bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Medical Systems
Authors: Mechanic David , Rochefort David A.
Published: July 2002

National health systems throughout the world face a number of pressures in common related to demography, epidemiology, developments in science and technology, medical demand, and rising public expectations. These pressures are producing convergence in the objectives and activities of these systems in several key areas, including cost-containment, health promotion, expansion of access, primary health care, patient choice, and the linkage between health and social services. At the same time, it is also necessary to recognize the role of political and governmental processes, as well as clinical and professional variables, in shaping different societal responses to health care challenges.
Intracellular Na
+
Concentration Is Elevated in Heart Failure But Na/K Pump Function Is Unchanged
Authors: Despa Sanda , Islam Mohammed A. , Weber Christopher R. , Pogwizd Steven M. , Bers Donald M.
Published: July 2002

Background

—

Intracellular sodium concentration ([Na
+
]
i
) modulates cardiac contractile and electrical activity through Na/Ca exchange (NCX). Upregulation of NCX in heart failure (HF) may magnify the functional impact of altered [Na
+
]
i
.

Methods and Results

—

We measured [Na
+
]
i
by using sodium binding benzofuran isophthalate in control and HF rabbit ventricular myocytes (HF induced by aortic insufficiency and constriction). Resting [Na
+
]
i
was 9.7±0.7 versus 6.6±0.5 mmol/L in HF versus control. In both cases, [Na
+
]
i
increased by ≈2 mmol/L when myocytes were stimulated (0.5 to 3 Hz). To identify the mechanisms responsible for [Na
+
]
i
elevation in HF, we measured the [Na
+
]
i
dependence of Na/K pump–mediated Na
+
extrusion. There was no difference in V
max
(8.3±0.7 versus 8.0±0.8 mmol/L/min) or
K
m
(9.2±1.0 versus 9.9±0.8 mmol/L in HF and control, respectively). Therefore, at measured [Na
+
]
i
levels, the Na/K pump rate is actually higher in HF. However, resting Na
+
influx was twice as high in HF versus control (2.3±0.3 versus 1.1±0.2 mmol/L/min), primarily the result of a tetrodotoxin-sensitive pathway.

Conclusions

—

Myocyte [Na
+
]
i
is elevated in HF as a result of higher diastolic Na
+
influx (with unaltered Na/K-ATPase characteristics). In HF, the combined increased [Na
+
]
i
, decreased Ca
2+
transient, and prolonged action potential all profoundly affect cellular Ca
2+
regulation, promoting greater Ca
2+
influx through NCX during action potentials. Notably, the elevated [Na
+
]
i
may be critical in limiting the contractile dysfunction observed in HF.
Circulatory Support for Long-Term Treatment of Heart Failure
Authors: Westaby Stephen , Banning Adrian P. , Saito Satoshi , Pigott David W. , Jin Xu Y. , Catarino Pedro A. , Robson Desiree , Moorjani Narain , Kardos Attila , Poole-Wilson Philip A. , Jarvik Robert , Frazier O.H.
Published: July 2002

Background
—

A lifetime mechanical solution for advanced heart failure must be reliable, with a low risk of life-threatening complications. After extensive laboratory testing, we began clinical trials with an axial flow pump for long-term treatment of New York Heart Association class IV, transplant-ineligible patients.

Methods and Results
—

The Jarvik 2000 is a continuous flow device that is implanted in the apex of the left ventricle with offloading to the descending thoracic aorta. Skull-based percutaneous power delivery was derived from cochlear implant technology. We used this system in 4 patients with end-stage dilated cardiomyopathy. Exercise capacity, quality of life, device parameters, and native heart function were monitored serially. One patient died from right heart failure at 3 months. The other patients were discharged from hospital between 3 and 8 weeks postoperatively and are currently New York Heart Association I or II. Follow-up lasted between 9 and 20 months. There has been no device failure or hemolysis. Native heart function and quality of life were markedly improved.

Conclusions
—

The Jarvik 2000 is a true assist (rather than replacement) device that functions synergistically with the native left ventricle and provides excellent quality of life. Adverse events are infrequent. This blood pump may provide a mechanical solution for end-stage heart failure in the community.
The use of analogies in developing outer space law
Authors: Peterson M. J.
Published: July 2002

Scholars focusing on international relations generally or foreign policy decision making are now paying increasing attention to the ways in which mental constructs—ideas, beliefs, ideologies, or worldviews—affect political actors' perceptions and behavior. The influence of mental constructs in political interaction is particularly visible when actors are trying to extend interaction into new areas or to establish new modes of cooperation. This study will illuminate the impact of mental constructs in these situations by examining the development of outer space law. The Soviets' successful launch of Sputnik in October 1957 shifted outer space from the realm of science fiction and speculation to the realm of real international concerns. Governments were faced with the problem of determining not only what they wanted to do in space but also what sorts of rules for unilateral activity and mutual interaction should prevail there.
Systemic Conflict and Regional Monetary Integration: The Case of Europe
Authors: Henning C. Randall
Published: July 2002

