1,273 research outputs found

    Heat stress in Africa under high intensity climate change.

    Get PDF
    Extreme weather events are major causes of loss of life and damage infrastructure worldwide. High temperatures cause heat stress on humans, livestock, crops and infrastructure. Heat stress exposure is projected to increase with ongoing climate change. Extremes of temperature are common in Africa and infrastructure is often incapable of providing adequate cooling. We show how easily accessible cooling technology, such as evaporative coolers, prevent heat stress in historic timescales but are unsuitable as a solution under climate change. As temperatures increase, powered cooling, such as air conditioning, is necessary to prevent overheating. This will, in turn, increase demand on already stretched infrastructure. We use high temporal resolution climate model data to estimate the demand for cooling according to two metrics, firstly the apparent temperature and secondly the discomfort index. For each grid cell we calculate the heat stress value and the amount of cooling required to turn a heat stress event into a non heat stress event. We show the increase in demand for cooling in Africa is non uniform and that equatorial countries are exposed to higher heat stress than higher latitude countries. We further show that evaporative coolers are less effective in tropical regions than in the extra tropics. Finally, we show that neither low nor high efficiency coolers are sufficient to return Africa to current levels of heat stress under climate change

    Estimating population size of the cave shrimp Troglocaris anophthalmus (Crustacea, Decapoda, Caridea) using mark–release–recapture data

    Get PDF
    Estimación del tamaño de la población del camarón cavernícola Troglocaris anophthalmus (Crustacea, Decapoda, Caridea) mediante la utilización de datos de marcaje, liberación y recaptura Se desconoce el tamaño de la población de numerosos invertebrados acuáticos cavernícolas que son vulnerables a la contaminación de las aguas subterráneas provocada por las actividades antropogénicas. En este estudio estimamos el tamaño de la población del camarón de agua dulce Troglocaris anophthalmus sontica (Crustacea, Decapoda, Caridea) mediante las técnicas de marcaje, liberación y recaptura. La subespecie se estudió en la Vipavaska jama (cueva de Vipava), en Eslovenia, y se calcularon la proporción de sexos y la distribución por edad. Incluso tras considerar el límite inferior de los intervalos de confianza, se halló un gran abundancia de camarones. No obstante, no se encontraron indicios de que haya diferencias en cuanto a la abundancia de camarón entre verano e invierno. La población estaba formada predominantemente por hembras. La facilidad de la captura y las elevadas cifras de población indican que estos camarones podrían utilizarse como bioindicadores en los ecosistemas cavernícolas.Population size estimates are lacking for many small cave–dwelling aquatic invertebrates that are vulnerable to groundwater contamination from anthropogenic activities. Here we estimated the population size of freshwater shrimp Troglocaris anophthalmus sontica (Crustacea, Decapoda, Caridea) based on mark–release–recapture techniques. The subspecies was investigated in Vipavska jama (Vipava cave), Slovenia, with estimates of sex ratio and age distribution. A high abundance of shrimps was found even after considering the lower limit of the confidence intervals. However, we found no evidence of differences in shrimp abundances between summer and winter. The population was dominated by females. Ease of capture and abundant population numbers indicate that these cave shrimps may be useful as a bioindicator in cave ecosystems.Estimación del tamaño de la población del camarón cavernícola Troglocaris anophthalmus (Crustacea, Decapoda, Caridea) mediante la utilización de datos de marcaje, liberación y recaptura Se desconoce el tamaño de la población de numerosos invertebrados acuáticos cavernícolas que son vulnerables a la contaminación de las aguas subterráneas provocada por las actividades antropogénicas. En este estudio estimamos el tamaño de la población del camarón de agua dulce Troglocaris anophthalmus sontica (Crustacea, Decapoda, Caridea) mediante las técnicas de marcaje, liberación y recaptura. La subespecie se estudió en la Vipavaska jama (cueva de Vipava), en Eslovenia, y se calcularon la proporción de sexos y la distribución por edad. Incluso tras considerar el límite inferior de los intervalos de confianza, se halló un gran abundancia de camarones. No obstante, no se encontraron indicios de que haya diferencias en cuanto a la abundancia de camarón entre verano e invierno. La población estaba formada predominantemente por hembras. La facilidad de la captura y las elevadas cifras de población indican que estos camarones podrían utilizarse como bioindicadores en los ecosistemas cavernícolas

    Reclaiming the political : emancipation and critique in security studies

    Get PDF
    The critical security studies literature has been marked by a shared commitment towards the politicization of security – that is, the analysis of its assumptions, implications and the practices through which it is (re)produced. In recent years, however, politicization has been accompanied by a tendency to conceive security as connected with a logic of exclusion, totalization and even violence. This has resulted in an imbalanced politicization that weakens critique. Seeking to tackle this situation, the present article engages with contributions that have advanced emancipatory versions of security. Starting with, but going beyond, the so-called Aberystwyth School of security studies, the argument reconsiders the meaning of security as emancipation by making the case for a systematic engagement with the notions of reality and power. This revised version of security as emancipation strengthens critique by addressing political dimensions that have been underplayed in the critical security literature

