Tech

As the authors posit, the collapse of the Soviet Union led to decreasing meat product consumption, abandonment of cultivated land, and restructuring of food sales chains; which, in turn, elicited a decrease in greenhouse gas emissions.

Leading Research Associate of the Space Ecology Lab Alexander Prischepov elucidates, "The decrease in greenhouse gas emissions, mostly carbon dioxide, is linked to the abandonment of arable land. There are about 70 to 80 million hectares of abandoned fields in Russia now. It's good for nature when there is a controlled abandonment process. Ecosystems are rejuvenated, soils are at rest, and carbon is deposited in them. If the abandonment process is uncontrolled, the land can be occupied by forests and hogweed; and more forests means that fires are more probable. Also, an afforested land plot is less economically viable when considered for agricultural use."

Globally, animal husbandry contributes 14.5% of all anthropogenic greenhouse gas emissions. It's about the same as the combined volume of emissions from all types of vehicles, including cars, ships, airplanes, etc.

The collapse of the Soviet Union, as the paper states, led to a decrease in income, which was the reason for the lowering meat and dairy consumption. Agricultural sales chains also changed. As a result, the total emission decreased by 7.61 billion tons of carbon dioxide equivalent from 1992 to 2001.

"The main factors of the decrease were the falling consumption of beef in the 1990s, increasing beef imports after 2000, mainly from Latin America, and the bonding of carbon in abandoned agricultural soils. As an example, this is approximately equal to a quarter of carbon dioxide emissions resulting from deforestation in Latin America in 1992 - 2001," says Prischepov.

Currently, Russia emits about 2.5 billion tons of greenhouse gases a year. The researchers are convinced that the decrease of emission in the former USSR may contribute to an appropriate increase in emissions in the countries - main exporters of agricultural goods to Russia and its neighbors.

Electrodes implanted in the brain help alleviate symptoms like the intrusive tremors associated with Parkinson's disease. But current probes face limitations due to their size and inflexibility. "The brain is squishy and these implants are rigid," said Shaun Patel. About four years ago, when he discovered Charles M. Lieber's ultra-flexible alternatives, he saw the future of brain-machine interfaces.

In a recent perspective titled "Precision Electronic Medicine," published in Nature Biotechnology, Patel, a faculty member at the Harvard Medical School and Massachusetts General Hospital, and Lieber, the Joshua and Beth Friedman University Professor, argue that neurotechnology is on the cusp of a major renaissance. Throughout history, scientists have blurred discipline lines to tackle problems larger than their individual fields. The Human Genome Project, for example, convened international teams of scientists to map human genes faster than otherwise possible.

"The next frontier is really the merging of human cognition with machines," Patel said. He and Lieber see mesh electronics as the foundation for those machines, a way to design personalized electronic treatment for just about anything related to the brain.

"Everything manifests in the brain fundamentally. Everything. All your thoughts, your perceptions, any type of disease," Patel said.

Scientists can pinpoint the general areas of the brain where decision-making, learning, and emotions originate, but tracing behaviors to specific neurons is still a challenge. Right now, when the brain's complex circuitry starts to misbehave or degrade due to psychiatric illnesses like addiction or Obsessive-Compulsive Disorder, neurodegenerative diseases like Parkinson's or Alzheimer's, or even natural aging, patients have only two options for medical intervention: drugs or, when those fail, implanted electrodes.

Drugs like L-dopa can quiet the tremors that prevent someone with Parkinson's from performing simple tasks like dressing and eating. But because drugs affect more than just their target, even common L-dopa side effects can be severe, ranging from nausea to depression to abnormal heart rhythms.

When drugs no longer work, FDA-approved electrodes can provide relief through Deep Brain Stimulation. Like a pace maker, a battery pack set beneath the clavicle sends automated electrical pulses to two brain implants. Lieber said each electrode "looks like a pencil. It's big."

