bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EPIDEMIOLOGY OF PSYCHIATRIC DISORDERS AND THE DE FACTO MENTAL HEALTH CARE SYSTEM
Authors: Norquist, M.D., M.S.P.H Garyson S. , Regier, M.D., M.P.H Darrel A.
Published: July 2002

▪ Abstract  Recent national epidemiologic studies have provided data on the number of people in the United States with mental and addictive disorders. Many of these people receive their care in the general medical care sector. This has important implications for diagnosis and treatment of mental and addictive disorders.
THE LUPUS ANTICOAGULANT/ANTIPHOSPHOLIPID SYNDROME
Authors: Shapiro, M.D Sandor S.
Published: July 2002

▪ Abstract  Lupus anticoagulants and anticardiolipin antibodies have been strongly associated with the risk of thrombosis, recurrent fetal loss, thrombocytopenia, and a number of other clinical manifestations that together have been referred to as the antiphospholipid syndrome. Despite growing evidence of the significance of this relationship, the pathogenetic mechanisms involved are largely unknown. Recent data suggest strongly that lupus anticoagulants (LACs) and anticardiolipin antibodies (ACAs) are antibodies to protein-phospholipid complexes rather than to phospholipids, as had originally been thought, and that other protein-phospholipid complexes, not recognized by standard assays for LACs or ACAs, may also exist in patients with the antiphospholipid syndrome. Although very recent experimental data may lead to new therapeutic approaches in this syndrome, at present we can only deal with the thrombotic risk by the use of long-term anticoagulation. This chapter reviews current methods of diagnosis, concepts of pathogenesis, and the basis for an approach to anticoagulation in patients at risk for thrombosis or other manifestations of the antiphospholipid syndrome.
PATHOGENESIS AND MANAGEMENT OF ACUTE PROMYELOCYTIC LEUKEMIA
Authors: Warrell Raymond P.
Published: July 2002

▪ Abstract  Acute promyelocytic leukemia, formerly a highly lethal disease, was recently shown to be highly responsive to treatment with the natural retinoid, all-trans retinoic acid. This compound induces terminal differentiation of the malignant cells and produces complete remission in most patients with this disease. The clinical response is due in part to the presence of a chromosomal break that occurs in a gene that encodes a nuclear retinoic acid receptor.
Functional Neuroimaging Studies of Depression: The Anatomy of Melancholia
Authors: Drevets Wayne C.
Published: July 2002

Functional brain imaging techniques, which permit noninvasive measures of neurophysiology and neuroreceptor binding, are powerful and sensitive tools for research aimed at elucidating the pathophysiology of major depression. The application of these technologies in depression research has produced several studies of resting cerebral blood flow (BF) and glucose metabolism in subjects imaged during various phases of illness and treatment. This review examines these data and the principles relevant to their interpretation and discusses the insights they provide into the anatomical correlates of depression. Within the anatomical networks implicated in emotional processing by other types of evidence, these BF and metabolic data demonstrate that major depression is associated with reversible, mood state–dependent, neurophysiological abnormalities in some structures and irreversible, trait-like abnormalities in other structures. In some of the regions in which trait-like abnormalities appear, abnormal metabolic activity appears at least partly related to the anatomical abnormalities identified in magnetic resonance imaging (MRI) studies of depression.
Novel Platelet Inhibitors
Authors: Bennett Joel S.
Published: July 2002

▪ Abstract  Platelet-inhibitory drugs are of proven benefit to individuals who suffer from atherosclerotic cardiovascular disease. Despite substantial effort to identify more potent platelet-inhibitory agents, aspirin, an irreversible inhibitor of platelet cyclooxygenase activity, remains the standard against which other drugs are judged. Drugs that appear to be at least as efficacious as aspirin in specific clinical settings include the thienopyridines ticlopidine and clopidogrel, specific inhibitors of ADP-stimulated platelet function, and the phosphodiesterase 3 inhibitor cilostazol. Ligand binding to the platelet integrin αIIbβ3 (GPIIb-IIIa), a prerequisite for platelet thrombus formation, has been a prominent target for drug development. Currently, three types of αIIbβ3 antagonists are available: the monoclonal antibody Fab fragment abciximab, cyclic peptides based on the Arg-Gly-Asp (RGD) or related amino acid motifs, and RGD-based peptidomimetics. The efficacy of each type of αIIbβ3 antagonist in the setting of acute coronary artery disease has been confirmed in multicenter clinical trials.
DEVELOPMENTAL PLASTICITY IN NEURAL CIRCUITS FOR A LEARNED BEHAVIOR
Authors: Bottjer Sarah W. , Arnold Arthur P.
Published: July 2002

