September 23, 2011, 10:46 AM EDT
By Leigh Baldwin
Sept. 23 (Bloomberg) -- A neutrino beam was measured as traveling faster than the speed of light, appearing to break the limit set by Albert Einstein in 1905.
The data come as a “complete surprise” and more research is needed before the results are verified, said Sergio Bertolucci, research director at the European Organization for Nuclear Research, or CERN, said in an e-mailed statement today.
Neutrinos, subatomic particles fired from CERN’s Geneva base to a laboratory 730 kilometers (454 miles) away in Gran Sasso, Italy, were clocked at a velocity 20 parts per million above the speed of light, the organization said. The tests first produced unusual results last year, with scientists spending the ensuing months trying to rule out any flaw in their methods that could have skewed the numbers.
“To me as a theoretician it screams systemic error,” Roberto Trotta, an astrophysicist at Imperial College, London, said in a telephone interview. “There is probably something in the experiment that the experimenters still don’t understand.”
Scientists involved in the trial said the research has been examined closely since the results occurred.
“After many months of studies and cross checks we have not found any instrumental effect that could explain the result of the measurement,” said Antonio Ereditato of the University of Bern in Switzerland, who worked on the research.
Replicate Experiment
Now the task is to replicate CERN’s experiment, possibly in Japan where there are several neutrino detectors, the most complex piece of equipment required, Trotta said. Until then, it’s too early to draw conclusions, he said.
“It’s not the first time you’re getting unexpected results from neutrino experiments,” Trotta said.
CERN’s findings fit with those of a 2007 experiment by the University of Minnesota, Subir Sarkar, a physicist at Oxford University in the U.K. They also chime with data recorded in 1987, when Japanese observers detected neutrinos from an explhttp://www.blogger.com/img/blank.gifoding star in the Large Magellanic Cloud, a galaxy visible from the earth’s southern hemisphere, hours before the supernova was seen by an amateur astrologer in New Zealand, he said.
“The implications are that Einstein’s special relativity is wrong and that’s earth-shattering stuff,” Trotta said.
Still, the most likely explanation is a mistake by CERN, not Einstein, Trotta said. “Extraordinary claims require extraordinary proof,” he said.
Business Week
