727 research outputs found

    Escape-Route Planning of Underground Coal Mine Based on Improved Ant Algorithm

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    When a mine disaster occurs, to lessen disaster losses and improve survival chances of the trapped miners, good escape routes need to be found and used. Based on the improved ant algorithm, we proposed a new escape-route planning method of underground mines. At first, six factors which influence escape difficulty are evaluated and a weight calculation model is built to form a weighted graph of the underground tunnels. Then an improved ant algorithm is designed and used to find good escape routes. We proposed a tunnel network zoning method to improve the searching efficiency of the ant algorithm. We use max-min ant system method to optimize the meeting strategy of ants and improve the performance of the ant algorithm. In addition, when a small part of the mine tunnel network changes, the system may fix the optimal routes and avoid starting a new processing procedure. Experiments show that the proposed method can find good escape routes efficiently and can be used in the escape-route planning of large and medium underground coal mines

    Corrections to LRT on Large Dimensional Covariance Matrix by RMT

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    In this paper, we give an explanation to the failure of two likelihood ratio procedures for testing about covariance matrices from Gaussian populations when the dimension is large compared to the sample size. Next, using recent central limit theorems for linear spectral statistics of sample covariance matrices and of random F-matrices, we propose necessary corrections for these LR tests to cope with high-dimensional effects. The asymptotic distributions of these corrected tests under the null are given. Simulations demonstrate that the corrected LR tests yield a realized size close to nominal level for both moderate p (around 20) and high dimension, while the traditional LR tests with chi-square approximation fails. Another contribution from the paper is that for testing the equality between two covariance matrices, the proposed correction applies equally for non-Gaussian populations yielding a valid pseudo-likelihood ratio test.Comment: 25 pages, 2 figures and 3 table

    Social Media Use for Farmers Market Communications in Illinois

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    Social media has been recognized as a powerful tool supporting communication of many topics in the agriculture industry. We explored the use of social media platforms among farmers market managers and specialty crop growers in Illinois through an online survey. Facebook, Instagram, and Twitter were platforms used by the majority of respondents. We found that social media was used primarily for communicating with consumers for marketing purposes. We identified major training needs of farmers market stakeholders related to using social media to promote business and convey food safety information

    Quantitative assessment of image motion blur in diffraction images of moving biological cells

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    Motion blur (MB) presents a significant challenge for obtaining high-contrast image data from biological cells with a polarization diffraction imaging flow cytometry (p-DIFC) method. A new p-DIFC experimental system has been developed to evaluate the MB and its effect on image analysis using a time-delay-integration (TDI) CCD camera. Diffraction images of MCF-7 and K562 cells have been acquired with different speed-mismatch ratios and compared to characterize MB quantitatively. Frequency analysis of the diffraction images shows that the degree of MB can be quantified by bandwidth variations of the diffraction images along the motion direction. The analytical results were confirmed by the p-DIFC image data acquired at different speed-mismatch ratios and used to validate a method of numerical simulation of MB on blur-free diffraction images, which provides a useful tool to examine the blurring effect on diffraction images acquired from the same cell. These results provide insights on the dependence of diffraction image on MB and allow significant improvement on rapid biological cell assay with the p-DIFC method

    Dietary compounds in modulation of gut microbiota-derived metabolites

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    Gut microbiota, a group of microorganisms that live in the gastrointestinal tract, plays important roles in health and disease. One mechanism that gut microbiota in modulation of the functions of hosts is achieved through synthesizing and releasing a series of metabolites such as short-chain fatty acids. In recent years, increasing evidence has indicated that dietary compounds can interact with gut microbiota. On one hand, dietary compounds can modulate the composition and function of gut microbiota; on the other hand, gut microbiota can metabolize the dietary compounds. Although there are several reviews on gut microbiota and diets, there is no focused review on the effects of dietary compounds on gut microbiota-derived metabolites. In this review, we first briefly discussed the types of gut microbiota metabolites, their origins, and the reasons that dietary compounds can interact with gut microbiota. Then, focusing on gut microbiota-derived compounds, we discussed the effects of dietary compounds on gut microbiota-derived compounds and the following effects on health. Furthermore, we give our perspectives on the research direction of the related research fields. Understanding the roles of dietary compounds on gut microbiota-derived metabolites will expand our knowledge of how diets affect the host health and disease, thus eventually enable the personalized diets and nutrients

    Larotrectinib treatment for infantile fibrosarcoma in newborns: a case report and literature review

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    Infantile fibrosarcoma (IFS) is a rare tumor in childhood characterized by a single, localized, painless mass that grows rapidly but has a relatively indolent biological behavior and a favorable prognosis. Eighty-five percent of infantile fibrosarcomas are associated with t (12;15) (p13;25) chromosomal translocation resulting in ETV6-NTRK3 gene fusion, which provides the target for targeted therapy. Here, we report a case of IFS in a newborn with a mass in the left lower extremity confirmed by imaging, histopathological examination, tissue FISH testing, and high-throughput sequencing to detect gene rearrangement. Based on gene fusion targeted drug testing results, the patient was treated with standard doses of larotrectinib, resulting in significant mass shrinkage with no adverse effects, demonstrating the treatment effect of targeted therapy. This case provides a reference for using larotrectinib in newborns with IFS
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