Archive for the ‘ Health and Sciences ’ Category

New Study: Young Children Surprisingly Perceptive

The way they weep and vomit without warning, it’s tempting to think that preschoolers are incapable of rational thought. As biologist and emeritus Harvard professor Edward Wilson has written, a prevailing view — one promoted by the famed developmental theorist Jean Piaget — has long been that very young children are “reflex-dominated” and “egocentric”: in other words, they see little outside themselves until they reach the age of reason (usually considered to be about 7).

But a paper published recently in the journal Psychological Science shows that very young children can be far more attuned to the “desires, preferences, beliefs [and] emotions” of others, including adults, than the Piaget theory assumes. The paper suggests that young children possess a skill many adults assume they lack: they are able to judge when a human behavior is statistically probable versus when it is unusual. Very young kids, it turns out, often know when adults are not acting as they usually do.

Three psychologists — Tamar Kushnir of Cornell; Fei Xu of the University of California, Berkeley; and Henry Wellman, who chairs the Center for Human Growth & Development at the University of Michigan — conducted the two experiments that went into the paper. For the first experiment, the scientists recruited 72 preschoolers (average age: 4 years, 1 month) from a small, unnamed Midwest city. They put the kids into a room with various boxes containing two different types of toys such as small plush baseballs and basketballs. The kids were told that a puppet that looked liked a squirrel (which was creatively called “Squirrel”) liked one group of toys — either the baseballs or the basketballs — but not other.

The different boxes in the room contained different proportions of the two types of toys. The conditions of the game changed with different groups to ensure randomness, but just for purposes of explanation, let’s look at the group of kids that was told that Squirrel liked to play with baseballs and not basketballs. Three boxes were opened in front of the kids. One had only 18% baseballs; another contained half baseballs and half basketballs; the last had all baseballs.

The children were then asked to pick toys for Squirrel. And something interesting happened: when the boxes containing only 18% baseballs were opened, the preschoolers usually chose to give one of the baseballs to the Squirrel. When the boxes contained half baseballs were opened, the kids would sometimes pick one for him and sometimes pick a basketball–or do nothing. And when the boxes that contained all baseballs were opened, the kids would often just sit there. Maybe they would wanly hand a baseball to Squirrel. After all, didn’t Squirrel understand his own preference? He could take whatever he wanted on his own. For the researchers, this was evidence that preschoolers can understand how other people’s desire works: they can take what they want.

The authors say this is the first scientific “evidence that young children can use intuitive statistical abilities to infer a psychological cause–a preference.” Anyone who has ever had to mind children sharing toys in a sandbox may argue they have seen similar behavior, but this is the first time we have clear data that kids pay attention to proportions when they think about preference. Even preschoolers, in other words, can see that some people might need more help getting what they want when less is available to them.

Scientists Crack Wheat’s Genetic Code

(LONDON) — British scientists have decoded the genetic sequence of wheat — one of the world’s oldest and most important crops — a development they hope could help the global staple meet the challenges of climate change, disease and population growth.

Wheat is grown across more of the world’s farmland than any other cereal, and researchers said Friday they’re posting its genetic code to the Internet in the hope that scientists can use it as a tool to improve farmers’ harvests. One academic in the field called the discovery “a landmark.”

“The wheat genome is the holy grail of plant genomes,” said Nick Talbot, a professor of biosciences at the University of Exeter who wasn’t involved in the research. “It’s going to really revolutionize how we breed it.”

University of Liverpool scientist Neil Hall, whose team cracked the code, said the information could eventually help breeders of varieties of wheat better identify genetic variations responsible for disease resistance, drought tolerance and yield. Although the genetic sequence remains a rough draft, and additional strains of wheat need to be analyzed for the work to be useful, Hall predicted it wouldn’t take long for his work to make an impact in the field.

“Hopefully the benefit of this work will come through in the next five years,” he said.

A genome is the full complement of an organism’s DNA, complex molecules which direct the formation and function of all living organisms. Sequencing an organism’s genome, gives unparalleled insight into how it is formed, develops and dies.

Wheat is a relative latecomer to the world of genetic sequencing. This year marks the 10th anniversary of the date the human genome was laid bare. Other crops have had their genetic codes unscrambled within the past few years — rice in 2005, corn in 2009, and soybeans earlier this year.

The reason for the delay in analyzing wheat’s genetic code, Hall said, was that the code is massive — far larger than corn or rice and five times the length of the one carried by humans.

