Tag Archives: hypothesis

Rainfall in South Pacific Was More Variable Before 20th Century

By Guest PostSeptember 14, 2013Science20th century, 50 year cycle, anthropogenic climate change, austin, bislama, cave formation, charles jackson, christopher maupin, climate modeler, dry periods, frederick taylor, good stone, hem gudfala ston, history of rainfall, hypothesis, island nation, jud partin, oxygen isotope level, oxygen isotopes, pacific convergence zone, pacific decadal variability, pdv, rainfall, rainfall in vanuatu, rainfall value, South Pacific, stalagmite, stalagmite data, university of texas, vanuatu

AUSTIN, Texas — A new reconstruction of climate in the South Pacific during the past 446 years shows rainfall varied much more dramatically before the start of the 20^thcentury than after. The finding, based on an analysis of a cave formation called a stalagmite from the island nation of Vanuatu, could force climate modelers to adjust their models. The models are adjusted to match the current levels of climate variability that are smaller now than they were in the recent past for this region.

“In this case, the present is not the key to the past, nor the future,” says Jud Partin, a research scientist associate at The University of Texas at Austin’s Institute for Geophysics who led the study. The institute is part of the Jackson School of Geosciences. “Instead, the past is the key to what may happen in the future.” (more…)

Prehistoric climate change

By Guest PostSeptember 7, 2013Environment, Scienceboundary layers, canada, comet in quebec, corossal crater, cosmic crash, dartmouth college, dry climate, environmental stress, environmental transformation, global climate shift, hypothesis, malcolm lecompte, mark demitroff, mastodons, mukul sharma, natufians, North America, prehistoric climate change, saber toothed cats, university of delaware, younger dryas period

Cosmic crash in Canada may have caused global climate shift 12,900 years ago

A dramatic global climate shift may be linked to the impact of an asteroid or comet in Quebec, according to researchers from the University of Delaware, Dartmouth College and Elizabeth City State University.

The findings appear in the Sept. 2 online Early Edition of the Proceedings of the National Academy of Sciences (PNAS). (more…)

Changes in language and word use reflect our shifting values, UCLA psychologist reports

By Guest PostAugust 17, 2013Culture, Generalauthority, belong, changes in language, Google, google books database, hypothesis, ngram viewer, non fiction publications, obedience, patricia greenfield, pray, rural environment, shifting values, socio demographic, textbooks, ucla psychologist, united states, urbanization, word use

Study analyzes more than 1 million books published over 200 years

A new UCLA analysis of words used in more than 1.5 million American and British books published between 1800 and 2000 shows how our cultural values have changed.

The increase or decrease in the use of certain words over the past two centuries — a period marked by growing urbanization, greater reliance on technology and the widespread availability of formal education — reveals how human psychology has evolved in response to major historical shifts, said Patricia Greenfield, a distinguished professor of psychology at UCLA and the author of the study. (more…)

How Did Earth’s Primitive Chemistry Get Kick Started?

By Guest PostAugust 2, 2013Scienceacetate, alkaline hydrothermal fluids, alkaline hydrothermal vents, ancient enzymes, atlantic ocean, bottom of oceans, chemical signature, distribution, earliest oceans, earth, enceladus, evolution, floor, future of life, hypothesis, icy worlds, jupiter, lauren white, laws of thermodynamics, mike russell, moon europa, nano engines, NASA, organic carbon, origin, polymers, primitive chemistry, saturn

How did life on Earth get started? Three new papers co-authored by Mike Russell, a research scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., strengthen the case that Earth’s first life began at alkaline hydrothermal vents at the bottom of oceans. Scientists are interested in understanding early life on Earth because if we ever hope to find life on other worlds — especially icy worlds with subsurface oceans such as Jupiter’s moon Europa and Saturn’s Enceladus — we need to know what chemical signatures to look for.

Two papers published recently in the journal Philosophical Transactions of the Royal Society B provide more detail on the chemical and precursor metabolic reactions that have to take place to pave the pathway for life. Russell and his co-authors describe how the interactions between the earliest oceans and alkaline hydrothermal fluids likely produced acetate (comparable to vinegar). The acetate is a product of methane and hydrogen from the alkaline hydrothermal vents and carbon dioxide dissolved in the surrounding ocean. Once this early chemical pathway was forged, acetate could become the basis of other biological molecules. They also describe how two kinds of “nano-engines” that create organic carbon and polymers — energy currency of the first cells — could have been assembled from inorganic minerals. (more…)

Older males make better fathers says new research on beetles

By Guest PostJune 27, 2013Sciencebeetles, birds, blackbirds, hypothesis, infidelity, megan head, nerc, offspring, older males, paternal care, paternity, perception of paternity, robins, species, university of exeter, younger males

Researchers at the University of Exeter found that older male burying beetles make better fathers than their younger counterparts.

The study found that mature males, who had little chance of reproducing again, invested more effort in both mating and in parental care than younger males.

The study, published in the journal Proceedings of the Royal Society of London – B, considered how the likelihood of paternity influenced the way that males cared for young. Older males were good fathers and looked after the young even when they were unsure whether the offspring were theirs. Younger males, who had a higher chance of reproducing again, tended to care less for offspring, particularly when they were uncertain of their paternity. (more…)

Biodiversity Protects Against Disease, Scientists Find

By Guest PostFebruary 15, 2013Natureamphibian eating birds, amphibian infections, amphibian species, aquatic parasite cycle, biodiversity, biodiversity matters, bird species, boulder, california tiger salamander, community of frogs, complex ecosystems, dan preston, decrease in disease, deformed frogs, disease transmission, doug levey, egrets, factor, grasslands, herons, humans, humans and wildlife, hypothesis, infection with ribeiroia, jason hoverman, katie richgels, large scale ecosystems, life cycle, lyme disease, malformations, national science foundation, northern leopard frog, organisms, parasite transmission, parasitic infections, pathogen, pieter johnson, pond, pond community, protects against disease, purdue university, replicate, reservoir hosts, ribeiroia ondatrae, salamanders, toads, university of colorado, west nile virus

Discovery resulted from study of amphibians in ponds

The richer the assortment of amphibian species in a pond, the more protection that community of frogs, toads and salamanders has against a parasitic infection that can cause severe deformities, including the growth of extra legs.

The findings, published in a paper in this week’s issue of the journal Nature, support the idea that greater biodiversity in large-scale ecosystems, such as forests or grasslands, may also provide greater protection against diseases, including those that affect humans.

A larger number of mammal species in an area may curb cases of Lyme disease, while a larger number of bird species may slow the spread of West Nile virus. (more…)

Study: Alternate Walking and Running to Save Energy, Maintain Endurance

By Guest PostFebruary 4, 2013Healthalternate walking, best strategy, bus stop, calculation, conserve energy, data, exoskeletons, goal, human body, human energy costs, hypothesis, leroy long, less energy, maintain endurance, manoj srinivasan, marathon finish line, natural environment, notion, ohio state university, optimize energy, pam frost gorder, physical factor, prosthetic devices, running, save energy, transition region, treadmill

COLUMBUS, Ohio — Forget “slow and steady wins the race.” A new study shows that, at least sometimes, the best way to conserve energy and reach your destination on time is to alternate between walking and running—whether your goal is the bus stop or a marathon finish line.

In the January 30, 2013 issue of the Journal of the Royal Society Interface, researchers examined how people budget their time as they travel on foot to reach a destination at a particular appointed time. The study found that when people have neither too much time nor too little time to reach their destination, they naturally switch back and forth between walking and running, which turns out to be the best strategy for saving energy. (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…)