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Author Cioni, P.; Strambini, G.B. url  openurl
  Title Pressure/temperature effects on protein flexibilty from acrylamide quenching of protein phosphorescence Type Journal Article
  Year 1999 Publication Journal of Molecular Biology Abbreviated Journal  
  Volume 291 Issue 4 Pages 955-964  
  Keywords phosphorescence; tryptophan; acrylamide; quenching; protein dynamics  
  Abstract Pressure is an effective modulator of protein structure and biological function. The influence of hydrostatic pressure ([less-than-or-equals, slant]3 kbar, 10-50[degree sign]C) on conformational dynamics was assessed from the rate of migration of acrylamide through the protein interior. Migration rates in apoazurin, alcohol dehydrogenase and alkaline phosphatase were obtained from the phosphorescence quenching rate constant (kq) of the deeply buried Trp residues. The dominant effect of applied pressure is to slow the diffusion process, although at low temperature, high pressure may also accelerate it. For apoazurin, alcohol dehydrogenase and alkaline phosphatase the activation free volumes, ΔVobs++, derived from the pressure-dependence of kq, ranges from +10, +16 and +20 ml mol-1 at 50[degree sign]C to -20, +5 and 0 ml mol-1 at 10[degree sign]C, respectively. Analysing ΔVobs++ in terms of a positive contribution from cavity expansion and a negative one from peptide hydration, the results emphasise that whereas at warm temperature the formation of cavities plays a dominant role in the migration process, at low temperature the required flexibility may be conferred by internal protein hydration. The relatively small magnitude of both ΔVobs++ and the activation enthalpy (ΔH++=10-20 kcal mol-1) indicates that acrylamide diffusion jumps inside these proteins appear to involve relatively small amplitude structural fluctuations not requiring major unfolding-like transitions. The implication of these findings for the thermodynamic stability of proteins under pressure is discussed.  
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  Call Number refbase @ user @ Serial 3975  
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Author Chapais, B.; Girard, M.; Primi, G. url  doi
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  Title Non-kin alliances, and the stability of matrilineal dominance relations in Japanese macaques Type Journal Article
  Year 1991 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 41 Issue 3 Pages 481-491  
  Keywords  
  Abstract Alliances among kin play a major role in a female's acquisition of her mother's dominance rank in many species of cercopithecines. It is noteworthy, however, that kin rarely form coalitions to challenge females from higher-ranking matrilines, and that matrilineal hierarchies are remarkably stable. One possible reason for the rarity of destabilizing coalitions is that members of high-ranking matrilines form alliances against lower ranking ones. In this paper the patterning of aggressive support among non-kin, and its effect on the stability of rank relations are analysed in a captive group of Japanese macaques, Macaca fuscata, composed of three unrelated matrilines. Analysis of the distribution of non-kin interventions in conflicts between matrilines over a 52-month period revealed a clear pattern of preferential support between the two dominant matrilines against the third-ranking one. This pattern was confirmed experimentally. Any member of the two dominant matrilines was unable, individually, to maintain its rank above the third-ranking matriline, but was able to do so in the presence of the other dominant matriline. Non-kin alliances appear to prevent subordinate females from challenging higher ranking females through revolutionary coalitions (formed among subordinates) or through bridging coalitions (formed among individuals ranking above and below the target). Non-kin support is interpreted in terms of cooperation versus reciprocal altruism.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 2863  
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Author Powell, G.V.N. url  openurl
  Title Experimental analysis of the social value of flocking by starlings (Sturnus vulgaris) in relation to predation and foraging Type Journal Article
  Year 1974 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 22 Issue 2 Pages 501-505  
  Keywords  
  Abstract In groups of ten, indidual starlings, Sturnus vulgaris, spent significantly less time in surveillance than did individuals in smaller groups and responded more quickly than single birds to a flying model hawk. Captive starlings in flocks reduce their individual surveillance efforts, but their combined efforts still enable them to be more effective than single birds in the detection of predators. Foraging behaviour of flocks was observed by placing single starlings with groups of tricoloured blackbirds, Agelaius tricolor; the starlings reduced the time they devoted to surveillance at the same rate as if they were with other starlings.  
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  Notes Approved no  
  Call Number Serial 2147  
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Author Beauchamp, G.; Kacelnik, A. url  doi
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  Title Effects of the knowledge of partners on learning rates in zebra finches Taeniopygia guttata Type Journal Article
  Year 1991 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 41 Issue 2 Pages 247-253  
  Keywords  
  Abstract Many interpretations of the adaptive value of group living involve tranfer of knowledge. However, according to learning theory, being in a pair with a knowledgeable partner can have paradoxical consequences. Obtaining food by following a skilled companion may reduce the ability of naive individuals to learn about clues that signal the occurrence of food. This study examined the relation between learning and following in paris of zebra finches. Knowledgeable partners were trained to obtain food from a computer-controlled dispenser by using the information provided by a signal. For non-knowledgeable partners, the signal was irrelevant and could not be used to predict foraging opportunities. The rate of learning about the signal by naive birds that shared the experience of either knowledgeable or nonknowledgeable tutors was then examined. Naive birds learned more slowly as a result of being in a pair with a knowledgeable than a non-knowledgeable partner. Well-informed mates acted as a reliable cue to predict foraging opportunities, and thus overshadowed the independent signal. The knowledge of a partner influences learning rates in naive individuals, but in the opposite direction to that predicted by earlier accounts of learning in social contexts.  
