Posts Tagged ‘Nature’

Zebra’s Stripes, Butterfly’s Wings: How Do Biological Patterns Emerge?

June 23, 2008

A zebra’s stripes, a seashell’s spirals, a butterfly’s wings: these are all examples of patterns in nature. The formation of patterns is a puzzle for mathematicians and biologists alike. How does the delicate design of a butterfly’s wings come from a single fertilized egg? How does pattern emerge out of no pattern?

Using computer models and live cells, researchers at Johns Hopkins have discovered a specific pattern that can direct cell movement and may help us understand how metastatic cancer cells move.

“Pattern formation is a classic problem in embryology,” says Denise Montell, Ph.D., a professor of biological chemistry at Hopkins. “At some point, cells in an embryo must separate into those that will become heart cells, liver cells, blood cells and so on. Although this has been studied for years, there is still a lot we don’t understand.”

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Flies Found To Have Internal Thermosensors To Monitor Environmental Temperatures

June 13, 2008

Flies, unlike humans, can’t manipulate the temperature of their surroundings so they need to pick the best spot for flourishing. New Brandeis University research in this week’s Nature reveals that they have internal thermosensors to help them.

Biologist Paul Garrity and his colleagues have discovered that the fruitfly Drosophila has four large heat-responsive neurons located in its brain. These are activated at temperatures just above the fly’s preferred temperature by an ion channel in the cell membrane known as dTrpA1, which itself acts as a molecular sensor of warmth.

This internal warmth-sensing pathway helps the fly to avoid slightly raised temperatures and acts together with a cold-avoidance pathway in the antennae to set the fly’s preferred temperature–enabling the fly to pick its optimal ambient temperature range for survival.

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Fish 380 Million Years Old Found With Unborn Embryo

June 6, 2008

In 2005, Museum Victoria’s expedition to the Gogo fossil sites in north Western Australia, led by Dr John Long, made a swag of spectacular fossil discoveries, including that of a complete fish, Gogonasus, showing unexpected features similar to early land animals.

Now the same team has made a new discovery: a remarkable 380-million-year-old fossil placoderm fish with intact embryo and mineralised umbilical cord.

The discovery, published in Nature, makes the fossil the world’s oldest known vertebrate mother. It also provides the earliest evidence of vertebrate sexual reproduction, wherein the males (which possessed clasping organs similar to modern sharks and rays) internally fertilised females.

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Mind Over Matter: Monkey Feeds Itself Using Its Brain

May 28, 2008

A monkey has successfully fed itself with fluid, well-controlled movements of a human-like robotic arm by using only signals from its brain, researchers from the University of Pittsburgh School of Medicine report in the journal Nature. This significant advance could benefit development of prosthetics for people with spinal cord injuries and those with “locked-in” conditions such as Lou Gehrig’s disease, or amyotrophic lateral sclerosis.

“Our immediate goal is to make a prosthetic device for people with total paralysis,” said Andrew Schwartz, Ph.D., senior author and professor of neurobiology at the University of Pittsburgh School of Medicine. “Ultimately, our goal is to better understand brain complexity.”

Previously, work has focused on using brain-machine interfaces to control cursor movements displayed on a computer screen. Monkeys in the Schwartz lab have been trained to command cursor movements with the power of their thoughts.

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First Transgenic Monkey Model Of Huntington’s Disease Developed

May 22, 2008

Scientists have developed the first genetically altered monkey model that replicates some symptoms observed in patients with Huntington’s disease, according to a new study funded by the National Institutes of Health. Researchers are now able to better understand this complex, devastating and incurable genetic disorder affecting the brain. This advance, reported in the May 18 advance of online publication edition of Nature, could lead to major breakthroughs in the effort to develop new treatments for a range of neurological diseases.

Huntington’s is an inherited disease caused by a defective gene that triggers certain nerve cells in the brain to die. Symptoms may include uncontrolled movements, mood swings, cognitive decline, balance problems, and eventually losing the ability to walk, talk or swallow. It affects five to 10 people in every 100,000. There is no known treatment to halt progression of the disease, only medications to relieve symptoms. Death typically occurs 15 to 20 years after onset.

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Female Concave-eared Frogs Draw Mates With Ultrasonic Calls

May 19, 2008

Most female frogs don’t call; most lack or have only rudimentary vocal cords. A typical female selects a mate from a chorus of males and then –silently — signals her beau. But the female concave-eared torrent frog, Odorrana tormota, has a more direct method of declaring her interest: She emits a high-pitched chirp that to the human ear sounds like that of a bird.

his is one of several unusual frog-related findings reported recently in the journal Nature.

O. tormota lives in a noisy environment on the brushy edge of streams in the Huangshan Hot Springs, in central China, where waterfalls and rushing water provide a steady din. The frog has a recessed eardrum, said Albert Feng, a professor of molecular and integrative physiology at the University of Illinois and team leader on the new study.

“In the world we know of only two species — the other one in southeast Asia — that have the concave ear,” Feng said. “The others all have eardrums on the body surface.”

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Platypus Genome Explains Animal’s Peculiar Features; Holds Clues To Evolution Of Mammals

May 8, 2008

The duck-billed platypus: part bird, part reptile, part mammal — and the genome to prove it.

An international consortium of scientists, led by Washington University School of Medicine in St. Louis, has decoded the genome of the platypus, showing that the animal’s peculiar mix of features is reflected in its DNA. An analysis of the genome, published today in the journal Nature, can help scientists piece together a more complete picture of the evolution of all mammals, including humans.

The platypus, classified as a mammal because it produces milk and is covered in a coat of fur, also possesses features of reptiles, birds and their common ancestors, along with some curious attributes of its own. One of only two mammals that lays eggs, the platypus also sports a duck-like bill that holds a sophisticated electrosensory system used to forage for food underwater. Males possess hind leg spurs that can deliver pain-inducing venom to its foes competing for a mate or territory during the breeding season.

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“Virtual Nature” Raises Concerns For Conservation

May 8, 2008

Biologists have found that in addition to promoting an unhealthy lifestyle, the rising use of video games correlates with a reduction in outdoor nature experiences, and experiencing only “virtual nature” has negative implications for conservation efforts.

Intrepid nature photographers now use high-definition photography to bring unparalleled images of wildlife and a “you-are-there” experience approaching virtual reality to the viewer. It can be at once informative, thrilling and terrifying — and all from the comfort of your easy-chair or sofa.

While such video gives the public a view of nature never before seen, two biologists warn this technological wonder represents a proverbial double-edge sword.

“Virtual nature, defined as nature experienced vicariously through electronic means, has potential benefits particularly for children dependent on adults for access to many natural areas … yet virtual nature appears to directly compete with time previously allocated to more beneficial, direct contact with the outdoors,” write biologists Oliver Pergams and Patricia Zaradic in the Spring 2007 issue of the Journal of Developmental Processes.

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In accordance with the data presented in this article, I, Kitty Mowmow, am hereby advising you to supplement your Kitty Mowmow’s Animal Expo viewing time (oooooh, look at all the pretty animal pictures and nifty articles!) with genuine contact with nature and non-human members of the animal kingdom.

So go for a walk, play in the mud, climb a tree, sit in a field, and pat a cow on the head.  And after you’re breathless with the thrill of a tactile experience with nature, you can thank me for my magnanimous suggestion. ;D

-Kitty Mowmow

Why We Look at Animals

February 13, 2008

What is it about nature, about animals in particular, that fuels our need to look at them? Why do we still feel a desire to connect with animals despite living in a post-industrial technocratic culture that requires little interaction with them? And is it possible that someday we won’t need this connection anymore?

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