747 research outputs found

    Regulation of D-galacturonate metabolism in Caulobacter crescentus by HumR, a LacI-family transcriptional repressor

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    The oligotrophic freshwater bacterium Caulobacter crescentus encodes a cluster of genes (CC_1487 to CC_1495) shown here to be necessary for metabolism of D-galacturonate, the primary constituent of pectin, a major plant polymer. Sequence analysis suggests that these genes encode a version of the bacterial hexuronate isomerase pathway. A conserved 14 bp sequence motif is associated with promoter regions of three operons within this cluster, and is conserved in homologous gene clusters in related alpha-Proteobacteria. Embedded in the hexuronate gene cluster is a gene (CC_1489) encoding a member of the LacI family of bacterial transcription factors. This gene product, designated here as HumR (hexuronate metabolism regulator), represses expression of the uxaA and uxaC operon promoters by binding to the conserved operator sequence. Repression is relieved in the presence of galacturonate or, to a lesser extent, by glucuronate. Other genes potentially involved in pectin degradation and hexuronate transport are also under the control of HumR. Adoption of a LacI-type repressor to control hexuronate metabolism parallels the regulation of xylose, glucose, and maltose utilization in C. crescentus, but is distinct from the use of GntR-type repressors to control pectin and hexuronate utilization in gamma-Proteobacteria such as Escherichia coli

    Contemplating Synergistic Algorithms for the NASA ACE Mission

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    ACE is a proposed Tier 2 NASA Decadal Survey mission that will focus on clouds, aerosols, and precipitation as well as ocean ecosystems. The primary objective of the clouds component of this mission is to advance our ability to predict changes to the Earth's hydrological cycle and energy balance in response to climate forcings by generating observational constraints on future science questions, especially those associated with the effects of aerosol on clouds and precipitation. ACE will continue and extend the measurement heritage that began with the A-Train and that will continue through Earthcare. ACE planning efforts have identified several data streams that can contribute significantly to characterizing the properties of clouds and precipitation and the physical processes that force these properties. These include dual frequency Doppler radar, high spectral resolution lidar, polarimetric visible imagers, passive microwave and submillimeter wave radiometry. While all these data streams are technologically feasible, their total cost is substantial and likely prohibitive. It is, therefore, necessary to critically evaluate their contributions to the ACE science goals. We have begun developing algorithms to explore this trade space. Specifically, we will describe our early exploratory algorithms that take as input the set of potential ACE-like data streams and evaluate critically to what extent each data stream influences the error in a specific cloud quantity retrieval

    A State-Level Agricultural Sector Policy Model: Baseline and Implications of the Dunkel Text on Agriculture for Iowa

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    A better understanding of the relationship between a state\u27s agricultural sector and the national agricultural economy increases the ability of agricultural interest groups to anticipate and understand policy developments. This paper develops and documents a state-level model of the Iowa agricultural sector. The model is used to evaluate the future performance of the Iowa agricultural economy, given a specific set of assumptions about the general economy, agricultural policies, the weather, and technological change. When the model is used to analyze the implications of the Dunkel text on agriculture, the increase in Iowa net farm income is found to be proportionally higher than the increase in U.S. net farm income, because Iowa\u27s agricultural economy is concentrated in commodities that benefit from the Dunkel text

    Oral anticoagulants for primary prevention, treatment and secondary prevention of venous thromboembolic disease, and for prevention of stroke in atrial fibrillation:systematic review, network meta-analysis and cost-effectiveness analysis

