2011年12月08日

あちらに誰かいますか? 宇宙人を探す新たな方法


Anyone Out There? A New Way to Look for Alien Life
( TIME )

Thanks largely to the Kepler space telescope, astronomers have
discovered more than 2,000 planets orbiting distant stars -- not half
bad considering that until recently we knew of only eight planets in
the entire universe, all of them in the immediate neighborhood. The
point of Kepler isn't simply to rack up numbers, though: the ultimate
goal is to find worlds similar to Earth -- places where there's a
chance that alien life might have taken hold. Those planets could then
get a closer look as a new, more powerful generation of telescopes
comes on line.

But the search for life across interstellar space will still not be
easy, and even the most advanced telescope on the drawing boards will
have to work hard to suss it out, so it will be key to choose the best
possible targets. That's the reasoning behind a new paper in the
journal Astrobiology in which environmental scientist Dirk Schulze-
Makuch, of Washington State University, along with nine other
colleagues, has proposed a new planet-classification scheme to make the
sifting process easier.

Actually, they've proposed two schemes, designed to let observers slice
their searches in two different ways. The first and crudest of their
methods is something they call the Earth Similarity Index, or ESI.
That's just what it sounds like: it's a measure of how closely an alien
world matches Earth in terms of size and temperature. The temperature
is important because biologists say liquid water is an essential
ingredient for life as we know it: nutrients can dissolve easily in
water in order to circulate to every part of an organism. Blood, after
all, is essentially just water with stuff dissolved in it.

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posted by K.Andoh | Comment(0) | 科学 | このブログの読者になる |

2011年12月05日

なぜ女性の心のほうが傷つきやすいのか?


Why Are Women More Vulnerable to Broken Hearts?
( TIME )

Women are a lot more likely to suffer a broken heart than men,
researchers say. The good news is that it probably won't kill you.

In the first national study of its kind, researchers at the University
of Arkansas looked at rates of "broken heart syndrome" -- when a
sudden shock or prolonged stress causes heart attack-like symptoms or
heart failure -- and found that it overwhelmingly affects women.

Broken heart syndrome can happen in response to shocking or suddenly
emotional events -- both positive ones like winning the lottery, or
negative ones like a car accident or the unexpected death of a loved
one. A flood of stress hormones and adrenaline causes part of the heart
to enlarge temporarily and triggers symptoms that can look like heart
attack: chest pain, shortness of breath, irregular heart rhythm. The
difference is that the factors that would normally cause heart attack,
such as a blocked artery, aren't present.

About 10% of sufferers will have a second episode at some point, but
most return to full heart function without permanent damage or need for
follow-up treatment. So, it looks like the way to mend a broken heart
is what Mom always said: just give it time.

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posted by K.Andoh | Comment(0) | 科学 | このブログの読者になる |

2011年11月21日

ペンギンもつらいよ トロント動物園が「同性愛」ペンギンを引き離す

Tough Love: Toronto Zoo to Separate ‘Gay’ Penguin Couple
( TIME )

It’s a romance suited for the pages of a children’s book. (Oh wait,
that sounds familiar.)

Buddy and Pedro are two male African penguins at the Toronto Zoo who
seem to have a connection -- a very special, loving connection -- that
has zookeepers wondering if their relationship is more than just a
bromance.

According to the Toronto Star, zookeepers have noticed that although
Buddy, 20, and Pedro, 10, swim and play with the other penguins in
their enclosure by day, they pair off and nest together at night as
well as exhibit other telltale mating behaviors, such as touching,
making braying sounds and defending their territory.

Does this mean that Buddy and Pedro are gay? Not exactly, as the term
doesn’t normally apply to animals. But according to research from the
University of California, Berkeley, birds -- and other animals, for
that matter -- are known to form same-sex relationships.

But unlike the Central Park penguins, these Toronto lovers won’t make
it past the courting phase. In accordance with the species’ survival
plan, the zoo staff will separate Buddy and Pedro so they can fulfill
their biological destiny: to create more African penguins.

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posted by K.Andoh | Comment(0) | 科学 | このブログの読者になる |

2011年11月10日

続・人口過剰の真の被害者が自然環境である訳


Why the Real Victim of Overpopulation Will Be the Environment
( TIME )

A billion people -- that's 1 in 7 -- go hungry around the world today,
but that's not because the planet is incapable of producing enough food
to feed them. After all, as much as half the food produced worldwide
ends up wasted, either rotting in the fields, the markets or in our
refrigerator. We could feed 7 billion, 8 billion, 9 billion and
probably more -- if we chose to do so.

That's one of the reasons I'm relatively sanguine about the population
issue. It's basically impossible to predict the future, and past
performance is no guarantee of future results. But humanity has been
pretty good so far at responding to the challenges this planet puts
before us, and I see little reason to expect that will change. More
people, after all, does mean more potential problem solvers, not just
more mouths to feed.

But there's an undeniable cost to all these people and all this growth:
the planet itself. Even as human beings have grown in numbers and
wealth, becoming healthier and more robust, other species have
suffered. A study last year in Science found that on average, 52
species of mammals, birds and amphibians move one category closer to
extinction every year. Almost one-fifth of existing vertebrates species
are threatened, including some 41% of amphibians. Another recent
Science study found that humans are destroying apex predators like
tigers, wolves or sharks, which then has a major knock-on effect down
the food chain.

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posted by K.Andoh | Comment(0) | 科学 | このブログの読者になる |

2011年11月07日

人口過剰の真の被害者が自然環境である訳


Why the Real Victim of Overpopulation Will Be the Environment
( TIME )

Maybe it's just the fact that the official day has been set for Oct. 31
-- Halloween -- but there's a distinct whiff of panic and fear around
the expected birth of the 7 billionth person on the planet. Here's
Roger Martin, chair of the NGO Population Matters, writing in the
Guardian recently:

The 7 Billion Day is a sobering reminder of our planet's predicament.
We are increasing by 10,000 an hour. The median UN forecast is 9.3
billion by 2050, but the range varies by 2.5 billion -- the total world
population in 1950 -- depending on how we work it out.

Things, of course, are a little darker in 2011, so suddenly more people
just seem like more mouths to feed, more competitors at the
marketplace, more straws in the milk shake. You can see it in the way
that immigration has once again become a hot-button political issue in
the U.S., or the rise of population-induced apocalyptic fears. Are we
going to breed ourselves out of existence? Is there room on the planet
to support 7 billion-plus people?

Take a deep breath. The answer is yes -- and not just because you could
fit 7 billion people in the state of Texas and it would only have the
population density of New York City, which I can tell you from personal
experience isn't that bad. We're a long way from Soylent Green
territory here. As Joel Cohen of Rockefeller University pointed out in
the New York Times recently, we have more than enough food, water and
other essentials to keep every one of the 7 billion -- and far more --
perfectly healthy.

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posted by K.Andoh | Comment(0) | 科学 | このブログの読者になる |

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