During implantation, Parkinson's patients are awake, so surgeons can calibrate the electrical pulses. Dial the electricity up, and the tremors calm. "Almost instantly, you can see the person regain control of their limbs," Patel said. "It blows my mind."

But, like with L-dopa, the large electrodes stimulate more than their intended targets, causing sometimes severe side effects like speech impediments. And, over time, the brain's immune system treats the stiff implants as foreign objects: Neural immune cells (glia cells) engulf the perceived invader, displacing or even killing neurons and reducing the device's ability to maintain treatment.

In contrast, Lieber's mesh electronics provoke almost no immune response. With close, long-term proximity to the same neurons, the implants can collect robust data on how individual neurons communicate over time or, in the case of neurological disorders, fail to communicate. Eventually, such technology could track how specific neural subtypes talk, too, all of which could lead to a cleaner, more precise map of the brain's communication network.

With higher resolution targets, future electrodes can act with greater precision, eliminating unwanted side effects. If that happens, Patel said, they could be tuned to treat any neurological disorder. And, unlike current electrodes, Lieber's have already demonstrated a valuable trick of their own: They encourage neural migration, potentially guiding newborn neurons to damaged areas, like pockets created by stroke.

"The potential for it is outstanding," Patel said. "In my own mind, I see this at the level of what started with the transistor or telecommunications."

The potential reaches beyond therapeutics: Adaptive electrodes could provide heightened control over prosthetic or even paralyzed limbs. In time, they could act like neural substitutes, replacing damaged circuitry to re-establish broken communication networks and recalibrate based on live feedback. "If you could actually interact in a precise and long-term way and also provide feedback information," Lieber said, "you could really communicate with the brain in the same way that the brain is communicating within itself."

A few major technology companies are also eager to champion brain-machine interfaces. Some, like Elon Musk's Neuralink, which plans to give paralyzed patients the power to work computers with their minds, are focused on assistive applications. Others have broader plans: Facebook wants people to text by imaging the words, and Brian Johnson's Kernel hopes to enhance cognitive abilities.

During his postdoctoral studies, Patel saw how just a short pulse of electricity--no more than 500 milliseconds of stimulation--could control a person's ability to make a safe or impulsive decision. After a little zap, subjects who almost always chose the risky bet, instead went with the safe option. "You would have no idea that it's happened," Patel said. "You're unaware of it. It's beyond your conscious awareness."

Such power demands intense ethical scrutiny. For people struggling to combat addiction or obsessive-compulsive disorder, an external pulse regulator could significantly improve their quality of life. But, companies that operate those regulators could access their client's most personal data--their thoughts. And, if enhanced learning and memory are for sale, who gets to buy a better brain? "One does need to be a little careful about the ethics involved if you're trying to make a superhuman," Lieber said. "Being able to help people is much more important to me at this time."

Mesh electronics still have several major challenges to overcome: scaling up the number of implanted electrodes, processing the data flood those implants deliver, and feeding that information back into the system to enable live recalibration.

"I always joke in talks that I'm doing this because my memory has gotten a little worse than it used to be," Lieber said. "That's natural aging. But does it have to be that way? What if you could correct it?" If he and Patel succeed in galvanizing researchers around mesh electronics, the question might not be if but when.

As Healthy Aging Month is underway this September, Florida State University researchers have found the companionship of a pet after the loss of a spouse can help reduce feelings of depression and loneliness in older adults.

The study, funded by The Gerontological Society of America and the WALTHAM Centre for Pet Nutrition and published in The Gerontologist, examined depressive symptoms and loneliness among people age 50 and older who experienced the loss of a spouse through death or divorce.

"Increasingly, there's evidence that our social support networks are really beneficial for maintaining our mental health following stressful events, despite the devastation we experience in later life when we experience major social losses," said Dawn Carr, lead author and FSU associate professor of sociology. "I was interested in understanding alternatives to human networks for buffering the psychological consequences of spousal loss."

Carr and her team compared individuals who experienced the loss of a spouse to those who stayed continuously married. Then they explored whether the effects of spousal loss differed for those who had a pet at the time of the death or divorce.

