lunes, 31 de octubre de 2011

Compilado AZyNE 31-10

Dynamical modeling of collective behavior from pigeon flight data: flock cohesion and dispersion, arXiv

Excerpt: Several models of flocking have been promoted based on simulations with qualitatively naturalistic behavior. In this paper we provide the first direct application of computational modeling methods to infer flocking behavior from experimental field data. We show that this approach is able to infer general rules for interaction, or lack of interaction, among members of a flock or, more generally, any community. Using experimental field measurements of homing pigeons in flight we demonstrate the existence of a basic distance dependent attraction/repulsion relationship and show that this rule is sufficient to explain collective behavior observed in nature.
See Also: Hierarchical group dynamics in pigeon flocks

Stuart Kauffman - The End Of A Physics Worldview: Heraclitus and the Watershed of Life, NECSI

Excerpt: At the dawn of Western philosophy and science, some 2,700 years ago, Heraclitus, declared that, "the world bubbles forth." There is, in this fragment of thought, a natural magic, a creativity beyond the entailing laws of modern physics. I believe Heraclitus was right about the evolution of the biosphere and human life. We live beyond entailing law in a natural magic we co-create.

Bombings, beheadings? Stats show a peaceful world,

Excerpt: Yes, thousands of people have died in bloody unrest from Africa to Pakistan, while terrorists plot bombings and kidnappings. Wars drag on in Iraq and Afghanistan. In peaceful Norway, a man massacred 69 youths in July. In Mexico, headless bodies turn up, victims of drug cartels. This month eight people died in a shooting in a California hair salon.
Yet, historically, we've never had it this peaceful.
That's the thesis of three new books, including one by prominent Harvard psychologist Steven Pinker. Statistics reveal dramatic reductions in war deaths, family violence, racism, rape, murder and all sorts of mayhem.

Evolution of Networks for Body Plan Patterning; Interplay of Modularity, Robustness and Evolvability, PLoS Comput Biol

Excerpt: An important question in evolutionary developmental biology is how the complex organisms we see around us have evolved, and how this complexity is encoded in their DNA. An often heard statement is that the gene regulatory networks underlying developmental processes are modular; that is, different functions are carried out by largely independent network parts. It is argued that this network modularity allows both for robust functioning and evolutionary tinkering, and that selection thus produces modular networks. Here we use a simulation model for the evolution of animal body plan patterning to investigate these ideas. (…)

10 Unsolved Mysteries, Scientific American

Excerpt: 1. How Did Life Begin?
2. How Do Molecules Form?
3. How Does the Environment Influence Our Genes?
4. How Does the Brain Think and Form Memories?
5. How Many Elements Exist?
6. Can Computers Be Made Out of Carbon?
7. How Do We Tap More Solar Energy?
8. What Is the Best Way to Make Biofuels?
9. Can We Devise New Ways to Create Drugs?
10. Can We Continuously Monitor Our Own Chemistry?

What we learned from 5 million books,

About this talk: Have you played with Google Labs' Ngram Viewer? It's an addicting tool that lets you search for words and ideas in a database of 5 million books from across centuries. Erez Lieberman Aiden and Jean-Baptiste Michel show us how it works, and a few of the surprising things we can learn from 500 billion words.

Change and Aging Senescence as an Adaptation, PLoS ONE

Excerpt: Understanding why we age is a long-lived open problem in evolutionary biology. Aging is prejudicial to the individual, and evolutionary forces should prevent it, but many species show signs of senescence as individuals age. Here, I will propose a model for aging based on assumptions that are compatible with evolutionary theory.

Diurnal and Seasonal Mood Vary with Work, Sleep, and Daylength Across Diverse Cultures, Science

Abstract: We identified individual-level diurnal and seasonal mood rhythms in cultures across the globe, using data from millions of public Twitter messages. We found that individuals awaken in a good mood that deteriorates as the day progresses"which is consistent with the effects of sleep and circadian rhythm"and that seasonal change in baseline positive affect varies with change in daylength. People are happier on weekends, but the morning peak in positive affect is delayed by 2 hours, which suggests that people awaken later on weekends.

Neutrality in evolutionary algorithms… What do we know?, Evolving Systems

Abstract: Over the last years, the effects of neutrality have attracted the attention of many researchers in the Evolutionary Algorithms (EAs) community. A mutation from one gene to another is considered as neutral if this modification does not affect the phenotype. This article provides a general overview on the work carried out on neutrality in EAs. Using as a framework the origin of neutrality and its study in different paradigms of EAs (e.g., Genetic Algorithms, Genetic Programming), we discuss the most significant works and findings on this topic. This work points towards open issues, which we belive the community needs to address.

A Geometric Approach to Complexity, SFI Working Papers

Abstract: We develop a geometric approach to complexity based on the principle that complexity requires interactions at different scales of description. Complex systems are more than the sum of their parts of any size, and not just more than the sum of their elements. Using information geometry, we therefore analyze the decomposition of a system in terms of an interaction hierarchy. In mathematical terms, we present a theory of complexity measures for finite random fields using the geometric framework of hierarchies of exponential families. Within our framework, previously proposed complexity measures find their natural place and gain a new interpretation.

Lee Cronin: Making matter come alive,

About this talk: Before life existed on Earth, there was just matter, inorganic dead "stuff." How improbable is it that life arose? And -- could it use a different type of chemistry? Using an elegant definition of life (anything that can evolve), chemist Lee Cronin is exploring this question by attempting to create a fully inorganic cell using a "Lego kit" of inorganic molecules -- no carbon -- that can assemble, replicate and compete.

Edward Tenner: Unintended consequences,

About this talk: Every new invention changes the world -- in ways both intentional and unexpected. Historian Edward Tenner tells stories that illustrate the under-appreciated gap between our ability to innovate and our ability to foresee the consequences.

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