Existing explanations of European monetary integration, emphasizing economic interdependence, issue linkage, institutions, and domestic politics, take a predominantly regional approach. In the international monetary thesis developed here, I argue that U.S. policy disturbances, transmitted through the international monetary system, created compelling incentives for European states to cooperate on exchange-rate and monetary policy. I develop a general theory of macroeconomic power, based on open economy macroeconomics, and show how the exercise of such influence can drive regional monetary integration. This article then tests the international thesis with reference to monetary integration within the European Union by examining four periods in which the United States acted to stabilize the international monetary system and seven episodes in which it disrupted the system. European governments and central banks reduced regional monetary cooperation when the United States supported system stability and strengthened it after each episode of disruption. The evidence thus strongly supports the inference that the link is causal.
Dental Hygiene and Nuclear War: How International Relations Looks from Economics
Authors: Eichengreen Barry
Published: July 2002

This article adopts economics as a perspective from which to view recent research in international relations. The most telling difference between international relations and economics, it argues, is in the connection between theory and empirical work. The strength of economics is the complementary and mutually supporting character of theoretical and empirical work. In international relations, in contrast, the connections between theory and empirics are looser. As a consequence, research in international relations has not converged to a core of common theoretical assumptions and an arsenal of commonly accepted empirical techniques.
On Feature Spreading and the Representation of Place of Articulation
Authors: Halle Morris , Vaux Bert , Wolfe Andrew
Published: July 2002

Since Clements (1985) introduced feature geometry, four major innovations have been proposed: Unified Feature Theory, Vowel-Place Theory, Strict Locality, and Partial Spreading. We set out the problems that each innovation encounters and propose a new model of feature geometry and feature spreading that is not subject to these problems. Of the four innovations, the new model-Revised Articulator Theory (RAT)-keeps Partial Spreading, but rejects the rest. RAT also introduces a new type of unary feature-one for each articulator-to indicate that the articulator is the designated articulator of the segment.
The Principle of Minimal Compliance
Authors: Richards Norvin
Published: July 2002

The syntactic literature discusses a number of phenomena in which a constraint that rules out a certain class of syntactic dependencies fails to rule out structures containing both an ill-formed dependency and a well-formed dependency; well-formed dependencies seem to be able to “help” dependencies that would be ill formed in isolation. In this article I attempt to provide a unified account of these phenomena. I postulate a principle that allows the computational system to “ignore” parts of a syntactic structure that have already been checked with respect to a particular constraint.
Topographic and Temporal Indices of Vowel Spectral Envelope Extraction in the Human Auditory Cortex
Authors: Diesch Eugen , Luce Thomas
Published: July 2002

The audirory-evoked neuromagnetic field elicited by single vowel formants and two-formant vowels was recorded under active listening conditions using a 37-channel magnetometer. There were three single formants with formant with a formant frequency of 200, 400, and 800 Hz, another single fromant with a fromant frequency of 2600 Hz, and three vowels that were constructed by linear superimposition of the high-onto one of the low-frequency formants. P50m and N100m latency values were inversely correlated with the formant frequency of single location was obtained along the postero-anterior axiz, which is orthogonal to the well-established latero-medial tonotopic gradient. Regardless of whether single formants or first formants of vowels were considered N100m sources were more anterior and sustained field sources wre more posterior for higher-frequency than for lower-frequency formants. The velocity of the apparent posterior-to-anterior movement across cortical sorface of N100m sources first reported by Rogers et al. [Rogers, R.L., Papanicolaou, A.C., Baumann, S.B., Saydjari,C., & Eisenberg, H.M. (1990). Neuromagnetic evidence of a dynamic excitation pattern generating the N100 auditory response. Electroencephalography and Clinical Neurophy-siology,77,237-240] decreased as a function of latency. The amount of deceleration was positively correlated with formant frequency. responses to the vowels were superadditive, indicating that the processes elicited by the constituents of composite stumuli interact at one or more stages of the afferent auditory pathway. Such interaction may account for the absence of a lateral-to-medial tonotopic mapping of first formant frequency. The source topography found may reflect activity in auditory fields adjacent to AI with the strenght of the contribution varying with formant frequency. Altematively, it may reflect sharpness-of-tuning and inhbitory response-area asymmetry gradients along isofrequency stripes within AI. Either alternative may be interpreted in terms of a sprctral blurring mechanism that abstracts spectral envelope information form the details of spectral composition, an important step towards the formation of invariant phonetic percepts.
An Empirical Explanation of the Chubb Illusion
Authors: Lotto R. Beau , Purves Dale
Published: July 2002

The perceived difference in brightness between elements of a patterned target is diminished when the target is embedded in a similar surround of higher luminance contrast (the Chubb illusion). Here we show that this puzzling effect can be explained by the degree to which imperfect transmittance is likely to have affected the light that reaches the eye. These observations indicate that this ‘illusion’ is yet another signature of the fundamentally empirical strategy of visual perception, in this case generated by the typical influence of transmittance on inherently ambiguous stimuli.
Visual Priming Within and Across Symbolic Format Using a Tachistoscopic Picture Identification Task: A PET Study
Authors: Lebreton Karine , Desgranges Béatrice , Landeau Brigitte , Baron Jean-Claude , Eustache Francis
Published: July 2002

