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Source: http://nbcsports.msnbc.com/id/21134540/vp/51154400#51154400
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Thursday, March 14, 2013
Tuesday, March 12, 2013
10 Reasons I Should Be VIP, & other #RRRVIP Essay Contest ...
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Saturday, March 9, 2013
Biobatteries catch breath
Mar. 7, 2013 ? An air-breathing bio-battery has been constructed by researchers from the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw. The core element providing the new power source with relatively high voltage and long lifetime is a carefully designed cathode taking up oxygen from air and composed of an enzyme, carbon nanotubes and silicate.
People are increasingly taking advantage of devices supporting various functions of our bodies. Today they include cardiac pacemakers or hearing aids; tomorrow it will be contact lenses with automatically changing focal length or computer-controlled displays generating images directly in the eye. None of these devices will work if not coupled to an efficient and long-lasting power supply source. The best solution seems to be miniaturised biofuel cells consuming substances naturally occurring in human body or in its direct surrounding.
Researchers from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw developed an efficient electrode for the use in construction of biofuel cells or zinc-oxygen biobatteries. After installation in a cell, the new biocathode generates a voltage, during many hours, that is higher than that obtained in existing power sources of similar design. The most interesting is that the device is air-breathing: it works at full efficiency when it can take oxygen directly from the air.
Common batteries and rechargeable batteries are unsuitable to power implants inside the human body as they use strong bases or acids. These agents can on no account get into the body. The battery housing must be therefore absolutely tight. But in line with reducing the battery size, it must be better isolated. In extreme cases, the weight of the housing of a common, miniaturised battery would be even a few dozen times greater than the weight of the battery's active components that generate electricity. And here biofuel cells offer an essential advantage: they do not require housing. To get electricity, it is enough to insert the electrodes into the body.
"One of the most popular experiments in electrochemistry is to make a battery by sticking appropriately selected electrodes into a potato. We are doing something similar, the difference is that we are focusing on biofuel cells and the improvement of the cathode. And, of course, to have the whole project working, we'd rather replace the potato with... a human being," says Dr Martin J?nsson-Niedzi??ka (IPC PAS).
In the experiments, Dr J?nsson-Niedzi??ka's group uses zinc-oxygen batteries. The principle of their operation is not new. The batteries constructed in this way had been popular before the time of alkaline power sources came. "At present, many laboratories work on glucose-oxygen biofuel cells. In the best case they generate a voltage of 0.6-0.7 V. A zinc-oxygen biobattery with our cathode is able to generate 1.75 V for many hours.," says Adrianna Z?oczewska, a PhD student at the IPC PAS, whose research has been supported under the International PhD Projects Programme of the Foundation for Polish Science.
The main component of the biocathode developed at the IPC PAS is an enzyme surrounded by carbon nanotubes and encapsulated in a porous structure -- a silicate matrix deposited on an oxygen permeable membrane. "Our group had been working for many years on techniques that were necessary to construct the cathode using enzymes, carbon nanotubes and silicate matrices," stresses Prof. Marcin Opa??o (IPC PAS).
An electrode so constructed is installed in a wall of a small container. To have the biofuel cell working, it is enough to pour an electrolyte (here: a solution containing hydrogen ions) and insert the zinc electrode in the electrolyte. The pores in the silicate matrix enable oxygen supply from the air and H+ ions from the solution to active centres of the enzyme, where oxygen reduction takes place. Carbon nanotubes facilitate transport of electrons from the surface of the semipermeable membrane.
A cell with the new biocathode is able to supply power with a voltage of 1.6 V, for a minimum one and a half of a week. The cell efficiency decreases with time, likely because of gradual deactivation of the enzyme on the biocathode. "Here not everything is dependent on us, but on the progress in biotechnology. The lifetime of a biofuel cells with our biocathode could be significantly prolonged, if the enzyme regeneration processes are successfully developed," says Dr J?nsson-Niedzi??ka.
In the experiments carried out so far, a stack of four batteries connected in series successfully powered a lamp composed of two LEDs. Before, however, the biofuel cells based on the design developed at the IPC PAS get popularised, the researchers must solve the problem of relatively low electric power that is common to all types of biofuel cells.
The research presented here is important not only in view of the miniaturisation of power supply sources for medical implants, biosensors or light-emitting tattoos. The processes responsible for electricity generation in biofuel cells are potentially suitable for use in electric power generation in a larger scale. The limiting factors here are the properties of the enzymes, so that further advancement in this area is essentially dependent on the development of the biotechnology.
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The above story is reprinted from materials provided by Institute of Physical Chemistry of the Polish Academy of Sciences, via AlphaGalileo.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.
