2,099 research outputs found

    Toshisada Nishida (1941–2011): Chimpanzee Rapport

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    Frans de Waal pays tribute to pioneering primatologist Toshisada Nishida, who transformed our understanding of chimpanzee behavior and culture and galvanized efforts to ensure their conservation

    Out of the darkness: A History of Huntington's Disease in Australia

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    Huntington’s disease (HD) is a genetic neurological condition which has a profound influence on the families it affects. The symptoms of the disease are challenging – in addition, social forces strongly influence the way the disease is experienced. It has been a deeply stigmatised condition, and its presence was often kept secret. In this dissertation, I have explored both social and medical aspects of the history of HD, primarily in Australia, building on the work of two scholars, Peter Harper (UK) and Alice Wexler (US). By tracing the histories of HD families, I discovered that HD has been part of the fabric of life in Australia since the convict era, and that some families with the disease were well-respected in their communities, in contrast to narratives which have presented the stigma as inevitable. Wexler has previously shown that in the US, the degree of stigma faced by HD families has varied over time, and my research found this to be also true of the disease in Australia. The earliest descriptions of the disease in the US were mostly made by physicians familiar with HD families. My research revealed a similar story - two physicians who published on HD both grew up in an area of Tasmania with relatively high rates of the disease. The impact of eugenic thinking in the stigmatization of HD in the US, Germany and the UK was noted more than 20 years ago, though its impact in other countries has remained unexplored. Eugenics as a formal movement was not successful in Australia, however eugenic ideas formed part of the social discourse. I show through medical journal articles, items in the popular press and educational organisations how those with hereditary diseases were labeled as “unfit”, promoting stigma which contributed to it being hidden. Finally I describe how the disease began to emerge from “the closet” in the early 1970s, with families and researchers forging a new collaboration to search for treatments, support families and reduce stigma

    Post-Conflict Affiliation by Chimpanzees with Aggressors: Other-Oriented versus Selfish Political Strategy

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    Consolation, i.e., post-conflict affiliation directed from bystanders to recent victims of aggression, has recently acquired an important role in the debate about empathy in great apes. Although similar contacts have been also described for aggressors, i.e., appeasement, they have received far less attention and their function and underlying mechanisms remain largely unknown. An exceptionally large database of spontaneous conflict and post-conflict interactions in two outdoor-housed groups of chimpanzees lends support to the notion that affiliation toward aggressors reduces the latter's aggressive tendencies in that further aggression was less frequent after the occurrence of the affiliation. However, bystander affiliation toward aggressors occurred disproportionally between individuals that were socially close (i.e., affiliation partners) which suggest that it did not function to protect the actor itself against redirected aggression. Contrary to consolation behavior, it was provided most often by adult males and directed toward high ranking males, whereas females engaged less often in this behavior both as actors and recipients, suggesting that affiliation with aggressors is unlikely to be a reaction to the distress of others. We propose that bystander affiliation toward aggressors may function to strengthen bonds between valuable partners, probably as part of political strategies. Our findings also suggest that this post-conflict behavior may act as an alternative to reconciliation, i.e., post-conflict affiliation between opponents, in that it is more common when opponents fail to reconcile

