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In recent years, proven artificial intelligence techniques have been rapidly adopted in the expanding field of computer animation. With the increasing complexity and interactivity of the environments in which computer animations involving autonomous actors are set, the interest in further contributions is extended to include computational models of behavioural and cognitive phenomena. We review some representative examples of current artificial intelligence research efforts that could point towards solutions satisfying these new challenging needs. >

The component PIII of the electroretinogram representing the optic generator potential was recorded after stimulation with short stimuli with different light intensity. It is shown that the impulse response function of a linear second order model with intensity-dependent coefficients can be well fit to the recordings. Two of its parameters, after logarithmic transformations, are linearly dependent on the luminance while the third parameter varies only within a small interval. It is therefore possible to describe the relation between PIII and luminance in a linearized second order model. Furthermore, both the type of the function relating the gain of the model to the luminance and its exponent are nearly identical with the psychophysic function relating luminance to subjective brightness. Further physiological implications are also considered.

Ambulatory health care in developing countries is often provided by medical or paramedical personnel commonly called village health workers. Medical problems within their realm of competence include diarrhea, infestation with worms, diseases affecting the eyes and the skin, and several kinds of infectious diseases. Also, assessment of malnutrition is among the tasks village health workers have to perform. A knowledge-based system is designed and implemented to provide decision support for those tasks. Expanded decision networks are used to represent the diagnostic processes for diarrhea and infestation with worms. The diagnostic procedures for diseases affecting the skin and the eyes are covered with a rule-based approach using two certainty factors. Treatment schemes and procedural knowledge about drug prescription are represented in a frame structure. The hybrid knowledge engineering tool VIE-KET is used to construct a modular consultation system that provides entry points for diagnosis, therapy, and dr...

The temperature dependence of the negative component P III of the rabbit's electroretinogram has been studied in former experiments. A mathematical model of this component is expressed by the transfer function of a second order system. By means of electronic computations of the parameters a good fit to the experimental curves has been attained. The influence of different temperature (10–30° C) is reflected in the model by changes of 2 constants only. The 10 values of these changes are rather high (>2). Possibilities and limitations of the model are discussed.

Potential fields of seizure waves in the rabbit's cortex were mapped by means of a computer and the relationships between their behaviour and the graphoelements were studied. Elementary seizure waves are due to circular potential fields moving in the 10−1 m/sec range over the cortex. More complex graphoelements are due to the superimposition of potential fields of different characteristics. Usually, regular repetitive seizure waves are due to potential fields moving in the same direction. At cytoarchitectonic borderlines the potential fields become distorted and fade out or elicit other potential fields to arise in the contiguous area. Transverse vertical incisions in the cortex prevent the potential fields not only from transgressing the incision but also from spreading along it. The polarity of the potential field that moves corresponds to the polarity of the more “peaked” phase (the steeper phase) of the grapho-element. In most cases the positive fields are the moving ones. The consequences of these observations for the nature of the EEG are discussed.

A computer program is presented which transforms simultaneous recordings of multiple electrodes into graphical approximate representations of isopotential lines.

The authors reinvestigated 84 out of a sample of 90 patients with delusional psychoses after an interval of 6–9 years. The results of the follow-up showed a pattern of episodic versus chronic course which compares to follow-up studies on classically diagnosed schizophrenias. The authors found evidence for their hypothesis concerning the nosological heterogeneity of this group of psychoses and propose a syndromatological classification apart from the delusional symptomatology itself. What they call background symptomatology was divided into axial syndromes. The authors feel that this results in subgroups that are more homogeneous for course and outcome than the usual classification systems.

A procedure is presented which enables the physician to forecast the course a disease will take by looking through a list of items with attached numbers, i.e. weights, and simply adding the weights of those items which hold true for a specific patient. The application of this procedure to three different diseases, namely schizophrenia, facial paresis, and aphasia is presented and proves its accuracy. Furthermore, a Monte Carlo Analysis of the procedure underlying this method--multiple linear regression of dichotomous items--leads to recommendations concerning the optimum definitions of items and the structuring of data. The procedure is compared with other methods used in computer diagnosis and its main advantage, apart from its high reliability, i.e. independence of computers in its application, is stressed. Its application to other diseases is encouraged and the presentation of data for processing by this Department is invited.

