210 research outputs found

    Genotyping of Salmonella enterica serovar Typhi strains isolated from 1959 to 2006 in China and analysis of genetic diversity by genomic microarray

    Get PDF
    Aim To determine the genotype of Salmonella enterica serovar Typhi (S. Typhi) strains in China and analyze their genetic diversity. Methods We collected S. Typhi strains from 1959 to 2006 in five highly endemic Chinese provinces and chose 40 representative strains. Multilocus sequence typing was used to determine the genotypes or sequence types (ST) and microarray-based comparative genomic hybridization (M-CGH) to investigate the differences in gene content among these strains. Results Forty representative S. Typhi strains belonged to 4 sequence types (ST1, ST2, ST890, and ST892). The predominant S. Typhi genotype (31/40) was ST2 and it had a diverse geographic distribution. We discovered two novel STs – ST890 and ST892. M-CGH showed that 69 genes in these two novel STs were divergent from S. Typhi Ty2, which belongs to ST1. In addition, 5 representative Typhi strains of ST2 isolated from Guizhou province showed differences in divergent genes. Conclusion We determined two novel sequence types, ST890 and ST892, and found that ST2 was the most prevalent genotype of S. Typhi in China. Genetic diversity was present even within a highly clonal bacterial population

    Nonlinear Jordan triple derivable mapping on ∗-type trivial extension algebras

    Get PDF
    The aim of the paper was to give a description of nonlinear Jordan triple derivable mappings on trivial extension algebras. We proved that every nonlinear Jordan triple derivable mapping on a 2 2 -torsion free * -type trivial extension algebra is a sum of an additive derivation and an additive antiderivation. As an application, nonlinear Jordan triple derivable mappings on triangular algebras were characterized

    A Multiobjective Programming Method for Ranking All Units Based on Compensatory DEA Model

    Get PDF
    In order to rank all decision making units (DMUs) on the same basis, this paper proposes a multiobjective programming (MOP) model based on a compensatory data envelopment analysis (DEA) model to derive a common set of weights that can be used for the full ranking of all DMUs. We first revisit a compensatory DEA model for ranking all units, point out the existing problem for solving the model, and present an improved algorithm for which an approximate global optimal solution of the model can be obtained by solving a sequence of linear programming. Then, we applied the key idea of the compensatory DEA model to develop the MOP model in which the objectives are to simultaneously maximize all common weights under constraints that the sum of efficiency values of all DMUs is equal to unity and the sum of all common weights is also equal to unity. In order to solve the MOP model, we transform it into a single objective programming (SOP) model using a fuzzy programming method and solve the SOP model using the proposed approximation algorithm. To illustrate the ranking method using the proposed method, two numerical examples are solved

    Mitigation of diffuse water pollution from agriculture in England and China, and the scope for policy transfer

    Get PDF
    • To mitigate diffuse water pollution from agriculture (DWPA) in China, the right mix of complementary policy approaches is needed. • The public agricultural extension service is relatively well resourced and is the primary means available to mitigate DWPA. The extension service needs re-orientation and re-skilling to help farmers maintain and increase agricultural productivity whilst balancing this with environmental protection. A new ethos of input use efficiency and environmental stewardship of natural resources is needed, based on 2-way knowledge exchange with farmers. Four policies to achieve this are: 1. A ‘reference level’ of enforceable regulation for all large commercial farms is needed. This can be transposed from existing laws with appropriate variation by farming system and region. Intensive livestock units have the greatest potential to cause significant pollution and take first priority. Resources for monitoring and enforcement of regulation are limited, but as land transfer and farm consolidation continue in accord with local needs, regulations for use of manure and chemical fertiliser in arable systems can be developed for large farms. 2. For small farms monitoring and enforcement of regulations is difficult. Simple, locally well-adapted guidelines are needed. Adoption by farmers must be achieved through an accredited advisory and voluntary approach developed by the public agricultural extension service and its wider agricultural knowledge and innovation systems partners. 3. Targeted incentive payment schemes should be used strategically to protect water resources from DWPA in key locations. For example, payments for retirement, or low intensity use, of vulnerable land adjacent to watercourses or in aquifer recharge zones used for water supply. 4. To support these approaches more applied research is needed to build an accessible and comprehensive knowledgebase. This should span, for example, from methods for public participation, through design of regulation and incentive payments, to design and costing of farm best management practices and estimation of modelling coefficients empirically derived for conditions in China. • None of these approaches are completely absent from China and attempts at international policy transfer or ‘lesson-drawing’ must consider what can be better developed rather than what could commence. Innovation in farmer participation, advice provision, design of incentive schemes, data sharing and applied research are leading examples

    Identification and characterization of class 1 integrons among Pseudomonas aeruginosa isolates from patients in Zhenjiang, China

    Get PDF
    SummaryObjectivesThe role of integrons in the spread of antibiotic resistance has been well established. The aim of this study was to investigate the resistance profiles of Pseudomonas aeruginosa isolated from patients in Zhenjiang to 13 antibiotics, and to identify the structure and dissemination of class 1 integrons.MethodsThe Kirby–Bauer disk diffusion assay was used to determine the rate of P. aeruginosa resistance. Class 1 integrons from multidrug-resistant isolates were amplified by PCR, and their PCR products were sequenced. We also analyzed the integron structures containing the same gene cassettes by restriction fragment length polymorphism (RFLP). Isolates were genotyped by pulsed-field gel electrophoresis (PFGE).ResultsThe resistance rates were between 29.6% and 90.1%. The prevalence of class 1 integrons was 38.0%. These integrons included five gene cassettes (aadB, aac6-II, blaPSE-1, dfrA17, and aadA5). The dfrA17 and aadA5 gene cassettes were found most often.ConclusionsClass 1 integrons were found to be widespread in P. aeruginosa isolated from clinical samples in the Zhenjiang area of China. The antibiotic resistance rates in class 1 integron-positive strains of P. aeruginosa were noticeably higher than those in class 1 integron-negative strains. PFGE showed that particular clones were circulating among patients

