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Science Tuesday - Bees, "Night Shining," Breast Cancer, and Travel Medicine
Bees Vanish, and Scientists Race for Reasons
By ALEXEI BARRIONUEVO, The New York Times, April 24, 2007
BELTSVILLE, Md., April 23 — What is happening to the bees?
More than a quarter of the country’s 2.4 million bee colonies have been lost — tens of billions of bees, according to an estimate from the Apiary Inspectors of America, a national group that tracks beekeeping. So far, no one can say what is causing the bees to become disoriented and fail to return to their hives.
As with any great mystery, a number of theories have been posed, and many seem to researchers to be more science fiction than science. People have blamed genetically modified crops, cellular phone towers and high-voltage transmission lines for the disappearances. Or was it a secret plot by Russia or Osama bin Laden to bring down American agriculture? Or, as some blogs have asserted, the rapture of the bees, in which God recalled them to heaven? Researchers have heard it all.
The volume of theories “is totally mind-boggling,” said Diana Cox-Foster, an entomologist at Pennsylvania State University. With Jeffrey S. Pettis, an entomologist from the United States Department of Agriculture, Dr. Cox-Foster is leading a team of researchers who are trying to find answers to explain “colony collapse disorder,” the name given for the disappearing bee syndrome.
“Clearly there is an urgency to solve this,” Dr. Cox-Foster said. “We are trying to move as quickly as we can.”
Dr. Cox-Foster and fellow scientists who are here at a two-day meeting to discuss early findings and future plans with government officials have been focusing on the most likely suspects: a virus, a fungus or a pesticide.
About 60 researchers from North America sifted the possibilities at the meeting today. Some expressed concern about the speed at which adult bees are disappearing from their hives; some colonies have collapsed in as little as two days. Others noted that countries in Europe, as well as Guatemala and parts of Brazil, are also struggling for answers.
“There are losses around the world that may or not be linked,” Dr. Pettis said.
The investigation is now entering a critical phase. The researchers have collected samples in several states and have begun doing bee autopsies and genetic analysis.
So far, known enemies of the bee world, like the varroa mite, on their own at least, do not appear to be responsible for the unusually high losses.
Genetic testing at Columbia University has revealed the presence of multiple micro-organisms in bees from hives or colonies that are in decline, suggesting that something is weakening their immune system. The researchers have found some fungi in the affected bees that are found in humans whose immune systems have been suppressed by the Acquired Immune Deficiency Syndrome or cancer.
“That is extremely unusual,” Dr. Cox-Foster said.
Meanwhile, samples were sent to an Agriculture Department laboratory in North Carolina this month to screen for 117 chemicals. Particular suspicion falls on a pesticide that France banned out of concern that it may have been decimating bee colonies. Concern has also mounted among public officials.
“There are so many of our crops that require pollinators,” said Representative Dennis Cardoza, a California Democrat whose district includes that state’s central agricultural valley, and who presided last month at a Congressional hearing on the bee issue. “We need an urgent call to arms to try to ascertain what is really going on here with the bees, and bring as much science as we possibly can to bear on the problem.”
So far, colony collapse disorder has been found in 27 states, according to Bee Alert Technology Inc., a company monitoring the problem. A recent survey of 13 states by the Apiary Inspectors of America showed that 26 percent of beekeepers had lost half of their bee colonies between September and March.
Honeybees are arguably the insects that are most important to the human food chain. They are the principal pollinators of hundreds of fruits, vegetables, flowers and nuts. The number of bee colonies has been declining since the 1940s, even as the crops that rely on them, such as California almonds, have grown. In October, at about the time that beekeepers were experiencing huge bee losses, a study by the National Academy of Sciences questioned whether American agriculture was relying too heavily on one type of pollinator, the honeybee.
Bee colonies have been under stress in recent years as more beekeepers have resorted to crisscrossing the country with 18-wheel trucks full of bees in search of pollination work. These bees may suffer from a diet that includes artificial supplements, concoctions akin to energy drinks and power bars. In several states, suburban sprawl has limited the bees’ natural forage areas.
So far, the researchers have discounted the possibility that poor diet alone could be responsible for the widespread losses. They have also set aside for now the possibility that the cause could be bees feeding from a commonly used genetically modified crop, Bt corn, because the symptoms typically associated with toxins, such as blood poisoning, are not showing up in the affected bees. But researchers emphasized today that feeding supplements produced from genetically modified crops, such as high-fructose corn syrup, need to be studied.
The scientists say that definitive answers for the colony collapses could be months away. But recent advances in biology and genetic sequencing are speeding the search.
Computers can decipher information from DNA and match pieces of genetic code with particular organisms. Luckily, a project to sequence some 11,000 genes of the honeybee was completed late last year at Baylor University, giving scientists a huge head start on identifying any unknown pathogens in the bee tissue.
“Otherwise, we would be looking for the needle in the haystack,” Dr. Cox-Foster said.
Large bee losses are not unheard of. They have been reported at several points in the past century. But researchers think they are dealing with something new — or at least with something previously unidentified.
