Complexity Digest 2001.38

17-Sep-2001

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Content

  1. Where Was U.S. Intelligence?, Wired News
    1. Commission Warned Bush, Salon
    2. Exec Summary of U.S. Commission on National Security Report, Washington File/ U.S. Dep of State
    3. U.S. Warned In 1995 Of Plot To Hijack Planes, Attack Buildings, CNN
    4. Trade Center Removed From Next 'Flight Simulator', USAToday/AP
  2. Emotions Are Rationale for Some Moral Dilemmas, Science Now
    1. An fMRI Investigation of Emotional Engagement in Moral Judgment, Science
    2. A Bioarchaeological Perspective On The History Of Violence, Ann Rev Anthropol
  3. The Origin Of State Societies In South America, Ann Rev Anthropol
  4. Pack Formation In Cycling And Orienteering, Nature
    1. Peers Under Pressure, Nature
  5. What--or Who--Did In the Neandertals?, Science
  6. Wealth Redistribution With Finite Resources, arXiv
    1. Asset-Asset Interactions And Clustering In Financial Markets, Physica A/arXiv
    2. Stochastic Volatility as a Simple Generator of Financial Power-laws and Long Memory, Working Papers
  7. Excitability of Human Axons, Clinical Neurophysiology
  8. Modeling And Simulation In Clinical Drug Development, Drug Discovery Today
  9. General Criterion For Controllable Conformational Transitions Of Single And Double Stranded DNA, arXiv
  10. The Quandary of Quantum Information, Science
    1. Exp. Realization of Noiseless Subsystems for Quantum Information Proc, Science
    2. A Quantum Conversation, S, cience
  11. Computer Networks As Social Networks, S, cience
  12. Answering Subcognitive Turing Test Questions, CogPrints
    1. Entropic Entropic Analysis Of The Role Of Words In Literary Texts, arXiv
  13. Machine Learning for Science: State of the Art and Future Prospects, Science
    1. Pathway Databases: A Case Study in Computational Symbolic Theories, Science
  14. Blazing Pathways Through Genetic Mountains, Science
  15. Flirting with Catastrophe, Science
    1. A Microscopic Basis for the Global Appearance of Energy Landscapes, Science
  16. Artificial Ants Solve Network Problems, BBC News
  17. Better Searching Through Science, Science
  18. Mathematical Fortune Telling, Complexity
  19. Sensory Perceptions, The Scientist
  20. Links & Snippets
    1. Other Articles
      1. The World-Wide Telescope, Science
      2. Dissociation Between Hand Motion And Population Vectors From Neural Activity In Motor Cortex, Nature

  1. Where Was U.S. Intelligence?, Wired News Next Article Bookmark and Share

    Excerpts: "You can even look at some of the things said at the (World Conference Against Racism) last week in Durban, to point out that we no longer should be focused on Cold War enemies and instead should be focused on those who are most antagonistic towards the United States, and that is the Middle East," Haberly said.

    Retired General Wesley Clark, former supreme NATO commander, told CNN that the attacks were not exactly out of the blue.

    "We've known for some time that some group has been planning this," (...)


    1. Commission Warned Bush, Salon Next Article Bookmark and Share

      Excerpts: But on Wednesday, two former senators, the bipartisan co-chairs of a Defense Department-chartered commission on national security, spoke with something between frustration and regret about how White House officials failed to embrace any of the recommendations to prevent acts of domestic terrorism delivered earlier this year.

      (…) the White House announced in May that it would have Vice President Dick Cheney study the potential problem of domestic terrorism -- which the bipartisan group had already spent two and a half years studying


    2. Exec Summary of U.S. Commission on National Security Report, Washington File/ U.S. Dep of State Next Article Bookmark and Share

      Excerpts: The combination of unconventional weapons proliferation with the persistence of international terrorism will end the relative invulnerability of the U.S. homeland to catastrophic attack. A direct attack against American citizens on American soil is likely over the next quarter century. (…) In the face of this threat, our nation has no coherent or integrated governmental structures.

