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Tuesday, March 29, 2011

On Constitutions

A Constitution is not Platonic panacea for justice and freedom, but the flesh-and-blood instantiation of ordinary human beings engaged in eternal power games – Alex O. Awiti, 2011

Monday, March 28, 2011

In Memory of Distinguished Scholar

Thomas Eisner, a world-renowned authority on animal behavior, chemical ecology and evolution,died on March 25 at his home in Ithaca NY at the age of 81. Eisner is widely regarded as the father of chemical ecology.

In nine books and on film, he chronicled his studies of insects and how they mate, trap their prey and fend off predators. His book "For Love of Insects" won the Best Science Book in the 2004 Independent Publisher Book Awards and the Louis Thomas Prize for Writing.

Eisner's passion for insects prompted him to draw from the fields of chemistry, biology, ecology, evolution, behavior, morphology and even engineering in his quest to understand insect physiology, adaptation and behavior.

He explored highly evolved processes and systems among insects, such as chemical defenses, that were previously unexplored. He referred to insects as "master chemists" and was an authority on their pheromones and chemical ecology.

In his career, Eisner made numerous discoveries of remarkable biological phenomena and science is eternally indebted to him.

Eisner earned the 1994 National Medal of Science, the highest scientific honor in the United States; the Committee on the National Medal of Science cited him for his "seminal contributions in the fields of insect behavior and chemical ecology and for his international efforts on biodiversity."

This text is an excerpt from an obituary written by Susan Lang, Cornell Chronicle.
Sent from my BlackBerry® smartphone from Zain Kenya

Wednesday, March 16, 2011

Collapse of Banana Republic?

Most countries would resent being called a banana republic. Ugandans take great pride at this label. A typical adult here eats at least three times his or her body weight in bananas each year. Different varieties are steamed, boiled, roasted, turned into gin and beer, or simply peeled and eaten raw. In Uganda it is banana for breakfast, lunch and dinner, 365 days a year. And the craving won’t go away.

But this craving is under threat. In recent years a devastating bacterial disease has swept across Uganda and, to a lesser extent, neighboring countries, causing annual banana crop losses to the region of more than $500m (£310m). The rapid spread of banana Xanthomonas wilt or known simply as BXW, which destroys the entire plant and contaminates the soil, has put at risk livelihoods of millions of families who depend on banana for staple food and income.

With no resistant varieties or chemical cures available, growers have been forced to destroy large banana crops or entire plantations. For smaller farmers the damage has been so severe, with families giving up banana production.
But scientists from Uganda’s National Banana Research Program working in collaboration with International Institute for Tropical Agriculture (IITA) and African Agricultural Technology Foundation (AATF) are hard at work building a better banana. This has involved adding to the fruit a sweet pepper gene, which produces a protein that kills cells infected by disease-spreading bacteria. This gene has been successfully transplanted into other vegetables, but never before in a banana.

Laboratory tests on the genetically modified bananas is promising, with six out of eight strains proving 100% resistant to BXW. Field tests have now started.

Results from the trials, expected later this year, could have a strong bearing on the country's food security and livelihood for a majority of households and more importantly, on agriculture and GM policy. GM crops are still banned in Uganda and the East African Community (EAC) region. In Uganda, the scientists had to obtain special permission.

Sunday, March 13, 2011

Maternal diet and disease risk in offsprings

Environmental factors interact with the genome throughout life to determine gene expression and, consequently, tissue function and disease risk. One such factor that is known to play an important role in determining long-term metabolic health is diet during critical periods of development.

A recent published the 08 March edition of PNAS by Ionel Sandovici of the University of Cambridge and others provides important insight into why children born to mothers who consumed an unhealthy diet during pregnancy have an increased risk of type 2 diabetes (T2D), a significant contributing factor to heart disease and cancer) later in life. The precise epigenetic mechanisms that underlie these effects remain largely unknown.

In conclusion, our study demonstrates that Hnf4a expression in islets is under tight epigenetic control that is dynamically modulated by maternal diet during early development and by aging. In particular, we demonstrated that the enhancer region is especially susceptible to epigenetic changes resulting from alterations in early nutrition and during the aging process. We propose that changes in promoter–enhancer interactions represent a more general epigenetic mechanism by which early nutrition interacts with the genome to influence gene expression and metabolic health

See full article

Sunday, March 6, 2011

Understanding Sleep-Wake Continuum

Why does the rustle of sheets wake us up on some nights, yet we sleep through the sound of our alarm clocks going off on others? Sleep scientists Scott McKinney of Massachusetts General Hospital in Boston and colleagues used a sophisticated computer program to find out.

The study by McKinney and Ellenbogen implicates tat a type of brain activity known as alpha waves may provide vital clues. With better monitoring of these waves, researchers might be able to develop therapies that could help all of us get a better night's sleep

Our brain activity changes throughout the day. When we're awake, our neurons chatter in short, frequent bursts. Measured on an electroencephalogram (EEG), these "alpha waves" look a lot like earthquake squiggles on a seismograph. When we sleep, our neuron chatter slows down, resulting in less squiggly theta and delta waves. Scientists have shown that alpha waves help us respond to the sights and sounds of our environment. Yet they seem to disappear during sleep, even though we are still able to respond to environmental cues, such as smoke or a passing police siren.

To find out what role these nighttime alpha waves play, McKinney and colleagues recruited 13 healthy subjects to spend several nights in the hospital's sleep lab. When the subjects' EEGs showed that they were sleeping deeply, the researchers played a variety of noises, from a jet engine to an ice machine. The noises started softly, at approximately 40 decibels—about as loud as a quiet home. The researchers gradually increased the noise until the person's EEG spiked, a sign that sleep had been disrupted.

The article concludes that the signal which transcends the boundaries of classical sleep stages, could potentially be used for real-time feedback to novel, adaptive drug delivery systems for inducing sleep.

See full article "Covert Waking Brain Activity Reveals Instantaneous Sleep Depth" in PLoS One.


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