Tag Archives: model

Pollination with Precision: How Flowers Do It

By Guest PostMay 23, 2012Naturearabidopsis plants, brown university, chaotic frenzy, female gametes, fertilization, gamete fusion, hap2, kristin beale, logistical efficiency, mark johnson, mechanism, microscope, model, mothers day, mutant sperm, ovule, pollen grains, pollen tubes, pollination, polytubey, precision, reproduction, sex cells, sperm

Pollination could be a chaotic disaster. With hundreds of pollen grains growing long tubes to ovules to deliver their sperm to female gametes, how can a flower ensure that exactly two fertile sperm reach every ovule? In a new study, Brown University biologists report the discovery of how plants optimize the distribution of pollen for successful reproduction.

PROVIDENCE, R.I. [Brown University] — Next Mother’s Day, say it with an evolved model of logistical efficiency — a flower. A new discovery about how nature’s icons of romance manage the distribution of sperm among female gametes with industrial precision helps explain why the delicate beauties have reproduced prolifically enough to dominate the earth.

In pollination, hundreds of sperm-carrying pollen grains stick to the stigma suspended in the middle of a flower and quickly grow a tube down a long shaft called a style toward clusters of ovules, which hold two female sex cells. This could be a chaotic frenzy, but for the plant to succeed, exactly two fertile sperm should reach the two cells in each ovule — no more, no less. No ovule should be left out, either because too many tubes have gone elsewhere, or because the delivered sperm don’t work. (more…)

UCLA Researchers Map Damaged Connections in Phineas Gage’s Brain

By Guest PostMay 18, 2012Science1848 case, alzheimer's disease, andrei irimia, arthur w toga, behavioral change, brain, brain disorder, carinna m torgerson, cerebral cortex, computed tomographic data, emotional function, famous case, frontal temporal dementia, gage skull, history, human connectome project, jack van horn, laboratory, limbic structure, loni, mark wheeler, micah c chambers, microscopic links, model, myelin sheath, nerve fibers, neuro imaging, neurons, neuroscience, phineas gage, railroad, rod, san francisco, skull, south america, trajectory, traumatic brain injury, vermont, white matter

Famous 1848 case of man who survived a terrible accident has modern parallel

Poor Phineas Gage. In 1848, the supervisor for the Rutland and Burlington Railroad in Vermont was using a 13-pound, 3-foot-7-inch rod to pack blasting powder into a rock when he triggered an explosion that drove the rod through his left cheek and out of the top of his head. As reported at the time, the rod was later found, “smeared with blood and brains.”

Miraculously, Gage lived, becoming the most famous case in the history of neuroscience — not only because he survived a horrific accident that led to the destruction of much of his left frontal lobe but also because of the injury’s reported effects on his personality and behavior, which were said to be profound. Gage went from being an affable 25-year-old to one that was fitful, irreverent and profane. His friends and acquaintances said he was “no longer Gage.” (more…)

Microbe That Can Handle Ionic Liquids

By Guest PostMay 17, 2012Environment, Scienceanthropogenic chemicals, biofuel production, biofuels, blake simmons, carbon, cellulosic biomass, enterobacter lignolyticus, fossil fuels, hannah wooa, industry, ionic liquids, jane khudyakov, jbei, kristen deangelis, michael thelen, microbe, microorganisms, model, patrik dhaeseleer, properties, scf1 strain, semicrystalline, sharon borglin, soil bacterium, sugar fermenting microbes, switchgrass, Technology, toxic effect, tropical rainforest microbe

New Find From Joint BioEnergy Institute Could Help Reduce Biofuel Production Costs

In the search for technology by which economically competitive biofuels can be produced from cellulosic biomass, the combination of sugar-fermenting microbes and ionic liquid solvents looks to be a winner save for one major problem: the ionic liquids used to make cellulosic biomass more digestible for microbes can also be toxic to them. A solution to this conundrum, however, may be in the offing.

Researchers with the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI), a multi-institutional partnership led by Berkeley Lab, have identified a tropical rainforest microbe that can endure relatively high concentrations of an ionic liquid used to dissolve cellulosic biomass. The researchers have also determined how the microbe is able to do this, a discovery that holds broad implications beyond the production of advanced biofuels. (more…)

Happiness Model Developed by MU Researcher Could Help People Go From Good to Great

By Guest PostMay 8, 2012Culture, Healthhappiness, happiness model, kennon sheldon, miserable, model, positive life, psychological basis, romantic relationship, sonja lyubomirsky, spice of life

COLUMBIA, Mo. — The sayings “variety is the spice of life” and “happiness isn’t getting what you want, but wanting what you get” seem to have a psychological basis, according to a new study by an MU psychologist who identified two keys to becoming happier and staying that way.