▪ Abstract  The neural substrate underlying learned vocal behavior in songbirds provides a textbook illustration of anatomical localization of function for a complex learned behavior in vertebrates. The song-control system has become an important model for studying neural systems related to learning, behavior, and development. The song system of zebra finches is characterized by a heightened capacity for both neural and behavioral change during development and has taught us valuable information regarding sensitive periods, rearrangement of synaptic connections, topographic specificity, cell death and neurogenesis, experience-dependent neural plasticity, and sexual differentiation. The song system differs in some interesting ways from some well-studied mammalian model systems and thus offers fresh perspectives on specific theoretical issues. In this highly selective review, we concentrate on two major questions: What are the developmental changes in the song system responsible for song learning and the restriction of learning to a sensitive period, and what factors explain the highly sexually dimorphic development of this system? We discuss the important role of sex steroid hormones and of neurotrophins in creating a male-typical neural song circuit (which can learn to produce complex vocalizations) instead of a reduced, female-typical song circuit that does not produce learned song.
THEHEALTHBENEFITS OFWINE
Authors: German J. Bruce , Walzem Rosemary L.
Published: July 2002

▪ Abstract  Epidemiologic studies from numerous disparate populations reveal that individuals with the habit of daily moderate wine consumption enjoy significant reductions in all-cause and particularly cardiovascular mortality when compared with individuals who abstain or who drink alcohol to excess. Researchers are working to explain this observation in molecular and nutritional terms. Moderate ethanol intake from any type of beverage improves lipoprotein metabolism and lowers cardiovascular mortality risk. The question now is whether wine, particularly red wine with its abundant content of phenolic acids and polyphenols, confers additional health benefits. Discovering the nutritional properties of wine is a challenging task, which requires that the biological actions and bioavailability of the >200 individual phenolic compounds be documented and interpreted within the societal factors that stratify wine consumption and the myriad effects of alcohol alone. Further challenge arises because the health benefits of wine address the prevention of slowly developing diseases for which validated biomarkers are rare. Thus, although the benefits of the polyphenols from fruits and vegetables are increasingly accepted, consensus on wine is developing more slowly. Scientific research has demonstrated that the molecules present in grapes and in wine alter cellular metabolism and signaling, which is consistent mechanistically with reducing arterial disease. Future research must address specific mechanisms both of alcohol and of polyphenolic action and develop biomarkers of their role in disease prevention in individuals.
SURFACE BIOLOGY OF DNA BY ATOMIC FORCE MICROSCOPY
Authors: Hansma Helen G
Published: July 2002

▪ Abstract  The atomic force microscope operates on surfaces. Since surfaces occupy much of the space in living organisms, surface biology is a valid and valuable form of biology that has been difficult to investigate in the past owing to a lack of good technology. Atomic force microscopy (AFM) of DNA has been used to investigate DNA condensation for gene therapy, DNA mapping and sizing, and a few applications to cancer research and to nanotechnology. Some of the most exciting new applications for atomic force microscopy of DNA involve pulling on single DNA molecules to obtain measurements of single-molecule mechanics and thermodynamics.
ADRENOMEDULLIN AND THE CONTROL OF FLUID AND ELECTROLYTE HOMEOSTASIS
Authors: Samson Willis K.
Published: July 2002

▪ Abstract  Two potent hypotensive peptides, adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP), are encoded by the adrenomedullin gene. AM stimulates nitric oxide production by endothelial cells, whereas PAMP acts presynaptically to inhibit adrenergic nerves that innervate blood vessels. Complementary, but mechanistically unique, actions also occur in the anterior pituitary gland where both peptides inhibit adrenocorticotropin release. In the adrenal gland both AM and PAMP inhibit potassium and angiotensin II-stimulated aldosterone secretion. Natriuretic and diuretic actions of AM reflect unique actions of the peptide on renal blood flow and tubular function. In the brain AM inhibits water intake and, in a physiologically relevant manner, salt appetite. Both AM and PAMP act in the brain to elevate sympathetic tone, effects that mirror the positive inotropic action of AM in the heart. Cardioprotective actions in the brain and heart may be important counter-regulatory actions that buffer the extreme hypotensive actions of the peptides when released in sepsis. Thus the biologic actions of the proadrenomedullin-derived peptides seem well coordinated to contribute to the physiologic regulation of volume and electrolyte homeostasis.
STRUCTURE AND EVOLUTION OF THErp1 COMPLEXCONFERRING RUST RESISTANCE IN MAIZE
Authors: Hulbert S. H.
Published: July 2002

▪ Abstract  Genetic analyses of the rp1 rust resistance complex of maize have demonstrated that recombination plays a central role in the creation of genetic diversity at the locus. The generation of rp1 diversity is promoted by a high rate of intragenic recombination coupled with a tendency for genes in the complex to mispair in meiosis. Among the novel rp1 genes that have been identified include genes with novel race-specificities and genes conferring lesion mimic phenotypes. Recombinants have also been identified that confer partial resistance which is apparently non-race-specific and may be useful in controlling maize rusts in a durable manner.
Globalization and Politics
Authors: Berger Suzanne
Published: July 2002

