51 research outputs found

    Changes of predominant species/biovars and sequence types of Brucellaisolates, Inner Mongolia, China

    Get PDF
    BACKGROUND: Human brucellosis incidence in China was divided into 3 stages, high incidence (1950-1960s), decline (1970-1980s) and re-emergence (1990-2000s). Human brucellosis has been reported in all the 32 provinces, of which Inner Mongolia has the highest prevalence, accounting for over 40% of the cases in China. To investigate the etiology alteration of human brucellosis in Inner Mongolia, the species, biovars and genotypes of 60 Brucella isolates from this province were analyzed. METHODS: Species and biovars of the Brucella strains isolated from outbreaks were determined based on classical identification procedures. Strains were genotyped by multi locus sequence typing (MLST). Sequences of 9 housekeeping genes were obtained and sequence types were defined. The distribution of species, biovars and sequence types (STs) among the three incidence stages were analyzed and compared. RESULTS: The three stages of high incidence, decline and re-emergence were predominated by B. melitensis biovar 2 and 3, B. abortus biovar 3, and B. melitensis biovar 1, respectively, implying changes in the predominant biovars. Genotyping by MLST revealed a total of 14 STs. Nine STs (from ST28 to ST36), accounting for 64.3% of all the STs, were newly defined and different from those observed in other countries. Different STs were distributed among the three stages. ST8 was the most common ST in 1950-1960s and 1990-2000s, while ST2 was the most common in 1970-1980s. CONCLUSIONS: The prevalence of biovars and sequence types of Brucella strains from Inner Mongolia has changed over time in the three stages. Compared with those from other countries, new sequence types of Brucella strains exist in China

    Observation of Weyl fermions in a magnetic non-centrosymmetric crystal

    Full text link
    Characterized by the absence of inversion symmetry, non-centrosymmetric materials are of great interest because they exhibit ferroelectricity, second harmonic generation, emergent Weyl fermions, and other fascinating phenomena. It is expected that if time-reversal symmetry is also broken, additional magneto-electric effects can emerge from the interplay between magnetism and electronic order. Here we report topological conducting properties in the non-centrosymmetric magnet PrAlGe. By photoemission spectroscopy, we observe an arc parametrizing surface-localized states---a topological arc. Using the bulk-boundary correspondence, we conclude that these arcs correspond to projected topological charges of ±1\pm{1} in the surface Brillouin zone, demonstrating the presence of magnetic Weyl quasiparticles in bulk. We further observe a large anomalous Hall response, arising from diverging bulk Berry curvature fields associated with the magnetic Weyl band structure. Our results demonstrate a topological phase with robust electronic surface states and anomalous transport in a non-centrosymmetric magnet for the first time, providing a novel material platform to study the interplay between magnetic order, band topology and transport.Comment: To appear in Nature Communications (2020

    Comparative Proteomics Analyses Reveal the virB of B. melitensis Affects Expression of Intracellular Survival Related Proteins

    Get PDF
    BACKGROUND: Brucella melitensis is a facultative, intracellular, pathogenic bacterium that replicates within macrophages. The type IV secretion system encoded by the virB operon (virB) is involved in Brucella intracellular survival. However, the underlying molecular mechanisms, especially the target proteins affected by the virB, remain largely unclear. METHODOLOGY/PRINCIPAL FINDINGS: In order to define the proteins affected by virB, the proteomes of wild-type and the virB mutant were compared under in vitro conditions where virB was highly activated. The differentially expressed proteins were identified by MALDI-TOF-MS. Forty-four down-regulated and eighteen up-regulated proteins which exhibited a 2-fold or greater change were identified. These proteins included those involved in amino acid transport and metabolism, lipid metabolism, energy production, cell membrane biogenesis, translation, post-translational modifications and protein turnover, as well as unknown proteins. Interestingly, several important virulence related proteins involved in intracellular survival, including VjbR, DnaK, HtrA, Omp25, and GntR, were down-regulated in the virB mutant. Transcription analysis of virB and vjbR at different growth phase showed that virB positively affect transcription of vjbR in a growth phase dependent manner. Quantitative RT-PCR showed that transcription of these genes was also affected by virB during macrophage cell infection, consistent with the observed decreased survival of the virB mutant in macrophage. CONCLUSIONS/SIGNIFICANCE: These data indicated that the virB operon may control the intracellular survival of Brucella by affecting the expression of relevant proteins

    Ladies First, Gentlemen Third! The Effect of Narrative Perspective on Medical Crowdfunding