      We therefore recommend the creation of a new independent National Homeland Security Agency (NHSA) with responsibility for planning, coordinating, and integrating various U.S. government activities involved in homeland security.


    3. U.S. Warned In 1995 Of Plot To Hijack Planes, Attack Buildings, CNN Next Article Bookmark and Share

      Excerpt: The FBI was warned six years ago of a terrorist plot to hijack commercial planes and slam them into the Pentagon, the CIA headquarters and other buildings, Philippine investigators told CNN.

      Philippine authorities learned of the plot after a small fire in a Manila apartment, which turned out to be the hideout of Ramzi Yousef, who was later convicted for his role in the 1993 bombing of the World Trade Center.


    4. Trade Center Removed From Next 'Flight Simulator', USAToday/AP Next Article Bookmark and Share

      Excerpts: In existing versions of Flight Simulator, players can pilot aircraft ranging from gliders to commercial jetliners over much of the world, with detailed scenery of New York and other cities. Players can "fly" their aircraft into the World Trade Center towers or any other structure portrayed. The structures don't blow up, but the program shows that the plane has crashed.(...)

      "Flight Simulator was designed to be a realistic program that is helpful to pilots and to aviation enthusiasts, and we want it to be realistic"


  2. Emotions Are Rationale for Some Moral Dilemmas, Science Now Next Article Bookmark and Share

    Excerpts: Sometimes people say it's okay to sacrifice one life to save five others. Other times, people say it's wrong. Philosophers have debated for decades why hypothetical moral dilemmas that are logically identical can elicit different answers. Now a brain imaging study suggests that people's emotional responses to certain dilemmas guide their reasoning.

    (…) the study doesn't resolve whether it's right or wrong to push someone into the path of a trolley, but it does begin to answer a related question: how people decide what's right and wrong.


    1. An fMRI Investigation of Emotional Engagement in Moral Judgment, Science Next Article Bookmark and Share

      Excerpts: The long-standing rationalist tradition in moral psychology emphasizes the role of reason in moral judgment. A more recent trend places increased emphasis on emotion. (…). In two functional magnetic resonance imaging (fMRI) studies using moral dilemmas as probes, we apply the methods of cognitive neuroscience to the study of moral judgment. We argue that moral dilemmas vary systematically in the extent to which they engage emotional processing and that these variations in emotional engagement influence moral judgment.

    2. A Bioarchaeological Perspective On The History Of Violence, Ann Rev Anthropol Next Article Bookmark and Share

      Abstract: Traumatic injuries in ancient human skeletal remains are a direct source of evidence for testing theories of warfare and violence that are not subject to the interpretative difficulties posed by literary creations such as historical records and ethnographic reports. Bioarchaeological research shows that throughout the history of our species, interpersonal violence, especially among men, has been prevalent. Cannibalism seems to have been widespread, and mass killings, homicides, and assault injuries are also well documented in both the Old and New Worlds. No form of social organization, mode of production, or environmental setting appears to have remained free from interpersonal violence for long.

  3. The Origin Of State Societies In South America, Ann Rev Anthropol Next Article Bookmark and Share

    Abstract: The earliest states developed in the central Andean highlands and along the central Pacific coast of western South America. The consensus in the archaeological literature is that state societies first developed in the central Andes in the early part of the first millennium C.E. A minority opinion holds that first-generation states developed as early as the late second millennium B.C.E. in the same area. The Andean region constitutes one of a few areas of first-generation state development in the world. This area therefore represents an important case study for the comparative analysis of state formation. This article outlines the arguments for state formation in South America, presents the evidence, analyzes the underlying assumptions about these arguments, and assesses the South American data in terms of contemporary anthropological theory of state evolution.

  4. Pack Formation In Cycling And Orienteering, Nature Next Article Bookmark and Share

    Excerpt: In cycling and orienteering competitions, competitors can become bunched into packs, which may mask an individual's true ability. Here we model this process with a view to determining when competitors' times are determined more by others than by their own ability. Our results may prove useful in helping to stage events so that pack formation can be avoided.

