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Author (up) Cheng, K.
Title Generalisation: mechanistic and functional explanations Type Journal Article
Year 2002 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 5 Issue 1 Pages 33-40
Keywords Adaptation, Physiological; Animals; Bees/*physiology; Cognition; Evolution; Models, Psychological
Abstract An overview of mechanistic and functional accounts of stimulus generalisation is given. Mechanistic accounts rely on the process of spreading activation across units representing stimuli. Different models implement the spread in different ways, ranging from diffusion to connectionist networks. A functional account proposed by Shepard analyses the probabilistic structure of the world for invariants. A universal law based on one such invariant claims that under a suitable scaling of the stimulus dimension, generalisation gradients should be approximately exponential in shape. Data from both vertebrates and invertebrates so far uphold Shepard's law. Some data on spatial generalisation in honeybees are presented to illustrate how Shepard's law can be used to determine the metric for combining discrepancies in different stimulus dimensions. The phenomenon of peak shift is discussed. Comments on mechanistic and functional approaches to generalisation are given.
Address Department of Psychology, Macquarie University, Sydney, NSW 2109, Australia. kcheng@axon.bhs.mq.edu.au
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:11957400 Approved no
Call Number Equine Behaviour @ team @ Serial 2612
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Author (up) Cheng, K.; Wignall, A.E.
Title Honeybees (Apis mellifera) holding on to memories: response competition causes retroactive interference effects Type Journal Article
Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 9 Issue 2 Pages 141-150
Keywords Animals; Bees/*physiology; Choice Behavior/physiology; *Cues; Memory/*physiology; Perceptual Masking/physiology; Space Perception/*physiology; Spatial Behavior/*physiology
Abstract Five experiments on honeybees examined how the learning of a second task interferes with what was previously learned. Free flying bees were tested for landmark-based memory in variations on a paradigm of retroactive interference. Bees first learned Task 1, were tested on Task 1 (Test 1), then learned Task 2, and were tested again on Task 1 (Test 2). A 60-min delay (waiting in a box) before Test 2 caused no performance decrements. If the two tasks had conflicting response requirements, (e.g., target right of a green landmark in Task 1 and left of a blue landmark in Task 2), then a strong decrement on Test 2 was found (retroactive interference effect). When response competition was minimised during training or testing, however, the decrement on Test 2 was small or nonexistent. The results implicate response competition as a major contributor to the retroactive interference effect. The honeybee seems to hold on to memories; new memories do not wipe out old ones.
Address Centre for the Integrative Study of Animal Behaviour and Department of Psychology, Macquarie University, Sydney, NSW 2109, Australia. ken@galliform.bhs.mq.edu.au
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:16374626 Approved no
Call Number Equine Behaviour @ team @ Serial 2477
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Author (up) Cheung, C.; Akiyama, T.E.; Ward, J.M.; Nicol, C.J.; Feigenbaum, L.; Vinson, C.; Gonzalez, F.J.
Title Diminished hepatocellular proliferation in mice humanized for the nuclear receptor peroxisome proliferator-activated receptor alpha Type Journal Article
Year 2004 Publication Cancer research Abbreviated Journal Cancer Res
Volume 64 Issue 11 Pages 3849-3854
Keywords Animals; Anticholesteremic Agents/pharmacology; Carcinogens/pharmacology; Cell Division; DNA Replication/drug effects; Fatty Acids/metabolism; Hepatocytes/cytology/drug effects/metabolism/*physiology; Humans; Mice; Mice, Transgenic; Oxidation-Reduction; Peroxisome Proliferators/pharmacology; Pyrimidines/pharmacology; Receptors, Cytoplasmic and Nuclear/genetics/*physiology; Species Specificity; Transcription Factors/genetics/*physiology
Abstract Lipid-lowering fibrate drugs function as agonists for the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha). Sustained activation of PPARalpha leads to the development of liver tumors in rats and mice. However, humans appear to be resistant to the induction of peroxisome proliferation and the development of liver cancer by fibrate drugs. The molecular basis of this species difference is not known. To examine the mechanism determining species differences in peroxisome proliferator response between mice and humans, a PPARalpha-humanized mouse line was generated in which the human PPARalpha was expressed in liver under control of the tetracycline responsive regulatory system. The PPARalpha-humanized and wild-type mice responded to treatment with the potent PPARalpha ligand Wy-14643 as revealed by induction of genes encoding peroxisomal and mitochondrial fatty acid metabolizing enzymes and resultant decrease of serum triglycerides. However, surprisingly, only the wild-type mice and not the PPARalpha-humanized mice exhibited hepatocellular proliferation as revealed by elevation of cell cycle control genes, increased incorporation of 5-bromo-2'-deoxyuridine into hepatocyte nuclei, and hepatomegaly. These studies establish that following ligand activation, the PPARalpha-mediated pathways controlling lipid metabolism are independent from those controlling the cell proliferation pathways. These findings also suggest that structural differences between human and mouse PPARalpha are responsible for the differential susceptibility to the development of hepatocarcinomas observed after treatment with fibrates. The PPARalpha-humanized mice should serve as models for use in drug development and human risk assessment and to determine the mechanism of hepatocarcinogenesis of peroxisome proliferators.
