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Dynamics of Social Interaction
Curated by Ashish Umre
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Beyond Big Data: Identifying Important Information for Real World Challenges

Beyond Big Data: Identifying Important Information for Real World Challenges | Social Foraging | Scoop.it

Much of human inquiry today is focused on collecting massive quantities of data about complex systems, with the underlying assumption that more data leads to more insight into how to solve the challenges facing humanity. However, the questions we wish to address require identifying the impact of interventions on the behavior of a system, and to do this we must know which pieces of information are important and how they fit together. Here we describe why complex systems require different methods than simple systems and provide an overview of the corresponding paradigm shift in physics. We then connect the core ideas of the paradigm shift to information theory and describe how a parallel shift could take place in the study of complex biological and social systems. Finally, we provide a general framework for characterizing the importance of information. Framing scientific inquiry as an effort to objectively determine what is important and unimportant rather than collecting as much information as possible is a means for advancing our understanding and addressing many practical biological and social challenges.

 

Yaneer Bar-Yam and Maya Bialik, Beyond Big Data: Identifying important information for real world challenges

http://www.necsi.edu/projects/yaneer/information/


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A New Method to Measure Consciousness Proposed

A New Method to Measure Consciousness Proposed | Social Foraging | Scoop.it

Leonardo Da Vinci, in his Treatise on Painting (Trattato della Pittura), advises painters to pay particular attention to the motions of the mind, moti mentali. “The movement which is depicted must be appropriate to the mental state of the figure,” he advises; otherwise the figure will be considered twice dead: “dead because it is a depiction, and dead yet again in not exhibiting motion either of the mind or of the body.” Francesco Melzi, student and friend to Da Vinci, compiled the Treatise posthumously from fragmented notes left to him. The vivid portrayal of emotions in the paintings from Leonardo’s school shows that his students learned to read the moti mentali of their subjects in exquisite detail.

 

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Intrinsic Noise Induces Critical Behavior in Leaky Markovian Networks Leading to Avalanching

Intrinsic Noise Induces Critical Behavior in Leaky Markovian Networks Leading to Avalanching | Social Foraging | Scoop.it

The role intrinsic statistical fluctuations play in creating avalanches – patterns of complex bursting activity with scale-free properties – is examined in leaky Markovian networks. Using this broad class of models, we develop a probabilistic approach that employs a potential energy landscape perspective coupled with a macroscopic description based on statistical thermodynamics. We identify six important thermodynamic quantities essential for characterizing system behavior as a function of network size: the internal potential energy, entropy, free potential energy, internal pressure, pressure, and bulk modulus. In agreement with classical phase transitions, these quantities evolve smoothly as a function of the network size until a critical value is reached. At that value, a discontinuity in pressure is observed that leads to a spike in the bulk modulus demarcating loss of thermodynamic robustness. We attribute this novel result to a reallocation of the ground states (global minima) of the system's stationary potential energy landscape caused by a noise-induced deformation of its topographic surface. Further analysis demonstrates that appreciable levels of intrinsic noise can cause avalanching, a complex mode of operation that dominates system dynamics at near-critical or subcritical network sizes. Illustrative examples are provided using an epidemiological model of bacterial infection, where avalanching has not been characterized before, and a previously studied model of computational neuroscience, where avalanching was erroneously attributed to specific neural architectures. The general methods developed here can be used to study the emergence of avalanching (and other complex phenomena) in many biological, physical and man-made interaction networks.

 

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Persistence of social signatures in human communication

We combine cell phone data with survey responses to show that a person’s social signature, as we call the pattern of their interactions with different friends and family members, is remarkably robust. People focus a high proportion of their communication efforts on a small number of individuals, and this behavior persists even when there are changes in the identity of the individuals involved. Although social signatures vary between individuals, a given individual appears to retain a specific social signature over time. Our results are likely to reflect limitations in the ability of humans to maintain many emotionally close relationships, both because of limited time and because the emotional “capital” that individuals can allocate between family members and friends is finite.

