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Author Biro, D.; Sumpter, D.J.T.; Meade, J.; Guilford, T.
Title From Compromise to Leadership in Pigeon Homing Type Journal Article
Year 2006 Publication Current Biology Abbreviated Journal Curr Biol
Volume 16 Issue 21 Pages 2123-2128
Keywords Animal Migration; Animals; Columbidae/*physiology; Decision Making; *Flight, Animal; *Homing Behavior; Models, Biological; Orientation; *Social Behavior; *Social Dominance
Abstract Summary A central problem faced by animals traveling in groups is how navigational decisions by group members are integrated, especially when members cannot assess which individuals are best informed or have conflicting information or interests , , , and . Pigeons are now known to recapitulate faithfully their individually distinct habitual routes home , and , and this provides a novel paradigm for investigating collective decisions during flight under varying levels of interindividual conflict. Using high-precision GPS tracking of pairs of pigeons, we found that if conflict between two birds' directional preferences was small, individuals averaged their routes, whereas if conflict rose over a critical threshold, either the pair split or one of the birds became the leader. Modeling such paired decision-making showed that both outcomes--compromise and leadership--could emerge from the same set of simple behavioral rules. Pairs also navigated more efficiently than did the individuals of which they were composed, even though leadership was not necessarily assumed by the more efficient bird. In the context of mass migration of birds and other animals, our results imply that simple self-organizing rules can produce behaviors that improve accuracy in decision-making and thus benefit individuals traveling in groups , and .
Address Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom. daro.biro@zoo.ox.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language Englisch Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-9822 ISBN Medium
Area Expedition Conference
Notes PMID:17084696 Approved no
Call Number (up) Serial 2026
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Author Uehara, T.; Yokomizo, H.; Iwasa, Y.
Title Mate-choice copying as Bayesian decision making Type Journal Article
Year 2005 Publication The American naturalist Abbreviated Journal Am Nat
Volume 165 Issue 3 Pages 403-410
Keywords Animals; *Bayes Theorem; *Choice Behavior; Female; Male; *Models, Biological; *Sexual Behavior, Animal
Abstract Mate-choice copying by females has been reported in fishes (e.g., guppies) and lekking birds. Presumably, females assess males' quality using both information from direct observation of males and information acquired by observing other females' choices. Here, we study mathematically the conditions under which mate-choice copying is advantageous on the basis of Bayesian decision theory. A female may observe the mate choice of another female, called the model female, who has performed an optimal choice based on her own judgment. The conditions required for the focal female to choose the same mate as that chosen by the model female should depend on the male's appearance to her, the reliability of her own judgment of male quality, and the reliability of the model females. When three or more females are involved, the optimal mate choice critically depends on whether multiple model females make decisions independently or they themselves copy the choices of others. If two equally reliable females choose different males, the choice of the second female, made knowing the choice of the first, should have a stronger effect on the choice of the third (focal) female. This “last-choice precedence” should be tested experimentally.
Address Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan. uehara@bio-math.biology.kyushu-u.ac.jp
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1537-5323 ISBN Medium
Area Expedition Conference
Notes PMID:15729669 Approved no
Call Number (up) Serial 1821
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Author Rosa, P.A.J.; Azevedo, A.M.; Aires-Barros, M.R.