The present work was aimed at characterizing picture priming effects from two complementary behavioral and functional neuroimaging (positron emission tomography, PET) studies. In two experiments, we used the same line drawings of common living/nonliving objects in a tachistoscopic identification task to contrast two forms of priming. In the within-format priming condition (picture-picture), subjects were instructed to perform a perceptual encoding task in the study phase, whereas in the cross-format priming condition (word-picture), they were instructed to perform a semantic encoding task. In Experiment 1, we showed significant priming effects in both priming conditions. However, the magnitude of priming effects in the same-format/perceptual encoding condition was higher than that in the different-format/semantic encoding condition, while the recognition performance did not differ between the two conditions. This finding supports the existence of two forms of priming that may be subserved by different systems. Consistent with these behavioral findings, the PET data for Experiment 2 revealed distinct priming-related patterns of regional cerebral blood flow (rCBF) decreases for the two priming conditions when primed items were compared to unprimed items. The same-format priming condition involved reductions in cerebral activity particularly in the right extrastriate cortex and left cerebellum, while the different-format priming condition was associated with rCBF decreases in the left inferior temporo-occipital cortex, left frontal regions, and the right cerebellum. These results suggest that the extrastriate cortex may subserve general aspects of perceptual priming, independent of the kind of stimuli, and that the right part of this cortex could underlie the same-format-specific system for pictures. These data also support the idea that the cross-format/semantic encoding priming for pictures represents a form of lexico-semantic priming subserved by a semantic neural network extending from left temporo-occipital cortex to left frontal regions. These results reinforce the distinction between perceptual and conceptual priming for pictures, indicating that different cerebral processes and systems are implicated in these two forms of picture priming.
Wada Testing Reveals Frontal Lateralization for the Memorization of Words and Faces
Authors: Kelley W. M. , Ojemann J. G. , Wetzel R. D. , Derdeyn C. P. , Moran C. J. , Cross D. T. , Dowling J. L. , Miller J. W. , Petersen S. E.
Published: July 2002

Neuroimaging studies have suggested that specific regions of the frontal and medial temporal cortex are engaged during memory formation. Further, there is specialization across these regions such that verbal materials appear to preferentially engage the left regions while nonverbal materials primarily engage the right regions. An open question, however, has been to what extent frontal regions contribute to successful memory formation. The present study investigates this question using a reversible lesion technique known as the Wada test. Patients memorized words and unfamiliar faces while portions of their left and right hemispheres were temporarily anesthetized with sodium amytal. Subsequent memory tests revealed that faces were remembered better than words following left-hemisphere anesthesia, whereas words were remembered better than faces following right-hemisphere anesthesia. Importantly, inspection of the circulation affected by the amytal further suggests that these memory impairments did not result from direct anesthetization of the medial temporal regions. Taken in the context of the imaging findings, these results suggest that frontal regions may also contribute to memory formation in normal performance.
Semantic Category Interference in Overt Picture Naming: Sharpening Current Density Localization by PCA
Authors: Maess Burkhard , Friederici Angela D. , Damian Markus , Meyer Antje S. , Levelt Willem J. M.
Published: July 2002

The study investigated the neuronal basis of the retrieval of words from the mental lexicon. The semantic category interference effect was used to locate lexical retrieval processes in time and space. This effect reflects the finding that, for overt naming, volunteers are slower when naming pictures out of a sequence of items from the same semantic category than from different categories. Participants named pictures blockwise either in the context of same-or mixed-category items while the brain response was registered using magnetoencephalography (MEG). Fifteen out of 20 participants showed longer response latencies in the same-category compared to the mixed-category condition. Event-related MEG signals for the participants demonstrating the interference effect were submitted to a current source density (CSD) analysis. As a new approach, a principal component analysis was applied to decompose the grand average CSD distribution into spatial subcomponents (factors). The spatial factor indicating left temporal activity revealed significantly different activation for the same-category compared to the mixed-category condition in the time window between 150 and 225 msec post picture onset. These findings indicate a major involvement of the left temporal cortex in the semantic interference effect. As this effect has been shown to take place at the level of lexical selection, the data suggest that the left temporal cortex supports processes of lexical retrieval during production.
Semantic Processing of Spoken Words in Alzheimer's Disease: An Electrophysiological Study
Authors: Revonsuo Antti , Portin Raija , Juottonen Kirsi , Rinne Juha O.
Published: July 2002

