Category Archives: Life Science

Using Viruses to Construct Electrodes and More

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.

Be Thankful for Marine Algae

photo of seaweed - algae

The Most Important Organism?

It is estimated that between 70% and 80% of the oxygen in the atmosphere is produced by marine plants . Nearly all marine plants are single celled, photosynthetic algae. Yup, that’s right, good ol’ scum on the pond…green gak…..slip slimein’ away. Even marine seaweed is many times colonial algae. They are a bunch of single cells trying to look like a big plant (see seaweed photo), but they are really individuals.

We need marine algae a whole lot more than they need us. Think about it….70% to 80% of all the oxygen we breathe comes from algae!

Photo: “Seaweed are not plants, but are algae. Not only does algae provide much of the Earth’s oxygen, they also are the base for almost all marine life.”

Far Eastern Leopard – Rarest Big Cat

World’s Rarest Big Cat Captured:

The team, led by biologists from the New York-based Wildlife Conservation Society, caught the 100-pound (45-kilogram) male in a snare last week while studying Siberian tigers in the Russian Far East, 20 miles (32 kilometers) from the Chinese border.

The chance capture gave biologists a priceless opportunity to study the elusive feline, and Melody Roelke (below), a specialist in big-cat genetics with the U.S. National Institutes of Health, wasn’t shy about getting a closer look.
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Among the scientists’ main concerns is whether Far Eastern leopards, also known as Amur leopards, can continue to sustain their tiny, isolated population, or whether disease and inbreeding may eventually wipe out the cats.

What is an Extremophile?

An extremophile is an organism that thrives under “extreme” conditions. The term frequently refers to prokaryotes and is sometimes used interchangeably with Archaea.
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The term extremophile is relatively anthropocentric. We judge habitats based on what would be considered “extreme” for human existence. Many organisms, for example, consider oxygen to be poisonous.

The site includes interesting photos and details on all sorts of extremophiles: Anaerobe (don’t require oxygen) – Endolith (live inside rocks) – Thermophile (enjoy over 40 Â°C).

How flowering plants beat the competition

How flowering plants beat out the competition on ancient earth:

as the world headed into a cooler, drier climate around 250 million years ago, the early seed-bearing plants had a distinct advantage over their simpler, spore-releasing relatives that then flourished in moist, warm swamps.

Seed-bearing plants also figured out better ways to get around. Some seeds sprout improbably elaborate barbs in order to snag a lift on passing animals. A significant number hitch a ride by growing a morsel called a elaiosome that entices ants to carry them off a few feet. Other seeds are textured or buoyant, so they can float away on wind or water.

The human appetite for seeds has resulted in new forms of dispersal as well. Thousands of years ago, people began collecting and cultivating nutrient-rich seeds, like corn, lentils, and oats, for food.

Prochlorococcus

She sees vistas in a tiny speck of life

Even to the most dedicated biologists, Prochlorococcus may appear to be an unpromising subject. “They have no features,” acknowledges Chisholm. “They just look like little black specks.” But she believes that these microbes are, in fact, a window onto a larger vista. A milliliter of ocean water can contain 100,000 Prochlorococcus cells.

“They’re the minimum form of life,” she says. “We’ve decoded their genome sequence and found that it’s made of 1,700 genes. That’s the smallest number of genes that can convert sunlight into life.”

Old Viruses Resurrected Through DNA

Old Viruses Resurrected Through DNA by Carl Zimmer:

About 100,000 segments of human DNA are remarkably similar to retroviruses, a class of viruses that includes HIV. Retroviruses insert a copy of their genes into the genome of their host cell. Scientists estimate that 8 percent of the human genome is made up of this viral DNA, known as human endogenous retroviruses, or HERVs.

Microbe Food

Microbes May Use Chemicals to Compete for Food

Microbes may compete with large animal scavengers by producing repugnant chemicals that deter higher species from consuming valuable food resources—such as decaying meat, seeds and fruit, a new study suggests.
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Hay hopes the research will make ecologists think more critically about the broad role of microbes in the ecosystem. Microbes are often omitted or relegated to a minor role in food web diagrams, but they should be depicted as direct competitors with larger animals, he said.

Sea Urchin Genome

Sea Urchin photo

Sea Urchin Genome Reveals Striking Similarities to Humans by Stefan Lovgren, National Geographic News:

The scientists identified more than 23,000 genes in the 814 million base pairs, or “letters,” of DNA code taken from the sea urchin.

The sea urchin represents the first sequenced genome from the echinoderms, which are the closest known relatives of the chordates, the group that includes vertebrates, animals with spinal columns. The genome includes analogs to many essential human genes that were previously thought to be exclusive to vertebrates.
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The eyeless sea urchin also has genes associated with taste, smell, hearing, balance—and surprisingly, even vision.