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Green neighborhoods may reduce childhood obesity

First study to look at effect of greenness on inner city children's weight over time

San Diego, October 28, 2008 – Childhood obesity can lead to type 2 diabetes, asthma, hypertension, sleep apnea and emotional distress. Obese children and youth are likely to be obese as adults, experience more cardiovascular disease, high blood pressure and stroke and incur higher healthcare costs. In an article published in the December 2008 issue of the American Journal of Preventive Medicine, researchers report that children living in inner city neighborhoods with higher "greenness" experienced lower weight gains compared to those in areas with less green space.

Researchers from the University of Washington, Indiana University-Purdue University and Indiana University School of Medicine followed more than 3800 children, predominantly African-American and poor, aged 3-16 over a two-year period. Using satellite imaging data to measure vegetation coverage, the investigators found that higher greenness was significantly associated with lower body mass index (BMI) changes in those children. In previous studies of adults, residential density tended to predict physical activity levels, with highly urban environments leading to more walking, less driving and lower BMI. The current study did not find this correlation for children.

Children and youth in urban environments may be active in a wider variety of open spaces (e.g., yards, parks, vacant lots) and less likely to constrain activity to streets and sidewalks. Greenness might indicate proximity to parks, playfields or other open spaces that promote either physical activity or increased time spent outdoors in active play.

Writing in the article, Janice F. Bell, PhD, MPH, Assistant Professor in the department of Health Services at the School of Public Health and Community Medicine, University of Washington, Seattle, and co-investigators state, "This study's findings align with previous research linking exposure to green landscapes with health improvements. Among adults, greenness is associated with less stress and lower BMI, improved self-reported health and shorter post-operative recovery periods. Among children and youth, the positive health effects of green landscapes include improved cognitive functioning and reduced attention deficit hyperactivity disorder symptoms. Ideally, future research in this area will be multidisciplinary – involving city planners, architects, geographers, psychologists and public health researchers – and will consider the ways children live and play in urban environments."

In a commentary published in the same issue of the American Journal of Preventive Medicine, Nick Wareham, MBBS, PhD, of the Institute of Metabolic Science, Cambridge, England, writes, "Previous research on factors associated with physical activity in children has used mostly cross-sectional designs and few prospective studies have been published. In addition, studies have focused mostly on individual biological or psychological factors, with little emphasis, until recently, on collective determinants such as the physical environment. By focusing on environmental determinants in a longitudinal study in children, the study by Bell et al makes an important contribution to the existing literature."

http://www.eurekalert.org/pub_releases/2008-10/ehs-gnm102608.php

Caste in the colony: How fate is determined between workers and queens

"The history of all past society has consisted in the development of class antagonisms…the exploitation of one part of society by the other". – Karl Marx and Frederick Engels, The Communist Manifesto.

Although diversity in social groups can increase group well being, it also may increase the potential for conflict. All societies are characterized by struggles for control: which individuals gain the spoils and which toil in the fields. In colonies of social insects this struggle is embodied by a reproductive division of labor. Some individuals (the queens) reproduce, while the workers provide the labor that maintains colony function. In many social insects queens enjoy nearly complete control over reproduction and workers have diversified in form and function to increase their efficiency at performing different labors.

How, then, is it determined which individuals, as developing larvae, becoming queens or different types of workers? A collaborative research team of scientists at four universities has found that caste determination in the Florida harvester ant is much more than meets the eye. Larvae become different castes (small workers, large workers, or new queens) based largely on the nutrition they receive. Those fed more insects than seeds are more likely to become larger individuals (queen>large worker>small worker). However, genetic differences also contribute and bias the larva's developmental pathway. Even once caste is determined, nutritional, social (colony size), and genetic factors all contribute, but in different ways, to how big an individual grows. "Caste determination in most social insects likely involves both nature and nurture, but most interestingly in this species, these two forces contribute differently in different castes," says lead researcher Chris R. Smith of the University of Illinois. Although genetic factors contribute to what caste an individual becomes, the environment of the larva is controlled by the workers. Quite generally, ant colonies are supreme examples of both conflict and cooperation – each extreme of the nature-nurture continuum.

