1,662 research outputs found

    Precision measurements of W detected at CMS

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    Particle Physics is a well-established field using its settled methods of data analysis and interpretation, along with techniques of detector calibration. At the dawn of the era of the Higgs boson discovery, with no clear sign of new Physics manifesting at the energy range covered by the Large Hadron Collider, the quest for significant deviations of the measured parameters of the Standard Model from their prediction is a mandatory plan. Produced copiously in the CMS and ATLAS experiments, the WW bosons provide a unique opportunity to set stringent limits to the Standard Model. The aim of the work described in this thesis has been to present a paradigm shift, introducing a change in the traditional conception of the WW precision measurements. A totally new method has been devised to obtain a precise assessment of the WW rapidity, transverse momentum and polarisation exploiting uniquely and exclusively the correlation between the transverse momentum and the pseudorapidity of muons emitted in WW semileptonic decays. This result gives the opportunity to perform a measurement of the WW mass, the holy grail of the precision measurements at the electroweak scale, without making any assumption on the WW production encoded in simulations. This thesis contains a set of innovative measurements of WW unpolarised cross section and angular coefficients and an assessment of the final uncertainty on the WW mass using data collected by the CMS experiment in 2016. The dominant experimental systematic in the measurement of the WW mass is the knowledge of the muon momentum scale, of which a high precision calibration is presented in this thesis. Finally, an entire chapter of this thesis is devoted to the description of the implementation of the innovative computing tools that have been devised in order to cope with the unprecedented complexity of the analysis under study

    About the rapidity and helicity distributions of the W bosons produced at LHC

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    WW bosons are produced at LHC from a forward-backward symmetric initial state. Their decay to a charged lepton and a neutrino has a strong spin analysing power. The combination of these effects results in characteristic distributions of the pseudorapidity of the leptons decaying from W+W^+ and W−W^- of different helicity. This observation may open the possibility to measure precisely the W+W^+ and W−W^- rapidity distributions for the two transverse polarisation states of WW bosons produced at small transverse momentum.Comment: 8 pages, 5 figure

    Use of multivariate discriminant methodologies in the analysis of phenotypic and genomic data of cattle

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    The present thesis is organized in 4 main chapters. The Chapter 1 is the general introduction and it regards the use of the multivariate statistical techniques in animal science, with a particular emphasis on the discriminant analysis. In Chapter 2, a new statistical method called Discriminant Association Method (DAM) was proposed. The DAM approach, developed by using multivariate statistical techniques, overcomes most of problems that affect the single SNP regression technique used in the ordinary GWAS. In Chapter 3, a new index to evaluate feed efficiency was defined: the residual concentrate intake (RCI). RCI identifies efficient and inefficient bovines in converting the concentrate. RCI can be quite simply evaluated and, in consequence, it could be easily included in genomic breeding programs. In the present research, the DAM method was applied to develop a GWAS for selecting markers associated to RCI. The research reported in Chapter 4 was aimed to develop an algorithm able to early identify highly persistent lactations. Four different models were fitted to individual lactations by using the first 90, 120 and 150 days in milking. Two multivariate statistical techniques were exploited: the canonical discriminant analysis (CDA) and the discriminant analysis (DA). The proposed algorithm combines the talent of curve models in depict features of the lactation and the ability of multivariate statistical techniques in distinguishing differences between groups

    Comparison of commercial and in-house Real-time PCR assays for quantification of Epstein-Barr virus (EBV) DNA in plasma

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    BACKGROUND: Epstein-Barr virus (EBV) DNA load monitoring is known to be useful for the diagnosis and monitoring of EBV-associated diseases. The aim of this study is to compare the performance of two real-time PCR assays for EBV DNA: a commercial kit as the Q-EBV Real-Time System (Q-EBV PCR, Amplimedical, Turin, Italy) and an in-house assay (EBV RQ-PCR). RESULTS: The range of linearity and the degree of precision of the two assays were similar. The clinical sensitivity of Q-EBV PCR was higher for reference samples containing less than 1,000 EBV DNA copies/ml. The absolute quantitative results of the two methods were statistically correlated (R(2 )= 0.7789; p < 0.0001), with the systematic overestimation by EBV RQ-PCR possibly linked to different amplification efficiency in calibration standards. CONCLUSION: Both the commercial and the in-house assay may be appropriate for clinical use, but common standards are advisable for comparable absolute values, as these would improve the clinical utility of EBV DNA load measurement

    Optimization of extraction of drugs containing polyphenols using an innovative technique

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    The role of polyphenols in human health nowadays is well established and these natural products, found in many plant species, are the active ingredients of drugs, food supplements and cosmetics. Extraction procedure is pivotal to obtain high quality herbal products but paradoxically this factor is often underrated and obsolete techniques are used. In this work we compared the classic and most used method of maceration and an innovative and standardized technique of extraction, Estrattore Naviglio((R)), processing ten common medicinal plants containing polyphenols and for each analysing specific biological markers such as flavonoids, anthocyanosides and caffeic derivatives in addition to total polyphenols content. Estrattore Naviglio((R)) guaranteed a significant improvement of the chemical quality of extracts combining effectiveness with rapidity and reproducibility. In this work we further investigated the optimization of drug extractions by replicating operations varying parameters setting on Estrattore Naviglio((R)) instrument

