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Tasmanian Devil Facial Tumor Disease (DFTD) has ravaged the world's largest carnivorous marsupial since it emerged in 1996, resulting in a population decline of over 90%. Conservation work to defeat the disease has including removing infected individuals from the population and new research explains how this gives us a unique opportunity to understand how human selection alters the evolution of cancerous cells. DFTD is an asexually reproducing clonal cell line, which during the last 16 years has been exposed to negative effects as infected devils, approximately 33% of the population, have been removed from one site, the Forestier Peninsula, in Tasmania between 2006 and 2010.
However, this parasitical disease has been able survive and counteract the effect of deleterious mutation, genomic instability as well as being able to infect more than 100,000 devils.
"In this study, we focus on the evolutionary response of DFTD to a disease suppression trial," said Beata Ujvari, from the, The University of Sydney. "Tumors collected from devils subjected to the removal programme showed accelerated temporal evolution of tetraploidy compared with tumors from other populations where no increase of tetraploid tumors were observed."
The disease eradication trial provides a unique opportunity to discover the long-term effects of human selection on DFTD evolution and to explore this, the team collected tumour tissue samples between 2006 and 2011 at 11 sites within the DFTD affected areas of Tasmania.
"Our study clearly demonstrates that DFTD tumors are able to rapidly respond to increased selection and adapt to a selective regime," said Ujvari. "The results suggest that ploidization may offer yet another pathway to which DFTD is able to adapt to the ever-changing evolutionary landscape sculptured by the devils' immune system. Our study is the first to show that anthropogenic selection may enhance cancer evolution in the wild, and it therefore cautions about what measures we employ to try to halt the spread of this devastating disease."
Beata Ujvari, Anne-Maree Pearse, Kate Swift, Pamela Hodson, Bobby Hua, Stephen Pyecroft, Robyn Taylor, Rodrigo Hamede, Menna Jones, Katherine Belov, Thomas Madsen. Anthropogenic selection enhances cancer evolution in Tasmanian devil tumours. Evolutionary Applications, 2014; 7 (2): 260 DOI: 10.1111/eva.12117
NASA is preparing for an April 14 launch to theInternational Space Station aboard the SpaceX-3 mission to test NASA’s first space-to-Earth optical communication system.
The Optical Payload for Lasercomm Science (OPALS)system will demonstrate up to 50 megabits per second transmission, compared to 200 to 400 kilobits per second for many deep-space missions.
Future deep space optical communication systems will provide more than one gigabit per second from Mars, NASA says.
Fast laser communications between Earth and spacecraft like the space station or NASA’s Mars Curiosity rover would enhance their connection to engineers and scientists on the ground as well as to the public, NASA says.
However, this mission is only intended for testing. As the space station orbits Earth, a ground telescope tracks it and transmits a laser beacon to OPALS. While maintaining lock on the uplink beacon, the orbiting instrument’s flight system will downlink a modulated laser beam with a formatted video.
Each demonstration, or test, will last approximately 100 seconds as the station instrument and ground telescope maintain line of sight. It will be used to study pointing, acquisition and tracking of the very tightly focused laser beams, taking into account the movement of the space station, and to study the characteristics of optical links through Earth’s atmosphere. NASA will also use OPALS to educate and train personnel in the operation of optical communication systems.
NASA says the success of OPALS will provide increased impetus for operational optical communications in NASA missions, noting that “the space station is a prime target for multi-gigabit-per-second optical links.”
Drilling operations at several natural gas wells in southwestern Pennsylvania released methane into the atmosphere at rates that were 100 to 1,000 times greater than federal regulators had estimated, new research shows.
Using a plane that was specially equipped to measure greenhouse gas emissions in the air, scientists found that drilling activities at seven well pads in the booming Marcellus shale formation emitted 34 grams of methane per second, on average. The EPA has estimated that such drilling releases between 0.04 grams and 0.30 grams of methane per second.
The study, published Monday in the Proceedings of the National Academy of Sciences, adds to a growing body of research that suggests the EPA is gravely underestimating methane emissions from oil and gas operations. The agency is expected to issue its own analysis of methane emissions from the oil and gas sector as early as Tuesday, which will give outside experts a chance to assess how well regulators understand the problem.
Carbon dioxide released by the combustion of fossil fuels is the biggest contributor to climate change, but methane — the chief component of natural gas — is about 20 to 30 times more potent when it comes to trapping heat in the atmosphere. Methane emissions make up 9% of the country's greenhouse gas emissions and are on track to increase, according to the White House.
The Pennsylvania study was launched in an effort to understand whether the measurements of airborne methane matched up with emissions estimates based on readings taken at ground level, the approach the EPA and state regulators have historically used.