Friday, September 23, 2011
Neutrinos Caught Speeding May Break Einstein’s Cosmic Limit
Friday, January 21, 2011
မြန်မာနိုင်ငံသားဆရာများနှင့် ဝေဖန်ပိုင်းခြားစဉ်းစားခြင်း
Thursday, 20 January 2011 15:27
ဒေါက်တာသိန်းလွင်
ချင်းမိုင်မြို့တွင် အခြေစိုက်သည့် ”မြန်မာနိုင်ငံသားများ ဆရာအတတ်ပညာသင်တန်း’ မှ ဝေဖန် ပိုင်းခြား စဉ်းစားရန် စာဖတ်ခြင်းနှင့် စာရေးခြင်း (RWCT) သင်ကြားနည်း စံနစ်များကို ပို့ချခဲ့သည်မှာ ဆယ်နှစ်ရှိပါပြီ။
RWCT သည် ကျောင်းသားများ၏ တက်ကြွစွာ သင်ယူခြင်းနှင့် ဝေဖန်ပိုင်းခြားစဉ်းစားခြင်းကို အားပေးသော နည်းစနစ်များ ဖြစ်ပါသည်။
ဝေဖန်ပိုင်းခြား စဉ်းစားခြင်းနည်းများကို အနောက်နိုင်ငံကျောင်းများတွင် ကျယ်ကျယ်ပြန့်ပြန့် အသုံးပြုနေသော်လည်း မြန်မာနိုင်ငံကျောင်းများတွင် အသုံးပြုရန် ခက်ခဲနေပါသေးသည်။ ဤဆောင်းပါးတွင် ကျွန်တော်ပြောလိုသည်မှာ ဝေဖန်ပိုင်းခြားစဉ်းစားခြင်းသည် အနောက်နိုင်ငံများ၏ အယူအဆ သက်သက်မျှသာ မဟုတ်ဘဲ အာရှ၏ အစဉ်အလာ အတွေးအခေါ်တစ်ရပ် ဖြစ်ပါသည်။
ဝေဖန်ပိုင်းခြားစဉ်းစားခြင်းသည် အာရှ၏ အတွေးအခေါ် ဖြစ်သည်ဆိုလျှင် အဘယ့်ကြောင့် မြန်မာနိုင်ငံ ကျောင်းများတွင် အလွတ်ကျက်သည့်နည်းကို သုံးနေသနည်းဟု မေးစရာရှိပါသည်။ ဤမေးခွန်းကို မဖြေမီ RWCT နည်းစနစ်၏ နောက်ခံသမိုင်းအကျဉ်းကို အရင်တင်ပြလိုပါသည်။
အဆိုပါနည်းစနစ်များကို ၁၉၉၈ ခုနှစ်တွင် အမေရိကန်တက္ကသိုလ် ဆရာသုံးဦး ((Jeanny Steele, Kurt Meredith, Charles Temple) တို့က ရေးသားခဲ့ကြပြီး သင်တန်းများ ပို့ချပေးခဲ့ပါသည်။ နိုင်ငံတကာ စာဖတ်အသင်း (IRA) နှင့် Open Society Institute တို့မှ ဤနည်းစနစ်များကို အရှေ့ဥရောပနိုင်ငံများသို့ ဖြန့်ဝေပေးခဲ့ကြပါသည်။
RWCT အကြောင်းကို ၂ဝဝဝ ခုနှစ်ရောက်မှ ကျွန်တော် စတင်ကြားဖူးခဲ့ပါသည်။ အင်္ဂလန်နိုင်ငံ၊ နယူးကာဆယ် တက္ကသိုလ်တွင် ပညာသင်နေစဉ်က မြန်မာနိုင်ငံပညာရေးသမိုင်းကို ပြန်လည်လေ့လာရာတွင် ကျွန်တော်၏ တွေ့ရှိချက်တစ်ရပ်ကို ဘွဲ့ယူစာတမ်းတွင် ထည့်သွင်းရေးသားခဲ့ပါသည်။
ကျွန်တော်၏ တွေ့ရှိချက်မှာ ”မြန်မာနိုင်ငံ ကျောင်းသားများသည် အလွတ်ကျက်မှတ်ရသည့် နည်းစနစ်ကြောင့် ဝေဖန်ပိုင်းခြားစဉ်းစားရန် အခွင့်အလမ်းများ ဆုံးရှုံးနေကြရသည်’ ဟု ဖြစ်ပါသည်။ ဤစာတမ်းကို နော်ဝေနိုင်ငံ အော်စလိုတက္ကသိုလ်တွင် ကျင်းပသည့် မြန်မာနိုင်ငံအကြောင်း ဆွေးနွေးပွဲတစ်ခုတွင် သွားရောက် ဖတ်ကြားခဲ့ပါသည်။ ဆွေးနွေးပွဲအပြီးတွင် OSI မှ အမျိုးသမီးတစ်ဦး ကျွန်တော့်ကို လာရောက်မိတ်ဆက်ပြီး အရှေ့ဥရောပနိုင်ငံကျောင်းများတွင် ဝေဖန်ပိုင်းခြားစဉ်းစားခြင်းကို မြှင့်တင်သည့် RWCT နည်းများကို ကျင့်သုံးနေကြောင်း ရှင်းပြပါသည်။ ကျွန်တော် အလွန်စိတ်ဝင်စားပါသည်။
အော်စလို ဆွေးနွေးပွဲပြီး၍ ကျွန်တော် ထိုင်းနိုင်ငံပြန်ရောက်ပြီး မကြာခင်တွင် OSI မှ အီးမေးလ် လာပါသည်။ ရိုမေးနီးယားနိုင်ငံတွင် RWCT ညီလာခံ ကျင်းပမည်ဖြစ်ကြောင်းနှင့် ကျွန်တော် တက်ရောက်ရန် ဆန္ဒရှိ မရှိ မေးပါသည်။
ကျွန်တော်က ညီလာခံ တက်လိုကြောင်း အကြောင်းပြန်ပြီးနောက် OSI မှ ကျွန်တော့်ထံ လေယာဉ်လက်မှတ် ပို့ပေးပါသည်။ ရိုမေးနီးယားနိုင်ငံ ဘူခါရက်လေဆိပ် ရောက်ပြီးနောက် လေဆိပ်မှ ကျွန်တော်၏ ပြည်ဝင်ခွင့်ကို ငြင်းပယ်သဖြင့် ညီလာခံမတက်နိုင်ဘဲ ထိုင်းနိုင်ငံသို့ ပြန်ခဲ့ရပါသည်။