    No full text
    As medical crowdfunding becomes increasingly popular, many fundraising campaigns fail to collect enough donations for patients in need and therefore it is important to explore how to craft an effective fundraising campaign. In practice, a majority of fundraising campaigns are narrated from the third-person perspective without knowing whether narrating from the third-person perspective is the most effective approach or not. In this research, we draw upon multiple theories and propose that the relative effectiveness of the first- vs. third-person perspective depends on patient gender. To test the hypotheses, we conduct a randomized field experiment on a leading medical crowdfunding platform in China, involving more than 1.2 million potential donors. The empirical results show that the third-person perspective is more effective in motivating donation-related behaviors for male-patient fundraising campaigns, whereas the first-person perspective is more effective for female-patient fundraising campaigns. Furthermore, we find that the choice of the narrative perspectives matters more for potential donors who do not yet have many historical donations or have fewer friends with donations on the focal fundraising campaigns. The findings generate important theoretical and managerial implications for medical crowdfunding

    Loss of Hsp90 Association Up-Regulates Src-Dependent ErbB2 Activity

    No full text
    The receptor tyrosine kinase ErbB2 plays a crucial role in tumorigenesis. We showed previously that the molecular chaperone Hsp90 protects ErbB2 from proteasome-mediated degradation by binding to a short loop structure in the N-lobe of the kinase domain. Here we show that loss of Hsp90 binding correlates with enhanced ErbB2 kinase activity and its transactivating potential, concomitant with constitutively increased phosphorylation of Tyr877, located in the activation loop of the kinase domain. We show further that Tyr877 phosphorylation is mediated by Src and that it is necessary for the enhanced kinase activity of ErbB2. Finally, computer modeling of the kinase domain suggests a phosphorylation-dependent reorientation of the activation loop, denoting the importance of Tyr877 phosphorylation for ErbB2 activity. These findings suggest that Hsp90 binding to ErbB2 participates in regulation of kinase activity as well as kinase stability

    Macro-to-micro transformation model for micro-expression recognition

    No full text
    International audienceAs one of the most important forms of psychological behaviors, micro-expression can reveal the real emotion. However, the existing labeled training samples are limited to train a high performance model. To overcome this limit, in this paper we propose a macro-to-micro transformation model which enables to transfer macro-expression learning to micro-expression. Doing so improves the efficiency of the micro-expression features. For this purpose, LBP and LBP-TOP are used to extract macro-expression features and micro-expression features, respectively. Furthermore, feature selection is employed to reduce redundant features. Finally, singular value decomposition is employed to achieve macro-to-micro transformation model. The experimental evaluation based on the incorporated database including CK+ and CASME2 demonstrates that the proposed model achieves a competitive performance compared with the existing micro-expression recognition methods

    The Big-Fish-Little-Pond Effect on Academic Self-Concept: A Meta-Analysis

    No full text
    The Big-fish-little-Pond effect is well acknowledged as the negative effect of class/school average achievement on student academic self-concept, which profoundly impacts student academic performance and mental development. Although a few studies have been done with regard to this effect, inconsistence exists in the effect size with little success in finding moderators. Here, we present a meta-analysis to synthesize related literatures to reach a summary conclusion on the BFLPE. Furthermore, student age, comparison target, academic self-concept domain, student location, sample size, and publication year were examined as potential moderators. Thirty-three studies with fifty-six effect sizes (total N = 1,276,838) were finally included. The random effects model led to a mean of the BFLPE at β = −0.28 (p < 0.001). Moreover, moderator analyses revealed that the Big-Fish-Little-Pond effect is an age-based process and an intercultural phenomenon, which is stronger among high school students, in Asia and when verbal self-concept is considered. This meta-analysis is the first quantitative systematic overview of BFLPE, whose results are valuable to the understanding of BFLPE and reveal the necessity for educators from all countries to learn about operative means to help students avoid the potential negative effect. Future research expectations are offered subsequently

    Enrichment of Minor Alleles of Common SNPs and Improved Risk Prediction for Parkinson's Disease

    No full text
    <div><p>Parkinson disease (PD) is the second most common neurodegenerative disorder in the aged population and thought to involve many genetic loci. While a number of individual single nucleotide polymorphisms (SNPs) have been linked with PD, many remain to be found and no known markers or combinations of them have a useful predictive value for sporadic PD cases. The collective effects of genome wide minor alleles of common SNPs, or the minor allele content (MAC) in an individual, have recently been shown to be linked with quantitative variations of numerous complex traits in model organisms with higher MAC more likely linked with lower fitness. Here we found that PD cases had higher MAC than matched controls. A set of 37564 SNPs with MA (MAF < 0.4) more common in cases (P < 0.05) was found to have the best predictive accuracy. A weighted risk score calculated by using this set can predict 2% of PD cases (100% specificity), which is comparable to using familial PD genes to identify familial PD cases. These results suggest a novel genetic component in PD and provide a useful genetic method to identify a small fraction of PD cases.</p></div
    • …
    corecore