2,347 research outputs found

    Stochastic inviscid shell models: well-posedness and anomalous dissipation

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    In this paper we study a stochastic version of an inviscid shell model of turbulence with multiplicative noise. The deterministic counterpart of this model is quite general and includes inviscid GOY and Sabra shell models of turbulence. We prove global weak existence and uniqueness of solutions for any finite energy initial condition. Moreover energy dissipation of the system is proved in spite of its formal energy conservation.Comment: v2 has updated introductio

    Mitochondrial DNA lineages of Italian Giara and Sarcidano horses

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    Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular variance, haplotype sharing, and clustering methods, were used to study the genetic relationships between the Sardinian and other horse breeds. The analyses yielded similar results, and the FST values indicated that a high percentage of the total genetic variation was explained by between-breed differences. Consistent with their distinct phenotypes and geographic isolation, the two Sardinian breeds were shown to consist of 2 distinct gene pools that had no gene flow between them. Giara horses were clearly separated from the other breeds examined and showed traces of ancient separation from horses of other breeds that share the same mitochondrial lineage. On the other hand, the data from the Sarcidano horses fit well with variation among breeds from the Iberian Peninsula and North-West Europe: genetic relationships among Sarcidano and the other breeds are consistent with the documented history of this breed

    Full Characterization of the First 1 Inch Industrial Prototype of a New Concept Photodetector

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    The VSiPMT (Vacuum Silicon PhotoMultiplier Tube) is an original design for an innovative light detector we proposed with the aim to create new scientific instrumentation for industrial applications and physics research. The idea behind this device is to replace the classical dynode chain of a photomultiplier tube with a silicon photomultiplier, the latter acting as an electron detector and amplifier. The VSiPMT offers very attractive features and unprecedented performance, definitely superior to every other photodetector with comparable sensitive surface, such as: negligible power cosumption, excellent photon counting, easy low-voltage-based stabilization and very good time performance. After the feasibility test of the idea, Hamamatsu Photonics realized for our research group two VSiPMT industrial prototypes, that have been fully characterized. The results of the full characterization of the 1-inch industrial prototype are presented in this work.Comment: 11 pages, 14 figure

    Global regularity for a slightly supercritical hyperdissipative Navier-Stokes system

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    We prove global existence of smooth solutions for a slightly supercritical hyperdissipative Navier--Stokes under the optimal condition on the correction to the dissipation. This proves a conjecture formulated by Tao [Tao2009]

    Global regularity for a logarithmically supercritical hyperdissipative dyadic equation

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    We prove global existence of smooth solutions for a slightly supercritical dyadic model. We consider a generalized version of the dyadic model introduced by Katz-Pavlovic [KatPav2004] and add a viscosity term with critical exponent and a supercritical correction. This model catches for the dyadic a conjecture that for Navier-Stokes equations was formulated by Tao [Tao2009

    Self-perceived cultural competence. A cross-sectional study about nurses' awareness and behavior

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    Background: Cultural competence is a valuable and intangible heritage of knowledge, relationships and identity. Cultural competence is fundamental in nursing: sharing the objectives of all patients - not only foreigners - promotes patient's participation in healthcare and supports nurses' professional development, enhancing the intellectual capital that guides quality care. The aim of this study is to evaluate nurses' self-perceived cultural competence. Study design: This is a cross-sectional study. Methods: A self-administered cultural-competence questionnaire was used. Nurses working in hospitals and territorial healthcare settings in Rome, Italy, were involved in this study, from March 2017 to February 2018. Results: This study involved 192 nurses. The mean age was 46.2 ± 7.9. Most of the nurses (77.6%) were women. The nurses' mean work experience was 21.4 ± 8.8 years; 65.1% of them had never attended any type of course concerning multiculturalism. The mean score of the nurses' cultural competence was 4.19 ± 0.57 (range = 2.75-5.71). In all, 41.7% of the nurses did not consider themselves neither competent nor incompetent. Conclusion: The results show that nurses have an acceptable level of cultural competence, slightly higher in the territorial context
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