This chapter reviews the issues at stake in current public and scholarly debates over the impact of changes in the international economy on domestic politics and society. Over the past two decades, there have been dramatic increases in the flow of portfolio capital, foreign direct investment, and foreign exchange trading across borders at the same time as barriers to trade in goods and services have come down. These changes raise many new questions about the effects of trade and capital mobility on the autonomy of nation-states and the relative power in society of various groups. The first signs of realignments within and between political parties of both the left and the right over issues of national independence and trade openness suggest a rich new terrain for political inquiry.
PERSONNEL SELECTION
Authors: Borman Walter C. , Hanson Mary Ann , Hedge Jerry W.
Published: July 2002

▪ Abstract  This chapter reviews literature from approximately mid-1993 through early 1996 in the areas of performance and criteria, validity, statistical and equal opportunity issues, selection for work groups, person-organization fit, applicant reactions to selection procedures, and research on predictors, including ability, personality, assessment centers, interviews, and biodata. The review revolves around three themes: (a) attention toward criteria and models of performance, (b) interest in personality measures as predictors of job performance, and (c) work on the person-organization fit selection model. In our judgment, these themes merge when it is recognized that development of performance models that differentiate criterion constructs reveal highly interpretable relationships between the predictor domain (i.e. ability, personality, and job knowledge) and the criterion domain (i.e. technical proficiency, extra-technical proficiency constructs such as prosocial organizational behavior, and overall job performance). These and related developments are advancing the science of personnel selection and should enhance selection practices in the future.
DEDUCTIVE REASONING
Authors: Johnson-Laird P. N.
Published: July 2002

▪ Abstract  This chapter describes the main accounts of deductive competence, which explain what is computed in carrying out deductions. It argues that people have a modicum of competence, which is useful in daily life and a prerequisite for acquiring logical expertise. It outlines the three main sorts of theory of deductive performance, which explain how people make deductions: They rely on factual knowledge, formal rules, or mental models. It reviews recent experimental studies of deductive reasoning in order to help readers to assess these theories of performance.
PREVENTING LEAD POISONING IN CHILDREN
Authors: Silbergeld Ellen K.
Published: July 2002

▪ Abstract  Lead poisoning is the most significant and prevalent disease of environmental origin among US children. Despite over 100 years' knowledge of the special hazards of lead exposure for young children, it has taken over a century for effective primary prevention to be adopted. Obstacles to primary prevention have included deliberate campaigns by industry to prevent restrictions upon such uses on lead as plumbing, paints, and gasoline additives; influence of industrial support of biomedical research at major US medical schools; lack of appropriate policy mechanisms to identify and control lead exposures; and opposition to investing resources in lead poisoning prevention. The removal of lead from gasoline, which began in the United States in 1972 and was completed in 1995, has resulted in almost fourfold reductions in median blood lead levels in US children from 1976 to 1991. Increased screening and interventions to identify and abate lead sources, such as lead in housing, also contributed to this major public health success. Nevertheless, lead exposures remain prevalent, although increasingly less generally distributed. Perhaps because of the renewed “ghettoization” of lead, support for lead poisoning prevention has waned. Objections to investing public and private resources in screening and source abatement have challenged the continuing commitment of public health officials to prevention. The demonstrable success and social benefits of preventing lead toxicity are cited in support of continued preventive health policies.
The Effects of Changing Weather on Public Health
Authors: Patz Jonathan A. , Engelberg David , Last John
Published: July 2002

▪ Abstract  Many diseases are influenced by weather conditions or display strong seasonality, suggestive of a possible climatic contribution. Projections of future climate change have, therefore, compelled health scientists to re-examine weather/disease relationships. There are three projected physical consequences of climate change: temperature rise, sea level rise, and extremes in the hydrologic cycle. This century, the Earth has warmed by about 0.5 degrees centigrade, and the mid-range estimates of future temperature change and sea level rise are 2.0 degrees centigrade and 49 centimeters, respectively, by the year 2100. Extreme weather variability associated with climate change may especially add an important new stress to developing nations that are already vulnerable as a result of environmental degradation, resource depletion, overpopulation, or location (e.g. low-lying coastal deltas). The regional impacts of climate change will vary widely depending on existing population vulnerability. Health outcomes of climate change can be grouped into those of: (a) direct physical consequences, e.g. heat mortality or drowning; (b) physical/chemical sequelae, e.g. atmospheric transport and formation of air pollutants; (c) physical/biological consequences, e.g. response of vector- and waterborne diseases, and food production; and (d) sociodemographic impacts, e.g. climate or environmentally induced migration or population dislocation. Better understanding of the linkages between climate variability as a determinant of disease will be important, among other key factors, in constructing predictive models to guide public health prevention.
Observer Agreement in the Angiographic Assessment of Arteriovenous Malformations of the Brain
Authors: Al-Shahi Rustam , Pal Nandita , Lewis Steff C. , Bhattacharya Jo J. , Sellar Robin J. , Warlow Charles P. ,   the AVM Observer Agreement Study Group
Published: July 2002

Purpose

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We aimed to determine intraobserver and interobserver agreement in the characterization of brain arteriovenous malformation (AVM) angioarchitecture on intra-arterial digital subtraction angiograms.

