HIV/AIDS, Security and Conflict: New Realities, New Responses

Ten years after the HIV/AIDS epidemic itself was identified as a threat to international peace and security, findings from the three-year AIDS, Security and Conflict Initiative (ASCI)(1) present evidence of the mutually reinforcing dynamics linking HIV/AIDS, conflict and security

What it takes to attain status in face-to-face groups: the importance of distinguishing between dominance and prestige hierarchies

Hierarchy is a defining feature of groups (Berger et al., 1972; Fiske, 2010; Sidanius & Pratto, 1999). In this thesis I examined what it takes to climb up this hierarchy in face-to-face groups. I did so from three angles: what people need to do in order to attain status, what kind of person people need to be in order to attain status, and what people may need to sacrifice in order to attain status. Moreover, I assessed the moderating effect on these relations of two fundamental processes underlying group hierarchies: dominance (i.e., assertively claiming status) and prestige (i.e., willingly being granted status). Before addressing the main questions of this thesis, I examined the impact of dominance and prestige processes on perceptions of group hierarchy types (Chapter 2). A vignette study found that assertively claiming status for oneself and willingly being granted status both emerged as viable ways of enhancing perceived status, above and beyond formal status. It also found that, at the group level, each type of process worked against the other: perceptions of each were undermined by mixing it with the other. This finding implies that groups can be classed along a hierarchy type continuum, ranging from highly dominance-based to highly prestige-based.Having empirically established how dominance and prestige processes jointly shape the types of hierarchies that exist in groups, I addressed the main questions of this thesis in a series of experimental and naturalistic studies. In Chapter 3, I examined the interpersonal behaviours that promote status in different types of group hierarchies. I found that agentic behaviour promoted status both in dominance-based and in prestige-based hierarchies. In contrast, communal behaviour augmented status in prestige-based hierarchies, but diminished status in dominance-based hierarchies. Thus, I found that status attainment is associated with diametrically different interpersonal behaviours in different hierarchy types. In Chapter 4, I assessed how the self-appraisals of people who engage in different status-promoting behaviours differ. I found that self-esteem was associated with behaviour that was high in agency and high in communion, whereas narcissism was associated with behaviour that was high in agency and low in communion. Thus, self-esteem related to behaviours that promote status in prestige-based groups, whereas narcissism related to behaviours that promote status in dominance-based groups.In Chapter 5, an experimental study found that the interpersonal warmth towards individuals increased with status in relatively prestige-based hierarchies and decreased with status in relatively dominance-based hierarchies. In other words, in prestige-based groups, being liked and being included were liable to go hand-in-hand, whereas in dominance-based groups, there was a trade-off between them: to attain status one might need to sacrifice inclusion. However, this finding needs to be interpreted with caution as I failed to replicate it in a subsequent naturalistic study.Together, these findings presented in this thesis convincingly demonstrate that hierarchy type is a diversifying feature of groups. As such, they powerfully illustrate the importance of distinguishing between dominance-based and prestige-based groups

Role of immigrant males and muzzle contacts in the uptake of a novel food by wild vervet monkeys.

The entry into and uptake of information in social groups is critical for behavioral adaptation by long-lived species in rapidly changing environments. We exposed five groups of wild vervet monkeys to a novel food to investigate the innovation of processing and consuming it. We report that immigrant males innovated in two groups, and an infant innovated in one group. In two other groups, immigrant males imported the innovation from their previous groups. We compared uptake between groups with respect to the initial innovator to examine the extent to which dispersing males could introduce an innovation into groups. Uptake of the novel food was faster in groups where immigrant males ate first rather than the infants. Younger individuals were more likely overall, and faster, to subsequently acquire the novel food. We also investigated the role of muzzle contact behavior in information seeking around the novel food. Muzzle contacts decreased in frequency over repeated exposures to the novel food. Muzzle contacts were initiated the most by naïve individuals, high rankers, and juveniles; and were targeted most towards knowledgeable individuals and high rankers, and the least towards infants. We highlight the potential importance of dispersers in rapidly exploiting novel resources among populations