    Critical role of metals in biochemical properties of xylose isomerase

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    Improving the activity of xylose isomerase (XI) is highly desired for achieving efficient fermentation of xylose in lignocellulosic biomass using XI-expressing S. cerevisiae. XI is a metalloenzyme which requires two bivalent metals for its catalytic activity. The enzyme from Piromyces sp. E2 (PirXI)[1],[2] is activated with various metal ions including Mg2+, Mn2+, Ca2+, Co2+, Zn2+ and Fe2+. The biochemical properties of PirXI are dependent on the types of its metal cofactors. Moreover, the enzyme shows different affinities towards these metals. Characterization of these properties is critical for understanding the enzyme behavior in vivo and to further adapt the enzyme to the cytosolic metal environment. Recently, we have shown that altered intracellular metal composition can improve anaerobic growth of a xylose-fermenting strain by enhancing the activity of PirXI[3]. Furthermore, our current study on PirXI and other studies on different XIs have shown that it is also possible to change the metal preferences of the enzyme[4]. A PirXI variant with a single amino acid substitution in the proximity of the metal binding residues showed significant changes in metal preference compared to the wild-type PirXI. Further exploration on metal specificity of PirXI is necessary to optimize the in vivo enzyme activity. References: 1.Kuyper M, Harhangi HR, Stave AK, Winkler AA, Jetten MS, de Laat WT, den Ridder JJ, Op den Camp HJ, van Dijken JP, Pronk JT, FEMS Yeast Research 4 (2003) 69-78 2.van Maris AJ, Winkler AA, Kuyper M, de Laat WT, van Dijken JP, Pronk JT, Adv Biochem Engin/Biotechnol (2007) 108: 179–204 3.Verhoeven MD, Lee M, Kamoen L, van den Broek M, Janssen DB, Daran JG, van Maris AJA, Pronk JT, Sci. Rep (2017) 7, 46155 4.van Tilbeurgh H, Jenkins J, Chiadmi M, Janin J, Wodak SJ, Mrabet NT, Lambeir AM, Biochemistry (1992) 31: 5467-547

    Social network analysis shows direct evidence for social transmission of tool use in wild chimpanzees

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    The authors are grateful to the Royal Zoological Society of Scotland for providing core funding for the Budongo Conservation Field Station. The fieldwork of CH was funded by the Leverhulme Trust, the Lucie Burgers Stichting, and the British Academy. TP was funded by the Canadian Research Chair in Continental Ecosystem Ecology, and received computational support from the Theoretical Ecosystem Ecology group at UQAR. The research leading to these results has received funding from the People Programme (Marie Curie Actions) and from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007–2013) REA grant agreement n°329197 awarded to TG, ERC grant agreement n° 283871 awarded to KZ. WH was funded by a BBSRC grant (BB/I007997/1).Social network analysis methods have made it possible to test whether novel behaviors in animals spread through individual or social learning. To date, however, social network analysis of wild populations has been limited to static models that cannot precisely reflect the dynamics of learning, for instance, the impact of multiple observations across time. Here, we present a novel dynamic version of network analysis that is capable of capturing temporal aspects of acquisition-that is, how successive observations by an individual influence its acquisition of the novel behavior. We apply this model to studying the spread of two novel tool-use variants, "moss-sponging'' and "leaf-sponge re-use,'' in the Sonso chimpanzee community of Budongo Forest, Uganda. Chimpanzees are widely considered the most "cultural'' of all animal species, with 39 behaviors suspected as socially acquired, most of them in the domain of tool-use. The cultural hypothesis is supported by experimental data from captive chimpanzees and a range of observational data. However, for wild groups, there is still no direct experimental evidence for social learning, nor has there been any direct observation of social diffusion of behavioral innovations. Here, we tested both a static and a dynamic network model and found strong evidence that diffusion patterns of moss-sponging, but not leaf-sponge re-use, were significantly better explained by social than individual learning. The most conservative estimate of social transmission accounted for 85% of observed events, with an estimated 15-fold increase in learning rate for each time a novice observed an informed individual moss-sponging. We conclude that group-specific behavioral variants in wild chimpanzees can be socially learned, adding to the evidence that this prerequisite for culture originated in a common ancestor of great apes and humans, long before the advent of modern humans.Publisher PDFPeer reviewe

    Agent-based Social Psychology: from Neurocognitive Processes to Social Data

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    Moral Foundation Theory states that groups of different observers may rely on partially dissimilar sets of moral foundations, thereby reaching different moral valuations. The use of functional imaging techniques has revealed a spectrum of cognitive styles with respect to the differential handling of novel or corroborating information that is correlated to political affiliation. Here we characterize the collective behavior of an agent-based model whose inter individual interactions due to information exchange in the form of opinions are in qualitative agreement with experimental neuroscience data. The main conclusion derived connects the existence of diversity in the cognitive strategies and statistics of the sets of moral foundations and suggests that this connection arises from interactions between agents. Thus a simple interacting agent model, whose interactions are in accord with empirical data on conformity and learning processes, presents statistical signatures consistent with moral judgment patterns of conservatives and liberals as obtained by survey studies of social psychology.Comment: 11 pages, 4 figures, 2 C codes, to appear in Advances in Complex System

    Synergistic effects of TNF-alpha and melphalan in an isolated limb perfusion model of rat sarcoma: a histopathological, immunohistochemical and electron microscopical study.

