16,085 research outputs found

    Kinematics of disk galaxies in (proto-)clusters at z=1.5

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    We observed star-forming galaxies at z~1.5 selected from the HyperSuprimeCam Subaru Strategic Program. The galaxies are part of two significant overdensities of [OII] emitters identified via narrow-band imaging and photometric redshifts from grizy photometry. We used VLT/KMOS to carry out Halpha integral field spectroscopy of 46 galaxies in total. Ionized gas maps, star formation rates and velocity fields were derived from the Halpha emission line. We quantified morphological and kinematical asymmetries to test for potential gravitational (e.g. galaxy-galaxy) or hydrodynamical (e.g. ram-pressure) interactions. Halpha emission was detected in 36 targets. 34 of the galaxies are members of two (proto-)clusters at z=1.47, confirming our selection strategy to be highly efficient. By fitting model velocity fields to the observed ones, we determined the intrinsic maximum rotation velocity Vmax of 14 galaxies. Utilizing the luminosity-velocity (Tully-Fisher) relation, we find that these galaxies are more luminous than their local counterparts of similar mass by up to ~4 mag in the rest-frame B-band. In contrast to field galaxies at z<1, the offsets of the z~1.5 (proto-)cluster galaxies from the local Tully-Fisher relation are not correlated with their star formation rates but with the ratio between Vmax and gas velocity dispersion sigma_g. This probably reflects that, as is observed in the field at similar redshifts, fewer disks have settled to purely rotational kinematics and high Vmax/sigma_g ratios. Due to relatively low galaxy velocity dispersions (sigma_v < 400 km/s) of the (proto-)clusters, gravitational interactions likely are more efficient, resulting in higher kinematical asymmetries, than in present-day clusters. (abbr.)Comment: Accepted for publication in A&A. 11 pages, 8 figures, 1 tabl

    Methanol Dehydrogenation on Pt Electrodes : Active Sites and Role of Adsorbed Spectators Revealed through Time-Resolved ATR-SEIRAS

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    ACKNOWLEDGMENT L.P.-M. acknowledges a doctoral scholarship within the Leverhulme Centre for Doctoral Training in Sustainable Production of Chemicals and Materials (Grant DS-2017-073).Peer reviewedPostprin

    Observational constraints to boxy/peanut bulge formation time

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    Boxy/peanut bulges are considered to be part of the same stellar structure as bars and both could be linked through the buckling instability. The Milky Way is our closest example. The goal of this letter is determining if the mass assembly of the different components leaves an imprint in their stellar populations allowing to estimate the time of bar formation and its evolution. To this aim we use integral field spectroscopy to derive the stellar age distributions, SADs, along the bar and disc of NGC 6032. The analysis shows clearly different SADs for the different bar areas. There is an underlying old (>=12 Gyr) stellar population for the whole galaxy. The bulge shows star formation happening at all times. The inner bar structure shows stars of ages older than 6 Gyrs with a deficit of younger populations. The outer bar region presents a SAD similar to that of the disc. To interpret our results, we use a generic numerical simulation of a barred galaxy. Thus, we constrain, for the first time, the epoch of bar formation, the buckling instability period and the posterior growth from disc material. We establish that the bar of NGC 6032 is old, formed around 10 Gyr ago while the buckling phase possibly happened around 8 Gyr ago. All these results point towards bars being long-lasting even in the presence of gas.Comment: Accepted for publication in MNRAS Letter

    Cytomolecular identification of individual wheat-wheat chromosome arm associations in wheat-rye hybrids

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    Chromosome pairing in the meiotic metaphase I of wheatrye hybrids has been characterized by sequential genomic and fluorescent in situ hybridization allowing not only the discrimination of wheat and rye chromosomes, but also the identification of the individual wheat and rye chromosome arms involved in the chromosome associations. The majority of associations (93.8%) were observed between the wheat chromosomes. The largest number of wheat-wheat chromosome associations (53%) was detected between the A and D genomes, while the frequency of B-D and A-B associations was significantly lower (32 and 8%, respectively). Among the A-D chromosome associations, pairing between the 3AL and 3DL arms was observed with the highest frequency, while the most frequent of all the chromosome associations (0.113/ cell) was found to be the 3DS-3BS. Differences in the pairing frequency of the individual chromosome arms of wheat-rye hybrids have been discussed in relation to the homoeologous relationships between the constituent genomes of hexaploid wheat

    Qualitative and Quantitative Detection of Chlamydophila pneumoniae DNA in Cerebrospinal Fluid from Multiple Sclerosis Patients and Controls

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    A standardized molecular test for the detection of Chlamydophila pneumoniae DNA in cerebrospinal fluid (CSF) would assist the further assessment of the association of C. pneumoniae with multiple sclerosis (MS). We developed and validated a qualitative colorimetric microtiter plate-based PCR assay (PCR-EIA) and a real-time quantitative PCR assay (TaqMan) for detection of C. pneumoniae DNA in CSF specimens from MS patients and controls. Compared to a touchdown nested-PCR assay, the sensitivity, specificity, and concordance of the PCR-EIA assay were 88.5%, 93.2%, and 90.5%, respectively, on a total of 137 CSF specimens. PCR-EIA presented a significantly higher sensitivity in MS patients (p = 0.008) and a higher specificity in other neurological diseases (p = 0.018). Test reproducibility of the PCR-EIA assay was statistically related to the volumes of extract DNA included in the test (p = 0.033); a high volume, which was equivalent to 100 µl of CSF per reaction, yielded a concordance of 96.8% between two medical technologists running the test at different times. The TaqMan quantitative PCR assay detected 26 of 63 (41.3%) of positive CSF specimens that tested positive by both PCR-EIA and nested-PCR qualitative assays. None of the CSF specimens that were negative by the two qualitative PCR methods were detected by the TaqMan quantitative PCR. The PCR-EIA assay detected a minimum of 25 copies/ml C. pneumoniae DNA in plasmid-spiked CSF, which was at least 10 times more sensitive than TaqMan. These data indicated that the PCR-EIA assay possessed a sensitivity that was equal to the nested-PCR procedures for the detection of C. pneumoniae DNA in CSF. The TaqMan system may not be sensitive enough for diagnostic purposes due to the low C. pneumoniae copies existing in the majority of CSF specimens from MS patients

