Genetic adaptation for high altitudes identified
Researchers from the Jacobs Schools of Engineering at UC San Diego have uncovered a genetic basis of chronic mountain sickness (CMS), also known as Monge’s disease. Caused by low-oxygen conditions at high altitudes CMS is characterized by headache, fatigue, sleepiness and depression. Severe cases can lead to life-threatening stroke or heart attack.
More than 140 million people permanently reside in high-altitude regions around the world. These geographically distinct populations have for the most part adapted to cope with low levels of oxygen in the blood (hypoxia). But there are many humans living at high elevations in the Andes mountain region of South America who are maladapted and suffer from CMS.
Computer scientists compared genetic variation between mountain-dwelling Peruvians with CMS and adapted subjects without CMS, using whole genome sequencing. Complex algorithms looked for evidence of natural selection and identified two genes with significantly increased expression in individuals susceptible to CMS.
The study validates a long-suspected genetic basis of adaptation to high altitudes. It also provides potential targets both for CMS treatment at high altitude as well as certain cardiovascular and brain diseases related to low oxygen levels in individuals living at any altitude.
Findings appear in the journal Genetics. News release at http://bit.ly/136jc1o
Computer simulation of cloth greatly enhanced
The special-effect appearance of cloth in movies and video games often looks unrealistic. It’s a long-standing technical problem now solved by UC San Diego computer scientists, who have developed a new computer model to simulate with unsurpassed accuracy the way cloth and light interact.
The model simulates how each thread in a piece of cloth scatters light by treating the fabric’s weaving pattern as a mesh of interwoven microcylinders – which scatters light the same way as hair – but oriented at 90 degrees from each other. In addition to its application by the entertainment industry, the model can also act as a framework to visualize what new fabrics would look like by simulating any combination of weaving pattern and thread types.
The findings were presented at SIGGRAPH 2013, one of world’s premiere technology conferences. News release at http://bit.ly/15wxghh
Snapshots of the cultural life of cities
Do cities have their own “visual signature?” They do, according to new-media researchers who analyzed millions of photographs posted on social networks.
The Phototrails project analyzed and compared 2.3 million photos, from 13 major cities around the world, uploaded during a three-month period to the Instagram photo-sharing social network. The team assessed information recorded by Instagram every time a photo is shared – date and time, geographic location, and filter applied to the photo – as well as visual attributes of the photos such as mean, median, standard deviation, brightness, hue and color saturation; the number of edges; contrast; and texture measurements.
From this analysis a unique visual signature for each city emerged.
Beyond comparing the visual signatures of cities, the study went deeper to explore specific cities and key events. For example, in the wake of Hurricane Sandy, researchers analyzed 23,000 Instagram photos from the Brooklyn area shared between Nov. 29 and 30, 2012, when Sandy made landfall. During this period, user-generated photos shows a steep drop in the number of photos posted, and changes in hue, after the lights went out.
The Phototrails project is a partnership among the City University of New York (CUNY), Calit2’s Qualcomm Institute at UC San Diego, and the University of Pittsburgh.
Findings appear in the online journal First Monday. More information and all of the visualizations are available at http://phototrails.net.
Lynne Friedmann is a science writer based in Solana Beach.
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