Hummingbirds evolved a strange taste for sugar

TASTY  Hummingbirds, like this Anna’s Hummingbird in California, detect sweet nectar with a converted savory-sensing protein, a new study suggests. 

Hummingbirds are drawn to nectar in an unusual way. Instead of depending on a sugar sensor found in many vertebrates, the flitting, frenetic birds use a repurposed sensor that normally responds to savory flavors,scientists report in the Aug. 22 Science.

Researchers led by Maude Baldwin of Harvard University and Yasuka Toda of University of Tokyo studied the genomes of 10 bird species and found no hint of the gene that encodes the sweet detector that most vertebrates rely on. Like those birds, hummingbirds probably also lack the gene, the researchers reasoned. But experiments on cells in dishes revealed that hummingbirds’ umami receptors, which normally detect savory amino acids, pick up the slack and detect sucrose, glucose and fructose.

In both lab tests and the wild, hummingbirds preferred liquid sweetened with sucrose over water. The birds lapped up a low-calorie sweetener called erythritol that the umami receptor can sense, but didn’t enjoy the sugar substitute aspartame, which didn’t get a response from the receptor.  Hummingbirds’ ability to sense sweets seems to set them apart from other birds, including their closest living relatives, insect-eating chimney swifts. The researchers suggest that a dinosaur ancestor of modern birds lost the sweet detector common to other vertebrates, and that hummingbirds later regained a sweet tooth. This distinction is what allows them to feast on nectar while other birds ignore it, the researchers say.

X-ray laser probes tiny quantum tornadoes in superfluid droplets

Date:

August 21, 2014

Source:

DOE/SLAC National Accelerator Laboratory

Summary:

An experiment at the Department of Energy's SLAC National Accelerator Laboratory revealed a well-organized 3-D grid of quantum 'tornadoes' inside microscopic droplets of supercooled liquid helium -- the first time this formation has been seen at such a tiny scale. The findings by an international research team provide new insight on the strange nanoscale traits of a so-called 'superfluid' state of liquid helium.

In this illustration, a patterned 3-D grid of tiny whirlpools, called quantum vortices, populate a nanoscale droplet of superfluid helium. Researchers found that in a micron-sized droplet, the density of vortices was 100,000 times greater than in any previous experiment on superfluids. An artistic rendering of a wheel-shaped droplet can be seen in the distance.

AN experiment at the Department of Energy's SLAC National Accelerator Laboratory revealed a well-organized 3-D grid of quantum "tornadoes" inside microscopic droplets of supercooled liquid helium -- the first time this formation has been seen at such a tiny scale.

The findings by an international research team provide new insight on the strange nanoscale traits of a so-called "superfluid" state of liquid helium. When chilled to extremes, liquid helium behaves according to the rules of quantum mechanics that apply to matter at the smallest scales and defy the laws of classical physics. This superfluid state is one of just a few examples of quantum behavior on a large scale that makes the behavior easier to see and study.

The results, detailed in the Aug. 22 issue of Science, could help shed light on similar quantum states, such as those in superconducting materials that conduct electricity with 100 percent efficiency or the strange collectives of particles, dubbed Bose-Einstein condensates, which act as a single unit.

"What we found in this experiment was really surprising. We did not expect the beauty and clarity of the results," said Christoph Bostedt, a co-leader of the experiment and a senior scientist at SLAC's Linac Coherent Light Source (LCLS), the DOE Office of Science User Facility where the experiment was conducted.

"We were able to see a manifestation of the quantum world on a macroscopic scale," said Ken Ferguson, a PhD student from Stanford University working at LCLS.

While tiny tornadoes had been seen before in chilled helium, they hadn't been seen in such tiny droplets, where they were packed 100,000 times more densely than in any previous experiment on superfluids, Ferguson said.

Studying the Quantum Traits of a Superfluid

Helium can be cooled to the point where it becomes a frictionless substance that remains liquid well below the freezing point of most fluids. The light, weakly attracting atoms have an endless wobble -- a quantum state of perpetual motion that prevents them from freezing. The unique properties of superfluid helium, which have been the subject of several Nobel prizes, allow it to coat and climb the sides of a container, and to seep through molecule-wide holes that would have held in the same liquid at higher temperatures.

In the LCLS experiment, researchers jetted a thin stream of helium droplets, like a nanoscale string of pearls, into a vacuum. Each droplet acquired a spin as it flew out of the jet, rotating up to 2 million turns per second, and cooled to a temperature colder than outer space. The X-ray laser took snapshots of individual droplets, revealing dozens of tiny twisters, called "quantum vortices," with swirling cores that are the width of an atom.

The fast rotation of the chilled helium nanodroplets caused a regularly spaced, dense 3-D pattern of vortices to form. This exotic formation, which resembles the ordered structure of a solid crystal and provides proof of the droplets' quantum state, is far different than the lone whirlpool that would form in a regular liquid, such as briskly stirred cup of coffee.

More Surprises in Store

Researchers also discovered surprising shapes in some superfluid droplets. In a normal liquid, droplets can form peanut shapes when rotated swiftly, but the superfluid droplets took a very different form. About 1 percent of them formed unexpected wheel-like shapes and reached rotation speeds never before observed for their classical counterparts.

Oliver Gessner, a senior scientist at Lawrence Berkeley Laboratory and a co-leader in the experiment, said, "Now that we have shown that we can detect and characterize quantum rotation in helium nanodroplets, it will be important to understand its origin and, ultimately, to try to control it."

Andrey Vilesov of the University of Southern California, the third experiment co-leader, added, "The experiment has exceeded our best expectations. Attaining proof of the vortices, their configurations in the droplets and the shapes of the rotating droplets was only possible with LCLS imaging."

He said further analysis of the LCLS data should yield more detailed information on the shape and arrangement of the vortices: "There will definitely be more surprises to come."

Other research collaborators were from the Stanford PULSE Institute; University of California, Berkeley; the Max Planck Society; Center for Free-Electron Laser Science at DESY; PNSensor GmbH; Chinese University of Hong Kong; and Kansas State University. This work was supported by the National Science Foundation, the U.S. Department of Energy Office of Science (Basic Energy Sciences) and the Max Planck Society.