 

Persistence of social signatures in human communication

Jari Saramäki, E. A. Leicht, Eduardo López, Sam G. B. Roberts, Felix Reed-Tsochas, and Robin I. M. Dunbar

PNAS

http://dx.doi.org/10.1073/pnas.1308540110


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IEEE Big Data 2014

IEEE Big Data 2014 | Social Foraging | Scoop.it

As cloud computing turning computing and software into commodity services, everything as a service in other words, it leads to not only a technology revolution but also a business revolution. Insights and impacts of various types of services (infrastructure as a service, platform as a service, software as a service, business process as a service) have to be reexamined.
2014 IEEE International Congress on Big Data (BigData 2014) aims to provide an international forum that formally explores various business insights of all kinds of value-added "services." Big Data is a key enabler of exploring business insights and economics of services.
BigData 2014's major topics include but not limited to: Big Data Architecture, Big Data Modeling, Big Data As A Service, Big Data for Vertical Industries (Government, Healthcare, etc.), Big Data Analytics, Big Data Toolkits, Big Data Open Platforms, Economic Analysis, Big Data for Enterprise Transformation, Big Data in Business Performance Management, Big Data for Business Model Innovations and Analytics, Big Data in Enterprise Management Models and Practices, Big Data in Government Management Models and Practices, and Big Data in Smart Planet Solutions.

 

3rd International Congress on Big Data
June 27 - July 2, 2014, Anchorage, Alaska, USA

http://www.ieeebigdata.org/2014/


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Towards Passive Political Opinion Polling using Twitter

Social media platforms, such as Twitter, provide a forum for political communication where politicians broadcast messages and where the general public engages in the discussion of pertinent political issues. The open nature of Twitter, together with its large volume of traffic, makes it a useful resource for new forms of ‘passive’ opinion polling , i.e. automatically monitoring and detecting which key issues the general public is concerned about and inferring their voting intentions. In this paper, we present a number of case studies for the automatic analysis of UK political tweets. We investigate the automated sentiment analysis of tweets from UK Members of Parliament (MPs) towards the main political parties. We then investigate using the volume and sentiment of the tweets from other users as a proxy for their voting intention and compare the results against existing poll data. Finally we conduct automatic identification of the key topics discussed by both the MPs and users on Twitter and compare them with the main political issues identified in traditional opinion polls. We describe our data collection methods, analysis tools and evaluation framework and discuss our results and the factors affecting their accuracy.

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M. Edward (Ed) Borasky's curator insight, January 6, 2014 7:15 PM

For a variety of statistical reasons I'm skeptical, but this is an important research area so I'm posting this.

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"Embodied Semantics": Short- and Long-Term Effects of Reading a Novel on Connectivity in the Brain

"Embodied Semantics": Short- and Long-Term Effects of Reading a Novel on Connectivity in the Brain | Social Foraging | Scoop.it

We sought to determine whether reading a novel causes measurable changes in resting-state connectivity of the brain and how long these changes persist. Incorporating a within-subjects design, participants received resting-state functional magnetic resonance imaging scans on 19 consecutive days. First, baseline resting state data for a “washin” period were taken for each participant for 5 days. For the next 9 days, participants read 1/9th of a novel during the evening and resting-state data were taken the next morning. Finally, resting-state data for a “wash-out” period were taken for 5 days after the conclusion of the novel. On the days after the reading, significant increases in connectivity were centered on hubs in the left angular/supramarginal gyri and right posterior temporal gyri. These hubs corresponded to regions previously associated with perspective taking and story comprehension, and the changes exhibited a timecourse that decayed rapidly after the completion of the novel. Long-term changes in connectivity, which persisted for several days after the reading, were observed in bilateral somatosensory cortex, suggesting a potential mechanism for “embodied semantics.”

