Scientific American 60 Second Science听抄（有音频文件）

angelatUID: 2277395

August 21, 2007: 60-Second Science
Online Game Offers Insights Into Epidemics  

A glitch in the World of Warcraft online role-playing game enabled a virtual disease to spread among the characters, which became useful for real epidemiologists to study. Kevin Begos reports.

The epidemic swept the world. Fortunately, it was only the world of warcraft, a popular online role-playing game. But that got the attention of real disease experts at Tufts and Rutgers Universities. That's because the accidental outbreak that attacked the virtual characters offered unique opportunity to study how social groups can help spread a disease.
In late 2005, the epidemic hit the world of warcraft played by millions. It all start with an error. One creature was supposed to infect a few virtual player with so-called corrupted blood. But some of the next(?) virtual inhabitants exploited a flaw to sread the disease to unsuspecting masses. The virtual quaratines game designers tried to impose didn't work. In part because the virtual people didn't follow them and so entire virtual cities were virtually destroyed.
The experts were fascinated because they've never had a way to realistically simulate how large groups of people will react to an epidemic. But the cure for real epidemic still won't be as easy as the virtual one was. They just reprogrammed the computers.

p.s 1 on hj , where ? is to be mostly "nastiest" , i doubt it

     2 how can write down when listen, i feel it's merely too fast?

kevinliu6883UID: 2338522

Battling Bitter Coffee: Chemists Identify Roasting As The Main Culprit
Science Daily — Bitter taste can ruin a cup of coffee. Now, chemists in Germany and the United States say they have identified the chemicals that appear to be largely responsible for java's bitterness, a finding that could one day lead to a better tasting brew. Their study, one of the most detailed chemical analyses of coffee bitterness to date, was presented  at the 234th national meeting of the American Chemical Society.


In a discovery that could lead to better tasting coffee, chemists report finding the compounds that are most responsible for the brew's bitter taste. (Credit: American Chemical Society)Ads by Google Advertise on this site

Research by others over the past few years has identified an estimated 25 to 30 compounds that could contribute to the perceived bitterness of coffee. But the main cause of coffee bitterness has remained largely unexplored until now, the researchers say.

"Everybody thinks that caffeine is the main bitter compound in coffee, but that's definitely not the case," says study leader Thomas Hofmann, Ph.D., a professor of food chemistry and molecular sensory science at the Technical University of Munich in Germany. Only 15 percent of java's perceived bitterness is due to caffeine, he estimates, noting that caffeinated and decaffeinated coffee both have similar bitterness qualities.

"Roasting is the key factor driving bitter taste in coffee beans. So the stronger you roast the coffee, the more harsh it tends to get," Hofmann says, adding that prolonged roasting triggers a cascade of chemical reactions that lead to the formation of the most intense bitter compounds.

Using advanced chromatography techniques and a human sensory panel trained to detect coffee bitterness, Hofmann and his associates found that coffee bitterness is due to two main classes of compounds: chlorogenic acid lactones and phenylindanes, both of which are antioxidants found in roasted coffee beans. The compounds are not present in green (raw) beans, the researchers note.

"We've known for some time that the chlorogenic acid lactones are present in coffee, but their role as a source of bitterness was not known until now," Hofmann says. Ironically, the lactones as well as the phenylindanes are derived from chlorogenic acid, which is not itself bitter.

Chlorogenic acid lactones, which include about 10 different chemicals in coffee, are the dominant source of bitterness in light to medium roast brews. Phenylindanes, which are the chemical breakdown products of chlorogenic acid lactones, are found at higher levels in dark roasted coffee, including espresso. These chemicals exhibit a more lingering, harsh taste than their precursors, which helps explain why dark-roasted coffees are generally more bitter, Hofmann says.

The type of brewing method used can also influence the perception of bitterness. Espresso-type coffee, which is made using high pressure combined with high temperatures, tends to produce the highest levels of bitter compounds. While home-brewed coffee and standard coffee shop brews are relatively similar in their preparation methods, their perceived bitterness can vary considerably depending on the roasting degree of the beans, the amount of coffee used, and the variety of beans used.

Some instant coffees are actually less bitter than regular coffee, Hofmann says. This is because their method of preparation, namely pressure extraction, degrades some of the bitter compounds. In some cases, as much as 30 to 40 percent fewer chlorogenic acid lactones are produced, leading to a reduced perception of bitterness, he says.

