toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Watts, D.J.; Strogatz, S.H. url  doi
openurl 
  Title Collective dynamics of /`small-world/' networks Type Journal Article
  Year 1998 Publication Abbreviated Journal Nature  
  Volume 393 Issue 6684 Pages 440-442  
  Keywords  
  Abstract Networks of coupled dynamical systems have been used to model biological oscillators Josephson junction arrays excitable media, neural networks spatial games11, genetic control networks12 and many other self-organizing systems. Ordinarily, the connection topology is assumed to be either completely regular or completely random. But many biological, technological and social networks lie somewhere between these two extremes. Here we explore simple models of networks that can be tuned through this middle ground: regular networks 'rewired' to introduce increasing amounts of disorder. We find that these systems can be highly clustered, like regular lattices, yet have small characteristic path lengths, like random graphs. We call them 'small-world' networks, by analogy with the small-world phenomenon (popularly known as six degrees of separation). The neural network of the worm Caenorhabditis elegans, the power grid of the western United States, and the collaboration graph of film actors are shown to be small-world networks. Models of dynamical systems with small-world coupling display enhanced signal-propagation speed, computational power, and synchronizability. In particular, infectious diseases spread more easily in small-world networks than in regular lattices.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor (down)  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes 10.1038/30918 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4989  
Permanent link to this record
 

 
Author Gosling, S.D. url  doi
openurl 
  Title Personality dimensions in spotted hyenas (Crocuta crocuta) Type Journal Article
  Year 1998 Publication Journal of Comparative Psychology (Washington, D.C. : 1983) Abbreviated Journal J Comp Psychol  
  Volume 112 Issue 2 Pages 107-118  
  Keywords Animals; Carnivora/*psychology; Female; Humans; Male; *Personality; Personality Assessment/statistics & numerical data; Psychometrics; Reproducibility of Results; Species Specificity; Temperament  
  Abstract Personality ratings of 34 spotted hyenas (Crocuta crocuta) were made by 4 observers who knew the animals well. Analyses suggest that (a) hyena personality traits were rated with generally high reliability; (b) 5 broad dimensions (Assertiveness, Excitability, Human-Directed Agreeableness, Sociability, and Curiosity) captured about 75% of the total variance; (c) this dimensional structure could not be explained in terms of dominance status, sex, age, or appearance; and (d) as expected, female hyenas were more assertive than male hyenas. Comparisons with previous research provide evidence for the cross-species generality of Excitability, Sociability, and especially Assertiveness. Discussion focuses on methodological issues in research on animal personality and on the potential contributions this research can make for understanding the biological and environmental bases of personality.  
  Address Department of Psychology, University of California, Berkeley 94720-1650, USA. samiam@uclink.berkeley.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor (down)  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0735-7036 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:9642781 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5019  
Permanent link to this record
 

 
Author Oakenfull, E.A.; Ryder, O.A. doi  openurl
  Title Mitochondrial control region and 12S rRNA variation in Przewalski's horse (Equus przewalskii) Type Journal Article
  Year 1998 Publication Animal Genetics Abbreviated Journal Anim Genet  
  Volume 29 Issue 6 Pages 456-459  
  Keywords Animals; DNA, Mitochondrial/*genetics; Female; *Genetic Variation; Horses/*genetics; Male; Pedigree; RNA, Ribosomal/*genetics  
  Abstract Variation in the control region and the 12S rRNA gene of all surviving mitochondrial lineages of Przewalski's horse was investigated. Variation is low despite the present day population being descended from 13 individuals probably representing animals from three different regions of its range. Phylogenetic comparison of these sequences, with sequences for the domestic horse, does not resolve the ancestral status of either horse.  
  Address Center for Reproduction of Endangered Species, Zoological Society of San Diego, CA 92112, USA  
  Corporate Author Thesis  
  Publisher Place of Publication Editor (down)  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0268-9146 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:9883508 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5040  
Permanent link to this record
 