Researchers flew their plane about a kilometer above a 2,800 square kilometer area in southwestern Pennsylvania that included several active natural gas wells. Over a two-day period in June 2012, they detected 2 grams to 14 grams of methane per second per square kilometer over the entire area. The EPA’s estimate for the area is 2.3 grams to 4.6 grams of methane per second per square kilometer.
A new jet-lag mobile app called Entrain released by University of Michiganmathematicians reveals previously unknown shortcuts that can help travelers entrain (synchronize) their circadian rhythms to new time zones as efficiently as possible.
Entrain is built around the premise that light, particularly from the sun and in wavelengths that appear to our eyes as the color blue, is the strongest signal to regulate circadian rhythms. These fluctuations in behaviors and bodily functions, tied to the planet’s 24-hour day, do more than guide us to eat and sleep. They govern processes in each one of our cells.
The study, published April 10, 2014, in Public Library of Science Computational Biology (open access journal), relies on two leading mathematical models that have been shown to accurately describe human circadian rhythms. The researchers used these equations and a technique called optimal control theory to calculate ideal adjustment schedules for more than 1,000 possible trips.
The app gives users access to these schedules. Start by entering your typical hours of light and darkness in your current time zone, then choose the time zone you’re traveling to and when, as well as the brightest light you expect to spend the most time in during your trip (indoor or outdoor.) The app offers a specialized plan and predicts how long it will you take to adjust.
The shortcuts the app offers are custom schedules of light and darkness depending on the itinerary. The schedules boil down to one block of time each day when you should seek the brightest light possible and another when you should put yourself in the dark, or at least in dim light. You don’t even have to be asleep.
If you must go outside, you can wear pink-tinted glasses to block blue wavelength light, the researchers say. And if the app prescribes “bright outdoor light” in the middle of the night, a therapeutic lightbox can do the job — yes, its shortcuts sometimes require odd hours.
The Entrain app is available now as a free app in the Apple store.
A below-ground experiment at the South Pole has now discovered three of the highest-energy neutrinos ever found, particles that may be created in the most violent explosions of the universe. These neutrinos all have energies at the absurdly high scale of petaelectronvolts — roughly the energy equivalent of one million times a proton’s mass. (As Albert Einstein showed in his famous E = mc2 equation, energy and mass are equivalent, and such a large amount of mass converts to an extreme level of energy.) The experiment, called IceCube, reported the discovery of the first two — nicknamed Ernie and Bert — last year, and announced the third Monday here at the American Physical Society meeting. “Internally, it’s known as Big Bird,” said IceCube physicist Chris Weaver of the University of Wisconsin–Madison.
These neutrinos are valuable because they are extremely standoffish, rarely ever interacting with other particles, and are uncharged, so their direction is never swayed by magnetic fields in the universe. Thus, their trajectories should point straight back to their source, which astronomers think could be a variety of intense events such as humongous black holes accreting matter, explosions called gamma-ray bursts or galaxies forming stars at furious rates.
This penchant for noninteraction also makes neutrinos extremely difficult to detect. The IceCube experiment looks for the very rare occasions when neutrinos collide with atoms in a cubic kilometer of ice buried underneath the South Pole. Such shielding is necessary to filter out collisions from other particles, but does not inhibit neutrinos. The experiment capitalizes on the naturally pure ice there, using a region that extends twice the depth of the Grand Canyon underground.
Thousands of light detectors are imbedded in the ice to catch the little blips of light created when neutrinos are caught. Such interactions are so infrequent that IceCube researchers had to search for two years to find these three high-energy neutrinos. During that time span the instrument also detected 34 neutrinos of somewhat lower energies. Some of these neutrinos are thought to be contamination created when charged particles called cosmic rays hit Earth’s atmosphere, but some portion of IceCube’s haul likely came directly from violent processes in the cosmos. Those particles are called astrophysical neutrinos. “It looks like we have reached compelling evidence for astrophysical neutrinos,” said U.W.–Madison physicist Albrecht Karle, a member of the IceCube team.
Researchers are programming robots to communicate with people using human-like body language and cues, an important step toward bringing robots into homes.
Researchers at the University of British Columbia enlisted the help of a human-friendly robot named Charlie to study the simple task of handing an object to a person. Past research has shown that people have difficulty figuring out when to reach out and take an object from a robot because robots fail to provide appropriate nonverbal cues.
“We hand things to other people multiple times a day and we do it seamlessly,” says AJung Moon, a PhD student in the Department of Mechanical Engineering. “Getting this to work between a robot and a person is really important if we want robots to be helpful in fetching us things in our homes or at work.”