"Now that we've clarified how the bitter compounds are formed, we're trying to find ways to reduce them," Hofmann says. He and his associates are currently exploring ways to specially process the raw beans after harvesting to reduce their potential for producing bitterness. They are also experimenting with different bean varieties in an effort to improve taste. But so far, none of these approaches - details of which are being kept confidential by the researchers - is ready for commercialization, he notes.

But the researchers are optimistic that a better cup of Joe is just around the corner. Perhaps no one could be happier about the news than Hofmann, who admits that he is an avid coffee-drinker with a passion for the dark-roasted varieties.

Funding for the study was provided by the Technical University of Munich, the University of Muenster, and The Procter and Gamble Company.

Note: This story has been adapted from a news release issued by American Chemical Society.

[ 本帖最后由 kevinliu6883 于 2007-8-23 01:57 编辑 ]

bayanmengUID: 2268438

Woo~~

kevinliu6883UID: 2338522

We may soon have better coffee through chemistry. Researchers have identified the key chemical that can sometimes turn black cup of joy into a bitter experience. The researchers announced their grants, work findings in August 21st at the national meeting of American Chemical Society in Boston. Studies over last few of years found some thirty compounds that contribute to the coffee’s bitterness. Says the study leader Thomas Hofmann, everybody thinks caffeine is the main bitter compound in coffee, but that’s definitely not the case. In fact he thinks only 15 % of coffee’s bite is caffeine based. Using the analytical tool of chromotography, along with taste testing, the scientists determined that bitterness is due to two main types of compounds that form during roasting. These are chlorogenic acid lactones the major contributors to light mediamous and finale indient which the lactones turned into from cooking, which come from most of bitter dark crops. So perhaps in future you’ll be order a ground die decaffeine…mocachino.

[ 本帖最后由 kevinliu6883 于 2007-8-23 02:43 编辑 ]

wlxzmUID: 2292462

We may soon have better coffee through chemistry. Researchers have indentified the key chemical that can sometimes turn the sublime cup of joy??? into a bitter wxperience. The researchers announces that grands breaking finding  August twenty first of teh national meeting of the American Chemical society in Boston. Study over the last few years have found some thirty componds that contrubut to coffee bitterness, says study leader XX, everybody thinks that coffeine is the main bitter compond of coffee, but taht's definitly not the case. In fact, he thinks only fifteen percent of coffee's bite is coffeine based. Using the analytical tool XX along with taste testing, the scientists determined that bitterness is due to two main componds that from during roasting. These are XX acid lactones that major contributors to light mediamous and final indient which the lactones turned into from cooking and which come from most of bitter dark crops. So perhapps in future you will be order a >>>>

liucirongUID: 2215759

August 22, 2007: 60-Second Science Recipe For Better Coffee

Chemists have identified the key compounds that can make coffee too bitter--and caffeine is not the main culprit. Steve Mirsky reports.

culprit [ˈkʌlprit]  a person or thing responsible for causing a problem: The main culprit in the current crisis seems to be modern farming techniques.

We may soon have better coffee through chemistry. Researchers have identified the key chemicals that can sometimes turn a sublime cup of Joe into a bitterer experience. The researchers announced their ground’s breaking finding Augest 21st at the national meeting of the American Chemical Society in Boston. “Studies over the last few year have found some 30 compounds that contribute to coffee bitterness”, says study leader Thomas Hofmann, “every body thinks that coffeine is the main bitter compound in coffee, but that’s definitely not the case.” In fact, he thinks only about 15% of caffee’s bitter is caffeine-based. Using the analytical – chromatography tool along with test(taste) testing, the scientists determined that bitterness is due to two main types of compounds that form during roasting. These are chlorogenic acid lactones, the majoy bitterness contributor in light to medium roasts, and phenylindanes, which the lactones turn into about? for the cooking, and which account for most of the bitterness in dark roasts. So perhaps in the future, you’ll be ordering a ground ** halfcaf dephenylindanerated ** Mochaccino.

