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Permalink Reply by Adriana on May 26, 2012 at 10:20am

Permalink Reply by doone on May 26, 2012 at 1:58pm

Ocean Currents

Permalink Reply by doone on May 26, 2012 at 4:57pm

Can Trees Actually Deter Crime?

http://www.theatlanticcities.com/neighborhoods/2012/05/can-trees-ac...

May 26, 2012

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Silly as it may seem to the public, there's an intense disagreement among scholars about the impact urban trees have on a city's crime rate. Some are convinced urban greenery increases crime — arguing that low trees and shrubs, in particular, create a natural hiding place for criminals. A 2001 case study of auto thieves in Washington, D.C., found that offenders often target areas near dense vegetation because it can "reduce effort and risk by offering concealment."

Others are convinced that urban trees have exactly the opposite effect. This crowd argues that trees actually decrease crime either by attracting more people to public places (Jane Jacobs' "eyes on the street" theory) or by signifying to criminals that people care about their neighborhood (James Q. Wilson's "broken windows" theory). Another 2001 study, this one of public housing in Chicago, found that "the greener a building’s surroundings were, the fewer crimes reported."

Where better to settle the score once and for all than Baltimore? If trees can have a positive impact on crime in the land of The Wire, then it seems safe to assume they can have an impact anywhere.

Well somebody tell Omar the game just changed. In the June issue of Landscape and Urban Planning, a team of environmental researchers led by Austin Troy of the University of Vermont report an inverse relationship between tree canopy and a variety of crimes in the Baltimore city and county regions. All told, Troy and colleagues conclude that "a 10% increase in tree canopy was associated with a roughly 12% decrease in crime."

For the study, the researchers examined crime and canopy rates over a long stretch of area from inner city Baltimore to the exurbs of Baltimore County. The crime rates varied greatly across the region: those in the city were 3.5 times the national average per block, while those in the outskirts were "nearly non-existent." (They limited their study to robberies, burglaries, thefts, and shootings, since assaults typically take place indoors.) So too did the canopy rates: some parts of the city have no greenery; some parts of the county achieve 87 percent coverage.

Troy and his colleagues ran all types of models to analyze the relationship between crime and canopy. Even after controlling for factors known to influence crime statistics — income, race, population density, and the like — they found the aforementioned link between more trees and less crime. While they doubt the connection is "purely causal," the strength of their figures suggest "some genuine relationship between trees and crime."

The results were not entirely straightforward. In some pockets of Baltimore city, for instance, the presence of trees indeed seemed to increase crime rates, just as some of the previous literature suggests. That was especially true in the outer harbor areas of Brooklyn Park, Wagners Point, and Dundalk — places with poorly groomed vegetation where "the concealment value of the vegetation outweighs its deterrent effect":

This last result clarifies much of the confused relationship between urban greenery and urban crime: While low dense brush seems to increase it, tall broad canopies seem to decrease it. That nuanced conclusion harmonizes with another study published earlier this year, in which U.S.D.A. Forest Service researcher Geoffrey Donovan (who has also linked urban tree coverage to home prices) reports the same mixed tree-crime associations in Portland, Oregon. If the evidence tells us anything certain, it's to keep your shrubbery close, but your canopies closer.

Top image: MR /Shutterstock.com

Permalink Reply by doone on May 26, 2012 at 10:57pm

Car-Sized Giant Turtle Discovered in Colombia Ate Alligators for Br...

By Ben Johnson and Slate V Staff

 | Posted Friday, May 18, 2012, at 4:39 PM ET

16

A prehistoric giant turtle fossil has been discovered in Colombia.

The Paleocene era would have been a terrible time to own a pet turtle, unless you had a garage to park it in.

Paleontologists have discovered a car-sized turtle in a Colombian coalmine that may have eaten alligators and ruled a large swath of land and fresh water.

After the Great Extinction that wiped out the dinosaurs 65 million years ago, reptiles continued to thrive, with some of them, like the 40-foot Titanoboa, growing to enormous sizes and dominating the post-apocalyptic epoch. This titanic turtle, dubbed Carbonemys cofrinii, was a Titanoba contemporary, at the size of a Fiat with a skull as big as a football. And in an era where ancient crocs preyed on small turtles, this 6-foot shell-dweller flipped the predator and prey relationship.

How did creatures like this get so big? Scientists think the lush, hot environment helped—as did a lack of predators. So, we’ve got the mutant turtles—now, we just need to figure out if they liked pizza and knew kung fu.