 
Author Matsumura, S.; Kobayashi, T. url  doi
openurl 
  Title A game model for dominance relations among group-living animals Type Journal Article
  Year 1998 Publication Behavioral Ecology and Sociobiology Abbreviated Journal Behav. Ecol. Sociobiol.  
  Volume 42 Issue 2 Pages 77-84  
  Keywords Dominance – Hawk-dove games – Resource-holding potential – Asymmetry – Evolutionarily stable strategy  
  Abstract Abstract   We present here an attempt to understand behaviors of dominant individuals and of subordinate individuals as behavior strategies in an asymmetric “hawk-dove” game. We assume that contestants have perfect information about relative fighting ability and the value of the resource. Any type of asymmetry, both relevant to and irrelevant to the fighting ability, can be considered. It is concluded that evolutionarily stable strategies (ESSs) depend on the resource value (V), the cost of injury (D), and the probability that the individual in one role will win (x). Different ESSs can exist even when values of V, D, and x are the same. The characteristics of dominance relations detected by observers may result from the ESSs that the individuals are adopting. The model explains some characteristics of dominance relations, for example, the consistent outcome of contests, the rare occurrence of escalated fights, and the discrepancy between resource holding potential (RHP) and dominance relations, from the viewpoint of individual selection.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor (down)  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5102  
Permanent link to this record
 

 
Author Keil, N.M., Sambraus, H.H. url  openurl
  Title “Intervenors” in agonistic interactions amongst domesticated goats Type Journal Article
  Year 1998 Publication Zeitschrift fur Säugetierkunde Abbreviated Journal Z. Säugetierk.  
  Volume 63 Issue 5 Pages 266-272  
  Keywords Behaviour; Domestication; Goat; Intervention; Rank order  
  Abstract Social behaviour was observed in individually marked goats in two herds. The goats from one herd (n = 98) were horned, those of the other herd (n = 83) were polled. By recording agonistic interactions within the herds, a dominance index was determined for each animal. In both herds, intervention took place. Intervention is defined as one animal pushing in between two fighters, and thus ending the fight. More cases of intervention took place per individual animal amongst the horned goats than amongst the polled ones. Goats which intervened in fights on several occasions usually had a high dominance index. Members of the herd which were observed intervening only once had an average dominance index in both herds of almost 0.5. In some cases, goats very low in the rank order intervened a fight. Only rarely did the intervenors have a lower dominance index than the two fighters. In 103 cases, the direct dominance relationship between a fighting animal and the intervenor was known. In 95 cases (92.2%), the intervenor was dominant to the herd member in this fight and in just eight cases (7.8%), it was subordinate. It could not be determined what advantage the intervenor gained from its activity. It is possible that, at least in certain cases, a particularly relationship existed between the intervenor and one of the fighters.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor (down)  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5236  
Permanent link to this record
 

 
Author Dugatkin, L.A. url  doi
openurl 
  Title Breaking up fights between others: a model of intervention behaviour Type Journal Article
  Year 1998 Publication Proceedings of the Royal Society of London. Series B: Biological Sciences Abbreviated Journal Proc. R. Soc. Lond. B  
  Volume 265 Issue 1394 Pages 433-437  
  Keywords  
  Abstract To examine when and why animals break up fights between others in their group, I modelled whether ‘winner’ and ‘loser’ effects might be one element driving the evolution of intervention behaviour. I considered one particular type of intervention: when the intervener simply breaks up fights between two others, but does not favour either party in so doing. When victories at time T + 1 are more likely given a victory at time T (i.e. winner effects), intervention is often favoured. Intervention is favoured in these circumstances because the intervening party in essence stops others from ‘getting on a roll’ and climbing up any hierarchy that exists. However, when loser effects alone are at work (defeats at time T + 1 are more likely given a defeat at time T), breaking up fights between others is never selected. If both winner and loser effects are operating simultaneously, then the likelihood of intervention behaviour evolving is a function of the relative strength of these two effects. The greater the winner effect relative to the loser effect, the more likely intervention behaviour is to evolve.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor (down)  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes 10.1098/rspb.1998.0313 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5240  
Permanent link to this record
 