    Impact of the PDFs on the Z and W lineshapes at LHC

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    The parton distribution functions (PDFs) of the proton play a role in determining the lineshape of ZZ and WW bosons produced at the LHC. In particular, the mode of the gauge boson virtuality is shifted with respect to the pole due to the dependence of the partonic luminosity on the boson virtuality. The knowledge of this shift contributes to the systematic uncertainty for a direct measurement of the boson mass. A detailed study of the shift and of its systematic uncertainty due to the limited knowledge of the PDFs is obtained using a tree-level model of ZZ and WW boson production in proton-proton collisions at s=13\sqrt{s}=13 TeV. A Monte Carlo simulation is further used to validate the tree-level model and study the dependence of the shift on the transverse momentum of the gauge bosons. The tree-level calculation is found to provide a good description of the shift. The systematic uncertainty on the lineshape due to the PDFs is estimated to be below one MeV in the phase-space relevant for a future high-precision mass measurement of the gauge boson masses at the LHC

    Conjugated Linoleic Acid and Brain Metabolism: A Possible Anti-Neuroinflammatory Role Mediated by PPARα Activation

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    Fatty acids play a crucial role in the brain as specific receptor ligands and as precursors of bioactive metabolites. Conjugated linoleic acid (CLA), a group of positional and geometric isomers of linoleic acid (LA, 18:2 n-6) present in meat and dairy products of ruminants and synthesized endogenously in non-ruminants and humans, has been shown to possess different nutritional properties associated with health benefits. Its ability to bind to peroxisome proliferator-activated receptor (PPAR) α, a nuclear receptor key regulator of fatty acid metabolism and inflammatory responses, partly mediates these beneficial effects. CLA is incorporated and metabolized into brain tissue where induces the biosynthesis of endogenous PPAR α ligands palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), likely through a positive feedback mechanism where PPAR α activation sustains its own cellular effects through ligand biosynthesis. In addition to PPAR α, PEA and OEA may as well bind to other receptors such as TRPV1, further extending CLA own anti-neuroinflammatory actions. Future studies are needed to investigate whether dietary CLA may exert antiinflammatory activity, particularly in the setting of neurodegenerative diseases and neuropsychiatric disorders with a neuroinflammatory basis

    Role of the (Mn)superoxide dismutase of Enterococcus faecalis in the in vitro interaction with microglia

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    Enterococcus faecalis is a significant human pathogen worldwide and is responsible for severenosocomial and community-acquired infections. Although enterococcal meningitis is rare,mortality is considerable, reaching 21 %. Nevertheless, the pathogenetic mechanisms of thisinfection remain poorly understood, even though the ability of E. faecalis to avoid or survivephagocytic attack in vivo may be very important during the infection process. We previouslyshowed that the manganese-cofactored superoxide dismutase (MnSOD) SodA of E. faecalis wasimplicated in oxidative stress responses and, interestingly, in the survival within mouse peritonealmacrophages using an in vivo\u2013in vitro infection model. In the present study, we investigated therole of MnSOD in the interaction of E. faecalis with microglia, the brain-resident macrophages. Byusing an in vitro infection model, murine microglial cells were challenged in parallel with the wildtypestrain JH2-2 and its isogenic sodA deletion mutant. While both strains were phagocytosedby microglia efficiently and to a similar extent, the DsodA mutant was found to be significantlymore susceptible to microglial killing than JH2-2, as assessed by the antimicrobial protectionassay. In addition, a significantly higher percentage of acidic DsodA-containing phagosomes wasfound and these also underwent enhanced maturation as determined by the expression ofendolysosomal markers. In conclusion, these results show that the MnSOD of E. faecaliscontributes to survival of the bacterium in microglial cells by influencing their antimicrobial activity,and this could even be important for intracellular killing in neutrophils and thus for E. faecalispathogenesis

    Use of a Plasma-Sprayed Titanium-Hydroxyapatite Femoral Stem in Hip Arthroplasty in Patients Older than 70 Years. Is Cementless Fixation a Reliable Option in the Elderly?

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    Background: Although cementless implants are increasing in popularity, the use of cementless femoral stems for total hip arthroplasty (THA) and hip hemiarthroplasty (HH) in elderly patients remains controversial. The aim of this study was to report the outcomes of a cementless stem used in a large multicentric cohort of elderly patients receiving elective THA and HH for displaced femoral neck fracture. Methods: A total of 293 patients (301 hips) aged 70 years or older (mean age, 78 years; range, 70–93) who received the same cementless plasma-sprayed porous titanium–hydroxyapatite stem were retrospectively evaluated after primary THA and HH to investigate stem survival, complications, and clinical and radiographic results. Results: Cumulative stem survival was 98.5% (95% CI, 96.4–99.4%; 91 hips at risks) with revision due to any reason as the end-point at 10-year follow-up (mean 8.6 years, range 4–12). No stem was revised due to aseptic loosening. The mean Forgotten Joint Score was 98.7. Radiographically, the implants showed complete osseointegration, with slight stress-shieling signs in less than 10% of the hips. Conclusion: The use of cementless stems was proven to be a reliable and versatile option even in elderly patients for elective THA and HH for femoral neck fracture
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