Category Archives: Life Science

Molecular Action May Help Keep Birds on Course

Four decades after scientists showed that migratory birds use Earth’s magnetic field to orient themselves during their seasonal journeys, researchers have at last found a molecular mechanism that may explain how they do it.

If the hypothesis is true, the planet’s magnetic field lines — which arch around Earth from north to south — may be plainly visible to birds, like the dashed line in the middle of a road.

The work, described online yesterday in the journal Nature, was conducted in a test tube and does not prove that birds actually use the mechanism. And researchers aligned with a competing model say they are not convinced.

But by identifying for the first time a molecule that reacts to very weak magnetic fields, the experiments prove the plausibility of a long-hypothesized method of avian navigation that has had a credibility problem because no one had ever found a molecule with the required sensitivity.

Fat Cell Count Set in Childhood

Fat cell number is set in childhood and stays constant in adulthood

As fat people have an abundance of fat tissue, the natural assumption is that fat people have more fat cells, or ‘adipocytes’. That’s only part of the story – it turns out that overweight and obese people not only have a surplus of fat cells, they have larger ones too.
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During adulthood, about 8% of fat cells die every year only to be replaced by new ones. As a result, adults have a constant number of fat cells, even those who lose masses of weight. Instead, it’s changes in the volume of fat cells that causes body weight to rise and fall.
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we couldn’t have a clearer indication of the importance of childhood as a window for preventing obesity and the chronic diseases affected by it – cancer, heart disease, diabetes and more.

The message is especially stark following the recent Foresight report, which estimated that if current trends are left unchecked, by 2050 a quarter of all UK children under the age of 16 will be obese. The knowledge that their fat cell count will then be set for life makes the cost of inaction even higher. Fortunately, it seems that the UK Government is taking appropriate steps and recently pledged over a third of a billion pounds on a concerted strategy to tackle childhood obesity.

Backyard Wildlife: Birds

photo of a bird

The last few days a bird like this one has been chasing a crow in my yard (unfortunately I have not been able to get an action picture of that). If you know what type of bird this is please add a comment.

When I see robins pecking away in the grass sometimes I see them get worms but my guess is they often are eating other stuff. I also see starlings feeding on my lawn. I found some online links that I quote below on what robins and starlings eat.

From the Yardener:

Next to beneficial insects, songbirds consume the most pest insects in your yard. Robins, blackbirds, flickers and starlings will eat a lot of webworms if they are in your lawn. Many seed-eating birds prey on caterpillars while raising their young. Encourage birds to settle in or near your yard and prey on fleas by offering them food, water, and shelter.

Cornell University: American Robin

The American Robin eats both fruit and invertebrates. Earthworms are important during the breeding season, but fruit is the main diet during winter. Robins eat different types of food depending on the time of day; they eat earthworms early in the day and more fruit later in the day.

History And Biology Of European Starlings In North America
Continue reading →

Colony Collapse Disorder Continues

1.1 Million Bee Colonies Dead This Year

The information provided here was generated by a survey conducted by the Apiary Inspectors of America. They took the survey in January and February this year, and in the process, gathered information from 18% of the colonies in the U.S.

The survey found that about 35% of all the colonies in the U.S. died last winter. Of those that died, 71% died of natural causes, 29% from symptoms that are suspect colony collapse disorder. Doing the math that comes to at least 10% of all the bees in the U.S. last year died of Colony Collapse Disorder.
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Considering all these factors, undue concern over IAPV detection is not warranted. While IAPV’s role in colony losses remains a priority in ongoing research, we do know that high levels of other common bee viruses, such as KBV, DWV, and ABPV, have also been linked with certain incidences of high colony mortality or decline in worker numbers. We also know that nearly all bee colonies are infected with at least one type of virus and that all these viruses are potentially pathogenic.

The research continues. As I have said before this is a great example of scientists in action trying to figure out what is happening.

Vanishing Giant Nests of Yellow-jackets

Giant wasp nest

Vanishing Nests

Only a year ago, an Auburn University research entomologist encountered a phenomenon that beggared description – 16 super-sized yellow jacket nests throughout central and south Alabama.

By the end of the summer, the number of reported nests increased to more than 80. Auburn researcher Dr. Charles Ray speculates there probably were hundreds more undetected nests throughout the state. One nest collector spotted 10 of these nests in Lowndes County alone, while an Alabama Cooperative Extension System agent in Covington County reported as many as 25 nests.

Why were these gigantic nests considered such oddities? Because entomologists such as Ray could go an entire career without seeing scarcely one of these huge nests. This year, though, the nests seem to have vanished as quickly as dissipating clouds. Working closely with Alabama Extension agents and other monitors throughout the state, Ray hasn’t turned up so much as one nest this year.

“The summer of 2006 may prove to be a once in a lifetime opportunity,” say Ray, who considers the discovery of the nests one of the high points of his career. So what accounts for this once in a lifetime occurrence? Ray speculates it had to do with an unusually mild 2006 winter. “The mid-20s was about as cold as it got that year – only about a day or two of really cold weather,” says Ray, adding that this extremely mild winter probably established optimal conditions for the yellow jackets the following spring.

Autism, Science and Politics

Clinton and Obama parrot the “vaccine and autism connection inconclusive” line by Tara C. Smith:

Ugh. At least they don’t say there’s “strong evidence” to support it like McCain. I can certainly get behind more research on environmental factors in autism development (and of course, additional funding for biomedical research, period), but we’ve been there/done that for vaccines. I wonder if either of them are even aware of The National Children’s Health Study?

