76446369
submission
carmendrahl writes:
Tomes upon tomes have been written about the history of Germany's nuclear program in the 1940s (see Heisenberg's War, or The Making of the Atomic Bomb). Now, an international team has conducted nuclear forensic analysis of three WWII-era uranium samples from Germany. The results strongly suggest that in their wartime experiments, Germany's researchers never achieved a self-sustained nuclear chain reaction-- the chemical underpinning of atomic weaponry. The study appears in the journal Angewandte Chemie . Led by Maria Wallenius of the European Commission's in-house science service, researchers examined samples of uranium from two "Heisenberg cubes"- named for Werner Heisenberg, and a "Wirtz plate"-- named for Karl Wirtz. The team measured ratios of isotopes of the elements uranium, strontium, plutonium, and thorium. They also measured abundances of certain rare earth elements. They verified the samples as authentic, dating them to the early 1940s, and localizing the area where the uranium ore was mined to the Czech Republic (which was under Nazi control at the time). They also demonstrated that the isotopes of uranium-236 and plutonium-239 occur in levels matching what would be expected naturally. ”This suggests that the uranium samples have not been exposed to a significant neutron fluence," Wallenius said in a statement.
67431101
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MTorrice writes:
In the U.S. alone, consumers discard over 32 million tons of plastic each year, only 9% of which is recycled. Polyethylene is one of the most popular and, unfortunately, persistent types of plastics. Bags, bottles, and packaging made from the polymer accumulate in landfills and oceans across the globe. Scientists have lamented that the material isn't biodegradable because microbes can’t chew up the plastic to render it harmless. However, a new study reports the first definitive molecular evidence that two species of bacteria, found in the guts of a common pantry pest, can thrive on polyethylene and break it apart.
66281053
submission
MTorrice writes:
Bioengineers want to connect electronics and neurons to make devices such as new cochlear implants or prosthetic limbs with a seemingly natural sense of touch. They also could build synthetic neural circuitry to use to study how the brain processes information or what goes wrong in neurodegenerative diseases.
As a step toward these applications, a team of researchers has developed a way to direct the growth of axons, the connection-forming arms of neurons. They use transparent silicon nitride microtubes on glass slides to encourage the cells’ axons to grow in specific directions. The cultured nerve cells grow aimlessly until they bump into one of the tubes. The axon then enters the tube, and its growth is accelerated 20-fold.
Silicon nitride already is used in some orthopedic devices, and could serve as a substrate for electronics to interface with the growing neurons.
60361853
submission
carmendrahl writes:
Lethal injections are typically regarded as far more humane methods for execution compared to predecessors such as hanging and firing squads.
But the truth about the procedure's humane-ness is unclear. Major medical associations have declared involvement of their member physicians in executions to be unethical, so that means that relatively inexperienced people administer the injections. Mounting supply challenges for the lethal drug cocktails involved are forcing execution teams to change procedures on the fly. This and other problems have contributed to recent crises in Oklahoma and Missouri.
As a new story and interactive graphic explains, states are turning to a number of compound cocktails to get around the supply problems.
56102475
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ckwu writes:
Scientists predict that the scarcity of phosphorus will increase over the next few decades as the growing demand for agricultural fertilizer depletes geologic reserves of the element. Meanwhile, phosphates released from wastewater into natural waterways can cause harmful algal blooms and low-oxygen conditions that can threaten to kill fish. Now a team of researchers has designed a system that could help solve both of these problems. It captures phosphorus from sewage waste and delivers clean water using a combined osmosis-distillation process. The system improves upon current methods by reducing the amounts of chemicals needed to precipitate a phosphorus mineral from the wastewater, thus bringing down the cost of the recovery process.
55363457
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Hugh Pickens DOT Com writes:
Discovery Magazine reports that the Bill and Melinda Gates Foundation has granted $100,000 to Boston University School of Medicine (BUSM) and Boston Medical Center (BMC) to develop a nanoparticle coating for condoms that will make them more comfortable and stronger while simultaneously keeping them thin to preserve – and increase – sensation in order to make them more appealing to use. According to the Gates Foundation, in the time that condoms have been in use, not much has changed: "[Condoms] have undergone very little technological improvement in the past 50 years. The primary improvement has been the use of latex as the primary material and quality-control measures, which allow for quality testing of each individual condom. Material science and our understanding of neurobiology has undergone revolutionary transformation in the last decade, yet that knowledge has not been applied to improve the product attributes of one of the most ubiquitous and potentially underutilized products on earth." The nanotechnology that the Boston doctors intend to use for their improved condoms will be superhydrophillic nanoparticles that coat the condom and trap water to make them more resilient and easier to use. "We believe that by altering the mechanical forces experienced by the condom, we may ultimately be able to make a thinner condom which reduces friction, thereby reducing discomfort associated with friction increases pleasure, thereby increasing condom use and decreases rates of unwanted pregnancy and infection transmission."
55362137
submission
carmendrahl writes:
Last fall, MIT researchers made news for developing two bioinspired cocktail toppers-- a moving cocktail boat and a floral pipette-- in collaboration with James Beard Award-winning chef José Andrés. Both the boat and floral pipette operate by taking advantage of surface tension-- either to propel the boat forward or to keep small drops of liquid inside the flower's petals. Some of those early garnishes were nominally edible. But to make them worthy of a restaurant debut requires balancing of flavors, temperature, density, and alcohol content, among other factors. A story and video go inside Andrés' company ThinkFoodGroup to see how the project is coming along. The toppers aren't available to the public just yet.
