1,212 research outputs found

    Femtosecond laser triggering of a sub-100 picosecond jitter high-voltage spark gap

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    Includes bibliographical references (page 3250).We have demonstrated sub-100 ps jitter operation of a pressurized high-voltage air spark gap triggered by a femtosecond Ti:Sapphire laser. Time delay statistical fluctuations with a standard deviation as low as +-σ=0.037 ns were obtained

    Theoretical Foundations of Remote Sensing for Glacier Assessment and Mapping

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    The international scientific community is actively engaged in assessing ice sheet and alpine glacier fluctuations at a variety of scales. The availability of stereoscopic, multitemporal, and multispectral satellite imagery from the optical wavelength regions of the electromagnetic spectrum has greatly increased our ability to assess glaciological conditions and map the cryosphere. There are, however, important issues and limitations associated with accurate satellite information extraction and mapping, as well as new opportunities for assessment and mapping that are all rooted in understanding the fundamentals of the radiation transfer cascade. We address the primary radiation transfer components, relate them to glacier dynamics and mapping, and summarize the analytical approaches that permit transformation of spectral variation into thematic and quantitative parameters. We also discuss the integration of satellite-derived information into numerical modeling approaches to facilitate understandings of glacier dynamics and causal mechanisms

    Effects of competition on acute phase proteins and lymphocyte subpopulations - oxidative stress markers in eventing horses

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    The aim of the study was to evaluate markers of the acute phase response (APR) in eventing horses by measuring acute phase proteins (APP) (haptoglobin, Hp, and serum amyloid A, SAA), lysozyme, protein adducts such as pentosidine‐like adducts (PENT), malondialdehyde adducts (MDA), hydroxynonenal adducts (HNE) and total advanced glycation/glycoxidation end products (AGEs), complete blood count and lymphocyte subpopulations (CD4+, CD8+ and CD21+) both at rest and at the end of an eventing competition. Blood samples were collected from eight Warmblood horses (medium age 10 ± 3) during an official national 2‐day event competition at rest (R) and 10 min after the arrival of the cross‐country test on the second day. Exercise caused a significant increase in red blood cell number, haemoglobin, packed cell volume, neutrophils, white blood cell and lymphocyte number; however, these values remained within the normal range. The CD4+ and CD8+ cells significantly increased, whereas the CD21+ lymphocytes decreased; a significant increase in serum SAA, lysozyme and protein carbonyl derivates was also observed. Two‐day event causes significant changes in APR markers such as lysozyme, protein carbonyl derivates (HNE, AGEs, PENT) and lymphocyte subpopulations. The data support the hypothesis that 2‐day event may alter significantly APR markers. Limitations of the study were the relatively small sample size and sampling time conditioned by the official regulations of the event. Therefore, further studies are needed to investigate the time required for recovery to basal values in order to define the possible effects on the immune function of the athlete horse

    The new Checklist of the Italian Fauna: marine Mollusca.

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    The mollusc fauna of the Mediterranean Sea is still considered as the best-known marine mollusc fauna in the world. The previous modern checklists of marine Mollusca were produced by joint teams of amateurs and professionals. During the last years the Italian Society of Malacology (Società Italiana di Malacologia – S.I.M.) maintained an updated version of the Mediterranean checklist, that served as the backbone for the development of the new Italian checklist. According to the current version (updated on April 1st, 2021), 1,777 recognised species of marine molluscs are present in the Italian Economic Exclusive Zone, including also the Tyrrhenian coasts of Corsica and the continental shelf of the Maltese archipelago. The new checklist shows an increase of 17% of the species reported in the 1995 Checklist. This is largely (yet not solely) due to the new wave of studies based on Integrative Taxonomy approaches. A total of 135 species (7.6%) are strictly endemic to the Italian waters; 44 species (2.5%) are alien and correspond to the 28% of the Mediterranean alien marine molluscs. All eight extant molluscan classes are represented. The families represented in the Italian fauna are 307, an increase of 14.6% from the first checklist, partly due to new records and partly to new phylogenetic systematics. Compared with the whole Mediterranean malacofauna, the Italian component represents 71% in species and 61% in families, which makes it a very remarkable part of the Mediterranean fauna

    Measurement of the front-end dead-time of the LHCb muon detector and evaluation of its contribution to the muon detection inefficiency

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    A method is described which allows to deduce the dead-time of the front-end electronics of the LHCb muon detector from a series of measurements performed at different luminosities at a bunch-crossing rate of 20 MHz. The measured values of the dead-time range from 70 ns to 100 ns. These results allow to estimate the performance of the muon detector at the future bunch-crossing rate of 40 MHz and at higher luminosity

