Replica Designer Watches

2013-08-02

Arctic sea-ice loss has widespread effects on wildlife

Aug. 1, 2013 — With sea ice at its lowest point in 1,500 years, how might ecological communities in the Arctic be affected by its continued accelerating melting over the next decades? Penn State University Professor of Biology Eric Post and an international team of scientists tackle this question by examining relationships among algae, plankton, whales, and terrestrial animals such as caribou, arctic foxes and walrus; as well as the effects of human exploration of previously inaccessible parts of the region.

Share This:

"Arctic sea ice has declined by more than 86,000 square kilometers -- a space slightly larger than the state of South Carolina -- per year," Post said. "That's an area of critical habitat for many species and the rate of loss is increasing." Post added that an acceleration of this rate likely will be due, in part, to the loss the white surface provided by ice that reflects sunlight -- thereby causing a cooling effect. The highly reflective ice, Post added, will be replaced by a much-less-reflective, darker surface of open water -- and the effect will be accelerated warming and accelerated melting.

A domino effect of sea-ice melting on terrestrial animals, Post explained, could happen through a disruption in the food chain. Sea-ice algae and sub-ice plankton, which together account for 57 percent of the total annual biological production in the Arctic Ocean, already are being immediately affected by sea-ice melting because ice loss triggers a significant change in the blooming times of these organisms. Likewise, land adjacent to areas of sea-ice loss will experience significant surface warming inland from the coastline, affecting soil conditions and plant growth. Post and his colleagues hypothesize that, while invertebrate ocean-dwelling animals -- such as zooplankton that feed on algae and phytoplankton in the seas -- already are being affected, larger terrestrial animals such as caribou could find their land-dwelling food sources disrupted, as well, due to temperature changes affecting plant communities inland.

"A change in population mixing could be another, indirect effect of sea-ice melting," Post said. He explained that populations of wolves and arctic foxes that currently are isolated only during the summer could become even more isolated. A longer period of the year without ice, which promotes travel between populations, could lead to a decline in crossbreeding.

However, for other species, the effect of sea-ice loss could be just the opposite: "We know that, for some species, sea ice acts as a barrier to intermixing," Post explained. "So for these species, ice loss and a lengthening of the ice-free season likely will increase population mixing, reducing genetic differentiation." Post explained that, for example, polar and grizzly bears already have been observed to have hybridized because polar bears now are spending more time on land, where they have contact with grizzlies.

While such mixing of populations is not necessarily cause for concern, Post explained, it could lead to drastic changes in disease dynamics. For example, a population that currently is a host to a certain pathogen could carry that pathogen to another, previously unexposed population. "In addition, a decrease in sea ice in arctic Canada likely will increase contact between eastern and western arctic species, promoting mixing of pathogen communities that previously were isolated," Post said. "For example, phocine distemper virus (PDV) currently affects eastern Arctic seals. But if these seals begin to mix with western arctic seals, the virus may reach other, naive populations."

Post added that greater accessibility of previously remote parts of the Arctic to human exploration could be yet another unexpected consequence of sea-ice loss. "Retreating sea ice, longer ice-free seasons, and loss of sea ice are expected to promote development of shipping lanes and increased shipping traffic in areas that formerly were rather inaccessible," Post said. "This increased marine access likely will accelerate the pace of mineral and petroleum exploration in the Arctic, which in turn could affect both terrestrial and marine animals; for example, bowhead whales and Pacific walrus."

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.

SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc

we are focus on the following fields,and hope we can help you.

Industrial IC Infineon Technologies Transistors Bipolar Transistors LED Texas Instruments(TI) IC LED part Voltage Regulators Transistors Resistor Arrays Vishay resistors NEC Diodes Resistors Other Parts NEC Transistors AVX Resistors INFLNEON Diodes FAIRCHILD diodes BB IC IR Diodes LINEAR IC DIODES Transistors MOTOROLA IC MAXIM IC Cypress IC YAGEO Resistors Low Ohmic Resistors Military IC TDK IC IR transistor Chip Inductors ON Transistors MURATA IC Schottky Diodes High Precision Resistors Zener Diodes Electronic News About US Atmel IC Transistors components Current Sensors Resistors
http://www.suvsystem.com/a/4604.aspx

'Soft' approach leads to revolutionary energy storage: Graphene-based supercapacitors

Published today in Science, a research team led by Professor Dan Li of the Department of Materials Engineering has developed a completely new strategy to engineer graphene-based supercapacitors (SC), making them viable for widespread use in renewable energy storage, portable electronics and electric vehicles.

SCs are generally made of highly porous carbon impregnated with a liquid electrolyte to transport the electrical charge. Known for their almost indefinite lifespan and the ability to re-charge in seconds, the drawback of existing SCs is their low energy-storage-to-volume ratio -- known as energy density. Low energy density of five to eight Watt-hours per litre, means SCs are unfeasibly large or must be re-charged frequently.

