Changes in agriculture increase high river flow rates

http://feeds.feedburner.com/~r/sciencedaily/plants_animals/agriculture_and_food/~4/UEOTqBUD3ZE

Just as a leaky roof can make a house cooler and wetter when it’s raining as well as hotter and dryer when it’s sunny, changes in land use can affect river flow in both rainy and dry times, say two University of Iowa researchers.While it may be obvious that changes in river water discharge across the U.S. Midwest can be related to changes in rainfall and agricultural land use, it is important to learn how these two factors interact in order to get a better understanding of what the future may look like, says Gabriele Villarini, UI assistant professor of civil and environmental engineering, assistant research engineer at IIHR — Hydroscience & Engineering and lead author of a published research paper on the subject.”We wanted to know what the relative impacts of precipitation and agricultural practices played in shaping the discharge record that we see today,” he says. “Is it an either/or answer or a much more nuanced one?”By understanding our past we are better positioned in making meaningful statements about our future,” he says.The potential benefits of understanding river flow are especially great in the central United States, particularly Iowa, where spring and summer floods have hit the area in 1993, 2008, 2013 and 2014, interrupted by the drought of 2012. Large economic damage and even loss of life have resulted, says co-author Aaron Strong, UI assistant professor in the Department of Urban and Regional Planning and with the Environmental Policy Program at the UI Public Policy Center.”What is interesting to note,” says Strong, “is that the impacts, in terms of flooding, have been exacerbated. At the same time, the impacts of drought, for in-stream flow, have been mitigated with the changes in land use composition that we have seen over the last century.”In order to study the effect of changes in agricultural practices on Midwest river discharge, the researchers focused on Iowa’s Raccoon River at Van Meter, Iowa. The 9,000-square-kilometer watershed has the advantage of having had its water discharge levels measured and recorded daily for most of the 20th century right on up to the present day. (The study focused on the period 1927-2012). During that period, the number of acres used for corn and soybean production greatly increased, roughly doubling over the course of the 20th century.Not surprisingly, they found that variability in rainfall is responsible for most of the changes in water discharge volumes.However, the water discharge rates also varied with changes in agricultural practices, as defined by soybean and corn harvested acreage in the Raccoon River watershed. In times of flood and in times of drought, water flow rates were exacerbated by more or less agriculture, respectively. The authors suggest that although flood conditions may be exacerbated by increases in agricultural production, this concern “must all be balanced by the private concerns of increased revenue from agricultural production through increased cultivation.””Our results suggest that changes in agricultural practices over this watershed — with increasing acreage planted in corn and soybeans over time — translated into a seven-fold increase in rainfall contribution to the average annual maximum discharge when we compare the present to the 1930s,” Villarini says.The UI research paper, “Roles of climate and agricultural practices in discharge changes in an agricultural watershed in Iowa,” can be found in the April 15 online edition of Agriculture, Ecosystems & Environment.Story Source:The above story is based on materials provided by University of Iowa. …


Read More: Changes in agriculture increase high river flow rates

#Agriculture, #Alternative-Medicine, #Alzheimer, #Climate, #Engineering, #Health, #Iowa, #King, #Program, #University

Bats inspire "micro air vehicle" designs: Small flying vehicles, complete with flapping wings, may now be designed

