Bioluminescence lights up the oceans

Mysteries still surround glow-in-the-dark creatures

The definition of bioluminescence "is easier than the pronunciation and spelling of the word: It is just visible light made by living animals," says Edith Widder, president of the Ocean Research and Conservation Association in Fort Pierce, Fla.
 
The word may be easy to define, but the chemical process is still poorly understood. Bioluminescence has apparently evolved independently at least 40 times in species belonging to more than 700 genera, or classifications of organisms. Widder notes in the journal Science that about 80 percent of those genera are found in the open ocean.
 

Examples of bioluminescent organisms include yellow-glowing Tompteris worms (upper left). Also pictured (clockwise) are the squid Abralia veranyi; northern krill, known by the scientific name Meganyctiphanes norvegica; the scaleless black dragon fish (Melanstomias bartonbeani); and deep-sea jellyfish (Atolla wyvillei).  

 

Spiders devour ants front-end first

Animal eating patterns involve complicated balancing of quantity vs. quality

A spider that only eats ants is choosy about which body parts of its prey it devours based on their nutritional value.

These new findings are the first to demonstrate that "specialist" predators relying on a single food source might have evolved feeding behaviors to maximize what they get out of meal time, the researchers say.

"We found that these spiders do have to balance their nutrient intake by choosing different body parts of their exclusive ant prey," said Stano Pekár, an assistant professor of ecology and zoology at Masaryk University in the Czech Republic and lead author of the research published in the April 15 issue of the journal Animal Behaviour. 

When chowing down on ants, the spiders consistently began with the protein-packed front parts before getting to the fattier hind segment, called a gaster or abdomen. The picky eating seemed to pay off: Spiders reared on just front-end ant pieces grew faster, bigger and lived longer than those served only gasters or even whole ants.

Yet when given the option, spiders still gobbled on the gaster rather than shunning it entirely for the front parts, hinting that the gaster contains vital nutrients not found elsewhere in the ant's body.

Feasting on ants
For the experiments, the researchers collected dozens of Zodarion rubidum, an ant-eating spider species found in Europe and the United States that has a light orange head and legs.

These spiders attack ants and inject them with powerful venom that paralyzes the prey in mere minutes.

When settling in for an ant banquet, Zodarion spiders puncture the insects' hard exoskeletons with fangs and inject enzymes that "liquefy the inner tissues," Pekár said. The spiders slurp out this mush before moving to different areas of the carcass. These spider eating sessions last from two to four hours.

To see how well the spiders lived on particular pieces of an ant, the researchers divided 60 of the arachnids into three dining clubs that were given the ants' front end (head, legs and thorax or mid-body), gasters or whole ants. Each group received a similar portion of fresh ant flesh by weight.

The spiders given only gasters fared poorly: All 20 died within six weeks of the start of the experiment, whereas eight of the spiders dining on front parts and three on whole ants were still alive and kicking at the experiment's end three months later.

When alive, the spiders kept on the gaster-only diet initially grew but then shriveled, while those eating the head, legs and thoraces thrived, with some tripling their weight. The spiders devouring entire ants also did well, but did not develop as fast or get as big as the front-end eaters.

The choicer parts of an ant To find out whether the spiders had ant-part preferences, the researchers gave 48 spiders small, medium or large whole ants. 

"When we provided [spiders] access to the entire prey, they responded by consistently choosing to feed first and mostly on the head and thorax," Pekár and his co-authors wrote.

Even when given gigantic ants that provided more than enough sustenance in the front-end parts alone, nearly all of the spiders spent at least an hour munching on the fatty ant derrieres.

"We thought maybe the spiders could live only on the protein" found up front, Pekár said, but after working over the thoraces and legs, the hungry spiders "always went for the gaster." This behavior implies that the gaster contains some essential nutrients not found elsewhere in the ant, but that protein is the priority.

While spiders given the protein-rich regimen fared best in the experiment, Pekár suspects those with a more well-rounded diet would ultimately do better. Having sucked out all they could from the front parts, the spiders with a whole ant might have over-gorged on the leftover gasters and done themselves a nutritional disservice during the short experiment, Pekár said.

Eating right also a hunters' burden
The findings jibe with the emerging view that for predators, achieving proper nutrition is trickier than simply finding enough prey to eat.

And what's true for persnickety spiders might also apply to nature's big, "generalist" carnivores.

