65989011
submission
vinces99 writes:
Freshwater fish with bellies full of shrews – one trout a few years back was found to have eaten 19 – aren’t as random as scientists have thought. In some years, probably when shrew populations boom, the small mouse-like land animals end up in the stomachs of a quarter of rainbow trout and Arctic grayling larger than a foot, according to University of Washington-led research in the coastal lakes and streams of Southwest Alaska.
“Not all the fish could eat shrews even if they were abundant. A fish must be larger than 12 inches to have a mouth big enough to swallow these prey whole,” said Pete Lisi, lead author of a paper in the October issue of Ecology of Freshwater Fish. “However, in pools where almost every fish was large enough to eat a shrew, it was only the largest fish that had shrews – often six to eight in their stomachs – many more than the next largest fish,” he said. “Big fish don’t share their treats.”
The work, which Lisi did while earning his doctorate at the UW, is a part of a larger ongoing project monitoring salmon and other fish and learning their life histories, including what they eat by examining stomach contents.
“Our data suggest a few of the fish are really good at getting shrews,” said Lisi, now at the University of Wisconsin-Madison. “Like the one trout that had 19 shrews in its gut, found in a neighboring river basin by fish and wildlife researchers."
65913619
submission
vinces99 writes:
A new study shows that the increase of atmospheric carbon dioxide that contributed to the end of the last ice age more than 10,000 years ago did not occur gradually but rather was characterized by three abrupt pulses. Scientists are not sure what caused these abrupt increases, during which carbon dioxide levels rose about 10 to 15 parts per million – or about 5 percent per episode – during a span of one to two centuries. It likely was a combination of factors, they say, including ocean circulation, changing wind patterns and terrestrial processes. The finding, published Oct. 30 in the journal Nature, casts new light on the mechanisms that take the Earth in and out of ice ages.
“We used to think that naturally occurring changes in carbon dioxide took place relatively slowly over the 10,000 years it took to move out of the last ice age,” said lead author Shaun Marcott, who did the work as a postdoctoral researcher at Oregon State University and is now at the University of Wisconsin-Madison. “This abrupt, centennial-scale variability of CO2 appears to be a fundamental part of the global carbon cycle.”
Previous research has hinted at the possibility that spikes in atmospheric carbon dioxide may have accelerated the last deglaciation, but that hypothesis had not been resolved, the researchers say. The key to the new finding is the analysis of an ice core from the West Antarctic that provided the scientists with an unprecedented glimpse into the past.
65477945
submission
vinces99 writes:
Under the rule of dictator Nicolae Ceausescu, thousands of Romanian children were placed in overcrowded orphanages with bleak conditions and minimal human contact, a legacy that continued even after the 1989 revolution. Only recently have research and public concern caused policy changes.
University of Washington research on children who began life in these institutions shows that early childhood neglect is associated with changes in brain structure. A paper published this month in Biological Psychiatry shows that children who spent their early years in these institutions have thinner brain tissue in cortical areas that correspond to impulse control and attention. “These differences suggest a way that the early care environment has dramatic and lasting effects for children’s functioning,” said lead author Katie McLaughlin, a UW assistant professor of psychology.
Since 2000, the Bucharest Early Intervention Project has worked to document and treat the children’s health. McLaughlin joined the team about six years ago to focus on brain development. This study is among the first in any setting to document how social deprivation in early life affects the thickness of the cortex, the thin folded layer of gray matter that forms the outer layer of the brain. The study provides “very strong support” for a link between the early environment and ADHD, McLaughlin said.
65307731
submission
vinces99 writes:
The largest migration on the planet is the movement of small animals from the surface of the open ocean, where they feed on plants under cover of darkness, to the sunless depths where they hide from predators during the day. University of Washington researchers have found that this regular migration helps shape our oceans. During the daylight hours below the surface the animals release ammonia, the equivalent of our urine, that turns out to play a significant role in marine chemistry, particularly in low-oxygen zones. Results are published online this week in the Proceedings of the National Academy of Sciences.