“There could be a number of factors that are weakening the bees or speeding up things that shorten their lives,” said Dr. W. Steve Sheppard, a professor of entomology at Washington State University. “The answer may already be with us.”
Scientists first learned of the bee disappearances in November, when David Hackenberg, a Pennsylvania beekeeper, told Dr. Cox-Foster that more than 50 percent of his bee colonies had collapsed in Florida, where he had taken them for the winter.
Dr. Cox-Foster, a 20-year veteran of studying bees, soon teamed with Dennis vanEngelsdorp, the Pennsylvania apiary inspector, to look into the losses.
In December, she approached W. Ian Lipkin, director of the Greene Infectious Disease Laboratory at Columbia University, about doing genetic sequencing of tissue from bees in the colonies that experienced losses. The laboratory uses a recently developed technique for reading and amplifying short sequences of DNA that has revolutionized the science. Dr. Lipkin, who typically works on human diseases, agreed to do the analysis, despite not knowing who would ultimately pay for it. His laboratory is known for its work in finding the West Nile disease in the United States.
Dr. Cox-Foster ultimately sent samples of bee tissue to researchers at Columbia, to the Agriculture Department laboratory in Maryland, and to Gene Robinson, an entomologist at the University of Illinois. Fortuitously, she had frozen bee samples from healthy colonies dating to 2004 to use for comparison.
After receiving the first bee samples from Dr. Cox-Foster on March 6, Dr. Lipkin’s team amplified the genetic material and started sequencing to separate virus, fungus and parasite DNA from bee DNA.
“This is like C.S.I. for agriculture,” Dr. Lipkin said. “It is painstaking, gumshoe detective work.”
Dr. Lipkin sent his first set of results to Dr. Cox-Foster, showing that several unknown micro-organisms were present in the bees from collapsing colonies. Meanwhile, Mr. vanEngelsdorp and researchers at the Agriculture Department lab here began an autopsy of bees from collapsing colonies in California, Florida, Georgia and Pennsylvania to search for any known bee pathogens.
At the University of Illinois, using knowledge gained from the sequencing of the bee genome, Dr. Robinson’s team will try to find which genes in the collapsing colonies are particularly active, perhaps indicating stress from exposure to a toxin or pathogen.
The national research team also quietly began a parallel study in January, financed in part by the National Honey Board, to further determine if something pathogenic could be causing colonies to collapse.
Mr. Hackenberg, the beekeeper, agreed to take his empty bee boxes and other equipment to Food Technology Service, a company in Mulberry, Fla., that uses gamma rays to kill bacteria on medical equipment and some fruits. In early results, the irradiated bee boxes seem to have shown a return to health for colonies repopulated with Australian bees.
“This supports the idea that there is a pathogen there,” Dr. Cox-Foster said. “It would be hard to explain the irradiation getting rid of a chemical.”
Still, some environmental substances remain suspicious.
Chris Mullin, a Pennsylvania State University professor and insect toxicologist, recently sent a set of samples to a federal laboratory in Raleigh, N.C., that will screen for 117 chemicals. Of greatest interest are the “systemic” chemicals that are able to pass through a plant’s circulatory system and move to the new leaves or the flowers, where they would come in contact with bees.
One such group of compounds is called neonicotinoids, commonly used pesticides that are used to treat corn and other seeds against pests. One of the neonicotinoids, imidacloprid, is commonly used in Europe and the United States to treat seeds, to protect residential foundations against termites and to help keep golf courses and home lawns green.
In the late 1990s, French beekeepers reported large losses of their bees and complained about the use of imidacloprid, sold under the brand name Gaucho. The chemical, while not killing the bees outright, was causing them to be disoriented and stay away from their hives, leading them to die of exposure to the cold, French researchers later found. The beekeepers labeled the syndrome “mad bee disease.”
The French government banned the pesticide in 1999 for use on sunflowers, and later for corn, despite protests by the German chemical giant Bayer, which has said its internal research showed the pesticide was not toxic to bees. Subsequent studies by independent French researchers have disagreed with Bayer. Alison Chalmers, an eco-toxicologist for Bayer CropScience, said at the meeting today that bee colonies had not recovered in France as beekeepers had expected. “These chemicals are not being used anymore,” she said of imidacloprid, “so they certainly were not the only cause.”
Among the pesticides being tested in the American bee investigation, the neonicotinoids group “is the number-one suspect,” Dr. Mullin said. He hoped results of the toxicology screening will be ready within a month.
‘Night Shining’ Noctilucent clouds seen from the International Space Station, left, and from the ground, right. They are now being observed as far south as Colorado.
First Mission to Explore Those Wisps in the Night Sky
By KENNETH CHANG, The New York Times, April 24, 2007
Two hundred seventy thousand feet above the ground, higher than 99.9 percent of the earth’s air, clouds still float around — thin, iridescent wisps of electric blue.
NASA is launching a small satellite to take a closer look at these clouds at the edge of outer space and to try to understand why, in recent years, they are appearing more often over more parts of the world. They are also becoming brighter.
The clouds are called noctilucent or “night shining,” because from the ground they can be seen only at night as they float about 50 miles above the surface, illuminated by light from a Sun that has already set below the horizon. (That is essentially the same effect that makes moonlight.)