    Performance of the Muon Identification at LHCb

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    The performance of the muon identification in LHCb is extracted from data using muons and hadrons produced in J/\psi->\mu\mu, \Lambda->p\pi and D^{\star}->\pi D0(K\pi) decays. The muon identification procedure is based on the pattern of hits in the muon chambers. A momentum dependent binary requirement is used to reduce the probability of hadrons to be misidentified as muons to the level of 1%, keeping the muon efficiency in the range of 95-98%. As further refinement, a likelihood is built for the muon and non-muon hypotheses. Adding a requirement on this likelihood that provides a total muon efficiency at the level of 93%, the hadron misidentification rates are below 0.6%.Comment: 17 pages, 10 figure

    Intrauterine Candida albicans infection causes systemic fetal candidiasis with progressive cardiac dysfunction in a sheep model of early pregnancy

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    Introduction: Several recent studies have identified a potential role for intrauterine Candida albicans in adverse pregnancy outcomes, including preterm birth. There is, however, a limited understanding of the impact of intrauterine candida infection on fetal well-being in early pregnancy. Using a sheep model of early pregnancy, the aims of this study were to determine (1) the ability of experimentally induced intrauterine C albicans to infect the fetus and (2) whether C albicans exposure in early pregnancy is associated with alterations in fetal cardiac function, as measured by spectral tissue Doppler imaging analysis of fetal cardiac function. Methods: Merino ewes carrying singleton pregnancies at 89 days’ gestation (term is ∌150 days) received C albicans (n = 8) via ultrasound-guided intra-amniotic injection. Saline-exposed fetuses served as controls (n = 6). Spectral tissue Doppler imaging echocardiography and amniotic fluid collection were performed at baseline and 24 and 72 hours after intrauterine C albicans injection. Fetal tissues were collected at postmortem for analysis of infection and inflammation. Results: Relative to saline control, intrauterine C albicans infection resulted in pronounced increases in amniotic fluid tumor necrosis factor α (TNF-α; P < .05) and cytokine/chemokine messenger RNA (interleukin [IL] 1ÎČ, IL-6, TNF-α, and monocyte chemoattractant protein 1; P < .05) in the fetal myocardium, lung, skin, and liver at 72 and 96 hours postinfection. Spectral tissue Doppler imaging showed diastolic dysfunction at 24 hours and severe biventricular diastolic dysfunction 72 hours postinfection. Conclusion: Intrauterine C albicans infection in a sheep model of early pregnancy causes systemic fetal candidiasis, which is associated with a robust systemic inflammatory response and progressive cardiac dysfunction detectable by spectral tissue Doppler imaging

    Performance of the LHCb muon system

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    The performance of the LHCb Muon system and its stability across the full 2010 data taking with LHC running at ps = 7 TeV energy is studied. The optimization of the detector setting and the time calibration performed with the first collisions delivered by LHC is described. Particle rates, measured for the wide range of luminosities and beam operation conditions experienced during the run, are compared with the values expected from simulation. The space and time alignment of the detectors, chamber efficiency, time resolution and cluster size are evaluated. The detector performance is found to be as expected from specifications or better. Notably the overall efficiency is well above the design requirementsComment: JINST_015P_1112 201

    The future of Cybersecurity in Italy: Strategic focus area

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    This volume has been created as a continuation of the previous one, with the aim of outlining a set of focus areas and actions that the Italian Nation research community considers essential. The book touches many aspects of cyber security, ranging from the definition of the infrastructure and controls needed to organize cyberdefence to the actions and technologies to be developed to be better protected, from the identification of the main technologies to be defended to the proposal of a set of horizontal actions for training, awareness raising, and risk management

    Quantum numbers of the X(3872)X(3872) state and orbital angular momentum in its ρ0Jψ\rho^0 J\psi decay

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    Angular correlations in B+→X(3872)K+B^+\to X(3872) K^+ decays, with X(3872)→ρ0J/ψX(3872)\to \rho^0 J/\psi, ρ0→π+π−\rho^0\to\pi^+\pi^- and J/ψ→Ό+Ό−J/\psi \to\mu^+\mu^-, are used to measure orbital angular momentum contributions and to determine the JPCJ^{PC} value of the X(3872)X(3872) meson. The data correspond to an integrated luminosity of 3.0 fb−1^{-1} of proton-proton collisions collected with the LHCb detector. This determination, for the first time performed without assuming a value for the orbital angular momentum, confirms the quantum numbers to be JPC=1++J^{PC}=1^{++}. The X(3872)X(3872) is found to decay predominantly through S wave and an upper limit of 4%4\% at 95%95\% C.L. is set on the fraction of D wave.Comment: 16 pages, 4 figure
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