Complexity Digest 2002.51
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- Virtual World Will Run On Real Cash, New Scientist
- Living Under the Virtual Volcano of Video Games This Holiday Season, NYTimes
- Video Game Report Card, National Institute on Media and the Family
- Annual Video Game Report Card, c-span.org (video)
- Rat-Brained Robot, Technology Review
- Designing A Robot That Can Sense Human Emotion, ScienceDaily
- Butterflies Point to Micro Machines, BBC News
- Butterflies' Flights Disclose Free Spirits, NYTimes
- Unconventional Lift-Generating Mechanisms In Free-Flying Butterflies, Nature
- Biomechanics: Frogs In And Out Of Phase, Nature
- Purdue Works To Transform Ebola Virus From Killer To Healer, Purdue News
- Zebrafish Hold Clue to Mending Hearts, BBC News
- Heart Regeneration in Zebrafish, Science
- Medics Need To Evolve, BioMedNet Magazine
- Interactive Labs, Trends in Genetics 2002
- Sea Squirt Is Genetically Sequenced, The Associated Press
- Microbes From Edge Of Space Revived, NewScientist.com
- Alliance For Cellular Signaling: Into Unknown Territory, Nature
- Overview of the Alliance for Cellular Signaling, Nature
- HIV: Conformational Camouflage, Nature
- Antioxidants in Photosynthesis and Human Nutrition, Science
- Complex Adaptive Systems: Exploring The Known, The Unknown And The Unknowable, Bull. Amer. Math. Soc
- Shape-Controlled Synthesis of Gold and Silver Nanoparticles, Science
- Nanocubes and Nanoboxes, Science
- Unsupervised Language Acquisition: Theory and Practice, arVix
- HebbNets: Dynamic Network with Hebbian Learning Rule, arVix
- Mental Models and Musical Minds, Science
- Study Shows How Brain Remembers Music, The Associated Press
- The Cortical Topography of Tonal Structures Underlying Western Music, Science
- The Mind Explains It All, NYTimes
- A Supercomputer to Save Earth?,, Associated Press
- Increasing River Discharge to the Arctic Ocean, Science
- Soil Warming and Carbon-Cycle Feedbacks to the Climate System, Science
- Cloudy Skies: Assessing Public Understanding of Global Warming, MIT Sloan Working Paper
- Sea-Floor Ecosystems: Trawling's a Drag for Marine Life, Say Studies
- The Internet in Everyday Life, Book Announcement
- 'Global Village' Not An Internet Reality: Sociologist
- Web Searches Take Cultural Pulse, Wired News
- Internet Growth and Economic Theory, Netnomics
- Consumer Choice Behavior and Electronic Shopping Systems A Theoretical Note, Netnomics
- The Economics of Animal Cooperation, Science
- Discounting and Reciprocity in an Iterated Prisoner's Dilemma,, Science
- Stock Market Crashes Are Predictable, Major Decline Is Coming In 2003 And 2004, Says UCLA Physicist,, ScienceDaily
- Chaos Theory Pioneers Win Japan Prize, Guardian/AP
- Complex Challenges: Global Terrorist Networks
- ISIS: Human Rights Severely Compromised By Sept 11, The Star Online
- Alleged Terror Leader Linked to Bali, The Guardian/AP
- Links & Snippets
- Other Publications
- Coming and Ongoing Webcasts
- Conference Announcements
- Public Conference Calls
- ComDig Announcement: New ComDig Archive in Beta Test
Virtual World Will Run On Real Cash, New Scientist
Excerpts: A virtual online world in which players can earn and spend real money will officially launch on 30 January 2003, (...).
Project Entropia is a 3D futuristic role-playing game in which players must colonise an alien planet, (...).
Unlike other online games, there will be no charge for downloading the software needed to play Project Entropia. Instead, players must convert real money into the currency of the game - Project Entropia Dollars - in order to buy the things they need to survive.
Living Under the Virtual Volcano of Video Games This Holiday Season, NYTimes
Excerpts: But what matters even more than the size of the video game world is its depth and complexity. (...)
But if you've played any of the new-generation video games - titles like "Splinter Cell" or "Blinx the Time Sweeper" or almost anything else released in the past year or two - you quickly realize that they create a sense of perceptual reality that is far more intense than anything the movies offer. No matter how much a movie absorbs you, you never really break the plane of the movie screen.
Excerpts: While the industry is making the same efforts to protect children it has over the past few years, research and anecdotal evidence show that the potential for harm from video games is much greater than previously understood. Increasing power (i.e., realism) of technology is one factor; our increased knowledge base is another. (...). Against this backdrop is an increasingly appalling attitude toward women--this issue, more than any other, exposes an industry willing to make money by continuing to push the envelope.
- Source: Video Game Report Card, David Walsh, Douglas Gentile, Marilyn VanOverbeke, Emily Chasco, National Institute on Media and the Family, 02/12/19
Excerpts: The device, (...), is in essence a rat-controlled robot, and marks the first instance in which cultured neurons have been used to control a robotic mechanism. (...), the knowledge gained could lead to computer chips modeled on biological systems-and perhaps even to computers that incorporate biological components. Such computers might one day learn, repair themselves, and perform certain tasks-such as dictation-at which binary-based systems are miserable. "(...) there is a world of emergent properties in these neural networks that we don't know anything about" (...).