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Enterprise SEO Strategy Conference Videos @ SEER Interactive

Enterprise SEO Strategy Conference Videos @ SEER Interactive | Social Foraging | Scoop.it
Enterprise SEO strategies can be applied to any company, large or small. Below you can view the videos from SEER's November 13th event, Big Wins for Big
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Novel Genetic Patterns May Make Us Rethink Biology and Individuality

Novel Genetic Patterns May Make Us Rethink Biology and Individuality | Social Foraging | Scoop.it

Professor of Genetics Scott Williams, PhD, of the Institute for Quantitative Biomedical Sciences (iQBS) at Dartmouth’s Geisel School of Medicine, has made two novel discoveries: first, a person can have several DNA mutations in parts of their body, with their original DNA in the rest—resulting in several different genotypes in one individual—and second, some of the same genetic mutations occur in unrelated people. We think of each person’s DNA as unique, so if an individual can have more than one genotype, this may alter our very concept of what it means to be a human, and impact how we think about using forensic or criminal DNA analysis, paternity testing, prenatal testing, or genetic screening for breast cancer risk, for example. Williams’ surprising results indicate that genetic mutations do not always happen purely at random, as scientists have previously thought. His work, done in collaboration with Professor of Genetics Jason Moore, PhD, and colleagues at Vanderbilt University, was published in PLOS Genetics journal.[1]


Genetic mutations can occur in the cells that are passed on from parent to child and may cause birth defects. Other genetic mutations occur after an egg is fertilized, throughout childhood or adult life, after people are exposed to sunlight, radiation, carcinogenic chemicals, viruses, or other items that can damage DNA. These later or “somatic” mutations do not affect sperm or egg cells, so they are not inherited from parents or passed down to children. Somatic mutations can cause cancer or other diseases, but do not always do so. However, if the mutated cell continues to divide, the person can develop tissue, or a part thereof, with a different DNA sequence from the rest of his or her body.

 

“We are in reality diverse beings in that a single person is genetically not a single entity—to be philosophical in ways I do not yet understand—what does it mean to be a person if we are variable within?” says Williams, the study’s senior author, and founding Director of the Center for Integrative Biomedical Sciences in iQBS. “What makes you a person? Is it your memory? Your genes?” He continues, “We have always thought, ‘your genome is your genome.’ The data suggest that it is not completely true.”

 

In the past, it was always thought that each person contains only one DNA sequence (genetic constitution). Only recently, with the computational power of advanced genetic analysis tools that examine all the genes in one individual, have scientists been able to systematically look for this somatic variation. “This study is an example of the type of biomedical research project that is made possible by bringing together interdisciplinary teams of scientists with expertise in the biological, computational and statistical sciences.” says Jason Moore, Director of the iQBS, who is also Associate Director for Bioinformatics at the Cancer Center, Third Century Professor, and Professor of Community and Family Medicine at Geisel.

 

Having multiple genotypes from mutations within one’s own body is somewhat analogous to chimerism, a condition in which one person has cells inside his or her body that originated from another person (i.e., following an organ or blood donation; or sometimes a mother and child—or twins—exchange DNA during pregnancy. Also, occasionally a person finds out that, prior to birth, he or she had a twin who did not survive, whose genetic material is still contained within their own body).[2] Chimerism has resulted in some famous DNA cases: one in which a mother had genetic testing that “proved” that she was unrelated to two of her three biological sons.[3]


As suggested by Maria Schnee (newphoenix.info)


1 Williams, Scott, et al., Recurrent tissue-specific mtDNA mutations are common in humans. http://www.plosgenetics.org/doi/pgen.1003929.


2 Strain L, Dean JC, Hamilton MP, Bonthron D. A true hermaphrodite chimera resulting from embryo amalgamation after in vitro fertilization. N Engl J Med 1998;(338):166-9/


3 Norton AT and Zehner O. Project MUSE: Today’s Research, Tomorrow’s Inspiration. http://www.academia.edu.

 
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Sustainability as an Emergent Property: What Can We Learn from the Super-Organisms?

Sustainability as an Emergent Property: What Can We Learn from the Super-Organisms? | Social Foraging | Scoop.it

In the ongoing drive to create and communicate about sustainability in the emerging economy, it can be useful to conceive of sustainability not as a quantifiable end goal, but as an emergent property. An emergent property arises when individual components or actions, combined together, collectively generate a higher-level aggregate experience. Think democracy. Or plague. Or community. One does not "do" sustainability anymore than one "does" community. One co-creates community through all of the little deeds — hosting the potluck, planning the carpool, sharing the tool shed. Like community, sustainability — or any emergent property — arises out of the contributions made and conditions created in service of a shared reality.