The clouds form in the polar regions from mid-May to mid-August in the Northern Hemisphere, mid-November to mid-February in the Southern Hemisphere.
“They’re beautiful,” said James M. Russell III, co-director of the Center for Atmospheric Sciences at Hampton University in Virginia and principal investigator of the NASA mission. “The pictures do a good job, but it’s not like seeing them.”
A British sky watcher named Thomas William Backhouse was perhaps the first to notice the odd blue wisps in 1885, and many scientists thought that the phenomenon was an atmospheric effect caused by ash thrown up by the gigantic volcanic eruption of Krakatoa in Indonesia two years earlier.
Although the ash settled out of the air, the noctilucent clouds persisted and spread.
At first they were seen only at higher latitudes in places like Norway, Russia and England. Now they can be seen as far south as Colorado, at about 40 degrees latitude.
The essential ingredients are temperatures from minus 225 to minus 190 degrees Fahrenheit, water vapor and particles of dust that serve as seeds for the ice crystals that form the clouds.
Since 1980, when regular space-based observations of noctilucent clouds began, their number has increased about 28 percent per decade, and they are reflecting more light, because the ice crystals are bigger.
“The most plausible and leading theory is CO2 buildup, which causes global warming,” Dr. Russell said. Increasing temperatures near the surface actually cause the upper part of the atmosphere to cool, and cooler temperatures could spur the formation of more clouds. “If that’s true and we are changing the atmosphere in a remote location like this, that means we’re changing the entire atmosphere,” he said.
The satellite, called Aeronomy of Ice in the Mesosphere, or AIM, is 55 inches high by 43 inches wide and weighs 430 pounds. As early as tomorrow, a modified jetliner will take off from Vandenberg Air Force Base, Calif., with a rocket plane holding the satellite attached on its underside. At 40,000 feet, the rocket plane will drop away and, after igniting its engine, shoot upward.
When the AIM reaches its orbit 370 miles above the Earth, its three instruments will photograph noctilucent clouds, measure the size of the ice crystals and note conditions like temperature, air pressure and moisture levels. The $140 million mission is the first dedicated to studying noctilucent clouds.
Among the questions scientists hope to answer are these: Where is the dust seeding the clouds coming from? Is it composed of tiny meteors from outer space, particles wafting up from the lower atmosphere, or possibly charged atoms created in that part in the atmosphere?
Another mystery: noctilucent clouds in the Southern Hemisphere are about half a mile higher than in the north.
Breast Cancer Not Linked to Abortion, Study Says
By NICHOLAS BAKALAR, The New York Times, April 24, 2007
There is no association between abortion and an increased risk for breast cancer, scientists reported yesterday in a large study.
There has been considerable debate over whether abortion, induced or spontaneous, is linked to breast cancer — a debate that may intensify with last week’s 5-4 Supreme Court ruling, which suggested that an abortion procedure could be banned if it posed a risk to a woman’s health.
The possibility of such a link has been suggested by some retrospective studies — that is, studies that looked for a history of abortion in women who had already been given a diagnosis of breast cancer.
But such studies are subject to error caused by inaccurate reporting. Because of personal sensitivities and the stigma associated with the operation, healthy women may be reluctant to reveal that they have had an abortion, while those with breast cancer, seeking a cause for their illness, are more likely to report one.
This study, published in The Archives of Internal Medicine, tracked women prospectively to see if those who reported having abortions were more likely to develop breast cancer in the future. They were not.
“There are still some states that require women to be informed about the risk of breast cancer if they get an abortion,” said Karin Michels, the lead author and an associate professor of epidemiology at Harvard. “I think that may not be justified based on the current evidence.”
Researchers studied 105,716 women enrolled in a study designed to examine associations between lifestyle and disease. The women were 29 to 46 years old at the beginning of the study in 1993, and 93 percent were premenopausal.
Initially, the women responded to a questionnaire about abortion, with 16,118 saying that they had had one or more induced abortions and 21,753 reporting one or more spontaneous abortions. The researchers collected data on breast cancer risk factors beginning in 1989, updating them every other year through 2003. There were 1,458 newly diagnosed cases of breast cancer during the study period.
The scientists found no difference in breast cancer incidence between the women who had had spontaneous or induced abortions and those who had not. Breast cancer incidence did not differ among women who had had an induced or spontaneous abortion before or after their first birth, or who had had no abortion at all.
At the same time, the authors write, it is well established that a full-term pregnancy before age 35 does reduce the long-term risk for breast cancer. So it might be said that a pregnant woman who aborts increases her risk for breast cancer compared with what it would be if she carried the pregnancy to full term.
Joel Brind, a professor of biology and endocrinology at Baruch College in Manhattan, found fault with the ways in which the study reported the data. Rather than reporting all of the abortions, he said, the researchers should have analyzed only those that occurred earliest in the study, allowing enough time after the abortion for breast cancer to develop.
“I see no reason why this study would change my opinion that having an abortion increases the risk about 30 percent over not having gotten pregnant in the first place,” Dr. Brind said. “I believe also that this particular study, were the data properly handled and reported, would have come up with a result in agreement with that.”