They found all individuals who lost their spouse experienced higher levels of depression. However, people without a pet experienced more significant increases in depressive symptoms and higher loneliness than those who had pets. In fact, those who had a pet and experienced the death or divorce of their spouse were no lonelier than older adults who didn't experience one of those events.

"That's an important and impressive finding," Carr said. "Experiencing some depression after a loss is normal, but we usually are able to adjust over time to these losses. Persistent loneliness, on the other hand, is associated with greater incidents of mortality and faster onset of disability, which means it's especially bad for your health. Our findings suggest that pets could help individuals avoid the negative consequences of loneliness after a loss."

Carr's team used data from a sample of older adults who participated in an experimental survey about human animal interaction as part of the University of Michigan's Health and Retirement Study in 2012, and linked the data with additional data collected between 2008 and 2014. They identified pet owners as those participants who either had a cat or a dog.

"In everyday life, having a cat or dog may not make you healthier," Carr said. "But when facing a stressful event, we might lean on a pet for support. You can talk to your dog. They're not going to tell you you're a bad person, they're just going to love you. Or you can pet your cat, and it's calming."

The researchers noted that additional studies should be conducted to explain why having pets helps maintain mental health better. However, Carr suggested part of it may relate to whether you feel like you matter to someone.

"Oftentimes, the relationship we have with our spouse is our most intimate, where our sense of self is really embedded in that relationship," Carr said. "So, losing that sense of purpose and meaning in our lives that comes from that relationship can be really devastating. A pet might help offset some of those feelings. It makes sense to think, 'Well at least this pet still needs me. I can take care of it. I can love it and it appreciates me.' That ability to give back and give love is really pretty powerful."

The findings have potential consequences for social policies. For instance, it may be beneficial to include companion animals in the treatment of people residing in senior-living facilities, or reducing barriers to pet ownership in such settings.

Drinking more coffee may help reduce the risk of developing gallstones, according to a new study published in the Journal of Internal Medicine.

Among 104,493 individuals, those who drank more than six cups of coffee per day had a 23% lower risk of developing symptomatic gallstones compared with individuals who did not drink coffee. Drinking one extra cup of coffee per day was associated with 3% lower risk. Also, individuals with certain genetic variants that have been linked to increased coffee consumption had a lower risk of gallstones.

Although the study only uncovered correlations, the authors highlighted several mechanisms by which coffee consumption might help prevent gallstones from forming.

A recent analysis of published studies examined the clinical consequences of medication adherence. The British Journal of Clinical Pharmacology analysis found that medication adherence is linked with lower risks of needing to be hospitalised and of dying early.

Individuals aged 50 years and older who were considered to have good medication adherence had a 17% lower risk of having a hospitalisation due to any cause compared with those considered non-adherent. Good adherence was also associated with a 21% reduction in long-term mortality risk compared with medication non-adherence.

"This review has provided a comprehensive and systematic assessment of the evidence on the association between medication non-adherence and adverse health outcomes in older populations. It has highlighted the critical need for further research in this area," the authors wrote.

Editor's Note: "The Health Research Board (HRB) supports excellent research that improves people's health, patient care and health service delivery. We aim to ensure that new knowledge is created and then used in policy and practice. In doing so, we support health system innovation and create new enterprise opportunities."

Use of hearing aids was linked with lower risks of being diagnosed with Alzheimer's disease, dementia, depression, anxiety, and injurious falls in an analysis of medical information on 114,862 older adults with hearing loss. The findings are published in the Journal of the American Geriatrics Society.

The risk of being diagnosed with Alzheimer's disease/dementia, anxiety/depression, and injurious falls within three years after being diagnosed with hearing loss was 18%, 11%, and 13% lower, respectively, for those who used hearing aids versus those who did not.

"Although we have shown an association between use of hearing aids and reduced risk of physical and mental decline, randomized trials are needed to determine whether, and to what extent, the relationship is causal," the authors wrote.

