2,203 research outputs found

    Study of W± boson in the ALICE muon spectrometer: considerations and analysis using the HLT tool

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    W± bosons produced in proton-proton collisions can be observed in the ALICE muon spectrometer via their decay into single muons at a transverse momentum, pt ~ Mw/2 40 GeV/c. However the identification of these single muons is complicated by a large amount of muonic background, especially in the low pt region. Therefore, it is necessary to apply precise pt cuts below the region of interest. This can be done by means of the High Level Trigger (HLT). In this paper we present the performance of detecting high pt muons at the HLT level. In order to improve the momentum resolution of the L0 trigger, fast clusterization of the tracking chambers together with L0 trigger matching and fast tracking reconstruction is applied. This will reduce the background in the high pt muon analysis

    The lived experiences of women principals in rural secondary schools regarding their career pathways

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    This interpretivist qualitative study explored lived experiences of rural secondary schools’ female principals' career development. Purposive sampling technique was employed to select eleven female principals from 11 rural public secondary schools in Ilembe District, KwaZulu-Natal, South Africa to provide in depth information to the study. A semi-structured interview guide was used in various audio-recorded interviews, which lasted between 20-30 minutes each to capture exact information. The audio-recorded data was systematically transcribed and coded to generate common themes for the presentation and discussion of findings. Findings revealed that some communities’ cultures continue to dominantly influence women principals’ career pathways, despite policies or efforts to promote gender equality in South Africa. The social attitude or ‘injustice’ against female principals in rural environments has limited their quest to pursue their careers further or to aspire to top administrative leadership positions in education. It is recommended that necessary government structures and other stakeholders in the education sector should provide the necessary support to encourage female principals in rural schools

    In vitro and in vivo hepatotoxicity study of Afriplex™ GRT through an inflammatory response

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    BACKGROUND : The focus on traditional and complementary medicine for supplementation and treatment of diseases is high. Aspalathus linearis commonly known as Rooibos showed several beneficial effects, this led to the standardized production of a pharmaceutical grade green rooibos extract (Afriplex TM GRT) with enhanced polyphenolic content. The aim of this study was to assess toxicity of Afriplex TM GRT in HepG2/C3A cells and Sprague Dawley rats. METHODS : Afriplex GRT TM (0.1, 1, 10, 100, or 1000 μg/mL) in DMSO was added to the media to the final 0.01% DMSO for treatment of HepG2/C3A for 1, 24 and 48 hrs followed by MTT and ATP assays. Sprague Dawley rats were grouped to Control, Afriplex TM GRT treated (10, 100 and 300 mg/kg); and acute (24hrs tetrachloromethane (CCl 4) injected hepatotoxicity control). Serum biochemistry, histology and Western blot analysis on liver were performed. RESULTS : Afriplex TM GRT significantly reduced cell viability at 100 and 1000μg/mL after 48 hrs. Acute CCl 4 treatment significantly increased serum alanine aminotransferase in rats. The highest extract treatment of 300 mg/kg significantly elevated aspartate amino transferase. There was severe macro vesicular in the CCl 4 group whereas mild to moderate micro vesicular steatosis was seen in the 300 mg/kg Afriplex TM GRT treated group. Highest extract treatment significantly reduced NFkB expression on Western blot analysis. CONCLUSION : The beneficial effects of pharmaceutical grade Afriplex GRT TM are concentration and dosage based. Afriplex GRT TM exerts its beneficial effects via NFkB as demonstrated by the dose dependent reduction of NFkB on Western blot analysis. More work need to be done to explore the exact mechanism that occurs in the NFkB pathway.The SAMRC Research Capacity Development and the National Research Foundation for the Thuthuka Grant.https://www.elsevier.com/locate/toxrephj2022BiochemistryGeneticsMicrobiology and Plant Patholog

    Aluminum as a source of background in low background experiments

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    Neutrinoless double beta decay would be a key to understanding the nature of neutrino masses. The next generation of High Purity Germanium experiments will have to be operated with a background rate of better than 10^-5 counts/(kg y keV) in the region of interest around the Q value of the decay. Therefore, so far irrelevant sources of background have to be considered. The metalization of the surface of germanium detectors is in general done with aluminum. The background from the decays of 22Na, 26Al, 226Ra and 228Th introduced by this metalization is discussed. It is shown that only a special selection of aluminum can keep these background contributions acceptable.Comment: 11 pages, 3 Tables, 11 Figures, accepted for publication in NIM

