Diberdayakan oleh Blogger.

Popular Posts Today

How an ancient whale graveyard ended up in a Chilean desert

Written By Unknown on Jumat, 28 Februari 2014 | 22.11

Scientists think they have figured out how a trove of ancient marine mammal fossils ended up in a Chilean desert 40 metres above sea level.

The fossils were found at Cerro Ballena — Spanish for "whale hill" — in Chile's Atacama desert in 2010 by crews who were expanding the Pan-American Highway from two to four lanes.

"It's the richest site for fossil marine mammals in the world," said Nick Pyenson, a paleobiologist with the Smithsonian Institution in an interview with CBC's As It Happens.

The fossils include almost complete skeletons, many of them overlapping, for 40 large whales, along with dolphins, seals, large fish related to swordfish or marlins, and extinct species such as aquatic sloths and dolphins with walrus-like faces that lived six million to nine million years ago.

At first glance, the grouping looks like some of the mass strandings today in which dozens of whales or dolphins wash up on beaches around the world. Most of them die within a few days.

Nick Pyenson

Nick Pyenson is the curator of fossil marine mammals at the Smithsonian's National Museum of Natural History in Washington, D.C. (Courtesy Nicholas Pyenson)

But Pyenson and his team came up with a slightly different explanation for the pile of fossils after carefully analyzing the condition, orientation and position of the bones using 3D imaging techniques. They concluded that the animals died suddenly at sea and then washed up on the same shore.

"The best explanation we have is toxins from harmful algal blooms likely caused the sudden death of all the marine organisms that we see at this site," he said. "And they were buried on a tidal flat that then became Cerro Ballena."

Similar events today can also cause the sudden mass deaths of marine mammals, he added.

"What's really interesting is that this didn't just happen once [at Cerro Ballena]. It happened four times," Pyenson said, adding that the fossil site has at least four layers.

Over time, overlapping tectonic plates pushed the former shoreline high up above sea level, where it is now a desert less than a kilometre from the modern-day coastline.

fossil whales

Most of the whales were found belly-up, suggesting they were already dead when they arrived on shore. (James F. Parham/California State University, Fullerton)

The researchers published their analysis and conclusions in the journal Proceedings of the Royal Society B this week.

Pyenson said a key clue was that most of the whales were buried belly up.

"Now, a whale doesn't strand belly up unless it arrives dead to the shoreline…. What we see at Cerro Ballena is actually a graveyard, not a murder site."

The fact that similar events happened repeatedly also pointed to toxic algae as the cause.

The fossils impeding the road construction were dug up by paleontologists and now reside in museums, allowing the highway expansion to go ahead. but the researchers think up to several hundred skeletons may remain undiscovered on either side of the highway.

"You can go there today and look on either side of road cut, and there are still whale skulls going into the cliff face," Pyenson said.

The researchers hope their new results will inspire enough interest that their Chilean colleagues can establish a field station at the site and preserve and study the remaining fossils.


22.11 | 0 komentar | Read More

Troubled Bitcoin exchange files for bankruptcy

The Mt. Gox bitcoin exchange in Tokyo filed for bankruptcy protection Friday and its chief executive said 850,000 bitcoins, worth several hundred million dollars, are unaccounted for.

The exchange's CEO Mark Karpeles appeared before Japanese TV news cameras, bowing deeply.

He said a weakness in the exchange's systems was behind a massive loss of the virtual currency involving 750,000 bitcoins from users and 100,000 of the company's own bitcoins. That would amount to about $473 million Cdn at recent prices.

Japan Bitcoin

Mt. Gox CEO Mark Karpeles bows in apology at a press conference at the Justice Ministry in Tokyo on Feb. 28, 2014. (Kyodo News/Associated Press)

The online exchange's unplugging earlier this week and accusations it had suffered a catastrophic theft have drawn renewed regulatory attention to a currency created in 2009 as a way to make transactions across borders without third parties such as banks.

It remains unclear if the missing bitcoins were stolen, voided by technological flaws or both.

"I am sorry for the troubles I have caused all the people," Karpeles, a Frenchman, said in Japanese at a Tokyo court.

Karpeles had not made a public appearance since rumours of the exchange's insolvency surfaced last month. He said in a web post Wednesday that he was working to resolve Mt. Gox's problems.

Collapse inevitable, finance minister says

The loss is a giant setback to the currency's image because its boosters have promoted bitcoin's cryptography as protecting it from counterfeiting and theft.

Bitcoin proponents have insisted that Mt. Gox is an isolated case, caused by the company's technological failures, and the potential of virtual currencies remains great.

Debts at Mt. Gox totaled more than 6.5 billion yen (about $70.9 million Cdn), surpassing its assets, according to Teikoku Databank, which monitors bankruptcies.

Just hours before the bankruptcy filing, Japanese Finance Minister Taro Aso had scoffed that a collapse was only inevitable.

"No one recognizes them as a real currency," he told reporters. "I expected such a thing to collapse."

Japan's financial regulators have been reluctant to intervene in the Mt. Gox situation, saying they don't have jurisdiction over something that's not a real currency.

They pointed to the Consumer Affairs Agency, which deals with product safety, as one possible place where disgruntled users may go for help.

The agency's minister Masako Mori urged extreme caution about using or investing in bitcoins. The agency has been deluged with calls about bitcoins since earlier this year.

"We're at a loss for how to help them," said Yuko Otsuki, who works in the agency's counselling department.

Bitcoin unwelcome in some countries

It's hard to know how many people around the world own bitcoins, but the currency has attracted outsize media attention and the fascination of millions as an increasing number of large retailers such as Overstock.com begin to accept it.

Speculative investors have jumped into the bitcoin fray, too, sending the currency's value fluctuating wildly in recent months. In December, the value of a single bitcoin hit an all-time high of $1,200. One bitcoin has cost about $500 lately.

'One must separate the Mt. Gox problem from the overall concept.'- Yang Weizhou, analyst at Mizuho Securities Co. in Tokyo

Roger Ver, a Tokyo resident who has provided seed capital for bitcoin ventures such as Blockchain.info, a registry of bitcoin transactions, said he believes bitcoin will survive, possibly emerging with better technology that's safer for users.

He said Mt. Gox people were likely sincere but had failed to run their business properly.

"Mt. Gox is a horrible tragedy. A lot of people lost a lot of money there, myself included," he said ahead of the bankruptcy filing. "I hope we can use this as a learning experience."

