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Author Ballew, R.M.; Sabelko, J.; Gruebele, M.
Title (up) Direct observation of fast protein folding: the initial collapse of apomyoglobin Type Journal Article
Year 1996 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.
Volume 93 Issue 12 Pages 5759-5764
Keywords Animals; Apoproteins/*chemistry; Circular Dichroism; Horses; Kinetics; Muscle, Skeletal/chemistry; Myoglobin/*chemistry; *Protein Folding; Spectrometry, Fluorescence; Spectrophotometry, Infrared; Temperature
Abstract The rapid refolding dynamics of apomyoglobin are followed by a new temperature-jump fluorescence technique on a 15-ns to 0.5-ms time scale in vitro. The apparatus measures the protein-folding history in a single sweep in standard aqueous buffers. The earliest steps during folding to a compact state are observed and are complete in under 20 micros. Experiments on mutants and consideration of steady-state CD and fluorescence spectra indicate that the observed microsecond phase monitors assembly of an A x (H x G) helix subunit. Measurements at different viscosities indicate diffusive behavior even at low viscosities, in agreement with motions of a solvent-exposed protein during the initial collapse.
Address School of Chemical Sciences and Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, 61801, USA
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ISSN 0027-8424 ISBN Medium
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Notes PMID:8650166 Approved no
Call Number Equine Behaviour @ team @ Serial 3798
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Author Johnstone, R.A.
Title (up) Eavesdropping and animal conflict Type Journal Article
Year 2001 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.
Volume 98 Issue 16 Pages 9177-9180
Keywords *Aggression; Animals; *Behavior, Animal; *Conflict (Psychology); Models, Theoretical
Abstract Fights between pairs of animals frequently take place within a wider social context. The displays exchanged during conflict, and the outcome of an encounter, are often detectable by individuals who are not immediately involved. In at least some species, such bystanders are known to eavesdrop on contests between others, and to modify their behavior toward the contestants in response to the observed interaction. Here, I extend Maynard Smith's well known model of animal aggression, the Hawk-Dove game, to incorporate the possibility of eavesdroppers. I show that some eavesdropping is favored whenever the cost of losing an escalated fight exceeds the value of the contested resource, and that its equilibrium frequency is greatest when costs are relatively high. Eavesdropping reduces the risk of escalated conflict relative to that expected by chance, given the level of aggression in the population. However, it also promotes increased aggression, because it enhances the value of victory. The net result is that escalated conflicts are predicted to occur more frequently when eavesdropping is possible.
Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, United Kingdom. raj1003@hermes.cam.ac.uk
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ISSN 0027-8424 ISBN Medium
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Notes PMID:11459936 Approved no
Call Number refbase @ user @ Serial 497
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Author Horner, V.; Whiten, A.; Flynn, E.; de Waal, F.B.M.
Title (up) Faithful replication of foraging techniques along cultural transmission chains by chimpanzees and children 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 37 Pages 13878-13883
Keywords Animals; Child, Preschool; Humans; *Imitative Behavior; Pan troglodytes/*psychology
Abstract Observational studies of wild chimpanzees (Pan troglodytes) have revealed population-specific differences in behavior, thought to represent cultural variation. Field studies have also reported behaviors indicative of cultural learning, such as close observation of adult skills by infants, and the use of similar foraging techniques within a population over many generations. Although experimental studies have shown that chimpanzees are able to learn complex behaviors by observation, it is unclear how closely these studies simulate the learning environment found in the wild. In the present study we have used a diffusion chain paradigm, whereby a behavior is passed from one individual to the next in a linear sequence in an attempt to simulate intergenerational transmission of a foraging skill. Using a powerful three-group, two-action methodology, we found that alternative methods used to obtain food from a foraging device (“lift door” versus “slide door”) were accurately transmitted along two chains of six and five chimpanzees, respectively, such that the last chimpanzee in the chain used the same method as the original trained model. The fidelity of transmission within each chain is remarkable given that several individuals in the no-model control group were able to discover either method by individual exploration. A comparative study with human children revealed similar results. This study is the first to experimentally demonstrate the linear transmission of alternative foraging techniques by non-human primates. Our results show that chimpanzees have a capacity to sustain local traditions across multiple simulated generations.
Address Centre for Social Learning and Cognitive Evolution, School of Psychology, University of St. Andrews, Fife KY16 9JP, United Kingdom
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ISSN 0027-8424 ISBN Medium
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Notes PMID:16938863 Approved no
Call Number refbase @ user @ Serial 159
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Author Hostikka, S.L.; Eddy, R.L.; Byers, M.G.; Hoyhtya, M.; Shows, T.B.; Tryggvason, K.
Title (up) Identification of a distinct type IV collagen alpha chain with restricted kidney distribution and assignment of its gene to the locus of X chromosome-linked Alport syndrome Type Journal Article
Year 1990 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.