Research Chimpanzees May Get a Break

A recent report by the Institute of Medicine leaves few urgent reasons standing for the continued use of chimpanzees in biomedical research. It is high time to think about their retirement, Frans de Waal argues, without neglecting prospects for non-invasive research on behavior, cognition, and genetics

Charge distribution in two-dimensional electrostatics

We examine the stability of ringlike configurations of N charges on a plane interacting through the potential $V(z_1,...,z_N)=\sum_i |z_i|^2-\sum_{i<j} ln|z_i-z_j|^2$. We interpret the equilibrium distributions in terms of a shell model and compare predictions of the model with the results of numerical simulations for systems with up to 100 particles.Comment: LaTe

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

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

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

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

Efficient, D-glucose insensitive, growth on D-xylose by an evolutionary engineered Saccharomyces cerevisiae strain

Optimizing D-xylose consumption in Saccharomyces cerevisiae is essential for cost-efficient cellulosic bioethanol production. An evolutionary engineering approach was used to elevate D-xylose consumption in a xylose-fermenting S. cerevisiae strain carrying the D-xylose-specific N367I mutation in the endogenous chimeric Hxt36 hexose transporter. This strain carries a quadruple hexokinase deletion that prevents glucose utilization, and allows for selection of improved growth rates on D-xylose in the presence of high D-glucose concentrations. Evolutionary engineering resulted in D-glucose-insensitive growth and consumption of D-xylose which could be attributed to glucose insensitive D-xylose uptake via a novel chimeric Hxt37 N367I transporter that emerged from a fusion of the HXT36 and HXT7 genes, and a down regulation of a set of Hxt transporters that mediate glucose sensitive xylose transport. RNA sequencing revealed the down-regulation of HXT1 and HXT2 which, together with the deletion of HXT7, resulted in a 21% reduction of the expression of all plasma membrane transporters genes. Morphological analysis showed an increased cell size and corresponding increased cell surface area of the evolved strain, which could be attributed to genome duplication. Mixed strain fermentation of the D-xylose-consuming strain DS71054-evo6 with the D-glucose consuming CEN.PK113-7D strain resulted in decreased residual sugar concentrations and improved ethanol production yields compared to a strain which sequentially consumes D-glucose and D-xylose

Clinician compliance with laboratory monitoring and prescribing guidelines in HIV 1-infected patients receiving tenofovir

Background. Tenofovir is part of the preferred first-line regimen for HIV-infected patients in South Africa (SA), but is associated with kidney toxicity. SA antiretroviral therapy (ART) guidelines recommend creatinine monitoring at baseline (ART start) and at 3, 6 and 12 months, and substituting tenofovir with zidovudine, stavudine or abacavir should creatinine clearance (CrCl) decrease to &lt;50 mL/min.Objective. To assess clinician compliance with tenofovir monitoring and prescribing guidelines.Methods. We described the proportion of adult patients on tenofovir-based first-line ART who were screened for baseline renal impairment, were monitored according to the SA antiretroviral treatment guidelines, and were switched from tenofovir if renal function declined.Results. We included 13 168 patients who started ART from 2010 to 2012. Creatinine concentrations were recorded in 11 712 (88.9%) patients on tenofovir at baseline, 9 135/11 657 (78.4%) at 3 months, 5 426/10 554 (51.4%) at 6 months, and 5 949/ 8 421 (70.6%) at 12 months. At baseline, 227 (1.9%) started tenofovir despite a CrCl &lt;50 mL/min. While on tenofovir, 525 patients had at least one CrCl of &lt;50 mL/min. Of 382 patients with ≥3 months’ follow-up after a CrCl &lt;50 mL/min, 114 (29.8%) stopped tenofovir within 3 months. Clinicians were more likely to stop tenofovir in patients with lower CrCl and CD4 count. Of 226 patients who continued to receive tenofovir and had further CrCls available, 156 (69.0%) had a CrCl ≥50 mL/min at their next visit.Conclusions. Creatinine monitoring is feasible where access to laboratory services is good. Kidney function recovered in most patients who continued to receive tenofovir despite a CrCl &lt;50 mL/min. Further research is needed to determine how best to monitor renal function with tenofovir in resource-limited settings