Category Archives: Life Science

Antibiotics Too Often Prescribed for Sinus Woes

This is not one of the more amazing articles, rather one more in the long line of those reporting on the overuse of anti-biotics: Antibiotics Too Often Prescribed for Sinus Woes:

But it’s hard to preach that wisdom to someone with a drippy, hurting sinus who wants immediate relief, Leopold acknowledged. Because more effective drugs are lacking, “patients are desperate, physicians are desperate, and it is not a happy situation,” he said.

I guess I am just out of touch but why do physicians think it is ok to practice bad medicine because people will whine if they try to practice sensible medicine? These stories often tell of doctors that can’t say no to patients even if it means going against what is the best medical advice. Is it any wonder that helath costs continue to escalate, now totaling 16% of GDP, with such practices accepted? How hard is it to say, yeah great you want x drug, that is not medically advisable and is only available by prescription because it is not advisable for people to decide they need it but rather physicians are suppose to make that decision.

And so the physician often makes the practical choice of giving what the patient wants, with a chance of relief, over the more abstract issue of antibiotic resistance, he said.

I understand this reality. I just find it very sad that that professionals sacrifice the future to today’s ignorance and short sightedness. I wish physicians would not reward those demanding they get what they want today since they are simultaneously condemning others to suffer the consequences of such decisions.

But I also want us to stop spending our grandchildren’s money today. Still the politicians act just like the physicians choosing to give the voters what they want today and let someone else deal with the consequences later. Current USA federal deficit: $8,841,291,672,873 (see live debt clock), $29,349 for every citizen of the USA. It seems pretty obvious the same willingness to sacrifice the future for an easier life today is at the root of the actions by both doctors and politicians. Thankfully some are trying to counter this behavior, by both parties, to varying success.

Bdelloid Rotifers Abandoned Sex 100 Million Years Ago

Who Needs Sex (or Males) Anyway? by Liza Gross:

If you own a birdbath, chances are you’re hosting one of evolutionary biology’s most puzzling enigmas: bdelloid rotifers. These microscopic invertebrates—widely distributed in mosses, creeks, ponds, and other freshwater repositories—abandoned sex perhaps 100 million years ago, yet have apparently diverged into nearly 400 species. Bdelloids (the “b” is silent) reproduce through parthenogenesis, which generates offspring with essentially the same genome as their mother from unfertilized eggs.

Scientists stumped by 100m years of chastity

Bdelloid rotifers are egg laying microscopic invertebrates — widely distributed in mosses, streams and ponds — which have managed to diverge into nearly 400 species without a scintilla of sex… Now a new study, published today in the journal PLoS biology, has confirmed the worst fears of scientists: the rotifers do indeed present a major challenge to the assumption that sex is necessary for organisms to diversify into species.
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Rather than mixing up DNA, creatures like the bdelloid rotifers can evolve solely through the build-up of mutations that occur in the ‘cloning’ process when a new rotifer is born. The new study proves that these differences are not random and can help rotifers adapt to a different environment, such as the legs or chest of a water louse. Bdelloids can be found happily swimming around in a puddle in your garden, hot springs or in freezing ponds in the Antarctic.

Learning About the Human Genome

You Don’t Miss Those 8,000 Genes, Do You? by Carl Zimmer:

Science moves forward by flow. One experiment leads to another. Observations accrue. What seem like side trips or even dead ends may bring a fuzzy picture further into focus. Yet science often seems as if it moves forward one bombshell at a time, marked by scientific papers and press conferences.
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When Craig Venter and his colleagues published their rough draft of the human genome in 2001 they identified 26,588 human genes. They then broke those genes down by their functions. Some were involved in building DNA, some in relaying signals, and so on. Remarkably, though, they classified 12809 genes–almost half–as “molecular function unknown.” Last week I wanted to know if those numbers still hold.
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They weren’t so easy to find. In 2003 some reports came out to the effect that the genome had shrunk down to 21,000 genes. But I couldn’t turn up much news in the past four years.
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The pie shows that we’re now down to just 18,308 genes. That’s over 8,000 genes fewer than six years ago. Many sequences that once looked like full-fledged genes, capable of generating a protein, now don’t make the grade. Some genes turned out to be pseudogenes–vestiges of genes that once worked but have been since wrecked by mutations. In other cases, DNA segments that appeared to be parts of separate genes have turned out to be part of the same gene.

Today scientists still don’t know the function of 5898 genes in the human genome. In other words, over the past six years about 7,000 genes either have been figured out or have vanished into the land of nevermind.

Great post. Read it.

Researchers Learn What Sparks Plant Growth

Researchers Learn What Sparks Plant Growth:

“How do organisms decide when to grow and when to stop growing? These questions are especially important in plants because they are rooted in the ground and must alter their shape and size in response to their local environment. Thus, it’s a question of survival,” added Chory. “It took us 10 years to develop the tools to ask the question. It is very satisfying for me to see the results.”
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“It’s been a matter of some debate for a very long time if one of these tissue layers controls plant growth or if all three layers have to work together,” Chory said. “Our paper shows very clearly that the epidermis is in control—in both driving and restricting growth. In addition, our studies show that the cells in the epidermis “talk” to the cells in the inner layers, communicating that they too should expand.”

In January we had a long stretch of warm weather. Shoots for early blooming flowers sprouted in my front yard. Then we had about 6 weeks of winter weather. I was wondering how the flowers would do (they do fine with a few days of freezing weather after sprouting – since they have evolved to bloom early). They did fine, photo above (by John Hunter, March 11th).

