80 research outputs found
Primary Beam and Dish Surface Characterization at the Allen Telescope Array by Radio Holography
The Allen Telescope Array (ATA) is a cm-wave interferometer in California,
comprising 42 antenna elements with 6-m diameter dishes. We characterize the
antenna optical accuracy using two-antenna interferometry and radio holography.
The distortion of each telescope relative to the average is small, with RMS
differences of 1 percent of beam peak value. Holography provides images of dish
illumination pattern, allowing characterization of as-built mirror surfaces.
The ATA dishes can experience mm-scale distortions across -2 meter lengths due
to mounting stresses or solar radiation. Experimental RMS errors are 0.7 mm at
night and 3 mm under worst case solar illumination. For frequencies 4, 10, and
15 GHz, the nighttime values indicate sensitivity losses of 1, 10 and 20
percent, respectively. The ATA.s exceptional wide-bandwidth permits
observations over a continuous range 0.5 to 11.2 GHz, and future retrofits may
increase this range to 15 GHz. Beam patterns show a slowly varying focus
frequency dependence. We probe the antenna optical gain and beam pattern
stability as a function of focus and observation frequency, concluding that ATA
can produce high fidelity images over a decade of simultaneous observation
frequencies. In the day, the antenna sensitivity and pointing accuracy are
affected. We find that at frequencies greater than 5 GHz, daytime observations
greater than 5 GHz will suffer some sensitivity loss and it may be necessary to
make antenna pointing corrections on a 1 to 2 hourly basis.Comment: 19 pages, 23 figures, 3 tables, Authors indicated by an double dagger
({\ddag}) are affiliated with the SETI Institute, Mountain View, CA 95070.
Authors indicated by a section break ({\S}) are affiliated with the Hat Creek
Radio Observatory and/or the Radio Astronomy Laboratory, both affiliated with
the University of California Berkeley, Berkeley C
Evaluating the impact of the Extractive Industries Transparency Initiative (EITI) on corruption in Zambia
The Extractive Industries Transparency Initiative (EITI) is internationally recognised as a leading anti-corruption scheme, which promotes transparency, accountability and good governance of public oil, gas, and mining revenues. This article provides the first rigorous quantitative investigation of the impact of EITI on corruption in Zambia. Using a case-comparison approach, called the Synthetic Control Method (SCM), we find that the implementation of EITI provoked a significant decrease in corruption in Zambia (with the corruption-reducing effect of EITI being, though, much stronger at the earlier stages of implementation)
The calm after the storm: re-starting ART treatments safely in the wake of the COVID-19 pandemic
The coronavirus disease 2019 (COVID-19) pandemic created a significant impact on medically assisted reproduction (MAR) services. ESHRE decided to mobilize resources in order to collect, analyse, monitor, prepare and disseminate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) knowledge specifically related to ART and early pregnancy. This article presents the impact of the SARS-CoV-2 pandemic focusing on reproductive healthcare. It details the rationale behind the guidance prepared to support MAR services in organizing and managing the re-start of treatments or in case of any future wave of COVID-19 disease. The guidance includes information on patient selection and informed consent, staff and patient triage and testing, adaptation of ART services, treatment planning and code of conduct. The initiatives detailed in this article are not necessarily COVID-specific and such action plans could be applied effectively to manage similar emergency situations in different areas of medicine, in the future
The calm after the storm : re-starting ART treatments safely in the wake of the COVID-19 pandemic
AbstractThe coronavirus disease 2019 (COVID-19) pandemic created a significant impact on medically assisted reproduction (MAR) services. ESHRE decided to mobilize resources in order to collect, analyse, monitor, prepare and disseminate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) knowledge specifically related to ART and early pregnancy. This article presents the impact of the SARS-CoV-2 pandemic focusing on reproductive healthcare. It details the rationale behind the guidance prepared to support MAR services in organizing and managing the re-start of treatments or in case of any future wave of COVID-19 disease. The guidance includes information on patient selection and informed consent, staff and patient triage and testing, adaptation of ART services, treatment planning and code of conduct. The initiatives detailed in this article are not necessarily COVID-specific and such action plans could be applied effectively to manage similar emergency situations in different areas of medicine, in the future.Abstract
The coronavirus disease 2019 (COVID-19) pandemic created a significant impact on medically assisted reproduction (MAR) services. ESHRE decided to mobilize resources in order to collect, analyse, monitor, prepare and disseminate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) knowledge specifically related to ART and early pregnancy. This article presents the impact of the SARS-CoV-2 pandemic focusing on reproductive healthcare. It details the rationale behind the guidance prepared to support MAR services in organizing and managing the re-start of treatments or in case of any future wave of COVID-19 disease. The guidance includes information on patient selection and informed consent, staff and patient triage and testing, adaptation of ART services, treatment planning and code of conduct. The initiatives detailed in this article are not necessarily COVID-specific and such action plans could be applied effectively to manage similar emergency situations in different areas of medicine, in the future
A picture of medically assisted reproduction activities during the COVID-19 pandemic in Europe
Study question: How did coronavirus disease 2019 (COVID-19) impact on medically assisted reproduction (MAR) services in Europe during the COVID-19 pandemic (March to May 2020)? Summary answer: MAR services, and hence treatments for infertile couples, were stopped in most European countries for a mean of 7 weeks. Main results and the role of chance: By aligning the data for each country with respective epidemiological data, we show a large variation in the time and the phase in the epidemic in the curve when MAR/ART treatments were suspended and restarted. Similarly, the duration of interruption varied. Fertility preservation treatments and patient supportive care for patients remained available during the pandemic
