March 29, 2007
Chernobyl-based birds avoid radioactive nests
00:01 28 March 2007 NewScientist.com news service Catherine Brahic
The nest boxes were all in the Red Forest, a few kilometres from Chernobyl’s reactor 4 which exploded in 1986 .
The nest boxes were mounted on trees, between 1.5 m and 2 m above the ground. Pied flycatchers (B) were more picky about avoiding nest boxes with higher levels of background radioactivity than great tits (A) .
Birds in Chernobyl choose to nest in sites with lower levels of background radioactivity, researchers discover, but how they can tell remains a mystery.
Anders Møller at Pierre and Marie Curie University in Paris, France, and Tim Mousseau at the University of South Carolina in Columbia, US, erected more than 200 nest boxes in the Red Forest, about 3 kilometres away from the nuclear reactor that exploded in 1986.
Using these artificial nests, they studied at the nesting habits of two species of birds – the great tit Parus major and the pied flycatcher Ficedula hypoleuca – between 2002 and 2003.
Moller and Mousseau wanted to see if either species would differentiate between nesting sites that had high and low levels of background radioactivity. The patchy distribution of background radioactivity in the area (due to the fact that radioactive material from the explosion did not settle uniformly) meant the nest boxes could be in very similar locations, with similar food supplies, but have widely varying levels of background radioactivity. Levels at some nest sites were as much as 2000 times natural levels elsewhere in the world.
Deformed sperm
The researchers found that both species had a definite preference for nest boxes with low radioactivity, with the pied flycatcher seemingly more sensitive than the great tit (see chart, bottom right).
Previous research done by Mousseau and colleagues (Trends in Ecology and Evolution, DOI: 10.1016/j.tree.2006.01.008) showed that higher radioactivity results in lower levels of antioxidants and also deformed sperm in barn swallows around Chernobyl. It therefore makes sense for birds to avoid more radioactive sites.
"It is not entirely clear exactly how the birds are able to tell which boxes are most contaminated", says Mousseau, adding that determining this will be very difficult without experimental manipulations.
Wildlife boom
A spokesperson for the Royal Society for the Protection of Birds told New Scientist that the study is interesting, but points out the unexpected benefits of the Chernobyl explosion. Reports show that the large human exclusion zone around the site has led to a boom in animal populations, including eagles, wolves and bears.
"Whatever effect the radioactivity is having, it seems to be less of a threat than human activities, such as agriculture," said the spokesperson.
"There have been few rigorous scientific analyses of background radiation and the natural abundance of species," responds Mousseau. "But every rock we turn over, every survey we do, we find some previously unreported effect of background radiation."
Immigrant influx
Mousseau believes that the reports of sustained animal populations around Chernobyl mask fluctuations within the populations.
He says studies he has carried out looking at where the barn swallow populations in Chernobyl come from suggest that "the populations are mostly sustained by immigrant birds", rather than birds returning to their nesting sites as they normally would.
So an overall picture showing constant population size could hide the fact that the local population is dwindling but being constantly replenished by neighbouring ones.
Journal reference: Proceedings of the Royal Society: B (DOI: 10.1098/rspb.2007.0005)
Source URL: http://environment.newscientist.com/article/dn11473?DCMP=NLC-nletter&nsref=dn11473
March 27, 2007
Rare species spotted in JNU's biodiversity park
A palm civet, an endangered species more commonly known as 'musang', was first spotted in the campus by Surya Prakash of the varsity's Life Sciences Department.
Prakash, who spotted the species last Friday, said it was interesting to find the animal in the national capital.
"I spotted the animal during the day, though it is a nocturnal creature, but what is more interesting is to find it in Delhi. It's an endangered species and Delhi is not listed in the places where it is found," he told PTI.
According to the Wildlife Institute of India, the palm civet is found in parts of Gujarat, Jammu and Kashmir, West Bengal, Assam and Andhra Pradesh.
"The JNU campus is full of fruit trees and has human habitation. This is the natural habitat for the palm civet and that could be the precise reason why it was found here," Prakash said.
Of late, the university has found a place in the capital's listed birding destinations. Its lush green campus is home to 125 species of birds and 40 species of butterflies.