Moon and her colleagues studied what people do with their heads, necks and eyes when they hand water bottles to one another. They then tested three variations of this interaction with Charlie and the 102 study participants.
Programming the robot to use eye gaze as a nonverbal cue made the handover more fluid. Researchers found that people reached out to take the water bottle sooner in scenarios where the robot moved its head to look at the area where it would hand over the water bottle or looked to the handover location and then up at the person to make eye contact.
“We want the robot to communicate using the cues that people already recognize,” says Moon. “This is key to interacting with a robot in a safe and friendly manner.”
For the past 50 years, our efforts to detect extraterrestrial civilizations have largely focused on the search for radio emissions. But this is hardly the only strategy at our disposal. Here are 14 intriguing ways we could prove that aliens really exist:
Security firm Kaspersky Lab has launched an interactive cyberthreat map that visualizes cyber security incidents occurring worldwide in real time. A quick glance shows that the world is a pretty scary place.
The interactive map is a promotional tool created by Kaspersky Lab, but it's fascinating nonetheless. Threats displayed include malicious objects detected during on-access and on-demand scans, email and web antivirus detections, as well as objects identified by vulnerability and intrusion detection sub-systems.
Every day Kaspersky Lab handles more than 300,000 malicious objects. Three years ago the figure was just 70,000 but antivirus technologies have also changed with the times and we have no problem coping with this huge stream of traffic. Where do the attacks come from? Where do users click on malicious links most often? Which types of malware are the most prevalent? These are the sort of questions being asked by lots of users. Our new map of the cyberworld threat landscape allows everyone to see the scale of cyber activity in real time and to get a taste of what it feels like to be one of our experts.
Navy researchers at the U.S. Naval Research Laboratory (NRL), Materials Science and Technology Division, demonstrate proof-of-concept of novel NRL technologies developed for the recovery of carbon dioxide (CO2) and hydrogen (H2) from seawater and conversion to a liquid hydrocarbon fuel.
Fueled by a liquid hydrocarbon—a component of NRL's novel gas-to-liquid (GTL) process that uses CO2 and H2 as feedstock—the research team demonstrated sustained flight of a radio-controlled (RC) P-51 replica of the legendary Red Tail Squadron, powered by an off-the-shelf (OTS) and unmodified two-stroke internal combustion engine.
Using an innovative and proprietary NRL electrolytic cation exchange module (E-CEM), both dissolved and bound CO2 are removed from seawater at 92 percent efficiency by re-equilibrating carbonate and bicarbonate to CO2 and simultaneously producing H2. The gases are then converted to liquid hydrocarbons by a metal catalyst in a reactor system.
"In close collaboration with the Office of Naval Research P38 Naval Reserve program, NRL has developed a game changing technology for extracting, simultaneously, CO2 and H2 from seawater," said Dr. Heather Willauer, NRL research chemist. "This is the first time technology of this nature has been demonstrated with the potential for transition, from the laboratory, to full-scale commercial implementation."
CO2 in the air and in seawater is an abundant carbon resource, but the concentration in the ocean (100 milligrams per liter [mg/L]) is about 140 times greater than that in air, and 1/3 the concentration of CO2 from a stack gas (296 mg/L). Two to three percent of the CO2 in seawater is dissolved CO2 gas in the form of carbonic acid, one percent is carbonate, and the remaining 96 to 97 percent is bound in bicarbonate.
NRL has made significant advances in the development of a gas-to-liquids (GTL) synthesis process to convert CO2 and H2 from seawater to a fuel-like fraction of C9-C16 molecules. In the first patented step, an iron-based catalyst has been developed that can achieve CO2 conversion levels up to 60 percent and decrease unwanted methane production in favor of longer-chain unsaturated hydrocarbons (olefins). These value-added hydrocarbons from this process serve as building blocks for the production of industrial chemicals and designer fuels.
An international study involving 380 patients has seen 90% of patients "cured" of Hepatitis C in the course of 12 weeks. Experts are calling the treatment a turning point in the treatment of the pernicious disease, which wreaks havoc on the livers of those it infects. Too bad it costs over $80,000 for a course of treatment.
The treatment goes by the name of Sovaldi and was created by Gilead Sciences. The BBChas a good rundown of the study: Researchers at the University of Texas Health Science Centre tested the new oral drug in 380 patients at 78 centres in Spain, Germany, England and the US in 2013. Two studies were carried out, one in patients for 12 weeks, and another, for 24 weeks. The patients had liver cirrhosis, indicating an advanced form of the virus.
After 12 weeks, 191 of 208 patients no longer had hepatitis C, which increased to 165 of 172 patients, or 96%, after 24 weeks. Lead researcher, Dr Fred Poordad said: "It is fantastic. I am so excited for the patients. There is finally hope for their future." He said the drug worked by targeting the protein that makes hepatitis C and stopping it from replicating. "Eventually the virus is extinguished," he said.
