3,333 research outputs found

    Proposed metrics to measure quality: Overview

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    The first quality-of-care framework in family planning was articulated over 25 years ago and a considerable amount of work has been done since then to measure quality in the context of routine service delivery, yet, we do not have agreed-upon indicators to measure quality that can be applied uniformly across different health systems and social contexts. This paper takes a slightly different approach and uses a common definition of quality from the outset. Indicators of quality are required for describing the nature of family planning services and quality of care offered by a health service delivery program, and for improving clients’ experience and health outcomes. Additionally, indicators are needed for monitoring quality of care over time in a single country (e.g., for quality improvement) as well as for comparing quality across countries (e.g., for understanding contraceptive discontinuation and unintended pregnancies). Different types of indicators are needed to serve these different needs for policy and program development. Keeping these needs in mind, we propose a new set of measures to assess quality across different levels and settings

    Effect of foregrounds on the cosmic microwave background radiation multipole alignment

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2011 The Authors. Monthly Notices of the Royal Astronomical Society © 2009 RAS. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.We analyse the effect of foregrounds on the observed alignment of the cosmic microwave background radiation (CMBR) quadrupole and octopole. The alignment between these multipoles is studied by using a symmetry-based approach which assigns a principal eigenvector (PEV) or an axis with each multipole. We determine the alignment between these multipoles and its significance using the internal linear combination (ILC) 5- and 7-yr maps. We also use the maps obtained by applying the internal power spectrum estimation (IPSE) procedure on the corresponding Wilkinson Microwave Anisotropy Probe data sets to assess its significance. The effect of foreground cleaning is studied in detail within the framework of the IPSE method both analytically and numerically. By using simulated CMBR data, including foregrounds and detector noise, we study how the PEVs of the simulated pure CMB maps differ from those of the corresponding clean maps. We find that, in general, the shift in the PEVs is relatively small and in random directions. Because of the random nature of the shift we conclude that the residual foregrounds can only lead to misalignment rather than cause alignment of multipoles. We also directly estimate the significance of the observed alignment by using simulated clean maps. We find that the results in this case are identical to those obtained by simple analytic estimates or by using simulated pure CMB maps

    Successful treatment of a T4 lung tumor with vertebral body invasion using fiducial markers in the thoracic spine for image-guided radiation therapy: A case report

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    <p>Abstract</p> <p>Introduction</p> <p>Paravertebral and paraspinal tumors pose a significant challenge in radiation therapy because of the radiation sensitivity of the spinal cord and the need for maximum treatment accuracy. Implantation of fiducial markers into vertebral bodies has been described as a method of increasing the accuracy of radiation treatment for single-dose stereotactic radiosurgery for spinal and paraspinal primary tumors and metastases. However, utilization of this technique has not been described for conventionally fractionated radiation therapy. This report is the first of its kind in the literature and describes successful treatment of a T4 primary lung tumor with vertebral body invasion with conventionally fractionated, image-guided radiotherapy using fiducial markers implanted in the thoracic spine.</p> <p>Case presentation</p> <p>Our patient was a 47-year-old African-American man who presented to our hospital with a history of several months of increasing left arm pain, chest pain, dyspnea on exertion, occasional dry cough, and weight loss. He was found to have stage IIIA T4, N0, M0 lung cancer with vertebral body invasion. He had fiducial markers placed in the thoracic spine for image-guided radiation treatment set-up. The patient received 74 Gy radiation therapy with concurrent chemotherapy, and daily matching of the fiducial markers on the treatment machine allowed for treatment of the tumor while sparing the dose to the adjacent spinal cord. With one year of clinical follow-up, the patient has had regression of the tumor with only asymmetric soft-tissue thickening seen on a computed tomographic scan and grade 1 dyspnea on exertion as the only side effects of the treatment.</p> <p>Conclusion</p> <p>Fiducial marker placement is a safe and effective technique for maximizing the accuracy and reproducibility for radiation treatment of lesions near the spinal cord. This technique may be used in conventionally fractionated radiation treatment regimens, such as those employed to treat a lung tumor with vertebral body invasion, to potentially improve clinical outcomes for patients.</p

    Gigawatt power electron beam generator

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    In this paper, the design and constructional details of a short-pulse electron beam generator are presented highlighting some of the novel features of its operation. The diagnostic results of the electron beam, both in the diode and in the drift region, are described. A 60-ns duration 200 keV, 30 kA electron beam has been obtained

    Incremental Medians via Online Bidding

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    In the k-median problem we are given sets of facilities and customers, and distances between them. For a given set F of facilities, the cost of serving a customer u is the minimum distance between u and a facility in F. The goal is to find a set F of k facilities that minimizes the sum, over all customers, of their service costs. Following Mettu and Plaxton, we study the incremental medians problem, where k is not known in advance, and the algorithm produces a nested sequence of facility sets where the kth set has size k. The algorithm is c-cost-competitive if the cost of each set is at most c times the cost of the optimum set of size k. We give improved incremental algorithms for the metric version: an 8-cost-competitive deterministic algorithm, a 2e ~ 5.44-cost-competitive randomized algorithm, a (24+epsilon)-cost-competitive, poly-time deterministic algorithm, and a (6e+epsilon ~ .31)-cost-competitive, poly-time randomized algorithm. The algorithm is s-size-competitive if the cost of the kth set is at most the minimum cost of any set of size k, and has size at most s k. The optimal size-competitive ratios for this problem are 4 (deterministic) and e (randomized). We present the first poly-time O(log m)-size-approximation algorithm for the offline problem and first poly-time O(log m)-size-competitive algorithm for the incremental problem. Our proofs reduce incremental medians to the following online bidding problem: faced with an unknown threshold T, an algorithm submits "bids" until it submits a bid that is at least the threshold. It pays the sum of all its bids. We prove that folklore algorithms for online bidding are optimally competitive.Comment: conference version appeared in LATIN 2006 as "Oblivious Medians via Online Bidding

