Category Archives: Life Science

Fun Fungi

Fungi, on the other hand, are fundamentally alien.
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Some lurk in the Earth, spreading out over hundreds of acres. Others live inside insects, forcing them to climb to the tip of a blade of grass, so that they can shower their spores down on new victims. Instead of ingesting their food, fungi dump their digestive enzymes into their surroundings and suck up the ensuing goo. Their reproductive cycles are like labyrinths. And of the estimated 1.5 million species of fungi on Earth, scientists have identified only five percent.

Flushed Drugs Pollute Water

Flushed drugs pollute water by Ron Seely (site broke the link so I removed it):

An extensive nationwide study by the U.S. Geologic Survey has found evidence of pharmaceuticals including antibiotics and hormonal drugs, such as birth control pills, in surface waters throughout the nation.
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Whether the presence of drugs in water translates into human health impacts is still being studied. But research has shown that drugs containing hormones such as estrogen are causing changes and deformities in fish and other aquatic creatures.

The World Health Organization indicates that human risk assessments have shown low concentrations of pharmaceuticals in drinking water have a negligible health risk. But WHO points out that long-term exposures have not been evaluated, especially in populations with other illnesses or with compromised immune systems. Also, according to the WHO, antibiotics in water supplies are a potential concern because the most frequently used antibiotics are becoming less effective as the infections they are designed to combat become resistant.

Ocean Warming’s Effect on Phytoplankton

Ocean warming’s effect on phytoplankton:

When the climate warms, there is a drop in the abundance of the ocean’s phytoplankton, the tiny plants that feed krill, fish and whales, according to scientists who say new research offers the first clues to the future of marine life under global warming.

Ocean temperatures have generally risen over the last 50 years as the atmosphere warms. And now nine years of NASA satellite data published today in the journal Nature show that the growth rate and abundance of phytoplankton around the world decreases in warm ocean years and increases in cooler ocean years.

Arctic Sharks

Arctic Shark photo

Arctic sharks found in QuÃ©bec by Brian Lin:

The Greenland shark typically inhabits the deep, dark waters between Greenland and the polar ice cap. At over six metres long and weighing up to 2,000 kilograms, it is the largest shark in the North Atlantic and the only shark in the world that lives under Arctic ice. Once heavily harvested for its vitamin A-rich oil — as many as 50,000 were caught annually according to a 1948 estimate — little is known about the animal.

Why Insects Can’t Fly Straight at Night

Why Insects Can’t Fly Straight at Night by Nicolas van der Leek:

Well, it’s simple really. The structure of their eyes (moths, mantises and plenty of other bugs) is distinctive. Under the microscope their eyes resemble a bunch of long tubes. So when the moth or mantis encounters an artificial light, suddenly when it swoops by the light slips out of its field of vision, and it swings round to get it to shine back into the tubes, and at a constant angle. Hence the chaotic, circular flying. They’re attempting to keep the light coming in at the same angle into the tube structure of their eyes.

Disrupting the Replication of Bacteria

UW-Madison researchers develop novel method to find new antibiotics:

Filutowicz’s approach involves looking for new drugs that render bacteria harmless by blocking the replication of—and thus eliminating—some of their DNA.

Bacterial DNA comes in two forms: chromosomal DNA, which is required for life, and plasmid DNA, which is not. The nonessential plasmid DNA contains many undesirable bacterial genes, including those that confer antibiotic resistance or lead to the production of toxins.

Filutowicz is seeking antibiotics that would selectively disrupt the replication of plasmid DNA, so that when bacteria reproduce, they would produce plasmid-free offspring that are harmless or susceptible to traditional antibiotics. Such compounds could dramatically alter the character of some of our nastiest microbial adversaries.

Anti-microbial ‘paint’

anti-microbial ‘paint’ kills flu, bacteria

A new “antimicrobial paint” developed at MIT can kill influenza viruses that land on surfaces coated with it, potentially offering a new weapon in the battle against a disease that kills nearly 40,000 Americans per year. If applied to doorknobs or other surfaces where germs tend to accumulate, the new substance could help fight the spread of the flu, says Jianzhu Chen, MIT professor of biology.
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The “antimicrobial paint,” which can be sprayed or brushed onto surfaces, consists of spiky polymers that poke holes in the membranes that surround influenza viruses. Influenza viruses exposed to the polymer coating were essentially wiped out. The researchers observed a more than 10,000-fold drop in the number of viruses on surfaces coated with the substance.
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One of the benefits of the new polymer coating is that it is highly unlikely that bacteria will develop resistance to it, Klibanov said. Bacteria can become resistant to traditional antibiotics by adjusting the biochemical pathways targeted by antibiotics, but it would be difficult for bacteria to evolve a way to stop the polymer spikes from tearing holes in their membranes.

Tree of Life

Tree of Life (showing 3,000 species, based on rRNA sequences), from the University of Texas. Humans are shown in the upper left “you are here.” I must admit this graphic doesn’t quite work for me but I figure some people might like it.

More Nutritious Wheat

A wheat gene, now present but inactive, could boost nutrition if it were active. Wheat’s lost gene helps nutrition

The gene occurs naturally in wheat, but has largely been silenced during the evolution of domestic varieties. Researchers found evidence that turning it back on could raise levels of the nutrients in wheat grains.

Writing in the journal Science, they suggest that new varieties with a fully functioning gene can be created through cross-breeding with wild wheat. “Wheat is one of the world’s major crops, providing approximately one-fifth of all calories consumed by humans,”
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“This experiment confirmed that this single gene was responsible for all these changes.”

The researchers deduced that the reverse process – enhancing GPC-B1 activity – ought to produce plants which have higher levels of these nutrients in their grains and mature faster. The UC Davis team is already making such varieties, not by genetic engineering but through crossing domesticated wheat plants with wild relatives.

H5N1 Influenza Evolution and Spread

H5N1 Influenza – Continuing Evolution and Spread from the New England Journal of Medicine:

The current H5N1 virus is apparently not well “fitted” to replication in humans, although the genetic makeup of a small proportion of humans supports attachment and replication of the virus, if not its transmission. The specific receptor for the current avian influenza virus ({alpha}2-3 sialic acid) is found deep in the respiratory tract of humans
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Clearly, we must prepare for the possibility of an influenza pandemic. If H5N1 influenza achieves pandemic status in humans – and we have no way to know whether it will – the results could be catastrophic.