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Updated: 3 days 21 hours ago

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.

Astrophysicist Adam Frank frames Earth's sustainability transgalactically

23 January 2015
The science popularizer says exoplanets across the Milky Way likely tell a lot about human-caused climate disruption’s ultimate effects.

Laser etching renders metals extremely water-repellent

22 January 2015
BBC: Metal surfaces etched by femtosecond laser pulses are more slippery than Teflon and have been shown to be very effective at repelling water. They are so hydrophobic that water drops actually bounce off them, says Chunlei Guo of the University of Rochester in New York, one of the authors of a paper published in the Journal of Applied Physics. Because the water droplets also remove dust particles from the surface, the materials are self-cleaning. Guo and his research team think the technique would be useful in developing countries to create hygienic surfaces for medical or sanitary uses.

Israel's arrest of Palestinian physicist spurs international protest

22 January 2015

Nature: Imad Ahmad Barghouthi, a theorist who studies space-plasma physics at Al-Quds University in Jerusalem, was detained without charges on 6 December 2014 as he crossed the border from the West Bank into Jordan. In response to Barghouthi's detainment, several international science organizations have sent letters of protest to the Israeli government and to European organizations that provide research funds to Israel. Barghouthi was on his way to Amman to catch a flight to the United Arab Emirates so that he could attend a meeting of the Arab Union of Astronomy and Space Sciences in Sharjah. Since his arrest, he has been held in an Israeli military prison without being charged under a policy that allows Israel to hold a potential security risk for three months. Jawad Boulos, Barghouthi's lawyer, believes that Barghouthi was detained because of statements he made in support of Palestinian activists during Israel's 2014 invasion of the Gaza Strip. Barghouthi is now scheduled to be released on 2 February, but could be held longer.

Senate amends Keystone XL bill to say that climate change is real

22 January 2015

Science: The US Senate voted 98 to 1 to approve an amendment to the Keystone XL Pipeline bill that says climate change is real and not a hoax . Proposed by Sheldon Whitehouse (D-RI), the amendment was one of several put forward by opponents of the pipeline, which would bring oil from Canada to the US. However, it was the only one to be approved. Other amendments that further stated that climate change was directly influenced by human activity and pollution had also been proposed. The Keystone XL bill is heavily supported by Republicans, many of whom have dodged the issue of climate change by saying they aren't scientists. Some, such as James Inhofe (R-OK), had called climate change a "hoax" in the past. Before the vote, Inhofe clarified that statement by saying the hoax is that people think that humanity can change the climate.

How did dwarf galaxies form?

22 January 2015
Confounding expectations, dwarf galaxies that lie on the plane of their galactic host resemble ones that lie in the host's halo.

Strong emotion aids memory

22 January 2015
New York Times: In humans, seemingly trivial memories, when associated with a strong emotional response, can be filed away and recalled much later. To study that phenomenon, Joseph Dunsmoor of New York University and coworkers conducted an experiment in which they showed participants a random series of photographs and asked them to categorize each image as either a tool or an animal. They were then shown another series of photos to categorize, but in this second round, half the participants received a mild shock when they saw tools, and half received the shock when they saw animals. In a series of tests to measure how well the participants remembered the photos, the results varied depending on when the test was given. Those who took it immediately remembered as many animal photos as they did tool photos. But those who took the test hours later remembered more items in the category for which they had received a shock.

Science-related excerpts from President Obama's State of the Union address

21 January 2015
It includes strong words on combating human-caused climate disruption.

Senators hope to amend Keystone XL bill with statement on climate change

21 January 2015
Science: The first bill under discussion by the Senate in the 114th Congress concerns the construction of the Keystone XL pipeline, which would bring oil from Canada to the US. The controversial bill is supported by the new Republican majority. Those senators who oppose it say the pipeline will exacerbate global warming and are pushing for amendments affirming that climate change is happening, that human activity is driving it, and that Congress should take action to address the issue. The goal of the amendments, says Charles Schumer (D-NY), is to put climate-change-denying senators in an awkward position. If they block the amendments, they could be accused of dodging the issue. If they let the amendments go to a vote, they will be forced to take an actual position on climate change, which could damage their standing with their constituencies.