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    BACKGROUND: Warfarin is effective for stroke prevention in atrial fibrillation (AF), but anticoagulation is underused in clinical care. The risk of venous thromboembolic disease during hospitalisation can be reduced by low-molecular-weight heparin (LMWH): warfarin is the most frequently prescribed anticoagulant for treatment and secondary prevention of venous thromboembolism (VTE). Warfarin-related bleeding is a major reason for hospitalisation for adverse drug effects. Warfarin is cheap but therapeutic monitoring increases treatment costs. Novel oral anticoagulants (NOACs) have more rapid onset and offset of action than warfarin, and more predictable dosing requirements.OBJECTIVE: To determine the best oral anticoagulant/s for prevention of stroke in AF and for primary prevention, treatment and secondary prevention of VTE.DESIGN: Four systematic reviews, network meta-analyses (NMAs) and cost-effectiveness analyses (CEAs) of randomised controlled trials.SETTING: Hospital (VTE primary prevention and acute treatment) and primary care/anticoagulation clinics (AF and VTE secondary prevention).PARTICIPANTS: Patients eligible for anticoagulation with warfarin (stroke prevention in AF, acute treatment or secondary prevention of VTE) or LMWH (primary prevention of VTE).INTERVENTIONS: NOACs, warfarin and LMWH, together with other interventions (antiplatelet therapy, placebo) evaluated in the evidence network.MAIN OUTCOME MEASURES: Efficacy Stroke, symptomatic VTE, symptomatic deep-vein thrombosis and symptomatic pulmonary embolism. Safety Major bleeding, clinically relevant bleeding and intracranial haemorrhage. We also considered myocardial infarction and all-cause mortality and evaluated cost-effectiveness.DATA SOURCES: MEDLINE and PREMEDLINE In-Process & Other Non-Indexed Citations, EMBASE and The Cochrane Library, reference lists of published NMAs and trial registries. We searched MEDLINE and PREMEDLINE In-Process & Other Non-Indexed Citations, EMBASE and The Cochrane Library. The stroke prevention in AF review search was run on the 12 March 2014 and updated on 15 September 2014, and covered the period 2010 to September 2014. The search for the three reviews in VTE was run on the 19 March 2014, updated on 15 September 2014, and covered the period 2008 to September 2014.REVIEW METHODS: Two reviewers screened search results, extracted and checked data, and assessed risk of bias. For each outcome we conducted standard meta-analysis and NMA. We evaluated cost-effectiveness using discrete-time Markov models.RESULTS: Apixaban (Eliquis(rcledR), Bristol-Myers Squibb, USA; Pfizer, USA) [5 mg bd (twice daily)] was ranked as among the best interventions for stroke prevention in AF, and had the highest expected net benefit. Edoxaban (Lixiana(rcledR), Daiichi Sankyo, Japan) [60 mg od (once daily)] was ranked second for major bleeding and all-cause mortality. Neither the clinical effectiveness analysis nor the CEA provided strong evidence that NOACs should replace postoperative LMWH in primary prevention of VTE. For acute treatment and secondary prevention of VTE, we found little evidence that NOACs offer an efficacy advantage over warfarin, but the risk of bleeding complications was lower for some NOACs than for warfarin. For a willingness-to-pay threshold of > £5000, apixaban (5 mg bd) had the highest expected net benefit for acute treatment of VTE. Aspirin or no pharmacotherapy were likely to be the most cost-effective interventions for secondary prevention of VTE: our results suggest that it is not cost-effective to prescribe NOACs or warfarin for this indication.CONCLUSIONS: NOACs have advantages over warfarin in patients with AF, but we found no strong evidence that they should replace warfarin or LMWH in primary prevention, treatment or secondary prevention of VTE.LIMITATIONS: These relate mainly to shortfalls in the primary data: in particular, there were no head-to-head comparisons between different NOAC drugs.FUTURE WORK: Calculating the expected value of sample information to clarify whether or not it would be justifiable to fund one or more head-to-head trials.STUDY REGISTRATION: This study is registered as PROSPERO CRD42013005324, CRD42013005331 and CRD42013005330.FUNDING: The National Institute for Health Research Health Technology Assessment programme

    Genomic Profiling of Advanced-Stage, Metaplastic Breast Carcinoma by Next-Generation Sequencing Reveals Frequent, Targetable Genomic Abnormalities and Potential New Treatment Options

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    Context.— Metastatic metaplastic breast carcinoma (MPBC) is an uncommon, but aggressive, tumor resistant to conventional chemotherapy. Objective.— To learn whether next-generation sequencing could identify potential targets of therapy for patients with relapsed and metastatic MPBC. Design.— Hybridization capture of 3769 exons from 236 cancer-related genes and 47 introns of 19 genes commonly rearranged in cancer was applied to a minimum of 50 ng of DNA extracted from 20 MPBC formalin-fixed, paraffin-embedded specimens and sequenced to high uniform coverage. Results.— The 20 patients with MPBC had a median age of 62 years (range, 42–86 years). There were 9 squamous (45%), 9 chondroid (45%), and 2 spindle cell (10%) MPBCs, all of which were high grade. Ninety-three genomic alterations were identified, (range, 1–11) with 19 of the 20 cases (95%) harboring an alteration that could potentially lead to a targeted treatment option. The most-common alterations were in TP53 (n = 69; 75%), PIK3CA (n = 37; 40%), MYC (n = 28; 30%), MLL2 (n = 28; 30%), PTEN (n = 23; 25%), CDKN2A/B (n = 19; 20%), CCND3 (n = 14; 15%), CCNE1 (n = 9; 10%), EGFR (n = 9; 10%), and KDM6A (n = 9; 10%); AKT3, CCND1, CCND2, CDK4, FBXW7, FGFR1, HRAS, NF1, PIK3R1, and SRC were each altered in a single case. All 16 MPBCs (100%) that were negative for ERBB2 (HER2) overexpression by immunohistochemistry and/or ERBB2 (HER2) amplification by fluorescence in situ hybridization were also uniformly (100%) negative for ERBB2 amplification by next-generation sequencing–based copy-number assessment. Conclusions.— Our results indicate that genomic profiling using next-generation sequencing can identify clinically meaningful alterations that have the potential to guide targeted treatment decisions in most patients with metastatic MPBC

