4,849 research outputs found
Simplified overflow analysis of an optical burst switch with fibre delay lines
No full textWe develop an approximate analytic model of an Optical Burst Switch with share-per-node fibre delay lines and tuneable wavelength converters by employing Equivalent Random Theory, an approach from circuit-switching analysis. Our model is formulated in terms of virtual traffic flows within the switch from which we derive expressions for burst blocking probability, fibre delay line occupancy and mean delay, which we then resolve numerically. Emphasis is on simplicity of the model to achieve good numerical efficiency so that the method can be useful for formulating dimensioning problems for large-scale networks. Solution values from the analysis are compared with discrete-event simulation results
Burst-by-Burst Adaptive Multiuser Detection CDMA: A Framework for Existing and Future Wireless Standards
No full textThis paper provides a broad overview of the multiuser detection literature of the past few years in a nonmathematical, easily accessible approach. The treatment is then extended to the comparative study of channel-quality controlled burst-by-burst (BbB) adaptive code division multiple access (CDMA) detection such as parallel interference cancellation, successive interference cancellation, and joint detection (JD). It is demonstrated that the best complexity versus performance tradeoff is constituted by the JD receivers. Furthermore, the BbB-adaptive variable spreading factor-based schemes considered were outperformed by the adaptive quadrature amplitude modulation-based JD-CDMA schemes investigated. For example, at a channel signal-to-noise ratio per bit value of = 14 dB the latter scheme provides an average bit per symbol (BPS) throughput of 3.39, while the former provides an average BPS throughput of only 2.83, although the complexity of the latter is lower. In conclusion, BbB-adaptive CDMA schemes provide an attractive performance versus complexity tradeoff and are amenable to employment in both existing and future generations of wireless systems. Keywords—Adaptive CMDA systems, adaptive transceivers, interference cancellation, multiuser detection
‘We were treated like we are nobody’: a mixed-methods study of medical doctors’ internship experiences in Kenya and Uganda
No full textWhat is already known on this topic:
Ensuring appropriate and well-supported medical internship training is important for health workforce production and health systems’ quality of care, however, there is a scarcity of studies focusing on medical officer interns in low-ncome and middle-income countries where resources are most restrained thus education and working conditions are worst.
What this study adds:
Most interns are satisfied with their job but many reported working unreasonable hours as long as 72 hours due to staff shortage.
Interns reported challenging scenarios where they had poor supervision and insufficient support due to consultants not being available, and sometimes interns were the only staff managing the wards or had to perform certain procedures unsupervised.
Some consultants also expressed concerns with interns’ preparedness coming into the internship as well as competence postinternship.
How this study might affect research, practice or policy:
We highlighted the need to improve the resource availability and capacity of internship hospitals, ensure interns’ preparedness before internship, prioritise the well-being of individual doctors and ensure standardised supervision, support systems and conducive learning environments are in place.
This study adds to the global literature on internship experiences of medical doctors and could also help others design evidence-based policies and interventions to address specific challenges during medical internships.Collaborators: Kenya & Uganda Medical Internship Experience Study Group: Dos Santos Ankomisyani, Mike English, David Gathara, Lyndah Kemunto, Wangechi King’ori, Daniel Mbuthia, Gilbert Munyoki, Joshua Munywoki, Catia Nicodemo, Jacinta Nzinga, Tom Richard Okello, Elizeus Rutebemberwa, Justus Simba, Raymond Tweheyo, Evelyn Wagaiyu, Fred Were, Yingxi Zhao.Data availability: statement Data are available on reasonable request. The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.Supplementary files are available online at: https://gh.bmj.com/content/8/11/e013398#supplementary-materials .Objective: Medical interns are an important workforce providing first-line healthcare services in hospitals. The internship year is important for doctors as they transition from theoretical learning with minimal hands-on work under supervision to clinical practice roles with considerable responsibility. However, this transition is considered stressful and commonly leads to burn-out due to challenging working conditions and an ongoing need for learning and assessment, which is worse in countries with resource constraints. In this study, we provide an overview of medical doctors’ internship experiences in Kenya and Uganda.