Volume 87 Issue 4 Pages 1606-1610
Keywords Amino Acid Sequence; Base Sequence; Chromosome Mapping; Cloning, Molecular; Collagen/*genetics; Epitopes/analysis; Female; Fluorescent Antibody Technique; Gene Library; *Genes; Humans; Immunoblotting; Kidney/cytology/*metabolism; Macromolecular Substances; Molecular Sequence Data; Nephritis, Hereditary/*genetics; Oligopeptides/chemical synthesis/immunology; Placenta/metabolism; Pregnancy; Restriction Mapping; Sequence Homology, Nucleic Acid; *X Chromosome
Abstract We have identified and extensively characterized a type IV collagen alpha chain, referred to as alpha 5(IV). Four overlapping cDNA clones isolated contain an open reading frame for 543 amino acid residues of the carboxyl-terminal end of a collagenous domain, a 229-residue carboxyl-terminal noncollagenous domain, and 1201 base pairs coding for a 3' untranslated region. The collagenous Gly-Xaa-Yaa repeat sequence has five imperfections that coincide with those in the corresponding region of the alpha 1(IV) chain. The noncollagenous domain has 12 conserved cysteine residues and 83% and 63% sequence identity with the noncollagenous domains of the alpha 1(IV) and alpha 2(IV) chains, respectively. The alpha 5(IV) chain has less sequence identity with the putative bovine alpha 3(IV) and alpha 4(IV) chains. Antiserum against an alpha 5(IV) synthetic peptide stained a polypeptide chain of about 185 kDa by immunoblot analysis and immunolocalization of the chain in human kidney was almost completely restricted to the glomerulus. The gene was assigned to the Xq22 locus by somatic cell hybrids and in situ hybridization. This may be identical or close to the locus of the X chromosome-linked Alport syndrome that is believed to be a type IV collagen disease.
Address Biocenter, University of Oulu, Finland
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Notes PMID:1689491 Approved no
Call Number Equine Behaviour @ team @ Serial 5291
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Author Chase, I.D.; Tovey, C.; Spangler-Martin, D.; Manfredonia, M.
Title (up) Individual differences versus social dynamics in the formation of animal dominance hierarchies Type Journal Article
Year 2002 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.
Volume 99 Issue 8 Pages 5744-5749
Keywords Animals; *Behavior, Animal; Fishes; Humans; *Social Behavior; *Social Dominance
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.
Address Department of Sociology, State University of New York, Stony Brook, NY 11794-4356, USA. Ichase@notes.cc.sunysb.edu
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Notes PMID:11960030 Approved no
Call Number refbase @ user @ Serial 442
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Author Liker, A.; Bókony, V.
Title (up) Larger groups are more successful in innovative problem solving in house sparrows Type Journal Article
Year 2009 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc Natl Acad Sci USA
Volume 106 Issue 19 Pages 7893-7898
Keywords
Abstract Group living offers well-known benefits to animals, such as better predator avoidance and increased foraging success. An important additional, but so far neglected, advantage is that groups may cope more effectively with unfamiliar situations through faster innovations of new solutions by some group members. We tested this hypothesis experimentally by presenting a new foraging task of opening a familiar feeder in an unfamiliar way to house sparrows in small and large groups (2 versus 6 birds). Group size had strong effects on problem solving: sparrows performed 4 times more and 11 times faster openings in large than in small groups, and all members of large groups profited by getting food sooner (7 times on average). Independently from group size, urban groups were more successful than rural groups. The disproportionately higher success in large groups was not a mere consequence of higher number of attempts, but was also related to a higher effectiveness of problem solving (3 times higher proportion of successful birds). The analyses of the birds' behavior suggest that the latter was not explained by either reduced investment in antipredator vigilance or reduced neophobia in large groups. Instead, larger groups may contain more diverse individuals with different skills and experiences, which may increase the chance of solving the task by some group members. Increased success in problem solving may promote group living in animals and may help them to adapt quickly to new situations in rapidly-changing environments.
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Call Number Equine Behaviour @ team @ Serial 6538
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Author Morand-Ferron, J.; Quinn, J.L.
Title (up) Larger groups of passerines are more efficient problem solvers in the wild Type Journal Article
Year 2011 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc Natl Acad Sci USA
Volume 108 Issue 38 Pages 15898-15903
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Abstract Group living commonly helps organisms face challenging environmental conditions. Although a known phenomenon in humans, recent findings suggest that a benefit of group living in animals generally might be increased innovative problem-solving efficiency. This benefit has never been demonstrated in a natural context, however, and the mechanisms underlying improved efficiency are largely unknown. We examined the problem-solving performance of great and blue tits at automated devices and found that efficiency increased with flock size. This relationship held when restricting the analysis to naive individuals, demonstrating that larger groups increased innovation efficiency. In addition to this effect of naive flock size, the presence of at least one experienced bird increased the frequency of solving, and larger flocks were more likely to contain experienced birds. These findings provide empirical evidence for the “pool of competence” hypothesis in nonhuman animals. The probability of success also differed consistently between individuals, a necessary condition for the pool of competence hypothesis. Solvers had a higher probability of success when foraging with a larger number of companions and when using devices located near rather than further from protective tree cover, suggesting a role for reduced predation risk on problem-solving efficiency. In contrast to traditional group living theory, individuals joining larger flocks benefited from a higher seed intake, suggesting that group living facilitated exploitation of a novel food source through improved problem-solving efficiency. Together our results suggest that both ecological and social factors, through reduced predation risk and increased pool of competence, mediate innovation in natural populations.