Designing A Robot That Can Sense Human Emotion, ScienceDaily
Excerpts: The project has two basic parts, and both are ambitious. One is to develop a system that can accurately detect a person's psychological state by analyzing the output of a variety of physiological sensors. The other is to process this information in real time (as it happens) and convert it into a form that a computer or robot can process. They looked specifically at variations in the interval between heartbeats (...). They identified two frequency bands that vary predictably with changes in stress levels. These bands are associated with the parasympathetic and sympathetic divisions of the autonomic nervous system.
Butterflies Point to Micro Machines, BBC News
Excerpts: Tiny machines that fly like insects will soon be a reality. That is the confident prediction of scientists who have just studied the remarkable aerobatics of the butterfly.(...) "We saw conventional aircraft-style aerodynamics, two different kinds of leading-edge vortices, rotational mechanisms, wake-capture mechanisms and the so-called clap and fling." (...) It is only by mimicking the insect world that micro air vehicles will get airborne efficiently. And while miniaturisation experiments are progressing fast, engineers confess they still have much to learn from the animal world.
- Source: Butterflies Point to Micro Machines, See also: Robin Wootton's lecture From Structure and Materials to Flight Behaviour: Fitness for Purpose in Insect Wings at SAB'02 - http://www.comdig2.de/conf/sab02/, BBC News, 2002-12-11
Butterflies' Flights Disclose Free Spirits, NYTimes
Excerpts: This is the first time that anyone has captured images that show what the wing beats of free-flying insects do (….). The red admiral butterflies, moving without restraint, show an extraordinary agility and complexity in their flight. Not only do they use many different wing strokes, they use them on successive wing beats. (...)
Rather than progressing from one sort of wing stroke to another as flying speed changes - the way horses go from walk to trot to canter - the butterflies behave more like Olympic gymnasts doing floor exercises.
Unconventional Lift-Generating Mechanisms In Free-Flying Butterflies, Nature
Excerpts: Flying insects generate forces that are too large to be accounted for by conventional steady-state aerodynamics. To investigate these mechanisms of force generation, we trained red admiral butterflies, Vanessa atalanta, to fly freely to and from artificial flowers in a wind tunnel, and used high-resolution, smoke-wire flow visualizations to obtain qualitative, high-speed digital images of the air flow around their wings. The images show that free-flying butterflies use a variety of unconventional aerodynamic mechanisms to generate force: wake capture, two different types of leading-edge vortex, active and inactive upstrokes, (...).
Biomechanics: Frogs In And Out Of Phase, Nature
Excperts: Many animals use several different gaits - patterns of locomotion that change abruptly at a critical speed. People walk to go slowly and run to go fast. Horses (...) walk, trot and gallop. In flight, birds and bats have slow and fast gaits. Many fish swim slowly with their fins and fast with their whole bodies. (...)
Frogs swim by kicking water backwards with their webbed feet. Usually they kick with both hind legs simultaneously (in-phase swimming), but (...) in slow swimming the hind legs move alternately (out-of-phase swimming).
Purdue Works To Transform Ebola Virus From Killer To Healer, Purdue News
Excperts: By redesigning the shell of Ebola, Purdue University researchers have transformed the feared virus into a benevolent workhorse for gene therapy - and as one of the first gene bearers that can be inhaled rather than injected, (...).
[They found] a way to simplify Ebola's outer shell as well, rendering it more easily produced in a laboratory and more effective at delivering genes to defective cells. Since unmodified Ebola enters through, and attacks, the lungs, defective lung cells could benefit most from therapy based on this discovery.
Zebrafish Hold Clue to Mending Hearts, BBC News
Experpts: A tropical fish's ability to "grow a new heart" may help scientists find a way of aiding the recovery of human patients. The zebrafish is one of the only vertebrates whose heart can recover in this way, even when a fifth of the organ's tissue is removed. In humans, even minor damage to the heart leaves a trail of scar tissue which makes full recovery difficult. Experts from the US hope that the secrets of the zebrafish's scar-free regeneration could be harnessed in human patients. They have found a gene in the zebrafish which appears to play a role in this remarkable healing process. (...) Chemical markers placed in certain cells revealed that a new heart wall formed and expanded rapidly upwards to reproduce the original shape of the organ. Two months after the wound was created, the hearts of these fish had completely recovered.
Heart Regeneration in Zebrafish, Science
Excerpts: Cardiac injury in mammals and amphibians typically leads to scarring, with minimal regeneration of heart muscle. Here, we demonstrate histologically that zebrafish fully regenerate hearts within 2 months of 20% ventricular resection. Regeneration occurs through robust proliferation of cardiomyocytes localized at the leading epicardial edge of the new myocardium. (...) Thus, injury-induced cardiomyocyte proliferation in zebrafish can overcome scar formation, allowing cardiac muscle regeneration. These findings indicate that zebrafish will be useful for genetically dissecting the molecular mechanisms of cardiac regeneration.
Excerpts: There is a fundamental flaw in the way that medical students are being taught, says a group of leading scientists, who believe that a more thorough understanding of evolutionary biology would reveal new ways to prevent and treat disease
Excerpts: What makes for a good lab? Obviously the principle investigator and members of the team are important. So too, of course, are the correct services and environmental conditions. But there is another aspect, less quantifiable but of great importance. It's the ability of a laboratory to maximize the possibilities for scientific interaction. Having spent many years as an architect designing laboratories, here I give my views on designing successfully for interaction.
