Number Of Different Behaviors Research Articles

Dark energy versus $\Omega\mathsf{_{m} = 1}$ in the growth of matter perturbations

We explore the possibility of discriminating dark energy models from the study of the growth of matter perturbations. For the sake of simplicity, instead of dealing with a great number of models, we have chosen a simple model of dark energy (px = ω0ρ γ, with ω0 0; px ,a ndρx being pressure and energy density), which is able to reproduce a great number of different behaviours. A combination of WMAP data with other results have been used to estimate model parameters. The study has been made for collapsing shells in spherical clusters virialized at redshifts z = 1, 0. 1a nd 0.025 with line-of-sight velocity dispersion σlos = 750 and 1000 km s −1 . According to shell velocities, our dark energy models are clearly differentiated from the Ωm0 = 1 model (the greater the σlos is, the more differentiated the models are). However, the differences among dark energy models are not so large. From our results, the nearest clusters with large σlos are the idoneous ones to discriminate models. In fact, we think that from observations of caustics in nearby spherical clusters, it would be possible to make an estimation of Ωm0.

Defining information flow quantity

We extend definitions of information flow so as to quantify the amount of information passed; in other words, we give a formal definition of the capacity of covert channels. Our definition uses the process algebra CSP, and is based upon counting the number of different behaviours of a high level user that can be distinguished by a low level user.

Apomorphine susceptibility and animal models for psychopathology: genes and environment.

Many years ago we found a bimodal distribution of a number of different behaviors in our regular outbred Wistar stock. This was observed in the response to novelty, the response in a resident-intruder test as well as in the stereotypy response to the dopamine agonist apomorphine. On the basis of that, we decided to selectively breed these animals, which resulted in the the APO-SUS and APO-UNSUS lines. The APO-SUS rats show a strong, stereotyped gnawing response, whereas APO-UNSUS show only a weak gnawing response. Follow-up studies have shown that the phenotypical expression of these rats depend on genetic and early and late environmental factors. Because these rats were not selected on the basis of a specific behavioral trait, but rather on the basis of a difference in susceptibility for a specific neurotransmitter, it is not surprising that these animals show major differences in the neurochemical state of the central nervous system. In fact, in many respects they represent mirror images of each other. Moreover, these animals show clear differences in their endocrine and immunological systems. APO-SUS rats can be characterized as having a hyper-reactive hypothalamus-pituitary-adrenal axis, and a dominance of the T(H2) system. Apart from discussing the main differences between APO-SUS and APO-UNSUS rats, the review specifically focuses on the former as a potential model for schizophrenia. We have been able to show that APO-SUS rats indeed share a large number of behavioral, neurochemical, endocrinological, and immunological similarities with patients suffering from schizophrenia. Because schizophrenia is also likely to result from an interaction between genetic and early stressful life events, the APO-SUS rat might represent a promising animal model for studying this severe mental disorder.

Two state model for sub-exponential fluorescence revisited

A two-state model for the stretched exponential law found in the asymptotic decay of the fluorescence is generalized. By assuming a modification of the Arrhenius law for the detrapping process we find that the exponent characterizing the stretched exponential decay, β, exhibits a number of different behaviors, in qualitative agreement with some recent experimental results. The microscopic origin of these modified Arrhenius-type laws is considered. It is shown that multiphonon absorption can lead to a β which is a decreasing function of temperature, as found experimentally.

Genotype to phenotype: challenges and opportunities

The application of genetic engineering methods to mice has greatly expanded the ability to study the molecular basis of physiology and behavior in health and disease. Targeted disruptions or insertions of single genes are unique in that they promise to elucidate the precise role of many endogenous factors important during ontogeny and adult life in a manner which is relatively precise and free of the side effects encountered with many pharmacologic probes. Though the deletion or insertion of a gene may be a relatively ‘clean’ process, interpretation of the resulting phenotype may not be straightforward, since most behaviors and physiologic processes are controlled by more than a single gene. In fact, the knocking out or insertion of a single gene may result in no phenotypic change. This may be the case, in particular, if there exist gene redundancy mechanisms whose presence may prevent abnormal phenotypes from becoming unmasked. Conversely, single genes are often essential in a number of different behaviors and physiologic processes. Hence, ablation of an individual gene may prove so drastic as to be lethal, or so widespread as to create an amalgam of phenotypes whose interpretation becomes confounded by the interactions of the various new physiologic changes or behaviors.

Development of Exploration and Investigation in the Norway Rat (Rattus norvegicus)

A cross-sectional study of the development of spontaneous exploratory behavior in the laboratory rat was conducted. Long-Evans hooded rat pups aged 11 to 28 days (n = 158, from 25 litters) were placed into a dimly illuminated arena for 10 min on 2 consecutive days. Analysis of videotaped records from the second session for each rat pup showed a relatively sudden emergence of locomotor exploration between 12 and 16 days of age. The behavioral topography of interactions with objects developed less uniformly, with some features (e.g., bout length) relatively unchanging and other features (e.g., number of bouts, number of different behaviors displayed) increasing with age. The data for locomotor exploration are consistent with an explanation that depends on maturation-driven emergence of species-typical behavior, but that explanation cannot account for the pattern of development for object investigation. These results provide further evidence that some important aspects of the character of exploratory behavior depend, at least partially, on experience, and that exploration is not in fact a single behavior system. In addition, they provide important baseline information for further studies of the structure and function of exploratory behavior.

