416 research outputs found
Fair and efficient transmission over GBPS dual ring networks
The advances in fiber optics technology provide large bandwidth and enable the support of a wide variety of services. New network architectures have been proposed, such as Metaring and Distributed Queue Dual Bus (DQDB), that try to take advantage of the new capabilities. Because of the very small packet transmission time relative to the feedback time a challenging issue in high speed networks is the efficient and fair share of the channel bandwidth among the competing users. In this thesis we first investigate and compare the performance of the Global and Local Fairness Mechanisms (GFM and LFM, respectively). They have been proposed recently for fair bandwidth allocation in high speed dual ring networks employing destination release. (a slot that has been read by its destination is immediately released and can be used again by other nodes). We show the sensitivity of both mechanisms to various system parameters, such as channel bandwidth and ring latency. We introduce the Dynamic Medium Access Control Mechanism (DMAC) which does not suffer from the limitations of GFM and LFM, introduces fairness in a very effective and efficient way, and is insensitive to the network parameters
Ethnic armies and ethnic conflict in Burma – Reconsidering the history of colonial militarization in the Kachin region of Burma during the Second World War
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The rise of linear borders in world politics
This article argues that the dominance of precise, linear borders as an ideal in the demarcation of territory is an outcome of a relatively recent and ongoing historical process, and that this process has had important effects on international politics since circa 1900. Existing accounts of the origins of territorial sovereignty are in wide disagreement largely because they fail to specify the relationship between territory and borders, often conflating the two concepts. I outline a history of the linearization of borders which is separate from that of territorial sovereignty, having a very different timeline and featuring different actors, and offer an explanation for the dominance of this universalizing system of managing and demarcating space, based on the concept of rationalization. Finally I describe two broad ways in which linearizing borders has affected international politics, by making space divisible in new ways, and underpinning hierarchies by altering the distribution of geographical knowledge resources
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The implications of climate change for the water environment in England
This paper reviews the implications of climate change for the water environment and its management in England. There is a large literature, but most studies have looked at flow volumes or nutrients and none have considered explicitly the implications of climate change for the delivery of water management objectives. Studies have been undertaken in a small number of locations. Studies have used observations from the past to infer future changes, and have used numerical simulation models with climate change scenarios. The literature indicates that climate change poses risks to the delivery of water management objectives, but that these risks depend on local catchment and water body conditions. Climate change affects the status of water bodies, and it affects the effectiveness of measures to manage the water environment and meet policy objectives.
The future impact of climate change on the water environment and its management is uncertain. Impacts are dependent on changes in the duration of dry spells and frequency of ‘flushing’ events, which are highly uncertain and not included in current climate scenarios. There is a good qualitative understanding of ways in which systems may change, but interactions between components of the water environment are poorly understood. Predictive models are only available for some components, and model parametric and structural uncertainty has not been evaluated. The impacts of climate change depend on other pressures on the water environment in a catchment, and also on the management interventions that are undertaken to achieve water management objectives.
The paper has also developed a series of consistent conceptual models describing the implications of climate change for pressures on the water environment, based around the source-pathway-receptor concept. They provide a framework for a systematic assessment across catchments and pressures of the implications of climate change for the water environment and its management
Rural Development Programme measures on cultivated land in Europe to mitigate greenhouse gas emissions – regional ‘hotspots’ and priority measures
