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Author Newman, M.E.J. url  doi
openurl 
  Title Mixing patterns in networks Type Journal Article
  Year 2003 Publication Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics Abbreviated Journal Phys Rev E Stat Nonlin Soft Matter Phys  
  Volume 67 Issue 2 Pt 2 Pages (down) 026126  
  Keywords  
  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.  
  Address Department of Physics, University of Michigan, Ann Arbor, MI 48109-1120, USA  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 1539-3755 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:12636767 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5215  
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Author Gorodnichenko, Y.; Roland, G. url  openurl
  Title Individualism, innovation, and long-run growth Type Journal Article
  Year 2011 Publication Proceedings of the National Academy of Sciences Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 108 Issue Supplement 4 Pages (down) 21316-21319  
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  Notes 10.1073/pnas.1101933108 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5941  
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Author Young, H.P. url  openurl
  Title The dynamics of social innovation Type Journal Article
  Year 2011 Publication Proceedings of the National Academy of Sciences Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 108 Issue Supplement 4 Pages (down) 21285-21291  
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  Notes 10.1073/pnas.1100973108 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5940  
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Author Frère, C.H.; Krützen, M.; Mann, J.; Connor, R.C.; Bejder, L.; Sherwin, W.B. url  doi
openurl 
  Title Social and genetic interactions drive fitness variation in a free-living dolphin population Type Journal Article
  Year 2010 Publication Proc Natl Acad Sci USA Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 107 Issue 46 Pages (down) 19949-19954  
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  Abstract The evolutionary forces that drive fitness variation in species are of considerable interest. Despite this, the relative importance and interactions of genetic and social factors involved in the evolution of fitness traits in wild mammalian populations are largely unknown. To date, a few studies have demonstrated that fitness might be influenced by either social factors or genes in natural populations, but none have explored how the combined effect of social and genetic parameters might interact to influence fitness. Drawing from a long-term study of wild bottlenose dolphins in the eastern gulf of Shark Bay, Western Australia, we present a unique approach to understanding these interactions. Our study shows that female calving success depends on both genetic inheritance and social bonds. Moreover, we demonstrate that interactions between social and genetic factors also influence female fitness. Therefore, our study represents a major methodological advance, and provides critical insights into the interplay of genetic and social parameters of fitness.  
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  Call Number Equine Behaviour @ team @ Serial 6412  
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Author Pruvost, M.; Bellone, R.; Benecke, N.; Sandoval-Castellanos, E.; Cieslak, M.; Kuznetsova, T.; Morales-Muñiz, A.; O'Connor, T.; Reissmann, M.; Hofreiter, M.; Ludwig, A. url  openurl
  Title Genotypes of predomestic horses match phenotypes painted in Paleolithic works of cave art Type Journal Article
  Year 2011 Publication Proceedings of the National Academy of Sciences Abbreviated Journal  
  Volume 108 Issue 46 Pages (down) 18626-18630  
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  Abstract Archaeologists often argue whether Paleolithic works of art, cave paintings in particular, constitute reflections of the natural environment of humans at the time. They also debate the extent to which these paintings actually contain creative artistic expression, reflect the phenotypic variation of the surrounding environment, or focus on rare phenotypes. The famous paintings “The Dappled Horses of Pech-Merle,” depicting spotted horses on the walls of a cave in Pech-Merle, France, date back ~25,000 y, but the coat pattern portrayed in these paintings is remarkably similar to a pattern known as “leopard” in modern horses. We have genotyped nine coat-color loci in 31 predomestic horses from Siberia, Eastern and Western Europe, and the Iberian Peninsula. Eighteen horses had bay coat color, seven were black, and six shared an allele associated with the leopard complex spotting (LP), representing the only spotted phenotype that has been discovered in wild, predomestic horses thus far. LP was detected in four Pleistocene and two Copper Age samples from Western and Eastern Europe, respectively. In contrast, this phenotype was absent from predomestic Siberian horses. Thus, all horse color phenotypes that seem to be distinguishable in cave paintings have now been found to exist in prehistoric horse populations, suggesting that cave paintings of this species represent remarkably realistic depictions of the animals shown. This finding lends support to hypotheses arguing that cave paintings might have contained less of a symbolic or transcendental connotation than often assumed.  
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  Notes 10.1073/pnas.1108982108 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5700  
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Author Sankey, C.; Henry, S.; André, N.; Richard-Yris, M.-A.; Hausberger, M. url  doi
openurl 
  Title Do Horses Have a Concept of Person? Type Journal Article
  Year 2011 Publication PLoS ONE Abbreviated Journal PLoS ONE  
  Volume 6 Issue 3 Pages (down) e18331 EP -  
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  Abstract <sec> <title>Background</title> <p>Animals' ability for cross-modal recognition has recently received much interest. Captive or domestic animals seem able to perceive cues of human attention and appear to have a multisensory perception of humans.</p> </sec> <sec> <title>Methodology/Principal Findings</title> <p>Here, we used a task where horses have to remain immobile under a vocal order to test whether they are sensitive to the attentional state of the experimenter, but also whether they behave and respond differently to the familiar order when tested by a familiar or an unknown person. Horses' response varied according to the person's attentional state when the order was given by an unknown person: obedience levels were higher when the person giving the order was looking at the horse than when he was not attentive. More interesting is the finding that whatever the condition, horses monitored much more and for longer times the unknown person, as if they were surprised to hear the familiar order given by an unknown voice.</p> </sec> <sec> <title>Conclusion/Significance</title> <p>These results suggest that recognition of humans may lie in a global, integrated, multisensory representation of specific individuals, that includes visual and vocal identity, but also expectations on the individual's behaviour in a familiar situation.</p> </sec>  