All excellent news, of course. The bad news is that the treatment is ridiculously expensive. Gilead has proposed a global, tiered pricing system that is based on each country's per capita gross national income. According to Reuters, the cost for a full course of treatment in the U.K. is about $57,000; the price in Germany around $66,000; and the price in America around $84,000. That's close to $1,000 a pill for U.S. residents. And in Egypt and other developing countries, the bill amounts to $900 - a whooping 99 percent less than in the U.S.
The company's price scheme has been called "unreasonably high" and "obscene" by care providers like Kaiser Permanente and Molina Healthcare, respectively. Even Congress asked Gilead to justify the price of their drug.
Typically studies of the effects of aging on cognitive-motor performance emphasize changes in elderly populations. Although some research is directly concerned with when age-related decline actually begins, studies are often based on relatively simple reaction time tasks, making it impossible to gauge the impact of experience in compensating for this decline in a real world task. The present study investigates age-related changes in cognitive motor performance through adolescence and adulthood in a complex real world task, the real-time strategy video game StarCraft 2. In this study, the scientists analyze the influence of age on performance using a dataset of 3,305 players, aged 16-44 .
Using a piecewise regression analysis, they find that age-related slowing of within-game, self-initiated response times begins at 24 years of age. They find no evidence for the common belief expertise should attenuate domain-specific cognitive decline. Domain-specific response time declines appear to persist regardless of skill level. A second analysis of dual-task performance finds no evidence of a corresponding age-related decline. Finally, an exploratory analyses of other age-related differences suggests that older participants may have been compensating for a loss in response speed through the use of game mechanics that reduce cognitive load.
MIT: A light lattice that traps atoms may help scientists build networks of quantum information transmitters.
Using a laser to place individual rubidium atoms near the surface of a lattice of light, scientists at MIT and Harvard University have developed a new method for connecting particles — one that could help in the development of powerful quantum computing systems.
The new technique, described in a paper published today in the journal Nature, allows researchers to couple a lone atom of rubidium, a metal, with a single photon, or light particle. This allows both the atom and photon to switch the quantum state of the other particle, providing a mechanism through which quantum-level computing operations could take place.
Moreover, the scientists believe their technique will allow them to increase the number of useful interactions occurring within a small space, thus scaling up the amount of quantum computing processing available.
“This is a major advance of this system,” says Vladan Vuletić, a professor in MIT’s Department of Physics and Research Laboratory for Electronics (RLE), and a co-author of the paper. “We have demonstrated basically an atom can switch the phase of a photon. And the photon can switch the phase of an atom.”
That is, photons can have two polarization states, and interaction with the atom can change the photon from one state to another; conversely, interaction with the photon can change the atom’s phase, which is equivalent to changing the quantum state of the atom from its “ground” state to its “excited” state. In this way the atom-photon coupling can serve as a quantum switch to transmit information — the equivalent of a transistor in a classical computing system. And by placing many atoms within the same field of light, the researchers may be able to build networks that can process quantum information more effectively.
It’s a flu virus so deadly that scientists once halted research on the disease because governments feared it might be used by terrorists to stage a biological attack.
Yet despite the fact that the H5N1 avian influenza has killed 60% of the 650 humans known to be infected since it was identified in Hong Kong 17 years ago, the “bird flu” virus has yet to evolve a means of spreading easily among people.
Now Dutch researchers have found that the virus needs only five favorable gene mutations to become transmissible through coughing or sneezing, like regular flu viruses.
World health officials have long feared that the H5N1 virus will someday evolve a knack for airborne transmission, setting off a devastating pandemic. While the new study suggests the mutations needed are relatively few, it remains unclear whether they’re likely to happen outside the laboratory.
Scientists at Karlsruhe Institute of Technology (KIT) andEvonik Industries have developed a self-healing chemistry that allows for rapid healing of a plastic material using mild heating, restoring its initial molecular structure. It is based on a reversible chemical crosslinking reaction.
The reaction happens at temperatures from 50°C (122°F) to 120°C (248°F).
The material can be restored completely in less than 5 minutes, and is bound even more strongly than before.
Flowability is enhanced at higher temperatures, so the material can also be molded.
The self-healing properties can be transferred to a variety of plastics, including fiber-reinforced plastics components for automotive vehicles and aircraft.
Healing is also possible for material with scratches.
The research results were published in the journal Advanced Materials. Research partners were the Leibniz Institute of Polymer Research, Dresden, and the Australian National University, Canberra.