Hot-spring bacteria reveal ability to use far-red light for photosynthesis

Date:

August 21, 2014

Source:

Penn State

Summary:

Bacteria growing in near darkness use a previously unknown process for harvesting energy and producing oxygen from sunlight, scientists have discovered. The discovery lays the foundation for further research aimed at improving plant growth, harvesting energy from the sun, and understanding dense blooms like those now occurring on Lake Erie and other lakes worldwide.

Bacteria growing in near darkness use a previously unknown process for harvesting energy and producing oxygen from sunlight, a research team led by a Penn State University scientist has discovered. The discovery lays the foundation for further research aimed at improving plant growth, harvesting energy from the Sun, and understanding dense blooms like those now occurring on Lake Erie and other lakes worldwide. A paper describing the discovery will be published in the Science Express edition of the journal Science on 21 August 2014.

"We have shown that some cyanobacteria, also called blue-green algae, can grow in far-red wavelengths of light, a range not seen well by most humans," said Donald A. Bryant, the Ernest C. Pollard Professor of Biotechnology and a professor of biochemistry and molecular biology at Penn State. "Most cyanobacteria can't 'see' this light either. But we have found a new subgroup that can absorb and use it, and we have discovered some of the surprising ways they manipulate their genes in order to grow using only these wavelengths," he said.

The scientists discovered that the cyanobacterial strain, named Leptolyngbya, completely changes its photosynthetic apparatus in order to use far-red light, which has wavelengths longer than 700 nanometers -- a little longer than the range of light that most people can see. The experiments by Bryant's team revealed that these cyanobacteria replace seventeen proteins in three major light-using complexes while also making new chlorophyll pigments that can capture the far-red light, and while using pigments called bilins in new ways. The scientists also discovered that the organisms accomplish this feat by quickly turning on a large number of genes to modify cellular metabolism and simultaneously turning off a large number of other genes -- a process that they have named Far-Red Light Photoacclimation (FaRLiP).

Because the genes that are turned on are the genes that determine which proteins the organism will produce, this massive remodeling of the available gene profile has a dramatic effect. "Our studies reveal that the particular cyanobacterium that we studied can massively change its physiology and metabolism, and its photosynthetic apparatus," Bryant said. "It changes the core components of the three major photosynthetic complexes, so one ends up with a very differentiated cell that is then capable of growing in far-red light. The impact is that they are better than other strains of cyanobacteria at producing oxygen in far-red light, and they are better even than themselves. Cells grown in far-red light produce 40 percent more oxygen when assayed in far-red light than cells grown in red light assayed under the same far-red light conditions."

To make these discoveries, Bryant's team used a variety of biological, genetic, physical, and chemical experiments in order to learn how this unusual photosynthesis system works as a whole. The team's investigations includes biochemical analyses, spectroscopic analyses, studies of the structures and functions of proteins, profiles of gene-transcription processes, and sequencing and comparisons of cyanobacteria genomes. "Our genome-sequence analyses of different cyanobacteria strains revealed 13 additional strains that also appear to be able to use far-red light for photosynthesis," Bryant said.

The Leptolyngbya cyanobacterial strain that Bryant's team studied is one that was collected at LaDuke hot spring in Montana, near Yellowstone National Park. This strain was living on the underside of a 2-milimeter-thick mat that is so dense with bacteria that only the far-red wavelengths of light can penetrate to the bottom. Another environment where understanding photosynthesis in far-red light may have important implications is in the surface crusts of deserts and other soils, which cover a large percentage of Earth's surface. "It is important to understand how this photosynthetic process works in global-scale environments where cyanobacteria may be photosynthesizing with far-red light, in order to more fully understand the global impact of photosynthesis in oxygen production, carbon fixation, and other events that drive geochemical processes on our planet," Bryant said.

The research raises questions about the possibility of introducing into plants the capacity to use far-red wavelengths for photosynthesis. But Bryant said much more basic research is required first. "Our research already has shown that it would not be enough to insert a new far-red-light-absorbing pigment into a plant unless you also have the right protein scaffolds to bind it so that it will work efficiently. In fact, it could be quite deleterious to just start sticking long-wavelength-absorbing chlorophylls into the photosynthetic apparatus," he said.

"We now have clearly established that photosynthesis can occur in far-red light, in a wavelength range where people previously did not think that oxygenic photosynthesis could take place, and we have provided details about many of the processes involved. Now there are a whole set of associated scientific questions that need to be answered about more of the details before we can begin to investigate any applications that may or may not be possible," Bryant said. "Our research has opened up many new questions for basic scientific research."

Laser device may end pin pricks, improve quality of life for diabetics

Date:

August 21, 2014

Source:

Princeton University, Engineering School

Summary:

Researchers have developed a way to use a laser to measure people's blood sugar, and, with more work to shrink the laser system to a portable size, the technique could allow diabetics to check their condition without pricking themselves to draw blood. In a new article, the researchers describe how they measured blood sugar by directing their specialized laser at a person's palm.

The new monitor uses a laser, instead of blood sample, to read blood sugar levels. The laser is directed at the person's palm, passes through skin cells and is partially absorbed by sugar molecules, allowing researchers to calculate the level of blood sugar.

Princeton University researchers have developed a way to use a laser to measure people's blood sugar, and, with more work to shrink the laser system to a portable size, the technique could allow diabetics to check their condition without pricking themselves to draw blood.

"We are working hard to turn engineering solutions into useful tools for people to use in their daily lives," said Claire Gmachl, the Eugene Higgins Professor of Electrical Engineering and the project's senior researcher. "With this work we hope to improve the lives of many diabetes sufferers who depend on frequent blood glucose monitoring."

In an article published June 23 in the journalBiomedical Optics Express, the researchers describe how they measured blood sugar by directing their specialized laser at a person's palm. The laser passes through the skin cells, without causing damage, and is partially absorbed by the sugar molecules in the patient's body. The researchers use the amount of absorption to measure the level of blood sugar.

