Complexity Digest 2003.02

13-Jan-2003

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Content

  1. Modelling Methodology And Forecast Failure, The Econometrics Journal
    1. Plan To Erase Dividend Tax Not Likely To Aid All Investors, Florida Today
    2. Some Unintended Consequences of Tax-free Dividends, Dean LeBaron's View From NH, webcast
  2. Now Playing: Reality Without the Downside, NYTimes
    1. 'Sims Online' Offers Surprises for the Sociable,, Reuters
  3. Technical Efficiency In Telecom And The Impact Of Incentive Regulation, Appl. Math. Model.
  4. The Rise of The Intelligent Enterprise, ACM Ubiquity
  5. 'Gadget Printer' Promises Industrial Revolution, New Scientist
  6. Practical Quantum Computers Are Another Step Closer, The Economist
    1. Quantum Computing: Putting It Into Practice, Nature
    2. Researchers Race to Put the Quantum Into Mechanics, Science
  7. Researchers Race to Put the Quantum Into Mechanics, J. Neurobiology
  8. Vampire Bat Saliva Compound Could Help Treat Strokes, Scientific American
  9. Genetic And Environmental Influences On Human Psychological Differences, J. Neurobiology
    1. Newborn Neurons Search for Meaning, Science
  10. Cloned Pigs Behave Like ... Pigs, Science Daily
  11. Complexity and Life, Emergence
    1. What Are 3-D Spider Webs For?, Alphagalileo
    2. Animal Behaviour: The Lobster Navigators, Nature
    3. True Navigation And Magnetic Maps In Spiny Lobsters, Nature
    4. Alternative Attractors May Boost Uncertainty And Sensitivity In Ecological Models, Eco. Modelling
    5. Social Slime Molds Meet Their Match, Science
  12. Molecular Evolution: Duplication, Duplication, Nature
    1. Role Of Duplicate Genes In Genetic Robustness Against Null Mutations, Nature
  13. Virtual Bird Brain Matches Nature's Tunes, New Scientist
    1. A Biologist Explores the Minds of Birds That Learn to Sing, NYTimes
    2. Selectivity for Conspecific Song in the Zebra Finch Auditory Forebrain, J. Neurophysiol
  14. Brain Can Generate Unexplained Noise In Ears, ScienceDaily
  15. To See Is to Attend, Science
  16. Immune Cognitive Modules, Autoimmune Disease, and Pathogenic Social Hierarchy, CogPrints
  17. Sensitive Robots Taught To Gauge Human Emotion, EE Times
    1. The Importance Of Depression, Nature
    2. Robots For The Masses, CNET News.com
    3. Giving Robots The Gift Of Sight, CNET News.com
  18. Wizard's Chess, NYTimes
    1. Venezuela Crisis Complicates Iraq Situation, Experts Say, NYTimes
    2. Brazil Needs A-Bomb Ability, Aide Says, Setting Off Furor, NYTimes
    3. After Oil, Clean Energy From A Fuel-Cell-Driven Global Hydrogen Web, E-Magazine
  19. Complex Challenges: Global Terrorist Networks
    1. Scientists Tell Washington Secrecy Impairs Research, Reuters
    2. Cascade-Based Attacks On Complex Networks, Phys Rev. E
    3. Al Qaeda Suspects in Germany Detained in Custody, Reuters
    4. Paris Frees Airport Worker Who Was Framed as Terror Suspect, NYTimes
  20. Links & Snippets
    1. Other Publications
    2. Coming and Ongoing Webcasts
    3. Conference Announcements
      1. Public Conference Calls
      2. Listening Post, Sound Exhibit
    4. ComDig Announcement: New ComDig Archive in Beta Test
  1. Modelling Methodology And Forecast Failure, The Econometrics Journal Next Article Bookmark and Share

    Abstract: We analyse by simulation the impact of modelˇVselection strategies (sometimes called preˇVtesting) on forecast performance in both constantˇV and nonˇVconstantˇVparameter processes. Restricted, unrestricted and selected models are compared when either of the first two might generate the data. We find little evidence that strategies such as generalˇVtoˇVspecific induce significant overˇVfitting, or thereby cause forecastˇVfailure rejection rates to greatly exceed nominal sizes. Parameter nonˇVconstancies put a premium on correct specification, but in general, modelˇVselection effects appear to be relatively small, and progressive research is able to detect the misˇVspecifications.
    1. Plan To Erase Dividend Tax Not Likely To Aid All Investors, Florida Today Next Article Bookmark and Share

      Excerpts: Typically, that means companies wanting to lower their tax bill will borrow money for various projects. An interest payment on borrowed money is tax-deductible; dividend payments are not. "Tax policy, therefore, biases corporate financing decisions in favor of raising new money by way of debt," said Scott, who also writes textbooks on corporate finance. (...) "It can't pay it out of a fictitious number, and that's what some accounting profits are," Scott said. "Thus, it makes the corporate accounting process more clear, less opaque.
    2. Some Unintended Consequences of Tax-free Dividends, Dean LeBaron's View From NH, webcast Next Article Bookmark and Share