Interaction between researchers is fundamental to scientific endeavour.
- Source: Interactive Labs, Adrian Gainer - mailto:pmsnightingaleassociates.com, Trends in Genetics 2002, 18:651-653
Excerpts: (...) Researchers have sequenced the gene structure of the sea squirt, a homely seafloor creature (...) that has intrigued scientists since the days of ancient Greece.
In a report appearing Friday in the journal Science, 87 scientists from five countries announced they have correctly assembled the 150 million DNA base pairs of the sea squirt genome. The humble creature is the seventh animal to be genetically sequenced. Mike Levine, a researcher at the University of California at Berkeley, and a coauthor of the study, said studying the genetics of the sea squirt gives a glimpse at the very early history of evolution, a time more than 550 million years ago when animals with backbones were just beginning the shift toward a new age of complexity. (...)
Microbes From Edge Of Space Revived, NewScientist.com
Excerpts: How the bugs got there is not known, but there are three possibilities: they were carried up on winds, they sneaked into the samples on Earth or they have flown through space and are aliens making their way down to our planet.
The latter possibility fits with a theory developed by Chandra Wickramasinghe and the late Fred Hoyle in the 1970s, which proposes that life originated elsewhere in the Universe and hitched a lift to Earth on a passing comet.
Alliance For Cellular Signaling: Into Unknown Territory, Nature
Excerpts: Cell biologists now realize that they have oversimplified the biochemistry of signalling pathways. They have long hypothesized that a signal, such as a hormone binding to its receptor, initiates a wave of excitation through a simple, linear chain of proteins. But it has become clear that the proteins don't work individually, but instead assemble fleetingly into molecular machines, the components of which are shared between pathways (...). "The inside of a cell is a thick soup of proteins talking to each other in ways we just don't understand," (...).
Overview of the Alliance for Cellular Signaling, Nature
Excerpts: The Alliance for Cellular Signaling is a large-scale collaboration designed to answer global questions about signalling networks. Pathways will be studied intensively in two cells - B lymphocytes (the cells of the immune system) and cardiac myocytes - to facilitate quantitative modelling. One goal is to catalyse complementary research in individual laboratories; to facilitate this, all alliance data are freely available for use by the entire research community
HIV: Conformational Camouflage, Nature
Excerpts: A study of the thermodynamics of antibody binding to a crucial HIV protein has shed light on why the virus so effectively evades the antibody arm of the immune response. Changes in the protein's conformation are the key.
Despite two decades of research, HIV has defied immunologists' best efforts to develop a broadly protective vaccine. (...) The authors reveal an unusual mechanism by which HIV might evade human antibodies, whether they are generated in response to a vaccine or to the viral infection itself.
Antioxidants in Photosynthesis and Human Nutrition, Science
Excerpts: The harnessing of solar energy by photosynthesis depends on a safety valve that effectively eliminates hazardous excess energy and prevents oxidative damage (...). Many of the compounds that protect plant cells also protect human cells. Improving plant resistance to stress may thus have the beneficial side effect of also improving the nutritional quality of plants in the human diet. The pathways that synthesize these compounds are becoming amenable to genetic manipulation, which may yield benefits as widespread as improved plant stress tolerance and improved human physical and mental health.
Complex Adaptive Systems: Exploring The Known, The Unknown And The Unknowable, Bull. Amer. Math. Soc
Abstract: The study of complex adaptive systems, from cells to societies, is a study of the interplay among processes operating at diverse scales of space, time and organizational complexity. In particular, for ecosystems and socioeconomic systems, much interest is focused on broad scale features such as diversity and resiliency, while evolution operates most powerfully at the level of individual agents. Understanding the evolution and development of complex adaptive systems thus involves understanding how cooperation, coalitions and networks of interaction emerge from individual behaviors and feed back to influence those behaviors. In this paper, some of the mathematical challenges are discussed.
Shape-Controlled Synthesis of Gold and Silver Nanoparticles, Science
Excerpts: Metal nanoparticles play important roles in many different areas. For example, they can serve as a model system to experimentally probe the effects of quantum confinement on electronic, magnetic, and other related properties. They have also been widely exploited for use in photography, catalysis, biological labeling, photonics, optoelectronics, information storage, surface-enhanced Raman scattering (SERS), and formulation of magnetic ferrofluids. The intrinsic properties of a metal nanoparticle are mainly determined by its size, shape, composition, crystallinity, and structure (solid versus hollow).
Nanocubes and Nanoboxes, Science
Excerpts: The engineer's "top down" approach to making nanometer-scale objects is to carve them out lithographically from a substrate; the chemist's "bottom up" approach is to assemble them from molecular-scale precursors. On page 2176 of this issue, Sun and Xia (1) use the latter approach to show that simple chemical reactions in solution can produce silver nanocubes of controllable size in high yield. A simple, quantitative
Unsupervised Language Acquisition: Theory and Practice, arVix
Absstract: In this thesis I present various algorithms for the unsupervised machine learning of aspects of natural languages using a variety of statistical models. The scientific object of the work is to examine the validity of the so-called Argument from the Poverty of the Stimulus advanced in favour of the proposition that humans have language-specific innate knowledge. (...) I carefully examine the interaction between the various components, and show how these algorithms can form the basis for a empiricist model of language acquisition. I therefore conclude that the Argument from the Poverty of the Stimulus is unsupported by the evidence.
