364 research outputs found

    Centrally endo-AIP Modules

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    In this paper, we introduce the concept of centrally endo-AIP modules. We call a module M centrally endo-AIP, if the left annihilator of any fully invariant submodule N of M in the endomorphism ring S = End(M) is a centrally s-unital ideal of S. We discuss some properties of centrally endo-AIP modules. We also study the endomorphism ring of centrally endo-AIP modules and characterize quasi-Baer modules in terms of centrally endo-AIP module

    Mincut Sensitivity Data Structures for the Insertion of an Edge

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    Fault Tolerant and Fully Dynamic DFS in Undirected Graphs: Simple Yet Efficient

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    We present an algorithm for a fault tolerant Depth First Search (DFS) Tree in an undirected graph. This algorithm is drastically simpler than the current state-of-the-art algorithms for this problem, uses optimal space and optimal preprocessing time, and still achieves better time complexity. This algorithm also leads to a better time complexity for maintaining a DFS tree in a fully dynamic environment

    Sectoral portfolio optimization by judicious selection of financial ratios via PCA

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    Embedding value investment in portfolio optimization models has always been a challenge. In this paper, we attempt to incorporate it by first employing principal component analysis (PCA) sector wise to filter out dominant financial ratios from each sector and thereafter, use the portfolio optimization model incorporating second order stochastic dominance (SSD) criteria to derive the final optimal investment. We consider a total of 11 well known financial ratios corresponding to each sector representing four categories of ratios, namely liquidity, solvency, profitability, and valuation. PCA is then applied sector wise over a period of 10 years from April 2004 to March 2014 to extract dominant ratios from each sector in two ways, one from the component solution and other from each category on the basis of their communalities. The two step Sectoral Portfolio Optimization (SPO) model integrating the SSD criteria in constraints is then utilized to build an optimal portfolio. The strategy formed using the former extracted ratios is termed as PCA-SPO(A) and the latter one as PCA-SPO(B). The results obtained from the proposed strategies are compared with the SPO model and two nominal SSD models, with and without financial ratios for computational study. Empirical performance of proposed strategies is assessed over the period of 6 years from April 2014 to March 2020 using a rolling window scheme with varying out-of-sample time line of 3, 6, 9, 12 and 24 months for S&P BSE 500 market. We observe that the proposed strategy PCA-SPO(B) outperforms all other models in terms of downside deviation, CVaR, VaR, Sortino ratio, Rachev ratio, and STARR ratios over almost all out-of-sample periods. This highlights the importance of value investment where ratios are carefully selected and embedded quantitatively in portfolio selection process.Comment: 26 pages, 12 table

    A study to evaluate pattern and purpose of smartphone usage and its dependence among medical students of government medical college in northern India

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    Background: Smartphone usage has become increasingly popular in recent decade. Though it’s of great utility in many aspects, excessive usage among youth has shown increased restlessness, careless lifestyles and greater susceptibility to stress. Aim & Objective: To assess the pattern and purpose of smartphone usage and its dependence among medical students. Methods & Material: A cross-sectional, descriptive study was conducted among 363 MBBS students of 1st, IInd and IIIrd professional year between October 2018 to December 2018 at a government medical college. A 20-item self-administrated questionnaire, focusing on purpose and pattern of use of smart phone and its dependence was filled by all the students. Data was collected, entered and analysed using SPSS Software. Result: Among 363 students, 53% participants were males and rest were females. 80% students were using smartphone for more than 2 years, while 60% were having daily usage of more than 3 hours. Significant association between severity of smartphone dependence and variables like MBBS professional year, daily phone call made and received, daily SMS received, daily WhatsApp message sent and received were observed. Dependence was mild in 8.8% of the students; Moderate in 72.2% while 19% were suffering from severe smartphone dependence. Conclusion: Smart phone dependence is an established and emerging psychological issue which needs attention and intervention. It is of serious concern that all medical students were suffering from smartphone dependence with varying grades of severity. Increased awareness regarding the harmful effects of smartphone addiction is the need of hour

    Long Non-Coding RNA Profile in Mantle Cell Lymphoma Identifies a Functional lncRNA ROR1-AS1 Associated With EZH2/PRC2 Complex.

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    Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma characterized by rapid disease progression. The needs for new therapeutic strategies for MCL patients call for further understanding on the molecular mechanisms of pathogenesis of MCL. Recently, long noncoding RNAs (lncRNAs) have been recognized as key regulators of gene expression and disease development, however, the role of lncRNAs in non-Hodgkin lymphoma and specifically in MCL is still unknown. Next generation RNA-sequencing was carried out on MCL patient samples along with normal controls and data was analyzed. As a result, several novel lncRNAs were found significantly overexpressed in the MCL samples with lncRNA ROR1-AS1 the most significant one. We cloned the ROR1-AS1 lncRNA in expression vector and ectopically transfected in MCL cell lines. Results showed that overexpression of ROR1-AS1 lncRNA promoted growth of MCL cells while decreased sensitivity to the treatment with drugs ibrutinib and dexamethasone. ROR-AS1 overexpression also decreased the mRNA expression of P16 (P = 0.21), and SOX11 (p = 0.017), without much effect on P53, ATM and P14 mRNA. RNA-immunoprecipitation assays demonstrated high affinity binding of lncRNA ROR1-AS1 with EZH2 and SUZ12 proteins of the polycomb repressive complex-2 (PRC2). Suppressing EZH2 activity with pharmacological inhibitor GSK343 abolished binding of ROR1-AS1 with EZH2. Taken together, this study identified a functional lncRNA ROR-AS1 involved with regulation of gene transcription via associating with PRC2 complex, and may serve as a novel biomarker in MCL patients

    An Experimental Comparison of Partitioning Strategies in Distributed Graph Processing

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    In this paper, we study the problem of choosing among partitioning strategies in distributed graph processing systems.To this end, we evaluate and characterize both the performance and resource usage of different partitioning strategies under various popular distributed graph processing systems, applications, input graphs, and execution environments. Through our experiments, we found that no single partitioning strategy is the best fit for all situations, and that the choice of partitioning strategy has a significant effect on resource usage and application run-time. Our experiments demonstrate that the choice of partitioning strategy depends on (1) the degree distribution of input graph, (2) the type and duration of the application, and (3) the cluster size. Based on our results, we present rules of thumb to help users pick the best partitioning strategy for their particular use cases. We present results from each system, as well as from all partitioning strategies implemented in one common system (PowerLyra).Ope
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