just 29 nm. Current methods are limited to separations of 80 nm. The potential increase in density of microchip circuitry could lead to much smaller chips and significant advances in processing power.

Doomsday Clock moves 2 minutes closer to midnight

23 January 2015

Science: The Doomsday Clock is maintained by the board of the Bulletin of the Atomic Scientists (BAS) as a representation of how close the world is to a global disaster. On 22 January, BAS executive director Kennette Benedict announced that the organization would be moving the clock hands 2 minutes closer to midnight, setting the symbolic time as 11:57pm. Benedict said that the reasons for the change include the recent stalling in nuclear disarmament talks and the growing threat of climate change. The time change is just the 18th since the clock's creation in 1947. It has ranged from just two minutes to midnight in 1953 to 17 minutes to midnight in 1991.

Donald Edwin Hudson

23 January 2015

Two planets may exist far beyond Pluto

23 January 2015
Ars Technica: Two new planets may have been discovered—in our solar system. Their presence has been detected through their apparent gravitational influence on a group of space rocks known as extreme trans-Neptunian objects, which orbit the Sun far beyond Neptune. One of the two possible planets, 2012 VP113, was first detected last year and appears to be about 250 astronomical units away; the second orbits at about 200 AU. If the two do indeed exist and turn out to be much more massive than Earth, their existence would contradict current models of the solar system. Further study will be required before the two objects’ status as planets can be confirmed.

Norman Rostoker

23 January 2015

Hans Kahlmann

23 January 2015

To maintain swarm, jellyfish can swim against current

23 January 2015
BBC: Jellyfish tend to congregate in large swarms called blooms, comprising hundreds to millions of organisms. Until recently no one knew exactly how they were able to form and maintain those blooms. Now researchers show that jellyfish can sense ocean currents, actively orient themselves, and swim against the current when necessary. Graeme Hays of Deakin University in Australia and colleagues tagged jellyfish with data loggers to measure their acceleration and orientation; the researchers also used floating sensors to monitor ocean currents. Because jellyfish blooms are proliferating and can disrupt human activities such as swimming and fishing, the researchers hope their findings will allow better predictions of bloom magnitude and movements. However, how the jellyfish know what direction to travel is still unknown.

Lawrence Ernest Williams

23 January 2015

How to obtain and write references

23 January 2015
What to do when Voldemort writes you a letter of recommendation (and other scenarios).

Vernon E. Leininger

23 January 2015

Trivial implausibility

23 January 2015
Despite a manifestly unscientific plot element, the comic series The Wake is a compelling read and a visual feast.

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