HebbNets: Dynamic Network with Hebbian Learning Rule, arVix
Abstract: It has been demonstrated that one of the most striking features of the nervous system, the so called 'plasticity' (i.e high adaptability at different structural levels) is primarily based on Hebbian learning which is a collection of slightly different mechanisms that modify the synaptic connections between neurons. The changes depend on neural activity and assign a special dynamic behavior to the neural networks. From a structural point of view, it is an open question what network structures may emerge in such dynamic structures under 'sustained' conditions when input to the system is only noise. In this paper we present and study the `HebbNets', networks with random noise input, in which structural changes are exclusively governed by neurobiologically inspired Hebbian learning rules. We show that Hebbian learning is able to develop a broad range of network structures, including scale-free small-world networks.
Mental Models and Musical Minds, Science
Excerpts: Music is found in all cultures and has a
remarkable diversity of forms. Cognitive scientists have
discovered highly specific and detailed knowledge of musical
structure even in individuals without extensive musical training.
Brain imaging has proved valuable for investigating the neural
basis of a variety of cognitive functions, including how the brain
processes music. These developments converge on page 2167
of this issue (…). They report that abstract patterns of
Western tonal musical structure are mirrored in patterns of brain
activity in human subjects.
Excerpts: (...) Sounds from the radio slip into a melody and suddenly your mind skips back to an evening of moonlight and romance and happy times. It happens to everybody, but until now science was unsure just why.
A new study by researchers at Dartmouth College in Hanover, N.H., suggests that recalling that melody is the job of a part of the brain known as the rostromedial prefrontal cortex. It is the part that remembers music and is even able to recognize a sour note in the midst of a familiar tune.
A team led by researcher Petr Janata of Dartmouth's Center for Cognitive Neuroscience explored the mind's memory for tunes by studying the brains of eight musicians as they listened to a bit of original music. (...)
The Cortical Topography of Tonal Structures Underlying Western Music, Science
Abstract: Western tonal music relies on a formal geometric structure that determines distance relationships within a harmonic or tonal space. In functional magnetic resonance imaging experiments, we identified an area in the rostromedial prefrontal cortex that tracks activation in tonal space. Different voxels in this area exhibited selectivity for different keys. Within the same set of consistently activated voxels, the topography of tonality selectivity rearranged itself across scanning sessions. The tonality structure was thus maintained as a dynamic topography in cortical areas known to be at a nexus of cognitive, affective, and mnemonic processing.
The Mind Explains It All, NYTimes
Excerpts: (...) the post hoc "explanation" of feelings and behaviors. Patients attribute their symptoms to specific life events - an approach that appears to make sense.
But this drive to come up with the causes of events is hardly limited to therapy patients. Neurophysiologists discovered the same phenomenon in a radically different context. While mapping the brain, they were amazed to find that when the area responsible for an emotion was electronically stimulated, subjects experienced the mechanically induced feeling, then instantly came up with reasons for their responses.
A Supercomputer to Save Earth?,, Associated Press
Excerpt: For the Japanese scientists using the $350 million computer, it means climate research, with its complex simulations and diverse mix of variables, is more accurate than ever before.
For the competition, however, it is a shrill wake-up call. Even the U.S. government admits its March activation signaled an end to American dominance of this high-profile field.
According to the Department of Energy, the Earth Simulator has put American scientists at a 10- to 100-fold disadvantage in weather studies. And there are much deeper implications.
Increasing River Discharge to the Arctic Ocean, Science
Excerpt: Synthesis of river-monitoring data reveals that the average annual discharge of fresh water from the six largest Eurasian rivers to the Arctic Ocean increased by 7% from 1936 to 1999. (...) Consequently, average annual discharge from the six rivers is now about 128 cubic kilometers per year greater than it was when routine measurements of discharge began. Discharge was correlated with changes in both the North Atlantic Oscillation and global mean surface air temperature. The observed large-scale change in freshwater flux has potentially important implications for ocean circulation and climate.
- Source: Increasing River Discharge to the Arctic Ocean, Bruce J. Peterson, Robert M. Holmes, James W., McClelland, Charles J. Vorosmarty, Richard B. Lammers, Alexander I. Shiklomanov, Igor A. Shiklomanov, and Stefan Rahmstorf, Science 2002 298: 2171-2173
Soil Warming and Carbon-Cycle Feedbacks to the Climate System, Science
Excerpt: In a decade-long soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon and nitrogen cycling in order to investigate the consequences of these changes for the climate system. Here we show that whereas soil warming accelerates soil organic matter decay and carbon dioxide fluxes to the atmosphere, this response is small and short-lived for a mid-latitude forest, (...). Our results challenge assumptions made in some climate models that lead to projections of large long-term releases of soil carbon in response to warming of forest ecosystems.
