Crying can strengthen personal relationships

[ScienceNology] - While crying is known to be a symptom of physical pain or stress, it has emotional benefits too and can make interpersonal relationships stronger, says a Tel Aviv University evolutionary biologist.

Dr. Oren Hasson of TAU’s Department of Zoology says that his analysis shows that while tears do signal physiological distress, they can also function as an evolution-based mechanism to bring people closer together.

"Crying is a highly evolved behavior. Tears give clues and reliable information about submission, needs and social attachments between one another. My research is trying to answer what the evolutionary reasons are for having emotional tears,” Dr. Hasson said.

"My analysis suggests that by blurring vision, tears lower defences and reliably function as signals of submission, a cry for help, and even in a mutual display of attachment and as a group display of cohesion," he reports,” Dr. Hasson added.

His research investigates the different kinds of tears we shed — tears of joy, sadness and grief — as well as the authenticity or sincerity of the tears.

Dr. Hasson says crying has unique benefits among friends and others in our various communities.

Approaching the topic with the deductive tools of an evolutionary biologist, Dr. Hasson investigated the use of tears in various emotional and social circumstances.

Tears are used to elicit mercy from an antagonistic enemy, he claims. They are also useful in eliciting the sympathy — and perhaps more importantly the strategic assistance — of people who were not part of the enemy group.

"This is strictly human. Emotional tears also signal appeasement, a need for attachment in times of grief, and a validation of emotions among family, friends and members of a group," Dr. Hasson said.

The study has been published recently in Evolutionary Psychology. (ANI)


Source : India.com , 25 August 2009

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DNA fingerprints can be fabricated

[ScienceNology] - Forensic analysis of DNA used as court evidence can be made-up , Israeli scientists have shown. A person trained in biology who has lab access can copy an innocent person’s details using “biological identity theft”.

In a paper published in the journal Forensic Science International: Genetics, the team reports on how they’ve managed to take a sample of blood taken from a woman and forge it into that of a man. They separated cells containing genetic material from the female sample before combining it with DNA taken from the male’s hair. If planted at the scene of a crime, this blood sample could potentially incriminate an innocent man.

Another approach would require access to the genetic profile of a person and access to the gene database. A trained geneticist would be able to construct fake genetic material by mixing samples with other gene characteristics. The results of this would be untraceable. The forgers wouldn’t even need access to real genetic material to make this possible.

“You can just engineer a crime scene,” said Dan Frumkin, lead author of the paper. “Any biology undergraduate could perform this.”

The paper goes on to suggest a method of identifying faked DNA.

Modern forensic science relies on DNA evidence to provide court evidence which decides thousands of sentences; both convicting people of crimes and clearing them of charges. The paper casts doubt on how reliable the evidence is and will be in future trials.







“Stealing an identity is now a possibility, potentially someone could come along and collect your DNA without access to a tissue sample and make it look like your DNA using various complicated techniques,” commented Gail Javitt, from the Berman Institute of Bioethics at John Hopkins University.

“From now on in criminal procedures, they have to be careful about having a real DNA, not a faked one,” she added. “Outside the criminal context, we need clear policies that it’s “hands off our DNA” and maintain the privacy of our genetic information.”

However, skeptics point out that the majority of criminals wouldn’t have either the knowledge nor access to the required equipment to fabricate DNA evidence.




A News from RussiaToday , 19 August 2009

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New images capture cell's ribosomes at work, could aid in molecular war against disease

[ScienceNology] - Researchers at the University of California, Berkeley, have for the first time captured elusive nanoscale movements of ribosomes at work, shedding light on how these cellular factories take in genetic instructions and amino acids to churn out proteins.

<-- An entire ribosome with its changes in position color-coded — ranging from blue, indicating no movement, to red, indicating large movements. (Cate research group, UC Berkeley image)

Ribosomes, which number in the millions in a single human cell, have long been considered the "black boxes" in molecular biology. "We know what goes in and what comes out of ribosomes, but we're only beginning to learn about what is going on in between," said the study's principal investigator, Jamie Cate, UC Berkeley associate professor in chemistry and molecular and cell biology, and a faculty scientist at Lawrence Berkeley National Laboratory.