Platinum has long been used as a catalyst to enable the oxidation reduction reaction at the center of fuel cell technology. But the metal's high cost is one factor that has hindered fuel cells from competing with cheaper ways of powering automobiles and homes.

Now researchers at the Georgia Institute of Technology have developed a new platinum-based catalytic system that is far more durable than traditional commercial systems and has a potentially longer lifespan. The new system could, over the long term, reduce the cost of producing fuel cells.

In the study, which was published July 15 in the ACS journal Nano Letters, the researchers described a possible new way to solve one of the key causes of degradation of platinum catalysts, sintering, a process in which particles of platinum migrate and clump together, reducing the specific surface area of the platinum and causing the catalytic activity to drop.

To reduce such sintering, the researchers devised a method to anchor the platinum particles to their carbon support material using bits of the element selenium.

"There are strategies out there to mitigate sintering, such as using platinum particles that are uniform in size to reduce chemical instability among them," said Zhengming Cao, a visiting graduate student at Georgia Tech. "This new method using selenium results in a strong metal-support interaction between platinum and the carbon support material and thus remarkably enhanced durability. At the same time, the platinum particles can be used and kept at a small to attain high catalytic activity from the increased specific surface area."

The process starts by loading nanoscale spheres of selenium onto the surface of a commercial carbon support. The selenium is then melted under high temperatures so that it spreads and uniformly covers the surface of the carbon. Then, the selenium is reacted with a salt precursor to platinum to generate particles of platinum smaller than two nanometers in diameter and evenly distributed across the carbon surface.

The covalent interaction between the selenium and platinum provides a strong link to stably anchor the platinum particles to the carbon.

"The resulting catalyst system was remarkable both for its high activity as a catalyst as well as its durability," said Younan Xia, professor and Brock Family Chair in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.

Because of the increased specific surface area of the nanoscale platinum, the new catalytic system initially showed catalytic activity three and a half times higher than the pristine value of a state-of-the-art commercial platinum-carbon catalyst. Then, the research team tested the catalytic system using an accelerated durability test. Even after 20,000 cycles of electropotential sweeping, the new system still provided a catalytic activity more than three times that of the commercial system.

The researchers used transmission electron microscopy at different stages of the durability test to examine why catalytic activity remained so high. They found that the selenium anchors were effective in keeping most of the platinum particles in place.

"After 20,000 cycles, most of the particles remained on the carbon support without detachment or aggregation," Cao said. "We believe this type of catalytic system holds great potential as a scalable way to increase the durability and activity of platinum catalysts and eventually improve the feasibility of using fuel cells for a wider range of applications."

People living with inflammatory autoimmune disease could benefit from an 'immune system reboot', and researchers have isolated specific cells to target.

The University of Queensland's Professor Ranjeny Thomas said the research findings give hope for similar new immunotherapies for people with diseases like rheumatoid arthritis and vasculitis.

"People with these diseases currently require daily medications to modify or suppress their immune system," she said.

"Rheumatoid arthritis and vasculitis have a huge impact on those living with them because there is no cure, and medication generally cannot be stopped.

"We think a better strategy would be to restore and re-regulate the specific part of the immune response that has gone wrong," Professor Thomas said.

She said such "precision medicines" were a big focus for researchers seeking new ways to treat and prevent autoimmune diseases.

Her research team has reported an "antigen-specific immunotherapy", and demonstrate that it could re-regulate the rogue immune T-cells that are markers of inflammatory arthritis or vasculitis in mice.

"We found that dendritic cells - conductors of the immune system orchestra - absorb tiny fat bubbles we generated, restoring immune regulation," Professor Thomas said.

"These fat bubbles, called liposomes, held the key to rebooting the immune system and calming the disease process.

"This study shows in mice that antigen-specific immunotherapy can be used to treat existing inflammatory autoimmune diseases, as well as to prevent future disease.

"Importantly, it shows that inflammatory activity is not a barrier to restoring regulation in the immune system."