Dr. Michels said that most of the abortions occurred more than 10 years before the breast cancer diagnosis, and that analyzing only the earliest abortions made no difference in the results. But she acknowledged that Dr. Brind raised a crucial issue.
“In analyzing data,” she said, “we have to be careful what we are comparing and take account of whether a woman who has had an induced abortion misses out on the potential benefit she would have had if she had a full-term pregnancy.
“We did analyze the data keeping this issue in mind,” Dr. Michels said, “and we did not find that an incomplete pregnancy deprives a woman of the protection a full-term pregnancy would have conferred.”
Cases: Wiping Out a Parasite, Not a Spirit of Adventure
By CLAIRE PANOSIAN DUNAVAN, M.D., The New York Times, April 24, 2007
Keith Aronowitz first noticed the crater on his elbow after returning from Bolivia. For a week or two, he simply ignored it. Then his friends began to worry.
“A buddy saw the hole in my arm,” recalled Mr. Aronowitz, a photographer and video editor, “and said: ‘Hey, you better see a doctor. That doesn’t look right.’ ”
O.K., he decided, I’ll see a dermatologist, and maybe I’ll even help her with the diagnosis. At the back of his mind, he was thinking of a recent National Geographic article. In it, the author also contracted a weird skin infection in South America. And it all started, the writer stated, with the bite of a sand fly.
When Mr. Aronowitz arrived at Madidi National Park — the same Amazon outpost visited by the National Geographic author — he, too, was bombarded by sand flies. Soon, their pesky bites left him covered in itchy bumps. Then came the elbow ulcer.
In Los Angeles, however, his doctor simply shrugged her shoulders when he proffered these clues. Instead, she handed him an all-purpose cream and glided off.
Another two months passed. The hole in Mr. Aronowitz’s elbow got bigger, deeper and juicier. That’s when he found me.
I’m a tropical medicine specialist who has seen plenty of exotic skin infections over the years. You could say my interest dates back to childhood. Growing up, I was always fascinated by the shallow scar on the cheek of my grandfather, a native of southern Turkey. “How’d you get it?” I asked him, touching the papery depression. “Oh, where I was born, everyone had this,” he replied. “First a fly bit you, then you got a sore. After a while it healed and never came back.”
Years later, as an infectious diseases trainee, I suddenly grasped my grandfather’s diagnosis. What he had was a classic case of “Old World” cutaneous leishmaniasis, also known as “Oriental sore,” “Baghdad boil” and “Aleppo evil.” I then spent two years studying immune responses to the common Middle Eastern blight.
First, the bite of the sand fly transmits the single-cell parasites. Then warrior lymphocytes flood the dermis, causing other cells sheltering the invading microbes to self-destruct. As the battle plays out and the good guys prevail, patients’ skin lesions slowly morph from volcanic nodules to thick-rimmed ulcers to patchy, irregular scars.
But certain cases of leishmaniasis acquired in South America are not so easily vanquished. After hearing Mr. Aronowitz’s story, I felt a little queasy. The region he visited harbors particularly nasty strains of leishmania that sometimes evade the immune system, later spreading like cancer to the nose, mouth and throat.
It was bad enough that my new patient had a ragged, crusty defect on his elbow. What if the parasite started in on his face? This was no longer a watch-and-wait situation — it was time to treat. Or try, at least.
My first choice was an antifungal drug that counters leishmania. Although the medicine bothered his stomach, Mr. Aronowitz faithfully downed the pills for two or three months. But when he stopped them, his elbow got itchy and red, and before long the sore was back.
Intravenous pentamidine — once a mainstay for AIDS patients with Pneumocystis pneumonia — was my next ploy. It bought my patient another year.
Now I was down to heavy-metal therapy. That’s right: the elephant gun for leishmaniasis is a toxic drug made from the chemical antimony.
Everything about the drug, Pentostam, is laborious. To procure it, I had to reach out to the Centers for Disease Control and Prevention in Atlanta and fill out piles of paperwork. Meanwhile, Mr. Aronowitz was outfitted with a semipermanent IV to receive the drug. A high price to pay for a few days in the rain forest.
Finally, it was showtime. Day after day for a month, the man with a hole in his elbow visited our hospital’s infusion center, patiently enduring ever-worsening aches and pains while the parasite poison coursed through his veins. He also underwent weekly blood tests and EKGs to make sure his kidneys, liver and heart remained healthy throughout the treatment.
Thankfully, this drug, Pentostam, was the charm; it cured Mr. Aronowitz’s infection with no lasting side effects. Four years later, his elbow is as smooth as silk.
Epilogue: Last spring, Mr. Aronowitz returned to the Amazon. This year, he recently told me, he’s planning another trip, to shoot a documentary about shamans.
He is philosophical about the danger.
“I don’t know why, but I’ve always been fascinated by the wild, green romanticism of it,” he said. “Sure there are insects and animals there. Maybe that’s why I like it.”
Since we’re friends, I can be frank. I’ll take my insects and parasites under the microscope.