  2. Now Playing: Reality Without the Downside, NYTimes Next Article Bookmark and Share

    Excerpts: The creator of this virtual world, There Inc., is calling it "the first online getaway," a sort of digital Club Med (...). And while chat is a major feature of There, the company's chief executive, Tom Melcher, said it offers much more, including avatars enlivened with artificial intelligence that look and act more realistically than typical game characters. They appear to breathe. Their eyes blink, and their body language - controlled by the user or left to software to animate - is meant to make conversations feel more natural.
    1. 'Sims Online' Offers Surprises for the Sociable,, Reuters Next Article Bookmark and Share

      Excerpts: ``The Sims Online'' may look like ``The Sims'' games, but it's a vastly different product because all the characters in the online game are controlled by real people. You can speak to them, you can relate to them, and you can role-play with them. It's like having a secret life in a world that is, for many reasons, friendlier than our own.(...) Then it's time to select a fictitious virtual city to live in (...), describe some likes/dislikes of your character, and choose a figure to represent yourself.
  3. Technical Efficiency In Telecom And The Impact Of Incentive Regulation, Appl. Math. Model. Next Article Bookmark and Share

    Abstract: Incentive regulation has become an important regulatory tool in the telecommunications industry in the United States. (...) a methodology for measuring technical efficiency and its change is introduced. This is a multiple-output/multiple-input distance function approach to measuring technical efficiency. The results of implementing this approach for 19 local exchange carriers for the 1988-1999 period indicate that in the production of local service, intrastate toll/access service, and interstate access to local loops, there was no change in technical efficiency between the 1988-1990 period and the 1991-1999 period, something that incentive regulation was specifically designed to promote.
  4. The Rise of The Intelligent Enterprise, ACM Ubiquity Next Article Bookmark and Share

    Excerpts: This vision of the IE represents the magical and compelling challenge of creating large-scale artifacts that closely resemble nature-born living organisms -- very much like the Darwinian picture of the world in which species are created, evolved and morphed into better forms and superior organizations. Some of these species have disappeared and can only be seen today in museums. There is no reason that something similar may not happen to some contemporary enterprises. It seems that the lessons from Mother Nature should be studied carefully by scientists, technologists, business people and dream-driven futurists.
  5. 'Gadget Printer' Promises Industrial Revolution, New Scientist Next Article Bookmark and Share

    Excerpts: (...) fully assembled electric and electronic gadgets to be printed in one go. The idea was revealed at a December workshop on robotic algorithms in Nice. Instead of creating a casing and then laboriously filling it with electronic circuit boards, components and switches, the plan is to print a complete and fully assembled device. The trick is to print layer upon layer of conducting and semiconducting polymers in such a way that the circuitry the device requires is built up as part of the bodywork.
  6. Practical Quantum Computers Are Another Step Closer, The Economist Next Article Bookmark and Share

    Excerpts: (...) a qubit can represent a one and a zero simultaneously. This allows each qubit to participate in more than one calculation at once, which is why a quantum computer can run a large number of computations in parallel. The problem is manipulating the qubits. Setting their initial values is hard. So is reading the results. And while the computation is performed, different qubits must interact with each other in carefully controlled ways-aptly known as entanglement-while being kept isolated from the environment outside the computer.
    1. Quantum Computing: Putting It Into Practice, Nature Next Article Bookmark and Share

      Excerpts: Building such a device would be extremely difficult, involving placing individual atoms at precisely known locations inside a silicon chip and then building tiny electrodes and transistors around them. These ideas have been demonstrated (...) and a device with two phosphorus atoms has been constructed. Early results suggest that these two atoms can be controlled and observed. Another proposal based on superconducting quantum interference devices (SQUIDs) has also made substantial progress (...). Several working single-SQUID devices have been constructed, and attempts to couple two SQUIDs are under way.
    2. Researchers Race to Put the Quantum Into Mechanics, Science Next Article Bookmark and Share

      Excerpts: Atoms, molecules, and other minuscule particles must constantly flit about because of a law of nature that says if you know precisely where something is, you can't know where it's going, and vice versa. The Heisenberg Uncertainty Principle is an unavoidable nuisance; experimental physicists have observed countless times that the smallest bits of stuff in nature wriggle whenever they try to pin them down. However, no one has directly observed the ineluctable quantum quivering--or zero-point motion--of a larger, humanmade object.
  7. Researchers Race to Put the Quantum Into Mechanics, J. Neurobiology Next Article Bookmark and Share

    Abstract: Sleep has been identified in all mammals and nonmammalian vertebrates that have been critically evaluated. In addition, sleep-like states have also been identified and described in several invertebrates. The completion of several genome sequencing projects has led to the expectation that fundamental aspects of sleep can be elucidated through genetic dissection. Indeed, studies in both the mouse and fly have begun to reveal tantalizing suggestions about the underlying principles that regulate sleep homeostasis. In this article we will review recent studies that have used genetic techniques to evaluate sleep in the fruit fly and the mouse.
  8. Vampire Bat Saliva Compound Could Help Treat Strokes, Scientific American Next Article Bookmark and Share

    Excerpts: (...) vampire bat saliva contains a potent clot-busting substance that could help a greater number of patients than current medications do. Scientists identified the medicinally promising bat compound, an enzyme known as desmoteplase or DSPA, more than a decade ago. The substance's true function--to thin a vampire victim's blood so that it flows freely, allowing the bat to feed--also makes it a candidate for treating strokes. During an ischemic stroke one or more clots block the supply of blood to the brain.
  9. Genetic And Environmental Influences On Human Psychological Differences, J. Neurobiology Next Article Bookmark and Share