“I’m very fascinated by these massive migrations,” said lead author Daniele Bianchi, a postdoctoral researcher in the UW School of Oceanography. “To me, it’s exciting to think about the effects of animal behavior on a large scale in the ocean.”
One might not think that peeing into the vastness of the oceans could have an effect. But the animals – which include tiny zooplankton, crustaceans such as krill, and fish such as lanternfish up to a few inches long – compensate for their small size with huge abundance throughout the world’s oceans. After a nighttime feast near the surface, these small creatures take a couple of hours to swim about 650 to 2,000 feet (200 to 600 meters) deep. Solid waste falls as pellets. The liquid waste is emitted more gradually.
65263791
submission
vinces99 writes:
Fusion energy almost sounds too good to be true – zero greenhouse gas emissions, no long-lived radioactive waste, a nearly unlimited fuel supply. Perhaps the biggest roadblock to adopting fusion energy is that the economics haven’t penciled out. Fusion power designs aren’t cheap enough to outperform systems that use fossil fuels such as coal and natural gas.
University of Washington engineers hope to change that. They have designed a concept for a fusion reactor that, when scaled up to the size of a large electrical power plant, would rival costs for a new coal-fired plant with similar electrical output. The team published its reactor design and cost-analysis findings last spring and will present results Oct. 17 at the International Atomic Energy Agency’s Fusion Energy Conference in St. Petersburg, Russia.
65234347
submission
vinces99 writes:
Children as young as 15 months can detect anger when watching other people’s social interactions and then use that emotional information to guide their own behavior, according to new University of Washington research. The study, published in the October/November issue of the journal Cognitive Development, is the first evidence that younger toddlers are capable of using multiple cues from emotions and vision to understand the motivations of the people around them.
“At 15 months of age, children are trying to understand their social world and how people will react,” said lead author Betty Repacholi, a faculty researcher at UW’s Institute for Learning and Brain Sciences and an associate professor of psychology. “In this study we found that toddlers who aren’t yet speaking can use visual and social cues to understand other people – that’s sophisticated cognitive skills for 15-month-olds.”
The findings also linked the toddlers’ impulsive tendencies with their tendency to ignore other people’s anger, suggesting an early indicator for children who may become less willing to abide by rules.
64800459
submission
vinces99 writes:
Brain cells that multiply to help birds sing their best during breeding season are known to die back naturally later in the year. For the first time researchers have described the series of events that cues new neuron growth each spring, and it all appears to start with a signal from the expiring cells the previous fall that primes the brain to start producing stem cells.
If scientists can further tap into the process and understand how those signals work, it might lead to ways to exploit these signals and encourage replacement of cells in human brains that have lost neurons naturally because of aging, severe depression or Alzheimer’s disease, said Tracy Larson, a University of Washington doctoral student in biology. She’s lead author of a paper in the Sept. 23 Journal of Neuroscience on brain cell birth that follows natural brain cell death.
Neuroscientists have long known that new neurons are generated in the adult brains of many animals, but the birth of new neurons – or neurogenesis – appears to be limited in mammals and humans, especially where new neurons are generated after there’s been a blow to the head, stroke or some other physical loss of brain cells, Larson said. That process, referred to as “regenerative” neurogenesis, has been studied in mammals since the 1990s. This is the first published study to examine the brain’s ability to replace cells that have been lost naturally, Larson said.
64603141
submission
vinces99 writes:
Using modern statistical tools, a new study led by the University of Washington and the United Nations finds that world population is likely to keep growing throughout the 21st century. The number of people on Earth is likely to reach 11 billion by 2100, the study concludes, about 2 billion higher than widely cited previous estimates. The paper published online Sept. 18 in the journal Science includes the most up-to-date numbers for future world population, and describes a new method for creating such estimates.