Professor Li's team has created an SC with energy density of 60 Watt-hours per litre -- comparable to lead-acid batteries and around 12 times higher than commercially available SCs.

"It has long been a challenge to make SCs smaller, lighter and compact to meet the increasingly demanding needs of many commercial uses," Professor Li said.

Graphene, which is formed when graphite is broken down into layers one atom thick, is very strong, chemically stable and an excellent conductor of electricity.

To make their uniquely compact electrode, Professor Li's team exploited an adaptive graphene gel film they had developed previously. They used liquid electrolytes -- generally the conductor in traditional SCs -- to control the spacing between graphene sheets on the sub-nanometre scale. In this way the liquid electrolyte played a dual role: maintaining the minute space between the graphene sheets and conducting electricity.

Unlike in traditional 'hard' porous carbon, where space is wasted with unnecessarily large 'pores', density is maximised without compromising porosity in Professor Li's electrode.

To create their material, the research team used a method similar to that used in traditional paper making, meaning the process could be easily and cost-effectively scaled up for industrial use.

"We have created a macroscopic graphene material that is a step beyond what has been achieved previously. It is almost at the stage of moving from the lab to commercial development," Professor Li said.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Stimulating brain cells can make false memories

Aug. 1, 2013 — Any crime scene investigator can tell you that memories are unreliable; the way people remember a place or event changes over time and varies between individuals. But for the mice in one lab at MIT, the accuracy of memories is even more suspect. Howard Hughes Medical Institute researchers in that lab have discovered how to alter the animals' memories by turning on neurons in the brain that are associated with the memories and updating them with new information.

Share This:

The new findings, which appear in the journal Science, illustrate that a mouse can be made to fear a cage by giving it a foot shock while at the same time reactivating a memory of the cage to associate the two.

"The kinds of things that once existed only in the realm of science fiction movies like Inception and Eternal Sunshine of the Spotless Mind are now experimentally possible," says Steve Ramirez, a graduate student in the lab of HHMI investigator Susumu Tonegawa and first author of the new work.

Researchers knew that memories are stored by the brain in a small set of neurons. Understanding how this information is encoded could be key to understanding how human memory works as well as memory disorders. But identifying exactly which neurons are linked to specific memories has been technically challenging.

Ramirez and Tonegawa, along with Xu Liu, a postdoctoral fellow in Tonegawa's lab at the Massachusetts Institute of Technology, had previously developed a way to pinpoint the specific handful of neurons that are activated in the brains of mice in any particular situation. The technique relies on optogenetics, a method of controlling brain cells through bursts of light developed by HHMI early career scientist Karl Deisseroth at Stanford University. The researchers engineered brain cells to produce a light-sensitive protein whenever the neurons were activated in a new setting or situation. Then, by shining a light onto the brain through a fiber optic cable connected to the mouse's skull, they could reactivate only that subset of neurons. Even without reactivating the cells, they could determine which cells had been activated by measuring which contained the light-sensitive protein. The approach was described in a 2012 Nature paper.

More recently, the scientists wondered if they could alter the way a mouse remembered a setting by activating neurons associated with it. They chose to test this idea by attempting to change whether or not a mouse was afraid of a particular cage.

"In mice, fear can be seen as a binary behavioral output," says Ramirez. "Either the animal is exploring a box that it's interested in, and it's curious and sniffing around. Or, if it's displaying fear behavior, it's huddled in a corner not moving. So it's a very easy, very powerful readout of memory."

To see whether they could make an animal associate fear with a previously neutral setting, Tonegawa's lab group first exposed mice to one of four unique cages. Each cage had distinct flooring materials, artificial smells, and different lighting. As the mice scouted out the new room, whichever neurons were activated produced the special light-sensitive protein.

Next, the mice were moved to a second cage. This time, as the mice explored, the scientists used light to turn on the neurons that had been activated in the first cage and simultaneously shocked the feet of the mice. Then the mice were put back in the first area -- where they'd never received a shock. The mice were clearly fearful of the setting, Ramirez says, spending more than a quarter of their time frozen in place.

"We were astonished that this worked on the very first mouse we ever tried," he says. "We got the animal to be scared of an environment where technically, nothing bad had ever happened to it."

By contrast, when the mice were put in a third cage that they'd never been in before, they exhibited no fear. And in a control group of mice that had received shocks in the second cage but no neuron reactivation, the first cage never induced fear.

After the successful experiment, Tonegawa, Ramirez, and Liu looked at the details of which neurons in the brain had been responsible for inducing the memory of the first cage. The neurons, they found, were located in the dentate gyrus, part of the hippocampus. The dentate gyrus has previously been implicated in the formation of memories, and is one of the areas of the brain with the most new neuron generation during adulthood. But most evidence about its importance came from instances in which the area had been damaged and memories lost.