Some rare species of birds that can be spotted there are Yellow Wattled Lapwing, Sirkeer Malkoha, Golden Oriole, Black Francolin, Alexandrine Parakeet, Plum Headed Parakeet, Yellow Crowned Woodpecker and Flameback White Capped Bunting Horned Owl.
http://www.hindu.com/thehindu/holnus/001200703251121.htm
March 26, 2007
Butterflies' migration to halt Taiwan's traffic
TAIPEI, Taiwan — Taiwan will cordon off part of a highway to create a safe passage for a massive seasonal butterfly migration in the coming days, an official said Saturday.
The milkweed butterflies — which are indigenous to the island off China and have distinct white dots on purple-brown wings — migrate in late March from southern Taiwan to the north, where they lay eggs and die.
Milkweed butterflies migrate in late March from southern Taiwan to the north, where they lay eggs and die. Taiwanese officials are going to great lengths to ensure safe passage this year.
The young butterflies then fly south every November to a warm mountain valley near the southern city of Kaohsiung to escape the winter cold.
Conservationists say Taiwan has about 2 million milkweed butterflies.
To protect the migrating butterflies, a 600-yard stretch of highway in southern Taiwan's Yunlin County will be sealed off in the coming days as the migration peaks, said Lee Tai-ming, head of the National Freeway Bureau.
Authorities will set up nets to make the butterflies fly higher and avoid passing cars, Lee said.
He said they will also install ultraviolet lights to guide the insects across an overpass.
Taiwan began the laborious task of tracking down the butterflies' 180-mile migration paths in recent years.
Taiwan originally had more types of milkweed butterflies, but the largest became extinct decades ago when they were routinely caught and made into specimens for sale.
Copyright © 2007 The Seattle Times Company
March 09, 2007
Sounds like Sci-Fi.... No! Its Nature's Wonder
From New Scientist Print Edition.
Rowan Hooper
Survival of the fittest, physically? or mentally?
12:12 06 March 2007
NewScientist.com news service
Roxanne Khamsi
Some male spiders up-and-leave right after sex for good reason – they risk being eaten by their female partners if they linger too long. In the process of making a swift exit, many leave part of their genitalia inside their mates.
Now a new study reveals that detaching part of the genital organ is not a means to help the male escape a murderous attack. Instead, the abandoned genitals act as "chastity belts" and block the entry of sperm from competitors into the female.
Gabriele Uhl at the University of Bonn, Germany, and colleagues watched wasp spiders (Argiope bruennichi) mate. During the act, a male must insert one of its two sperm-carrying organs, known as pedipalps, into the female’s genital openings. After delivering the sperm, the tip of the pedipalp becomes stuck inside the female, forming a plug in her reproductive tract.
To find out if leaving behind part of the pedipalp helped the males escape death, researchers compared the damage to this organ during first-time sexual encounters with damage sustained in subsequent encounters.
Evolutionary benefit
The experienced males monitored in the experiment had mated once before and only had a single remaining pedipalp intact. These males would enjoy no evolutionary benefit from surviving after mating a second time because they have generally lost both of their pedipalps at this point, and can therefore no longer inseminate females.
According to Uhl, if detaching the pedipalp did offer a survival benefit, one would expect to see it happen more among virgin males, which could mate again, than experienced males, which could not. But the researchers found an equal amount of pedipalp damage among these two groups.
They therefore concluded that detachment of the pedipalp tip cannot significantly enhance a male spider’s chance of escaping attack by his mate.
Uhl’s team also found that a pedipalp tip left inside a female affected how long she copulated for in subsequent encounters. Normally virgin females mate for about 16 seconds, but those with a pedipalp plug mate for only half as long.
This is important because female spiders are more likely to deliver the offspring of those males with which they copulate longest, Uhl says.
She concludes that the pedipalp plug acts as a chastity belt to prevent sperm from competing spiders from entering the females. Uhl's group has also found other types of wasp spiders with a similar "plugging mechanism".
Journal reference: Behavioral Ecology (DOI: 10.1093/beheco/ar1074)
Source URL :http://www.newscientist.com/article/dn11319?DCMP=NLC-nletter&nsref=dn11319
March 04, 2007
Save a life by donating your baby's cord blood
Posted Monday, February 26, 2007
Source URL :http://www.dailyherald.com/health/story.asp?id=285342
Flyers in upscale doctors' offices portray it as the hot new baby-shower gift: a registry where friends and family chip in almost $2,000 to start privately banking a newborn's umbilical cord blood, just in case of future illness.
That idea of biological insurance is a long shot that most mothers-to-be can safely ignore, say new guidelines from the nation's pediatricians that urge more parents to donate their babies' cord blood - so that it might save someone's life today.
