Tag Archives: Life Science

Nearly 1 million Children Potentially Misdiagnosed with ADHD in the USA

Nearly 1 million children in the United States are potentially misdiagnosed with attention deficit hyperactivity disorder simply because they are the youngest – and most immature – in their kindergarten class, according to new research by , Todd Elder, a Michigan State University economist.

These children are significantly more likely than their older classmates to be prescribed behavior-modifying stimulants such as Ritalin, said Todd Elder, whose study will appear in a forthcoming issue of the Journal of Health Economics (closed science, unfortunately). Michigan State should stop funding closed journals with free content – other schools have decided to put science first, before supporting a few outdated business models of select journals.

Such inappropriate treatment is particularly worrisome because of the unknown impacts of long-term stimulant use on children’s health, Elder said. It also wastes an estimated $320 million-$500 million a year on unnecessary medication – some $80 million-$90 million of it paid by Medicaid, he said.

ADHD is the most commonly diagnosed behavioral disorder for kids in the United States, with at least 4.5 million diagnoses among children under age 18, according to the Centers for Disease Control and Prevention.

The youngest kindergartners were 60 percent more likely to be diagnosed with ADHD than the oldest children in the same grade. Similarly, when that group of classmates reached the fifth and eighth grades, the youngest were more than twice as likely to be prescribed stimulants.

Overall, the study found that about 20 percent – or 900,000 – of the 4.5 million children currently identified as having ADHD likely have been misdiagnosed.

Ants, Ants, Ants

Ants really are amazing. The internet makes it easy to learn about these creatures. My Dad found them fascinating and I picked up that view. I had a flying one, flying around my house yesterday.

“Ants: The Invisible Majority” including Dr. Brian Fisher, chairman of the Department of Entomology at the Cal Academy of Sciences looking for ants in San Francisco. He created AntWeb, an online resource. The video discusses the Argentine Ant super colonies.

Are you ready for a world without antibiotics?

[Professor Tim Walsh] “This is potentially the end. There are no antibiotics in the pipeline that have activity against NDM 1-producing enterobacteriaceae. We have a bleak window of maybe 10 years, where we are going to have to use the antibiotics we have very wisely, but also grapple with the reality that we have nothing to treat these infections with.”

And this is the optimistic view – based on the assumption that drug companies can and will get moving on discovering new antibiotics to throw at the bacterial enemy. Since the 1990s, when pharma found itself twisting and turning down blind alleys, it has not shown a great deal of enthusiasm for difficult antibiotic research. And besides, because, unlike with heart medicines, people take the drugs for a week rather than life, and because resistance means the drugs become useless after a while, there is just not much money in it.
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“The emergence of antibiotic resistance is the most eloquent example of Darwin’s principle of evolution that there ever was,” says Livermore. “It is a war of attrition. It is naive to think we can win.”

I have been writing about the huge risks we are talking with our future for years. The careless misuse of antibiotics is very costly (in human lives, in the future). Bacteria pose great risks to us. We need to take antibiotics to fight serious threats. The misuse of antibiotics by doctors, patients, agri-business… is the problem. And we are all living a much riskier future because far to little is being done to reduce the misuse of antibiotics.

More and more antibiotic treatments are losing effectiveness as bacteria evolve resistance. The evolution is accelerated by misuse. This costs lives today, but is likely to costs many thousands and hundreds of thousands and possible more in the next 50 years.

The NDM-1-producing bacteria were highly resistant to all antibiotics except tigecycline and colistin. In some cases, isolates were resistant to all antibiotics. The emergence of NDM-1 positive bacteria is potentially a serious global public health problem as there are few new anti-Gram-negative antibiotics in development and none that are effective against NDM-1.

Being sociable is good for your health

With a little help from your friends you can live longer

A circle of close friends and strong family ties can boost a person’s health more than exercise, losing weight or quitting cigarettes and alcohol, psychologists say.
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Holt-Lunstad’s team reviewed 148 studies that tracked the social interactions and health of 308,849 people over an average of 7.5 years. From these they worked out how death rates varied depending on how sociable a person was.

Being lonely and isolated was as bad for a person’s health as smoking 15 cigarettes a day or being an alcoholic. It was as harmful as not exercising and twice as bad for the health as being obese.