  Address  
  Corporate Author Thesis  
  Publisher Public Library of Science Place of Publication Editor  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5708  
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Author Warmuth, V.; Eriksson, A.; Bower, M.A.; Cañon, J.; Cothran, G.; Distl, O.; Glowatzki-Mullis, M.-L.; Hunt, H.; Luís, C.; do Mar Oom, M.; Yupanqui, I.T.; Zabek, T.; Manica, A. url  doi
openurl 
  Title European Domestic Horses Originated in Two Holocene Refugia Type Journal Article
  Year 2011 Publication PLoS ONE Abbreviated Journal PLoS ONE  
  Volume 6 Issue 3 Pages (down) e18194 EP -  
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  Abstract <p>The role of European wild horses in horse domestication is poorly understood. While the fossil record for wild horses in Europe prior to horse domestication is scarce, there have been suggestions that wild populations from various European regions might have contributed to the gene pool of domestic horses. To distinguish between regions where domestic populations are mainly descended from local wild stock and those where horses were largely imported, we investigated patterns of genetic diversity in 24 European horse breeds typed at 12 microsatellite loci. The distribution of high levels of genetic diversity in Europe coincides with the distribution of predominantly open landscapes prior to domestication, as suggested by simulation-based vegetation reconstructions, with breeds from Iberia and the Caspian Sea region having significantly higher genetic diversity than breeds from central Europe and the UK, which were largely forested at the time the first domestic horses appear there. Our results suggest that not only the Eastern steppes, but also the Iberian Peninsula provided refugia for wild horses in the Holocene, and that the genetic contribution of these wild populations to local domestic stock may have been considerable. In contrast, the consistently low levels of diversity in central Europe and the UK suggest that domestic horses in these regions largely derive from horses that were imported from the Eastern refugium, the Iberian refugium, or both.</p>  
  Address  
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  Publisher Public Library of Science Place of Publication Editor  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5710  
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Author Plotnik, J.M.; de Waal, F.B.M.; Reiss, D. doi  openurl
  Title Self-recognition in an Asian elephant Type Journal Article
  Year 2006 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 103 Issue 45 Pages (down) 17053-17057  
  Keywords Animals; Asia; *Behavior, Animal; Cognition; Elephants/*psychology; Female; Photic Stimulation  
  Abstract Considered an indicator of self-awareness, mirror self-recognition (MSR) has long seemed limited to humans and apes. In both phylogeny and human ontogeny, MSR is thought to correlate with higher forms of empathy and altruistic behavior. Apart from humans and apes, dolphins and elephants are also known for such capacities. After the recent discovery of MSR in dolphins (Tursiops truncatus), elephants thus were the next logical candidate species. We exposed three Asian elephants (Elephas maximus) to a large mirror to investigate their responses. Animals that possess MSR typically progress through four stages of behavior when facing a mirror: (i) social responses, (ii) physical inspection (e.g., looking behind the mirror), (iii) repetitive mirror-testing behavior, and (iv) realization of seeing themselves. Visible marks and invisible sham-marks were applied to the elephants' heads to test whether they would pass the litmus “mark test” for MSR in which an individual spontaneously uses a mirror to touch an otherwise imperceptible mark on its own body. Here, we report a successful MSR elephant study and report striking parallels in the progression of responses to mirrors among apes, dolphins, and elephants. These parallels suggest convergent cognitive evolution most likely related to complex sociality and cooperation.  
  Address Living Links, Yerkes National Primate Research Center, and Department of Psychology, Emory University, 532 North Kligo Circle, Atlanta, GA 30322, USA  
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  Series Volume Series Issue Edition  
  ISSN 0027-8424 ISBN Medium  
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  Notes PMID:17075063 Approved no  
  Call Number refbase @ user @ Serial 408  
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Author Weisbecker, V.; Goswami, A. url  doi
openurl 
  Title Brain size, life history, and metabolism at the marsupial/placental dichotomy Type Journal Article
  Year 2010 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.  
  Volume 107 Issue 37 Pages (down) 16216-16221  
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  Abstract The evolution of mammalian brain size is directly linked with the evolution of the brain's unique structure and performance. Both maternal life history investment traits and basal metabolic rate (BMR) correlate with relative brain size, but current hypotheses regarding the details of these relationships are based largely on placental mammals. Using encephalization quotients, partial correlation analyses, and bivariate regressions relating brain size to maternal investment times and BMR, we provide a direct quantitative comparison of brain size evolution in marsupials and placentals, whose reproduction and metabolism differ extensively. Our results show that the misconception that marsupials are systematically smaller-brained than placentals is driven by the inclusion of one large-brained placental clade, Primates. Marsupial and placental brain size partial correlations differ in that marsupials lack a partial correlation of BMR with brain size. This contradicts hypotheses stating that the maintenance of relatively larger brains requires higher BMRs. We suggest that a positive BMR–brain size correlation is a placental trait related to the intimate physiological contact between mother and offspring during gestation. Marsupials instead achieve brain sizes comparable to placentals through extended lactation. Comparison with avian brain evolution suggests that placental brain size should be constrained due to placentals’ relative precociality, as has been hypothesized for precocial bird hatchlings. We propose that placentals circumvent this constraint because of their focus on gestation, as opposed to the marsupial emphasis on lactation. Marsupials represent a less constrained condition, demonstrating that hypotheses regarding placental brain size evolution cannot be generalized to all mammals.  
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  Call Number Equine Behaviour @ team @ Serial 5338  
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Author Wascher, C.A.F.; Fraser, O.N.; Kotrschal, K. url  doi
openurl 
  Title Heart Rate during Conflicts Predicts Post-Conflict Stress-Related Behavior in Greylag Geese Type Journal Article
  Year 2010 Publication PLoS ONE Abbreviated Journal PLoS ONE  
  Volume 5 Issue 12 Pages (down) e15751  
  Keywords  
  Abstract Background

