Extremely Obese Children Have Higher Prevalence of Psoriasis, Higher Heart Disease Risk

ScienceDaily (May 18, 2011) — Children who are overweight or obese have a significantly higher prevalence of psoriasis, and teens with psoriasis, regardless of their body weight, have higher cholesterol levels, according to a Kaiser Permanente study published online in the Journal of Pediatrics. The study findings suggest that higher heart disease risk for patients with psoriasis starts in childhood in the form of higher cholesterol levels.

Psoriasis is a chronic inflammatory disease of the skin that often starts early in life and, according to the National Psoriasis Foundation, affects more than 7 million Americans.

"This study suggests a link between obesity and psoriasis in children," said study lead author Corinna Koebnick, PhD, a research scientist at the Kaiser Permanente Southern California's Department of Research & Evaluation in Pasadena, Calif. "But our study findings also suggest that the higher heart disease risk for patients with psoriasis starts in childhood in the form of higher cholesterol levels. We may need to monitor youth with psoriasis more closely for cardiovascular risk factors, especially if they are obese."

Researchers used electronic health records to study 710,949 racially and ethnically diverse children and found that obese children were almost 40 percent more likely to have psoriasis than normal weight children. Extremely obese children were almost 80 percent more likely to have psoriasis than normal weight children. Additionally, among youth with psoriasis, it was four times more likely that the psoriasis would be severe or more widespread in obese youth than what was seen in normal weight children. Additionally, teens with psoriasis had 4 to16 percent higher cholesterol levels and liver enzymes, regardless of their weight, than youth without this condition.

"Very little is known about psoriasis in children where the disease is mostly viewed and treated as a burdensome skin condition and less considered a metabolic disease," adds Dr. Koebnick.

"Psoriasis may also put children at risk for metabolic disease, as seen in adults, so studies such as these are extremely important in helping primary care providers learn the best way to care for these children," notes co-author Amy Porter, MD, Southern California Permanente Medical Group's regional physician lead for weight management, and pediatrician at Kaiser Permanente's Baldwin Park Medical Center.

Epidemiologic studies in adults have shown that patients with psoriasis are at a higher risk of developing metabolic conditions such as diabetes, hypertension, heart attack and stroke. In adults, obesity has also been linked to a higher risk of developing psoriasis, and obesity, like psoriasis, is also associated with an increased risk of cardiovascular disease, metabolic syndrome and diabetes.

"Both conditions are characterized by a chronic low-level inflammation," notes Dr. Koebnick. "Yet, we know little to nothing about the metabolic risk of psoriasis, especially when combined with obesity in children." Psoriasis in children may increase blood cholesterol levels, and this may additionally be triggered by the presence of obesity. While the present study has limitations due to its cross-sectional design where both body weight and information on psoriasis were assessed at the same time, future studies based on this cohort will address these issues.

"It has been well described that adults with psoriasis have increased cardiovascular risk factors, but we have now examined these issues in children. As we follow these patients over 30-40 years, we will be able to determine if these increased cardiovascular risk factors in turn increase the risk for major adverse cardiac events," said study senior author, Jashin J. Wu, M.D., director of clinical research and the associate residency program, and director for the department of dermatology at Kaiser Permanente Los Angeles Medical Center.

This study is part of the Kaiser Permanente Southern California Children's Health Study, Kaiser Permanente's ongoing work to identify and treat childhood obesity through research and community programs.

Other study authors included: Mary Helen Black, MS, PhD, Ning Smith, MS, and Steven J. Jacobsen, MD, PhD, from the Kaiser Permanente Department of Research & Evaluation in Pasadena, Calif.; Amy H. Porter, MD, from the Kaiser Permanente Baldwin Park Medical Center; and Jack K. Der-Sarkissian, MD, and Jashin J Wu, MD from the Kaiser Permanente Medical Center, Los Angeles.

Source: Sciencedaily.com

In Japan Reactor Failings, Danger Signs for the U.S.