Open access paper: Social Relationships and Mortality Risk: A Meta-analytic Review.

Monarch Migration Research

Monarch Butterfly

Monarch butterflies – renowned for their lengthy annual migration to and from Mexico – complete an even more spectacular journey home than previously thought.

New research from the University of Guelph reveals that some North American monarchs born in the Midwest and Great Lakes fly directly east over the Appalachians and settle along the eastern seaboard. Previously, scientists believed the majority of monarchs migrated north directly from the Gulf Coast.

Unfortunately the press release doesn’t provide a link to the study – maybe it is not open science. Often organization focused on closed science don’t do well providing web links (though even open science organizations fall down on this more than they should).

“It solves the long-standing mystery of why monarchs always show up later on the east coast compared to the interior,” he said. “Importantly, it means that the viability of east coast populations is highly dependent upon productivity on the other side of the mountains.”

Monarchs travel thousands of kilometres each year from wintering sites in central Mexico back to North America’s eastern coast, a journey that requires multiple generations (in the same year) produced at various breeding regions.

Biologists had suspected that monarchs fly back from Mexico west-to-east over the Appalachians, but no evidence existed to support the theory. “Ours is the first proof of longitudinal migration,” Miller said.

For the study, the researchers collected 90 monarch samples from 17 sites between Maine and Virginia in June and July of 2009. They also collected 180 samples of milkweed (the only plant monarch larvae can eat) from 36 sites along the eastern coast between May and July of that year.

They then used hydrogen and carbon isotope measurements to determine when and where the monarchs were born. Isotope values in milkweed vary longitudinally and can be measured in monarch wings, Miller said. The researchers discovered that 88 per cent of the monarchs sampled originated in the Midwest and Great Lakes regions.

“This means that the recolonization of the east coast is by second-generation monarchs that hatched around the Great Lakes and then migrated eastward over the Appalachians,” Miller said. “We must target the Great Lakes region to conserve the east coast monarch populations.”

Full press release

White House Bee Hive

The White House added a bee hive last year. An Excellent White House Bee Adventure

On Tuesday, March 24, [2009] the first known hive of bees at the White House arrived at their location on the South Lawn. You don’t have to count on my crummy photo to see them: just stop by the fence on the Ellipse (south) side: two deeps and a medium of Maryland mixed breed bees, with known Russian and Caucasian genetics.
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During the 2008 campaign, Michelle Obama emphasized healthy, local food, and since arriving here has tasked her family’s personal chef, Sam Kass, with putting a garden in to supply fresh produce for the Executive Mansion and educational events for the community. Charlie realized that this was a chance to include bees, and to show their important role in putting one of every three bites on your plate. Charlie allocated (free of charge, people!) one of his own hives for the White House Victory Garden, and it will both provide hive products and an teaching opportunities.

Parasites in the Gut Help Develop a Healthy Immune System

It has long been known that microbes in the gut help to develop a healthy immune system, hence the rise in popularity of probiotic yoghurts that encourage ‘friendly’ bacteria. But new research by Professors Richard Grencis and Ian Roberts shows that larger organisms such as parasitic worms are also essential in maintaining our bodily ‘ecosystem’. “The worms have been with us throughout our evolution and their presence, along with bacteria, in the ecosystem of the gut is important in the development of a functional immune system.”

Parasite Rex is a great book, I have written about previously looking at parasites and their affect on human health.

Professor Grencis adds: “If you look at the incidence of parasitic worm infection and compare it to the incidence of auto-immune disease and allergy, where the body’s immune system over-reacts and causes damage, they have little overlap. Clean places in the West, where parasites are eradicated, see problems caused by overactive immune systems. In the developing world, there is more parasitic worm infection but less auto-immune and allergic problems.

“We are not suggesting that people deliberately infect themselves with parasitic worms but we are saying that these larger pathogens make things that help our immune system. We have evolved with both the bugs and the worms and there are consequences of that interaction, so they are important to the development of our immune system.”

Whipworm, also known as Trichuris, is a very common type of parasitic worm and infects many species of animals including millions of humans. It has also been with us and animals throughout evolution. The parasites live in the large intestine, the very site containing the bulk of the intestinal bacteria.