55361837
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Nerval's Lobster writes:
A little over a year after Microsoft released Windows 8, and a mere three months after it pushed out a major update with Windows 8.1, rumors abound that Windows 9 is already on its way. According to Paul Thurrott’s Supersite for Windows, Microsoft will begin discussing the next version of Windows (codenamed “Threshold,” at least for the moment) at April’s BUILD conference. “Threshold is more important than any specific updates,” he wrote. “Windows 8 is tanking harder than Microsoft is comfortable discussing in public, and the latest release, Windows 8.1, which is a substantial and free upgrade with major improvements over the original release, is in use on less than 25 million PCs at the moment.” Microsoft intends Threshold to clean up at least a portion of Windows 8’s mess. Development on the latest operating system will supposedly begin in late April, which means developers who attend BUILD won’t have access to an early alpha release—in fact, it could be quite some time before Microsoft locks down any new features, although it might double down on Windows 8’s controversial “Modern” (previously known as “Metro”) design interface. Yet if Thurrott’s reporting proves correct, Microsoft isn’t abandoning the new Windows interface that earned such a lackluster response—it’s betting that the format, once tweaked, will somehow revive the operating system’s fortunes. With Ballmer leaving the company and a major reorganization underway, it’ll be the next Microsoft CEO’s task to make sure that Windows 9 is a hit; in fact, considering that rumored 2015 release date, shepherding the OS could become that executive’s first major test.
55357025
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KentuckyFC writes:
Back in 2008, Slashdot reported that researchers were developing ways of turning cellphones into radiation detectors. Since then a few apps have even appeared that claim to do this. However, convincing evidence that they work as advertised is hard to come by. Now government researchers at Idaho National Labs have created their own app that uses an ordinary smartphone as a gamma ray detector, put it through its paces in the lab and published the results. The pixels in smartphone cameras can detect gamma rays in the same way as they pick up visible light. So when the lens is covered, the image should reveal evidence of gamma ray exposure once other noise has been removed, such as that from heat and current leakage. These guys have tested several types of Android smartphone with a variety of gamma ray sources at various different doses. The researchers say the phones give a reasonable measure of radiation dose, can detect the direction of source (by comparing the measurements from the front and back cameras) and can even measure the energy of the gamma rays by measuring the length of the tracks that appear in the image. While the results do not match the quality of bespoke detectors, that may not matter since in many circumstances cellphones are likely to be the only sensors that are available. That could be useful for emergency services, air travelers wanting to monitor their extra radiation dose on routes over the arctic and people who live in areas with a higher than average background radiation level.
53421413
submission
carmendrahl writes:
Exposure to certain pesticides, including rotenone and paraquat, has been associated with a higher incidence of Parkinson's disease in population studies. But how did scientists come to think of a link between Parkinson's disease and pesticides in the first place? The answer involves the 1980s drug underworld, where criminals were synthesizing modified versions of illegal drugs such as heroin to stay one step ahead of the law. One molecule in some designer heroin cocktails, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), breaks down in the human body into 1-methyl-4-phenylpyridinium (MPP+), a nerve cell killer. Heroin addicts exposed to this molecule got Parkinson's-like symptoms. As for the connection to pesticides, MPP+ is a weed killer that was used in the 70s. It also closely resembles the structure of the pesticide paraquat. The saga, therefore, put scientists on high alert to the possibility that pesticides might play a role in developing Parkinson's.
51392573
submission
MTorrice writes:
A new type of headphone heats up carbon nanotubes to crank out tunes. The tiny speaker doesn’t rely on moving parts and instead produces sound through the thermoacoustic effect. When an alternating current passes through the nanotubes, the material heats and cools the air around it; as the air warms, it expands, and as it cools, it contracts. This expansion and contraction creates sound waves. The new nanotube speaker could be manufactured at low cost in the same facilities used to make computer chips, the researchers say.
51098743
submission
carmendrahl writes:
Eukaryotic cells, which are defined by having a nucleus, rarely grow larger than 10 m in diameter. Scientists know a few reasons why this is so. A new study suggests another reason--gravity. Studying egg cells from the frog Xenopus laevis, which reach as big as 1 mm across and are common research tools, Princeton researchers Marina Feric and Clifford Brangwynne noticed that the insides of the eggs' nuclei settled to the bottom when they disabled a mesh made from the cytoskeleton protein actin. They think the frog eggs evolved the mesh to counteract gravity, which according to their calculations becomes significant if cells get bigger than 10 m in diameter.
49946317
submission
carmendrahl writes:
Famed astronomer Galileo Galilei is best known for taking on the Catholic Church by championing the idea that the Earth moves around the sun. But he also engaged in a debate with a philosopher about why ice floats on water. While his primary arguments were correct, he went too far, belittling legitimate, contradictory evidence given by his opponent, Ludovico delle Colombe. Galileo's erroneous arguments during the water debate are a useful reminder that the path to scientific enlightenment is not often direct and that even our intellectual heroes can sometimes be wrong.
49454903
submission
carmendrahl writes:
The abundance of shale gas in the U.S. is expected to lower the cost of petrochemicals for fuel and other applications. That's making it harder for plant-based, renewable feedstocks to compete in terms of price. In the search for cost-competitive crops, companies are testing plants other than traditional biofuel sources such as corn and sugarcane. In a video, watch how the firm Canergy is test-growing a relative of sugarcane called energy cane, which is expected to yield 5 times the ethanol per acre compared to corn.
46776673
submission
MTorrice writes:
Medical researchers think specially tailored RNA sequences could kill tumor cells or encourage wound healing by turning off genes in patients’ cells. Now researchers have developed a nanocoating for bandages or other medical materials that could deliver these fragile gene-silencing RNAs right where they’re needed. The team hopes to produce a bandage that shuts down genes standing in the way of healing in chronic wounds.