    Abstract: Psychological researchers typically distinguish five major domains of individual differences in human behavior: cognitive abilities, personality, social attitudes, psychological interests, and psychopathology. In this article we: discuss a number of methodological errors commonly found in research on human individual differences(...) briefly outline the basic quantitative methods used in human behavioral genetic research; review the major criticisms of behavior genetic designs, with particular emphasis on the twin and adoption methods (...). We conclude that there is now strong evidence that virtually all individual psychological differences, when reliably measured, are moderately to substantially heritable.
    1. Newborn Neurons Search for Meaning, Science Next Article Bookmark and Share

      Excerpt: Indeed, until recently, brain neurons were thought to be irreplaceable. Adult brains, we were taught, are unable to make new neurons, so those with which we are endowed at birth must last a lifetime. Major cracks in that dogma began to appear in the 1980s with the discovery that some songbirds--warm-blooded vertebrates like ourselves--give birth to waves of new brain neurons seasonally. Then researchers observed the birth of new neurons--a process called neurogenesis--in the brains of adult mammals, and the old view came crashing down.
  10. Cloned Pigs Behave Like ... Pigs, Science Daily Next Article Bookmark and Share

    Excerpts: The behavior of cloned pigs, produced last year at Texas A&M, were compared to pigs bred normally. "We found the variation within a litter of clones to be as variable or greater (than the normal litters) at least 80 percent of the time for all the tests that we did, they were pretty much regular litters of pigs". Two litters of cloned pigs were compared to two litters of "control" pigs in tests that measured the variation in food preference, temperament and how pigs spend their time. They played, ate, slept, fought and responded to outside stimuli with the same range of behavior as the others.
  11. Complexity and Life, Emergence Next Article Bookmark and Share

    Excerpts: And so more and more biologists are looking for a different answer to Schrodinger's old question, "What is Life?" The conceptual revolution that is now taking place in biology is a pro-found shift of emphasis from the structure of genetic sequences to the organization of metabolic networks. It is a shift from reductionist to systemic thinking. The issue, simply stated, is this: To understand the nature of life, it is not enough to understand DNA, proteins, and the other molecular structures that are the building blocks of living organisms,
    1. What Are 3-D Spider Webs For?, Alphagalileo Next Article Bookmark and Share

      Excerpts: The classic radial or "orb" spider web captures flying insects efficiently with a small amount of silk but such flat webs leave spiders exposed to their own predators. The derived "araneoid sheet web weavers" transformed the flat orb web into, usually, three-dimensional cobwebs and sheet webs. These webs surround spiders with tangles of silk that can provide both physical protection and early warning of predators. (...) these three-dimensional webs are associated with a dramatic decrease in predation by mud-dauber wasps (...). This escape from predation is accompanied by a dramatic increase in both spider species diversity and abundance.
    2. Animal Behaviour: The Lobster Navigators, Nature Next Article Bookmark and Share

      Excerpt: When experimentally displaced in geomagnetic space, spiny lobsters act as if to make their way home. This is a fascinating case of navigation by an invertebrate using a magnetic map sense. (...) From the results of elegant displacement experiments in both geographical and geomagnetic space, they conclude that the impressive homing capacity of spiny lobsters is probably based on a map sense involving geomagnetic cues. This is the first time that such true navigational capability has been plausibly ascribed to an invertebrate.
    3. True Navigation And Magnetic Maps In Spiny Lobsters, Nature Next Article Bookmark and Share

      Excerpt: Animals are capable of true navigation if, after displacement to a location where they have never been, they can determine their position relative to a goal without relying on familiar surroundings, cues that emanate from the destination, or information collected during the outward journey. (...)Lobsters tested in a field north of the capture site oriented themselves southwards, whereas those tested in a field south of the capture site oriented themselves northwards. (...) imply that true navigation in spiny lobsters, and perhaps in other animals, is based on a magnetic map sense.
    4. Alternative Attractors May Boost Uncertainty And Sensitivity In Ecological Models, Eco. Modelling Next Article Bookmark and Share

      Abstract: Numerous ecosystems, ranging from coral reefs, and forests to deserts and lakes have been shown to possess alternative stable states. In this paper we show that alternative attractors also have important consequences (...) we found that the uncertainty in the model results may be remarkably high under some conditions. We demonstrate that this high uncertainty is caused by the alternative stable states of the model: if the noise on the parameters exceeds a critical threshold, the model uncertainty can increase steeply, due to switches to the other equilibrium. In the vicinity of catastrophical bifurcation points, uncertainty approaches infinity (...).
    5. Social Slime Molds Meet Their Match, Science Next Article Bookmark and Share

      Excerpt: And with good reason--if knockout cells reached the aggregate, their reduced adhesion would displace them toward the trailing edge of the slug, an area that preferentially develops into spores. This would cause the good, green-beard cells to finish last. Such cheating is apparently disfavored, and green-beard alleles resist displacement by less adhesive mutants, just as green beards must have originally spread to supplant them. But might mutations also occur in beard genes encoding other colors, leading to clone-specific and thus nepotistic (rather than promiscuous) cooperation?
  12. Molecular Evolution: Duplication, Duplication, Nature Next Article Bookmark and Share

