Records |
Author |
Dyson, H.J.; Beattie, J.K. |
Title |
Spin state and unfolding equilibria of ferricytochrome c in acidic solutions |
Type |
Journal Article |
Year |
1982 |
Publication |
The Journal of Biological Chemistry |
Abbreviated Journal |
J Biol Chem |
Volume |
257 |
Issue |
5 |
Pages |
2267-2273 |
Keywords |
Animals; *Cytochrome c Group; Electron Spin Resonance Spectroscopy; Heme; Horses; Hydrogen-Ion Concentration; Kinetics; Ligands; Myocardium; Protein Binding; Protein Conformation; Spectrophotometry; Temperature |
Abstract |
Equilibrium, stopped flow, and temperature-jump spectrophotometry have been used to identify processes in the unfolding of ferricytochrome c in acidic aqueous solutions. A relaxation occurring in approximately 100 microseconds involves perturbation of a spin-equilibrium between two folded conformers of the protein with methionine-80 coordinated or dissociated from the heme iron. The protein unfolds more slowly, in milliseconds, with dissociation and protonation of histidine-18. These two transitions appear cooperative in equilibrium measurements at low (0.01 M) ionic strength, but are separated at higher (0.10 M) ionic strength. They are resolved under both conditions in the dynamic measurements. The spin-equilibrium description permits a unified explanation of a number of properties of ferricytochrome c in acidic aqueous solutions. |
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Language |
English |
Summary Language |
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Original Title |
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Edition |
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ISSN |
0021-9258 |
ISBN |
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Notes |
PMID:6277891 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
3807 |
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Author |
Ahrendt, L.P.; Christensen, J.W.; Ladewig, J. |
Title |
The ability of horses to learn an instrumental task through social observation |
Type |
Abstract |
Year |
2012 |
Publication |
Applied Animal Behaviour Science |
Abbreviated Journal |
Appl. Anim. Behav. Sci. |
Volume |
139 |
Issue |
1 |
Pages |
105-113 |
Keywords |
Horse; Social learning; Social interaction; Instrumental task; Investigative behaviour; Aggression |
Abstract |
The ability of horses to learn through social observation may ease the implementation of new management systems, because the use of automatic feeders etc. by naive horses could be facilitated by observation of experienced horses. However, previous studies found no documentation for observational learning abilities in horses. This study aimed to investigate the ability of horses to learn an instrumental task from a familiar conspecific when social interaction was allowed during the demonstration. Two similar experiments were performed. In the first experiment, Observer horses (n=11) participated in ten successive demonstrations, where a trained Demonstrator opened an operant device by pushing a sliding lid aside with the muzzle in order to obtain a food reward. Immediately after the demonstrations the Observer horses were given the opportunity to operate the device alone. Control horses (n=11) were aware that the device contained food but were presented to the operant device without demonstration of the task. The learning criterion was at least two openings. Accomplishment of and latency to accomplish the learning criterion, and investigative behaviour towards the operant device were recorded. Five Observers and one Control, out of the eleven horses in each treatment group, accomplished the learning criterion. Even though this presents a high odds ratio (OR) in favour of the Observer treatment (OR=7.6), there was no significant difference between the treatment groups (P=0.15). Analysis of investigative behaviour showed, however, that the demonstrations increased the motivation of the Observer horses to investigate the device. Subsequently, a similar experiment was performed in a practical setting with 44 test horses (mixed age, gender and breed). We used the same operant device and the same number and type of demonstrations, although the horses were held on a loose rope to minimise aggression. In this second experiment, six of 23 Observer horses and five of 21 Control horses learned the instrumental task, representing no influence of the demonstration. Thus, this study did not demonstrate an ability of horses to learn an instrumental task through observation. |
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Edition |
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ISSN |
0168-1591 |
ISBN |
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no |
Call Number |
Equine Behaviour @ team @ S0168-1591(12)00087-1 |
Serial |
5773 |
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Author |
Hertsch, B.; Becker, C. |
Title |
[Occurrence of aseptic necrosis of the palmar and plantar ligament in the horse--a contribution to the differentiation of sesamoid bone diseases] |
Type |
Journal Article |
Year |
1986 |
Publication |
DTW. Deutsche tierarztliche Wochenschrift |
Abbreviated Journal |
Dtsch Tierarztl Wochenschr |
Volume |
93 |
Issue |
6 |
Pages |
263-266 |
Keywords |
Animals; Diagnosis, Differential; Horse Diseases/*pathology; Horses; Ligaments, Articular/*pathology; Osteonecrosis/*pathology; Sesamoid Bones/*pathology |
Abstract |
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Language |
German |
Summary Language |
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Original Title |
Zum Vorkommen der aseptischen Nekrose im Ligamentum palmare bzw. plantare beim Pferd--ein Beitrag zur Differenzierung der Gleichbeinerkrankungen |
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Edition |
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ISSN |
0341-6593 |
ISBN |
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Notes |
PMID:3527654 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
150 |
Permanent link to this record |