Patients suffering from Alzheimer's disease (AD) have severe difficulties in tasks requiring the use of semantic knowledge. The semantic deficits associated with AD have been extensively studied by using behavioral methods. Many of these studies indicate that AD patients have a general deficit in voluntary access to semantic representations but that the structure of the representations themselves might be preserved. However, several studies also provide evidence that to some extent semantic representations in AD may in fact be degraded. Recently, a few studies have utilized event-related brain potentials (ERPs) that are sensitive to semantic factors in order to investigate the electrophysiological correlates of the semantic impairment in AD. Interest has focused on the N400 component, which is known to reºect the on-line semantic processing of linguistic and pictorial stimuli. The results from studies of N400 changes in AD remain somewhat controversial: Some studies report normal or enlarged N400 components in AD, whereas others report diminished ones. One issue not reported in previous studies is whether word-elicited ERPs other than N400 remain normal in AD. In the present study our aim was to find out whether the ERP waveforms N1, P2, N400, and Late Positive Component (LPC) to semantically congruous and incongruous spoken words are abnormal in AD and whether such abnormalities specifically reºect deficiencies in semantic activation in AD. Auditory ERPs from 20 scalp sites to semantically congruous and incongruous final words in spoken sentences were recorded from 17 healthy elderly adults and 9 AD patients. The early ERP waveforms N1 and P2 were relatively normal for the AD patients, but the N400 and LPC effects (amplitude difference between congruous and incongruous conditions) were significantly reduced. We interpret the present results as showing that semantic-conceptual activation and other high-level integration processes are defective in AD. However, a word congruity effect earlier than N400 (phonological mismatch negativity), reflecting lexical selection processes, is at least to some extent preserved in AD.
Perseveration and Strategy in a Novel Spatial Self-Ordered Sequencing Task for Nonhuman Primates: Effects of Excitotoxic Lesions and Dopamine Depletions of the Prefrontal Cortex
Authors: Collins P. , Roberts A. C. , Dias R. , Everitt B. J. , Robbins T. W.
Published: July 2002

Damage to the prefrontal cortex disrupts the performance of self-ordered sequencing tasks, although the precise mechanisms by which this effect occurs is unclear. Active working memory, inhibitory control, and the ability to generate and perform a sequence of responses are all putative cognitive abilities that may be responsible for the impaired performance that results from disruption of prefrontal processing. In addition, the neurochemical substrates underlying prefrontal cognitive function are not well understood, although active working memory appears to depend upon an intact mesocortical dopamine system. The present experiments were therefore designed to evaluate explicitly the contribution of each of these abilities to successful performance of a novel spatial self-ordered sequencing task and to examine the contribution of the prefrontal cortex and its dopamine innervation to each ability in turn.

Excitotoxic lesions of the prefrontal cortex of the common marmoset profoundly impaired the performance of the self-ordered sequencing task and induced robust perseverative responding. Task manipulations that precluded perseveration ameliorated the effect of this lesion and revealed that the ability to generate and perform sequences of responses was unaffected by excitotoxic damage to prefrontal cortex. In contrast, large dopamine and noradrenaline depletions within the same areas of prefrontal cortex had no effect on any aspect of the self-ordered task but did impair the acquisition of an active working memory task, spatial delayed response, to the same degree as the excitotoxic lesion. These results demonstrate that a lesion of the ascending monoamine projections to the pre-frontal cortex is not always synonymous with a lesion of the prefrontal cortex itself and thereby challenge existing concepts concerning the neuromodulation of prefrontal cognitive function.
Calculation of Interspike Intervals for Integrate-and-Fire Neurons with Poisson Distribution of Synaptic Inputs
Authors: Burkitt A. N. , Clark G. M.
Published: July 2002

We present a new technique for calculating the interspike intervals of integrate-and-fire neurons. There are two new components to this technique. First, the probability density of the summed potential is calculated by integrating over the distribution of arrival times of the afferent post-synaptic potentials (PSPs), rather than using conventional stochastic differential equation techniques. A general formulation of this technique is given in terms of the probability distribution of the inputs and the time course of the postsynaptic response. The expressions are evaluated in the gaussian approximation, which gives results that become more accurate for large numbers of small-amplitude PSPs. Second, the probability density of output spikes, which are generated when the potential reaches threshold, is given in terms of an integral involving a conditional probability density. This expression is a generalization of the renewal equation, but it holds for both leaky neurons and situations in which there is no time-translational invariance. The conditional probability density of the potential is calculated using the same technique of integrating over the distribution of arrival times of the afferent PSPs. For inputs with a Poisson distribution, the known analytic solutions for both the perfect integrator model and the Stein model (which incorporates membrane potential leakage) in the diffusion limit are obtained. The interspike interval distribution may also be calculated numerically for models that incorporate both membrane potential leakage and a finite rise time of the postsynaptic response. Plots of the relationship between input and output firing rates, as well as the coefficient of variation, are given, and inputs with varying rates and amplitudes, including inhibitory inputs, are analyzed. The results indicate that neurons functioning near their critical threshold, where the inputs are just sufficient to cause firing, display a large variability in their spike timings.
Training Feedforward Neural Networks with Gain Constraints
Authors: Hartman Eric
Published: July 2002

