lossjean
高级会员
注册日期: 2011-10-31
发贴数: 135
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| 发贴日期: 2011-11-25 14:55 | IP 已记录
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WASHINGTON – Grandma may have been right about keeping a teakettle warming on the stove in winter to moisten the air. Rashard Mendenhall Jersey . Studies of seasonal influenza have long found indications that flu spreads better in dry air. Now, new research being published Tuesday in Proceedings of the National Academy of Science, indicates that the key is the absolute humidity -- which measures the amount of water present in the air, regardless of temperature -- not the more commonly reported relative humidity. Relative humidity varies depending on air temperature; absolute humidity doesnt. The correlations were surprisingly strong. When absolute humidity is low, influenza virus survival is prolonged and transmission rates go up, said Jeffrey Shaman, an Oregon State University atmospheric scientist who specializes in ties between climate and disease transmission The finding is very important for the scientific community and the medical community to know to develop better prediction models of influenza, Shaman said in a telephone interview. It will offer the chance to better understand and forecast the spread of the disease. For the public, he added, it offers a more elegant explanation for why we see these seasonal spikes in flu. And, he added, it shows that in some cases it may be worthwhile to add humidity to the air. Beware of overdoing it, though — too much humidity can lead to other problems, such as mold. The correlation with flu and low humidity is important because in cold winter weather, when flu is most common, even a high relative humidity reading may indicate little actual moisture in the air, and the less moisture there is, the happier the flu virus seems to be. Shaman and co-author Melvin Kohn, an epidemiologist with the Oregon Department of Health Services, reanalyzed data from a study published in 2007 in the journal PLoS Pathogens by researchers at Mount Sinai School of Medicine in New York. That report found there were more flu cases when it was colder and drier. The Oregon researchers said relative humidity could only explain about 12 percent of the variability of influenza virus transmission and 36 percent of virus survival in the 2007 study. In their new analysis, Shaman and Kohn said using absolute humidity explains 50 percent of influenza transmission and 90 percent of virus survival. So why is relative humidity misleading? The answer is that more moisture can be present in warm air than in cold. Some people like to say warm air can hold more moisture than cold air. While thats not scientifically correct, it is a convenient way to think about it. What that means is warm air at 30 percent relative humidity and cold air at 60 percent relative humidity may actually have the same amount of water in the air. So, while the cold air sounds moist, it might be pretty dry -- just what the flu likes. Absolute humidity is expressed in weight of water, grams or pounds, in a volume of air, such as a cubic meter or yard. The higher the reading the wetter. The wetter, the worse for flu virus. In some areas of the country, a typical summer day can have four times as much water vapor as a typical winter day -- a difference that exists both indoors and outdoors, Shaman said. Consequently, outbreaks of influenza typically occur in winter when low absolute humidity conditions strongly favor influenza survival and transmission. Saints Jimmy Graham Jersey . 600. Blake Wood had no intention of being a footnote in history. After getting ahead of A-Rod in the count, the Royals reliever threw a pitch high and tight that deflected of the New York sluggers left hand and put him down in a heap. womens Ryan Fitzpatrick Jersey . "Its not going to take that long," Posada said. "They say whatever they want to say, Ill be here before that." Posada suffered the injury when he was hit with a foul ball on Sunday in a game against Twins. Jonathan Vilma Jersey Big Size . In the standout match of the competition so far, nine-time winner Madrid looks to maintain its perfect record in Group G on Tuesday and pull five points clear of Milan, which has lifted the trophy seven times and has a better recent record in Europe than its opponent. Santonio Holmes Jersey . The 42-year-old father, Chen Chuanliu, says he lost his four-year-old daughter last month and the extreme measure was the only way to keep his son safe. Since Friday, he has been tethering the boy so he can leave to pick up customers. Replica Johnson Jersey .C. - NASCAR will test drivers for performance-enhancing drugs next month under a tougher policy that also bans using illegal drugs and abusing prescription medications. Authentic Tom Brady Jersey . The Niagara Falls, Ont., native loss to American Sam Querrey 6-4, 6-4 in