New words:
Sublime: [səˈblaim] of very high quality and causing great admiration: sublime beauty
Bitterer--bitter  [ˈbitə]
Help Note: more bitter and most bitter are the usual comparative and superlative forms, but bitterest can also be used.
analytical [ˌænəˈlitik]
chromatography 色谱法; 层析法(is the collective term for a family of laboratory techniques for the separation of mixtures. It involves passing a mixture dissolved in a "mobile phase" .......)
medium [ˈmi:diəm] : in the middle between two sizes, amounts, lengths, temperatures
ground--grind to break or crush sth into very small pieces between two hard surfaces or using a special machine: to grind coffee / corn

Grammer mistakes:
that bitterness is due to>>>>>>>>due-- adjective, noun, adverb

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ps.
dark roasted (coffee) 深度烘焙
medium roasted 中度烘焙
light roasted 浅度烘焙
Mochaccino:
a cappuccino coffee containing chocolate syrup or chocolate flavouring, blend of mocha and cappuccino
decaf： decaffeinate的简写，去咖啡因的
halfcaf：由50% regular coffee, 50% decaffeinated coffee混合制成咖啡的
dephenylindanerated：按照caffein派生decaffeinate的规则造出来的词 ^_^提到了几种咖啡的非正式说法:Joe, java
~~~~~~~~~~~~~~~~~~~~~~~
Related Materials
Chemists Find What Makes Coffee Bitter
From:http://www.livescience.com/strangenews/070821_bitter_coffee.html

By Jeanna Bryner, LiveScience Staff Writer
posted: 21 August 2007 01:33 pm ET

Chemists have figured out why dark-roasted coffees are so bitter, a finding that could lead to a smoother cup of java.

Using chemical analyses and follow-up taste tests by humans trained to detect coffee bitterness, the scientists discovered the compounds that make coffee bitter and also how they form.

"Everybody thinks that caffeine is the main bitter compound in coffee, but that's definitely not the case," said study leader Thomas Hofmann, a professor of food chemistry and molecular sensory science at the Technical University of Munich in Germany.

Just 15 percent of coffee's bitter taste comes from caffeine, said Hofmann, who presented his findings today at a meeting of the American Chemical Society in Boston.

Hofmann and his colleagues found two classes of compounds give coffee the bulk of its bitterness. Both pungent perpetrators are antioxidants found in roasted coffee beans, not in the green (raw) beans.

One class, called chlorogenic acid lactones, is present at high levels in light- to medium-roast brews. Dark roasts, such as espresso, showed high levels of phenylindanes, which form when the chlorogenic acid lactones break down and give a more lingering, harsh taste than their precursors, Hofmann said.

"Roasting is the key factor driving bitter taste in coffee beans. So the stronger you roast the coffee, the more harsh it tends to get," Hofmann said. He added that prolonged roasting leads to the formation of the most intense bitter compounds found in dark roasts.

How the beans are brewed also affects bitterness, the scientists found. The high pressures and temperatures used for brewing espresso-type coffees produce the highest levels of bitter compounds.

"Now that we've clarified how the bitter compounds are formed, we're trying to find ways to reduce them," Hofmann said.







[ 本帖最后由 liucirong 于 2007-8-23 12:53 编辑 ]

liucirongUID: 2215759

I have a question about the word bitter

bitter 's comparative form is "more bitter"
and superlative form is "most bitter" or "bitterest"


however i heard that Steve said "bitterer"

is it "bitterer" is the other correct comparative form of "bitter"?

liucirongUID: 2215759

a cup of Joe
a cup of coffee.
Etymology:
There is no clear origin for the use of "joe" to mean coffee; though, we have a few stories being created to explain where it came from.
1) A persistent one alleges that it derives from the ban imposed by Admiral Josephus "Joe" Daniels, Secretary of the Navy, on serving alcohol aboard US Navy ships, except on very special occasions. Coffee, it is said, became the beverage of choice and started to be called "Joe" in reference to him. The problem with this story is the dates. "Cup of joe" appears in the written record in 1930 but the order to ban alcohol - General Order 99 - was issued on 1 June 1914. It banned officers' wine messes, which had only been permitted since 1893; ships had otherwise been dry since the spirit ration was abolished in 1862. It seems hardly likely that the loss of a wine mess limited to officers on board otherwise alcohol-free ships would have led to a nickname for coffee that only started to be written down 16 years after the order.
2) Prof. Jonathan Lighter, in the Random House Historical Dictionary of American Slang, leans towards another story: that it came from the Stephen Foster song "Old Black Joe", with the resultant mental link between "black" and "coffee". It is true that the song - written in 1860 - was extremely popular at one time, but it makes no reference to coffee, so linking the two is implausible.
3) The most probable suggestion is that it is a modification of "java" or "jamoke" for coffee, perhaps under the influence of one or other of the many expressions at the time that contained the word "Joe" - for example, "an ordinary Joe" (though "GI Joe" for an enlisted man in the US military is from the next decade). It is significant that an early example appears in 1931 in the Reserve Officer's Manual by a man named Erdman: "Jamoke, Java, Joe. Coffee. Derived from the words Java and Mocha, where originally the best coffee came from".