"This study gives us information on the basic mechanism that could be happening in the brain when memories or false memories are formed," says Ramirez. "Next, we want to see if we can do the same with not only fear memories but pleasure memories or memories of objects or memories of other mice."

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

New type of protein modification may play a role in cancer and diabetes

"It appears to be an intrinsic feedback mechanism in glucose metabolism, but I suspect that its other functions throughout the cell will prove at least as interesting when they are more fully elucidated," said Benjamin F. Cravatt, chair of the Department of Chemical Physiology and member of the Skaggs Institute for Chemical Physiology at TSRI.

Cravatt and his postdoctoral fellow Raymond E. Moellering reported the finding in the August 2, 2013 issue of the journal Science.

In Search of New Protein Modifiers

The Cravatt laboratory has long studied the natural chemical modifications that can change the functions of proteins "on the fly," switching their biological activities on or off or otherwise altering them. The better known of these modifications include phosphorylation, the addition of a small molecule known as a phosphate group, and acetylation, the addition of an acetyl group.

In search of new protein modifiers, Cravatt and Moellering, whose postdoctoral fellowship is sponsored in part by the Howard Hughes Medical Institute and the Damon Runyon Cancer Research Foundation, decided to investigate a small molecule known as 1,3-bisphosphoglycerate (1,3-BPG). The molecule's chemical makeup suggested that it might readily react with some proteins to form semipermanent, function-altering modifications. 1,3-BPG is one of the main "intermediate" molecules produced during glycolysis, which is a core metabolic pathway that converts glucose to cellular fuel.

"1,3-BPG's intrinsic reactivity seemed odd to us, considering that it is such a central metabolite," remembered Moellering.

Moellering's initial test-tube experiments showed that 1,3-BPG does indeed react with certain lysine amino acids to modify GAPDH, the enzyme that mediates the production of 1,3-BPG. "That gave us the first indication that this reaction does happen, and that we should therefore start looking for it in cells," he said.

A Role in Glucose Metabolism

After devising new methods to detect this unique lysine modification in human cell cultures, Moellering soon found it -- on other glucose-metabolizing enzymes, as well as on proteins seemingly unrelated to glucose metabolism.

"With every step we took, the project became more interesting, because we were finding signs that this reaction occurs frequently in cells and in animal tissues, and in unexpected cellular locations, too," Moellering said.

He detected the signature of the new lysine modification not only on proteins in the main volume of the cell (the cytosol), but also in the DNA-containing cell nucleus and even on the cell's membrane compartments.

"It appears that wherever GAPDH goes within cells, it is capable of catalyzing the localized production of 1,3-BPG, which in turn reacts with nearby proteins to modify their structure and function," said Cravatt.

Moellering found that when 1,3-BPG's lysine modification occurs on glucose-metabolizing enzymes, it tends to inhibit their activities, causing a slowdown of central glucose processing and a consequent buildup of certain glucose metabolites in the processing pathway. Moellering and Cravatt suspect that these overabundant metabolites may end up being shunted into other cellular processes besides basic fuel-making -- processes that contribute to the synthesis of new molecules and even cell proliferation.

Moellering also discovered that 1,3-BPG and the modification it makes on proteins become more prevalent as glucose levels rise. Within the context of glucose metabolism, 1,3-BPG's modification thus seems to act as a "very old, maybe ancient feedback mechanism for regulating that central metabolic pathway," Moellering said.

Looking Ahead

The abnormal processing of glucose within cells features in a number of major diseases including cancer and diabetes. "Cancer cells, for example, bring in as much as 20 times more glucose than non-cancerous cells of the same type," Moellering noted. He now wants to find out whether 1,3-BPG is part of the problem in such cells. At abnormally high levels, it conceivably could help force glucose metabolism toward the runaway cell proliferation that is a hallmark of cancer.

Cravatt and Moellering also want to learn more about what 1,3-BPG's lysine modification does in the nuclei and membrane compartments of cells, where they found evidence of it. "We suspect that it works to connect glucose metabolism to other pathways, perhaps as a kind of signaling mechanism," said Moellering.

Already Moellering has uncovered evidence that there are enzymes that work to reverse 1,3-BPG's modification of lysines -- which underscores the likelihood that this modification represents a fundamental, dynamic mechanism in cells. "We'd like to discover which enzymes catalyze the removal of the modification," said Cravatt, "because then, in principle, we could use inhibitors of these enzymes to control the levels of the modification and get a better understanding of its biological functions as well as the conditions under which it occurs."