TOKYO — Emergency vents that American officials have said would prevent devastating hydrogen explosions at nuclear plants in the United States were put to the test in Japan — and failed to work, according to experts and officials with the company that operates the crippled Fukushima Daiichi plant.

The failure of the vents calls into question the safety of similar nuclear power plants in the United States and Japan. After the venting failed at the Fukushima plant, the hydrogen gas fueled explosions that spewed radioactive materials into the atmosphere, reaching levels about 10 percent of estimated emissions at Chernobyl, according to Japan’s nuclear regulatory agency.

Venting was critical to relieving pressure that was building up inside several reactors after the March 11 tsunami knocked out the plant’s crucial cooling systems. Without flowing water to cool the reactors’ cores, they had begun to dangerously overheat.

American officials had said early on that reactors in the United States would be safe from such disasters because they were equipped with new, stronger venting systems. But Tokyo Electric Power Company, which runs the plant, now says that Fukushima Daiichi had installed the same vents years ago.

Government officials have also suggested that one of the primary causes of the explosions was a several-hour delay in a decision to use the vents, as Tokyo Electric managers agonized over whether to resort to emergency measures that would allow a substantial amount of radioactive materials to escape into the air.

But the release this week of company documents and interviews with experts provides the most comprehensive evidence yet that mechanical failures and design flaws in the venting system also contributed to delays. The documents paint a picture of increasing desperation at the plant in the early hours of the disaster, as workers who had finally gotten the go-ahead to vent realized that the system would not respond to their commands.

While venting would have allowed some radioactive materials to escape, analysts say that those releases would have been far smaller than those that followed the explosions at three of the plant’s reactors, which blew open containment buildings meant to serve as a first line of defense against catastrophe. The blasts may also have been responsible for breaches in containment vessels that have complicated efforts to cool the fuel rods and contain radioactive leaks from the site.

One reason the venting system at the plant, which was built by General Electric, did not work is that it relied on the same sources of electricity as the rest of the plant: backup generators that were in basements at the plant and vulnerable to tsunamis. But the earthquake may also have damaged the valves that are part of the venting system, preventing them from working even when operators tried to manually open them, Tokyo Electric officials said.

In either case, regulators in the United States and Japan will now need to determine if such systems at similar plants designed by G.E. need to undergo expensive and time-consuming retrofitting or redesign to allow them to function even in severe accidents.

“Japan is going to teach us lessons,” said David Lochbaum at the Union of Concerned Scientists. “If we’re in a situation where we can’t vent where we need to, we need to fix that.”

Officials from General Electric did not comment on Tuesday.

The seriousness of the crisis at the Fukushima plant became evident within hours of the quake and the tsunami that rushed over the plant’s sea wall.

Just 12 hours after the quake, the pressure inside Reactor No. 1 had reached roughly twice the maximum pressure the unit had been designed to withstand, raising fears that the vessels that house fuel rods would rupture, setting a possible meltdown in motion. With the pressure high, pumping in additional cooling water also was not possible.

Read full story at: http://nyti.ms/mNbeMt

Source: Nytimes.com

Can Batteries Replace Power Generators?

When the Long Island Power Authority said last summer that it was going to need new power capacity in the next few years, most people assumed that meant new generating stations or new transmission cables. But of the 16 companies that submitted proposals, one, AES Energy Storage, took an entirely different tack: it proposed batteries.

When all is said and done, batteries are not a source of energy; in fact, they consume it. For every 10 kilowatt-hours put into a battery, only about nine come back out. The battery is a little like a savings account at a bank, but with a negative interest rate. Still, withdrawals are possible at times when they are most useful.

Batteries are a temporary source of energy and power, with the instantaneous ability to meet load and do work. AES is proposing the use of a 400-megawatt battery, with the same output as a medium-size natural gas plant, that can operate for four hours. It would be about 10 times larger than the biggest grid-connected battery system now in service.

AES said the battery would also be a cleaner energy choice. That’s because the alternative would probably be new simple-cycle natural gas plants, which are relatively low in efficiency and have a high output of carbon dioxide and conventional pollutants per kilowatt-hour.