The achievement, described in the Aug. 21 issue of the journal Science, could eventually lead to significant advances in the fight against human disease, the researchers said.

They point out that many infectious diseases involve ribosomal warfare between humans and our bacterial or viral invaders. Important antibiotic drugs, like spectinomycin, capreomycin and aminoglycosides, exploit the structural differences between human and bacterial ribosomes to selectively attack the bacteria. Some viruses, like polio and hepatitis C, hijack human ribosomes, forcing them to pump out proteins that are beneficial for the viruses.

<-- The stages of a ribosome subunit as it moves. At the top right is its starting position; below it are pairs of images, showing three subsequent positions (still images at left, movement vectors at right). The arrows indicate the direction of movement. (Cate research group, UC Berkeley image)

"Inside the ribosome, antibiotics and viruses are using chemistry to either fight or promote disease," said Cate, who conducted the work with research specialist Wen Zhang and graduate student Jack Dunkle, both co-lead authors of the study, in his lab at UC Berkeley. "But what sort of chemistry? The short answer is that we have a lot still to learn. Once we find out, that knowledge could lead to more effective antibiotics, or new treatments against devastating diseases like hepatitis C."

In the protein manufacturing process, the genetic code - or instruction manual - for making proteins lies inside a cell's double-stranded DNA. When the cell needs to produce more proteins, the DNA unzips into two separate strands, exposing the protein code so it can be duplicated by single-stranded messenger RNA (mRNA). The mRNA dutifully delivers that code to the ribosome, which somehow reads the instructions, or "data tape," as each amino acid is added to a growing protein chain.

At the same time, other RNA molecules, called transfer RNA (tRNA), bring to the ribosome amino acids, the raw building blocks needed for protein construction.

To help elucidate the ribosome's movements as it interacts with mRNA and tRNA, the researchers used X-ray crystallography to obtain a highly detailed picture of the ribosome - a mere 21 nanometers wide - from an Escherichia coli bacterium. In addition to revealing atomic level detail, the technique allowed the researchers to capture the ribosome mid-action, a challenge because it acts fast, adding 20 new amino acids to a protein chain every second.

"Scientists used to think that the ribosome made a simple two-stage ratcheting motion by rotating back and forth as it interacts with mRNA and tRNA," said Cate, who is also a member of the California Institute for Quantitative Biomedical Research (QB3) at UC Berkeley. "What we captured were images of the ribosome in intermediate stages between the rotations, showing that there are at least four steps in this ratcheting mechanism."

"We suspect that the ribosome changes its conformation in so many steps to allow it to interact with relatively big tRNAs while keeping the two segments of the ribosome from flying apart," said Cate. "It's much more complicated than the simple ratcheting mechanism in a socket wrench."

Cate said that while this study marked a major accomplishment in cracking open the "black box" of ribosomal function, there are far more details yet to be revealed. Advances in imaging techniques over the next decade should allow researchers to go beyond the snapshots taken in this study to high-resolution movies of a ribosome's movements, he said.

"I'm looking forward to producing a movie of a ribosome with enough resolution and enough frames per millisecond that we can see what is happening at a molecular level," said Cate. "It would be great to watch and really understand how the ribosome makes a protein, how antibiotics interfere with a bacterial ribosome, or why a strand of genetic code in a hepatitis C virus is so effective at hijacking a human ribosome. We still have a long way to go, but we're working hard."

This research was supported by the National Institutes of Health and the U.S. Department of Energy. By Sarah Yang, Media Relations


A Press Release from the University of California - Berkeley , 20 August 2009

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Cross-breeding could create rice varieties that can survive flooding and fungi

[ScienceNology] - Japanese research teams have pinpointed the genes in hardy varieties of rice that help the plants to outgrow rising paddy-field waters and fend off fungal infections. Having these genes in more vulnerable rice varieties could save billions of dollars and feed millions more people.

The two papers are "very welcome at a time of increasingly difficult challenges to rice growing", says Michael Jackson, a plant physiologist at the University of Bristol, UK.