© 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.Agriculture is a significant source of GHG emissions, contributing 10% of total emissions within the EU-28. Emissions from European agriculture have been reduced, albeit at the expense of crop yield and the risk of production displacement (the transfer of production, and associated emissions, to land outside of Europe). This article assesses the impact on GHG emissions of selected European Rural Development Program measures, representative of a diversity of management strategies implemented on cultivated land, within nine European Member States. Climatic zone and underlying spatial environmental variables were accounted for using a novel technique, “Regional Variation Categories,” developed with European-scale GIS data sets. Production displacement is assessed with two benchmarks: (1) compared with existing crop production and (2) relative to a “minimum requirement” land management scenario, where an emissions reduction of less than this does not constitute mitigation. Most measures reduce emissions relative to the baseline crop scenario; however, many do not reduce emissions beyond the “minimum requirement,” this being limited to measures such as catch crops and within-field grass areas to prevent soil erosion. The selection and targeting of measures to maximize agricultural GHG mitigation on cultivated land within Europe is discussed...Peer reviewedFinal Published versio
Rumours, sects and rallies : the ethnic politics of recent Hmong Millenarian movements in Vietnam’s highlands
Contrary to modernist assumptions, millenarianism has not died out but continues to influence the politics of many marginalised groups in upland Southeast Asia, including the Hmong. This article summarises and analyses post-World War II Hmong millenarian activity in Vietnam, focusing on three case studies from the 1980s onwards, within the political backdrop of ongoing government suspicions of ethnic separatism and foreign interference. Far from being isolated or peripheral, Hmong millenarian rumours and movements interact with overseas diasporas, human rights agencies and international religious networks to influence state responses, sometimes in unexpected ways
Patient journey for those with chronic low back pain in Brazil: a semi-systematic review on the best approach
Background. Managing patients with chronic low back pain (CLBP) in many countries, including Brazil, is a major challenge at the primary and specialty care level. Moreover, the information about epidemiology and patient management with CLBP is sparse. The primary objective of this semi-systematic review was to build local evidence about the prevalence and management pattern of CLBP. Methods. This semi-systematic review used Medline, Embase, and Biosis via Ovid the platform and additional resources (Google, Google Scholar, Incidence and Prevalence Database, World Health Organization, Brazilian Ministry of Health, and anecdotal information from local experts) to identify relevant literature between 2002–2020 to map the patient journey. Original full-text articles from Brazil in English containing data on pre-defined patient journey touchpoints (awareness, screening, diagnosis, treatment, adherence, and control) were screened. Data were synthesized using a simple or weighted mean, as applicable for patient journey components. Results. Of 297 records including those provided by local experts, eight studies were included for analysis. Awareness of CLBP and CLBP-NeP was 30.4% and 12%, respectively. According to published studies, adherence and symptoms control of patients was estimated with a similar percentage of 38% and 18%, respectively for CLBP and CLBP-NeP. CLBP-NeP prevalence (3.6%) was lower than that of CLBP (20.6%). Except for a comparable percentage of the treated population, for CLBP (39.1%) and CLBP-NeP (38%), the percentage of remaining touchpoints are higher in the case of CLBP than in CLBP-NeP, implying an improved patient journey for CLBP. Conclusion. The study highlights the usefulness to improve patient outcomes at the national level by measuring these mapping patient journey touchpoints. The outcome of this evidence-based study was fruitful to bridges the know-do gap in CLBP patients. Therefore, it is recommended to ensure continuing medical education, patient awareness, and health system preparedness while embracing the emerging insights on pain management.Histórico - O tratamento de pacientes com lombalgia crônica (LC) em muitos países, incluindo o Brasil, é um grande desafio no nível de atendimento primário e especializado. Além disso, as informações sobre epidemiologia e tratamento de pacientes com LC são escassas. O objetivo principal desta revisão semi-sistemática foi a construção de evidências locais sobre a prevalência e o padrão de tratamento da LC. Métodos. Esta revisão semi-sistemática utilizou Medline, Embase e Biosis via plataforma Ovid e recursos adicionais (Google, Google Scholar, Banco de dados de incidência e prevalência, Organização Mundial da Saúde, Ministério da Saúde do Brasil e informações anedóticas de especialistas locais) para identificar literatura relevante entre 2002 e 2020 para mapear a jornada do paciente. Artigos de texto completos e originais do Brasil em inglês contendo dados sobre pontos de contato predefinidos na jornada do paciente (conscientização, triagem, diagnóstico, tratamento, adesão e controle) foram selecionados. Os dados foram obtidos usando uma média simples ou ponderada, conforme aplicável para os componentes da jornada do paciente. Resultados. De 297 registros, incluindo os fornecidos por especialistas locais, oito estudos foram incluídos para análise. A conscientização da LC e da LC-NeP foi de 30,4% e 12%, respetivamente. De acordo com estudos publicados, a adesão e o controle dos sintomas dos pacientes foram estimados com