1,268 research outputs found

    Geiger-Mode Avalanche Photodiodes in Particle Detection

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    It is well known that avalanche photodiodes operated in the Geiger mode above the breakdown voltage offer a virtually infinite sensitivity and time accuracy in the picosecond range that can be used for single photon detection. However, their performance in particle detection remains still unexplored. In this contribution, we are going to expose the different steps that we have taken in order to prove the efficiency of Geiger mode avalanche photodiodes in the aforementioned field. In particular, we will present an array of pixels of 1mmx1mm fabricated with a standard CMOS technology for characterization in a test beam.Comment: 7 pages, 2 figures, Proceedings of LCWS1

    Opportunity lost: Mystification, elite politics and financial reform in the UK

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    The first phase of the crisis in Britain – from the 2007 failure of Northern Rock to the post Lehman systemic crisis of autumn 2008 – was a demystifying moment, when finance sector alibis, technocratic expertise and the assumptions of the political classes were tested and found wanting under pressure of unanticipated events. The banking rescue of 2007-8 amounted to the socialization of banking losses at a cost to the UK taxpayer of up to £1,000 billion or more (if we include contingent liabilities and exclude quantitative easing). British taxpayers got very little in return. The challenge of a brief democratic moment was met by the restatement of old pre-crisis narratives about the importance of ‘flexible’, market responsive regulation, and about the social value of finance. The result so far is marginalisation of left and radical forces (or no change on the past twenty-five years). Against this background, this essay has two interlinked aims. First, it presents an analysis of political obstacles to democratic control and reform of the finance sector that caused the financial crisis of 2007-8; a crisis that, after extreme intervention to save banks and support markets, has by 2010-11 become a fiscal crisis for individual states and a sovereign debt crisis for the eurozone. Second, it addresses (in this context) the role of ‘ideology’ within the socio-political process by examining how discourses format the world through what is now called ‘performativity’. And it shows how this new kind of discursive description can be developed and integrated with more established kinds of institutional analysis so as to generate new insights into the political obstacles to reform. The argument below is illustrated with UK evidence and our aim is to provide an analysis of national peculiarities, but the issues raised are relevant to other jurisdictions (national and supra national). We hope to raise broad questions about the mechanisms of elite power in present day capitalism where the importance of narrative has intensified since Reagan and Thatcher. We also aim to encourage reflection on how narrative power could be challenged so as to deliver a more democratic reform of finance

    Atividade biológica das toxinas do Bt, Cry 1A(b) e Cry 1F em Spodoptera frugiperda (Smith) (Lepidoptera: noctuidae).

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    Atualmente, há duas diferentes toxinas do Bacillus thuringiensis (Bt) disponíveis em milho transgênico. Entretanto, há poucas informações sobre a toxicidade dessas proteínas puras Cry 1A(b) e Cry 1F para a lagarta-do-cartucho do milho (LCM), Spodoptera frugiperda, (Smith) usando o método de tratamento superficial da dieta. Os bioensaios foram conduzidos, usando um gradiente de concentração para as duas toxinas. Cada tratamento foi infestado artificialmente com larvas da LCM recém-eclodidas e mantidas sob temperatura constante e no escuro. Dez dias após a infestação, o número de larvas sobreviventes e a inibição de crescimento baseado na biomassa foram avaliados. Os dados de mortalidade foram submetidos à análise de "Probit". As CL50 estimadas para Cry1A(b) e Cry1F foram, respectivamente, 689,81 ng/cm2 e 36,46 ng/cm2. A CL50 foi suficiente para inibir o acúmulo de biomassa das larvas em 91,61% e 89,81% para Cry1Ab e Cry1F, respectivamente. As larvas que sobreviveram por dez dias nas dietas tratadas com o Cry 1A(b) foram transferidas para dieta não tratadas e observadas até a emergência dos adultos. Das larvas sobreviventes, 62,8% recuperaram seu desenvolvimento, acumulando a biomassa de uma pupa normal. Portanto, a atividade biológica da toxina do Bt vai além da simples toxicidade, incluindo uma significativa inibição de alimentação. Esse fato tem implicações importantes para o desenvolvimento de estratégias para o manejo da resistência

    Benchmarking genetically improved BarraCUDA on epigenetic methylation NGS datasets and nVidia GPUs

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    BarraCUDA uses CUDA graphics cards to map DNA reads to the human genome. Previously its software source code was genetically improved for short paired end next generation sequences. On longer noisy epigenetics strings using nVidia Titan and twin Tesla K40 the same GI-ed code is more than 3 times faster than bwa-meth on an 8 core CPU

    Isolamento e caracterização de bactérias endofíticas não patogênicas em milho.