Olfaction in utero: Behavioral studies of the mouse fetus

On the day before birth, mouse fetuses were tested for their behavioral responses to iso-amyl acetate and iso-valeric acid delivered into the nasal cavity in liquid phase. Pilot studies established that most subjects responded to most concentrations used with an increase in total behaviors and number of different behaviors displayed. When iso-amyl acetate was systematically delivered at three concentrations (10 −3 M, 10 −4 M and 10 −5 M) subjects showed significant responses to each. In contrast, responses were not evident when saline was the stimulus. The magnitude of the average behavioral response did not decline with decreasing concentration of odorant. In a second experiment, the ability of the fetus to discriminate between iso-amyl acetate and iso-valeric acid was studied. Results establish that the fetuses responded differently to the two odorants. Given the immaturity of the mouse's accessory olfactory system before birth and the observed responses to concentrations of odorants below the threshold of the trigeminal system, the results suggest that the mouse fetus has a functionally competent main olfactory system including the ability to discriminate between purified odorants. The results are discussed in terms of current models of chemosensory ontogeny.

A Pair of Identified Interneurons inAplysiathat Are Involved in Multiple Behaviors Are Necessary and Sufficient for the Arterial-Shortening Component of a Local Withdrawal Reflex

A bilateral pair of cerebral interneurons, called CC5, contribute to the generation of a number of different behaviors involving head movements. Each cell sends its axon to the ipsilateral and contralateral pedal and pleural ganglia. A weak tactile stimulus to the head excites the ipsilateral CC5; a strong stimulus excites both the ipsilateral and contralateral cells. Firing of CC5 produces powerful shortening of the ipsilateral pedal artery (PA) by means of monosynaptic excitation of the pedal artery shortener (PAS) neuron, the single motor neuron for the artery. A weak touch to a tentacle excites the ipsilateral PAS and evokes a local withdrawal response accompanied by shortening of the ipsilateral PA. In vivo recording of the pedal artery nerve (PAn) showed that PAS was activated bilaterally during defensive head withdrawal elicited by a strong stimulus and was activated unilaterally by a weak stimulus. The responses were eliminated by cutting the ipsilateral cerebral-pleural connective (C-PLC). Electrical stimulation of the cerebral-pleural connective provided evidence that all of the excitatory input to PAS via this connective is provided by CC5. A variety of experimental results indicates that during a local withdrawal reflex of the tentacle, CC5 is necessary and sufficient for the unilateral PA-shortening component of the response and therefore functions as a command neuron for a component of the behavior. The data suggest that during defensive head withdrawal, the two CC5 neurons may act conjointly as a two-neuron command system that is necessary and sufficient for the bilateral arterial-shortening component of the behavior.

Drug therapy for prevention of atrial fibrillation

Atrial fibrillation is not a homogeneous entity, and many factors are responsible for a number of different behaviors, clinical consequences, and reactions to therapy. Therefore, the conventional evaluation of preventive treatments is not really adapted to provide the correct answers to difficult problems of therapeutic indications, as the 2 components of the benefit-risk ratio are not really known. Like ventricular fibrillation, atrial fibrillation may be primary or secondary to organized tachyarrhythmias, and reentrant flutter or automatic atrial tachycardia may well form the actual target for treatment. The autonomic nervous system is never absent as a determinant of the onset of arrhythmia, and the vagalas well as the sympathetic action may predominate and explain why a treatment may or may not be effective in situations that are identical only in appearence. The electrophysiologic milieu formed by the atrial tissue probably accounts for the perpetuation of the process of atrial fibrillation or its self-termination, and drugs themselves may contribute to modify the milieu in a way that in the end may be favorable or not. Finally, the presence or the absence of heart disease and heart failure largely contributes to the state of the vagosympathetic balance, to the hemodynamic consequences of atrial fibrillation, and ultimately to the proper toxic effects of drugs. The overall consequence of these complex situations is that any precise therapeutic decision algorithm for atrial fibrillation is always simplistic and that any global evaluation of drug efficacy or toxicity is not really meaningful as long as the category of patients treated is not precisely determined: no drug appears better or worse than others, but simply more or less adapted to various situations.

Using reflexive behaviors of the medicinal leech to study information processing

The interneuronal network that produces local bending in the leech is distributed, in the sense that most of the interneurons involved are activated in all forms of local bending, even those in which their outputs would produce inappropriate movements. Such networks have been found to control a number of different behaviors in a variety of animals. This article reviews three issues: the physiological and modeling observations that led to the conclusion that local bending in leeches is controlled by a distributed system; what distributed processing means for this and other behaviors; and why the leech interneuronal network may have evolved to be distributed in the first place.