Claire Panosian Dunavan is a professor of medicine and infectious diseases at the University of California, Los Angeles.
By ALEXEI BARRIONUEVO, The New York Times, April 24, 2007
BELTSVILLE, Md., April 23 — What is happening to the bees?
More than a quarter of the country’s 2.4 million bee colonies have been lost — tens of billions of bees, according to an estimate from the Apiary Inspectors of America, a national group that tracks beekeeping. So far, no one can say what is causing the bees to become disoriented and fail to return to their hives.
As with any great mystery, a number of theories have been posed, and many seem to researchers to be more science fiction than science. People have blamed genetically modified crops, cellular phone towers and high-voltage transmission lines for the disappearances. Or was it a secret plot by Russia or Osama bin Laden to bring down American agriculture? Or, as some blogs have asserted, the rapture of the bees, in which God recalled them to heaven? Researchers have heard it all.
The volume of theories “is totally mind-boggling,” said Diana Cox-Foster, an entomologist at Pennsylvania State University. With Jeffrey S. Pettis, an entomologist from the United States Department of Agriculture, Dr. Cox-Foster is leading a team of researchers who are trying to find answers to explain “colony collapse disorder,” the name given for the disappearing bee syndrome.
“Clearly there is an urgency to solve this,” Dr. Cox-Foster said. “We are trying to move as quickly as we can.”
Dr. Cox-Foster and fellow scientists who are here at a two-day meeting to discuss early findings and future plans with government officials have been focusing on the most likely suspects: a virus, a fungus or a pesticide.
About 60 researchers from North America sifted the possibilities at the meeting today. Some expressed concern about the speed at which adult bees are disappearing from their hives; some colonies have collapsed in as little as two days. Others noted that countries in Europe, as well as Guatemala and parts of Brazil, are also struggling for answers.
“There are losses around the world that may or not be linked,” Dr. Pettis said.
The investigation is now entering a critical phase. The researchers have collected samples in several states and have begun doing bee autopsies and genetic analysis.
So far, known enemies of the bee world, like the varroa mite, on their own at least, do not appear to be responsible for the unusually high losses.
Genetic testing at Columbia University has revealed the presence of multiple micro-organisms in bees from hives or colonies that are in decline, suggesting that something is weakening their immune system. The researchers have found some fungi in the affected bees that are found in humans whose immune systems have been suppressed by the Acquired Immune Deficiency Syndrome or cancer.
“That is extremely unusual,” Dr. Cox-Foster said.
Meanwhile, samples were sent to an Agriculture Department laboratory in North Carolina this month to screen for 117 chemicals. Particular suspicion falls on a pesticide that France banned out of concern that it may have been decimating bee colonies. Concern has also mounted among public officials.
“There are so many of our crops that require pollinators,” said Representative Dennis Cardoza, a California Democrat whose district includes that state’s central agricultural valley, and who presided last month at a Congressional hearing on the bee issue. “We need an urgent call to arms to try to ascertain what is really going on here with the bees, and bring as much science as we possibly can to bear on the problem.”
So far, colony collapse disorder has been found in 27 states, according to Bee Alert Technology Inc., a company monitoring the problem. A recent survey of 13 states by the Apiary Inspectors of America showed that 26 percent of beekeepers had lost half of their bee colonies between September and March.
Honeybees are arguably the insects that are most important to the human food chain. They are the principal pollinators of hundreds of fruits, vegetables, flowers and nuts. The number of bee colonies has been declining since the 1940s, even as the crops that rely on them, such as California almonds, have grown. In October, at about the time that beekeepers were experiencing huge bee losses, a study by the National Academy of Sciences questioned whether American agriculture was relying too heavily on one type of pollinator, the honeybee.
Bee colonies have been under stress in recent years as more beekeepers have resorted to crisscrossing the country with 18-wheel trucks full of bees in search of pollination work. These bees may suffer from a diet that includes artificial supplements, concoctions akin to energy drinks and power bars. In several states, suburban sprawl has limited the bees’ natural forage areas.
So far, the researchers have discounted the possibility that poor diet alone could be responsible for the widespread losses. They have also set aside for now the possibility that the cause could be bees feeding from a commonly used genetically modified crop, Bt corn, because the symptoms typically associated with toxins, such as blood poisoning, are not showing up in the affected bees. But researchers emphasized today that feeding supplements produced from genetically modified crops, such as high-fructose corn syrup, need to be studied.
The scientists say that definitive answers for the colony collapses could be months away. But recent advances in biology and genetic sequencing are speeding the search.
Computers can decipher information from DNA and match pieces of genetic code with particular organisms. Luckily, a project to sequence some 11,000 genes of the honeybee was completed late last year at Baylor University, giving scientists a huge head start on identifying any unknown pathogens in the bee tissue.
“Otherwise, we would be looking for the needle in the haystack,” Dr. Cox-Foster said.
Large bee losses are not unheard of. They have been reported at several points in the past century. But researchers think they are dealing with something new — or at least with something previously unidentified.
“There could be a number of factors that are weakening the bees or speeding up things that shorten their lives,” said Dr. W. Steve Sheppard, a professor of entomology at Washington State University. “The answer may already be with us.”
