713 research outputs found

    Genetic Characterization of Zika Virus Strains: Geographic Expansion of the Asian Lineage

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    Zika virus (ZIKV) is a mosquito-transmitted flavivirus found in both Africa and Asia. Human infection with the virus may result in a febrile illness similar to dengue fever and many other tropical infections found in these regions. Previously, little was known about the genetic relationships between ZIKV strains collected in Africa and those collected in Asia. In addition, the geographic origins of the strains responsible for the recent outbreak of human disease on Yap Island, Federated States of Micronesia, and a human case of ZIKV infection in Cambodia were unknown. Our results indicate that there are two geographically distinct lineages of ZIKV (African and Asian). The virus has circulated in Southeast Asia for at least the past 50 years, whereupon it was introduced to Yap Island resulting in an epidemic of human disease in 2007, and in 2010 was the cause of a pediatric case of ZIKV infection in Cambodia. This study also highlights the danger of ZIKV introduction into new areas and the potential for future epidemics of human disease

    Prevalence of carbapenem resistance and its potential association with antimicrobial use in humans and animals in rural communities in Vietnam

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    Background Vietnam and Southeast Asia are hotspots for antimicrobial resistance; however, little is known on the prevalence of carriage of carbapenem resistance in non-hospitalized humans and in animals. Carbapenem-resistant Enterobacteriaceae (CRE), particularly Escherichia coli (CREC) and Klebsiella pneumoniae (CRKP) and also Acinetobacter baumannii (CRAB) are emerging threats worldwide. Methods We investigated healthy humans (n = 652), chickens (n = 237), ducks (n = 150) and pigs (n = 143) in 400 small-scale farms in the Mekong Delta of Vietnam. Samples (rectal swabs, faecal swabs) were investigated for carriage of CRE/CRAB and were further characterized phenotypically and genotypically. Results In the Mekong Delta of Vietnam, the prevalence of CRE isolates in human rectal swabs was 0.6%, including 4 CREC and 1 CRKP. One pig was infected with CREC (prevalence 0.7%). CRAB was isolated from chickens (n = 4) (prevalence 2.1%) and one duck (prevalence 0.7%). CRKP was isolated from a human who was also colonized with CREC. The CRKP strain (ST16), from an 80 year-old person with pneumonia under antimicrobial treatment, genetically clustered with clinical strains isolated in a hospital outbreak in southern Vietnam. The prevalence of CRE was higher among humans that had used antimicrobials within 90 days of the sampling date than those had not (4.2% versus 0.2%) (P = 0.005). All CRE/CRAB strains were MDR, although they were susceptible to colistin and neomycin. The carbapenemase genes identified in study strains were blaNDM and blaOXA. Conclusions The finding of a CRKP strain clustering with previous hospital outbreak raises concerns about potential transmission of carbapenem-resistant organisms from hospital to community settings or vice-versa

    Pregnancy weight gain and breast cancer risk

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    BACKGROUND: Elevated pregnancy estrogen levels are associated with increased risk of developing breast cancer in mothers. We studied whether pregnancy weight gain that has been linked to high circulating estrogen levels, affects a mother's breast cancer risk. METHODS: Our cohort consisted of women who were pregnant between 1954–1963 in Helsinki, Finland, 2,089 of which were eligible for the study. Pregnancy data were collected from patient records of maternity centers. 123 subsequent breast cancer cases were identified through a record linkage to the Finnish Cancer Registry, and the mean age at diagnosis was 56 years (range 35 – 74). A sample of 979 women (123 cases, 856 controls) from the cohort was linked to the Hospital Inpatient Registry to obtain information on the women's stay in hospitals. RESULTS: Mothers in the upper tertile of pregnancy weight gain (>15 kg) had a 1.62-fold (95% CI 1.03–2.53) higher breast cancer risk than mothers who gained the recommended amount (the middle tertile, mean: 12.9 kg, range 11–15 kg), after adjusting for mother's age at menarche, age at first birth, age at index pregnancy, parity at the index birth, and body mass index (BMI) before the index pregnancy. In a separate nested case-control study (n = 65 cases and 431 controls), adjustment for BMI at the time of breast cancer diagnosis did not modify the findings. CONCLUSIONS: Our study suggests that high pregnancy weight gain increases later breast cancer risk, independently from body weight at the time of diagnosis