People living with rheumatoid arthritis or vasculitis have rogue T-cells that attack the body's own tissues, escaping the normal regulation that keeps these cells in check.

The antigen-specific liposome immunotherapy treatment helps restore immune cells to healthy function.

The research brings doctors closer to understanding the best ways to use precision medicine for human inflammatory autoimmune diseases.

when they feel safe to communicate the absence of danger or share their location. This "chatter" from multiple bird species could therefore be a useful cue to other creatures that there is no imminent threat.

To test this hypothesis, the researchers observed the behavior of 54 wild Eastern gray squirrels (Sciurus carolinensis) in public parks and residential areas in Ohio in response to threat, which they simulated by playing back a recording of the call of a red-tailed hawk (Buteo jamaicensis), a common predator of both squirrels and small birds. They followed the predator's call with a playback of either multi-species songbird bird chatter or ambient sounds lacking bird calls and monitored the behavior of each squirrel for 3 minutes.

The researchers found that all squirrels showed an increase in predator vigilance behaviors, such as freezing, looking up, or fleeing, after they heard the hawk's call. However, squirrels that were played bird chatter afterwards performed fewer vigilance behaviors and returned to normal levels of watchfulness more quickly than squirrels that did not hear bird calls after the hawk's call. This suggests that the squirrels are able to tap into the casual chatter of many bird species as an indicator of safety, allowing them to quickly return to getting on with normal behaviors like foraging rather than remaining on high alert after a threat has passed.

The authors add: "We knew that squirrels eavesdropped on the alarm calls of some bird species, but we were excited to find that they also eavesdrop on non-alarm sounds that indicate the birds feel relatively safe. Perhaps in some circumstances, cues of safety could be as important as cues of danger."

A recent study investigated around 100,000 localized seismic events to search for patterns in the data. University of Tokyo Professor Satoshi Ide discovered that earthquakes of differing magnitudes have more in common than was previously thought. This suggests development of early warning systems may be more difficult than hoped. But conversely, similarities between some events indicate that predictable characteristics may aid researchers attempting to forecast seismic events.

Since the 1980s seismologists - earthquake researchers - have wondered how feasible it might be to predict how an earthquake will behave given some information about its initial conditions. In particular whether you can tell the eventual magnitude based on seismic measurements near the point of origin, or epicenter. Most researchers consider this idea too improbable given the randomness of earthquake behavior, but Ide thinks there's more to it than that.

"Taking inspiration from a study comparing different-sized earthquakes, I decided to analyze a seismic data set from a region known as the Tohoku-Hokkaido subduction zone in eastern Japan," said Ide. "A systematic comparison of around 100,000 seismic events over 15 years leads me to believe earthquakes are not different in random ways but share many similarities."

To draw comparisons between different earthquakes, Ide first selected the larger examples from the data set with magnitudes greater than 4.5. He also selected smaller earthquakes in the same regions as these larger ones. Ide then ascertained mathematically how similar seismic signals were between pairs of large and small earthquakes. He used a statistical function for the comparison of signals called a cross-correlation on data from 10 seismic stations close to the pairs of earthquakes in each case.

"Some pairs of large and small earthquakes start with exactly the same shaking characteristics, so we cannot tell the magnitude of an earthquake from initial seismic observations," explained Ide. "This is bad news for earthquake early warning. However, for future forecasting attempts, given this symmetry between earthquakes of different magnitudes, it is good to know they are not completely random."

A new vaccine developed by Griffith University Institute for Glycomics researchers has the potential to treat and prevent toxic shock caused by invasive streptococcal disease, which kills more than 160,000 people every year.

"Streptococcal toxic shock syndrome is an acute condition like meningococcus - if you get exposed to the organism you can be dead within a matter of days or less. So we're hopeful that what we've discovered can help save lives," program leader and laboratory head Professor Michael Good said.