Some countries have reacted sternly to bitcoin's emergence, but many people remain fans of its potential.

Vietnam's communist government said Thursday that trading in bitcoin and other electronic currencies is illegal, and warned its citizens not to use or invest in them.

Late last year, China banned its banks and payment systems from handling bitcoin, although people still use them online. Thailand earlier put a blanket prohibition on using bitcoins and Russia has effectively banned them.

There was still considerable appetite for bitcoin in China, where it has become attractive as an investment since tightly-regulated state banks offer very low interest rates on deposits.

Virtual currencies regulation needed

Even some with money tied up in Mt. Gox were undaunted.

Huang Zhaobin, a 21-year-old student in Chengdu, said he had lost 50,000 to 60,000 yuan (about $9,090 to $10,900 Cdn) from the Mt. Gox closure.

"Actually this money itself is the benefit from bitcoin investment," said Huang, who plowed 10,000 yuan (about 1,818 Cdn) into bitcoins about three months ago.

"If it is legal, I will continue to invest for sure as it is the trend in the world."

In Singapore, Tembusu Terminals, a joint venture specializing in crypto-currencies, announced Friday its first bitcoin ATM in the city-state and plans for many more. In Hong Kong, a group opened what it said was the world's first bitcoin retail store.

Yang Weizhou, analyst at Mizuho Securities Co. in Tokyo, said laws to regulate virtual currencies may have to be created by countries including Japan.

She said lawsuits from those who lost money were likely, and any court rulings would chart unexplored territory and help define the reach of virtual money.

The trend toward such technology for peer-to-peer payments wouldn't replace traditional money but was here to stay because of its convenience, she said.

"It is undeniable," she said. "One must separate the Mt. Gox problem from the overall concept."


22.11 | 0 komentar | Read More

'Rock snot' algae outbreaks blamed on climate change

New research reveals a nasty, mucus-like algae bloom that emerged in Eastern Canada in 2006 may not be an invasive species after all. Instead, it appears to be a native species that was once subdued by cooler temperatures, but is now proliferating due to global warming.

Michelle Lavery

UNB graduate student Michelle Lavery was the lead author on a report indicating didymo is a native algae species. It was previously believed to have been an invasive species from elsewhere. (CBC)

Didymo is a thick, slippery algae nicknamed "rock snot" for reasons obvious to anyone who has seen or touched it. The algae is a concern for fish populations such as Atlantic salmon, as it lines river bottoms, hiding food and making it more difficult for some species to forage.

"It's like a really bad seventies shag carpet," said University of New Brunswick graduate student Michelle Lavery, the lead author on a report done in collaboration with researchers at Queens University, Brock University, and l'Institut national de la recherche scientifique (INRS). The study was published in the Canadian Journal of Fisheries and Aquatic Sciences.

Didymo was not known in eastern Canada until it suddenly appeared in New Brunswick and Quebec rivers and lakes in 2006, leading many to think it had been introduced from somewhere else. It has also been observed east of the Rockies in Alberta and in British Columbia, where its appearance was thought to be linked to the use of felt-soled fishing boots. Such boots have been banned in some U.S. states over concerns that they might be transferring didymo.

The new research reveals the slimy, porous algae that has been reshaping eastern Canadian rivers is not the new kid on the block everyone thought it was.

Didymo

The researchers believe didymo blooms have become more common due to warmer temperatures as a result of climate change. (CBC)

"We found it in dated sediments from 1970," says Lavery. "And it's also been reported in historical reports from 1910 to 1896 even."

Researchers believe warming temperatures brought didymo back to prominence in recent years. Some of the evidence for this comes from layers of sediment from the bottom of a lake in the region that provided information about how the populations of different kinds of algae changed over time.

"We've seen a trend in the fossilized algae community from that lake that shows a very strong trend towards increased temperatures and the associated lake effects that come with increased temperatures," said Lavery.

People are still being advised to make efforts to keep didymo from spreading by washing waders and fishing gear when moving from river to river.

The study was funded by the Atlantic Salmon Conservation Foundation and the Natural Sciences and Engineering Research Council of Canada.

Didymo

People are worried about the impact of didymo on fish populations, as it forms thick mats at the bottom of rivers, making it harder for the fish to find their food. (Michel Chouinard/Queen's University)


22.11 | 0 komentar | Read More

Unnatural selection: Cities triggering genetic changes in wild things

Written By Unknown on Kamis, 27 Februari 2014 | 22.11

Plants and animals have a long history of acclimatizing to city living - think of raccoons and their expert pillaging of compost bins. But now biologists are beginning to see signs that something more fundamental is happening. They say wild things may be changing at a genetic level to survive cities and their polluting, habitat-fragmenting ways.

Fish in New York's chemically-laden Hudson River have evolved a genetic variation that gives them resistance to PCBs, for example. Birds nesting under highway overpasses in Nebraska have developed shorter, more agile wings, allowing them to quickly swerve from oncoming traffic.

And weeds occupying patches of earth surrounding sidewalk trees in France have evolved to produce fewer dispersing seeds, which travel on the breeze and fall uselessly onto concrete. Instead, they produce compact seeds that drop close to the plant where they can germinate.

On one hand, urban evolution is not new. Peppered moths in Britain changed colour from white to black in heavily polluted areas during the Industrial Revolution. White moths were picked off by predators while the black ones, camouflaged in a newly sooty environment, survived to breed more black moths.

What may be different this time is the number of city-dwelling creatures evolving to live in inhospitable habitats.

As cities grow in population and size, so too does their influence on the environment. One hundred years ago, two out of every 10 people were city-dwellers. Today, more than half of us live in cities that are spreading across more and more of the planet.

A small but growing number of scientists say urban evolution may be accelerating in tandem with that growth. And there could be tradeoffs that we are only beginning to glimpse.

It pays to downsize

University of Tulsa ecologist Charles Brown says he was surprised it took just 30 years for the cliff swallows in his study to evolve shorter wings that help them avoid traffic.

Since 1982, he and Mary Bomberger Brown, an ornithologist at the University of Nebraska–Lincoln, have been studying a group of birds that make their gourd-shaped mud nests under highway overpasses in southwestern Nebraska.