“Although the Declaration of Independence upholds the right to pursue happiness, that search can be a never-ending quest,” said Kennon Sheldon, professor of psychological sciences in the College of Arts and Sciences. “Previous research shows that an individual’s happiness can increase after major life changes, such as starting a new romantic relationship, but over time happiness tends to return to a previous level. Through our research, we developed a model to help people maintain higher levels of happiness derived from beneficial changes. The model consists of two major components: the need to keep having new and positive life-changing experiences and the need to keep appreciating what you already have and not want more too soon.” (more…)

A NASA Weather ‘Eye in the Sky’ Marks 10 Years

By Guest PostMay 7, 2012Environment, Scienceairs, amsu a, atmosphere, atmospheric infrared sounder, bae systems, boston, carbon dioxide, climate change, climate research, earth, energy cycle, eric fetzer, eye, global water, greenhouse gases, hyperspectral sounding, instrument, jet propulsion laboratory, model, monster, moustafa chahine, NASA, sky, tom pagano, water vapor, weather forecasting, weather satellites

For 10 years, it has silently swooped through space in its orbital perch 438 miles (705 kilometers) above Earth, its nearly 2,400 spectral “eyes” peering into Earth’s atmosphere, watching. But there’s nothing alien about NASA’s Atmospheric Infrared Sounder, or AIRS, instrument, a “monster” of weather and climate research that celebrates its 10th birthday in orbit May 4.

AIRS, built by BAE Systems, Boston, under the direction of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., is one of six instruments flying on NASA’s Aqua spacecraft as part of NASA’s Earth Observing System. AIRS, along with its partner microwave instrument, the Advanced Microwave Sounding Unit (AMSU-A), has faithfully measured our planet’s atmospheric temperature, water vapor, clouds and greenhouse gases with unprecedented accuracy and stability. Over the past decade, AIRS and AMSU-A have improved our understanding of Earth’s global water and energy cycles, climate change and trends and how Earth’s climate system is responding to increased greenhouse gases. (more…)

Plastic Pollution

By Guest PostMay 2, 2012Environmentalgae, bacteria, dylan meyer, environmental group, factor, giora proskurowski, historical weather data, kara lavendar law, liver function, mathematical model, model, north atlantic expedition, ocean, pacific garbage patch, plastic marine debris, plastic particles, plastic pollution, pollutant, recipe, skye moret ferguson, teresa messmore, tobias kukulka, university of delaware, university of washington, wind

Wind pushes plastics deeper into oceans, driving trash estimates up

Decades of research into how much plastic litters the sea may have only skimmed the surface. A new study reveals that wind drives confetti-sized pieces of plastic debris deeper underwater than previously believed, more than doubling earlier estimates of the pollutant’s presence in oceans.

“In windy conditions the traditional approach to measuring plastic marine debris captures only a small fraction of plastic pieces,” said Tobias Kukulka, assistant professor of physical ocean science and engineering in the University of Delaware’s College of Earth, Ocean, and Environment. “Our study helps to better understand how much plastic there is and where, as well as the complexity of the ocean dynamics at work.” (more…)

Geologists Correct a Rift in Africa

By Guest PostMarch 26, 2012Scienceafrica today, australia, climate change, earth crust, east africa, east african rift, eric roberts, ethiopia, geological sciences, giant arc, great rift valley, human evolution, human species, james cook university, Kenya, malawi, michael gottfried, michigan state university, model, nancy stevens, nature geoscience, ohio university, plate boundary, rukwa rift, system, tectonic forces, uganda, vertebrate fossils, volcanic ash

EAST LANSING, Mich. — The huge changes in the Earth’s crust that influenced human evolution are being redefined, according to research published today in Nature Geoscience.

The Great Rift Valley of East Africa – the birthplace of the human species – may have taken much longer to develop than previously believed.

“We now believe that the western portion of the rift formed about 25 million years ago, and is approximately as old as the eastern part, instead of much younger as other studies have maintained,” said Michael Gottfried, Michigan State University associate professor of geological sciences. “The significance is that the Rift Valley is the setting for the most crucial steps in primate and ultimately human evolution, and our study has major implications for the environmental and landscape changes that form the backdrop for that evolutionary story.” (more…)

Scholars Say Global Governance Overhaul Needed For Earth’s Sustainability

By Guest PostMarch 19, 2012Environmentearth, environmental change, environmental institution, environmental scholar, frank biermann, geo engineering, global governance, model, Nanotechnology, reform, rio de janeiro, societal change, steven bernstein, subsystem, sustainable development, synthetic biology, un, united nations

A group of the world’s leading environmental scholars are sounding the alarm that human societies need to transform their national and international environmental institutions into a more coherent and robust planetary stewardship model to steer away from rapid and irreversible changes to the Earth’s subsystems.

University of Toronto political scientist Steven Bernstein is one of the authors of a paper which appears in Science on March 16, 2012. (more…)