ညီလာခံကျင်းပသူများက ကျွန်တော့်အား စာနာပြီး RWCT ဆရာလေးဦးကို ချင်းမိုင်သို့ စေလွတ်ခဲ့ပါသည်။ RWCT နည်းစနစ်များကို ထိုဆရာများထံမှ ကျွန်တော်သင်ယူပြီးနောက် ပြန်လည်ပို့ချနိုင်သည့် သင်တန်းဆရာအဖြစ် အသိအမှတ်ပြုခြင်းခံရပါသည်။
၂ဝဝ၁ ခုနှစ်မှစ၍ မြန်မာနိုင်ငံသား ဆရာများကို RWCT နည်းစနစ်များ ဖြန့်ဝေပေးခဲ့ပါသည်။ အစပိုင်းနှစ်များတွင် ထိုင်းမြန်မာနယ်စပ် ဒုက္ခသည်စခန်းရှိ ကျောင်းများမှ ဆရာ ဆရာမများနှင့် မဲဆောက် မြန်မာရွေ့ပြောင်း အလုပ် သမားများ၏ ကလေးများအတွက် ဖွင့်လှစ်ထားသော ကျောင်းများမှ ဆရာ ဆရာမများကို သင်တန်းပို့ချခဲ့ပါသည်။ ၂ဝဝ၅ ခုနှစ်တွင် ချင်းမိုင်မြို့တွင် ဖွင့်လှစ်သည့် သင်တန်းတွင် မြန်မာနိုင်ငံအတွင်းရှိ ဘုန်းတော်ကြီးသင် ကျောင်းများမှ ဘုန်းတော်ကြီး တစ်ပါးနှင့် ဆရာ ဆရာမများ ပါဝင် တက်ရောက်ကြပါသည်။
အဆိုပါ ဘုန်းတော်ကြီးသည် စာချကိုယ်တော်တစ်ပါးဖြစ်ပြီး ဗုဒ္ဓစာပေကျန်းဂန်နှံစပ်သူ ဖြစ်ပါသည်။ ဘုန်းတော်ကြီးက ဝေဖန်ပိုင်းခြား စဉ်းစားခြင်းသည် ဗုဒ္ဓ၏ သင်ကြားနည်း ဖြစ်ကြောင်း ဆွေးနွေးတင်ပြပါသည်။ ကာလာမရွာသားများအား ဗုဒ္ဓဟောကြားသော တရားတွင် ဝေဖန်ပိုင်းခြား စဉ်းစားမှုရှိရန် ဆုံးမထားပါသည်။
‘အစဉ်အလာရှိသောကြောင့်လည်း လက်ခံခြင်းမပြုနှင့်၊ မကြာခဏ ကြားနေရသောကြောင့်လည်း လက်ခံခြင်း မပြုနှင့်၊ ဟောပြောသော ပုဂ္ဂိုလ်၏ အရှိန်အဝါကြောင့်လည်း လက်ခံခြင်းမပြုနှင့်၊ ဆရာသမားက ပြောသည်ဆိုသောကြောင့်လည်း လက်ခံခြင်းမပြုနှင့်၊ ကိုယ်တိုင် လေ့လာဆန်းစစ်ပြီးမှသာ လက်ခံရန်’ ဟောကြားပါသည်။
ဝေဖန်ပိုင်းခြားစဉ်းစားခြင်းသည် အာရှ၏အစဉ်အလာ ယဉ်ကျေးမှုဖြစ်သော ဗုဒ္ဓတရားတော်နှင့် ကိုက်ညီသည် ဆိုလျှင် အဘယ့်ကြောင့် မြန်မာနိုင်ငံ ကျောင်းများတွင် ဤအစဉ်အလာကောင်းများ ကွယ်ပျောက်နေပါသနည်း။ ကျွန်တော်၏ အယူအဆမှာ ဗုဒ္ဓ၏ တရားတော်များ တိမ်ကောကွယ်ပျောက်ခြင်း မရှိစေရန် ရဟန်းတော်များက နှုတ်တိုက်အာဂုံ ရွတ်ဆိုခဲ့ကြပါသည်။ နှစ်ပေါင်း ၅ဝဝ ကျော် အကြာတွင် စာပေအရေးအသား ပေါ်ပေါက်လာပြီးနောက် ဗုဒ္ဓကျမ်းဂန်များကို ပေထက်အက္ခရာ တင်နိုင်ကြသော်လည်း အလွတ်ကျက်သည့် အလေ့အထမှာ ယနေ့အထိ ကျင့်သားရနေဆဲ ဖြစ်ပါသည်။
RWCT နည်းစနစ်တွင် အလေးထားသည့် တက်ကြွစွာသင်ယူခြင်းနှင့် ဗုဒ္ဓ၏ သင်ကြားနည်းကိုလည်း နှိုင်းယှဉ်ကြည့်မိပါသည်။ ဦးရွေအောင်ရေးသားသည့် ‘ဗုဒ္ဓ၏ သင်ကြားနည်းများ’ စာအုပ်တွင် ထူးခြားချက် တစ်ရပ်ကို တွေ့မိပါသည်။
ဖခင်ကိုသတ်၍ ထီးနန်းရယူခဲ့သည့် အဇာတသတ်ဘုရင်သည် မိမိ၏ အမှားအတွက် တုန်လှုပ်ပြီး ဗုဒ္ဓထံ လာရောက်စဉ်တွင် ရဟန်း ၅ဝဝအား သင်ကြားပြသနေ့သည့် ဗုဒ္ဓကို တွေ့မြင်ရကြောင်းနှင့် ရဟန်း ၅ဝဝ တို့က တိတ်ဆိတ်ငြိမ်သက်စွာ သင်ယူနေကြသည်ကို ထိတ်လန့်မိကြောင်း ရေးသားထားပါသည်။ သူကဲ့သို့ သက်ဦးဆံပိုင် ဘုရင်ကတောင် လူတွေကို ဤကဲ့သို့ ငြိမ်သက်အောင် မလုပ်နိုင်ဘဲ ဗုဒ္ဓက လုပ်နိုင်စွမ်းသဖြင့် ကြည်ညိုမိကြောင်း ပါရှိပါသည်။
