1,005 research outputs found

    Anaerobic Oxidation of Short-Chain Alkanes in Hydrothermal Sediments: Potential Influences on Sulfur Cycling and Microbial Diversity

    Get PDF
    Short-chain alkanes play a substantial role in carbon and sulfur cycling at hydrocarbon-rich environments globally, yet few studies have examined the metabolism of ethane (C2)(C_2), propane (C3)(C_3), and butane (C4)(C_4) in anoxic sediments in contrast to methane (C1)(C_1). In hydrothermal vent systems, short-chain alkanes are formed over relatively short geological time scales via thermogenic processes and often exist at high concentrations. The sediment-covered hydrothermal vent systems at Middle Valley (MV, Juan de Fuca Ridge) are an ideal site for investigating the anaerobic oxidation of C1–C4C_1–C_4 alkanes, given the elevated temperatures and dissolved hydrocarbon species characteristic of these metalliferous sediments. We examined whether MV microbial communities oxidized C1–C4C_1–C_4 alkanes under mesophilic to thermophilic sulfate-reducing conditions. Here we present data from discrete temperature (25, 55, and 75∘C75^{\circ}C) anaerobic batch reactor incubations of MV sediments supplemented with individual alkanes. Co-registered alkane consumption and sulfate reduction (SR) measurements provide clear evidence for C1–C4C_1–C_4 alkane oxidation linked to SR over time and across temperatures. In these anaerobic batch reactor sediments, 16S ribosomal RNA pyrosequencing revealed that Deltaproteobacteria, particularly a novel sulfate-reducing lineage, were the likely phylotypes mediating the oxidation of C2–C4C_2–C_4 alkanes. Maximum C1–C4C_1–C_4 alkane oxidation rates occurred at 55∘C55^{\circ}C, which reflects the mid-core sediment temperature profile and corroborates previous studies of rate maxima for the anaerobic oxidation of methane (AOM). Of the alkanes investigated, C3C_3 was oxidized at the highest rate over time, then C4C_4, C2C_2, and C1C_1, respectively. The implications of these results are discussed with respect to the potential competition between the anaerobic oxidation of C2–C4C_2–C_4 alkanes with AOM for available oxidants and the influence on the fate of C1C_1 derived from these hydrothermal systems.Molecular and Cellular BiologyOrganismic and Evolutionary Biolog

    Avoimen systeemin magmaattisten prosessien diagnosointi Magmakammiosimulaattorilla. Osa I: pääalkuaineet ja faasitasapainot

    Get PDF
    The Magma Chamber Simulator (MCS) is a thermodynamic tool for modeling the evolution of magmatic systems that are open with respect to assimilation of partial melts or stoped blocks, magma recharge + mixing, and fractional crystallization. MCS is available for both PC and Mac. In the MCS, the thermal, mass, and compositional evolution of a multicomponent-multiphase composite system of resident magma, wallrock, and recharge reservoirs is tracked by rigorous self-consistent thermodynamic modeling. A Recharge-Assimilation (Assimilated partial melt or Stoped blocks)-Fractional Crystallization (R(n)AS(n)FC;n(tot) The trace element and isotope MCS computational tool (MCS-Traces) is described in a separate contribution (part II).Peer reviewe

    Report of the AACP Task Force on Patient-Centered Medical Homes and Accountable Care Organizations

    Get PDF
    A task force was convened by the American Association of Colleges of Pharmacy (AACP) to provide rationale for academic pharmacy engagement with organizations/institutions providing new models of team-based patient care designed to improve patient access, care quality, and affordable care. Descriptions of new care models, such as patient centered medical homes (PCMHs) and accountable care organizations (ACO), were included as well as descriptions of existing partnerships with academic pharmacy

    Systematic assessment of long-read RNA-seq methods for transcript identification and quantification

    Get PDF
    The Long-read RNA-Seq Genome Annotation Assessment Project (LRGASP) Consortium was formed to evaluate the effectiveness of long-read approaches for transcriptome analysis. The consortium generated over 427 million long-read sequences from cDNA and direct RNA datasets, encompassing human, mouse, and manatee species, using different protocols and sequencing platforms. These data were utilized by developers to address challenges in transcript isoform detection and quantification, as well as de novo transcript isoform identification. The study revealed that libraries with longer, more accurate sequences produce more accurate transcripts than those with increased read depth, whereas greater read depth improved quantification accuracy. In well-annotated genomes, tools based on reference sequences demonstrated the best performance. When aiming to detect rare and novel transcripts or when using reference-free approaches, incorporating additional orthogonal data and replicate samples are advised. This collaborative study offers a benchmark for current practices and provides direction for future method development in transcriptome analysis

