Author Archives: Guest Post

Aztec Conquest Altered Genetics among Early Mexico Inhabitants, New DNA Study Shows

By Guest PostFebruary 3, 2013Science1395 ad, adna, alter, ancient dna, anthropological research, archeological dig, austin, aztec conquest, aztec empire, aztec imperialism, capital, case of xaltocan, colonization, dna study, early mexico inhabitants, exodus, genetic evidence, genetic impact, genetic shift, genetic transition, genetics, historical events, imperial conquest, jaime mata míguez, lisa overholtzer, mesoamerican populations, mexican city state, migration, mitochondrial adna, otomi inhabitants, otomi people, otomi population, otomi skull, post conquest era, pre aztec, university of texas, washington state university, wichita state university, xaltocan, xaltocan dig site, xaltocan households

AUSTIN, Texas — For centuries, the fate of the original Otomí inhabitants of Xaltocan, the capital of a pre-Aztec Mexican city-state, has remained unknown. Researchers have long wondered whether they assimilated with the Aztecs or abandoned the town altogether.

According to new anthropological research from The University of Texas at Austin, Wichita State University and Washington State University, the answers may lie in DNA. Following this line of evidence, the researchers theorize that some original Otomies, possibly elite rulers, may have fled the town. Their exodus may have led to the reorganization of the original residents within Xaltocan, or to the influx of new residents, who may have intermarried with the Otomí population. (more…)

Right Target, but Missing the Bulls-Eye for Alzheimer’s

By Guest PostFebruary 3, 2013Health, Scienceabeta, abeta40, abeta42, abeta42 protein, aleksey lomakin, alzheimer's disease, america, amino acids, amyloid beta, atul deshpande, brain, bulls eye, causes of death, chemical synthesis, computer simulations, david teplow, destroy neurons, disorder, george b benedek, gregory cole, hairpin like structure, late life dementia, mingfeng yang, molecular biology, mutant abeta peptides, pearl necklace, plaques, protein, robin roychaudhuri, sally frautschy, sequence, toxic actions, toxic form, ucla

UCLA researchers discover new point of attack for drug therapy

Alzheimer’s disease is the most common cause of late-life dementia. The disorder is thought to be caused by a protein known as amyloid-beta, or Abeta, which clumps together in the brain, forming plaques that are thought to destroy neurons. This destruction starts early, too, and can presage clinical signs of the disease by up to 20 years.

For decades now, researchers have been trying, with limited success, to develop drugs that prevent this clumping. Such drugs require a “target” — a structure they can bind to, thereby preventing the toxic actions of Abeta. (more…)

Secret of Scent Lies in Molecular Vibrations

By Guest PostFebruary 2, 2013General, Sciencealexander fleming, athens, atom, bonds, british chemist, bsrc, chemists, cyclopentadecanone, deuterium odorants, electron cloud, Greece, hydrogen atom, hydrogen musk molecules, inelastic electron tunnelling, lcn, luca turin, malcolm dyson, mass, molecular shape, molecular vibrations, nano scale changes, quantum mechanism, secret of scent, simon gane, spectroscope, ucl scientists, vibration of molecule

Molecular vibrations, rather than molecular shape, give substances their distinct smell according to a new study by UCL scientists.

In a study designed to find out how smell is written into a molecule’s structure, scientists tested whether changing how a molecule vibrates on a nano-scale changes its smell.

Molecules are made of atoms connected by bonds. The arrangement of bonds and atoms defines the vibration of the molecule. Chemists can therefore identify molecules by their vibrations, using a spectroscope. (more…)

Flies of the World Embrace Vegetarianism

By Guest PostFebruary 2, 2013Nature, Scienceagricultural pests, animal kingdom, australia, bracken ferns, brassicas, canolas, change of lifestyle, convergent phenotypes, cyanogenic compounds, detoxify the plants, earth, evolutionary biologists, Facebook, family drosophilidae, fly detectives, genetic changes, genetic pathways, genome biology evolution, good model organisms, hawaii, hawaiian lineage, herbivores, herbivorous fly species, insects, levels of alcohol, microbe eating flies, mt lemmon, mustard plants, new zealand, noah whiteman, North America, north american flies, organisms, papua new guinea, richard lapoint, scaptomyza nigrita, South Pacific, toxic plants, united kingdom, university of arizona, vegetarianism

Microbe-eating flies from at least three different locations around the world recently have evolved into herbivores, feeding on some of the most toxic plants on Earth. Fly detectives and UA evolutionary biologists Noah Whiteman and Richard Lapoint are trying to find out what genetic pathways led the flies to such a major change of lifestyle.

For millennia, they buzzed through the woods, contentedly munching yeasts off the surfaces of leaves, bracken and rotting duff on the forest floor. But now, flies in the family Drosophilidae, whose disparate members dwell in areas all across the planet, have evolved into all-out vegetarians with a wicked diet of plants that are deadly to most other organisms.

