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Minggu, 18 Maret 2012

Global flower trade threatens rare palm


Demand for leaves from an endangered palm, found in Central and South America, is threatening the species' long term survival, a study warns.
Leaves from the xate palm are used by the international flower trade, and are mostly harvested from wild trees.
UK researchers said training locals to cultivate the trees, thus easing the pressure on the wild population, only had a limited success.
The findings have been published in the journal Plos One.
"One of the reasons why florists like this leaf so much is because once you have cut it, it stays green for 30-40 days," explained co-author Sophie Williams, a researcher from Bangor University, Wales.
"There can be about two weeks from the forest to the florist, yet they can still store it for another two or three weeks."
Previous studies had said that the plant, which generally has five leaves, would be damaged if more than two leaves were removed at any one time.
The peak in demand, which is estimated to be worth $4m each year, for the leaves coincides with Mothers' Day and Palm Sunday.
Once harvested, the leaves are transported to Cancun, Mexico, before being exported to destinations including Miami and Amsterdam.
Barriers to growth
Overharvesting is a common threat facing many threatened plant species, and cultivation training is seen as one way to ease the pressure on wild populations.

 

In 2006, the UK Darwin Initiative Project and the Belize Botanic Garden set up a training programme, with the aim of giving locals the knowledge to grow and harvest the species rather than harvesting wild palms.

Xate palm (Image: Sophie Williams)

In detail: Xate palm

  • Xate is pronounced "Shatay"
  • Scientific name: Chamaedorea ernesti-agusti
  • Can reach two metres in height
  • The plants generally grow up to five leaves
  • It is a shade species; direct sunlight bleaches the leaves
  • Harvesting more than two leaves from an individual plant damages its reproductive capabilities

Ms Williams and the team, which included a researcher from the Royal Botanic Gardens, Kew, used the study to assess whether the training programme had a beneficial effect.
"People will often state that we need environmental education or training, and people often see it as a panacea to protect species," she told BBC News.
"I agree that we need these things, but we also need to think about the context in which we are doing them.
"The training programme was great... but we need to look at other factors that could prevent the training from having an impact.
"Just increasing knowledge and awareness doesn't always lead to positive action all the time, and that is often because… there are barriers."
These barriers included long-term land tenure. This could act as a deterrent because it takes four years for the palm (Chamaedorea ernesti-agusti; another common name is fishtail palm) to grow before its leaves can be harvested.
If a farmer could not secure tenure of some land for long enough, then it would not be cost-effective to invest in cultivating the crop.
Access to seeds is another potential problem that could dilute the impact of a training programme.
Ms Williams said if there was not a supply of seeds for farmers, then it could encourage seeds to be taken from the wild population.
This practice, studies suggest, can be more damaging to the palms than harvesting leaves.
Ms Williams, a PhD student, said the next stage of her research is to assess whether increased cultivation is an effective conservation tool and eases the pressure on wild plants, or merely increases the supply of the economically important crop.

sumber : bbc

Dampak Keyboard QWERTY pada Makna Kata

Pakar psikologi sosial di New School for Social Research mengatakan bahwa kesulitan dalam menggunakan obyek tertentu berpengaruh pada cara orang menilai obyek tersebut.
Salah satu contoh adalah nama orang. Dikatakan bahwa semakin sulit seseorang melafalkan nama orang lain, seseorang tersebut akan semakin sulit menilai orang itu secara positif.
Kini, ada contoh kasus baru yang dikaji peneliti. Dikatakan bahwa semakin sulit seseorang mengetik suatu kata di keyboard, maka semakin negatif pula makna kata itu.



Kyle Jasmine dan Daniel Casasanto dari University of College London meneliti tentang QWERTY effect, dampak pada makna kata yang dihasilkan ketika orang mengetik dengan keyboard QWERTY.
Jasmine mengungkapkan, kata-kata yang dengan huruf lebih banyak di sebelah kanan keyboard QWERTY (sebelah kanan T, G, dan B) memiliki makna lebih positif.
Contohnya, kata "POOL" yang berarti kolam memiliki makna lebih positif daripada kata "DESERT" yang berarti gurun. Contoh lain adalah kata "IKAN" dan "DERAS".