In the first study, published in Nature on 19 August, Motoyuki Ashikari, at Nagoya University in Japan, and his colleagues found two genes that help plants to keep their leaves above water when partially submerged. In the second study, published in Science on 20 August, a team led by Shuichi Fukuoka at the National Institute of Agrobiological Sciences in Tsukuba, Japan, has found a gene that helps some types of rice fight off fungal infection — and successfully isolated it from a linked stretch of DNA responsible for the terrible flavour of the wild varieties.

Snorkel genes

The Nature study focused on the threat posed by deep flooding, which affects more than 25% of global rice-producing land. Most rice plants (Oryza sativa) die if completely submerged for more than a few days. But some rice varieties can survive the conditions by rapidly shooting up in height. These plants are typically far less productive, however, so researchers have sought the genes responsible for flood tolerance in the hope of introducing them into high-yielding rice varieties.

In 2006, a team led by David Mackill at the International Rice Research Institute in the Philippines discovered similar flood-tolerance genes — a genetic cluster called Submergence 1 that allowed plants to survive for more than two weeks by entering a dormant state when completely submerged.

Ashikari's team examined three genomic regions that they had found helped rice to grow. In the region that added the greatest growth boost, they mapped a pair of genes — dubbed SNORKEL1 and SNORKEL2 — that together can trigger growth of up to 8 metres in the face of rising water levels

Julia Bailey-Serres, a molecular geneticist at the University of California, Riverside, says that the Submergence and Snorkel genes can now be crossed into common rice varieties to protect crops exposed to different flooding scenarios. When flooding is deep and quick, Submergence genes might be best; but when floodwaters climb in a progressive and prolonged fashion, Snorkel genes will be more effective. "It provides two strategies and they both have their importance," she says.

Intriguingly, the same plant hormone, ethylene, stimulates both the escape strategies. "What has happened with natural selection apparently is that that pathway is where things are tweaked evolutionarily," says Bailey-Serres. The mutation in the Snorkel pathway probably came first, though, adds Ashikari. Some wild rice species possess Snorkel genes, whereas only domesticated breeds contain the Submergence genes, he says.

Fighting fungus

Flooding is not the only threat to the world's largest diet staple. Rice blast disease destroys around 10-30% of global rice crops — enough food to feed about 60 million people each year. Some rice plants are resistant to the pernicious fungus responsible the disease, but the rice from these plants often has undesirable qualities, such as lower stickiness and poor flavour, so they have not been introduced into widely consumed rice varieties. Some researchers have speculated that blast-immunity genes might directly confer terrible taste, but Fukuoka and his colleagues have shown that resistance and bad taste can be teased apart.

The team cloned a gene called Pi21, and showed that plants with two rare deletions had around 10 times fewer blast lesions than wild-type rice, yet these same plants tasted awful. Fukuoka's group crossed the resistance gene into a tastier breed, and mapped the foul flavour to a point a few thousand nucleotides downstream of the Pi21 gene, indicating that Pi21 itself does not harm the rice's taste.

Both research teams are breeding more-durable rice varieties. No genetic engineering is required, says Ashikari, because all of these genes can be transferred by crossing. Once these new cultivars are made, however, they still need to be tested — both in the paddy and on the plate. "We need to see how these behave in field situations and how they can be used in a rice breeding programme," says Mackill.

By: Elie Dolgin

 

A News from Nature.com , 20 August 2009

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Scientists discover 18 new species of invertebrates

Scientists have discovered 18 new species of invertebrates, including spiders, snails, millipedes, earthworms and centipedes. The discoveries were made over eight days by researches for the environmental charity Earthwatch at the Mkhambathi nature reserve on the Wild Coast in the Eastern Cape.

But scientists have warned that the ecosystem there could be threatened by proposed developments for a toll road and titanium mining – denying them the chance to identify other species in the area.

Jan Venter, an ecologist working for Eastern Cape Parks, which manages the reserve, said the team suspects that another 18 species might be discovered.

"To get so many species in one survey shows the importance of the reserve. It's a very special area, conservation-wise. If we do another survey, we'll find just as many.".

Experts predict that the 2 million identified species on the planet could represent only 2 per cent of all those that exist. Many of these are likely to be in South Africa, one of the most biodiverse countries in the world.

