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Elusive leptin

By Guest PostApril 25, 2014Scienceakt1, baaltempel in palmyra, cannabis users, celia morgan, childrens behavior, columba livia, diabetes, dschingis khans, einhorn auf reisen, hormone, imperien im kommen, imperium romanum, Israel, kalten krieg, kathleen vohs, lan chaplin, lipid metabolism, michael gehler, obesity, pathway, psychology of money, psychosis risk, robert rollinger, sowjetunion, species, type 2 diabetes

Researchers find first evidence of fat-regulating hormone in avian species

Since leptin was discovered 20 years ago, more than 115,000 papers have been published on this protein in humans, and another 5,000 have appeared on leptin in mice.

Leptin’s popularity is not surprising, as the hormone is the principal marker for the development of morbid obesity in humans. Leptin and its receptor play critical roles in the control of food intake and energy expenditure, thereby affecting body weight, abdominal fatness, thermogenesis, insulin sensitivity, and lipid metabolism. (more…)

Evolutionary study finds neglected fin may have a function

By Guest PostMarch 12, 2014Nature, Scienceadipose fin, Chicago, convergent evolution, evolutionary study, field museum, function, michael coates, neglected fin, new model, species, thomas stewart, university of chicago

Fin’s emergence in many species challenges assumption that it’s a useless remnant

Although present in more than 6,000 living species of fish, the adipose fin, a small appendage that lies between the dorsal fin and tail, has no clear function and is thought to be vestigial. A new study analyzing their origins, however, finds that these fins arose repeatedly and independently in multiple species. In addition, adipose fins appear to have repeatedly and independently evolved skeletal elements, offering a glimpse into how new tissue types and structural complexity evolve in vertebrate appendages.

Adipose fins therefore represent a prime example of convergent evolution and offer a new model for exploring the evolution of vertebrate limbs and appendages, report University of Chicago scientists in the Proceedings of the Royal Society B on March 5. (more…)

New Study Finds Extreme Longevity in White Sharks

By Guest PostJanuary 12, 2014Nature, Scienceadvantage of radiocarbon, age, ear bones, fin rays, great white sharks, greg skomal, growth rate, indian ocean, layers of tissue, li ling hamady, lifespan, lisa natanson, longevity, marine organisms, mineralized tissue, nefsc lab, northwestern atlantic ocean, ocean, ocean ecology, oceanographic institution, otoliths, sexual maturity, simon thorrold, southwestern pacific ocean, species, subtropical waters, temperate, time stamp, vertebra layers, vertebrae, whoi, woods hole, world

Great white sharks—top predators throughout the world’s ocean—grow much slower and live significantly longer than previously thought, according to a new study led by the Woods Hole Oceanographic Institution (WHOI).

In the first successful radiocarbon age validation study for adult white sharks, researchers analyzed vertebrae from four females and four males from the northwestern Atlantic Ocean. Age estimates were up to 73 years old for the largest male and 40 years old for the largest female. (more…)

Taking a New Look at Carbon Nanotubes

By Guest PostDecember 7, 2013Scienceactin filaments, advancing nanotube technology, anisotropic, berkeley lab, carbon nanotubes, crystal, Environment, feng wang, functional device, fused silica substrate, graphene nanoribbons, human hair, kaihui liu, molecule, na, nanobiomaterials, nanorods, numerical aperture, optical anisotropy, plethora, polarization, semiconductor nanowires, species, substrates, xiaoping hong

Berkeley Researchers Develop Technique For Imaging Individual Carbon Nanotubes

Despite their almost incomprehensibly small size – a diameter about one ten-thousandth the thickness of a human hair – single-walled carbon nanotubes come in a plethora of different “species,” each with its own structure and unique combination of electronic and optical properties. Characterizing the structure and properties of an individual carbon nanotube has involved a lot of guesswork – until now.

Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have developed a technique that can be used to identify the structure of an individual carbon nanotube and characterize its electronic and optical properties in a functional device. (more…)

Imperiled Mussels May be Further Harmed by Climate Change

By Guest PostDecember 5, 2013Environment, Natureaquatic food web, climate change, danger of extinction, freshwater mussels, freshwater science, global climate change, good water, habitat alteration, indicator, native mussel populations, North America, potential effect, rising water temperatures, river studies center, sediment quality, species, teresa newton, U.S. Geological Survey, us river, usgs scientists, washboard mussels

Rising water temperatures as a result of climate change may harm already endangered or threatened native freshwater mussels in North America, according to a new U.S. Geological Survey report.

During laboratory tests, USGS scientists and partners found that the heart and growth rates of some species of young freshwater mussels declined as a result of elevated water temperatures, and many died. Freshwater mussels have been compared to the “canary in the coal mine” in that they are indicators of good water and sediment quality in U.S. rivers. They are also important in the aquatic food web, filter large amounts of water and suspended particles, and serve as food for other organisms. The study is published in the December issue of the journal Freshwater Science. (more…)

Dogs likely originated in Europe more than 18,000 years ago, UCLA biologists report

By Guest PostNovember 16, 2013Nature, Scienceancient dog fossil, ancient hunter, carnivore, co evolutionary process, coyotes, daniel greenfield, dog, dog like animals, dogs from europe, domestic dogs, druid peak, east asia, Europe, european hunter, european wolves, evolutionary biology, finland, fossil, genetic analysis, genetic data, illinois, klaus koepfli, koster archaeological site, late pleistocene, middle east, middle east origin, migration, mitochondrial dna, modern dogs, North America, olaf thalmann, old world, origin, proximity to humans, robert wayne, species, two wolves, ucla biologist, university of turku, western russia, wolf like animals, yellowstone national park

Wolves likely were domesticated by European hunter–gatherers more than 18,000 years ago and gradually evolved into dogs that became household pets, UCLA life scientists report.

“We found that instead of recent wolves being closest to domestic dogs, ancient European wolves were directly related to them,” said Robert Wayne, a professor of ecology and evolutionary biology in UCLA’s College of Letters and Science and senior author of the research. “This brings the genetic record into agreement with the archaeological record. Europe is where the oldest dogs are found.” (more…)

Useful pesticides

By Guest PostOctober 16, 2013Environmentchronic disease, ecosystems, herbicides, human health, insects, invasion, malaria, mechanical removal, milk production, negative impact, paul smith, plague, species, termites, typhoid fever, useful pesticides, vermin, weeds, yellow fever

We all know about the harm that can be caused by pesticides. While being misused, pesticides can have a negative impact on the plants, animals and human health. Animals that eat the treated with pesticides plants, have a small amount of pesticides left in their organisms. Being a food to a human, such animals represent a certain risk to human health. Not only the meat can be intoxicated with pesticides but also eggs, milk and the further products of milk production.

While working with pesticides, people accumulate them in the organism, what, in turn, may lead to the chronic diseases. Human needs have increased immensely, and people nowadays can’t eliminate the use of pesticides. (more…)

Effects of Climate Change on West Nile Virus

By Guest PostSeptember 11, 2013Environment, Healthandrew comrie, brain, canada, cdc, changes in climate, climate change, climate change models, climate-driven, cory morin, culex quinquefasciatus, effect, encephalitis, immune response, infectious cycle, inflammation, meningitis, mosquito population model, mosquito populations, North America, precipitation, southern us, species, temperature, united states, university of arizona, virus carrying mosquitoes, west nile vector, west nile virus

A study projects how climate change may affect virus-carrying mosquitoes across the southern U.S. Changes are expected to vary with region, and the southern states should see a trend toward longer seasons of mosquito activity and smaller midsummer mosquito populations

The varied influence of climate change on temperature and precipitation may have an equally wide-ranging effect on the spread of West Nile virus, suggesting that public health efforts to control the virus will need to take a local rather than global perspective, according to a study published this week in the scientific journal Proceedings of the National Academy of Sciences. (more…)

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