- Source: Soil Warming and Carbon-Cycle Feedbacks to the Climate System, J. M. Melillo, P. A. Steudler, J. D. Aber, K. Newkirk, H. Lux, F. P., Bowles, C. Catricala, A. Magill, T. Ahrens, S. Morrisseau, Science 2002 298: 2173
Cloudy Skies: Assessing Public Understanding of Global Warming, MIT Sloan Working Paper
Excerpt: Surveys show most Americans believe global warming is real. But many advocate delaying action until there is more evidence that warming is harmful. The stock and flow structure of the climate, however, means "wait and see" policies guarantee further warming. Atmospheric CO2 concentration is now higher than any time in the last 420,000 years, and growing faster than any time in the past 20,000 years. (...) Emissions must therefore fall by more than half even to stabilize CO2 at present record levels. Such reductions greatly exceed the Kyoto targets, while the Bush administration's Clear Skies Initiative calls for continued emissions growth. Does the public understand these physical facts? We report experiments assessing people's intuitive understanding of climate change. We presented highly educated graduate students with descriptions of greenhouse warming drawn from the IPCC's nontechnical reports. Subjects were then asked to identify the likely response to various scenarios for CO2 emissions or concentrations. The tasks require no mathematics, only an understanding of stocks and flows and basic facts about climate change. Overall performance was poor. (...) Such beliefs support wait and see policies, but violate basic laws of physics. We discuss implications for education and public policy.
Follow Up: We've presented the results in various seminars, including public policy and climate science audiences. People find the results quite surprising and a little depressing. We've also collected additional data using alternate response modes (e.g., graphical vs multiple choice). For the graphical response mode we used two treatments: one asking people to draw the rate of CO2 removal from the atmosphere as well as emissions, and one asking for emissions only. The results show the problems demonstrated in the paper are robust to the response mode and to the explicit prompt for the removal rate. Indeed, of those asked to show both removal and emissions, only 34% of the subjects (mostly MIT and Harvard grad students, most with technical background) drew trajectories that conformed to conservation of mass. We're in the process of writing these results up for publication.
Sea-Floor Ecosystems: Trawling's a Drag for Marine Life, Say Studies
Excerpts: Trawlers are catching more than fish these days. The boats are also capturing the attention of marine scientists, conservationists, and fisheries managers, (...) . Critics say boats dragging heavy nets across the sea floor kill nontarget species such as corals and harm even commercially valuable populations by flattening habitat (Science, 18 December 1998, p. ¡K). But many fishers have argued that the impacts are short lived and that "tilling" the sea floor can augment food supplies for certain prized table fish. That idea took a battering here.
Excerpts: The Internet in Everyday Life_ is about the second age of the Internet as it descends from the firmament and becomes embedded in everyday life. The first age of the Internet was a bright light shining above everyday concerns. In the euphoria, many analysts lost their perspective. The rapid contraction of the dot.com economy has brought down to earth the once-euphoric belief in the infinite possibility of Internet life. It is not as if the Internet disappeared. Instead, the light that dazzled overhead has become embedded in everyday things.
- Source: The Internet in Everyday Life, Barry Wellman and Caroline Haythornthwaite, eds. Oxford: Blackwell. Forthcoming, November 2002. 588 pages. ISBN: 0-631-23508-6
'Global Village' Not An Internet Reality: Sociologist
Excerpts: The Internet is not isolating people as critics have feared, but it's not transforming communities into global villages either, say U of T researchers. Where Marshall McLuhan saw new communications media as minimizing local boundaries in the "global village," the scholars have found the Internet is being used more for local, not long distance, contact. "People worldwide have as many face-to-face relationships as they ever had but the good and bad news is they are adding Internet communication on top of that," says sociologist Barry Wellman.
Web Searches Take Cultural Pulse, Wired News
Excerpts: "(...)all of popular culture is displayed in search terms (...).The Zeitgeist is an aggregate of 55 billion searches, or about 150 million searches a day, according to Google. "The 2002 Year-End Zeitgeist enables you to look at the past year through the collective eyes of the world on the Internet," the company says. As with Lycos' list, the most popular terms on Google related to mass media: "Spiderman," "Shakira" and "Eminem," to name a few of the most popular searches.
Internet Growth and Economic Theory, Netnomics
Excerpts: This paper focuses on economic implications of the Internet. We argue that some effects of the Internet can be understood within the context of traditional economics. Specifically, the Internet has the potential to make market more contestable and hence more competitive. Policy issues are also discussed.
Consumer Choice Behavior and Electronic Shopping Systems A Theoretical Note, Netnomics
Abstract: The aim of this paper is to provide an overview of alternative approaches in modeling consumer choice behavior with respect to making purchases either in the traditional manner or using an electronic shopping system. We concentrate on the effects of two specific features: the amount of time spent on shopping and the shopping experience. We consider a simple two-good situation (...). The models suggest that both time saved and an increase in shopping experience related to Web-based shopping will lead to increased purchasing at a Web shop.
The Economics of Animal Cooperation, Science
Excerpts: Human cooperation often depends on a delayed reciprocity in which each partner risks short-term costs to achieve a long-term mutual advantage. Are nonhuman animals capable of such cooperation? The evidence has been equivocal . However, in a set of clever experiments published on page2216 of this issue, Stephens et al. demonstrate that captive blue jays are indeed capable of sustained cooperation. Furthermore, the authors present evidence as to why it has been so difficult to observe sustained reciprocity in animal cooperation studies.
Discounting and Reciprocity in an Iterated Prisoner's Dilemma,, Science
Excerpts: The Iterated Prisoner's Dilemma (IPD) is a central paradigm in the study of animal cooperation. (...) We studied the effects of discounting and strategic reciprocity on cooperation in captive blue jays. Our results demonstrate an interaction between discounting and reciprocity. Blue jays show high stable levels of cooperation in treatments with reduced discounting when their opponent reciprocates, but their levels of cooperation decline in all other treatment combinations. This suggests that stable cooperation requires both reduced discounting and reciprocity, and it offers an explanation of earlier failures to find cooperation (...).
