| Records |
| Author |
Abbruzzetti, S.; Viappiani, C.; Sinibaldi, F.; Santucci, R. |
| Title |
Kinetics of histidine dissociation from the heme Fe(III) in N-fragment (residues 1-56) of cytochrome c |
Type |
Journal Article |
| Year |
2004 |
Publication |
The Protein Journal |
Abbreviated Journal |
Protein J |
| Volume |
23 |
Issue |
8 |
Pages |
519-527 |
Keywords  |
Animals; Cytochromes c/*chemistry; Enzyme Activation; Histidine/*chemistry; Horses; Hydrogen-Ion Concentration; Kinetics; Lasers; Ligands; Peptide Mapping; Photolysis; Spectrophotometry |
| Abstract |
We have here investigated the dissociation kinetics of the His side chains axially ligated to the heme-iron in the ferric (1-56 residues) N-fragment of horse cyt c. The ligand deligation induced by acidic pH-jump occurs as a biexponential process with different pre-exponential factors, consistent with a structural heterogeneity in solution and the presence of two differently coordinated species. In analogy with GuHCl-denatured cyt c, our data indicate the presence in solution of two ferric forms of the N-fragment characterized by bis-His coordination, as summarized in the following scheme: His18-Fe(III)-His26 <==> His18-Fe(III)-His33. We have found that the pre-exponential factors depend on the extent of the pH-jump. This may be correlated with the different pKa values shown by His26 and His33; due to steric factors, His26 binds to the heme-Fe(III) less strongly than His33, as recently shown by studies on denatured cyt c. Interestingly, the two lifetimes are affected by temperature but not by the extent of the pH-jump. The lower pKa for the deligation reaction required the use of an improved laser pH-jump setup, capable of inducing changes in H+ concentration as large as 1 mM after the end of the laser pulse. For the ferric N-fragment, close activation entropy values have been determined for the two histidines coordinated to the iron; this result significantly differs from that for GuHCl-denatured cyt c, where largely different values of activation entropy were calculated. This underlines the role played by the missing segment (residues 57-104) peptide chain in discriminating deligation of the “nonnative” His from the sixth coordination position of the metal. |
| Address |
Dipartimento di Fisica, Universita degli Studi di Parma, Parco Area delle Scienze 7/A 43100 Parma, Italy |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1572-3887 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:15648974 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3770 |
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| Author |
Hoang, L.; Maity, H.; Krishna, M.M.G.; Lin, Y.; Englander, S.W. |
| Title |
Folding units govern the cytochrome c alkaline transition |
Type |
Journal Article |
| Year |
2003 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
J Mol Biol |
| Volume |
331 |
Issue |
1 |
Pages |
37-43 |
| Keywords |
Animals; Cytochrome c Group/*chemistry; Horses; Hydrogen/chemistry; Hydrogen-Ion Concentration; Kinetics; Models, Molecular; *Protein Folding; Protein Structure, Tertiary; Spectrum Analysis; Titrimetry |
| Abstract |
The alkaline transition of cytochrome c is a model for protein structural switching in which the normal heme ligand is replaced by another group. Stopped flow data following a jump to high pH detect two slow kinetic phases, suggesting two rate-limiting structure changes. Results described here indicate that these events are controlled by the same structural unfolding reactions that account for the first two steps in the reversible unfolding pathway of cytochrome c. These and other results show that the cooperative folding-unfolding behavior of protein foldons can account for a variety of functional activities in addition to determining folding pathways. |
| Address |
Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6059, USA. lhoang@mail.upenn.edu |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0022-2836 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:12875834 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3781 |
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| Author |
Wilson, M.T.; Ranson, R.J.; Masiakowski, P.; Czarnecka, E.; Brunori, M. |
| Title |
A kinetic study of the pH-dependent properties of the ferric undecapeptide of cytochrome c (microperoxidase) |
Type |
Journal Article |
| Year |
1977 |
Publication |
European Journal of Biochemistry / FEBS |
Abbreviated Journal |
Eur J Biochem |
| Volume |
77 |
Issue |
1 |
Pages |
193-199 |
| Keywords |
Animals; Cyanides; *Cytochrome c Group/metabolism; Ferric Compounds; Horses; Hydrogen-Ion Concentration; Imidazoles; Kinetics; Mathematics; Myocardium/enzymology; *Oligopeptides/metabolism; *Peptide Fragments/metabolism; Protein Binding; Spectrophotometry; Temperature |