Michelle Hamer, a scientist at the South African National Biodiversity Institute, said: "These discoveries are important because they highlight just how little we know about our biodiversity, even in a relatively well-studied country like South Africa … many of the species we collected seem to be unique to a small area in or around Mkhambathi."

"There is also a lot of pressure to develop tourism infrastructure inside the reserve. This means that many of these species could have disappeared before even being discovered. If we understand the importance of the area in terms of its invertebrate fauna, then we can try to protect it.

"Will it make a difference … if these species go extinct? We don't know for sure, but we do know that every species that is removed … results in some weakening of the ecosystem."

The freshly discovered species are now being named and described in South African research institutes.

By: Ben Leach


A news from Telegraph.co.uk , 19 August 2009

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Birds enjoy sunbathing as much as humans

The RSPB said it receives up to 100 calls during hot spells, from people concerned at seeing birds lying with their feathers and wings exposed to the sun.

But they have said it is nothing to be worried about, the animals are simply sunbathing.

Studies from the University of New Mexico suggest that birds sun themselves after heavy rain, which can cause them to suddenly lose their feathers, beacause it helps to soothe their skin.

It is thought the sun helps straightens the birds' feathers and helps the preen oil to spread through.

Gemma Rogers from the RSPB said: "People become concerned about these birds, because they seem to have a glazed expression in their eyes, because they are not focusing on anything, because they are entranced by the sun."

"They don't let themselves overheat at all. The feathers would protect them as well, so I don't think they need the factor 30."

The biggest concern, she said, is that predators will attack while the birds enjoy a peaceful moment in the sun.

"They are on the ground, they have their heads up, their legs wide open, but usually they fly away once a predator approaches. Their hearing is very acute as well, so even if they aren't focusing they will hear something coming."

While blackbirds are the most commonly spotted sunbathers, pigeons and sparrows enjoy the sun also.

Sparrows also appear to enjoy going to the beach as much as humans, according to Miss Rogers.

"Sparrows often find a hot sandy area as well to have a sand or dust bath. That looks really strange. They bed themselves down and get in there and cover their feathers."

But it is thought the dust soaks up excess preening oil and removes dry skin and mites.

While they may enjoy the heat however, the RSPB called on people to put water out to stop birds overheating and becoming dehydrated.

"We have had a lot of water for them this summer, but during hot spells they do need to cool down," Miss Rogers added.


A news from Telegraph.co.uk , 18 August 2009

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Russia should include European mink in red book - expert

The European mink, one of the most endangered mammals in the world, should be included in the Red Data Book of Russia, a spokesman at the International Union of Game Biologists Congress said on Tuesday.

The European mink population declined rapidly in the 20th century across many European countries, Igor Tumanov said.

"The European mink is mostly found in northern and northwestern Russia, some minks also live in the country's central region," he said, adding that the European mink's habitat has significantly decreased over the last 25 years, and resources necessary for the animal's survival have declined by 25-33%.

Tumanov pointed out that man-made environmental changes, including coastal pollution, are the main cause of the decline in numbers in both Russia and Europe. In addition the rapid rise of the American mink has compounded the problem, the expert said, adding that Russia needed to introduce a hunting ban on the mammal.

Governmental organizations and scientists accept that urgent measures are required to protect the European mink, which is already classified as vulnerable in the Red Data Book of the International Union for Conservation of Nature (IUCN).


A News from Rianovosti , 18 August 2009

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Plant that eats rats and insects discovered in Philippines

The plant is among the largest of all pitchers and is believed to be the largest meat-eating shrub, dissolving rats with acid-like enzymes.

The team of botanists, led by British experts Stewart McPherson and Alastair Robinson, found the plant on Mount Victoria in the Philippines.

They were inspired to search for the plant after word that it is existed came from two Christian missionaries who described seeing a large carnivorous pitcher in 2000 after they climbed the mountain.

Mr McPherson, of Poole Dorset, said: "The plant produces spectacular traps which catch not only insects, but also rodents. It is remarkable that it remained undiscovered until the 21st century."

