215 research outputs found

    Classification of ideal submanifolds of real space forms with type number 2\leq 2

    Full text link
    Roughly speaking, an ideal immersion of a Riemannian manifold into a real space form is an isometric immersion which produces the least possible amount of tension from the ambient space at each point of the submanifold. The main purpose of this paper is to completely classify all non-minimal ideal submanifolds of real space forms with type number 2\leq 2.Comment: 19 page

    Effects of terracing on soil water and canopy transpiration of Pinus tabulaeformis in the Loess Plateau of China

    Get PDF
    Terracing has long been considered one of the most effective measures for soil water conservation and site improvement. However, few studies regarding the quantitative effects of terracing on soil water dynamics and vegetation water use efficiency were reported. To fill these knowledge gaps, in this study, soil water content and canopy transpiration from 2014 to 2015 were monitored in both terrace and slope environments in the semiarid Loess Plateau of China. Results showed that terracing had positive influences on soil water content among layers. Mean soil water content of the terrace site was 25.4% and 13.7% higher than that in the slope site in 2014 and 2015, and canopy transpiration at the terrace site increased by 9.1% and 4.8%, respectively. Canopy conductance at the terrace site was 3.9% higher than that at the slope site and it decreased logarithmically with the increase of vapor pressure deficit. This study highlighted the critical role of terracing in soil-water improvement and water-stress mitigation in semiarid environments. Thus, terracing has the potential to enhance sustainable vegetation restoration in water-limited regions

    Strongly Clean Matrices Over Power Series

    Get PDF
    WOS: 000406980000008An n x n matrix A over a commutative ring is strongly clean provided that it can be written as the sum of an idempotent matrix and an invertible matrix that commute. Let R be an arbitrary commutative ring, and let A(x) is an element of M-n (R[[x]]). We prove, in this note, that A(x) is an element of M-n (R[[x]]) is strongly clean if and only if A(0) is an element of M-n (R) is strongly clean. Strongly clean matrices over quotient rings of power series are also determined

    On Medium *-Clean Rings

    Get PDF
    WOS: 000454919400015A *-ring R is called a medium *-clean ring if every element in R is the sum or difference of an element in its Jacobson radical and a projection that commute. We prove that a ring R is medium *-clean if and only if R is strongly *-clean and R/J(R) is a Boolean ring, Z3 or the product of such rings, if and only if R weakly J-*-clean and a2R is uniquely *-clean for all aR, if and only if every idempotent lifts modulo J(R), R is abelian and R/J(R) weakly *-Boolean. A subclass of medium *-clean rings with many nilpotents is thereby characterized.Natural Science Foundation of Zhejiang Province, ChinaNatural Science Foundation of Zhejiang Province [LY17A010018]The authors would like to thank the referee for his/her careful reading and valuable remarks that improved the presentation of our work. H. Chen was supported by the Natural Science Foundation of Zhejiang Province, China (no. LY17A010018)

    The P-Drazin İnverse for Operator Matrix Over Banach Algebras

    Get PDF
    An element a in a Banach algebra A has p-Drazin inverse provided that there exists b2 comm(a) such that b = b2a, ak ↋ ak+1b 2 J(A) for some k 2 N. In this paper, we present new conditions for a block operator matrix to have p-Drazin inverse. As applications, we prove the p-Drazin invertibility of the block operator matrix under certain spectral conditions. © 2020, University of Nis. All rights reserved

    Drug use and HIV infection status of detainees in re-education through labour camps in Guangxi Province, China

    Get PDF
    This study describes HIV disease burden and patterns of drug use before and during incarceration among detainees in Re-education-Through-Labour-Camps (RTLCs) in China. A cross-sectional survey of 576 men and 179 women from three RTLCs was conducted in Guangxi Province, China. Over three-quarters of study participants were detained due to drug-related offences. Over half of the women (n = 313, 54.3%) and twothirds of men (n = 119, 66.5%) had been previously been incarcerated in a compulsory detoxification treatment centre (CDTC), and around one-third (men n = 159, 27.6%; women n = 50, 27.9%) in a RTLC. Of those surveyed, 49 men (8.5%) and one (0.6%) woman reported ever using drugs while in a CDTC and/or RTLC. Previous incarceration in CDTCs and RTLCs were associated with HIV infection among both male (OR = 2.15 [1.11–4.15]) and female (OR = 3.87 [1.86–9.04]) detainees. Being married/cohabiting with a partner (OR = 0.53, [0.30–0.93]) and being employed (OR = 0.46, [0.22–0.95]) were associated with a reduced odds of HIV infection among male detainees. A significant proportion of RTLC detainees had a history of drug use and a limited number of inmates had used illegal substances whilst in custody. Repeat incarcerations in CDTCs/RTLCs were associated with higher risks of HIV infection

    Effects of Melanocortin 3 and 4 Receptor Deficiency on Energy Homeostasis in Rats

