3,388 research outputs found
Gestural Communication and Mating Tactics in Wild Chimpanzees
The extent to which primates can flexibly adjust the production of gestural communication according to the presence and visual attention of the audience provides key insights into the social cognition underpinning gestural communication, such as an understanding of third party relationships. Gestures given in a mating context provide an ideal area for examining this flexibility, as frequently the interests of a male signaller, a female recipient and a rival male bystander conflict. Dominant chimpanzee males seek to monopolize matings, but subordinate males may use gestural communication flexibly to achieve matings despite their low rank. Here we show that the production of mating gestures in wild male East African chimpanzees (Pan troglodytes schweunfurthii) was influenced by a conflict of interest with females, which in turn was influenced by the presence and visual attention of rival males.
When the conflict of interest was low (the rival male was present and looking away), chimpanzees used visual/ tactile gestures over auditory gestures. However, when the conflict of interest was high (the rival male was absent, or was present and looking at the signaller) chimpanzees used auditory gestures over visual/ tactile gestures. Further, the production of mating gestures was more common when the number of oestrous and non-oestrus females in the party increased, when the female was visually perceptive and when there was no wind. Females played an active role in mating behaviour, approaching for copulations more often when the number of oestrus females in the party increased and when the rival male was absent, or was present and looking away. Examining how social and ecological factors affect mating tactics in primates may thus contribute to understanding the previously unexplained reproductive success of subordinate male chimpanzees
Visual Attention, Indicative Gestures, and Calls Accompanying Gestural Communication Are Associated With Sociality in Wild Chimpanzees (Pan troglodytes schweinfurthii)
The challenges of life in complex social groups may select for complex communication to regulate interactions among conspecifics. Whereas the association between social living and vocalizations has been explored in nonhuman primates, great apes also have a rich repertoire of gestures, and how the complexity of gestural communication relates to sociality is still unclear. We used social network analysis to examine the relationship between the duration of time pairs of chimpanzees spent in proximity (within 10 m) and the rates of gestural communication accompanied by visual attention of the signaler, one-to-one calls, indicative gestures (collectively self-relevance cues), and synchronized pant-hoot calls. Pairs of chimpanzees that spent a longer duration of time in proximity had a higher rate of visual gestures accompanied by these behaviors. Further, individual chimpanzees that had a greater number of proximity bonds had a larger social network maintained through gestures accompanied by synchronized pant-hoot calls. In contrast, gestures unaccompanied by these behaviors were not positively associated with either proximity bonds in pairs of chimpanzees or individual differences in sociality. These results suggest that self-relevance cues and synchronized pant-hoot calls accompanying gestures may increase the efficiency of gestural communication in social bonding and that multimodal communication may have played a key role in language evolution. © 2018 American Psychological Association
Prevalence and factors associated with the use of alternative (folk) medicine practitioners in 8 countries of the former Soviet Union.
BACKGROUND: Research suggests that since the collapse of the Soviet Union there has been a sharp growth in the use of complementary and alternative medicine (CAM) in some former Soviet countries. However, as yet, comparatively little is known about the use of CAM in the countries throughout this region. Against this background, the aim of the current study was to determine the prevalence of using alternative (folk) medicine practitioners in eight countries of the former Soviet Union (fSU) and to examine factors associated with their use. METHODS: Data were obtained from the Living Conditions, Lifestyles and Health (LLH) survey undertaken in eight former Soviet countries (Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia and Ukraine) in 2001. In this nationally representative cross-sectional survey, 18428 respondents were asked about how they treated 10 symptoms, with options including the use of alternative (folk) medicine practitioners. Multivariate logistic regression analysis was used to determine the factors associated with the treatment of differing symptoms by such practitioners in these countries. RESULTS: The prevalence of using an alternative (folk) medicine practitioner for symptom treatment varied widely between countries, ranging from 3.5% in Armenia to 25.0% in Kyrgyzstan. For nearly every symptom, respondents living in rural locations were more likely to use an alternative (folk) medicine practitioner than urban residents. Greater wealth was also associated with using these practitioners, while distrust of doctors played a role in the treatment of some symptoms. CONCLUSIONS: The widespread use of alternative (folk) medicine practitioners in some fSU countries and the growth of this form of health care provision in the post-Soviet period in conditions of variable licensing and regulation, highlights the urgent need for more research on this phenomenon and its potential effects on population health in the countries in this region
Persistence in gestural communication predicts sociality in wild chimpanzees.