Cliff swallows

Cliff swallows are seen here nesting under a highway bridge in North Platte, Nebraska. They have evolved shorter wings, a life-saving attribute that allows them to take off quickly and be more agile in the face on oncoming traffic. (Charles Brown, University of Tulsa)

Over the years, they recorded a steady drop in the number of road-killed birds.  This came as a surprise, because the colonies were growing and traffic had not declined. But as they compared the wing length of road-killed birds with those caught in nearby mist nets, they were in for another surprise - those caught in mist nets had noticeably shorter wings.

The researchers, who published their results last year in the journal Current Biology, believe net-caught birds avoided road deaths thanks to shorter wings that let them dodge traffic. Unlike their road-killed cousins, they survived long enough to pass down genes for shorter wings.

But is such urban evolution a necessary and positive development, or an evil to combat?

"It often results in an organism becoming better adapted to its environment," says Brown. "I suppose it's good if we are hoping that the organism persists."

Isaac Wirgin has a different view. He is a specialist in environmental medicine at New York University Medical Center and a lead author of a 2011 study in the journal Science on pollution-resistant tomcod fish in the Hudson River.

'Usually evolution theory says if you adapt to something - like this resistance phenotype in tomcod - you're less good at reproduction or life expectancy, or you're more sensitive to other stressors.'- Isaac Wirgin, specialist in environmental medicine

"In my mind, it's not a good thing," he says. "Usually evolution theory says if you adapt to something - like this resistance phenotype in tomcod - you're less good at reproduction or life expectancy, or you're more sensitive to other stressors."

While he did not delve into the potential cost of the tomcods' resistance to polychlorinated biphenyls (PCBs), a 2003 study by Duke University researchers found Atlantic killifish resistance to polycyclic aromatic hydrocarbons (PAHs) exacted a toll.

Killifish in Virginia's Elizabeth River developed a resistance to the acute toxicity, heart deformities and cancers linked to PAH exposure after a former wood treatment plant contaminated the river. At the same time, the fish developed a notably decreased tolerance of low oxygen levels - a periodic and natural stressor in many waterways. 

In the case of the tomcod, there may also be wider ecosystem reverberations. From 1947 to 1976, two General Electric plants upstream of the mouth of the Hudson River released nearly 600,000 kilograms of PCBs into the water. Fish larvae exposed to PCBs often develop gross deformities such as missing jaws, which leads to starvation.  

But Wirgin and his colleagues discovered in tomcod a natural variant of a gene called AHR2 that acts as a shield against PCBs.

The AHR2 gene gives instructions for building a particular protein in the fish. In order to do damage, PCBs must first bind to this protein. The gene's variant gives slightly different protein-building instructions, making it hard for PCBs to latch on.

Today, nearly all tomcod in the Hudson River carry this variant. Other populations of tomcod - in Canada and New England for example - do not.

Yet the Hudson River tomcods' superhero powers of resistance could spell trouble for predators. They are a favourite snack for larger fish, which ingest PCBs with every bite.

There is no research on how this bioaccumulation affects tomcod-munching fish, but it suggests urban evolution has the potential to affect entire food webs.

Seeds of change

Meanwhile, Pierre-Olivier Cheptou, lead author of a 2008 weed study published in PNAS, highlights other implications.

He compared the common weed, Crepis sancta, occupying small patches of earth surrounding sidewalk trees in Montpellier, France, with those in the surrounding countryside.

Seeds in France

Université de Montpellier evolutionary ecologist Pierre-Olivier Cheptou and his grad student collect seeds from weeds growing in patches of earth surrounding sidewalk trees in Montpellier, France. Their research indicates the plants have evolved to produce seeds that fall close by where they have a good chance of landing on soil, adapting to the lack of unpaved green space in the region. (S. Popy)

​Cheptou and his colleagues found that over five to 12 generations, the urban weeds evolved to produce significantly more non-dispersing seeds than their country cousins.

Fewer dispersing seeds means reduced gene flow among already-isolated plants.

"What is selected in the short term, such as reduced dispersal in the city, may lead to extinction in the longer term because reducing dispersal means reducing new colonization," says the Université de Montpellier evolutionary ecologist.

So far, most studies of such adaptive changes have focused on species with short life spans - weeds, fish, birds, insects and worms. That's because the more generations that pass, the greater the opportunity for evolution.

Now scientists are turning their attention to longer-lived mammals.

Evolutionary ecologist Albrecht Schulte-Hostedde of Laurentian University is studying urban chipmunks to uncover potential adaptations in physiology, immune function and behaviour.

While it's too early for results, he says chances are good he will discover the evolutionary fingerprint of city living.

"On the one hand we can celebrate that some species are adapting and thriving," says Schulte-Hostedde. "On the other, we are left with reduced biodiversity in terms of the number of species that are capable of adaptation to urban environments."


22.11 | 0 komentar | Read More

715 new planets discovered by NASA

Planet Bonanza

NASA Wednesday confirmed a bonanza of 715 newly discovered planets circling stars other than our sun. NASA'ss Kepler planet-hunting telescope nearly doubled the number of planets scientists have discovered in the galaxy. (NASA/Associated Press)

The Earth's galaxy is looking far more crowded. NASA has confirmed a bonanza of 715 newly discovered planets outside the solar system.

Douglas Hudgins, NASA's exoplanet exploration program scientist, called Wednesday's announcement a major step toward the planet-hunting Kepler telescope's ultimate goal: "finding Earth 2.0."

It's also a big step in "the possibility of life elsewhere," said Lisa Kaltenegger, a Harvard and Max Planck Institute astronomer who wasn't part of the discovery team.

Scientists using the Kepler telescope pushed the number of planets discovered in the galaxy to about 1,700. Twenty years ago, astronomers had not found any planets circling stars other than the ones revolving around the sun.

"We almost doubled just today the number of planets known to humanity," NASA planetary scientist Jack Lissauer said in a teleconference.

Astronomers used a new confirmation technique to come up with the largest single announcement of a batch of exoplanets — what planets outside our solar system are called.

Wednesday's announcements also were about implications for life behind those big numbers.

All the new planets are in systems like ours where multiple planets circle a star. The 715 planets came from looking at just 305 stars. They were nearly all in size closer to Earth than gigantic Jupiter.

And four of those new exoplanets orbit their stars in "habitable zones" where it is not too hot or not too cold for liquid water which is crucial for life to exist.

The four new habitable zone planets are all at least twice as big as Earth so that makes them more likely to be gas planets instead of rocky ones like Earth — and less likely to harbour life.