    Excerp: Duplicated genes are common in genomes, perhaps because they provide redundancy: if one copy is inactivated, the other can still work. A new study quantifies the effects of deleting 'singletons' and duplicated genes in yeast. (...) In eukaryotes (loosely speaking, those organisms, such as humans, whose DNA is packaged into cell nuclei), genomes seem to be far from optimally designed, in that most stretches of DNA sequence do not code for proteins, and even those small portions that do are often duplicated. Why do organisms tolerate such apparent wastage?
    1. Role Of Duplicate Genes In Genetic Robustness Against Null Mutations, Nature Next Article Bookmark and Share

      Excerpt: Deleting a gene in an organism often has little phenotypic effect, owing to two mechanisms of compensation. The first is the existence of duplicate genes: that is, the loss of function in one copy can be compensated by the other copy or copies. The second mechanism of compensation stems from alternative metabolic pathways, regulatory networks, and so on. The relative importance of the two mechanisms has not been investigated except for a limited study, which suggested that the role of duplicate genes in compensation is negligible.
  13. Virtual Bird Brain Matches Nature's Tunes, New Scientist Next Article Bookmark and Share

    Excerpts: Adding a virtual brain to a computer model of a singing bird has allowed scientists to figure out how birds compose their songs. The feat hints that we might one day be able to map some of the complex circuitry in an animal's brain just by listening to its calls. When birds sing, they force air from their lungs past folds of tissue in the voice box. (...) developed a simple computer model that mimics this process to produce sound.
    1. A Biologist Explores the Minds of Birds That Learn to Sing, NYTimes Next Article Bookmark and Share

      Excerpts: These birds are among the few vocal-learning animal groups. By measuring a certain gene that is activated in their brains when they are producing their learned vocalizations, (...). None of these creatures are closely related to one another. These pathways are not found in more closely related birds that do not learn vocalizations. Our findings indicate that brain pathways for a complex behavior can evolve in very similar ways, multiple times. There's the possibility that human language brain pathways have also evolved in ways similar to these birds.
    2. Selectivity for Conspecific Song in the Zebra Finch Auditory Forebrain, J. Neurophysiol Next Article Bookmark and Share

      Excerpts: The selectivity of neurons in the zebra finch auditory forebrain for natural sounds was investigated systematically. The principal auditory forebrain area in songbirds consists of the tonotopically organized field L complex, which, by its location in the auditory processing stream, can be compared with the auditory cortex of mammals. (...) Such preferential responses to natural sounds cannot be explained by linear frequency tuning or simple nonlinear intensity tuning and requires linear or nonlinear spectro-temporal neuronal transfer functions tuned to the acoustical properties of song.
  14. Brain Can Generate Unexplained Noise In Ears, ScienceDaily Next Article Bookmark and Share

    Excerpts: Unexplained and severe tinnitus--a ringing or buzzing in the ears-can be temporarily reduced in some patients by "jamming" the brain's electrical activity with focused magnetic stimulation, (...). The results confirm that some phantom sounds are generated by abnormal activity in the brain itself. "Controlled clinical trials are now necessary to evaluate whether this method can permanently reduce and thus cure tinnitus," said senior author Christian Gerloff, M.D, of the University of Tuebingen in Germany. Many people experience tinnitus, defined as the perception of sound in the absence of an obvious source, at some point in their lives.
  15. To See Is to Attend, Science Next Article Bookmark and Share

    Excerpts: (...) trained two monkeys to perform a task that required them to prepare, but not immediately execute, a rapid eye movement or saccade. The monkeys had to plan a saccade from a central "home" location to a remembered location marked by a briefly flashed target dot (...).If the probe was a "C" they were to make the saccade, (...). In this monkey task, the maintained eye movement plan resulted in an increase in visual sensitivity at the saccade goal that was dependent on attention.
  16. Immune Cognitive Modules, Autoimmune Disease, and Pathogenic Social Hierarchy, CogPrints Next Article Bookmark and Share

    Contributing Editor's Note: Systemic lupus erythematosus (SLE) is an autoimmune disease without a cure. The causes of the disease are still not known. More information can be found here.
    Abstract: Examining elevated rates of systemic lupus erythematosus in African-American women from the perspective of the emerging theory of immune cognition suggests the disease constitutes an internalized physiological image of external patterns of psychosocial stress, a 'pathogenic social hierarchy' involving the synergism of racism and gender discrimination. The disorder represents the punctuated resetting of 'normal' immune self-image to a self-attacking 'excited' state, a process formally analogous to models of punctuated equilibrium in evolutionary theory. We speculate that this punctuated onset takes place in the context of an immunological 'cognitive module' similar to what has been proposed by evolutionary psychologists for the human mind. We discuss the broader implications of a high rate of this disorder within a marginalized population, finding it to be a leading indicator for phenomena likely to entrain powerful subgroups into a larger pattern of embedding pathology.
  17. Sensitive Robots Taught To Gauge Human Emotion, EE Times Next Article Bookmark and Share

    Excerpts: Robotics designers are working with psychologists here at Vanderbilt University to improve human-machine interfaces by teaching robots to sense human emotions. Such "sensitive" robots would change the way they interact with humans based on an evaluation of a person's mood. Consequently, the team's research project has two parts: sensing the unique patterns of behavior that mark an individual person's emotions, and converting that information in real-time into actuator-style commands to the robot to facilitate communications between humans and machines.
    1. The Importance Of Depression, Nature Next Article Bookmark and Share

