1,073 research outputs found

    Photon counting compressive depth mapping

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    We demonstrate a compressed sensing, photon counting lidar system based on the single-pixel camera. Our technique recovers both depth and intensity maps from a single under-sampled set of incoherent, linear projections of a scene of interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional reconstructions are required to image a three-dimensional scene. We demonstrate intensity imaging and depth mapping at 256 x 256 pixel transverse resolution with acquisition times as short as 3 seconds. We also show novelty filtering, reconstructing only the difference between two instances of a scene. Finally, we acquire 32 x 32 pixel real-time video for three-dimensional object tracking at 14 frames-per-second.Comment: 16 pages, 8 figure

    Radical Hysterectomy with Pelvic Lymphadenectomy: Indications, Technique, and Complications

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    Radical hysterectomy with pelvic lymphadenectomy remains the treatment of choice for women with Stages IA2 and IB1 carcinoma of the cervix, and selected patients with Stage II endometrial cancer. Improvement in surgical techniqe, administration of prophylactic antibiotics, thromboemolic prophylaxis, and advances in critical care medicine have resulted in lower operative morbidity associated with this procedure. Major urinary tract complications such as ureteral injury or vesico-vaginal fistula are now extremely rare (<1%). Five-year survival rates following this procedure vary according to a number of clinical and histologic variables, and may be as high as 90% in women without lymph node metastases

    Aerosol lidar observations of atmospheric mixing in Los Angeles: Climatology and implications for greenhouse gas observations

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    Atmospheric observations of greenhouse gases provide essential information on sources and sinks of these key atmospheric constituents. To quantify fluxes from atmospheric observations, representation of transport—especially vertical mixing—is a necessity and often a source of error. We report on remotely sensed profiles of vertical aerosol distribution taken over a 2 year period in Pasadena, California. Using an automated analysis system, we estimate daytime mixing layer depth, achieving high confidence in the afternoon maximum on 51% of days with profiles from a Sigma Space Mini Micropulse LiDAR (MiniMPL) and on 36% of days with a Vaisala CL51 ceilometer. We note that considering ceilometer data on a logarithmic scale, a standard method, introduces, an offset in mixing height retrievals. The mean afternoon maximum mixing height is 770 m Above Ground Level in summer and 670 m in winter, with significant day‐to‐day variance (within season σ = 220m≈30%). Taking advantage of the MiniMPL’s portability, we demonstrate the feasibility of measuring the detailed horizontal structure of the mixing layer by automobile. We compare our observations to planetary boundary layer (PBL) heights from sonde launches, North American regional reanalysis (NARR), and a custom Weather Research and Forecasting (WRF) model developed for greenhouse gas (GHG) monitoring in Los Angeles. NARR and WRF PBL heights at Pasadena are both systematically higher than measured, NARR by 2.5 times; these biases will cause proportional errors in GHG flux estimates using modeled transport. We discuss how sustained lidar observations can be used to reduce flux inversion error by selecting suitable analysis periods, calibrating models, or characterizing bias for correction in post processing.Key PointsAerosol lidar maps LA mixing depth in space (pilot mobile study) and time (2 years data)Automatic mixing depth retrieval system finds daily variability far exceeds seasonal differencePBL heights in models used for GHG monitoring show biases that will carry over to flux estimatesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134180/1/jgrd53200_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134180/2/jgrd53200.pd

    Predicting declines in physical function in persons with multiple chronic medical conditions: what we can learn from the medical problem list

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    BACKGROUND: Primary care physicians are caring for increasing numbers of persons with comorbid chronic illness. Longitudinal information on health outcomes associated with specific chronic conditions may be particularly relevant in caring for these populations. Our objective was to assess the effect of certain comorbid conditions on physical well being over time in a population of persons with chronic medical conditions; and to compare these effects to that of hypertension alone. METHODS: We conducted a secondary analysis of 4-year longitudinal data from the Medical Outcomes Study. A heterogeneous population of 1574 patients with either hypertension alone (referent) or one or more of the following conditions: diabetes, coronary artery disease, congestive heart failure, respiratory illness, musculoskeletal conditions and/or depression were recruited from primary and specialty (endocrinology, cardiology or mental health) practices within HMO and fee-for-service settings in three U.S. cities. We measured categorical change (worse vs. same/better) in the SF-36(R) Health Survey physical component summary score (PCS) over 4 years. We used logistic regression analysis to determine significant differences in longitudinal change in PCS between patients with hypertension alone and those with other comorbid conditions and linear regression analysis to assess the contribution of the explanatory variables. RESULTS: Specific diagnoses of CHF, diabetes and/or chronic respiratory disease; or 4 or more chronic conditions, were predictive of a clinically significant decline in PCS. CONCLUSIONS: Clinical recognition of these specific chronic conditions or 4 or more of a list of chronic conditions may provide an opportunity for proactive clinical decision making to maximize physical functioning in these populations