Dr Manisha Pandey, the lead researcher on the study, said streptococcus (Strep A) is the same bacteria group that causes common and non-life-threatening ailments such as school sores and tonsillitis, which are easily spread via coughing, sneezing and sharing food and drinks.

She said in about 1 in 100 cases, the organism enters the body and becomes invasive streptococcal disease (ISD). ISD can be life-threatening, with mortality rates exceeding 25% in even the best-equipped facilities tasked with treating it.

When ISD occurs, some strains can make more toxins than others and cause streptococcal toxic shock syndrome (STSS).

STSS occurs when a toxin made by the Strep A organism binds to a human protein on certain cells and activates T-cells in the immune system that prompt a cytokine or highly inflammatory response.

This agitates white blood cells which then release potent immune hormones that can result in death.

The international research team, which includes scientists from Melbourne and Edmonton, Canada, used a transgenic (DNA altered genes) mouse model to develop a world-first STSS vaccine candidate - named 'J8' - that showed a 1000-1,000,000 fold reduction of the bacterial burden in the spleen and blood after infection.

Antibodies developed from the streptococcal M protein and streptococcal pyrogenic exotoxin (SpeC) also cleared the infection in treated transgenic mice and ablated the mitogenic and inflammatory activity caused by the M protein.

"About four years ago, we became aware of a cluster of bad cases of streptococcal infection resulting in a couple of deaths due to invasive streptococcal disease and toxic shock," Prof Good said.

"Invasive streptococcal disease and toxic shock are increasing in prevalence around the world and are particularly prevalent among disadvantaged populations - it occurs in remote parts of the state among Aboriginal communities, and affects the very young and very old the most.

"We were looking at a vaccine candidate to prevent streptococcal infections. At the time we were looking at it to prevent rheumatic heart disease, which is also caused by Strep A, and thought that the vaccine might prevent streptococcal toxic shock.

" However, that doesn't help people who come in who haven't been vaccinated and those who are acutely ill with toxic shock.

"In our transgenic mice model, we showed that two proteins are important for the disease - Superantigen toxin (SpeC) and the M protein, which our vaccine candidate J8 comes from.

"We vaccinated the transgenic mice - and it could prevent toxic shock, but as importantly we were able to make antibodies in normal mice which we could use to treat sick mice.

"When the transgenic mice became very ill, we treated them with the vaccine antibodies and they recovered overnight - the organisms as well as the toxin were cleared from their blood."

Prof Good said now that antibodies have been generated, the next step would be to make monoclonal antibodies (antibodies made by identical immune cells that are clones of a unique parent cell), that could be suitable for a human trial study of J8's efficacy against invasive streptococcal disease.

The research has been published in Science Advances.

Urban heat islands are a phenomenon where the temperature in a city is noticeably higher than in the surrounding rural area. When combined with the sort of heatwave that hit many parts of Europe at the beginning of July, urban heat can pose a real threat to the elderly, sick or other vulnerable people. Scientists at ETH Zurich have researched urban heat islands across the globe and have found that the effectiveness of heat-reduction strategies in cities varies depending on the regional climate. "We already know that plants create a more pleasant environment in a city, but we wanted to quantify how many green spaces are actually needed to produce a significant cooling effect," says Gabriele Manoli, former postdoc with the Chair of Hydrology and Water Resources Management at ETH Zurich and lead author of the recently published article in the journal Nature.

More green spaces: not always the most efficient solution

Manoli and his colleagues from ETH Zurich, Princeton University and Duke University studied data from some 30,000 cities worldwide and their surrounding environment, taking into consideration the average summer temperature, the population size and the annual rainfall. The urban heat island phenomenon is more pronounced the bigger the city and the more rainfall in that region. As a general rule, more rain encourages plant growth in the surrounding area, making this cooler than the city. This effect is the strongest when annual rainfall averages around 1500 millimetres as in Tokyo, but does not increase further with more rain.

