722 research outputs found

    OPTIMIZING INTELLIGENCE, SURVEILLANCE, AND RECONNAISSANCE INPUTS FOR THE SYNTHETIC THEATER OPERATIONS RESEARCH MODEL

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    We consider the task of a mission planner for a unit charged with conducting intelligence, surveillance, and reconnaissance (ISR) on an area of operations in a theater-level conflict for enemy combatants using the Synthetic Theater Operations Research Model (STORM). This relies upon effective intelligence planner inputs regarding revisit interval and sensor resolution for enemy combatants. Further complicating the problem is that the entire area of operations (AO), encompassing large geographical expanses, must be searched within the mission’s time constraints. Mission planning to coordinate the search assets and cover the search area while meeting intelligence inputs has proven to be difficult, often producing infeasible solutions. We present a mixed-integer linear program that effectively prescribes plans for assets to search optimally in the AO. The program is applicable, implementable, and adaptable to STORM's settings across all campaigns and produces an average of 54.6% and a median of 22.8% improvement in search coverage relative to existing heuristics.Outstanding ThesisMajor, United States Marine CorpsApproved for public release. Distribution is unlimited

    Safety Enhancements at Short-Storage-Space Railroad Crossings

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    2019-1033A short storage space railroad crossing has insufficient distance between the crossing and the highway intersection stop line to safely store a design vehicle. The current Michigan Department of Transportation (MDOT) project (OR 19-032), led by Texas A&M Transportation Institute (TTI), aimed to provide guidance on these crossing types. This study examined the crash data, surroundings of the crossing, and driver behavioral patterns using naturalistic driving and simulation data to identify suitable countermeasures and build communication between MDOT Traffic & Safety and Office of Rail to refine the guidelines. This project conducted four major tasks: 1) a comprehensive review on short-storage crossing related studies, 2) data preparation and development of safety indices for short-storage crossing locations, 3) development of driver behavior related safety scoring for different passive treatments using data from SHRP-2 naturalistic driving study (NDS) and simulation, and 4) development of a guidance document and final report on short-storage crossings in Michigan. The findings of literature review show that little research has been conducted to empirically evaluate the effectiveness of different treatments for grade crossings with short storage, outside of traffic signal preemption strategies. The results also revealed that the highest number of crashes occurred in southeast Michigan (Detroit area), and the lowest number occurred in the sparsely populated northern part of the state. The findings also show that short storage locations are mostly on local undivided roadways. Both NDS and simulation study results indicate that drivers face difficulties in following signs and markings near the short storage locations. This study can help authorities in identifying the issues of driver-related distraction and sign following patterns and can aid in improving short storage crossing safety. In addition, this project provided recommendations for modifications to the language in six relevant MDOT publications

    Non-conformal examples of AdS/CFT

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    Asymptotically anti-de Sitter spacetimes with Poincare invariance along the boundary can describe, via the AdS/CFT correspondence, either relevant deformations of a conformal field theory or non-conformal vacuum states. I consider examples of both types constructed in the framework of five-dimensional gauged supergravity. I explain the proof and motivation of a gravitational ``c-theorem'' which is independent of dimension. I show how one class of examples can be elevated to ten-dimensional geometries involving distributions of parallel D3-branes. For these cases some peculiar properties of two-point functions emerge, and I close with speculations on their physical origin.Comment: 16 pages, two figures, latex. Strings '99 tal

    Transactivation of EGFR by LPS induces COX-2 expression in enterocytes

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    Necrotizing enterocolitis (NEC) is the leading cause of gastrointestinal morbidity and mortality in preterm infants. NEC is characterized by an exaggerated inflammatory response to bacterial flora leading to bowel necrosis. Bacterial lipopolysaccharide (LPS) mediates inflammation through TLR4 activation and is a key molecule in the pathogenesis of NEC. However, LPS also induces cyclooxygenase-2 (COX-2), which promotes intestinal barrier restitution through stimulation of intestinal cell survival, proliferation, and migration. Epidermal growth factor receptor (EGFR) activation prevents experimental NEC and may play a critical role in LPS-stimulated COX-2 production. We hypothesized that EGFR is required for LPS induction of COX-2 expression. Our data show that inhibiting EGFR kinase activity blocks LPS-induced COX-2 expression in small intestinal epithelial cells. LPS induction of COX-2 requires Src-family kinase signaling while LPS transactivation of EGFR requires matrix metalloprotease (MMP) activity. EGFR tyrosine kinase inhibitors block LPS stimulation of mitogen-activated protein kinase ERK, suggesting an important role of the MAPK/ERK pathway in EGFR-mediated COX-2 expression. LPS stimulates proliferation of IEC-6 cells, but this stimulation is inhibited with either the EGFR kinase inhibitor AG1478, or the selective COX-2 inhibitor Celecoxib. Taken together, these data show that EGFR plays an important role in LPS-induction of COX-2 expression in enterocytes, which may be one mechanism for EGF in inhibition of NEC