    The limits of discourse: masculinity as vulnerability

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    For many, gender equity being fair to women and men is a zero sum game in which men should be willing to give up their privileges for the creation of a more equitable and just society. The idea that men might benefit from gender equity seems, for many, unthinkable. This was brought home a few years ago in a gender studies test, when students answering a question on what men might gain from gender equality explained instead how women would benefit. In this Perspective I reflect on the ways in which popular discourses around gender may inadvertently undermine movement towards gender and social justice. Dismissing my students' answers as the result of poor teaching or learning misses a key point: It seems to be extraordinarily difficult for most people to recognise how gender creates masculine vulnerabilities or how gender equity could benefit men. I suggest that if we are to improve women's lives through the reduction of violence, feminist teachers and activists need to think creatively about how to help men and boys understand that performances of masculinity deeply compromise their own lives

    Charge separation relative to the reaction plane in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}= 2.76 TeV

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    Measurements of charge dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudo-rapidity range η<0.8|\eta| < 0.8 are presented as a function of the collision centrality, particle separation in pseudo-rapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge dependent azimuthal correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286

    Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 5.02 TeV

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    Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 <pT,assoc<pT,trig< < p_{\rm{T}, assoc} < p_{\rm{T}, trig} < 5.0 GeV/cc is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range η<0.9|\eta|<0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton--parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161

    A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE

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    In this small note we are concerned with the solution of Forward-Backward Stochastic Differential Equations (FBSDE) with drivers that grow quadratically in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem is a comparison result that allows comparing componentwise the signs of the control processes of two different qgFBSDE. As a byproduct one obtains conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio

    Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider

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    Measurements of multi-particle azimuthal correlations (cumulants) for charged particles in p-Pb and Pb-Pb collisions are presented. They help address the question of whether there is evidence for global, flow-like, azimuthal correlations in the p-Pb system. Comparisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a Δη|\Delta \eta| gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high-multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of v2{4}v_{2}\{4\} to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find v2{4}v2{6}0v_{2}\{4\} \simeq v_{2}\{6\}\neq 0 which is indicative of a Bessel-Gaussian function for the v2v_{2} distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four- and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a Δη>1.4|\Delta\eta| > 1.4 gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87

    Transverse sphericity of primary charged particles in minimum bias proton-proton collisions at s=0.9\sqrt{s}=0.9, 2.76 and 7 TeV

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    Measurements of the sphericity of primary charged particles in minimum bias proton--proton collisions at s=0.9\sqrt{s}=0.9, 2.76 and 7 TeV with the ALICE detector at the LHC are presented. The observable is linearized to be collinear safe and is measured in the plane perpendicular to the beam direction using primary charged tracks with pT0.5p_{\rm T}\geq0.5 GeV/c in η0.8|\eta|\leq0.8. The mean sphericity as a function of the charged particle multiplicity at mid-rapidity (NchN_{\rm ch}) is reported for events with different pTp_{\rm T} scales ("soft" and "hard") defined by the transverse momentum of the leading particle. In addition, the mean charged particle transverse momentum versus multiplicity is presented for the different event classes, and the sphericity distributions in bins of multiplicity are presented. The data are compared with calculations of standard Monte Carlo event generators. The transverse sphericity is found to grow with multiplicity at all collision energies, with a steeper rise at low NchN_{\rm ch}, whereas the event generators show the opposite tendency. The combined study of the sphericity and the mean pTp_{\rm T} with multiplicity indicates that most of the tested event generators produce events with higher multiplicity by generating more back-to-back jets resulting in decreased sphericity (and isotropy). The PYTHIA6 generator with tune PERUGIA-2011 exhibits a noticeable improvement in describing the data, compared to the other tested generators.Comment: 21 pages, 9 captioned figures, 3 tables, authors from page 16, published version, figures from http://aliceinfo.cern.ch/ArtSubmission/node/308
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