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Tuesday, March 5, 2013
Alleged press shots out LG Optimus F5 as Verizon's mid-range Lucid 2
About a week ago, we went hands-on with LG's new mid-range LTE-capable Optimus F5 and F7 smartphones at MWC. At the time it was unknown where these handsets would land in the US, but it appears that we now have the goods on the former. According to a pair of alleged press shots obtained by UnwiredView, LG's F5 will be showing up on Verizon in the not so distant future. Said to be a follow up to last year's Lucid, this mid-tier device's main bullet points include a modest 4.3-inch qHD display, a 1.2GHz dual-core Snapdragon processor, a 5-megapixel rear-facing camera (capable of 1080p video capture) and Android 4.1.2. Sure, the Lucid 2's specs remind us more of a keyboard shortcut and less of a powerful storm -- we just hope that its price tag will also be a refresh. If so, that should make this device a considerable option for first-time smartphone buyers looking to make the jump to LTE.
Filed under: Cellphones, Mobile, LG
Source: UnwiredView
Source: http://www.engadget.com/2013/03/04/lg-f5-verizon-lucid2-press-shots/
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Sunday, March 3, 2013
New study reveals how sensitive US East Coast regions may be to ocean acidification
Mar. 1, 2013 ? A continental-scale chemical survey in the waters of the eastern U.S. and Gulf of Mexico is helping researchers determine how distinct bodies of water will resist changes in acidity. The study, which measures varying levels of carbon dioxide (CO2) and other forms of carbon in the ocean, was conducted by scientists from 11 institutions across the U.S. and was published in the journal Limnology and Oceanography.
"Before now, we haven't had a very clear picture of acidification status on the east coast of the U.S.," says Zhaohui 'Aleck' Wang, the study's lead author and a chemical oceanographer at Woods Hole Oceanographic Institution (WHOI). "It's important that we start to understand it, because increase in ocean acidity could deeply affect marine life along the coast and has important implications for people who rely on aquaculture and fisheries both commercially and recreationally."
Coastal ocean acidification, Wang says, can occur when excess carbon dioxide is absorbed by, flushed into or generated in coastal waters, setting off a chain of chemical reactions that lowers the water's pH, making it more acidic. The process disproportionately affects species like oysters, snails, pteropods, and coral, since those organisms cannot effectively form shells in a more acidic environment.
According to the survey, says Wang, different regions of coastal ocean will respond to an influx of CO2 in different ways. "If you put the same amount of CO2 into both the Gulf of Maine and the Gulf of Mexico right now, the ecosystem in the Gulf of Maine would probably feel the effects more dramatically," he says. "Acidity is already relatively high in that region, and the saturation of calcium carbonate -- the mineral that many organisms need to make shells -- is particularly low. It's not a great situation."
Excess CO2 can enter coastal waters from a variety of different sources, Wang says. One large source is carbon dioxide in the atmosphere, which has been steadily increasing in concentration worldwide for the past hundred and fifty years. The higher those levels of atmospheric CO2 rise, more CO2 gas will be absorbed into seawater by contact, says Wang. Another potential culprit, he notes, is nutrient-rich runoff from land. Rainfall and other surface flows can wash fertilizers and other byproducts of human activities into river systems and ground water, and ultimately, into the coastal ocean, delivering an excess of nutrients and often an explosion of biological activity that can lead to decreased oxygen and increased CO2 and acidity.
"This happens regularly in the Gulf of Mexico," says Wang. "The Mississippi River dumps enormous amounts of nitrogen and other nutrients into the Gulf, which spawns large algal blooms that lead to production of large amount of organic matter. In the process of decomposing the organic matter, the microbes consume oxygen in the water and leave carbon dioxide behind, making the water more acidic. If this process happens in the Gulf of Maine, the ecosystem there may be even more vulnerable since the Gulf of Maine is a semi-enclosed system and it may take longer time for low pH, low oxygen water to disperse."
Wang and his colleagues conducted their fieldwork in 2007 aboard the R/V Ronald H. Brown. Starting in the waters off Galveston, Texas, they worked their way around the Louisiana and west Florida coasts, past the Florida Straight, and up the eastern seaboard, collecting samples along nine different transects that ran from the coast to deep ocean off the shelf break, up to 480km (300 miles) offshore.
During the cruise, the researchers measured seawater samples for total dissolved inorganic carbon (DIC), which is made up of a combination of carbonate, bicarbonate, dissolved CO2 and carbonic acid. The team compared this measurement to the water's total alkalinity, a measure of how much base is in a water sample. The ratio of the two is a marker for water's ability to "buffer" or resist changes in acidity. Waters with a high ratio of alkalinity to DIC, Wang says, would be less susceptible to acidification than waters that showed a much lower ratio.
After analyzing their data, Wang and colleagues found that, despite a "dead zone" of low oxygen and high acidity outside the mouth of the Mississippi, the Gulf of Mexico on the whole showed a high ratio of alkalinity to DIC, meaning it would be more resistant to acidification. As the team traveled farther north, however, they saw the ratio steadily decreases north of Georgia. The waters in the Gulf of Maine, Wang says, on average had the lowest alkalinity to DIC ratio of any region along the eastern seaboard, meaning that it would be especially vulnerable to acidification should CO2 levels rise in those waters.