Sabbir Liakat, the paper's lead author, said the team was pleasantly surprised at the accuracy of the method. Glucose monitors are required to produce a blood-sugar reading within 20 percent of the patient's actual level; even an early version of the system met that standard. The current version is 84 percent accurate, Liakat said.

"It works now but we are still trying to improve it," said Liakat, a graduate student in electrical engineering.

When the team first started, the laser was an experimental setup that filled up a moderate-sized workbench. It also needed an elaborate cooling system to work. Gmachl said the researchers have solved the cooling problem, so the laser works at room temperature. The next step is to shrink it.

"This summer, we are working to get the system on a mobile platform to take it places such as clinics to get more measurements," Liakat said. "We are looking for a larger dataset of measurements to work with."

The key to the system is the infrared laser's frequency. What our eyes perceive as color is created by light's frequency (the number of light waves that pass a point in a certain time). Red is the lowest frequency of light that humans normally can see, and infrared's frequency is below that level. Current medical devices often use the "near-infrared," which is just beyond what the eye can see. This frequency is not blocked by water, so it can be used in the body, which is largely made up of water. But it does interact with many acids and chemicals in the skin, so it makes it impractical to use for detecting blood sugar.

Mid-infrared light, however, is not as much affected by these other chemicals, so it works well for blood sugar. But mid-infrared light is difficult to harness with standard lasers. It also requires relatively high power and stability to penetrate the skin and scatter off bodily fluid. (The target is not the blood but fluid called dermal interstitial fluid, which has a strong correlation with blood sugar.)

The breakthrough came from the use of a new type of device that is particularly adept at producing mid-infrared frequencies -- a quantum cascade laser.

In many lasers, the frequency of the beam depends on the material that makes up the laser -- a helium-neon laser, for example, produces a certain frequency band of light. But in a quantum cascade laser, in which electrons pass through a "cascade" of semiconductor layers, the beam can be set to one of a number of different frequencies. The ability to specify the frequency allowed the researchers to produce a laser in the mid-infrared region. Recent improvements in quantum cascade lasers also provided for increased power and stability needed to penetrate the skin.

To conduct their experiment, the researchers used the laser to measure the blood sugar of three healthy people before and after they each ate 20 jellybeans, which raise blood sugar levels. The researchers also checked the measurements with a finger-prick test. They conducted the measurements repeatedly over several weeks.

The researchers said their results indicated that the laser measurements readings produced average errors somewhat larger than the standard blood sugar monitors, but remained within the clinical requirement for accuracy.

"Because the quantum cascade laser can be designed to emit light across a very wide wavelength range, its usability is not just for glucose detection, but could conceivably be used for other medical sensing and monitoring applications," Gmachl said.

Fish and coral smell a bad neighborhood: Marine protected areas might not be enough to help overfished reefs recover

Date:

August 21, 2014

Source:

Georgia Institute of Technology

Summary:

Pacific corals and fish can both smell a bad neighborhood, and use that ability to avoid settling in damaged reefs. Damaged coral reefs emit chemical cues that repulse young coral and fish, discouraging them from settling in the degraded habitat, according to new research. The study shows for the first time that coral larvae can smell the difference between healthy and damaged reefs when they decide where to settle.

Testing fish in a choice chamber
 A new study in Science showed that
young fish have an overwhelming
  preference for water from healthy reefs. ...

Pacific corals and fish can both smell a bad neighborhood, and use that ability to avoid settling in damaged reefs.

Damaged coral reefs emit chemical cues that repulse young coral and fish, discouraging them from settling in the degraded habitat, according to new research. The study shows for the first time that coral larvae can smell the difference between healthy and damaged reefs when they decide where to settle.

Coral reefs are declining around the world. Overfishing is one cause of coral collapse, depleting the herbivorous fish that remove the seaweed that sprouts in damaged reefs. Once seaweed takes hold of a reef, a tipping point can occur where coral growth is choked and new corals rarely settle.

The new study shows how chemical signals from seaweed repel young coral from settling in a seaweed-dominated area. Young fish were also not attracted to the smell of water from damaged reefs. The findings suggest that designating overfished coral reefs as marine protected areas may not be enough to help these reefs recover because chemical signals continue to drive away new fish and coral long after overfishing has stopped.

"If you're setting up a marine protected area to seed recruitment into a degraded habitat, that recruitment may not happen if young fish and coral are not recognizing the degraded area as habitat," said Danielle Dixson, an assistant professor in the School of Biology at the Georgia Institute of Technology in Atlanta, and the study's first author.

The study will be published August 22 in the journal Science. The research was sponsored by the National Science Foundation (NSF), the National Institutes of Health (NIH), and the Teasley Endowment to Georgia Tech.

The new study examined three marine areas in Fiji that had adjacent fished areas. The country has established no-fishing areas to protect its healthy habitats and also to allow damaged reefs to recover over time.

Juveniles of both corals and fishes were repelled by chemical cues from overfished, seaweed-dominated reefs but attracted to cues from coral-dominated areas where fishing is prohibited. Both coral and fish larvae preferred certain chemical cues from species of coral that are indicators of a healthy habitat, and they both avoided certain seaweeds that are indicators of a degraded habitat.

The study for the first time tested coral larvae in a method that has been used previously to test fish, and found that young coral have strong preferences for odors from healthy reefs.

"Not only are coral smelling good areas versus bad areas, but they're nuanced about it," said Mark Hay, a professor in the School of Biology at Georgia Tech and the study's senior author. "They're making careful decisions and can say, 'settle or don't settle.'"

The study showed that young fish have an overwhelming preference for water from healthy reefs. The researchers put water from healthy and degraded habitats into a flume that allowed fish to choose to swim in one stream of water or the other. The researchers tested the preferences of 20 fish each from 15 different species and found that regardless of species, family or trophic group, each of the 15 species showed up to an eight times greater preference for water from healthy areas.

The researchers then tested coral larvae from three different species and found that they preferred water from the healthy habitat five-to-one over water from the degraded habitat.

Chemical cues from corals also swayed the fishes' preferences, the study found. The researchers soaked different corals in water and studied the behavior of fish in that water, which had picked up chemical cues from the corals. Cues of the common coralAcropora nasuta enhanced attraction to water from the degraded habitat by up to three times more for all 15 fishes tested. A similar preference was found among coral larvae.

