| |
Records |
Links |
|
Author |
Tsong, T.Y. |
|
| |
Title |
Conformational relaxations of urea- and guanidine hydrochloride-unfolded ferricytochrome c |
Type |
Journal Article |
| |
Year |
1977 |
Publication |
The Journal of Biological Chemistry |
Abbreviated Journal |
J Biol Chem |
|
| |
Volume |
252 |
Issue |
24 |
Pages |
8778-8780 |
|
| |
Keywords |
*Cytochrome c Group; Guanidines/*pharmacology; Protein Conformation/drug effects; Spectrometry, Fluorescence; Urea/*pharmacology |
|
| |
Abstract |
Several recent studies of protein the unfolded proteins. In urea- and guanidine HCl-unfolded ferricytochrome c (horse heart), an acid-induced spin state transformation of the heme group has been detected by the heme absorptions, Trp-59 fluorescence, and the intrinsic viscosity of protein. Kinetics of this second conformational transition, by the temperature jump and stopped flow methods, are complex. One rapid reaction (tau1), pH-independent, occurs in a 50-mus range; the second reaction (tau2), in a 1-ms range, depends linearly upon pH and is faster at the alkaline side; a third reaction (tau3), in a 1-s range, shows a sigmoidal transition at pH 5.1 and is faster at the acidic side. The results are consistent with a kinetic scheme which involves protein conformational changes in the transformation of the heme coordination state. The kinetics, along with previous equilibrium studies, indicate that ligand or charge interactions within a protein molecule are not completely prohibited even in strongly denaturing conditions, such as in high concentrations of urea and guanidine HCl. Thus, local structures of peptide chain associated with these interactions can exist in the unfolded protein. |
|
| |
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 |
0021-9258 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:200618 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
3882 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
King, A.J.; Douglas, C.M.S.; Huchard, E.; Isaac, N.J.B.; Cowlishaw, G. |
|
| |
Title |
Dominance and affiliation mediate despotism in a social primate |
Type |
Journal Article |
| |
Year |
2008 |
Publication |
Current Biology : CB |
Abbreviated Journal |
Curr Biol |
|
| |
Volume |
18 |
Issue |
23 |
Pages |
1833-1838 |
|
| |
Keywords |
Animals; *Authoritarianism; Behavior, Animal/*physiology; Cooperative Behavior; *Decision Making; Feeding Behavior; Female; *Group Processes; Male; Papio ursinus/*psychology; *Social Dominance |
|
| |
Abstract |
Group-living animals routinely have to reach a consensus decision and choose between mutually exclusive actions in order to coordinate their activities and benefit from sociality. Theoretical models predict “democratic” rather than “despotic” decisions to be widespread in social vertebrates, because they result in lower “consensus costs”-the costs of an individual foregoing its optimal action to comply with the decision-for the group as a whole. Yet, quantification of consensus costs is entirely lacking, and empirical observations provide strong support for the occurrence of both democratic and despotic decisions in nature. We conducted a foraging experiment on a wild social primate (chacma baboons, Papio ursinus) in order to gain new insights into despotic group decision making. The results show that group foraging decisions were consistently led by the individual who acquired the greatest benefits from those decisions, namely the dominant male. Subordinate group members followed the leader despite considerable consensus costs. Follower behavior was mediated by social ties to the leader, and where these ties were weaker, group fission was more likely to occur. Our findings highlight the importance of leader incentives and social relationships in group decision-making processes and the emergence of despotism. |
|
| |
Address |
Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK. andrew.king@ioz.ac.uk |
|
| |
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 |
0960-9822 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:19026539 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
5124 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Jacobs, A.; Maumy, M.; Petit, O. |
|
| |
Title |
The influence of social organisation on leadership in brown lemurs (Eulemur fulvus fulvus) in a controlled environment |
Type |
Journal Article |
| |
Year |
2008 |
Publication |
Behavioural Processes |
Abbreviated Journal |
Behav. Process. |
|
| |
Volume |
79 |
Issue |
2 |
Pages |
111-113 |
|
| |
Keywords |
Animals; *Decision Making; Dominance-Subordination; *Exploratory Behavior; Female; Group Structure; *Leadership; Lemur/*psychology; Male; Sex Factors; *Social Environment |
|
| |
Abstract |