Heavy infections of whipworm can cause bloody diarrhoea, with long-standing blood loss leading to iron-deficiency anaemia, and even rectal prolapse. But light infections have relatively few symptoms.
Continue reading →

All present-day Life on Earth Has A Single Ancestor

All present-day life arose from a single ancestor

All life on Earth shares a single common ancestor, a new statistical analysis confirms.
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Because microorganisms of different species often swap genes, some scientists have proposed that multiple primordial life forms could have tossed their genetic material into life’s mix, creating a web, rather than a tree of life.
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A universal common ancestor is at least 10^2,860 times more probable than having multiple ancestors, Theobald calculates.
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For his analysis, Theobald selected 23 proteins that are found across the taxonomic spectrum but have structures that differ from one species to another. He looked at those proteins in 12 species – four each from the bacterial, archaeal and eukaryotic domains of life.

Then he performed computer simulations to evaluate how likely various evolutionary scenarios were to produce the observed array of proteins. Theobald found that scenarios featuring a universal common ancestor won hands down against even the best-performing multi-ancestor models.

Very interesting. Surprising too. As the article points out this doesn’t mean all life ever on Earth evolved from the single ancestor – life that has gone extinct could be from outside this single “tree.”

Variation in Human DNA

Variation on the order of thousands to hundreds of thousands of DNA’s smallest pieces – large swaths varying in length or location or even showing up in reverse order – appeared 4,205 times in a comparison of DNA from just four people.

Those structural differences popped into clear view through computer analysis of more than 500 linear feet of DNA molecules analyzed by the powerful genome mapping system developed over nearly two decades by David C. Schwartz, professor of chemistry and genetics at UW-Madison.

“We probably have the most comprehensive view of the human genome ever,” Schwartz says. “And the variation we’re seeing in the human genome is something we’ve known was there and important for many years, but we haven’t been able to fully study it.”

To get a better picture of those structural variations, Schwartz and his team developed the Optical Mapping System, a wholly new type of genome analysis that directly examines millions of individual DNA molecules.

“Our newer genome analysis systems, if commercialized, promise genome analysis in one hour, at under $1,000,” Schwartz says. “And we require that high speed and low cost to power the new field of personal genomics.”

Read full press release

Bee Colonies Continue to Collapse

The activity to find the causes of Colony Collapse Disorder provides a view into the scientific inquiry process of complex living systems. Finding answers is not easy.

Fears for crops as shock figures from America show scale of bee catastrophe

Disturbing evidence that honeybees are in terminal decline has emerged from the United States where, for the fourth year in a row, more than a third of colonies have failed to survive the winter.

The decline of the country’s estimated 2.4 million beehives began in 2006, when a phenomenon dubbed colony collapse disorder (CCD) led to the disappearance of hundreds of thousands of colonies. Since then more than three million colonies in the US and billions of honeybees worldwide have died and scientists are no nearer to knowing what is causing the catastrophic fall in numbers.
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It is estimated that a third of everything we eat depends upon honeybee pollination.
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Potential causes range from parasites, such as the bloodsucking varroa mite, to viral and bacterial infections, pesticides and poor nutrition stemming from intensive farming methods.
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“We believe that some subtle interactions between nutrition, pesticide exposure and other stressors are converging to kill colonies,” said Jeffery Pettis, of the ARS’s bee research laboratory.
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“It’s getting worse,” he said. “The AIA survey doesn’t give you the full picture because it is only measuring losses through the winter. In the summer the bees are exposed to lots of pesticides. Farmers mix them together and no one has any idea what the effects might be.” Pettis agreed that losses in some commercial operations are running at 50% or greater.

High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health (open access paper on the topic, March 2010)

The 98 pesticides and metabolites detected in mixtures up to 214 ppm in bee pollen alone represents a remarkably high level for toxicants in the brood and adult food of this primary pollinator. This represents over half of the maximum individual pesticide incidences ever reported for apiaries. While exposure to many of these neurotoxicants elicits acute and sublethal reductions in honey bee fitness, the effects of these materials in combinations and their direct association with CCD or declining bee health remains to be determined.