A Medical Sociologist Looks at Health Promotion

Let me start by expressing my profound gratitude to the Medical Sociology Section for the Leo G. Reeder Award; it is an exceptional honor, and gives me the opportunity to thank my colleagues and friends who have motivated, supported, and inspired me over the years. Like many of us, I have spent much of my career trying to help health professionals obtain the public's cooperation in extinguishing risky behaviors and undertaking healthy lifestyles. Surrounded by all these attempts at health promotion, it was inevitable that I would develop some notions about it. As that great American philosopher Lawrence Peter Berra (whom some of you may remember as Yogi Berra, former catcher and manager for the New York Yankees) put it, You can observe a lot by watching. So, I'd like to offer a few personal observations about what I've come to feel are some dark sides of the health promotion movement, issues that I think deserve considerable attention from medical sociologists. I would begin with the notion that health promotion has exhorted the public to undertake a large number of different behaviors. I employ the word prematurely because of the considerable disagreement that exists among health professionals concerning the validity and interpretation of the data underlying these recommen-

The use of microcomputer-based psychomotor tests for the evaluation of benzodiazepine effects on human performance: a review with emphasis on temazepam.

1. The literature relating to the effects of benzodiazepines in general, and temazepam in particular, on human psychomotor performance as assessed using microcomputer-based testing batteries is surveyed. 2. The adverse effects of central nervous system depressants on performance is an important mediocolegal issue and frequently comes into question in on-the-road and on-the-job accidents. The use of microcomputer-based testing batteries allows for performance evaluation both in the laboratory and at-the-scene, as well as providing the opportunity to model a large number of different behaviours required in routine yet complex psychomotor tasks. 3. The conclusions in general are: (1) The benzodiazepines as a class of drugs impair both cognitive and motor performance. These effects are often subtle when low doses are involved or when testing occurs the morning following evening administration of the medication. (2) No single psychomotor task adequately simulates complex daily tasks such as automobile driving. A battery of tests that evaluates a number of the components of such tasks is necessary to determine adequately the full range of effects of these medications.

Skinner, Creativity, and the Problem of Spontaneous Behavior

Behavior is generative, by which I mean that it is probabilistic, continuous in time, and always novel. At first glance, B.F. Skinner's work would seem to make contact with generative aspects of behavior, since he studied the “emitted” behavior of “freely moving organisms,” since he analyzed language, music, literature, and other creative activities, and since he himself was an exceptionally creative individual. In fact, Skinner's work focuses on the effects of various interventions on ongoing behavior; it says little about where that behavior comes from in the first place. Generativity theory suggests that simple behavioral processes of the sort Skinner studied operate simultaneously on the probabilities of a large number of different behaviors. Instantiated in a computer model, the theory has successfully emulated complex, novel performances in both human and animal subjects, and it may some day allow for the real-time simulation of novel performances in individual human subjects.

Interobserver Agreement as a Function of the Number of Behaviors Recorded Simultaneously

Interobserver agreement scores were analyzed using the Interval-by-Interval and Occurrence-Agreement methods to determine the number of different behaviors an observer may reliably record at a time. Observer pairs recorded 1, 4, 6, 9, 11, and 14 different behaviors at a time from videotape recordings of a classroom. The results suggest that at least 14 behaviors may be recorded simultaneously by experienced, well-trained observers without a decrement in inter observer agreement.

Pattern regulation in epimorphic fields.

We have described a formal model for pattern regulation in epimorphic fields in which positional information is specified in terms of polar coordinates in two dimensions. We propose that cells within epimorphic fields behave according to two simple rules, the shortest intercalation rule and the complete circle rule, for both of which there is direct experimental evidence. It is possible to understand a large number of different behaviors of epimorphic fields as a straight-forward consequence of these two rules, and the model therefore provides a context in which to view many of the results of experimental embryology. Although we have confined our discussion to cockroach legs, the imaginal disks of Drosophila, and regenerating and developing amphibian limbs, the fact that the model can explain regulative behavior in such evolutionarily diverse animals suggests that it may have general applicability to epimorphic fields. The predictions which the model makes should make it possible to assess its applicability to other developing systems, and to investigate the cellular mechanisms involved.

Neuronal Circuits Involved in Learning: The Use of Modifiable Synapses in the Simulation of Behavior

Our present knowledge of brain structure and function requires that any model of neuronal circuitry designed to account for learning must satisfy three conditions. It must (1) meet economy restrictions on the number of cells in the brain, (2) use the same set of cells to account for a number of different behaviors, and (3) not require a detailed embryological specification of its connections. Previously published models have failed to meet one or more of these conditions. In this paper, a model is presented which does satisfy them, and in doing so accounts in detail for classical conditioning, operant conditioning, and other learning tasks. The model employs the types of synapses proposed by Burke and Hebb in simple modular circuits as a means of providing independent storage of information at each modifiable synapse.