Records |
Author |
Rosa, P.A.J.; Azevedo, A.M.; Aires-Barros, M.R. |
Title |
Application of central composite design to the optimisation of aqueous two-phase extraction of human antibodies |
Type |
Journal Article |
Year |
2007 |
Publication |
Journal of Chromatography. A |
Abbreviated Journal |
J Chromatogr A |
Volume |
1141 |
Issue |
1 |
Pages |
50-60 |
Keywords |
Analysis of Variance; Animals; Antibodies/*chemistry/*isolation & purification; Buffers; Chemical Fractionation/*methods; Horses; Humans; Hydrophobicity; Isoelectric Point; Models, Biological; Molecular Weight; Myoglobin/chemistry/isolation & purification; Osmolar Concentration; Phase Transition; Polyethylene Glycols; Serum Albumin/chemistry/isolation & purification; Sodium Chloride |
Abstract |
The partition of human antibodies in aqueous two-phase systems (ATPSs) of polyethylene glycol (PEG) and phosphate was systematically studied using first pure proteins systems and then an artificial mixture of proteins containing 1mg/ml human immunoglobulin G (IgG), 10mg/ml serum albumin and 2mg/ml myoglobin. Preliminary results obtained using pure proteins systems indicated that the PEG molecular weight and concentration, the pH value and the salts concentration had a pronounced effect on the partitioning behaviour of all proteins. For high ionic strengths and pH values higher than the isoelectric point (pI) of the contaminant proteins, IgG could be selectively recovered on the top phase. According to these results, a face centred composite design was performed in order to optimise the purification of IgG from the mixture of proteins. The optimal conditions for the isolation of IgG were observed for high concentrations of NaCl and low concentrations of both phase forming components. The best purification was achieved using an ATPS containing 8% (w/w) PEG 3350, 10% (w/w) phosphate pH 6 and 15% (w/w) NaCl. A recovery yield of 101+/-7%, a purity of 99+/-0% and a yield of native IgG of 97+/-4% were obtained. Back extraction studies of IgG to a new phosphate phase were performed and higher yields were obtained using 10% phosphate buffer at pH 6. The total extraction yield was 76% and the purity 100%. |
Address |
IBB Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Tecnico, Av Rovisco Pais, 1049-001 Lisbon, Portugal |
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English |
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ISSN |
0021-9673 |
ISBN |
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Notes |
PMID:17196214 |
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no |
Call Number |
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Serial |
1842 |
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Author |
Zhang, T.-Y.; Parent, C.; Weaver, I.; Meaney, M.J. |
Title |
Maternal programming of individual differences in defensive responses in the rat |
Type |
Journal Article |
Year |
2004 |
Publication |
Annals of the New York Academy of Sciences |
Abbreviated Journal |
Ann N Y Acad Sci |
Volume |
1032 |
Issue |
|
Pages |
85-103 |
Keywords |
Adaptation, Biological; Aggression/*physiology; Animals; Evolution; Female; Gene Expression/physiology; Humans; Individuality; *Maternal Behavior; Phenotype; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Stress, Psychological/physiopathology |
Abstract |
This paper describes the results of a series of studies showing that variations in mother-pup interactions program the development of individual differences in behavioral and endocrine stress responses in the rat. These effects are associated with altered expression of genes in brain regions, such as the amygdala, hippocampus, and hypothalamus, that regulate the expression of stress responses. Studies from evolutionary biology suggest that such “maternal effects” are common and often associated with variations in the quality of the maternal environment. Together these findings suggest an epigenetic process whereby the experience of the mother alters the nature of the parent-offspring interactions and thus the phenotype of the offspring. |
Address |
McGill Program for the Study of Behavior, Genes and Environment, Douglas Hospital Research Centre, Department of Psychiatry, McGill University, 6875 boul. LaSalle, Montreal (Quebec), Canada H4H 1R3 |
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English |
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Edition |
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ISSN |
0077-8923 |
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Conference |
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Notes |
PMID:15677397 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
4132 |
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Author |
de Wall, F.B.; Aureli, F. |
Title |
Conflict resolution and distress alleviation in monkeys and apes |
Type |
Journal Article |
