Capacity Requirements of Traffic Handling Schemes in Multi-Service Networks

Cataloged from PDF version of article.This paper deals with the impact of traffic handling mechanisms on capacity for different network architectures. Three traffic handling models are considered: per-flow, class-based and best-effort (BE). These models can be used to meet service guarantees, the major differences being in their complexity of implementations and in the quantity of network resources that must be provided. In this study, the performance is fixed and the required capacity determined for various combinations of traffic handling architectures for edge-core networks. This study provides a comparison of different QoS architectures. One key result of this work is that on the basis of capacity requirements, there is no significant difference between semi-aggregate traffic handling and per-flow traffic handling. However, best-effort handling requires significantly more capacity as compared to the other methods. (C) 2004 Elsevier B.V. All rights reserve

Peasant farmer–raptor conflicts around Chembe Bird Sanctuary, Zambia, Central Africa: poultry predation, ethno–biology, land use practices and conservation

Los conflictos entre campesinos y rapaces alrededor del refugio de Chembe Bird, en Zambia, África central: depredación de aves de corral, etnobiología, prácticas de uso de la tierra y conservación Las rapaces prestan servicios ecosistémicos a las comunidades rurales de África: (1) depredando roedores, (2) regulando las poblaciones de serpientes dañinas, (3) configurando las creencias culturales y (4) formando parte de las atracciones turísticas. Sin embargo, los campesinos las relacionan con la disminución de las aves de corral, las profecías telepáticas y la brujería tradicional. En consecuencia, las rapaces son perseguidas por los humanos. Mediante una técnica de análisis cualitativo de contenido, analizamos la interacción entre los campesinos y las rapaces en zonas adyacentes al refugio de Chembe Bird. Nuestros resultados revelan las prácticas, actitudes y percepciones negativas que podrían poner en peligro de extinción a cinco rapaces en la zona de estudio. A fin de mejorar la coexistencia entre agricultores y rapaces, proponemos utilizar medidas transformadoras de carácter conceptual (por ejemplo, sensibilizar a las partes interesadas, garantizar el cumplimiento riguroso de la legislación relativa a las rapaces y proteger su hábitat, así como reforzar el capital social relacional) y medidas prácticas (como proporcionar cercados apropiados y aves de corral de fenotipos de alta resistencia).Los conflictos entre campesinos y rapaces alrededor del refugio de Chembe Bird, en Zambia, África central: depredación de aves de corral, etnobiología, prácticas de uso de la tierra y conservación Las rapaces prestan servicios ecosistémicos a las comunidades rurales de África: (1) depredando roedores, (2) regulando las poblaciones de serpientes dañinas, (3) configurando las creencias culturales y (4) formando parte de las atracciones turísticas. Sin embargo, los campesinos las relacionan con la disminución de las aves de corral, las profecías telepáticas y la brujería tradicional. En consecuencia, las rapaces son perseguidas por los humanos. Mediante una técnica de análisis cualitativo de contenido, analizamos la interacción entre los campesinos y las rapaces en zonas adyacentes al refugio de Chembe Bird. Nuestros resultados revelan las prácticas, actitudes y percepciones negativas que podrían poner en peligro de extinción a cinco rapaces en la zona de estudio. A fin de mejorar la coexistencia entre agricultores y rapaces, proponemos utilizar medidas transformadoras de carácter conceptual (por ejemplo, sensibilizar a las partes interesadas, garantizar el cumplimiento riguroso de la legislación relativa a las rapaces y proteger su hábitat, así como reforzar el capital social relacional) y medidas prácticas (como proporcionar cercados apropiados y aves de corral de fenotipos de alta resistencia).Raptors provide ecosystem services to African rural communities by: (1) preying on rodents, (2) regulating harmful snake populations, (3) shaping cultural beliefs, and (4) being part of tourist attractions. Peasant farmers, however, connect them with poultry depletion, telepathic omens, and traditional witchcraft. Consequently, raptors suffer human–induced persecution. Using a qualitative content analysis technique, we investigated the interaction between farmers and raptors in areas adjoining the Chembe Bird Sanctuary. Our results unravel negative perceptions, attitudes and practices that could threaten the extinction of five raptors in the study area. We propose the use of transformative cognitive measures (e.g., raising stakeholder awareness, ensuring stringent law enforcement for raptors and protecting their habitat, and strengthening relational social capital) and physical measures (e.g., providing appropriate fencing and poultry breeding of high resilient phenotypes) to improve the co–existence between farmers and raptors

Design optimisation of high-brightness laser diodes for external cavity operation in the BRIDLE project