    Clinical features and risk factors of sepsis-induced cardiomyopathy in children with sepsis

    Get PDF
    Objective To investigate the clinical features and risk factors of sepsis-induced cardiomyopathy in children with sepsis, aiming to provide reference for enhancing the diagnosis and treatment levels of clinicians. Methods Clinical data of children with sepsis were retrospectively analyzed. All patients were divided into the sepsis-induced cardiomyopathy group and non-sepsis-induced cardiomyopathy group according to whether sepsis-induced cardiomyopathy occurred.Clinical characteristics and outcomes were compared between two groups. The risk factors of sepsis-induced cardiomyopathy were analyzed. Results Three hundred and ninty-eight children with sepsis were included in this study, and the incidence of sepsis-induced cardiomyopathy was 15.58%(62/398). The age of children in the sepsis-induced cardiomyopathy group was 49 (18, 108) months, older than 19 (6, 52) months in the non-sepsis-induced cardiomyopathy group. The incidence of septic shock in the sepsis-induced cardiomyopathy group was 83.87%(52/62), which was higher than 42.56% (143/336) in the non-sepsis-induced cardiomyopathy group. The mortality rate in the sepsis-induced cardiomyopathy group was 29.03% (18/62), significantly higher than 14.58% (49/336) in the non-sepsis-induced cardiomyopathy group. All differences were statistically significant (all P < 0.05).Multivariate Logistic regression analysis showed that the influence of age on sepsis-induced cardiomyopathy was statistically significant (OR=1.010, 95%CI 1.003-1.017, P = 0.006). The higher the lactic acid level, the higher the risk of sepsis-induced cardiomyopathy, with statistical significance (OR=1.163, 95%CI 1.034-1.308, P = 0.012). The higher the cTnI level, the higher the risk of sepsis-induced cardiomyopathy, with statistical significance (OR=9.929, 95%CI 4.651-21.197, P < 0.001). Conclusions Compared with children with non-sepsis-induced cardiomyopathy, children with sepsis-induced cardiomyopathy are more prone to septic shock and have higher mortality. Age, lactic acid and cTnI levels are the independent influencing factors for sepsis-induced cardiomyopathy in children

    Fertilization drives distinct biotic and abiotic factors in regulating functional groups of protists in a 5-year fertilization system

    Get PDF
    IntroductionProtists play an important role in nutrient cycling, microbiome stability and soil fertility maintenance. However, the driving force of protistan functional groups remains poorly understood in agricultural ecosystems.MethodsWe investigated the impacts of fertilization regimes on the diversity, composition and functional groups of protists and further disentangled the effects of multiple factors shaping the community composition of functional groups in a 5-year fertilization regime (CK, no fertilization; M, organic fertilization; MNPK, combined inorganic and organic fertilization; NPK, inorganic fertilization).ResultsFertilization significantly changed the community composition of protists rather than diversity. The MNPK treatment significantly increased the relative abundance of phototrophs and decreased that of the parasites and consumers. Partial least squares path modeling indicated that fertilization indirectly regulated protistan consumers via changes in the P content, which affected the composition of consumers mainly by regulating fungal community composition. Soil moisture (SM) and available phosphorus (AP) were identified as the top predictors for the composition of parasites, and the composition of phototrophs was mainly affected by SM, indicating that parasites and phototrophs were more sensitive to abiotic factors in the fertilization system.DiscussionTaken together, our findings highlight that fertilization significantly affects the composition of functional groups of protists and their biotic or abiotic regulatory processes, which have implications for the potential changes in their ecosystem functions for soil management systems

    Fecal Metabolomics and Potential Biomarkers for Systemic Lupus Erythematosus

    Get PDF
    The role of metabolomics in autoimmune diseases has been a rapidly expanding area in researches over the last decade, while its pathophysiologic impact on systemic lupus erythematosus (SLE) remains poorly elucidated. In this study, we analyzed the metabolic profiling of fecal samples from SLE patients and healthy controls based on ultra-high-performance liquid chromatography equipped with mass spectrometry for exploring the potential biomarkers of SLE. The results showed that 23 differential metabolites and 5 perturbed pathways were identified between the two groups, including aminoacyl-tRNA biosynthesis, thiamine metabolism, nitrogen metabolism, tryptophan metabolism, and cyanoamino acid metabolism. In addition, logistic regression and ROC analysis were used to establish a diagnostic model for distinguishing SLE patients from healthy controls. The combined model of fecal PG 27:2 and proline achieved an area under the ROC curve of 0.846, and had a good diagnostic efficacy. In the present study, we analyzed the correlations between fecal metabolic perturbations and SLE pathogenesis. In summary, we firstly illustrate the comprehensive metabolic profiles of feces in SLE patients, suggesting that the fecal metabolites could be used as the potential non-invasive biomarkers for SLE
    corecore