Sunday, April 26, 2015

Are bees 'hooked' on nectar containing pesticides?

Summary : Bees are attracted to nectar containing common pesticides, scientists have discovered. This could increase their chances of exposure to high levels of pesticides.


Bees are attracted to nectar containing common pesticides, scientists at Newcastle University and Trinity College Dublin have discovered. This could increase their chances of exposure to high levels of pesticides.

Previous studies have suggested that exposure of this kind can affect bees' fitness. The research, published in Nature, discovered that buff-tailed bumblebees and honeybees could not taste the three most commonly used neonicotinoid pesticides and so did not avoid them. In fact, the bees showed a preference for food which contained pesticides: when the bees were given a choice between sugar solution, and sugar solution containing neonicotinoids, they chose the neonicotinoid-laced food.

The lab-based study also showed that the bumblebees ate more of the food containing pesticides than the honeybees, and so were exposed to higher doses of toxins.

Bees and other pollinating insects are important for increasing crop yields -- their value has been estimated to be worth at least €153billion per year globally. When pollinating crops, they can be exposed to pesticides in floral nectar and pollen. Several controversial studies have shown that neonicotinoids have negative effects on bee foraging and colony fitness. As a result, public concern has grown over the impact of neonicotinoids on bees and other pollinators. In April 2013, the EU introduced a temporary ban on the use of neonicotinoid pesticides on flowering crops, while further scientific and technical evidence was gathered.

Professor Geraldine Wright, lead scientist on the study at the Institute of Neuroscience at Newcastle University, said: "Bees can't taste neonicotinoids in their food and therefore do not avoid these pesticides. This is putting them at risk of poisoning when they eat contaminated nectar.

Source : ScienceDaily.com

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The above story is based on materials provided by Newcastle University. Note: Materials may be edited for content and length.

Friday, June 27, 2014

Organic agriculture boosts biodiversity on farmlands

Does organic farming foster biodiversity? The answer is yes, however, the number of habitats on the land plays an important role alongside the type and intensity of farming practices. These are the findings of an international study that looked at ten regions in Europe and two in Africa. The results has been published in Nature Communications. The study shows that even organic farms have to actively support biodiversity by, for example, conserving different habitats on their holdings.

An international team, including scientists from Technische Universität München (TUM), investigated the contribution of organic farming to supporting farmland biodiversity between 2010 and 2013. Researchers wanted to explore whether organic farms are home to more species than their conventional neighbors. The team used uniform methods across Europe to capture data and analyze it to establish the impact of farming methods and intensity and of landscape features on biodiversity.

"Organic farming is beneficial to the richness of plant and bee species. However, observed benefits concentrate on arable fields," says TUM's Prof. Kurt-Jürgen Hülsbergen. His Chair for Organic Agriculture and Agronomy analyzed 16 Bavarian dairy farms.

The study investigated farms in twelve regions with different production systems. In each region, farms were selected randomly, half of them certified organic for at least five years. In Switzerland, grassland-based cattle farms were studied and in Austria the study looked at arable farms. In Italy and Spain, researchers focused on farms with permanent crops such as wine and olives, and on small-scale subsistence farms in Uganda.

More species because of field boundaries

More species were found in organic arable fields than in non-organic fields. In contrast, there was little difference in grasslands or vineyards. Organic farming benefited the four taxonomic groups of plants, earthworms, spiders and bees -- which were sampled as surrogates for the multitude of creatures living on farmland -- in different ways. In general, more species of plants and bees were found on organic than on non-organic fields, but not more species of spiders and earthworms.

If types of field boundaries such as grass verges or hedges were included in the comparison, the difference between organic and non-organic decreases. "Obviously, most species found in fields on organic farms tend to be concentrated in boundary areas on non-organic farms. There was little difference in the total number of species on the farms," explains Max Kainz, who headed the sub-project at TUM. The occurrence of rare or threatened species did not increase on organic farms, according to Kainz.