    Election proximity and representation focus in party-constrained environments

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    Do elected representatives have a time-constant representation focus or do they adapt their focus depending on election proximity? In this article, we examine these overlooked theoretical and empirical puzzles by looking at how reelection-seeking actors adapt their legislative behavior according to the electoral cycle. In parliamentary democracies, representatives need to serve two competing principals: their party and their district. Our analysis hinges on how representatives make a strategic use of parliamentary written questions in a highly party-constrained institutional context to heighten their reselection and reelection prospects. Using an original data set of over 32,000 parliamentary questions tabled by Portuguese representatives from 2005 to 2015, we examine how time interacts with two key explanatory elements: electoral vulnerability and party size. Results show that representation focus is not static over time and, in addition, that electoral vulnerability and party size shape strategic use of parliamentary questions

    In Vivo Analysis of MEF2 Transcription Factors in Synapse Regulation and Neuronal Survival

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    MEF2 (A–D) transcription factors govern development, differentiation and maintenance of various cell types including neurons. The role of MEF2 isoforms in the brain has been studied using in vitro manipulations with only MEF2C examined in vivo. In order to understand specific as well as redundant roles of the MEF2 isoforms, we generated brain-specific deletion of MEF2A and found that Mef2aKO mice show normal behavior in a range of paradigms including learning and memory. We next generated Mef2a and Mef2d brain-specific double KO (Mef2a/dDKO) mice and observed deficits in motor coordination and enhanced hippocampal short-term synaptic plasticity, however there were no alterations in learning and memory, Schaffer collateral pathway long-term potentiation, or the number of dendritic spines. Since previous work has established a critical role for MEF2C in hippocampal plasticity, we generated a Mef2a, Mef2c and Mef2d brain-specific triple KO (Mef2a/c/dTKO). Mef2a/c/d TKO mice have early postnatal lethality with increased neuronal apoptosis, indicative of a redundant role for the MEF2 factors in neuronal survival. We examined synaptic plasticity in the intact neurons in the Mef2a/c/d TKO mice and found significant impairments in short-term synaptic plasticity suggesting that MEF2C is the major isoform involved in hippocampal synaptic function. Collectively, these data highlight the key in vivo role of MEF2C isoform in the brain and suggest that MEF2A and MEF2D have only subtle roles in regulating hippocampal synaptic function

    Azimuthal anisotropy and correlations at large transverse momenta in p+pp+p and Au+Au collisions at sNN\sqrt{s_{_{NN}}}= 200 GeV

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    Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au+Au collisions at sNN\sqrt{s_{_{NN}}}= 200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au+Au collisions to those in p+pp+p at the same energy. Elliptic anisotropy, v2v_2, is found to reach its maximum at pt3p_t \sim 3 GeV/c, then decrease slowly and remain significant up to pt7p_t\approx 7 -- 10 GeV/c. Stronger suppression is found in the back-to-back high-ptp_t particle correlations for particles emitted out-of-plane compared to those emitted in-plane. The centrality dependence of v2v_2 at intermediate ptp_t is compared to simple models based on jet quenching.Comment: 4 figures. Published version as PRL 93, 252301 (2004