Acropora corals easily bleach, are strongly affected by algal competition, and are prone to other stresses. The data demonstrate that chemical cues from these corals are attractive to fish and corals because they are found primarily in healthy habitats. Chemical cues from hardy corals, which can grow even in overfished habitats, were less attractive to juvenile fishes or corals.

The researchers also soaked seaweed in water and tested fish and coral preferences in that water. Cues from the common seaweed Sargassum polycystum, which can bloom and take over a coral reef, reduced the attractiveness of water to fish by up to 86 percent compared to water without the seaweed chemical cues. Chemical cues from the seaweed decreased coral larval attraction by 81 percent.

"Corals avoided that smell more than even algae that's chemically toxic to coral but doesn't bloom," Dixson said.

Future work will involve removing plots of seaweed from damaged reefs and studying how that impacts reef recovery.

A minimum amount of intervention at the right time and the right place could jump start the recovery of overfished reefs, Hay said. That could bring fish back to the area so they settle and eat the seaweed around the corals. The corals would then get bigger because the seaweed is not overgrown. Bigger corals would then be more attractive to more fish.

"What this means is we probably need to manage these reefs in ways that help remove the most negative seaweeds and then help promote the most positive corals," Hay said.

This research is supported by the National Science Foundation (NSF), under award number OCE-0929119, and the National Institutes of Health, under award number U01-TW007401. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agency.

https://www.youtube.com/watch?v=eo6rHkL7Fck#t=61

Water splitter runs on an ordinary AAA battery

Date:

August 22, 2014

Source:

Stanford University

Summary:

Although touted as zero-emissions vehicles, most fuel cell vehicle run on hydrogen made from natural gas. Now scientists have developed a low-cost, emissions-free device that uses an ordinary AAA battery to produce hydrogen by water electrolysis. Unlike other water splitters that use precious-metal catalysts, the electrodes in this device are made of inexpensive and abundant nickel and iron.

Stanford scientists have developed a low-cost device that uses an ordinary AAA battery to split water into oxygen and hydrogen gas. Gas bubbles are produced from electrodes made of inexpensive nickel and iron

Hogjie Dai and colleagues have developed a cheap, emissions-free device that uses a 1.5-volt battery to split water into hydrogen and oxygen. The hydrogen gas could be used to power fuel cells in zero-emissions vehicles.

Stanford University Professor Hongjie Dai has developed an emissions-free electrolytic device that splits water into hydrogen and oxygen at room temperature.

In 2015, American consumers will finally be able to purchase fuel cell cars from Toyota and other manufacturers. Although touted as zero-emissions vehicles, most of the cars will run on hydrogen made from natural gas, a fossil fuel that contributes to global warming.

Now scientists at Stanford University have developed a low-cost, emissions-free device that uses an ordinary AAA battery to produce hydrogen by water electrolysis. The battery sends an electric current through two electrodes that split liquid water into hydrogen and oxygen gas. Unlike other water splitters that use precious-metal catalysts, the electrodes in the Stanford device are made of inexpensive and abundant nickel and iron.

"Using nickel and iron, which are cheap materials, we were able to make the electrocatalysts active enough to split water at room temperature with a single 1.5-volt battery," said Hongjie Dai, a professor of chemistry at Stanford. "This is the first time anyone has used non-precious metal catalysts to split water at a voltage that low. It's quite remarkable, because normally you need expensive metals, like platinum or iridium, to achieve that voltage."

In addition to producing hydrogen, the novel water splitter could be used to make chlorine gas and sodium hydroxide, an important industrial chemical, according to Dai. He and his colleagues describe the new device in a study published in the Aug. 22 issue of the journal Nature Communications.

The promise of hydrogen

Automakers have long considered the hydrogen fuel cell a promising alternative to the gasoline engine. Fuel cell technology is essentially water splitting in reverse. A fuel cell combines stored hydrogen gas with oxygen from the air to produce electricity, which powers the car. The only byproduct is water -- unlike gasoline combustion, which emits carbon dioxide, a greenhouse gas.

Stanford scientists have developed a low-cost device that uses an ordinary AAA battery to split water into oxygen and hydrogen gas. Gas bubbles are produced by electrodes made of inexpensive nickel and iron.

Earlier this year, Hyundai began leasing fuel cell vehicles in Southern California. Toyota and Honda will begin selling fuel cell cars in 2015. Most of these vehicles will run on fuel manufactured at large industrial plants that produce hydrogen by combining very hot steam and natural gas, an energy-intensive process that releases carbon dioxide as a byproduct.

Splitting water to make hydrogen requires no fossil fuels and emits no greenhouse gases. But scientists have yet to develop an affordable, active water splitter with catalysts capable of working at industrial scales.

"It's been a constant pursuit for decades to make low-cost electrocatalysts with high activity and long durability," Dai said. "When we found out that a nickel-based catalyst is as effective as platinum, it came as a complete surprise."

Saving energy and money

The discovery was made by Stanford graduate student Ming Gong, co-lead author of the study. "Ming discovered a nickel-metal/nickel-oxide structure that turns out to be more active than pure nickel metal or pure nickel oxide alone," Dai said. "This novel structure favors hydrogen electrocatalysis, but we still don't fully understand the science behind it."

The nickel/nickel-oxide catalyst significantly lowers the voltage required to split water, which could eventually save hydrogen producers billions of dollars in electricity costs, according to Gong. His next goal is to improve the durability of the device.

"The electrodes are fairly stable, but they do slowly decay over time," he said. "The current device would probably run for days, but weeks or months would be preferable. That goal is achievable based on my most recent results"

The researchers also plan to develop a water splitter than runs on electricity produced by solar energy.

"Hydrogen is an ideal fuel for powering vehicles, buildings and storing renewable energy on the grid," said Dai. "We're very glad that we were able to make a catalyst that's very active and low cost. This shows that through nanoscale engineering of materials we can really make a difference in how we make fuels and consume energy."