So far Kepler has found nine exoplanets in the habitable zone, NASA said. Astronomers expect to find more when they look at all four years of data collected by the now-crippled Kepler; so far they have looked at two years.

Planets in the habitable zone are likely to be farther out from their stars because it is hot close in. And planets farther out take more time orbiting, so Kepler has to wait longer to see it again.

Another of Kepler's latest discoveries indicates that "small planets are extremely common in our galaxy," said MIT astronomer Sara Seagar, who wasn't part of the discovery team. "Nature wants to make small planets."

And, in general, smaller planets are more likely to be able to harbour life than big ones, Kaltenegger said.


22.11 | 0 komentar | Read More

Explore the polar bear tundra on Google Street View

You can now pay a virtual visit to wild polar bears on the tundra via Google Street View.

The stunning tundra landscape of Cape Churchill and Wapusk National Park in Northern Manitoba — polar bears and all — went online today in honour of International Polar Bear Day.

"I think the whole thing is going to be really exciting," said Krista Wright, executive director of the conservation group Polar Bears International, which partnered with Google on the project.

"You have the opportunity to see polar bears in natural habitat. There's imagery of sparring bears – this behaviour that we see with male bears where they stand up on their hind legs and kind of play fight. There's images of a mom nursing a cub."

Wright said the goal is to connect people to the polar bears and inspire them to gain a better understanding of how climate change is affecting the Arctic and what impact that is having on bears and other creatures that are dependent on sea ice.

Polar Bear

Google Street View captured images of wild polar bears in their natural environment at Cape Churchill in northern Manitoba during their annual gathering in October and November. (Google)

In the case of polar bears, they rely on the sea ice as a hunting ground for ringed seals, the staple of their diet. Hundreds of them gather at Cape Churchill on the Western Hudson Bay from mid-October to November waiting for the ice to freeze so they can end months of fasting and begin their hunting season.

The unique gathering takes place here because it is the first part of the bay to freeze over. But as the climate warms, the ice freezes later even at this latitude, and the bears have to go longer and longer without food.

The new footage was taken during this fall gathering of polar bears with Google's Street View Trekker – 15 cameras mounted atop a backpack – from aboard tundra buggies operated by the local tour company Frontiers North. The vehicles are specially designed to take tourists and scientists out on the tundra to observe polar bears.

Aaron Brindle, a spokesperson for Google, who co-led the project, said it's "very much a true reflection" of what it's like to explore the tundra during bear season.

"Just to be clear, you're not going to be seeing the polar bear through telescopic lens of a professional photographer," he said.

Google Trekker

The images were captured using the Google Trekker, which consists of 15 cameras mounted atop a backpack. (Google)

Polar bears will be visible, he added, but "sometimes they'll be hard to spot, sometimes they'll be closer up."

Wright offers a tip to those hoping to see polar bears: "The bears are really close to the sea ice, often."

Wright said other highlights of the Street View imagery include a chance to explore remote Wapusk National Park and to see how people live in a northern town like Churchill.

The town has unique features such as a "polar bear jail" for temporarily holding bears that have wandered into town to protect the public. And it has a single complex housing the town's hospital, school, library, hockey rink and movie theatre so no one has to brave the cold or risk a polar bear encounter to get from one to the other, Wright said.

The imagery isn't just a public outreach tool – it also has scientific value, Wright said. She added that the sea ice and surrounding ecosystem are changing "drastically" due to climate change.

"So it provides an opportunity to document what it looks like now, the potential to document what it looks like next year, five years from now, 10 years from now."

Polar Bears International has been trained by Google to capture Street View images and did so independently after the first week of the polar bear season. Wright said the group hopes to bring Street View back next year.

In the meantime, she hopes the images will inspire people to participate in International Polar Bear Day activities, such as the group's thermostat challenge. Polar Bears International is encouraging people to adjust their thermostat a few degrees to reduce their energy use and show their commitment to greenhouse gas reductions.


22.11 | 0 komentar | Read More

Concerned about kids' screen time? The antidote is nature

Written By Unknown on Rabu, 26 Februari 2014 | 22.11

While experts worry about the ills of the internet age and the health problems linked to kids' hours of screen time, Richard Louv says there is an antidote - and it's free.

Louv is the author of Last Child in the Woods and The Nature Principle, and he coined the term "nature deficit disorder." He says spending time in nature has a wide range of benefits for physical and mental health.

Richard Louv

Richard Louv is the author of Last Child in the Woods and The Nature Principle, and he coined the term "nature deficit disorder." He says spending time in nature has a wide range of benefits for physical and mental health. (Courtesy Richard Louv)

"The symptoms of attention deficit disorder go down in kids as young as five. In schools, first there's evidence it's connected to cognitive development, the ability to learn, and executive development which is the ability to control ourselves," Louv says.

At the same time, there's growing evidence that lack of time in nature is linked to rising rates of depression, attention deficit disorder and other health conditions, Louv says.

"An emerging body of scientific evidence suggests not spending much time outdoors connected to the natural world can be connected to rising rates of depression, attention deficit disorder, Vitamin D deficiency (an epidemic in the world), and child obesity."

How do you help kids manage or curb their screen time? Kids, what do you think it would it be like to put down your screens for a week? Send your tips and suggestions to community@cbc.ca or tweet us with the hashtag #CBCRewired.

There are a couple of theories about why exposure to nature is so beneficial.

The "biophilia" theory says humans are hard-wired genetically for an affiliation with the natural world and suffer when they're deprived of it.

A second school of thought is called Attention Restoration Theory (ART), which has been the basis of recent studies by Canadian researcher Marc Berman. It suggests the brain relaxes in nature, entering a state of contemplative attention that is restorative or refreshing. In contrast, in busy urban settings the brain's working memory is bombarded with distractions and attention systems are on alert.

Berman's research found a walk in nature could improve memory and mood in people diagnosed with depression.

Louv says there's enough evidence of the physical and mental health benefits of time in nature that schools should be mandated to include it in the standard curriculum.

He suggests families also make time for outings in wild places. He suggests creating or joining one of the growing number of family nature clubs that are popping up around the world (see a directory of them here).

Audio: Hear Richard Louv talking about the effects of a good dose of nature:

Louv says families are so busy, spending time in nature has to be a conscious choice. But it's one he passionately advocates.