    Photon Counting Compressive Depth Mapping

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    We demonstrate a compressed sensing, photon counting lidar system based on the single-pixel camera. Our technique recovers both depth and intensity maps from a single under-sampled set of incoherent, linear projections of a scene of interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional reconstructions are required to image a three-dimensional scene. We demonstrate intensity imaging and depth mapping at 256 × 256 pixel transverse resolution with acquisition times as short as 3 seconds. We also show novelty filtering, reconstructing only the difference between two instances of a scene. Finally, we acquire 32 × 32 pixel real-time video for three-dimensional object tracking at 14 frames-per-second

    Novel use Of Hydroxyurea in an African Region with Malaria (NOHARM): a trial for children with sickle cell anemia

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    Hydroxyurea treatment is recommended for children with sickle cell anemia (SCA) living in high-resource malaria-free regions, but its safety and efficacy in malaria-endemic sub-Saharan Africa, where the greatest sickle-cell burden exists, remain unknown. In vitro studies suggest hydroxyurea could increase malaria severity, and hydroxyurea-associated neutropenia could worsen infections. NOHARM (Novel use Of Hydroxyurea in an African Region with Malaria) was a randomized, double-blinded, placebo-controlled trial conducted in malaria-endemic Uganda, comparing hydroxyurea to placebo at 20 ± 2.5 mg/kg per day for 12 months. The primary outcome was incidence of clinical malaria. Secondary outcomes included SCA-related adverse events (AEs), clinical and laboratory effects, and hematological toxicities. Children received either hydroxyurea (N = 104) or placebo (N = 103). Malaria incidence did not differ between children on hydroxyurea (0.05 episodes per child per year; 95% confidence interval [0.02, 0.13]) vs placebo (0.07 episodes per child per year [0.03, 0.16]); the hydroxyurea/placebo malaria incidence rate ratio was 0.7 ([0.2, 2.7]; P = .61). Time to infection also did not differ significantly between treatment arms. A composite SCA-related clinical outcome (vaso-occlusive painful crisis, dactylitis, acute chest syndrome, splenic sequestration, or blood transfusion) was less frequent with hydroxyurea (45%) than placebo (69%; P = .001). Children receiving hydroxyurea had significantly increased hemoglobin concentration and fetal hemoglobin, with decreased leukocytes and reticulocytes. Serious AEs, sepsis episodes, and dose-limiting toxicities were similar between treatment arms. Three deaths occurred (2 hydroxyurea, 1 placebo, and none from malaria). Hydroxyurea treatment appears safe for children with SCA living in malaria-endemic sub-Saharan Africa, without increased severe malaria, infections, or AEs. Hydroxyurea provides SCA-related laboratory and clinical efficacy, but optimal dosing and monitoring regimens for Africa remain undefined. This trial was registered at www.clinicaltrials.gov as #NCT01976416

    Detecting Urban Emissions Changes and Events With a Near‐Real‐Time‐Capable Inversion System

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    In situ observing networks are increasingly being used to study greenhouse gas emissions in urban environments. While the need for sufficiently dense observations has often been discussed, density requirements depend on the question posed and interact with other choices made in the analysis. Focusing on the interaction of network density with varied meteorological information used to drive atmospheric transport, we perform geostatistical inversions of methane flux in the South Coast Air Basin, California, in 2015–2016 using transport driven by a locally tuned Weather Research and Forecasting configuration as well as by operationally available meteorological products. We find total‐basin flux estimates vary by as much as a factor of two between inversions, but the spread can be greatly reduced by calibrating the estimates to account for modeled sensitivity. Using observations from the full Los Angeles Megacities Carbon Project observing network, inversions driven by low‐resolution generic wind fields are robustly sensitive (p < 0.05) to seasonal differences in methane flux and to the increase in emissions caused by the 2015 Aliso Canyon natural gas leak. When the number of observing sites is reduced, the basin‐wide sensitivity degrades, but flux events can be detected by testing for changes in flux variance, and even a single site can robustly detect basin‐wide seasonal flux variations. Overall, an urban monitoring system using an operational methane observing network and off‐the‐shelf meteorology could detect many seasonal or event‐driven changes in near real time—and, if calibrated to a model chosen as a transfer standard, could also quantify absolute emissions.Key PointsLA CH4 flux estimates differ by driving meteorology but agree when calibrated for model sensitivityAliso Canyon leak can be detected by inversions using operational meteorologyOperational meteorology driven inversions significantly detect seasonal emission changes even with only one sitePeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149534/1/jgrd55279-sup-0001-Text_SI-S01.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149534/2/jgrd55279.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149534/3/jgrd55279_am.pd
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