Even organic farms need to increase habitats

To sustain farmland biodiversity, which is currently under grave threat, researchers have identified complement organic farming methods with dedicated efforts to conserve habitats. To increase the number of habitats, the authors of the study recommend adding structural elements, such as woods, grass verges and fallow land, to farms. "Surprisingly, viewed across all regions, we did not find a higher number of natural habitats on organic farms than non-organic farms," reports Kainz.

"However, it was clear that habitat diversity is the key to species diversity," adds Prof. Hülsbergen. He continues: "The results of the study underline the importance of maintaining and expanding natural landscape features -- something that the EU's Greening Program has been trying to accomplish." If these additional habitats are different to the rest of the farm, for example hedges in grassland farms or herbaceous strips in arable farms, they have a huge impact on the biodiversity of a farm.

Source: Sciencedaily.com

Packing hundreds of sensors into a single optical fiber for use in harsh environments

By fusing together the concepts of active fiber sensors and high-temperature fiber sensors, a team of researchers at the University of Pittsburgh has created an all-optical high-temperature sensor for gas flow measurements that operates at record-setting temperatures above 800 degrees Celsius.

This technology is expected to find industrial sensing applications in harsh environments ranging from deep geothermal drill cores to the interiors of nuclear reactors to the cold vacuum of space missions, and it may eventually be extended to many others.

The team describes their all-optical approach in a paper published today in The Optical Society's (OSA) journal Optics Letters. They successfully demonstrated simultaneous flow/temperature sensors at 850 C, which is a 200 C improvement on an earlier notable demonstration of MEMS-based sensors by researchers at Oak Ridge National Laboratory.
The basic concept of the new approach involves integrating optical heating elements, optical sensors, an energy delivery cable and a signal cable within a single optical fiber. Optical power delivered by the fiber is used to supply energy to the heating element, while the optical sensor within the same fiber measures the heat transfer from the heating element and transmits it back.

"We call it a 'smart optical fiber sensor powered by in-fiber light'," said Kevin P. Chen, an associate professor and the Paul E. Lego Faculty Fellow in the University of Pittsburg's Department of Electrical and Computer Engineering.

The team's work expands the use of fiber-optic sensors well beyond traditional applications of temperature and strain measurements. "Tapping into the energy carried by the optical fiber enables fiber sensors capable of performing much more sophisticated and multifunctional types of measurements that previously were only achievable using electronic sensors," Chen said.

In microgravity situations, for example, it's difficult to measure the level of liquid hydrogen fuel in tanks because it doesn't settle at the bottom of the tank. It's a challenge that requires the use of many electronic sensors -- a problem Chen initially noticed years ago while visiting NASA, which was the original inspiration to develop a more streamlined and efficient approach.

"For this type of microgravity situation, each sensor requires wires, a.k.a. 'leads,' to deliver a sensing signal, along with a shared ground wire," explained Chen. "So it means that many leads -- often more than 40 -- are necessary to get measurements from the numerous sensors. I couldn't help thinking there must be a better way to do it."

It turned out, there is. The team looked to optical-fiber sensors, which are one of the best sensor technologies for use in harsh environments thanks to their extraordinary multiplexing capabilities and immunity to electromagnetic interference. And they were able to pack many of these sensors into a single fiber to reduce or eliminate the wiring problems associated with having numerous leads involved.

Source: Sciencedaily.com

Friday, June 3, 2011

Tsunami Sensor Detects Mysterious Background Signal in Panama


ScienceDaily (June 3, 2011) — An unusual signal detected by the seismic monitoring station at the Smithsonian Tropical Research Institute's research facility on Barro Colorado Island results from waves in Lake Gatun, the reservoir that forms the Panama Canal channel, scientists report. Understanding seismic background signals leads to improved earthquake and tsunami detection in the Caribbean region where 100 tsunamis have been reported in the past 500 years.

