Social network and dominance hierarchy analyses at Chimpanzee Sanctuary Northwest

Different aspects of sociality bear considerable weight on the individual- and group-level welfare of captive nonhuman primates. Social Network Analysis (SNA) is a useful tool for gaining a holistic understanding of the dynamic social relationships of captive primate groups. Gaining a greater understanding of captive chimpanzees through investigations of centrality, preferred and avoided relationships, dominance hierarchy, and social network diagrams can be useful in advising current management practices in sanctuaries and other captive settings. In this study, we investigated the dyadic social relationships, group-level social networks, and dominance hierarchy of seven chimpanzees (Pan troglodytes) at Chimpanzee Sanctuary Northwest. We used focal-animal and instantaneous scan sampling to collect 106.75 total hours of associative, affiliative, and agonistic data from June to September 2016. We analyzed our data using SOCPROG to derive dominance hierarchies and network statistics, and we diagrammed the group\u27s social networks in NetDraw. Three individuals were most central in the grooming network, while two others had little connection. Through agonistic networks, we found that group members reciprocally exhibited agonism, and the group\u27s dominance hierarchy was statistically non-linear. One chimpanzee emerged as the most dominant through agonism but was least connected to other group members across affiliative networks. Our results indicate that the conventional methods used to calculate individuals\u27 dominance rank may be inadequate to wholly depict a group\u27s social relationships in captive sanctuary populations. Our results have an applied component that can aid sanctuary staff in a variety of ways to best ensure the improvement of group welfare

Contingency in requests of signing chimpanzees (\u3ci\u3ePan troglodytes\u3c/i\u3e)

Conversational interactions depend on partners making contingent responses. This experiment examined the responses of five chimpanzees (Pan troglodytes), Washoe, Moja, Tatu, Dar and Loulis, to four conversational conditions. Following the chimpanzee’s request, a human interlocutor either: (1) complied with the request, (2) provided an unrequested item or activity, (3) refused to comply or (4) did not respond to the request. The chimpanzees’ responses were contingent on the conversational input of the interlocutor. When their requests were satisfied, the chimpanzees most often ceased signing. However, when their requests were misunderstood, refused or not acknowledged, the chimpanzees repeated and revised. This pattern of responses is comparable to patterns of conversational responses in human children

Gender and risk of adverse outcomes in heart failure.

Congestive heart failure (CHF) is the leading cause of hospitalization in the elderly, and these patients are at high risk for subsequent hospitalization. Whether gender affects the risk of rehospitalization in patients who have CHF is less well understood. We studied a random sample of 1,700 adults who had been hospitalized with CHF (from July 1, 1999 to June 30, 2000) and identified all readmissions through June 30, 2001. We used proportional hazards regression to evaluate whether gender affects the risk of all-cause and CHF-specific rehospitalization, after adjusting for differences in demographic characteristics, health-related behaviors, co-morbid conditions, left ventricular systolic function status, and use of CHF therapies. Among 1,591 adults who had confirmed CHF, 752 were women (47.3%). Women were older than men (73 vs 71 years, p \u3c0.001) and more likely to have preserved systolic function (55.3% vs 40.9%, p \u3c0.001), hypertension (83.1% vs 75.2%, p \u3c0.001), and prior renal insufficiency (46.8% vs 34.6%, p \u3c0.001). No significant differences existed between women and men with respect to crude rates of any readmission (144.7 vs 134.6 per 100 person-years, p = 0.36) or CHF-specific readmission (39.9 vs 37.4 per 100 person-years, p = 0.65). After adjusting for potential confounders, there was no significant difference between women and men with respect to risk of any readmission (adjusted hazard ratio 0.88, 95% confidence interval 0.76 to 1.02) or readmission for CHF (adjusted hazard ratio 0.89, 95% confidence interval 0.71 to 1.11). Among a contemporary, diverse population of patients who had CHF, rates of readmission overall and for CHF remained high, but gender was not independently associated with a differential risk of readmission