2015年8月31日 星期一
2015年8月29日 星期六
宿醉 hangovers：預防與無解
Scientists think they may have found a new way to prevent hangoversDrinking pear juice before starting alcohol could keep hangovers at bay and lower the blood alcohol level, according to new research.
THE INDEPENDENT · 3,809 次分享 · 2015年8月3日
Drinking water doesn't prevent a hangover, study says
8 hours ago
From the section Health
Image captionResearchers concluded there was only one proven way to prevent a hangover: drink lessRaiding the fridge or downing glasses of water after a night of heavy drinking won't improve your sore head the next day, Dutch research suggests.
Instead, a study concluded, the only way to prevent a hangover is to drink less alcohol.
More than 800 students were asked how they tried to relieve hangover symptoms, but neither food nor water was found to have any positive effect.
The findings are being presented at a conference in Amsterdam.
A team of international researchers from the Netherlands and Canada surveyed students' drinking habits to find out whether hangovers could be eased or if some people were immune to them.
Among 826 Dutch students, 54% ate food after drinking alcohol, including fatty food and heavy breakfasts, in the hope of staving off a hangover.
With the same aim, more than two-thirds drank water while drinking alcohol and more than half drank water before going to bed.
Although these groups showed a slight improvement in how they felt compared with those who hadn't drunk water, there was no real difference in the severity of their hangovers.
Image captionThe study says there is no effective cure for a hangover - and we all get them if we drink enough alcoholPrevious research suggests that about 25% of drinkers claim never to get hangovers.
So the researchers questioned 789 Canadian students about their drinking in the previous month and the hangovers they experienced, finding that those who didn't get a hangover simply consumed "too little alcohol to develop a hangover in the first place".
Of those students who drank heavily, with an estimated blood alcohol concentration of more than 0.2%, almost no-one was immune to hangovers.
According to lead author Dr Joris Verster, from Utrecht University, the relationship was pretty straightforward.
"The more you drink, the more likely you are to get a hangover.
"Drinking water may help against thirst and a dry mouth, but it will not take away the misery, the headache and the nausea."
'No cure'
Dr Verster said part of the problem was that scientists still do not know what causes a hangover.
"Research has concluded that it's not simply dehydration - we know the immune system is involved, but before we know what causes it, it's very unlikely we'll find an effective cure."
He said the next step was to carry out more controlled trials on hangovers.
Dr Michael Bloomfield, from University College, London, said the economic costs of alcohol abuse ran into hundreds of billions of euros every year.
"It's therefore very important to answer simple questions like, 'How do you avoid a hangover?'
"Whilst further research is needed, this new research tells us that the answer is simple - drink less."
The paper is presented at the European College of Neuropsychopharmacology conference.
What strategies do people use when they have drunk too much alcohol?
Find out why alcohol can make you feel awful the morning after.
BBC iWonder - How can I avoid a hangover?
2015年8月28日 星期五
High-tech project will restore recorded Native American voices
High-tech project will restore recorded Native American voices
California Magazine Thursday, August 27, 2015
Anthropologist Alfred Kroeber and the man he named Ishi on the right. On the left is Sam Batwi, an English-speaking Yana who tried to communicate with Ishi.
Decades of wear and tear haven’t been kind to the 2,713 wax cylinders in UC Berkeley’s Phoebe Hearst Museum of Anthropology, which linguists and anthropologists have used for over a century to study the languages and cultural practices of Native California. But a new project promises to revitalize these old, fragile recordings — the first of which was recorded by famed anthropologist Alfred Kroeber in 1901 — with cutting-edge optical scanning technology.
The prospect excites scholars and Native communities because the collection itself is a trove of Native American recordings, particularly from California — ceremonies, songs and traditional stories that capture slices of cultures that are in many cases endangered or extinct. Among its best known is Ishi’s retelling of the Story of Wood Duck, the only recording of the extinct Yahi language. Ishi was recorded between 1911 and 1914 by Berkeley anthropologist T.T. Waterman, who began translating the story but didn’t finish because the fuzzy sound quality made the words too difficult to discern.
“This is a record of native Californian speech and mythology and worldview that was very important to Ishi, the only recording of this that we know of,” says Hearst anthropologist Ira Jacknis, “and it’s still partially untranslated.” So Jacknis is excited about the potential of a remastered recording: With it, linguists can finally translate the whole thing. “It would let us get so much closer to what Ishi was saying,” he says.