 

Those of us in the business of sustainability therefore find ourselves, at least partially, in the business of emergence. This fact has two implications for our work. The first is that sustainability, like any emergent property, must be developed collectively. Like an ant in his colony, the individual's primary value is as a component of the whole. The second implication is that sustainability, as an emergent property, cannot be mandated from above. It arises, to some extent inexplicably, from the ground up.

 

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Sharing Entanglement without Sending It

Sharing Entanglement without Sending It | Social Foraging | Scoop.it

To challenge the limited understanding of the then-young quantum theory, Einstein, Podolsky, and Rosen constructed, in 1935, their EPR Gedankenexperiment, in which they introduced entangled states that exhibit strange correlations over macroscopic distances. By now we have learned that entangled states are an element of physical reality. They lie at the heart of quantum physics and can, in fact, be used as a powerful resource in emerging quantum technologies. Yet we find out in amazement that we have still not completely captured the full scope of the fascinating nature of entanglement.

 

Three different international groups have now reported in Physical Review Letters experiments of distributing entanglement between two distant parties by sending a nonentangled carrier. These arrangements instead place the carrier in a “cheaper,” so-called separable state, which exhibit correlations that can be established remotely between separated parties.

 

Entanglement is typically characterized by anomalously strong correlations between presently noninteracting parties, typically called Alice and Bob, which have normally interacted in the past. A common setup uses a nonlinear crystal to create an entangled pair of orthogonally polarized photons that are then sent separately, one to Alice and the other to Bob. In the field of quantum information science, the remote establishment of entanglement is key for most applications because it introduces purely nonclassical correlations and the counterintuitive nature of quantum physics. It enables such remarkable tasks as quantum teleportation, efficient quantum communication, fundamental tests of quantum physics, and long-distance quantum cryptography.

 

References

A. Einstein, B. Podolsky, and N. Rosen, “Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?” Phys. Rev. 47, 777 (1935).A. Fedrizzi, M. Zuppardo, G. G. Gillett, M. A. Broome, M. P. Almeida, M. Paternostro, A. G. White, and T. Paterek, “Experimental Distribution of Entanglement with Separable Carriers,” Phys. Rev. Lett. 111, 230504 (2013).C. Peuntinger, V. Chille, L. Mišta, N. Korolkova, M. Förtsch, J. Korger, C. Marquardt, and G. Leuchs, “Distributing Entanglement with Separable States,” Phys. Rev. Lett. 111, 230506 (2013).C. E. Vollmer, D. Schulze, T. Eberle, V. Händchen, J. Fiurášek, and R. Schnabel, “Experimental Entanglement Distribution by Separable States,” Phys. Rev. Lett. 111, 230505 (2013).R. F. Werner, “Quantum States with Einstein-Podolsky-Rosen Correlations Admitting a Hidden-Variable Model,” Phys. Rev. A 40, 4277 (1989).C. H. Bennett, D. P. DiVincenzo, J. A. Smolin, and W. K. Wootters, “Mixed-state Entanglement And Quantum Error Correction,” Phys. Rev. A 54, 3824 (1996).T. S. Cubitt, F. Verstraete, W. Dür, and J. I. Cirac, “Separable States Can Be Used To Distribute Entanglement,” Phys. Rev. Lett. 91, 037902 (2003).A. Steltsov, H. Kampermann, and D. Bruß, “Quantum Cost for Sending Entanglement,” Phys. Rev. Lett. 108, 250501 (2012).T. K. Chuan, J. Maillard, K. Modi, T. Paterek, M. Paternostro, and M. Piani, “Quantum Discord Bounds the Amount of Distributed Entanglement,” Phys. Rev. Lett. 109, 070501 (2012).L. Mišta, Jr. and N. Korolkova, “Distribution of Continuous-Variable Entanglement by Separable Gaussian States,” Phys. Rev A 77, 050302 (2008).