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_science/~4/zc_z87CQAXM

By exploring how creatures in nature are able to fly by flapping their wings, Virginia Tech researchers hope to apply that knowledge toward designing small flying vehicles known as “micro air vehicles” with flapping wings.More than 1,000 species of bats have hand membrane wings, meaning that their fingers are essentially “webbed” and connected by a flexible membrane. But understanding how bats use their wings to manipulate the air around them is extremely challenging — primarily because both experimental measurements on live creatures and the related computer analysis are quite complex.In Virginia Tech’s study of fruit bat wings, the researchers used experimental measurements of the movements of the bats’ wings in real flight, and then used analysis software to see the direct relationship between wing motion and airflow around the bat wing. They report their findings in the journal Physics of Fluids.”Bats have different wing shapes and sizes, depending on their evolutionary function. Typically, bats are very agile and can change their flight path very quickly — showing high maneuverability for midflight prey capture, so it’s of interest to know how they do this,” explained Danesh Tafti, the William S. Cross professor in the Department of Mechanical Engineering and director of the High Performance Computational Fluid Thermal Science and Engineering Lab at Virginia Tech.To give you an idea of the size of a fruit bat, it weighs roughly 30 grams and a single fully extended wing is about 17 x 9 cm in length, according to Tafti.Among the biggest surprises in store for the researchers was how bat wings manipulated the wing motion with correct timing to maximize the forces generated by the wing. “It distorts its wing shape and size continuously during flapping,” Tafti noted.For example, it increases the area of the wing by about 30 percent to maximize favorable forces during the downward movement of the wing, and it decreases the area by a similar amount on the way up to minimize unfavorable forces. The force coefficients generated by the wing are “about two to three times greater than a static airfoil wing used for large airplanes,” said Kamal Viswanath, a co-author who was a graduate research assistant working with Tafti when the work was performed and is now a research engineer at the U.S. Naval Research Lab’s Laboratories for Computational Physics and Fluid Dynamics.This study was just an initial step in the researchers’ work. “Next, we’d like to explore deconstructing the seemingly complex motion of the bat wing into simpler motions, which is necessary to make a bat-inspired flying robot,” said Viswanath. The researchers also want to keep the wing motion as simple as possible, but with the same force production as that of a real bat.”We’d also like to explore other bat wing motions, such as a bat in level flight or a bat trying to maneuver quickly to answer questions, including: What are the differences in wing motion and how do they translate to air movement and forces that the bat generates? …


Read More: Bats inspire "micro air vehicle" designs: Small flying vehicles, complete with flapping wings, may now be designed

#American, #Area, #Cancer, #Computational, #Cross, #Department, #Engineering, #Flight, #Health, #Pregnancy, #Virginia

Researchers hijack cancer migration mechanism to "move" brain tumors

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_health/~4/3pWs49Ta29s

One factor that makes glioblastoma cancers so difficult to treat is that malignant cells from the tumors spread throughout the brain by following nerve fibers and blood vessels to invade new locations. Now, researchers have learned to hijack this migratory mechanism, turning it against the cancer by using a film of nanofibers thinner than human hair to lure tumor cells away.Instead of invading new areas, the migrating cells latch onto the specially-designed nanofibers and follow them to a location — potentially outside the brain — where they can be captured and killed. Using this technique, researchers can partially move tumors from inoperable locations to more accessible ones. Though it won’t eliminate the cancer, the new technique reduced the size of brain tumors in animal models, suggesting that this form of brain cancer might one day be treated more like a chronic disease.”We have designed a polymer thin film nanofiber that mimics the structure of nerves and blood vessels that brain tumor cells normally use to invade other parts of the brain,” explained Ravi Bellamkonda, lead investigator and chair of the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “The cancer cells normally latch onto these natural structures and ride them like a monorail to other parts of the brain. By providing an attractive alternative fiber, we can efficiently move the tumors along a different path to a destination that we choose.”Details of the technique were reported February 16 in the journal Nature Materials. The research was supported by the National Cancer Institute (NCI), part of the National Institutes of Health; by Atlanta-based Ian’s Friends Foundation, and by the Georgia Research Alliance. In addition to the Coulter Department of Biomedical Engineering, the research team included Children’s Healthcare of Atlanta and Emory University.Treating the Glioblastoma multiforme cancer, also known as GBM, is difficult because the aggressive and invasive cancer often develops in parts of the brain where surgeons are reluctant to operate. Even if the primary tumor can be removed, however, it has often spread to other locations before being diagnosed.New drugs are being developed to attack GBM, but the Atlanta-based researchers decided to take a more engineering approach. …


Read More: Researchers hijack cancer migration mechanism to "move" brain tumors

#Alternative-Medicine, #Cancer, #Coulter, #Engineering, #Georgia, #Health, #Institute, #Pregnancy, #Professor, #Science

Herding robots: New system combines control programs so fleets of robots can collaborate