As part of a $37.5 million U.S. presidential initiative to improve earthquake monitoring following the devastating tsunami in the Indian Ocean in 2004, a seismic sensor was installed on Barro Colorado Island in 2006. The sensor is one of more than 150 sensors that comprise the U.S. Geological Survey's Global Seismographic Network.

Barro Colorado Island is a hilltop that was isolated by the waters of the reservoir created when the Chagres River was dammed to form Lake Gatun, a critical part of the Panama Canal. The Barro Colorado seismic monitoring station is a collaboration between the U.S. Geological Survey, the U.S. National Oceanic and Atmospheric Administration, the University of Panama and STRI.

Ultra-sensitive devices at the station pick up a large range of ground motion from felt earthquakes to nanometer-scale seismic background noise. The instruments at the station include very sensitive broadband seismometers used to detect distant earthquakes and low-gain accelerometers that measure ground movement and withstand violent local earthquakes and explosions.

The sensors detect signals from many different sources that include cars, boats and machinery operating up to several kilometers away. They also pick up the background "hum of the Earth" caused by ocean waves breaking on continental shelves around the world.

Scientists noticed that sensors on Barro Colorado recorded an intriguing wave pattern at an intermediate frequency. They suspected that this pattern could be caused by standing waves in Lake Gatun. Standing waves, also known as "seiches," are common in enclosed bodies of water like lakes and harbors where waves moving in opposite directions interact. By installing a water-level detection meter along the shoreline, researchers confirmed that changes in the water level of the lake correspond to the unusual seismic signal.

This is not the first report of seiches in Lake Gatun. Earlier reports correlated the release of methane gasses in the sediments below the canal to seiches and bottom currents in the lake. The Panama Canal Authority provided data about the depth of the Canal channel and of Lake Gatun that the authors used to model wave patterns in the lake.

Boat traffic and wind speed correlate with the unusual wave pattern, which was more common during the day than it was at night, but more information is needed to confirm what is actually causing the waves.

This report, published in the Journal of Geophysical Research, provides a new method to quantify the impact of water movements as recorded by land-based seismometers. A more exact understanding of the seismic signals resulting from water movements will improve estimates of other phenomena like tsunami impacts.

Source: Sciencedaily.com

Coping With Climate Change: Can We Predict Which Species Will Be Able to Move Far or Fast Enough to Adapt?


ScienceDaily (May 11, 2011) — As global temperatures rise, suitable sites for many plants and animals are shifting to cooler and higher ground. Can we predict which species will be able to move far or fast enough to keep up? A new study says the secrets to success in the face of a warming world are still elusive.

Rather than sticking around and sweating it out, some groups of plants and animals are responding to rising temperatures by migrating northward and upward to higher latitudes and elevations, studies show.

But when researchers working at the National Evolutionary Synthesis Center and the National Center for Ecological Analysis and Synthesis took a closer look at recent range shifts, they noticed a peculiar pattern: some species are migrating much farther and faster than others.

"Some species are moving well ahead of the curve, while others seem to be stuck behind," said lead author Amy Angert, a biologist at Colorado State University.
Pinpointing what sets the fastest-shifting species apart from the stragglers could help scientists and policymakers predict which species are likely to be left behind in a warming world, the researchers said.

"The species that aren't able to expand their range are the ones we need to spend more resources protecting," said co-author Sarah Gilman of Claremont McKenna College in California.

The researchers wondered if general traits such as body size, diet and lifespan might help scientists predict which species are likely to keep pace as weather warms.

To find out, they looked at data gathered from more than 400 species of birds, plants, insects and mammals known to have shifted their ranges to different degrees in the last century in response to warming.

The data set included North American birds such as house finches and bald eagles, dragonflies and damselflies in Europe, grasses and other plants in the Swiss Alps, and small mammals such as shrews, mice and chipmunks in the Sierra Nevada of California.

The species quickest to expand their range should be those that reproduce the fastest, disperse the farthest, and are the least picky about food, shelter, or mates, models predict.