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Miro Svetlik's curator insight, January 4, 2014 6:32 AM

Again a step closer to Quantum Cryptography. It is a time that we will see the commercial implementation of quantum encryption. It will also have quite an impact on Digital currencies which are based on current cryptography. We are living in brave new world.

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The neuro-pianist

Music performance is considered one of the most complex human activities. It involves not only hundreds of muscles, coordinated to produce the desired musical result, but also a variety of cognitive mechanisms, including complex emotional and analytic processes (Zatorre et al., 2007). The study of music performance has yielded important insights into brain processes, including neural plasticity (Schlaug et al., 1995; Schlaug, 2001; Münte et al., 2002; Schneider et al., 2005), motor control (Slobounov et al., 2002; Watson, 2006), rhythmic control (Rammsayer and Altenmüller, 2006; Repp and Doggett, 2007; Goebl and Palmer, 2009), and emotional communication (Gabrielsson and Juslin, 1996; Juslin, 1997; Juslin and Laukka, 2003). The information acquired through systematic studies is invaluable in its contribution to our understanding of brain mechanisms underlying music perception and performance. However, such studies are limited in their ability to simulate the atmosphere of a concert performance, or to systematically follow the long period of training required to master a musical piece. Hence, it may be beneficial to obtain additional information by studying the strategies employed by professional concert artists to optimize their practice routines and their performance under stressful conditions. Such strategies enable them to confront many of the physiological constraints dictated by the muscular and central nervous system. In this short note, we highlight some key properties of these strategies and their possible relevance to studying other complex human activities

 

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The Advantage of Arriving First: Characteristic Times in Finite Size Populations of Error-Prone Replicators

The Advantage of Arriving First: Characteristic Times in Finite Size Populations of Error-Prone Replicators | Social Foraging | Scoop.it

We study the evolution of a finite size population formed by mutationally isolated lineages of error-prone replicators in a two-peak fitness landscape. Computer simulations are performed to gain a stochastic description of the system dynamics. More specifically, for different population sizes, we compute the probability of each lineage being selected in terms of their mutation rates and the amplification factors of the fittest phenotypes. We interpret the results as the compromise between the characteristic time a lineage takes to reach its fittest phenotype by crossing the neutral valley and the selective value of the sequences that form the lineages. A main conclusion is drawn: for finite population sizes, the survival probability of the lineage that arrives first to the fittest phenotype rises significantly.

 

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A Theoretically Based Index of Consciousness Independent of Sensory Processing and Behavior

One challenging aspect of the clinical assessment of brain-injured, unresponsive patients is the lack of an objective measure of consciousness that is independent of the subject’s ability to interact with the external environment. Theoretical considerations suggest that consciousness depends on the brain’s ability to support complex activity patterns that are, at once, distributed among interacting cortical areas (integrated) and differentiated in space and time (information-rich). We introduce and test a theory-driven index of the level of consciousness called the perturbational complexity index (PCI). PCI is calculated by (i) perturbing the cortex with transcranial magnetic stimulation (TMS) to engage distributed interactions in the brain (integration) and (ii) compressing the spatiotemporal pattern of these electrocortical responses to measure their algorithmic complexity (information). We test PCI on a large data set of TMS-evoked potentials recorded in healthy subjects during wakefulness, dreaming, nonrapid eye movement sleep, and different levels of sedation induced by anesthetic agents (midazolam, xenon, and propofol), as well as in patients who had emerged from coma (vegetative state, minimally conscious state, and locked-in syndrome). PCI reliably discriminated the level of consciousness in single individuals during wakefulness, sleep, and anesthesia, as well as in patients who had emerged from coma and recovered a minimal level of consciousness. PCI can potentially be used for objective determination of the level of consciousness at the bedside.