Other authors of the study are Wu Zhou, Oak Ridge National Laboratory (co-lead author); Mingyun Guan, Meng-Chang Lin, Bo Zhang, Di-Yan Wang and Jiang Yang, Stanford; Mon-Che Tsai and Bing-Joe Wang, National Taiwan University of Science and Technology; Jiang Zhou and Yongfeng Hu, Canadian Light Source Inc.; and Stephen J. Pennycook, University of Tennessee.

Coronary calcium predicts heart disease risk in patients with chronic kidney disease

Date:

August 22, 2014

Source:

American Society of Nephrology

Summary:

Calcium build-up in the coronary artery walls was more useful for correctly predicting kidney disease patients' risk of heart disease than other measures of atherosclerosis, such as thickness of the carotid artery walls and narrowing of the arteries in the legs, a new study reports.

Calcium buildup in the coronary arteries may be a better indicator of kidney disease patients' risk of heart disease than traditional risk factors used in the general population, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology(JASN). The findings provide valuable new information that could help safeguard the heart health of patients with kidney disease.

Heart disease is the leading cause of death in individuals with chronic kidney disease (CKD). Some studies have found that conventional risk factors for predicting an individual's likelihood of developing heart disease aren't as useful in CKD patients as they are in the general population.

Kunihiro Matsushita, MD, PhD (Johns Hopkins Bloomberg School of Public Health) and his colleagues looked to see if calcium measurements within blood vessel walls might be helpful. Because the kidney helps regulate the body's calcium levels, individuals with chronic kidney disease often have altered calcium metabolism, which may influence the usefulness of calcium in the coronary artery walls as an indicator of heart disease.

The researchers studied 6553 adults aged 45 to 84 years who did not have prior cardiovascular disease and who were participating in the Multi-Ethnic Study of Atherosclerosis. Among the participants, 1284 had CKD.

During a median follow-up of 8.4 years, 650 cardiovascular events (coronary heart disease, stroke, heart failure, and peripheral artery disease) occurred, with 236 of the events occurring in participants with CKD. The investigators found that calcium build-up in the coronary artery walls was more useful for correctly determining CKD patients' risk of cardiovascular disease (particularly coronary heart disease and heart failure) than other measures of atherosclerosis such as thickness of the carotid artery walls and narrowing of the arteries in the legs.

"Our research is important since it assures the usefulness of coronary artery calcium for better cardiovascular disease prediction in persons with CKD, a population at high risk for cardiovascular disease but with potential caveats for the use of traditional risk factors," said Dr. Matsushita.

Fungus deadly to AIDS patients found to grow on trees

Date:

August 22, 2014

Source:

Duke University

Summary:

Researchers have pinpointed the environmental source of fungal infections that have been sickening HIV/AIDS patients in Southern California for decades. It literally grows on trees. The discovery is based on the science project of a 13-year-old girl, who spent the summer gathering soil and tree samples from areas around Los Angeles hardest hit by infections of the fungus named Cryptococcus gattii (CRIP-to-cock-us GAT-ee-eye).

This false-color electron microscope image catches the fungus Cryptococcus gattii in the act of producing its infectious spores. The club-shaped blue structure is a reproductive organ called the basidium, which projects off the fungus body like an apple off a tree. The spores are colored yellow, and are like seeds that can give rise to a new organism.

Researchers have pinpointed the environmental source of fungal infections that have been sickening HIV/AIDS patients in Southern California for decades. It literally grows on trees.The discovery is based on the science project of a 13-year-old girl, who spent the summer gathering soil and tree samples from areas around Los Angeles hardest hit by infections of the fungus namedCryptococcus gattii (CRIP-to-cock-us GAT-ee-eye).

Cryptococcus, which encompasses a number of species including C. gattii, causes life-threatening infections of the lungs and brain and is responsible for one third of all AIDS-related deaths.

The study, which appears Aug. 21 in PLOS Pathogens, found strong genetic evidence that three tree species -- Canary Island pine, Pohutukawa and American sweetgum -- can serve as environmental hosts and sources of these human infections.

"Just as people who travel to South America are told to be careful about drinking the water, people who visit other areas like California, the Pacific Northwest and Oregon need to be aware that they are at risk for developing a fungal infection, especially if their immune system is compromised," said Deborah J. Springer, Ph.D., lead study author and postdoctoral fellow in the Center for Microbial Pathogenesis at Duke University School of Medicine.

A few years ago, Duke's chairman of Molecular Genetics and Microbiology, Joseph Heitman M.D., was contacted by longtime collaborator and UCLA infectious disease specialist Scott Filler, M.D., whose daughter Elan was looking for a project to work on during her summer break. They decided it would be fun to send her out in search of fungi living in the greater Los Angeles area.

The student sampled 109 swabs of more than 30 tree species and 58 soil samples, grew and isolated the Cryptococcus fungus, and then sent those specimens to Springer at Duke. Springer DNA-sequenced the samples from California and compared the sequences to those obtained from HIV/AIDS patients with C. gattii infections.

She was surprised to find that specimens from three of the tree species were genetically almost indistinguishable from the patient specimens.

The researchers also found that the C. gattii isolated from the environment were fertile, reproducing either by sexual or asexual reproduction.

"That finding is important for long-term prevalence in the environment, because this fungal pathogen will be able to grow, reproduce, disperse spores, and serve as a source of ongoing infections," Springer said.

Low birth weight linked to higher incidence of type 2 diabetes in African American women

Date:

August 22, 2014

Source:

Boston University Medical Center

Summary:

African American women born at a low or very low birth weight may be at a higher risk for developing type 2 diabetes. The findings may explain in part the higher occurrence of type 2 diabetes in African American populations, which has a high prevalence of low birth weight.

African American women born at a low or very low birth weight may be at a higher risk for developing type 2 diabetes. The findings, which appear in Diabetes Care, may explain in part the higher occurrence of type 2 diabetes in African American populations, which has a high prevalence of low birth weight.

Researchers from Boston University's Slone Epidemiology Center followed more than 21,000 women enrolled in the Black Women's Health Study over the course of 16 years, analyzing characteristics such as birth weight, current age, family history of diabetes, body mass index, physical activity and socioeconomic status.