* The material uses a new low-temperature reversible system based on covalent chemistry, using “hetero Diels–Alder (HDA)” reactions via a new cyanodithioester compound with cyclopentadiene.
Bennu (the asteroid formerly known as “1999 RQ36”) is a time capsule from 4.5 billion years ago. A pristine, carbonaceous asteroid containing the original material from the solar nebula, from which our Solar System formed.
This is the first U.S. mission to return samples from an asteroid to Earth, addressing multiple NASA Solar System Exploration objectives to understand not just the origin of the Solar System, but the origin of water and organic material on Earth.
Key OSIRIS-REx science objectives include:
Return and analyze a sample
Create maps of the asteroid
Document the sample site
Measure the orbit deviation caused by non-gravitational forces
Compare observations at the asteroid to ground-based observations
The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) will launch from Earth and travel for nearly two years to the asteroid Bennu. Upon arrival, OSIRIS-REx will map the total surface, creating a detailed shape model of the asteroid. OSIRIS-REx will also measure the magnitude of the Yarkovsky effect, a factor in the orbits of asteroids that may pose a threat to Earth. The craft will then approach — not land upon — Bennu, and extend a robotic arm to obtain a sample of pristine surface material (at least 60 grams or 2.1 ounces).
Returning to Earth in a Sample Return Capsule, a proven model originally used during the NASA Stardust mission, the material will then be studied by scientists at the NASA Johnson Space Center and from around the world for clues about the composition of the very early Solar System, the source of what may have made life possible on Earth. The data collected at the asteroid will aid our understanding of asteroids that pose an impact hazard to Earth, and the OSIRIS-REx spacecraft will be a pathfinder for future spacecraft that perform reconnaissance on any newly-discovered threatening objects.
Consider a pair of brothers, identical twins. One gets a job as an astronaut and rockets into space. The other gets a job as an astronaut, too, but on this occasion he decides to stay home. After a year in space, the traveling twin returns home and they reunite.
In March of 2015, NASA astronaut Scott Kelly will join cosmonaut Mikhail Kornienko on a one-year mission to the International Space Station. Their lengthy stay aims to explore the effects of long-term space flight on the human body.
The interesting thing about Scott is, he's a twin. His brother Mark is also an astronaut, now retired. While Scott, the test subject, spends one year circling Earth at 17,000 mph, Mark will remain behind as a control.
"We will be taking samples and making measurements of the twins before, during, and after the one-year mission," says Craig Kundrot of NASA's Human Research Program at the Johnson Space Center. "For the first time, we'll be able two individuals who are genetically identical."
NASA's study won't test the flow of time. The ISS would have to approach the speed of light for relativistic effects to kick in. Just about everything else is covered, though. NASA's Human Research Program recently announced the selection of 10 research proposals to study the twins' genetics, biochemistry, vision, cognition and much more.
A few examples to give the flavor of the research: "We already know that the human immune system changes in space. It's not as strong as it is on the ground," explains Kundrot. "In one of the experiments, Mark and Scott will be given identical flu vaccines, and we will study how their immune systems react."
Another experiment will look at telomeres—little molecular "caps" on the ends of human DNA. Here on Earth, the loss of telomeres has been linked to aging. In space, telomere loss could be accelerated by the action of cosmic rays. Comparing the twins' telomeres could tell researchers if space radiation is prematurely aging space travelers.
Meanwhile in the gut, says Kundrot, "there is a whole microbiome essential to human digestion. One of the experiments will study what space travel does to the inner bacteria which, by the way, outnumber human cells by 10-to-1."
Other proposals are equally fascinating. One seeks to discover why astronaut vision changes in space. "Sometimes, their old glasses from Earth don't work," notes Kundrot. Another will probe a phenomenon called "space fog"—a lack of alertness and slowing of mental gears reported by some astronauts in orbit.
"These will not be 10 individual studies," says Kundrot. "The real power comes in combining them to form an integrated picture of all levels from biomolecular to psychological. We'll be studying the entire astronaut."
Rescue bid launched to save Hainan gibbon from becoming first ape driven to extinction by humans.
China’s wildlife conservation efforts are under scrutiny as scientists battle to save a species found only in a tiny corner of an island in the South China Sea. The Hainan gibbon is the world’s rarest primate and its long-term survival is in jeopardy, according to an analysis.
Only 23 to 25 of the animals are thought to remain, clustered in less than 20 square kilometers of forest in China’s Hainan Island. The species (Nomascus hainanus), which numbered more than 2,000 in the late 1950s, has been devastated through the destruction of habitat from logging, and by poaching. Extinction would give the gibbon the unwelcome distinction of being the first ape to be wiped out because of human actions. To hammer out a plan to save it, international primate researchers convened an emergency summit in Hainan last month.
