Clipmarks | kmcolo's science collection

Ecosystems: Ag modifications of hydrology create surprise

Sat, 03 May 2008 18:02:00 GMT

clipped by: kmcolo

Agricultural expansion and intensification have altered the quantity and quality of global water flows. Research suggests that these changes have increased the risk of catastrophic ecosystem regime shifts. We identify and review evidence for agriculture-related regime shifts in three parts of the hydrological cycle: interactions between agriculture and aquatic systems, agriculture and soil, and agriculture and the atmosphere. We describe the processes that shape these regime shifts and the scales at which they operate. As global demands for agriculture and water continue to grow, it is increasingly urgent for ecologists to develop new ways of anticipating, analyzing and managing nonlinear changes across scales in human-dominated landscapes.

Tags: science, ecosystems, non-linear systems, complexity, water, agriculture

Grass For Gas: Corn in the Hole

Mon, 14 Jan 2008 23:12:42 GMT

clipped by: kmcolo
clipper's remarks: The use of switchgrass as the feedstock for ethanol production holds promise.

Clip Source: www.sciam.com

Farmers in Nebraska and the Dakotas brought the U.S. closer to becoming a biofuel economy, planting huge tracts of land for the first time with switchgrass—a native North American perennial grass (Panicum virgatum) that often grows on the borders of cropland naturally—and proving that it can deliver more than five times more energy than it takes to grow it.

switchgrass ethanol delivers 540 percent of the energy used to produce it, compared with just roughly 25 percent more energy returned by corn-based ethanol according to the most optimistic studies.

Tags: alternative energy, energy, science, environment

Escalating Ice Loss Found in Antarctica

Mon, 14 Jan 2008 16:16:31 GMT

clipped by: kmcolo
clipper's remarks:

The new finding comes days after the head of the Intergovernmental Panel on Climate Change said the group's next report should look at the "frightening" possibility that ice sheets in Greenland and Antarctica could melt rapidly at the same time.

Clip Source: www.washingtonpost.com

Climatic changes appear to be destabilizing vast ice sheets of western Antarctica that had previously seemed relatively protected from global warming, researchers reported yesterday, raising the prospect of faster sea-level rise than current estimates.

researchers found that the rate of ice loss in the affected areas has accelerated over the past 10 years -- as it has on most glaciers and ice sheets around the world.

"Without doubt, Antarctica as a whole is now losing ice yearly, and each year it's losing more," said Eric Rignot, lead author of a paper published online in the journal Nature Geoscience.

Rignot said the tonnage of yearly ice loss in Antarctica is approaching that of Greenland, where ice sheets are known to be melting rapidly in some parts and where ancient glaciers have been in retreat.

Tags: climate change, global warming, antarctica, science

Potential AIDS breakthrough

Thu, 10 Jan 2008 20:23:54 GMT

clipped by: kmcolo
clipper's remarks: This work used siRNA, or short interfering RNA to block the production of human proteins that the HIV uses in its propagation.

Clip Source: select.nytimes.com

Using a new type of genetic screen, researchers at Harvard Medical School have identified 273 proteins that the AIDS virus needs to survive in human cells, opening up new potential targets for drugs.

“This is just terrific work,” said Dr. Robert C. Gallo, director of the Institute of Human Virology at the University of Maryland and a co-discoverer of the virus. “I think it’s destined to be one of the top papers in this field for the decade.”

This is hypothesis-generating, not hypothesis-solving. It creates a lot of work

Tags: health, medicine, aids, hiv, science, rna, sirna

Podcast: Why is the Universe Right for Life?

Sun, 06 Jan 2008 18:20:55 GMT

clipped by: kmcolo
clipper's remarks: A very interesting interview about one person's concept of how the universe has come to beget life. If you like strange, mind bending, quantum mechanical concepts, this is for you.

Clip Source: www.sciencefriday.com

In this segment, Ira talks with author and cosmologist Paul Davies about his book "Cosmic Jackpot: Why Our Universe is Just Right for Life". It's a brain-twisting look at cosmology, quantum physics, and the role of life in the cosmos. This is a holiday rebroadcast of a previously recorded Science Friday, so please don't try to call in. Teachers, find more information about using Science Friday as a classroom resource in the Kids' Connection.

