182 research outputs found
ROLE of inter-related population-level host traits in determining pathogen richness and zoonotic risk
No full textAbstractZoonotic diseases are an increasingly important source of human infectious diseases, and host pathogen richness of reservoir host species is a critical driver of spill-over risk. Population-level traits of hosts such as population size, host density and geographic range size have all been shown to be important determinants of host pathogen richness. However, empirically identifying the independent influences of these traits has proven difficult as many of these traits directly depend on each other. Here we develop a mechanistic, metapopulation, susceptible-infected-recovered model to identify the independent influences of these population-level traits on the ability of a newly evolved pathogen to invade and persist in host populations in the presence of an endemic pathogen. We use bats as a case study as they are highly social and an important source of zoonotic disease. We show that larger populations and group sizes had a greater influence on the chances of pathogen invasion and persistence than increased host density or the number of groups. As anthropogenic change affects these traits to different extents, this increased understanding of how traits independently determine pathogen richness will aid in predicting future zoonotic spill-over risk.</jats:p
Harmony and discord within the English ‘counter-culture’, 1965-1975, with particular reference to the ‘rock operas’ Hair, Godspell, Tommy and Jesus Christ Superstar
No full textPhDThis thesis considers the discrete, historically-specific theatrical and musical sub-genre of ‘Rock Opera’ as a lens through which to examine the cultural, political and social changes that are widely assumed to have characterised ‘The Sixties’ in Britain. The musical and dramatic texts, creation and production of Hair (1967), Tommy (1969), Godspell (1971), Jesus Christ Superstar (1970) and other neglected ‘Rock Operas’ of the period are analysed. Their great popularity with ‘mainstream’ audiences is considered and contrasted with the overwhelmingly negative and often internally contradictory reaction towards them from the English ‘counter-culture’. This examination offers new insights into both the ‘counter-culture’ and the ‘mainstream’ against which it claimed to define and differentiate itself.
The four ‘Rock Operas’, two of which are based upon Christian scriptures, are considered as narratives of spiritual quest. The relationship between the often controversial quests for re-defined forms of faith and the apparently precipitous ‘secularization’ and ‘de-Christianization’ of British society during the 1960s and 1970s is considered.
The thesis therefore analyses the ‘Rock Operas’ as significant, enlightening prisms through which to view many of the profound societal debates – over ‘faith’ and ‘belief’ in the widest senses, sexuality, the Vietnam war, generational conflict, drugs and ‘spiritual enlightenment’, and race – which were, to some considerable extent, elevated onto the national, political agenda by the activities of the broadly-defined ‘counter-culture’. It considers subsequent representations of the ‘counter-culture’ as the root of a contested but enduring popular legacy of ‘The Sixties' as a period of profound cultural change
Evaluating Bayesian spatial methods for modelling species distributions with clumped and restricted occurrence data.
No full textStatistical approaches for inferring the spatial distribution of taxa (Species Distribution Models, SDMs) commonly rely on available occurrence data, which is often clumped and geographically restricted. Although available SDM methods address some of these factors, they could be more directly and accurately modelled using a spatially-explicit approach. Software to fit models with spatial autocorrelation parameters in SDMs are now widely available, but whether such approaches for inferring SDMs aid predictions compared to other methodologies is unknown. Here, within a simulated environment using 1000 generated species' ranges, we compared the performance of two commonly used non-spatial SDM methods (Maximum Entropy Modelling, MAXENT and boosted regression trees, BRT), to a spatial Bayesian SDM method (fitted using R-INLA), when the underlying data exhibit varying combinations of clumping and geographic restriction. Finally, we tested how any recommended methodological settings designed to account for spatially non-random patterns in the data impact inference. Spatial Bayesian SDM method was the most consistently accurate method, being in the top 2 most accurate methods in 7 out of 8 data sampling scenarios. Within high-coverage sample datasets, all methods performed fairly similarly. When sampling points were randomly spread, BRT had a 1-3% greater accuracy over the other methods and when samples were clumped, the spatial Bayesian SDM method had a 4%-8% better AUC score. Alternatively, when sampling points were restricted to a small section of the true range all methods were on average 10-12% less accurate, with greater variation among the methods. Model inference under the recommended settings to account for autocorrelation was not impacted by clumping or restriction of data, except for the complexity of the spatial regression term in the spatial Bayesian model. Methods, such as those made available by R-INLA, can be successfully used to account for spatial autocorrelation in an SDM context and, by taking account of random effects, produce outputs that can better elucidate the role of covariates in predicting species occurrence. Given that it is often unclear what the drivers are behind data clumping in an empirical occurrence dataset, or indeed how geographically restricted these data are, spatially-explicit Bayesian SDMs may be the better choice when modelling the spatial distribution of target species
Monetary Policy in a World Without Money
No full textThis paper considers whether the development of electronic money' poses any threat to the ability of central banks to control the value of their national currencies through conventional monetary policy. It argues that even if the demand for base money for use in facilitating transactions is largely or even completely eliminated, monetary policy should continue to be effective. Macroeconomic stabilization depends only upon the ability of central banks to control a short-term nominal interest rate, and this would continue to be possible, in particular through the use of a channel' system for the implementation of policy, like those currently used in Canada, Australia and New Zealand.