Scientists first learned of the bee disappearances in November, when David Hackenberg, a Pennsylvania beekeeper, told Dr. Cox-Foster that more than 50 percent of his bee colonies had collapsed in Florida, where he had taken them for the winter.
Dr. Cox-Foster, a 20-year veteran of studying bees, soon teamed with Dennis vanEngelsdorp, the Pennsylvania apiary inspector, to look into the losses.
In December, she approached W. Ian Lipkin, director of the Greene Infectious Disease Laboratory at Columbia University, about doing genetic sequencing of tissue from bees in the colonies that experienced losses. The laboratory uses a recently developed technique for reading and amplifying short sequences of DNA that has revolutionized the science. Dr. Lipkin, who typically works on human diseases, agreed to do the analysis, despite not knowing who would ultimately pay for it. His laboratory is known for its work in finding the West Nile disease in the United States.
Dr. Cox-Foster ultimately sent samples of bee tissue to researchers at Columbia, to the Agriculture Department laboratory in Maryland, and to Gene Robinson, an entomologist at the University of Illinois. Fortuitously, she had frozen bee samples from healthy colonies dating to 2004 to use for comparison.
After receiving the first bee samples from Dr. Cox-Foster on March 6, Dr. Lipkin’s team amplified the genetic material and started sequencing to separate virus, fungus and parasite DNA from bee DNA.
“This is like C.S.I. for agriculture,” Dr. Lipkin said. “It is painstaking, gumshoe detective work.”
Dr. Lipkin sent his first set of results to Dr. Cox-Foster, showing that several unknown micro-organisms were present in the bees from collapsing colonies. Meanwhile, Mr. vanEngelsdorp and researchers at the Agriculture Department lab here began an autopsy of bees from collapsing colonies in California, Florida, Georgia and Pennsylvania to search for any known bee pathogens.
At the University of Illinois, using knowledge gained from the sequencing of the bee genome, Dr. Robinson’s team will try to find which genes in the collapsing colonies are particularly active, perhaps indicating stress from exposure to a toxin or pathogen.
The national research team also quietly began a parallel study in January, financed in part by the National Honey Board, to further determine if something pathogenic could be causing colonies to collapse.
Mr. Hackenberg, the beekeeper, agreed to take his empty bee boxes and other equipment to Food Technology Service, a company in Mulberry, Fla., that uses gamma rays to kill bacteria on medical equipment and some fruits. In early results, the irradiated bee boxes seem to have shown a return to health for colonies repopulated with Australian bees.
“This supports the idea that there is a pathogen there,” Dr. Cox-Foster said. “It would be hard to explain the irradiation getting rid of a chemical.”
Still, some environmental substances remain suspicious.
Chris Mullin, a Pennsylvania State University professor and insect toxicologist, recently sent a set of samples to a federal laboratory in Raleigh, N.C., that will screen for 117 chemicals. Of greatest interest are the “systemic” chemicals that are able to pass through a plant’s circulatory system and move to the new leaves or the flowers, where they would come in contact with bees.
One such group of compounds is called neonicotinoids, commonly used pesticides that are used to treat corn and other seeds against pests. One of the neonicotinoids, imidacloprid, is commonly used in Europe and the United States to treat seeds, to protect residential foundations against termites and to help keep golf courses and home lawns green.
In the late 1990s, French beekeepers reported large losses of their bees and complained about the use of imidacloprid, sold under the brand name Gaucho. The chemical, while not killing the bees outright, was causing them to be disoriented and stay away from their hives, leading them to die of exposure to the cold, French researchers later found. The beekeepers labeled the syndrome “mad bee disease.”
The French government banned the pesticide in 1999 for use on sunflowers, and later for corn, despite protests by the German chemical giant Bayer, which has said its internal research showed the pesticide was not toxic to bees. Subsequent studies by independent French researchers have disagreed with Bayer. Alison Chalmers, an eco-toxicologist for Bayer CropScience, said at the meeting today that bee colonies had not recovered in France as beekeepers had expected. “These chemicals are not being used anymore,” she said of imidacloprid, “so they certainly were not the only cause.”
Among the pesticides being tested in the American bee investigation, the neonicotinoids group “is the number-one suspect,” Dr. Mullin said. He hoped results of the toxicology screening will be ready within a month.
‘Night Shining’ Noctilucent clouds seen from the International Space Station, left, and from the ground, right. They are now being observed as far south as Colorado.
First Mission to Explore Those Wisps in the Night Sky
By KENNETH CHANG, The New York Times, April 24, 2007
Two hundred seventy thousand feet above the ground, higher than 99.9 percent of the earth’s air, clouds still float around — thin, iridescent wisps of electric blue.
NASA is launching a small satellite to take a closer look at these clouds at the edge of outer space and to try to understand why, in recent years, they are appearing more often over more parts of the world. They are also becoming brighter.
The clouds are called noctilucent or “night shining,” because from the ground they can be seen only at night as they float about 50 miles above the surface, illuminated by light from a Sun that has already set below the horizon. (That is essentially the same effect that makes moonlight.)