Permalink Reply by doone on May 27, 2012 at 10:41am

B. F. SKINNER’S IDEAS ARE MAKING AN UNLIKELY COMEBACK

B. F. Skinner’s notorious theory of behavior modification was denounced by critics 50 years ago as a fascist, manipulative vehicle for government control. But Skinner’s ideas are making an unlikely comeback today, powered by smartphone apps that are transforming us into thinner, richer, all-around-better versions of ourselves. The only thing we have to give up? Free will.

David H. Freedman in The Atlantic:

Most of us know someone who lost weight years ago and has kept it off, and we all see celebrities who claim to have slimmed down for good using plain old diet and exercise, from Bill Clinton to Drew Carey to Jennifer Hudson. But we keep hearing that the vast majority of us—98 percent is a figure that gets thrown about—can’t expect to do the same.

Alcoholics don’t seem to face such dismal prospects, thanks to Alcoholics Anonymous and similar multistep programs, which are widely regarded as effective treatments. With obesity, we’re apparently at a loss for a clear answer. Fads like the Atkins diet slowly fade in popularity after dieters watch the weight return. We’re left with the impression that the techniques needed to permanently lose weight don’t exist, or apply to only a tiny percentage of the population, who must be freaks of willpower or the beneficiaries of exotic genes. Scientists and journalists have lined up in recent years to pronounce the diet-and-exercise regimen a nearly lost cause—a view argued in no fewer than three cover stories and another major article in The New York Times Magazine over the past 10 years, and in a cover story in this magazine two years ago.

All of which is odd, because weight-loss experts have been in fairly strong agreement for some time that a particular type of diet-and-exercise program can produce modest, long-term weight loss for most people. But this program tends to be based in clinics operated by relatively high-priced professionals, and requires a significant time commitment from participants—it would be as if the only way to get treated for alcoholism were to check into the Betty Ford Center. The problem is not that we don’t know of a weight-control approach that works; it’s that what works has historically been expensive and inconvenient.

More here.

Posted by Abbas Raza at 11:20 PM | Permalink

COMMENTS

Link broken.
http://www.theatlantic.com/magazine/archive/2012/06/the-perfected-s...

Permalink Reply by doone on May 27, 2012 at 1:58pm

Can Science Embrace Awe?

Philip Ball insists it's not reserved for religion:

Pretending that science is performed by people who have undergone a Baconian purification of the emotions only deepens the danger that it will seem alien and odd to outsiders, something carried out by people who do not think as they do. [Lorraine] Daston believes that we have inherited a “view of intelligence as neatly detached from emotional, moral and aesthetic impulses, and a related and coeval view of scientific objectivity that brand[s] such impulses as contaminants”.

It is easy to understand the historical origins of this attitude: the need to distinguish science from credulous “enthusiasm”, to develop an authoritative voice, to strip away the pretensions of the mystical Re nais sance magus who acquired knowledge through personal revelation. We no longer need these defences, however; worse, they become a defensive reflex that exposes scientists to the caricature of the emotionally constipated boffin, hiding within thickets of jargon.

Permalink Reply by doone on May 27, 2012 at 3:00pm

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Nnew genetic method developed to pinpoint individuals geographic origin

http://www.sciencedaily.com/releases/2012/05/120524112531.htm

May 27, 2012

ScienceDaily (May 24, 2012) — Understanding the genetic diversity within and between populations has important implications for studies of human disease and evolution. This includes identifying associations between genetic variants and disease, detecting genomic regions that have undergone positive selection and highlighting interesting aspects of human population history.

Now, a team of researchers from the UCLA Henry Samueli School of Engineering and Applied Science, UCLA's Department of Ecology and Evolutionary Biology and Israel's Tel Aviv University has developed an innovative approach to the study of genetic diversity called spatial ancestry analysis (SPA), which allows for the modeling of genetic variation in two- or three-dimensional space.

Their study is published online this week in the journal Nature Genetics.

With SPA, researchers can model the spatial distribution of each genetic variant by assigning a genetic variant's frequency as a continuous function in geographic space. By doing this, they show that the explicit modeling of the genetic variant frequency -- the proportion of individuals who carry a specific variant -- allows individuals to be localized on a world map on the basis of their genetic information alone.