တက်ကြွစွာသင်ယူခြင်း ဆိုသည်မှာ ခန္ဓာကိုယ် လှုပ်ရှားတက်ကြွခြင်းဟု နားလည်ခဲ့သော ကျွန်တော်သည် RWCT နှင့် ဗုဒ္ဓ၏ သင်ကြားနည်းမှာ ကွဲပြားသည်ဟု အစတွင် ထင်ခဲ့ပါသည်။ တက်ကြွစွာ သင်ယူခြင်းသည် စိတ်ပိုင်းဆိုင်ရာ (ဦးနှောက်) လှုပ်ရှားမှုကို ဆိုလိုသည်ဟု နားလည်လာသောအခါ RWCT နှင့် ဗုဒ္ဓဝါဒ တစ်ထပ်တည်းကျသည်ဟု မြင်လာပါသည်။
ပဠာစာရီဇာတ်တော်တွင် လင်သေသားဆုံး၍ အရူးတပိုင်းဖြစ်နေသော ပဠာစာရီသည် ဗုဒ္ဓထံသွားရောက်ကာ လင်နှင့်သားကို ပြန်ရှင်အောင် လုပ်ပေးဖို့ တောင်းဆိုခဲ့ပါသည်။ ဗုဒ္ဓက လူမသေဘူးသေးသော အိမ်မှ မုံညင်းဆီယူခဲ့ရန် မှာကြားသဖြင့် တစ်အိမ်တက်တစ်အိမ်ဆင်း မုံညင်းဆီတောင်းရင်း တရားရသွားသော ပဠာစာရီကို ဗုဒ္ဓ၏သင်ကြားမှုသည် RWCT နည်းစနစ်မှ အားပေးသည့် လက်တွေ့နှင့် အဆက်အစပ်ပြု၍ သင်ကြားခြင်းနှင့်လည်း တူညီပါသည်။
ဤအထက်ပါအချက်များကြောင့် RWCT နည်းစနစ်ဖြစ်သည့် ဝေဖန်ပိုင်းခြားစဉ်းစားခြင်းသည် အာရှ၏ ယဉ်ကျေးမှု အစဉ်အလာတစ်ရပ်ဖြစ်ကြောင်း ကျွန်တော် ယုံကြည်ပါသည်။ ဤယုံကြည်မှုသည် ကျွန်တော့်အား တွန်းအားဖြစ်စေပြီး RWCT နှင့် အခြားယဉ်ကျေးမှုများ၏ ဆက်စပ်မှုကိုလည်း ဆက်လက်လေ့လာသွားပါမည်။
လေးစားစွာ
ဒေါက်တာသိန်းလွင်
(မြန်မာနိုင်ငံသားများ ဆရာအတတ်ပညာသင်တန်း)
maukkha
Tuesday, January 4, 2011
Walking Faster May Lead to a Longer Life
Study Shows a Link Between Walking Speed and Life Span
By Kelli Miller Stacy
Reviewed by Laura J. Martin, MD
WebMD Health News
Jan. 4, 2011 -- A swift stride puts you on the path to a longer, healthier life, researchers say.
Scientists reporting in The Journal of the American Medical Association say that older adults who typically walk 1 meter per second or faster live longer than expected. A walking, or gait, speed of 1 meter per second is equal to 3.28 feet per second.
Walking speed can be an important sign of someone's overall health. A slow walking speed may be due to multiple causes including heart, lung, or nervous system problems, or even joint pain. Several studies have suggested that a person with a walking speed slower than 0.6 meters per second (less than 2 feet per second) may be at increased risk for poor health and function.
Stephanie Studenski, MD, MPH, of the University of Pittsburgh, analyzed the collective results of nine previous studies to determine if walking speed explained survival differences among older adults and whether it could be used to predict longevity.
Study participants walked at their usual pace from a standing start, while researchers calculated distance in meters and time in seconds. The average age of the participants was 73.5; a majority were white women.
Faster Pace Boosts Life Span
The average walking speed for the study participants was 0.92 meters per second, or about 3 feet per second. A person's predicted life expectancy for each sex and age group increased the faster they could walk.
