Optimizing custody is child"s play for physicists

http://feeds.feedburner.com/~r/sciencedaily/living_well/~4/j3HyxRPhM80

Ensuring that parents in recomposed families see their children regularly is a complex network problem.Physics can provide insights into societal trends. Problems involving interactions between people linked in real-life networks can be better understood by using physical models. As a diversion from his normal duties as a theoretical physicist, Andrs Gomberoff from the Andres Bello University in Santiago, Chile, set out to resolve one of his real-life problems: finding a suitable weekend for both partners in his recomposed family to see all their children at the same time. He then joined forces with a mathematician and a complex systems expert. This resulted in a study published in EPJ B, showing that solving this problem essentially equates to minimizing the energy in a material model.The authors assume that they deal with a network of people who are connected, either because they are in a current relationship or because they are ex-partners. Another assumption is that all involved in the network are willing to cooperate and communicate in an open manner.They then attempt to verify whether it is possible to find a custody arrangement whereby all parents see all of their children together every other weekend, thus satisfying the expectations of all members of the network. The answer is that it is not possible, in general, to have such an agreement.However, they also found that it is possible to have an arrangement in which one of the parents gets to see all of their children every other weekend. They also found an algorithm to maximize the level of contentment of members of this extended family network. Maximizing the number of parents spending time with their own children and those of their current partners was akin to minimizing the energy of a particular magnetic material called a spin glass.Who said that physics can’t have real-life applications?Story Source:The above story is based on materials provided by Springer Science+Business Media. Note: Materials may be edited for content and length.


Read More: Optimizing custody is child"s play for physicists

#Alternative-Medicine, #Business, #Chile, #Drs, #Energy, #Maximizing, #People, #Real, #Science, #Springer

Temperature and ecology: Rival Chilean barnacles keep competition cool

http://feeds.feedburner.com/~r/sciencedaily/earth_climate/ecology/~4/4KH4zrlJiX4

Here are two facts that make the lowly barnacle important: They are popular models for ecology research, and they are very sensitive to temperature. Given that, the authors of a new study about a bellwether community of two barnacle species in Chile figured they might see clear effects on competition between these two species if they experimentally changed temperature. In the context of climate change, such an experiment could yield profound new insights into the biological future of a major coastline that is prized for its ecological, aesthetic, and economic values.But in the study to be printed in the April 2014 issue of the Journal of Experimental Marine Biology and Ecology, the scientists found no significant effect of temperature on competition at all. That surprising non-finding may have its own implications.”The dominant if somewhat dated narrative in marine ecology, and ecology more broadly, is that competition is a major structuring force in natural communities,” said co-author Heather Leslie, assistant professor of environmental studies and biology at Brown University. “We know it’s a more nuanced story, but to find cases where it’s a bit of a draw is really unusual.”Moreover, temperature did not turn out to be the mediating factor.”Temperature wasn’t the beast that we often think of it being, which in itself is surprising,” Leslie said.Plenty of studies of other co-occurring barnacles would have suggested otherwise. In the North Atlantic, there is a well-documented and clear dynamic between two barnacle species, the little gray barnacle (Chthamalus fragilis) and the northern rock barnacle (Semibalanus balanoides). The little gray barnacle can only survive high up on the rocks, where it is hottest and driest, because farther down it gets thoroughly routed by the northern rock barnacle. Temperature, in other words, provides the little gray’s only refuge.The picture in Chile was downright unclear. Previous studies had yielded conflicting hints about how temperature might affect the competition between two southern hemisphere barnacle species, Jehlius cirratus and Notochthalamus scabrosus. Led by Emily Lamb, who began the work as a Brown undergraduate concentrating in environmental science and is now a research assistant at the Estacin Costera de Investigaciones Marinas (ECIM) in Chile, the team devised an experiment to get a more definitive answer.Made in the shadeLike their northern cousins, the Chilean barnacles Jehlius and Notochthalamus live in a clearly stratified society with Jehlius more abundant higher up and Notochthalamus more abundant lower down into the tide. …


Read More: Temperature and ecology: Rival Chilean barnacles keep competition cool

#Cancer, #Chile, #Chilean, #Environmental, #Jehlius, #Major, #Notochthalamus, #Species, #Temperature

Conserving potato agrobiodiversity: Top-down and bottom-up approach needed

http://feeds.feedburner.com/~r/sciencedaily/plants_animals/agriculture_and_food/~4/uuOd66NqAW8

Mashed, smashed and fried, Americans love potatoes, but only a few varieties are grown in much of North American agriculture. In South America, where potatoes originated, more than 5,000 varieties continue to exist. A Penn State geographer is gathering all the information he can about the agrobiodiversity of these uniquely adapted tubers with an eye toward sustainability of this fourth largest food crop worldwide.”In the U.S. we rely primarily on 10 to 12 types of potatoes total,” said Karl Zimmerer, department head and professor of geography. “In fact, mostly we use only 5 to 8 varieties. In South America, by contrast, there are 74 different types of potatoes in a single field. The fields, tubers and landscapes are visually stunning.”Zimmerer has studied high-agrobiodiversity land use for over 20 years, but until recently, those studies have been on the ground. He first looked at diversity within individual potato fields and then scaled up to individual communities and landscapes. People in a community have expert knowledge of 150 to 180 varieties of potato, he said.”People in Peru, for example, love to eat potatoes and think that theirs are vastly superior to what we have in flavor, texture, starchiness and color,” said Zimmerer. “They want to hang on to their high-agrobiodiversity potatoes and we want them to hang due to nutritional, ecological and other conservation advantages.”Scaling up even more, Zimmerer looked at potato fields on the landscape level — typically groups of 5 to 15 communities — and regions that contain upward of 30 or 40 communities. …


Read More: Conserving potato agrobiodiversity: Top-down and bottom-up approach needed

#Alternative-Medicine, #Alzheimer, #Cancer, #Chile, #Colombia, #Ecuador, #Major, #Professor, #Venezuela

Drastic chemical change occurring in birth of planetary system: Has the solar system also experienced it?

http://feeds.feedburner.com/~r/sciencedaily/top_news/top_science/~4/xnR5PO4oiLw

A new star is formed by gravitational contraction of an interstellar molecular cloud consisting of gas and dust. In the course of this process, a gas disk (protoplanetary disk), whose size is on the order of 100 AU, forms around the protostar and evolves into a planetary system. The Solar System was also formed in this way about 4.6 billion years ago, and life was eventually born on Earth. How unique in the Universe is the situation which happened for the Solar System? In order to answer this question, understanding the formation of protoplanetary disks as well as the associated chemical evolution in various star forming regions is essential. There have been extensive observational efforts made towards this goal. Until now, most of them have focused on changes in the physical structure and the kinematics during the formation process. However, it was very difficult to distinguish the protoplanetary disk from the infalling envelope clearly with such conventional approaches.The chemical evolution associated with disk formation has scarcely been studied observationally because of the insufficient sensitivity and spatial resolution of previous radio telescopes. As a result, a chemical model calculation with many assumptions is the only approach. Naturally, the physical and chemical changes in the disk formation should be coupled with each other. …


Read More: Drastic chemical change occurring in birth of planetary system: Has the solar system also experienced it?

#Agriculture, #Alternative-Medicine, #Chile, #Disk, #Distribution, #Health, #Physics, #Science, #Solarsystem, #Study