Address Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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 0008-5472 ISBN Medium
Area Expedition Conference
Notes PMID:15172993 Approved no
Call Number refbase @ user @ Serial 74
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Author (up) Chiandetti, C.; Regolin, L.; Sovrano, V.A.; Vallortigara, G.
Title Spatial reorientation: the effects of space size on the encoding of landmark and geometry information Type Journal Article
Year 2007 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 10 Issue 2 Pages 159-168
Keywords Animals; Chickens/*physiology; *Feeding Behavior; Male; Orientation/*physiology; Pattern Recognition, Visual/*physiology; *Space Perception
Abstract The effects of the size of the environment on animals' spatial reorientation was investigated. Domestic chicks were trained to find food in a corner of either a small or a large rectangular enclosure. A distinctive panel was located at each of the four corners of the enclosures. After removal of the panels, chicks tested in the small enclosure showed better retention of geometrical information than chicks tested in the large enclosure. In contrast, after changing the enclosure from a rectangular-shaped to a square-shaped one, chicks tested in the large enclosure showed better retention of landmark (panels) information than chicks tested in the small enclosure. No differences in the encoding of the overall arrangement of landmarks were apparent when chicks were tested for generalisation in an enclosure differing from that of training in size together with a transformation (affine transformation) that altered the geometric relations between the target and the shape of the environment. These findings suggest that primacy of geometric or landmark information in reorientation tasks depends on the size of the experimental space, likely reflecting a preferential use of the most reliable source of information available during visual exploration of the environment.
Address Department of Psychology and B.R.A.I.N. Centre for Neuroscience, University of Trieste, Via S. Anastasio 12, 34123, Trieste, Italy. cchiandetti@univ.trieste.it
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:17136416 Approved no
Call Number Equine Behaviour @ team @ Serial 2433
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Author (up) Chiba, K.; Ikai, A.; Kawamura-Konishi, Y.; Kihara, H.
Title Kinetic study on myoglobin refolding monitored by five optical probe stopped-flow methods Type Journal Article
Year 1994 Publication Proteins Abbreviated Journal Proteins
Volume 19 Issue 2 Pages 110-119
Keywords Animals; Chromatography, Gel; Circular Dichroism; Horses; Kinetics; Metmyoglobin/analogs & derivatives/chemistry; Myoglobin/*chemistry; *Protein Folding; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Urea
Abstract The refolding kinetics of horse cyanometmyoglobin induced by concentration jump of urea was investigated by five optical probe stopped-flow methods: absorption at 422 nm, tryptophyl fluorescence at around 340 nm, circular dichroism (CD) at 222 nm, CD at 260 nm, and CD at 422 nm. In the refolding process, we detected three phases with rate constants of > 1 x 10(2) s-1, (4.5-9.3) s-1, and (2-5) x 10(-3) s-1. In the fastest phase, a substantial amount of secondary structure (approximately 40%) is formed within the dead time of the CD stopped-flow apparatus (10.7 ms). The kinetic intermediate populated in the fastest phase is shown to capture a hemindicyanide, suggesting that a “heme pocket precursor” recognized by hemindicyanide must be constructed within the dead time. In the middle phase, most of secondary and tertiary structures, especially around the captured hemindicyanide, have been constructed. In the slowest phase, we detected a minor structural rearrangement accompanying the ligand-exchange reaction in the fifth coordination of ferric iron. We present a possible model for the refolding process of myoglobin in the presence of the heme group.