The guidelines come as the government begins setting up the first national cord-blood banking system, aiming to prevent some 12,000 deaths a year - if public banks can compete with marketing-savvy private companies that now house the bulk of the world's preserved cord blood.
Cord blood is rich in stem cells, the building blocks that produce blood - and the same stem cells that make up the bone-marrow transplants that help many people survive certain cancers and other diseases. But cord blood has some advantages: These younger stem cells are more easily transplanted into unrelated people than bone marrow is, and they can be thawed at a moment's notice, much easier than searching out a bone-marrow donor.
There should be plenty for both private and public banking, says an optimistic Dr. Elizabeth Shpall of the public M.D. Anderson Cord Blood Bank. After all, cord blood from most of the nation's 4 million annual births is thrown away.
Chief hurdles: Improving consumer awareness - and the small number of hospitals that allow donations.
Her own work illustrates the industry's stark socio-economic contrasts: At Houston's Ben Taub General Hospital, Shpall finds the mostly Hispanic mothers-to-be not only unable to afford private banking - few have even heard that cord blood has a medical use.
Armed with a $3 million federal grant to improve much-needed minority donations, she is working with Spanish-language TV and radio programs that in a few months will begin telling Houston moms about their cord blood choices, and which hospitals allow donations.
Her message: "Unless you have a family member with cancer, it's unlikely you would ever need it, and you would be doing a service to humanity to donate it."
Today, about 50,000 cord blood donations are stored in more than 20 public banks around the country. The new National Cord Blood Inventory aims to triple that number, enough that virtually anyone who needs stem cell treatment could find a match - especially minority patients who today seldom can as most bone marrow donors are white.
Private banks have an estimated 400,000 units stored.
What's the controversy? Deciding who really needs to store a child's own cord blood for later use. Private storage costs $1,500 to $1,900 up front, and about $125 a year thereafter, although some offer special programs for lower-income families.
Guidelines published last month by the American Academy of Pediatrics say:
• Parents should consider private storage only if an older sibling has cancer or certain genetic diseases that cord blood is proven to treat.
• Everyone else should consider donating their child's cord blood. The odds that a child would need an infusion of his or her own cord blood later in life are slim, between one in 1,000 and one in 200,000.
Private banks vehemently disagree, arguing that as scientists learn more about stem cells, the blood could create personalized treatments for heart disease or other more common killers.
"That's still considered very experimental," counters Dr. Mitchell Cairo of Columbia University Medical Center, who co-authored the new guidelines.
Also, doctors don't even know if cord blood remains usable after being stored for decades.
Still, last month Illinois doctors reported the first apparent success in treating a child's leukemia with her own cord blood - something usually impossible because that blood so often carries the cancer-triggering genetic defect.
The report has expectant parents calling Advocate Hope Children's Hospital to ask if they, too, should store their babies' cord blood, says Dr. Ammar Hayani, who performed the transplant only after genetic testing showed that patient's cord blood was defect-free.
"It's probably overadvertised by some of these companies as this biological insurance. That's probably overdramatization of its potential," says Hayani, who advises parents of the pediatric academy's guidelines. "But I think parents need to know" both sides' arguments, he says.
About 11 states have recently passed legislation to try to increase the information that expectant parents receive about their cord blood choices: store it, donate it or discard it.
It's no different than how families choose between public or private schools, says Steve Grant of Cord Blood Registry, which began offering the baby-gift option last year after noticing grandparents putting up the money.
"The competitive nature seems misplaced to me," he says. "Family banking is not in any way detracting from the ability to build a public system."
Flyers in upscale doctors' offices portray it as the hot new baby-shower gift: a registry where friends and family chip in almost $2,000 to start privately banking a newborn's umbilical cord blood, just in case of future illness.
That idea of biological insurance is a long shot that most mothers-to-be can safely ignore, say new guidelines from the nation's pediatricians that urge more parents to donate their babies' cord blood - so that it might save someone's life today.
The guidelines come as the government begins setting up the first national cord-blood banking system, aiming to prevent some 12,000 deaths a year - if public banks can compete with marketing-savvy private companies that now house the bulk of the world's preserved cord blood.
Cord blood is rich in stem cells, the building blocks that produce blood - and the same stem cells that make up the bone-marrow transplants that help many people survive certain cancers and other diseases. But cord blood has some advantages: These younger stem cells are more easily transplanted into unrelated people than bone marrow is, and they can be thawed at a moment's notice, much easier than searching out a bone-marrow donor.