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Tags: podcast, sceince friday, science, philosophy, quantum mechanics, life, creation

Abrupt Climate Change and Our Future

Wed, 19 Dec 2007 17:18:00 GMT

clipped by: kmcolo
clipper's remarks: A video lecture by Lonnie Thompson at this fall's AGU meeting.

Clip Source: www.visualwebcaster.com

Tags: climate change, global warming, science, video, lecture

The Evolution of Evolution: how culture changes genes

Mon, 17 Dec 2007 08:38:38 GMT

clipped by: abailart
clipper's remarks: Not, as stated, a new idea: been around a long time in complexity theory, and quantum consciousness theory, for instance. This is a short, pithy statement of the claim, read it in a couple of minutes.

Clip Source: www.slate.com

Now we're in the midst of the next mutation in evolutionary theory: Human evolution didn't slow as we advanced from nature to culture. It accelerated and changed. Culture, born of natural selection, became natural selection's driving force.

This is the message of a new study of the human genome. If true, it radically complicates the debate between nature and nurture. The question is no longer simply whether our genes are the source of civilization, but whether they're also its product.

Organisms evolve in response to changing environments. This can lead, paradoxically, to the evolution of traits that change the environment. Once that happens, the process becomes dialectical, and its speed increases, because culture changes more rapidly than nature does.

Much of what now passes for "natural selection" isn't exactly natural. It's social.

It may be true that today's God a human creation. But so, in a way, is today's evolution.

Is low intelligence to blame for short life expectancy ?

Fri, 10 Nov 2006 12:24:25 GMT

clipped by: Oldude59

Clip Source: bps-research-digest.blogspot.com

People in countries with a large gap between the rich and poor have short life expectancies, not because of the economic inequality and lack of resources, but rather because they are unintelligent. That’s the controversial claim of Satoshi Kanazawa of the London School of Economics, who has used data from the UN and World Bank to look at the associations between average life expectancy, prosperity and economic inequality within over 120 countries around the world.

The economic historian Richard Wilkinson has argued that economic inequality leads to shorter life expectancy because being at the bottom of the social pile puts people under prolonged stress. But Kanazawa rejects this hypothesis. He argues his data show that once population IQ is taken into account, a country’s average life expectancy is no longer related to economic development and inequality. Indeed, he found IQ was between seven and eight times more strongly related to life-expectancy than were measures of income inequality.

To support his case further, Kanazawa also focused on 29 sub-Saharan countries which have changed little since ancient times. In these countries where modern threats are absent, Kanazawa found IQ is not related to life-expectancy whereas income inequality is.

Tags: belief, clipmarks, concept, research, politics

Good news for wine drinking mice

Wed, 01 Nov 2006 20:50:49 GMT

clipped by: kmcolo
clipper's remarks: And maybe for wine drinking people but certainly for wine makers and sellers!

Clip Source: www.nytimes.com

Substance in Red Wine Extends Life of Mice

Can you have your cake and eat it? Is there a free lunch after all, red wine included? Researchers at the Harvard Medical School and the National Institute of Aging report that a natural substance found in red wine, known as resveratrol, offsets the bad effects of a high-calorie diet in mice and significantly extends their lifespan.

Tags: health, diet, wine, science

Climate: Back to the future

Mon, 12 Jun 2006 16:15:31 GMT

clipped by: kmcolo
clipper's remarks: "With no more carbon dioxide warming the greenhouse than today, the globe was a good 3°C warmer, and sea level was a whopping 25 meters higher."

Clip Source: www.sciencemag.org

Science 9 June 2006:
Vol. 312. no. 5779, pp. 1456 - 1457
DOI: 10.1126/science.312.5779.1456a

PALEOCLIMATOLOGY:
Looking Way Back for the World's Climate Future

Researchers worry that if they cannot recall the distant climatic past, the world may be condemned to repeat it. And repeating the warmth of the early Pliocene epoch of 3 million to 4 million years ago would be a shocker. With no more carbon dioxide warming the greenhouse than today, the globe was a good 3°C warmer, and sea level was a whopping 25 meters higher. But how could such a modest stock of greenhouse gas fuel such warming? Unfortunately, no one knows.

On page 1485 of this issue, a group of climate researchers takes a look back at the Pliocene, pulls together models of oceanic and atmospheric behavior under those conditions, and concludes that humans may already have put the world on a path back to that epoch. "It's a very interesting period to study, a great scientific puzzle," says paleoceanographer David Lea of the University of California (UC), Santa Barbara. "I like the way they're thinking." But better paleo-data and more realistic modeling will be needed before anyone knows for sure.