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    bitstream/item/58846/1/Pesq.And.-31-1.pd

    ncRNA orthologies in the vertebrate lineage.

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    Annotation of orthologous and paralogous genes is necessary for many aspects of evolutionary analysis. Methods to infer these homology relationships have traditionally focused on protein-coding genes and evolutionary models used by these methods normally assume the positions in the protein evolve independently. However, as our appreciation for the roles of non-coding RNA genes has increased, consistently annotated sets of orthologous and paralogous ncRNA genes are increasingly needed. At the same time, methods such as PHASE or RAxML have implemented substitution models that consider pairs of sites to enable proper modelling of the loops and other features of RNA secondary structure. Here, we present a comprehensive analysis pipeline for the automatic detection of orthologues and paralogues for ncRNA genes. We focus on gene families represented in Rfam and for which a specific covariance model is provided. For each family ncRNA genes found in all Ensembl species are aligned using Infernal, and several trees are built using different substitution models. In parallel, a genomic alignment that includes the ncRNA genes and their flanking sequence regions is built with PRANK. This alignment is used to create two additional phylogenetic trees using the neighbour-joining (NJ) and maximum-likelihood (ML) methods. The trees arising from both the ncRNA and genomic alignments are merged using TreeBeST, which reconciles them with the species tree in order to identify speciation and duplication events. The final tree is used to infer the orthologues and paralogues following Fitch's definition. We also determine gene gain and loss events for each family using CAFE. All data are accessible through the Ensembl Comparative Genomics ('Compara') API, on our FTP site and are fully integrated in the Ensembl genome browser, where they can be accessed in a user-friendly manner.Database URL: http://www.ensembl.org

    Extracting Hα\alpha flux from photometric data in the J-PLUS survey

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    We present the main steps that will be taken to extract Hα\alpha emission flux from Javalambre Photometric Local Universe Survey (J-PLUS) photometric data. For galaxies with z0.015z\lesssim0.015, the Hα\alpha+[NII] emission is covered by the J-PLUS narrow-band filter F660F660. We explore three different methods to extract the Hα\alpha + [NII] flux from J-PLUS photometric data: a combination of a broad-band and a narrow-band filter (rr' and F660F660), two broad-band and a narrow-band one (rr', ii' and F660F660), and a SED-fitting based method using 8 photometric points. To test these methodologies, we simulated J-PLUS data from a sample of 7511 SDSS spectra with measured Hα\alpha flux. Based on the same sample, we derive two empirical relations to correct the derived Hα\alpha+[NII] flux from dust extinction and [NII] contamination. We find that the only unbiased method is the SED fitting based one. The combination of two filters underestimates the measurements of the Hα\alpha + [NII] flux by a 28%, while the three filters method by a 9%. We study the error budget of the SED-fitting based method and find that, in addition to the photometric error, our measurements have a systematic uncertainty of a 4.3%. Several sources contribute to this uncertainty: differences between our measurement procedure and the one used to derive the spectroscopic values, the use of simple stellar populations as templates, and the intrinsic errors of the spectra, which were not taken into account. Apart from that, the empirical corrections for dust extinction and [NII] contamination add an extra uncertainty of 14%. Given the J-PLUS photometric system, the best methodology to extract Hα\alpha + [NII] flux is the SED-fitting based one. Using this method, we are able to recover reliable Hα\alpha fluxes for thousands of nearby galaxies in a robust and homogeneous way.Comment: 11 pages, 14 figures. Minor changes to match the published versio

    Selection of the fall armyworm Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) for survival on Cry 1A (b) Bt toxin.

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    Plantas transgênicas que expressam toxinas da bactéria Bacillus thuringiensis (Bt) representam um importante avanço para o controle de lepidópteros-pragas de milho. Híbridos de milho Bt expressando a toxina Cry1A(b) têm mostrado significativo nível de resistência à lagarta-do-cartucho (LCM), Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), embora larvas dessa espécie tenham sido observadas em campo e em laboratório sobrevivendo nesses híbridos. Resistência de S. frugiperda também tem sido registrada para diferentes inseticidas. Em bioensaios, seleção de insetos sobreviventes mostrou um aumento do nível de tolerância à toxina do Bt Cry1A(b) em populações da lagarta-do-cartucho, após quatro gerações, indicando que essa tolerância é herdada. Palavras-chave: Insecta, resistência, plantas transgênicas
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