Funding for the study, "Functional Lysine Modification by an Intrinsically Reactive Primary Glycolytic Metabolite," was provided by the National Institutes of Health (CA087660), the Skaggs Institute for Chemical Biology at TSRI and the Damon Runyon Cancer Research Foundation.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Atmel IC Diodes Freescale Semiconductor Diodes Inc Connectors NXP Transistors MOTOROLA IC Multi-units Transistors ALTERA IC Vishay resistors Transistors Freescale IDT IC NEC Transistors Thick Film Resistors LINEAR IC IC(Integrated Circuits) Metal Can Packages Transistors Military IC Renesas parts IC ON Transistors Other Parts Discrete Semiconductor Transistors Chip Inductors Capacitor About US Low Ohmic Resistors TI IC Current Sensors Resistors ST Diodes Infineon Technologies Transistors AD IC HARRIS IC Zener Diodes NXP Diodes Resistor Arrays ROHM Resistors PANASONIC Resistors IR Diodes Industrial IC DIODES Transistors
http://www.suvsystem.com/a/4596.aspx

As climate, disease links become clearer, study highlights need to forecast future shifts

Aug. 1, 2013 — Climate change is affecting the spread of infectious diseases worldwide, according to an international team of leading disease ecologists, with serious impacts to human health and biodiversity conservation. Writing in the journal Science, they propose that modeling the way disease systems respond to climate variables could help public health officials and environmental managers predict and mitigate the spread of lethal diseases.

Share This:

The issue of climate change and disease has provoked intense debate over the past decade, particularly in the case of diseases that affect humans, according to the University of Georgia's Sonia Altizer, who is the study's lead author.

"For a lot of human diseases, responses to climate change depend on the wealth of nations, healthcare infrastructure and the ability to take mitigating measures against disease," said Altizer, an associate professor in the UGA Odum School of Ecology. "The climate signal, in many cases, is hard to tease apart from other factors like vector control and vaccine and drug availability."

Climate warming already is causing changes in diseases affecting wildlife and agricultural ecosystems, she said. "In many cases, we're seeing an increase in disease and parasitism. But the impact of climate change on these disease relationships depends on the physiology of the organisms involved, the location on the globe and the structure of ecological communities."

At the organism level, climate change can alter the physiology of both hosts and parasites. Some of the clearest examples are found in the Arctic, where temperatures are rising rapidly, resulting in faster developing parasites. A lungworm that affects muskoxen, for instance, can now be transmitted over a longer period each summer, making it a serious problem for the populations it infects.

"The Arctic is like a 'canary in the global coal mine,'" said co-author Susan Kutz of the University of Calgary and Canadian Cooperative Wildlife Health Centre.

"Climate warming in the Arctic is occurring more rapidly than elsewhere, threatening the health and sustainability of Arctic plants and animals, which are adapted to a harsh and highly seasonal environment and are vulnerable to invasions by 'southern' species -- both animals and parasites."

A changing climate also is affecting entire plant and animal communities. This is particularly evident in tropical marine environments such as the world's coral reef ecosystems. In places like the Caribbean, warmer water temperatures have stressed corals and facilitated infections by pathogenic fungi and bacteria. When corals -- the framework builders of the ecosystem -- succumb, the myriad of species that depend on them are also at risk.

"Biodiversity loss is a well-established consequence of climate change," said coauthor Richard Ostfeld of the Cary Institute of Ecosystem Studies. "In a number of infectious disease systems, such as Lyme disease and West Nile virus, biodiversity loss is tied to greater pathogen transmission and increased human risk. Moving forward, we need models that are sensitive to both direct and indirect effects of climate change on infectious disease."

Where human health is concerned, there is not only the direct risk from pathogens like dengue, malaria and cholera, all of which are linked to warmer temperatures, but indirect risks from threats to agricultural systems and game species crucial for subsistence and cultural activities.

"Earth's changing climate and the global spread of infectious diseases are threatening human health, agriculture and wildlife. Solving these problems requires a comprehensive approach that unites scientists from biology, the geosciences and the social sciences," said Sam Scheiner, National Science Foundation program director for the joint NSF-National Institutes of Health Ecology and Evolution of Infectious Diseases Program.

The study was funded in part by the National Science Foundation.

"We need to transcend simple arguments about which is more important -- climate change or socioeconomics -- and ask just how much harder will it be to control diseases as the climate warms?" Ostfeld said. "Will it be possible at all in developing countries?"

To respond to that challenge, Altizer and her colleagues -- Kutz, Ostfeld, Pieter T. J. Johnson of the University of Colorado Boulder and C. Drew Harvell of Cornell University -- laid out an agenda for future research and action.

One recommendation is to expand data about the physiological responses hosts and parasites have to temperature changes to help develop early warning systems.

"We'd like to be able to predict, for example, that if the climate warms by a certain amount, then in a particular host-parasite system we might see an increase from one to two transmission cycles per year," Altizer said. "But we'd also like to try to tie these predictions to actions that might be taken."

Such forecasting is well established in crop disease management and has been used to both preventatively close coral reefs and target areas at risk of malaria outbreaks.

"We face a tough task in the oceans, where disease outbreaks can be out of sight and undetected," Harvell said. "Because some coral disease outbreaks are predictable from warming events, we are developing forecasting programs to help us respond before the outbreak begins."

