3,015 research outputs found

    Portable Asteroids on Hypercube Or Transputers

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    A multi-player 3D Asteroids video game designed to be used as a testbed for evaluating controller algorithms was described in [l.] The original version of the game and a separate interactive 3D graphics interface for a human player were implemented, based on CrOS III and VERTEX, on an NCUBE-l hypercube equipped with a parallel Real-Time Graphics board. The Asteroids and interactive graphics interface programs are examples of parallel programs which communicate with each other in a space-shared multi-processor environment. We have successfully ported the Asteroids and the interactive graphics interface to run on NCUBE using ParaSoft EXPRESS. The new version of these programs were further ported to run on a SUN 386i with an add-on Transputer board. We present general design considerations that enable easy migration of communicating parallel programs to any other hardware platform that runs EXPRESS. We also report specific experience of porting Asteroids and an associated interactive player interface program on an NCUBE hypercube to a SUN 386i Transputer-based system, with no modification of codes

    Learning to Plan Near-Optimal Collision-Free Paths

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    A new approach to find a near-optimal collision-free path is presented. The path planner is an implementation of the adaptive error back-propagation algorithm which learns to plan “good”, if not optimal, collision-free paths from human-supervised training samples. Path planning is formulated as a classification problem in which class labels are uniquely mapped onto the set of maneuverable actions of a robot or vehicle. A multi-scale representational scheme maps physical problem domains onto an arbitrarily chosen fixed size input layer of an error back-propagation network. The mapping does not only reduce the size of the computation domain, but also ensures applicability of a trained network over a wide range of problem sizes. Parallel implementation of the neural network path planner on hypercubes or Transputers based on Parasoft EXPRESS is simple and efficient, Simulation results of binary terrain navigation indicate that the planner performs effectively in unknown environment in the test cases

    PC-CUBE: A Personal Computer Based Hypercube

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    PC-CUBE is an ensemble of IBM PCs or close compatibles connected in the hypercube topology with ordinary computer cables. Communication occurs at the rate of 115.2 K-band via the RS-232 serial links. Available for PC-CUBE is the Crystalline Operating System III (CrOS III), Mercury Operating System, CUBIX and PLOTIX which are parallel I/O and graphics libraries. A CrOS performance monitor was developed to facilitate the measurement of communication and computation time of a program and their effects on performance. Also available are CXLISP, a parallel version of the XLISP interpreter; GRAFIX, some graphics routines for the EGA and CGA; and a general execution profiler for determining execution time spent by program subroutines. PC-CUBE provides a programming environment similar to all hypercube systems running CrOS III, Mercury and CUBIX. In addition, every node (personal computer) has its own graphics display monitor and storage devices. These allow data to be displayed or stored at every processor, which has much instructional value and enables easier debugging of applications. Some application programs which are taken from the book Solving Problems on Concurrent Processors (Fox 88) were implemented with graphics enhancement on PC-CUBE. The applications range from solving the Mandelbrot set, Laplace equation, wave equation, long range force interaction, to WaTor, an ecological simulation

    EST analysis of gene expression in early cleavage-stage sea urchin embryos

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    A set of 956 expressed sequence tags derived from 7-hour (mid-cleavage) sea urchin embryos was analyzed to assess biosynthetic functions and to illuminate the structure of the message population at this stage. About a quarter of the expressed sequence tags represented repetitive sequence transcripts typical of early embryos, or ribosomal and mitochondrial RNAs, while a majority of the remainder contained significant open reading frames. A total of 232 sequences, including 153 different proteins, produced significant matches when compared against GenBank. The majority of these identified sequences represented ‘housekeeping’ proteins, i.e., cytoskeletal proteins, metabolic enzymes, transporters and proteins involved in cell division. The most interesting finds were components of signaling systems and transcription factors not previously reported in early sea urchin embryos, including components of Notch and TGF signal transduction pathways. As expected from earlier kinetic analyses of the embryo mRNA populations, no very prevalent protein-coding species were encountered; the most highly represented such sequences were cDNAs encoding cyclins A and B. The frequency of occurrence of all sequences within the database was used to construct a sequence prevalence distribution. The result, confirming earlier mRNA population analyses, indicated that the poly(A) RNA of the early embryo consists mainly of a very complex set of low-copy-number transcripts

    The use of prophylactic fluconazole in immunocompetent high-risk surgical patients: a meta-analysis