Interplay between network configurations and network governance mechanisms in supply networks a systematic literature review
No full textPurpose: This work systematically reviews the extant academic management literature on supply networks. It specifically examines how network configurations and network governance mechanisms influence each other in supply networks.
Design: 125 analytical and empirical studies were identified using an evidence-based approach to review the literature mainly published between 1985 and 2012.
Synthesis: Drawing on a multi-disciplinary theoretical foundation, this work develops an integrative framework to identify three distinct yet interdependent themes that characterize the study of supply networks: a) Network Configurations (structures and relationships); b) Network Governance Mechanisms (formal and informal); and c) The Interplay between Network Configurations and Network Governance Mechanisms.
Findings: Network configurations and network governance mechanisms mutually influence each other and cannot be considered in isolation. Formal and informal governance mechanisms provide better control when used as complements rather than as substitutes. The choice of governance mechanism depends on the nature of exchange; role of management; desired level of control; level of flexibility in formal contracts; and complementary role of formal and informal governance mechanism.
Research implications: This nascent field has thematic and methodological research opportunities for academics. Comparative network analysis using longitudinal case studies offers a rich area for further study.
Practical Implications: The complexity surrounding the conflicting roles of managers at the organisation and network levels poses a significant challenge during the development and implementation stage of strategic network policies.
Originality/value: This review reveals that formal and informal governance mechanisms provide better control when used as complements rather than as substitutes
Contact tracing is an imperfect tool for controlling COVID-19 transmission and relies on population adherence
No full textEmerging evidence suggests that contact tracing has had limited success in the UK in reducing the R number across the COVID-19 pandemic. We investigate potential pitfalls and areas for improvement by extending an existing branching process contact tracing model, adding diagnostic testing and refining parameter estimates. Our results demonstrate that reporting and adherence are the most important predictors of programme impact but tracing coverage and speed plus diagnostic sensitivity also play an important role. We conclude that well-implemented contact tracing could bring small but potentially important benefits to controlling and preventing outbreaks, providing up to a 15% reduction in R. We reaffirm that contact tracing is not currently appropriate as the sole control measure.</p
Educação preventiva ao uso indevido de drogas no trabalho
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção.O uso indevido de drogas nas Organizações apresenta-se como fator gerador de inquietação e desconfiança em todas as relações e níveis organizacionais. Pesquisas nacionais e internacionais indicam um vertiginoso incremento no consumo de drogas nesta última década em todos os espaços sociais e, conseqüentemente, na maioria das Organizações. Esforços no sentido de redução da oferta de drogas, apesar de intensos, não têm conseguido evitar esta escalada. Por outro lado, ações isoladas que visem à redução da demanda muito pouco têm contribuído para uma real minimização do consumo de drogas. A integração de ações visando a redução (da oferta, da demanda e de danos), além de uma 'modernização' no aparato policial e no 'Poder Judiciário', tem sido a maneira mais eficaz com que alguns países e agências internacionais têm enfrentado o problema com relativo sucesso. As Organizações, por sua vez, têm promovido inúmeras ações, objetivando não só a prevenção ao consumo de drogas (redução da demanda), como também um adequado encaminhamento de 'trabalhadores, já usuários/dependentes de drogas". Estes fatos motivaram a elaboração desta pesquisa que, em linhas gerais, pretende, a partir de uma Organização Militar de Saúde, apresentar a construção de um Programa de Educação Preventiva ao Uso lndevido de Drogas no Trabalho. Para tanto, utilizou-se de uma amostra constituída de 38 trabalhadores jovens, e os acompanhou durante um período de 12 meses, período no qual realizam o Serviço Militar Constitucional. Através de um processo sócio-interacionista a partir do construcionismo social, de Gergen e Bateson e na aprendizagem integrativa sugerida pela ciência da complexidade, e tomando como base os trabalhos do epistemiologista francês Edgar Morin, atividades em forma de oficinas foram desenvolvidas visando, a partir do resgate histórico, da convivência interativa, da valorização do ético e a sintonia com o estético, a ampliação da autonomia e do protagonismo para uma melhor qualidade de vida no trabalho e para esses trabalhadores. Através do método de simulação e resolução integrativa, nos quais o uso de drogas ou a violência estavam presentes, técnicas de resolução de conflitos, mediação e negociação pró - ativa dentre outras, foram praticadas com vistas à geração da aprendizagem solidária e da resolução participativa. Previa-se que após este aprendizado, os