    Azimuthal anisotropy in Au+Au collisions at sqrtsNN = 200 GeV

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    The results from the STAR Collaboration on directed flow (v_1), elliptic flow (v_2), and the fourth harmonic (v_4) in the anisotropic azimuthal distribution of particles from Au+Au collisions at sqrtsNN = 200 GeV are summarized and compared with results from other experiments and theoretical models. Results for identified particles are presented and fit with a Blast Wave model. Different anisotropic flow analysis methods are compared and nonflow effects are extracted from the data. For v_2, scaling with the number of constituent quarks and parton coalescence is discussed. For v_4, scaling with v_2^2 and quark coalescence is discussed.Comment: 26 pages. As accepted by Phys. Rev. C. Text rearranged, figures modified, but data the same. However, in Fig. 35 the hydro calculations are corrected in this version. The data tables are available at http://www.star.bnl.gov/central/publications/ by searching for "flow" and then this pape

    Curcumin-induced HDAC inhibition and attenuation of medulloblastoma growth in vitro and in vivo

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    <p>Abstract</p> <p>Background</p> <p>Medulloblastoma is the most common brain tumor in children, and its prognosis is worse than for many other common pediatric cancers. Survivors undergoing treatment suffer from serious therapy-related side effects. Thus, it is imperative to identify safer, effective treatments for medulloblastoma. In this study we evaluated the anti-cancer potential of curcumin in medulloblastoma by testing its ability to induce apoptosis and inhibit tumor growth <it>in vitro </it>and <it>in vivo </it>using established medulloblastoma models.</p> <p>Methods</p> <p>Using cultured medulloblastoma cells, tumor xenografts, and the Smo/Smo transgenic medulloblastoma mouse model, the antitumor effects of curcumin were tested <it>in vitro </it>and <it>in vivo</it>.</p> <p>Results</p> <p>Curcumin induced apoptosis and cell cycle arrest at the G2/M phase in medulloblastoma cells. These effects were accompanied by reduced histone deacetylase (HDAC) 4 expression and activity and increased tubulin acetylation, ultimately leading to mitotic catastrophe. In <it>in vivo </it>medulloblastoma xenografts, curcumin reduced tumor growth and significantly increased survival in the Smo/Smo transgenic medulloblastoma mouse model.</p> <p>Conclusions</p> <p>The <it>in vitro </it>and <it>in vivo </it>data suggest that curcumin has the potential to be developed as a therapeutic agent for medulloblastoma.</p

    Rapidity and Centrality Dependence of Proton and Anti-proton Production from Au+Au Collisions at sqrt(sNN) = 130GeV

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    We report on the rapidity and centrality dependence of proton and anti-proton transverse mass distributions from Au+Au collisions at sqrt(sNN) = 130GeV as measured by the STAR experiment at RHIC. Our results are from the rapidity and transverse momentum range of |y|<0.5 and 0.35 <p_t<1.00GeV/c. For both protons and anti-protons, transverse mass distributions become more convex from peripheral to central collisions demonstrating characteristics of collective expansion. The measured rapidity distributions and the mean transverse momenta versus rapidity are flat within |y|<0.5. Comparisons of our data with results from model calculations indicate that in order to obtain a consistent picture of the proton(anti-proton) yields and transverse mass distributions the possibility of pre-hadronic collective expansion may have to be taken into account.Comment: 4 pages, 3 figures, 1 table, submitted to PR

    Mesoporous monoliths of inverse bicontinuous cubic phases of block copolymer bilayers

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    Solution self-assembly of block copolymers into inverse bicontinuous cubic mesophases is a promising new approach for creating porous polymer films and monoliths with highly organized bicontinuous mesoporous networks. Here we report the direct self-assembly of block copolymers with branched hydrophilic blocks into large monoliths consisting of the inverse bicontinuous cubic structures of the block copolymer bilayer. We suggest a facile and scalable method of solution self-assembly by diffusion of water to the block copolymer solution, which results in the unperturbed formation of mesoporous monoliths with large-pore (&gt;25nm diameter) networks weaved in crystalline lattices. The surface functional groups of the internal large-pore networks are freely accessible for large guest molecules such as protein complexes of which the molecular weight exceeded 100kDa. The internal double-diamond (Pn3m) networks of large pores within the mesoporous monoliths could be replicated to self-supporting three-dimensional skeletal structures of crystalline titania and mesoporous silica.open2
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