| Abstract |
The ferric form of the haem undecapeptide, derived from horse cytochrome c by peptic digestion, undergoes at least three pH-induced transitions with pK values of 3.4, 5.8 and 7.6. Temperature-jump experiments suggest that the first of these is due to the binding of a deprotonated imidazole group to the feric iron while the second and third arise from the binding of the two available amino groups present (the alpha-NH2 of valine and the epsilon-NH2 of lysine). Molecular models indicate that steric retraints on the peptide dictate that these amino groups may only coordinate to iron atoms via intermolecular bonds, thus leading to the polymerization of the peptide. Cyanide binding studies are in agreement with these conclusions and also yield a value of 3.6 X 10(6) M-1 s-1 for the intrinsic combination constant of CN- anion with the haem. A model is proposed which describes the pH-dependent properties of the ferric undecapeptide. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0014-2956 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:20304 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3814 |
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| Author |
Vollmerhaus, B.; Roos, H.; Gerhards, H.; Knospe, C. |
| Title |
[Phylogeny, form and function of canine teeth in the horse] |
Type |
Journal Article |
| Year |
2003 |
Publication |
Anatomia, histologia, embryologia |
Abbreviated Journal |
Anat Histol Embryol |
| Volume |
32 |
Issue |
4 |
Pages |
212-217 |
| Keywords |
Animals; Cuspid/*anatomy & histology/radiography; Evolution; Horses/*anatomy & histology; Male; Phylogeny; *Social Dominance |
| Abstract |
The canine teeth of the horse developed phylogenically from the simple, pointed, short-rooted tooth form of the leaf eating, in pairs living, Eocene horse Hyracotherium and served up to the Oligocene as a means of defense (self preservation). In the Miocene the living conditions of the Merychippus changed and they took to eating grass and adopted as a new behavior the life in a herd. The canine teeth possibly played an important role in fights for social ranking; they changed from a crown form to knife-like shape. In the Pliohippus the canine tooth usually remained in male horses and since the Pliocene, it contributed to the fights between stallions, to ensure that the offspring only came from the strongest animals (preservation of the species). Form and construction of the canine tooth are described and discussed in detail under the above mentioned phylogenic and ethologic aspects. |
| Address |
Institut fur Tieranatomie und Chirurgische Tierklinik der Universitat Munchen, Veterinarstrasse 13, D 80539 Munchen, Deutschland. c-neumueller@anat.vetmed.uni-muenchen.de |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
German |
Summary Language |
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Original Title |
[Zur Phylogenie, Form und Funktion der Dentes canini des Pferdes] |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0340-2096 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:12919071 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
672 |
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| Author |
Pearce, G.P.; May-Davis, S.; Greaves, D. |
| Title |
Femoral asymmetry in the Thoroughbred racehorse |
Type |
Journal Article |
| Year |
2005 |
Publication |
Australian Veterinary Journal |
Abbreviated Journal |
Aust Vet J |
| Volume |
83 |
Issue |
6 |
Pages |
367-370 |
| Keywords |
Animals; Cumulative Trauma Disorders/pathology/*veterinary; Femur/*pathology; Horse Diseases/*pathology/physiopathology; Horses; Locomotion; Physical Conditioning, Animal/*physiology |
| Abstract |
OBJECTIVE: To investigate the occurrence of geometrical asymmetries in the macro-architecture of left and right femurs from Thoroughbred racehorses previously used in competitive training and racing in New South Wales, Australia. METHODS: Detailed postmortem measurements were made of 37 characteristics of left and right femurs from eleven Thoroughbred racehorses euthanased for reasons unrelated to the study. Measurements focused on articulating surfaces and sites of attachment of muscles and ligaments known to be associated with hindlimb locomotion. RESULTS: Five measurements were significantly larger in left compared to right femurs (P < 0.05). The regions showing significant differences between left and right limbs were proximal cranial and overhead medio-lateral widths, greater trochanter depth, depth of the fovea in the femoral head and distal inter-epicondylar width. CONCLUSION: The left-right differences in femoral morphology were associated with sites of muscle and ligament attachment known to be involved with hindlimb function in negotiating turns. These differences may be the result of selection pressure for racing performance on curved race tracks and/or adaptations related to asymmetrical loading of the outside hindlimb associated with repeated negotiation of turns on such tracks. |