Bornean Clouded Leopard

Borneo’s clouded leopard identified as new cat species:

Scientists have discovered that the clouded leopard found on the islands of Borneo and Sumatra is an entirely new species of cat. The secretive rainforest animal was originally thought to be the same species as the one found in mainland South-east Asia. The news comes just a few weeks after a WWF report showed that scientists had identified at least 52 new species of animals and plants over the past year on Borneo.

Photo: WWF-Canon / Alain Compost

Magnificent Flying Machine

A magnificent flying machine

The next time you attempt to swat a fly, remember that you are trying to destroy a flying machine that engenders awe and bafflement in scientists, engineers and professors of aerodynamics. Thanks to remarkable flying skills that make the housefly the Ferrari of the insect world, it is unlikely you will achieve a direct hit. While fleeing a rolled-up newspaper, the insect can change course in as little as 30 thousandths of a second.

This and other flying insects have plagued the worlds of science and engineering ever since the first calculation of bumble-bee flight was attempted at GÃ¶ttingen University in the 1930s. Conventional aerodynamics suggested the insect should not generate enough lift to fly. The sums caused consternation.

In the past few years, however, remarkable advances have been made. The so-called “bumble-bee paradox” was solved by Dr Charles Ellington and colleagues from Cambridge University when, with the help of a robot insect, they highlighted the bee’s secret: extra lift is generated during a downstroke by a spiral vortex that travels along the leading edge of each wing, from base to tip.

Attacking Bacterial Walls

Bacterial Walls Come Tumbling Down:

Penicillin and many newer antibiotics work by blocking a piece of the machinery bacteria use to construct their durable outer walls. Without these tough, protective coatings, bacteria die. The enzymatic machinery (known as PBP2) studied by Strynadka’s group has two main parts: One end assembles long sugar fibers; the other end stitches them together with bits of protein to form a sturdy interlocking mesh shell.
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“This enzyme is an awesome target for antibiotics,” said Strynadka. “We have a totally new understanding of how the enzyme works and how a very good animal antibiotic inhibits the enzyme.” Although moenomycin is poorly absorbed by the human body, the new understanding of exactly how it interferes with bacterial enzyme function should help scientists design modified versions that are more suitable for use in people.

Understanding the structure of this enzyme should also speed up screening and design of new antibiotics, which are in constant demand as microbes continually evolve new ways to evade the drugs that researchers design to thwart them. The time it takes for bacteria to develop resistance to new antibiotics has been as short as one year for penicillin V and as long as 30 years for vancomycin.

Invasive Plants: Tamarisk

To Save the West, Kill a Plant by Josh McDaniel:

The tamarisk, an invasive species introduced to the United States from Eurasia, is a deep-rooted plant that aggressively obtains water from the soil and groundwater. A single mature tree can produce up to 500,000 seeds per year, crowding out native plants along rivers and creeks and reducing wildlife habitat. The species now infests all the major rivers, springs, ditches, and wetlands in ten states—including Texas, Arizona, Utah, Colorado, New Mexico, Nevada, and California—and is rapidly expanding into others.

In the delicately dry ecosystems of the southwestern United States, that is a serious problem, adding up to over 800 billion gallons of lost water per year across the parched region. “That is equal to the water needs of 20 million people or one million acres of irrigated farmland,” said Tim Carlson, an environmental engineer and director of the Tamarisk Coalition, which aims to control the plant.

Living systems include risks for those that attempt to engineer improvement. The past is littered with examples of attempts to intervene that go wrong.

“One night, after I gave a presentation on tamarisk, an older gentleman came up to me and told me that he had earned his Eagle Scout rank by planting tamarisk to prevent soil erosion after the Dust Bowl era in the 1930s,” Carlson recalled. “He said he would gladly earn it again by helping me remove it.”

I don’t think there is a simple answer. We are going to have intentional and unintentional consequences results from our actions. To me the lesson is to learn from our past that we often have unintended consequences that are worse than we envisioned and we need to be careful. We can’t assume there are no risks that we don’t know about. There are risks we can’t predict.

Robo-Salamander

Robot Salamander

Novel salamander robot crawls its way up the evolutionary ladder:

A group of European researchers has developed a spinal cord model of the salamander and implemented it in a novel amphibious salamander-like robot. The robot changes its speed and gait in response to simple electrical signals, suggesting that the distributed neural system in the spinal cord holds the key to vertebrates’ complex locomotor capabilities.

In a paper appearing in the March 9, 2007 issue of the journal Science, scientists from the EPFL in Switzerland and the INSERM research center/University of Bordeaux in France introduce their robot, Salamandra Robotica. This four-legged yellow creature reveals a great deal about the evolution of vertebrate locomotion. It’s also a vivid demonstration that robots can be used to test and verify biological concepts, and that very often nature herself offers ideal solutions for robotics design.

The researchers used a numerical model of the salamander’s spinal cord to explore three fundamental issues related to this vertebrate’s movement: what were the changes in the spinal cord that made it possible to evolve from aquatic to terrestrial locomotion? How are the limb and axial movements coordinated? And how is a simple electrical signal from the brain stem translated by the spinal cord into a change in gait?

Tracking Changes in Individual Molecules

Watching a Biological Jigsaw Puzzle Come Together

Scientists have recorded the action involved in assembling telomerase, an enzyme used by cells to protect their genes during the potentially dangerous process of DNA replication. Using a sophisticated technique for tracking structural changes in individual molecules in real time, they have revealed how three of the protein and RNA components of the enzyme come together, altering their shapes along the way to ensure that the next piece will fit.
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In these more complicated systems, it’s much harder to guess what is going on in the assembly process. But by directly watching things as they happen, this sort of powerful approach will give a lot of new insights.

Very cool stuff. It just keeps coming doesn’t it?