    We integrated equations of motion in discrete time steps for interacting competitors moving in one dimension from start to finish, with passing allowed.


    1. Peers Under Pressure, Nature Next Article Bookmark and Share

      Excerpt: Other scientists and editors argue that the Internet has helped to reduce abuses. One common fear is that reviewers may be deliberately slow in responding if they wish to delay a rival's paper. But instantaneous communication by e-mail has greatly reduced the scope for reviewers to blame non-delivery of manuscripts and reports for such tardiness. Also, the availability of literature online means that researchers who plagiarize information gained during peer review are more likely to be found out.

  5. What--or Who--Did In the Neandertals?, Science Next Article Bookmark and Share

    Excerpt: (…) Neandertals--who were braving the European ice ages many thousands of years before modern humans arrived on the continent--were more robust and cold adapted than their more slender cousins, whom most researchers consider to be relatively recent arrivals from Africa. But the key difference between the two species, Finlayson suggested, was that modern humans had more "complex social networks" and thus were better at dispersing across the landscape. Neandertals, on the other hand, tended to stay in one locale(…)

  6. Wealth Redistribution With Finite Resources, arXiv Next Article Bookmark and Share

    Abstract: We present a simplified model for the exploitation of finite resources by interacting agents, where each agent receives a random fraction of the available resources. An extremal dynamics ensures that the poorest agent has a chance to change its economic welfare. After a long transient, the system self-organizes into a critical state that maximizes the average performance of each participant. Our model exhibits a new kind of wealth condensation, where very few extremely rich agents are stable in time and the rest stays in the middle class.


    1. Asset-Asset Interactions And Clustering In Financial Markets, Physica A/arXiv Next Article Bookmark and Share

      Abstract: The collective phenomena of a liquid market is characterized in terms of a particle system scenario. This physical analogy enables us to disentangle intrinsic features from purely stochastic ones. The latter are the result of environmental changes due to a `heat bath' acting on the many-asset system, quantitatively described in terms of a time dependent effective temperature. The remaining intrinsic properties can be widely investigated by applying standard methods of classical many body systems. As an example, we consider a large set of stocks traded at the NYSE and determine the corresponding asset--asset `interaction' potential. In order to investigate in more detail the cluster structure suggested by the short distance behavior of the interaction potential, we perform a connectivity analysis of the spatial distribution of the particle system. In this way, we are able to draw conclusions on the intrinsic cluster persistency independently of the specific market conditions.


    2. Stochastic Volatility as a Simple Generator of Financial Power-laws and Long Memory, Working Papers Next Article Bookmark and Share

      Abstract: There has been renewed interest in power-laws and various types of self-similarity in many financial time series. Most of these tests are visual in nature, and do not consider a wide range of possible candidate stochastic models capable of generating the observed results. This paper presents a relatively simple stochastic volatility model which is able to display power laws and scale invariance similar to actual financial data even though it constructed to have none of these properties. The primary mechanism is that volatility is assumed to have a driving process with a half life that is long relative to the tested aggregation ranges. It is argued that this might be a reasonable feature for financial, and other macroeconomic time series.

      Editor's Note: The explicit use of exponential timescales in discrete, stochastic models might potentially provide some insight into the robustness of financial systems and possible routes for their control.


  7. Excitability of Human Axons, Clinical Neurophysiology Next Article Bookmark and Share

    Excerpt: The excitability of human axons can be studied reliably using the technique of threshold tracking, which allows the strength of a test stimulus to be adjusted by computer to activate a defined fraction of the maximal nerve or muscle action potential. The stimulus current that just evokes the target response is considered the 'threshold' for that response (…). Each of these measurements depends on membrane potential and on other biophysical properties of the axons. Together they can provide new information about the pathophysiology underlying abnormalities in excitability in neuropathy.