Methods: Using a convergent mixed-methods approach, we collected data from a survey of 854 medical interns and junior doctors and semistructured interviews with 54 junior doctors and 14 consultants. Data collection and analysis were guided by major themes identified from a previous global scoping review (well-being, educational environment and working environment and condition), using descriptive analysis and thematic analysis respectively for quantitative and qualitative data.
Findings: Most medical interns are satisfied with their job but many reported suffering from stress, depression and burn-out, and working unreasonable hours due to staff shortages. They are also being affected by the challenging working environment characterised by a lack of adequate resources and a poor safety climate. Although the survey data suggested that most interns were satisfied with the supervision received, interviews revealed nuances where many interns faced challenging scenarios, for example, poor supervision, insufficient support due to consultants not being available or being ‘treated like we are nobody’.
Conclusion: We highlight challenges experienced by Kenyan and Ugandan medical interns spanning from burn-out, stress, challenging working environment, inadequate support and poor quality of supervision. We recommend that regulators, educators and hospital administrators should improve the resource availability and capacity of internship hospitals, prioritise individual doctors’ well-being and provide standardised supervision, support systems and conducive learning environments.This work is supported by an Africa Oxford travel grant (AfOx-209). YZ is supported by the University of Oxford Clarendon Fund Scholarship, an Oxford Travel Abroad Bursary and a Keble Association grant. ME is supported by a Wellcome Trust Senior Research Fellowship (#207522). CN receives funding from the Economic and Social Research Council (grant number ES/T008415/1). National Institute for Health Research Applied Research Collaboration Oxford and Thames Valley at Oxford Health NHS Foundation Trust. Consortium iNEST (Interconnected North-Est Innovation Ecosystem) funded by the European Union NextGenerationEU (Piano Nazionale di Ripresa e Resilienza (PNRR)–Missione 4 Componente 2, Investimento 1.5 – D.D. 1058 23/06/2022, ECS_00000043), and Horizon Europe [grant number ES/T008415/1
Publisher Correction: Global estimates on the number of people blind or visually impaired by cataract: a meta-analysis from 2000 to 2020 (Eye, (2024), 10.1038/s41433-024-02961-1)
No full textCorrection to: Eyehttps://doi.org/10.1038/s41433-024-02961-1, published online 09 March 2024 The original online version of this article was revised. First of all, the author list has been corrected from “Konrad Pesudovs, Van Charles Lansingh, John H. Kempen, Ian Tapply, Arthur G. Fernandes, Maria V. Cicinelli, Alessandro Arrigo, Nicolas Leveziel, Paul Svitil Briant, Theo Vos, Serge Resnikoff, Hugh R. Taylor, Tabassom Sedighi, Seth Flaxman, Jaimie Steinmetz, Rupert R. A. Bourne, Vision Loss Expert Group of the Global Burden of Disease Study and the GBD 2019 Blindness and Vision Impairment Collaborators” to include only the following institutional authors “Vision Loss Expert Group of the Global Burden of Disease Study and the GBD 2019 Blindness and Vision Impairment Collaborators”. The list of the individual authors and affiliations now appear at the end of the original paper. Furthermore, the following Article Note has been added: “These authors contributed equally: Jaimie Steinmetz and Rupert R. A. Bourne. These authors share the last authorship: Seth Flaxman and Jaimie Steinmetz.” The title of Table 1 has been corrected from “Number of people (mean [95% UI]) with blindness (presenting visual acuity <3/60) or MSVI (presenting visual acuity <6/18, ≥3/60) due to Cataract, the age-standardized prevalence (%) in people of all ages and aged ≥50 years (mean [95% UI]), and the percentage of all blindness or MSVI attributed to Cataract (95% UI) in world regions in 2020” to “Number of people of all ages (mean [95% UI]) with blindness (presenting visual acuity <3/60) or MSVI (presenting visual acuity <6/18, ≥3/60) due to Cataract, the age-standardized prevalence (%) in people aged ≥50 