“The consensus over the past 20 years or so was that world population, which is currently around 7 billion, would go up to 9 billion and level off or probably decline,” said corresponding author Adrian Raftery, a UW professor of statistics and of sociology. “We found there’s a 70 percent probability the world population will not stabilize this century. Population, which had sort of fallen off the world’s agenda, remains a very important issue.”
The paper explains the most recent United Nations population data released in July. This is the first U.N. population report to use modern statistics, known as Bayesian statistics, that combines all available information to generate better predictions.
Most of the anticipated growth is in Africa, where population is projected to quadruple from around 1 billion today to 4 billion by the end of the century. The main reason is that birth rates in sub-Saharan Africa have not been going down as fast as had been expected. There is an 80 percent chance that the population in Africa at the end of the century will be between 3.5 billion and 5.1 billion people.
64175499
submission
vinces99 writes:
The number of California blue whales has rebounded to near historical levels, according to new research by the University of Washington, and while the number of blue whales struck by ships is likely above allowable U.S. limits, such strikes do not immediately threaten that recovery. This is the only population of blue whales known to have recovered from whaling – blue whales as a species having been hunted nearly to extinction.
Blue whales – nearly 100 feet in length and weighing 190 tons as adults – are the largest animals on Earth and the heaviest ever, weighing more than twice as much as the largest known dinosaur, the Argentinosaurus. They are an icon of the conservation movement and many people want to minimize harm to them, according to Trevor Branch, UW assistant professor of aquatic and fishery sciences.
“The recovery of California blue whales from whaling demonstrates the ability of blue whale populations to rebuild under careful management and conservation measures,” said Cole Monnahan, a UW doctoral student in quantitative ecology and resource management and lead author of a paper on the subject posted online Sept. 5 by the journal Marine Mammal Science. Branch and André Punt, a UW professor of aquatic and fisheries sciences, are co-authors.
California blue whales, most visible while feeding 20 to 30 miles off the California coast, range fom the equator to the Gulf of Alaska. Today they number about 2,200, according to monitoring by other research groups, which is likely about 97 percent of the historical levels.
63927433
submission
vinces99 writes:
Jaundice in newborns is one of the last things a parent wants to deal with, but it’s unfortunately a common condition in babies less than a week old. Skin that turns yellow can be a sure sign that a newborn is jaundiced and isn’t adequately eliminating the chemical bilirubin. But that discoloration is sometimes hard to see, and severe jaundice left untreated can harm a baby. University of Washington engineers and physicians have developed a smartphone application that checks for jaundice in newborns and can deliver results to parents and pediatricians within minutes. It could serve as a screening tool to determine whether a baby needs a blood test – the gold standard for detecting high levels of bilirubin.
“Virtually every baby gets jaundiced, and we’re sending them home from the hospital even before bilirubin levels reach their peak,” said James Taylor, a UW professor of pediatrics and medical director of the newborn nursery at UW Medical Center. “This smartphone test is really for babies in the first few days after they go home. A parent or health care provider can get an accurate picture of bilirubin to bridge the gap after leaving the hospital.”
The research team will present its results at the Association for Computing Machinery’s International Joint Conference on Pervasive and Ubiquitous Computing in September in Seattle.
63907519
submission
vinces99 writes:
Scientists have developed what they believe is the thinnest-possible semiconductor, a new class of nanoscale materials made in sheets only three atoms thick. The University of Washington researchers have demonstrated that two of these single-layer semiconductor materials can be connected in an atomically seamless fashion known as a heterojunction. This result could be the basis for next-generation flexible and transparent computing, better light-emitting diodes, or LEDs, and solar technologies.
“Heterojunctions are fundamental elements of electronic and photonic devices,” said senior author Xiaodong Xu, a UW assistant professor of materials science and engineering and of physics. “Our experimental demonstration of such junctions between two-dimensional materials should enable new kinds of transistors, LEDs, nanolasers, and solar cells to be developed for highly integrated electronic and optical circuits within a single atomic plane.”