“With the right conservation management, it is still possible to conserve and recover the Hainan gibbon population,” says meeting co-chair Samuel Turvey, who studies animal extinctions at the Zoological Society of London (ZSL). “But given the current highly perilous state of the species, we cannot afford to wait any longer before initiating a more proactive and coordinated recovery programme.” He adds that the meeting was a successful first step towards saving the animal and that a plan of action is being finalized.
The plan will be based in part on a ‘population viability analysis’ that models the potential size of the gibbon population in coming decades for a range of different scenarios. It is being drawn up by Kathy Traylor Holzer, a conservation planner at the Conservation Breeding Specialist Group in Apple Valley, Minnesota. “It’s one of the smallest populations I’ve ever worked with,” says Traylor Holzer. “That number — in one place — is extremely scary.”
The lunar eclipses of 2014 are the first of four consecutive total lunar eclipses - a series known as a tetrad. During the 5000-year period from -1999 to +3000, there are 4378 penumbral eclipses (36.3%), 4207 partial lunar eclipses (34.9%) and 3479 total lunar eclipses (28.8%). Approximately 16.3% (568) of all total eclipses belong to one of the 142 tetrads occurring over this period (Espenak and Meeus, 2009). The mechanism causing tetrads involves the eccentricity of Earth's orbit in conjunction with the timing of eclipse seasons (Meeus, 2004).
During the present millennium, the first eclipse of every tetrad occurs sometime from February to July. In later millennia, the first eclipse date gradually falls later in the year because of precession.
Italian astronomer Giovanni Schiaparelli first pointed out that the frequency of tetrads is variable over time. He noticed that tetrads were relatively plentiful during one 300-year interval, while none occurred during the next 300 years. For example, there are no tetrads from 1582 to 1908, but 17 tetrads occur during the following 2 and 1/2 centuries from 1909 to 2156. The ~565-year period of the tetrad "seasons" is tied to the slowly decreasing eccentricity of Earth's orbit. Consequently, the tetrad period is gradually decreasing (Meeus, 2004). In the distant future when Earth's eccentricity is 0, tetrads will no longer be possible.
The umbral magnitudes of the total eclipses making up a tetrad are all relatively small. For the 300-year period 1901 to 2200, the largest umbral magnitude of a tetrad eclipse is 1.4251 on 1949 Apr 13. For comparison, some other total eclipses during this period are much deeper. Two examples are the total eclipses of 2000 Jul 16 and 2029 Jun 26 with umbral magnitudes of 1.7684 and 1.8436, respectively.
David Newman, a physicist at the University of Alaska, believes that smaller grids would reduce the likelihood of severe outages, such as the 2003 Northeast blackout that cut power to 50 million people in the United States and Canada for up to two days.
Newman and co-authors make their case in the journal Chaos. North America has three power grids that transmit electricity from hundreds of power plants to millions of consumers. Each grid is huge, because the more power plants and power lines in a grid, the better it can even out local variations in the supply and demand or respond if some part of the grid goes down.
But large grids are vulnerable to the rare but significant possibility of a grid-wide blackout like the one in 2003, when overloaded transmission lines hit unpruned foliage in Ohio, combined with a software bug a power-plant alarm system.
“The problem is that grids run close to the edge of their capacity because of economic pressures. Electric companies want to maximize profits, so they don’t invest in more equipment than they need,” Newman said.
In their new paper, the researchers ask whether the grid has an optimal size, one large enough to share power efficiently but small enough to prevent enormous blackouts.
The team based its analysis on the Western United States grid, which has more than 16,000 nodes. Nodes include generators, substations, and transformers, which convert high-voltage electricity into low-voltage power for homes and business.
The model started by comparing one 1,000-bus grid with ten 100-bus networks. It then assessed how well the grids shared electricity in response to virtual outages.
“We found that for the best tradeoff between providing backup power and blackout risk, the optimal size was 500 to 700 nodes,” Newman said.
The University of California, Berkeley, and UC San Francisco are launching the Innovative Genomics Initiative (IGI) to lead a revolution in genetic engineering based on a new technology already generating novel strategies for gene therapy and the genetic study of disease.
The Li Ka Shing Foundation has provided a $10 million gift to support the initiative, establishing the Li Ka Shing Center for Genomic Engineering and an affiliated faculty chair at UC Berkeley. The two universities also will provide $2 million in start-up funds.
At the core of the initiative is a revolutionary technology discovered two years ago at UC Berkeley by Jennifer A. Doudna, executive director of the initiative and the new faculty chair. The technology, precision "DNA scissors" referred to as CRISPR/Cas9, has exploded in popularity since it was first published in June 2012 and is at the heart of at least three start-ups and several heavily-attended international meetings. Scientists have referred to it as the "holy grail" of genetic engineering and a "jaw-dropping" breakthrough in the fight against genetic disease. In honor of her discovery and earlier work on RNA, Doudna received last month the Lurie Prize of the Foundation for the National Institutes of Health.