As for why cheetahs eat particular portions of a gazelle, for example, the thinking had been that the "cheetah did not consume the entire gazelle, because he was stuffed by half of it," Pekár told LiveScience. "But now we see that this is not the full truth. The cheetah did not consume some muscles of the gazelle because he was [already] stuffed with proteins, for example."

Overall, animals' eating patterns involve a complicated balancing of quantity versus quality.

"Nutrition is one of the most important things that animals do," said David Raubenheimer, a professor of nutritional ecology at Massey University in Auckland, New Zealand who has not involved in the study. "I would expect them to evolve the ability to capitalize on any opportunity they have for getting the best they can."

 

First birds were poor fliers

Experts say feathers weren’t strong enough to flap

The earliest birds did not have strong enough feathers to take to the air by flapping their wings and were gliders at best, researchers said Thursday.

While modern birds have feathers with a strong central shaft that is hollow to reduce weight, the earliest-known bird Archaeopteryx and another ancient ancestor had feathers that were much thinner and weaker.

Robert Nudds of the University of Manchester and Gareth Dykearchaeoptery of University College Dublin calculated in a report in the Friday issue ofl Science that even if their feather shafts were solid, they would still have been barely strong enough to allow gliding.

Archaeopteryx lived in the late Jurassic period, about 140 million years ago, and Confuciusornis in the early Cretaceous, around 100 million years ago.

It is widely believed among paleontologists that the first birds arose from small, feathered dinosaurs.

One theory is that birds evolved from small dinosaurs living in trees that initially used feathers to control their descent like a parachute, then glided through the forest canopy and eventually flapped their wings to achieve true flight.

"Some thrust generation by these fossil birds cannot be discounted, but the vigorous flapping flight of modern birds is highly unlikely," the researchers concluded.

Nudds said poor flight ability suggests that the early birds lived in trees and would launch in order to glide to another tree. If they landed on the ground they could clamber back up to gain height for their next glide.

"If Archaeopteryx and Confuciusornis were arboreal dwellers, which is suggested by my data, then it also suggests that avian flight originated in the trees and not on the ground," he said.

"Fossil wings that superficially resemble those of existing birds don't necessarily indicate flapping flight ability," concluded Nudds, who added that the origin of avian flapping flight is likely to be more recent than previously thought.

 

5 minutes in the green can boost mood

Outdoor exercise improves mental health, study finds

Just five minutes of exercise a day in the great outdoors can improve mental health, according to a study released on Saturday, and policymakers should encourage more people to spend time in parks and gardens.

Researchers from the University of Essex found that as little as five minutes of a "green activity" such as walking, gardening, cycling or farming can boost mood and self esteem.

"We believe that there would be a large potential benefit to individuals, society and to the costs of the health service if all groups of people were to self-medicate more with green exercise," Barton said in a statement about the study, which was published in the journal Environmental Science & Technology.

Many studies have shown that outdoor exercise can reduce the risk of mental illness and improve a sense of well-being, but Jules Pretty and Jo Barton, who led this study, said that until now no one knew how much time needed to be spent on green exercise for the benefits to show.

Barton and Pretty looked at data from 1,252 people of different ages, genders and mental health status taken from 10 existing studies in Britain.

They analyzed activities such as walking, gardening, cycling, fishing, boating, horse-riding and farming.

They found that the greatest health changes occurred in the young and the mentally ill, although people of all ages and social groups benefited. The largest positive effect on self-esteem came from a five-minute dose of "green exercise."

All natural environments were beneficial, including parks in towns or cities, they said, but green areas with water appeared to have a more positive effect.

 

Chicken nuggets put to the test: taste vs. health

Consumer Reports warns kiddie favorite is loaded with salt, fat

Consumer Reports put chicken nuggets to the test and found many brands are loaded with salt and fat.

After evaluating 14 supermarket brands of refrigerated and frozen chicken nuggets — including two chicken-like nuggets made from soy — Consumer Reports Health said that choosing a healthier nugget will mean sacrificing flavor.

While none of the 14 brands received a "poor" nutritional rating from the health website, which is associated with Consumer Reports magazine, the only brand to get a "very good" nutrition rating — Health is Wealth — didn't get high marks in taste.

The site also urged consumers not to be misled by brands that are advertised as natural or organic, terms that aren't necessarily indicators of nutritious foods.

For instance, Consumer Reports said that while Tyson accurately claims its chicken nuggets are "100 percent all natural," one serving (about 3 to 4 ounces) of its nuggets has 270 calories, 17 grams of fat and 470 milligrams of sodium.

It's generally recommended that people consume fewer than 65 grams of fat and 2,300 milligrams a sodium a day.

