1,595 research outputs found

    Gaze discrimination learning in olive baboons (Papio anubis)

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    The ability to discriminate between pairs of photographs according to the portrayed model’s visual attention status was examined in four olive baboons. Two baboons successfully managed to solve the problem, even when attention was demonstrated by eye direction alone. A third showed an ability to discriminate head direction but not eye direction. In order to investigate further their ability to discriminate attention, the two successful baboons and two naïve baboons were presented with a simple object-choice task accompanied by experimenter-given cues. There was no evidence of transfer from the photographic stimuli to a real model; only one baboon showed signs of using the experimenter’s attention to chose between two objects, and only after over 300 trials. These results could suggest that the baboons used simple physical cues rather than a concept of attention to solve the picture discrimination but alternative explanations are also discussed

    If Not Now, Then When? : Pathways to Embed Climate Change Within Social Policy

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    Climate change is arguably the defining issue of our time, with global impacts. Yet to date, scholarship within social policy has remained relatively fragmented and disparate, leaving an urgent need to start comprehensively embedding environmental thinking across all domains of the discipline (Williams, 2021). Responding to this challenge, this paper draws together existing work at the nexus of social policy, the environment, and climate change. The paper then presents findings from workshops held with social policy scholars, policymakers, and practitioners, using these discussions to propose pathways to embed climate change within the discipline. The paper represents a significant contribution to knowledge within the field as it seeks to both broaden discussions about social policy and climate change; to identify theoretical and empirical relationships that exist between the two fields but have not been fully recognised in existing scholarship; and to bring new perspectives and voices into the discussion

    Use of human visual attention cues by Olive baboons (Papio anubis) in a competitive task

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    The ability of four olive baboons (Papio anubis) to use human gaze cues during a competitive task was investigated; the baboons were allowed to remove only the non-fixated one of two simultaneously presented food items. Three baboons successfully learned to exploit the human’s head orientation as a cue to obtain a food item, and one individual also learned to use eye direction alone. As the baboons did not receive prior training with gross gestural cues, their performance suggests that the competitive paradigm may be more conducive to gaze monitoring in nonhuman primates than the standard object-choice paradigm. However, the baboons were insensitive to whether the experimenter could actually perceive the food item and therefore use of visual orientation cues may not be indicative of visual perspective-taking abilities in baboons. Performance was disrupted by the introduction of a screen and objects to conceal the food items, and to a lesser degree by the absence of movement in cues presented

    Maximising HIV prevention by balancing the opportunities of today with the promises of tomorrow: a modelling study

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    SummaryBackgroundMany ways of preventing HIV infection have been proposed and more are being developed. We sought to construct a strategic approach to HIV prevention that would use limited resources to achieve the greatest possible prevention impact through the use of interventions available today and in the coming years.MethodsWe developed a deterministic compartmental model of heterosexual HIV transmission in South Africa and formed assumptions about the costs and effects of a range of interventions, encompassing the further scale-up of existing interventions (promoting condom use, male circumcision, early antiretroviral therapy [ART] initiation for all [including increased HIV testing and counselling activities], and oral pre-exposure prophylaxis [PrEP]), the introduction of new interventions in the medium term (offering intravaginal rings, long-acting injectable antiretroviral drugs) and long term (vaccine, broadly neutralising antibodies [bNAbs]). We examined how available resources could be allocated across these interventions to achieve maximum impact, and assessed how this would be affected by the failure of the interventions to be developed or scaled up.FindingsIf all interventions are available, the optimum mix would place great emphasis on the following: scale-up of male circumcision and early ART initiation with outreach testing, as these are available immediately and assumed to be low cost and highly efficacious; intravaginal rings targeted to sex workers; and vaccines, as these can achieve a large effect if scaled up even if imperfectly efficacious. The optimum mix would rely less on longer term developments, such as long-acting antiretroviral drugs and bNAbs, unless the costs of these reduced. However, if impossible to scale up existing interventions to the extent assumed, emphasis on oral PrEP, intravaginal rings, and long-acting antiretroviral drugs would increase. The long-term effect on the epidemic is most affected by scale-up of existing interventions and the successful development of a vaccine.InterpretationWith current information, a strategic approach in which limited resources are used to maximise prevention impact would focus on strengthening the scale-up of existing interventions, while pursuing a workable vaccine and developing other approaches that can be used if further scale-up of existing interventions is limited.FundingBill & Melinda Gates Foundation

    The mediated innovation model: a framework for researching media influence in language change

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    Linguistic innovations that arise contemporaneously in highly distant locations, such as quotative be like, have been termed ‘global linguistic variants’. This is not necessarily to suggest fully global usage, but to invoke more general themes of globalisation vis-à-vis space and time. This research area has grown steadily in the last twenty years, and by asserting a role for mass media, researchers have departed intrepidly from sociolinguistic convention. Yet they have largely relied on quite conventional sociolinguistic methodologies, only inferring media influence post hoc. This methodological conservatism has been overcome recently, but uncertainty remains about the overall shape of the new epistemological landscape. In this paper, I review existing research on global variants, and propose an epistemological model for researching media influence in language change: the mediated innovation model. I also analyse the way arguments are constructed in existing research, including the use of rhetorical devices to plug empirical gaps – a worthy sociolinguistic topic in its own right