  8. Modeling And Simulation In Clinical Drug Development, Drug Discovery Today Next Article Bookmark and Share

    Abstract: There is a growing need to (…) use technologies that can both increase and more efficiently facilitate the flow of products through the development pipeline. This article describes how the twin processes of modeling and simulation are being used to improve the efficiency of the clinical drug-development process, and consequently how these methodologies have delivered significant benefits in the drive to save time, money (and additionally assisted in ensuring an 'optimal quality' drug label) in the development of novel therapeutic agents.

  9. General Criterion For Controllable Conformational Transitions Of Single And Double Stranded DNA, arXiv Next Article Bookmark and Share

    Abstract: Chain-like macromolecules in solution, whether biological or synthetic, transform from a spatially extended conformation to a compact one upon change of temperature or solvent qualities. This sharp transition plays a key role in various phenomena, including DNA condensation, protein folding, and the behaviour of polymer solutions. In biological processes such as DNA condensation the collapse is sensitively induced by a small amount of added molecules. Here we derive a general criterion for the effect of such agents on conformational transitions. We find two different scenarios depending on chain stiffness. If the persistence length -the characteristic distance along which the chain retains its direction-is smaller than the range of attractive correlations induced by the agent (typically up to several nanometres), the chain contracts gradually.

    Stiffer chains undergo sharp collapse. We thereby suggest that the enhanced rigidity of double-stranded DNA as compared to the single strand is a prerequisite for sharp, controllable conformational transitions.


  10. The Quandary of Quantum Information, Science Next Article Bookmark and Share

    Excerpts: A second quirk of qubits that makes the quantum computer incredibly powerful is entanglement. (…) In principle, this more-than-the-sum-of-their-parts effect allows qubits to be linked into larger and larger quantum systems capable of storing staggering amounts of information. Two entangled qubits can be equivalent to four sets of two bits--(0, 0), (0, 1), (1, 0), and (1, 1)--all at once. Three entangled qubits are equivalent to the eight different combinations of three bits all at once, and so on and so on exponentially.

    1. Exp. Realization of Noiseless Subsystems for Quantum Information Proc, Science Next Article Bookmark and Share

      Excerpts: We demonstrate the protection of one bit of quantum information against all collective noise in three nuclear spins. Because no subspace of states offers this protection, the quantum bit was encoded in a proper noiseless subsystem. We therefore realize a general and efficient method for protecting quantum information. Robustness was verified for a full set of noise operators that do not distinguish the spins. Verification relied on the most complete exploration of engineered decoherence to date. The achieved fidelities show improved information storage (…).

    2. A Quantum Conversation, S, cience Next Article Bookmark and Share

      Excerpts: Bob: Hey, I'm just a biologist! (…) After all, biological systems use analog values so that instead of being limited to just 0s and 1s, they can take advantage of continuous degrees of freedom to let a signal be somewhere in between, say 1/3 or 3/4.

      Alice: (…) You are right, though, that part of the power of a quantum computer lies in its ability to continuously represent an arbitrary mixture of states.


  11. Computer Networks As Social Networks, S, cience Next Article Bookmark and Share

    Excerpt: Computer networks are inherently social networks, linking people, organizations, and knowledge. They are social institutions that should not be studied in isolation but as integrated into everyday lives. The proliferation of computer networks has facilitated a deemphasis on group solidarities at work and in the community and afforded a turn to networked societies that are loosely bounded and sparsely knit. The Internet increases people's social capital, increasing contact with friends and relatives who live nearby and far away.

  12. Answering Subcognitive Turing Test Questions, CogPrints Next Article Bookmark and Share

    Abstract: Robert French has argued that a disembodied computer is incapable of passing a Turing Test that includes subcognitive questions. Subcognitive questions are designed to probe the network of cultural and perceptual associations that humans naturally develop as we live, embodied and embedded in the world. In this paper, I show how it is possible for a disembodied computer to answer subcognitive questions appropriately, contrary to French’s claim. My approach to answering subcognitive questions is to use statistical information extracted from a very large collection of text. In particular, I show how it is possible to answer a sample of subcognitive questions taken from French, by issuing queries to a search engine that indexes about 350 million Web pages. This simple algorithm may shed light on the nature of human (sub-) cognition, but the scope of this paper is limited to demonstrating that French is mistaken: a disembodied computer can answer subcognitive questions.