Consumer Reports gave Tyson's nuggets a "fair" rating for nutrition.

"Whatever the claims that are being made, you definitely want to turn to the nutritional panel on the product and see if it matches what you're looking for," said Gayle Williams, deputy editor of Consumer Reports Health.Oliver pushed nuggets into the news recently when he made them on his ABC reality program, "Jamie Oliver's Food Revolution." He thought the process of grinding up the chicken parts would gross out the children he made them for, but they ate them eagerly.

Of the 14 items tested, only Health is Wealth received a "very good" nutritional rating, with 130 calories, 4 grams of fat and 230 milligrams of sodium. Testers, however, didn't care for the taste.

"There's the rub. The brand may be more nutritious than others, but if your kids won't eat it, what good is it?" said Williams.

On taste, three brands earned a "very good" rating: Market Pantry (from Target, which told the magazine it was changing its formulation), Bell & Evans Breaded and Kirkland Signature Disney (Costco). Each received a "good" nutritional rating.

And McDonald's nuggets? The site asked children to compare them against the others. McDonald's came out on top, but earned only a "fair" nutrition rating.

 

Folic acid doesn’t cut risk of stroke, study finds

In the U.S., any health benefits already achieved via food fortification 

Studies have linked low blood levels of a chemical lowered by folic acid to reduced rates of stroke. However, folic acid supplements don't seem to prevent strokes, according to a review of clinical trials involving more than 39,000 participants.

"We do not have evidence that would warrant boosting folic acid supplementation for stroke reduction," researcher Dr. Jeffrey Saver told Reuters Health.

Saver and colleagues at the UCLA Stroke Center in Los Angeles identified 13 well-designed clinical trials of folic acid and stroke. Participants in all the trials had been diagnosed with conditions such as kidney and heart disease, as well as stroke.

There were 784 strokes among 20,415 participants taking folic acid, compared to 791 strokes reported among 18,590 people who did not take the supplements.

The analysis, in the American Heart Association's journal Stroke, settles the question about whether folic acid supplementation leads to a major reduction in stroke, Saver said.

"The answer is 'no,'" Saver said.

Still, the researchers suggest more research into folic acid and stroke, particularly for men and those in the earliest stages of heart disease. Data from both of those groups suggested there might be an effect, although researchers could not determine whether or not that was due to chance.

Those potential benefits appeared in trials carried out in countries whose food supplies were not fortified with folic acid. In the U.S., the benefits of folic acid supplementation may have already been achieved through food fortification, Saver noted. In an effort to reduce the birth defect spina bifida, the U.S. Food and Drug Administration required the addition of folic acid to all enriched cereal-grain foods starting in 1998.

"Extra pills don't make that much additional difference," Saver said.

 

More kids eat dinner from Uncle Sam

13 states, plus D.C., provide after-school supper programs

BRATTLEBORO, Vt. - While the other preschoolers were warming up to the vegetable pesto lasagna, 3-year-old Avery Bennett dove in with no hesitation.

"Can I have some more lasagna?" Bennett said from her booster seat. "I love it."

She moved on to her seconds, and the other kids at the evening care program in Brattleboro were also chomping down the dish made of spinach, peppers, carrots, tomato, fresh basil and cheese.

More low-income school kids could soon have access to free nutritious dinners like the lasagna that Avery loved. A U.S. Department of Agriculture program in Vermont, 12 other states and the District of Columbia provides reimbursements for the suppers, served at after-school programs for at-risk kids in communities where at least 50 percent of households fall below the poverty level.

"What it allows us to do is provide those kids with an extra nutritious meal before they go home because some kids go home to nothing," said Susan Eckes, director of child nutrition programs for the Food Bank of Northern Nevada in McCarran, Nev.

Around the country, about 49,000 children benefit from the after-school meals each day. The program is expected to cost a total of $8 million from 2009 to 2013, the USDA said.

With more families losing jobs and homes, the need is growing, officials said.

The number of Americans who live in food-insecure households — which at times don't have enough nutritious food — rose from 36 million people in 2007 to 49 million in 2008, according to the most recent report from USDA's Economic Research Service.

Among those, 16.7 million were children, up from 12.4 million in 2007.

Nearly one in four children in the U.S. are food insecure and about one in five live in poverty, according to a report from Feeding America, a network of 200 food banks around the country.

"As the economy gets worse, we're seeing more and more kids," said Beth Baldwin-Page, executive director of the Boys & Girls Club of Brattleboro.