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Communication Efficiency and Congestion of Signal Traffic in Large-Scale Brain Networks

Communication Efficiency and Congestion of Signal Traffic in Large-Scale Brain Networks | Social Foraging | Scoop.it

The complex connectivity of the cerebral cortex suggests that inter-regional communication is a primary function. Using computational modeling, we show that anatomical connectivity may be a major determinant for global information flow in brain networks. A macaque brain network was implemented as a communication network in which signal units flowed between grey matter nodes along white matter paths. Compared to degree-matched surrogate networks, information flow on the macaque brain network was characterized by higher loss rates, faster transit times and lower throughput, suggesting that neural connectivity may be optimized for speed rather than fidelity. Much of global communication was mediated by a “rich club” of hub regions: a sub-graph comprised of high-degree nodes that are more densely interconnected with each other than predicted by chance. First, macaque communication patterns most closely resembled those observed for a synthetic rich club network, but were less similar to those seen in a synthetic small world network, suggesting that the former is a more fundamental feature of brain network topology. Second, rich club regions attracted the most signal traffic and likewise, connections between rich club regions carried more traffic than connections between non-rich club regions. Third, a number of rich club regions were significantly under-congested, suggesting that macaque connectivity actively shapes information flow, funneling traffic towards some nodes and away from others. Together, our results indicate a critical role of the rich club of hub nodes in dynamic aspects of global brain communication.

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Interference and Shaping in Sensorimotor Adaptations with Rewards

Interference and Shaping in Sensorimotor Adaptations with Rewards | Social Foraging | Scoop.it

When a perturbation is applied in a sensorimotor transformation task, subjects can adapt and maintain performance by either relying on sensory feedback, or, in the absence of such feedback, on information provided by rewards. For example, in a classical rotation task where movement endpoints must be rotated to reach a fixed target, human subjects can successfully adapt their reaching movements solely on the basis of binary rewards, although this proves much more difficult than with visual feedback. Here, we investigate such a reward-driven sensorimotor adaptation process in a minimal computational model of the task. The key assumption of the model is that synaptic plasticity is gated by the reward. We study how the learning dynamics depend on the target size, the movement variability, the rotation angle and the number of targets. We show that when the movement is perturbed for multiple targets, the adaptation process for the different targets can interfere destructively or constructively depending on the similarities between the sensory stimuli (the targets) and the overlap in their neuronal representations. Destructive interferences can result in a drastic slowdown of the adaptation. As a result of interference, the time to adapt varies non-linearly with the number of targets. Our analysis shows that these interferences are weaker if the reward varies smoothly with the subject's performance instead of being binary. We demonstrate how shaping the reward or shaping the task can accelerate the adaptation dramatically by reducing the destructive interferences. We argue that experimentally investigating the dynamics of reward-driven sensorimotor adaptation for more than one sensory stimulus can shed light on the underlying learning rules.

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Guided Self-Organization: Inception (Emergence, Complexity and Computation): Mikhail Prokopenko

Is it possible to guide the process of self-organisation towards specific patterns and outcomes? Wouldn’t this be self-contradictory? After all, a self-organising process assumes a transition into a more organised form, or towards a more structured functionality, in the absence of centralised control. Then how can we place the guiding elements so that they do not override rich choices potentially discoverable by an uncontrolled process?
This book presents different approaches to resolving this paradox. In doing so, the presented studies address a broad range of phenomena, ranging from autopoietic systems to morphological computation, and from small-world networks to information cascades in swarms. A large variety of methods is employed, from spontaneous symmetry breaking to information dynamics to evolutionary algorithms, creating a rich spectrum reflecting this emerging field.
Demonstrating several foundational theories and frameworks, as well as innovative practical implementations, Guided Self-Organisation: Inception, will be an invaluable tool for advanced students and researchers in a multiplicity of fields across computer science, physics and biology, including information theory, robotics, dynamical systems, graph theory, artificial life, multi-agent systems, theory of computation and machine learning.


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António F Fonseca's curator insight, January 7, 2014 2:56 AM

A potpourri about self organization, maybe good ideas for new theories.

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What Is This “Polar Vortex” That Is Freezing the U.S.?

What Is This “Polar Vortex” That Is Freezing the U.S.? | Social Foraging | Scoop.it

The polar vortex. It might not affect the brain per se, but it has totally consumed our thoughts.


