10,241 research outputs found

    Analysis and correction of the magnetic field effects in the Hybrid Photo-Detectors of the RICH2 Ring Imaging Cherenkov detector of LHCb

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    The Ring Imaging Cherenkov detectors of the LHCb experiment at the Large Hadron Collider at CERN are equipped with Hybrid Photo-Detectors. These vacuum photo-detectors are affected by the stray magnetic field of the LHCb magnet, which degrades their imaging properties. This effect increases the error on the Cherenkov angle measurement and would reduce the particle identification capabilities of LHCb. A system has been developed for the RICH2 Ring Imaging Cherenkov detector to perform a detailed characterisation of the magnetic distortion effects. It is described, along with the methods implemented to correct for these effects, restoring the optimal resolution.Comment: 16 pages, 11 figure

    Benthic nitrogen cycling in the North Sea

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    We present new data on the rates of sedimentary denitrification and its component processes (canonical denitrification, anammox and dissimilatory nitrate reduction to ammonium) for intertidal and subtidal sites in the North Sea using nitrogen isotope addition methods. We find overall average denitrification rates of 6.3 (range 0.4-10.6) µmol m-2h-1, similar to those previously reported for this region and other temperate shelf environments. We find canonical denitrification to be the dominant (>90%) process of the three. At the subtidal sites, most of the denitrification is supported by nitrate generated within the sediments, while at the intertidal site the main source is from the water column. We go on to consider the impact of these rates on nitrogen cycling within the North Sea region and compare the sediment core incubation rate results to estimates derived from modelling approaches. Model rates are somewhat higher than those directly measured and we consider possible reasons for this

    A novel format for recombinant antibody-interleukin-2 fusion proteins exhibits superior tumor-targeting properties in vivo

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    The targeted delivery of interleukin-2 to the tumor is gaining attention as an avenue to potentiate the action of T and NK cells at the site of disease. We have previously described the fusion of the L19 antibody, specific to the EDB domain of fibronectin, with human interleukin-2, using a non-covalent homodimeric diabody format. Here, we describe four novel formats for the L19-IL2 fusion, featuring different arrangements of antibody and IL2. A comparative quantitative biodistribution analysis in tumor-bearing mice using radioiodinated proteins revealed that the novel format (L19L19-IL2, with the antibody in single-chain diabody format) exhibited the best biodistribution results. In vitro assays on peripheral blood mononuclear cells showed a decrease activation of regulatory T cells when single IL2 domain was used. In vivo, both L19-IL2 and L19L19-IL2 inhibited tumor growth in immunocompetent mouse models of cancer. T-cell analysis revealed similar levels of CD4+ and FoxP3+ cells, with an expansion of the CD8+ T cell in mice treated with L19-IL2 and L19L19-IL2. The percentage of CD4+ regulatory T cells was markedly decreased with L19L19-IL2 combined with a mouse-specific PD-1 blocker. Collectively, these data indicate that the new L19L19-IL2 format exhibits favorable tumor-homing properties and mediates a potent anti-cancer activity in vivo

    The SXI telescope on board EXIST: scientific performances

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    The SXI telescope is one of the three instruments on board EXIST, a multiwavelength observatory in charge of performing a global survey of the sky in hard X-rays searching for Supermassive Black Holes. One of the primary objectives of EXIST is also to study with unprecedented sensitivity the most unknown high energy sources in the Universe, like high redshift GRBs, which will be pointed promptly by the Spacecraft by autonomous trigger based on hard X-ray localization on board. The recent addition of a soft X-ray telescope to the EXIST payload complement, with an effective area of ~950 cm2 in the energy band 0.2-3 keV and extended response up to 10 keV will allow to make broadband studies from 0.1 to 600 keV. In particular, investigations of the spectra components and states of AGNs and monitoring of variability of sources, study of the prompt and afterglow emission of GRBs since the early phases, which will help to constrain the emission models and finally, help the identification of sources in the EXIST hard X-ray survey and the characterization of the transient events detected. SXI will also perform surveys: a scanning survey with sky coverage of about 2pi and limiting flux of 5x10^{-14}cgs plus other serendipitous. We give an overview of the SXI scientific performance and also describe the status of its design emphasizing how it has been derived by the scientific requirements.Comment: 9 pages, 6 figures, to be published in Proc. of SPIE, vol 7435-11, 200

    The Effect of Using Exoskeleton of Blue Crab (Callinectes sapidus) as a Dietary Calcium Source on the Egg Characteristics of Layer Hens (Gallus gallus domesticus)