 
Author Henzi, S.P.; Lycett, J.E.; Weingrill, T. url  doi
openurl 
  Title Mate guarding and risk assessment by male mountain baboons during inter-troop encounters Type Journal Article
  Year 1998 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 55 Issue 6 Pages 1421-1428  
  Keywords  
  Abstract Aggressive herding of females is a frequent but not invariant response by male savannah baboons,Papio cynocephalus, to encounters with other troops. While males in some troops are consistently more likely to herd than those in others, not all inter-troop encounters result in herding, even within particular troops. This suggests that males assess the risk of male invasion posed by each encounter and respond accordingly. We used data from baboon troops in the Drakensberg mountains to determine the rules males follow in deciding whether to herd. Consistent differences between troops were explained only by the adult sex ratio. Males were more likely to herd if the sex ratio of their own troop was female biased, a finding that is concordant with the observation that males are more likely to immigrate into troops where the sex ratio is more female biased than the population average. Differences within troops were a consequence only of encounter distance, with herding being more likely at closer distances. We found a negative correlation between the angle of approach to the other troop and the subsequent angle of deflection. We interpret this to mean that herding functions to increase the distance between the interacting troops, thereby curtailing opportunities for strange males to inspect the troop and determine its sex ratio. In this way, possibly unlike those in other populations, the decision rules of these male baboons are geared to protecting longer-term reproductive prospects.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor (down)  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-3472 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5311  
Permanent link to this record
 

 
Author Wittling, W.; Block, A.; Schweiger, E.; Genzel, S. url  doi
openurl 
  Title Hemisphere Asymmetry in Sympathetic Control of the Human Myocardium Type Journal Article
  Year 1998 Publication Brain and Cognition Abbreviated Journal Brain Cogn.  
  Volume 38 Issue 1 Pages 17-35  
  Keywords  
  Abstract Hemisphere asymmetry in sympathetic control of myocardial performance was studied in healthy human subjects using lateralized film presentation for selective sensory stimulation of the hemispheres and impedance cardiography for the evaluation of cardiac output, systolic time intervals and myocardial contractility. Results revealed a clear and consistent right hemisphere predominance in sympathetically mediated control of various components of myocardial performance. There is reason to assume that the obtained hemisphere differences in autonomic control of the heart are self-reliant processes not depending on emotion-related hemisphere asymmetry. As far as we know, this is the first study examining the distinct roles of the cerebral hemispheres in neural control of ventricular myocardial functions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor (down)  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0278-2626 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5351  
Permanent link to this record
 

 
Author Potts, R. doi  openurl
  Title Variability selection in hominid evolution Type Journal Article
  Year 1998 Publication Evolutionary Anthropology: Issues, News, and Reviews Abbreviated Journal Evol. Anthropol.  
  Volume 7 Issue 3 Pages 81-96  
  Keywords variability selection; hominids; environment; adaptation; natural selection; evolution  
  Abstract Variability selection (abbreviated as VS) is a process considered to link adaptive change to large degrees of environment variability. Its application to hominid evolution is based, in part, on the pronounced rise in environmental remodeling that took place over the past several million years. The VS hypothesis differs from prior views of hominid evolution, which stress the consistent selective effects associated with specific habitats or directional trends (e.g., woodland, savanna expansion, cooling). According to the VS hypothesis, wide fluctuations over time created a growing disparity in adaptive conditions. Inconsistency in selection eventually caused habitat-specific adaptations to be replaced by structures and behaviors responsive to complex environmental change. Key hominid adaptations, in fact, emerged during times of heightened variability. Early bipedality, encephalized brains, and complex human sociality appear to signify a sequence of VS adaptations—i.e., a ratcheting up of versatility and responsiveness to novel environments experienced over the past 6 million years. The adaptive results of VS cannot be extrapolated from selection within a single environmental shift or relatively stable habitat. If some complex traits indeed require disparities in adaptive setting (and relative fitness) in order to evolve, the VS idea counters the prevailing view that adaptive change necessitates long-term, directional consistency in selection. © 1998 Wiley-Liss, Inc.  
  Address  
  Corporate Author Thesis  
  Publisher John Wiley & Sons, Inc. Place of Publication Editor (down)  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1520-6505 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5461  
Permanent link to this record
 

 
Author Barton, N. doi  openurl
  Title Evolutionary biology: The geometry of adaptation Type Journal Article
  Year 1998 Publication Nature Abbreviated Journal Nature  
  Volume 395 Issue 6704 Pages 751-752  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor (down)  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes 10.1038/27338 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5469  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print