    Implications of a Production Entitlement Guarantee (PEG) Program for World Commodity Markets, 1992-2000

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    A Production Entitlement Guarantee (PEG) program would replace existing agricultural policies with a program that would allow governments to subsidize only a fixed proportion of each farmer\u27s historical production. World supply and demand conditions would determine the price farmers receive for any production in excess of the guaranteed PEG quality because all import barriers and export subsidies would be eliminated. A dynamic multicountry, multicommodity model is used to evaluate the impact of replacing current agricultural policies in the United States, the European Community, Japan, and Canada with a PEG program. For all countries and commodities, the guaranteed PEG quantity is set equal to 80 percent of each farmer\u27s average production between 1985 and 1989. Government payments are made to farmers on their PEG production as partial compensation for revenue losses. Except for programs with environmental aims, all other programs that subsidize or protect domestic agriculture would be eliminated

    A State-Level Agricultural Sector Policy Model: Baseline and Implications of the Dunkel Text on Agriculture for Iowa

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    A better understanding of the relationship between a state\u27s agricultural sector and the national agricultural economy increases the ability of agricultural interest groups to anticipate and understand policy developments. This paper develops and documents a state-level model of the Iowa agricultural sector. The model is used to evaluate the future performance of the Iowa agricultural economy, given a specific set of assumptions about the general economy, agricultural policies, the weather, and technology change. When the model is used to analyze the implications of the Dunkel text on agriculture, the increase in Iowa net farm income is found to be proportionally higher then the increase in U.S. net farm income, because Iowa\u27s agricultural economy is concentrated in commodities that benefit from the Dunkel text

    Genome-wide Association of Lipid-lowering Response to Statins in Combined Study Populations

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    Background: Statins effectively lower total and plasma LDL-cholesterol, but the magnitude of decrease varies among individuals. To identify single nucleotide polymorphisms (SNPs) contributing to this variation, we performed a combined analysis of genome-wide association (GWA) results from three trials of statin efficacy. Methods and Principal Findings: Bayesian and standard frequentist association analyses were performed on untreated and statin-mediated changes in LDL-cholesterol, total cholesterol, HDL-cholesterol, and triglyceride on a total of 3932 subjects using data from three studies: Cholesterol and Pharmacogenetics (40 mg/day simvastatin, 6 weeks), Pravastatin/Inflammation CRP Evaluation (40 mg/day pravastatin, 24 weeks), and Treating to New Targets (10 mg/day atorvastatin, 8 weeks). Genotype imputation was used to maximize genomic coverage and to combine information across studies. Phenotypes were normalized within each study to account for systematic differences among studies, and fixed-effects combined analysis of the combined sample were performed to detect consistent effects across studies. Two SNP associations were assessed as having posterior probability greater than 50%, indicating that they were more likely than not to be genuinely associated with statin-mediated lipid response. SNP rs8014194, located within the CLMN gene on chromosome 14, was strongly associated with statin-mediated change in total cholesterol with an 84% probability by Bayesian analysis, and a p-value exceeding conventional levels of genome-wide significance by frequentist analysis (P = 1.8×108^{−8}). This SNP was less significantly associated with change in LDL-cholesterol (posterior probability = 0.16, P = 4.0×106^{−6}). Bayesian analysis also assigned a 51% probability that rs4420638, located in APOC1 and near APOE, was associated with change in LDL-cholesterol. Conclusions and Significance: Using combined GWA analysis from three clinical trials involving nearly 4,000 individuals treated with simvastatin, pravastatin, or atorvastatin, we have identified SNPs that may be associated with variation in the magnitude of statin-mediated reduction in total and LDL-cholesterol, including one in the CLMN gene for which statistical evidence for association exceeds conventional levels of genome-wide significance.Trial Registration PRINCE and TNT are not registered. CAP is registered at Clinicaltrials.gov NCT0045182
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