Address Laboratory of Biodynamics, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Kanagawa, Japan
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 0887-3585 ISBN Medium
Area Expedition Conference
Notes PMID:8090705 Approved no
Call Number Equine Behaviour @ team @ Serial 3799
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Author (up) Chiesa, A.D.; Pecchia, T.; Tommasi, L.; Vallortigara, G.
Title Multiple landmarks, the encoding of environmental geometry and the spatial logics of a dual brain Type Journal Article
Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 9 Issue 4 Pages 281-293
Keywords Animals; Association Learning/*physiology; Chickens; *Cues; Dominance, Cerebral/*physiology; *Environment; Exploratory Behavior/*physiology; Logic; Space Perception/*physiology; Spatial Behavior/physiology
Abstract A series of place learning experiments was carried out in young chicks (Gallus gallus) in order to investigate how the geometry of a landmark array and that of a walled enclosure compete when disoriented animals could rely on both of them to re-orient towards the centre of the enclosure. A square-shaped array (four wooden sticks) was placed in the middle of a square-shaped enclosure, the two structures being concentric. Chicks were trained to ground-scratch to search for food hidden in the centre of the enclosure (and the array). To check for effects of array degradation, one, two, three or all landmarks were removed during test trials. Chicks concentrated their searching activity in the central area of the enclosure, but their accuracy was inversely contingent on the number of landmarks removed; moreover, the landmarks still present within the enclosure appeared to influence the shape of the searching patterns. The reduction in the number of landmarks affected the searching strategy of chicks, suggesting that they had focussed mainly on local cues when landmarks were present within the enclosure. When all the landmarks were removed, chicks searched over a larger area, suggesting an absolute encoding of distances from the local cues and less reliance on the relationships provided by the geometry of the enclosure. Under conditions of monocular vision, chicks tended to rely on different strategies to localize the centre on the basis of the eye (and thus the hemisphere) in use, the left hemisphere attending to details of the environment and the right hemisphere attending to the global shape.
Address Department of Psychology and B.R.A.I.N. Centre for Neuroscience, University of Trieste, via S. Anastasio 12, 34100, Trieste, Italy
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:16941155 Approved no
Call Number Equine Behaviour @ team @ Serial 2443
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Author (up) Chilton, N.B.
Title The use of nuclear ribosomal DNA markers for the identification of bursate nematodes (order Strongylida) and for the diagnosis of infections Type Journal Article
Year 2004 Publication Animal Health Research Reviews / Conference of Research Workers in Animal Diseases Abbreviated Journal Anim Health Res Rev
Volume 5 Issue 2 Pages 173-187
Keywords Animals; Birds; Cats; DNA Primers; DNA, Helminth/*analysis; DNA, Ribosomal/*analysis; Dogs; Horses; Molecular Diagnostic Techniques/veterinary; Ruminants; Strongylida/*genetics; Strongylida Infections/diagnosis/*veterinary
Abstract Many bursate nematodes are of major importance to animal health. Animals are often parasitized by multiple species that differ in their prevalence, relative abundance and/or pathogenicity. Implementation of effective management strategies for these parasites requires reliable methods for their detection in hosts, identification to the species level and measurement of intensity of infection. One major problem is the difficulty of accurately identifying and distinguishing many species of bursate nematode because of the remarkable morphological similarity of their eggs and larvae. The inability to identify, with confidence, individual nematodes (irrespective of their life-cycle stage) to the species level by morphological methods has often led to a search for species-specific genetic markers. Studies over the past 15 years have shown that sequences of the internal transcribed spacers of ribosomal DNA provide useful genetic markers, providing the basis for the development of PCR-based diagnostic tools. Such molecular methods represent powerful tools for studying the systematics, epidemiology and ecology of bursate nematodes and, importantly, for the specific diagnosis of infections in animals and humans, thus contributing to improved control and prevention strategies for these parasites.
Address Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada. neil.chilton@usask.ca
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 1466-2523 ISBN Medium
Area Expedition Conference
Notes PMID:15984323 Approved no
Call Number Equine Behaviour @ team @ Serial 2628
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Author (up) Chmel, L.; Hasilikova, A.; Hrasko, J.; Vlacilikova, A.