Year |
1997 |
Publication |
Annals of the New York Academy of Sciences |
Abbreviated Journal |
Ann N Y Acad Sci |
Volume |
807 |
Issue |
|
Pages |
317-328 |
Keywords |
*Adaptation, Psychological; Animals; Arousal; *Conflict (Psychology); Empathy; Haplorhini/*psychology; Hominidae/*psychology; Humans; Learning; Models, Psychological; *Social Behavior; Stress, Psychological |
Abstract |
Research on nonhuman primates has produced compelling evidence for reconciliation and consolation, that is, postconflict contacts that serve to respectively repair social relationships and reassure distressed individuals, such as victims of attack. This has led to a view of conflict and conflict resolution as an integrated part of social relationships, hence determined by social factors and modifiable by the social environment. Implications of this new model of social conflict are discussed along with evidence for behavioral flexibility, the value of cooperation, and the possibility that distress alleviation rests on empathy, a capacity that may be present in chimpanzees and humans but not in most other animals. |
Address |
Yerkes Regional Primate Research Center, Emory University, Atlanta, Georgia 30322, USA. dewaal@rmy.emory.edu |
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ISSN |
0077-8923 |
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Notes |
PMID:9071360 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
2882 |
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Author |
Wolf, M.; van Doorn, G.S.; Leimar, O.; Weissing, F.J. |
Title |
Life-history trade-offs favour the evolution of animal personalities |
Type |
Journal Article |
Year |
2007 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
447 |
Issue |
7144 |
Pages |
581-584 |
Keywords |
Aggression/physiology/psychology; Animals; Behavior, Animal/*physiology; *Evolution; Exploratory Behavior/physiology; Models, Biological; Personality/*physiology; Predatory Behavior/physiology; Reproduction/physiology; Risk-Taking; Selection (Genetics) |
Abstract |
In recent years evidence has been accumulating that personalities are not only found in humans but also in a wide range of other animal species. Individuals differ consistently in their behavioural tendencies and the behaviour in one context is correlated with the behaviour in multiple other contexts. From an adaptive perspective, the evolution of animal personalities is still a mystery, because a more flexible structure of behaviour should provide a selective advantage. Accordingly, many researchers view personalities as resulting from constraints imposed by the architecture of behaviour (but see ref. 12). In contrast, we show here that animal personalities can be given an adaptive explanation. Our argument is based on the insight that the trade-off between current and future reproduction often results in polymorphic populations in which some individuals put more emphasis on future fitness returns than others. Life-history theory predicts that such differences in fitness expectations should result in systematic differences in risk-taking behaviour. Individuals with high future expectations (who have much to lose) should be more risk-averse than individuals with low expectations. This applies to all kinds of risky situations, so individuals should consistently differ in their behaviour. By means of an evolutionary model we demonstrate that this basic principle results in the evolution of animal personalities. It simultaneously explains the coexistence of behavioural types, the consistency of behaviour through time and the structure of behavioural correlations across contexts. Moreover, it explains the common finding that explorative behaviour and risk-related traits like boldness and aggressiveness are common characteristics of animal personalities. |
Address |
Theoretical Biology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands |
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ISSN |
1476-4687 |
ISBN |
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Medium |
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Conference |
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Notes |
PMID:17538618 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
4098 |
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Author |
Bell, A.M. |
Title |
Evolutionary biology: animal personalities |
Type |
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Year |
2007 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
447 |
Issue |
7144 |
Pages |
539-540 |
Keywords |
Aggression/physiology/psychology; Animals; Behavior, Animal/*physiology; *Evolution; Humans; *Models, Biological; Personality/genetics/*physiology; Reproduction/genetics/physiology; Risk-Taking; Selection (Genetics) |
Abstract |
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ISSN |
1476-4687 |