The survival differences were especially notable among patients age 75 and older. The predicted 10-year survival rate varied greatly with walking speeds, from 19% to 87% in men and from 35% to 91% in women.
“Gait speeds of 1.0 meter [3.28 feet]/second or higher consistently demonstrated survival that was longer than expected by age and sex alone. In this older adult population the relationship of gait speed with remaining years of life was consistent across age groups, but the absolute number of expected remaining years of life was larger at younger ages,” the researchers write.
Calculating life expectancy based on walking speed, sex, and age was as accurate as predictions based on other factors, such as age, sex, overall health, mobility, hospitalization, and smoking history.
Walking Speed Predicts Survival
Considering a person's walking speed along with their age and sex is a simple, inexpensive, and useful way to estimate a patient's expected length of life, the researchers say. All that is needed is a stopwatch and a walkway. Life expectancy estimates can help doctors develop a better, individualized plan of care for patients.
"Gait speed might help identify older adults with a high probability of living for 5 or 10 more years, who may be appropriate targets for preventive interventions that require years for benefit," the team writes.
Regular walking speed measurements could also be used to monitor a person over time to check for signs of ailing health, the researchers say.
Not everyone agrees that walking speed measurements should sway preventive care at the current time. In an accompanying editorial to the journal article, Rome-based researcher Matteo Cesari, MD, PhD, says that walking speed improvements have not been definitively linked with better health outcomes. He encourages future research to determine if a person's walking speed may change the way in which he or she is labeled "geriatric."
WebMD Health News
Monday, December 13, 2010
မလုပ်ချင်ဆုံးအလုပ်၊ မလုပ်လိုသောအလုပ်
မလုပ်ချင်ဆုံးအလုပ်၊ မလုပ်လိုသောအလုပ်ကို အခုရက်ပိုင်းမှာ လုပ်နေမိတယ်။ ဒါပေမဲ့ လုပ်သင့်လုပ်ထိုက်တယ်လို့ ယူဆမိသည့်အတွက် မျက်နှာပူပူနဲ့ လုပ်နေမိတယ်။ တော်သေးသာက ဖုန်းနှင့်သာဆက်သွယ်ပြီး လုပ်တယ်ဆိုတော့ မျက်နှာပူသက်သာလို့ ဖြေသာမိပါတယ်။
ဘယ့်အလုပ်များဘာလိမ့်။
ဆင်းရဲပင်ပန်းစွာ အလုပ်ကြိုးစားပြီး ရှာဖွေစုဆောင်းထားသော ချွေးနည်းစာ တစိတ်တပိုင်းလေးကို တစုံတရာအတွက် အလှူငွေများ ထည့်ပေးကြပါရန် မေတ္တာရပ်ခံနေမိသောအလုပ် ဖြစ်ပါတယ်။
ဘယ့်တစုံတရာအတွက်များဘာလိမ့်။
မိမိတို့ဘဝ အတတ်ပညာတွေပြည့်စုံပြီး တင့်တောင့်တင့်တယ်ဖြစ်အောင် မြေတောင်မြောက်ပေးခဲ့သော အနန္တေ အနန္တ ဂိုဏ်းဝင် အာစရိယဆရာသမားများကို ပူဇော်နိုင်ရန် ဖြစ်ပါတယ်။
Thursday, October 28, 2010
Technology China's fastest supercomputer Tianhe-1 sets new record
Updated: 2010-10-28 17:11
BEIJING - China's Tianhe-1 has overtaken Nebulae to regain top spot as China's fastest computer according to a new list of China's Top 100 supercomputers released Thursday.
On the biannual world TOP 500 list published in June, China's Nebulae machine took the second spot only after the US' Jaguar system, while Tianhe-1 took seventh place.
Housed at the National Center for Supercomputing in northern port city of Tianjin, Tianhe-1, meaning Milky Way, has a sustained computing speed of 2,507 trillion calculations, or 2.507 petaflops, per second.
It has a theoretical speed of 4.7 petaflops per second, according to a R&D research member of Tianhe-1. A petaflop is equivalent to 1,000 trillion calculations.
Nebulae housed in Shenzhen is capable of sustained computing of 1.271 petaflop per second (PFlop/s) on the Linpack benchmark, a measure for ranking supercomputers in world Top 500 list.
The US leads the world in supercomputing and is home to more than half of the top 500 supercomputers. The Jaguar system at Oak Ridge National Laboratory in Tennessee has a speed of 1.75 PFlop/s.
The enhanced Tianhe-1 has upgraded Intel CPUs, NVIDIA GPUs, and new domestically developed Feiteng-1000 CPUs have been installed, the developer the National University of Defense Technology (NUDT) said.