Inaccurate input-output gains (partial derivatives of outputs with respect to inputs) are common in neural network models when input variables are correlated or when data are incomplete or inaccurate. Accurate gains are essential for optimization, control, and other purposes. We develop and explore a method for training feedforward neural networks subject to inequality or equality-bound constraints on the gains of the learned mapping. Gain constraints are implemented as penalty terms added to the objective function, and training is done using gradient descent. Adaptive and robust procedures are devised for balancing the relative strengths of the various terms in the objective function, which is essential when the constraints are inconsistent with the data. The approach has the virtue that the model domain of validity can be extended via extrapolation training, which can dramatically improve generalization. The algorithm is demonstrated here on artificial and real-world problems with very good results and has been advantageously applied to dozens of models currently in commercial use.
Metabolically Efficient Information Processing
Authors: Balasubramanian Vijay , Kimber Don , II Michael J. Berry
Published: July 2002

Energy-efficient information transmission may be relevant to biological sensory signal processing as well as to low-power electronic devices. We explore its consequences in two different regimes. In an “immediate” regime, we argue that the information rate should be maximized subject to a power constraint, and in an “exploratory” regime, the transmission rate per power cost should be maximized. In the absence of noise, discrete inputs are optimally encoded into Boltzmann distributed output symbols. In the exploratory regime, the partition function of this distribution is numerically equal to 1. The structure of the optimal code is strongly affected by noise in the transmission channel. The Arimoto-Blahut algorithm, generalized for cost constraints, can be used to derive and interpret the distribution of symbols for optimal energy-efficient coding in the presence of noise. We outline the possibilities and problems in extending our results to information coding and transmission in neurobiological systems.
Patterns of Synchrony in Neural Networks with Spike Adaptation
Authors: Vreeswijk C. van , Hansel D.
Published: July 2002

We study the emergence of synchronized burst activity in networks of neurons with spike adaptation. We show that networks of tonically firing adapting excitatory neurons can evolve to a state where the neurons burst in a synchronized manner. The mechanism leading to this burst activity is analyzed in a network of integrate-and-fire neurons with spike adaptation. The dependence of this state on the different network parameters is investigated, and it is shown that this mechanism is robust against inhomogeneities, sparseness of the connectivity, and noise. In networks of two populations, one excitatory and one inhibitory, we show that decreasing the inhibitory feedback can cause the network to switch from a tonically active, asynchronous state to the synchronized bursting state. Finally, we show that the same mechanism also causes synchronized burst activity in networks of more realistic conductance-based model neurons.
A Lagrange Multiplier and Hopfield-Type Barrier Function Method for the Traveling Salesman Problem
Authors: Dang Chuangyin , Xu Lei
Published: July 2002

A Lagrange multiplier and Hopfield-type barrier function method is proposed for approximating a solution of the traveling salesman problem. The method is derived from applications of Lagrange multipliers and a Hopfield-type barrier function and attempts to produce a solution of high quality by generating a minimum point of a barrier problem for a sequence of descending values of the barrier parameter. For any given value of the barrier parameter, the method searches for a minimum point of the barrier problem in a feasible descent direction, which has a desired property that lower and upper bounds on variables are always satisfied automatically if the step length is a number between zero and one. At each iteration, the feasible descent direction is found by updating Lagrange multipliers with a globally convergent iterative procedure. For any given value of the barrier parameter, the method converges to a stationary point of the barrier problem without any condition on the objective function. Theoretical and numerical results show that the method seems more effective and efficient than the softassign algorithm.
Convergence Properties of the Softassign Quadratic Assignment Algorithm
Authors: Rangarajan Anand , Yuille Alan , Mjolsness Eric
Published: July 2002

The softassign quadratic assignment algorithm is a discrete-time, continuous-state, synchronous updating optimizing neural network. While its effectiveness has been shown in the traveling salesman problem, graph matching, and graph partitioning in thousands of simulations, its convergence properties have not been studied. Here, we construct discrete-time Lyapunov functions for the cases of exact and approximate doubly stochastic constraint satisfaction, which show convergence to a fixed point. The combination of good convergence properties and experimental success makes the softassign algorithm an excellent choice for neural quadratic assignment optimization.
Wind Daruma
Authors: Tatsumi Hijikata
Published: July 2002

For the first time in English, we present many of Hijikata's aesthetic and poetic texts. These texts are put into context by Kurihara Nanako's introductory essay. The section includes an interview with Hijikata and a conversation between Hijikata and Japanese experimental theatre innovator Suzuki Tadashi.
Exclude and Include for Audio Sources and Sinks: Analogs of Mute & Solo Are Deafen & Attend
Authors: Cohen Michael
Published: July 2002