years (mean [95% UI]), and the percentage of all blindness or MSVI attributed to Cataract in people aged ≥50 years (95% UI) in world regions in 2020”. The following Data Availability statement was added: “Data sources for the Global Vision Database are listed at the following weblink http://www.anglia.ac.uk/verigbd. Fully disaggregated data is not available publicly due to data sharing agreements with some principal investigators yet requests for summary data can be made to the corresponding author.” Furthermore, the information in the “Funding” section was incomplete. The following information was added: “This study was funded by Brien Holden Vision Institute, Fondation Thea, Fred Hollows Foundation, Bill & Melinda Gates Foundation, Lions Clubs International Foundation (LCIF), Sightsavers International, and University of Heidelberg.” The “Competing interests” section has been corrected from “The authors declare no competing interests” to the following detailed information: GBD 2019 Blindness and Vision Impairment Collaborators Declarations N S Bayileyegn reports participation on a Data Safety Monitoring Board or Advisory Board with Jimma University, and leadership or fiduciary roles in board, society, committee or advocacy groups, paid or unpaid with Jimma University as a discipline committee member; outside the submitted work. S Bhaskar reports grants or contracts from the Japan Society for the Promotion of Science (JSPS), JSPS International Fellowship, Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Australian Academy of Science, Grant-in-Aid for Scientific Research (KAKENHI); leadership or fiduciary roles in board, society, committee or advocacy groups, paid or unpaid with Rotary District 9675 as the District Chair of Diversity, Equity, and Inclusion; the Global Health & Migration Hub Community and the Global Health Hub Germany (Berlin, Germany) as the Chair and Manager; PLOS One, BMC Neurology, Frontiers In Neurology, Frontiers in Stroke, Frontiers in Public Health and BMC Medical Research Methodology as an Editorial Board Member; and with the College of Reviewers, Canadian Institutes of Health Research (CIHR), and the Government of Canada as a Member; outside the submitted work
Addressing geographical variation in the progression of non-communicable diseases in Peru: the CRONICAS cohort study protocol.
No full textBackground The rise in non-communicable diseases in developing countries has gained increased attention. Given that around 80% of deaths related to non-communicable diseases occur in low- and middle-income countries, there is a need for local knowledge to address such problems. Longitudinal studies can provide valuable information about disease burden of non-communicable diseases in Latin America to inform both public health and clinical settings. Methods The CRONICAS cohort is a longitudinal study performed in three Peruvian settings that differ by degree of urbanisation, level of outdoor and indoor pollution and altitude. The author sought to enrol an age- and sex-stratified random sample of 1000 participants at each site. Study procedures include questionnaires on socio-demographics and well-known risk factors for cardiopulmonary disease, blood draw, anthropometry and body composition, blood pressure and spirometry before and after bronchodilators. All participants will be visited at baseline, at 20 and 40 months. A random sample of 100 households at each site will be assessed for 24 h particulate matter concentration. Primary outcomes include prevalence of risk factors for cardiopulmonary diseases, changes in blood pressure and blood glucose over time and decline in lung function. Discussion There is an urgent need to characterise the prevalence and burden of non-communicable diseases in low- and middle-income countries. Peru is a middle-income country currently undergoing a rapid epidemiological transition. This longitudinal study will provide valuable information on cardiopulmonary outcomes in three different settings and will provide a platform to address potential interventions that are locally relevant or applicable to other similar settings in Latin America
Fast identification of biological pathways associated with a quantitative trait using group lasso with overlaps.