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"Caste determination in a polymorphic social insect: nutritional, social, and genetic factors" by C.R. Smith (University of Illinois Urbana-Champaign), K.E. Anderson (University of Arizona), C.V. Tillberg (Linfield College), J. Gadau (Arizona State University), and A.V. Suarez (University of Illinois Urbana-Champaign). American Naturalist (2008) 172:497-507 DOI: 10.1086/590961
University of Chicago Press Journals

Growth in the global carbon budget

Today the new Global Carbon Budget was launched simultaneously by Global Carbon Project co-chair Michael Raupach in France at the Paris Observatory, and in the USA at Capitol Hill, Washington by GCP Executive Director Pep Canadell.

The Global Carbon Project posted the most recent figures for the worlds' carbon budget, a key to understanding the balance of carbon added to the atmosphere, the underpinning of human induced climate change. Despite the increasing international sense of urgency, the growth rate of emissions continued to speed up, bringing the atmospheric CO₂ concentration to 383 parts per million (ppm) in 2007.

Anthropogenic CO₂ emissions have been growing about four times faster since 2000 than during the previous decade, despite efforts to curb emissions in a number of Kyoto Protocol signatory countries. Emissions from the combustion of fossil fuel and land use change reached 10 billion tones of carbon in 2007. Natural CO₂ sinks are growing but slower than the atmospheric CO₂ growth, which has been increasing at 2 ppm since 2000 or 33% faster than the previous 20 years.

Dr. Pep Canadell, executive director of the Global Carbon Project said "This new update of the carbon budget shows the acceleration of both CO₂ emissions and atmospheric accumulation are unprecedented and most astonishing during a decade of intense international developments to address climate change."

Emissions growth for 2000-2007 was above even the most fossil fuel intensive scenario of the Intergovernmental Panel on Climate Change (SRES-IPCC). While the developing nations of China and India continue to increase emissions, China has improved the carbon intensity of their economy since 2005, based on data from the National Energy Administration in China.

Decreasing forest cover, almost exclusively from deforestation in tropical countries, was responsible for an estimated 1.5 billion tons of emissions to the atmosphere above what was gained through new plantings. Although the oceans carbon uptake was expected to rise with the higher atmospheric concentration of CO₂, in 2007 it was reduced by a net 10 million tons.

Natural land and ocean CO₂ sinks, which have removed 54% (or 4.8 billion tons per year) of all CO₂ emitted from human activities during the period 2000-2007, are now becoming less efficient. While the size of these sinks continues to grow in response to greater concentrations of CO₂ in the atmosphere, they are losing efficiency as feedbacks between the carbon cycle and climate increase.

Global Carbon Project

Lime In Seawater May Reduce CO2 To Pre-Industrial Days

Scientists say they have found a workable way of reducing CO2 levels in the atmosphere by adding lime to seawater. And they think it has the potential to dramatically reverse CO2 accumulation in the atmosphere, reports Cath O’Driscoll in SCI’s Chemistry & Industry magazine published today.

Shell is so impressed with the new approach that it is funding an investigation into its economic feasibility. ‘We think it’s a promising idea,’ says Shell’s Gilles Bertherin, a coordinator on the project. ‘There are potentially huge environmental benefits from addressing climate change – and adding calcium hydroxide to seawater will also mitigate the effects of ocean acidification, so it should have a positive impact on the marine environment.’

Adding lime to seawater increases alkalinity, boosting seawater’s ability to absorb CO2 from air and reducing the tendency to release it back again.

However, the idea, which has been bandied about for years, was thought unworkable because of the expense of obtaining lime from limestone and the amount of CO2 released in the process.

Tim Kruger, a management consultant at London firm Corven is the brains behind the plan to resurrect the lime process. He argues that it could be made workable by locating it in regions that have a combination of low-cost ‘stranded’ energy considered too remote to be economically viable to exploit – like flared natural gas or solar energy in deserts – and that are rich in limestone, making it feasible for calcination to take place on site.

Kruger says: ‘There are many such places – for example, Australia’s Nullarbor Plain would be a prime location for this process, as it has 10 000km3 of limestone and soaks up roughly 20MJ/m2 of solar irradiation every day.’

The process of making lime generates CO2, but adding the lime to seawater absorbs almost twice as much CO2. The overall process is therefore ‘carbon negative’.

