78683385
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MTorrice writes:
Neonicotinoid pesticides have been blamed for declines in bee populations worldwide. The chemicals don’t kill bees, instead neonicotinoids impair the insects’ abilities to learn, navigate, forage for nectar, and reproduce, according to studies published over the past several years.
Now, researchers report that bees exposed to the pesticides also become less effective pollinators for crops.
The study is the first to demonstrate that neonicotinoids can decrease the quality of a food crop by affecting bee pollination. About 30% of our food comes from crops, including fruits, nuts, seeds, and oils, that depend on insect pollinators, according to Dara A. Stanley of Royal Holloway, University of London, who led the new study. “Basically,” she says, “you can’t have a balanced diet without insect pollination.”
77203571
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MTorrice writes:
After a nice long bout of aerobic exercise, some people experience what’s known as a “runner’s high”: a feeling of euphoria coupled with reduced anxiety and a lessened ability to feel pain. For decades, scientists have associated this phenomenon with an increased level in the blood of -endorphins, opioid peptides thought to elevate mood.
Now, German researchers have shown the brain’s endocannabinoid system—the same one affected by marijuana’s 9-tetrahydrocannabinol (THC)—may also play a role in producing runner’s high, at least in mice.
76967199
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MTorrice writes:
Our chromosomes hold a partial record of prehistoric viral infections: About 8% of our genomes come from DNA that viruses incorporated into the cells of our ancestors. Over many millennia, these viral genes have accumulated mutations rendering them mostly dormant.
But one of these viruses can reawaken in some patients with amyotrophic lateral sclerosis (ALS), a progressive muscle wasting disease commonly known as Lou Gehrig’s disease. A new study demonstrates that this so-called endogenous retrovirus can damage neurons, possibly contributing to the neurodegeneration seen in the disease.
The findings raise the possibility that antiretroviral drugs, similar to those used to treat HIV, could slow the progression of ALS in some patients.
76676567
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MTorrice writes:
Scientists in Wisconsin have succeeded in growing three-dimensional brainlike tissue structures derived from human embryonic stem cells. Unlike previous miniature model brains, the new structures can be easily reproduced and they contain vascular cells and microglia, a type of immune cell.
These brain mimics may provide a fast, low cost way to screen drugs and chemicals for their ability to disrupt human brain development, the team reports. Current toxicity screening tests use multiple generations of rats and cost about $1 million to test one chemical.
75939555
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MTorrice writes:
A new study concludes that a brain protein causes the rare, Parkinson’s-like disease called multiple systems atrophy (MSA) by acting like a prion, the misbehaving type of protein infamously linked to mad cow disease. The researchers say the results are the most definitive demonstration to date that proteins involved in many neurodegenerative disorders, such as Alzheimer’s and Parkinson’s, exhibit prionlike behavior: They can misfold into shapes that then coax others to do the same, leading to protein aggregation that forms neurotoxic clumps. If these other diseases are caused by prionlike proteins, then scientists could develop treatments that slow or stop disease progression by designing molecules that block prion propagation.
74054431
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MTorrice writes:
When bugs explode against the wings of oncoming airplanes, they create a sticky problem for aerospace engineers. Their blood, or hemolymph, clings to an airplane’s wings, disrupting the smooth airflow over them and sapping the aircraft’s fuel efficiency. NASA scientists are now developing coatings that help aircraft shed or repel bug guts during flight. After screening nearly 200 different coating formulations, the NASA researchers recently flight-tested a handful of promising candidates, showing that they could reduce the amount of insect insides stuck to the wings by up to 40%. With further optimization, such coatings could allow planes to use 5% less fuel.
73082775
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MTorrice writes:
An international research team has built electronic, flexible patches that can measure the mechanical properties of skin and other biological tissue. The sensors consist of nanoribbons of a piezoelectric material, lead zirconate titanate, which deforms when jolted with electrical energy and, conversely, produces electricity when it’s deformed. The researchers mapped the skin elasticity of dozens of patients in the clinic, building up quantitative data on healthy and damaged tissue. The information could help doctors better assess conditions such as dermatitis and skin cancer. The team believes that similar sensors could be implanted inside the body to monitor blood vessels and other soft tissue for damage or dysfunction.
71340127
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MTorrice writes:
A foam composed of a polymer derived from crustacean shells may prevent more soldiers from falling victim to the most prolific killer on the battlefield: blood loss.