"Professor Doudna's breakthrough discovery in genomic editing is leading us into a new era of possibilities that we could have never before imagined," said Li Ka-shing, chairman of the Li Ka Shing Foundation. "It is a great privilege for my foundation to engage with two world-class public institutions to launch the Innovative Genomics Initiative in this quest for the holy grail to fight genetic diseases."
In the 18 months since the discovery of this technology was announced, more than 125 papers have been published based on the technique. Worldwide, researchers are using Cas9 to investigate the genetic roots of problems as diverse as sickle cell anemia, diabetes, cystic fibrosis, AIDS and depression in hopes of finding new drug targets. Others are adapting the technology to reengineer yeast to produce biofuels and wheat to resist pests and drought.
The new genomic engineering technology significantly cuts down the time it takes researchers to test new therapies. CRISPR/Cas 9 allows the creation in weeks rather than years of animal strains that mimic a human disease, allowing researchers to test new therapies. The technique also makes it quick and easy to knock out genes in human cells or in animals to determine their function, which will speed the identification of new drug targets for diseases.
"We now have a very easy, very fast and very efficient technique for rewriting the genome, which allows us to do experiments that have been impossible before," said Doudna, a professor of molecular and cell biology in the California Institute for Quantitative Biosciences (QB3) and an investigator in the Howard Hughes Medical Institute at UC Berkeley. "We are grateful to Mr. Li Ka-shing for his support of our initiative, which will propel ground-breaking advances in genomic engineering."
A new type of pertussis vaccine introduced in the late 1990s may have led to the return of a disease that was nearly eradicated 40 years ago. Public opposition to vaccination hasn’t helped matters.
Whooping cough has turned up in North America after decades of near absence, and we have only ourselves to blame. In the last several years, the highly contagious microbe that causes whooping cough has spawned a string of outbreaks, adeptly piercing the shield of vaccination that once afforded solid protection against it. The last time whooping cough was this pervasive in the United States, Dwight Eisenhower was president and newscasters were smoking cigarettes on TV.
Caused by the Bordetella pertussis bacterium, whooping cough is emerging from the shadows in response to a fateful switch of vaccines embraced in the 1990s, just when it seemed the disease was licked. The vaccine used today has proved less potent than its predecessor. Meanwhile, curious changes are appearing in the pertussis bacterium itself, possibly in response to the weaker vaccine, and they may further undermine its effect. To top it off, a phobia against vaccines has induced some parents to skip or delay their kids’ shots, contributing to the disease’s spread.
“The newer vaccine’s protection wanes over time, the pathogen is morphing and more patients aren’t getting vaccinated on time,” says Jason Glanz, an epidemiologist at the University of Colorado Denver and the Kaiser Permanente Institute for Health Research Colorado. “Put them together and you get greatly increased risk.”
The rise and fall of acid rain is a global experiment whose results are preserved in the geologic record. By analyzing samples from the Greenland ice sheet, University of Washington atmospheric scientists found clear evidence of the U.S. Clean Air Act. They also discovered a link between air acidity and how nitrogen is preserved in layers of snow, according to a paperpublished this week in the Proceedings of the National Academy of Sciences.
Forty-five years ago, acid rain was killing fish and dissolving stone monuments on the East Coast. Air pollution rose beginning with the Industrial Revolution and started to improve when the U.S. Clean Air Act of 1970 required coal power plants and other polluters to scrub sulfur out of their smokestacks.
UW researchers began their study of ice cores interested in smog, not acid rain. They discovered a link between the two forms of pollution in the geologic record.
“How much the nitrate concentrations in ice core records can tell about NOx and the chemistry in the past atmosphere is a longstanding question in the ice-core community,” said lead author Lei Geng, a UW postdoctoral researcher in atmospheric sciences.
Unlike other gases, short-lived NOx can’t be measured directly from air bubbles trapped in ice cores. Within a day or two most of the NOx changes into nitrate, a water-soluble molecule essential to life that gets deposited in soil and snow.
Earlier research by co-author Eric Steig, a UW professor of Earth and space sciences, suggested that comparing amounts of the two stable forms of nitrogen – nitrogen-15 and nitrogen-14 – in nitrate could pinpoint the emission sources of NOx. Ice cores from Greenland and North American lake sediments showed the nitrogen-15 ratio gradually decreasing since 1850, suggesting a corresponding rise in human emissions.