    Beyond Nanopore Sequencing in Space: Identifying the Unknown

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    Astronaut Kate Rubins sequenced DNA on the International Space Station (ISS) for the first time in August 2016 (Figure 1A). A 2D sequencing library containing an equal mixture of lambda bacteriophage, Escherichia coli, and Mus musculus was prepared on the ground with a SQK_MAP006 kit and sent to the ISS frozen and loaded into R7.3 flow cells. After a total of 9 on-orbit sequencing runs over 6 months, it was determined that there was no decrease in sequencing performance on-orbit compared to ground controls (1). A total of ~280,000 and ~130,000 reads generated on-orbit and on the ground, respectively, identified 90% of reads that were attributed to 30% lambda bacteriophage, 30% Escherichia coli, and 30% M. musculus (Figure 1B). Extensive bioinformatics analysis determined comparable 2D and 1D read accuracies between flight and ground runs (Figure 1C), and data collected from the ISS were able to construct directed assemblies of E.coli and lambda genomes at 100% and M. musculus mitochondrial genome at 96.7%. These findings validate sequencing as a viable option for potential on-orbit applications such as environmental microbial monitoring and disease diagnosis. Current microbial monitoring of the ISS applies culture-based techniques that provide colony forming unit (CFU) data for air, water, and surface samples. The identity of the cultured microorganisms in unknown until sample return and ground-based analysis, a process that can take up to 60 days. For sequencing to benefit ISS applications, spaceflight-compatible sample preparation techniques are required. Subsequent to the testing of the MinION on-orbit, a sample-to-sequence method was developed using miniPCR and basic pipetting, which was only recently proven to be effective in microgravity. The work presented here details the in- flight sample preparation process and the first application of DNA sequencing on the ISS to identify unknown ISS-derived microorganisms

    A Model of Yukawa Hierarchies

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    We present a model for the observed hierarchies among the Yukawa couplings of the standard model in the context of an effective low energy theory with an anomalous U(1) symmetry. This symmetry, a generic feature of superstring compactification, is a remnant of the Green-Schwarz anomaly cancellation mechanism. The gauge group is that of the standard model, augmented by X, the anomalous U(1), and two family-dependent phase symmetries Y(1)Y^{(1)} and Y(2)Y^{(2)}. The correct hierarchies are reproduced only when sin2θw=3/8sin^2\theta_w=3/8 at the cut-off. To cancel anomalies, right-handed neutrinos and other standard model singlets must be introduced. Independently of the charges of the right-handed neutrinos, this model produces the same neutrino mixing matrix and an inverted hierarchy of neutrino masses. The heaviest is the electron neutrino with a mass 1\sim 1 meV, and mixing of the order of λc3\lambda_c^3 with each of the other two neutrinos.Comment: 15 pages, no figures, LaTex. Revised version, containing minor typographical corrections, as well as a substantial revision of the final three paragraphs of the text. Submitted to Physics Letters

    Early detection of influenza outbreaks using the DC Department of Health's syndromic surveillance system

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    <p>Abstract</p> <p>Background</p> <p>Since 2001, the District of Columbia Department of Health has been using an emergency room syndromic surveillance system to identify possible disease outbreaks. Data are received from a number of local hospital emergency rooms and analyzed daily using a variety of statistical detection algorithms. The aims of this paper are to characterize the performance of these statistical detection algorithms in rigorous yet practical terms in order to identify the optimal parameters for each and to compare the ability of two syndrome definition criteria and data from a children's hospital versus vs. other hospitals to determine the onset of seasonal influenza.</p> <p>Methods</p> <p>We first used a fine-tuning approach to improve the sensitivity of each algorithm to detecting simulated outbreaks and to identifying previously known outbreaks. Subsequently, using the fine-tuned algorithms, we examined (i) the ability of unspecified infection and respiratory syndrome categories to detect the start of the flu season and (ii) how well data from Children's National Medical Center (CNMC) did versus all the other hospitals when using unspecified infection, respiratory, and both categories together.</p> <p>Results</p> <p>Simulation studies using the data showed that over a range of situations, the multivariate CUSUM algorithm performed more effectively than the other algorithms tested. In addition, the parameters that yielded optimal performance varied for each algorithm, especially with the number of cases in the data stream. In terms of detecting the onset of seasonal influenza, only "unspecified infection," especially the counts from CNMC, clearly delineated influenza outbreaks out of the eight available syndromic classifications. In three of five years, CNMC consistently flags earlier (from 2 days up to 2 weeks earlier) than a multivariate analysis of all other DC hospitals.</p> <p>Conclusions</p> <p>When practitioners apply statistical detection algorithms to their own data, fine tuning of parameters is necessary to improve overall sensitivity. With fined tuned algorithms, our results suggest that emergency room based syndromic surveillance focusing on unspecified infection cases in children is an effective way to determine the beginning of the influenza outbreak and could serve as a trigger for more intensive surveillance efforts and initiate infection control measures in the community.</p
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