Batteries, on the other hand, could be charged at night using relatively cheap capacity from Long Island’s most efficient generators, combined cycle gas plants. Those use about 7,000 B.T.U.’s of energy per kilowatt-hour, compared with 10,000 or 11,000 for the simple-cycle plants.

Can a battery qualify if the utility wants power?

In fact, in the complicated world of the electric grid, batteries can do some jobs better than generation stations. One is providing a service called spinning reserve. At a power plant, that means spinning a turbine and burning fuel, but not actually making any energy, sitting in standby in case more power is suddenly needed. A battery can sit at the ready without actually spinning or using fuel.

Another is frequency regulation. Alternating current is supposed to change directions 60 times per second, but in reality is always just a little faster or a little slower than that. Plants that provide frequency regulation will add or subtract energy at precise intervals to keep the number of alternations near 60.

Power plants that do this work get extra wear and tear, and modern gas-fired turbines are not as good for that job as old-fashioned steam plants were. Batteries, though, can take up the slack.

John Zahurancik, vice president of operations and deployment at AES, pointed out that getting permission to build batteries is easier than getting the go-ahead to build more power plants. No new permits for air emissions or water consumption would be needed, for example, he said.

The Long Island Power Authority said it was just beginning to evaluate the responses to its request for proposals, which was issued last August. It has not said which submissions met its terms and will be evaluated, and whether proposals for energy storage can compete. Officials there also declined to say whether any of the other bids were submitted by storage companies.

AES already operates an 8-megawatt battery installation in Johnson City, N.Y., near Binghamton and a 12-megawatt system in Chile. It is building a 32-megawatt system in West Virginia adjacent to a 97-megawatt wind farm. Batteries paired with wind farms can smooth out the wind turbines’ highly variable output.

The company’s Long Island proposal is still in an early phase; AES has not, for example, chosen precisely what type of battery it would use.

Source: Nytimes.com

Tarantulas Shoot Silk from Their Feet

ScienceDaily (May 17, 2011) — Climbing is possibly one of the riskiest things an adult tarantula can do. Weighing in at anything up to 50g, the dry attachment systems that keep daintier spiders firmly anchored are on the verge of failure in these colossal arachnids.

"The animals are very delicate. They wouldn't survive a fall from any height," explains Claire Rind from the University of Newcastle, UK.

In 2006, Stanislav Gorb and his colleagues published a paper in Nature suggesting that tarantulas may save themselves from falling by releasing silk threads from their feet. However, this was quickly refuted by another group that could find no evidence of the silk. Fascinated by spiders and intrigued by the scientific controversy, Rind decided this was too good a challenge to pass up and discovered that tarantulas shoot silk from their feet when they lose their footing. She publishes her results in The Journal of Experimental Biology.

Teaming up with undergraduate Luke Birkett, Rind tested how well three ground-dwelling Chilean rose tarantulas kept their footing on a vertical surface. Gently placing one of the animals in a very clean aquarium with microscope slides on the floor, the duo cautiously upended the aquarium to see if the tarantula could hang on. "Given that people said tarantulas couldn't stay on a vertical surface, we didn't want to find that they were right," remembers Rind. But the spider didn't fall, so the duo gave the aquarium a gentle shake. The tarantula slipped slightly, but soon regained its footing. So the spider had held on against the odds, but would Rind find silk on the microscope slides?

Looking at the glass by eye, Rind couldn't see anything, but when she and Birkett looked closely under a microscope, they found minute threads of silk attached to the microscope slide where the spider had stood before slipping.

Next, Rind had to prove that the silk had come from the spiders' feet and not their web-spinning spinnerets. Filming the Chilean rose tarantulas as they were rotated vertically, Rind, Benjamin-James Duncan and Alexander Ranken disregarded any tests where other parts of the spiders' bodies contacted the glass and confirmed that the feet were the source of the silk. Also, the arachnids only produced their safety threads when they slipped.