"If we know from where each individual in our study originated, what we observe is that some variation is more common in one part of the world and less common in another part of the world," said Eleazar Eskin, an associate professor of computer science at UCLA Engineering. "How common these variants are in a specific location changes gradually as the location changes.

"In this study, we think of the frequency of variation as being defined by a specific location. This gives us a different way to think about populations, which are usually thought of as being discrete. Instead, we think about the variant frequencies changing in different locations. If you think about a person's ancestry, it is no longer about being from a specific population -- but instead, each person's ancestry is defined by the location they're from. Now ancestry is a continuum."

The team reports the development of a simple probabilistic model for the spatial structure of genetic variation, with which they model how the frequency of each genetic variant changes as a function of the location of the individual in geographic space (where the gene frequency is actually a function of the x and y coordinates of an individual on a map).

"If the location of an individual is unknown, our model can actually infer geographic origins for each individual using only their genetic data with surprising accuracy," said Wen-Yun Yang, a UCLA computer science graduate student.

"The model makes it possible to infer the geographic ancestry of an individual's parents, even if those parents differ in ancestry. Existing approaches falter when it comes to this task," said UCLA's John Novembre, an assistant professor in the department of ecology and evolution.

SPA is also able to model genetic variation on a globe.

"We are able to also show how to predict the spatial structure of worldwide populations," said Eskin, who also holds a joint appointment in the department of human genetics at the David Geffen School of Medicine at UCLA. "In just taking genetic information from populations from all over the world, we're able to reconstruct the topology of the global populations only from their genetic information."

Using the framework, SPA can also identify loci showing extreme patterns of spatial differentiation.

"These dramatic changes in the frequency of the variants potentially could be due to natural selection," Eskin said. "It could be that something in the environment is different in different locations. Let's say a mutation arose that has some advantageous property in a certain environment. So you can imagine then that a kind of force for genetic selection would make this mutation more common in that environment."

The research team began to examine all of the genes, and for each gene they computed how sharp of a change there was in the frequencies. They soon discovered that the genes which had the largest and most extreme changes are the ones that are known to have experienced selection in the recent past.

"So this is a new method for finding genes that are also undergoing selection in humans," Yang said.

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The above story is reprinted from materials provided by University of California - Los Angeles. The original article was written by Wileen Wong Kromhout.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Wen-Yun Yang, John Novembre, Eleazar Eskin, Eran Halperin. A model-based approach for analysis of spatial structure in genetic data. Nature Genetics, 2012; DOI: 10.1038/ng.2285

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Permalink Reply by doone on May 27, 2012 at 3:02pm

• Browser Tool
• Maya collapse: Trade patterns for crucial substance played key role

http://www.sciencedaily.com/releases/2012/05/120523135538.htm

May 27, 2012

ScienceDaily (May 23, 2012) — Shifts in exchange patterns provide a new perspective on the fall of inland Maya centers in Mesoamerica approximately 1,000 years ago. This major historical process, sometimes referred to as the "Maya collapse" has puzzled archaeologists, history buffs, and the news media for decades.

The new research was published online May 23 in the journal Antiquity.

"Our research strongly suggests that changing patterns of trade were instrumental in prompting the 'Maya collapse,'" said Gary Feinman, curator of anthropology at The Field Museum, which collaborated with the University of Illinois at Chicago on the study.

The new research casts doubt on the idea that climate change was the sole or principal cause, Feinman said, noting that some Maya centers, which flourished after the collapse, were located in the driest parts of the Maya region. Feinman said that climate change, along with breakdowns in leadership, warfare, and other factors, contributed to the collapse, but the shifting exchange networks may have been a key factor.

For the Maya, who did not have metal tools, obsidian (or volcanic glass) was highly valued because of its sharp edges for use as cutting instruments. Maya lords and other elites derived power from controlling access to obsidian, which could be traded for important goods or sent as gifts to foster important relationships with other Mayan leaders.

The Field Museum researchers found that prior to the fall of the Maya inland centers, obsidian tended to flow along inland riverine networks. But over time, this material began to be transported through coastal trade networks instead, with a corresponding increase in coastal centers' prominence as inland centers declined.

The shift in trade might have involved more than obsidian. Field researcher Mark Golitko said, "The implication is that other valuable goods important to these inland centers were also slowly being cut off." Golitko led the Social Network Analysis that graphically depicts the change in trade patterns.

