Category Archives: Life Science

Dennis Bray Podcast on Microbes As Computers

Carl Zimmer interviews Dennis Bray in an interesting podcast:

Dennis Bray is an active professor emeritus in both the Department of Physiology and Department of Neuroscience at the University of Cambridge. He studies the behavior of microbes–how they “decide” where to swim, when to divide, and how best to manage the millions of chemical reactions taking place inside their membranes. For Bray, microbes are tiny, living computers, with genes and proteins serving the roles of microprocessors.

2009 Nobel Prize in Chemistry: the Structure and Function of the Ribosome

graphic image of the components of a cell

Cross section of a cell by the Royal Swedish Academy of Sciences. A ribosome is about 25 nanometters (a millionth of a millimeter) in size. A cell contains tens of thousands of ribosomes.

The Nobel Prize in Chemistry for 2009 awards studies of one of life’s core processes: the ribosome’s translation of DNA information into life. Ribosomes produce proteins, which in turn control the chemistry in all living organisms. As ribosomes are crucial to life, they are also a major target for new antibiotics.

This year’s Nobel Prize in Chemistry awards Venkatraman Ramakrishnan, Thomas A. Steitz and Ada E. Yonath for having showed what the ribosome looks like and how it functions at the atomic level. All three have used a method called X-ray crystallography to map the position for each and every one of the hundreds of thousands of atoms that make up the ribosome.

Inside every cell in all organisms, there are DNA molecules. They contain the blueprints for how a human being, a plant or a bacterium, looks and functions. But the DNA molecule is passive. If there was nothing else, there would be no life.

The blueprints become transformed into living matter through the work of ribosomes. Based upon the information in DNA, ribosomes make proteins: oxygen-transporting haemoglobin, antibodies of the immune system, hormones such as insulin, the collagen of the skin, or enzymes that break down sugar. There are tens of thousands of proteins in the body and they all have different forms and functions. They build and control life at the chemical level.

Details from the Nobel Prize site (which continues to do a great job providing scientific information to the public openly).
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2009 Nobel Prize in Physiology or Medicine

This year’s Nobel Prize in Physiology or Medicine is awarded to three scientists who have solved a major problem in biology: how the chromosomes can be copied in a complete way during cell divisions and how they are protected against degradation. The Nobel Laureates have shown that the solution is to be found in the ends of the chromosomes – the telomeres – and in an enzyme that forms them – telomerase.

The long, thread-like DNA molecules that carry our genes are packed into chromosomes, the telomeres being the caps on their ends. Elizabeth Blackburn and Jack Szostak discovered that a unique DNA sequence in the telomeres protects the chromosomes from degradation. Carol Greider and Elizabeth Blackburn identified telomerase, the enzyme that makes telomere DNA. These discoveries explained how the ends of the chromosomes are protected by the telomeres and that they are built by telomerase.

If the telomeres are shortened, cells age. Conversely, if telomerase activity is high, telomere length is maintained, and cellular senescence is delayed. This is the case in cancer cells, which can be considered to have eternal life. Certain inherited diseases, in contrast, are characterized by a defective telomerase, resulting in damaged cells. The award of the Nobel Prize recognizes the discovery of a fundamental mechanism in the cell, a discovery that has stimulated the development of new therapeutic strategies.

Scientists began to investigate what roles the telomere might play in the cell. Szostak’s group identified yeast cells with mutations that led to a gradual shortening of the telomeres. Such cells grew poorly and eventually stopped dividing. Blackburn and her co-workers made mutations in the RNA of the telomerase and observed similar effects in Tetrahymena. In both cases, this led to premature cellular ageing – senescence. In contrast, functional telomeres instead prevent chromosomal damage and delay cellular senescence. Later on, Greider’s group showed that the senescence of human cells is also delayed by telomerase. Research in this area has been intense and it is now known that the DNA sequence in the telomere attracts proteins that form a protective cap around the fragile ends of the DNA strands.