Tianhe-1 has begun trial use among target clients including Tianjin Meteorological Bureau and the National Offshore Oil Corporation data center. "It can also serve the animation industry and bio-medical research," said Liu Guangming, director of the National Center for Supercomputing in Tianjin.
In September 2009, the NUDT created Tianhe-1 with a sustained computing speed of 0.5631 PFlop/s, the fastest supercomputer in China at that time.
The new technical data of Tianhe-1 has been submitted to the world Top 500 list and the next list will be released in November.
Related readings:
Supercomputer ranks second fastest in world
Chinese supercomputer ranked second-fastest
Xinhua
Wednesday, October 13, 2010
Walking 6 to 9 Miles a Week May Help Save Memory
Brain's gray matter doesn't seem to shrink with this amount of exercise, study finds
By Alan Mozes
HealthDay Reporter
WEDNESDAY, Oct. 13 (HealthDay News) -- Walking about six miles a week appears to protect against brain shrinkage in old age, which in turn helps stem the onset of memory problems and cognitive decline, new research reveals.
"We have always been in search of the drug or the magic pill to help treat brain disorders," noted Kirk I. Erickson, an assistant professor of psychology at the University of Pittsburgh and the study's lead author. "But really what we are after may be, at least partially, even simpler than that. Just by walking regularly, and so maintaining a little bit of moderate physical activity, you can reduce your likelihood of developing Alzheimer's disease and [can] spare brain tissue."
A report on the research, which was supported by the U.S. National Institute on Aging, is published online Oct. 13 in Neurology.
Erickson and his colleagues began tracking the physical activity and cognitive (or thinking) patterns of nearly 300 adults in 1989. At the start, all participants were in good cognitive health, they averaged 78 years old and about two-thirds were women. The researchers charted how many blocks each person walked in a week.
Nine years later, they were given a high-resolution MRI scan to measure brain size. All were deemed to be "cognitively normal."
But four years after that, testing showed that a little more than one-third of the participants had developed mild cognitive impairment or dementia.
By correlating cognitive health, brain scans and walking patterns, the research team found that being more physically active appeared to marginally lower the risk for developing cognitive impairment.
But more specifically, they concluded that the more someone walks, the more gray matter tissue the person will have a decade or more down the road in regions of the brain -- namely the hippocampus, the inferior frontal gyrus and the supplementary motor area -- that are central to cognition.
And among the more physically active participants who had retained more gray matter a decade out, the chances of developing cognitive impairment were cut in half, the study found.
However, the researchers stressed that the relationship between walking and gray matter volume appears to apply only to people who regularly walk relatively long distances that equal about six to nine miles a week.
Walking more than the six- to nine-mile range, however, did not have cognitive benefit, the study found.
"That's because the size of our brain regions can only be so large," Erickson said, adding that the opposite isn't true. "So with no exercise, there can be significant deterioration and decay with age."
However, he added, "what we often tend to think of as an inevitable component or characteristic of aging -- memory decline and brain decay -- is clearly not inevitable. There's plenty of evidence now, and this study is part of that, that shows that we can retain our brain tissue and retain our memories well into late adulthood by maintaining an active and engaged lifestyle."
Dr. Steven V. Pacia, chief of neurology at Lenox Hill Hospital in New York City, described the study's finding as both "intriguing" and an "undoubtedly positive message to send to the public."
"My first reaction to studies like this is that only in America do we have to prove to people that it's good to walk," he said with a chuckle.
"But it stands to reason that being active as we age is going to have a beneficial effect on the brain, just as being inactive is going to have a negative impact," Pacia noted. "Because the brain lives in the environment of the body."
But there may be a catch. "This is just an observational study," Pacia noted. "And while we may assume that the relationship between the brain and activity is a prevention-of-atrophy issue -- just like it is with muscle and bone -- this study doesn't actually prove that. We don't yet know enough about the use-it-or-lose-it notion with respect to brain and exercise. So we do need more research to look at that."
More information
The U.S. National Institute on Aging has more on healthy aging.
SOURCES: Kirk I. Erickson, Ph.D., assistant professor, department of psychology, University of Pittsburgh; Steven V. Pacia, M.D., chief, division of neurology, Lenox Hill Hospital, New York City; Oct. 13, 2010, Neurology, online
Last of Chilean miners is raised safely to surface
By MICHAEL WARREN, Associated Press Writer 
AP/Roberto Candia
Miner Luis Urzua, the last miner to be rescued, celebrates next to Chile's President Sebastian Pinera after being pulled to safety.
SAN JOSE MINE, Chile – The last of the Chilean miners, the foreman who held them together when they were feared lost, was raised from the depths of the earth Wednesday night — a joyous ending to a 69-day ordeal that riveted the world. No one has ever been trapped so long and survived.