The team, which found the plant in 2007 following a two-month expedition, published details of their discovery in the Botanical Journal of Linnean Society earlier this year following a three-year study of all 120 species of pitcher plant.

They decided to name the plant Nepenthes attenboroughii, after the wildlife broadcaster Sir David.

"My team and I named it in honour of Sir David whose work has inspired generations toward a better understanding of the beauty and diversity of the natural world," added Mr McPherson.

Sir David, 83, said: "I was contacted by the team shortly after the discovery and they asked if they could name it after me. I was delighted and told them, 'Thank you very much'.

"I'm absolutely flattered. This is a remarkable species the largest of its kind. I'm told it can catch rats then eat them with its digestive enzymes. It's certainly capable of that."


By: Chris Irvine



Via : Telegraph.co.uk , 17 August

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Biological clocks of insects could lead to more effective pest control

Researchers at Oregon State University have discovered that the circadian rhythms or biological “clocks” in some insects can make them far more susceptible to pesticides at some times of the day instead of others.

With further research, the scientists said, it may be possible to tap into this genetic characteristic, identify the times that a target insect is most vulnerable to a specific pesticide, and use that information to increase the effectiveness, reduce costs and decrease the amounts of pesticide necessary for insect control.

Approaches such as this may also be highly useful in programs of “integrated pest management,” the researchers said, which aim to minimize pesticide use, prevent development of resistance to pesticides, and use a broad range of physical or chemical control measures to enhance the long-term effectiveness of an insect control program in crop agriculture.

The findings were just published in PLoS ONE, a professional journal, in work supported by the U.S. Department of Agriculture, National Institutes of Health and National Science Foundation.

“We found that it took triple the dose of one pesticide to have the same lethal effect on fruit flies at the time of day their defenses were strongest, compared to when they were weakest,” said Louisa Hooven, a postdoctoral fellow in the OSU Department of Zoology and lead author on the study. “A different pesticide took twice the dose. This makes it pretty clear that the time of day of an exposure to a pesticide can make a huge difference in its effectiveness.”

In recent years, researchers have found that the genes which are sensitive to the natural rhythms of day and night can have a wide range of biological effects, on everything from fertility to feeding patterns, sleep, hormone production, stress, productivity, medication effectiveness and many other functions. And they operate in multiple cells in many or most plant and animal species, including humans.

In the newest work, circadian rhythms appear to coordinate “xenobiotic metabolizing” genes, or the genes responsible for breaking down and detoxifying various poisons, such as pesticides. Besides that, it’s possible that circadian clocks may also affect absorption, distribution, excretion, and molecular targets of toxicity.

“This rhythmic defense mechanism may have evolved in order to disarm the noxious compounds that plants produce to avoid being eaten by an insect,” said Jadwiga Giebultowicz, a professor of zoology at OSU. Other co-authors on this work included OSU undergraduate students Katherine Sherman and Shawn Butcher.

The OSU study found that insect defenses against two commonly used pesticides, propoxur and fipronil, were strongest during mid-day, and weakest around dawn, dusk or the middle of the night. The effectiveness of two other pesticides studied – deltamethrin and malathion – did not seem to be so strongly associated with time of day, at least with fruit flies.

“For this approach to be useful in agriculture or other places pesticides are used, we will need to test specific insects against specific pesticides, and we will probably find differences in time of maximum effectiveness for various pest-pesticide configurations,” Giebultowicz said. “In some cases we may be able to greatly improve the effectiveness of pesticides or allow the use of reduced doses.”

Although many pesticides have a residual effect, the researchers said, the timing of the first exposure can be critical. Many pesticides are repellent to insects, and if they are not killed immediately they may simply avoid the residue, or in some cases develop resistance to the pesticide – a critical and costly problem in modern agriculture. Pesticide resistance has been a driving force behind the evolution of the field of integrated pest management, as growers realized that sustainable pest control is not as simple as using the same pesticide, year after year, which often becomes increasingly ineffective and more expensive.

The new findings, the OSU researchers said, are also another example of how circadian rhythms are important in other detoxification systems in biology. In human medicine, a field called “chronopharmacology” is already developing, based on the observation that some medications are far more effective if administered at one time of the day instead of another.