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    INTRODUCTION: High-risk surgical patients are at increased risk of fungal infections and candidaemia. Evidence from observational and small randomised controlled studies suggests that prophylactic fluconazole may be effective in reducing fungal infection and mortality. We evaluated the effects of prophylactic fluconazole on the incidence of candidaemia and hospital mortality in immunocompetent high-risk surgical patients. METHODS: Randomised controlled studies involving the use of fluconazole in immunocompetent high-risk surgical patients from the Cochrane Controlled Trial Register (2005, issue 1) and from the EMBASE and MEDLINE databases (1966–30 April 2005), without any language restriction, were included. Two reviewers reviewed the quality of the studies and performed data extraction independently. RESULTS: Seven randomised controlled studies with a total of 814 immunocompetent high-risk surgical patients were considered. The use of prophylactic fluconazole was associated with a reduction in the proportion of patients with candidaemia (relative risk [RR] = 0.21, 95% confidence interval [CI] = 0.06–0.72, P = 0.01; I(2 )= 0%) and fungal infections other than lower urinary tract infection (RR = 0.39, 95% CI = 0.24–0.65, P = 0.0003; I(2 )= 0%), but was associated with only a trend towards a reduction in hospital mortality (RR = 0.82, 95% CI = 0.62–1.08, P = 0.15; I(2 )= 7%). The proportion of patients requiring systemic amphotericin B as a rescue therapy for systemic fungal infection was lower after prophylactic use of fluconazole (RR = 0.35, 95% CI = 0.17–0.72, P = 0.004; I(2 )= 0%). The proportion of patients colonised with or infected with fluconazole-resistant fungi was not significantly different between the fluconazole group and the placebo group (RR = 0.66, 95% CI = 0.22–1.96, P = 0.46; I(2 )= 0%). CONCLUSION: The use of prophylactic fluconazole in immunocompetent high-risk surgical patients is associated with a reduced incidence of candidaemia but with only a trend towards a reduction in hospital mortality

    Neural Networks and Dynamic Complex Systems

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    We describe the use of neural networks for optimization and inference associated with a variety of complex systems. We show how a string formalism can be used for parallel computer decomposition, message routing and sequential optimizing compilers. We extend these ideas to a general treatment of spatial assessment and distributed artificial intelligence

    Parasitic copepods from Egyptian Red Sea fishes: Bomolochidae Claus, 1875

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    © The Author(s) 2015 Open Access - This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The attached file is the published version of the article

    Comparison of trigger point injections versus traditional therapies in the management of post-surgical pain in patients who had anterior cervical surgery: A Retrospective Study

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    Introduction: The opioid epidemic has launched the United States into a public health crisis, resulting in a greater emphasis on non-opioid multimodal pain control methods. At our institution, postoperative posterior neck stiffness and myofascial pain is a common concern after anterior cervical discectomy and fusion or anterior cervical corpectomy with fusion surgery (hereinafter ACS), likely due to prolonged intraoperative positioning in neck extension. Studies have shown successful analgesic outcomes of trigger point injections with local anesthetic for generalized myofascial pain.1-2 This retrospective pilot study aimed to evaluate whether trigger point injections with bupivacaine decreases postsurgical pain compared with traditional therapies in patients undergoing ACS and thereby decrease the amount of opioid medication used. Methods: After IRB approval, we retrospectively reviewed medical records of all patients who received ACS from January 2019 to March 2020 at a single university hospital. We identified patients who received trigger point injections (TP) versus standard care (SC). We excluded patients if TP was performed \u3e3hr from surgery, in recovery for opioid use disorder, underwent a posterior approach, staged surgery, or sustained cervical trauma. The primary outcomes were pain control through the Visual Analog Scale (VAS) and calculated oral morphine equivalents (OME) taken at 6, 12, and 24 hours post-operatively. Secondary outcomes included length of stay (LOS). Results: 137 patients received anterior cervical surgery (100 SC, 37 TP), 62 were excluded. A total of 75 (47 SC, 28 TP) patients were included in this study. The average OME at 6 hours significantly decreased when comparing SC vs TP (32 vs 22, p=0.025). There was no significant difference in average VAS at all time points and average OME at 12 and 24 hours (Table 1). 50% of patients were discharged by 18 hours. Discussion: Our results suggest that TP with bupivacaine significantly reduce opioid consumption within 6 hours of the postoperative period, without increasing overall pain level. There is an opportunity for TP to be included in non-opioid multimodal pain regimens for postoperative myofascial neck pain, especially during the opioid crisis. Limitations of this retrospective study were the small number of study participants, that many patients were discharged before 18 hours and some may have been on chronic pain therapy. The identified limitations will help inform our future investigations and design a prospective randomized control study

    The Masses of Transition Circumstellar Disks: Observational Support for Photoevaporation Models

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    We report deep Sub-Millimeter Array observations of 26 pre-main-sequence (PMS) stars with evolved inner disks. These observations measure the mass of the outer disk (r ~20-100 AU) across every stage of the dissipation of the inner disk (r < 10 AU) as determined by the IR spectral energy distributions (SEDs). We find that only targets with high mid-IR excesses are detected and have disk masses in the 1-5 M_Jup range, while most of our objects remain undetected to sensitivity levels of M_DISK ~0.2-1.5 M_Jup. To put these results in a more general context, we collected publicly available data to construct the optical to millimeter wavelength SEDs of over 120 additional PMS stars. We find that the near-IR and mid-IR emission remain optically thick in objects whose disk masses span 2 orders of magnitude (~0.5-50 M_Jup). Taken together, these results imply that, in general, inner disks start to dissipate only after the outer disk has been significantly depleted of mass. This provides strong support for photoevaporation being one of the dominant processes driving disk evolution.Comment: Accepted for publication by ApJL, 4 pages and 3 figure
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