The new technique, developed by Berkeley Lab physicist Carl Haber, goes back to the sound’s source: It takes high-res images of the wax cylinders’ ridges, which the scientists can then edit to get rid of the accumulated mold, dirt, and grime and create an audio file without ambient noise.
Read the full story at California Magazine.
2015年8月27日 星期四
the October 1927 Fifth Solvay International Conference on Electrons and Photons
Fifth Conference[edit]
Perhaps the most famous conference was the October 1927 Fifth Solvay International Conference on Electrons and Photons, where the world's most notable physicists met to discuss the newly formulated quantum theory. The leading figures were Albert Einstein and Niels Bohr. Einstein, disenchanted with Heisenberg's uncertainty principle, remarked "God does not play dice". Bohr replied, "Einstein, stop telling God what to do". (See Bohr–Einstein debates.) 17 of the 29 attendees were or became Nobel Prize winners, includingMarie Curie, who alone among them, had won Nobel Prizes in two separate scientific disciplines.[2]
This conference was also the culmination of the struggle between Einstein and the scientific realists, who wanted strict rules of scientific method as laid out by Charles Peirce andKarl Popper, versus Bohr and the instrumentalists, who wanted looser rules based on outcomes. Starting at this point, the instrumentalists won, instrumentalism having been seen as the norm ever since,[3] although the debate has been actively continued by the likes of Alan Musgrave.
https://en.wikipedia.org/wiki/Solvay_Conference
第五次索爾維會議[編輯]
可能最著名的一次索爾維會議是1927年10月召開的第五次索爾維會議。此次會議主題為「電子和光子」，世界上最主要的物理學家聚在一起討論新近表述的量子理論。會議上最出眾的角色是愛因斯坦和尼爾斯·波耳。前者以「上帝不會擲骰子」的觀點反對海森堡的不確定性原理，而波耳反駁道，「愛因斯坦，不要告訴上帝怎麼做」——這一爭論被稱為波耳-愛因斯坦論戰。參加這次會議的二十九人中有十七人獲得或後來獲得諾貝爾獎。
Interesting Engineering 和 Siu Yik Fai 跟其他 25 人
Think of the brain power represented in one image.
2015年8月26日 星期三
試管內的突破：有辦法將癌細胞轉為"溫和" Scientists find way to 'turn off cancer' by reverting cancerous cells to benign tissue
Scientists find way to 'turn off cancer' by reverting cancerous cells to benign tissue
Although in early stages, research in the US has been hailed as promising
ROSE TROUP BUCHANAN
Tuesday 25 August 2015
Researchers at the US Mayo Clinic demonstrated a method to turn cancerous breast and bladder cells benign, according to their study published in the Nature Cell Biology.
The study, which although in its early stages has been hailed by cancer charities as “crucial”, works by focusing on the PLEKHA7 protein that clumps healthy cells together.
Led by Panos Anastasiadis, researchers found that when the usual sequence of cell regulation is disrupted, cancerous cells quickly occur and multiply out of control, but by adding mircoRNAs molecules scientists were able to prevent cancer.
The research represents "an unexpected new biology that provides the code, the software for turning off cancer," according to the Mr Anastasiadis, chair of the department of cancer biology at the Mayo Clinic's campus in Florida.
READ MORE: SCIENTISTS DISCOVER HOW 'OBESITY GENE' WORKS
BBC PRESENTER VICTORIA DERBYSHIRE REVEALS THAT SHE HAS BREAST CANCER
However, the tests have only been carried out in a test tube so it remains unclear whether the results can be replicated in people and if so, it is thought patients would still require chemotherapy.
"By administering the affected microRNAs in cancer cells to restore their normal levels, we should be able to re-establish the brakes and restore normal cell function,” Dr Anastasiadis told theBBC.
"Initial experiments in some aggressive types of cancer are indeed very promising."
2015年8月22日 星期六
Study of Holocaust survivors finds trauma passed on to children's genes
Study of Holocaust survivors finds trauma passed on to children's genes
New finding is first example in humans of the theory of epigenetic inheritance: the idea that environmental factors can affect the genes of your children
Genetic changes stemming from the trauma suffered by Holocaust survivors are capable of being passed on to their children, the clearest sign yet that one person’s life experience can affect subsequent generations.