The research was published online this week in Nature Materials. The researchers discovered that two flat semiconductor materials can be connected edge-to-edge with crystalline perfection. They worked with two single-layer, or monolayer, materials – molybdenum diselenide and tungsten diselenide – that have very similar structures, which was key to creating the composite two-dimensional semiconductor.
63784297
submission
vinces99 writes:
Following rapid warming in the late 20th century, this century has so far seen surprisingly little increase in the average temperature at the Earth’s surface. More than a dozen theories have now been proposed for the so-called global warming hiatus, ranging from air pollution to volcanoes to sunspots. New research from the University of Washington shows the heat absent from the surface is plunging deep in the north and south Atlantic Ocean, and is part of a naturally occurring cycle. The study is published Aug. 22 in Science.
Subsurface ocean warming explains why global average air temperatures have flatlined since 1999, despite greenhouse gases trapping more solar heat at the Earth’s surface. “Every week there’s a new explanation of the hiatus,” said corresponding author Ka-Kit Tung, a UW professor of applied mathematics and adjunct faculty member in atmospheric sciences. “Many of the earlier papers had necessarily focused on symptoms at the surface of the Earth, where we see many different and related phenomena. We looked at observations in the ocean to try to find the underlying cause.”
What they found is that a slow-moving current in the Atlantic, which carries heat between the two poles, sped up earlier this century to draw heat down almost a mile (1,500 meters). Most previous studies focused on shorter-term variability or particles that could block incoming sunlight, but they could not explain the massive amount of heat missing for more than a decade.
63339855
submission
vinces99 writes:
Imagine a world in which your wristwatch or other wearable device communicates directly with your online profiles, storing information about your daily activities where you can best access it – all without requiring batteries. Or, battery-free sensors embedded around your home that could track minute-by-minute temperature changes and send that information to your thermostat to help conserve energy. This not-so-distant “Internet of Things” reality would extend connectivity to perhaps billions of devices. Sensors could be embedded in everyday objects to help monitor and track everything from the structural safety of bridges to the health of your heart. But having a way to cheaply power and connect these devices to the Internet has kept this from taking off.
Now, University of Washington engineers have designed a new communication system that uses radio frequency signals as a power source and reuses existing Wi-Fi infrastructure to provide Internet connectivity to these devices. Called Wi-Fi backscatter, this technology is the first that can connect battery-free devices to Wi-Fi infrastructure. The researchers will publish their results at the Association for Computing Machinery’s Special Interest Group on Data Communication‘s annual conference this month in Chicago. The team also plans to start a company based on the technology.
63186293
submission
vinces99 writes:
Soon, protection from HIV infection could be as simple as inserting a medicated, disappearing fabric minutes before having sex. University of Washington bioengineers have discovered a potentially faster way to deliver a topical drug that protects women from contracting HIV. Their method spins the drug into silk-like fibers that quickly dissolve when in contact with moisture, releasing higher doses of the drug than possible with other topical materials such as gels or creams.
“This could offer women a potentially more effective, discreet way to protect themselves from HIV infection by inserting the drug-loaded materials into the vagina before sex,” said Cameron Ball, a UW doctoral student in bioengineering and lead author on a paper in the August issue of Antimicrobial Agents and Chemotherapy.
63144221
submission
vinces99 writes:
As the climate warms and sea ice retreats, the North is changing. An ice-covered expanse now has a season of increasingly open water that is predicted to extend across the whole Arctic Ocean before the middle of this century. Storms thus have the potential to create Arctic swell – huge waves that could add a new and unpredictable element to the region. A University of Washington researcher made the first study of waves in the middle of the Arctic Ocean and detected house-sized waves during a September 2012 storm. The results were recently published in Geophysical Research Letters.
“As the Arctic is melting, it’s a pretty simple prediction that the additional open water should make waves,” said lead author Jim Thomson, an oceanographer with the UW Applied Physics Laboratory. His data show that winds in mid-September 2012 created waves of 5 meters (16 feet) high during the peak of the storm. The research also traces the sources of those big waves: high winds, which have always howled through the Arctic, combined with the new reality of open water in summer.