The study results indicate that women with low birth weight had a 13 percent higher chance of developing type 2 diabetes than those with normal birth weight, and those with very low birth weight had a 40 percent higher chance of developing the disease. Low birth weight was defined as less than 2.5 kg, and very low birth weight as less than 1.5 kg. It appeared that body size did not play a role in this relationship as there was a clear association between birth weight and diabetes even for women who were not obese.

Although previous studies have shown that birth characteristics such as birth weight can have a major impact on adult health, this is the first large-scale study to demonstrate this effect in an African American population.

"African American women are at increased risk of developing type 2 diabetes, and also have higher rates of low birth weight than white women," said Edward Ruiz-Narváez, ScD, assistant professor of epidemiology at Boston University School of Public Health. "Our study shows a clear relationship between birth weight and diabetes that highlights the importance of further research for this at-risk group."

According to the researchers, there are two leading hypotheses for the phenomenon. The first, known as the "thrifty phenotype hypothesis," states that once the newborn body perceives that it lacks nutrition, it reprograms itself to absorb more nutrition, causing an imbalance in metabolism that eventually leads to type 2 diabetes. The second, known as the "fetal insulin hypothesis," states that genes that are responsible for impaired insulin secretion also have a negative effect on birth weight. Some of these genes have been discovered in recent studies, supporting the latter hypothesis.

Canola genome sequence reveals evolutionary 'love triangle'

Date:

August 22, 2014

Source:

University of Georgia

Summary:

Scientists recently published the genome of Brassica napus -- commonly known as canola -- in the journal Science. Their discovery paves the way for improved versions of the plant, which is used widely in farming and industry.

Canola fields or Rapeseed plant. 

An international team of scientists including researchers from the University of Georgia recently published the genome of Brassica napus-commonly known as canola -- in the journal Science. Their discovery paves the way for improved versions of the plant, which is used widely in farming and industry.

Canola is grown across much of Canada and its native Europe, but the winter crop is increasingly cultivated in Georgia. Canola oil used for cooking is prized for its naturally low levels of saturated fat and rich supply of omega-3 fatty acids, but the plant is also used to produce feed for farm animals and as an efficient source for biodiesel.

"This genome sequence opens new doors to accelerating the improvement of canola," said Andrew Paterson, Regents Professor, director of UGA's Plant Genome Mapping Laboratory and co-corresponding author for the study. "We can use this knowledge to tailor the plant's flowering time, make it more resistant to disease and improve a myriad of other traits that will make it more profitable for production in Georgia and across the country."

Canola has one of the most complex genomes among flowering plants, forming thousands of years ago during the Neolithic Era when two plant species-Brassica rapaand Brassica oleracea-combined in the wild. Plants in the B. rapa family include turnips and cabbages, while B. oleracea encompasses cauliflower, cabbage, collards, broccoli, kale and other common vegetables.

The Plant Genome Mapping Laboratory played prominent roles in the sequencing bothB. rapa and B. oleracea in 2011 and 2014, respectively.

"Understanding the genomes of B. rapa and B. oleracea was key to piecing together the canola genome," Paterson said. "It's like a genetic love triangle between the three species, with canola sometimes favoring genes from B. rapa or B. oleracea or sometimes both."

While much the world's canola is used to make cooking oil and protein-rich animal feed, it is also used in the production of lipstick, lip gloss, soap, lotion, printing ink and de-icing agents.

The growing interest in carbon reduction and more environmentally friendly fuel alternatives is also good news for canola growers, as this genome sequence may ultimately help researchers develop feedstocks that are suited to more sustainable biofuel production.

Global canola production has grown rapidly over the past 40 years, rising from the sixth largest oil crop to the second largest, according to the U.S. Department of Agriculture.

Much of the production in America is concentrated along the northern plains, but the recent construction of a canola processing plant near the South Carolina-Georgia border has spurred interest for growers in the Southeast.

Additional UGA researchers for the project include Xiyin Wang, assistant research scientist and co-first author for the paper; Tae-ho Lee and Yupeng Wang, former postdoctoral researchers; and current and former graduate students Hui Guo, Huizhe Jin, Jingping Li, Xu Tan, Haibao Tang, and Yupeng Wang.

Playing hunger games: Are gamified health apps putting odds in your favor?

Date:

August 22, 2014

Source:

Brigham Young University

Summary:

For many people, finding motivation to exercise is a challenge. Thankfully, there are Zombies chasing you. At least that's the approach of Zombies, Run! -- one of more than 31,000 health and fitness apps on the market today, and one of the growing number of apps that use games to increase physical activity. Gamification is currently the popular trend for mobile fitness apps, but whether or not it's the best way to exercise remains to be seen.

For many people, finding motivation to exercise is a challenge. Thankfully, there are Zombies chasing you.

At least that's the approach of Zombies, Run! -- one of more than 1,000 health and fitness apps on the market today, and one of the growing number of apps that use games to increase physical activity.

Gamification is currently the popular trend for mobile fitness app makers looking to cash in to help people get fit. Whether or not it's the best way to exercise remains to be seen.

"It's just been assumed that gamified apps will work, but there has been no research to show that they're effective for people long-term," said Cameron Lister, lead author of a new BYU study on gamified health apps appearing in the Journal of Medical Internet Research. "Does earning a badge on your screen actually change your health behavior?"

Lister, along with BYU health science professor Josh West, analyzed more than 2,000 health and fitness apps and found that the majority of the most popular and widely used apps feature gamification.

As part of their study, the duo also downloaded and used 132 of the apps personally to see how well they worked. In addition to Zombies, Run! they tried out:

• Pact: An app that pits users against friends to see who keeps their exercise routine. Those who keep their goals make money at the expense of those who don't.
• Fitbit: Users can enlist friends to help them reach goals by sharing stats, joining fitness challenges or competing on leaderboards.
• DietBet: Like Pact, users put their money on the line to keep weight loss goals. Those who lose 4 percent of their starting weight in four weeks earn money from those who don't.

The researchers are concerned that gamification is ignoring key elements of behavior change and could be demotivating in the long run. For example, over time people can view the rewards and badges on these apps as work instead of play. Once the rewards disappear, the motivation drops.

