Selasa, 27 Januari 2009

Emperor penguins face extinction


Gentoo penguins (file photo)
Less ice could spell bad news for a great many species

Emperor penguins, whose long treks across Antarctic ice to mate have been immortalised by Hollywood, are heading towards extinction, scientists say.

Based on predictions of sea ice extent from climate change models, the penguins are likely to see their numbers plummet by 95% by 2100.

That corresponds to a decline to just 600 breeding pairs in the world.

The research is published in the journal Proceedings of the National Academy of Sciences.

Emperor penguins, the largest species, are unique in that they are the only penguins that breed during the harsh Antarctic winters.

Colonies gather far inland after long treks across sea ice, where the females lay just one egg that is tended by the male. That means that the ice plays a major role in their overall breeding success.

What is more, the extent of sea ice cover influences the abundance of krill and the fish species that eat them - both food sources for the penguins.

Hal Caswell of the Woods Hole Oceanographic Institute and his colleagues used projections of sea ice coverage from the Intergovernmental Panel on Climate Change's (IPCC) last report.

In addition, they used a "population dynamics" model describing the mating patterns and breeding success of emperor penguins.

The model has been honed using 43 years' worth of observations of an emperor colony in Antarctica's Terre Adelie.

Slow learners

While there are a number of models and scenarios in the IPCC report, the team used only 10 of them - those that fit with existing satellite data on sea ice.

They then ran 1,000 simulations of penguin population growth or decline under each of those 10 climate scenarios.

The results suggest that by the year 2100, emperor penguins in the region are likely to experience a reduction in their numbers by 95% or more.

The likelihood of this occurring, according to the researchers, is at least a one-in-three chance and possibly more than eight out of 10.

Though the penguins could avert disaster by shifting their breeding patterns with the climate, the study's lead author Stephanie Jenouvrier said that was unlikely.

"Unlike some other Antarctic bird species that have altered their life cycles, penguins don't catch on so quickly," she said.

"They are long-lived organisms, so they adapt slowly. This is a problem because the climate is changing very fast."

'Conservative approach'

Several prior studies have shown that climate change can affect the reproduction and geographic distribution of species, but this is the first that makes predictions about the ultimate fate of a species as a whole.

"I don't see any reason not to take these predictions very seriously," said Dan Reuman, a population biologist at Imperial College London.

Larsen ice sheet (Nasa)
Particularly warm seasons cause Antarctic ice to break up early

"The study is based on a wide range of climate forecasts, it takes a conservative approach, it's based on a large amount of data on penguin demography, and the model accurately forecasts the data that already exist."

Dr Reuman suggests that more of this kind of work should be done to understand the species-by-species effects of climate change, and thereby the influence on whole communities.

It is an idea echoed by Joel Cohen, head of the Laboratory of Populations at Rockefeller University.

"The emperor penguin is an important species in its own right, but the whole communities in which it's embedded are also of importance," he told BBC News.

The penguins also serve as a species that particularly draws attention to the crisis in their region, he added.

"They are to Antarctica what the polar bear is to the Arctic.

"This study takes our knowledge, puts it together, gives us some insights, arouses concern and suggests that we ought to be understanding this situation a lot better."


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Microsoft has stepped up the battle to win back users with the latest release of its Internet Explorer browser


Web Slice in IE8
Web Slices keep track of changing content

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The US software giant says IE 8 is faster, easier to use and more secure than its competitors.

"We have made IE 8 the best browser for the way people really do use the web," said Microsoft's Amy Barzdukas.

"Microsoft needs to say these things because it continues to lose market share to Firefox, Chrome and Safari," said Gartner analyst Neil MacDonald.

Recent figures have shown that Microsoft's dominance in this space has been chipped away by competitors.

At the end of last year, data from Net Applications showed the software giant's market share dropped below 70% for the first time in eight years to 68%.

Meanwhile Mozilla broke the 20% barrier for the first time in its history with 21% of users using its browser Firefox.

Focus

The beta version of IE 8 was released last March and today the company has put out its first release candidate for the public. This is the last stage for the browser before it is finalised, although very few changes are expected.

Ms Barzdukas told the BBC: "What we are seeing for many consumers in particular is that their computing experience is a browsing experience.

IE8 address bar
The 'smart address bar' makes finding previously visited sites easier

"The role of the browser has become more and more important. Our focus is on delivering the best experience possible and one that is faster, easier and more secure."

To that end IE 8 offers performance upgrades to speed up page loading, new navigation features and tab isolation so that if you hit a bad site only that tab closes and not the whole browser.

WebSlices will give users a way to keep updated about a particular item on a web page like stock prices, the weather or an eBay auction.

Accelerators let users access Web services like maps or translations in a small window without having to leave the page.

"We believe with IE 8 much of the performance discussion is off the table," said Ms Barzdukas.

Security

Microsoft is making much of its security enhancements, which Ms Barzdukas said makes IE 8 "hands down the most secure browser on the market."

These include "InPrivate Filtering" which means users can see and block when a third-party content provider might be tracking their activities on the Web in an effort to target advertisements.