The researchers also pointed out that certain human communities, such as those of indigenous peoples in the Arctic, could be disproportionately impacted by climate-disease interactions.

"A better understanding of the impacts of parasitism on wildlife health, and an ability to make accurate predictions of future wildlife sustainability, is particularly important to aboriginal people across the Arctic who depend on wildlife as a source of food, income and a focus of cultural activities," Kutz said.

Johnson continued, "Because disease represents the product of multiple interacting species, including hosts, pathogens and other members of the food web, forecasting responses to ongoing climate shifts is a tremendous challenge," he said. "Given the rising importance of infectious diseases not only for human health but also wildlife conservation, it's also a challenge for which we are in sore need of a solution. We hope our work contributes to that."

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Multi-units Transistors IR transistor ON Diodes Cypress IC VISHAY IC Switching Diodes About US Renesas parts IC LED Connectors High Precision Resistors Metal Can Packages Transistors Xilinx IC Chip Fuses Current Sensors Resistors Switches YAGEO Resistors AD IC Military IC LITTELFUSE Diodes MAXIM IC Resistors Chip Inductors Infineon Technologies Transistors ON Transistors NXP Diodes Voltage Regulators Transistors NEC Transistors Ligitek LED Low Ohmic Resistors Digital Transistors ELPIDA IC PANASONIC Resistors Atmel IC HARRIS IC Rectifier Diodes SANYO IC LINEAR IC DIODES Transistors TI IC
http://www.suvsystem.com/a/4593.aspx

Extreme wildfires in Western U.S. likely fueled by climate change

These erratic fires are harder to contain and often result in catastrophic damage and loss of property and life. Although not analyzed in the study, the recent Arizona wildfire that began with a lightning strike and killed 19 firefighters appeared to be such an unpredictable, fast-spreading blaze, according to a state report.

The MSU-led study, which appears in the Journal of Applied Meteorology and Climatology, predicts the trend will continue in the western United States.

"Our findings suggest that future lower atmospheric conditions may favor larger and more extreme wildfires, posing an additional challenge to fire and forest management," said Lifeng Luo, MSU assistant professor of geography and lead author on the study.

The researchers analyzed current and future climate patterns projected by multiple regional climate models and their effect on the spread of fire in a mountainous region that includes Arizona, Idaho, Nevada, New Mexico, Utah and Wyoming. The study focused on August, the most active month for wildfires in the western United States.

August 2012 saw 3.6 million acres burn in the region, the most of any August since 2000. However, there were only 6,948 fires in August 2012 -- the second fewest in that 12-year timeframe -- meaning the fires were much larger.

Large wildfires are mainly driven by natural factors including the availability of fuel (vegetation), precipitation, wind and the location of lightning strikes. In particular, the researchers found that exceptionally dry and unstable conditions in the earth's lower atmosphere will continue contributing to "erratic and extreme fire behavior."

"Global climate change may have a significant impact on these factors, thus affecting potential wildfire activity across many parts of the world," the study says.

Co-authors include Ying Tang and Shiyuan Zhong from MSU, and Xindu Bian and Warren Heilman from the USDA Forest Service.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Other Parts MAXIM IC SANYO IC NXP Transistors ALTERA IC Resistor Arrays Fast Recovery Diodes High Precision Resistors NEC Transistors Chip Fuses INFLNEON Diodes Xilinx IC TDK IC Fairchild Semiconductor Transistors ELPIDA IC chip Filter saws NXP Diodes Bipolar Transistors LINEAR IC NS IC Microchip IC Current Sensors Resistors Electronic News PANASONIC Resistors TOSHIBA Diodes INTERSIL IC Connectors Fleld Effect Transistors IC(Integrated Circuits) Switching Diodes Transistors Discrete Semiconductor Transistors Renesas parts IC Rectifier Diodes ON Transistors TI IC ON Diodes Thin Film Resistors AVX Resistors Military IC
http://www.suvsystem.com/a/4585.aspx

Existing cropland could feed four billion more by dropping biofuels and animal feed

Aug. 1, 2013 — The world's croplands could feed 4 billion more people than they do now just by shifting from producing animal feed and biofuels to producing exclusively food for human consumption, according to new research from the Institute on the Environment at the University of Minnesota.

Share This:

Even a smaller, partial shift from crop-intensive livestock such as feedlot beef to food animals such as chicken or pork could increase agricultural efficiency and provide food for millions, the study says.

"We essentially have uncovered an astoundingly abundant supply of food for a hungry world, hidden in plain sight in the farmlands we already cultivate," says graduate research assistant Emily Cassidy, lead author of the paper published in Environmental Research Letters. "Depending on the extent to which farmers and consumers are willing to change current practices, existing croplands could feed millions or even billions more people."