Title Application of central composite design to the optimisation of aqueous two-phase extraction of human antibodies Type Journal Article
Year 2007 Publication Journal of Chromatography. A Abbreviated Journal J Chromatogr A
Volume 1141 Issue 1 Pages 50-60
Keywords Analysis of Variance; Animals; Antibodies/*chemistry/*isolation & purification; Buffers; Chemical Fractionation/*methods; Horses; Humans; Hydrophobicity; Isoelectric Point; Models, Biological; Molecular Weight; Myoglobin/chemistry/isolation & purification; Osmolar Concentration; Phase Transition; Polyethylene Glycols; Serum Albumin/chemistry/isolation & purification; Sodium Chloride
Abstract The partition of human antibodies in aqueous two-phase systems (ATPSs) of polyethylene glycol (PEG) and phosphate was systematically studied using first pure proteins systems and then an artificial mixture of proteins containing 1mg/ml human immunoglobulin G (IgG), 10mg/ml serum albumin and 2mg/ml myoglobin. Preliminary results obtained using pure proteins systems indicated that the PEG molecular weight and concentration, the pH value and the salts concentration had a pronounced effect on the partitioning behaviour of all proteins. For high ionic strengths and pH values higher than the isoelectric point (pI) of the contaminant proteins, IgG could be selectively recovered on the top phase. According to these results, a face centred composite design was performed in order to optimise the purification of IgG from the mixture of proteins. The optimal conditions for the isolation of IgG were observed for high concentrations of NaCl and low concentrations of both phase forming components. The best purification was achieved using an ATPS containing 8% (w/w) PEG 3350, 10% (w/w) phosphate pH 6 and 15% (w/w) NaCl. A recovery yield of 101+/-7%, a purity of 99+/-0% and a yield of native IgG of 97+/-4% were obtained. Back extraction studies of IgG to a new phosphate phase were performed and higher yields were obtained using 10% phosphate buffer at pH 6. The total extraction yield was 76% and the purity 100%.
Address IBB Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Tecnico, Av Rovisco Pais, 1049-001 Lisbon, Portugal
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9673 ISBN Medium
Area Expedition Conference
Notes PMID:17196214 Approved no
Call Number (up) Serial 1842
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Author Candura, S.M.; Verni, P.; Minelli, C.M.; Rosso, G.L.; Cappelli, M.I.; Strambi, S.; Martellosio, V.
Title [Occupational risks among public safety and security forces] Type Journal Article
Year 2006 Publication Giornale Italiano di Medicina del Lavoro ed Ergonomia Abbreviated Journal G Ital Med Lav Ergon
Volume 28 Issue 1 Pages 53-62
Keywords Burnout, Professional/etiology; Climate; Health Education; Humans; *Law Enforcement; Noise/adverse effects; *Occupational Diseases/chemically induced/etiology/prevention & control; *Occupational Health; *Police; Risk Assessment; Risk Factors; Stress Disorders, Post-Traumatic/etiology; Stress, Psychological/etiology; Vibration/adverse effects
Abstract The present paper tries to identify the occupational risk factors (physical, chemical, biological, psychological), variable depending on jobs and tasks, to which the heterogeneous public safety/security workers are exposed. The fight against criminality and public order maintenance imply (sometimes fatal) traumatic risks, and expose to psychophysical and sensorial tiring, unfavourable macro- and microclimatic conditions, the risk of baropathy (air navigation, underwater activities), noise (generated by firearms and several other sources), vibrations and shakings (automatic weapons, transport vehicles), the risk of electric injury, ionizing (X and gamma rays) and non-inonizing (ultraviolet rays, microwaves and radiofrequencies, electromagnetic fields) radiations. Chemical hazards include carbon monoxide and other combustion products (fires, urban traffic), substances released in chemical accidents, tear gases, lead (firing grounds, metal works, environmental pollution), solvents, lubrificants and cutting oils (mechanic repair and maintenance), laboratory materials and reagents, irritant and/or sensitizing agents contained in gloves. The main biological risks are tetanus, blood-borne diseases (viral hepatitis, AIDS), aerogenous diseases (e.g., tuberculosis, Legionnaire's disease, epidemic cerebrospinal meningitis), dog- or horse-transmitted zoonosis. Finally, emotional, psychosomatic and behavioural stress-related disorders (e.g., burn-out syndrome, post-traumatic stress disorder) are typically frequent. The presence of numerous and diversified hazards among public safety/security forces imposes the adoption of occupational medicine measures, including risk assessment, health education, technical and environmental prevention, personal protective devices, sanitary surveillance and biological monitoring, clinical interventions (diagnosis, therapy and rehabilitation of occupational accidents and illnesses), prompt medico-legal evaluation of occupational-related compensation claims.