Pressure is one of the best tools that medics have to fight bleeding, but they can’t use it on severe wounds near organs. Here, compression could do more harm than good. First responders have no way to effectively dam blood flows from these noncompressible injuries, which account for the majority of hemorrhagic deaths. The new foam could help stop bleeding in these types of injuries.
It relies on chitosan, a biopolymer that comes from processed crustacean shells. By modifying the chitosan, the developers gave the material the ability to anchor blood cells into gel-like networks, essentially forming blood clots. The researchers dispersed the modified chitosan in water to create a fluid they could spray directly onto noncompressible wounds.
70485727
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MTorrice writes:
This year marks the 100th anniversary of the first large-scale use of chemical weapons during World War I. Sarah Everts at Chemical & Engineering News remembers the event with a detailed account of the day in 1915 when the German Army released chlorine gas on its enemies, igniting a chemical arms race. Read the diaries of soldiers involved in the first gas attack.
By the end of WWI, scientists working for both warring parties had evaluated some 3,000 different chemicals for use as weapons. Even though poison gas didn’t end up becoming an efficient killing weapon on WWI battlefields—it was responsible for less than 1% of WWI’s fatalities--its adoption set a precedent for using chemicals to murder en masse. In the past century, poison gas has killed millions of civilians around the world: commuters on the Tokyo subway, antigovernment demonstrators in Syria, and those incarcerated in Third Reich concentration camps. Everts profiles chemist Fritz Haber, the man who lobbied to unleash the gas that day in 1915.
67773889
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MTorrice writes:
The 2008 recession hammered the U.S. auto industry, driving down sales of 2009 models to levels 35% lower than those before the economic slump. A new study has found that because sales of new vehicles slowed, the average age of the U.S. fleet climbed more than expected, increasing the rate of air pollutants released by the fleet.
In 2013, the researchers studied the emissions of more than 68,000 vehicles on the roads in three cities—Los Angeles, Denver, and Tulsa. They calculated the amount of pollution released per kilogram of fuel burned for the 2013 fleet and compared the rates to those that would have occurred if the 2013 fleet had the same age distribution as the prerecession fleet. For the three cities, carbon monoxide emissions were greater by 17 to 29%, hydrocarbons by 9 to 14%, nitrogen oxide emissions by 27 to 30%, and ammonia by 7 to 16%.
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
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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.
65513669
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MTorrice writes:
Many drugs that treat bacterial and fungal infections were found in microbes growing in the dirt. These organisms synthesize the compounds to fend off other bacteria and fungi around them. To find possible new drugs, chemists try to coax newly discovered microbial species to start making their arsenal of antimicrobial chemicals in the lab. But fungi can be stubborn, producing just a small set of already-known compounds.
Now, one team of chemists has hit upon a curiously effective and consistent trick to prod the organisms to start synthesizing novel molecules: Cheerios inside bags. Scientists grew a soil fungus for four weeks in a bag full of Cheerios and discovered a new compound that can block biofilm formation by an infectious yeast. The chemists claim that Cheerios are by far the best in the cereal aisle at growing chemically productive fungi.
65331949
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MTorrice writes:
Environmental scientists monitor particulate matter pollution because it poses risks to human health and can affect the climate. Ultrafine particles, up to 100 nm in diameter, are produced by vehicle exhaust and other combustion processes. They also form when volatile chemicals from other sources condense in the atmosphere, often through reactions triggered by sunlight.
Now atmospheric scientists propose that personal care products, such as antiperspirants, could be a potential source of ultrafine particulate matter. On the basis of data from the U.S. and Finland, they find that airborne nanoparticles in highly populated areas often contain silicon. They hypothesize that organic silicon compounds found in cosmetics waft into the air, get oxidized, and contribute to the growth of nanoparticles.
64635643
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MTorrice writes:
Bioengineers can harness DNA’s remarkable ability to self-assemble to build two- and three-dimensional nanostructures through DNA origami. Until now, researchers using this approach have been limited to building structures that are tens of square nanometers in size. Now a team reports the largest individual DNA origami structures to date, which reach sizes of hundreds of square nanometers. What’s more, they have developed a less expensive way to synthesize the DNA strands needed, overcoming a tremendous obstacle to scaling up the technology.