Stock Market Crashes Are Predictable, Major Decline Is Coming In 2003 And 2004, Says UCLA Physicist,, ScienceDaily
Excerpts: (...) has found patterns that occur in market crashes dating back for centuries. Their statistical signatures are evident long in advance, he concludes. Sornette has developed algorithms - based on sophisticated mathematics, statistical modeling techniques and collective behavior theory - that enable him to analyze more than two dozen stock markets worldwide. Applying techniques of physics to economic data, he has developed a quantitative model that can predict the signatures of a coming stock market crash. "Economic forecasting is often not effective at predicting changes of direction, but our algorithms are very good at doing so."
Chaos Theory Pioneers Win Japan Prize, Guardian/AP
Excerpts: Japanese science foundation has awarded the Japan Prize to two American mathematicians for their pioneering work in chaos theory. Benoit B. Mandelbrot of Yale University and James A. Yorke of the University of Maryland will share the $410,000 award. (...) Yorke, 61, who coined the mathematical use of the term ``chaos,'' was cited for finding universal properties underlying such diverse phenomena as the motion of the planets, turbulence in flowing water and yearly ups and downs in wild animal populations. The foundation singled out the 78-year-old Mandelbrot for his discovery of fractal geometry, which can be used to study irregular shapes in nature such as clouds or coastlines. (...)
Complex Challenges: Global Terrorist Networks
ISIS: Human Rights Severely Compromised By Sept 11, The Star Online
Excerpts: Human rights have been severely and extensively compromised (...), said Institute of Strategic and International Studies director-general Datuk Mohamed Jawhar Hassan. (...) He said the undesirable consequences of the present campaign against international terrorism and surrounding global security environment include ethnic and religious profiling and stereotyping, polarisation and tension between ethnic and religious groups, emboldening of state terrorism. Others include erosion of the credibility and effectiveness of international laws and institutions which will weaken the global and security order, threats to the security and sovereignty of individual states and international peace (...).
Alleged Terror Leader Linked to Bali, The Guardian/AP
Excerpts: A militia commander connected to the al-Qaida-linked group Jemaah Islamiyah took part in planning meetings for the Bali bombings, police said Saturday, the latest evidence tying the radical Islamic terror network to the deadly blasts. Police staged a re-enactment of those meetings Saturday after flying eight Islamic militant suspects in handcuffs and ski masks from Bali to the central Indonesian town Solo. (...) Officials in several countries have blamed the attack on Jemaah Islamiyah, whose alleged goal is to establish a pan-Islamic state in Southeast Asia.
Links & Snippets
- Physiology: Is Brain Sympathetic To Bone?, Jeffrey S. Flier, Nature 420, 619 - 622 (2002);doi:10.1038/420619a, The fat-derived hormone leptin is best known for its effects on weight. But it also influences bone density, and new work reveals a role for the sympathetic nervous system in mediating this effect.
- Progressive Evolution: Aspirational Thinking, Henry Gee, Nature 420, 611 (2002); doi:10.1038/420611a, Those evolving-human commercials are just nature philosophy brought up to date, doi:10.1038/420611a
- Genome-Wide Coexpression Dynamics: Theory And Application, Ker-Chau Li, Proc. Natl. Acad. Sci. USA published 16 December 2002, 10.1073/pnas.252466999
- On the mechanism of the probabilistic nature of ventricular defibrillation threshold, Masaaki Yashima, Young-Hoon Kim, Sean Armin, Tsu-Juey Wu, Yasushi, Miyauchi, William J. Mandel, Peng-Sheng Chen, and Hrayr S.Karagueuzian, AJP: Heart 2003 January 1; 284(1): p. H249-H255
- Opinion: Outbreak at Sea, Jonathan Kaplan, NYTimes, 02/12/16, Ships are ideal incubators, and there is no entirely effective way of preventing viruses from spreading on them.
- The End Of History, Tech Version?, Kenneth James, Business Times, 02/12/19, Some tech prophets see humans made irrelevant by machines. But there's a choice
- International: Bush Ordering Missile Shield, Eric Schmitt, NYTimes, 02/12/18, If it works, the modest antimissile system could intercept a limited attack from a state like North Korea.