The conclusion from a research team at New York’s Mount Sinai hospital led by Rachel Yehuda stems from the genetic study of 32 Jewish men and women who had either been interned in a Nazi concentration camp, witnessed or experienced torture or who had had to hide during the second world war.
They also analysed the genes of their children, who are known to have increased likelihood of stress disorders, and compared the results with Jewish families who were living outside of Europe during the war. “The gene changes in the children could only be attributed to Holocaust exposure in the parents,” said Yehuda.
Her team’s work is the clearest example in humans of the transmission of trauma to a child via what is called “epigenetic inheritance” - the idea that environmental influences such as smoking, diet and stress can affect the genes of your children and possibly even grandchildren.
The idea is controversial, as scientific convention states that genes contained in DNA are the only way to transmit biological information between generations. However, our genes are modified by the environment all the time, through chemical tags that attach themselves to our DNA, switching genes on and off. Recent studies suggest that some of these tags might somehow be passed through generations, meaning our environment could have and impact on our children’s health.
Other studies have proposed a more tentative connection between one generation’s experience and the next. For example, girls born to Dutch womenwho were pregnant during a severe famine at the end of the second world war had an above-average risk of developing schizophrenia. Likewise, another studyhas showed that men who smoked before puberty fathered heavier sons than those who smoked after.
The team were specifically interested in one region of a gene associated with the regulation of stress hormones, which is known to be affected by trauma. “It makes sense to look at this gene,” said Yehuda. “If there’s a transmitted effect of trauma, it would be in a stress-related gene that shapes the way we cope with our environment.”
They found epigenetic tags on the very same part of this gene in both the Holocaust survivors and their offspring, the same correlation was not found in any of the control group and their children.
Through further genetic analysis, the team ruled out the possibility that the epigenetic changes were a result of trauma that the children had experienced themselves.
“To our knowledge, this provides the first demonstration of transmission of pre-conception stress effects resulting in epigenetic changes in both the exposed parents and their offspring in humans,” said Yehuda, whose work was published in Biological Psychiatry.
It’s still not clear how these tags might be passed from parent to child. Genetic information in sperm and eggs is not supposed to be affected by the environment - any epigenetic tags on DNA had been thought to be wiped clean soon after fertilisation occurs.
However, research by Azim Surani at Cambridge University and colleagues, has recently shown that some epigenetic tags escape the cleaning process at fertilisation, slipping through the net. It’s not clear whether the gene changes found in the study would permanently affect the children’s health, nor do the results upend any of our theories of evolution.
Whether the gene in question is switched on or off could have a tremendous impact on how much stress hormone is made and how we cope with stress, said Yehuda. “It’s a lot to wrap our heads around. It’s certainly an opportunity to learn a lot of important things about how we adapt to our environment and how we might pass on environmental resilience.”
The impact of Holocaust survival on the next generation has been investigated for years - the challenge has been to show intergenerational effects are not just transmitted by social influences from the parents or regular genetic inheritance, said Marcus Pembrey, emeritus professor of paediatric genetics at University College London.
“Yehuda’s paper makes some useful progress. What we’re getting here is the very beginnings of a understanding of how one generation responds to the experiences of the previous generation. It’s fine-tuning the way your genes respond to the world.”
Can you inherit a memory of trauma?
Researchers have already shown that certain fears might be inherited through generations, at least in animals.
Scientists at Emory University in Atlanta trained male mice to fear the smell of cherry blossom by pairing the smell with a small electric shock. Eventually the mice shuddered at the smell even when it was delivered on its own.
Despite never having encountered the smell of cherry blossom, the offspring of these mice had the same fearful response to the smell - shuddering when they came in contact with it. So too did some of their own offspring.
On the other hand, offspring of mice that had been conditioned to fear another smell, or mice who’d had no such conditioning had no fear of cherry blossom.
The fearful mice produced sperm which had fewer epigenetic tags on the gene responsible for producing receptors that sense cherry blossom. The pups themselves had an increased number of cherry blossom smell receptors in their brain, although how this led to them associating the smell with fear is still a mystery.
