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

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

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

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^d) 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^daccumulation 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

Modelling the impacts of agricultural management practices on river water quality in Eastern England

Agricultural diffuse water pollution remains a notable global pressure on water quality, posing risks to aquatic ecosystems, human health and water resources and as a result legislation has been introduced in many parts of the world to protect water bodies. Due to their efficiency and cost-effectiveness, water quality models have been increasingly applied to catchments as Decision Support Tools (DSTs) to identify mitigation options that can be introduced to reduce agricultural diffuse water pollution and improve water quality. In this study, the Soil and Water Assessment Tool (SWAT) was applied to the River Wensum catchment in eastern England with the aim of quantifying the long-term impacts of potential changes to agricultural management practices on river water quality. Calibration and validation were successfully performed at a daily time-step against observations of discharge, nitrate and total phosphorus obtained from high-frequency water quality monitoring within the Blackwater sub-catchment, covering an area of 19.6 km2. A variety of mitigation options were identified and modelled, both singly and in combination, and their long-term effects on nitrate and total phosphorus losses were quantified together with the 95% uncertainty range of model predictions. Results showed that introducing a red clover cover crop to the crop rotation scheme applied within the catchment reduced nitrate losses by 19.6%. Buffer strips of 2 m and 6 m width represented the most effective options to reduce total phosphorus losses, achieving reductions of 12.2% and 16.9%, respectively. This is one of the first studies to quantify the impacts of agricultural mitigation options on long-term water quality for nitrate and total phosphorus at a daily resolution, in addition to providing an estimate of the uncertainties of those impacts. The results highlighted the need to consider multiple pollutants, the degree of uncertainty associated with model predictions and the risk of unintended pollutant impacts when evaluating the effectiveness of mitigation options, and showed that high-frequency water quality datasets can be applied to robustly calibrate water quality models, creating DSTs that are more effective and reliable

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