    Get PDF
    Melanocortin-3 and 4 receptors (MC3R and MC4R) can regulate energy homeostasis, but their respective roles especially the functions of MC3R need more exploration. Here Mc3r and Mc4r single and double knockout (DKO) rats were generated using CRISPR-Cas9 system. Metabolic phenotypes were examined and data were compared systematically. Mc3r KO rats displayed hypophagia and decreased body weight, while Mc4r KO and DKO exhibited hyperphagia and increased body weight. All three mutants showed increased white adipose tissue mass and adipocyte size. Interestingly, although Mc3r KO did not show a significant elevation in lipids as seen in Mc4r KO, DKO displayed even higher lipid levels than Mc4r KO. DKO also showed more severe glucose intolerance and hyperglycaemia than Mc4r KO. These data demonstrated MC3R deficiency caused a reduction of food intake and body weight, whereas at the same time exhibited additive effects on top of MC4R deficiency on lipid and glucose metabolism. This is the first phenotypic analysis and systematic comparison of Mc3r KO, Mc4r KO and DKO rats on a homogenous genetic background. These mutant rats will be important in defining the complicated signalling pathways of MC3R and MC4R. Both Mc4r KO and DKO are good models for obesity and diabetes research

    Psychological distress among re-education through labour camp detainees in Guangxi Autonomous Region, China

    Full text link
    There is currently no information about the prevalence of, and factors contributing to psychological distress experienced by re-education through labour camp detainees in China. [Methods:] A cross-sectional face-to-face survey was conducted in three labour camps in Guangxi, China. The questionnaire covered socio-demographic characteristics; sexually transmissible infections (STIs); drug use; psychological distress (K-10); and health service usage and access inside the labour camps. K-10 scores were categorised as ≤30 (low to moderate distress) and  >30 or more (highly distressed). Univariate and multivariate logistic regression models identified factors independently associated with high K-10 scores for men and women separately. [Results:] In total, 755 detainees, 576 (76%) men and 179 (24%) women, participated in the health survey. The study found 11.6% men versus 11.2% women detainees experienced high psychological distress, but no significant gender differences were observed (p> 0.05). Multivariate logistic regression showed that multiple physical health problems were significantly associated with high psychological distress among men. [Conclusion:] Drug treatment and forensic mental health services need to be established in detention centres in China to treat more than 10% of detainees with drug use and mental health disorders

    Identifying immune cell infiltration and effective diagnostic biomarkers in Crohn’s disease by bioinformatics analysis

    Get PDF
    BackgroundCrohn’s disease (CD) has an increasing incidence and prevalence worldwide. It is currently believed that both the onset and progression of the disease are closely related to immune system imbalance and the infiltration of immune cells. The aim of this study was to investigate the molecular immune mechanisms associated with CD and its fibrosis through bioinformatics analysis.MethodsThree datasets from the Gene Expression Omnibus data base (GEO) were downloaded for data analysis and validation. Single sample gene enrichment analysis (ssGSEA) was used to evaluate the infiltration of immune cells in CD samples. Immune cell types with significant differences were identified by Wilcoxon test and Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis. Differentially expressed genes (DEGs) were screened and then subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional correlation analysis, as well as protein-protein interaction (PPI) network analysis. The cytoHubba program and the GSE75214 dataset were used to screen for hub genes and plot Receiver operating characteristic (ROC)curves to screen for possible biomarkers of CD based on diagnostic efficacy. The hub genes of CD were correlated with five significantly different immune cells. In addition, validation was performed by real time quantitative PCR (RT-qPCR) experiments in colonic tissue of CD intestinal fibrosis rats to further identify hub genes that are more related to CD intestinal fibrosis.ResultsThe DEGs were analyzed separately by 10 algorithms and narrowed down to 9 DEGs after taking the intersection. 4 hub genes were further screened by the GSE75214 validation set, namely COL1A1, CXCL10, MMP2 and FGF2. COL1A1 has the highest specificity and sensitivity for the diagnosis of CD and is considered to have the potential to diagnose CD. Five immune cells with significant differences were screened between CD and health controls (HC). Through the correlation analysis between five kinds of immune cells and four biomarkers, it was found that CXCL10 was positively correlated with activated dendritic cells, effector memory CD8+ T cells. MMP2 was positively correlated with activated dendritic cells, gamma delta T cells (γδ T) and mast cells. MMP2 and COL1A1 were significantly increased in colon tissue of CD fibrosis rats.ConclusionMMP2, COL1A1, CXCL10 and FGF2 can be used as hub genes for CD. Among them, COL1A1 can be used as a biomarker for the diagnosis of CD. MMP2 and CXCL10 may be involved in the development and progression of CD by regulating activated dendritic cell, effector memory CD8+ T cell, γδ T cell and mast cell. In addition, MMP2 and COL1A1 may be more closely related to CD intestinal fibrosis
    corecore