Methods

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Five experienced interventional neuroradiologists independently reviewed 40 anonymized angiograms obtained at the time of first-ever AVM diagnosis. The allocation of the films to observers was balanced for AVM size and complexity. Every observer was compared with himself and all the others by distributing the films in 2 batches 3 months apart. The observers used standard forms to collect both quantitative and categorized qualitative angiographic data. To measure agreement we used the kappa statistic (κ) for nominal data, weighted κ for ordinal and discrete interval data, and Bland & Altman analysis for continuous data.

Results

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Intraobserver agreement was generally moderate to substantial, with 95% confidence intervals ranging from fair to almost perfect. However, for every characteristic, interobserver agreement was less than intraobserver agreement. Interobserver agreement was generally slight to moderate, with 95% confidence intervals ranging from less than chance to almost perfect.

Conclusion

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This study demonstrates the need for robust and generalizeable definitions of AVM angioarchitecture and methods of nidus size measurement—with proof of good intraobserver and interobserver agreement—for future efforts to understand the prognosis and best treatment of AVMs.
Living Melodies: Coevolution of Sonic Communication
Authors: Dahlstedt Palle , Nordahl Mats G.
Published: July 2002

The authors have constructed an artificial world of coevolving communicating agents. The behavior of the agents is described in terms of a simple genetic programming framework, which allows the evolution of foraging behavior and movement in order to reproduce, as well as sonic communication. The sound of the entire world is used as musical raw material for the work. Musically interesting and useful structures are found to emerge.
Navajo Verb Stem Position and the Bipartite Structure of the Navajo Conjunct Sector
Authors: Hale Ken
Published: July 2002

The Navajo verb stem appears at the rightmost edge of the verb word. In numerous cases it forms a lexical constituent with a preverb, occurring at the leftmost edge of the surface verb word, much in the manner of Dutch and German verb-particle arrangements in verb-second finite clauses. In Navajo the initial and final positions are separated by eight morpheme order “slots” recognized in the Athabaskan literature (and described in detail for Navajo in Young and Morgan 1987). A phonological solution to this and a number of other deep-surface disparities is explored here, based on the insights of earlier works on the Navajo verb, including Speas 1984, 1990, McDonough 1996, 2000, and Rice 1989, 2000.
Alignment in Manam Stress
Authors: Buckley Eugene
Published: July 2002

Derivational analyses of Manam stress, in particular that of Halle and Kenstowicz (1991), employ abstract intermediate representations to account for the interaction of the basic right-to-left trochaic foot structure, the special status of extrametrical suffixes and clitics, and the disrupting effect of “stress shift” caused by closed syllables and vowels in hiatus. Such analyses are empirically inadequate, failing to account for secondary stress, and theoretically problematic, using ad hoc rules to produce the necessary effects. The analysis presented here uses alignment in Optimality Theory to generate the basic stress pattern and two well-motivated constraints, ONSET and CLASH, to account for stress shift in a natural way.
A Computational Model of Information Processing in the Frontal Cortex and Basal Ganglia
Authors: Amos Andrew
Published: July 2002

Performance on the Wisconsin Card Sort Test (WCST) of patients with schizophrenia, Parkinson's disease (PD), and Huntington's disease (HD) was simulated by a neural network model constructed on principles derived from neuroanatomic loops from the frontal cortex through the basal ganglia and thalamus. The model provided a computational rationale for the empirical pattern of perseverative errors associated with frontal cortex dysfunction and random errors associated with striatal dysfunction. The model displayed perseverative errors in performance when the gain parameter of the activation function in units representing frontal cortex neurons was reduced as an analog of reduced dopamine release. Random errors occurred when the gain parameter of the activation function in units representing striatal neurons was reduced, or when the activation level was itself reduced as an analog of a striatal lesion. The model demonstrated that the perseveration of schizophrenic, Huntington's, and demented Parkinsonian patients may be principally due to ineffective inhibition of previously learned contextual rules in the frontal cortex, while the random errors of Parkinson's and Huntington's patients are more likely to be due to unsystematic errors of matching in the striatum. The model also made specific, empirically falsifiable predictions that can be used to explore the utility of these putative mechanisms of information processing in the frontal cortex and basal ganglia.
Neural Specialization for Letter Recognition
Authors: Polk Thad A. , Stallcup Matthew , Aguirre Geoffrey K. , Alsop David C. , D'Esposito Mark , Detre John A. , Farah Martha J.
Published: July 2002

Functional magnetic resonance imaging (fMRI) was used to estimate neural activity while subjects viewed strings of consonants, digits, and shapes. An area on or near the left fusiform gyrus was found that responded significantly more to letters than digits. Similar results were obtained when consonants were used whose visual features were matched with the digits and when an active matching task was used, suggesting that the results cannot be easily attributed to artifacts of the stimuli or task. These results demonstrate that neural specialization in the human brain can extend to a category of stimuli that is culturally defined and that is acquired many years postnatally.
The Impact of Spike Timing Variability on the Signal-Encoding Performance of Neural Spiking Models
Authors: Manwani Amit , Steinmetz Peter N. , Koch Christof
Published: July 2002