No full textWhere causal SNPs (single nucleotide polymorphisms) tend to accumulate within biological pathways, the incorporation of prior pathways information into a statistical model is expected to increase the power to detect true associations in a genetic association study. Most existing pathways-based methods rely on marginal SNP statistics and do not fully exploit the dependence patterns among SNPs within pathways.We use a sparse regression model, with SNPs grouped into pathways, to identify causal pathways associated with a quantitative trait. Notable features of our "pathways group lasso with adaptive weights" (P-GLAW) algorithm include the incorporation of all pathways in a single regression model, an adaptive pathway weighting procedure that accounts for factors biasing pathway selection, and the use of a bootstrap sampling procedure for the ranking of important pathways. P-GLAW takes account of the presence of overlapping pathways and uses a novel combination of techniques to optimise model estimation, making it fast to run, even on whole genome datasets.In a comparison study with an alternative pathways method based on univariate SNP statistics, our method demonstrates high sensitivity and specificity for the detection of important pathways, showing the greatest relative gains in performance where marginal SNP effect sizes are small
Environmental impact of endoscopic submucosal dissection versus piecemeal resection for large colonic adenomas : a post hoc analysis of the resect colon study
No full textInternational audienceAims Last ESGE guidelines supposed that endoscopic peacemeal resection (P-EMR) are less impacting the environment than endoscopic submucosal dissection (ESD) for colonic adenoma’s resection. The prospective randomized multi centric RESECT study compared resection of colonic adenomas > 25 mm by P-EMR or ESD. In this post-hoc analysis we investigated the environmental impact of these procedures.Methods An independant eco-audit studied the two groups of RESECT colon on 4 parameters : endoscopes and disposable medical products, electricity consumed, anesthetic products, patient transport. We modeled 2 additional care organizations : ESD in expert hospital and P-EMR in local hospital.Results The calculated global environmental impact in the ESD RESECT group is 14614 eqkgCO2 against 20205 eqkgCO2 in the P-EMR RESECT group.If all P-EMR were performed in local hospital, the impact would be 11501 eqkgCO2 considering the same recurrence rate of 5% as in expert centers.Conclusions The ESD technique, which is discreetly more impactful in terms of the devices used but offers a curative treatment in a single session, reduces considerably the environmental impact by reducing the associated controls and transports. If P-EMR could be performed in a local center with the same level of quality, things would be more balanced. In the end, if a patient is referred to an expert center, then DSM should be chosen both for its efficiency results and for its reduced environmental impact. Ideally, DSM should be made available in the community
The burden of unintentional drowning: global, regional and national estimates of mortality from the Global Burden of Disease 2017 Study.
No full textFranklin RC, Peden AE, Hamilton EB, et al. The burden of unintentional drowning: global, regional and national estimates of mortality from the Global Burden of Disease 2017 Study. Injury prevention : journal of the International Society for Child and Adolescent Injury Prevention. 2020:injuryprev-2019-043484.BACKGROUND: Drowning is a leading cause of injury-related mortality globally. Unintentional drowning (International Classification of Diseases (ICD) 10 codes W65-74 and ICD9 E910) is one of the 30 mutually exclusive and collectively exhaustive causes of injury-related mortality in the Global Burden of Disease (GBD) study. This study's objective is to describe unintentional drowning using GBD estimates from 1990 to 2017.; METHODS: Unintentional drowning from GBD 2017 was estimated for cause-specific mortality and years of life lost (YLLs), age, sex, country, region, Socio-demographic Index (SDI) quintile, and trends from 1990 to 2017. GBD 2017 used standard GBD methods for estimating mortality from drowning.; RESULTS: Globally, unintentional drowning mortality decreased by 44.5% between 1990 and 2017, from 531956 (uncertainty interval (UI): 484107 to 572854) to 295210 (284493 to 306187) deaths. Global age-standardised mortality rates decreased 57.4%, from 9.3 (8.5 to 10.0) in 1990 to 4.0 (3.8 to 4.1) per 100000 per annum in 2017. Unintentional drowning-associated mortality was generally higher in children, males and in low-SDI to middle-SDI countries. China, India, Pakistan and Bangladesh accounted for 51.2% of all drowning deaths in 2017. Oceania was the region with the highest rate of age-standardised YLLs in 2017, with 45434 (40850 to 50 539) YLLs per 100000 across both sexes.; CONCLUSIONS: There has been a decline in global drowning rates. This study shows that the decline was not consistent across countries. The results reinforce the need for continued and improved policy, prevention and research efforts, with a focus on low- and middle-income countries. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ
Global trends of hand and wrist trauma: a systematic analysis of fracture and digit amputation using the Global Burden of Disease 2017 Study.