To find out if predictions hold true, the researchers compiled data on how far each species had shifted, and compared it to various intrinsic features of the species themselves, such as their mode of dispersal, breeding rate, and dietary preferences.

The result? Global warming's winners and losers may be hard to predict based on broad traits related to dispersal ability or reproduction, the researchers explained.

"For each group we found one or more traits that do explain some variation in recent range shifts, but none with clear influence across all groups," wrote Angert, who studies the effects of climate change on range shifts in monkeyflowers.

One possibility is that the traits that really matter for a species' ability to move to more suitable sites -- such as temperature tolerance -- are difficult to measure or find a proxy for, the authors argue.

Another possibility is that external factors, such as habitat fragmentation and availability, may be just as important as the species themselves. Plants and animals on mountain peaks or near the poles may simply have nowhere cooler to go, the researchers explained.

The findings were published in Ecology Letters.

Other authors on the paper include Lisa Crozier of the Northwest Fisheries Science Center in Seattle, Leslie Rissler of the University of Alabama, Josh Tewksbury of the University of Washington, and Amanda Chunco of the University of North Carolina at Chapel Hill.

Source: Sciencedaily.com

Thursday, May 26, 2011

Joaquin Phoenix Reveals Cold-Blooded Horrors


Millions of reptiles are slaughtered each year and turned into shoes, handbags, belts, and other accessories. These helpless animals are viewed as a commodity by those who poach and hunt them, and these creatures suffer as their skin is pulled off their bodies while they are still alive. Oscar-nominated and Golden Globe- and Grammy-winning actor Joaquin Phoenix refuses to support an industry based on such cruelty and takes a behind-the-scenes look at the exotic-skins trade in his exclusive video for PETA.

Joaquin is calling for major fashion houses, such as Christian Louboutin and Jimmy Choo, to choose compassion over cruelty by eliminating exotic-skins from their collections. Please join Joaquin and send Christian Louboutin and Jimmy Choo a polite message asking them to stop selling exotic-skins.

Compassionate companies, such as Nike, H&M, and Overstock.com, have agreed not to sell exotic-skins. With tons of fashionable and cruelty-free alternatives there is no reason for animals to suffer for a wardrobe.

Help Joaquin and PETA send a powerful message not only to the cruel exotic-skins industry but also to designers, retailers, and others who directly profit from the suffering caused by this barbaric business.

Take the pledge now to shed exotic-skins from your wardrobe!

Source: Peta.org

Tuesday, May 24, 2011

Bacteria Use Caffeine as Food Source

ScienceDaily — A new bacterium that uses caffeine for food has been discovered by a doctoral student at the University of Iowa. The bacterium uses newly discovered digestive enzymes to break down the caffeine, which allows it to live and grow.

"We have isolated a new caffeine-degrading bacterium, Pseudomonas putida CBB5, which breaks caffeine down into carbon dioxide and ammonia," says Ryan Summers, who presented his research at the 111th General Meeting of the American Society for Microbiology in New Orleans.

Caffeine itself is composed of carbon, nitrogen, hydrogen and oxygen, all of which are necessary for bacterial cell growth. Within the caffeine molecule are three structures, known as methyl groups, composed of 1 carbon and 3 hydrogens atoms. This bacterium is able to effectively remove these methyl groups (a process known as N-demethylization) and essentially live on caffeine.

Summers and his colleagues have identified the three enzymes responsible for the N-demethylization and the genes that code for these enzymes. Further testing showed that the compounds formed during break down of caffeine are natural building blocks for drugs used to treat asthma, improve blood flow and stabilize heart arrhythmias.

Currently these pharmaceuticals are difficult to synthesize chemically. Using CBB5 enzymes would allow for easier pharmaceutical production, thus lowering their cost. Another potential application is the decaffeination of coffee and tea as an alternative to harsh chemicals currently used.

"This work, for the first time, demonstrates the enzymes and genes utilized by bacteria to live on caffeine," says Summers.

Source: Sciencedaily.com

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