Category Archives: Life Science

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.

Using Viruses to Construct Electrodes and More

She harnesses viruses to make things

Manufacturing was once the province of human hands, then of machines. Angela Belcher, professor of materials science and engineering and biological engineering at MIT, has pushed manufacturing in another, much smaller, direction: Her lab has genetically engineered viruses that can construct useful objects like electrodes and wires.
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Her lab employed this method to form an electrode that can be used in a lithium ion battery like the rechargeable ones used in electronics. The result looks like an innocuous length of celluloid tape, the sort you could use to wrap a package.

“It’s self-assembled,” says Belcher. “The viruses make these materials at room temperature.” So there’s little pollution.
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Belcher hopes to be making prototypes within the next two years. “Actual devices are five to 10 years off.”

New Understanding of Human DNA

Very interesting Genetic breakthrough that reveals the differences between humans (bozo website broke the link – poor usability):

The discovery has astonished scientists studying the human genome – the genetic recipe of man. Until now it was believed the variation between people was due largely to differences in the sequences of the individual ” letters” of the genome.

It now appears much of the variation is explained instead by people having multiple copies of some key genes that make up the human genome.

Until now it was assumed that the human genome, or “book of life”, is largely the same for everyone, save for a few spelling differences in some of the words. Instead, the findings suggest that the book contains entire sentences, paragraphs or even whole pages that are repeated any number of times.

Fascinating information that I must admit I am still trying to grok.

The studies published today have found that instead of having just two copies of each gene – one from each parent – people can carry many copies, but just how many can vary between one person and the next.

The studies suggest variations in the number of copies of genes is normal and healthy. But the scientists also believe many diseases may be triggered by an abnormal loss or gain in the copies of some key genes.

It will be very interesting to see how this understanding develops.