Saturdays semifinals, missing a chance to return to the final. Premier Buffalo Bills Jersey . Kyle Korver hit a go-ahead three-pointer during Chicagos game-ending 16-1 run in the series opener, and drained another critical three with 1:04 remaining on Monday after the Pacers cut their deficit to two. The Bulls, who got 17 points and 16 rebounds from Carlos Boozer, sealed the victory at the free throw line and will carry a 2-0 series lead into Game 3 Thursday in Indianapolis. Replica Hines Ward Jersey . Petersburg and Bayern Munich, a leading Spanish newspaper reported Wednesday. El Pais said a probe by Judge Baltasar Garzon has turned up a taped telephone conversation of suspected Russian gang member Gennady Petrov mentioning that 50 million of an unspecified currency had been paid to Bayern.DJ Kennington has been the king of the ovals in 2010. He picked up his third win of the season on an oval track by taking the checkered flag Wednesday night in the Velocity Prairie Thunder at Auto Clearing Motor Speedway. The St. Thomas, Ont., driver - who had started from the pole after setting the fast time in qualifying - gained the lead following a round of pit stops late in the race. He led a race-high 132 laps en route to his seventh series victory Kennington credited his crew for the victory after they got him out first following the final round of pit stops. “I have to hand it to my crew for this one. The Castrol Edge Dodge team did a great job on that last stop,” he said. “They got me out first and if I didnt win it from there, then it was my fault.” He also felt some measure of justice. In his last outing on July 31 at Motoplex Speedway in Vernon, B.C., he dominated much of the race and arguably had the best car on the track, but settled for a second-place finish behind Scott Steckly. “I think we let one get away last time,” he stated. “(Thomson) was awfully strong tonight. Im not sure we had the better car, but we did have a better pit stop.” JR Fitzpatrick, who is locked in a back-and-forth battle for the championship with Kennington and held a six-point edge coming into the event, charged from 14th on the grid to finish second. Fitzpatrick had made a run at Kennington on the restart just after all the leaders pitted, but could not make it stick. With the win, Kennington vaulted back past Fitzpatrick to take a 14-point lead in the standings. "Were still struggling a little bit with this new Schick Hydro Chevrolet. Its just not where we need it to be,” said Fitzpatrick, who hails from Cambridge, Ont. “Its real close, but we still have a little bit to go before we can start seriously challenging for wins on ovals.” In addition to looking forward to competing in Saturdays NASCAR Nationwide Series event at Watkins Glen (N.Y.) for JR Motorsports, Fitzpatrick is also anticipaating a heated points race with his good friend Kennington as the Canadian Tire Series enters the second half of the schedule. Ravens Michael Oher Jersey. “There are some tracks that I really like coming up, but it will be a battle all the way to the end. (Kennington) has his stuff really hooked up right now,” he said. “And were definitely going to get better.” Third place in the race went to Don Thomson Jr., who was happy with his effort, but was far from satisfied after displaying a very strong car in the event. “We need to win some races in this Home Hardware Chevrolet,” said the Hamilton, Ont., driver. “Weve had some good finishes, but Im ready to put this thing in Victory Lane.” After starting alongside each other on the front row, Thomson and Kennington exchanged the lead throughout the first half of the race. Thomson began to pull away midway through the 250-lap event, but his margin was erased when the caution came out on Lap 203. Pit stops put him back to fifth, but he fought back to get past Steckly late in the race to notch his third podium finish of the year. Currently sitting 129 points in back of Kennington in the point standings, Thomson, with a win or two, could jump into the championship fray with Kennington and his teammate Fitzpatrick. “I dont really look at the points that much. If you win races, then that takes care of itself,” said Thomson. “It looks like (Fitzpatrick) and (Kennington) are strong in the points, but I wouldnt mind getting in there with them.” Steckly and John Gaunt, who both stayed within striking distance all evening long, finished fourth and fifth, respectively. Jason Hathaway, Kerry Micks, Mark Dilley, Anthony Simone and Nathan Weenk completed the top 10. The race was slowed just three times due to caution for 36 laps and the race lead changed five times between Kennington and Thomson. In the championship point standings, Steckly and Thomson are closing in on the top two, as they try to make a push for the title as the season winds down. ' ' '
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主题: WASHINGTON – Grandma may have been right