Many scientists speculated that telomere shortening could be the reason for ageing, not only in the individual cells but also in the organism as a whole. But the ageing process has turned out to be complex and it is now thought to depend on several different factors, the telomere being one of them. Research in this area remains intense.

The 3 awardees are citizens of the USA; two were born elsewhere.
Read more about their research at the Nobel Prize web site.

Molecular biologist Elizabeth Blackburn–one of Time magazine’s 100 “Most Influential People in the World” in 2007–made headlines in 2004 when she was dismissed from the President’s Council on Bioethics after objecting to the council’s call for a moratorium on stem cell research and protesting the suppression of relevant scientific evidence in its final report.

Webcast of Dr. Elizabeth Blackburn speaking at Google:
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Norman E. Borlaug 1914-2009

The Father Of the Green Revolution

Norman E. Borlaug, 95, an American plant pathologist who won the Nobel Peace Prize in 1970 for starting the “Green Revolution” that dramatically increased food production in developing nations and saved countless people from starvation, died Saturday at his home in Dallas.

“More than any other single person of this age, he has helped provide bread for a hungry world,” the Nobel committee said in honoring him. “Dr. Borlaug has introduced a dynamic factor into our assessment of the future and its potential.”
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In his lecture accepting the Nobel Prize, he said an adequate supply of food is “the first component of social justice. . . . Otherwise there will be no peace.”
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In 1977, Dr. Borlaug received the Medal of Freedom, the highest civilian honor of the U.S. government.

Billions Served: Norman Borlaug interviewed by Ronald Bailey

As a matter of fact, Mother Nature has crossed species barriers, and sometimes nature crosses barriers between genera–that is, between unrelated groups of species. Take the case of wheat. It is the result of a natural cross made by Mother Nature long before there was scientific man. Today’s modern red wheat variety is made up of three groups of seven chromosomes, and each of those three groups of seven chromosomes came from a different wild grass. First, Mother Nature crossed two of the grasses, and this cross became the durum wheats, which were the commercial grains of the first civilizations spanning from Sumeria until well into the Roman period. Then Mother Nature crossed that 14-chromosome durum wheat with another wild wheat grass to create what was essentially modern wheat at the time of the Roman Empire.

Durum wheat was OK for making flat Arab bread, but it didn’t have elastic gluten. The thing that makes modern wheat different from all of the other cereals is that it has two proteins that give it the doughy quality when it’s mixed with water. Durum wheats don’t have gluten, and that’s why we use them to make spaghetti today. The second cross of durum wheat with the other wild wheat produced a wheat whose dough could be fermented with yeast to produce a big loaf. So modern bread wheat is the result of crossing three species barriers, a kind of natural genetic engineering.
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I see no difference between the varieties carrying a BT gene or a herbicide resistance gene, or other genes that will come to be incorporated, and the varieties created by conventional plant breeding. I think the activists have blown the health risks of biotech all out of proportion.
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the data that’s put out by the World Health Organization and [the U.N.’s Food and Agriculture Organization], there are probably 800 million people who are undernourished in the world. So there’s still a lot of work to do.

I am a bit more cautious about supporting genetic engineering in our food supply but I agree with him that we need to remain focused on the lives of hundreds of millions of hungry people (which is far too often ignored). I am worried about the risks to the environment and human health. I am also worried about the concentration of food plants in a greatly reduced genetic varieties that are more productive in general but increase the risks of massive food failures (due to limited genetic varieties).

40 New Species Found in Papua New Guinea

The rat is not afraid of humans, which could make it vulnerable. Photo by the BBC.

Yet another discovery of dozens of new species has been made. The rat that’s the size of a cat: 40 new species in ‘lost world’ at a remote volcano in Papua New Guinea.

In the kilometre-deep crater of Mount Bosavi, they found a habitat teeming with life which has evolved in isolation since the volcano last erupted 200,000 years ago.