- Improving Science Education, Colleges and universities should use evidence of student learning as a basis for measuring teaching effectiveness in undergraduate science, technology, engineering and mathematics education, says a new National Academies report. Schools should also provide faculty with ongoing teaching instruction and establish endowments to reward excellent teaching, the report suggests.Press release
- The Next 50 Years, Howard Smith, Peter Fingar, Darwin Magazine, 02/12
- Lasers reveal rewiring of the living brain, Alison Motluk, New Scientist, 02/12/18
- Bidirectional Synaptic Plasticity In The Cerebellum-Like Mammalian Dorsal, Cochlear Nucleus,Kiyohiro Fujino and Donata Oertel, PNAS published 16 December 2002, 10.1073/pnas.0135345100
- An Epigenetic Mouse Model For Molecular And Behavioral Neuropathologies, Related To Schizophrenia Vulnerability, L. Tremolizzo, G. Carboni, W. B. Ruzicka, C. P. Mitchell, I. Sugaya, P. Tueting, R. Sharma, D. R. Grayson, E. Costa, and A. Guidotti, PNAS published 12 December 2002, 10.1073/pnas.262658999
- Fractal Magnets May Fracture Old Technologies, Mike Martin, NewsFactor Network, 02/12/13
- Ontogenetic Growth (Communication arising): Modelling Universality and Scaling, Jayanth R. Banavar, John Damuth, Amos Maritan & Andrea Rinaldo, Nature 420, 626 (2002); doi:10.1038/420626a
- The Role Of The Amygdala In Conditioned Flavor Preference, Gilbert P.E., Campbell A. & Kesner R.P., Neurobiol. of Learning and Mem., Vol. 79, No. 1, pp:118-121(4) Jan. 2003, DOI:10.1016/S1074-7427(02)00013-8
- Vocal Clans In Sperm Whales (Physeter Macrocephalus), L. E. Rendell & H. Whitehead, Alphagalileo/Proc. B Biological Sc., 2002/12/17
- Song And The Song Control Pathway In The Brain Can Develop Independently Of Exposure To Song In The Sedge Warbler, S. Leitner, J. Nicholson, B. Leisler, T. J. DeVoogd & C. K. Catchpole, Proc. Biol. Sc., The Royal Society Vol. 269, Number 1509, pp:2519-2524, Dec. 2002, DOI: 10.1098/rspb.2002.2172
- Light Shed On Vision And Hearing Disorders, E. Peerenboom, Alphagalileo, 2002/12/16
- Self-Organizing Continuous Attractor Networks And Path Integration: Two-Dimensional Models Of Place Cells, S. M. Stringer, E. T. Rolls, T. P. Trappenberg & I. E. T. Araujo, Network: Comput. Neural Syst. , 13, pp:429-446, Nov. 2002, DOI: 10.1088/0954-898X/13/4/301
- Ontogenetic Dissociation Between Habit Learning And Recognition Memory In Capuchin Monkeys (Cebus Apella), Resende M.C., Tavares M.C.H. & Tomaz C., Neurobiol. of Learning and Mem., Vol. 79, No. 1, pp: 19-24(6), Jan. 2003, DOI : 10.1016/S1074-7427(02)00015-1
- Learning-Based Complexity Evaluation Of Radial Basis Function Networks, K. Najarian, Neural Processing Letters, 16 (2):, pp:137-150, Oct. 2002
- Neural Network Based Optimal Routing Algorithm For Communication Networks, P. Venkatara, S. Ghosal & B. P. Vijay Kumar, Neural Networks, Vol. 15, Issue 10, pp:1289-1298, Dec. 2002, DOI: 10.1016/S0893-6080(02)00067-9
- The Mind's Eye: Cognitive And Applied Aspects Of Eye Movement Research, J. Hyönä, R. Radach, H. Deubel (Eds.), Elsevier, 2003, ISBN: 0-444-51020-6
- Art and Complexity, J. Casti, A. Karlqvist (Eds.), Elsevier, ISBN: 0-444-50944-5, 2003
- Bifurcations and Patterns in Compromise Processes, E. Ben-Naim, P.L. Krapivsky, S. Redner, arXiv
- Linking Brain And Behavior In Sleep-Dependent Learning And Memory Consolidation, Robert Stickgold, Roar Fosse, and Matthew P. Walker, PNAS 10.1073/pnas.012689199, 02/12/16, The modulation of our brains' neural circuitry by ongoing life experience (''neuronal plasticity'') remains an excit-ing and intensely studied topic.
- Dynamics Of Microtubule Asters In Microfabricated Chambers: The Role Of Catastrophes, Cendrine Faivre-Moskalenko and Marileen Dogterom, PNAS published 16 December 2002, 10.1073/pnas.252407099
- Crop Pollination From Native Bees At Risk From Agricultural Intensification, Claire Kremen, Neal M. Williams, and Robbin W. Thorp, PNAS published 16 December 2002, 10.1073/pnas.262413599
- Interaction Of Pollinators And Herbivores On Plant Fitness Suggests A Pathway For Correlated Evolution Of Mutualism- And Antagonism-Related Traits, Carlos M. Herrera, Monica Medrano, Pedro J. Rey, Alfonso M. Sanchez-Lafuente, Maria B. Garcia, Javier Guitian, and Antonio J. Manzaneda, PNAS published 13 December 2002, 10.1073/pnas.252362799
- A Molecular Switch Underlies A Human Telomerase Disease, Luis R. Comolli, Ivan Smirnov, Lifeng Xu, Elizabeth H. Blackburn, Thomas L. James, PNAS published 13 December 2002, 10.1073/pnas.262663599
- Some Mathematical Challenges In Materials Science, J. E. Taylor, Bull. Amer. Math. Soc., 40, pp:69-87, 2003
- Recovery Of Hidden Information Through Synaptic Dynamics, M. I. Rabinovich, R. D. Pinto, H. D. I. Abarbane , E. Tumer, G. Stiesberg, R. Huerta & A. I. Selverston, Network: Comput. Neural Syst. , 13, pp: 487-501, Nov. 2002, DOI: 10.1088/0954-898X/13/4/304
- Interference Competition And Species Coexistence, P. Amarasekare, Proc. Biol. Sc.,The Royal Society, Vol. 269, Number 1509, pp:2541-2550, Dec. 2002, DOI: 10.1098/rspb.2002.2181
- Modelling Infection As A Two-Step Process Combining Gene-For-Gene And Matching-Allele Genetics, Agrawal & Lively, The Royal Society Proc. B ( Biol. Sc.), 2002/12/13, DOI: 10.1098/rspb.2002.2193
- Commentary: Design Then Mutate, Jeff Hasty, Proc. Natl. Acad. Sci. USA, 10.1073/pnas.012694899, The development of a systematic design process for synthetic gene regulatory networks is an intriguing prospect …
- Traveling Salesmen in the Presence of Competition. Sandor P. Fekete, Rudolf Fleischer, Aviezri Fraenkel, and Matthias Schmitt. arXiv. 2002-12-3.
