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Valero, N. (2003). West Nile virus: a new challenge? Invest Clin, 44(3), 175–177.
Abstract: West Nile Virus (WNV), a member of the family Flaviviridae, was first isolated in 1937. Since the original isolation of the WNV outbreaks have occurred with increase in frequency of cases in humans and horses, apparent increase in severe human disease and high avian death rates. In 1999, 2000 and 2002 outbreaks of the WNV encephalitis were reported in horses, birds and humans from New York and Canada. Ornithophilic mosquitoes are the principal vectors of the WNV and birds of several species chiefly migrants appear to be the major introductory or amplifying host. The pattern of outbreaks in the old and new world suggests that viremic migratory birds may also contribute to movement of the virus. If so, Central America, Caribbean Islands and countries of South America including Venezuela, are in potential risk for suffering a severe outbreak for WNV, since several species of birds have populations that pass trough New York and cross the western north Atlantic or Caribbean Sea. It is important the knowledge of the ecology of WNV as well of the efficacy of control efforts in order to minimize the public health impact in these countries, where all population is susceptible to this infection.
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Barker, S. C. (2003). The Australian paralysis tick may be the missing link in the transmission of Hendra virus from bats to horses to humans. Med Hypotheses, 60(4), 481–483.
Abstract: Hendra virus is a new virus of the family Paramyxoviridae. This virus was first detected in Queensland, Australia, in 1994; although, it seems that the virus has infected fruit-eating bats (flying-foxes) for a very long time. At least 2 humans and 15 horses have been killed by this virus since it first emerged as a virus that may infect mammals other than flying-foxes. Hendra virus is thought to have moved from flying-foxes to horses, and then from horses to people. There is a reasonably strong hypothesis for horse-to-human transmission: transmission of virus via nasal discharge, saliva and/or urine. In contrast, there is no strong hypothesis for flying-fox-to-human transmission. I present evidence that the Australian paralysis tick, Ixodes holocyclus, which has apparently only recently become a parasite of flying-foxes, may transmit Hendra virus and perhaps related viruses from flying-foxes to horses and other mammals.
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Branchi, I., Bichler, Z., Berger-Sweeney, J., & Ricceri, L. (2003). Animal models of mental retardation: from gene to cognitive function. Neurosci Biobehav Rev, 27(1-2), 141–153.
Abstract: About 2-3% of all children are affected by mental retardation, and genetic conditions rank among the leading causes of mental retardation. Alterations in the information encoded by genes that regulate critical steps of brain development can disrupt the normal course of development, and have profound consequences on mental processes. Genetically modified mouse models have helped to elucidate the contribution of specific gene alterations and gene-environment interactions to the phenotype of several forms of mental retardation. Mouse models of several neurodevelopmental pathologies, such as Down and Rett syndromes and X-linked forms of mental retardation, have been developed. Because behavior is the ultimate output of brain, behavioral phenotyping of these models provides functional information that may not be detectable using molecular, cellular or histological evaluations. In particular, the study of ontogeny of behavior is recommended in mouse models of disorders having a developmental onset. Identifying the role of specific genes in neuropathologies provides a framework in which to understand key stages of human brain development, and provides a target for potential therapeutic intervention.
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Singer, E. R., Saxby, F., & French, N. P. (2003). A retrospective case-control study of horse falls in the sport of horse trials and three-day eventing. Equine Vet J, 35(2), 139–145.
Abstract: REASONS FOR PERFORMING STUDY: Serious injuries to horses and riders in horse trials (HT) and three-day events (3DE) are usually associated with falls of horses, which invariably involve falls of the riders. Many potential causes for these falls have been discussed. OBJECTIVES: The aim of this case-control study was to investigate the risk factors for horse falls on the cross-country phase of horse trials and three-day events. METHODS: Using retrospective data, significant risk factors identified with unvariable analysis (P value <0.2) were entered into a multivariable logistic regression model. Significant risk factors (P value <0.05) were included in the final model. RESULTS: It was revealed that a number of course, obstacle and rider variables were significantly and independently associated with the risk of falling. Falling was associated with obstacles sited downhill (Odds ratio [OR] 8.41) and with obstacles with ditches in front (OR = 5.77). CONCLUSIONS: The relationship between course variables and the risk of falling was characterised and showed a significantly increased risk with increasing numbers of jumps on the course and for jumping efforts later in the course. In contrast, after allowing for the total number of obstacles on the course, an increase in the total number of jumping efforts appeared to have a protective effect. A later cross-country start time was associated with a decreased risk of a horse fall. Amateur event riders were approximately 20 times more likely to fall than professional riders. POTENTIAL CLINICAL RELEVANCE: This study has identified a number of risk factors associated with horse falls and highlights areas that can be altered to improve safety in cross-country competitions.
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Adolphs, R. (2003). Cognitive neuroscience of human social behaviour. Nat Rev Neurosci, 4(3), 165–178.
Abstract: We are an intensely social species--it has been argued that our social nature defines what makes us human, what makes us conscious or what gave us our large brains. As a new field, the social brain sciences are probing the neural underpinnings of social behaviour and have produced a banquet of data that are both tantalizing and deeply puzzling. We are finding new links between emotion and reason, between action and perception, and between representations of other people and ourselves. No less important are the links that are also being established across disciplines to understand social behaviour, as neuroscientists, social psychologists, anthropologists, ethologists and philosophers forge new collaborations.