Audio: Hear Richard Louv tell his personal story of how he became convinced of the benefits of nature:

You can watch a video about Louv's work here, and hear him describe the sense of wonder that nature inspires in many people.


22.11 | 0 komentar | Read More

Unnatural selection: Cities triggering genetic changes in wild things

Plants and animals have a long history of acclimatizing to city living - think of raccoons and their expert pillaging of compost bins. But now biologists are beginning to see signs that something more fundamental is happening. They say wild things may be changing at a genetic level to survive cities and their polluting, habitat-fragmenting ways.

Fish in New York's chemically-laden Hudson River have evolved a genetic variation that gives them resistance to PCBs, for example. Birds nesting under highway overpasses in Nebraska have developed shorter, more agile wings, allowing them to quickly swerve from oncoming traffic.

And weeds occupying patches of earth surrounding sidewalk trees in France have evolved to produce fewer dispersing seeds, which travel on the breeze and fall uselessly onto concrete. Instead, they produce compact seeds that drop close to the plant where they can germinate.

On one hand, urban evolution is not new. Peppered moths in Britain changed colour from white to black in heavily polluted areas during the Industrial Revolution. White moths were picked off by predators while the black ones, camouflaged in a newly sooty environment, survived to breed more black moths.

What may be different this time is the number of city-dwelling creatures evolving to live in inhospitable habitats.

As cities grow in population and size, so too does their influence on the environment. One hundred years ago, two out of every 10 people were city-dwellers. Today, more than half of us live in cities that are spreading across more and more of the planet.

A small but growing number of scientists say urban evolution may be accelerating in tandem with that growth. And there could be tradeoffs that we are only beginning to glimpse.

It pays to downsize

University of Tulsa ecologist Charles Brown says he was surprised it took just 30 years for the cliff swallows in his study to evolve shorter wings that help them avoid traffic.

Since 1982, he and Mary Bomberger Brown, an ornithologist at the University of Nebraska–Lincoln, have been studying a group of birds that make their gourd-shaped mud nests under highway overpasses in southwestern Nebraska.

Cliff swallows

Cliff swallows are seen here nesting under a highway bridge in North Platte, Nebraska. They have evolved shorter wings, a life-saving attribute that allows them to take off quickly and be more agile in the face on oncoming traffic. (Charles Brown, University of Tulsa)

Over the years, they recorded a steady drop in the number of road-killed birds.  This came as a surprise, because the colonies were growing and traffic had not declined. But as they compared the wing length of road-killed birds with those caught in nearby mist nets, they were in for another surprise - those caught in mist nets had noticeably shorter wings.

The researchers, who published their results last year in the journal Current Biology, believe net-caught birds avoided road deaths thanks to shorter wings that let them dodge traffic. Unlike their road-killed cousins, they survived long enough to pass down genes for shorter wings.

But is such urban evolution a necessary and positive development, or an evil to combat?

"It often results in an organism becoming better adapted to its environment," says Brown. "I suppose it's good if we are hoping that the organism persists."

Isaac Wirgin has a different view. He is a specialist in environmental medicine at New York University Medical Center and a lead author of a 2011 study in the journal Science on pollution-resistant tomcod fish in the Hudson River.

'Usually evolution theory says if you adapt to something - like this resistance phenotype in tomcod - you're less good at reproduction or life expectancy, or you're more sensitive to other stressors.'- Isaac Wirgin, specialist in environmental medicine

"In my mind, it's not a good thing," he says. "Usually evolution theory says if you adapt to something - like this resistance phenotype in tomcod - you're less good at reproduction or life expectancy, or you're more sensitive to other stressors."

While he did not delve into the potential cost of the tomcods' resistance to polychlorinated biphenyls (PCBs), a 2003 study by Duke University researchers found Atlantic killifish resistance to polycyclic aromatic hydrocarbons (PAHs) exacted a toll.

Killifish in Virginia's Elizabeth River developed a resistance to the acute toxicity, heart deformities and cancers linked to PAH exposure after a former wood treatment plant contaminated the river. At the same time, the fish developed a notably decreased tolerance of low oxygen levels - a periodic and natural stressor in many waterways. 

In the case of the tomcod, there may also be wider ecosystem reverberations. From 1947 to 1976, two General Electric plants upstream of the mouth of the Hudson River released nearly 600,000 kilograms of PCBs into the water. Fish larvae exposed to PCBs often develop gross deformities such as missing jaws, which leads to starvation.  

But Wirgin and his colleagues discovered in tomcod a natural variant of a gene called AHR2 that acts as a shield against PCBs.

The AHR2 gene gives instructions for building a particular protein in the fish. In order to do damage, PCBs must first bind to this protein. The gene's variant gives slightly different protein-building instructions, making it hard for PCBs to latch on.

Today, nearly all tomcod in the Hudson River carry this variant. Other populations of tomcod - in Canada and New England for example - do not.

Yet the Hudson River tomcods' superhero powers of resistance could spell trouble for predators. They are a favourite snack for larger fish, which ingest PCBs with every bite.

There is no research on how this bioaccumulation affects tomcod-munching fish, but it suggests urban evolution has the potential to affect entire food webs.

Seeds of change

Meanwhile, Pierre-Olivier Cheptou, lead author of a 2008 weed study published in PNAS, highlights other implications.

He compared the common weed, Crepis sancta, occupying small patches of earth surrounding sidewalk trees in Montpellier, France, with those in the surrounding countryside.

Seeds in France

Université de Montpellier evolutionary ecologist Pierre-Olivier Cheptou and his grad student collect seeds from weeds growing in patches of earth surrounding sidewalk trees in Montpellier, France. Their research indicates the plants have evolved to produce seeds that fall close by where they have a good chance of landing on soil, adapting to the lack of unpaved green space in the region. (S. Popy)

​Cheptou and his colleagues found that over five to 12 generations, the urban weeds evolved to produce significantly more non-dispersing seeds than their country cousins.

Fewer dispersing seeds means reduced gene flow among already-isolated plants.

"What is selected in the short term, such as reduced dispersal in the city, may lead to extinction in the longer term because reducing dispersal means reducing new colonization," says the Université de Montpellier evolutionary ecologist.

So far, most studies of such adaptive changes have focused on species with short life spans - weeds, fish, birds, insects and worms. That's because the more generations that pass, the greater the opportunity for evolution.