“The isotope records really closely follow the atmospheric acidity trends,” said co-author Becky Alexander, a UW associate professor of atmospheric sciences. “You can really see the effect of the Clean Air Act in 1970, which had the most dramatic impact on emission of acid from coal-fired power plants.”
Researchers at the University of Missouri have discovered rare, fossilized embryos that may provide valuable insight into a time of rapid expansion and diversification among the world's first organisms, according to a release from the school.
Known as the "Cambrian explosion," most of the world's marine
invertebrates first appeared in the fossil record during this period. While much of the record is comprised of skeletal structures - which may or may not give researchers an accurate picture of prehistoric organisms - the University of Missouri find includes previously undiscovered soft-tissue fossils, which could help with future interpretations of evolutionary history.
"Before the Ediacaran and Cambrian Periods, organisms were unicellular and simple," said James Schiffbauer, assistant professorof geological sciences at the University of Missouri. "The Cambrian Period, which occurred between 540 million and 485 million years ago, ushered in the advent of shells."
He said the shells and exoskeletons become fossilized over time, giving scientists clues into how organisms existed millions of years ago. He added that the development of shells provided "protection and structural integrity for organisms."
Schiffbauer's work focuses on harder-to-find, soft-tissue organisms that were not preserved as well and, thus, are less plentiful. His team, which includes Missouri University doctoral student Jesse Broce, now is studying fossilized embryos in rocks that provide rare opportunities to study the origins and developmental biology of early animals during the Cambrian explosion.
Broce collected fossils from the lower Cambrian Shuijingtuo Formation in the Hubei Province in southern China and analyzed samples to determine the chemical makeup of the rocks. Soft tissue fossils have different chemical patterns than harder, skeletal remains, allowing researchers to identify the processes that contributed to their preservation.
Novel study uncovers the way coughs and sneezes stay airborne for long distances.
The next time you feel a sneeze coming on, raise your elbow to cover up that multiphase turbulent buoyant cloud you’re about to expel.
That’s right: A novel study by MIT researchers shows that coughs and sneezes have associated gas clouds that keep their potentially infectious droplets aloft over much greater distances than previously realized.
“When you cough or sneeze, you see the droplets, or feel them if someone sneezes on you,” says John Bush, a professor of applied mathematics at MIT, and co-author of a new paper on the subject. “But you don’t see the cloud, the invisible gas phase. The influence of this gas cloud is to extend the range of the individual droplets, particularly the small ones.”
Indeed, the study finds, the smaller droplets that emerge in a cough or sneeze may travel five to 200 times further than they would if those droplets simply moved as groups of unconnected particles — which is what previous estimates had assumed. The tendency of these droplets to stay airborne, resuspended by gas clouds, means that ventilation systems may be more prone to transmitting potentially infectious particles than had been suspected.
With this in mind, architects and engineers may want to re-examine the design of workplaces and hospitals, or air circulation on airplanes, to reduce the chances of airborne pathogens being transmitted among people.
The researchers used high-speed imaging of coughs and sneezes, as well as laboratory simulations and mathematical modeling, to produce a new analysis of coughs and sneezes from a fluid-mechanics perspective. Their conclusions upend some prior thinking on the subject. For instance: Researchers had previously assumed that larger mucus droplets fly farther than smaller ones, because they have more momentum, classically defined as mass times velocity.
Specifically, the study finds that droplets 100 micrometers — or millionths of a meter — in diameter travel five times farther than previously estimated, while droplets 10 micrometers in diameter travel 200 times farther. Droplets less than 50 micrometers in size can frequently remain airborne long enough to reach ceiling ventilation units.
Four teenage girls have received vaginas grown from their own cells in a lab. And they work. These girls were born with underdeveloped or missing vaginas because of a rare condition called Mayer-Rokitansky-Küster-Hauser Syndrome that affects about 1 in 5,000 women. While their labia looked like those of other girls, their vaginas, cervixes and wombs, which are necessary for menstruation and childbirth, never fully formed.
Medical researchers took a vaginal tissue sample from each patient, who were between 13 and 18 at the time, and used them to grow cells in the lab. After four weeks, the researchers had enough cells to layer them on to degradable scaffolding — “like the layers of a cake,” lead researcher Anthony Atala of the Wake Forest School of Medicine explained.Then they were implanted.
The surgeries were done between 2005 and 2008. Atala and the team monitored the women for long-term complications before publishing the results in the medical journal The Lancet this week. The achievement was the work of a large team listed here.
The technique is a potentially important alternative to reconstructing tissue using grafts from other parts of the body, which medical researchers say produces too many complications. The trick was growing cells until they were mature enough to “recruit” other cells once implanted in the body and form tissue that includes blood vessels and nerves.