Global Warming New York | Search results for "virus"

In the late 1980s thousands of chickens died from a cancer caused by a virus known as avian leukosis virus J because they were all descended from a few roosters susceptible to the disease. [More] 25 Years Later: The AIDS Vaccine Search Goes On Not long after the virus that causes AIDS was identified, Margaret Heckler, then the U.S. secretary of health and human services, told a group of reporters that the discovery would enable scientists to develop a vaccine to prevent AIDS. “We hope to have such a vaccine ready for testing in approximately two years,” she declared proudly. It was 1984. Government officials have certainly been spectacularly wrong on other occasions but rarely has a large portion of the scientific community been so overly optimistic as well. Twenty-five years after isolating HIV, we still have no effective vaccine. One year ago a major clinical trial of a candidate made by Merck was shut down because it became obvious that the vaccine was not working and might even be doing harm. This past summer another vaccine hopeful was shelved and its trial canceled before it could begin because there was no reason to believe its results would be any better. [More]

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In the late 1980s thousands of chickens died from a cancer caused by a virus known as avian leukosis virus J because they were all descended from a few roosters susceptible to the disease. [More] 25 Years Later: The AIDS Vaccine Search Goes On Not long after the virus that causes AIDS was identified, Margaret Heckler, then the U.S. secretary of health and human services, told a group of reporters that the discovery would enable scientists to develop a vaccine to prevent AIDS. “We hope to have such a vaccine ready for testing in approximately two years,” she declared proudly. It was 1984. Government officials have certainly been spectacularly wrong on other occasions but rarely has a large portion of the scientific community been so overly optimistic as well. Twenty-five years after isolating HIV, we still have no effective vaccine. One year ago a major clinical trial of a candidate made by Merck was shut down because it became obvious that the vaccine was not working and might even be doing harm. This past summer another vaccine hopeful was shelved and its trial canceled before it could begin because there was no reason to believe its results would be any better. [More]

Tags: vaccine, year, virus, aids, trial

In the late 1980s thousands of chickens died from a cancer caused by a virus known as avian leukosis virus J because they were all descended from a few roosters susceptible to the disease. [More] 25 Years Later: The AIDS Vaccine Search Goes On Not long after the virus that causes AIDS was identified, Margaret Heckler, then the U.S. secretary of health and human services, told a group of reporters that the discovery would enable scientists to develop a to prevent AIDS. “We hope to have such a vaccine ready for testing in approximately two years,” she declared proudly. It was 1984. Government officials have certainly been spectacularly wrong on other occasions but rarely has a large portion of the scientific community been so overly optimistic as well. Twenty-five years after isolating HIV, we still have no effective vaccine. One year ago a major clinical trial of a candidate made by Merck was shut down because it became obvious that the vaccine was not working and might even be doing harm. This past summer another vaccine hopeful was shelved and its trial canceled before it could begin because there was no reason to believe its results would be any better. [More]

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[The following is an exact transcript of this podcast.] [More] Birds of a Feather: Commercial Producers Play Chicken with Avian Flu In the late 1980s thousands of chickens died from a cancer caused by a virus known as avian leukosis virus J because they were all descended from a few roosters susceptible to the disease. [More]

Tags: virus, chicken, avian, cloners, caused

[The following is an exact transcript of this podcast.] [More] Birds of a Feather: Commercial Producers Play Chicken with Avian Flu In the late 1980s thousands of chickens died from a cancer caused by a virus known as avian leukosis virus J because they were all descended from a few roosters susceptible to the disease. [More]

Tags: virus, chicken, avian, cloners, caused

[The following is an exact transcript of this podcast.] [More] Birds of a Feather: Commercial Producers Play Chicken with Avian Flu In the late 1980s thousands of chickens died from a cancer caused by a virus known as avian leukosis virus J because they were all descended from a few roosters susceptible to the disease. [More]

Tags: virus, chicken, avian, cloners, caused

Pioneering ecologist Joseph Grinnell in 1914 began a seven year survey of the animals living in Yosemite National Park in California. Even then, human impacts such as the transformation of the Central Valley into an agricultural oasis were changing the landscape and the animals who lived there. [More] Bad Biodiversity Ups West Nile Odds [The following is an exact transcript of this podcast.] If you're worried about news reports of West Nile virus, you might want to go take a census of the birds in your backyard. Because certain species of birds actually help the virus thrive. And they're not exactly exotic jungle fowl. In fact, they’re our more familiar feathered friends. [More]