Now scientists are turning their attention to longer-lived mammals.

Evolutionary ecologist Albrecht Schulte-Hostedde of Laurentian University is studying urban chipmunks to uncover potential adaptations in physiology, immune function and behaviour.

While it's too early for results, he says chances are good he will discover the evolutionary fingerprint of city living.

"On the one hand we can celebrate that some species are adapting and thriving," says Schulte-Hostedde. "On the other, we are left with reduced biodiversity in terms of the number of species that are capable of adaptation to urban environments."


22.11 | 0 komentar | Read More

Extreme heat days multiply despite global warming 'hiatus'

The number of extremely hot days has been increasing steadily globally despite a "pause" in the rise of average surface temperatures over the past 15 years, a new study has found.

"This analysis shows that not only is there no pause in the evolution of the warmest daily extremes over land but that they have continued unabated over the observational record," said the paper published Wednesday in Nature Climate Change.

"Furthermore, the available evidence suggests that the most 'extreme' extremes show the greatest change."

The average global temperature is a common measure of climate change used by scientists and policymakers, including the Intergovernmental Panel on Climate Change.

'The term pause, as applied to the recent evolution of global annual mean temperatures, is ill-chosen and even misleading in the context of climate change.'- Sonia Seneviratne and her research team

The panel's most recent report, released in September, noted that between 1998 and 2012, the average global temperature over land changed very little, despite an increase in the greenhouse gas concentrations that are expected to drive global temperature increases. The panel called this a "temperature hiatus" and said the temporary pause in global surface warming may have been caused by natural variability or by oceans absorbing extra heat.

The "hiatus" was used by some lobbyists to argue that climate change is not an urgent problem.

However, based on their results, the Swiss, Australian and Canadian authors of the new paper argue that in fact, global average temperatures can hide trends in extreme temperatures.

heat-thermometer

The average global temperature is a common measure of climate change used by scientists and policymakers, including the Intergovernmental Panel on Climate Change. (iStock)

The new study, led by Sonia Seneviratne of the Institute of Atmospheric and Climate Science in Zurich, looked at existing temperature data and tracked the number of extremely hot days (days when the temperature was hotter than it was 90 per cent of the time for that day of the year) each year from 1997 and 2012 compared to the average for 1979 to 2010. The study, whose co-authors included Environment Canada scientist Brigitte Mueller, then mapped the amount of land area where the number of hot days exceeded a certain cutoff e.g. there were 10 or 30 or 50 more hot days than normal.

What they found was that the amount of land area affected by each threshold level of extreme heat increased steadily over time.

In their commentary, they argued that extreme heat events, rather than average temperatures, have a greater impact on human health, agriculture, ecosystems and infrastructure.

"We highlight that the term pause, as applied to the recent evolution of global annual mean temperatures," the researchers wrote, "is ill-chosen and even misleading in the context of climate change."

The paper noted that extremely warm temperatures can be amplified by phenomena such as melting ice and snow in the Arctic or drying soil in temperate regions – different factors than those that affect average global temperatures.

The researchers suggest that the average temperatures have likely held steady despite an increase in extreme summer heat due to a cooling of ocean surface temperatures and a cooling of winter temperatures in boreal regions.


22.11 | 0 komentar | Read More

CSEC used airport Wi-Fi to track Canadian travellers: Edward Snowden documents

Written By Unknown on Sabtu, 01 Februari 2014 | 22.11

A top secret document retrieved by U.S. whistleblower Edward Snowden and obtained by CBC News shows that Canada's electronic spy agency used information from the free internet service at a major Canadian airport to track the wireless devices of thousands of ordinary airline passengers for days after they left the terminal.

After reviewing the document, one of Canada's foremost authorities on cyber-security says the clandestine operation by the Communications Security Establishment Canada (CSEC) was almost certainly illegal.

Ronald Deibert told CBC News: "I can't see any circumstance in which this would not be unlawful, under current Canadian law, under our Charter, under CSEC's mandates."

The spy agency is supposed to be collecting primarily foreign intelligence by intercepting overseas phone and internet traffic, and is prohibited by law from targeting Canadians or anyone in Canada without a judicial warrant.

As CSEC chief John Forster recently stated: "I can tell you that we do not target Canadians at home or abroad in our foreign intelligence activities, nor do we target anyone in Canada.

"In fact, it's prohibited by law. Protecting the privacy of Canadians is our most important principle."

But security experts who have been apprised of the document point out the airline passengers in a Canadian airport were clearly in Canada.

CSEC said in a written statement to CBC News that it is "mandated to collect foreign signals intelligence to protect Canada and Canadians. And in order to fulfill that key foreign intelligence role for the country, CSEC is legally authorized to collect and analyze metadata."

Metadata reveals a trove of information including, for example, the location and telephone numbers of all calls a person makes and receives — but not the content of the call, which would legally be considered a private communication and cannot be intercepted without a warrant.

"No Canadian communications were (or are) targeted, collected or used," the agency says.

In the case of the airport tracking operation, the metadata apparently identified travelers' wireless devices, but not the content of calls made or emails sent from them.

Black Code

Deibert is author of the book Black Code: Inside the Battle for Cyberspace, which is about internet surveillance, and he heads the world-renowned Citizen Lab cyber research program at the University of Toronto's Munk School of Global Affairs.

He says that whatever CSEC calls it, the tracking of those passengers was nothing less than an "indiscriminate collection and analysis of Canadians' communications data," and he could not imagine any circumstances that would have convinced a judge to authorize it.

Cellphone-travel

A passenger checks his cellphone while boarding a flight in Boston in October. The U.S. Federal Aviation Administration issued new guidelines under which passengers will be able to use electronic devices from the time they board to the time they leave the plane, which will also help electronic spies to keep tabs on them. (Associated Press)

The latest Snowden document indicates the spy service was provided with information captured from unsuspecting travellers' wireless devices by the airport's free Wi-Fi system over a two-week period.

Experts say that probably included many Canadians whose smartphone and laptop signals were intercepted without their knowledge as they passed through the terminal.

The document shows the federal intelligence agency was then able to track the travellers for a week or more as they — and their wireless devices — showed up in other Wi-Fi "hot spots" in cities across Canada and even at U.S. airports.

That included people visiting other airports, hotels, coffee shops and restaurants, libraries, ground transportation hubs, and any number of places among the literally thousands with public wireless internet access.