While it's unclear exactly why the ratio of alkalinity to DIC is low in those northern waters, Wang thinks part of the issue may be linked to alkalinity sources to the region. For example, the Labrador Coastal Current brings relatively fresh, low alkalinity water down from the Labrador Sea to the Gulf of Maine and Middle Atlantic Bight.
If this current is the major source of alkalinity to the region, he says, it may mean that the Gulf of Maine's fate could be linked to changes in global climate that, through melting sea ice and glaciers, increase the flow of fresh water to the Gulf of Maine. However, whether this freshening is accompanied by a decreases in seawater alkalinity and "buffer" capacity remains unknown.
Since the waters of the northeast U.S. are already susceptible to rising acidity, Wang says this raises big questions about how species of marine life -- many of which are important to the commercial fishing and shellfish industry there -- will fare in the future. "For example, how are oysters going to do? What about other shellfish? If the food chain changes, how are fish going to be impacted?" Wang asks. "There's a whole range of ecological and sociological questions." There is a great need for need for more robust coastal ocean chemistry monitoring and coastal ocean acidification studies, he adds. A better understanding of the changing chemistry will help fisheries regulators to better manage the stocks.
Also collaborating on the study were Rik Wanninkhof and Tsung-Hung Peng from the National Oceanic and Atmospheric Administration's Atlantic Oceanographic and Meteorological Laboratory, Wei-Jun Cai and Wei-Jen Huang of the University of Georgia, Robert H. Byrne of the University of South Florida, and Xinping Hu of Texas A&M University.
This research was supported by the NOAA Global Carbon Cycle Program.
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The above story is reprinted from materials provided by Woods Hole Oceanographic Institution.
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Journal Reference:
- Zhaohui Aleck Wang, Rik Wanninkhof, Wei-Jun Cai, Robert H. Byrne, Xinping Hu, Tsung-Hung Peng, Wei-Jen Huang. The marine inorganic carbon system along the Gulf of Mexico and Atlantic coasts of the United States: Insights from a transregional coastal carbon study. Limnology and Oceanography, 2013; 58 (1): 325 DOI: 10.4319/lo.2013.58.1.0325
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.
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Saturday, March 2, 2013
Clogged heart arteries can foreshadow stroke
Feb. 28, 2013 ? Blockages in your heart arteries could mean you're more likely to have a stroke, even if you're considered low risk, according to research in the American Heart Association journal Stroke.
"This study demonstrates that stroke risk is tightly aligned with coronary atherosclerosis, showing the closely related nature of cardiovascular and cerebrovascular disease," said Dirk M. Hermann, M.D., the study's lead investigator and professor of vascular neurology and dementia at the University Hospital Essen in Germany.
"This raises the need for intensified interdisciplinary efforts for providing adequate disease prevention and management strategies."
In the study, researchers used the non-invasive electron beam-computed tomography, a variation of the conventional CT scan, to determine how much plaque had built up in the coronary arteries of 4,180 patients who had no previous strokes or heart attacks. The patients, men and women 45-75 years old, were followed for about eight years.
During the study, 92 strokes occurred.
The blockages, caused by coronary artery calcification (CAC), were significantly higher in those who had a stroke than those who didn't. Those who had CAC levels of more than 400 Hounsfield units (HU), a density measurement, were three times more likely to have a stroke than those with CAC levels below 399 HU.
CAC measurements were more potent in predicting stroke in patients younger than 65 and those at low risk for cardiovascular disease, researchers said.
CAC levels were an accurate predictor of stroke in men and women regardless of whether patients suffered from atrial fibrillation, a form of irregular heartbeat often associated with stroke.
"Not only atrial fibrillation but also CAC has to be taken into account as a marker of risk for stroke events," Hermann said.
Study patients who suffered a stroke were about 65 years old, had a higher body mass index and were more likely to have high blood pressure, diabetes and high cholesterol levels. Although the study was conducted in Germany, Hermann said the findings among the middle-aged participants are likely generalizable to Americans in the same age group.
Co-principal investigators were R. Erbel, M.D.; K. H. J?ckel, Ph.D.; and S. Moebus, Ph.D. Author disclosures are on the manuscript.
The Heinz Nixdorf Foundation, German Ministry of Education and Science and German Research Foundation funded the study.
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The above story is reprinted from materials provided by American Heart Association.
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Journal Reference:
- Dirk M. Hermann, Janine Gronewold, Nils Lehmann, Susanne Moebus, Karl-Heinz J?ckel, Marcus Bauer, and Raimund Erbel. Coronary Artery Calcification Is an Independent Stroke Predictor in the General Population. Stroke, 2013; DOI: 10.1161/STROKEAHA.111.678078
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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.
Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/~3/J3jTtjasxx8/130228171500.htm
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