2,298 research outputs found
An analysis of the transient behavior of infiltrated tungsten composites including the effect of the melt layer Final report
Transient one dimensional heat transfer analysis of infiltrated tungsten composite
An economic analysis of ischaemic heart disease in Switzerland
Aims Direct and indirect costs of ischaemic heart disease were assessed in Switzerland, for the period 1988-1993, in order to evaluate the economic consequences of more intensive treatment of the disease and of the decreasing mortality from ischaemic heart disease in the working population. Methods and Results A societal perspective was taken for a prevalence-based assessment of the direct (total resources consumed by outpatients and inpatients) and indirect (due to morbidity, invalidity, and premature death, using the human capital approach) costs. The results showed the total costs were 21 million US dollars per 100 000 population in the year 1993 (47% direct, 53% indirect costs). The largest components were the direct costs of inpatient care and indirect costs due to premature death (each approximately 25% of the total). Trends showed a large increase in direct costs (+9% per year, constant dollars). Indirect costs stabilized or decreased slightly due to the reduction of work losses. Conclusions Today's medicine and preventive measures have proven effective for ischaemic heart disease, although such remedies have required increasingly large financial resources. However, society benefits because indirect costs decrease, although this gain does not compensate for all direct cost
Local Detection of Quantum Correlations with a Single Trapped Ion
As one of the most striking features of quantum mechanics, quantum
correlations are at the heart of quantum information science. Detection of
correlations usually requires access to all the correlated subsystems. However,
in many realistic scenarios this is not feasible since only some of the
subsystems can be controlled and measured. Such cases can be treated as open
quantum systems interacting with an inaccessible environment. Initial
system-environment correlations play a fundamental role for the dynamics of
open quantum systems. Following a recent proposal, we exploit the impact of the
correlations on the open-system dynamics to detect system-environment quantum
correlations without accessing the environment. We use two degrees of freedom
of a trapped ion to model an open system and its environment. The present
method does not require any assumptions about the environment, the interaction
or the initial state and therefore provides a versatile tool for the study of
quantum systems.Comment: 6 Pages, 5 Figures + 6 Pages, 1 Figure of Supplementary Materia
Betatron radiation diagnostics for AWAKE Run 2
AWAKE Run 2 aims to preserve the transverse normalised emittance of an externally injected electron beam throughout acceleration, requiring a new diagnostic to measure the beam emittance after the accelerating plasma stage. Spectroscopy of the betatron emission from the electron beam could be suitable for this case. The method of trace-space reconstruction from a measured betatron spectrum is described via a simplified analytical model in order to assess its suitability the AWAKE experiment. The expected betatron emission from witness electrons at AWAKE is characterised using 3D quasi-static PIC simulations, revealing a measurable quantity of UV to soft x-ray emission. Practical challenges for the measurement are discussed
Commissioning of the electron injector for the AWAKE experiment
The advanced wakefield experiment (AWAKE) at CERN is the first proton beam-driven plasma wakefield acceleration experiment. The main goal of AWAKE RUN 1 was to demonstrate seeded self-modulation (SSM) of the proton beam and electron witness beam acceleration in the plasma wakefield. For the AWAKE experiment, a 10-meter-long Rubidium-vapor cell together with a high-power laser for ionization was used to generate the plasma. The plasma wakefield is driven by a 400 GeV/c proton beam extracted from the super proton synchrotron (SPS), which undergoes a seeded self-modulation process in the plasma. The electron witness beam used to probe the wakefields is generated from an S-band RF photo-cathode gun and then accelerated by a booster structure up to energies between 16 and 20 MeV. The first run of the AWAKE experiment revealed that the maximum energy gain after the plasma cell is 2 GeV, and the SSM mechanism of the proton beam was verified. In this paper, we will present the details of the AWAKE electron injector. A comparison of the measured electron beam parameters, such as beam size, energy, and normalized emittance, with the simulation results was performed
Loss of HIV-infected patients on potent antiretroviral therapy programs in Togo: risk factors and the fate of these patients
