731 research outputs found

    Long living carriers in a strong electron-phonon interacting two-dimensional doped semiconductor

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    Carrier doping by the electric field effect has emerged recently as an ideal route for monitoring many-body physics in two-dimensional (2D) materials where the Fermi level is tuned in a way that -- indirectly -- the strength of the interactions can also be scanned. The possibility of systematic doping in combination with high resolution photoemission has allowed to uncover a genuinely many-body electron spectrum in single-layer MoS2 transition metal dichalcogenide, resolving three clear quasi-particle states, where only one state should be expected if the electron-phonon interaction vanished. Our analysis combines first-principles and consistent complex plane analytic approaches and brings into light the presence and the physical origin of two gaps and the three quasi-particle bands which are unambiguously present in the photoemission spectrum. One of these states, though being strongly interacting with the accompanying virtual phonon cloud, presents a notably long lifetime which is an appealing property when trying to understand and take advantage of many-body interactions to modulate the transport properties.Comment: Editorially accepted for publication in "Communications Physics" (14 pages, 3 figures

    INSTALLATION OF THE LHC EXPERIMENTAL INSERTIONS

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    The installation of the LHC experimental insertions, and particularly the installation of the Low-Beta quadrupoles, raises many technical challenges due to the stringent alignment specifications and to the difficulty of access in very confined areas. The compact layout with many lattice elements, vacuum components, beam control instrumentation and the presence of shielding does not allow for any improvisation in the installation procedure. This paper reviews all the constraints that need to be taken into account when installing the experimental insertions. It describes the chronological sequence of installation and discusses the technical solutions that have been adopted

    Phase transitions in number theory: from the birthday problem to Sidon sets

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    In this work, we show how number theoretical problems can be fruitfully approached with the tools of statistical physics. We focus on g-Sidon sets, which describe sequences of integers whose pairwise sums are different, and propose a random decision problem which addresses the probability of a random set of k integers to be g-Sidon. First, we provide numerical evidence showing that there is a crossover between satisfiable and unsatisfiable phases which converts to an abrupt phase transition in a properly defined thermodynamic limit. Initially assuming independence, we then develop a mean-field theory for the g-Sidon decision problem. We further improve the mean-field theory, which is only qualitatively correct, by incorporating deviations from independence, yielding results in good quantitative agreement with the numerics for both finite systems and in the thermodynamic limit. Connections between the generalized birthday problem in probability theory, the number theory of Sidon sets and the properties of q-Potts models in condensed matter physics are briefly discusse

    Cyprus' image—a sun and sea destination—as a detrimental factor to seasonal fluctuations. Exploration into motivational factors for holidaying in Cyprus

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    Cyprus is established as a summer destination. To aid the destination in developing its winter season as well, this research uses a qualitative inductive approach to explore the tourists’ current image of the island and their motivations of visiting it. The research indicates that the current image, which essentially portrays Cyprus as a sun-and-sea destination is thought to dissuade tourists from perceiving the island as a year-round destination. Nonetheless, increasing the pull factors of the destination through the development of unique special interest products can help in extending the tourism season as well as broaden its narrow image

    Health effects of the Federal Bureau of Prisons tobacco ban

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    BACKGROUND: Tobacco smoking remains the leading cause of preventable death in America, claiming 450,000 lives annually. Chronic Obstructive Pulmonary Disease, caused by smoking in the vast majority of cases, became the third leading cause of death in the U.S. in 2008. The burden of asthma, often exacerbated by tobacco exposure, has widespread clinical and public health impact. Despite this considerable harm, we know relatively little about the natural history of lung disease and respiratory impairment in adults, especially after smoking cessation. METHODS/DESIGN: Our paper describes the design and rationale for using the 2004 Federal Bureau of Prisons tobacco ban to obtain insights into the natural history of respiratory diseases in adult men and women of different races/ethnicities who are imprisoned in federal medical facilities. We have developed a longitudinal study of new prison arrivals, with data to be collected from each participant over the course of several years, through the use of standardized questionnaires, medical chart reviews, lung function tests, six-minute walk tests, and stored serum for the analysis of present and future biomarkers. Our endpoints include illness exacerbations, medication and health services utilization, lung function, serum biomarkers, and participants\u27 experience with their health and nicotine addiction. DISCUSSION: We believe the proposed longitudinal study will make a substantial contribution to the understanding and treatment of respiratory disease and tobacco addiction

    miR-28 regulates the germinal center reaction and blocks tumor growth in preclinical models of non-Hodgkin lymphoma