    Genomics of perivascular space burden unravels early mechanisms of cerebral small vessel disease

    Get PDF
    Perivascular space (PVS) burden is an emerging, poorly understood, magnetic resonance imaging marker of cerebral small vessel disease, a leading cause of stroke and dementia. Genome-wide association studies in up to 40,095 participants (18 population-based cohorts, 66.3 ± 8.6 yr, 96.9% European ancestry) revealed 24 genome-wide significant PVS risk loci, mainly in the white matter. These were associated with white matter PVS already in young adults (N = 1,748; 22.1 ± 2.3 yr) and were enriched in early-onset leukodystrophy genes and genes expressed in fetal brain endothelial cells, suggesting early-life mechanisms. In total, 53% of white matter PVS risk loci showed nominally significant associations (27% after multiple-testing correction) in a Japanese population-based cohort (N = 2,862; 68.3 ± 5.3 yr). Mendelian randomization supported causal associations of high blood pressure with basal ganglia and hippocampal PVS, and of basal ganglia PVS and hippocampal PVS with stroke, accounting for blood pressure. Our findings provide insight into the biology of PVS and cerebral small vessel disease, pointing to pathways involving extracellular matrix, membrane transport and developmental processes, and the potential for genetically informed prioritization of drug targets.Etude de cohorte sur la santé des étudiantsStopping cognitive decline and dementia by fighting covert cerebral small vessel diseaseStudy on Environmental and GenomeWide predictors of early structural brain Alterations in Young student

    Genetic Variants For Head Size Share Genes and Pathways With Cancer

    Get PDF
    The size of the human head is highly heritable, but genetic drivers of its variation within the general population remain unmapped. We perform a genome-wide association study on head size (N = 80,890) and identify 67 genetic loci, of which 50 are novel. Neuroimaging studies show that 17 variants affect specific brain areas, but most have widespread effects. Gene set enrichment is observed for various cancers and the p53, Wnt, and ErbB signaling pathways. Genes harboring lead variants are enriched for macrocephaly syndrome genes (37-fold) and high-fidelity cancer genes (9-fold), which is not seen for human height variants. Head size variants are also near genes preferentially expressed in intermediate progenitor cells, neural cells linked to evolutionary brain expansion. Our results indicate that genes regulating early brain and cranial growth incline to neoplasia later in life, irrespective of height. This warrants investigation of clinical implications of the link between head size and cancer

    Identification of 12 new susceptibility loci for different histotypes of epithelial ovarian cancer.

    Get PDF
    To identify common alleles associated with different histotypes of epithelial ovarian cancer (EOC), we pooled data from multiple genome-wide genotyping projects totaling 25,509 EOC cases and 40,941 controls. We identified nine new susceptibility loci for different EOC histotypes: six for serous EOC histotypes (3q28, 4q32.3, 8q21.11, 10q24.33, 18q11.2 and 22q12.1), two for mucinous EOC (3q22.3 and 9q31.1) and one for endometrioid EOC (5q12.3). We then performed meta-analysis on the results for high-grade serous ovarian cancer with the results from analysis of 31,448 BRCA1 and BRCA2 mutation carriers, including 3,887 mutation carriers with EOC. This identified three additional susceptibility loci at 2q13, 8q24.1 and 12q24.31. Integrated analyses of genes and regulatory biofeatures at each locus predicted candidate susceptibility genes, including OBFC1, a new candidate susceptibility gene for low-grade and borderline serous EOC

    Refined histopathological predictors of BRCA1 and BRCA2 mutation status: A large-scale analysis of breast cancer characteristics from the BCAC, CIMBA, and ENIGMA consortia

    Get PDF
    Introduction: The distribution of histopathological features of invasive breast tumors in BRCA1 or BRCA2 germline mutation carriers differs from that of individuals with no known mutation. Histopathological features thus have utility for mutation prediction, including statistical modeling to assess pathogenicity of BRCA1 or BRCA2 variants of uncertain clinical significance. We analyzed large pathology datasets accrued by the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and the Breast Cancer Association Consortium (BCAC) to reassess histopathological predictors of BRCA1 and BRCA2 mutation status, and provide robust likelihood ratio (LR) estimates for statistical modeling. Methods: Selection criteria for study/center inclusion were estrogen receptor (ER) status or grade data available for invasive breast cancer diagnosed younger than 70 years. The dataset included 4,477 BRCA1 mutation carriers, 2,565 BRCA2 mutation carriers, and 47,565 BCAC breast cancer cases. Country-stratified estimates of the
    • …
    corecore