Demand for crops is expected to double by 2050 as population grows and increasing affluence boosts meat consumption. Meat takes a particularly big toll on food security because it takes up to 30 crop calories to produce a single calorie of meat. In addition, crops are increasingly being used for biofuels rather than food production. This study sought to quantify the benefit to food security that would accrue if some or all of the lands used to produce animal feed and fuel were reallocated to directly produce food for people.

To get at that question, Cassidy and colleagues first mapped the extent and productivity of 41 major crops between 1997 and 2003, adjusting numbers for imports and exports and calculating conversion efficiencies of animal feed using U.S. Department of Agriculture data. The researchers assumed humans need an average of 2,700 calories per day, and grazing lands and animals were not included in the study. Among the team's findings:

Only 12 percent of crop calories used for animal feed end up as calories consumed by humans.
Only 55 percent of crop calories worldwide directly nourish people.
Growing food exclusively for direct human consumption could boost available food calories up to 70 percent
U.S. agriculture alone could feed an additional 1 billion people by shifting crop calories to direct human consumption.
When calculated on the basis of protein rather than calories, results were similar. For instance, of all plant protein produced, 49 percent ends up in human diets.

In addition to the global findings, the research team looked at allocation of crop calories in four key countries: India, China, Brazil and the U.S. They found that while India allocates 90 percent of calories to feeding people, the other three allocate 58 percent, 45 percent, and 27 percent, respectively.

Noting the major cultural and economic dimensions involved, the researchers acknowledged that while a complete shift from animal to plant-based diets may not be feasible, even a partial shift would benefit food security. Quantifying the impact of various strategies, they found that a shift from crop-intensive beef to pork and chicken could feed an additional 357 million people, and a shift to nonmeat diets that include eggs and milk could feed an additional 815 million people.

The researchers emphasized that they are not making diet prescriptions or recommendations, just pointing out opportunities for gains in food production. They noted that humans can completely meet protein needs with plant-based diets, but that crop systems would need to shift (e.g., toward more production of protein-rich legumes) to meet human dietary needs.

"The good news is that we already produce enough calories to feed a few billion more people," Cassidy says. "As our planet gets more crowded or we experience disasters like droughts and pests, we can find ways of using existing croplands more efficiently."

In addition to her role as Global Landscapes Initiative graduate research assistant with the Institute on the Environment, Cassidy is a graduate student in the Natural Resources Science and Management program in the University of Minnesota's College of Food, Agriculture and Natural Resource Sciences.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

The when and where of the Y: Research on Y chromosomes uncovers new clues about human ancestry

But even though we all trace our family lineage to a few common ancestors, scientists still don't know exactly when and how those few ancestors started to give rise to the incredible diversity of today's population.

A brand-new finding, made using advanced analysis of DNA from all over the world, sheds new light on this mystery. By studying the DNA sequence of Y chromosomes of men from many different populations, scientists have determined that their male most recent common ancestor (MRCA) lived sometime between 120,000 and 156,000 years ago.

It's the first time the human ancestry has been traced back through the male line by sequencing the DNA of many entire Y chromosomes.

And, it agrees reasonably well with previous findings about our female most recent common ancestor, made by studying DNA carried down through the human race's female line. Such studies used DNA from mitochrondria -- structures inside cells -- and placed that time of the most recent common ancestor between 99,000 and 148,000 years ago. That agreement makes the new finding especially significant:

The research was done by a team of scientists from Stanford University, the University of Michigan Medical School, Stony Brook University, and their colleagues, and is published in the journal Science.

The team hopes their work will lead to further research on Y chromosomes as vehicles for studying human history -- and tracing male lineages back to the common "Adam" ancestors.

Jeffrey Kidd, Ph.D., an Assistant Professor of Human Genetics and Computational Medicine & Bioinformatics who worked on the new study, notes that only recently has it become possible to sequence Y chromosomes, because of technical limitations of previous approaches.

The new paper details how the team was able to make reliable measurements of the sequence variation along the Y chromosome -- which is handed down only from father to son without exchanging, or recombining, genetic material with other chromosomes.

Kidd notes that this initial paper on Y chromosome sequence diversity provides important first evidence that the male most recent common ancestor did not live more recently than the female most recent common ancestor.

"We're interested in understanding the historical relationships between many different human populations, and the migration patterns that have led to the peopling of the world," he says. "We hope that others will make use of this approach and sequence additional chromosomes of interest that are related to the peopling of specific places."

The study involved Y chromosomes obtained through the Human Genome Diversity Project, and from other sources. It included chromosomes from 69 men in several populations in sub-Saharan Africa, and from Siberia, Cambodia, Pakistan, Algeria and Mexico.

The great migrations of our ancestors out of Africa, across Asian and Europe and into the Americas all helped shape today's populations -- as did more recent forces related to colonialism and ever-growing global mobility.

Genetic studies such as this one may help anthropologists understand those migrations -- and their timing -- even better by giving them a genetic "clock" to use when studying today's humans, or potentially DNA extracted from ancient bones. It may also help scientists understand the great genetic diversity seen across Africa, and the evolution process that led to modern humans.