    Appraising the value of evidence generation activities : an HIV modelling study

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    Introduction: The generation of robust evidence has been emphasised as a priority for global health. Evidence generation spans a wide range of activities including clinical trials, surveillance programmes and health system performance measurement. As resources for healthcare and research are limited, the desirability of research expenditure should be assessed on the same basis as other healthcare resources, that is, the health gains from research must be expected to exceed the health opportunity costs imposed as funds are diverted to research rather than service provision. Methods: We developed a transmission and costing model to examine the impact of generating additional evidence to reduce uncertainties on the evolution of a generalised HIV epidemic in Zambia. Results: We demonstrate three important points. First, we can quantify the value of additional evidence in terms of the health gain it is expected to generate. Second, we can quantify the health opportunity cost imposed by research expenditure. Third, the value of evidence generation depends on the budgetary policies in place for managing HIV resources under uncertainty. Generating evidence to reduce uncertainty is particularly valuable when decision makers are required to strictly adhere to expenditure plans and when transfers of funds across geographies/programmes are restricted. Conclusion: Better evidence can lead to health improvements in the same way as direct delivery of healthcare. Quantitative appraisals of evidence generation activities are important and should reflect the impact of improved evidence on population health, evidence generation costs and budgetary policies in place

    Pictorial gaze cues do not enhance long tailed macaques’ performance on a computerised object location task

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    The perception of pictorial gaze cues was examined in long-tailed macaques (Macaca fascicularis). A computerised object location task was used to explore whether the monkeys would show faster response time to locate a target when its appearance was preceded with congruent as opposed to incongruent gaze cues. Despite existing evidence that macaques preferentially attend to the eyes in facial images and also visually orient with depicted gaze cues, the monkeys did not show faster response times on congruent trials either in response to schematic or photographic stimuli. These findings coincide with those reported for baboons tested with a similar paradigm in which gaze cues preceded a target identification task (Fagot and Deruelle 2002). When tested with either pictorial stimuli or interactants, non human primates readily follow gaze but do not seem to use this mechanism to identify a target object; there seems to be some mismatch in performance between attentional changes and manual responses to gaze cues on ostensibly similar tasks

    PrEP as a feature in the optimal landscape of combination HIV prevention in sub-Saharan Africa

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    INTRODUCTION: The new WHO guidelines recommend offering pre-exposure prophylaxis (PrEP) to people who are at substantial risk of HIV infection. However, where PrEP should be prioritised, and for which population groups, remains an open question. The HIV landscape in sub-Saharan Africa features limited prevention resources, multiple options for achieving cost saving, and epidemic heterogeneity. This paper examines what role PrEP should play in optimal prevention in this complex and dynamic landscape. METHODS: We use a model that was previously developed to capture subnational HIV transmission in sub-Saharan Africa. With this model, we can consider how prevention funds could be distributed across and within countries throughout sub-Saharan Africa to enable optimal HIV prevention (that is, avert the greatest number of infections for the lowest cost). Here, we focus on PrEP to elucidate where, and to whom, it would optimally be offered in portfolios of interventions (alongside voluntary medical male circumcision, treatment as prevention, and behaviour change communication). Over a range of continental expenditure levels, we use our model to explore prevention patterns that incorporate PrEP, exclude PrEP, or implement PrEP according to a fixed incidence threshold. RESULTS: At low-to-moderate levels of total prevention expenditure, we find that the optimal intervention portfolios would include PrEP in only a few regions and primarily for female sex workers (FSW). Prioritisation of PrEP would expand with increasing total expenditure, such that the optimal prevention portfolios would offer PrEP in more subnational regions and increasingly for men who have sex with men (MSM) and the lower incidence general population. The marginal benefit of including PrEP among the available interventions increases with overall expenditure by up to 14% (relative to excluding PrEP). The minimum baseline incidence for the optimal offer of PrEP declines for all population groups as expenditure increases. We find that using a fixed incidence benchmark to guide PrEP decisions would incur considerable losses in impact (up to 7%) compared with an approach that uses PrEP more flexibly in light of prevailing budget conditions. CONCLUSIONS: Our findings suggest that, for an optimal distribution of prevention resources, choices of whether to implement PrEP in subnational regions should depend on the scope for impact of other possible interventions, local incidence in population groups, and total resources available. If prevention funding were to become restricted in the future, it may be suboptimal to use PrEP according to a fixed incidence benchmark, and other prevention modalities may be more cost-effective. In contrast, expansions in funding could permit PrEP to be used to its full potential in epidemiologically driven prevention portfolios and thereby enable a more cost-effective HIV response across Africa
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