The key to understanding Pliocene and possibly future climate, say climate dynamicist Alexey Fedorov of Yale University and his colleagues, could be the climate changes occurring at mid- to high northern latitudes. Those changes might constitute a climatic switch: Throw it one way, and trigger a permanent El Niño in the Pacific Ocean capable of warming the whole world. Throw it the other way, and El Niño and La Niña alternate in a cooler world as they do today.

Tags: climate, climate change, global warming, paleo-reconstructions, paleoclimate, model

Nature offers guidance on organising dynamic networks

Tue, 30 May 2006 18:22:50 GMT

clipped by: kmcolo

Clip Source: www.astrobiology.com

Nature offers guidance on organising dynamic networks

Today, for many, computer networks are an indispensable infrastructure that interconnects people, places and organisations. But increasingly they are beginning to creak as their complexity grows. Biological systems through years of evolution can offer clues on how to cope, as a research project has demonstrated.

BISON is inspired by Complex Adaptive Systems like ants, fireflies and even single cells. "Complexity in computing is already a problem, and traditional methods are no longer adequate to address the problems," says Babaoglu, BISON’s coordinator. "And it's going to get worse as the internet becomes increasingly complex. Biological systems, on the other hand, are incredibly resilient and amazingly robust, so we're taking inspiration from a system that we know works."

In the computing paradigm, tiny packets of data, called ants, are sent out to find the most efficient routing choice based on the twin needs of connectivity and power management. Called AntHocNet, it is an attempt to create an ACO routing algorithm, which works efficiently in Mobile Ad hoc Networks, combining reactive path finding and repairing with proactive path maintenance and improvement.

"We were successful in developing robust, adaptive protocols," said Babaoglu. "But we were surprised that their performance was so good. We expected to lose performance, but our protocols are comparable to what's available today."

Tags: complex systems, computers

Climate sensitivity constrained by temperature reconstructions over the past seven centuries

Tue, 25 Apr 2006 18:14:41 GMT

clipped by: kmcolo
clipper's remarks: "Then the 5–95 per cent range shrinks to 1.5–6.2 K, thus substantially reducing the probability of very high climate sensitivity."

Clip Source: www.nature.com

Nature 440, 1029-1032 (20 April 2006) | doi:10.1038/nature04679; Received 8 July 2005; ; Accepted 28 February 2006

Climate sensitivity constrained by temperature reconstructions over the past seven centuries

Gabriele C. Hegerl¹, Thomas J. Crowley¹, William T. Hyde¹ and David J. Frame²

The magnitude and impact of future global warming depends on the sensitivity of the climate system to changes in greenhouse gas concentrations. The commonly accepted range for the equilibrium global mean temperature change in response to a doubling of the atmospheric carbon dioxide concentration¹, termed climate sensitivity, is 1.5–4.5 K (ref. 2). A number of observational studies^3,^4,^5,^6,^7,^8,^9,¹⁰, however, find a substantial probability of significantly higher sensitivities, yielding upper limits on climate sensitivity of 7.7 K to above 9 K (refs 3–8). Here we demonstrate that such observational estimates of climate sensitivity can be tightened if reconstructions of Northern Hemisphere temperature over the past several centuries are considered. We use large-ensemble energy balance modelling and simulate the temperature response to past solar, volcanic and greenhouse gas forcing to determine which climate sensitivities yield simulations that are in agreement with proxy reconstructions. After accounting for the uncertainty in reconstructions and estimates of past external forcing, we find an independent estimate of climate sensitivity that is very similar to those from instrumental data. If the latter are combined with the result from all proxy reconstructions, then the 5–95 per cent range shrinks to 1.5–6.2 K, thus substantially reducing the probability of very high climate sensitivity.

Tags: climate change, global warming, climate sensitivity, models

Gender differences in agression

Mon, 24 Apr 2006 23:56:52 GMT

clipped by: kmcolo
clipper's remarks: Women are more likely than men to experience their own acts of aggression as a loss of self-control than as trying to gain control over others. The authors propose that this has to do with women having a higher tolerance level for anger before inhibitory control is lost.