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_science/~4/0p80EGz2e5U

A new system combines simple control programs to enable fleets of robots — or other “multiagent systems” — to collaborate in unprecedented ways.Writing a program to control a single autonomous robot navigating an uncertain environment with an erratic communication link is hard enough; write one for multiple robots that may or may not have to work in tandem, depending on the task, is even harder.As a consequence, engineers designing control programs for “multiagent systems” — whether teams of robots or networks of devices with different functions — have generally restricted themselves to special cases, where reliable information about the environment can be assumed or a relatively simple collaborative task can be clearly specified in advance.This May, at the International Conference on Autonomous Agents and Multiagent Systems, researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) will present a new system that stitches existing control programs together to allow multiagent systems to collaborate in much more complex ways. The system factors in uncertainty — the odds, for instance, that a communication link will drop, or that a particular algorithm will inadvertently steer a robot into a dead end — and automatically plans around it.For small collaborative tasks, the system can guarantee that its combination of programs is optimal — that it will yield the best possible results, given the uncertainty of the environment and the limitations of the programs themselves.Working together with Jon How, the Richard Cockburn Maclaurin Professor of Aeronautics and Astronautics, and his student Chris Maynor, the researchers are currently testing their system in a simulation of a warehousing application, where teams of robots would be required to retrieve arbitrary objects from indeterminate locations, collaborating as needed to transport heavy loads. The simulations involve small groups of iRobot Creates, programmable robots that have the same chassis as the Roomba vacuum cleaner.Reasonable doubt”In [multiagent] systems, in general, in the real world, it’s very hard for them to communicate effectively,” says Christopher Amato, a postdoc in CSAIL and first author on the new paper. “If you have a camera, it’s impossible for the camera to be constantly streaming all of its information to all the other cameras. Similarly, robots are on networks that are imperfect, so it takes some amount of time to get messages to other robots, and maybe they can’t communicate in certain situations around obstacles.”An agent may not even have perfect information about its own location, Amato says — which aisle of the warehouse it’s actually in, for instance. Moreover, “When you try to make a decision, there’s some uncertainty about how that’s going to unfold,” he says. “Maybe you try to move in a certain direction, and there’s wind or wheel slippage, or there’s uncertainty across networks due to packet loss. So in these real-world domains with all this communication noise and uncertainty about what’s happening, it’s hard to make decisions.”The new MIT system, which Amato developed with co-authors Leslie Kaelbling, the Panasonic Professor of Computer Science and Engineering, and George Konidaris, a fellow postdoc, takes three inputs. One is a set of low-level control algorithms — which the MIT researchers refer to as “macro-actions” — which may govern agents’ behaviors collectively or individually. The second is a set of statistics about those programs’ execution in a particular environment. …


Read More: Herding robots: New system combines control programs so fleets of robots can collaborate

#Agriculture, #Amato, #Computerscience, #Engineering, #George, #King, #Mit, #Video

Optimizing donor kidney distribution in the United States

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_health/~4/JHcIskAW8R4

Northwestern University’s Sanjay Mehrotra has developed an innovative model that could help ease kidney distribution inequities among regions in the U.S. and ultimately help save hundreds of lives. His mathematical model, which takes into account a number of different factors, simulates and optimizes donor kidney distribution.Mehrotra will discuss his research in a presentation titled “Addressing Allocation Inefficiencies and Geographic Disparities” at the American Association for the Advancement of Science (AAAS) annual meeting in Chicago. His presentation is part of a symposium titled “Transplant Organ Shortage: Informing National Policies Using Management Sciences” to be held from 10 to 11:30 a.m. CST Friday, Feb. 14, in Columbus IJ of the Hyatt Regency Chicago.Mehrotra also will participate in a press briefing to be held at 1 p.m. CST the same day in Vevey Room 3 of the Swisstel Chicago.In addition to Mehrotra, two other Northwestern professors will discuss issues related to organ shortage during both the symposium and press briefing.Michael Abecassis, M.D., chief of the division of organ transplantation and founding director of the Comprehensive Transplant Center at Northwestern University Feinberg School of Medicine, will offer a brief overview of the current issues facing organ allocation.John Friedewald, M.D., associate professor in medicine and surgery at Feinberg and director of clinical research at Northwestern University Feinberg School of Medicine Comprehensive Transplant Center and transplant nephrologist at Northwestern Memorial Hospital, will speak about policy changes in kidney allocation that were developed during his recent term as chair of the United Network for Organ Sharing Kidney Transplantation Committee.Nearly 100,000 people in the United States are waiting for kidney transplants, but only 17,000 kidneys are available annually from both living and deceased donors. There are major regional inequalities in access to organs because of supply and demand disparities among different areas of the country. A person in one state might get a kidney within a year, while someone in another state might wait up to four years. As a consequence, nearly 5,000 people die each year waiting for a kidney transplant.Logistically, organ allocation is a difficult problem. …