Non-immersive perspectives in virtual environments enable flexible paradigms of perception, especially in the context of frames of reference for conferencing and musical audition. Traditional mixing idioms for enabling and disabling various audio sources employ mute and solo functions, that, along with cue, selectively disable or focus on respective channels. Exocentric interfaces which explicitly model not only sources but also sinks, motivate the generalization of mute and solo (or cue) to exclude and include, manifested for sinks as deafen and attend (confide and harken). Such functions, which narrow stimuli by explicitly blocking out and/or concentrating on selected entities, can be applied not only to other users' sinks for privacy, but also to one's own sinks for selective attendance or presence. Multiple sinks are useful in groupware, where a common environment implies social inhibitions to rearranging shared sources like musical voices or conferees, as well as individual sessions in which spatial arrangement of sources, like the configuration of a concert orchestra, has mnemonic value. A taxonomy of modal narrowcasting functions is proposed, and an audibility protocol is described, comprising revoke, renounce, grant, and claim methods, invocable by these narrowcasting commands to control superposition of soundscapes.
John von Neumann and the Evolutionary Growth of Complexity: Looking Backward, Looking Forward
Authors: McMullin Barry
Published: July 2002

In the late 1940s John von Neumann began to work on what he intended as a comprehensive “theory of [complex] automata.” He started to develop a book length manuscript on the subject in 1952. However, he put it aside in 1953, apparently due to pressure of other work. Due to his tragically early death in 1957, he was never to return to it. The draft manuscript was eventually edited, and combined for publication with some related lecture transcripts, by Burks in 1966. It is clear from the time and effort that von Neumann invested in it that he considered this to be a very significant and substantial piece of work. However, subsequent commentators (beginning even with Burks) have found it surprisingly difficult to articulate this substance. Indeed, it has since been suggested that von Neumann's results in this area either are trivial, or, at the very least, could have been achieved by much simpler means. It is an enigma. In this paper I review the history of this debate (briefly) and then present my own attempt at resolving the issue by focusing on an analysis of von Neumann's problem situation. I claim that this reveals the true depth of von Neumann's achievement and influence on the subsequent development of this field, and further that it generates a whole family of new consequent problems, which can still serve to inform—if not actually define—the field of artificial life for many years to come.
The PerfectC. ELEGANSProject: An Initial Report
Authors: Kitano Hiroaki , Hamahashi Shugo , Luke Sean
Published: July 2002

The soil nematode Caenorhabditis Elegans (C. elegans) is the most investigated of all multicellular organisms. Since the proposal to use it as a model organism, a series of research projects have been undertaken, investigating various aspects of this organism. As a result, the complete cell lineage, neural circuitry, and various genes and their functions have been identified. The complete C. elegans DNA sequencing and gene expression mapping for each cell at different times during embryogenesis will be identified in a few years. Given the abundance of collected data, we believe that the time is ripe to introduce synthetic models of C. elegans to further enhance our understanding of the underlying principles of its development and behavior. For this reason, we have started the Perfect C. elegans Project, which aims to produce ultimately a complete synthetic model of C. elegans' cellular structure and function. This article describes the goal, the approach, and the initial results of the project.
The Simulated Evolution of Biochemical Guilds: Reconciling Gaia Theory and Natural Selection
Authors: Downing Keith , Zvirinsky Peter
Published: July 2002

Gaia theory, which states that organisms both affect and regulate their environment, poses an interesting problem to Neo-Darwinian evolutionary biologists and provides an exciting set of phenomena for artificial-life investigation. The key challenge is to explain the emergence of biotic communities that are capable, via their implicit coordination, of regulating large-scale biogeochemical factors such as the temperature and chemical composition of the biosphere, but to assume no evolutionary mechanisms beyond contemporary natural selection. Along with providing an introduction to Gaia theory, this article presents simulations of Gaian emergence based on an artificial-life model involving genetic algorithms and guilds of simple metabolizing agents. In these simulations, resource competition leads to guild diversity; the ensemble of guilds then manifests life-sustaining nutrient recycling and exerts distributed control over environmental nutrient ratios. These results illustrate that standard individual-based natural selection is sufficient to explain Gaian self-organization, and they help clarify the relationships between two key metrics of Gaian activity: recycling and regulation.
The Politics of Collective Inaction: NATO's Response to the Prague Spring
Authors: McGinn John G.
Published: July 2002

The North Atlantic Treaty Organization (NATO) kept close track of developments in Czechoslovakia throughout 1968, but the alliance did not pursue a coherent policy toward the uprising. A close examination of NATO actions from January 1968 until the invasion on 20–21 August helps explain why a coordinated approach never materialized. Certain structural features of the alliance and a host of domestic and external distractions precluded a joint response. NATO members worked individually rather than collectively to avert Soviet military action through quiet diplomacy, but these efforts made almost no difference.
THE BITCH HAD IT COMING TO HER: Rhetoric and Interpretation in Ezekiel 16
Authors: Day Peggy
Published: July 2002