It remains unclear whether the variability of neuronal spike trains in vivo arises due to biological noise sources or represents highly precise encoding of temporally varying synaptic input signals. Determining the variability of spike timing can provide fundamental insights into the nature of strategies used in the brain to represent and transmit information in the form of discrete spike trains. In this study, we employ a signal estimation paradigm to determine how variability in spike timing affects encoding of random time-varying signals. We assess this for two types of spiking models: an integrate-and-fire model with random threshold and a more biophysically realistic stochastic ion channel model. Using the coding fraction and mutual information as information-theoretic measures, we quantify the efficacy of optimal linear decoding of random inputs from the model outputs and study the relationship between efficacy and variability in the output spike train. Our findings suggest that variability does not necessarily hinder signal decoding for the biophysically plausible encoders examined and that the functional role of spiking variability depends intimately on the nature of the encoder and the signal processing task; variability can either enhance or impede decoding performance.
Optimization of the Kernel Functions in a Probabilistic Neural Network Analyzing the Local Pattern Distribution
Authors: Galleske I. , Castellanos J.
Published: July 2002

This article proposes a procedure for the automatic determination of the elements of the covariance matrix of the gaussian kernel function of probabilistic neural networks. Two matrices, a rotation matrix and a matrix of variances, can be calculated by analyzing the local environment of each training pattern. The combination of them will form the covariance matrix of each training pattern. This automation has two advantages: First, it will free the neural network designer from indicating the complete covariance matrix, and second, it will result in a network with better generalization ability than the original model. A variation of the famous two-spiral problem and real-world examples from the UCI Machine Learning Repository will show a classification rate not only better than the original probabilistic neural network but also that this model can outperform other well-known classification techniques.
GABAergic Inhibitory Control of the Transient and Sustained Components of Orientation Selectivity in a Model Microcolumn in Layer 4 of Cat Visual Cortex
Authors: Bush Paul , Priebe Nicholas
Published: July 2002

Recently proposed models of orientation tuning in layer 4 of cat primary visual cortex (Somers, Nelson, & Sur, 1995; Douglas, Koch, Mahowald, Martin, & Suarez, 1995) rely on widespread inhibitory intracortical connections to suppress the nonoptimal component of a broadly tuned thalamic input, while local excitatory intracortical connections amplify the optimal component. However, new experimental data (Ferster, Chung, & Wheat, 1996) and theoretical analyses (Ferster, 1987; Krukowski, Priebe, & Miller, 1996) show that the temporally modulated component of thalamic input is well tuned and that the cortical circuitry must simply subtract an unmodulated DC component at nonoptimal orientations to obtain sharp tuning. In addition, within a single hypercolumn in layer 4, inhibitory and excitatory layer 4 neurons have approximately equal-sized axonal fields, making the most of their synapses within their own dendritic field (Kisvarday, Martin, Whitteridge, & Somogyi, 1985; Martin & Whitteridge, 1984). We have constructed a model of a single microcolumn in which GABAB inhibition subtracts the DC and controls the sustained response, while GABAA inhibition controls the response to transient and suprathreshold inputs. The model fits experimental data based on stimulation with drifting sine-wave gratings as well as flashed bars, explains a counterintuitive property of the GABAB K+ conductance, and at suboptimal orientations and submaximal contrasts produces an exponential distribution of firing frequencies.
Complex Response to Periodic Inhibition in Simple and Detailed Neuronal Models
Authors: Bernasconi Corrado , Schindler Kaspar , Stoop Ruedi , Douglas Rodney
Published: July 2002

Constant current injection with superimposed periodic inhibition gives rise to phase locking as well as chaotic activity in rat neocortical neurons. Here we compare the behavior of a leaky integrate-and-fire neural model with that of a biophysically realistic model of the rat neuron to determine which membrane properties influence the response to such stimuli. We find that only the biophysical model with voltage-sensitive conductances can produce chaotic behavior.
Interest Management in Large-Scale Virtual Environments
Authors: Morse Katherine L. , Bic Lubomir , Dillencourt Michael
Published: July 2002

Large-scale distributed simulations model the activities of thousands of entities interacting in a virtual environment simulated over wide-area networks. Originally these systems used protocols that dictated that all entities broadcast messages about all activities, including remaining immobile or inactive, to all other entities, resulting in an explosion of incoming messages for all entities, most of which were of no interest. Using a filtering mechanism called interest management, some of these systems now allow entities to express interest in only the subset of information that is relevant to them. This paper surveys ten such systems, describing the purpose of the system, its scope, and the salient characteristics of its interest management scheme. We present the first taxonomy for such systems and classify the ten systems according to the taxonomy. The analysis of the classification reveals the fundamental nature of interest management and points to potential areas of research.
Estimation of Virtually Perceived Length
Authors: Keyson David V.
Published: July 2002