Title The influence of some ecological factors on keratinophilic fungi in the soil Type Journal Article
Year 1972 Publication Sabouraudia Abbreviated Journal Sabouraudia
Volume 10 Issue 1 Pages 26-34
Keywords Animals; Arthrodermataceae/growth & development/isolation & purification/metabolism; Carbohydrates; Czechoslovakia; Ecology; Fungi/growth & development/*isolation & purification/metabolism; Hair; Horses; Humic Substances; Humidity; Keratins/metabolism; Microsporum/isolation & purification; Mitosporic Fungi/isolation & purification; Phosphates; Seasons; Soil; *Soil Microbiology; Species Specificity; Temperature; Trichophyton/isolation & purification
Abstract
Address
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 0036-2174 ISBN Medium
Area Expedition Conference
Notes PMID:5063162 Approved no
Call Number Equine Behaviour @ team @ Serial 2719
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Author (up) Christensen, H.A.; Herrer, A.
Title Attractiveness of sentinel animals to vectors of leishmaniasis in Panama Type Journal Article
Year 1973 Publication The American Journal of Tropical Medicine and Hygiene Abbreviated Journal Am J Trop Med Hyg
Volume 22 Issue 5 Pages 578-584
Keywords Animals; Cricetinae; Dogs; Ecology; Horses; *Insect Vectors; Leishmania/isolation & purification; Leishmaniasis, Mucocutaneous/*etiology; Male; Panama; *Phlebotomus; Rats
Abstract
Address
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 0002-9637 ISBN Medium
Area Expedition Conference
Notes PMID:4729738 Approved no
Call Number Equine Behaviour @ team @ Serial 2712
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Author (up) Christensen, J.W.; Rundgren, M.; Olsson, K.
Title Training methods for horses: habituation to a frightening stimulus Type Journal Article
Year 2006 Publication Equine veterinary journal Abbreviated Journal Equine Vet J
Volume 38 Issue 5 Pages 439-443
Keywords Animals; Behavior, Animal/*physiology; *Conditioning (Psychology); *Fear; Heart Rate/*physiology; Horses/physiology/*psychology; Learning; Male; Random Allocation; *Reinforcement (Psychology); Safety; Time Factors
Abstract REASONS FOR PERFORMING STUDY: Responses of horses in frightening situations are important for both equine and human safety. Considerable scientific interest has been shown in development of reactivity tests, but little effort has been dedicated to the development of appropriate training methods for reducing fearfulness. OBJECTIVES: To investigate which of 3 different training methods (habituation, desensitisation and counter-conditioning) was most effective in teaching horses to react calmly in a potentially frightening situation. HYPOTHESES: 1) Horses are able to generalise about the test stimulus such that, once familiar with the test stimulus in one situation, it appears less frightening and elicits a reduced response even when the stimulus intensity is increased or the stimulus is presented differently; and 2) alternative methods such as desensitisation and counter-conditioning would be more efficient than a classic habituation approach. METHODS: Twenty-seven naive 2-year-old Danish Warmblood stallions were trained according to 3 different methods, based on classical learning theory: 1) horses (n = 9) were exposed to the full stimulus (a moving, white nylon bag, 1.2 x 0.75 m) in 5 daily training sessions until they met a predefined habituation criterion (habituation); 2) horses (n = 9) were introduced gradually to the stimulus and habituated to each step before the full stimulus was applied (desensitisation); 3) horses (n = 9) were trained to associate the stimulus with a positive reward before being exposed to the full stimulus (counter-conditioning). Each horse received 5 training sessions of 3 min per day. Heart rate and behavioural responses were recorded. RESULTS: Horses trained with the desensitisation method showed fewer flight responses in total and needed fewer training sessions to learn to react calmly to test stimuli. Variations in heart rate persisted even when behavioural responses had ceased. In addition, all horses on the desensitisation method eventually habituated to the test stimulus whereas some horses on the other methods did not. CONCLUSIONS AND POTENTIAL RELEVANCE: Desensitisation appeared to be the most effective training method for horses in frightening situations. Further research is needed in order to investigate the role of positive reinforcement, such as offering food, in the training of horses.
Address Danish Institute of Agricultural Sciences, Department of Animal Health, Welfare and Nutrition, Tjele, Denmark
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 0425-1644 ISBN Medium
Area Expedition Conference
Notes PMID:16986605 Approved no
Call Number Serial 1783
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