The electroretinogram of isolated retinae of human eyes which had to be enucleated owing to an absolute glaucoma was split into two components: a negative one identified as P III and an oscillating one. By means of electronic computations two corresponding mathematical functions were fit successively to the experimental curve and then added for comparison. Though this synthetisized curve differs markedly from the empirical one in the later part, it shows a close fit in the initial state. Limitations of the mathematical simulation model are discussed.

Wenn in Krisenzeiten Betriebe geschlossen und die Beschaftigten auf die Strase gesetzt werden, kommt es gelegentlich zur Besetzung, Ubernahme und Weiterfuhrung der Produktion durch die Arbeiter_innen selbst, in den letzten Jahren unter anderem im Fahrradwerk von Bike Systems in Nordhausen (2007) in der ehemaligen Baumaterialfabrik Vio.me in Thessaloniki (2011) und in der Teebeutelfabrik Fralib in Marseille (2012). Besondere Aufmerksamkeit erlangten die vielen Betriebsbesetzungen in Argentinien seit Anfang der 2000er Jahre, wie die des Fliesenherstellers Zanon in der Provinz Neuquen (2001). Diese Betriebsbesetzungen beginnen meist in dem Moment, in dem die ArbeiterInnen ihre Lohnquelle durch Konkurs und Produktionsstopp verlieren. In den anschliesenden Auseinandersetzungen mussen sich die Betriebsbesetzer_innen nicht nur mit dem Unternehmer herumschlagen, sondern oft auch mit dem Staat, der die kapitalistischen Besitzverhaltnisse schutzen will. Unter Umstanden bildet sich in diesen Kampfen ein neues Arbeiterkollektiv heraus, das die hierarchische Betriebsorganisation abschafft und Formen kooperativer Produktion ausprobiert. Wie aber funktionieren und entwickeln sich solche Formen im Rahmen des Kapitalismus? Bieten sie eine Perspektive, die uber diesen hinausweist – quasi als Keimzellen einer Okonomie ohne Ausbeutung? Zur Beantwortung dieser Fragen bietet das Buch von Juan Pablo Hudson wertvolles Material. Von Mitte bis Ende der 2000er Jahre beobachtete er in Rosario, Argentinien, mehr als ein Dutzend von den Arbeiter_innen ubernommene Betriebe (Empresas Recupe

Despite their dynamic nature, social commitments have been rarely used for monitoring purposes. Few attention has been paid to the relationship between commitments and the temporal dimension and to the corresponding run-time verification. Building on previous work, we present a declarative axioma- tization of time-aware social commitments, extending their basic life cycle with time-related transitions and with compensation mechanisms. The formalization is based on a reactive version of the Event Calculus, able to monitor the commitments evolution during a system's execution, checking if the interacting agents are honoring them or not.

A direct construction of first-passage-time (FPT) probability density functions (pdf’s) for a preassigned diffusion process in terms of the FPT pdf’s of Ornstein-Uhlenbeck (OU) process restricted between constant bound- aries is provided.

International audience; This paper is a result of more than 3 decades of intensive research and development. It exhibits several keys to understanding and conceiving technologies considered or even proved by the standards of modern science as impossible to produce, such as, for instance, the automated synthesis of recursive programs. The paper shows a direction that allows to escape from limits of contemporary science and to open human's mind and effort towards others, maybe unstated, "dreams" as well as towards winning over what seem to be the invincible enemies of Humanity. The paper illustrates that no Science can exist without a correct perception, assimilation and transmission of these keys and without influencing, in an adequate way, the Patent Law as well as the final understanding of the globalization.