2015年8月21日 星期五
Projects seek concrete solutions to global warming
Web Stories
Projects seek concrete solutions to global warming
Posted August 20, 2015; 02:30 p.m.
When it comes to global warming, most people worry about power plants. Claire Whitethinks about another kind of plant — those that make cement.
"Cement production and cement powder are a major component of greenhouse gas emissions," said White, an assistant professor of civil and environmental engineering and theAndlinger Center for Energy and the Environment at Princeton University. "It accounts for between 5 and 8 percent of human-made carbon dioxide."
Along with co-researchers from across the University, White is exploring ways to manufacture cement with a much lower contribution to global warming. Some of these cement substitutes completely eliminate the need to burn limestone at high temperature, a critical step in standard cement production that accounts for much of the CO2 emissions. By using waste components such as slag from steel manufacturing instead of cement powder, manufacturers can cut greenhouse emissions by 80 to 90 percent, White said.
"To make conventional cement, you need to dig raw materials out of the ground and heat them to very high temperatures. You are essentially driving off CO2 molecules," she said. "These alternate forms of cement — called alkali activated or geopolymer cements — either use byproducts from industrial processes or use entirely different methods to create the end product."
Claire White (right), assistant professor of civil and environmental engineering and the Andlinger Center for Energy and the Environment, worked with postdoctoral research associate Antoine Morandeau to invent ways to produce cement with a much lower contribution to global warming. (Photo by Frank Wojciechowski for the Office of Engineering Communications)
Cement mixed with water creates the binding agent, which forms concrete when other materials are incorporated, including crushed rock and sand. As a basic building material, concrete with some similarities to today's material has been used for thousands of years in structures such the Pantheon in Rome and the Guggenheim Museum in New York. Today, concrete is the second-most used resource by volume worldwide after water.
White began studying low-carbon versions of cement as a graduate student at the University of Melbourne in Australia. A research team there was studying the durability of alternate forms of cement, and turned to the former Soviet Union for field research. The Soviets had built a number of structures using a type of cement that relies on slag, a byproduct of steel production, as a substitute for limestone.
"For the Soviets it was a cost and material supply issue," White said. "The researchers examined structures built between 1964 and 1982. From a visual standpoint, they are still quite sound."
Although that is an encouraging sign, it is not necessarily proof of the material's durability. Many of these materials, called alkali-activated cements, have been around for years, but the idea of using them in widespread production to reduce greenhouse gas emissions is relatively new. The problem is that cement lasts so long that construction standards demand decades of reliability.
"Even with regular concrete formulations being employed today, you don't have an extensive historical database," said Dale Bentz, a chemical engineer with the National Institute of Standards and Technology who specializes in cement research. "It is even more difficult for the new materials."
Bentz said one challenge in evaluating possible new cements is simulating the decades of wear and variety of environmental conditions that concrete structures face. To do that, scientists can conduct experiments in which they subject concrete samples to simulated aging, or they can construct computer models to simulate aging in the concrete.
"You have to be careful that you are not changing the underlying chemistry," White said. "We can bump up the concentration of chemicals responsible for degradation. But the difficult thing is trying to make sure you are replicating natural conditions."
An X-ray image of a cement sample shows small cracks that formed as it dried. Research funded by the Princeton E-ffiliates Partnership Fund has revealed ways to reduce this cracking in new generations of cement that are less environmentally damaging. (Image courtesy of Claire White, Department of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment)
One of White's projects, supported by the Andlinger E-ffiliates Partnership Fund, involves using X-ray tomography to study methods for eliminating tiny cracks that develop as some of the alternative cements dry. These micro-cracks, some of which are invisible to the naked eye, can weaken concrete over the long term. White's team has been working to understand their development and propose efficient ways to minimize the cracking.
"We found that by adding really small quantities of zinc oxide nanoparticles, the crack density at the cement surface is reduced," she said.
White's team also is developing models to simulate aging on a variety of cements. The goal, she said, is to rapidly evaluate weaknesses that emerge as concretes age and to propose solutions. While laboratory experiments can be extremely effective, modeling would allow researchers to test new methods more quickly.
"We don't have data indicating how well they will last for 50 to 100 years," she said. "This is an area in which university research is ideal," she said. "We have the ability to take a longer view."