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May 11, 2008

Running Out of Fish

I have posted before about the overfishing problems: Fishless Future - SelFISHing - Chinook Salmon Vanish Without a Trace. Here is an emotional article on the problem - How the world’s oceans are running out of fish

Ninety years of industrial-scale exploitation of fish has, he and most scientists agree, led to ‘ecological meltdown’. Whole biological food chains have been destroyed.

In 2002, the year an EU report revealed that the Senegalese fish biomass had declined 75 per cent in 15 years, Brussels bought rights for four years’ fishing of tuna and bottom-dwelling fish on the Senegal coasts, for just $4m a year. In 2006, access for 43 giant EU factory fishing vessels to Mauritania’s long coastline was bought for £24.3m a year. It’s estimated that these deals have put 400,000 west African fishermen out of work; some of them now take to the sea only as ferrymen for desperate would-be migrants to the Canary Islands and Europe.

Protecting up to 40 per cent of the world’s oceans in permanent refuges would enable the recovery of fish stocks and help replenish surrounding fisheries. ‘The cost, according to a 2004 survey, would be between £7bn and £8.2bn a year, after set-up. But put that against the £17.6bn a year we currently spend on harmful subsidies that encourage overfishing.’

The Newfoundland cod fishery, for 500 years the world’s greatest, was exhausted and closed in 1992, and there’s still no evidence of any return of the fish. Once stocks dip below a certain critical level, the scientists believe, they can never recover because the entire eco-system has changed.
May 8, 2008

Curious Platypus Genome is No Surprise

Platypus Genome Found Fittingly Strange by Rick Weiss

a team of scientists has determined the platypus’s entire genetic code. And right down to its DNA, it turns out, the animal continues to strain credulity, bearing genetic modules that are in turn mammalian, reptilian and avian.

There are genes for egg laying — evidence of its reptilian roots. Genes for making milk, which the platypus does in mammalian style despite not having nipples. Genes for making snake venom, which the animal stores in its legs. And there are five times as many sex-determining chromosomes as scientists know what to do with.

“It’s such a wacky organism,” said Richard Wilson, director of the Genome Sequencing Center at Washington University in St. Louis, who with colleague Wesley Warren led the two-year effort, described today in the journal Nature.

Yet in its wackiness, Wilson said, the platypus genome offers an unprecedented glimpse of how evolution made its first stabs at producing mammals. It tells the tale of how early mammals learned to nurse their young; how they matched poisonous snakes at their venomous game; and how they struggled to build a system of fertilization and gestation that would eventually, through relatives that took a different tack, give rise to the first humans.

“As we learn more about things like platypuses,” Wilson said, “we also learn more about ourselves and where we came from and how we work.”

Very cool stuff. Related: Platypus genome explains animal’s peculiar features; holds clues to evolution of mammals - Platypus genome mapping boon for human and livestock researchers - Platypus genetic code unravelled - Weird Creatures - Evolution is Fundamental to Science - Long-Eared Jerboa - Cat Joins Exclusive Genome Club - Your Inner Fish

May 7, 2008

Elephants Classify Human Ethnic Groups that Hunt Them by Odor

Wash Your Clothes: Elephants Can Smell You a Mile Away

…in Amboseli National Park in Kenya. Elephants in the region encounter different ethnic groups, including the Maasai, whose young men spear elephants, and the Kamba, agricultural villagers who pose no threat at all.

The researchers observed elephants exposed to the scent from identical cloth garments, some worn by Maasai men, others by Kamba men and some that were unworn. The Maasai scent produced the strongest reactions, with elephants moving farther and faster to distance themselves from the odor source, often not stopping until reaching tall grass. The elephants also took far longer to calm down than those exposed to scents from the Kamba and unworn cloths.

Related: Fighting Elephant Poaching With Science - Effect of People on Other Species - Water Buffaloes, Lions and Crocodiles Oh My - Curious Cat Travel Photos: Kenya

May 6, 2008

Breastfeeding Linked to More Intelligent Kids

McGill study links breastfeeding to increased intelligence

The largest randomized study of breastfeeding ever (14,000 children for 6.5 years) conducted reports that breastfeeding raises children’s IQs and improves their academic performance, a McGill researcher and his team have found.

“Our study provides the strongest evidence to date that prolonged and exclusive breastfeeding makes kids smarter,” said Kramer, a Professor of Pediatrics and of Epidemiology & Biostatistics in the McGill University Faculty of Medicine and lead investigator in the study.

Kramer and his colleagues evaluated the children in 31 Belarusian hospitals and clinics. Half the mothers were exposed to an intervention that encouraged prolonged and exclusive breastfeeding. The remaining half continued their usual maternity hospital and outpatient pediatric care and follow-up. This allowed the researchers to measure the effect of breastfeeding on the children’s cognitive development without the results being biased by differences in factors such as the mother’s intelligence or her way of interacting with her baby.

The children’s cognitive ability was assessed by IQ tests administered by the children’s pediatricians and by their teachers’ ratings of their academic performance in reading, writing, mathematics and other subjects. Both sets of measures were significantly higher in the group randomized to the breastfeeding promotion intervention.