Clip Source: www.ingentaconnect.com

Gender differences in social representations of aggression: The phenomenological experience of differences in inhibitory control?

Source: British Journal of Psychology, Volume 97, Number 2, May 2006, pp. 139-153(15)

Abstract:

Women are more likely than men to experience acts of aggression as expressive (a loss of self-control) than as instrumental (control over others). We propose that this might arise from differences in behavioural restraint. If women have better inhibitory control, aggressive behaviour should occur less frequently yet should be experienced as more emotionally `out of control' because women can tolerate higher levels of anger before inhibitory control is breached. Participants (N=606) aged 13–24 completed the Multidimensional Personality Questionnaire (MPQ), the State-Trait Anger Expression Inventory-2 (STAXI-2) and Expagg. A more expressive view of aggression was associated with higher levels of STAXI anger control and higher levels of MPQ constraint. However, it was the harm avoidance component of constraint, rather than control versus impulsivity, that was the stronger predictor. While behavioural inhibition is built on an infrastructure of fear, the latter may be more important in explaining gender differences in social representations of aggression.

Tags: women, men, psychology, aggression

Figure: Climate change hot-spots

Sat, 22 Apr 2006 21:24:09 GMT

clipped by: kmcolo
clipper's remarks: Article abstract: http://clipmarks.com/clipmark/03B6F816-481C-4E07-A9E0-35542ACD82EA/

Clip Source: www.agu.org

GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L08707, doi:10.1029/2006GL025734, 2006

Figure

Figure 1. Regional Climate Change Index (RCCI) over 26 land regions of the World calculated from 20 coupled AOGCMs and 3 IPCC emission scenarios (A1B, A2, B1). The models used are BCCR-BCM2-0, CCMA-3-T47, CNRM-CM3, CSIRO-MK3, GFDL-CM2-0, GFDL-CM2-1, GISS-AOM, GISS-EH, GISS-ER, IAP-FGOALS, INMCM3, IPSL-CM4, MIROC3-2H, MIROC3-2M, MIUB-ECHO-G, MPI-ECHAM5, MRI-CGCM2, NCAR-CCSM3, NCAR-PCM1, UKMO-HADCM3. See also Table 1 of GB05a and http://www-pcmdi.llnl.gov. Enhanced EPS [1.7 MB]

Tags: climate change, global warming, figure, regional climate change

Solids that flow like a liquid without viscosity

Fri, 24 Mar 2006 16:13:40 GMT

clipped by: kmcolo

Clip Source: www.sciencemag.org

Science 24 March 2006:
Vol. 311. no. 5768, p. 1693
DOI: 10.1126/science.311.5768.1693a

CONDENSED-MATTER PHYSICS:
Free-Flowing Supersolid Confirmed, But Origins Remain Murky

Adrian Cho

BALTIMORE, MARYLAND--Since it was first reported that solid helium could flow without resistance, like a liquid devoid of viscosity, three other groups have reproduced the bizarre effect. But data presented here last week at an American Physical Society meeting also suggest that the "supersolid" flow occurs only in crystals riddled with defects. (Read more.)

Tags: materials science

Clipmarks | kmcolo's science collection

Ecosystems: Ag modifications of hydrology create surprise

Grass For Gas: Corn in the Hole

Escalating Ice Loss Found in Antarctica

Potential AIDS breakthrough

Podcast: Why is the Universe Right for Life?

Listen:

Tools:

Abrupt Climate Change and Our Future

The Evolution of Evolution: how culture changes genes

Is low intelligence to blame for short life expectancy ?

Good news for wine drinking mice

Climate: Back to the future

PALEOCLIMATOLOGY:Looking Way Back for the World's Climate Future

Nature offers guidance on organising dynamic networks

Climate sensitivity constrained by temperature reconstructions over the past seven centuries

Letter

Climate sensitivity constrained by temperature reconstructions over the past seven centuries

Gender differences in agression

Gender differences in social representations of aggression: The phenomenological experience of differences in inhibitory control?

Figure: Climate change hot-spots

Figure

Solids that flow like a liquid without viscosity

CONDENSED-MATTER PHYSICS:Free-Flowing Supersolid Confirmed, But Origins Remain Murky

PALEOCLIMATOLOGY:
Looking Way Back for the World's Climate Future

CONDENSED-MATTER PHYSICS:
Free-Flowing Supersolid Confirmed, But Origins Remain Murky