Address Scuola di Specializzazione in Medicina del Lavoro, Universita degli Studi di Pavia, Italy
Corporate Author Thesis
Publisher Place of Publication Editor
Language Italian Summary Language Original Title Rischi professionali nelle Forze dell'Ordine
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1592-7830 ISBN Medium
Area Expedition Conference
Notes PMID:16705889 Approved no
Call Number (up) Serial 1871
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Author Linklater, W.L.
Title Adaptive explanation in socio-ecology: lessons from the Equidae Type Journal Article
Year 2000 Publication Biological Reviews of the Cambridge Philosophical Society Abbreviated Journal Biol. Rev.
Volume 75 Issue 1 Pages 1-20
Keywords *Adaptation, Physiological; Animals; Ecology; Equidae/*physiology; Female; Male; Phylogeny
Abstract Socio-ecological explanations for intra- and interspecific variation in the social and spatial organization of animals predominate in the scientific literature. The socio-ecological model, developed first for the Bovidae and Cervidae, is commonly applied more widely to other groups including the Equidae. Intraspecific comparisons are particularly valuable because they allow the role of environment and demography on social and spatial organization to be understood while controlling for phylogeny or morphology which confound interspecific comparisons. Feral horse (Equus caballus Linnaeus 1758) populations with different demography inhabit a range of environments throughout the world. I use 56 reports to obtain 23 measures or characteristics of the behaviour and the social and spatial organization of 19 feral horse populations in which the environment, demography, management, research effort and sample size are also described. Comparison shows that different populations had remarkably similar social and spatial organization and that group sizes and composition, and home range sizes varied as much within as between populations. I assess the few exceptions to uniformity and conclude that they are due to the attributes of the studies themselves, particularly to poor definition of terms and inadequate empiricism, rather than to the environment or demography per se. Interspecific comparisons show that equid species adhere to their different social and spatial organizations despite similarities in their environments and even when species are sympatric. Furthermore, equid male territoriality has been ill-defined in previous studies, observations presented as evidence of territoriality are also found in non-territorial equids, and populations of supposedly territorial species demonstrate female defence polygyny. Thus, territoriality may not be a useful categorization in the Equidae. Moreover, although equid socio-ecologists have relied on the socio-ecological model derived from the extremely diverse Bovidae and Cervidae for explanations of variation in equine society, the homomorphic, but large and polygynous, and monogeneric Equidae do not support previous socio-ecological explanations for relationships between body size, mating system and sexual dimorphism in ungulates. Consequently, in spite of the efforts of numerous authors during the past two decades, functional explanations of apparent differences in feral horse and equid social and spatial organization and behaviour based on assumptions of their current utility in the environmental or demographic context remain unconvincing. Nevertheless, differences in social cohesion between species that are insensitive to intra- and interspecific variation in habitat and predation pressure warrant explanation. Thus, I propose alternative avenues of inquiry including testing for species-specific differences in inter-individual aggression and investigating the role of phylogenetic constraints in equine society. The Equidae are evidence of the relative importance of phylogeny and biological structure, and unimportance of the present-day environment, in animal behaviour and social and spatial organization.
Address Institute of Natural Resources, Massey University, Palmerston North, New Zealand
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1464-7931 ISBN Medium
Area Expedition Conference
Notes PMID:10740891 Approved no
Call Number (up) Serial 2024
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Author Dubois, F.; Giraldeau, L.-A.; Hamilton, I.M.; Grant, J.W.A.; Lefebvre, L.