Among the new species was the the Bosavi Woolly Rat. One of the biggest rats in the world, it measures just over 32 inches from nose to tail and weighs 3lb. The silvery grey mammal has dense fur and its teeth suggest it has a largely vegetarian diet and probably builds nests in tree hollows or underground.
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It is estimated that along with the giant rat and cuscus the expedition found about 16 species of frogs, one species of gecko, at least three species of fish, at least 20 of insects and spiders and possibly one new species of bat.
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Further evidence of the rich wildlife of the tropical location came with the discovery of the Bosavi Silky Cuscus. This animal, which resembles a small bear, is a marsupial that lives up in trees, feeding on fruits and leaves.

Weighing in at some 4.5lb, it has thick silky fur adapted for the mountain environment in which it lives. Dr Helgen has identified it as a new subspecies in the group of strange marsupials known as cuscuses.
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The habitat in the area is currently regarded as pristine, but less than 20 miles to the south of Mount Bosavi extensive logging operations are happening.

How to Stay Healthy: Avoiding the Flu

It is no secret that washing your hands is a great strategy to stay healthy. Still few people take care to wash their hands thoroughly frequently during each day. The H1N1 Flu is just the latest sickness that washing your hands protects you from.

The CDC recommends you take these everyday steps to protect your health to protect yourself from the flu:

Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hand cleaners are also effective. Though the scientific evidence is not as extensive as that on hand washing and alcohol-based sanitizers, other hand sanitizers that do not contain alcohol may be useful for killing flu germs on hands.
Avoid touching your eyes, nose or mouth. Germs spread this way.
Try to avoid close contact with sick people.

And to keep others healthy you should

Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it. [others also suggest coughing into you elbow instead of your hands, again to reduce the spread of germs.]
If you are sick with flu-like illness, CDC recommends that you stay home for at least 24 hours after your fever is gone except to get medical care or for other necessities. (Your fever should be gone without the use of a fever-reducing medicine.) Keep away from others as much as possible to keep from making others sick.

The spread of this 2009 H1N1 flu is thought to be happening in the same way that seasonal flu spreads. Flu viruses are spread mainly from person to person through coughing or sneezing of people with influenza. Sometimes people may become infected by touching something with flu viruses on it and then touching their mouth or nose.

The incidence of H1N1flu is likely to be high this flu season based on results in the Southern Hemishpere. Symptoms are those of the flu: fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue; can include diarrhea and vomiting.

The CDC includes weekly flu statistics on their web site. Since mid-April to August 30, 2009, a total of 9,079 hospitalizations and 593 deaths associated with 2009 influenza A (H1N1) viruses have been reported to CDC an increase from 8,843 hospitalizations and 556 deaths from the prior week.

Engineer Tried to Save His Sister and Invented a Breakthrough Medical Device

Here is another remarkable example of the great benefit engineers provide society.

How a software engineer tried to save his sister and invented a breakthrough medical device

I wanted to help my sister as much as I could. I went to Medline, where there are hundreds of thousands of documents describing clinical studies, to see what I could find.

There are billions of dollars spent every year on clinical studies. I was surprised to discover that there were sometimes clinical studies of treatments for which there were no clinical applications. The trials would show successful results but no clinical applications.

I found a 1987 Italian funded set of clinical studies that showed successful treatment of tumors by the application of chemotherapy directly into the tumors. But I could find nothing since then.
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It took us two years to do the engineering. And it has taken the FDA seven years and two months to approve the product for sale. We were able to shorten the FDA process a little by saying that it was similar to other devices that had already been approved.

Great stuff.