Research into the molecular mechanisms underlying circadian rhythms was pioneered in fruit flies, but the OSU researchers hope their future research will shed light on how the biological clock influences responses to chemicals in humans.

“A fundamental understanding of the functional significance of circadian rhythms in chemical exposures may facilitate strategies to reduce adverse events in humans, promote control of pest species and reduce pesticide use,” the researchers wrote in their report.

“Our study strongly suggest that time of day should be included in insect control strategies and human risk assessment of chemical exposures, including pesticides,” they said. “In some cases, the clock, together with the dose, may make the poison.”



A News from Oregon State University , 12 August 2009

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Scientists find a common link of bird flocks, breast milk and trust

What do flocks of birds have in common with trust, monogamy, and even the release of breast milk? According to a new report in the journal Science, they are regulated by virtually identical neurochemicals in the brain, known as oxytocin in mammals and mesotocin in birds.

Neurobiologists at Indiana University showed that if the actions of mesotocin are blocked in the brains of zebra finches, a highly social songbird, the birds shift their social preferences. They spend significantly less time with familiar individuals and more time with unfamiliar individuals. The birds also become less social, preferring to spend less time with a large group of same-sex birds and more time with a smaller group. Conversely, if birds are administered mesotocin instead of the blocker, the finches become more social and prefer familiar partners.

Perhaps most striking is the fact that none of the treatments affect males -- only females.

According to James Goodson, lead author on the study, the sex differences in birds provide important clues to the evolutionary history of oxytocin functions in humans and other mammals. "Oxytocin is an evolutionarily descendant of mesotocin and has long been associated with female reproductive functions -- things such as pair bonding with males, giving birth, providing maternal care and ejecting milk for infants," said Goodson.

Goodson and colleagues have found hints of similar processes in fish, and he speculates that oxytocin-like neuropeptides have played special roles in female affiliation ever since the peptides first evolved. That was sometime around 450 million years ago, about the same time that jaws evolved.

"The ancient properties of this system appear to be retained in all major vertebrate groups, and date back to our common ancestor with sharks," says co-author Marcy Kingsbury, associate scientist at IU Bloomington.

But if all vertebrates possess similar neuropeptide circuits, why don't they all live in big groups -- flocks, schools or herds? A possible answer to that question is provided in the second part of the Science study. The authors speculated that the behavioral actions of mesotocin may differ across species depending upon the distribution of "receptors" for the chemical in the brain -- that is, places where mesotocin can attach to brain cells and alter their activity.

Using a radioactive compound that attaches to oxytocin-like receptors, the authors mapped the distribution of receptors in three finch species that form flocks and two species that are territorial and highly aggressive. What they found was that the flocking species had many more receptors in a part of the brain known as the lateral septum. And when they blocked those receptors in female zebra finches, the birds became less social.

According to Goodson, these findings suggest that it is actually the concentration and location of receptors that determines whether an individual prefers spending time in large groups. Natural selection could act to increase the number of receptors expressed by certain lateral septum neurons, or by altering the regions where receptor genes are expressed, depending on whether female sociality is favored or not among the individuals of a species.

If Goodson's discovery holds true for other birds and even mammals, the concentration of receptors for mesotocin (and oxytocin) in the lateral septum could accurately predict whether an individual is naturally gregarious.

"The lateral septum is structurally very similar in reptiles, birds and mammals," Goodson said. "To our knowledge, it plays an important role in the social and reproductive behaviors of all land vertebrates."

What might be next for Goodson's research group?

"We still don't understand why mesotocin and oxytocin are so potent in females, but not always in males," Goodson said. "And we also don't fully understand how the lateral septum functions to influence sociality." But he is convinced that his group's ongoing studies of songbirds will soon provide the answers.

IU Bloomington Associate Scientist Marcy Kingsbury, postdoctoral fellow David Kabelik, research associate Sara Schrock and Ph.D. student James Klatt also contributed to this research. It was funded with a grant from the National Institutes of Health (NIMH).



A News release from Indiana University , 13 August 2009

Photo of Zebra finches bird in congress by Graeme S. Chapman

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