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
Evidence-based guideline : unexplained infertility
The GDG would like to acknowledge the help of many clinicians and professional organizations who refereed the content of the guideline and submitted helpful comments to the draft version. Special thanks to the steering committee of the ESHRE SIG Andrology for the feedback on the formulations of the key questions and the final draft of the guideline.Peer reviewe
The association between short-acting β2-agonist over-prescription, and patient-reported acquisition and use on asthma control and exacerbations : data from Australia
Acknowledgements Author Contribution The authors meet criteria for authorship as recommended by the International Committee of Medical Journal Editors. All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis, and interpretation, or in all these areas. The first draft of the manuscript was written by Dr. Rebecca Vella and all authors took part in drafting, revising or critically reviewing the article. All authors gave final approval of the version to be published. All authors have agreed on the journal to which the article has been submitted and agree to be accountable for all aspects of the work. All authors have given approval for the submission of this article. The authors received no direct compensation related to the development of the manuscript. Funding This study was conducted by Optimum Patient Care Australia (OPCA) and was partially funded by AstraZeneca and Optimum Patient Care Australia (OPCA). The cost of the Open Access Fees were provided by AstraZeneca. No funding was received by the Observational & Pragmatic Research Institute Pte Ltd (OPRI) for its contribution.Peer reviewedPostprin
Patient and general practitioner attitudes to taking medication to prevent cardiovascular disease after receiving detailed information on risks and benefits of treatment: a qualitative study
Abstract Background There are now effective drugs to prevent cardiovascular disease and guidelines recommend their use. Patients do not always choose to accept preventive medication at levels of risk reduction recommended in guidelines. The purpose of the study was to identify and explore the attitudes of patients and general practitioners towards preventative medication for cardiovascular disease (CVD) after they have received information about it; to identify implications for practice and prescribing. Methods Qualitative interviews with GPs and patients following presentation of in depth information about CVD risks and the absolute effects of medication. Setting: GP practices in Birmingham, United Kingdom. Results In both populations: wide variation on attitudes to preventative medication; concerns about unnecessary drug taking & side effects; preferring to consider lifestyle changes first. In patient population: whatever their attitudes to medication were, the vast majority explained that they would ultimately do what their GP recommended; there was some misunderstanding of the distinction between curative and preventative medication. A common theme was the degree of trust in their doctors' judgement and recommendations, which contrasted with scepticism of the role of pharmaceutical companies and academics. Scepticism in guidelines was also common among doctors although many nevertheless recommended treatment for their patients Conclusions A guideline approach to prescribing preventative medication could be against the interests and preferences of the patient. GPs must take extra care to explain what preventative medication is and why it is recommended, attempt to discern preferences and make recommendations balancing these potentially conflicting concerns.</p
Restrictive Versus A Liberal Transfusion Strategy in Patients With Spontaneous Intracerebral Hemorrhage: A Secondary Analysis of TRAIN Randomized Clinical Trial
BACKGROUND: Red blood cell transfusions are commonly administered to anemic patients with spontaneous intracerebral hemorrhage (ICH); however, the optimal hemoglobin threshold to initiate transfusion is uncertain in this population. Therefore, we aimed to assess the impact of 2 different hemoglobin thresholds to guide transfusion on the neurological outcome of anemic critically ill patients with ICH. METHODS: This is a secondary analysis of a prospective, multicenter, phase 3 randomized study conducted in 72 intensive care units across 22 countries from 2017 to 2022. Eligible patients for the original trial had an acute brain injury, hemoglobin values ≤9 g/dL within the first 10 days after admission, and an expected intensive care unit stay of at least 72 hours; in this study, only patients with spontaneous ICH were assessed. Patients were randomly assigned to undergo a restrictive (transfusion triggered by hemoglobin ≤7 g/dL) or a liberal (transfusion triggered by hemoglobin ≤9 g/dL) strategy over a 28-day period. The primary outcome was the occurrence of an unfavorable neurological outcome, defined as a Glasgow Outcome Scale Extended score of 1 to 5, at 180 days following randomization. RESULTS: A total of 144 patients with spontaneous ICH were analyzed: 45.8% of them were male, with a mean age of 58.4 (SD, 13.4). Mean Glasgow Coma Scale on admission was 7.3 (SD, 3.3), and 75.7% of patients had a volume of hematoma >30 mL. Among all patients, 73 were randomized to the restrictive transfusion strategy, while 71 to the liberal one. Baseline characteristics were comparable between the 2 groups. At 180 days after randomization, patients assigned to the liberal transfusion strategy had a nonsignificant decrease in the probability of unfavorable neurological outcome (71.8 versus 84.7%; risk ratio, 0.85 [95% CI, 0.71-1.01]; P=0.06). Also, the occurrence of the composite outcome (mortality and organ failure at day 28) was significantly lower in the liberal group (71.8% versus 87.7%, risk ratio, 0.82 [95% CI, 0.69-0.97]; P=0.02). CONCLUSIONS: A liberal transfusion strategy was associated with a lower risk of mortality and organ failure, but not of unfavorable outcome in patients presenting with spontaneous ICH, compared with a restrictive strategy. However, the study cohort might have been underpowered to detect clinically relevant differences between the 2 interventions
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