    Re-imagining the Borders of US Security after 9/11: Securitisation, Risk, and the Creation of the Department of Homeland Security

    Get PDF
    The articulation of international and transnational terrorism as a key issue in US security policy, as a result of the 9/11 attacks, has not only led to a policy rethink, it has also included a bureaucratic shift within the US, showing a re-thinking of the role of borders within US security policy. Drawing substantively on the 'securitisation' approach to security studies, the article analyses the discourse of US security in order to examine the founding of the Department of Homeland Security, noting that its mission provides a new way of conceptualising 'borders' for US national security. The securitisation of terrorism is, therefore, not only represented by marking terrorism as a security issue, it is also solidified in the organisation of security policy-making within the US state. As such, the impact of a 'war on terror' provides an important moment for analysing the re-articulation of what security is in the US, and, in theoretical terms, for reaffirming the importance of a relationship between the production of threat and the institutionalisation of threat response. © 2007 Taylor & Francis

    A Suite of Early Eocene (~55 Ma) Climate Model Boundary Conditions

    Get PDF
    We describe a set of early Eocene (~ 55 Ma) climate model boundary conditions constructed in a self-consistent reference frame and incorporating recent data and methodologies. Given the growing need for uniform experimental design within the Eocene climate modelling community and the challenges faced in simulating the prominent features of Eocene climate, we make publicly available our data sets of Eocene topography, bathymetry, tidal dissipation, vegetation, aerosol distributions and river runoff. Major improvements in our boundary conditions over previous efforts include the implementation of the ANTscape palaeotopography of Antarctica, more accurate representations of the Drake Passage and Tasman Gateway, as well as an approximation of sub grid cell topographic variability. Our boundary conditions also include for the first time modelled estimates of Eocene aerosol distributions and tidal dissipation, both consistent with our palaeotopography and palaeobathymetry. The resolution of our data sets is unprecedented and will facilitate high resolution climate simulations. In light of the inherent uncertainties involved in reconstructing global boundary conditions for past time periods these data sets should be considered as one interpretation of the available data and users are encouraged to modify them according to their needs and interpretations. This paper marks the beginning of a process for reconstructing a set of accurate, open-access Eocene boundary conditions for use in climate models

    Cues and knowledge structures used by mental-health professionals when making risk assessments

    Get PDF
    Background: Research into mental-health risks has tended to focus on epidemiological approaches and to consider pieces of evidence in isolation. Less is known about the particular factors and their patterns of occurrence that influence clinicians’ risk judgements in practice. Aims: To identify the cues used by clinicians to make risk judgements and to explore how these combine within clinicians’ psychological representations of suicide, self-harm, self-neglect, and harm to others. Method: Content analysis was applied to semi-structured interviews conducted with 46 practitioners from various mental-health disciplines, using mind maps to represent the hierarchical relationships of data and concepts. Results: Strong consensus between experts meant their knowledge could be integrated into a single hierarchical structure for each risk. This revealed contrasting emphases between data and concepts underpinning risks, including: reflection and forethought for suicide; motivation for self-harm; situation and context for harm to others; and current presentation for self-neglect. Conclusions: Analysis of experts’ risk-assessment knowledge identified influential cues and their relationships to risks. It can inform development of valid risk-screening decision support systems that combine actuarial evidence with clinical expertise

    Using XML and XSLT for flexible elicitation of mental-health risk knowledge

    Get PDF
    Current tools for assessing risks associated with mental-health problems require assessors to make high-level judgements based on clinical experience. This paper describes how new technologies can enhance qualitative research methods to identify lower-level cues underlying these judgements, which can be collected by people without a specialist mental-health background. Methods and evolving results: Content analysis of interviews with 46 multidisciplinary mental-health experts exposed the cues and their interrelationships, which were represented by a mind map using software that stores maps as XML. All 46 mind maps were integrated into a single XML knowledge structure and analysed by a Lisp program to generate quantitative information about the numbers of experts associated with each part of it. The knowledge was refined by the experts, using software developed in Flash to record their collective views within the XML itself. These views specified how the XML should be transformed by XSLT, a technology for rendering XML, which resulted in a validated hierarchical knowledge structure associating patient cues with risks. Conclusions: Changing knowledge elicitation requirements were accommodated by flexible transformations of XML data using XSLT, which also facilitated generation of multiple data-gathering tools suiting different assessment circumstances and levels of mental-health knowledge
    corecore