Two climate extremes illustrate well the role of vegetation on the urban heat island phenomenon: very dry regions on the one hand, and tropical areas on the other. Through carefully targeted planting, a city like Phoenix in the USA could achieve cooler temperatures than the surrounding countryside, where conditions are almost desert-like. By comparison, a city surrounded by tropical forests, such as Singapore, would need far more green spaces to reduce temperatures, but this would also create more humidity. In cities located in tropical zones, other cooling methods are therefore expected to be more effective, such as increased wind circulation, more use of shade and new heat-dispersing materials. "There is no single solution," Manoli says. "It all depends on the surrounding environment and regional climate characteristics."

Useful information for city planners

Manoli explains that the main benefit of the study is a preliminary classification of cities, in the form of a clear visualisation guiding planners on possible approaches to mitigate the urban heat island effect. "Even so, searching for solutions to reduce temperatures in specific cities will require additional analysis and in-depth understanding of the microclimate," he stresses. "Such information, however, is based on data and models available to city planners and decision-makers only in a handful of cities, such as Zurich, Singapore or London."

Manoli is currently analysing data from other periods of the year and is studying which types of plant are most suitable for reducing temperatures. The support provided by the Branco Weiss Fellowship allowed the environmental engineer to work with scientists from the areas of physics, urban studies and social sciences with a specific focus on interdisciplinary research topics.

In summer heat, cities may swelter more than nearby suburbs and rural areas. And while the size of this urban heat island effect varies widely among the world's cities, heat island intensity can largely be explained by a city's population and precipitation level, researchers reported in a paper published Sept. 4 in the journal Nature.

Understanding a city's heat island effect is critical for developing strategies to reduce energy use and stave off dangerously high temperatures, said Elie Bou-Zeid, one of the study's authors and a professor in Princeton's Department of Civil and Environmental Engineering. The analysis suggests that cooling cities by planting more vegetation may be more effective in drier regions than in wetter ones.

Using summer temperature data from more than 30,000 world cities, Bou-Zeid worked with colleagues at ETH Zurich and Duke University to develop a new model for urban heat islands. The novelty of the model is that it uses population and precipitation as proxies for a complex array of factors involving climate, environment and urban engineering.

One of the model's benefits is its simplicity. Although it cannot capture details of individual cities, it can give planners a quick and broadly accurate view of possible solutions and their effects on a city's temperature.

"There are a few cities -- New York, London, Baltimore -- that are studied intensively, and we don't know very much about a large range of other cities," said Bou-Zeid. "With a reduced model that only needs information on precipitation and population, we are hoping to provide a simple framework that can give guidance to any city" in planning heat mitigation efforts.

The heat island effect, defined in the study as the surface temperature difference between urban and rural areas, is somewhat larger for cities with higher populations. One key reason is that these cities tend to have larger areas as well as more high-rise buildings that do not dissipate heat as effectively as lower structures.

The researchers also found that the heat island effect increases as a city's average annual precipitation increases, since its surroundings become greener and cooler, but only up to a point. Beyond a precipitation level of about 39 inches (100 centimeters) per year -- similar to that of Washington, D.C. -- a city's temperature boost does not rise much above 2 degrees Fahrenheit (1.25 degrees Celsius). This has implications for approaches to cooling wetter cities.

Although planting vegetation can lower city temperatures through evapotranspiration, there are limits to this approach. Southeast Asian cities such as Singapore have high precipitation and large areas of green cover, but have strong urban heat island effects because nearby rainforests inevitably contain far more plant life than the city. On the other hand, drier cities such as Phoenix can be even cooler than surrounding areas in the summer if irrigation is used to grow plants in the city.

"In places that are already wet and vegetated, adding more vegetation is not going to help," explained Bou-Zeid. Lowering summer temperatures in these cities will require different solutions, such as increasing shading or ventilation, or building with novel materials. Still, all cities can reap other benefits from green areas, such as improved air quality and opportunities for recreation.

