6,512 research outputs found
Study of VV Scattering Processes as a Probe of Electroweak Symmetry Breaking
An exploratory study has been performed in order to assess the possibility of
probing the symmetry breaking mechanism through the fusion process using
the CMS detector. A model independent analysis was carried out with no
assumption on the mechanism restoring the unitarity in the scattering amplitude
and without any degrees of freedom beyond the SM. In order to explore the
sensitivity of the analysis method to an heavy Higgs resonance, we analyzed a
data set produced using an Higgs boson mass of . Moreover, in order to
consider the fusion cross section in a region where no resonances are
present, a sample corresponding to the no-Higgs scenario, that in the SM is
equivalent to a very high Higgs mass, has been also studied.Comment: conferenc
Vibronic interaction in crystals with the Jahn-Teller centers in the elementary energy bands concept
The order-disorder type phase transition caused by the vibronic interaction
(collective Jahn-Teller effect) in a monoclinic CuInPS crystal is
analyzed. For this purpose, a trigonal protostructure model of CuInPS
is created, through a slight change in the crystal lattice parameters of the
CuInPS paraelectric phase. In parallel to the group-theoretical
analysis, the DFT-based {\it ab initio} band structure calculations of the
CuInPS protostructure, para-, and ferriphases are performed. Using the
elementary energy bands concept, a part of the band structure from the vicinity
of the forbidden energy gap, which is created by the -electron states of
copper, has been related with a certain Wyckoff position where the
Jahn-Teller's centers are localized. A construction procedure of the vibronic
potential energy matrix is generalized for the case of crystal using the
elementary energy bands concept and the group theoretical method of invariants.
The procedure is illustrated by the creation of the adiabatic potentials of the
- vibronic coupling for the protostructure and paraphase of
the CuInPS crystal. A structure of the obtained adiabatic potentials is
analyzed, followed by conclusions on their transformation under a phase
transition and the discussion on the possibility for the spontaneous
polarization to arise in this crystal.Comment: 17 pages, 7 figure
Adverse childhood experiences increase HIV risk factors in Agbogbloshie, Ghana
Adverse Childhood Experiences (ACEs) have been associated with increased risk factors for HIV transmission, but the causal pathway is uncertain. This study documents the prevalence of ACEs by gender and their association with HIV risk factors and assesses depressive symptoms as mediating this relationship. A cross-sectional survey was conducted in 2019 among a representative sample of men and women, aged 18–24 years, living in an informal settlement in Accra, Ghana. Data on sociodemographic characteristics, ACEs, ten HIV risk factors (five sexual behaviors, HIV/AIDS knowledge, sexual assault, three substance use behaviors), and depressive symptoms were collected. Multiple logistic regression models were estimated to assess the independent association between four or more ACEs and each of the ten HIV risk factors. Structural equation models examined depressive symptoms as a mediator in these associations. A third (34.6%) of participants reported four or more ACEs, and among those who experienced four or more ACEs 60% were men and 40% were women. Gender did not modify the effect of the association between four or more ACEs and HIV factors and therefore the multiple regression analysis was not stratified by gender. After controlling for sociodemographic covariates and depressive symptoms, having experienced four or more ACEs was associated with alcohol use (OR = 3.88; 95% CI: 1.34, 11.21), injection drug use (OR = 2.78; 95% CI: 1.15, 6.73), low knowledge of HIV (OR = 3.59; 95% CI: 1.43, 9.00), sexually transmitted infection (OR = 3.70; 95% CI: 1.15, 11.96), and sexual assault (OR = 3.58; 95% CI: 1.07, 12.05). There was some evidence that depressive symptoms could be mediating the association between reporting four or more ACEs and ever having a sexually transmitted infection. The mitigation of ACEs and depressive symptoms has the potential to decrease HIV risk factors and thus reduce the risk for HIV transmission among youth living in informal settlements
Genetic basis for variation in wheat grain yield in response to varying nitrogen application
Nitrogen (N) is a major nutrient needed to attain optimal grain yield (GY) in all environments. Nitrogen fertilisers represent a significant production cost, in both monetary and environmental terms. Developing genotypes capable of taking up N early during development while limiting biomass production after establishment and showing high N-use efficiency (NUE) would be economically beneficial. Genetic variation in NUE has been shown previously. Here we describe the genetic characterisation of NUE and identify genetic loci underlying N response under different N fertiliser regimes in a bread wheat population of doubled-haploid lines derived from a cross between two Australian genotypes (RAC875 × Kukri) bred for a similar production environment. NUE field trials were carried out at four sites in South Australia and two in Western Australia across three seasons. There was genotype-by-environment- by-treatment interaction across the sites and also good transgressive segregation for yield under different N supply in the population. We detected some significant Quantitative Trait Loci (QTL) associated with NUE and N response at different rates of N application across the sites and years. It was also possible to identify lines showing positive N response based on the rankings of their Best Linear Unbiased Predictions (BLUPs) within a trial. Dissecting the complexity of the N effect on yield through QTL analysis is a key step towards elucidating the molecular and physiological basis of NUE in wheat.Saba Mahjourimajd, Julian Taylor, Beata Sznajder, Andy Timmins, Fahimeh Shahinnia, Zed Rengel, Hossein Khabaz-Saberi, Haydn Kuchel, Mamoru Okamoto, Peter Langridg