We report on the design aspects of high performance diode lasers for application in high-brightness spectral beam combining and coherent beam combining modules. Key performance trade-offs are identified and potential solutions are explored

An investigation of factors associated with the health and well-being of HIV-infected or HIV-affected older people in rural South Africa

BackgroundDespite the severe impact of HIV in sub-Saharan Africa, the health of older people aged 50+ is often overlooked owing to the dearth of data on the direct and indirect effects of HIV on older people's health status and well-being. The aim of this study was to examine correlates of health and well-being of HIV-infected older people relative to HIV-affected people in rural South Africa, defined as participants with an HIV-infected or death of an adult child due to HIV-related cause. MethodsData were collected within the Africa Centre surveillance area using instruments adapted from the World Health Organization (WHO) Study on global AGEing and adult health (SAGE). A stratified random sample of 422 people aged 50+ participated. We compared the health correlates of HIV-infected to HIV-affected participants using ordered logistic regressions. Health status was measured using three instruments: disability index, quality of life and composite health score. ResultsMedian age of the sample was 60 years (range 50-94). Women HIV-infected (aOR 0.15, 95% confidence interval (CI) 0.08-0.29) and HIV-affected (aOR 0.20, 95% CI 0.08-0.50), were significantly less likely than men to be in good functional ability. Women's adjusted odds of being in good overall health state were similarly lower than men's; while income and household wealth status were stronger correlates of quality of life. HIV-infected participants reported better functional ability, quality of life and overall health state than HIV-affected participants. Discussion and Conclusions The enhanced healthcare received as part of anti-retroviral treatment as well as the considerable resources devoted to HIV care appear to benefit the overall well-being of HIV-infected older people; whereas similar resources have not been devoted to the general health needs of HIV uninfected older people. Given increasing numbers of older people, policy and programme interventions are urgently needed to holistically meet the health and well-being needs of older people beyond the HIV-related care system. <br/

Caregiver perceptions and experiences of paediatric emergency department attendance during the COVID-19 pandemic: a mixed-methods study

BACKGROUND: During the early stages of the COVID-19 pandemic, concerns were raised about reduced attendance at hospitals, particularly in paediatric emergency departments, which could result in preventable poorer outcomes and late presentations among children requiring emergency care. We aimed to investigate the impact of COVID-19 on health-seeking behaviour and decision-making processes of caregivers presenting to paediatric emergency services at a National Health Service (NHS) Trust in London. MATERIALS AND METHODS: We conducted a mixed-methods study (survey and semi-structured interviews) across two hospital sites between November-December 2020. Data from each study were collected concurrently followed by data comparison. RESULTS: Overall, 100 caregivers participated in our study; 80 completed the survey only, two completed the interview only and 18 completed both. Our quantitative study found that almost two-thirds (63%, n = 62) of caregivers attended the department within two days of their child becoming ill. Our qualitative study identified three major themes which were underpinned by concepts of trust, safety and uncertainty and were assessed in relation to the temporal nature of the pandemic and the caregivers' journey to care. We found most caregivers balanced their concerns of COVID-19 and a perceived "overwhelmed" NHS by speaking to trusted sources, predominantly general practitioners (GPs). CONCLUSION: Caregivers have adapted their health-seeking behaviour throughout the pandemic as new information and guidance have been released. We identified several factors affecting decisions to attend; some existed before the pandemic (e.g., concerns for child's health) whilst others were due to the pandemic (e.g., perceived risks of transmission when accessing healthcare services). We recommend trusted medical professionals, particularly GPs, continue to provide reassurance to caregivers to seek emergency paediatric care when required. Communicating the hospital safety procedures and the importance of early intervention to caregivers could additionally provide reassurance to those concerned about the risks of accessing the hospital environment

Strengthening integration of chronic care in Africa: protocol for the qualitative process evaluation of integrated HIV, diabetes and hypertension care in a cluster randomised controlled trial in Tanzania and Uganda