Title Distraction sneakers decrease the expected level of aggression within groups: a game-theoretic model Type Journal Article
Year 2004 Publication The American Naturalist Abbreviated Journal Am Nat
Volume 164 Issue 2 Pages E32-45
Keywords *Aggression; Animals; Behavior, Animal/*physiology; Columbidae/*physiology; Competitive Behavior; Cooperative Behavior; *Game Theory; Hawks/*physiology; Models, Biological
Abstract Hawk-dove games have been extensively used to predict the conditions under which group-living animals should defend their resources against potential usurpers. Typically, game-theoretic models on aggression consider that resource defense may entail energetic and injury costs. However, intruders may also take advantage of owners who are busy fighting to sneak access to unguarded resources, imposing thereby an additional cost on the use of the escalated hawk strategy. In this article we modify the two-strategy hawk-dove game into a three-strategy hawk-dove-sneaker game that incorporates a distraction-sneaking tactic, allowing us to explore its consequences on the expected level of aggression within groups. Our model predicts a lower proportion of hawks and hence lower frequencies of aggressive interactions within groups than do previous two-strategy hawk-dove games. The extent to which distraction sneakers decrease the frequency of aggression within groups, however, depends on whether they search only for opportunities to join resources uncovered by other group members or for both unchallenged resources and opportunities to usurp.
Address Departement des Sciences Biologiques, Universite du Quebec a Montreal, Case postale 8888 Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada. frede_dubois@yahoo.fr
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1537-5323 ISBN Medium
Area Expedition Conference
Notes PMID:15278850 Approved no
Call Number (up) Serial 2130
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Author Whiten, A.
Title Social complexity and social intelligence Type Conference Article
Year 2000 Publication Novartis Foundation Symposium Abbreviated Journal Novartis Found Symp
Volume 233 Issue Pages 185-96; discussion 196-201
Keywords Animals; Brain/anatomy & histology/*physiology; Humans; *Intelligence/physiology; Learning; Models, Psychological; Primates; *Social Behavior; Social Problems
Abstract When we talk of the 'nature of intelligence', or any other attribute, we may be referring to its essential structure, or to its place in nature, particularly the function it has evolved to serve. Here I examine both, from the perspective of the evolution of intelligence in primates. Over the last 20 years, the Social (or 'Machiavellian') Intelligence Hypothesis has gained empirical support. Its core claim is that the intelligence of primates is primarily an adaptation to the special complexities of primate social life. In addition to this hypothesis about the function of intellect, a secondary claim is that the very structure of intelligence has been moulded to be 'social' in character, an idea that presents a challenge to orthodox views of intelligence as a general-purpose capacity. I shall outline the principal components of social intelligence and the environment of social complexity it engages with. This raises the question of whether domain specificity is an appropriate characterization of social intelligence and its subcomponents, like theory of mind. As a counter-argument to such specificity I consider the hypothesis that great apes exhibit a cluster of advanced cognitive abilities that rest on a shared capacity for second-order mental representation.
Address School of Psychology, University of St Andrews, St Andrews, Fife KY16 9JU, UK
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1528-2511 ISBN Medium
Area Expedition Conference
Notes PMID:11276903 Approved no
Call Number (up) Serial 2084
Permanent link to this record
 

 
Author Huber, L.; Gajdon, G.K.
Title Technical intelligence in animals: the kea model Type Journal Article
Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 9 Issue 4 Pages 295-305
Keywords Animals; *Comprehension; *Intelligence; Models, Psychological; Observation; *Parrots; *Problem Solving; Psychological Theory; Social Environment; *Tool Use Behavior
Abstract The ability to act on information flexibly is one of the cornerstones of intelligent behavior. As particularly informative example, tool-oriented behavior has been investigated to determine to which extent nonhuman animals understand means-end relations, object affordances, and have specific motor skills. Even planning with foresight, goal-directed problem solving and immediate causal inference have been a focus of research. However, these cognitive abilities may not be restricted to tool-using animals but may be found also in animals that show high levels of curiosity, object exploration and manipulation, and extractive foraging behavior. The kea, a New Zealand parrot, is a particularly good example. We here review findings from laboratory experiments and field observations of keas revealing surprising cognitive capacities in the physical domain. In an experiment with captive keas, the success rate of individuals that were allowed to observe a trained conspecific was significantly higher than that of naive control subjects due to their acquisition of some functional understanding of the task through observation. In a further experiment using the string-pulling task, a well-probed test for means-end comprehension, we found the keas finding an immediate solution that could not be improved upon in nine further trials. We interpreted their performance as insightful in the sense of being sensitive of the relevant functional properties of the task and thereby producing a new adaptive response without trial-and-error learning. Together, these findings contribute to the ongoing debate on the distribution of higher cognitive skills in the animal kingdom by showing high levels of sensorimotor intelligence in animals that do not use tools. In conclusion, we suggest that the 'Technical intelligence hypothesis' (Byrne, Machiavellian intelligence II: extensions and evaluations, pp 289-211, 1997), which has been proposed to explain the origin of the ape/monkey grade-shift in intelligence by a selection pressure upon an increased efficiency in foraging behavior, should be extended, that is, applied to some birds as well.