The reconciliation of the timing of "Adam" and "Eve," however, may be this study's most important immediate implication.

"This has been a conundrum in human genetics for a long time," said Carlos D. Bustamante, PhD, a professor of genetics at Stanford and senior author of the study. "Previous research has indicated that the male MRCA lived much more recently than the female MRCA. But now our research shows that there's no discrepancy. In fact, if anything, the Y chromosome may be a bit older."

In addition to Kidd and Bustamante, the research team includes U-M's Elzbieta Sliwerska, Stanford's G. David Poznik, Brenna M. Henn, Muh-Ching Yee, Ghia M. Euskirchen, Alice A. Lin, Michael Snyder, and Peter A. Underhill, and Lluis Quintana-Murci from Institut Pasteur in Paris.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

Climate change occurring ten times faster than at any time in past 65 million years

Aug. 1, 2013 — The planet is undergoing one of the largest changes in climate since the dinosaurs went extinct. But what might be even more troubling for humans, plants and animals is the speed of the change. Stanford climate scientists warn that the likely rate of change over the next century will be at least 10 times quicker than any climate shift in the past 65 million years.

Share This:

If the trend continues at its current rapid pace, it will place significant stress on terrestrial ecosystems around the world, and many species will need to make behavioral, evolutionary or geographic adaptations to survive.

Although some of the changes the planet will experience in the next few decades are already "baked into the system," how different the climate looks at the end of the 21st century will depend largely on how humans respond.

The findings come from a review of climate research by Noah Diffenbaugh, an associate professor of environmental Earth system science, and Chris Field, a professor of biology and of environmental Earth system science and the director of the Department of Global Ecology at the Carnegie Institution. The work is part of a special report on climate change in the current issue of Science.

Diffenbaugh and Field, both senior fellows at the Stanford Woods Institute for the Environment, conducted the targeted but broad review of scientific literature on aspects of climate change that can affect ecosystems, and investigated how recent observations and projections for the next century compare to past events in Earth's history.

For instance, the planet experienced a 5 degree Celsius hike in temperature 20,000 years ago, as Earth emerged from the last ice age. This is a change comparable to the high-end of the projections for warming over the 20th and 21st centuries.

The geologic record shows that, 20,000 years ago, as the ice sheet that covered much of North America receded northward, plants and animals recolonized areas that had been under ice. As the climate continued to warm, those plants and animals moved northward, to cooler climes.

"We know from past changes that ecosystems have responded to a few degrees of global temperature change over thousands of years," said Diffenbaugh. "But the unprecedented trajectory that we're on now is forcing that change to occur over decades. That's orders of magnitude faster, and we're already seeing that some species are challenged by that rate of change."

Some of the strongest evidence for how the global climate system responds to high levels of carbon dioxide comes from paleoclimate studies. Fifty-five million years ago, carbon dioxide in the atmosphere was elevated to a level comparable to today. The Arctic Ocean did not have ice in the summer, and nearby land was warm enough to support alligators and palm trees.

"There are two key differences for ecosystems in the coming decades compared with the geologic past," Diffenbaugh said. "One is the rapid pace of modern climate change. The other is that today there are multiple human stressors that were not present 55 million years ago, such as urbanization and air and water pollution."

Record-setting heat

Diffenbaugh and Field also reviewed results from two-dozen climate models to describe possible climate outcomes from present day to the end of the century. In general, extreme weather events, such as heat waves and heavy rainfall, are expected to become more severe and more frequent.

For example, the researchers note that, with continued emissions of greenhouse gases at the high end of the scenarios, annual temperatures over North America, Europe and East Asia will increase 2-4 degrees C by 2046-2065. With that amount of warming, the hottest summer of the last 20 years is expected to occur every other year, or even more frequently.

By the end of the century, should the current emissions of greenhouse gases remain unchecked, temperatures over the northern hemisphere will tip 5-6 degrees C warmer than today's averages. In this case, the hottest summer of the last 20 years becomes the new annual norm.

"It's not easy to intuit the exact impact from annual temperatures warming by 6 C," Diffenbaugh said. "But this would present a novel climate for most land areas. Given the impacts those kinds of seasons currently have on terrestrial forests, agriculture and human health, we'll likely see substantial stress from severely hot conditions."

The scientists also projected the velocity of climate change, defined as the distance per year that species of plants and animals would need to migrate to live in annual temperatures similar to current conditions. Around the world, including much of the United States, species face needing to move toward the poles or higher in the mountains by at least one kilometer per year. Many parts of the world face much larger changes.

The human element

Some climate changes will be unavoidable, because humans have already emitted greenhouse gases into the atmosphere, and the atmosphere and oceans have already been heated.

"There is already some inertia in place," Diffenbaugh said. "If every new power plant or factory in the world produced zero emissions, we'd still see impact from the existing infrastructure, and from gases already released."