‘This process has the potential to reverse the accumulation of CO2 in the atmosphere. It would be possible to reduce CO2 to pre-industrial levels,’ Kruger says.

And Professor Klaus Lackner, a researcher in the field from Columbia University, says: ‘The theoretical CO2 balance is roughly right…it is certainly worth thinking through carefully.’

The oceans are already the world’s largest carbon sink, absorbing 2bn tonnes of carbon every year. Increasing absorption ability by just a few percent could dramatically increase CO2 uptake from the atmosphere.

This project is being developed in an open source manner. To find out more, please go to www.cquestrate.com, a new website, launched today.

Geologists study China earthquake for glimpse into future

The May 12 earthquake that rocked Sichuan Province in China was the first there in recorded history and unexpected in its magnitude. Now a team of geoscientists is looking at the potential for future earthquakes due to earthquake-induced changes in stress.

Around the world, earthquakes like the one in China are associated with triggered aftershocks that are very large. In 1999, a 7.1 earthquake in Duzce, Turkey, followed a 7.4 magnitude earthquake in Izmit, Turkey. In 2004, an 8.7 magnitude earthquake struck three months after the Sumatra Andaman earthquake of magnitude 9.2. While analysis of the Turkish earthquakes was not timely enough to shed light on the second earthquake there, the researchers believe that information on the Sumatra Andaman earthquake did illuminate the situation.

For the May 12 earthquake, the researchers performed analysis of co-seismic stress transfer onto Sichuan basin faults using broad ranges because at this time, exact values for all the various factors are unknown. The researchers report in today's (July 6) advanced online edition of Nature that "this approach enables rapid mapping of faults with heightened rupture likelihood."

"We knew that the fault was there and we knew it was active," says Eric Kirby, associate professor of geosciences at Penn State. "I had done some previous work in the area, but I do not think anyone would have anticipated the size of this earthquake."

The May earthquake in Sichuan Provence was 7.9 in magnitude and collapsed buildings, destroyed villages and killed thousands of people. The earthquake occurred in the area where the Sichuan basin and the Longmen Mountains meet. This is on the eastern edge of the Tibetan Plateau in an area deformed by the collision of the Indian and Asian tectonic plates. The area is crisscrossed with fault lines.

The researchers, who include Tom Parsons, research geophysicist, U.S. Geological Survey, Chen Ji, assistant professor of Earth sciences, University of California-Santa Barbara, and Kirby, used a model to see how the Sichuan earthquake, which took place on the Beichuan fault, affected other portions of that fault and others in the area. They looked at physical characteristics of the faults including the directions and amounts of movement of the faults – whether and how much they moved up and down and side to side, and the estimates of the frictional resistance to motion along the fault.

"The Sichuan earthquake seemed to rupture on the northern portion of the Beichuan fault," says Kirby. "It does not seem to have involved the southwestern branch."

According to the model, after the May 12 earthquake, stress increased on faults running parallel to the Wenchuan-Maowen fault and the two major faults that are perpendicular and to the north of the fault. Some smaller faults south of the earthquake zone show a decrease in stress. However, according to the model, the majority of the faults in the area are still stressed.

"The occurrence of triggered earthquakes after a major earthquake can be months, years or decades," says Kirby. "Sumatra seems to be a really nice example. Also, the historic record in Turkey shows a series of earthquakes that progress from east to west over 60 years."

The data used in the model consists of ranges rather than actual measurements because of the difficulty of obtaining information from that area of China at the moment. The models always use a range of friction because the movement of the faults changes the friction sometimes in unknown or unexpected ways.

"The model takes what we think we know about the faults in the region and asks what was the change to stress associated with the earthquake," says Kirby. "The model shows where an increase in the potential for failure may occur, but we do not know the trigger point for these faults. The analysis does not say there is going to be an earthquake, just that the potential exists on some of the faults."

Geologists Discover Signs of Volcanoes Blowing their Tops in the Deep Ocean

Evidence of Violent Eruptions on Gakkel Ridge in the Arctic Defies Assumptions about Seafloor Pressure and Volcanism

A research team led by the Woods Hole Oceanographic Institution (WHOI) has uncovered evidence of explosive volcanic eruptions deep beneath the ice-covered surface of the Arctic Ocean. Such violent eruptions of splintered, fragmented rock—known as pyroclastic deposits—were not thought possible at great ocean depths because of the intense weight and pressure of water and because of the composition of seafloor magma and rock.

