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Author Gröschl, M.; Wagner, R.; Rauh, M.; Dörr, H.G. url  doi
openurl 
  Title Stability of salivary steroids: the influences of storage, food and dental care Type Journal Article
  Year 2001 Publication Steroids Abbreviated Journal  
  Volume 66 Issue (up) 10 Pages 737-741  
  Keywords Cortisol; 17OH-Progesterone; Progesterone; Saliva; Stability  
  Abstract We studied influences of dental care, food and storage on the reproducibility of salivary steroid levels. Cortisol (F), 17OH-progesterone (17OHP) and Progesterone (P) were measured using adapted commercial radioimmunoassays. Saliva samples of healthy adults (n = 15; m:8; f:7) were collected directly before and after dental care, and directly before and after breakfast with various foodstuffs. A second experiment investigated stability of steroids under different storage conditions. Four series of identical saliva portions (I: Native saliva; II: Centrifuged saliva; III: Saliva with trifluor acetate (TFA); IV: Saliva with 0.5% NaN3) were stored at room temperature and at 4°C for up to three weeks. To demonstrate influences of repeated thawing and re-freezing of saliva on steroid values, saliva samples (n = 15) were divided into identical portions. These portions were frozen and re-thawed up to 5 times before measurement. Neither dental care nor intake of bread or milk effected the reproducibility of F, 170HP, and P. Steroid levels decreased significantly in the course of three weeks under different storage conditions (P < 0.001). This decrease was clinically relevant from the second week onward, with exception of NaN3 treated samples. After repeated freezing and re-thawing 17OHP and P decreased slightly (about 5%). Only F decreased significantly after the third thawing (P < 0.001). The results show the usefulness of standardized handling of saliva samples for improving reproducibility and reliability of salivary steroid measurements.  
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  ISSN 0039-128x ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5561  
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Author McCreery, E.K.; Robbins, R.L. doi  openurl
  Title Proximate Explanations For Failed Pack Formation In Lycaon Pictus Type Journal Article
  Year 2001 Publication Behaviour Abbreviated Journal Behaviour  
  Volume 138 Issue (up) 11 Pages 1467-1479  
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  Abstract Among the most social of all canids, the endangered African wild dog lives in packs in which the alpha pair typically monopolizes breeding while nonreproductive members help care for the offspring. Consequently, the size of the breeding population is directly related to the number of packs in the population. Although the formation of new packs affects both individual fitness and population dynamics, little is known about the process of pack formation and the proximate factors that influence the outcome. In this paper, seven cases of attempted pack formation are documented, of which four failed. Three possible explanations for pack annulment are considered: group size, mate competition, and mate choice (i.e. group compatibility). Our observations suggest that group compatibility can influence whether stable reproductive units form. The influence of individual behavior, via the process of pack formation, on population dynamics is discussed. The potential conservation application of the theoretical study of wild dog pack formation is highlighted.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 2199  
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Author Biegler, R.; McGregor, A.; Krebs, J.R.; Healy, S.D. url  doi
openurl 
  Title A larger hippocampus is associated with longer-lasting spatial memory 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 (up) 12 Pages 6941-6944  
  Keywords  
  Abstract Volumetric studies in a range of animals (London taxi-drivers, polygynous male voles, nest-parasitic female cowbirds, and a number of food-storing birds) have shown that the size of the hippocampus, a brain region essential to learning and memory, is correlated with tasks involving an extra demand for spatial learning and memory. In this paper, we report the quantitative advantage that food storers gain from such an enlargement. Coal tits () a food-storing species, performed better than great tits (), a nonstoring species, on a task that assessed memory persistence but not on a task that assessed memory resolution or on one that tested memory capacity. These results show that the advantage to the food-storing species associated with an enlarged hippocampus is one of memory persistence.  