| Address |
Faculty of Rural Management, University of Sydney, Leeds Parade, Orange, New South Wales 2800. gpp28@cam.ac.uk |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0005-0423 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:15986917 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
4036 |
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| Author |
Hall, R.A.; Broom, A.K.; Smith, D.W.; Mackenzie, J.S. |
| Title |
The ecology and epidemiology of Kunjin virus |
Type |
Journal Article |
| Year |
2002 |
Publication |
Current Topics in Microbiology and Immunology |
Abbreviated Journal |
Curr Top Microbiol Immunol |
| Volume |
267 |
Issue |
|
Pages |
253-269 |
| Keywords |
Animals; Culicidae/virology; Ecosystem; Horse Diseases/etiology; Horses; Humans; Insect Vectors; Population Surveillance; West Nile Fever/*epidemiology/*etiology/veterinary; West Nile virus/classification/genetics/immunology/*isolation & purification |
| Abstract |
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| Address |
Department of Microbiology and Parasitology, School of Molecular and Microbial Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0070-217X |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:12082993 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
2642 |
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| Author |
Vlasak, A.N. |
| Title |
Global and local spatial landmarks: their role during foraging by Columbian ground squirrels (Spermophilus columbianus) |
Type |
Journal Article |
| Year |
2006 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
| Volume |
9 |
Issue |
1 |
Pages |
71-80 |
| Keywords |
Animals; Cues; Feeding Behavior/*psychology; Female; *Memory; Mental Recall; Orientation; Sciuridae/*psychology; *Space Perception; *Spatial Behavior |
| Abstract |
Locating food and refuge is essential for an animal's survival. However, little is known how mammals navigate under natural conditions and cope with given environmental constraints. In a series of six experiments, I investigated landmark-based navigation in free-ranging Columbian ground squirrels (Spermophilus columbianus). Squirrels were trained individually to find a baited platform within an array of nine identical platforms and artificial landmarks set up on their territories. After animals learned the location of the food platform in the array, the position of the latter with respect to local artificial, local natural, and global landmarks was manipulated, and the animal's ability to find the food platform was tested. When only positions of local artificial landmarks were changed, squirrels located food with high accuracy. When the location of the array relative to global landmarks was altered, food-finding accuracy decreased but remained significant. In the absence of known global landmarks, the presence of a familiar route and natural local landmarks resulted in significant but not highly accurate performance. Squirrels likely relied on multiple types of cues when orienting towards a food platform. Local landmarks were used only as a secondary mechanism of navigation, and were not attended to when a familiar route and known global landmarks were present. This study provided insights into landmark use by a wild mammal in a natural situation, and it demonstrated that an array of platforms can be employed to investigate landmark-based navigation under such conditions. |
| Address |
Biology Department, University of Pennsylvania, Philadelphia, PA 19104, USA. avlasak@sas.upenn.edu |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1435-9448 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:16163480 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
2483 |
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| Author |
Gibson, B.M.; Shettleworth, S.J.; McDonald, R.J. |
| Title |
Finding a goal on dry land and in the water: differential effects of disorientation on spatial learning |
Type |
Journal Article |
| Year |
2001 |
Publication |
Behavioural brain research |
Abbreviated Journal |
Behav. Brain. Res. |
| Volume |
123 |
Issue |
1 |
Pages |
103-111 |
| Keywords |
Animals; Cues; Environment; Male; Maze Learning/*physiology; Orientation/*physiology; Rats; Rats, Long-Evans; Spatial Behavior/*physiology; Water |
| Abstract |
