1,121 research outputs found

    Causes of Ineradicable Spurious Predictions in Qualitative Simulation

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    It was recently proved that a sound and complete qualitative simulator does not exist, that is, as long as the input-output vocabulary of the state-of-the-art QSIM algorithm is used, there will always be input models which cause any simulator with a coverage guarantee to make spurious predictions in its output. In this paper, we examine whether a meaningfully expressive restriction of this vocabulary is possible so that one can build a simulator with both the soundness and completeness properties. We prove several negative results: All sound qualitative simulators, employing subsets of the QSIM representation which retain the operating region transition feature, and support at least the addition and constancy constraints, are shown to be inherently incomplete. Even when the simulations are restricted to run in a single operating region, a constraint vocabulary containing just the addition, constancy, derivative, and multiplication relations makes the construction of sound and complete qualitative simulators impossible

    Histopathologic and immunohistochemical investigations of dental abscess formed in maxillofacial area

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    Background: An abscess is a pocket of pus that forms around the root of an infected tooth. In this study, we aimed to investigate the extracellular matrix proteases ADAMTS1, ADAMTS4, osteonectin, and osteopontin expressions in abscess fluid cells in jaws after implantation and prosthesis operation. Materials and methods: In this clinical study, abscess fluids belonging to 17 patients who applied to the Department of Oral and Maxillofacial Surgery were examined histopathologically and immunohistochemically. In the histopathological examination of the abscess fluid, separation of chromatin bridges in the nuclei of neutrophil cells, pyknosis and apoptotic changes in the nucleus, degenerative change in the cytoplasm, and occasional vacuolar structures were observed. Results: The positive reaction of ADAMTS1 was observed in fibroblast cells, plasma cells, and macrophage cells. The positive reaction of ADAMTS4 was observed in fibroblast cells, osteoclast cells, and some apoptotic leukocyte cells. Osteopontin expression in osteoclastic cells and polymorphonuclear cells was defined as positive. Osteonectin expression was positive in polymorphonuclear leukocytes and hypertrophic fibroblast cells. Conclusions: ADAMTS1 and ADAMTS4 may induce bone destruction with its distinctive property in alveolar bone resorption, which promotes the activation of osteoclasts, which can accelerate the destruction of the extracellular matrix in the acute phase. Furthermore, osteoclastic activity increased with the increase of osteonectin and osteopontin protein expression due to inflammation in the abscess cases

    Genetic diversity and population structure of Turkish native cattle breeds

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    Cattle are an important livestock species for human life, but certain breeds are at risk of extinction. Maintaining genetic diversity plays an important role in sustainable breeding and conservation programmes in farm animals. The aim of this study was to determine genetic diversity among five Turkish native cattle breeds. A total of 199 Turkish native cattle of the Native Southern Yellow (n = 40), South Anatolian Red (n = 40), Anatolian Grey Cattle (n = 40), Native Black Cattle (n = 39) and East Anatolian Red (n = 40) breeds were investigated using 22 autosomal microsatellite markers. The analysis revealed considerable genetic variation among these breeds. All loci were polymorphic, and a total of 545 alleles were found. Among these loci, only INRA032 was at Hardy-Weinberg equilibrium. Thirty-four private alleles with frequencies greater than 5% were found. Expected heterozygosity and polymorphic information content indexes were 0.87 and 0.88, respectively. Native Southern Yellow, South Anatolian Red and Native Black Cattle breeds were closely related.Keywords: animal genetic resources, microsatellite, genetic relationship, genetic conservatio

    SIMULTANEOUS ROUTING AND LOADING METHOD FOR MILK-RUN USING HYBRID GENETIC SEARCH ALGORITHM

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    Milk-run methodology is proposed to manage the procurement of orders from suppliers. The heuristic solution methods in the literature generally apply stepwise approach to route and load the vehicles. In this study we propose a hybrid genetic local search algorithm which simultaneous solves vehicle routing and order loading problems. This is the main contribution of the study. We consider volume and weight capacities (multi capacitated) of different types of transportation vehicles (heterogeneous fleet). Because of high adaptability and easy utilization, genetic algorithms are the most preferred approach of meta-heuristics. The chromosome structure of the proposed genetic algorithm is constituted by random numbers to eliminate infeasibility. The best chromosome of each generation is improved using local search method during the algorithm runs. We applied the algorithm to a real manufacturing company that produces welding robots and other process automation equipment. The results showed the effectiveness of the algorithm

    Pathways of bond topology transitions at the interface of silicon nanocrystals and amorphous silica matrix