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Notes |
PMID:17538607 |
Approved |
no |
Call Number |
Equine Behaviour @ team @ |
Serial |
4099 |
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Author |
Grosenick, L.; Clement, T.S.; Fernald, R.D. |
Title |
Fish can infer social rank by observation alone |
Type |
Journal Article |
Year |
2007 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
445 |
Issue |
7126 |
Pages |
429-432 |
Keywords |
Aggression/physiology; Animals; Cognition/*physiology; Female; Fishes/*physiology; Learning/*physiology; Male; Models, Biological; *Social Dominance; Territoriality |
Abstract |
Transitive inference (TI) involves using known relationships to deduce unknown ones (for example, using A > B and B > C to infer A > C), and is thus essential to logical reasoning. First described as a developmental milestone in children, TI has since been reported in nonhuman primates, rats and birds. Still, how animals acquire and represent transitive relationships and why such abilities might have evolved remain open problems. Here we show that male fish (Astatotilapia burtoni) can successfully make inferences on a hierarchy implied by pairwise fights between rival males. These fish learned the implied hierarchy vicariously (as 'bystanders'), by watching fights between rivals arranged around them in separate tank units. Our findings show that fish use TI when trained on socially relevant stimuli, and that they can make such inferences by using indirect information alone. Further, these bystanders seem to have both spatial and featural representations related to rival abilities, which they can use to make correct inferences depending on what kind of information is available to them. Beyond extending TI to fish and experimentally demonstrating indirect TI learning in animals, these results indicate that a universal mechanism underlying TI is unlikely. Rather, animals probably use multiple domain-specific representations adapted to different social and ecological pressures that they encounter during the course of their natural lives. |
Address |
Department of Biological Sciences, Stanford University, Stanford, California, 94305, USA. logang@stanford.edu |
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ISSN |
1476-4687 |
ISBN |
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Notes |
PMID:17251980 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
600 |
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Author |
Gentner, T.Q.; Fenn, K.M.; Margoliash, D.; Nusbaum, H.C. |
Title |
Recursive syntactic pattern learning by songbirds |
Type |
Journal Article |
Year |
2006 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
440 |
Issue |
7088 |
Pages |
1204-1207 |
Keywords |
Acoustic Stimulation; *Animal Communication; Animals; Auditory Perception/*physiology; Humans; *Language; Learning/*physiology; Linguistics; Models, Neurological; Semantics; Starlings/*physiology; Stochastic Processes |
Abstract |
Humans regularly produce new utterances that are understood by other members of the same language community. Linguistic theories account for this ability through the use of syntactic rules (or generative grammars) that describe the acceptable structure of utterances. The recursive, hierarchical embedding of language units (for example, words or phrases within shorter sentences) that is part of the ability to construct new utterances minimally requires a 'context-free' grammar that is more complex than the 'finite-state' grammars thought sufficient to specify the structure of all non-human communication signals. Recent hypotheses make the central claim that the capacity for syntactic recursion forms the computational core of a uniquely human language faculty. Here we show that European starlings (Sturnus vulgaris) accurately recognize acoustic patterns defined by a recursive, self-embedding, context-free grammar. They are also able to classify new patterns defined by the grammar and reliably exclude agrammatical patterns. Thus, the capacity to classify sequences from recursive, centre-embedded grammars is not uniquely human. This finding opens a new range of complex syntactic processing mechanisms to physiological investigation. |
Address |
Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois 60637, USA. tgentner@ucsd.edu |
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1476-4687 |
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Conference |
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Notes |
PMID:16641998 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
353 |
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Author |
Flack, J.C.; Girvan, M.; de Waal, F.B.M.; Krakauer, D.C. |
Title |
Policing stabilizes construction of social niches in primates |
Type |
Journal Article |
Year |
2006 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