A key challenge for primates is coordinating behaviour with conspecifics in large, complex social groups. Gestures play a key role in this process and chimpanzees show considerable flexibility communicating through single gestures, sequences of gestures interspersed with periods of response waiting (persistence), and rapid sequences where gestures are made in quick succession, too rapid for the response waiting to have occurred. The previous studies examined behavioural reactions to single gestures and sequences, but whether this complexity is associated with more complex sociality at the level of the dyad partner and the group as a whole is not well understood. We used social network analysis to examine how the production of single gestures and sequences of gestures was related to the duration of time spent in proximity and individual differences in proximity in wild East African chimpanzees (Pan troglodytes schweinfurthii). Pairs of chimpanzees that spent a longer duration of time in proximity had higher rates of persistence sequences, but not a higher rate of single gestures or rapid sequences. The duration of time spent in proximity was also related to the rate of responding to gestures, and response to gesture by activity change. These results suggest that communicative persistence and the type of response to gestures may play an important role in regulating social interactions in primate societies
Social and ecological complexity is associated with gestural repertoire size of wild chimpanzees.
Increasing our understanding of primate gestural communication can provide new insights into language evolution. A key question in primate communication is the association between the social relationships of primates and their repertoire of gestures. Such analyses can reveal how primates use their repertoire of gestural communication to maintain their networks of family and friends, much as humans use language to maintain their social networks. In this study we examined the association between the repertoire of gestures (overall, manual and bodily gestures, gestures of different modalities) and social bonds (presence of reciprocated grooming), coordinated behaviours (travel, resting, co-feeding), and the complexity of ecology (e.g. noise, illumination) and sociality (party size, audience), in wild East African chimpanzees (Pan troglodytes schweinfurthii). A larger repertoire size of manual, visual gestures was associated with the presence of a relationship based on reciprocated grooming and increases in social complexity. A smaller repertoire of manual tactile gestures occurred when relationship was based on reciprocated grooming. A smaller repertoire of bodily gestures occurred between partners who jointly travelled for longer. Whereas gesture repertoire size was associated with social complexity, complex ecology also influenced repertoire size. The evolution of a large repertoire of manual, visual gestures may have been a key factor that enabled for larger social groups to emerge during evolution. Thus, the evolution of the larger brains in hominins may have co-occurred with an increase in the cognitive complexity underpinning gestural communication and this in turn may have enabled hominins to live in more complex social groups. This article is protected by copyright. All rights reserved
Selenium, selenoproteins and neurodegenerative diseases
© The Royal Society of Chemistry 2015. It is unsurprising that our understanding of the role of selenium in neurological function is somewhat immature, considering its relatively recent discovery as an essential element to human health. Selenocysteine, the 21st amino acid, is the defining feature of the 25 selenoprotein-encoding genes so far discovered within the human genome. The low abundance of these proteins in the brain belies the integral role they play in normal neurological function, from well-characterised antioxidant activity in the periphery to poorly understood mechanisms that modulate mitochondrial function and response to brain pathology. Selenium has been identified as playing a role in several neurodegenerative disorders, including Alzheimer's and Parkinson's disease, though its function as a 'cause or effect' of disease process remains unclear. This review discusses selenium metabolism in detail, specifically with regard to the role it plays within the central nervous system, and examines the most current literature investigating how selenium may be involved in chronic diseases of the central nervous system
Glutathione peroxidase 4: A new player in neurodegeneration?
© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. Glutathione peroxidase 4 (GPx4) is an antioxidant enzyme reported as an inhibitor of ferroptosis, a recently discovered non-apoptotic form of cell death. This pathway was initially described in cancer cells and has since been identified in hippocampal and renal cells. In this Perspective, we propose that inhibition of ferroptosis by GPx4 provides protective mechanisms against neurodegeneration. In addition, we suggest that selenium deficiency enhances susceptibility to ferroptotic processes, as well as other programmed cell death pathways due to a reduction in GPx4 activity. We review recent studies of GPx4 with an emphasis on neuronal protection, and discuss the relevance of selenium levels on its enzymatic activity
Male solitary drinking and hazardous alcohol use in nine countries of the former Soviet Union.