      Excerpts: We, and other animals, can generally pinpoint the source of a sound in space regardless of how loud it is. A study involving experimentation and computer modelling reveals how our brains perform this clever task. (...). All synapses exhibit depression - a decrease in the strength of the connection that occurs after rapid and repeated use - and this might seem like a bad idea, a design fault that prevents synapses from keeping up with the demands placed on them.
    2. Robots For The Masses, CNET News.com Next Article Bookmark and Share

      Excerpts: A start-up company says it has developed a navigation system that is cheap enough to bring robots to the mass-consumer market. Pasadena, Calif.-based Evolution Robotics said its technology that lets a robot determine its position relative to its environment is based on wheel sensors and a Webcam that cost less than $50. That's a fraction of the cost of current robot navigation systems relying on laser range finders (...). The company asserts that its relatively inexpensive system "will result in a new generation of products that were previously inconceivable."
    3. Giving Robots The Gift Of Sight, CNET News.com Next Article Bookmark and Share

      Excerpts: Moravec's system consists of stereoscopic digital cameras and a 3D grid set up in the robot's computer brain. The system determines the robot's distance from objects by noticing the different placement of the object in the two camera images and applying a geometric equation. The grid, which is made up of 32 million digital cells, is used to help handle incomplete or potentially misleading visual data. For example, an object visible in one camera lens might be blocked from the view of the other, (...).
  18. Wizard's Chess, NYTimes Next Article Bookmark and Share

    Excerpts: Right now the world must seem like a potentially deadly game of three-dimensional chess to the Bush administration. In Asia, its allies don't agree with each other about whether a North Korea with nuclear arms is an international danger. But they are very certain they don't want the United States to do anything that might trigger an angry response. The American people are confused by the contradictions between their government's approach to North Korea and Iraq, and frustrated by the sudden lack of clarity in their government's foreign policy.
    1. Venezuela Crisis Complicates Iraq Situation, Experts Say, NYTimes Next Article Bookmark and Share

      Excerpts: But many Latin American experts say the administration's efforts have been too little, too late. They contend that the Bush administration, distracted by Iraq, allowed Venezuela's problems to fester. Others say the administration committed two blunders last year that have hurt its credibility with Mr. Chavez and other Latin American leaders: in April, by appearing to endorse an attempted coup against the Chavez government, and in December by briefly joining the opposition's call for early elections.
    2. Brazil Needs A-Bomb Ability, Aide Says, Setting Off Furor, NYTimes Next Article Bookmark and Share

      Excerpts: A senior official in the left-wing government that took power last week has set off a furor here and alarmed neighboring countries by arguing that Brazil, Latin America's largest nation, should acquire the capacity to produce a nuclear weapon. (...) Mr. Amaral's remarks, coming as the United States faces a nuclear crisis with North Korea and is preparing for war with Iraq over its weapons programs, has reawakened debate over Brazil's own nuclear energy and research program, the most advanced in Latin America.
    3. After Oil, Clean Energy From A Fuel-Cell-Driven Global Hydrogen Web, E-Magazine Next Article Bookmark and Share

      Excerpts: More than a year after the terrorist attacks on the World Trade Center (...) at the heart of our collective fear is the struggle to control oil (...). Can a combination of technological innovation, global cooperation and strategic thinking take oil off the international chessboard of power politics and replace it with the ultimate energy carrier, lighter-than-air, and potentially non-polluting hydrogen? In recent months U.S. government concern over the availability of oil in the Middle East has intensified because of (...) the prospect of war with Iraq, and the likelihood of more terrorist attacks by the Al Qaeda network.
  19. Complex Challenges: Global Terrorist Networks Next Article Bookmark and Share

    1. Scientists Tell Washington Secrecy Impairs Research, Reuters Next Article Bookmark and Share

      Excerpts: The government may be worried that enemies are plotting a biological attack, but it should not react by muzzling researchers and classifying their findings as secret, (...). While certain biotechnology researchers may need to be discreet about what they publish, a wide-ranging crackdown on the publication of information would do more harm than good, said the specialists, who included John Marburger, the science adviser of President Bush. Scientific research can benefit humanity only if its traditions of free information sharing and open questioning of research findings are allowed (...).
    2. Cascade-Based Attacks On Complex Networks, Phys Rev. E Next Article Bookmark and Share

      Abstract: We live in a modern world supported by large, complex networks. Examples range from financial markets to communication and transportation systems. In many realistic situations the flow of physical quantities in the network, as characterized by the loads on nodes, is important. We show that for such networks where loads can redistribute among the nodes, intentional attacks can lead to a cascade of overload failures, which can in turn cause the entire or a substantial part of the network to collapse. This is relevant for real-world (...) such as the Internet and power grids.
    3. Al Qaeda Suspects in Germany Detained in Custody, Reuters Next Article Bookmark and Share

      Excerpts: An extradition request by the United States could cause a legal battle with Germany, as German law does not allow the extradition of suspects if they could face the death penalty in the state they are extradited to. In November Berlin only agreed to cooperate in the U.S. trial of French national Zacarias Moussaoui, charged over the September 11 attacks, after Washington assured Germany their evidence would not be used to obtain the death penalty.
    4. Paris Frees Airport Worker Who Was Framed as Terror Suspect, NYTimes Next Article Bookmark and Share

      Excerpts: An airport baggage handler found with weapons and explosives in his car was released today after France's antiterrorism police determined that he had been framed by a former Foreign Legionnaire and in-laws who blamed him for the death of his wife. (...) The baggage handler, Abdrezak Besseghir, 27, had been in custody since Dec. 28 when he was arrested at Roissy-Charles de Gaulle airport outside Paris. Automatic weapons, five cakes of plastic explosive, two detonators and a safety fuse were found in the trunk of his car.
  20. Links & Snippets Next Article Bookmark and Share

    1. Other Publications Next Article Bookmark and Share


      1. National: In a First , U.S. Puts Limits on California's Thirst, Dean E. Murphy, NYTimes, 03/01/05,The federal government has said no to California's dipping into the Colorado River for more than its allotted share.