The clouds form in the polar regions from mid-May to mid-August in the Northern Hemisphere, mid-November to mid-February in the Southern Hemisphere.
“They’re beautiful,” said James M. Russell III, co-director of the Center for Atmospheric Sciences at Hampton University in Virginia and principal investigator of the NASA mission. “The pictures do a good job, but it’s not like seeing them.”
A British sky watcher named Thomas William Backhouse was perhaps the first to notice the odd blue wisps in 1885, and many scientists thought that the phenomenon was an atmospheric effect caused by ash thrown up by the gigantic volcanic eruption of Krakatoa in Indonesia two years earlier.
Although the ash settled out of the air, the noctilucent clouds persisted and spread.
At first they were seen only at higher latitudes in places like Norway, Russia and England. Now they can be seen as far south as Colorado, at about 40 degrees latitude.
The essential ingredients are temperatures from minus 225 to minus 190 degrees Fahrenheit, water vapor and particles of dust that serve as seeds for the ice crystals that form the clouds.
Since 1980, when regular space-based observations of noctilucent clouds began, their number has increased about 28 percent per decade, and they are reflecting more light, because the ice crystals are bigger.
“The most plausible and leading theory is CO2 buildup, which causes global warming,” Dr. Russell said. Increasing temperatures near the surface actually cause the upper part of the atmosphere to cool, and cooler temperatures could spur the formation of more clouds. “If that’s true and we are changing the atmosphere in a remote location like this, that means we’re changing the entire atmosphere,” he said.
The satellite, called Aeronomy of Ice in the Mesosphere, or AIM, is 55 inches high by 43 inches wide and weighs 430 pounds. As early as tomorrow, a modified jetliner will take off from Vandenberg Air Force Base, Calif., with a rocket plane holding the satellite attached on its underside. At 40,000 feet, the rocket plane will drop away and, after igniting its engine, shoot upward.
When the AIM reaches its orbit 370 miles above the Earth, its three instruments will photograph noctilucent clouds, measure the size of the ice crystals and note conditions like temperature, air pressure and moisture levels. The $140 million mission is the first dedicated to studying noctilucent clouds.
Among the questions scientists hope to answer are these: Where is the dust seeding the clouds coming from? Is it composed of tiny meteors from outer space, particles wafting up from the lower atmosphere, or possibly charged atoms created in that part in the atmosphere?
Another mystery: noctilucent clouds in the Southern Hemisphere are about half a mile higher than in the north.
Breast Cancer Not Linked to Abortion, Study Says
By NICHOLAS BAKALAR, The New York Times, April 24, 2007
There is no association between abortion and an increased risk for breast cancer, scientists reported yesterday in a large study.
There has been considerable debate over whether abortion, induced or spontaneous, is linked to breast cancer — a debate that may intensify with last week’s 5-4 Supreme Court ruling, which suggested that an abortion procedure could be banned if it posed a risk to a woman’s health.
The possibility of such a link has been suggested by some retrospective studies — that is, studies that looked for a history of abortion in women who had already been given a diagnosis of breast cancer.
But such studies are subject to error caused by inaccurate reporting. Because of personal sensitivities and the stigma associated with the operation, healthy women may be reluctant to reveal that they have had an abortion, while those with breast cancer, seeking a cause for their illness, are more likely to report one.
This study, published in The Archives of Internal Medicine, tracked women prospectively to see if those who reported having abortions were more likely to develop breast cancer in the future. They were not.
“There are still some states that require women to be informed about the risk of breast cancer if they get an abortion,” said Karin Michels, the lead author and an associate professor of epidemiology at Harvard. “I think that may not be justified based on the current evidence.”
Researchers studied 105,716 women enrolled in a study designed to examine associations between lifestyle and disease. The women were 29 to 46 years old at the beginning of the study in 1993, and 93 percent were premenopausal.
Initially, the women responded to a questionnaire about abortion, with 16,118 saying that they had had one or more induced abortions and 21,753 reporting one or more spontaneous abortions. The researchers collected data on breast cancer risk factors beginning in 1989, updating them every other year through 2003. There were 1,458 newly diagnosed cases of breast cancer during the study period.
The scientists found no difference in breast cancer incidence between the women who had had spontaneous or induced abortions and those who had not. Breast cancer incidence did not differ among women who had had an induced or spontaneous abortion before or after their first birth, or who had had no abortion at all.
At the same time, the authors write, it is well established that a full-term pregnancy before age 35 does reduce the long-term risk for breast cancer. So it might be said that a pregnant woman who aborts increases her risk for breast cancer compared with what it would be if she carried the pregnancy to full term.
Joel Brind, a professor of biology and endocrinology at Baruch College in Manhattan, found fault with the ways in which the study reported the data. Rather than reporting all of the abortions, he said, the researchers should have analyzed only those that occurred earliest in the study, allowing enough time after the abortion for breast cancer to develop.
“I see no reason why this study would change my opinion that having an abortion increases the risk about 30 percent over not having gotten pregnant in the first place,” Dr. Brind said. “I believe also that this particular study, were the data properly handled and reported, would have come up with a result in agreement with that.”
