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Povinelli, D. J., & Vonk, J. (2003). Chimpanzee minds: suspiciously human? Trends. Cognit. Sci., 7(4), 157–160.
Abstract: Chimpanzees undoubtedly form concepts related to the statistical regularities in behavior. But do they also construe such abstractions in terms of mental states – that is, do they possess a [`]theory of mind'? Although both anecdotal and experimental data have been marshaled to support this idea, we show that no explanatory power or economy of expression is gained by such an assumption. We suggest that additional experiments will be unhelpful as long as they continue to rely upon determining whether subjects interpret behavioral invariances in terms of mental states. We propose a paradigm shift to overcome this limitation.
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Pongrácz, P., Miklósi, Á., Kubinyi, E., Topál, J., & Csányi, V. (2003). Interaction between individual experience and social learning in dogs. Anim. Behav., 65(3), 595–603.
Abstract: We investigated the interaction between individual experience and social learning in domestic dogs,Canis familiaris . We conducted two experiments using detour tests, where an object or food was placed behind a transparent, V-shaped wire-mesh fence, such that the dogs could get the reward by going around the fence. In some groups, two open doors were offered as an alternative, easier way to reach the reward. In experiment 1 we opened the doors only in trial 1, then closed them for trials 2 and 3. In experiment 2 other dogs were first taught to detour the fence with closed doors after they had observed a detouring human demonstrator, then we opened the doors for three subsequent trials. In experiment 1 all dogs reached the reward by going through the doors in trial 1, but their detouring performance was poor after the doors had been closed, if they had to solve the task on their own. However, dogs in the experimental group that were allowed to watch a detouring human demonstrator after the doors had been closed showed improved detouring ability compared with those that did not receive a demonstration of detouring. In experiment 2 the dogs tended to keep on detouring along the fence even if the doors had been opened, giving up a chance to get behind the fence by a shorter route. These results show that dogs can use information gained by observing a human demonstrator to overcome their own mistakenly preferred solution in a problem situation. In a reversed situation social learning can also contribute to a preference for a less adaptive behaviour. However, only repeated individual and social experience leads to a durable manifestation of maladaptive behaviour. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.
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Plotnik, J., Nelson, P. A., & de Waal, F. B. M. (2003). Visual field information in the face perception of chimpanzees (Pan troglodytes). Ann N Y Acad Sci, 1000, 94–98.
Abstract: Evidence for a visual field advantage (VFA) in the face perception of chimpanzees was investigated using a modification of a free-vision task. Four of six chimpanzee subjects previously trained on a computer joystick match-to-sample paradigm were able to distinguish between images of neutral face chimeras consisting of two left sides (LL) or right sides (RR) of the face. While an individual's ability to make this distinction would be unlikely to determine their suitability for the VFA tests, it was important to establish that distinctive information was available in test images. Data were then recorded on their choice of the LL vs. RR chimera as a match to the true, neutral image; a bias for one of these options would indicate an hemispatial visual field advantage. Results suggest that chimpanzees, unlike humans, do not exhibit a left visual field advantage. These results have important implications for studies on laterality and asymmetry in facial signals and their perception in primates.
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Pinchbeck, G. L., Clegg, P. D., Proudman, C. J., Morgan, K. L., & French, N. P. (2003). Case-control study to investigate risk factors for horse falls in hurdle racing in England and Wales. Vet. Rec., 152(19), 583–587.
Abstract: Between March 1, 2000 and August 31, 2001, a case-control study was conducted on 12 racecourses in England and Wales to identify and quantify the risk factors associated with horse falls in hurdle races. The cases and controls were defined so that variables relating to the horse, the jockey, the race and racecourse, and the jump could be considered. The cases were defined as a jumping effort at a hurdle flight that resulted in a fall, and the controls were defined as a successful jump over a hurdle at any of the 12 racecourses within 14 days before or after the case fall. Conditional logistic regression was used to examine the univariable and multivariable relationships between the predictor variables and the risk of falling. The risk of falling was significantly associated with the position of the jump in the race, and with the distance and speed of the race. A horse's previous racing experience and history were also significantly associated with the risk of falling and horses participating in their first hurdle race were at almost five times greater risk of falling than horses that had hurdled before.
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Passler, S., & Pfeffer, M. (2003). Detection of antibodies to alphaviruses and discrimination between antibodies to eastern and western equine encephalitis viruses in rabbit sera using a recombinant antigen and virus-specific monoclonal antibodies. J Vet Med B Infect Dis Vet Public Health, 50(6), 265–269.
Abstract: Three arthropod-borne alphaviruses, western equine encephalitis viruses (WEEV), eastern equine encephalitis viruses (EEEV) and Venezuelan equine encephalitis viruses are the aetiological agents of a sometimes severe encephalomyelitis in equines and humans in the New World. With regard to the different ecology and epidemiology of these viruses, a method applied in serological screening should be able to distinguish between them as well as other related members of the genus Alphavirus in the American continent. However, this has been hampered in the past by (a) the close antigenic relationship between alphaviruses in traditional serological assays, especially in the routinely used haemagglutination-inhibition, and (b) the need of biosafety level 3 facilities to grow the viral antigens. An epitope blocking assay using an EEEV glycoprotein E1-expressing recombinant Sindbis virus and virus-specific monoclonal antibodies (mAbs) binding to the E1 of EEEV (strain NJ/60) and the E1 of Sindbis virus was established using automated flow cytometry. The test was evaluated using sera of infected and vaccinated rabbits. A cut-off value of 30% inhibition for antigenic complex-specific seroconversion was found to be sufficient for the detection of the respective infection. By using three different mAbs in parallel, we were able to detect alphavirus genus-, EEEV- and WEEV-complex-specific serum antibodies. As this test is based on the inhibition of binding of virus-specific mAbs, sera of every origin other than mouse can be tested. Thus, this assay may prove useful in the serological screening of a variety of animal species during an outbreak investigation.