The document shows CSEC had so much data it could even track the travellers back in time through the days leading up to their arrival at the airport, these experts say.

While the documents make no mention of specific individuals, Deibert and other cyber experts say it would be simple for the spy agency to have put names to all the Canadians swept up in the operation. 

All Canadians with a smartphone, tablet or laptop are "essentially carrying around digital dog tags as we go about our daily lives," Deibert says.

Anyone able to access the data that those devices leave behind on wireless hotspots, he says, can obtain "extraordinarily precise information about our movements and social relationships."

Trial run for NSA

The document indicates the passenger tracking operation was a trial run of a powerful new software program CSEC was developing with help from its U.S. counterpart, the National Security Agency.

In the document, CSEC called the new technologies "game-changing," and said they could be used for tracking "any target that makes occasional forays into other cities/regions."

Sources tell CBC News the technologies tested on Canadians in 2012 have since become fully operational.

CSEC claims "no Canadian or foreign travellers' movements were 'tracked,'" although it does not explain why it put the word "tracked" in quotation marks.

Deibert says metadata is "way more powerful than the content of communications. You can tell a lot more about people, their habits, their relationships, their friendships, even their political preferences, based on that type of metadata."

The document does not say exactly how the Canadian spy service managed to get its hands on two weeks' of travellers' wireless data from the airport Wi-Fi system, although there are indications it was provided voluntarily by a "special source."

The country's two largest airports — Toronto and Vancouver — both say they have never supplied CSEC or other Canadian intelligence agency with information on passengers' Wi-Fi use.

Alana Lawrence, a spokesperson for the Vancouver Airport Authority, says it operates the free Wi-Fi there, but does "not in any way store any personal data associated with it," and has never received a request from any Canadian intelligence agency for it.

A U.S.-based company, Boingo, is the largest independent supplier of Wi-Fi services at other Canadian airports, including Pearson International in Toronto.

Spokesperson Katie O'Neill tells CBC News: "To the best of our knowledge, [Boingo] has not provided any information about any of our users to the Canadian government, law enforcement or intelligence agencies."

It is also unclear from the document how CSEC managed to penetrate so many wireless systems to see who was using them — specifically, to know every time someone targeted at the airport showed up on one of those other Wi-Fi networks elsewhere.

Deibert and other experts say the federal intelligence agency must have gained direct access to at least some of the country's main telephone and internet pipelines, allowing the mass-surveillance of Canadian emails and phone calls.

'Blown away'

Ontario's privacy commissioner Ann Cavoukian says she is "blown away" by the revelations.

"It is really unbelievable that CSEC would engage in that kind of surveillance of Canadians. Of us.

"I mean that could have been me at the airport walking around… This resembles the activities of a totalitarian state, not a free and open society."

 Ann Cavoukian

Privacy commissioner Ann Cavoukian. (Colin Perkel/Canadian Press)

Experts say the document makes clear CSEC intended to share both the technologies and future information generated by it with Canada's official spying partners — the U.S., Britain, New Zealand and Australia, the so-called Five Eyes intelligence network.

Indeed, the spy agency boasts in its leaked document that, in an apparently separate pilot project, it obtained access to two communications systems with more than 300,000 users, and was then able to "sweep" an entire mid-sized Canadian city to pinpoint a specific imaginary target in a fictional kidnapping.

The document dated May 2012 is a 27-page power-point presentation by CSEC describing its airport tracking operation.

While the document was in the trove of secret NSA files retrieved by Snowden, it bears CSEC's logo and clearly originated with the Canadian spy service.

Wesley Wark, a renowned authority on international security and intelligence, agrees with Deibert.

"I cannot see any way in which it fits CSEC's legal mandate."

Wark says the document suggests CSEC was "trying to push the technological boundaries" in part to impress its other international counterparts in the Five-Eyes intelligence network.

"This document is kind of suffused with the language of technological gee-whiz."

Wark says if CSEC's use of "very powerful and intrusive technological tools" puts it outside its mandate and even the law, "then you are in a situation for democracy where you simply don't want to be."   

Like Wark and other experts interviewed for this story, Deibert says there's no question Canada needs CSEC to be gathering foreign intelligence, "but they must do it within a framework of proper checks and balances so their formidable powers can never be abused. And that's the missing ingredient right now in Canada."

The only official oversight of CSEC's spying operations is a retired judge appointed by the prime minister, and reporting to the minister of defence who is also responsible for the intelligence agency.

"Here we clearly have an agency of the state collecting in an indiscriminate and bulk fashion all of Canadian communications and the oversight mechanism is flimsy at best," Deibert says.

"Those to me are circumstances ripe for potential abuse."

CSEC spends over $400 million a year, and employs about 2,000 people, almost half of whom are involved in intercepting phone conversations, and hacking into computer systems supposedly in other countries.

It has long been Canada's most secretive spy agency, responding to almost all questions about its operations with reassurances it is doing nothing wrong.

Privacy watchdog Cavoukian says there has to be "greater openness and transparency because without that there can be no accountability.

"This trust-me model that the government is advancing and CSEC is advancing – 'Oh just trust us, we're doing the right thing, don't worry' — yes, worry! We have very good reason to worry."

In the U.S., Snowden exposed massive metadata collection by the National Security Agency, which is said to have scooped up private phone and internet records of more than 100 million Americans.

A U.S. judge recently called the NSA's metadata collection an Orwellian surveillance program that is likely unconstitutional.

The public furor over NSA snooping prompted a White House review of the American spy agency's operations, and President Barack Obama recently vowed to clamp down on the collection and use of metadata.

Cavoukian says Canadians deserve nothing less.

"Look at the U.S. — they've been talking about these matters involving national security for months now very publicly because the public deserves answers.

"And that's what I would tell our government, our minister of national defence and our prime minister: We demand some answers to this."


22.11 | 0 komentar | Read More

Keystone XL gets environmental OK from U.S. State Dept.

The U.S. State Department gave a vote of confidence to the Keystone XL pipeline on Friday, saying in a report that it has no major environmental objections to the construction of the megaproject.

The report says development of the massive pipeline to move oil from Alberta to refineries on the U.S. Gulf Coast won't significantly increase the rate of oil extraction and release an unacceptable level of greenhouse gases.

That had been a key hurdle standing in the way of the project's approval. Calgary-based TransCanada has been seeking approval for the 1,800-kilometre, $7-billion project for several years.