BACKGROUND: Despite evidence that many people engage in solitary drinking and that it might be associated with negative consequences, to date, little research has focused on this form of drinking behaviour. This study examined the prevalence and factors associated with solitary drinking, and assessed whether it is linked with hazardous alcohol use among males in nine countries of the former Soviet Union (fSU). METHODS: Data came from a cross-sectional population-based survey undertaken in 2010/11 in Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia, and Ukraine. Information was obtained on the frequency of solitary drinking among male regular drinkers (i.e., those consuming alcoholic drinks at least once a month), and on problem drinking (CAGE) and heavy episodic drinking (HED). Logistic regression analysis was used to examine associations between the variables. RESULTS: The prevalence of occasional and frequent solitary drinking ranged from 8.4% (Georgia) to 42.4% (Azerbaijan), and 3.1% (Kazakhstan) to 8.2% (Armenia), respectively. Solitary drinking was associated with being older, divorced/widowed, living alone, having a bad/very bad household financial situation, lower levels of social support, and poor self-rated health. Occasional solitary drinking was linked to problem drinking and HED, while frequent solitary alcohol use was related to problem drinking. CONCLUSIONS: Solitary drinking is relatively common among male regular drinkers in the fSU and is linked to older age, social and economic disadvantage, and hazardous alcohol use
Binge drinking among adolescents in Russia: prevalence, risk and protective factors.
Despite evidence that alcohol misuse has been having an increasingly detrimental effect on adolescent wellbeing in Russia in recent years this phenomenon has been little researched. Using data from 2112 children from the Arkhangelsk Social and Health Assessment (SAHA) 2003, this study examined which factors acted as 'risk' or 'protective' factors for adolescent binge drinking within three domains we termed the 'family environment', the 'alcohol environment' and 'deviant behaviour'. The results showed that in the presence of comparatively moderate levels of binge drinking among both boys and girls, being able to access alcohol easily, being unaware of the risks of binge drinking and having peers who consumed alcohol increased the risk of adolescent binge drinking - as did playing truant, smoking and marijuana use, while parental warmth was protective against binge drinking for girls. Our finding that risk and protective factors occur across domains suggests that any interventions targeted against adolescent binge drinking may need to simultaneously focus on risk behaviours in different domains, while at the same time, broader social policy should act to limit the availability of alcohol to adolescents in Russia more generally
Between-centre differences and treatment effects in randomized controlled trials: A case study in traumatic brain injury
BACKGROUND: In Traumatic Brain Injury (TBI), large between-centre differences in outcome exist and many clinicians believe that such differences influence estimation of the treatment effect in randomized controlled trial (RCTs). The aim of this study was to assess the influence of between-centre differences in outcome on the estimated treatment effect in a large RCT in TBI. METHODS: We used data from the MRC CRASH trial on the efficacy of corticosteroid infusion in patients with TBI. We analyzed the effect of the treatment on 14 day mortality with fixed effect logistic regression. Next we used random effects logistic regression with a random intercept to estimate the treatment effect taking into account between-centre differences in outcome. Between-centre differences in outcome were expressed with a 95% range of odds ratios (OR) for centres compared to the average, based on the variance of the random effects (tau2). A random effects logistic regression model with random slopes was used to allow the treatment effect to vary by centre. The variation in treatment effect between the centres was expressed in a 95% range of the estimated treatment ORs. RESULTS: In 9978 patients from 237 centres, 14-day mortality was 19.5%. Mortality was higher in the treatment group (OR = 1.22, p = 0.00010). Using a random effects model showed large between-centre differences in outcome (95% range of centre effects: 0.27- 3.71), but did not substantially change the estimated treatment effect (OR = 1.24, p = 0.00003). There was limited, although statistically significant, between-centre variation in the treatment effect (OR = 1.22, 95% treatment OR range: 1.17-1.26). CONCLUSION: Large between-centre differences in outcome do not necessarily affect the estimated treatment effect in RCTs, in contrast to current beliefs in the clinical area of TBI
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