117 research outputs found
A Case Study of the Ethanol CleanCook Stove Intervention and Potential Scale-Up in Ethiopia
Background Approximately 80% of Ethiopia\u27s energy consumption is dominated by woody biomass fuel use, resulting in 91.2âŻmillionâŻtons of firewood and 4.2âŻmillionâŻtons of charcoal consumed annually. Ethiopia\u27s dependency on non-sustainable energy, especially for cooking, has been a major concern for the nation for the past 30âŻyears, contributing to deforestation, climate change, and adverse human health impacts. Objectives Our objective was to document the work of Gaia Association and the implementation of the ethanol CleanCook stove in the refugee camp and urban settings of Ethiopia. We then assessed the potential for the scale-up of ethanol as a household fuel. Methods We utilized the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework to evaluate the effectiveness and sustainability of the ethanol cookstove intervention. We obtained secondary data from a variety of sources to evaluate a.) The performance of the CleanCook ethanol stove; b.) Effectiveness of the ethanol cookstove implementation; and, c.) Barriers to scale-up and commercialization of ethanol use as a household fuel. In addition, we conducted primary analysis of qualitative surveys to evaluate the perceptions of the ethanol and adoption of the CleanCook stove. Results Our case study results provide critical insight into the 13-year implementation of the CleanCook ethanol stove in Ethiopia. Laboratory tests demonstrate that the CleanCook stove reduces harmful emissions compared to biomass stoves, and preliminary field tests show 24-hour average PM2.5 levels of 200âŻÎŒg/m3. To-date 8731 CleanCook stoves were distributed to refugee households, while an additional 500 were sold at a subsided price to low-income urban households. CleanCook stove users report the continued use of multiple stoves. Conclusions The CleanCook ethanol stove has been implemented as an energy intervention for the vulnerable refugee population in Ethiopia for over 13âŻyears. There has been limited success of a subsidized CleanCook stove among low-income households in Addis Ababa. This case study demonstrates the complexities of promoting a new fuel for household cooking, and the numerous obstacles and stagnations in implementation. Ethanol demonstrates some potential for scale-up and commercialization as a household fuel in Addis Ababa, but it may require simultaneous stabilization of ethanol supply, growth of a city-wide distribution infrastructure, and an affordably priced stove and fuel
Correspondence between T. Melden, George C. Stokes, and John Shary
Correspondence regarding lot 282, Shary Subdivision between November 1, 1930 and October 15, 1942 between T. Melden, George C. Stokes, John Shary, Pearl Stokes, and attorneys for the United Irrigation Company.https://scholarworks.utrgv.edu/johnshary/1024/thumbnail.jp
Subintimal angioplasty of chronic total occlusion in iliac arteries: A safe and durable option
BackgroundTraditionally, aortobifemoral bypass has been the intervention of choice for iliac artery chronic total occlusions (CTOs). However, it is associated with significant morbidity and mortality, limiting its use in high-risk patients. To reduce procedural risk, subintimal angioplasty (SIA) for femoropopliteal CTO has been utilized by many, but few have extended this endovascular technique to treating iliac artery CTOs. We present our experience with 101 successful SIAs for iliac artery CTOs.MethodsA retrospective review of consecutive patients with iliac artery CTOs treated with subintimal angioplasty from June 2000 to January 2009 was completed. Demographic and risk factor data were obtained, along with procedural data. Primary and secondary patency, survival, freedom from claudication, and limb salvage rates were determined by Kaplan-Meier survival analysis. Univariate and multivariate analyses were completed to identify factors adversely affecting primary patency.ResultsOne hundred twenty patients underwent an attempted SIA of an iliac artery CTO, and 101 iliac artery CTOs were successfully treated, giving a technical success rate of 84%. Technical failure was due to the inability to re-enter the lumen in all cases. Indications for intervention were lifestyle-altering claudication in 64 patients (63%) and critical limb ischemia (CLI), in 37 (37%). Eighty-five patients underwent percutaneous SIA, while 11 patients underwent a combined SIA with surgical outflow procedure. Lesions were classified as TransAtlantic InterSociety Consensus (TASC) B, 39 (39%); TASC C, 27 (27%); and TASC D, 35 (35%). In 82 (81%) lesions, stents were deployed with an average of 1.2 (range, 0-3) stents utilized. A re-entry device was used in 14 (14%) lesions. Major complication rate was 3.0%, with a 30-day mortality rate of 1.0%. Primary and secondary patency rates at 1, 2, and 3 years were 86% and 94%, 76% and 92%, and 68% and 80%, respectively. Survival rate was 67% at 5 years, reflecting the poor health of this cohort. Limb salvage for CLI patients at 1 and 5 years was 97% and 95%, respectively. Freedom from claudication at 1 and 3 years was 89% and 73%. Univariate analysis identified hyperlipidemia, coronary artery disease, and prior surgical bypass in treated limb as factors for loss of primary patency; however, on multivariate analysis, no factors remained statistically significant.ConclusionThis study demonstrates that SIA of iliac CTOs is feasible and can be performed safely and effectively, even in high-risk patients. Excellent patency and limb salvage rates can be achieved. In our experience, the safety and durability of SIA makes it an attractive first-line therapy for iliac artery occlusive disease