Two previous studies, Martin et al. (J. Exp. Psychol. Anim. Behav. Process. 23 (1997) 183) and Dudchenko et al. (J. Exp. Psychol. Anim. Behav. Process. 23 (1997) 194), report that, compared to non-disoriented controls, rats disoriented before testing were disrupted in their ability to learn the location of a goal on a dry radial-arm maze task, but that both groups learned at the same rate in the Morris water maze. However, the radial-arm maze task was much more difficult than the water maze. In the current set of experiments, we examined the performance of control and disoriented rats on more comparable dry land and water maze tasks. Compared to non-disoriented rats, rats that were disoriented before testing were significantly impaired in locating a goal in a circular dry arena, but not a water tank. The results constrain theoretical explanations for the differential effects of disorientation on different spatial tasks. |
| Address |
Department of Psychology, University of Toronto, 100 St. George Street, Toronto, Ontario, Canada M5S 3G3. gibson@psych.utoronto.ca |
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Place of Publication |
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Editor |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0166-4328 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:11377733 |
Approved |
no |
| Call Number |
refbase @ user @ |
Serial |
372 |
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| Author |
Riedel, J.; Buttelmann, D.; Call, J.; Tomasello, M. |
| Title |
Domestic dogs (Canis familiaris) use a physical marker to locate hidden food |
Type |
Journal Article |
| Year |
2006 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
| Volume |
9 |
Issue |
1 |
Pages |
27-35 |
| Keywords |
Animals; Cues; Dogs/*psychology; Female; Gestures; Humans; Male; *Nonverbal Communication; *Recognition (Psychology); Signal Detection (Psychology); Visual Perception |
| Abstract |
Dogs can use the placement of an arbitrary marker to locate hidden food in an object-choice situation. We tested domestic dogs (Canis familiaris) in three studies aimed at pinning down the relative contributions of the human's hand and the marker itself. We baited one of two cups (outside of the dogs' view) and gave the dog a communicative cue to find the food. Study 1 systematically varied dogs' perceptual access to the marker placing event, so that dogs saw either the whole human, the hand only, the marker only, or nothing. Follow-up trials investigated the effect of removing the marker before the dog's choice. Dogs used the marker as a communicative cue even when it had been removed prior to the dog's choice and attached more importance to this cue than to the hand that placed it although the presence of the hand boosted performance when it appeared together with the marker. Study 2 directly contrasted the importance of the hand and the marker and revealed that the effect of the marker diminished if it had been associated with both cups. In contrast touching both cups with the hand had no effect on performance. Study 3 investigated whether the means of marker placement (intentional or accidental) had an effect on dogs' choices. Results showed that dogs did not differentiate intentional and accidental placing of the marker. These results suggest that dogs use the marker as a genuine communicative cue quite independently from the experimenter's actions. |
| Address |
Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6 D-04103, Leipzig, Germany. riedel@eva.mpg.de |
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Place of Publication |
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English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
1435-9448 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:15846526 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
2488 |
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| Author |
Steinhoff, H.J.; Schrader, J.; Schlitter, J. |
| Title |
Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals |
Type |
Journal Article |
| Year |
1992 |
Publication |
Biochimica et Biophysica Acta |
Abbreviated Journal |
Biochim Biophys Acta |
| Volume |
1121 |
Issue |
3 |
Pages |
269-278 |
| Keywords |
Animals; Crystallization; Horses; Kinetics; Methemoglobin/*chemistry; Solutions; Spectrum Analysis; Temperature; Thiocyanates/*chemistry |
| Abstract |
Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed. |
| Address |
Institut fur Biophysik, Ruhr-Universitat Bochum, Germany |
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Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0006-3002 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
PMID:1627604 |
Approved |
no |
| Call Number |
Equine Behaviour @ team @ |
Serial |
3800 |
| Permanent link to this record |