Canadian Natural Resources Minister Joe Oliver welcomed the report's findings and said he hoped for a speedy approval of the project.

hi-transcanada-keystone852-

A final decision may not come for several months, but this study is seen as a critical step in determining whether the project will go ahead.

"This is the fifth federal study on the environmental impact of the Keystone XL pipeline. Each previous one has stated that building Keystone XL would not adversely affect the environment," Oliver said.

He noted that the report says that not building the project would actually lead to the release of as much as 28 to 42 per cent more greenhouse gases, because of energy consumed moving the same volume of oil via other means, such as by rail, trucks or barges.

"The benefits to the U.S. and Canada are clear. We await a timely decision on this project," Oliver said.

Long project

Friday's report is a step closer toward final approval, but far from the final one.

The State Department has yet to rule on whether the project is in America's best interest for non-environmental reasons and there is no date set for that ruling. Beyond that, ultimately the approval for the project will rest with the White House, which has yet to OK the deal. Obama sent the plan back to the State Department for further study before the last presidential election in 2011.

"Approval or denial of any one crude oil transport project … is unlikely to significantly impact the rate of extraction in the oilsands or the continued demand for heavy crude oil at refineries in the United States," the report says.

The report calls for a 90-day comment period, where stakeholders and interested parties are asked to comment on the report's environmental assessment of the project.

The Canadian government and other backers of the project welcome the report's conclusions. Alberta Premier Alison Redford called the report "an important step toward approval of a pipeline that will build our economic partnership with our friends in the U.S. and help foster North American energy security and independence."

The American Petroleum Institute CEO Jack Gerard declared the report had put environmental concerns to rest.

"Five years, five federal reviews, dozens of public meetings, over a million comments and one conclusion ─ the Keystone XL pipeline is safe for the environment," said Gerard.

"This long-awaited project should now be swiftly approved. It's time to put thousands of Americans to work," he added. 

But the pipeline's many opponents are already vowing to redouble their efforts to see that it's ultimately halted.

Tim Gray of Canadian group Environmental Defence said the U.S. should be dealing with carbon pollution rather than building pipelines.

"The bottom line is that it will never be easy to build a pipeline anywhere in North America. The opposition to the pipeline is strong in Canada too," Gray said. 

Opposition mounting

There's already a lawsuit in Nebraska to prevent the governor from forcing landowners to allow the pipeline on their property. And there's a State Department internal investigation into conflict-of-interest allegations against contractors who worked on the report, but had also done past work for pipeline builder TransCanada Corp.

Project opponents made it abundantly clear that they wouldn't be deterred.

"In addition to the fact that [the report authors] ignored the science, interagency criticism, basic economics of the industry and TransCanada's own recent admission that the pipeline is the key to opening up the tarsands, the fact that a foreign oil company and foreign government were given critical intelligence ahead of everyone else tells you all you need to know about how useless this [report] is," an adviser to billionaire Keystone opponent Tom Steyer told The Canadian Press on Friday.

Shares of TransCanada rose slightly on the news, just over one per cent in the minutes after the release of the report.

TransCanada CEO Russ Girling welcomed the decision, saying the pipeline capacity the company can sell in advance is all spoken for. TransCanada emphasized the enhanced security of the pipeline compared to shipping oil by rail, which many of its customers are doing.

"From a safety perspective, this will be the safest pipeline built to date in the U.S. From that perspective, this pipeline is in the national interest of the U.S," Girling said in a teleconference.

"Keystone XL has been shown time and time again to be the safest way to transport North American oil, to get oil to refineries in the Midwest and the Gulf Coast. It will have a minimal impact on the environment and it will not exacerbate environmental emissions," he said.


22.11 | 0 komentar | Read More

Yahoo, federal law enforcement probing theft of email passwords

Usernames and passwords of some of Yahoo's email customers have been stolen and used to gather personal information about people those Yahoo mail users have recently corresponded with, the company said Thursday.

Yahoo didn't say how many accounts have been affected. Yahoo is the second-largest email service worldwide, after Google's Gmail, according to the research firm comScore. There are 273 million Yahoo mail accounts worldwide, including 81 million in the United States.

It's the latest in a string of security breaches that have allowed hackers to nab personal information using software that analysts say is ever more sophisticated. Up to 70 million customers of Target stores had their personal information and credit and debit card numbers compromised late last year, and Neiman Marcus was the victim of a similar breach in December.

"It's an old trend, but it's much more exaggerated now because the programs the bad guys use are much more sophisticated now," says Avivah Litan, a security analyst at the technology research firm Gartner. "We're clearly under attack."

Using names to appear legitimate

Yahoo Inc. said in a blog post on its breach that "The information sought in the attack seems to be names and email addresses from the affected accounts' most recent sent emails."

That could mean hackers were looking for additional email addresses to send spam or scam messages. By grabbing real names from those sent folders, hackers could try to make bogus messages appear more legitimate to recipients.

"It's much more likely that I'd click on something from you if we email all the time," says Richard Mogull, analyst and CEO of Securois, a security research and advisory firm.

The bigger danger: access to email accounts could lead to more serious breaches involving banking and shopping sites.

That's because many people reuse passwords across many sites, and also because many sites use email to reset passwords. Hackers could try logging in to such a site with the Yahoo email address, for instance, and ask that a password reminder be sent by email.

2nd mishap in 2 months

Litan said hackers appear to be "trying to collect as much information as they can on people. Putting all this stuff together makes it easier to steal somebody's identity."

Yahoo said the usernames and passwords weren't collected from its own systems, but from a third-party database.

Because so many people use the same passwords across multiple sites, it's possible hackers broke in to some service that lets people use email addresses as their usernames. The hackers could have grabbed passwords stored at that service, filtered out the accounts with Yahoo addresses and used that information to log in to Yahoo's mail systems, said Johannes Ullrich, dean of research at the SANS Institute, a group devoted to security research and education.

The breach is the second mishap for Yahoo's mail service in two months. In December, the service suffered a multi-day outage that prompted Yahoo CEO Marissa Mayer to issue an apology.

Yahoo said it is resetting passwords on affected accounts and has "implemented additional measures" to block further attacks. The company would not comment beyond the information in its blog post. It said it is working with federal law enforcement.


22.11 | 0 komentar | Read More
techieblogger.com Techie Blogger Techie Blogger