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    The study focuses on the ability to use the exoskeleton of blue crab as alternative calcium and carotenoid supplement for layer hens and its effects on egg characteristics. Three groups of eighty layer hens each were fed a base feed formulation following the standards of the University of the Philippines Los Baños. The feeds were base feed as negative control (NG), a base feed with natural egg yolk colorants (capsorubin and lutein) as positive control (PG), and a base feed with 1% ground blue crab exoskeletons, as experimental (EG). The feeding lasted four weeks before egg collection. The eggs were weighed for their albumen, yolk, shell, and egg weight. The egg yolk color was determined using a DSM Fan and a digital Chroma meter, and the shell thickness using digital calipers. Statistical treatment was done through Kruskal Wallis test using SPSS software. Results showed that eggs of EG had significantly heavier shells with a mean of 5.93±0.11g, compared to 5.83±0.08g of the NG and 5.55±0.08g of the PG. Eggshell thickness was not significantly different among the three groups. Egg yolk color was significantly different in PG with a mean DSM gradient value of 11.96±0.11, compared to 5.92±0.14 of the NG and 6.48±0.20 of EG. Ground blue crab exoskeleton as a calcium supplement may increase the weight of the eggshells but may not intensify the egg yolk color

    Central venous catheter insertion: a bedside procedure for haematological patients.

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    The present management of onco-haematologic patients may require continuous infusion of cytotoxic drugs, use of drugs or concentrated ion solutions which are toxic for the endothelial wall of small vessels, infusion of large amounts of antibiotics or antimycotics, red blood cell and platelet transfusion, and not rarely parenteral nutrition. Such a complex therapy needs a vascular access by a central vein catheter (CVC) insertion. Many types of CVC are available at present: tunnelled Hickman or Hickmanlike catheters, subcutaneous ports, tunnelled catheters with Groshong valve, external untunnelled catheters

    Tilting mutation of weakly symmetric algebras and stable equivalence

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    We consider tilting mutations of a weakly symmetric algebra at a subset of simple modules, as recently introduced by T. Aihara. These mutations are defined as the endomorphism rings of certain tilting complexes of length 1. Starting from a weakly symmetric algebra A, presented by a quiver with relations, we give a detailed description of the quiver and relations of the algebra obtained by mutating at a single loopless vertex of the quiver of A. In this form the mutation procedure appears similar to, although significantly more complicated than, the mutation procedure of Derksen, Weyman and Zelevinsky for quivers with potentials. By definition, weakly symmetric algebras connected by a sequence of tilting mutations are derived equivalent, and hence stably equivalent. The second aim of this article is to study these stable equivalences via a result of Okuyama describing the images of the simple modules. As an application we answer a question of Asashiba on the derived Picard groups of a class of self-injective algebras of finite representation type. We conclude by introducing a mutation procedure for maximal systems of orthogonal bricks in a triangulated category, which is motivated by the effect that a tilting mutation has on the set of simple modules in the stable category.Comment: Description and proof of mutated algebra made more rigorous (Prop. 3.1 and 4.2). Okuyama's Lemma incorporated: Theorem 4.1 is now Corollary 5.1, and proof is omitted. To appear in Algebras and Representation Theor

    Understanding why fat, oil and grease (FOG) bioremediation can be unsuccessful

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    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Commercial kitchen wastewaters are typically strong organic and fat-rich effluents, often identified as major contributors to fatberg formation and associated blockages in sewers. Experimental trials were done using synthetic kitchen wastewater to understand the complex reactions involved in microbial remediation in grease traps/separators prior discharge in sewers. The principle organic components (FOG, carbohydrate and protein nitrogen), were varied using ranges observed in a previous study on real kitchen wastewater characterisation. A model bacterium, Bacillus licheniformis NCIMB 9375, was used to evaluate microbial utilisation of the different organic fractions in relation to fat, oil and grease (FOG) degradation. Novel results in the treatment of these effluents showed that, the presence and concentration of alternative carbon sources and the ratio of carbon to nitrogen (COD:N) had great influence on FOG-degradation response. For example, FOG removal decreased from 24 to 10 mg/l/h when glucose was substitute for starch at equivalent concentrations (500mg/l); and from 26 to 5 mg/l/h when initial COD:N increased from 45:1 to 147:1. The dominant influence of COD:N was validated using a commercial bioadditive and real kitchen wastewater adjusted to different COD:N ratios, confirming the strong influence of kitchen wastewater composition on bioremediation outcomes. These results can therefore have major implications for biological management of FOG in kitchens and sewers as they provide a scientific explanation for bioremediation success or failure
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