      2.Opinion: California Curbed , NYTimes, 03/01/08, The decision by Interior Secretary Gale Norton to reduce water flows from the Colorado River to California's Imperial Valley and urban consumers in Southern California was right on the mark.

      3.The Future Of Behavioral Health And Primary Care: Drowning In The Mainstream Or Left On The Bank? , Harold Alan Pincus, Psychosomatics 2003 February 1; 44(1): p. 1-11

      4.First Speed Of Gravity Measurement Revealed , New Scientist, Hazel Muir, 03/01/07

      5.Science: Golf Ball Dimples , C. Claiborne Ray, NYTimes, 03/01/07, This week's question: How do the dimples on a golf ball aid its flight?

      6.Science: How the Spiny Lobster Finds Home: Magnetism , Anahad O'connor, NYTimes, 03/01/07, Spiny lobsters can travel over long distances at night and find their way home using only the earth's magnetic field.

      7.Coordinated Turn-and-Reach Movements. I. Anticipatory Compensation for Self-Generated Coriolis and Interaction Torques , Pascale Pigeon, Simone B. Bortolami, Paul DiZio, and James R. Lackner, J. Neurophysiol. 2003 January 1; 89(1): p. 276-289

      8.Functional Organization of Speed Tuned Neurons in Visual Area MT , Jing Liu, William T. Newsome, J. Neurophysiol. 2003 January 1; 89(1): p. 246-256

      9.Computational Diversity In The Cochlear Nucleus Angularis Of The Barn Owl , Christine Koeppl and Catherine E Carr, J. Neurophysiol. published 27 December 2002, 10.1152/jn.00635.2002

      10.The Control of Seizure-Like Activity in the Rat Hippocampal Slice , Houman Khosravani, Peter L. Carlen, and Jose L. Perez Velazquez, Biophys. J. 2003 January 1; 84(1): p. 687-695

      11.Cooperativity in Forced Unfolding of Tandem Spectrin Repeats , Richard Law, Philippe Carl, Sandy Harper, Paul Dalhaimer, David W., Speicher, and Dennis E. Discher, Biophys. J. 2003 January 1; 84(1): p. 533-544

      12.The Biology Of Aging , Troen BR, Mt Sinai J Med 2003 Jan 70(1): p. 3-22

      13.21st Century Leadership Challenge: Creating And Sustaining Healthy , Healing Work Cultures And Integrated Service At The Point Of Care, Wesorick B, Nurs Adm Q 2002 Fall 26(5): p. 18-32

      14.Invariant Representations Of Visual Patterns In A Temporal Population Code , Reto Wyss, Peter Konig, and Paul F. M. J. Verschure, Proc. Natl. Acad. Sci. USA 2003 January 7; 100(1): p. 324-329

      15.Evidence That Exposure Of The Telomere 3' Overhang Sequence Induces Senescence , Guang-Zhi Li, Mark S. Eller, Reza Firoozabadi, and Barbara A., Gilchrest, PNAS published 6 January 2003, 10.1073/pnas.0235444100

      16.Artificial Cells: Unique Insights Into Exocytosis Using Liposomes And Lipid Nanotubes , Ann-Sofie Cans, Nathan Wittenberg, Roger Karlsson, Leslie Sombers, Mattias Karlsson, Owe Orwar, and Andrew Ewing, PNAS published 3 January 2003, 10.1073/pnas.232702599

      17.Warmer Paleotemperatures For Terrestrial Ecosystems , Elizabeth A. Kowalski and David L. Dilcher, PNAS 2003;100 167-170

      18.Engineers Trust Moore's Law , Jan. 7, 2002, Over two-thirds of engineers believe Moore's law will hold true for at least another five years, according to a survey by IEEE Spectrum magazine. "Many respondents, though, seemed just as convinced that some emerging technology would topple Moore's Law. Among the suggested candidates were...

      19.Feasible Chaotic Encryption , January 3, 2003, Researchers in Beijing have demonstrated a way to hide messages in chaotic signals for two-way voice transmission on a computer network. The researchers claim the scheme is reasonably secure (it would take an intruder armed with a personal computer more than a million times the lifetime of the...

      20.Mit Targets High-Tech Innovations , For U.S. Soldiers, Jan. 6, 2002, American soldiers may wear Kevlar vests that will protect against biological agents as well as stop bullets. With the flick of a switch, the sleeves of their uniform may stiffen into anti-shrapnel armor or a medical splint. They may carry night-vision contacts lenses, while a patch on their...

      21.Interface Gets The Point , January 1/8, 2003,Researchers are trying to get a computer to recognize gestures by correlating speech signals and hand velocity. The system could eventually enable more natural human-computer interfaces in applications like crisis management, surgery, vvideo games, and biometric...