Ezek. 16:35-43 describes the punishment invoked upon personified Jerusalem for breach of covenant. Virtually all modern scholars maintain that the description is modelled on real life punishments for adultery in ancient Israel. This paper argues that the role played by Jerusalem's metaphoric lovers, who participate in the punishment rather than, as adulterers themselves, being subject to it, proves that the dominant interpretation of the passage is untenable. The paper proposes that the rhetorical dynamics of the passage have been a powerful influence in leading scholars to maintain this demonstrably false position. This proposal is illustrated by examining how scholars focus their ire solely on personified Jerusalem as adulteress, while at the same time exonerating the male lovers. Interpreting the punishment in this fashion conforms to the passage's rhetorical strategy of creating a unified, male-identified subject position that uses sexual difference to focus the reader's fury solely on the woman. The text accuses personified Jerusalem of the covenant infractions of apostasy and im68 proper foreign alliances, and invokes punishments that are standard for these crimes. The commentators, on the other hand, deleteriously influenced by the rhetorical dynamics of the passage, put personified Jerusalem to death for the enormity of her sexual offenses. This inappropriate literalizing of the sexual language of the vehicle of the metaphor has resulted in an erroneous interpretation of the passage.
The Status of Animals in Biblical and Christian Thought: A Study in Colliding Values
Authors: Preece Rod , Fraser David
Published: July 2002

A common contemporary view is that the Bible and subsequent Christian thought authorize humans to exploit animals purely as means to human ends. This paper argues that Biblical and Christian thought have given rise to a more complex ethic of animal use informed by its pastoralist origins, Biblical pronouncements that permit different interpretations, and competing ideas and doctrines that arose during its development, and influenced by the rich and often contradictory features of ancient Hebrew and Greco-Roman traditions. The result is not a uniform ethic but a tradition of unresolved debate. Differing interpretations of the Great Chain of Being and the conflict over animal experimentation demonstrate the colliding values inherent in the complex history of Biblical and Christian thought on animals.
A Union of Christianity, Humanity, and Philanthropy: The Christian Tradition and the Prevention of Cruelty to Animals in Nineteenth-Century England.
Authors: Li Chien-Hui
Published: July 2002

This paper offers an historical perspective to the discussion of the relationship between Christianity and nonhuman-human animal relationships by examining the animal protection movement in English society as it first took root in the nineteenth century. The paper argues that the Christian beliefs of many in the movement, especially the evangelical outlook of their faith, in a considerable way affected the character as well as the aims and scope of the emergent British animal welfare movement - although the church authorities did not take an active part in the discussion and betterment of the conditions of animals. An explicitly Christian discourse, important in creating and sustaining the important philanthropic tradition in Britain, mobilized the movement. The paper also traces the gradual decrease of the centrality of the movement's Christian elements later in the century when evolutionary ideas as well as other developments in society shed alternative light on the relationship between human and nonhuman animals and brought about different trends in the movement. This paper sees Christianity not as a static and defining source of influence but as a rich tradition containing diverse elements that people drew upon and used to create meanings for them. The paper implicitly suggests that both a religion's doctrines in theory and the outcome of a complex interaction with the changing society in which the religion is practiced determine its potential to influence animal-human relationships.
Language, Power and the Social Construction of Animals
Authors: Stibbe Arran
Published: July 2002

This paper describes how language contributes to the oppression and exploitation of animals by animal product industries. Critical Discourse Analysis, a framework usually applied in countering racism and sexism, is applied to a corpus of texts taken from animal industry sources. The mass confinement and slaughter of animals in intensive farms depend on the implicit consent of the population, signaled by its willingness to buy animal products produced in this way. Ideological assumptions embedded in everyday discourse and that of the animal industries manufacture and maintain this consent. Through analysis of texts, this paper attempts to expose these assumptions and discusses implications for countering the domination and exploitation of animals.
Subfossil records of Rana cf. lessonae, Rana arvalis and Rana cf. dalmatina from Middle Saxon (c. 600-950 AD) deposits in eastern England: evidence for native status
Authors: Gleed-Owen C.P.
Published: July 2002

Owing to debate over the possible native status of Rana lessonae in England, a zooarchaeological survey was aimed at finding remains of R. lessonae older than known introductions. One ilium of R. cf. lessonae has been identified from a Middle Saxon site in Lincolnshire (c. 600-950 AD), and ilia of R. arvalis and R. cf. dalmatina show that these species were also present in England during Saxon times.
Nematode infection patterns in four sympatric lizards from a restinga habitat (Jurubatiba) in Rio de Janeiro state, southeastern Brazil
Authors: Van Sluys Monique , Hatano Fábio , Vicente Joaquim , Galdino Conrado A.C. , Cunha-Barros Mônica , Vrcibradic Davor , Rocha Carlos Frederico
Published: July 2002

Specimens of the four most abundant diurnal lizards (Tropidurus torquatus, Cnemidophorus littoralis, Mabuya macrorhyncha and M. agilis) inhabiting the restinga of Jurubatiba, Rio de Janeiro state, Brazil were examined for nematodes. Eight species of nematodes were found. Tropidurus torquatus had the richest (8 species) and most diverse nematode fauna, whereas that of C. littoralis was the poorest (2 species) and less diverse. Tropidurus torquatus also had the highest overall prevalence (92%) and mean infection intensity (37.2; standard deviation 82.0; range 2-549). Similarities in nematode faunal composition between host species was generally low, except between the two Mabuya species.
Microhabitat, activity, and density of a dwarf gecko (Sphaerodactylus parvus) on Anguilla, West Indies
Authors: Powell Robert , Henderson Robert , Lindsay Cory , Nava Saul
Published: July 2002