Dr. Michels said that most of the abortions occurred more than 10 years before the breast cancer diagnosis, and that analyzing only the earliest abortions made no difference in the results. But she acknowledged that Dr. Brind raised a crucial issue.
“In analyzing data,” she said, “we have to be careful what we are comparing and take account of whether a woman who has had an induced abortion misses out on the potential benefit she would have had if she had a full-term pregnancy.
“We did analyze the data keeping this issue in mind,” Dr. Michels said, “and we did not find that an incomplete pregnancy deprives a woman of the protection a full-term pregnancy would have conferred.”
Cases: Wiping Out a Parasite, Not a Spirit of Adventure
By CLAIRE PANOSIAN DUNAVAN, M.D., The New York Times, April 24, 2007
Keith Aronowitz first noticed the crater on his elbow after returning from Bolivia. For a week or two, he simply ignored it. Then his friends began to worry.
“A buddy saw the hole in my arm,” recalled Mr. Aronowitz, a photographer and video editor, “and said: ‘Hey, you better see a doctor. That doesn’t look right.’ ”
O.K., he decided, I’ll see a dermatologist, and maybe I’ll even help her with the diagnosis. At the back of his mind, he was thinking of a recent National Geographic article. In it, the author also contracted a weird skin infection in South America. And it all started, the writer stated, with the bite of a sand fly.
When Mr. Aronowitz arrived at Madidi National Park — the same Amazon outpost visited by the National Geographic author — he, too, was bombarded by sand flies. Soon, their pesky bites left him covered in itchy bumps. Then came the elbow ulcer.
In Los Angeles, however, his doctor simply shrugged her shoulders when he proffered these clues. Instead, she handed him an all-purpose cream and glided off.
Another two months passed. The hole in Mr. Aronowitz’s elbow got bigger, deeper and juicier. That’s when he found me.
I’m a tropical medicine specialist who has seen plenty of exotic skin infections over the years. You could say my interest dates back to childhood. Growing up, I was always fascinated by the shallow scar on the cheek of my grandfather, a native of southern Turkey. “How’d you get it?” I asked him, touching the papery depression. “Oh, where I was born, everyone had this,” he replied. “First a fly bit you, then you got a sore. After a while it healed and never came back.”
Years later, as an infectious diseases trainee, I suddenly grasped my grandfather’s diagnosis. What he had was a classic case of “Old World” cutaneous leishmaniasis, also known as “Oriental sore,” “Baghdad boil” and “Aleppo evil.” I then spent two years studying immune responses to the common Middle Eastern blight.
First, the bite of the sand fly transmits the single-cell parasites. Then warrior lymphocytes flood the dermis, causing other cells sheltering the invading microbes to self-destruct. As the battle plays out and the good guys prevail, patients’ skin lesions slowly morph from volcanic nodules to thick-rimmed ulcers to patchy, irregular scars.
But certain cases of leishmaniasis acquired in South America are not so easily vanquished. After hearing Mr. Aronowitz’s story, I felt a little queasy. The region he visited harbors particularly nasty strains of leishmania that sometimes evade the immune system, later spreading like cancer to the nose, mouth and throat.
It was bad enough that my new patient had a ragged, crusty defect on his elbow. What if the parasite started in on his face? This was no longer a watch-and-wait situation — it was time to treat. Or try, at least.
My first choice was an antifungal drug that counters leishmania. Although the medicine bothered his stomach, Mr. Aronowitz faithfully downed the pills for two or three months. But when he stopped them, his elbow got itchy and red, and before long the sore was back.
Intravenous pentamidine — once a mainstay for AIDS patients with Pneumocystis pneumonia — was my next ploy. It bought my patient another year.
Now I was down to heavy-metal therapy. That’s right: the elephant gun for leishmaniasis is a toxic drug made from the chemical antimony.
Everything about the drug, Pentostam, is laborious. To procure it, I had to reach out to the Centers for Disease Control and Prevention in Atlanta and fill out piles of paperwork. Meanwhile, Mr. Aronowitz was outfitted with a semipermanent IV to receive the drug. A high price to pay for a few days in the rain forest.
Finally, it was showtime. Day after day for a month, the man with a hole in his elbow visited our hospital’s infusion center, patiently enduring ever-worsening aches and pains while the parasite poison coursed through his veins. He also underwent weekly blood tests and EKGs to make sure his kidneys, liver and heart remained healthy throughout the treatment.
Thankfully, this drug, Pentostam, was the charm; it cured Mr. Aronowitz’s infection with no lasting side effects. Four years later, his elbow is as smooth as silk.
Epilogue: Last spring, Mr. Aronowitz returned to the Amazon. This year, he recently told me, he’s planning another trip, to shoot a documentary about shamans.
He is philosophical about the danger.
“I don’t know why, but I’ve always been fascinated by the wild, green romanticism of it,” he said. “Sure there are insects and animals there. Maybe that’s why I like it.”
Since we’re friends, I can be frank. I’ll take my insects and parasites under the microscope.
Claire Panosian Dunavan is a professor of medicine and infectious diseases at the University of California, Los Angeles.