    Contributing Editor's Note: The idea of using the information found in the World Wide Web for simulating subcognitive intelligence, instead of hand-feeding huge knowledge bases is very interesting. But the information found on the Web is different from the one we have in our minds. Perhaps further development of this idea might lead to a different kind of intelligence (i.e. nor human nor animal).


    1. Entropic Entropic Analysis Of The Role Of Words In Literary Texts, arXiv Next Article Bookmark and Share

      Abstract: Beyond the local constraints imposed by grammar, words concatenated in long sequences carrying a complex message show statistical regularities that may reflect their linguistic role in the message. In this paper, we perform a systematic statistical analysis of the use of words in literary English corpora. We show that there is a quantitative relation between the role of content words in literary English and the Shannon information entropy defined over an appropriate probability distribution. Without assuming any previous knowledge about the syntactic structure of language, we are able to cluster certain groups of words according to their specific role in the text.


  13. Machine Learning for Science: State of the Art and Future Prospects, Science Next Article Bookmark and Share

    Excerpt: Recent advances in machine learning methods, along with successful applications across a wide variety of fields such as planetary science and bioinformatics, promise powerful new tools for practicing scientists. This viewpoint highlights some useful characteristics of modern machine learning methods and their relevance to scientific applications. We conclude with some speculations on near-term progress and promising directions.

    Machine learning (ML) is the study of computer algorithms capable of learning to improve their performance of a task on the basis of their own previous experience.


    1. Pathway Databases: A Case Study in Computational Symbolic Theories, Science Next Article Bookmark and Share

      Excerpts: A pathway database (DB) is a DB that describes biochemical pathways, reactions, and enzymes. The EcoCyc pathway DB (see http://ecocyc.org) (…)is an example of a computational symbolic theory, which is a DB that structures a scientific theory within a formal ontology so that it is available for computational analysis. It is argued that by encoding scientific theories in symbolic form, we open new realms of analysis and understanding for theories that would otherwise be too large and complex for scientists to reason with effectively.


  14. Blazing Pathways Through Genetic Mountains, Science Next Article Bookmark and Share

    Excerpt: It is now widely accepted that high-throughput data sources will shed essential understanding on the inner workings of cellular and organism function. One key challenge is to distill the results of such experiments into an interpretable computational form that will be the basis of a predictive model. A predictive model represents the gold standard in understanding a biological system and will permit us to investigate the underlying cause of diseases and help us to develop therapeutics.


  15. Flirting with Catastrophe, Science Next Article Bookmark and Share

    Excerpt: Wales (1) uses catastrophe theory to analyze the reaction path followed by atomic and molecular clusters that are undergoing a conformational change from one local minimum to another. Such a path passes through a transition point (a saddle of index d = 1). If the local minima are geometrically and energetically distinct, the path is asymmetrical and the transition point generally more closely resembles the energetically higher of the two minima. This empirical rule is known as Hammond's postulate.

    1. A Microscopic Basis for the Global Appearance of Energy Landscapes, Science Next Article Bookmark and Share

      Excerpt: It is shown that the appearance of a multidimensional potential energy surface, or potential energy landscape, can be related to the form of the interatomic or intermolecular potential. Catastrophe theory enables us to describe how the geometry of the surface changes with parameters (…). The principal result is an unexpected connection between barrier heights, path lengths, and vibrational frequencies, with applications to a wide variety of problems in chemical physics, ranging from Hammond's postulate in organic chemistry, to the relaxation dynamics of complex systems such as glasses and biomolecules.

  16. Artificial Ants Solve Network Problems, BBC News Next Article Bookmark and Share

    Excerpt: The artificial ants were let loose on simulations of the US National Science Foundation network and the telecommunications network run by NTT in Japan.