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    The interface chemistry of silicon nanocrystals (NCs) embedded in amorphous oxide matrix is studied through molecular dynamics simulations with the chemical environment described by the reactive force field model. Our results indicate that the Si NC-oxide interface is more involved than the previously proposed schemes which were based on solely simple bridge or double bonds. We identify different types of three-coordinated oxygen complexes, previously not noted. The abundance and the charge distribution of each oxygen complex is determined as a function of the NC size as well as the transitions among them. The oxidation at the surface of NC induces tensile strain to Si-Si bonds which become significant only around the interface, while the inner core remains unstrained. Unlike many earlier reports on the interface structure, we do not observe any double bonds. Furthermore, our simulations and analysis reveal that the interface bond topology evolves among different oxygen bridges through these three-coordinated oxygen complexes.Comment: 5 pages 6 figures 1 tabl

    Analysis of Strain Fields in Silicon Nanocrystals

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    Strain has a crucial effect on the optical and electronic properties of nanostructures. We calculate the atomistic strain distribution in silicon nanocrystals up to a diameter of 3.2 nm embedded in an amorphous silicon dioxide matrix. A seemingly conflicting picture arises when the strain field is expressed in terms of bond lengths versus volumetric strain. The strain profile in either case shows uniform behavior in the core, however it becomes nonuniform within 2-3 \AA distance to the nanocrystal surface: tensile for bond lengths whereas compressive for volumetric strain. We reconsile their coexistence by an atomistic strain analysis.Comment: Published in Applied Physics Letters Vol. 94, 191914 (2009

    Investigation of temporal bone asymmetry in cases with unilateral tinnitus: morphometric and multicentric clinical study

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    The aim of this multicentric study was to compare the anatomical structures of temporal bone in patients with unilateral tinnitus with their healthy ears. We also aimed at evaluating whether age and gender-related asymmetrical changes occur in temporal bones or not. Fifty two ears of 26 patients who had unilateral tinnitus were included into the retrospective study. The patients who had subjective nonpulsatile tinnitus and who previously had temporal computed tomography according to their file records were accepted to study. Temporal CT scans and audiometric results of patients were examined retrospectively. Middle ear volume, diameter of internal acoustic meats and diameter of jugular bulb were evaluated by both anatomist and radiologist, interobserverly. Internal acoustic meats and jugular bulb were found larger in the ears that had tinnitus than healthy ears; however, there was no statistically significance. The stereological morphometrical study of temporal bone asymmetry in humans correlate with sex is of importance for both otolarygologs and anatomists. These results will contribute to data on middle ear volume, internal acustic meats and jugular bulb sizes

    The Evaporative Stress Index as an indicator of agricultural drought in Brazil: An assessment based on crop yield impacts

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    To effectively meet growing food demands, the global agronomic community will require a better understanding of factors that are currently limiting crop yields and where production can be viably expanded with minimal environmental consequences. Remote sensing can inform these analyses, providing valuable spatiotemporal information about yield-limiting moisture conditions and crop response under current climate conditions. In this paper we study correlations for the period 2003-2013 between yield estimates for major crops grown in Brazil and the Evaporative Stress Index (ESI) - an indicator of agricultural drought that describes anomalies in the actual/reference evapotranspiration (ET) ratio, retrieved using remotely sensed inputs of land surface temperature (LST) and leaf area index (LAI). The strength and timing of peak ESI-yield correlations are compared with results using remotely sensed anomalies in water supply (rainfall from the Tropical Rainfall Mapping Mission; TRMM) and biomass accumulation (LAI from the Moderate Resolution Imaging Spectroradiometer; MODIS). Correlation patterns were generally similar between all indices, both spatially and temporally, with the strongest correlations found in the south and northeast where severe flash droughts have occurred over the past decade, and where yield variability was the highest. Peak correlations tended to occur during sensitive crop growth stages. At the state scale, the ESI provided higher yield correlations for most crops and regions in comparison with TRMM and LAI anomalies. Using finer scale yield estimates reported at the municipality level, ESI correlations with soybean yields peaked higher and earlier by 10 to 25 days in comparison to TRMM and LAI, respectively. In most states, TRMM peak correlations were marginally higher on average with municipality-level annual corn yield estimates, although these estimates do not distinguish between primary and late season harvests. A notable exception occurred in the northeastern state of Bahia, where the ESI better captured effects of rapid cycling of moisture conditions on corn yields during a series of flash drought events. The results demonstrate that for monitoring agricultural drought in Brazil, value is added by combining LAI with LST indicators within a physically based model of crop water use. Published by Elsevier Inc.Embrapa Visiting Scientist Program ; Labex US, an international scientific cooperation program - Brazilian Agricultural Research Corporation - Embrapa, ; United States Department of Agriculture (USDA
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