Sphaerodactylus parvus is a dwarf gecko endemic to the Anguilla Bank in the Lesser Antilles, West Indies. Aspects of S. parvus ecology were studied at six sites on Anguilla. Geckos were encountered most frequently in association with rock spills, and gecko population densities (0-5.2/m2) were correlated positively with rock densities. A disproportionate number of rocks which harbored S. parvus were on complex substrates of smaller rocks, leaf litter, and small sticks. Geckos became active in the late afternoon and early evening (after air temperature dropped below under-rock temperature). Activity peaked between 1900 h and 2100 h, but S. parvus was active in leaf litter until at least shortly past midnight. Potential problems associated with field studies of these diminutive gekkonids are discussed.
TEMPORAL STABILITY IN THE INDIVIDUAL FEATURES IN THE CALLS OF EAGLE OWLS (BUBO BUBO)
Authors: Lengagne Thierry
Published: July 2002

Most studies dealing with individual pattern in acoustic signals are based on recordings made within a few hours or a few days. However, in long-lived animals, individual signatures are likely to be involved in social contact and pairing over several years. Variability of calls and more particularly of individual specific pattern over years has been poorly investigated. This study examines calls produced by a nocturnal long-lived raptor, eagle owls (Bubo bubo) in order (1) to determine which call structures are individually specific and (2) to examine variability of these individual structures over 2 years. A computerised sound analysis and subsequent data were submitted to univariate and multivariate statistics to determine individual specific cues of the call. A first analysis conducted on 116 calls emitted by 9 wild males recorded on a short time period enables to identify each emitter without any mistake. Analysis conducted on 70 calls emitted by 5 captive birds recorded during two different years emphasised a weak variation of all call parameters. Discriminant analysis correctly classified 100% of the individual eagle owls and thus, it is possible to reliably assign a call to the individual caller based on the acoustic properties of the vocalisation. We therefore conclude that territorial calls emitted by eagle owls may constitute an individual pattern over several years. The possible biological role of individual signatures and their use for monitoring population purpose are discussed.
THE ROLE OF AN ESTUARY ENVIRONMENT FOR REGENERATION OF CLAWS IN THE AMERICAN LOBSTER, HOMARUS AMERICANUS H. MILNE EDWARDS, 1837 (DECAPODA)
Authors: Maynard Donald , Wade Elmer , Landsburg Wade , Moriyasu Mikio
Published: July 2002

The life history of the American lobster, Homarus americanus, has been studied in the Bideford River estuary, Malpeque Bay, on the northern shore of Prince Edward Island, Canada. Lobsters migrate into the bay in early summer and two distinct moultings take place in May-June and in September. Lobsters with missing claws moult in both seasons, while uninjured individuals mainly moult in May-June. Neither uninjured lobsters nor individuals with missing claws larger than 43 mm CL moult twice a year in the estuary. A high percentage (30-40%) of individuals has missing claws in summer and the percentage of animals with regenerated small claws increases towards October-November. After the regeneration of missing claws, lobsters appear to emigrate to deeper water outside the bay. The estuarine environment might be used as a moulting and regenerating area for injured animals in spring-fall. Conversely, this environment does not appear to sustain high reproductive activities, because a low prevalence of mature females is observed throughout the year in this environment. These findings reveal the diversity of habitats used by different stages and groups of lobsters, especially the importance of an estuarine environment for moulting of claw regenerating lobsters. Le cycle de vie du homard americain, Homarus americanus, a ete etudie dans l'estuaire de la riviere Bideford, Baie de Malpeque, au nord de l'Ile du Prince Edouard, Canada. Les homards migrent vers la baie au debut de l'ete et deux mues distinctes ont lieu en mai-juin et en septembre. Les homards depourvus de pinces muent aux deux saisons, tandis que les individus intacts muent principalement en mai-juin. Aucun homard intact, comme aucun individu sans pinces, de taille superieure a 43 mm (CL) ne mue deux fois l'an dans l'estuaire. Un pourcentage eleve (30-40%) d'individus ont des pinces manquantes en ete et le pourcentage d'animaux avec des petites pinces regenerees a augmente vers octobre-novembre. Apres la regeneration des pinces, les homards semblent emigrer en eau plus profonde en dehors de la baie. L'environnement estuarien pourrait etre utilise comme une aire de mue et de regeneration pour les animaux blesses entre le printemps et l'automne. En revanche, cet environnement ne semble pas soutenir une activite elevee de reproduction en raison d'une faible prevalence de femelles a maturite tout au long de l'annee. Ces resultats revelent la diversite des habitats utilises par les differents stades et groupes de homards, en particulier l'importance de l'environnement estuarien pour la mue et la regeneration des pinces.