Increasingly, information is presented to users in a spatial domain in which distances and orientation between objects imply some meaning. Perception of distances between objects may be influenced by actual movement through space, and distances may be represented by visual, tactual, or auditory means. This paper examines the judgment of linear path distances that were either tactually, visually, or visually and tactually presented to subjects. Tactual paths were virtually created using force-feed-back fields. Additionally, the influence of a constant simulated-friction force in terms of distance judgments was examined. Based on the method of direct estimation of magnitude, a high correlation between tactual and visual estimates for eight path lengths was found. The results of the tactual condition with simulated friction indicated that the perceived distance between felt objects can be manipulated without requiring longer movements of an input device. In general, results indicated that the spatial relations between objects can be accurately communicated by virtual tactual paths.
Conditions Enabling the Evolution of Inter-Agent Signaling in an Artificial World
Authors: Reggia James A. , Schulz Reiner , Wilkinson Gerald S. , Uriagereka Juan
Published: July 2002

In the research described here we extend past computational investigations of animal signaling by studying an artificial world in which a population of initially noncommunicating agents evolves to communicate about food sources and predators. Signaling in this world can be either beneficial (e.g., warning of nearby predators) or costly (e.g., attracting predators or competing agents). Our goals were twofold: to examine systematically environmental conditions under which grounded signaling does or does not evolve, and to determine how variations in assumptions made about the evolutionary process influence the outcome. Among other things, we found that agents warning of nearby predators were a common occurrence whenever predators had a significant impact on survival and signaling could interfere with predator success. The setting most likely to lead to food signaling was found to be difficult-to-locate food sources that each have relatively large amounts of food. Deviations from the selection methods typically used in traditional genetic algorithms were also found to have a substantial impact on whether communication evolved. For example, constraining parent selection and child placement to physically neighboring areas facilitated evolution of signaling in general, whereas basing parent selection upon survival alone rather than survival plus fitness measured as success in food acquisition was more conducive to the emergence of predator alarm signals. We examine the mechanisms underlying these and other results, relate them to existing experimental data about animal signaling, and discuss their implications for artificial life research involving evolution of communication.
Three Generations of Automatically Designed Robots
Authors: Pollack Jordan B. , Lipson Hod , Hornby Gregory , Funes Pablo
Published: July 2002

The difficulties associated with designing, building, and controlling robots have led their development to a stasis: Applications are limited mostly to repetitive tasks with predefined behavior. Over the last few years we have been trying to address this challenge through an alternative approach: Rather than trying to control an existing machine or create a general-purpose robot, we propose that both the morphology and the controller should evolve at the same time. This process can lead to the automatic design of special-purpose mechanisms and controllers for specific short-term objectives. Here we provide a brief review of three generations of our recent research, which underlies the robots shown on the cover of this issue: Automatically designed static structures, automatically designed and manufactured dynamic electromechanical systems, and modular robots automatically designed through a generative DNA-like encoding.
Could More Force Have Saved the Soviet System?
Authors: Clemens Walter C.
Published: July 2002

One of the leading specialists on the Soviet Union, Jerry Hough, has published a lengthy book analyzing events in the late 1980s and early 1990s that brought about the disintegration of the Soviet state. This essay challenges Hough's interpretations. It finds shortcomings both in his general approach and in many of his specific claims.
IF THE LORD'S ANOINTED HAD LIVED
Authors: Davies Philip
Published: July 2002

The assassination of a Jewish high priest in 171 bce removed the one figure who might have been able to unite the Jews of Judah and successfully mediate between them and the Seleucid king. Had this popular character survived and returned to Judah, the successful revolt of a Maccabean-led Judean faction against the Seleucids would probably not have happened, and there would have been no Hasmonean dynasty, no interlude of national independence and a different history of relations with Rome, one that did not result in loss of land or temple (or priesthood). What kind of Judaism, almost certainly without Christianity (and without Islam?) would have persisted? What kind of religion would a Constantine have officially adopted (if any)? What sort of Western civilization, if any, might have resulted?
SIMPLICIUS OR PRISCIANUS? ON THE AUTHOR OF THE COMMENTARY ON ARISTOTLE'S DE ANIMA (CAG XI): A METHODOLOGICAL STUDY
Authors: Hadot Ilsetraut
Published: July 2002

This article represents a new contribution to the author's debate with C. Steel as to the authenticity of the Commentary on Aristotle's De Anima, attributed by the manuscripts to the 6th-century A.D. Neoplatonist philosopher Simplicius. On the basis of what he claims are stylistic and doctrinal differences between the In DA and Simplicius' other commentaries, Steel has argued that the In DA cannot be by Simplicius, but is instead to be attributed to his contemporary Priscian of Lydia. In the present article, it is argued (1) that the alleged stylistic differences between the In DA and Simplicius' other commentaries can be explained by other considerations: in particular, the vocabulary and style of the Neoplatonist commentators is largely determined by the text commented upon, as well as the level of studies of the audience for whom each commentary is intended. (2) The alleged doctrinal differences between the In DA and Simplicius' other commentaries simply do not exist. Careful examination of Steel's arguments shows that they suffer from serious methodological flaws, including the failure to take into consideration Simplicius' Commentary on the Manual of Epictetus, and the ambiguity of Neoplatonic philosophical terminology. It is concluded that in the whole of Steel's argumentation, there is not one decisive argument which would allow us to conclude that the commentary on the De Anima, attributed by direct and indirect tradition to Simplicius, is inauthentic.
SPRACHLICHE BEOBACHTUNGEN ZU PS. XC 5F.
Authors: Müller Hans-Peter
Published: July 2002