As I write these words, temperatures across half the U.S. are plummeting like a rock. Extreme lows are forecast by tonight: -32 degrees Fahrenheit in Fargo, N.D.; -21 degrees F in Madison, Wisc.; -15 degrees F in Chicago and Indianapolis, according to the National Weather Service. Wind chills will reach a bizarre 60 degrees below zero F in some places, freezing exposed skin within one minute. That number is more typical for Mars—at night, according to the Curiosity roverNASA has free-wheeling over there.


As each hour passes, more and more television and radio reporters are attributing the insane cold to a “polar vortex” up in northern Canada. Vortex, yes, but upper Canada? Not exactly. One forecaster called the beast a hurricane in the Arctic, which is dramatic but wrong. So what is this mysterious marvel and why is it invading America?


 

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Domain-Based Lexicon Enhancement for Sentiment Analysis

General knowledge sentiment lexicons have the advantage of widerterm coverage. However, such lexicons typically have inferior performance forsentiment classification compared to using domain focused lexicons or machinelearning classifiers. Such poor performance can be attributed to the fact that somedomain-specific sentiment-bearing terms may not be available from a generalknowledge lexicon. Similarly, there is difference in usage of the same term be-tween domain and general knowledge lexicons in some cases. In this paper, wepropose a technique that uses distant-supervision to learn a domain focused sen-timent lexicon. The technique further combines general knowledge lexicon withthe domain focused lexicon for sentiment analysis. Implementation and eval-uation of the technique on Twitter text show that sentiment analysis benefitsfrom the combination of the two knowledge sources. The technique also per-forms better than state-of-the-art machine learning classifiers trained with distant-supervision dataset.

 

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Phenotypic Transformation Affects Associative Learning in the Desert Locust

Phenotypic Transformation Affects Associative Learning in the Desert Locust | Social Foraging | Scoop.it

HighlightsAssociative aversive learning is phase dependent, whereas appetitive learning is notGregarization blocks the formation of new aversive memoriesRetention of previously acquired associative memories is unaffected by gregarizationA behavioral feedback loop promotes override of a previously acquired aversive memorySummary

In desert locusts, increased population densities drive phenotypic transformation from the solitarious to the gregarious phase within a generation [1,2,3,4]. Here we show that when presented with odor-food associations, the two extreme phases differ in aversive but not appetitive associative learning, with solitarious locusts showing a conditioned aversion more quickly than gregarious locusts. The acquisition of new learned aversions was blocked entirely in acutely crowded solitarious (transiens) locusts, whereas appetitive learning and prior learned associations were unaffected. These differences in aversive learning support phase-specific feeding strategies. Associative training with hyoscyamine, a plant alkaloid found in the locusts’ habitat [5,6], elicits a phase-dependent odor preference: solitarious locusts avoid an odor associated with hyoscyamine, whereas gregarious locusts do not. Remarkably, when solitarious locusts are crowded and then reconditioned with the odor-hyoscyamine pairing as transiens, the specific blockade of aversive acquisition enables them to override their prior aversive memory with an appetitive one. Under fierce food competition, as occurs during crowding in the field, this provides a neuroecological mechanism enabling locusts to reassign an appetitive value to an odor that they learned previously to avoid.

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Scientists Successfully Model a Living Cell with Software

Scientists Successfully Model a Living Cell with Software | Social Foraging | Scoop.it

The crucial insight came to me as i leisurely rode my bike home from work. It was Valentine's Day, 2008. While I cruised along, my mind mulled over a problem that had been preoccupying me and others in my field for more than a decade. Was there some way to simulate life—including all the marvelous, mysterious and maddeningly complex biochemistry that makes it work—in software?

 

A working computer model of living cells, even if it were somewhat sketchy and not quite accurate, would be a fantastically useful tool. Research biologists could try out ideas for experiments before committing time and money to actually do them in the laboratory. Drug developers, for example, could accelerate their search for new antibiotics by homing in on molecules whose inhibition would most disrupt a bacterium. Bioengineers like myself could transplant and rewire the genes of virtual microorganisms to design modified strains having special traits—the ability to fluoresce when infected by a certain virus, say, or perhaps the power to extract hydrogen gas from petroleum—without the risks involved in altering real microbes. Eventually, if we can learn to make models sophisticated enough to simulate human cells, these tools could transform medical research by giving investigators a way to conduct studies that are currently impractical because many kinds of human cells cannot be cultured.