    Subtropical mode water variability in a climatologically forced model in the northwestern Pacific Ocean

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    Author Posting. © American Meteorological Society, 2012. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 42 (2012): 126–140, doi:10.1175/2011JPO4513.1.A climatologically forced high-resolution model is used to examine variability of subtropical mode water (STMW) in the northwestern Pacific Ocean. Despite the use of annually repeating atmospheric forcing, significant interannual to decadal variability is evident in the volume, temperature, and age of STMW formed in the region. This long time-scale variability is intrinsic to the ocean. The formation and characteristics of STMW are comparable to those observed in nature. STMW is found to be cooler, denser, and shallower in the east than in the west, but time variations in these properties are generally correlated across the full water mass. Formation is found to occur south of the Kuroshio Extension, and after formation STMW is advected westward, as shown by the transport streamfunction. The ideal age and chlorofluorocarbon tracers are used to analyze the life cycle of STMW. Over the full model run, the average age of STMW is found to be 4.1 yr, but there is strong geographical variation in this, from an average age of 3.0 yr in the east to 4.9 yr in the west. This is further evidence that STMW is formed in the east and travels to the west. This is qualitatively confirmed through simulated dye experiments known as transit-time distributions. Changes in STMW formation are correlated with a large meander in the path of the Kuroshio south of Japan. In the model, the large meander inhibits STMW formation just south of Japan, but the export of water with low potential vorticity leads to formation of STMW in the east and an overall increase in volume. This is correlated with an increase in the outcrop area of STMW. Mixed layer depth, on the other hand, is found to be uncorrelated with the volume of STMW.E.M.D. acknowledges support of the Doherty Foundation and National Science Foundation (OCE-0849808). S.R.J was sponsored by the National Science Foundation (OCE-0849808). Participation of S.P. and F.B. was supported by the National Science Foundation by its sponsorship of the National Center for Atmospheric Research.2012-07-0

    Eukaryotic Cells Producing Ribosomes Deficient in Rpl1 Are Hypersensitive to Defects in the Ubiquitin-Proteasome System

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    It has recently become clear that the misassembly of ribosomes in eukaryotic cells can have deleterious effects that go far beyond a simple shortage of ribosomes. In this work we find that cells deficient in ribosomal protein L1 (Rpl1; Rpl10a in mammals) produce ribosomes lacking Rpl1 that are exported to the cytoplasm and that can be incorporated into polyribosomes. The presence of such defective ribosomes leads to slow growth and appears to render the cells hypersensitive to lesions in the ubiquitin-proteasome system. Several genes that were reasonable candidates for degradation of 60S subunits lacking Rpl1 fail to do so, suggesting that key players in the surveillance of ribosomal subunits remain to be found. Interestingly, in spite of rendering the cells hypersensitive to the proteasome inhibitor MG132, shortage of Rpl1 partially suppresses the stress-invoked temporary repression of ribosome synthesis caused by MG132.United States. National Institutes of Health (GM25532)United States. National Institutes of Health (ARRAGM25532-S1)United States. National Institutes of Health (GM085177)United States. National Institutes of Health (CAI-3330)Natural Sciences and Engineering Research Council of Canada (NSERC

    Recommendations from the International Consensus Conference on Anemia Management in Surgical Patients (ICCAMS)

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    Background: Perioperative anemia has been associated with increased risk of red blood cell transfusion and increased morbidity and mortality following surgery. The optimal approach to the diagnosis and management of perioperative anemia is not fully established. Objective: To develop consensus recommendations for anemia management in surgical patients. Methods: An international expert panel reviewed the current evidence and developed recommendations using modified RAND Delphi methodology. Results: The panel recommends that all patients be screened for anemia prior to surgery. Appropriate therapy for anemia should be guided by an accurate diagnosis of the etiology. The need to proceed with surgery in some patients with anemia is expected to persist. However, early identification and effective treatment of anemia has the potential to reduce the risks associated with surgery and improve clinical outcomes. As with preoperative anemia, postoperative anemia should be treated in the perioperative period. Conclusions: Early identification and effective treatment of anemia has the potential to improve clinical outcomes in surgical patients

    LSST Science Book, Version 2.0

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    A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo
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