2,501 research outputs found

    Study of orifice fabrication technologies for the liquid droplet radiator

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    Eleven orifice fabrication technologies potentially applicable for a liquid droplet radiator are discussed. The evaluation is focused on technologies capable of yielding 25-150 microns diameter orifices with trajectory accuracies below 5 milliradians, ultimately in arrays of up to 4000 orifices. An initial analytical screening considering factors such as trajectory accuracy, manufacturability, and hydrodynamics of orifice flow is presented. Based on this screening, four technologies were selected for experimental evaluation. A jet straightness system used to test 50-orifice arrays made by electro-discharge machining (EDM), Fotoceram, and mechanical drilling is discussed. Measurements on orifice diameter control and jet trajectory accuracy are presented and discussed. Trajectory standard deviations are in the 4.6-10.0 milliradian range. Electroforming and EDM appear to have the greatest potential for Liquid Droplet Radiator applications. The direction of a future development effort is discussed

    Status of major southern California marine sport fish species with management recommendations, based on analyses of catch and size composition data collected on board commercial passenger fishing vessels from 1985 through 1987

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    This report on the status of major southern California marine sport fish species, together with management recommendations, is based on analyses of catch and size composition data, which were collected on board Commercial Passenger Fishing Vessels (CPFV) from 1985 through 1987. The project was designed to determine the status of those fishes that support the CPFV industry, and to make management recommendations when deemed necessary. We collected and analyzed data based on random, stratified, on-board sampling of weekday (excluding holidays), open CPFV's on a year-round basis. We sampled 1/2-day, 3/4-day, and full-day type trips at a level of 5%. The survey area extended from below the United States-Mexican border to Point Arguello. Catch estimates were extrapolated to include weekday as well as weekend and holiday, open and chartered CPFV's. We sampled 736 CPFV trips in 1985, 650 in 1986, and 631 in 1987. We encountered 180 species of fishes, including 49 species of rockfishes. We performed detailed analyses on 14 non-rockfish species and 12 rockfish species, as well as all fishes as a group and all rockfishes as a group. We found a moderate increase in total catch of combined fish species between this study and one in the mid-1970's, due primarily to sizeable increases in catches of Pacific mackerel, kelp bass, barred sand bass, and barracuda. However, we also found that there has been more than a 50% decline in the CPFV rockfish catches, due primarily to substantial decreases in catches of bocaccio, chilipepper, and olive rockfish. We have recommended that the current 15-rockfish bag limit regulation be reduced to a 10-rockfish bag limit, and that additional and equitable conservation measures also be implemented on the commercial rockfish fishery. (385pp.

    Efficient Universal Noiseless Source Codes

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    Although the existence of universal noiseless variable-rate codes for the class of discrete stationary ergodic sources has previously been established, very few practical universal encoding methods are available. Efficient implementable universal source coding techniques are discussed in this paper. Results are presented on source codes for which a small value of the maximum redundancy is achieved with a relatively short block length. A constructive proof of the existence of universal noiseless codes for discrete stationary sources is first presented. The proof is shown to provide a method for obtaining efficient universal noiseless variable-rate codes for various classes of sources. For memoryless sources, upper and lower bounds are obtained for the minimax redundancy as a function of the block length of the code. Several techniques for constructing universal noiseless source codes for memoryless sources are presented and their redundancies are compared with the bounds. Consideration is given to possible applications to data compression for certain nonstationary sources

    Confocal Endomicroscopy of Colorectal Polyps

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    Confocal laser endomicroscopy (CLE) is one of several novel methods that provide real-time, high-resolution imaging at a micron scale via endoscopes. CLE has the potential to be a disruptive technology in that it can change the current algorithms that depend on biopsy to perform surveillance of high-risk conditions. Furthermore, it allows on-table decision making that has the potential to guide therapy in real time and reduce the need for repeated procedures. CLE and related technologies are often termed “virtual biopsy” as they simulate the images seen in traditional histology. However, the imaging of living tissue allows more than just pragmatic convenience; it also allows imaging of living tissue such as active capillary circulation, cellular death, and vascular and endothelial translocation, thus extending beyond what is capable in traditional biopsy. Immediate potential applications of CLE are to guide biopsy sampling in Barrett's esophagus and inflammatory bowel disease surveillance, evaluation of colorectal polyps, and intraductal imaging of the pancreas and bile duct. Data on these applications is rapidly emerging, and more is needed to clearly demonstrate the optimal applications of CLE. In this paper, we will focus on the role of CLE as applied to colorectal polyps detected during colonoscopy

    The Distribution of Metallicity in the IGM at z~2.5: OVI and CIV Absorption in the Spectra of 7 QSOs