Researchers Work to Protect Bats Against Deadly Disease

Researchers work to protect Wisconsin bats against deadly disease

Redell, who studies bats for the Department of Natural Resources, lives every day now with the threat of a disease called white-nose syndrome hanging over his head. The disease, though not yet in Wisconsin, has killed more than 90 percent of the cave bats in Eastern states such as New York and Vermont. Experts predict it could make its way to Wisconsin, with its eight species and hundreds of thousands of bats, in as little as two years.
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One female little brown bat – with a body less than the length of your thumb – can eat its body weight in insects in one evening, Redell said. Such is the insect-hunting prowess of the bats that they are thought to save farmers billions of dollars in crop losses, according to Sheryl L. Ducummon, with Bat Conservation International.

In a recent scientific article on the ecological and economic importance of bats, Ducummon reported that, in one summer, the 150 bats in an average colony of big brown bats can conservatively eat 38,000 cucumber beetles, which attack corn and other farm crops. Damage from the beetle and their larvae cost corn farmers as much as $1 billion a year.

The loss of such an insect-eating force could be devastating, Redell said. The approximate 1 million bats that have already died of white-nose syndrome in the last three years on the East Coast would have eaten 700,000 tons of insects were they still hunting the night skies, he said.

Bats perform other important tasks, too. Several Western species serve crucial roles as pollinators for desert plants such as agave and as seed dispersers for dozens of species of cacti.
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“I mean, this is like a mouse that flies, but it has the predatory capabilities of a polar bear,” Blehert said. “They are physically adapted to command the night sky. You’re talking about a little thing with a body less than half the size of your thumb whose heartbeat can get up to 1,000 beats a minute when they are flying but that can slow when they are hibernating in the winter to 4 beats a minute. And they live 20 to 25 years!”

Bats really are amazing and very valuable animals.

Friday Fun: Bristol Zoo’s Human Exhibit

Photo of the Homo Sapiens zoo sign at the Bristol Zoo

A mysterious sign has appeared on the side of the Zoo’s popular Coral CafÃ©, designating the area as a place to spot one of the world’s most widespread species – Homo sapiens. The notice, which appeared without warning this week, shows humans ‘on display’ inside the cafÃ© and includes tongue-in-cheek description of the species and its characteristics.

Zoo staff were surprised and amused to discover the new fixture. Dr Jo Gipps, Director of Bristol Zoo Gardens, said: “This is definitely not one of the Zoo’s own signs, it is clearly a prank and a very good one too. It looks completely genuine. We think it’s great sign and we have absolutely no intention of removing it, however I think one of them is probably enough.”

From the sign:

After a gestation period of nine months, the you usually live in the parents’ next for around 16 years. While the parents are out foraging for food, juveniles are looked after in large groups by other adults.

In adolescence, the offspring adopt a more nocturnal lifestyle and engage in ritualized activities of drinking fermented liquids and dancing to rhythmical sounds, which scientists believe may help them to find a mate.
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They are known to adopt other species as pets, particularly dogs (canis lupus familians) and cats (felis catus).

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HHMI Science Internships

Undergraduate Scholars Live the Scientific Life at Janelia Farm

With Janelia Farm lab heads as their mentors, the students have delved into projects that include identifying the neurons that control feeding behavior in fruit flies, designing better labeling molecules for use with sophisticated microscopy techniques, increasing the longevity of dragonflies, and developing computer programs for automated image analysis. The Janelia environment, they said, provides a unique opportunity to focus intently on research.
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The summer program offers students more than just hands-on experience in the lab – it aims to expose them to a more complete picture of what it is to work and think as a scientist does. An important component of the program is a weekly seminar in which students present their work to one another and field questions. Likewise, scholars are encouraged to attend the campus’s frequent seminars, conferences, and journal clubs, for exposure to research other their own.

For Gloria Wu, who is majoring in biochemistry at the University of California, Berkeley, the interdisciplinary nature of research at Janelia Farm and the diversity of backgrounds among her fellow scholars were important assets. “A lot of students are coming from math or computer science backgrounds, and that really stimulates a lot of discussion between us, so we can see other approaches to solving biological questions. That is something really wonderful about this program,” she said.