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Call Number Equine Behaviour @ team @ Serial 6539
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Author Mettke-Hofmann, C.; Gwinner, E.
Title (up) Long-term memory for a life on the move Type Journal Article
Year 2003 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.
Volume 100 Issue 10 Pages 5863-5866
Keywords Animals; Germany; Israel; Memory/*physiology; Models, Biological; Periodicity; Songbirds/*physiology
Abstract Evidence is accumulating that cognitive abilities are shaped by the specific ecological conditions to which animals are exposed. Long-distance migratory birds may provide a striking example of this. Field observations have shown that, at least in some species, a substantial proportion of individuals return to the same breeding, wintering, and stopover sites in successive years. This observation suggests that migrants have evolved special cognitive abilities that enable them to accomplish these feats. Here we show that memory of a particular feeding site persisted for at least 12 months in a long-distance migrant, whereas a closely related nonmigrant could remember such a site for only 2 weeks. Thus, it seems that the migratory lifestyle has influenced the learning and memorizing capacities of migratory birds. These results build a bridge between field observations suggesting special memorization feats of migratory birds and previous neuroanatomical results from the same two species indicating an increase in relative hippocampal size from the first to the second year of life in the migrant but not in the nonmigrant.
Address Max Planck Research Centre for Ornithology, Department of Biological Rhythms and Behaviour, Von-der-Tann-Strasse 7, 82346 Andechs, Germany. mettke-hofmann@erl.ornithol.mpg.de
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Notes PMID:12719527 Approved no
Call Number refbase @ user @ Serial 511
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Author Drea, C.M.; Wallen, K.
Title (up) Low-status monkeys “play dumb” when learning in mixed social groups Type Journal Article
Year 1999 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.
Volume 96 Issue 22 Pages 12965-12969
Keywords
Abstract Many primates, including humans, live in complex hierarchical societies where social context and status affect daily life. Nevertheless, primate learning studies typically test single animals in limited laboratory settings where the important effects of social interactions and relationships cannot be studied. To investigate the impact of sociality on associative learning, we compared the individual performances of group-tested rhesus monkeys (Macaca mulatta) across various social contexts. We used a traditional discrimination paradigm that measures an animal's ability to form associations between cues and the obtaining of food in choice situations; but we adapted the task for group testing. After training a 55-member colony to separate on command into two subgroups, composed of either high- or low-status families, we exposed animals to two color discrimination problems, one with all monkeys present (combined condition), the other in their “dominant” and “subordinate” cohorts (split condition). Next, we manipulated learning history by testing animals on the same problems, but with the social contexts reversed. Monkeys from dominant families excelled in all conditions, but subordinates performed well in the split condition only, regardless of learning history. Subordinate animals had learned the associations, but expressed their knowledge only when segregated from higher-ranking animals. Because aggressive behavior was rare, performance deficits probably reflected voluntary inhibition. This experimental evidence of rank-related, social modulation of performance calls for greater consideration of social factors when assessing learning and may also have relevance for the evaluation of human scholastic achievement.
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Notes 10.1073/pnas.96.22.12965 Approved no
Call Number Serial 2093
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Author Begall, S.; Cervený, J.; Neef, J.; Vojtech, O.; Burda, H.
Title (up) Magnetic alignment in grazing and resting cattle and deer Type Journal Article
Year 2008 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc. Natl. Acad. Sci. U.S.A.
Volume 105 Issue 36 Pages 13451-13455
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Abstract We demonstrate by means of simple, noninvasive methods (analysis of satellite images, field observations, and measuring “deer beds” in snow) that domestic cattle (n = 8,510 in 308 pastures) across the globe, and grazing and resting red and roe deer (n = 2,974 at 241 localities), align their body axes in roughly a north–south direction. Direct observations of roe deer revealed that animals orient their heads northward when grazing or resting. Amazingly, this ubiquitous phenomenon does not seem to have been noticed by herdsmen, ranchers, or hunters. Because wind and light conditions could be excluded as a common denominator determining the body axis orientation, magnetic alignment is the most parsimonious explanation. To test the hypothesis that cattle orient their body axes along the field lines of the Earth's magnetic field, we analyzed the body orientation of cattle from localities with high magnetic declination. Here, magnetic north was a better predictor than geographic north. This study reveals the magnetic alignment in large mammals based on statistically sufficient sample sizes. Our findings open horizons for the study of magnetoreception in general and are of potential significance for applied ethology (husbandry, animal welfare). They challenge neuroscientists and biophysics to explain the proximate mechanisms.
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Notes 10.1073/pnas.0803650105 Approved no
Call Number Equine Behaviour @ team @ Serial 5316
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