Researchers compiled information on obsidian collected at Maya sites, and used chemical analysis to identify the source(s) that produced obsidian found through archaeological studies at each location. Obsidian from three sources in Guatemala and several sources in central Mexico and Honduras were identified. The researchers generated data for each of four time periods: Classic (approximately 250-800 AD),

Terminal classic (approximately 800-1050 AD), Early Postclassic (approximately 1050-1300 AD), and Late Postclassic (approximately 1300-1520AD). Using Social Network Analysis (SNA) software, the researchers developed maps illustrating which sites had the same or similar percentages of each type of obsidian, in each of the four time periods. These percentages were then utilized to infer the likely network structure through which obsidian was transported

A comparison of the resulting SNA maps show that Classic period networks were located in inland, lowland areas along rivers, mostly in what is today the northern part of Guatemala, the Mexican state of Chiapas, the southern Yucatan, and western Belize. However, maps bearing data from later time periods show that inland networks diminished in importance and coastal networks were thriving, in what today is the northern Yucatan and coastal Belize.

The SNA data "is a very visual way to let us infer the general layout of the networks that transported obsidian, and the likely paths it took," Golitko said.

Feinman termed the study results significant. "The use of SNA to display and analyze the obsidian data graphically gives us a new perspective on these data, some of which has been present for years."

The study did not explore the question of why the transport networks began to shift. Feinman said there may have been military animosities that made the inland, river routes less safe or easy to use, and added that during this period the seagoing transport may have become more efficient with larger canoes. He noted that scientists simply don't have the definitive answers to some of these questions.

Does this study provide lessons for modern-day civilizations? Not directly, Golitko said. However, he believes it does suggest that major impacts follow when large-scale social and economic networks or communication channels break down. The consequences of the breakdown of obsidian supply to parts of the Maya region, he said, is a lesson for the increasingly connected world in which we live today.

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Story Source:

The above story is reprinted from materials provided by Field Museum, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

1. Mark Golitko, James Meierhoff, Gary M. Feinman and Patrick Ryan Williams. Complexities of collapse: the evidence of Maya obsidian as revealed by social network graphical analysis. Antiquity, Volume: 86 Number: 332 [link]

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Permalink Reply by doone on May 28, 2012 at 7:38am

HORSESHOE CRABS AND VELVET WORMS

Constance Casey in the New York Times:

Richard Fortey has spent most of his life looking at fossils, the imprints of the skeletons of the very thoroughly dead. Here he sets out — like a more deeply thoughtful David Attenborough, without the cameras — to describe the distinguished groups of organisms that are still recognizable and thriving after millions and millions of years. The horseshoe crabs, velvet worms and other venerable creatures he encounters are Earth’s true conservatives. “We’ve devised a system that works very well for our niche,” they would tell us. “No big changes necessary. Maybe just a tweak at the molecular level.” As Fortey says, “to look at a living horseshoe crab is to see a portrait of a distant ancestor repainted by time, but with many of its features still unchanged.”

Fortey’s dozen or so subjects have survived the many cataclysms the planet has thrown at them over the past 450 million years. As if repeated earthquakes, volcanic eruptions and ice sheets weren’t enough, there were two mass-extinction events. The best known was the disaster 65 million years ago that led to the downfall of the dinosaurs. We’re less familiar with the more devastating earlier extinction — about 251 million years ago — that erased 90 percent of life from the sea and almost as large a percentage of the little things struggling on land. The horseshoe crab made it through; its fossil remains date from 450 million years ago.

Somewhere then, perhaps at the bottom of a poisoned sea, with tsunamis rolling above, some organisms stayed alive, including something we would recognize as the horseshoe crab if it clambered up onto the beach. It’s astonishing to consider that the lucky few — arthropods, snails, clams, jellyfish, worms and a few small four-legged creatures on land — that survived the worst extinction gave rise to everything that followed, including us.

More here.

Posted by Abbas Raza at 11:05 PM | Permalink 

Permalink Reply by doone on May 28, 2012 at 4:09pm

What a Tune

May. 28, 2012

Permalink Reply by doone on May 28, 2012 at 5:14pm

A great blog with Brain images http://neuroimages.tumblr.com/

Permalink Reply by doone on May 30, 2012 at 10:43pm

Keeping the sand as clean as the water is a big part of coastal preservation. Beach clean-up days have a great impact, thanks to active citizens. Keeping an eye on development is also part of ensuring we have beaches in the future.

Photo by Clark Little

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