Luis Urzua ascended smoothly through 2,000 feet of rock, completing a 22 1/2-hour rescue operation that unfolded with remarkable speed and flawless execution. Before a jubilant crowd of about 2,000 people, he became the 33rd miner to be rescued.
"We have done what the entire world was waiting for," he told Chilean President Sebastian Pinera immediately after his rescue. "The 70 days that we fought so hard were not in vain. We had strength, we had spirit, we wanted to fight, we wanted to fight for our families, and that was the greatest thing."
The president told him: "You are not the same, and the country is not the same after this. You were an inspiration. Go hug your wife and your daughter." With Urzua by his side, he led the crowd in singing the national anthem.
The rescue exceeded expectations every step of the way. Officials first said it might be four months before they could get the men out; it turned out to be 69 days and about 8 hours.
Once the escape tunnel was finished, they estimated it would take 36 to 48 hours to get all the miners to the surface. That got faster as the operation went along, and all the men were safely above ground in 22 hours, 37 minutes.
The rescue workers who talked the men through the final hours still had to be hoisted to the surface.
In nearby Copiapo, about 3,000 people gathered in the town square, where a huge screen broadcast live footage of the rescue. The exuberant crowd waved Chilean flags of all sizes and blew on red vuvuzelas as cars drove around the plaza honking their horns, their drivers yelling, "Long live Chile!"
"The miners are our heroes," said teary-eyed Copiapo resident Maria Guzman, 45.
One by one throughout the day, the men had emerged to the cheers of exuberant Chileans and before the eyes of a transfixed globe. While the operation picked up speed as the day went on, each miner was greeted with the same boisterous applause from rescuers.
"Welcome to life," Pinera told Victor Segovia, the 15th miner out. On a day of superlatives, it seemed no overstatement.
They rejoined a world intensely curious about their ordeal, and certain to offer fame and jobs. Previously unimaginable riches awaited men who had risked their lives going into the unstable gold and copper mine for about $1,600 a month.
The miners made the smooth ascent inside a capsule called Phoenix — 13 feet tall, barely wider than their shoulders and painted in the white, blue and red of the Chilean flag. It had a door that stuck occasionally, and some wheels had to be replaced, but it worked exactly as planned.
Beginning at midnight Tuesday, and sometimes as quickly as every 25 minutes, the pod was lowered the nearly half-mile to where 700,000 tons of rock collapsed Aug. 5 and entombed the men.
Then, after a quick pep talk from rescue workers who had descended into the mine, a miner would climb in, make the journey upward and emerge from a manhole into the blinding sun.
The rescue was planned with extreme care. The miners were monitored by video on the way up for any sign of panic. They had oxygen masks, dark glasses to protect their eyes from the unfamiliar sunlight and sweaters for the jarring transition from subterranean swelter to chilly desert air.
As they neared the surface, a camera attached to the top of the capsule showed a brilliant white piercing the darkness not unlike what accident survivors describe when they have near-death experiences.
The miners emerged looking healthier than many had expected and even clean-shaven. Several thrust their fists upwards like prizefighters, and Mario Sepulveda, the second to taste freedom, bounded out and led his rescuers in a rousing cheer. Franklin Lobos, who played for the Chilean national soccer team in the 1980s, briefly bounced a soccer ball on his foot and knee.
"We have prayed to San Lorenzo, the patron saint of miners, and to many other saints so that my brothers Florencio and Renan would come out of the mine all right. It is as if they had been born again," said Priscila Avalos. One of her brothers was the first miner rescued, and the other was due out later in the evening.
Health Minister Jaime Manalich said some of the miners probably will be able to leave the hospital Thursday — earlier than projected — but many had been unable to sleep, wanted to talk with families and were anxious. One was treated for pneumonia, and two needed dental work.
"They are not ready to have a moment's rest until the last of their colleagues is out," he said.
As it traveled down and up, down and up, the rescue capsule was not rotating as much inside the 2,041-foot escape shaft as officials expected, allowing for faster trips.
The first man out was Florencio Avalos, who emerged from the missile-like chamber and hugged his sobbing 7-year-old son, his wife and the Chilean president.
No one in recorded history has survived as long trapped underground. For the first 17 days, no one even knew whether they were alive. In the weeks that followed, the world was captivated by their endurance and unity.
News channels from North America to Europe and the Middle East carried live coverage of the rescue. Pope Benedict XVI said in Spanish that he "continues with hope to entrust to God's goodness" the fate of the men. Iran's state English-language Press TV followed events live for a time. Crews from Russia and Japan and North Korean state TV were at the mine.
The images beamed to the world were extraordinary: Grainy footage from beneath the earth showed each miner climbing into capsule, then disappearing upward through an opening. Then a camera showed the pod steadily rising through the dark, smooth-walled tunnel.