439 |
Issue |
7075 |
Pages |
426-429 |
Keywords |
Animals; Conflict (Psychology); Female; Macaca nemestrina/*physiology/*psychology; Male; Models, Biological; *Social Behavior |
Abstract |
All organisms interact with their environment, and in doing so shape it, modifying resource availability. Termed niche construction, this process has been studied primarily at the ecological level with an emphasis on the consequences of construction across generations. We focus on the behavioural process of construction within a single generation, identifying the role a robustness mechanism--conflict management--has in promoting interactions that build social resource networks or social niches. Using 'knockout' experiments on a large, captive group of pigtailed macaques (Macaca nemestrina), we show that a policing function, performed infrequently by a small subset of individuals, significantly contributes to maintaining stable resource networks in the face of chronic perturbations that arise through conflict. When policing is absent, social niches destabilize, with group members building smaller, less diverse, and less integrated grooming, play, proximity and contact-sitting networks. Instability is quantified in terms of reduced mean degree, increased clustering, reduced reach, and increased assortativity. Policing not only controls conflict, we find it significantly influences the structure of networks that constitute essential social resources in gregarious primate societies. The structure of such networks plays a critical role in infant survivorship, emergence and spread of cooperative behaviour, social learning and cultural traditions. |
Address |
Santa Fe Institute, Santa Fe, New Mexico 87501, USA. jflack@santafe.edu |
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1476-4687 |
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Notes |
PMID:16437106 |
Approved |
no |
Call Number |
refbase @ user @ |
Serial |
298 |
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Author |
Rands, S.A.; Cowlishaw, G.; Pettifor, R.A.; Rowcliffe, J.M.; Johnstone, R.A. |
Title |
Spontaneous emergence of leaders and followers in foraging pairs |
Type |
Journal Article |
Year |
2003 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
423 |
Issue |
6938 |
Pages |
432-434 |
Keywords |
Animals; *Energy Metabolism; Food; *Food Chain; *Models, Biological; Motor Activity; *Social Behavior; Time Factors |
Abstract |
Animals that forage socially often stand to gain from coordination of their behaviour. Yet it is not known how group members reach a consensus on the timing of foraging bouts. Here we demonstrate a simple process by which this may occur. We develop a state-dependent, dynamic game model of foraging by a pair of animals, in which each individual chooses between resting or foraging during a series of consecutive periods, so as to maximize its own individual chances of survival. We find that, if there is an advantage to foraging together, the equilibrium behaviour of both individuals becomes highly synchronized. As a result of this synchronization, differences in the energetic reserves of the two players spontaneously develop, leading them to adopt different behavioural roles. The individual with lower reserves emerges as the 'pace-maker' who determines when the pair should forage, providing a straightforward resolution to the problem of group coordination. Moreover, the strategy that gives rise to this behaviour can be implemented by a simple 'rule of thumb' that requires no detailed knowledge of the state of other individuals. |
Address |
Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. s.rands@zoo.cam.ac.uk |
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ISSN |
0028-0836 |
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Notes |
PMID:12761547 |
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no |
Call Number |
Equine Behaviour @ team @ |
Serial |
5138 |
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Author |
Johnson, D.D.P.; Stopka, P.; Knights, S. |
Title |
Sociology: The puzzle of human cooperation |
Type |
Journal Article |
Year |
2003 |
Publication |
Nature |
Abbreviated Journal |
Nature |
Volume |
421 |
Issue |
6926 |
Pages |
911-2; discussion 912 |
Keywords |
Altruism; *Cooperative Behavior; Evolution; Humans; *Models, Biological; Punishment; Reward; Risk |
Abstract |
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Address |
Olin Institute for Strategic Studies, Harvard University, Cambridge, Massachusetts 02138, USA. dominic@post.harvard.edu |
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0028-0836 |
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Notes |
PMID:12606989 |
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no |
Call Number |
refbase @ user @ |
Serial |
467 |
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