Introduction: In sub-Saharan Africa, the burden of non-communicable diseases (NCDs), particularly diabetes mellitus (DM) and hypertension, has increased rapidly in recent years, although HIV infection remains a leading cause of death among young-middle-aged adults. Health service coverage for NCDs remains very low in contrast to HIV, despite the increasing prevalence of comorbidity of NCDs with HIV. There is an urgent need to expand healthcare capacity to provide integrated services to address these chronic conditions. Methods and analysis: This protocol describes procedures for a qualitative process evaluation of INTE-AFRICA, a cluster randomised trial comparing integrated health service provision for HIV infection, DM and hypertension, to the current stand-alone vertical care. Interviews, focus group discussions and observations of consultations and other care processes in two clinics (in Tanzania, Uganda) will be used to explore the experiences of stakeholders. These stakeholders will include health service users, policy-makers, healthcare providers, community leaders and members, researchers, non-governmental and international organisations. The exploration will be carried out during the implementation of the project, alongside an understanding of the impact of broader structural and contextual factors. Ethics and dissemination: Ethical approval was granted by the Liverpool School of Tropical Medicine (UK), the National Institute of Medical Research (Tanzania) and TASO Research Ethics Committee (Uganda) in 2020. The evaluation will provide the opportunity to document the implementation of integration over several timepoints (6, 12 and 18 months) and refine integrated service provision prior to scale up. This synergistic approach to evaluate, understand and respond will support service integration and inform monitoring, policy and practice development efforts to involve and educate communities in Tanzania and Uganda. It will create a model of care and a platform of good practices and lessons learnt for other countries implementing integrated and decentralised community health services

Separate phase-locking and coherent combining of two laser diodes in a Michelson cavity

We describe a new coherent beam combining architecture based on passive phase-locking of two laser diodes in a Michelson external cavity on their rear facet, and their coherent combination on the front facet. As a proof-of-principle, two ridge lasers have been coherently combined with >90 % efficiency. The phase-locking range, and the resistance of the external cavity to perturbations have been thoroughly investigated. The combined power has been stabilized over more than 15 min with an optical feedback as well as with an automatic adjustment of the driving currents. Furthermore, two high-brightness high-power tapered laser diodes have been coherently combined in a similar arrangement; the combining efficiency is 70% and results in an output power of 4 W. We believe that this new configuration combines the simplicity of passive self-organizing architectures with the optical efficiency of master-oscillator power-amplifier ones

Adult non-communicable disease mortality in Africa and Asia: evidence from INDEPTH Health and Demographic Surveillance System sites.

BACKGROUND: Mortality from non-communicable diseases (NCDs) is a major global issue, as other categories of mortality have diminished and life expectancy has increased. The World Health Organization's Member States have called for a 25% reduction in premature NCD mortality by 2025, which can only be achieved by substantial reductions in risk factors and improvements in the management of chronic conditions. A high burden of NCD mortality among much older people, who have survived other hazards, is inevitable. The INDEPTH Network collects detailed individual data within defined Health and Demographic Surveillance sites. By registering deaths and carrying out verbal autopsies to determine cause of death across many such sites, using standardised methods, the Network seeks to generate population-based mortality statistics that are not otherwise available. OBJECTIVE: To describe patterns of adult NCD mortality from INDEPTH Network sites across Africa and Asia, according to the WHO 2012 verbal autopsy (VA) cause categories, with separate consideration of premature (15-64 years) and older (65+ years) NCD mortality. DESIGN: All adult deaths at INDEPTH sites are routinely registered and followed up with VA interviews. For this study, VA archives were transformed into the WHO 2012 VA standard format and processed using the InterVA-4 model to assign cause of death. Routine surveillance data also provide person-time denominators for mortality rates. RESULTS: A total of 80,726 adult (over 15 years) deaths were documented over 7,423,497 person-years of observation. NCDs were attributed as the cause for 35.6% of these deaths. Slightly less than half of adult NCD deaths occurred in the 15-64 age group. Detailed results are presented by age and sex for leading causes of NCD mortality. Per-site rates of NCD mortality were significantly correlated with rates of HIV/AIDS-related mortality. CONCLUSIONS: These findings present important evidence on the distribution of NCD mortality across a wide range of African and Asian settings. This comes against a background of global concern about the burden of NCD mortality, especially among adults aged under 70, and provides an important baseline for future work

A multi-perspective dynamic feature concept in adaptive NC machining of complex freeform surfaces

This paper presents a new concept of feature for freeform surface machining that defines the changes in feature status during real manufacturing situations which have not been sufficiently addressed by current international standards and previous research in feature technology. These changes are multi-perspective, including (i) changes in depth-of-cut: the geometry of a feature in the depth-of-cut direction changes during different machining operations such as roughing, semi-finishing and finishing; (ii) changes across the surface: a surface may be divided into different machining regions (effectively sub-features) for the selection of appropriate manufacturing methods for each region such as different cutting tools, parameters, set-ups or machine tools; and (iii) changes in resources or manufacturing capabilities may require the re-planning of depth-of-cuts, division of machining regions and manufacturing operations (machines, tools, set-ups and parameters). Adding the above dynamic information to the part information models in current CAD systems (which only represent the final state of parts) would significantly improve the accuracy, efficiency and timeliness of manufacturing planning and optimisation, especially for the integrated NC machining planning for complex freeform surfaces. A case study in an aircraft manufacturing company will be included in this paper