Der Artikel beschäftigt sich mit cruces interpretum in Ps. xc 5f. zeramtām (V.5a) erschließt sich von phöniz. 'zrm „ich wurde fortgerissen“ KAI 14,3.13 her und bedeutet entsprechend „du raffst sie hinweg“. HLP I (5b.6a) meint nicht „vergehen“, sondern „sprießen“, was sich sowohl aus dem Kontext, als auch lexikalisch ergibt. Zur Syntax: zeramtām wird omnitemporal, jihjû (5a) konsekutiv(-final) gebraucht. wehālāp/ wejābāš (6) sind Habitative; Aramaismen liegen nicht vor.
ΣΧΟΙΝΟΣ IN THE SEPTUAGINT
Authors: Aitken James
Published: July 2002

The lexeme σχο νοsigma 'reed, rush' in the LXX denotes a 'pen' once and translates twice the name 'Shittim'. Although some explanation is needed for these instances, they are explicable translations. In Jer. xviii 15, however, the glosses 'reed' or 'measure' do not make sense in the context, and 'way' is probably to be preferred. This would be a metaphorical application of the meaning 'measure', popular in Hellenistic geographers. The same meaning also makes sense of the context of LXX Ps. cxxxviii 3, where 'bed' is the normal gloss suggested. The meaning 'bed' is derived from Schleusner and Brenton, and, although it is not attested elsewhere in Greek, has been adopted by the Supplements to LSJ and even incorrectly categorized there under a gloss with a different denotation. The interpretation of σχο νοsigma as 'way' is supported by similar metaphorical uses in the LXX for words from the semantic field of 'way'.
FUNCTIONAL IMPLICATIONS OF FLUCTUATING ASYMMETRY AMONG ENDEMIC POPULATIONS OF GASTEROSTEUS ACULEATUS
Authors: Bergstrom  , Reimchen
Published: July 2002

Fluctuating asymmetry (FA) has been used as a measure of developmental stability across many taxa, with asymmetric individuals presumed to have reduced fitness. FA has also been suggested for use in conservation biology as a measure of the health of populations. Here we assess the suitability of these uses of FA by using a novel measure of asymmetry in the bony lateral plates of threespine stickleback (Gasterosteus aculeatus) from 60 insular and endemic freshwater populations from the Queen Charlotte Islands. The frequency of asymmetric G. aculeatus individuals among populations varied from 1% to 76% with a mean of 42%. Extreme variation in the frequency of asymmetries among lateral plate positions within samples was also observed. Plates important to the structural integrity of predator defences were least asymmetric, either due to selection against asymmetry at these positions or to variation in the temporal development of the plates. These results emphasize the need for caution when interpreting differential levels of FA among traits in individuals and populations, as the differences may be due to variation in the strength or direction of selection for symmetry, and not exclusively to differences in fitness.
COPING IN FEMALE MICE FROM LINES BIDIRECTIONALLY SELECTED FOR MALE AGGRESSION
Authors: R.F.Benus
Published: July 2002

In male house mice, differences have been reported in behavioural strategies to cope with challenges. These differences are related to a differentiation in territorial aggression. In the present study it was investigated whether consistent differences exist in response to challenges among female mice. For this purpose, females from lines selected for male s hort and l ong a ttack l atency in a resident-intruder paradigm were used. SAL females were significantly and consistently more prone to engage a non-social challenge than LAL females, both during development as in adulthood. This was measured in an unfamiliar object test and an open field test. To assess the response of females to social challenges, SAL and LAL dams were confronted with an intruder at regular intervals during the lactation period. SAL as well as LAL dams showed very short attack latencies and there were no differences between SAL and LAL mice. It is suggested that the pup protection function of maternal aggression does not allow the development of significant variation in maternal aggression. This infers that maternal aggression is not a suited parameter to assess the response of female mice to a social challenge.
CYST PRODUCTION IN THE FAIRY SHRIMP, STREPTOCEPHALUS PROBOSCIDEUS (ANOSTRACA) IN RELATION TO ALGAL AND LORICATED ROTIFER DIET
Authors: Sarma  , Dumont  , Ali A. Jawahar
Published: July 2002