Introduction: National programs are facing challenges of loss to follow-up of people living with HIV/AIDS (PLWHA) on antiretroviral therapy (ART). We sought to identify risk factors associated with early loss to follow-up among HIV-infected patients on ART in Togo and the outcome of such patients. Methods: This was a retrospective cross-sectional study using medical records of all patients older than age 15 years enrolled at 28 treatment centers who were on ART programs and who were lost to follow-up from 2008 to 2011. Results: Of the 16,617 patients on ART, 1,216 (7.3%) were lost to follow-up. Most (94.1%) were infected with HIV-1 and 32.6% were in WHO stage III or IV. The median CD4 count was 118/mm3 (IQR: 58-178 cells/mm3). No telephone number was mentioned in the medical records of 212 patients. Of the 1004 patients whose phone number was listed, 802 patients (79.9%) were not reachable on the recorded number, 114 patients (11.4%) were alive and 88 patients (8.8%) had died. In multivariate analysis, factors associated with loss to follow-up during the first 6 months of ART were: age below 35 years (OR=1.6; 95%CI: 1.2-2.2), female sex (OR=1.8; 95%CI: 1.3-2.5), WHO stage III or IV (OR=1.7; 95%CI: 1.3-2.2), existence of an opportunistic infection (OR=2.3; 95%CI: 1.5-3.1), and follow-up in a public centre (OR=1.9; 95%CI: 1.2-3.3). Conclusion: This study identified several factors associated with lost to follow-up during the first 6 months of ART, and confirmed high mortality among these patients. The National AIDS Program should strengthen medical support of PLWHA in Togo including active case follow-up.Key words: Africa, HIV, human immunodeficiency virus, lost to follow-up, people living with HIV, Tog
Pregnancy outcomes following 24-chromosome preimplantation genetic diagnosis in couples with balanced reciprocal or Robertsonian translocations
ObjectiveTo report live birth rates (LBR) and total aneuploidy rates in a series of patients with balanced translocations who pursued in vitro fertilization (IVF)–preimplantation genetic diagnosis (PGD) cycles.DesignRetrospective cohort analysis.SettingGenetic testing reference laboratory.Patient(s)Seventy-four couples who underwent IVF-PGD due to a parental translocation.Intervention(s)IVF cycles and embryo biopsies were performed by referring clinics. Biopsy samples were sent to a single reference lab for PGD for the translocation plus 24-chromosome aneuploidy screening with the use of a single-nucleotide polymorphism (SNP) microarray.Main Outcome Measure(s)LBR per biopsy cycle, aneuploidy rate, embryo transfer (ET) rate, miscarriage rate.Result(s)The LBR per IVF biopsy cycle was 38%. LBR for patients reaching ET was 52%. Clinical miscarriage rate was 10%. Despite a mean age of 33.8 years and mean of 7 embryos biopsied, there was a 30% chance for no chromosomally normal embryos. Maternal age >35 years, day 3 biopsy, and having fewer than five embryos available for biopsy increased the risk of no ET.Conclusion(s)IVF-PGD for translocation and aneuploidy screening had good clinical outcomes. Patients carrying a balanced translocation who are considering IVF-PGD should be aware of the high risk of no ET, particularly in women ≥35 years old
Effects of zinc on leaf decomposition by fungi in streams : studies in microcosms
The effect of zinc on leaf decomposition by aquatic fungi was studied in microcosms. Alder leaf disks were precolonized for 15 days at the source of the Este River, and exposed to different zinc concentrations during 25 days. Leaf mass loss, fungal biomass (based on ergosterol concentration), fungal production (rates of [1-14C]acetate incorporation into ergosterol), sporulation rates and species richness of aquatic hyphomycetes were determined. At the source of the Este River decomposition of alder leaves was fast and 50% of the initial mass was lost in 25 days. A total of 18 aquatic hyphomycete species were recorded during 42 days of leaf immersion. Articulospora tetracladia was the dominant species, followed by Lunulospora curvula and two unidentified species with sigmoid conidia. Cluster analysis suggested that zinc concentration and exposure time affected the structure of aquatic hyphomycete assemblages, even though richness had not been severely affected. Both zinc concentration and exposure time significantly affected leaf mass loss, fungal production and sporulation, but not fungal biomass. Zinc exposure reduced leaf mass loss, inhibited fungal production and affected fungal reproduction by either stimulating or inhibiting sporulation rates. The results of this work suggested zinc pollution might depress leaf decomposition in streams due to changes in the structure and activity of aquatic fungi.Fundação para a Ciência e a Tecnologia (FCT) – Programa Operacional “Ciência, Tecnologia, Inovação” (POCTI) - POCTI/34024/BSE/2000
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