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"Jumping Genes" Linked to Schizophrenia

"Jumping Genes" Linked to Schizophrenia | Social Foraging | Scoop.it

ome so-called jumping genes that copy and paste themselves throughout the genome may be linked to schizophrenia, new research suggests.

 

The new study, published Jan. 2 in Neuron, suggests these jumping genes may alter how neurons (or nerve cells in the brain) form during development, thereby increasing the risk of schizophrenia, study co-author Dr. Tadafumi Kato, a neurobiologist at the RIKEN Brain Science Institute in Japan, wrote in an email.

 

Jumping genes, or retrotransposons, are mobile genetic elements that copy and paste themselves at different places throughout the genome. About half of the human genome is made of these mysterious elements, compared with the 1 percent of genes that actually code for making proteins, Kato said.

 

Earlier studies had found that a certain type of jumping gene, known as long interspersed nuclear element-1 (LINE-1), was active in human brain cells. Kato and his colleagues wondered whether they might play a role in mental illness. [Inside the Brain: A Photo Journey Through Time]

 

To find out, the team conducted a post-mortem analysis of 120 human brains, 13 from patients who had been diagnosed with schizophrenia.

 

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Rise Of The Insect Drones

Rise Of The Insect Drones | Social Foraging | Scoop.it
Nature spent millions of years perfecting flapping-wing flight. Now engineers can reproduce it with machines.

Via Miguel Prazeres
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Going from Good to Great with Complex Tasks

Going from Good to Great with Complex Tasks | Social Foraging | Scoop.it

It is a common belief that consciously thinking about what we are doing interferes with our performance. The origins of this idea go far back. Consider, for instance, the centipede’s dilemma:

 

A centipede was happy – quite!
Until a toad in fun
Said, "Pray, which leg moves after which?"
This raised her doubts to such a pitch,
She fell exhausted in the ditch
Not knowing how to run.

 

The centipede performs a very complex task with ease, unless she thinks about the task. The story was thought to illustrate something fundamental about human nature. English psychologist George Humphrey wrote “[the poem] contains a profound truth which is illustrated daily in the lives of all of us.” Humphrey and others thought that not having to think about everything that we do provides a great advantage. According to the famed philosopher Alfred North Whitehead, “Civilization advances by extending the number of important operations which we can perform without thinking about them.” Whitehead believed that thinking must be reserved only for decisive moments.

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Understanding Evolutionary Potential in Virtual CPU Instruction Set Architectures

Understanding Evolutionary Potential in Virtual CPU Instruction Set Architectures | Social Foraging | Scoop.it

We investigate fundamental decisions in the design of instruction set architectures for linear genetic programs that are used as both model systems in evolutionary biology and underlying solution representations in evolutionary computation. We subjected digital organisms with each tested architecture to seven different computational environments designed to present a range of evolutionary challenges. Our goal was to engineer a general purpose architecture that would be effective under a broad range of evolutionary conditions. We evaluated six different types of architectural features for the virtual CPUs: (1) genetic flexibility: we allowed digital organisms to more precisely modify the function of genetic instructions, (2) memory: we provided an increased number of registers in the virtual CPUs, (3) decoupled sensors and actuators: we separated input and output operations to enable greater control over data flow. We also tested a variety of methods to regulate expression: (4) explicit labels that allow programs to dynamically refer to specific genome positions, (5) position-relative search instructions, and (6) multiple new flow control instructions, including conditionals and jumps. Each of these features also adds complication to the instruction set and risks slowing evolution due to epistatic interactions. Two features (multiple argument specification and separated I/O) demonstrated substantial improvements in the majority of test environments, along with versions of each of the remaining architecture modifications that show significant improvements in multiple environments. However, some tested modifications were detrimental, though most exhibit no systematic effects on evolutionary potential, highlighting the robustness of digital evolution. Combined, these observations enhance our understanding of how instruction architecture impacts evolutionary potential, enabling the creation of architectures that support more rapid evolution of complex solutions to a broad range of challenges.

 

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