Researchers found jagged, glassy rock fragments spread out over a 10 square kilometer (4 square mile) area around a series of small volcanic craters about 4,000 meters (2.5 miles) below the sea surface. The volcanoes lie along the Gakkel Ridge, a remote and mostly unexplored section of the mid-ocean ridge system that runs through the Arctic Ocean.

“These are the first pyroclastic deposits we've ever found in such deep water, at oppressive pressures that inhibit the formation of steam, and many people thought this was not possible,” said WHOI geophysicist Rob Reves-Sohn, lead author and chief scientist for the Arctic Gakkel Vents Expedition (AGAVE) of July 2007. “This means that a tremendous blast of CO2 was released into the water column during the explosive eruption.”

The paper, which was co-authored by 22 investigators from nine institutions in four countries, was published in the June 26 issue of the journal Nature.

Seafloor volcanoes usually emit lobes and sheets of lava during an eruption, rather than explosive plumes of gas, steam, and rock that are ejected from land-based volcanoes. Because of the hydrostatic pressure of seawater, ocean eruptions are more likely to resemble those of Kilauea than Mount Saint Helens or Mount Pinatubo.

Making just the third expedition ever launched to the Gakkel Ridge—and the first to visually examine the seafloor--researchers used a combination of survey instruments, cameras, and a seafloor sampling platform to collect samples of rock and sediment, as well as dozens of hours of high-definition video. They saw rough shards and bits of basalt blanketing the seafloor and spread out in all directions from the volcanic craters they discovered and named Loke, Oden, and Thor.

They also found deposits on top of relatively new lavas and high-standing features—such as Duque’s Hill and Jessica’s Hill--indications that the rock debris had fallen or precipitated out of the water, rather than being moved as part of a lava flow that erupted from the volcanoes.

Closer analysis has shown that the some of the tiny fragments are angular bits of quenched glass known to volcanologists as limu o Pele, or “Pele's seaweed.” These fragments are formed when lava is stretched thin around expanding gas bubbles during an explosion. Reves-Sohn and colleagues also found larger blocks of rock—known as talus—that could have been ejected by explosive blasts from the seafloor.

Much of Earth’s surface is made up of oceanic crust formed by volcanism along seafloor mid-ocean ridges. These volcanic processes are tied to the rising of magma from Earth’s mantle and the spreading of Earth’s tectonic plates. Submerged under several kilometers of cold water, the volcanism of mid-ocean ridges tends to be relatively subdued compared to land-based eruptions.

To date, there have been scattered signs of pyroclastic volcanism in the sea, mostly in shallower water depths. Samples of sediment and rock collected on other expeditions have hinted at the possibilities at depths down to 3,000 meters, but the likelihood of explosive eruptions at greater depths seemed slim.

One reason is the tremendous pressure exerted by the weight of seawater, known as hydrostatic pressure. More importantly, it is very difficult to build up the amount of steam and carbon dioxide gas in the magma that would be required to explode a mass of rock up into the water column. (Far less energy is needed to do so in air.) In fact, the buildup of CO2 in magma in the sea crust would have to be ten times higher than anyone has ever observed in seafloor samples.

The findings from the Gakkel Ridge expedition appear to show that deep-sea pyroclastic eruptions can and do happen. “The circulation and plumbing of the Gakkel Ridge might be different,” said Reves-Sohn. “There must be a lot more volatiles in the system than we thought.” The research team hypothesizes that excess gas may be building up like foam or froth near the ceiling of the magma chambers beneath the crust, waiting to pop like champagne beneath a cork.

“Are pyroclastic eruptions more common than we thought, or is there something special about the conditions along the Gakkel Ridge?” said Reves-Sohn. “That is our next question.”

Support for the Arctic Gakkel Vents Expedition and for vehicle development was provided by the National Science Foundation’s Office of Polar Programs; the NSF Division of Ocean Sciences; the Gordon Center for Subsurface Sensing and Imaging Systems, an NSF Engineering Research Center; the NASA Astrobiology Program; and the WHOI Deep Ocean Exploration Institute.

The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans’ role in the changing global environment.

Pictures of volcanoe eruptions

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