Read More: Optimizing donor kidney distribution in the United States

#Alzheimer, #Chief, #Comprehensive, #Engineering, #Health-Insurance, #Management, #Mehrotra, #National, #Network, #Organ, #Professor, #Science

Paclitaxel Nanoparticles to Treat Late Stage Peritoneal Mesothelioma

A group of graduate students and postdoctoral fellows at Boston Universityare trying to find a better treatment for late-stage peritoneal mesothelioma. The group is developing a method to deliver chemotherapy drugs directly to tumor cells withnanoparticleswhich are absorbed by the tumor cells and release the drugs. The detailedstudypublished February 4, on the BU College of Engineering site is part of a four part series detailing current research projects being performed bytheGrinstaff Group.The Grinstaff Group chose to focus on peritoneal mesothelioma because it is easier to isolate and does not metastasize like other cancers, theoretically making it easier to attack with an innovative drug delivery system, in this case – nanoparticles loaded with paclitaxel, a chemotherapy drug commonly used to treat mesothelioma.The nanoparticles are composed of squiggly …


Read More: Paclitaxel Nanoparticles to Treat Late Stage Peritoneal Mesothelioma

#Engineering, #Grinstaff, #Grinstaffgroup, #King, #Mesothelioma, #Nanoparticles, #Paclitaxel, #Professor, #School, #Study, #Universityare

Cochlear implant with no exterior hardware can be wirelessly recharged

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_health/~4/Jdg-8JyXQqg

Cochlear implants — medical devices that electrically stimulate the auditory nerve — have granted at least limited hearing to hundreds of thousands of people worldwide who otherwise would be totally deaf. Existing versions of the device, however, require that a disk-shaped transmitter about an inch in diameter be affixed to the skull, with a wire snaking down to a joint microphone and power source that looks like an oversized hearing aid around the patient’s ear.Researchers at MIT’s Microsystems Technology Laboratory (MTL), together with physicians from Harvard Medical School and the Massachusetts Eye and Ear Infirmary (MEEI), have developed a new, low-power signal-processing chip that could lead to a cochlear implant that requires no external hardware. The implant would be wirelessly recharged and would run for about eight hours on each charge.The researchers describe their chip in a paper they’re presenting this week at the International Solid-State Circuits Conference. The paper’s lead author — Marcus Yip, who completed his PhD at MIT last fall — and his colleagues Rui Jin and Nathan Ickes, both in MIT’s Department of Electrical Engineering and Computer Science, will also exhibit a prototype charger that plugs into an ordinary cell phone and can recharge the signal-processing chip in roughly two minutes.”The idea with this design is that you could use a phone, with an adaptor, to charge the cochlear implant, so you don’t have to be plugged in,” says Anantha Chandrakasan, the Joseph F. and Nancy P. Keithley Professor of Electrical Engineering and corresponding author on the new paper. “Or you could imagine a smart pillow, so you charge overnight, and the next day, it just functions.”Adaptive reuseExisting cochlear implants use an external microphone to gather sound, but the new implant would instead use the natural microphone of the middle ear, which is almost always intact in cochlear-implant patients.The researchers’ design exploits the mechanism of a different type of medical device, known as a middle-ear implant. Delicate bones in the middle ear, known as ossicles, convey the vibrations of the eardrum to the cochlea, the small, spiral chamber in the inner ear that converts acoustic signals to electrical. In patients with middle-ear implants, the cochlea is functional, but one of the ossicles — the stapes — doesn’t vibrate with enough force to stimulate the auditory nerve. A middle-ear implant consists of a tiny sensor that detects the ossicles’ vibrations and an actuator that helps drive the stapes accordingly.The new device would use the same type of sensor, but the signal it generates would travel to a microchip implanted in the ear, which would convert it to an electrical signal and pass it on to an electrode in the cochlea. …


Read More: Cochlear implant with no exterior hardware can be wirelessly recharged

#Circuits, #Engineering, #Francisco, #International, #Massachusetts, #Medical, #Mit, #Science, #University