Tags: virus, nile, west, birds, animals

Climate change is warming the tropics, too. Average temperatures have increased by 1.4 degrees Fahrenheit (0.78 degree Celsius) in the last 30 years, making them as warm as at any point in the past 2 million years. That increased warmth, however, is not good news for tropical plants and insects, according to a new study in Science. [More] Using Math to Explain How Life on Earth Began Back in March the press went crazy for Martin A. Nowak’s study on the value of punishment. A Harvard University mathematician and biologist, Nowak had signed up some 100 students to play a computer game in which they used dimes to punish and reward one another. The popular belief was that costly punishment would promote cooperation between two equals, but Nowak and his colleagues proved the theory wrong. Instead they found that punishment often triggers a spiral of retaliation, making it detrimental and destructive rather than beneficial. Far from gaining, people who punish tend to escalate conflict, worsen their fortunes and eventually lose out. “Nice guys finish first,” headlines cheered. It wasn’t the first time Nowak’s computer simulations and mathematics forced a rethinking of a complex phenomenon. In 2002 he worked out equations that can predict the way cancer evolves and spreads, such as when mutations emerge in a metastasis and chromosomes become unstable. And in the early 1990s his model of disease progression demonstrated that HIV develops into AIDS only when the virus replicates fast enough so that the diversity of strains reaches a critical level, one that overwhelms the immune system. Immunologists later found out he had the mechanism right [see “How HIV Defeats the Immune System,” by Martin A. Nowak and Andrew J. McMichael; Scientific American, August 1995]. Now Nowak is out to do it again, this time by modeling the origin of life. Specifically, he is trying to capture “the transition from no life to life,” he says. [More]

Tags: nowak, life, punishment, increased, time

Not long after the virus that causes AIDS was identified, Margaret Heckler, then the U.S. secretary of health and human services, told a group of reporters that the discovery would enable scientists to develop a vaccine to prevent AIDS. “We hope to have such a vaccine ready for testing in approximately two years,” she declared proudly. It was 1984. Government officials have certainly been spectacularly wrong on other occasions but rarely has a large portion of the scientific community been so overly optimistic as well. Twenty-five years after isolating HIV, we still have no effective vaccine. One year ago a major clinical trial of a candidate made by Merck was shut down because it became obvious that the vaccine was not working and might even be doing harm. This past summer another vaccine hopeful was shelved and its trial canceled before it could begin because there was no reason to believe its results would be any better. [More] Taking Wing: Uncovering the Evolutionary Origins of Bats Editor's Note: This story will be published in the December 2008 issue of Scientific American. Survey the sky at twilight on a summer’s eve, and you just might glimpse one of evolution’s most spectacular success stories: bats. With representatives on every continent except Antarctica, they are extraordinarily diverse, accounting for one in every five species of mammal alive today. The key to bats’ rise to prominence is, of course, their ability to fly, which permits them to exploit resources that other mammals cannot reach. But their ascension was hardly a foregone conclusion: no other mammal has conquered the air. Indeed, exactly how these rulers of the night sky arose from terrestrial ancestors is a question that has captivated biologists for decades. [More]

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[The following is an exact transcript of this podcast.] [More] Birds of a Feather: Commercial Producers Play Chicken with Avian Flu In the late 1980s thousands of chickens died from a cancer caused by a virus known as avian leukosis virus J because they were all descended from a few roosters susceptible to the disease. [More]

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[The following is an exact transcript of this podcast.] If you're worried about news reports of West Nile virus, you might want to go take a census of the birds in your backyard. Because certain species of birds actually help the virus thrive. And they're not exactly exotic jungle fowl. In fact, they’re our more familiar feathered friends. [More] Sultry to Scorching: Rising Temps May Be Too Hot for Tropical Species Climate change is warming the tropics, too. Average temperatures have increased by 1.4 degrees Fahrenheit (0.78 degree Celsius) in the last 30 years, making them as warm as at any point in the past 2 million years. That increased warmth, however, is not good news for tropical plants and insects, according to a new study in Science. [More]

Tags: species, virus, years, degree, tropical

Back in March the press went crazy for Martin A. Nowak’s study on the value of punishment. A Harvard University mathematician and biologist, Nowak had signed up some 100 students to play a computer game in which they used dimes to punish and reward one another. The popular belief was that costly punishment would promote cooperation between two equals, but Nowak and his colleagues proved the theory wrong. Instead they found that punishment often triggers a spiral of retaliation, making it detrimental and destructive rather than beneficial. Far from gaining, people who punish tend to escalate conflict, worsen their fortunes and eventually lose out. “Nice guys finish first,” headlines cheered. It wasn’t the first time Nowak’s computer simulations and mathematics forced a rethinking of a complex phenomenon. In 2002 he worked out equations that can predict the way cancer evolves and spreads, such as when mutations emerge in a metastasis and chromosomes become unstable. And in the early 1990s his model of disease progression demonstrated that HIV develops into AIDS only when the virus replicates fast enough so that the diversity of strains reaches a critical level, one that overwhelms the immune system. Immunologists later found out he had the mechanism right [see “How HIV Defeats the Immune System,” by Martin A. Nowak and Andrew J. McMichael; Scientific American, August 1995]. Now Nowak is out to do it again, this time by modeling the origin of life. Specifically, he is trying to capture “the transition from no life to life,” he says. [More] One Quarter of World's Mammals Face Extinction The baiji dolphin is functionally extinct, orangutans are disappearing and even some species of bats--the most numerous of mammals--are dying out. A new survey of the world's 5,487 mammal species--from rodents to humans--reveals that one in four are facing imminent extinction. [More]

Tags: nowak, life, punishment, mammal, punish