There should be plenty for both private and public banking, says an optimistic Dr. Elizabeth Shpall of the public M.D. Anderson Cord Blood Bank. After all, cord blood from most of the nation's 4 million annual births is thrown away.
Chief hurdles: Improving consumer awareness - and the small number of hospitals that allow donations.
Her own work illustrates the industry's stark socio-economic contrasts: At Houston's Ben Taub General Hospital, Shpall finds the mostly Hispanic mothers-to-be not only unable to afford private banking - few have even heard that cord blood has a medical use.
Armed with a $3 million federal grant to improve much-needed minority donations, she is working with Spanish-language TV and radio programs that in a few months will begin telling Houston moms about their cord blood choices, and which hospitals allow donations.
Her message: "Unless you have a family member with cancer, it's unlikely you would ever need it, and you would be doing a service to humanity to donate it."
Today, about 50,000 cord blood donations are stored in more than 20 public banks around the country. The new National Cord Blood Inventory aims to triple that number, enough that virtually anyone who needs stem cell treatment could find a match - especially minority patients who today seldom can as most bone marrow donors are white.
Private banks have an estimated 400,000 units stored.
What's the controversy? Deciding who really needs to store a child's own cord blood for later use. Private storage costs $1,500 to $1,900 up front, and about $125 a year thereafter, although some offer special programs for lower-income families.
Guidelines published last month by the American Academy of Pediatrics say:
• Parents should consider private storage only if an older sibling has cancer or certain genetic diseases that cord blood is proven to treat.
• Everyone else should consider donating their child's cord blood. The odds that a child would need an infusion of his or her own cord blood later in life are slim, between one in 1,000 and one in 200,000.
Private banks vehemently disagree, arguing that as scientists learn more about stem cells, the blood could create personalized treatments for heart disease or other more common killers.
"That's still considered very experimental," counters Dr. Mitchell Cairo of Columbia University Medical Center, who co-authored the new guidelines.
Also, doctors don't even know if cord blood remains usable after being stored for decades.
Still, last month Illinois doctors reported the first apparent success in treating a child's leukemia with her own cord blood - something usually impossible because that blood so often carries the cancer-triggering genetic defect.
The report has expectant parents calling Advocate Hope Children's Hospital to ask if they, too, should store their babies' cord blood, says Dr. Ammar Hayani, who performed the transplant only after genetic testing showed that patient's cord blood was defect-free.
"It's probably overadvertised by some of these companies as this biological insurance. That's probably overdramatization of its potential," says Hayani, who advises parents of the pediatric academy's guidelines. "But I think parents need to know" both sides' arguments, he says.
About 11 states have recently passed legislation to try to increase the information that expectant parents receive about their cord blood choices: store it, donate it or discard it.
It's no different than how families choose between public or private schools, says Steve Grant of Cord Blood Registry, which began offering the baby-gift option last year after noticing grandparents putting up the money.
"The competitive nature seems misplaced to me," he says. "Family banking is not in any way detracting from the ability to build a public system."
March 02, 2007
Taming the wild
Some genetically modified fish appear to undergo a personality change when they leave laboratory conditions for a more natural environment, according to new research.
Transgenic fish that behave ferociously in a bare tank, appear meek under more natural conditions, meaning it will not be easy for biologists to predict the ecological consequences of escaped GM animals.
Salmon genetically engineered to overproduce growth hormone can put on up to 25 times the weight of wild salmon and could provide "aqua-culturists" with a faster way to raise fish to market size.
However, lab tests suggested that transgenic fish are more aggressive predators than wild salmon, raising concerns that they could harm native fish if they escape into the wild.
Stream tanks
Fredrik Sundström and colleagues at Canada's Center for Aquaculture and Environmental Research, Fisheries and Oceans, in Vancouver, tested whether the GM fish would have the same superiority in more natural conditions.
When they raised the fish in stream tanks complete with gravel, large rocks, logs and natural food items, they found that the GM fish still grew a little faster and ate a little more than unmodified fish, but their advantage was much smaller than when the fish lived in a simple metal tank and ate food in pellet form.
That does not mean escaped GM fish would not cause ecological damage, says Sundström, only that biologists will need to work harder to answer the question. “You can’t use fish reared in the lab to predict what will happen in nature,” he says.
Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0608767104)