Beyond the Standard Model Higgs Searches at ATLAS

The discovery of a neutral Higgs boson with large decay branching fraction to tau and muon pairs final states, as well as the discovery of a charged Higgs boson would represent a strong evidence of New Physics beyond the Standard Model. The potential discovery of these processes with the ATLAS detector at the Large Hadron Collider is presented. The studies are based on the analysis of Monte Carlo signal and background data simulated in detail through the experimental apparatus

Experimental evaluation of the power balance model of speed skating

Prediction of speed skating performance with a power balance model requires assumptions about the kinetics of energy production, skating efficiency, and skating technique. The purpose of this study was to evaluate these parameters during competitive imitations for the purpose of improving model predictions. Elite speed skaters (n = 8) performed races and submaximal efficiency tests. External power output (Po) was calculated from movement analysis and aerodynamic models and ice friction measurements. Aerobic kinetics was calculated from breath-by-breath oxygen uptake (V̇O2). Aerobic power (Paer) was calculated from measured skating efficiency. Anaerobic power (Pan) kinetics was determined by subtracting P aer from Po. We found gross skating efficiency to be 15.8% (1.8%.). In the 1,500-m event, the kinetics of Pan was characterized by a first-order system as Pan = 88 + 556e-0.0494t (in W, where t is time). The rate constant for the increase in Paer was -0.153 s-1, the time delay was 8.7 s, and the peak Paer was 234 W; Paer was equal to 234[1 - e-0.153(t-8.7)] (in W). Skating position changed with preextension knee angle increasing and trunk angle decreasing throughout the event. We concluded the pattern of P aer to be quite similar to that reported during other competitive imitations, with the exception that the increase in Paer was more rapid. The pattern of Pan does not appear to fit an "all-out" pattern, with near zero values during the last portion of the event, as assumed in our previous model (De Koning JJ, de Groot G, and van Ingen Schenau GJ. J Biomech 25: 573-580, 1992). Skating position changed in ways different from those assumed in our previous model. In addition to allowing improved predictions, the results demonstrate the importance of observations in unique subjects to the process of model construction

Anisotropic susceptibilities in the honeycomb Kitaev system α−RuCl3

The magnetic insulator α−RuCl3 is a promising candidate to realize Kitaev interactions on a quasi-two-dimensional honeycomb lattice. We perform extensive susceptibility measurements on single crystals of α−RuCl3, including angle dependence of the in-plane longitudinal and transverse susceptibilities, which reveal a unidirectional anisotropy within the honeycomb plane. By comparing the experimental results to a high-temperature expansion of a Kitaev-Heisenberg-Γ spin Hamiltonian with bond anisotropy, we find excellent agreement with the observed phase shift and periodicity of the angle-resolved susceptibilities. Within this model, we show that the pronounced difference between in-plane and out-of-plane susceptibilities as well as the finite transverse susceptibility are rooted in strong symmetric off-diagonal Γ spin exchange. The Γ couplings and relationships between other terms in the model Hamiltonian are quantified by extracting relevant Curie-Weiss intercepts from the experimental data

Propiconazole is an activator of AHR and causes concentration additive effects with an established AHR ligand

Consumers are exposed to pesticide residues and other food contaminants via the diet. Both can exert adverse effects on different target organs via the activation of nuclear receptor pathways. Hepatotoxic effects of the widely used triazole fungicide propiconazole (Pi) are generally attributed to the activation of the constitutive androstane receptor (CAR) or the pregnane X receptor (PXR). We now investigated the effects of Pi on the aryl hydrocarbon receptor (AHR) and possible mixture toxicity when Pi is present in combination with BbF, an AHR ligand. In silico docking simulations indicate that Pi can bind to human AHR. Subsequent dual luciferase reporter gene assays in human HepG2 cells showed that Pi activates the AHR in vitro. This concentration-dependent activation was confirmed by real-time RT-PCR analyses of the model AHR target genes CYP1A1 and CYP1A2 in human HepaRG and HepG2 cells. In addition, induction of CYP1A1 protein levels and enzyme activity were recorded. Similarly, increased mRNA expression and enzyme activity of Cyp1a1 and Cyp1a2 was observed in livers of rats treated with Pi for 28 days via the diet. Gene expression analysis in AHR-knockout HepaRG cells showed no induction of CYP1A1 and CYP1A2, whereas gene expression in CAR-, and PXR-knockout cells was induced. Finally, mixture effects of Pi and BbF were analyzed in human cell lines: modeling of concentration\u2013response curves revealed concentration additivity. In conclusion, our results demonstrate that the triazole Pi is an activator of AHR in silico, in vitro and in vivo and causes additive effects with an established AHR ligand