      22.Fracture Protection: Nanotubes Toughen Up Ceramics , Jessica Gorman, Science News, Vol. 163, No. 1, Jan. 4, 2003, p. 3., also available in Audible format. Ceramics are famous for being hard but easy to break. Now, researchers have demonstrated that adding carbon nanotubes to a ceramic material can nearly triple its resistance to fracturing.

      23.Hawaii's Hated Frogs Tiny Invaders Raise A Big Ruckus , Janet Raloff, Science News, Vol. 163, No. 1, Jan. 4, 2003, p. 11., also available in Audible format. In the mid-1980s, potted plants from the Caribbean began arriving in Honolulu carrying frogs.

      24.Routes To Remembering: The Brains Behind Superior Memory , Eleanor A. Maguire, Elizabeth R. Valentine, John M. Wilding & Narinder Kapur, Nature Neuroscience 6(January):90-95., also available in Audible format.

      25.Breathtaking Science A Small Region Within The Brainstem Creates The Normal Breathing Rhythm ,Science News, Vol. 163, No. 1, Jan. 4, 2003, p. 8., also available in Audible format.

      26.Electroluminescent Device With Reversible Switching Between Red And Green Emission , S. Welter, K. Brunner, J. W. Hofstraat, L. De Cola, Nature, 03/01/02

      27.Synaptic Depression In The Localization Of Sound , Daniel L. Cook, Peter C. Schwindt, Lucinda A. Grande & William J.Spain, Nature, 03/01/02

      28.Biomechanics: A Catapult Action For Rapid Limb Protraction , Alan M. Wilson, Johanna C. Watson & Glen A. Lichtwark, Nature, 03/01/02

      29.Protein Knots: A Tangled Problem , William R. Taylor & Kuang Lin, Nature 421, 25 (2003);doi:10.1038/421025a

      30.Obituary : Arthur T. Winfree (1942-2002), Leon Glass, Nature 421, 34 (2003); doi:10.1038/421034a

      31.How New York Exams Rewrite Literature (A Sequel) , Michael Winerip, NYTimes, 03/01/08, (...) historian quoted on the exam believes that a test question based on his work has more than one correct answer.

      32.Scaling Theory: Application To Marine Ornithology , D. C. Schneider, Ecosystems 5:736-748, 2003/01/07, DOI: 10.1007/s10021-002-0156-y

      33.The Use Of Space By Animals As A Function Of Accessibility And Preference , J. Matthiopoulos , Eco. Modelling, Vol. 159, Issues 2-3, pp:239-268, 2003/01/15, DOI: 10.1016/S0304-3800(02)00293-4

      34.Neural Network Modelling Of Coastal Algal Blooms , J. H. W. Lee , Y. Huang, M. Dickman & A. W. Jayawardena, Eco. Modelling, Vol. 159, Issues 2-3, pp:179-201, 2003/01/15, DOI: 10.1016/S0304-3800(02)00281-8

      35.Fractional Kinetic Description of Chaotic Transport in Complex Dynamical Systems . Ramy Naboulsi. arXiv . 2003-01-08

      36. On the Origins of Autobiographical Memory . Ian Q. Whishaw and Douglas G. Wallace. Behavioural Brain Research . 138 (2): 113-119. 2003-01-22.
      37.Is Human Sentence Parsing Serial Or Parallel? Evidence From Event-Related Brain Potentials, J. M. Hopf , M. Baderb, M. Mengb & J. Bayerb, Cognitive Brain Research, Vol. 15, Issue 2, Jan. 2003, pp:165-177, DOI: 10.1016/S0926-6410(02)00149-0

      38.Parametric Analysis Of Event-Related Potentials In Semantic Comprehension: Evidence For Parallel Brain Mechanisms , J. Dien , G. A. Frishkoffb, A. Cerbonea & D. M. Tuckerb, Cognitive Brain Research, Vol. 15, Issue 2, Jan. 2003, pp:137-153, DOI: 10.1016/S0926-6410(02)00147-7

      39.Olfaction And Face Encoding In Humans: A Magnetoencephalographic Study , P. Walla , B. Hufnagl, J. Lehrner, D. Mayer, G. indinger, H. Imhof, L. Deecke & W. Lang, Cognitive Brain Research, Vol. 15, Issue 2, Jan. 2003, pp:105-115, DOI: 10.1016/S0926-6410(02)00144-1

      40.Branching Out: New System Created By Rensselaer Researchers Speeds The Mapping Of Blood Vessel Networks In Live Tumors , ScienceDaily, 2002/12/27

      41.Purdue Researchers Discover Basis For Biological Clock , ScienceDaily, 2003/01/07

      42.Leading Cloning Experts Challenge Clonaid To Prove Claim , ScienceDaily, 2003/01/07

      43.A Short History Of Computational Complexity , L. Fortnow (NEC) & S. Homer in D. van Dalen, J. Dawson & A. Kanamori, (Eds.) The History Of Mathematical Logic, North-Holland, Amsterdam, To appear 2003.