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  Notes Approved no  
  Call Number Serial 2115  
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Author Syme, G.J.; Syme, L.A. url  openurl
  Title The concept of spatial leadership in farm animals: An experiment with sheep Type Journal Article
  Year 1975 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 23 Issue Part 4 Pages 921-925  
  Keywords  
  Abstract The concept of spatial leadership as applied to farm animals is discussed with particular emphasis on methodological problems. Using three experimental procedures forced spatial leadership orders were measured in a group of Romney ewes. Comparisons between orders showed the effects of both the different experimental tasks and the social context on leadership structure. Both these variables were found to affect the orders obtained. The results are interpreted in terms of the utility of the concept of spatial leadership in domestic animals and the necessity for more systematic procedural investigations in this area.  
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  Notes Approved no  
  Call Number Serial 2039  
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Author Huizinga, H.A.; Boukamp, M.; Smolders, G. url  openurl
  Title Estimated parameters of field performance testing of mares from the Dutch Warmblood riding horse population Type Journal Article
  Year 1990 Publication Livestock Production Science Abbreviated Journal  
  Volume 26 Issue 4 Pages 291-299  
  Keywords competition; genetic parameters; horse breeding; mares; performance test  
  Abstract The field performance testing (FPT) of mares of the Dutch Warmblood riding horse population is evaluated. Phenotypic and genetic parameters of scored traits are estimated and the genetic relationship with performance of half-sibs in dressage and jumping competition are estimated. Data from 1984 to 1987 are used, covering scores from 2023 at least 3-year-old mares. Seven subjectively scored traits are considered, walk, trot, canter, riding ability, character, jumping ability and total score. Analysis of data is according to a sire model. Variance and covariance components are estimated by Restricted Maximum Likelihood (REML) procedures. Estimates of heritability are moderately low for gaits (average 0.19), jumping ability (0.15) and total score (0.17) and extremely low for riding ability (0.03) and character (0.06). Dressage in competition is most correlated with riding ability (0.83) and is moderately correlated with total score (0.41) from FPT of mares. Jumping competition is most correlated with jumping ability (0.48) and not correlated with total score (0.05) from field test of mares. Some possible bias owing to previous knowledge and preselection is discussed. It is concluded that efficiency of present FPT of mares is limited for selection of broodmares for dressage and jumping ability in competition.  
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  Call Number refbase @ user @ Serial 3964  
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Author Huizinga, H.A.; Korver, S.; van der Meij, G.J.W. url  openurl
  Title Stationary performance testing of stallions from the Dutch Warmblood riding horse population. 2. Estimated heritabilities of and correlations between successive judgements of performance traits Type Journal Article
  Year 1991 Publication Livestock Production Science Abbreviated Journal  
  Volume 27 Issue 2-3 Pages 245-254  
  Keywords dressage; genetic parameters; horse; jumping; performance; stallion  
  Abstract The length of test period of stationary performance testing (SPT) of stallions of the Dutch Warmblood riding horse population is evaluated. Heritability of successive judgements of traits and the phenotypic and genetic relations between successive judgements are estimated. Data from 1983-1988 are used, covering scores from 206 mostly 3-year-old stallions. Ten subjectively scored traits are considered: walk, trot, canter, riding ability, jumping ability, free jumping, cross country, character, stable behaviour, training report. Traits are successively scored at about 25, 50, 80 and 100 days in SPT. Missing scores are predicted on basis of the available scores using multiple partial regression coefficients. Validity of this method is checked in an independent data set for walk, trot and canter. The correlations between predicted and realized scores average 0.74, 0.77 and 0.79 when first, first and second, and first, second and third judgements are available, respectively. Variance and covariance components are estimated by restricted maximum likelihood (REML) procedures. Data from SPT are analysed using an animal model. Estimates of heritability are high and constant for gaits during the successive judgements. Except for stable behaviour estimates of heritability, the traits decrease slightly during the successive judgements. Estimates of the phenotypic and genetic correlations between successive judgements are high. It is concluded that length of SPT can be shortened and selection during SPT can be intensified.  