Keywords: Animals; Antibodies, Monoclonal/*immunology; Antibodies, Viral/*analysis/blood; DNA Primers; Encephalitis Virus, Eastern Equine/genetics/*immunology; Encephalitis Virus, Western Equine/genetics/*immunology; Encephalomyelitis, Equine/*diagnosis/*virology; Epitopes; Fluorescent Antibody Technique/*veterinary; Horses; Rabbits; Recombination, Genetic; Reverse Transcriptase Polymerase Chain Reaction/veterinary
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Nicol, C. J., Potzsch, C., Lewis, K., & Green, L. E. (2003). Matched concurrent case-control study of risk factors for feather pecking in hens on free-range commercial farms in the UK. Br Poult Sci, 44(4), 515–523.
Abstract: 1. The aim of the study was to compare the management and husbandry of free-range flocks in the UK where feather pecking was either present (case) or absent (control). 2. One hundred flocks were enrolled into a concurrent case-control study: 50 where birds had recently started feather pecking, and 50 matched control flocks where birds of the same age had not started feather pecking. 3. Information was obtained from a detailed interview with the flock manager, and by direct inspection of the flock, house and range. 4. Initial univariate analyses revealed that case flocks were more likely to comprise ISA Brown than Lohmann, were more likely to be restricted from litter areas to prevent floor eggs, and were less likely to use the outside range. 5. Cluster analysis indicated that feather pecking was not associated with any particular husbandry system. 6. The only influential risk factor significant in the multivariable conditional logistic regression analysis was use of the outdoor range. The risk of feather pecking was reduced 9-fold in flocks where more than 20% of birds used the range on sunny days (odds ratio = 0.12). Use of the range was positively associated with the presence of trees and/or hedges on the range.
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Newman, M. E. J. (2003). The Structure and Function of Complex Networks. SIAM Rev., 45(2), 167–256.
Abstract: Inspired by empirical studies of networked systems such as the Internet, social networks, and biological networks, researchers have in recent years developed a variety of techniques and models to help us understand or predict the behavior of these systems. Here we review developments in this field, including such concepts as the small-world effect, degree distributions, clustering, network correlations, random graph models, models of network growth and preferential attachment, and dynamical processes taking place on networks.
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Newman, M. E. J. (2003). Mixing patterns in networks. Phys Rev E Stat Nonlin Soft Matter Phys, 67(2 Pt 2), 026126.
Abstract: We study assortative mixing in networks, the tendency for vertices in networks to be connected to other vertices that are like (or unlike) them in some way. We consider mixing according to discrete characteristics such as language or race in social networks and scalar characteristics such as age. As a special example of the latter we consider mixing according to vertex degree, i.e., according to the number of connections vertices have to other vertices: do gregarious people tend to associate with other gregarious people? We propose a number of measures of assortative mixing appropriate to the various mixing types, and apply them to a variety of real-world networks, showing that assortative mixing is a pervasive phenomenon found in many networks. We also propose several models of assortatively mixed networks, both analytic ones based on generating function methods, and numerical ones based on Monte Carlo graph generation techniques. We use these models to probe the properties of networks as their level of assortativity is varied. In the particular case of mixing by degree, we find strong variation with assortativity in the connectivity of the network and in the resilience of the network to the removal of vertices.
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Nelson, E. E., Shelton, S. E., & Kalin, N. H. (2003). Individual differences in the responses of naive rhesus monkeys to snakes. Emotion, 3(1), 3–11.
Abstract: The authors demonstrated individual differences in inhibited behavior and withdrawal responses of laboratory-born rhesus monkeys when initially exposed to a snake. Most monkeys displayed a small significant increase in their behavioral inhibition in the presence of a snake. A few monkeys had marked responses, and some actively withdrew. Although the responses of the most extreme laboratory-born monkeys were comparable to feral-born monkeys, the responses of the laboratory-born monkeys rapidly habituated. The individual differences in the responses of naive monkeys likely reflect a continuum from orienting to wariness to fear. A neurobiological model is presented that addresses potential mechanisms underlying these individual differences, their relation to fear, and how they may predispose to phobia development.
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Neiworth, J. J., Steinmark, E., Basile, B. M., Wonders, R., Steely, F., & DeHart, C. (2003). A test of object permanence in a new-world monkey species, cotton top tamarins (Saguinus oedipus). Anim. Cogn., 6(1), 27–37.
Abstract: Cotton top tamarins were tested in visible and invisible displacement tasks in a method similar to that used elsewhere to test squirrel monkeys and orangutans. All subjects performed at levels significantly above chance on visible ( n=8) and invisible ( n=7) displacements, wherein the tasks included tests of the perseverance error, tests of memory in double and triple displacements, and “catch” trials that tested for the use of the experimenter's hand as a cue for the correct cup. Performance on all nine tasks was significantly higher than chance level selection of cups, and tasks using visible displacements generated more accurate performance than tasks using invisible displacements. Performance was not accounted for by a practice effect based on exposure to successive tasks. Results suggest that tamarins possess stage 6 object permanence capabilities, and that in a situation involving brief exposure to tasks and foraging opportunities, tracking objects' movements and responding more flexibly are abilities expressed readily by the tamarins.
Keywords: Animals; Feeding Behavior; Female; Male; *Memory; *Saguinus; *Visual Perception
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