One suggestion is for the apps to also focus on skill development.

"There's a missed opportunity to influence healthy behavior because most gamified health apps are only aimed at motivation," West said. "Motivation is important, but people also need to develop skills that makes behavior change easy to do."

According to the study, the most common form of motivation in the apps centered on social or peer pressure (45% of apps), followed by digital rewards (24%), competitions (18%), and leaderboards (14%).

"It's like people assuming that you hate health and you hate taking care of your body so they offer to give you some stuff in order for you to do what they want you to do," Lister said. "But really, you should intrinsically want to be healthy and be engaged in healthy activity."

While they found the health games are fun and engaging, West and Lister aren't sure they can sustain major changes in healthy behavior. They believe more research needs to be carried out in an industry projected to hit the $2.8 billion mark by 2016.

But funding for this type of research is scarce because the technology is so new and developers either don't have the money or are conflicted about subjecting their apps to scrutiny.

"I would caution developers and users to not have unrealistic expectations about the potential impact of gamified apps," West said. "Everybody wants to know if they result in more sustainable behavior change but we just don't know yet."

Voyager map details Neptune's strange moon Triton

Date:

August 22, 2014

Source:

NASA/Jet Propulsion Laboratory

Summary:

NASA's Voyager 2 spacecraft gave humanity its first close-up look at Neptune and its moon Triton in the summer of 1989. Like an old film, Voyager's historic footage of Triton has been "restored" and used to construct the best-ever global color map of that strange moon. The map, produced by Paul Schenk, a scientist at the Lunar and Planetary Institute in Houston, has also been used to make a movie recreating that historic Voyager encounter, which took place 25 years ago, on August 25, 1989.

The Voyager 2 spacecraft flew by Triton, a moon of Neptune, in the summer of 1989.
 

NASA's Voyager 2 spacecraft gave humanity its first close-up look at Neptune and its moon Triton in the summer of 1989. Like an old film, Voyager's historic footage of Triton has been "restored" and used to construct the best-ever global color map of that strange moon. The map, produced by Paul Schenk, a scientist at the Lunar and Planetary Institute in Houston, has also been used to make a movie recreating that historic Voyager encounter, which took place 25 years ago, on August 25, 1989.

The new Triton map has a resolution of 1,970 feet (600 meters) per pixel. The colors have been enhanced to bring out contrast but are a close approximation to Triton's natural colors. Voyager's "eyes" saw in colors slightly different from human eyes, and this map was produced using orange, green and blue filter images.

In 1989, most of the northern hemisphere was in darkness and unseen by Voyager. Because of the speed of Voyager's visit and the slow rotation of Triton, only one hemisphere was seen clearly at close distance. The rest of the surface was either in darkness or seen as blurry markings.

The production of the new Triton map was inspired by anticipation of NASA's New Horizons encounter with Pluto, coming up a little under a year from now. Among the improvements on the map are updates to the accuracy of feature locations, sharpening of feature details by removing some of the blurring effects of the camera, and improved color processing.

Although Triton is a moon of a planet and Pluto is a dwarf planet, Triton serves as a preview of sorts for the upcoming Pluto encounter. Although both bodies originated in the outer solar system, Triton was captured by Neptune and has undergone a radically different thermal history than Pluto. Tidal heating has likely melted the interior of Triton, producing the volcanoes, fractures and other geological features that Voyager saw on that bitterly cold, icy surface.

Pluto is unlikely to be a copy of Triton, but some of the same types of features may be present. Triton is slightly larger than Pluto, has a very similar internal density and bulk composition, and has the same low-temperature volatiles frozen on its surface. The surface composition of both bodies includes carbon monoxide, carbon dioxide, methane and nitrogen ices.

Voyager also discovered atmospheric plumes on Triton, making it one of the known active bodies in the outer solar system, along with objects such as Jupiter's moon Io and Saturn's moon Enceladus. Scientists will be looking at Pluto next year to see if it will join this list. They will also be looking to see how Pluto and Triton compare and contrast, and how their different histories have shaped the surfaces we see.

Although a fast flyby, New Horizons' Pluto encounter on July 14, 2015, will not be a replay of Voyager but more of a sequel and a reboot, with a new and more technologically advanced spacecraft and, more importantly, a new cast of characters. Those characters are Pluto and its family of five known moons, all of which will be seen up close for the first time next summer.

Triton may not be a perfect preview of coming attractions, but it serves as a prequel to the cosmic blockbuster expected when New Horizons arrives at Pluto next year.

The new Triton map and movie can be found at: http://www.lpi.usra.edu/icy_moons/

In another historic milestone for the Voyager mission, Aug. 25 also marks the two-year anniversary of Voyager 1 reaching interstellar space.

The Voyager mission is managed by NASA's Jet Propulsion Laboratory, in Pasadena, California, for NASA's Science Mission Directorate at NASA Headquarters in Washington. Caltech manages JPL for NASA. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, manages the New Horizons mission for NASA's SMD.

For more information about the Lunar and Planetary Institute, visit:http://www.lpi.usra.edu

For more information about Voyager, visit: http://www.nasa.gov/voyager andhttp://voyager.jpl.nasa.gov

For more information about New Horizons mission, visit: http://pluto.jhuapl.edu andhttp://www.nasa.gov/newhorizons

Epigenetic changes in children with Crohn's disease seen in study

Date:

August 22, 2014

Source:

Wolters Kluwer Health: Lippincott Williams and Wilkins

Summary:

A wide range of epigenetic changes -— alterations in DNA across the genome that may be related to key environmental exposures -— in children with Crohn's disease (CD), has been observed and reported in a new study. Crohn's disease is a painful, medically incurable illness that may attack anywhere along the digestive system. Crohn's disease and ulcerative colitis, which involves only the large intestine (colon), are the two main types of inflammatory bowel disease.

A New study finds a wide range of epigenetic changes -- alterations in DNA across the genome that may be related to key environmental exposures -- in children with Crohn's disease (CD), reportsInflammatory Bowel Diseases, official journal of the Crohn's & Colitis Foundation of America (CCFA). The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

The study provides "compelling evidence" of alterations of DNA in several regions of the genome in children with CD, according to Professor Jack Satsangi of University of Edinburgh and colleagues. In addition to providing new insights into how genes and the environment interact, the results may have early implications for clinical management of CD.