The more dramatic changes that could occur by the end of the century, however, are not written in stone. There are many human variables at play that could slow the pace and magnitude of change -- or accelerate it.

Consider the 2.5 billion people who lack access to modern energy resources. This energy poverty means they lack fundamental benefits for illumination, cooking and transportation, and they're more susceptible to extreme weather disasters. Increased energy access will improve their quality of life -- and in some cases their chances of survival -- but will increase global energy consumption and possibly hasten warming.

Diffenbaugh said that the range of climate projections offered in the report can inform decision-makers about the risks that different levels of climate change pose for ecosystems.

"There's no question that a climate in which every summer is hotter than the hottest of the last 20 years poses real risks for ecosystems across the globe," Diffenbaugh said. "However, there are opportunities to decrease those risks, while also ensuring access to the benefits of energy consumption."

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

we are focus on the following fields,and hope we can help you.

买戒指银镯谨防假冒

　　订婚戒指，戴着戴着褪色了

　　花1000元购买的“中东蜜蜡”手镯，原来是合成塑料做的；象征“情比金坚”的订婚戒指，戴着戴着褪色了；买了想给孩子戴的银镯，放了一阵子发黑发绿…… 来自鹿城工商分局的消息称，工商部门近日来接到多起有关饰品类的举报投诉。

　　“中东蜜蜡”变身合成塑料？

　　7月上旬，周女士向工商部门投诉，她在市区踏碓巷某饰品店购买了一只价格1000元的“中东蜜蜡”手镯，佩戴一段时间后手镯没有随着体温发生任何色泽变化，怀疑是假货要求鉴定。

　　经专业机构检测，手镯是合成塑料制成。经调解，店主同意退回1000元并额外赔偿周女士600元。据工商人员介绍，近年来，消费者反映购买玛瑙、翡翠、水晶、蜜蜡、彩石等玉石遭遇成色不均、填充物甚至为纯玻璃塑料制品的情形逐渐增多，玉石市场较为混乱。

　　18K戒指褪色属正常？

　　包小姐在市区某百货专柜购买了价值7000多元的18K黄金情侣对戒。佩戴一段时间后，包小姐发现该戒指出现褪色，专柜给出了“人体汗液的代谢物导致18K戒指褪色属正常情况”的解释。包小姐认为专柜事先没有告知这个情况，有重大责任，便向工商部门求助。

　　经确认该戒指系足金产品之后，调解人员认为18K(75%的黄金+15%的其他金属)黄金戒指在佩戴时，由于汗液中的代谢物与戒指中的其他金属起了化学反应导致戒指颜色发生变化，会直接影响佩戴效果，是消费者购物前应当知情的重要信息，商家此行为侵犯了消费者的知情权。

　　经调解，专柜同意以优惠1000元的价格给包小姐等额调换其他产品。

　　银手镯竟然发黑发绿？

　　今年2月，阚先生通过市区人民中路某旅行社前往云南旅游，在丽江购物点以500元价格给孙女购买了一对儿童纯银手镯。由于孙女年纪小不懂佩戴，阚先生一直收藏着手镯不曾拿出，直到6月再次打开盒子时，发现银手镯的表面竟然发黑发绿，像镀了一层铜锈，遂求助于工商部门。

　　工商部门调查发现，阚先生购买手镯时并未索要发票，只有一张简单的收据，收据上丽江购物点的店址系虚构，电话无法打通，旅行社也拒不承认带阚先生去过这家购物点。由于证据不足，阚先生只能自认倒霉。

　　购买饰品务必索要发票

　　工商人员提醒市民，在购买金石玉器前，应先了解一下佩戴首饰的基本常识，减少纠纷的出现。比如人体的汗液中有1%是氯代物、乳酸、尿素氨等物质。这些物质与首饰中的银和铜接触后，会发生化学反应，产生氯化银和硫化铜，并呈现深黑色的化学盐。此外，应尽量减少金银首饰与洗洁精、化妆品、香水、发胶等化学物品接触，避免用力拉扯金银饰品，以免变形。

　　应对饰品尤其是玉石产品的属性和特点有一些了解，选购时可用相应的方法辨别真伪。以蜜蜡为例，蜜蜡同玛瑙、琥珀等一样是树木脂液化石，佩戴后色泽会随着人体酸碱度的不同而发生变化。密度略大于水，放在1:4的饱和盐水中不会下沉；将针烧红刺入会闻到淡淡的松香味，塑料则发出辛辣臭味并粘住针头。

　　同时，由于饰品价值较高，市民在购买时一定要主动索要正规发票。若是异地购买，应仔细校对发票上的卖方信息和商品信息是否存在出入，必要时拍照保存更多证据，一旦发生纠纷可向旅行社追溯连带责任。朱奕郑柳影

TAG:买戒指银镯谨防假冒