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Lee, R. D. (2003). Rethinking the evolutionary theory of aging: transfers, not births, shape senescence in social species. Proc Natl Acad Sci U S A, 100(16), 9637–9642.
Abstract: The classic evolutionary theory of aging explains why mortality rises with age: as individuals grow older, less lifetime fertility remains, so continued survival contributes less to reproductive fitness. However, successful reproduction often involves intergenerational transfers as well as fertility. In the formal theory offered here, age-specific selective pressure on mortality depends on a weighted average of remaining fertility (the classic effect) and remaining intergenerational transfers to be made to others. For species at the optimal quantity-investment tradeoff for offspring, only the transfer effect shapes mortality, explaining postreproductive survival and why juvenile mortality declines with age. It also explains the evolution of lower fertility, longer life, and increased investments in offspring.
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Preston, S. D., & de Waal, F. B. M. (2002). Empathy: Its ultimate and proximate bases. Behav Brain Sci, 25(1), 1–20; discussion 20–71.
Abstract: There is disagreement in the literature about the exact nature of the phenomenon of empathy. There are emotional, cognitive, and conditioning views, applying in varying degrees across species. An adequate description of the ultimate and proximate mechanism can integrate these views. Proximately, the perception of an object's state activates the subject's corresponding representations, which in turn activate somatic and autonomic responses. This mechanism supports basic behaviors (e.g., alarm, social facilitation, vicariousness of emotions, mother-infant responsiveness, and the modeling of competitors and predators) that are crucial for the reproductive success of animals living in groups. The Perception-Action Model (PAM), together with an understanding of how representations change with experience, can explain the major empirical effects in the literature (similarity, familiarity, past experience, explicit teaching, and salience). It can also predict a variety of empathy disorders. The interaction between the PAM and prefrontal functioning can also explain different levels of empathy across species and age groups. This view can advance our evolutionary understanding of empathy beyond inclusive fitness and reciprocal altruism and can explain different levels of empathy across individuals, species, stages of development, and situations.
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Zentall, T. R., Galizio, M., & Critchfied, T. S. (2002). Categorization, concept learning, and behavior analysis: an introduction. J Exp Anal Behav, 78(3), 237–248.
Abstract: Categorization and concept learning encompass some of the most important aspects of behavior, but historically they have not been central topics in the experimental analysis of behavior. To introduce this special issue of the Journal of the Experimental Analysis of Behavior (JEAB), we define key terms; distinguish between the study of concepts and the study of concept learning; describe three types of concept learning characterized by the stimulus classes they yield; and briefly identify several other themes (e.g., quantitative modeling and ties to language) that appear in the literature. As the special issue demonstrates, a surprising amount and diversity of work is being conducted that either represents a behavior-analytic perspective or can inform or constructively challenge this perspective.
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Chase, I. D., Tovey, C., Spangler-Martin, D., & Manfredonia, M. (2002). Individual differences versus social dynamics in the formation of animal dominance hierarchies. Proc. Natl. Acad. Sci. U.S.A., 99(8), 5744–5749.
Abstract: Linear hierarchies, the classical pecking-order structures, are formed readily in both nature and the laboratory in a great range of species including humans. However, the probability of getting linear structures by chance alone is quite low. In this paper we investigate the two hypotheses that are proposed most often to explain linear hierarchies: they are predetermined by differences in the attributes of animals, or they are produced by the dynamics of social interaction, i.e., they are self-organizing. We evaluate these hypotheses using cichlid fish as model animals, and although differences in attributes play a significant part, we find that social interaction is necessary for high proportions of groups with linear hierarchies. Our results suggest that dominance hierarchy formation is a much richer and more complex phenomenon than previously thought, and we explore the implications of these results for evolutionary biology, the social sciences, and the use of animal models in understanding human social organization.
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Pepperberg, I. M. (2002). In search of king Solomon's ring: cognitive and communicative studies of Grey parrots (Psittacus erithacus). Brain Behav Evol, 59(1-2), 54–67.
Abstract: During the past 24 years, I have used a modeling technique (M/R procedure) to train Grey parrots to use an allospecific code (English speech) referentially; I then use the code to test their cognitive abilities. The oldest bird, Alex, labels more than 50 different objects, 7 colors, 5 shapes, quantities to 6, 3 categories (color, shape, material) and uses 'no', 'come here', wanna go X' and 'want Y' (X and Y are appropriate location or item labels). He combines labels to identify, request, comment upon or refuse more than 100 items and to alter his environment. He processes queries to judge category, relative size, quantity, presence or absence of similarity/difference in attributes, and show label comprehension. He semantically separates labeling from requesting. He thus exhibits capacities once presumed limited to humans or nonhuman primates. Studies on this and other Greys show that parrots given training that lacks some aspect of input present in M/R protocols (reference, functionality, social interaction) fail to acquire referential English speech. Examining how input affects the extent to which parrots acquire an allospecific code may elucidate mechanisms of other forms of exceptional learning: learning unlikely in the normal course of development but that can occur under certain conditions.
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