The present note is devoted to a bird's eye view of an interdisciplinary research area in which the authors have been engaged during the past few years. Here the controversial question concerning the validity of the loose-coupling versus the lever-arm models in the actomyosin dynamics is addressed by re-interpreting the washboard model earlier proposed by some of us. Specifically, we consider the diffusive motion with jumps of a particle in the presence of an asymmetric periodic potential with a unique minimum subject to half-period wide shifts occurring at random Poisson distributed times. A number of relevant quantities are explicitly obtained via averages of functions of the random variable representing the particle position.

An analysis of the random process modeling the number of firings and the distribution of interspike intervals is carried out far a re- turn process in the presence of certain special classes of random refractoriness.

International audience

The upcrossing problem through preassigned boundaries for non-stationary Gauss-Markov processes is studied with a view to model single neuron’s activity. A special care is devoted to the analysis of the behavior of the obtained densities in the limit of diverging correlation times. The results of some numerical computation for various choices of the parameters are finally presented.

In this paper we consider a network consisting of two Stein’s neuronal units, where the effect of the firing of the first unit is a jump of the membrane potential of the second unit. We perform an analysis of the interaction between these units based on Monte-Carlo simulations performed by means of an ad-hoc procedure. Our results include the analysis of the interspike intervals under varying firing conditions as well as the number of spikes of the second neuron during the ISI’s of the first neuron.

On the grounds of a set of data obtained in single molecule experiments on actomyosin dynamics under external applied loads, we postulate a joint mechanism consisting of a thermal component coupled with a deterministic unit-step, as invoked by the "lever-arm" theory, are simultaneously acting in determining myosin dynamics.

The output distribution function and some of its statistical features are analyzed for single neurons modeled via an instantaneous return process in the presence of random refractoriness. Various types of probability density functions (pdf) for the refractoriness are taken into account for a quantitative comparison of the asymptotic behaviors of inter-spike intervals pdf and its statistical features. Finally, it is shown that rather general conditions exist under which the interspike density is asymptotically independent of the form of the refractoriness distribution.

We consider a jump-diffusion process that appears to be suitable to describe the dis-placement performed during the rising phase by a single myosin head along an actin filament as reported in numerous current publications by T. Yanagida and his co-workers. We obtain the transition density of the considered process under the Markovian assumption that the instants of occurrence of the jumps are distributed according to a Poisson process. Two different distributions for the random amplitude of the jumps are considered in detail: the Gaussian distribution and a mixture of two Gaussian distributions. By means of the present phenomenological model, certain significant analogies and qualitative agreements with the biological data are pointed out.

The instantaneous return process in the presence of refractoriness is investigated for diffusion models of single neuron's activity. Steady-state probability densities and asymptotic moments of the neuronal membrane potential are explicitly obtained in a form that is suitable for quantitative evaluations. Some results for the Ornstein-Uhlenbeck and Feller neuronal models are outlined.

Aiming at the construction of non-Markov models for single neuron’s activity, the asymptotic behavior of the upcrossing first passage time probability density function through certain time-varying boundaries, is established for a class of stationary Gaussian processes. The goodness of the theoretical results is then tested, in specific instances, by means of a simulation method implemented on a large scale parallel computer.

A particular class of time-homogeneous diffusion processes defined over the interval I = [r, r2) is considered, where r is a regular or an entrance boundary and r2 is a natural boundary. For these processes the transition probability density function, the Laplace transform of the first passage time density and its moments afe explicitly obtained in terms of the mean first passage time.

A quantitative analysis of a stochastic model for a population consisting of competing species in the presence of colonizations, deaths and replacements is performed within the framework of survival problems. Various computation results are obtained and thoroughly discussed.

The instantaneous return process is investigated for Ornstein-Uhlenbeck, Feller and Capocelli-Ricciardi neuronal models under the assumptions that after each firing the neuron 's membrane potential is reset to a unique fixed value. Steady-state probability densities are calculated and closed form expressions are obtained for asymptotic mean and variance of the neuronal membrane potential.