In East Prairie, Mo., kids who may have skipped the meal from time to time are coming every day, said Lester Gillespie, youth program director at the Susanna Wesley Family Learning Center, which serves 150 meals a day at two sites to kids age 5 to 18.

A lack of nutritious food, especially in the first three to five years, can have lasting effects on the health and development of children. Filling their stomachs with nutritional meals helps them learn and concentrate, officials have said.

"What we've noticed is that when kids are eating nutritional meals, they tend not to get involved in negative activities such as doing graffiti or committing delinquent acts because when their stomach is full they make good decisions," said Gillespie.

Programs in Connecticut, Delaware, Illinois, Maryland, Michigan, Missouri, Nevada, New York, Oregon, Pennsylvania, West Virginia, Wisconsin, the District of Columbia and now in Vermont are eligible for reimbursement for suppers.

The USDA requires the sites to offer nutritionally balanced suppers with milk, a protein, fruit, vegetables and bread or a grain item.

Delaware, where the supper program is one of the fastest-growing child nutrition programs in the state, has gone a step further, prohibiting the use of any grain product that contains more than 6 grams of sugar or any product where more than 35 percent of calories are derived from fat.

The Brattleboro Boys & Girls Club started offering dinners on its own two and a half years ago. When it learned the supper program was being expanded to Vermont, it applied for and just starting getting the federal reimbursement of $2.68 per meal.

Three days a week, the club offers dinners feeding 40 to 60 kids on a Thursday night to up to 100 on Friday.

"It's popular. Unfortunately, it's necessary," said Ricky Davidson, unit director.

"We see families getting evicted left and right. They don't have a place to live, let alone cook food," Baldwin-Page said.

Bernie Parent, 18, of Brattleboro has relied on the meals since he and his mother became homeless last year.

Now living on his own in an apartment, going to high school, and working at the Boys & Girls Club, he still relies on the three free dinners each week.

"It helps out a lot," he said.

 

Being a supertaster is no piece of cake

Being a “supertaster” may sound like a foodie’s dream come true, but in reality, it’s no picnic.

Coffee and alcohol are unpalatable – along with tomatoes, Parmesan cheese, strawberries, condiments and most sweets.

“I can’t stand cake,” says Michelle Triplett, a 31-year-old stay-at-home mom and supertaster from Olympia, Wash., who spoke, coincidentally, on her birthday.  “It’s too sweet for me. And when I drink beer, I gag. It’s like drinking urine.”

Supertasters detect components – like salt or bitterness -- in food that others can’t, says Dr. Alan Hirsch, founder and neurological director of the Smell & Taste Treatment and Research Foundation in Chicago.

“[Supertasters] have densities of taste buds that are 10 to 100 times greater than the normal population,” he says. “As a result, supertasters are much more sensitive to spicy foods and they can taste … very mild flavors.”

Triplett, whose favorite meals are turkey sandwiches and macaroni and cheese, says the blander the better, since most everything else is, as They Might Be Giants put it in their song “John Lee Supertaster,” simply “too much.” 

The condition is genetic, tends to affect women more than men and affects 25 percent of the U.S. population; non-tasters (people with a reduced ability to taste) make up another 25 percent with the rest of the population described as medium or normal tasters.

While there are some benefits -- supertasters tend to avoid sugars, salts and fats, so they suffer less from obesity and cardiovascular disease – there’s a potential downside. Supertasters often avoid green vegetables because of their bitter taste, so they miss out on cancer-fighting flavanoids and other nutrients.

 “Many vegetables have bitterness in them -- like green pepper – so a supertaster may avoid [them],” says Hirsch.  Other problem veggies include broccoli, Brussels sprouts, cabbage, kale, olives and spinach.

 “When I get Brussels sprouts on my tongue, I immediately want to pull that whole patch of tongue off,” says Triplett. Tomato-based foods, apples and blueberries are also too potent for her.

Supertasters are also more prone to burning mouth syndrome, a condition in which a person’s tongue or mouth feels like it’s on fire.

“It’s horribly disabling,” says Hirsch. “You can’t eat food, you can only drink water and it can be quite painful.

If you think you’re a supertaster, a five-minute survey developed by Cornell University can help. There’s also a home test involving blue food coloring. Or a simple taste test – available for a small fee -- that uses a filter paper impregnated with a chemical known 6-n-propylthiouracil (PROP).  Non-tasters won’t taste anything on the paper; medium tasters will taste a small amount of bitterness. Supertasters, however, will find the chemical “stomach-wrenchingly bitter.”