IE8 screenshot
Intenet Explorer 8 is being touted as faster, easier and safer than ever

Web publishers and online advertisers have in the past expressed concern over this feature because it could "frustrate the business model".

"InPrivate Browsing" is also being touted as a major improvement which allows a user to start a browsing session during which the history of sites viewed will not be recorded.

Some bloggers have nicknamed the feature "porn mode" because it keeps online activity a secret and prevents those with access to a PC from seeing where other users of the same PC have been.

Online privacy advocates like the Centre for Democracy and Technology have called the features "a great step forward in terms of giving users more control".

Defectors

So will this be enough to persuade defectors to return to the IE fold?

"Microsoft does have the advantage of its browser being shipped with its operating system so people that want to shift have to do a lot of work to shift," said Mr MacDonald, a vice-president of analyst firm Gartner

Google logo
Google's new web browser is called Chrome

"It's an area the European Union is looking at and I will let the lawyers figure that out but I don't think this will bring back the defectors. However it shows that competition in the browser space is good for innovation and good for the industry," said Mr MacDonald.

The EU last week accused Microsoft of harming competition by bundling its IE browser with its Windows operating system.

The Redmond-based company has said it is examining the preliminary finding and has not ruled out requesting a formal hearing.

Greg Sterling of Search Engine Land said if the product delivers, users will stick with it and others may well return.

"If this is a truly significant improvement, it will gain users' loyalty and lure others back.

"At the end of the day if it has the functionality and features people want, they will respond to it. For those who have an emotional stake in this, and who like the idea of the underdog like Firefox, it's unlikely to sway them," said Mr Sterling.

Microsoft's Ms Barzdukas refused to get drawn into the numbers game but said she is positive IE 8 will hold its own against competitors.

"We have long advocated providing choice to customers and respect peoples' ability to choose.

"You can accuse me of bias, but I believe with IE 8 we will deliver the browser people will want to choose," said Ms Barzdukas.


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Israeli jets target Gaza tunnels

Israeli jets target Gaza tunnels

Israeli airstrikes have targeted the Gaza Strip's border with Egypt, as part of Israel's response to an attack on one of its frontier patrols on Tuesday.

Residents near the town of Rafah fled as missiles hit tunnels through which Israel says militants smuggle arms.

The strikes came ahead of US envoy George Mitchell's visit to promote a permanent Israel-Hamas ceasefire.

Both sides declared ceasefires on 17 and 18 January to end Israel's three-week offensive on Gaza.


The land, air and sea assault killed about 1,300 Palestinians, including 400 children. Thirteen Israelis died.

It is not clear whether there were any casualties from the airstrikes, but the latest violence is a sign of just how fragile the truce is, says the BBC's Bethany Bell in Jerusalem.

Push for peace
Israel had responded to Tuesday's roadside bomb - which killed one soldier and wounded three - by immediately sending troops and tanks into Gaza backed by helicopters.Footage of the jeep attack which killed an Israeli soldier

Ensuing fighting around the town of Khan Younis and the Kissufim border crossing left one Palestinian dead, medical sources said.

Prime Minister Ehud Olmert threatened further strikes, saying the incursion was merely an initial reaction and that Israel's full response was still to come, Haaretz newspaper reported on its website.

Both Mr Mitchell and EU foreign policy chief Javier Solana are in the region to push for peace talks.


Mixed with the rubble and shrapnel on the floor is a shell collection, a pink hairbrush, belts, handbags, a fragment of cardboard printed with a Barbie and lots of school books, caked with dried blood
Jeremy Bowen

Bowen diary: Family tragedy
Counting casualties of Gaza's war
Aid worker diary: Part 22
Mr Mitchell, newly appointed by US President Barack Obama, is to hold talks with Mr Olmert and Palestinian President Mahmoud Abbas, although correspondents say he is not expected to meet Hamas officials.

He has already held talks in Cairo about Egypt's mediation efforts.

Israeli and Palestinian faction representatives have visited Cairo for talks with Egyptian officials since the ceasefires came into effect.

Hamas wants an end of Israel's punishing blockade of Gaza. Israel wants a long-term ceasefire and curbs on Hamas rearming.

During Mr Mitchell's visit, Israelis will want to hear what ideas the US has for advancing the peace process, as well as how Washington will tackle the Iranian nuclear issue, our correspondent says. But with Israeli elections due to take place in two weeks, it is likely the US envoy will spend much of his time listening, as Mr Obama has asked him to do, our correspondent adds.

Mr Mitchell's visit is being seen by many Israelis as a sign of US engagement, and by others as a sign of pressure.

Tunnels working

The Gaza Strip's southern frontier is peppered with tunnels into Egypt that were pummelled by air-strikes during Israel's offensive.

One of Israel's stated goals was to halt the smuggling of weapons - including rockets that were being fired against Israeli towns - into the coastal enclave through the network of tunnels.

But smuggling resumed shortly after the non-negotiated cease-fires were declared.

Residents along the border say food, fuel and other goods are moving through the several dozen tunnels that are still operational.

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