      44.Neural Substrates Of Memory: From Synapse To System , J. Dubnau , A. S. Chiang & T. Tully, J. Neurobiology, Vol. 54, Issue 1, pp:238-253, Jan. 2003, DOI 10.1002/neu.10170

      45.The Organic Codes:An Introduction to Semantic Biology , M Barbieri, Cambridge Univ. Press , Jan. 2003, ISBN: 0521531004

      46.Developmental Stability As The Primary Function Of The Pigmentation Patterns In Bivalve Shells? Vincent Bauchau , Belg.J.Zool., 2001, 131, suppl. 2:23-28; Pigmentation patterns on seashells are complex and highly diverse. The structure ot these patterns can be explained but processes similar to cellular-automata (reviewed in the paper). However the primary function of the pigmentation patterns, if any, remains a puzzle. In this paper I propose that the pigmentation is intimately associated with the regulation of the growth of the shell to achieve developmental stability.

    2. Coming and Ongoing Webcasts Next Article Bookmark and Share


      1.The Center for Business Innovation Bi-Monthly Web Cast , 03/01/15, TOPIC: CBI Future Scan Version 6.0, WHO: David McIntosh, Director of the CBI Network

      2..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.)

      3.. Artificial Life Conference (A-Life 8) , Sydney, Australia, 02/12/09-13

      4..Universes, Edge Video, 02/11

      5..Novel Properties of Nano-Materials Symposium , Natl Taiwan Normal Univ, 02/12/13-14

      6..Dean LeBaron's Archive of Daily Video Commentary Ongoing Since February 1998

    3. Conference Announcements Next Article Bookmark and Share


      1. Conference on Swarming and Network Enabled Command, Control, Communications, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR), McLean, VA, 03/01/13-14

      2. Sackler Colloquium on "Chemical Communication in a Post-Genomic World" , Irvine, CA, 03/01/17-19

      3.Plexus Ontario Fractal Meeting , Toronto, Canada, 03/01/23

      4.3rd Gathering of the Center for Self-Organizing Leadership , St. George, Utah, 03/01/24-26

      5.INSC 2003, International Nonlinear Sciences Conference Research and Applications in the Life Sciences ,Vienna, Austria, 03/02/07-09

      6.Complexity Science In Practice: Understanding & Acting To Improve Health and Health Care, Mayo Clinic Rochester, Minnesota USA, 03/03/21-22

      7.Fourth International Conference on Intelligent Data Engineering and Automated Learning (IDEAL'03) , Hong Kong, 03/03/21-23

      8.2003 AAAI Spring Symposium Series, Computational Synthesis: From Basic Building Blocks To High Level Functionality , Stanford, 03/03/24-27

      9.Jahrestagung 2003 des AKSOE (Physics of Socio-Economical Systems), Dresden, Germany, 03/03/24-28

      10.Uncertainty and Surprise: Questions on Working with the Unexpected , U. of Texas at Austin, Texas, 03/04/10-12

      11.Agent-Based Simulation 4, Montpellier, France, 03/04/28-30

      12.SPIE's 1st Intl Symp on Fluctuations and Noise , Santa Fe, NM, 03/06/01-04

      13.21st ICDE World Conf on Open Learning and Distance Education , Hong Kong, 03/06/01-05

      14.17th Workshop on Parallel and Distributed Simulation (PADS 2003) , San Diego, California, 03/06/10-13

      15.2003 Summer Computer Simulation Conference (SCSC '03) , Montreal, Canada, 03/06/20-24

      16.5th Intl Conf "Symmetry in Nonlinear Mathematical Physics" , Kiev, Ukraine, 03/06/23-29, Mirror

      17.9th International Conference on Auditory Display , Boston, MA, 03/07/07-09, Wkshp on Assistive Technologies for the Blind, 03/07/06

      18.2003 Genetic and Evolutionary Computation Conference (GECCO-2003) ,sazChicago, IL,03/07/12-16

      19.2nd Intl Joint Conf on Autonomous Agents and Multi-Agent Systems (AAMAS-2003) , Melbourne, Australia, 03/07/14-18

      20.7th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2003) , Orlando, Florida, 03/07/27-30

      21.2003 IEEE/WIC Intl Joint Conf. Web Intelligence and Intelligent Agent Technology, Beijing, China, 03/10/13-17

      1. Public Conference Calls Next Article Bookmark and Share


        1. PlexusCalls - Pat Rush & Bob Lindberg in health concern conversation with Keith McCandless and Linda Rusch, 03/01/10, Audio File Available Now , mp3 (28mb)
        PlexusCalls - John Holland in Conversation - Audio File Available Now , mp3 (28mb)
        2. Are Disease and Aging Information/Complexity Loss Syndromes? , PlexusCalls, 02/11/08, 1 - 2 pm EST (To learn more about Ary Goldbergerˇ¦s work and HeartSongs , Music of the Heart. ) Audio File Available Now , mp3 (27mb)
        3. Brenda Zimmerman in Conversation - Audio File Available Now , mp3 (24mb)
        4. The Complexity of Entrepreneurship: A Launchcyte Story , PlexusCalls, 02/11/22, 1 - 2 pm EST
      2. Listening Post, Sound Exhibit Next Article Bookmark and Share

        Excerpts: The visible and audible text in this installation is live, collected in real-time from thousands of chat rooms, forums, newsgroups, bulletin boards, and other public online communication channels.
        • Source: Listening Post, Mark Hansen and Ben Rubin, Whitney Museum of American Art, New York, 02/12/17-03/03/08
    4. ComDig Announcement: New ComDig Archive in Beta Test Bookmark and Share

      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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