The National Children’s Study will examine the effects of environmental influences on the health and development of more than 100,000 children across the United States, following them from before birth until age 21. The goal of the study is to improve the health and well-being of children.

Variables examined will include vaccinations received, and development of autism will be one of the outcomes examined. What more can you ask for? Obama and Clinton’s claims of ignorance on the part of the scientific community when it comes to vaccines and autism show that we don’t have any real science defenders in the running.

Orangutan Attempts to Hunt Fish with Spear

photo of orangutan attempting spear fishing

Orangutan attempts to hunt fish with spear:

A male orangutan, clinging precariously to overhanging branches, flails the water with a pole, trying desperately to spear a passing fish. It is the first time one has been seen using a tool to hunt. The extraordinary image, a world exclusive, was taken in Borneo on the island of Kaja, where apes are rehabilitated into the wild
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This individual had seen locals fishing with spears on the Gohong River. Although the method required too much skill for him to master, he was later able to improvise by using the pole to catch fish already trapped in the locals’ fishing lines.

Cool. The photos is from a new book on orangutans, The Thinkers Of The Jungle, which also includes the first photograph of an orangutan swimming.

Wheat Rust Research

By increasing the production of wheat it is said Norman Borlaug has saved more lives than anyone else who ever lived, for which he was awarded the 1970 Nobel Peace Prize. See his New York Times opinion piece: Stem Rust Never Sleeps

Today, wheat provides about 20 percent of the food calories for the world’s people. The world wheat harvest now stands at about 600 million metric tons.

In the last decade, global wheat production has not kept pace with rising population, or the increasing per capita demand for wheat products in newly industrializing countries. At the same time, international support for wheat research has declined significantly. And as a consequence, in 2007-08, world wheat stocks (as a percentage of demand) dropped to their lowest level since 1947-48. And prices have steadily climbed to the highest level in 25 years.

The new strains of stem rust, called Ug99 because they were discovered in Uganda in 1999, are much more dangerous than those that, 50 years ago, destroyed as much as 20 percent of the American wheat crop. Today’s lush, high-yielding wheat fields on vast irrigated tracts are ideal environments for the fungus to multiply, so the potential for crop loss is greater than ever.

If publicly financed international researchers move together aggressively and systematically, high-yielding replacement wheat varieties can be developed and made available to farmers before stem rust disease becomes a global epidemic.

The Bush administration was initially quick to grasp Ug99’s threat to American wheat production. In 2005, Mike Johanns, then secretary of agriculture, instructed the federal agriculture research service to take the lead in developing an international strategy to deal with stem rust. In 2006, the Agency for International Development mobilized emergency financing to help African and Asian countries accelerate needed wheat research.

But more recently, the administration has begun reversing direction. The State Department is recommending ending American support for the international agricultural research centers that helped start the Green Revolution, including all money for wheat research. And significant financial cuts have been proposed for important research centers, including the Department of Agriculture’s essential rust research laboratory in St. Paul.

This shocking short-sightedness goes against the interests not only of American wheat farmers and consumers but of all humanity. It is tantamount to the United States abandoning its pledge to help halve world hunger by 2015.

Walking Without Shoes

You Walk Wrong

Last year, researchers at the University of the Witwatersrand in Johannesburg, South Africa, published a study titled “Shod Versus Unshod: The Emergence of Forefoot Pathology in Modern Humans?” in the podiatry journal The Foot. The study examined 180 modern humans from three different population groups (Sotho, Zulu, and European), comparing their feet to one another’s, as well as to the feet of 2,000-year-old skeletons. The researchers concluded that, prior to the invention of shoes, people had healthier feet. Among the modern subjects, the Zulu population, which often goes barefoot, had the healthiest feet while the Europeans – i.e., the habitual shoe-wearers – had the unhealthiest
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My new Vivo Barefoots aren’t perfect – they’re more or less useless in rain or snow, and they make me look like I’m off to dance in The Nutcracker. But when I don’t wear them now, I kind of miss them. Not because they’re supposedly making my feet healthier, but because they truly make walking more fun. It’s like driving a stick shift after years at the wheel of an automatic – you suddenly feel in control of an intricate machine, rather than coasting on cruise control. Now I better understand what Walt Whitman meant when he wrote (and I hate to quote another Transcendentalist, but they were serious walking enthusiasts): “The press of my foot to the earth springs a hundred affections.”

Bacteriophages: The Most Common Life-Like Form on Earth

There are more bacteriophages on Earth than any other life-like form. These small viruses are not clearly a form of life, since when not attached to bacteria they are completely dormant. Bacteriophages attack and eat bacteria and have likely been doing so for over 3 billion years. Although initially discovered early last century, the tremendous abundance of phages was realized more recently when it was found that a single drop of common seawater typically contains millions of them. Extrapolating, phages are likely to be at least a billion billion times more numerous than humans. Pictured above is an electron micrograph of over a dozen bacteriophages attached to a single bacterium. Phages are very small — it would take about a million of them laid end-to-end to span even one millimeter. The ability to kill bacteria makes phages a potential ally against bacteria that cause human disease, although bacteriophages are not yet well enough understood to be in wide spread medical use.

Photo credit: Wikipedia Electron micrograph of bacteriophages attached to a bacterial cell. These viruses have the size and shape of coliphage T1.; Insert: Mike Jones