    Retinal blood vessels extraction using probabilistic modelling

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    © 2014 Kaba et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.The analysis of retinal blood vessels plays an important role in detecting and treating retinal diseases. In this review, we present an automated method to segment blood vessels of fundus retinal image. The proposed method could be used to support a non-intrusive diagnosis in modern ophthalmology for early detection of retinal diseases, treatment evaluation or clinical study. This study combines the bias correction and an adaptive histogram equalisation to enhance the appearance of the blood vessels. Then the blood vessels are extracted using probabilistic modelling that is optimised by the expectation maximisation algorithm. The method is evaluated on fundus retinal images of STARE and DRIVE datasets. The experimental results are compared with some recently published methods of retinal blood vessels segmentation. The experimental results show that our method achieved the best overall performance and it is comparable to the performance of human experts.The Department of Information Systems, Computing and Mathematics, Brunel University

    Cost-Utility Analysis of a Medication Adherence Management Service Alongside a Cluster Randomized Control Trial in Community Pharmacy.

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    Background: It is necessary to determine the cost utility of adherence interventions in chronic diseases due to humanistic and economic burden of non-adherence. Purpose: To evaluate, alongside a cluster-randomized controlled trial, the cost-utility of a pharmacist-led medication adherence management service (MAMS) compared with usual care in community pharmacies. Materials and Methods: The trial was conducted over six months. Patients with treatments for hypertension, asthma or chronic obstructive pulmonary disease (COPD) were included. Patients in the intervention group (IG) received a MAMS based on a brief complex intervention, whilst patients in the control group (CG) received usual care. The cost–utility analysis adopted a health system perspective. Costs related to medications, healthcare resources and adherence intervention were included. The effectiveness was estimated as quality-adjusted life years (QALYs), using a multiple imputation missing data model. The incremental cost–utility ratio (ICUR) was calculated on the total sample of patients. Results: A total of 1186 patients were enrolled (IG: 633; CG: 553). The total intervention cost was estimated to be € 27.33 ± 0.43 per patient for six months. There was no statistically significant difference in total cost of medications and healthcare resources per patient between IG and CG. The values of EQ-5D-5L at 6 months were significantly higher in the IG [IG: 0.881 ± 0.005 vs CG: 0.833 ± 0.006; p = 0.000]. In the base case, the service was more expensive and more effective than usual care, resulting in an ICUR of € 1,494.82/QALY. In the complete case, the service resulted in an ICUR of € 2,086.30/QALY, positioned between the north-east and south-east quadrants of the cost–utility plane. Using a threshold value of € 20,000/QALY gained, there is a 99% probability that the intervention is cost-effective. Conclusion: The medication adherence management service resulted in an improvement in the quality of life of the population with chronic disease, with similar costs compared to usual care. The service is cost-effective

    Niche partitioning by photosynthetic plankton as a driver of CO2-fixation across the oligotrophic South Pacific Subtropical Ocean

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    Oligotrophic ocean gyre ecosystems may be expanding due to rising global temperatures [1-5]. Models predicting carbon flow through these changing ecosystems require accurate descriptions of phytoplankton communities and their metabolic activities [6]. We therefore measured distributions and activities of cyanobacteria and small photosynthetic eukaryotes throughout the euphotic zone on a zonal transect through the South Pacific Ocean, focusing on the ultraoligotrophic waters of the South Pacific Gyre (SPG). Bulk rates of CO2 fixation were low (0.1 mu mol Cl--(1) d(-1)) but pervasive throughout both the surface mixed-layer (upper 150 m), as well as the deep chlorophyll a maximum of the core SPG. Chloroplast 16S rRNA metabarcoding, and single-cell (CO2)-C-13 uptake experiments demonstrated niche differentiation among the small eukaryotes and picocyanobacteria. Prochlorococcus abundances, activity, and growth were more closely associated with the rims of the gyre. Small, fast-growing, photosynthetic eukaryotes, likely related to the Pelagophyceae, characterized the deep chlorophyll a maximum. In contrast, a slower growing population of photosynthetic eukaryotes, likely comprised of Dictyochophyceae and Chrysophyceae, dominated the mixed layer that contributed 65-88% of the areal CO2 fixation within the core SPG. Small photosynthetic eukaryotes may thus play an underappreciated role in CO2 fixation in the surface mixed-layer waters of ultraoligotrophic ecosystems

    Higgs production as a probe of anomalous top couplings

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    The LHC may be currently seeing the first hints of the Higgs boson. The dominant production mode for the Higgs at the LHC involves a top-quark loop. An accurate measurement of Higgs production cross-sections and decay widths can thus be used to obtain limits on anomalous top couplings. We find that such an exercise could potentially yield constraints that are stronger than those derived from low-energy observables as well as direct bounds expected from the top pair-production process.Comment: Version published in JHE
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