How does a growing organism determine what its final body size will be? In the moth Manduca sexta, also known as the tobacco hornworm and recognisable by its distinctive blue-green caterpillar, adult body size is largely determined at the end of larval life, when the caterpillar has reached it final weight and is about to metamorphose into a moth.
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World's smallest snake found in Barbados
(PhysOrg.com) -- The world's smallest species of snake, with adults averaging just under four inches in length, has been identified on the Caribbean island of Barbados. The species -- which is as thin as a spaghetti noodle and small enough to rest comfortably on a U.S. quarter --was discovered by Blair Hedges, an evolutionary biologist at Penn State. Hedges and his colleagues also are the discoverers of the world's smallest frog and lizard species, which too were found on Caribbean islands. The most recent discovery will be published on 4 August 2008 in the journal
Zootaxa.
Exotic Chameleon Spends Most of its Life as an Egg
(PhysOrg.com) -- Scientists have discovered a chameleon species that spends a good two-thirds of its life inside an egg:
Furcifer labordi lives about 8-9 months as an embryo, and has a post-hatching lifespan of just 4-5 months. As far as the scientists know, this strange life history is unique among all land vertebrates, and may help researchers better understand how certain ecological and hormonal factors influence life history evolution.
Adult stem cells improve fracture healing
In an approach that could become a new treatment for the 10 to 20 percent of people whose broken bones fail to heal, researchers at the University of North Carolina at Chapel Hill have shown that transplantation of adult stem cells can improve healing of fractures.
ATV study to improve fit, safety among kids
The University of Kentucky is conducting a first-ever study of its kind to analyze all-terrain vehicle (ATV) safety, particularly in children. UK trauma surgeon Dr. Andrew Bernard is the primary investigator of a comprehensive multi-year investigation which will measure a number of physical and behavioral issues accompanying pediatric ATV usage. The research will begin June 9 at the Wenner Gren Biomedical Research Facility on the UK campus.
At the synapse: Gene may shed light on neurological disorders
In our brains, where millions of signals move across a network of neurons like runners in a relay race, all the critical baton passes take place at synapses. These small gaps between nerve cell endings have to be just the right size for messages to transmit properly. Synapses that grow too large or too small are associated with motor and cognitive impairment, learning and memory difficulties, and other neurological disorders.
Drug therapy for PKU reverses heart damage
A pricy drug used to treat a rare but well-known genetic disorder may hold wider promise as a treatment for millions of Americans with potentially lethal enlarged hearts, due mainly to high blood pressure, a study from Johns Hopkins shows.
New study finds number of fat cells stays constant throughout life
The radioactive carbon-14 produced by above-ground nuclear testing in the 1950s and '60s has helped researchers determine that the number of fat cells in a human's body, whether lean or obese, is established during the teenage years. Changes in fat mass in adulthood can be attributed mainly to changes in fat cell volume, not an increase in the actual number of fat cells.
A consistent, worldwide association between short sleep duration and obesity
A study published in the May 1 issue of the journal SLEEP is the first attempt to quantify the strength of the cross-sectional relationships between duration of sleep and obesity in both children and adults. Cross-sectional studies from around the world show a consistent increased risk of obesity among short sleepers in children and adults, the study found.