- Quantum Iterated Function Systems. Artur Lozinski, Karol Zyczkowski, Wojciech Slomczynski. arXiv. 2002-12-5.
- Mining the Web for Lexical Knowledge to Improve Keyphrase Extraction: Learning from Labeled and Unlabeled Data. Peter D. Turney. arXiv. 2002-12-8.
- Modeling Rumors: The No Plane Pentagon French Hoax Case. Serge Galam. arXiv. 2002-11-25.
- An Invitation to Quantum Game Theory. E. W. Piotrowski, J. Sladkowski. arXiv. 2002-11-28.
Coming and Ongoing Webcasts
- Annual Video Game Report Card, Speakers: Sen. Joseph Lieberman (D-CT); Rep. Betty McCollum (D-MN); David Walsh, President, National Institute on Media & the Family, c-span.org, 12/19/2002, clip11782 (50 min.)
- Artificial Life Conference (A-Life 8), Sydney, Australia, 02/12/09-13
- Universes, Edge Video, 02/11
- Novel Properties of Nano-Materials Symposium, Natl Taiwan Normal Univ, 02/12/13-14
- Dean LeBaron's Archive of Daily Video Commentary, Ongoing Since February 1998
- One-Week Intensive Course: Complex Physical, Biological and Social Systems, NECSI, Cambridge, MA, 03/01/06-10
- Plexus New England Fractal Meeting, Cambridge, MA 03/01/06
- Hawaii International Conference On System Sciences (HICSS-36), Big Island, Hawaii, 03/01/06-09
- Scientific Openness and National Security, Washington, DC, 03/01/09
- Conference on Swarming and Network Enabled Command, Control, Communications, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR), McLean, VA, 03/01/13-14
- Sackler Colloquium on "Chemical Communication in a Post-Genomic World", Irvine, CA, 03/01/17-19
- Plexus Ontario Fractal Meeting, Toronto, Canada, 02/01/23
- 3rd Gathering of the Center for Self-Organizing Leadership, St. George, Utah, 03/01/24-26
- INSC 2003, International Nonlinear Sciences Conference Research and Applications in the Life Sciences,Vienna, Austria, 03/02/07-09
- Complexity Science In Practice: Understanding & Acting To Improve Health and Health Care, Mayo Clinic Rochester, Minnesota USA, 03/03/21-22
- Fourth International Conference on Intelligent Data Engineering and Automated Learning (IDEAL'03), Hong Kong, 03/03/21-23
- 2003 AAAI Spring Symposium Series, Computational Synthesis: From Basic Building Blocks To High Level Functionality, Stanford, 03/03/24-27
- Jahrestagung 2003 des AKSOE (Physics of Socio-Economical Systems), Dresden, Germany, 03/03/24-28
- Uncertainty and Surprise: Questions on Working with the Unexpected, U. of Texas at Austin, Texas, 03/04/10-12
- Agent-Based Simulation 4, Montpellier, France, 03/04/28-30
- SPIE's 1st Intl Symp on Fluctuations and Noise, Santa Fe, NM, 03/06/01-04
- 21st ICDE World Conf on Open Learning and Distance Education, Hong Kong, 03/06/01-05
- 17th Workshop on Parallel and Distributed Simulation (PADS 2003), San Diego, California, 03/06/10-13
- 2003 Summer Computer Simulation Conference (SCSC '03), Montreal, Canada, 03/06/20-24
- 5th Intl Conf "Symmetry in Nonlinear Mathematical Physics", Kiev, Ukraine, 03/06/23-29, Mirror
- 2003 Genetic and Evolutionary Computation Conference (GECCO-2003), Chicago, IL,03/07/12-16
- 2nd Intl Joint Conf on Autonomous Agents and Multi-Agent Systems (AAMAS-2003), Melbourne, Australia, 03/07/14-18
- 7th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2003), Orlando, Florida, 03/07/27-30
- 2003 IEEE/WIC Intl Joint Conf. Web Intelligence and Intelligent Agent Technology, Beijing, China, 03/10/13-17
Public Conference Calls
- PlexusCalls - John Holland in Conversation - Audio File Available Now, mp3 (28mb)
- Are Disease and Aging Information/Complexity Loss Syndromes?, PlexusCalls, 02/11/08, 1 - 2 pm EST (To learn more about Ary Goldberger’s work and HeartSongs, Music of the Heart.) Audio File Available Now, mp3 (27mb)
- Brenda Zimmerman in Conversation - Audio File Available Now, mp3 (24mb)
- The Complexity of Entrepreneurship: A Launchcyte Story, PlexusCalls, 02/11/22, 1 - 2 pm EST
ComDig Announcement: New ComDig Archive in Beta Test
We are in the process of upgrading the Complexity Digest archives to a format with improved search capabilities. Also, we will finally be able to adequately publish the valuable feedback and comments from our knowledgable readers. You are cordially invited to become a beta tester of our new ComDig2 archive.
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