“The effect of breastfeeding on brain development and intelligence has long been a popular and hotly debated topic,” says Dr. Kramer. “While most studies have been based on association, however, we can now make a causal inference between breastfeeding and intelligence – because of the randomized design of our study.”

Related: Brain Development - How The Brain Rewires Itself - The Brain is Wired to Mull Over Decisions - Breast-feeding called smart choice

May 5, 2008

Molecular Action May Help Keep Birds on Course

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.

Related: Monarch Butterfly Migration - Mini Helicopter Masters Insect Navigation Trick - Other bird tagged posts

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.

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.

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.

Related: $500 Million to Reduce Childhood Obesity in USA - Obesity Epidemic Explained - Kind Of - Drinking Soda and Obesity

May 4, 2008

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.

Related: Backyard Wildlife: Sharpshinned Hawk - Cool Crow Research - Backyard Wildlife: Fox - Backyard Wildlife: Turtle

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
(more…)

May 3, 2008

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.

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.

Related: The Study of Bee Colony Collapses Continues - Bye Bye Bees - Scientists Search for Clues To Bee Mystery

May 2, 2008

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.

Related: Giant Wasp Nests - 24 hectare Spider Web - Wasps Used to Detect Explosives

April 29, 2008

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.

Related: Scientists and Engineers in Congress - Science and Engineering in Politics - The A to Z Guide to Political Interference in Science

April 28, 2008

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

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.

Related: Borneo Orangutan Survival Foundation UK - Bornean Clouded Leopard - Savanna Chimpanzees Hunt with Tools - First Lungless Frog Found in Borneo - Chimps Used Stone “Hammers” - more fun posts on the blog

April 27, 2008

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.

Related: Diplomacy and Science Research - Five Scientists Who Made the Modern World - 2004 Medal of Science Winners - U.S. Slipping on Science

April 24, 2008

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

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.”

Related: Ministry of Silly Walks - Treadmill Desks

Bacteriophages: The Most Common Life-Like Form on Earth

photo of bacteriophage

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 ago. 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

Related: webcast of Bacteriophage T4 - types of microbes - What are Viruses? - Amazing Science: Retroviruses - Using Bacteria to Carry Nanoparticles Into Cells

Amazon Molly Fish are All Female

No sex for all-girl fish species

A fish species, which is all female, has survived for 70,000 years without reproducing sexually, experts believe.

The species, found in Texas and Mexico, interacts with males of other species to trigger its reproduction process. The offspring are clones of their mother and do not inherit any of the male’s DNA. Typically, when creatures reproduce asexually, harmful changes creep into their genes over many generations.

One theory is that the fish may occasionally be taking some of the DNA from the males that trigger reproduction, in order to refresh their gene pool.

Dr Laurence Loewe, of the university’s School of Biological Sciences, said: “What we have shown now is that this fish really has something special going on and that some special tricks exist to help this fish survive. “Maybe there is still occasional sex with strangers that keeps the species alive. Future research may give us some answers.”

He added that their findings could also help them understand more about how other creatures operate. “I think one of the interesting things is that we are learning more about how other species might use these tricks as well,” he said. “It might have a more general importance.”

Related: Female Sharks Can Reproduce Alone - Only Dad’s Genes - Bdelloid Rotifers Abandoned Sex 100 Million Years Ago - Sex and the Seahorse - more posts about fish

April 22, 2008

E. Coli Individuality

Expressing Our Individuality, the Way E. Coli Do by Carl Zimmer

A good counterexample is E. coli, a species of bacteria that lives harmlessly in every person’s gut by the billions. A typical E. coli contains about 4,000 genes (we have about 20,000). Feeding on sugar, the microbe grows till it is ready to split in two. It makes two copies of its genome, almost always managing to produce perfect copies of the original. The single microbe splits in two, and each new E. coli receives one of the identical genomes. These two bacteria are, in other words, clones.

A colony of genetically identical E. coli is, in fact, a mob of individuals. Under identical conditions, they will behave in different ways. They have fingerprints of their own.

E. coli appears to follow a universal rule. Other microbes exploit noise, as do flies, worms and humans. Some of the light-sensitive cells in our eyes are tuned to green light, and others to red. The choice is a matter of chance. One protein may randomly switch on the green gene or the red gene, but not both.

In our noses, nerve cells can choose among hundreds of different kinds of odor receptors. Each cell picks only one, and evidence suggests that the choice is controlled by the unpredictable bursts of proteins within each neuron. It’s far more economical to let noise make the decision than to make proteins that can control hundreds of individual odor receptor genes.

Identical genes can also behave differently in our cells because some of our DNA is capped by carbon and hydrogen atoms called methyl groups. Methyl groups can control whether genes make proteins or remain silent. In humans (as well as in other organisms like E. coli), methyl groups sometimes fall off of DNA or become attached to new spots. Pure chance may be responsible for changing some methyl groups; nutrients and toxins may change others.

Related: Androgenesis - Sick spinach: Meet the killer E coli - Parasite Rex

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