sujeitos da pesquisa poderiam tornar-se verdadeiramente pró - ativos, portanto, mais hábeis na resolução de problemas. Esperava-se a incorporação de estilos saudáveis de viver, preservando mais adequadamente, a própria vida e a saúde. Também, esperava-se o aprimoramento do senso -crítico, da autonomia, a aquisição de habilidades e competências individuais e coletivas na tomada de decisões e, dessa forma tomarem-se melhores pessoas e melhores cidadãos. A eficácia do Programa foi sistematicamente avaliada quer via questionários estruturados (avaliação pontual), avaliando conhecimento, atitudes, comportamentos e ações efetivas para o não uso de drogas e tomadas de decisão. Estes itens foram avaliados em três ocasiões específicas (na admissão, no 3º e no 12º mês). Outras técnicas de avaliação sistemáticas (forma circular), foram intensamente utilizadas nos encontros -Oficinas. Os resultados superaram valores preditivos de 25% iniciais e permitiu concluir que este programa preventivo, pode ser uma boa ferramenta ergonômíca capaz de prevenir o uso de drogas no trabalho e melhorar encaminhamentos, nos casos de trabalhadores já envolvidos com o uso/abuso de drogas, minimizando com isso, os inúmeros desgastes organizacionai
The diverse roles of inhibition in identified neural circuits
No full textInhibitory interneurons represent a diverse population of cell types in the central nervous system, whose general role is to suppress activity of target neurons. The timing of spikes in principal neurons has millisecond precision, and I asked what are the roles of inhibition in shaping the temporal codes that emerge from different parallel local neural circuits. First I investigated the local circuitry of melanopsin-containing ganglion cells in the mouse retina, which are intrinsically photosensitive and responsible for circadian photoentrainment. Using transsynaptic viral tracing, I identified three types of melanopsin-containing ganglion cell, and found that inhibitory (GABAergic) dopaminergic amacrine cells are presynaptic to one of these types. These results provided a direct circuitry link between the medium time scale process of light-dark adaptation, which involves dopamine, and the longer time scale of the circadian rhythm. Next I characterised a subpopulation of genetically-identified neurons in the mouse retina, in order to compare the precise timing of inhibition in different circuits at a high temporal resolution. I identified eight physiologically and morphologically distinct ganglion cell types and found that each circuit could be described by a 'motif' that represented the inhibitory-excitatory interactions that lead to cell-type-specific firing patterns. The cell would fire only when the change in excitation was faster than the change in inhibition. Therefore the role of inhibition is to detect 'irrelevance' in the visual scene, only allowing the ganglion cell to fire at specific time points relating to functions that are both parallel and complementary to the other cell types. Finally, I looked deeper within the neural circuitry of one of the genetically-identified cell types, to study the mechanism of 'fast inhibition' in detecting approaching objects. Through two-photon targeted paired recordings of postsynaptic ganglion cells and presynaptic amacrine cells, I found evidence that the AII amacrine cell - a well-characterised glycinergic inhibitory interneuron known to be involved in night vision circuits - conveys fast inhibitory information to the ganglion cell via an electrical synapse with an excitatory neuron of day vision circuitry only during non-approach motion. Therefore, it appears that the role of inhibition is to dynamically interact with direct excitatory neural pathways during 'irrelevant' stimulation, suppressing or completely blocking activity, resulting in precisely timed spikes that occur in the brief moments when excitation changes faster than inhibition
A comparative study of forecasting container throughput through time series analysis
No full textThis paper shows different techniques used in the operational research to encounter with forecasting the total container throughput handling. Each techniques approached has its objective and constraints regarding to the research problem. The container throughput is responsible for large investments in port infrastructure development as the aims is to established a sufficiently accurate forecasting decision support system since they try to follow the global trends in the optimization of port operations and facilities
A downscaling approach to compare COVID-19 count data from databases aggregated at different spatial scales
No full textAs the COVID-19 pandemic continues to threaten various regions around the world, obtaining accurate and reliable COVID-19 data is crucial for governments and local communities aiming at rigorously assessing the extent and magnitude of the virus spread and deploying efficient interventions. Using data reported between January and February 2020 in China, we compared counts of COVID-19 from near-real-time spatially disaggregated data (city level) with fine-spatial scale predictions from a Bayesian downscaling regression model applied to a reference province-level data set. The results highlight discrepancies in the counts of coronavirus-infected cases at the district level and identify districts that may require further investigation
- …