percentual semelhante de 38% e 18%, respetivamente para a LC e a LC-NeP. A prevalência de LC-NeP (3,6%) foi menor que a de LC (20,6%). Com exceção de uma porcentagem comparável da população tratada, para LC (39,1%) e LC-NeP (38%), a porcentagem de pontos de contato restantes foi maior no caso de LC do que no LC-NeP, o que implicava uma melhora no trajeto do paciente para a LC. Conclusão. O estudo destaca a necessidade de melhorar os resultados dos pacientes em nível nacional, medindo esses pontos de contato da jornada do paciente. O resultado deste estudo baseado em evidências é importante para preencher a lacuna de conhecimento do paciente com LC. Portanto, recomenda-se garantir a educação médica contínua, a conscientização do paciente e a restruturação do sistema de saúde brasileiro, ao mesmo tempo em que adota novas práticas sobre o gerenciamento da dor
Relationship between clinical signs and postmortem test status in cattle experimentally infected with the bovine spongiform encephalopathy agent
<p>Abstract</p> <p>Background</p> <p>Various clinical protocols have been developed to aid in the clinical diagnosis of classical bovine spongiform encephalopathy (BSE), which is confirmed by postmortem examinations based on vacuolation and accumulation of disease-associated prion protein (PrP<sup>d</sup>) in the brain. The present study investigated the occurrence and progression of sixty selected clinical signs and behaviour combinations in 513 experimentally exposed cattle subsequently categorised postmortem as confirmed or unconfirmed BSE cases. Appropriate undosed or saline inoculated controls were examined similarly and the data analysed to explore the possible occurrence of BSE-specific clinical expression in animals unconfirmed by postmortem examinations.</p> <p>Results</p> <p>Based on the display of selected behavioural, sensory and locomotor changes, 20 (67%) orally dosed and 17 (77%) intracerebrally inoculated pathologically confirmed BSE cases and 21 (13%) orally dosed and 18 (6%) intracerebrally inoculated but unconfirmed cases were considered clinical BSE suspects. None of 103 controls showed significant signs and were all negative on diagnostic postmortem examinations. Signs indicative of BSE suspects, particularly over-reactivity and ataxia, were more frequently displayed in confirmed cases with vacuolar changes in the brain. The display of several BSE-associated signs over time, including repeated startle responses and nervousness, was significantly more frequent in confirmed BSE cases compared to controls, but these two signs were also significantly more frequent in orally dosed cattle unconfirmed by postmortem examinations.</p> <p>Conclusions</p> <p>The findings confirm that in experimentally infected cattle clinical abnormalities indicative of BSE are accompanied by vacuolar changes and PrP<sup>d </sup>accumulation in the brainstem. The presence of more frequently expressed signs in cases with vacuolar changes is consistent with this pathology representing a more advanced stage of disease. That BSE-like signs or sign combinations occur in inoculated animals that were not confirmed as BSE cases by postmortem examinations requires further study to investigate the potential causal relationship with prion disease.</p
Legacy effects override soil properties for CO 2 and N 2 O but not CH 4 emissions following digestate application to soil
The application of organic materials to soil can recycle nutrients and increase organic matter in agricultural lands. Digestate can be used as a nutrient source for crop production but it has also been shown to stimulate greenhouse gas (GHG) emissions from amended soils. While edaphic factors, such as soil texture and pH, have been shown to be strong determinants of soil GHG fluxes, the impact of the legacy of previous management practices is less well understood. Here we aim to investigate the impact of such legacy effects and to contrast them against soil properties to identify the key determinants of soil GHG fluxes following digestate application. Soil from an already established field experiment was used to set up a pot experiment, to evaluate N2O, CH4 and CO2 fluxes from cattle‐slurry‐digestate amended soils. The soil had been treated with farmyard manure, green manure or synthetic N‐fertilizer, 18 months before the pot experiment was set up. Following homogenization and a preincubation stage, digestate was added at a concentration of 250 kg total N/ha eq. Soil GHG fluxes were then sampled over a 64 day period. The digestate stimulated emissions of the three GHGs compared to controls. The legacy of previous soil management was found to be a key determinant of CO2 and N2O flux while edaphic variables did not have a significant effect across the range of variables included in this experiment. Conversely, edaphic variables, in particular texture, were the main determinant of CH4 flux from soil following digestate application. Results demonstrate that edaphic factors and current soil management regime alone are not effective predictors of soil GHG flux response following digestate application. Knowledge of the site management in terms of organic amendments is required to make robust predictions of the likely soil GHG flux response following digestate application to soil
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