Aprill2007UID: 2385095

不是很容易听，:) 加油！

EHSSSUID: 2348947

August 22

Based on kevinliu6883

We may soon have better coffee through chemistry. Researchers have identified the key chemical that can sometimes turn black(sublime) cup of joy into a bitter experience. The researchers announced their grants, work findings in August 21st at the national meeting of American Chemical Society in Boston. Studies over last few of years found some thirty compounds that contribute to the coffee’s bitterness. Says the study leader Thomas Hofmann, everybody thinks (that ) caffeine is the main bitter compound in coffee, but that’s definitely not the case. In fact he thinks only 15 % of coffee’s bite is caffeine based. Using the analytical tool of chromotography, along with taste testing, the scientists determined that bitterness is due to two main types of compounds that form during roasting. These are chlorogenic acid lactones the major (bitterness) contributors to light mediamous(medium roasts) and finale indient which the lactones turned into from cooking, which come from most of bitter dark crops. So perhaps in future you’ll be order a ground die(day halfcaf) decaffeine…mocachino.

kelediguoUID: 149939

2007-8-22
We may soon have better coffee through chemistry. Researchers have identified the key chemicals that can sometimes turn a sublime cup of Joe into a bitter experience. The researchers announced their grounds, breaking findings August 21st at the national meeting of the American Chemical Society in Boston. “Studies over the last few years have found some 30 compounds that contribute to coffee bitterness,” said study leader Thomas Hofmann. Everybody thinks that caffeine is the main bitter compound in coffee but that’s definitely not the case. In fact, he thinks only about 15% of coffee’s bite is caffeine based. Using the analytical tool—chromatography, along with taste testing, the scientists determine that bitterness is due to two main types of compounds that form during roasting. These are chlorogenic acid lactones--the major bitterness contributors in light to medium roasts, and phenylindanes which the lactones turn into upon further cooking and which account for most of the bitterness in dark roasts. So perhaps in the future, you’ll be ordering a grande half-caf dephenylindanerated caramel mochaccino.

kevinliu6883UID: 2338522

Women Really do Prefer Pink
What do women want? Well according to market of anything, as long as it’s pint, from baby blanket to cellar phone, the first step female consumers to have pint product. Well research published this weekend’s Current Biology may solve the practice. Although feminist may say red, researchers from NewcastleUniversity asked more than 200 people to choose their preferable color from a rage from white green to blue yellow. They found women cross the board strongly prefer reddish hues, well the men not so much. Further they gave their subjects the band of sex inventory to measurer feminity. They found, the more feminy you are, the more you prefer reddish hues. Since the study cross the culture, scientists say preference may be part of our nature. They speculated hunt and gathering day women who may have gathered more than hunt, honk skill for spot red fruit. They also suggest women more sensitive to blush skin in order to better read emotional status. So the sensitive to reddishness, they say stalk. They may explain the Cliché and again be pretty and pink.

Like White On Rice?
White rice is one of world most popular staple foods, but white rice also shows that human has been nebula gene since they dominated civilization. White rice evolved from wild red rice ten thousand years. And new studies found that all white rice in the world is derived from two rice subspecies that experienced almost identical mutations. The study appeared in the Journal of Public Laboratory Science Genetics. The mutation showed the proteins that originally lead to coloring rice. The researchers think the ancient farmers like the odd white rice. And they widely spread, first cross Himalayan region, then cross the rest of world. Was the color or lack color made ingredients more attractive? Maybe not, because white rice variety cooked fast, which requires less fuel. Also insect sent diseases were easy to spot on the white straint. So next time you bring a full follop of rice to your mouth, remember thousands of ancient genetists till today keep you from seeing red.


[ 本帖最后由 kevinliu6883 于 2007-8-24 10:26 编辑 ]

kevinliu6883UID: 2338522

Dr. Anya Hurlbert, a professor of visual neuroscience at Newcastle University in England, wondered why all the products aimed at her daughter have a pinkish tint.

So Hurlbert created a study, involving 208 young men and women, to determine whether girls really do prefer pink. The answer, reported in Monday's issue of the journal Current Biology is that females do have a preference for pinkish colors that males don't.

"We find very clear differences between the males and females we have tested," she said. "We haven't yet found any exceptions."