No full textCrowe CS, Massenburg BB, Morrison SD, et al. Global trends of hand and wrist trauma: a systematic analysis of fracture and digit amputation using the Global Burden of Disease 2017 Study. Injury prevention : journal of the International Society for Child and Adolescent Injury Prevention. 2020:injuryprev-2019-043495.BACKGROUND: As global rates of mortality decrease, rates of non-fatal injury have increased, particularly in low Socio-demographic Index (SDI) nations. We hypothesised this global pattern of non-fatal injury would be demonstrated in regard to bony hand and wrist trauma over the 27-year study period.; METHODS: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 was used to estimate prevalence, age-standardised incidence and years lived with disability for hand trauma in 195 countries from 1990 to 2017. Individual injuries included hand and wrist fractures, thumb amputations and non-thumb digit amputations.; RESULTS: The global incidence of hand trauma has only modestly decreased since 1990. In 2017, the age-standardised incidence of hand and wrist fractures was 179 per 100000 (95% uncertainty interval (UI) 146 to 217), whereas the less common injuries of thumb and non-thumb digit amputation were 24 (95% UI 17 to 34) and 56 (95% UI 43 to 74) per 100 000, respectively. Rates of injury vary greatly by region, and improvements have not been equally distributed. The highest burden of hand trauma is currently reported in high SDI countries. However, low-middle and middle SDI countries have increasing rates of hand trauma by as much at 25%.; CONCLUSIONS: Certain regions are noted to have high rates of hand trauma over the study period. Low-middle and middle SDI countries, however, have demonstrated increasing rates of fracture and amputation over the last 27 years. This trend is concerning as access to quality and subspecialised surgical hand care is often limiting in these resource-limited regions. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ
Grand Challenges in global eye health : a global prioritisation process using Delphi method
No full textFunding Information: The Lancet Global Health Commission on Global Eye Health is supported by The Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity (grant number GR001061), National Institute for Health Research Moorfields Biomedical Research Centre, Wellcome Trust, Sightsavers, The Fred Hollows Foundation, the Seva Foundation, and British Council for the Prevention of Blindness and Christian Blind Mission. MJB is supported by the Wellcome Trust (207472/Z/17/Z). JR's position at the University of Auckland is funded by the Buchanan Charitable Foundation, New Zealand. Funding Information: The Lancet Global Health Commission on Global Eye Health is supported by The Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity (grant number GR001061), National Institute for Health Research Moorfields Biomedical Research Centre, Wellcome Trust, Sightsavers, The Fred Hollows Foundation, the Seva Foundation, and British Council for the Prevention of Blindness and Christian Blind Mission. MJB is supported by the Wellcome Trust (207472/Z/17/Z). JR's position at the University of Auckland is funded by the Buchanan Charitable Foundation, New Zealand. Editorial note: the Lancet Group takes a neutral position with respect to territorial claims in published maps and institutional affiliations. Publisher Copyright: © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: We undertook a Grand Challenges in Global Eye Health prioritisation exercise to identify the key issues that must be addressed to improve eye health in the context of an ageing population, to eliminate persistent inequities in health-care access, and to mitigate widespread resource limitations. Methods: Drawing on methods used in previous Grand Challenges studies, we used a multi-step recruitment strategy to assemble a diverse panel of individuals from a range of disciplines relevant to global eye health from all regions globally to participate in a three-round, online, Delphi-like, prioritisation process to nominate and rank challenges in global eye health. Through this process, we developed both global and regional priority lists. Findings: Between Sept 1 and Dec 12, 2019, 470 individuals complete round 1 of the process, of whom 336 completed all three rounds (round 2 between Feb 26 and March 18, 2020, and round 3 between April 2 and April 25, 2020) 156 (46%) of 336 were women, 180 (54%) were men. The proportion of participants who worked in each region ranged from 104 (31%) in sub-Saharan Africa to 21 (6%) in central Europe, eastern Europe, and in central Asia. Of 85 unique challenges identified after round 1, 16 challenges were prioritised at the global level; six focused on detection and treatment of conditions (cataract, refractive error, glaucoma, diabetic retinopathy, services for children and screening for early detection), two focused on addressing shortages in human resource capacity, five on other health service and policy factors (including strengthening policies, integration, health information systems, and budget allocation), and three on improving access to care and promoting equity. Interpretation: This list of Grand Challenges serves as a starting point for immediate action by funders to guide investment in research and innovation in eye health. It challenges researchers, clinicians, and policy makers to build collaborations to address specific challenges. Funding: The Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity, National Institute for Health Research Moorfields Biomedical Research Centre, Wellcome Trust, Sightsavers, The Fred Hollows Foundation, The Seva Foundation, British Council for the Prevention of Blindness, and Christian Blind Mission. Translations: For the French, Spanish, Chinese, Portuguese, Arabic and Persian translations of the abstract see Supplementary Materials section.Peer reviewe
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