Adult fairy shrimps, Streptocephalus proboscideus (Frauenfeld, 1873) reared separately using algae (Scenedesmus acutus Meyen), a large loricate rotifer (Brachionus calyciflorus Pallas, 1766) and mixtures of algal and animal diets (1 : 1 ratio on a dry weight basis) at a rate of 17 mug DW ml 1 day 1 produced a mean number of 184 +/- 38, 111 +/- 14, and 160 +/- 14 cysts per brood, respectively. Of these, the rotifer-only diet was significantly inferior to both other food types. Measurements of cyst volume revealed an effect of food type. With all three types, S. proboscideus produced cysts in the size range of 3.0-9.0 x 106 mum3. However, sizes smaller than 3:0 x 106 mum3 occurred in algae-fed anostracans and those larger than 9:0 x 106 mum3 in rotifer-fed individuals. When the mean cyst production was expressed in terms of volume instead of numbers, there was a suggestion that the mixture of algae and rotifers was the superior combination, while females reared on rotifers produced a significantly (38%) lower total cyst volume. Hatchability of cysts, either dried or un-dried, was not significantly different between treatments. Des adultes de l'Anostrace Streptocephalus proboscideus (Frauenfeld, 1873), ont ete eleves en utilisant separement des algues (Scenedesmus acutus Meyen), un grand rotifere (Brachionus calyciflorus Pallas, 1766) et des melanges d'aliments algaux et animaux (proportion 1 : 1 sur la base du poids sec) a un taux de 17 mug DW ml-1 jour-1. Ils ont produit un nombre moyen de cystes de, respectivement, 184 +/- 38, 111 +/- 14 et 160 +/- 14 par ponte. Parmi ces regimes, celui de rotiferes exclusivement etait significativement inferieur aux deux autres. Les mesures de volume des cystes revelaient un effet du type de nourriture. Avec les trois types, S. proboscideus produisait des cystes dans la gamme de tailles de 3,0-9,0 x 106 mum3. Cependant, des tailles inferieures a 3,0 x 106 mum3 etaient observees chez les Anostraces algivores et des tailles superieures a 9,0 x 106 mum3 chez les individus nourris de rotiferes. Quand la production moyenne de cystes etait exprimee, non en terme de nombre, mains en volume, il semblait que le melange d'algues et de rotiferes etait la meilleure combinaison, alors que les femelles nourries de rotiferes produisaient un volume total de cystes significativement inferieur (38%). La capacite d'eclosion des cystes, seches ou non, ne differait pas de facon significative suivant les traitements.
New records of Criconematoidea (Nematoda) from South Africa, with the description of Criconema zantene n. sp.
Authors: Tiedt Louwrens , Van Den Berg Esther
Published: July 2002

Criconema zantene n. sp., found in the rhizosphere of a Podocarpus sp. tree, is described and illustrated. Females are characterised by having 46-56 body annuli covered with tile-like scales, stylet 101-122 μm long, one lip annulus with a greater diameter than first body annulus, distinct submedian lobes, tooth-like lobes on posterior body annuli with a double row of lobes on first annulus directly posterior to vulva, a sigmoid vagina and an overhanging anterior vulval lip. Second, third and fourth stage juveniles with varying numbers of longitudinal rows of filamented scales on cuticle. Criconema princeps (Andrássy, 1962) Raski & Luc, 1985, Mesocriconema dherdei (De Grisse, 1967) Loof & De Grisse, 1989 and Paratylenchus straeleni (De Coninck, 1931) Oostenbrink, 1960 are reported from South Africa for the first time. These species are briefly discussed, illustrated and morphometrics given. Additional data is given for C. pauciannulatum Van den Berg, 1992.
High-resolution transmission electron microscopy of mixed-layer clays dispersed in PVP-10: a new technique to distinguish detrital and authigenic illitic material
Authors: Uhlík P. , Šucha V. , Elsass F. , Čaplovičová M.
Published: July 2002

The results of a new technique for the measurement of the thickness distribution of fundamental particles are reported. The technique is based on high-resolution transmission electron microscopy (HRTEM) of Na-saturated mixed-layer illite-smectite dispersed in polyvinylpyrrolidone (PVP-10). Intercalation of PVP-10 increases the spacing of expandable interlayers and changes the arrangement of particles so that the number of layers per fundamental particle can be counted easily on HRTEM images. The data obtained by HRTEM on PVP-10-intercalated illite-smectite of hydrothermal origin are compared with data from the Pt-shadowing technique. A good agreement between the two methods for the measured thickness distributions, mean thickness and expandability confirms the reliability of the new technique. The same technique is applied to a set of four sedimentary samples with different expandabilities (83-18%). The thickness of illite particles from shales and claystones has a lognormal distribution. Detrital anddiscrete illite particles can be distinguished from the thickness distribution of authigenic illite.
Textural and geochemical micro-analysis in the interpretation of clay mineral characteristics: lessons from sandstone hydrocarbon reservoirs
Authors: Hurst A.
Published: July 2002

Back-scattered electron images of clay minerals from sandstones are used, together with complementary micro-analytical methods, to identify and quantify mineral microporosity and geochemistry. Clay minerals typically have a range of microporosity from 10 to >90% dependent on texture and paragenesis. Fibrous clays are highly microporous; detrital clays have low microporosity but specific clay minerals have broad ranges of microporosity. The often quoted mineral-chemical association between thorium (Th) and kaolinite cannot be substantiated by micro-analysis. The Th content of clay minerals is associated with micro-inclusions within the kaolinite which form diagenetically or are derived from precursor minerals.