Epigenetic Changes in Childhood-Onset Crohn's Disease

The researchers performed a "genome-wide" study in children with newly diagnosed CD, before any treatment, to look for possible epigenetic changes that may affect gene behavior. Epigenetic changes reflect the impact of a wide range of environmental factors on genes.

The results showed strong evidence of such changes at 65 different sites across the genome. Nineteen sites showed clustering of epigenetic changes, pointing at genetic pathways that might be relevant to CD development.

Similar patterns were present in a separate group of children who had been treated for CD, as well as in a group of treated adults.

The study highlighted "highly significant" changes in two specific gene locations (loci), which include genes responsible for immune and cellular functions that could contribute to the development of CD. Two probes for these loci were highly accurate in predicting which children would have CD, providing a potentially useful "biomarker" for use as a diagnostic test.

'Exciting and Immediate Implications' for Clinical Management

One specific gene location seemed particularly important, as it has been implicated in a number of different cancers, including colorectal cancer. The same area has a known role in the development of T-cells, a key type of immune cell.

The study also identified a number of other loci that might play a role in the development of CD, warranting further study.

The new research adds to the growing body of evidence of epigenetic changes in diseases such as rheumatoid arthritis, multiple sclerosis, type 2 diabetes, and obesity. The findings highlight the importance of combining information on DNA changes, genes, and gene expression in future studies of these and other complex diseases, Dr Satsangi and colleagues believe.

Crohn's disease is a painful, medically incurable illness that may attack anywhere along the digestive system. Crohn's disease and ulcerative colitis, which involves only the large intestine (colon), are the two main types of inflammatory bowel disease. Some 1.4 million American adults and children suffer from CD or ulcerative colitis. Although much more research is needed to understand the epigenetic changes, the investigators believe their findings could lead to advances in clinical management of childhood-onset CD in the near future. They write, "There are exciting and immediate implications for early clinical translation; the discovery of easily accessible biomarkers in peripheral blood to predict disease susceptibility, progression or response to therapy and the potential for new therapeutic targets."

Creating pomegranate drug to stem Alzheimer's, Parkinson's

Date:

August 22, 2014

Source:

University of Huddersfield

Summary:

Research will look to produce compound derivatives of punicalagin for a drug that would treat neuro-inflammation and slow down the progression of Alzheimer's disease, scientists report. The onset of Alzheimer's disease can be slowed and some of its symptoms curbed by a natural compound that is found in pomegranate. Also, the painful inflammation that accompanies illnesses such as rheumatoid arthritis and Parkinson's disease could be reduced, according to the findings of the two-year project.

The key breakthrough by Dr Olajide and his co-researchers is to demonstrate that punicalagin, which is a polyphenol – a form of chemical compound – found in pomegranate fruit, can inhibit inflammation in specialised brain cells known as micrologia. This inflammation leads to the destruction of more and more brain cells, making the condition of Alzheimer’s sufferers progressively worse.

Dr.Olumayokun Olajide's research will look to produce compound derivatives of punicalagin for a drug that would treat neuro-inflammation and slow down the progression of Alzheimer's disease

The onset of Alzheimer's disease can be slowed and some of its symptoms curbed by a natural compound that is found in pomegranate. Also, the painful inflammation that accompanies illnesses such as rheumatoid arthritis and Parkinson's disease could be reduced, according to the findings of a two-year project headed by University of Huddersfield scientist Dr Olumayokun Olajide, who specialises in the anti-inflammatory properties of natural products.

Now, a new phase of research can explore the development of drugs that will stem the development of dementias such as Alzheimer's, which affects some 800,000 people in the UK, with 163,000 new cases a year being diagnosed. Globally, there are at least 44.4 million dementia sufferers, with the numbers expected to soar.

The key breakthrough by Dr Olajide and his co-researchers is to demonstrate that punicalagin, which is a polyphenol -- a form of chemical compound -- found in pomegranate fruit, can inhibit inflammation in specialised brain cells known as micrologia. This inflammation leads to the destruction of more and more brain cells, making the condition of Alzheimer's sufferers progressively worse.

There is still no cure for the disease, but the punicalagin in pomegranate could prevent it or slow down its development.

Dr Olajide worked with co-researchers -- including four PhD students -- in the University of Huddersfield's Department of Pharmacy and with scientists at the University of Freiburg in Germany. The team used brain cells isolated from rats in order to test their findings. Now the research is published in the latest edition of the journalMolecular Nutrition & Food Research and Dr Olajide will start to disseminate his findings at academic conferences.

He is still working on the amounts of pomegranate that are required, in order to be effective.

"But we do know that regular intake and regular consumption of pomegranate has a lot of health benefits -- including prevention of neuro-inflammation related to dementia," he says, recommending juice products that are 100 per cent pomegranate, meaning that approximately 3.4 per cent will be punicalagin, the compound that slows down the progression of dementia.

Dr Olajide states that most of the anti-oxidant compounds are found in the outer skin of the pomegranate, not in the soft part of the fruit. And he adds that although this has yet to be scientifically evaluated, pomegranate will be useful in any condition for which inflammation -- not just neuro-inflammation -- is a factor, such as rheumatoid arthritis, Parkinson's and cancer.

The research continues and now Dr Olajide is collaborating with his University of Huddersfield colleague, the organic chemist Dr Karl Hemming. They will attempt to produce compound derivatives of punicalagin that could the basis of new, orally administered drugs that would treat neuro-inflammation.

Dr Olajide has been a Senior Lecturer at the University of Huddersfield for four years. His academic career includes a post as a Humboldt Postdoctoral Research Fellow at the Centre for Drug Research at the University of Munich. His PhD was awarded from the University of Ibadan in his native Nigeria, after an investigation of the anti-inflammatory properties of natural products.

He attributes this area of research to his upbringing. "African mothers normally treat sick children with natural substances such as herbs. My mum certainly used a lot of those substances. And then I went on to study pharmacology!"