Social stressors are known to be among the most potent stressors in group-living animals. This is not only manifested in individual physiology (heart rate, glucocorticoids), but also in how individuals behave directly after a conflict. Certain ‘stress-related behaviors’ such as autopreening, body shaking, scratching and vigilance have been suggested to indicate an individual's emotional state. Such behaviors may also alleviate stress, but the behavioral context and physiological basis of those behaviors is still poorly understood.

Methodology/Principal Findings

We recorded beat-to-beat heart rates (HR) of 22 greylag geese in response to agonistic encounters using fully implanted sensor-transmitter packages. Additionally, for 143 major events we analyzed the behavior shown by our focal animals in the first two minutes after an interaction. Our results show that the HR during encounters and characteristics of the interaction predicted the frequency and duration of behaviors shown after a conflict.

Conclusions/Significance

To our knowledge this is the first study to quantify the physiological and behavioral responses to single agonistic encounters and to link this to post conflict behavior. Our results demonstrate that ‘stress-related behaviors’ are flexibly modulated by the characteristics of the preceding aggressive interaction and reflect the individual's emotional strain, which is linked to autonomic arousal. We found no support for the stress-alleviating hypothesis, but we propose that stress-related behaviors may play a role in communication with other group members, particularly with pair-partners.
 
  Address  
  Corporate Author Thesis  
  Publisher Public Library of Science Place of Publication Editor  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5298  
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