Studies on leadership during group movements in several lemur species showed that females were responsible for the travelling choices concerning time and direction. Interestingly, in these species females are dominant over males. We investigated the influence of social organisation upon leadership processes by studying a lemur species in which social organisation is characterized by the absence of female dominance: the brown lemur (Eulemur fulvus fulvus). The study was conducted on a semi-free ranging group of 11 individuals and the analysis performed on 69 group movements showed that all the individuals could initiate a group movement. In 34 cases, the whole group moved. There was no significant difference in the number of start attempts or in the number of group members involved from one initiator to another. Moreover, there was no effect of sex or age of the initiator on the number of individuals following it or on the speed of the joining process. Therefore, the leadership observed is widely distributed to all group members. These results support the hypothesis of an influence of social organisation upon the decision-making processes but still remain to be studied in a more relevant ecological context. |
|
| |
Address |
IPHC-DEPE, Equipe d'ethologie des primates, UMR 7178, Centre National de la Recherche Scientifique-Universite Louis Pasteur and Centre de Primatologie, Strasbourg, France |
|
| |
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 |
0376-6357 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:18586413 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
5127 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Conradt, L.; Roper, T.J. |
|
| |
Title |
Group decision-making in animals |
Type |
Journal Article |
| |
Year |
2003 |
Publication |
Nature |
Abbreviated Journal |
Nature |
|
| |
Volume |
421 |
Issue |
6919 |
Pages |
155-158 |
|
| |
Keywords |
Animals; Behavior, Animal/*physiology; *Decision Making; Democracy; Group Processes; *Models, Biological; Population Density; Social Behavior |
|
| |
Abstract |
Groups of animals often need to make communal decisions, for example about which activities to perform, when to perform them and which direction to travel in; however, little is known about how they do so. Here, we model the fitness consequences of two possible decision-making mechanisms: 'despotism' and 'democracy'. We show that under most conditions, the costs to subordinate group members, and to the group as a whole, are considerably higher for despotic than for democratic decisions. Even when the despot is the most experienced group member, it only pays other members to accept its decision when group size is small and the difference in information is large. Democratic decisions are more beneficial primarily because they tend to produce less extreme decisions, rather than because each individual has an influence on the decision per se. Our model suggests that democracy should be widespread and makes quantitative, testable predictions about group decision-making in non-humans. |
|
| |
Address |
School of Biological Sciences, University of Sussex, Brighton BN1 9QG, UK. l.conradt@sussex.ac.uk |
|
| |
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 |
0028-0836 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:12520299 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
5136 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Guttridge, T.L.; Dijk, S.; Stamhuis, E.J.; Krause, J.; Gruber, S.H.; Brown, C. |
|
| |
Title |
Social learning in juvenile lemon sharks, Negaprion brevirostris |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
|
Abbreviated Journal |
Animal Cognition |
|
| |
Volume |
16 |
Issue |
1 |
Pages |
55-64 |
|
| |
Keywords |
Local and stimulus enhancement; Group living; Social facilitation; Social information use; Elasmobranchs |
|
| |
Abstract |
Social learning is taxonomically widespread and can provide distinct behavioural advantages, such as in finding food or avoiding predators more efficiently. Although extensively studied in bony fishes, no such empirical evidence exists for cartilaginous fishes. Our aim in this study was to experimentally investigate the social learning capabilities of juvenile lemon sharks, Negaprion brevirostris. We designed a novel food task, where sharks were required to enter a start zone and subsequently make physical contact with a target in order to receive a food reward. Naive sharks were then able to interact with and observe (a) pre-trained sharks, that is, ‘demonstrators’, or (b) sharks with no previous experience, that is, ‘sham demonstrators’. On completion, observer sharks were then isolated and tested individually in a similar task. During the exposure phase observers paired with ‘demonstrator’ sharks performed a greater number of task-related behaviours and made significantly more transitions from the start zone to the target, than observers paired with ‘sham demonstrators’. When tested in isolation, observers previously paired with ‘demonstrator’ sharks completed a greater number of trials and made contact with the target significantly more often than observers previously paired with ‘sham demonstrators’. Such experience also tended to result in faster overall task performance. These results indicate that juvenile lemon sharks, like numerous other animals, are capable of using socially derived information to learn about novel features in their environment. The results likely have important implications for behavioural processes, ecotourism and fisheries. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Springer-Verlag |
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 |
|
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
5697 |
|
| Permanent link to this record |