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  Call Number refbase @ user @ Serial 3963  
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Author Huizinga, H.A.; van der Werf, J.H.J.; Korver, S.; van der Meij, G.J.W. url  openurl
  Title Stationary performance testing of stallions from the Dutch Warmblood riding horse population. 1. Estimated genetic parameters of scored traits and the genetic relation with dressage and jumping competition from offspring of breeding stallions Type Journal Article
  Year 1991 Publication Livestock Production Science Abbreviated Journal  
  Volume 27 Issue 2-3 Pages 231-244  
  Keywords dressage; genetic parameters; horse; jumping; performance; stallion  
  Abstract The stationary performance testing (SPT) of stallions as breeding candidates in the Dutch Warmblood riding horse population is evaluated. Genetic and phenotypic parameters of traits scored during SPT and the genetic correlation of these traits with performances in dressage and jumping competition from offspring of breeding stallions are estimated. Data from 1978-1988 are used, covering scores from 337 3-year-old stallions. Eight subjectively scored traits are considered. These traits are: walk; trot; canter; riding ability; show jumping; free jumping; cross country; character. SPT lasts for a period of 100 days. Data from SPT are analysed using an animal model. The relations between SPT of stallions and performances in jumping and dressage competition are analysed with an animal model for SPT data and a sire model for competition data. Variance and covariance components are estimated by restricted maximum likelihood (REML) procedures. Estimates of heritability are high (0.64) for gaits and riding ability, intermediate (0.41) for cross country and medium-high (0.31) for jumping. Estimated genetic correlation between show jumping scored during SPT and jumping in competition from offspring of breeding stallions is 0.84; for dressage this relation is 0.83. Some possible bias due to selection and the subjectivity of scoring is discussed. It is indicated that selection on SPT of stallions before entering breeding service is an effective tool to breed for ability of performance in competition.  
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  Call Number refbase @ user @ Serial 3962  
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Author Huizinga, H.A.; van der Meij, G.J.W. url  openurl
  Title Estimated parameters of performance in jumping and dressage competition of the Dutch Warmblood horse Type Journal Article
  Year 1989 Publication Livestock Production Science Abbreviated Journal  
  Volume 21 Issue 4 Pages 333-345  
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  Abstract The objective of this study is to estimate several genetic parameters in the Dutch Warmblood riding horse population. The traits involved are performances in jumping and dressage competition. The following parameters are estimated: heritabilities for jumping and dressage; phenotypic and genetic correlations between jumping and dressage; and phenotypic and genetic correlations between performances at different ages. These parameters are estimated by restricted maximum likelihood (REML). Data are from 6899 horses with performances in jumping and 10 408 horses with performances in dressage competition. The horses are sired by 205 and 237 stallions for the two traits, respectively. The progeny range in age from 4 to 8 years old. The performance trait is a cumulatively derived score, that reflects the level of performance in competition. A square root transformation of the score is most appropriate to normalize the data. For estimation of phenotypic and genetic parameters the data is split into two data sets according to the age of the sires (offspring sired by older vs. younger stallions). For estimating correlations between performances at 4, 5 and 6 years of age, performances of the offspring out of previous years are linked to the data. The most unbiased estimates of heritability for jumping and dressage are from data derived from the youngest offspring sired by the younger stallions and are 0.20 and 0.10, respectively. Genetic correlation between jumping and dressage ranges from -0.27 to 0.10. The phenotypic correlation between these traits ranges from 0.15 to 0.26. Phenotypic and genetic correlations between performances at 4, 5 and 6 years average 0.95 and 0.75, respectively. These latter results have important implications for genetic evaluation of breeding candidates in the population.  
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  Call Number refbase @ user @ Serial 3966  
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Author Lynch, J.J.; Hinch, G.N.; Bouissou, M.F.; Elwin, R.L.; Green, G.C.; Davies, H.I. url  openurl
  Title Social organization in young Merino and Merino x Border Leicester ewes Type Journal Article
  Year 1989 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 22 Issue 1 Pages 49-63  
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  Abstract The social behaviour of two groups of Merino ewes and one group of Merino x Border Leicester ewes was studied. Each group comprised eight sheep, 15 months of age and, within each group, the animals were of similar liveweight. Dominance rankings were established at each test, but there was little consistency in ewe rank over time. Similarly, little consistency was found in ewe ranking for movement order between pens, and for exploratory and fear test rankings. However, with tests on movement orders, some consistency in the sheep which ranked first was shown. In the field, no aggression was seen while sheep were grazing and there were no occasions when ranking related to movement could be observed. There were short-term associations between pairs of sheep, but these occurred in less than half the individuals. Although the spatial distribution was not studied, the lack of long-term association between pairs would suggest that strong spatial preference does not occur. It is concluded that the social organization of single-age Merino and Merino x Border Leicester ewes is not based on dominance or leadership ranking nor on long-term associations between individuals.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ room B 3.029 Serial 2036  
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