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    We present a direct measurement of the metallicity distribution function for the high redshift intergalactic medium. We determine the shape of this function using survival statistics, which account for both detections and non-detections of OVI and CIV associated with HI absorption in quasar spectra. Our OVI sample probes the metal content of ~50% of all baryons at z~2.5. We find a median intergalactic abundance of [O,C/H]=-2.82; the differential abundance distribution is approximately lognormal with mean ~-2.85 and \sigma=0.75 dex. Some 60-70% the Lya forest lines are enriched to observable levels ([O,C/H]>-3.5) while the remaining ~30% of the lines have even lower abundances. Thus we have not detected a universal metallicity floor as has been suggested for some Population III enrichment scenaria. In fact, we argue that the bulk of the intergalactic metals formed later than the first stars that are thought to have triggered reionization. We do not observe a significant trend of decreasing metallicity toward the lower density IGM, at least within regions that would be characterized as filaments in numerical simulations. However, an [O/H] enhancement may be present at somewhat high densities. We estimate that roughly half of all baryons at these redshifts have been enriched to [O/H]>=-3.5. We develop a simple model for the metallicity evolution of the IGM, to estimate the chemical yield of galaxies formed prior to z~2.5. We find that the typical galaxy recycled 0.1-0.4% of its mass back into the IGM as heavy elements in the first 3 Gyr after the Big Bang.Comment: 23 pages in emulateapj, 19 figures. Accepted to ApJ, pending review of new changes. Revised comparison between our results and Schaye et al (2003

    Deep Multi-Modal Classification of Intraductal Papillary Mucinous Neoplasms (IPMN) with Canonical Correlation Analysis

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    Pancreatic cancer has the poorest prognosis among all cancer types. Intraductal Papillary Mucinous Neoplasms (IPMNs) are radiographically identifiable precursors to pancreatic cancer; hence, early detection and precise risk assessment of IPMN are vital. In this work, we propose a Convolutional Neural Network (CNN) based computer aided diagnosis (CAD) system to perform IPMN diagnosis and risk assessment by utilizing multi-modal MRI. In our proposed approach, we use minimum and maximum intensity projections to ease the annotation variations among different slices and type of MRIs. Then, we present a CNN to obtain deep feature representation corresponding to each MRI modality (T1-weighted and T2-weighted). At the final step, we employ canonical correlation analysis (CCA) to perform a fusion operation at the feature level, leading to discriminative canonical correlation features. Extracted features are used for classification. Our results indicate significant improvements over other potential approaches to solve this important problem. The proposed approach doesn't require explicit sample balancing in cases of imbalance between positive and negative examples. To the best of our knowledge, our study is the first to automatically diagnose IPMN using multi-modal MRI.Comment: Accepted for publication in IEEE International Symposium on Biomedical Imaging (ISBI) 201

    Evaluation of the angiotensin II receptor blocker azilsartan medoxomil in African-American patients with hypertension

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    The efficacy and safety of azilsartan medoxomil (AZL-M) were evaluated in African-American patients with hypertension in a 6-week, double-blind, randomized, placebo-controlled trial, for which the primary end point was change from baseline in 24-hour mean systolic blood pressure (BP). There were 413 patients, with a mean age of 52years, 57% women, and baseline 24-hour BP of 146/91mmHg. Treatment differences in 24-hour systolic BP between AZL-M 40mg and placebo (-5.0mmHg; 95% confidence interval, -8.0 to -2.0) and AZL-M 80mg and placebo (-7.8mmHg; 95% confidence interval, -10.7 to -4.9) were significant (P.001 vs placebo for both comparisons). Changes in the clinic BPs were similar to the ambulatory BP results. Incidence rates of adverse events were comparable among the treatment groups, including those of a serious nature. In African-American patients with hypertension, AZL-M significantly reduced ambulatory and clinic BPs in a dose-dependent manner and was well tolerated

    Perusing The Headwaters Of Diversity Among University Presidents

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    Females and minorities are gaining clout in higher education as the numbers of graduates in each of these groups indicate.  Diversity among university presidents is a reality.  Indications are that the number of women receiving advanced degrees will continue to grow for some time.  Low estimates of graduation rates among women and minorities from years ago do not hold.  The impacts of this reality in higher education will continue to be felt for some time

    New light on the ‘Drummer of Tedworth’: conflicting narratives of witchcraft in Restoration England

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    This paper presents a definitive text of hitherto little-known early documents concerning ‘The Drummer of Tedworth’, a poltergeist case that occurred in 1662-3 and became famous not least due to its promotion by Joseph Glanvill in his demonological work, Saducismus Triumphatus. On the basis of these and other sources, it is shown how responses to the events at Tedworth evolved from anxious piety on the part of their victim, John Mompesson, to confident apologetic by Glanvill, before they were further affected by the emergence of articulate scepticism about the case
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