A Milky Way Band

APOD: 2007 September 30 - A Milky Way Band

Netcraft: June 2007 Web Server Survey

Netcraft: June 2007 Web Server Survey

ScienceDaily: Lakes Boiling With Methane Discovered In Alaska

ScienceDaily: Lakes Boiling With Methane Discovered In Alaska

Last month, UAF researcher Katey Walter brought a National Public Radio crew to Alaska’s North Slope, hoping to show them examples of what happens when methane is released when permafrost thaws beneath lakes.

When they reached their destination, Walter and the crew found even more than they bargained for: a lake violently boiling with escaping methane.

“It was cold, wet and windy. We were dropped off in the middle of nowhere by a helicopter and paddled out to a huge methane plume in the middle of the lake with no idea what to expect, how strong the bubbling plume would be, whether or not our raft would stay afloat, how dangerous it would be to breath the gas,” said Walter, an assistant professor in UAF’s Institute of Northern Engineering and International Arctic Research Center. “The violent streams of bubbles made the lake appear as if it were boiling, but the water was pretty cold."

Walter studies methane emissions from arctic lakes, especially the connection between thawing permafrost and climate change. As permafrost around a lake’s edges thaws, the organic material in it--dead plants and animals--can enter the lake bottom, where bacteria convert it to methane, which bubbles into the atmosphere, sometimes in a spectacular fashion. Methane is much more potent greenhouse gas than carbon dioxide.

Walter said this summer’s fieldwork indicates that methane hotspots, such as the one she and the crew experienced, can come from various sources, not just thawing permafrost. Her next goal is to identify and quantify the sources of the methane hotspots around Alaska.

“It is unlikely that this methane plume was related to permafrost thaw,” said Walter, adding that the methane boiling out of the lake was more likely related to natural gas seepage. “Should large quantities of methane be released from methane hydrates, for instance, in association with permafrost thaw, then we could have large sudden increases in atmospheric methane with potentially large affects on global temperatures.”

Walter’s project is one of many at UAF happening as part of the International Polar Year, an international event that will focus research efforts and public attention on the Earth’s polar regions.

Note: This story has been adapted from a news release issued by University of Alaska Fairbanks.

The Center for Models of Life

A model of information and dominance

Our model consists of a social network of agents, each having a memory. This individual memory is a simple local picture of where other agents are in the network together with a priority of relative interest in each agent. The agents communicate with other agents and modify their memory when they get new information about other agents. Based on this memory they also build new social connections to get better access to agents they find interesting.

The strong coupling between the agents' believes, the inner world, and their positions in the dynamic network structure, the outer world, has interesting consequences. The system can for example not be reset by either resetting the agents' inner or outer world. They have to be reset simultaneously, because otherwise information about the old system will be stored in the world that was not reset and enable a partial recovery of the system.

In the model, a social system on the size of a large school class is simplified into a number of agents. These agents form a network that dynamically adjusts itself to facilitate a hunt-gatherer behavior in information space, which in turn is reflected in a tribal organization of the evolving social network. This tribal organization is sensitive to information manipulation, as illustrated by influence of particularly convincing demagogues.

The model allows us to consider the impact of certain charismatic people. Thanks to their larger charisma, they can influence their fellow agents to think disproportionately more about them, or equivalently, about political objectives of which they are the main representative. Thus, our model allows for new analysis of the effects of celebrities, politicians or prophets in a social system.

Scenario 1: Consider the introduction of a single politician, or of several politicians or media persons. We find that the associated engineering of communication tends to streamline the social network into hierarchical structures around a celebrity center of fashionable persons.

Scenario 2: If two politicians garner votes with different strategies, one only by advocating for himself and the other with an antagonistic strategy to purposefully win votes from the other side, the antagonistic politician will do much better. The antagonistic strategy is so effective that it outcompetes a much stronger win-any-vote-strategy.

Scenario 3: Two competing antagonistic politicians, form a system where equal sharing of influence is unstable, in the sense that the system tends to choose one of the candidates on the cost of the other. In terms of biology or physics, the system develops bistability where a monoculture dominates for long periods of time. The state of a bistable system is historically dependent, determined on the few times in history where the two conflicting beliefs are of equal strength. It is tempting to compare persistent segregation in our model with the geographical segregation of religious beliefs in the real world.

This applet and others can be found at The Center for Models of Life.

ScienceDaily: A Startling Diary Reveals The Onset Of Autism

ScienceDaily: A Startling Diary Reveals The Onset Of Autism

It appears that children with autism develop normally for six months, and then begin developing atypically," says Rutherford. "As typical children begin to accelerate in social development, the child with autism makes only minor gains."

During the first six months, both twins smiled, engaged in socially responsive vocalization, and showed a preference for family members over other people. By the age of one, however, the male twin showed less eye contact, less verbal communication, and less affection toward others than did his sister. His sleep patterns were also noticeably different from his sister's. By the age of two, the boy had developed a fixation on particular patterns and puzzles; at age three, a child psychologist noted the boy "did not offer comfort if others are in distress and will not come for comfort is he is hurt." The mother's diary tells of her son's facial expressions that ranged from limited to "spaced-out'.

"chaos"

Networks create “instant world telescope” (Media Release)

Networks create “instant world telescope” (Media Release):

via Slashdot

Last week a CSIRO telescope near Coonabarabran NSW was used simultaneously with one near Shanghai, China, and five in Europe to observe a distant galaxy called 3C273.

“This is the first time we’ve been able to instantaneously connect telescopes half a world apart,” Dr Tasso Tzioumis, VLBI operations and development manager at CSIRO’s Australia Telescope National Facility said.

“It’s a fantastic technical achievement, and a tribute to the ability of the network providers to work together.”

Data from the telescopes was streamed...to a research centre in Europe, where it was processed with a special-purpose digital processor.

The results were then transmitted to Xi’an, China, where they were watched live by experts in advanced networking at the 24th APAN (Asia-Pacific Advanced Network) Meeting.

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The telescope-linking technique, VLBI (very long baseline interferometry) used to take weeks or months.
“We used to record data on tapes or disks at each telescope, along with time signals from atomic clocks. The tapes or disks would then be shipped to a central processing facility to be combined,” Dr Tzioumis said