6,494 research outputs found

    A model for the submarine depthkeeping team

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    The most difficult task the depthkeeping team must face occurs during periscope-depth operations during which they may be required to maintain a submarine several hundred feet long within a foot of ordered depth and within one-half degree of ordered pitch. The difficulty is compounded by the facts that wave generated forces are extremely high, depth and pitch signals are very noisy and submarine speed is such that overall dynamics are slow. A mathematical simulation of the depthkeeping team based on the optimal control models is described. A solution of the optimal team control problem with an output control restriction (limited display to each controller) is presented

    Z\gamma\gamma production with leptonic decays and triple photon production at NLO QCD

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    We present a calculation of the O(alpha_s) QCD corrections to the production of a Z boson in association with two photons and to triple photon production at hadron colliders. All final-state photons are taken as real. For the Z boson, we consider the decays both into charged leptons and into neutrinos including all off-shell effects. Numerical results are obtained via a Monte Carlo program based on the structure of the VBFNLO program package. This allows us to implement general cuts and distributions of the final-state particles. We find that the NLO QCD corrections are sizable and significantly exceed the expectations from a scale variation of the leading-order result. In addition, differential distributions of important observables change considerably. The prediction of two-photon-associated Z production with Z decays into neutrinos from the charged-lepton rate works well, once we use an additional cut on the invariant mass of the charged-lepton pair.Comment: 14 pages, 10 figures, 2 table

    The Chemokine CCL2 Mediates the Seizure-enhancing Effects of Systemic Inflammation

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    Epilepsy is a chronic disorder characterized by spontaneous recurrent seizures. Brain inflammation is increasingly recognized as a critical factor for seizure precipitation, but the molecular mediators of such proconvulsant effects are only partly understood. The chemokine CCL2 is one of the most elevated inflammatory mediators in patients with pharmacoresistent epilepsy, but its contribution to seizure generation remains unexplored. Here, we show, for the first time, a crucial role for CCL2 and its receptor CCR2 in seizure control. We imposed a systemic inflammatory challenge via lipopolysaccharide (LPS) administration in mice with mesial temporal lobe epilepsy. We found that LPS dramatically increased seizure frequency and upregulated the expression of many inflammatory proteins, including CCL2. To test the proconvulsant role of CCL2, we administered systemically either a CCL2 transcription inhibitor (bindarit) or a selective antagonist of the CCR2 receptor (RS102895). We found that interference with CCL2 signaling potently suppressed LPS-induced seizures. Intracerebral administration of anti-CCL2 antibodies also abrogated LPS-mediated seizure enhancement in chronically epileptic animals. Our results reveal that CCL2 is a key mediator in the molecular pathways that link peripheral inflammation with neuronal hyperexcitability

    La memoria di un signore del primo Trecento : i cartulari di Guido Savina da Fogliano

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    The aim of the paper is to analyze a source \u2018ignored\u2019 by local historiography: the cartulari of Guido Savina da Fogliano. Among the first cartularies (made by lords) to appeared in the Italian scene, those documents allow us to deepen the studies on the family which was one of the most important in Reggio during the 13th-14th centuries (and beyond). Made by Guido Savina, leading member of the Reggio Emilia family in the first three decades of the 14th century, the analysis of the cartularies offers a number of new points of view through which observe the history of the family: on one hand, the content of the document consolidates and extends what it is already known about the Fogliano. On the other hand, in the cartulary the history of the family is \u2018disassembled in photograms\u2019, which are then reshaped and rebuilt to show not just a simple chronology of family events, but rather to create a clear picture of the family and of its main member at that time. a speech, a storytelling made by goods, rights and privileges, in which the absolute protagonist is the family but, above all, Guido Savina da Fogliano

    NLO QCD corrections to W+W- gamma and Z Z gamma production with leptonic decays

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    The computation of the NLO QCD corrections to the cross sections for W+W- gamma and ZZgamma production in hadronic collisions is presented. We consider the case of a real photon in the final state, but include full leptonic decays of the W and Z bosons. Numerical results for the LHC and the Tevatron are obtained through a fully flexible parton level Monte Carlo based on the structure of the VBFNLO program, allowing an easy implementation of arbitrary cuts and distributions. We show the dependence on scale variations of the integrated cross sections and provide evidence that NLO QCD corrections strongly modify the LO predictions for observables at the LHC both in magnitude and in shape

    NLO QCD corrections to processes with multiple electroweak bosons

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    The VBFNLO program package is a collection of Monte Carlo programs for the calculation of NLO QCD corrections to vector boson fusion cross sections, double and triple vector boson production, or the production of two electroweak bosons in association with an additional jet. An overview is given of the processes and features implemented in VBFNLO. WWgamma and Wgamma jet production are discussed as examples.Comment: 6 pages, 3 figures; talk given at RADCOR 2009 - 9th International Symposium on Radiative Corrections (Applications of Quantum Field Theory to Phenomenology), October 25 - 30 2009, Ascona, Switzerlan

    Molecular mechanisms underlying muscle wasting in huntington’s disease

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    Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder caused by pathogenic expansions of the triplet cytosine-adenosine-guanosine (CAG) within the Huntingtin gene. These expansions lead to a prolongation of the poly-glutamine stretch at the N-terminus of Huntingtin causing protein misfolding and aggregation. Huntingtin and its pathological variants are widely expressed, but the central nervous system is mainly affected, as proved by the wide spectrum of neurological symptoms, including behavioral anomalies, cognitive decline and motor disorders. Other hallmarks of HD are loss of body weight and muscle atrophy. This review highlights some key elements that likely provide a major contribution to muscle atrophy, namely, alteration of the transcriptional processes, mitochondrial dysfunction, which is strictly correlated to loss of energy homeostasis, inflammation, apoptosis and defects in the processes responsible for the protein quality control. The improvement of muscular symptoms has proven to slow the disease progression and extend the life span of animal models of HD, underlining the importance of a deep comprehension of the molecular mechanisms driving deterioration of muscular tissue

    Genetic variability in three Italian beef cattle breeds derived from pedigree information

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    The aim of the present work was to estimate genetic variability in Chianina (CH), Marchigiana (MC) and Romagnola (RO) breeds using pedigree information. Different approaches based on probability of identity-by-descent (effective population size through an increase in inbreeding Ne) or probability of gene origin (total number of founders f, effective number of founders fe, ancestors fa and founder genomes fg) were used. Reference populations were defined using female animals born between 1996 and 2000 where both parents are known. Generation intervals were 5.35, 4.93 and 5.15 years for CH, MC and RO, respectively. The total number of founders were 7092, 11947, 3928, for CH, MC and RO, respectively. Complete generation equivalent showed the relative high quality of pedigree information: 5.66 for CH, 4.54 for MC and 4.95 for RO. For CH, MC and RO, respectively, a fe value of 152.1, 70.9 and 89.8, a fa value of 73.6, 48.0 and 59.5 and a fg value of 39.5, 25.0 and 38.5, were calculated. When inbreeding was used effective population sizes were 138, 122 and 124 for CH, MC and RO, respectively. Parameters derived from the probabilities of gene origin were variable among the investigated breeds and the results for MC demonstrate the need to pay specific attention to breeding strategies
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