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  Notes 10.1073/pnas.121034798 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4743  
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Author Mouritsen, K.N. openurl 
  Title Hitch-hiking parasite: a dark horse may be the real rider Type Journal Article
  Year 2001 Publication International Journal for Parasitology Abbreviated Journal Int J Parasitol  
  Volume 31 Issue (up) 13 Pages 1417-1420  
  Keywords Animals; *Behavior, Animal; Ecology; Host-Parasite Relations; Snails/*parasitology; Trematoda/growth & development/*physiology; Trematode Infections/transmission  
  Abstract Many parasites engaged in complex life cycles manipulate their hosts in a way that facilitates transmission between hosts. Recently, a new category of parasites (hitch-hikers) has been identified that seem to exploit the manipulating effort of other parasites with similar life cycle by preferentially infecting hosts already manipulated. Thomas et al. (Evolution 51 (1997) 1316) showed that the digenean trematodes Microphallus papillorobustus (the manipulator) and Maritrema subdolum (the hitch-hiker) were positively associated in field samples of gammarid amphipods (the intermediate host), and that the behaviour of Maritrema subdolum rendered it more likely to infect manipulated amphipods than those uninfected by M. papillorobustus. Here I provide experimental evidence demonstrating that M. subdolum is unlikely to be a hitch-hiker in the mentioned system, whereas the lucky candidate rather is the closely related but little known species, Microphallidae sp. no. 15 (Parassitologia 22 (1980) 1). As opposed to the latter species, Maritrema subdolum does not express the appropriate cercarial behaviour for hitch-hiking.  
  Address Department of Marine Ecology, Institute of Biological Sciences, University of Aarhus, Finlandsgade 14, DK-8200 Aarhus N, Denmark. kim.mouritsen@stonebow.otago.ac.nz  
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  Series Volume Series Issue Edition  
  ISSN 0020-7519 ISBN Medium  
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  Notes PMID:11595227 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2645  
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Author Peake, T.M.; Terry, A.M.; McGregor, P.K.; Dabelsteen, T. doi  openurl
  Title Male great tits eavesdrop on simulated male-to-male vocal interactions Type Journal Article
  Year 2001 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci  
  Volume 268 Issue (up) 1472 Pages 1183-1187  
  Keywords Animals; Male; Songbirds/*physiology; *Vocalization, Animal  
  Abstract Animal communication generally occurs in the environment of a network of several potential signallers and receivers. Within a network environment, it is possible to gain relative information about conspecifics by eavesdropping on signalling interactions. We presented male great tits with the opportunity to gain such information by simulating singing interactions using two loudspeakers. Interactions were presented so that relevant information was not available in the absolute singing behaviour of either individual, only in the relative timing of their songs in the interaction as a whole. We then assayed the information extracted by focal males by subsequently introducing one of the 'interactants' (i.e. loudspeakers) into the territory of the focal male. Focal males responded with a reduced song output to males that had just 'lost' an interaction. Focal males did not respond significantly differently to 'winners' as compared with intruders recently involved in an interaction that contained no consistent information. Focal males also responded by switching song types more often when encountering males that had recently been involved in a low-intensity interaction. These results provide the clearest evidence yet that male songbirds extract information from signal interactions between conspecifics in the field.  
  Address Department of Animal Behaviour, Zoological Institute, Tagensvej 16, University of Copenhagen, 2200 Copenhagen N, Denmark. tmpeake@zi.ku.dk  
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  Series Volume Series Issue Edition  
  ISSN 0962-8452 ISBN Medium  
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  Notes PMID:11375107 Approved no  
  Call Number refbase @ user @ Serial 712  
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Author Tebbich, S.; Taborsky, M.; Fessl, B.; Blomqvist, D. url  doi
openurl 
  Title Do woodpecker finches acquire tool-use by social learning? Type Journal Article
  Year 2001 Publication Proceedings of the Royal Society of London B: Biological Sciences Abbreviated Journal Proc. Roy. Soc. Lond. B Biol. Sci.  