Overcoming Postcommunist Labour Weakness: Attritional and Enabling Effects of MNCs in Central and Eastern Europe
Based on micro-level analysis of the developments in the steel sector in Poland, Romania and Slovakia, this paper examines the effects of multinational corporations (MNCs) on labour unions in Central and Eastern Europe. It makes a three-fold argument. First, it shows that union weakness can be attributed to unions’ strategies during the restructuring and privatization processes of postcommunist transition. Consequently, tactics used for union regeneration in the West are less applicable to CEE. Rather, the overcoming of postcommunist legacy is linked to the power of transnational capital. Through attritional and enabling effects, ownership by MNCs forces the unions to focus their efforts on articulating workers’ interests. The paper examines the emerging system of industrial relations in the sector and explores the development of the capabilities needed to overcome postcommunist legacies
Wp-2 basic investigation of transition effect
An important goal of the TFAST project was to study the effect of the location of transition in relation to the shock wave on the separation size, shock structure and unsteadiness of the interaction area. Boundary layer tripping (by wire or roughness) and flow control devices (Vortex Generators and cold plasma) were used for boundary layer transition induction. As flow control devices were used here in the laminar boundary layer for the first time, their effectiveness in transition induction was an important outcome. It was intended to determine in what way the application of these techniques induces transition. These methods should have a significantly different effect on boundary layer receptivity, i.e. the transition location. Apart from an improved understanding of operation control methods, the main objective was to localize the transition as far downstream as possible while ensuring a turbulent character of interaction. The final objective, involving all the partners, was to build a physical model of transition control devices. Establishing of such model would simplify the numerical approach to flow cases using such devices. This undertaking has strong support from the industry, which wants to include these control devices in the design process. Unfortunately only one method of streamwise vortices was developed and investigated in the presented study
First Measurement of Chiral Dynamics in \pi^- \gamma -> \pi^- \pi^- \pi^+
The COMPASS collaboration at CERN has investigated the \pi^- \gamma -> \pi^-
\pi^- \pi^+ reaction at center-of-momentum energy below five pion masses,
sqrt(s) < 5 m(\pi), embedded in the Primakoff reaction of 190 GeV pions
impinging on a lead target. Exchange of quasi-real photons is selected by
isolating the sharp Coulomb peak observed at smallest momentum transfers, t' <
0.001 (GeV/c)^2. Using partial-wave analysis techniques, the scattering
intensity of Coulomb production described in terms of chiral dynamics and its
dependence on the 3\pi-invariant mass m(3\pi) = sqrt(s) were extracted. The
absolute cross section was determined in seven bins of with an
overall precision of 20%. At leading order, the result is found to be in good
agreement with the prediction of chiral perturbation theory over the whole
energy range investigated.Comment: 10 pages, 5 figure
Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering
A semi-inclusive measurement of charged hadron multiplicities in deep
inelastic muon scattering off an isoscalar target was performed using data
collected by the COMPASS Collaboration at CERN. The following kinematic domain
is covered by the data: photon virtuality (GeV/), invariant
mass of the hadronic system GeV/, Bjorken scaling variable in the
range , fraction of the virtual photon energy carried by the
hadron in the range , square of the hadron transverse momentum
with respect to the virtual photon direction in the range 0.02 (GeV/ (GeV/). The multiplicities are presented as a
function of in three-dimensional bins of , , and
compared to previous semi-inclusive measurements. We explore the
small- region, i.e. (GeV/), where
hadron transverse momenta are expected to arise from non-perturbative effects,
and also the domain of larger , where contributions from
higher-order perturbative QCD are expected to dominate. The multiplicities are
fitted using a single-exponential function at small to study
the dependence of the average transverse momentum on , and . The power-law behaviour of the
multiplicities at large is investigated using various
functional forms. The fits describe the data reasonably well over the full
measured range.Comment: 28 pages, 20 figure
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