Micromotors deliver therapeutic materials to mouse’s stomach

21 January 2015
BBC: For the first time, powerful microscale motors have been tested in a living organism. Researchers at the University of California, San Diego, report in the journal ACS Nano that they successfully inserted artificial micromotors, consisting of zinc-coated polymer tubes just 20 μm long, into the stomach of a mouse. The zinc reacted with the stomach acid and produced hydrogen bubbles that propelled the tiny machines into the stomach lining. As the machines dissolved, they released their cargo. The researchers believe that such artificial micromotors, which convert energy into movement, could deliver drugs much more effectively than conventional medicines, which rely on passive diffusion. The method could one day be used to treat peptic ulcers and other illnesses.

LHC restart and new underground experiment may be last chance for WIMPs

21 January 2015
Nature: Weakly interacting massive particles (WIMPs) are one explanation for the composition of dark matter, the invisible material that makes up 85% of the universe's mass. However, in the past few years several experiments have failed to detect any WIMPs. Although the Large Hadron Collider (LHC) at CERN was thought capable of creating the particles during its previous run at 8 TeV, it did not. The most sensitive direct detection experiment yet, the Large Underground Xenon (LUX) project, also failed to find any candidate events during its first run in 2013. It's possible that the existence of WIMPs could be ruled out soon if neither the LHC, with an upgraded target collision energy of 14 TeV, nor XENON1T, a direct detection experiment 50 times as sensitive as LUX, finds any. If so, that would open the door to other possible dark-matter explanations that had been considered more "exotic" than WIMPs.

X-ray imaging reveals ancient writing on charred papyrus scrolls

21 January 2015
Los Angeles Times: In AD 79 when Mount Vesuvius erupted, it destroyed several ancient Roman towns, including Herculaneum, which had a extensive library. The blast of heat from the volcano carbonized, but did not completely destroy, the library's hundreds of handwritten papyrus scrolls. Discovered almost 300 years ago, the papyri are too damaged and fragile to be unrolled and read, although several attempts have been made. Because the ink used was carbon based, it has proven almost impossible to distinguish between it and the baked paper, even with such sophisticated techniques as x-ray computed tomography. Now Vito Mocella of the Institute for Microelectronics and Microsystems in Naples, Italy, and colleagues have tried a different technique, x-ray phase-contrast tomography, with which they have been able to make out a few words and letters by differentiating among phase shifts in the x-ray light as it passes through the different materials. The researchers hope the technique will open up new opportunities to read other ancient papyri and learn more about ancient Greek literature and philosophy.

Earthquakes shown to release some greenhouse gases

20 January 2015

Science: Tetrafluoromethane (CF4) is a greenhouse gas that persists in the atmosphere for 50 000 to 100 000 years. It is commonly produced by the weathering of granite and other metamorphic rocks by rainfall. Now Daniel Deeds of the US Geological Survey and his colleagues have discovered that CF4 is also produced by tectonic activity. Surprised to find the chemical in groundwater samples collected near an active fault in the Mojave Desert, the researchers then examined 14 samples taken from aquifers along part of the San Andreas Fault. All but one of the samples showed higher CF4 levels than did water that had been exposed to the air. That suggested the gas was being absorbed from stone deep underground. The researchers also found that the samples from closer to the fault had higher concentrations of the gas than did those from farther away. Whether the CF4 is produced by the fracturing of rocks during earthquakes or by pressure stresses is not clear. However, the discovery that CF4 levels are not exclusively tied to weathering means they are no longer a reliable indicator of past changes in climate.

Artificial heart recipient able to return home

20 January 2015
New York Times: An artificial heart manufactured by French company Carmat has been successfully implanted in a second human patient. Created by French surgeon Alain Carpentier, the device was first used in 2013 when it was implanted in a terminally ill 76-year-old man, who survived for 74 days. The second patient, a 68-year-old man, underwent surgery in August 2014 and is now doing so well that he has been released from the hospital and sent home. The device is made from both synthetic materials and animal tissues and requires an external battery pack. Because there are so many more people needing heart transplants than there are available organs, the artificial heart could extend the lives of those who are diagnosed with heart failure and have no other options.

Charles L. Opitz

20 January 2015

Geysers on Europa called into question

19 December 2014
New Scientist: Despite the detection by the Hubble Space Telescope last year of 200-km-high water jets erupting from the surface of Jupiter’s moon Europa, no evidence of such a geyser has been seen since. Donald Shemansky, of the University of Southern California, reported the finding at the American Geophysical Union conference in San Francisco on 18 December. Furthermore, data from NASA’s Cassini spacecraft, which flew by Jupiter in 2001, have failed to confirm the existence of the watery plumes. Either a mistake was made or the phenomenon is very rare, says Robert Pappalardo of NASA’s Jet Propulsion Laboratory in Pasadena, California.

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