Quantum Measurement Theory in Gravitational-Wave Detectors
The fast progress in improving the sensitivity of the gravitational-wave (GW)
detectors, we all have witnessed in the recent years, has propelled the
scientific community to the point, when quantum behaviour of such immense
measurement devices as kilometer-long interferometers starts to matter. The
time, when their sensitivity will be mainly limited by the quantum noise of
light is round the corner, and finding the ways to reduce it will become a
necessity. Therefore, the primary goal we pursued in this review was to
familiarize a broad spectrum of readers with the theory of quantum measurements
in the very form it finds application in the area of gravitational-wave
detection. We focus on how quantum noise arises in gravitational-wave
interferometers and what limitations it imposes on the achievable sensitivity.
We start from the very basic concepts and gradually advance to the general
linear quantum measurement theory and its application to the calculation of
quantum noise in the contemporary and planned interferometric detectors of
gravitational radiation of the first and second generation. Special attention
is paid to the concept of Standard Quantum Limit and the methods of its
surmounting.Comment: 147 pages, 46 figures, 1 table. Published in Living Reviews in
Relativit
Stretching and challenging the boundaries of law: varieties of knowledge in biotechnologies regulation
The paper addresses the question of adaptation of existing regulatory frameworks in the face of innovation in biotechnologies, and specifically the roles played in this by various expert knowledge practices. We identify two overlapping ideal types of adaptation: first, the stretching and maintenance of a pre-existing legal framework, and second, a breaking of existing classifications and establishment of a novel regime. We approach this issue by focusing on varieties of regulatory knowledge which, contributing to and parting of political legitimacy, in principle enable the making of legally binding decisions about risks and benefits of technologies. We base the discussion around two case studies, one of animal biotechnology ethical regulation, the other of âadvanced therapyâ medicinal product regulation, both in the context of European Union frameworks. Specifically, we explore the knowledge configurations constituting expert committees and other institutional formations of expert regulatory knowledge in their political context. We show that where sectoral and moral boundaries are challenged, different modes of regulatory knowledge beyond scientific forms â legal, procedural, moral, economic and industrial â can shape regulatory innovations either by maintenance of regimes through commensuration and stretching, or through differentiation and separation creating new frameworks. We conclude that establishing an essential techno-scientific difference between pre-existing and novel technologies does not in itself require new regulatory structures, and that the regulatory strategy that is followed will be determined by a combination of different forms of knowledge
Longitudinal observation and decline of neutralizing antibody responses in the three months following SARS-CoV-2 infection in humans
Antibody responses to SARS-CoV-2 can be detected in most infected individuals 10â15âd after the onset of COVID-19 symptoms. However, due to the recent emergence of SARS-CoV-2 in the human population, it is not known how long antibody responses will be maintained or whether they will provide protection from reinfection. Using sequential serum samples collected up to 94âd post onset of symptoms (POS) from 65 individuals with real-time quantitative PCR-confirmed SARS-CoV-2 infection, we show seroconversion (immunoglobulin (Ig)M, IgA, IgG) in >95% of cases and neutralizing antibody responses when sampled beyond 8âd POS. We show that the kinetics of the neutralizing antibody response is typical of an acute viral infection, with declining neutralizing antibody titres observed after an initial peak, and that the magnitude of this peak is dependent on disease severity. Although some individuals with high peak infective dose (ID50â>â10,000) maintained neutralizing antibody titres >1,000 at >60âd POS, some with lower peak ID50 had neutralizing antibody titres approaching baseline within the follow-up period. A similar decline in neutralizing antibody titres was observed in a cohort of 31 seropositive healthcare workers. The present study has important implications when considering widespread serological testing and antibody protection against reinfection with SARS-CoV-2, and may suggest that vaccine boosters are required to provide long-lasting protection
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and â„1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (nâ=â5069) or prospectively (nâ=â5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (â€6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; pâ=â0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
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