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    Non-Hodgkin lymphoma comprises a variety of neoplasms, many of which arise from germinal center (GC)-experienced B cells. microRNA-28 (miR-28) is a GC-specific miRNA whose expression is lost in numerous mature B-cell neoplasms. Here we show that miR-28 regulates the GC reaction in primary B cells by impairing class switch recombination and memory B and plasma cell differentiation. Deep quantitative proteomics combined with transcriptome analysis identified miR-28 targets involved in cell-cycle and B-cell receptor signaling. Accordingly, we found that miR-28 expression diminished proliferation in primary and lymphoma cells in vitro. Importantly, miR-28 reexpression in human Burkitt (BL) and diffuse large B-cell lymphoma (DLBCL) xenografts blocked tumor growth, both when delivered in viral vectors or as synthetic, clinically amenable, molecules. Further, the antitumoral effect of miR-28 is conserved in a primary murine in vivo model of BL. Thus, miR-28 replacement is uncovered as a novel therapeutic strategy for DLBCL and BL treatment.This work was supported by a Ministerio de Economia y Competitividad's research training program (Formacion de Personal Investigador [FPI]) fellowship (N.B.-I.); the Ramon y Cajal program (RYC-2009-04503) funded by the Ministerio de Educacion, Cultura y Deporte and the European Research Council Proof of Concept program (HEAL-BY-MIRNA 713728) (V.G.d.Y.); the Centro Nacional de Investigaciones Cardiovaculares (CNIC) (A.F.A.-P., S.M.M., A.R.R.); the Ministerio de Economia y Competitividad (SAF2010-21394, SAF2013-42767-R), the European Research Council Starting Grant program (BCLYM-207844), and Proof of Concept program (HEAL-BY-MIRNA 713728) (A.R.R.); the People Programme-Marie Curie Actions (FP7-PIIF-2012-328177), Spanish Ministry of Economy and Competitiveness (MINECO; SAF2013-45787-R), and Gobierno de Navarra (GN-106/2014) (S.R.); and the Ministerio de Economia y Competitividad (BIO2012-37926 and BIO2015-67580-P), Instituto de Salud Carlos III (Fondo de Investigacion Sanitaria [FIS] grants PRB2 [IPT13/0001, Proteo-Red], the Fundacion La Marato TV3, and Redes tematicas de investigacion cooperativa en salud [RETICS] [RD12/0042/00056, RIC]) (J.V.). This work has been cofunded by Fondo Europeo de Desarrollo Regional (FEDER) funds. The CNIC is supported by the and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (MINECO award SEV-2015-0505).S

    Comparison of direct and indirect methods to maximise the detection of Babesia caballi and Theileria equi infections in Central Southern Italy

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    : Equine piroplasmosis is a disease of equids, caused by tick-borne apicomplexan protozoan pathogens Babesia caballi and Theileria equi, which, according to the World Organisation for Animal Health (OIE), can be diagnosed by enzyme-linked immunosorbent assay (ELISA), immunofluorescent antibody test (IFAT) and polymerase chain reaction (PCR). The present study was conducted to evaluate and compare the assays available for the diagnosis of equine piroplasmosis. Data employed were obtained from 1300 blood samples collected between 2012-2014 from asymptomatic and symptomatic equines (horses and donkeys) of central-southern regions of Italy and analyzed by ELISA, IFAT, PCR (one commercial and one from literature) and blood smear microscopic examination. Statistical differences of the proportions of positivity for each parasite and group (asymptomatic and symptomatic) among the methods were verified by the z test to identify the most sensitive. The concordance between each pair of methods - for each parasite and within the groups - and trends in detection of suspect samples of four hypothetical diagnostic algorithms using serological and biomolecular assays were evaluated to identify the most suitable laboratory diagnostic workflow. The results of this study highlighted a lower capacity to detect suspect samples of commercial ELISA for B. caballi in all groups when compared to biomolecular methods and IFAT; and of the commercial PCRs in asymptomatic animals, identifying a PCR from literature and IFAT as the best choice for a combined diagnosis. For T. equi, IFAT detected more suspect samples than ELISA, even if the latter showed good performance and some samples were positive only by the ELISA and PCR, indicating that their simultaneous employment is still advantageous. Host-parasite interaction, amino-acid/genetic diversity and differences in detection limits among the assays could be among the reasons in explaining the present results. In view of further studies, ELISA should be used in combination with PCR, that should regularly be included in the laboratory diagnosis to maximise the detection of early infections and support the evaluation of pharmacological treatment
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