"Our results show that there is no one-size-fits-all solution to reduce city-scale warming," said Gabriele Manoli, a research fellow at ETH Zurich and the study's lead author. "The efficiency of heat mitigation strategies varies across geographic regions, and any effort aimed at greening and cooling world cities should be put in the context of local hydro-climatic conditions." Given that urban areas will face the combined effects of global climate change and population growth, these results can provide guidance for the climate-sensitive design of future cities.

Bou-Zeid and his colleagues are working to extend their model to examine seasonal variations in the urban heat island effect. Their framework could also be used to create more tailored models for specific regions of the world.

The Global Precipitation Measurement mission or GPM core satellite provided information about the rate in which rain was falling within the Eastern Atlantic Ocean's latest tropical storm, Gabrielle.

Tropical Depression 8 formed around 5 p.m. EDT on Tuesday, Sept. 3. Twelve hours later at 5 a.m. EDT on Sept. 4, the storm intensified into a tropical storm and was renamed Gabrielle.

The GPM or Global Precipitation Measurement mission's core satellite passed over Tropical Storm Gabrielle in the eastern North Atlantic Ocean on Sept. 4 at 3:56 a.m. EDT (0756 UTC). GPM found the heaviest rainfall north and east of the center where it was falling at a rate of over 40 mm (about 1.6 inch) per hour. The National Hurricane Center said of that area, "A large curved band of thunderstorms has become better defined in the northern semicircle." Lighter rainfall rates were measured around that area.

GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.

NOAA's National Hurricane Center noted at 11 a.m. EDT (1500 UTC), the center of Tropical Storm Gabrielle was located near latitude 20.5 degrees north and longitude 33.8 degrees west. That's about 715 miles (1,150 km) west-northwest of the Cabo Verde Islands. Gabrielle is moving toward the northwest near 9 mph (15 kph), and this motion is expected to continue through Saturday, with an increase in forward speed expected late in the week. Maximum sustained winds have increased to near 50 mph (85 kph) with higher gusts. Little change in strength is forecast during the next few days. The estimated minimum central pressure is 1003 millibars.

For updated forecasts, visit: http://www.nhc.noaa.gov

Researchers have developed a new model to optimize radiation therapy and significantly increase the number of tumour cells killed during treatment.

The new mathematical model, outlined in a recent study led by a University of Waterloo student, can use information about where the majority of the cells in a tumour are located allowing for radiation treatment to be administered to the densest area.

Much consideration is currently usually given to optimal scheduling and dosing when radiation therapy is being prescribed, but the researchers found the treatment could be far more effective at killing brain tumour cells if oncologists also use the information on cell density, and irradiate the densest area of the tumour.

"Typically, cells in a tumour are packed at a higher density in the middle and less as you go further out, but that fact is not fully taken into account in current radiation treatment," said Cameron Meaney, a PhD candidate in Waterloo's Department of Applied Mathematics. "If we have a better understanding of tumour cell density, then we could design treatment in a better way to kill more cells."

In developing their mathematical model to spatially optimize radiation therapy in brain tumours, the researchers set a cap on the total dose a patient could receive throughout their treatment. They then divided the tumour into multiple portions: with the area most densely populated with cells being one portion and the remainder of cells the other. In some instances, they prescribed the dosage of radiation given to each portion, and in other cases, they allowed the model to determine the best ratio.

"It turned out that not necessarily in all cases do you want to distribute the radiation dose evenly between the fractions," Meaney said. "What our model has shown is that perhaps what's best is if we take the total radiation dose that we're allowed to give a patient and administer it over a small area at high strength where the cells are most dense instead of spreading it over a big area with semi-weak strength."

Given the results of their study, the researchers have proposed the following procedure for spatial optimization of radiation: image the tumour twice, determine the dose and treatment schedule, ascertain the physical limitations of the radiation apparatus, then optimize the first radiation fraction using their mathematical model.

Finally, using the growth model deduced from the initial two images to simulate the development of the tumour cells between fractions, oncologists can use the derived cell density profile prior to each instance of radiation application as input to optimize the shape of the radiation beam.