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    Isolated limb perfusion (ILP) with tumour necrosis factor alpha (TNF-alpha) and melphalan has shown impressive results in patients with irresectable soft tissue sarcomas and stage III melanoma of the extremities. The mechanisms of the reported in vivo synergistic anti-tumour effects of TNF-alpha and melphalan are not precisely understood. We have developed an ILP model in the rat using a non-immunogenic sarcoma in which similar in vivo synergy is observed. The aim of this present study was to analyse the morphological substrate for this synergistic response of TNF-alpha in combination with melphalan to shed more light on the pathomechanisms involved. Histology of the tumours from saline- (n = 14) and melphalan-treated (n = 11) rats revealed apparently vital tumour cells in over 80% of the cross-sections. Interstitial oedema and coagulation necrosis were observed in the remaining part of the tumour. Haemorrhage was virtually absent. TNF-alpha (n = 22) induced marked oedema, hyperaemia, vascular congestion, extravasation of erythrocytes and haemorrhagic necrosis (20-60% of the cross-sections). Oedema and haemorrhage suggested drastic alterations of permeability and integrity of the microvasculature. Using light and electron-microscopy, we observed that haemorrhage preceded generalised platelet aggregation. Therefore, we suggest that the observed platelet aggregation was the result of the microvascular damage rather than its initiator. Remarkably, these events hardly influenced tumour growth. However, perfusion with the combination of TNF-alpha and melphalan (n = 24) showed more extensive haemorrhagic necrosis (80-90% of the cross-sections) and revealed a prolonged remission (mean 11 days) in comparison with the other groups of rats. Electron microscopical analysis revealed similar findings as described after TNF-alpha alone, although the effects were more prominent at all time points after perfusion. In conclusion, our findings suggest that the enhanced anti-tumour effect after the combination of TNF-alpha with melphalan results from potentiation of the TNF-alpha-induced vascular changes accompanied by increased vascular permeability and platelet aggregation. This may result in additive cytotoxicity or inhibition of growth of residual tumour cells

    Chimpanzees Help Each Other upon Request

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    Background: The evolution of altruism has been explained mainly from ultimate perspectives. However, it remains to be investigated from a proximate point of view how and in which situations such social propensity is achieved. We investigated chimpanzees' targeted helping in a tool transfer paradigm, and discuss the similarities and differences in altruism between humans and chimpanzees. Previously it has been suggested that chimpanzees help human experimenters by retrieving an object which the experimenter is trying to reach. In the present study, we investigated the importance of communicative interactions between chimpanzees themselves and the influence of conspecific partner's request on chimpanzees' targeted helping. Methodology/Principal Findings: We presented two tool-use situations ( a stick-use situation and a straw-use situation) in two adjacent booths, and supplied non-corresponding tools to paired chimpanzees in the two booths. For example, a chimpanzee in the stick-use situation was supplied with a straw, and the partner in the straw-use situation possessed a stick. Spontaneous tool transfer was observed between paired chimpanzees. The tool transfer events occurred predominantly following recipients' request. Even without any hope of reciprocation from the partner, the chimpanzees continued to help the partner as long as the partner required help. Conclusions/Significance: These results provide further evidence for altruistic helping in chimpanzees in the absence of direct personal gain or even immediate reciprocation. Our findings additionally highlight the importance of request as a proximate mechanism motivating prosocial behavior in chimpanzees whether between kin or non-kin individuals and the possible confounding effect of dominance on the symmetry of such interactions. Finally, in contrast to humans, our study suggests that chimpanzees rarely perform acts of voluntary altruism. Voluntary altruism in chimpanzees is not necessarily prompted by simple observation of another's struggle to attain a goal and therefore an accurate understanding of others' desires in the absence of communicative signals

    Entropic effects on the Size Evolution of Cluster Structure

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    We show that the vibrational entropy can play a crucial role in determining the equilibrium structure of clusters by constructing structural phase diagrams showing how the structure depends upon both size and temperature. These phase diagrams are obtained for example rare gas and metal clusters.Comment: 5 pages, 3 figure
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