Among the first rescued was the youngest miner, Jimmy Sanchez, at 19 the father of a months-old baby. Two hours later came the oldest, Mario Gomez, 63, who suffers from a lung disease common to miners and had been on antibiotics inside the mine. He dropped to his knees after he emerged, bowed his head in prayer and clutched the Chilean flag.
Gomez's wife, Lilianett Ramirez, pulled him up from the ground and embraced him. The couple had talked over video chat once a week, and she said that he had repeated the promise he made to her in his initial letter from inside the mine: He would marry her properly in a church wedding, followed by the honeymoon they never had.
The lone foreigner among them, Carlos Mamani of Bolivia, was visited at a nearby clinic by Pinera and Bolivian President Evo Morales. The miner could be heard telling the Chilean president how nice it was to breathe fresh air and see the stars.
Most of the men emerged clean-shaven. More than 300 people at the mine alone had worked on the rescue or to sustain them during their long wait by lowering rocket-shaped tubes dubbed "palomas," Spanish for carrier pigeons. Along with the food and medicine came razors and shaving cream.
Estimates for the rescue operation alone have soared beyond $22 million, though the government has repeatedly insisted that money is not a concern.
The men emerged in good health. But at the hospital in Copiapo, where miner after miner walked from the ambulance to a waiting wheelchair, it became clear that psychological issues would be as important to treat as physical ones.
Dr. Guillermo Swett said Sepulveda told him about an internal "fight with the devil" that he had inside the mine. He said Sanchez appeared to be having a hard time adjusting, and seemed depressed.
"He spoke very little and didn't seem to connect," the doctor said.
The entire rescue operation was meticulously choreographed. No expense was spared in bringing in topflight drillers and equipment — and boring three separate holes into the copper and gold mine. Only one has been finished — the one through which the miners exited.
Mining is Chile's lifeblood, providing 40 percent of state earnings, and Pinera put his mining minister and the operations chief of state-owned Codelco, the country's biggest company, in charge of the rescue.
It went so well that its managers abandoned a plan to restrict images of the rescue. A huge Chilean flag that was to obscure the hole from view was moved aside so the hundreds of cameras perched on a hill above could record images that state TV also fed live.
That included the surreal moment when the capsule dropped for the first time into the chamber, where the bare-chested miners, most stripped down to shorts because of the underground heat, mobbed the rescuer who emerged to serve as their guide to freedom.
"This rescue operation has been so marvelous, so clean, so emotional that there was no reason not to allow the eyes of the world — which have been watching this operation so closely — to see it," a a beaming Pinera told a news conference after the first miner safely surfaced.
The miners' vital signs were closely monitored throughout the ride. They were given a high-calorie liquid diet donated by NASA, designed to prevent nausea from any rotation of the capsule as it travels through curves in the 28-inch-diameter escape hole.
Engineers inserted steel piping at the top of the shaft, which is angled 11 degrees off vertical before plunging like a waterfall. Drillers had to curve the shaft to pass through "virgin" rock, narrowly avoiding collapsed areas and underground open spaces in the overexploited mine, which had operated since 1885.
U.S. President Barack Obama said the rescue had "inspired the world." The crews included many Americans, including a driller operator from Denver and a team from Center Rock Inc. of Berlin, Pa., that built and managed the piston-driven hammers that pounded the hole through rock laced with quartzite, some of the hardest and most abrasive rock.
Chile has promised that its care of the miners won't end for six months at least — not until they can be sure that each man has readjusted.
Psychiatrists and other experts in surviving extreme situations predict their lives will be anything but normal. Since Aug. 22, when a narrow bore hole broke through to their refuge and the miners stunned the world with a note, scrawled in red ink, disclosing their survival, their families have been exposed in ways they never imagined.
Miners had to describe their physical and mental health in detail with teams of doctors and psychologists. In some cases, when both wives and lovers claimed the same man, everyone involved had to face the consequences.
As trying as their time underground was, the miners now face challenges so bewildering that no amount of coaching can fully prepare them. Rejoining a world intensely curious about their ordeal, they have been invited to presidential palaces, to take all-expenses-paid vacations and to appear on countless TV shows. Book and movie deals are pending, along with job offers.
Sepulveda's performance exiting from the shaft appeared to confirm what many Chileans thought when they saw his engaging performances in videos sent up from below — that he could have a future as a TV personality.
But he tried to quash the idea as he spoke to viewers of Chile's state television channel while sitting with his wife and children shortly after his rescue.
"The only thing I'll ask of you is that you don't treat me as an artist or a journalist, but as a miner," he said. "I was born a miner and I'll die a miner."
Associated Press Writers Frank Bajak, Franklin Briceno, Peter Prengaman, Vivian Sequera and Eva Vergara contributed to this report.
Associated Press