Menurut Jasmine, hal itu terkait dengan kemudahan mengetik. Lebih mudah bagi manusia untuk mengetik huruf di sebelah kanan keyboard QWERTY daripada yang ada di sebelah kiri.
"Jika mudah, maka cenderung memiliki makna positif. Jika sulit, maka akan sebaliknya," ungkap Jasmine seperti dikutip Wired pada Rabu (7/3/2012).
Faktor yang semakin mendukung hasil penelitian tersebut adalah huruf yang terkesan padat di sebelah kiri sehingga semakin menyulitkan pengetikan. Orang juga cenderung mengetik huruf di sebelah kanan lebih cepat.

Dalam eksperimen, Jasmine menganalisis 1.000 kata dalam bahasa Inggris, Spanyol, dan Belanda. Ia menemukan bahwa QWERTY effect memang terbukti.
Dalam eksperimen lain, 8.000 juru ketik juga diminta Mechanical Turk Service di Amazon.com untuk memberi kesan atas sebuah kata yang dihasilkan keyboard QWERTY. Hasilnya juga serupa.
Jasmine menuturkan, "Ini adalah demonstrasi pertama yang menunjukkan bagaimana kata-kata membentuk makna dalam waktu tertentu." Apakah Anda percaya efek QWERTY ini?

sumber : kompas

Neutrinos clocked at light-speed in new Icarus test

An experiment to repeat a test of the speed of subatomic particles known as neutrinos has found that they do not travel faster than light.
Results announced in September suggested that neutrinos can exceed light speed, but were met with scepticism as that would upend Einstein's theory of relativity.
A test run by a different group at the same laboratory has now clocked them travelling at precisely light speed.
The results in September, from the Opera group at the Gran Sasso underground laboratory in Italy, shocked the world, threatening to upend a century of physics as well as relativity - which holds the speed of light to be the Universe's absolute speed limit.
Now the Icarus group, based at the same laboratory, has weighed in again, having already cast some doubt on the original Opera claim.
Shortly after that claim, Nobel laureate Sheldon Glashow co-authored a Physical Review Letters paper that modelled how faster-than-light neutrinos would behave as they travelled.
In November, the Icarus group showed in a paper posted on the online server Arxiv that the neutrinos displayed no such behaviour.
However, they have now supplemented that indirect result with a test just like that carried out by the Opera team.
Speedy result
The Icarus experiment uses 600 tonnes - 430,000 litres - of liquid argon to detect the arrival of neutrinos sent through 730km of rock from the Cern laboratory in Switzerland.
Since their November result, the Icarus team have adjusted their experiment to do a speed measurement.

Start Quote

I didn't trust the result right from the beginning”
Sandro CentroIcarus collaboration
What was missing was information from Cern about the departure time of the neutrinos, which the team recently received to complete their analysis.
The result: they find that the neutrinos do travel at the same speed as light, within a small error range.
"We are completely compatible with the speed of light that we learn at school," said Sandro Centro, co-spokesman for the Icarus collaboration.
Dr Centro said that he was not surprised by the result.
"In fact I was a little sceptical since the beginning," he told BBC News. "Now we are 100% sure that the speed of light is the speed of neutrinos."
Most recently, the Opera team conceded that their initial result may have been compromised by problems with their equipment.
Rumours have circulated since the Opera result was first announced that the team was not unified in its decision to announce their findings so quickly, and Dr Centro suggested that researchers outside the team were also suspicious.
"I didn't trust the result right from the beginning - the way it was produced, the way it was managed," he said.
"I think they were a little bit in a hurry to publish something that was astonishing, and at the end of the day it was a wrong measurement."
Four different experiments at Italy's Gran Sasso lab make use of the same beam of neutrinos from Cern.
Later this month, they will all be undertaking independent measurements to finally put an end to speculation about neutrino speeds.
The Minos experiment in the US and the T2K experiment in Japan may also weigh in on the matter in due course - if any doubt is left about the neutrinos' ability to beat the universal speed limit.

sumber : BBC

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