But where on the spiders' feet was the silk coming from? Having collected all of the moulted exoskeletons from her Mexican flame knee tarantula, Fluffy, when she was young, Rind looked at them with a microscope and could see minute threads of silk protruding from microscopic hairs on Fluffy's feet. Next, the team took a closer look at moults from Fluffy, the Chilean rose tarantulas and Indian ornamental tarantulas with scanning electron microscopy and saw minute reinforced silk-producing spigots, which extended beyond the microscopic attachment hairs on the spiders' feet, widely distributed across the foot's surface. Rind also looked at the tarantula family tree, and found that all three species were only distantly related, so probably all tarantula feet produce the life-saving silk threads.

Finally, having noticed the distribution of the spigots, Rind realised that tarantulas could be the missing link between the first silk-producing spiders and modern web spinners. She explains that the spread of spigots on the tarantula's foot resembled the distribution of the silk spigots on the abdomen of the first silk spinner, the extinct Attercopus spider from 386 million years ago. The modern tarantula's spigots also looked more similar to mechanosensory hairs that are distributed over the spider's entire body, possibly making them an evolutionary intermediate in the development of silk spinning. So, not only has Fluffy settled a heated scientific debate but she also may be a link to the silk spinners of the past.

Source: Sciencedaily.com

There's No Magic Number for Saving Endangered Species

ScienceDaily (May 17, 2011) — A new study offers hope for species such as the Siberian Tiger that might be considered 'too rare to save', so long as conservation efforts can target key threats.

The findings have important implications for conserving some of the world's most charismatic endangered species, which often exist in populations far smaller than the many thousands of individuals that earlier studies had argued were necessary for viability.

Charismatic examples include the mountain gorilla, which likely now number 1,000 or less, the approximately 450 remaining Amur or Siberian tigers, the 180-500 remaining mature Philippine eagles, and the 70 wild Puerto Rican parrots.

The findings of a UK-US research team, the largest critical review of the use of minimum viable population (MVP) (*1) numbers in conservation, dispute the use of a universal MVP as a yardstick for conservation policies. According to the researchers there is no single population size that can be used as a catch-all guideline to save endangered species.

Co-author of the report, Dr. Philip Stephens, School of Biological and Biomedical Sciences, Durham University, said: "Populations usually show rapid declines as a result of human activities such as hunting and habitat conversion. The results of the study are encouraging and show that if we can remove the negative effects of human activities, even relatively small populations could be viable in the long term."

Dr. Greg Hayward, the U.S. Forest Service's (USFS) regional ecologist for Alaska said: "This is good news for biologists working to save species like the tiger. There's a lot of work to do to arrest the effects of poaching, prey loss and habitat destruction. However, if that work is successful, the tiger might yet be able to recover, despite the relatively small size of most tiger populations."

The study, published in the journal, Trends in Ecology and Evolution, shows that population sizes required for long-term viability vary, both within and among species, and depend on the specific circumstances in which the population is found. Estimates of viable population sizes were typically reduced to hundreds rather than thousands of individuals for populations that were relatively stable.

Previous studies have suggested that the allocation of conservation effort should be related to the number of individuals in threatened populations. For species which would require intense effort to raise numbers to 5,000 individuals, it might be too late to act and better to concentrate limited conservation resources elsewhere, the previous studies have suggested.

Researchers on the US-UK team argue that conservationists should not give up on saving an endangered species if its population is below an MVP figure, and they advise policy-makers to be cautious about setting guidelines for 'safe' population sizes.

The researchers also warn against potential complacency and stress the need to look in detail at the specific threats that a species faces. They argue that no population size is likely to be safe from extinction when conservation activities fail to reduce the impact of the factors causing the population to decline.

Dr. Curt Flather, a research ecologist with the USFS Rocky Mountain Research Station in Colorado said: "The enormous variability in estimates shows that many populations also need to be highly abundant to be viable. The extinction of the passenger pigeon, which numbered 3 to 5 billion individuals in North America during the 1800s, is a reminder that population size alone is no guarantee against extinction."

Read more at http://www.sciencedaily.com/releases/2011/05/110516201101.htm

Source: Sciencedaily.com