One reason for the outsize genome is that strains such as the Chinese spring wheat analyzed by Hall’s team carry six copies of the same gene (most creatures carry two.) Another is that wheat has a tangled ancestry, tracing its descent from three different species of wild grass.

But sequencing techniques have improved dramatically over the past decade. The process used in this case is called pyrosequencing, a technique which involves extracting DNA, suspending it in fluid, breaking it apart with bursts of gas and using chemical reactions and a high-resolution camera to infer its makeup.

Hall said the machine used enabled his team to analyze a million strands of DNA at a time. The whole process took about a year to complete.

Although the code may yet see use by genetic engineers hoping to craft artificial strains of wheat, Hall was at pains to stress the conventional applications of his work. Until now, breeders seeking to combine the best traits of two strains of wheat would cross the pair, grow the hybrid crop and hope for the best.

Although the process has been used by farmers since wheat was first cultivated 10,000 years ago, Talbot described it as laborious and inefficient.

“Very often we were talking about 10-15 years of intensive breeding programs,” he said. “We’re talking now about doing things in less than five.”

Talbot noted that rice cultivation had already benefited from the publication of its genetic code — and led to the development of vitamin-enriched and drought-resistant strains. He said that his own field of specialty, the study of the destructive rice blast fungus, had been revolutionized as a result of having the genome sequence.

The cracking of wheat’s code comes at a time when prices have shot up in the wake of crop failures in Russia, highlighting how the vagaries of world food production can hit import-dependent countries such as Egypt.

Concerns over climate change, water shortages and population growth have loomed in the background for years. New risks include a mutant form of stem rust. The reddish, wind-borne fungus — known to scientists as Ug99 — has devastated wheat crops in places such as Kenya, where up to 80 percent of the wheat in afflicted farmers’ fields have been ruined.

Alexander Evans, an expert in resource scarcity issues at New York University, welcomed the announcement as something that would “very helpful” in getting farmers to grow food that will meet those challenges.

But as one British paper hailed the announcement as the most significant breakthrough in wheat farming for 10 millenia, Evans warned against putting too much faith in genetics, saying that reforming the politics and economics of food distribution was easily as important.

“We have to be very careful about saying that science will feed the world,” he said.

One More Way to Avoid Diabetes: Breastfeed

New moms know that breastfeeding can be good for babies, providing them with much-needed nutrition as well as a shot of antibodies and other cells that help build immune systems. Now, evidence suggests that the practice may keep the mothers themselves healthier too.

Researchers led by Dr. Eleanor Bimla Schwarz at University of Pittsburgh found that women who breastfeed are half as likely to develop type 2 diabetes as women who do not. That’s a big statistical difference, and although it’s not clear what is behind the gap, scientists speculate that it has something to do with pregnancy pounds that expectant moms gain. Breastfeeding helps moms lose the abdominal fat they gain during pregnancy more efficiently. And while abdominal — or visceral — fat is important for the gestating baby’s development, it can be detrimental to a mother’s health if it continues to build after delivery, since it’s been linked to greater risk of metabolic disorders such as insulin resistance and heart disease as well as diabetes.

“When you look at mammals, you have to consider lactation as part of the pregnancy experience,” says Schwarz. “When women don’t breastfeed after pregnancy, or lactation is curtailed or prematurely discontinued, women end up retaining more fat than they would have if they breastfed. Then the mother’s health can suffer.”

Animal studies have helped reveal other reasons this is so. Breastfeeding, those studies found, can increase a mother’s response to insulin, allowing her to break down glucose more effectively and keep sugar metabolism in check. Lactation also inhibits hormones that promote growth hormone activity, which can also affect insulin levels. In addition, studies have shown that when women do develop diabetes during pregnancy, known as gestational diabetes, breastfeeding the newborn can improve their glucose metabolism and help stabilize the condition.

Despite the growing body of research establishing the health benefits of breastfeeding, moms in the U.S. remain resistant.The American Academy of Pediatrics recommends that new mothers breastfeed their infants for at least six months, yet only 14% of women do. For the 86% who don’t, Schwarz says lifestyle interventions such as exercise and changes in the diet can go a long way toward lowering their diabetes risk — even if it doesn’t replace the health dividends the babies would be receiving if they were breastfed. “This [study] shows that perhaps counseling these women to try to reduce their personal risk of developing diabetes should be something that doctors should consider,” says Schwarz. “And if you are pregnant or thinking about getting pregnant, or currently breastfeeding, then stick with it because it’s important to both your baby’s and your own health.”