Address Department for Behavior, Neurobiology and Cognition, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria. ludwig.huber@univie.ac.at
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1435-9448 ISBN Medium
Area Expedition Conference
Notes PMID:16909237 Approved no
Call Number (up) Serial 2085
Permanent link to this record
 

 
Author Dubois, F.; Giraldeau, L.-A.
Title The forager's dilemma: food sharing and food defense as risk-sensitive foraging options Type Journal Article
Year 2003 Publication The American Naturalist Abbreviated Journal Am Nat
Volume 162 Issue 6 Pages 768-779
Keywords Animals; Competitive Behavior/*physiology; *Environment; Feeding Behavior/*physiology; *Game Theory; *Models, Biological; Population Density; Population Dynamics
Abstract Although many variants of the hawk-dove game predict the frequency at which group foraging animals should compete aggressively, none of them can explain why a large number of group foraging animals share food clumps without any overt aggression. One reason for this shortcoming is that hawk-dove games typically consider only a single contest, while most group foraging situations involve opponents that interact repeatedly over discovered food clumps. The present iterated hawk-dove game predicts that in situations that are analogous to a prisoner's dilemma, animals should share the resources without aggression, provided that the number of simultaneously available food clumps is sufficiently large and the number of competitors is relatively small. However, given that the expected gain of an aggressive animal is more variable than the gain expected by nonaggressive individuals, the predicted effect of the number of food items in a clump-clump richness-depends on whether only the mean or both the mean and variability associated with payoffs are considered. More precisely, the deterministic game predicts that aggression should increase with clump richness, whereas the stochastic risk-sensitive game predicts that the frequency of encounters resulting in aggression should peak at intermediate clump richnesses or decrease with increasing clump richness if animals show sensitivity to the variance or coefficient of variation, respectively.
Address Departement des Sciences Biologiques, Universite du Quebec a Montreal, Case postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada. fdubois@u-bourgogne.fr
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-0147 ISBN Medium
Area Expedition Conference
Notes PMID:14737714 Approved no
Call Number (up) Serial 2132
Permanent link to this record
 

 
Author Wilson, A.M.; McGuigan, M.P.; Su, A.; van Den Bogert, A.J.
Title Horses damp the spring in their step Type Journal Article
Year 2001 Publication Nature Abbreviated Journal Nature
Volume 414 Issue 6866 Pages 895-899
Keywords Animals; Biomechanics; Elasticity; Forelimb; Gait; Horses/anatomy & histology/*physiology; Leg Bones/*physiology; Locomotion; Models, Biological; Muscle Fibers/physiology; Muscle, Skeletal/anatomy & histology/*physiology; Tendons/anatomy & histology/*physiology; Vibration
Abstract The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle-tendon units.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle. Despite being apparently redundant for such a mechanism, the muscle fibres in the digital flexors are well developed. Here we show that the mechanical arrangement of the elastic leg permits it to vibrate at a higher frequency of 30-40 Hz that could cause fatigue damage to tendon and bone. Furthermore, we show that the digital flexor muscles have minimal ability to contribute to or regulate significantly the 2.5-Hz cycle of movement, but are ideally arranged to damp these high-frequency oscillations in the limb.
Address Department of Veterinary Basic Sciences, The Royal Veterinary College, Hatfield, Herts AL9 7TA, UK. awilson@rvc.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English 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 PMID:11780059 Approved no
Call Number (up) Equine Behaviour @ team @ Serial 2300
Permanent link to this record