What, University of Arizona scientists would like to know, has caused these flies, yeast-feeders for nearly 80 million years, to independently go cold turkey with respect to their formerly meaty diets? (more…)

Ridges on Mars Suggest Ancient Flowing Water

By Guest PostFebruary 2, 2013Scienceactive hydrology, ancient martian subsurface, applied physics lab, biosphere, brown university, craters on mars, curiosity rover, flowing water, fluid flow, fossils of cracks, fracture conduits, gale crater, habitable environment, hydrothermal fluid, hypothesis, jack mustard, johns hopkins university, landing site, lee saper, mars reconnaissance orbiter, martian surface, mineral hardened material, minerals, NASA, nili fossae, nilosyrtis, orientation data, planetary exploration, regional scale volcanism, ridges, subsurface hydrology, surrounding rocks

Ridges in impact craters on Mars appear to be fossils of cracks in the Martian surface, formed by minerals deposited by flowing water. Water flowing beneath the surface suggests life may once have been possible on Mars.

PROVIDENCE, R.I. [Brown University] — Networks of narrow ridges found in impact craters on Mars appear to be the fossilized remnants of underground cracks through which water once flowed, according to a new analysis by researchers from Brown University.

The study, in press in the journal Geophysical Research Letters, bolsters the idea that the subsurface environment on Mars once had an active hydrology and could be a good place to search for evidence of past life. The research was conducted by Lee Saper, a recent Brown graduate, with Jack Mustard, professor of geological sciences. (more…)

Motion Control Keeps Electric Car’s Four Wheels—and Four Motors—on the Road

By Guest PostFebruary 2, 2013Science, Technologybrake, built in, central computer, city car, columbus metro school, east liberty, electric car, electric motor, electrical cable, experimental car, fishtailing, fiwa, freedom of movement, future vehicle architectures, gas pedal, junmin wang, lithium-ion battery, motion control system, ohio state university, rongrong wang, sports car, steering wheel, stem, traction

COLUMBUS, Ohio — It weighs half as much as a sports car, and turns on a dime—so its no surprise that the electric car being developed at Ohio State University needs an exceptional traction and motion control system to keep it on the road.

With four wheels that turn independently, each with its own built-in electric motor and set of batteries, the experimental car is the only one of its kind outside of commercial carmakers’ laboratories. (more…)

New Research Will Help Shed Light on Role of Amazon Forests in Global Carbon Cycle

By Guest PostFebruary 1, 2013Environmentabsorbing, alan di vittorio, Amazon, amazon basin, amazon forest landscape, analytical method, annual carbon accumulation, atmosphere, berkeley lab, biogeochemical process, biogeochemistry, brazil, carbon cycle, carbon cycling, carbon dioxide pollution, carbon sequestration, central amazon, climate change, climatic warming, co2 concentration, CO2 emissions, daniel marra, dar roberts, earth, forest carbon budgets, forest mortality patterns, gabriel ribeiro, Germany, global climate system, global warming effect, human activities, hurricane katrina, impact, jeffrey chambers, joerg tews, manaus, max planck institute, mortality map, natural disturbances, old growth forests, pixel, planet, plot based analyses, positive feedback mechanism, robinson negron juarez, satellite images, simulation modeling, spatial scale, superstorm sandy, terrestrial ecosystems, tree mortality patterns, trends, tropical, tulane university

Berkeley Lab scientists devise new tools for detecting previously unknown tree mortality.

The Earth’s forests perform a well-known service to the planet, absorbing a great deal of the carbon dioxide pollution emitted into the atmosphere from human activities. But when trees are killed by natural disturbances, such as fire, drought or wind, their decay also releases carbon back into the atmosphere, making it critical to quantify tree mortality in order to understand the role of forests in the global climate system. Tropical old-growth forests may play a large role in this absorption service, yet tree mortality patterns for these forests are not well understood.

Now scientist Jeffrey Chambers and colleagues at the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) have devised an analytical method that combines satellite images, simulation modeling and painstaking fieldwork to help researchers detect forest mortality patterns and trends. This new tool will enhance understanding of the role of forests in carbon sequestration and the impact of climate change on such disturbances. (more…)

Effort to Enforce HIV ‘Health Threat’ Law Raises Questions

By Guest PostFebruary 1, 2013General, Healthadvocates, blood draw, community, database, diagnose, epidemiological data, health threat law, hiv positive woman, hiv surveillance technologies, hiv-positive, local jurisdictions, medical information, michigan health officials, people, policymakers, public health policy, sex, sexual partners, sexually transmitted diseases, stakeholders, trevor hoppe, university of michigan

ANN ARBOR — Michigan health officials are using HIV surveillance technologies to assist in enforcing a “health threat” law that makes it illegal for HIV-positive people to have sex without disclosing their status.

A new University of Michigan study reveals that health officials employ the state’s names reporting database, alongside partner services referrals, for law enforcement purposes. However, this is bad social policy for a variety of reasons, says Trevor Hoppe, the study’s author and a doctoral candidate in sociology and women’s studies. (more…)