    At periodic intervals, artificial ants were let loose from each node on these networks and told to find a route to a given destination. (...)

    When congestion was simulated on the artificial networks, the ants beat all the other popular routing systems in the speed with which they reconfigured the network to avoid the traffic jams.


  17. Better Searching Through Science, Science Next Article Bookmark and Share

    Excerpt: In the beginning, the Web was without form, and void. Vast heaps of information grew upon the deep, and it was good for one's desktop. But users across the land were befuddled and could not find their way. There arose the tribes of the Yahoos, the HotBots, and the AltaVistas to bring order out of chaos. Google and CiteSeer prospered and lent guidance. But researchers and scientists, learned ones who had built the Web in their own image, yearned for something more. ...

  18. Mathematical Fortune Telling, Complexity Next Article Bookmark and Share

    Abstract: This is an informal introduction to the physics of dynamical systems and chaos at the level of (...) state-vector, phase-space, and strange attractor are defined and illustrated. Subsequently, we describe a method to produce forecasts for the behavior of complex nonlinear systems using the past behavior of the system. Finally, examples are provided to illustrate the practical utility of the method. Examples include: forecasting of presidential elections; the logistic (…) lending, insurance, quality control, noise-reduction, and pattern recognition.

  19. Sensory Perceptions, The Scientist Next Article Bookmark and Share

    Excerpt: The mapped human and mouse genomes, and advances in molecular biology, are catapulting senses research. With these new concepts and tools, scientists can focus on the specific genes and proteins within the sensory neurons. (…) understanding the connections between the senses and the brain, (…) how these connections are made over a lifetime.
    > "Loss of a sense disrupts the information that we need to interact with our environments, but even worse, it disrupts the information we need to interact with each other. (...) can rob us of pleasure and diminish the quality of our lives."

  20. Links & Snippets Next Article Bookmark and Share

    1. Other Articles Next Article Bookmark and Share

      1. The World-Wide Telescope, Alexander Szalay and Jim Gray, Science 2001 293: 2037
      2. Dissociation Between Hand Motion And Population Vectors From Neural Activity In Motor Cortex, S H Scott, P L Gribble, K M Graham & D W Cabel, Nature 413, 161 - 165 (2001)
      3. Artificial Intelligence And A-Life, New Scientist, 2001
      4. Effects Of Regulation On A Self-Organized Market, G. Cuniberti, A. Valleriani, J. L. Vega, Quantitative Finance 1, 332-335 (2001), arXiv cond-mat/0108533
      5. Cell Phone Health Risk Cannot Be Dismissed, WHO Says, MedScape, 2001

      1. The World-Wide Telescope, Science Next Article Bookmark and Share

        Editor's Note: The terrorist attacks against the World Trade Center and the Pentagon already had enormous consequences not only in the U.S. The U.S. government named Osama bin Laden and his al-Qaeda organisation as the main suspect for the attack. The organization of al-Qaeda as a network of semi-autonomous cells with a world-wide distribution has many similarities with a complex, adaptive system. The past terror attacks, that were attributed to bin Laden had one thing in common: they caught the victims by surprise and the method and location of the attacks always changed.

        The immediate response to the attack, however, seemed to follow the traditional method of "preparing for the last war": Jet fighters closely protected the airspace over New York and Washington AFTER the attack, and airport security was tightened to a degree that old ladies had to give up their nail clippers and airport cafeterias had their plastic knives confiscated (personal observation at Detroit airport on 9/16/01). On an international level it is not clear what the consequences of a military campaign against countries like Afghanistan might be.

        We see this situation as a major challenge for any researcher in the field of complex adaptive system. We invite our readers to send us suggestions and/or links to potential contributions that Complex Systems might contribute in solving the global terrorism problem.


      2. Dissociation Between Hand Motion And Population Vectors From Neural Activity In Motor Cortex, Nature Bookmark and Share


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