  Volume 268 Issue (up) 1482 Pages 2189-2193  
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  Abstract Tool–use is widespread among animals, but except in primates the development of this behaviour is poorly known. Here, we report on the first experimental study to our knowledge of the mechanisms underlying the acquisition of tool–use in a bird species. The woodpecker finch Cactospiza pallida, endemic to the Galápagos Islands, is a famous textbook example of tool–use in animals. This species uses modified twigs or cactus spines to pry arthropods out of tree holes. Using nestlings and adult birds from the field, we tested experimentally whether woodpecker finches learn tool–use socially. We show that social learning is not essential for the development of tool–use: all juveniles developed tool–use regardless of whether or not they had a tool–using model. However, we found that not all adult woodpecker finches used tools in our experiments. These non–tool–using individuals also did not learn this task by observing tool–using conspecifics. Our results suggest that tool–use behaviour depends on a very specific learning disposition that involves trial–and–error learning during a sensitive phase early in ontogeny.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5914  
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Author Johnstone, R.A. doi  openurl
  Title 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 (up) 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 Gulotta, M.; Gilmanshin, R.; Buscher, T.C.; Callender, R.H.; Dyer, R.B. openurl 
  Title Core formation in apomyoglobin: probing the upper reaches of the folding energy landscape Type Journal Article
  Year 2001 Publication Biochemistry Abbreviated Journal Biochemistry  
  Volume 40 Issue (up) 17 Pages 5137-5143  
  Keywords Animals; Apoproteins/*chemistry; Computer Simulation; Horses; Hydrogen-Ion Concentration; Kinetics; Models, Molecular; Myoglobin/*chemistry; *Protein Folding; Protein Structure, Secondary; Protein Structure, Tertiary; Spectrometry, Fluorescence/instrumentation/methods; Thermodynamics; Tryptophan/chemistry  
  Abstract An acid-destabilized form of apomyoglobin, the so-called E state, consists of a set of heterogeneous structures that are all characterized by a stable hydrophobic core composed of 30-40 residues at the intersection of the A, G, and H helices of the protein, with little other secondary structure and no other tertiary structure. Relaxation kinetics studies were carried out to characterize the dynamics of core melting and formation in this protein. The unfolding and/or refolding response is induced by a laser-induced temperature jump between the folded and unfolded forms of E, and structural changes are monitored using the infrared amide I' absorbance at 1648-1651 cm(-1) that reports on the formation of solvent-protected, native-like helix in the core and by fluorescence emission changes from apomyoglobin's Trp14, a measure of burial of the indole group of this residue. The fluorescence kinetics data are monoexponential with a relaxation time of 14 micros. However, infrared kinetics data are best fit to a biexponential function with relaxation times of 14 and 59 micros. These relaxation times are very fast, close to the limits placed on folding reactions by diffusion. The 14 micros relaxation time is weakly temperature dependent and thus represents a pathway that is energetically downhill. The appearance of this relaxation time in both the fluorescence and infrared measurements indicates that this folding event proceeds by a concomitant formation of compact secondary and tertiary structures. The 59 micros relaxation time is much more strongly temperature dependent and has no fluorescence counterpart, indicating an activated process with a large energy barrier wherein nonspecific hydrophobic interactions between helix A and the G and H helices cause some helix burial but Trp14 remains solvent exposed. These results are best fit by a multiple-pathway kinetic model when U collapses to form the various folded core structures of E. Thus, the results suggest very robust dynamics for core formation involving multiple folding pathways and provide significant insight into the primary processes of protein folding.  
  Address Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA  
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  ISSN 0006-2960 ISBN Medium  
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  Notes PMID:11318635 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3789  
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Author McGreevy, P.D.; Webster, A.J.; Nicol, C.J. openurl 
  Title Study of the behaviour, digestive efficiency and gut transit times of crib-biting horses Type Journal Article
  Year 2001 Publication The Veterinary record Abbreviated Journal Vet. Rec.  
  Volume 148 Issue (up) 19 Pages 592-596  
  Keywords Animals; Behavior, Animal/*physiology; Case-Control Studies; *Digestion; *Gastrointestinal Motility/drug effects; Horse Diseases/*physiopathology; Horses/*physiology/psychology; Male; Stereotyped Behavior/*physiology; Sulfapyridine/blood; Sulfasalazine/diagnostic use/pharmacology  
  Abstract The spontaneous behaviour and the apparent digestibility of dry matter and fibre and transit times of digesta were compared in four normal horses and four crib-biters. A technique was developed for measuring total gut transit times (TGTT) by using single-stool analysis of the passage of radio-opaque polyethylene markers. Longer TGTT were recorded in the crib-biters than in the normal horses but the orocaecal transit times did not differ. The crib-biters rested less than the normal horses.  
  Address Department of Clinical Veterinary Science, University of Bristol, Langford  
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  Series Volume Series Issue Edition  
  ISSN 0042-4900 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:11386445 Approved no  
  Call Number refbase @ user @ Serial 86  
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Author Virga, V.; Houpt, K.A. openurl 
  Title Prevalence of placentophagia in horses Type Journal Article
  Year 2001 Publication Equine veterinary journal Abbreviated Journal Equine Vet J  
  Volume 33 Issue (up) 2 Pages 208-210  
  Keywords Animals; *Behavior, Animal; Colic/epidemiology/*veterinary; Exploratory Behavior; *Feeding Behavior; Female; Horse Diseases/*epidemiology; Horses; Incidence; New York/epidemiology; *Placenta; Postpartum Period; Pregnancy; Prevalence; Questionnaires  
  Abstract  
  Address Animal Behavior Clinic, Cornell University Hospital for Animals, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0425-1644 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:11266073 Approved no  
  Call Number refbase @ user @ Serial 31  
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