The female tilt toward pink, she speculated, arose from evolutionary influences millions of years ago. "Females were the ones who gathered red fruit against a green background," she said. "Red is healthy in faces and in fruits."

[ 本帖最后由 kevinliu6883 于 2007-8-24 09:02 编辑 ]

kevinliu6883UID: 2338522

Some 10,000 years ago white rice evolved from wild red rice and began spreading around the globe. But how did this happen"

Researchers at Cornell and elsewhere have determined that 97.9 percent of all white rice is derived from a mutation (a deletion of DNA) in a single gene originating in the Japonica subspecies of rice. Their report, published online in the journal PloS (Public Library of Science) Genetics, suggests that early farmers favored, bred and spread white rice around the world.

The researchers report that this predominant mutation is also found in the Indica subspecies of white rice. They have found a second independent mutation (a single DNA substitution) in the same gene in several Aus varieties of rice in Bangladesh, accounting for the remaining 2.1 percent of white rice varieties. Neither of these two mutations is found in any wild red rice species.

Both mutations produce shortened versions of the same protein in which the missing part is responsible for activating the molecular pathway leading to grain color in rice.

"We think that other domains of this protein are critical for other functions in the plant, because we never see the protein entirely deleted, just the part of the molecule that affects the pathway for grain color," said Susan McCouch, Cornell professor of plant breeding and genetics and the paper's senior author. Megan Sweeney, Cornell Ph.D. '06 and postdoctoral associate, was the paper's lead author.

The researchers speculate that ancient farmers actively bred and spread white rice varieties first throughout the Himalayan region and then the rest of the world because the varieties cooked faster (requiring less fuel), their hulls were easier to remove compared with red rice, and disease and insects were easier to see amid the white grains. The farmers also may have favored one mutation over the other because it may have produced favorable grains more consistently, the researchers say.

In 2006 the researchers first identified the gene that makes the rice seed's bran layer, or pericarp, white. This gave rice breeders and engineers a genetic marker to help develop new breeds. The Cornell researchers regularly introduce favorable genes from wild red rices into elite white cultivars to improve yields and provide better responses to stress, but they generally select against the gene for red pericarp because it is associated with such unfavorable "weedy" linked traits as seed dormancy and "shattering" (where seeds fall easily from the stalk).

"Breeders can now begin to screen for the red pericarp gene while selecting against closely linked traits like shattering and dormancy," said McCouch. The new tools may lead to more diverse domestic rice varieties.

Also, breeders are interested in using the marker to predict whether new generations will contain white or red grains, using DNA from young seedlings, long before the plants set seed.

McCouch noted that due to the genetics of pericarp color in rice (white grain is recessive and maternally inherited), when white grains appear in the panicle (the grain clusters on the stems), it is an indication that all seeds in the clusters will be white -- and offspring from these seeds will continue to produce white-grain plants. The researchers theorize that women who shucked rice for cooking thousands of years ago would have recognized the value of the white seeds and may have set aside selected panicles for breeding and planting.


###
Scott Williamson and Carlos Bustamante, both researchers in Cornell's Department of Biological Statistics and Computational Biology, were also co-authors on this paper. The research was supported by the Plant Genome Program of the National Science Foundation, the Generation Challenge Program, Chengbuk National University and Korea's National Institute of Agricultural Biotechnology.

wlxzmUID: 2292462

2007年8月23
White rice is one of the world's most popular staple food,  but white rice also show that humans have been manipulating genes       since it's on civilization. White rice evolve from wild white rice ten thousands years ago, and new atudy finds that all white rice in    the world is       derived from two rice subspieces that experience the almost identical mutations. The study appears in Journal       Public Library of Science   Genetics. The mutations whorten the protein that order XX would lead color of the rice. The reseachers   think that ancient famer like     the art white rice. And actually breaded and spreaded it first across XX region and then across  the   rest of the world. Was the color or XXthat made the grain more attractive? Maybe not, because white rice varietys cooked faster,   which requires less fuel, also, insects and   diseases were easier to spot on the light white rice strains. So next time you bring a full spoon of white rice to your mouth, remembr that thousands of ancient genetists to today keep you from seeing red.