Kondo effect under the influence of spin–orbit coupling in a quantum wire

The analysis of the impact of spin–orbit coupling (SOC) on the Kondo state has generated considerable controversy, mainly regarding the dependence of the Kondo temperature T K on SOC strength. Here, we study the one-dimensional (1D) single impurity Anderson model (SIAM) subjected to Rashba (α) and Dresselhaus (β) SOC. It is shown that, due to time-reversal symmetry, the hybridization function between impurity and quantum wire is diagonal and spin independent (as it is the case for the zero-SOC SIAM), thus the finite-SOC SIAM has a Kondo ground state similar to that for the zero-SOC SIAM. This similarity allows the use of the Haldane expression for T K, with parameters renormalized by SOC, which are calculated through a physically motivated change of basis. Analytic results for the parameters of the SOC-renormalized Haldane expression are obtained, facilitating the analysis of the SOC effect over T K. It is found that SOC acting in the quantum wire exponentially decreases T K while SOC at the impurity exponentially increases it. These analytical results are fully supported by calculations using the numerical renormalization group (NRG), applied to the wide-band regime, and the projector operator approach, applied to the infinite-U regime. Literature results, using quantum Monte Carlo, for a system with Fermi energy near the bottom of the band, are qualitatively reproduced, using NRG. In addition, it is shown that the 1D SOC SIAM for arbitrary α and β displays a persistent spin helix SU(2) symmetry similar to the one for a 2D Fermi sea with the restriction α = β.VL acknowledges a PhD scholarship from the Brazilian Agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), process 160071/2015-1, and financial support from the Generalitat Valenciana through Grant reference Prometeo 2017/139. MM acknowledges a PhD scholarship from the Brazilian Agency Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). GBM acknowledges financial support from CNPq, processes 424711/2018-4 and 305150/2017-0. EVA acknowledges financial support from CNPq, process 306000/2017-2

Timpanismo e empiema de bolsa gutural conseqüente a garrotilho

Strangles is a contagious disease that affect the equine upper respiratory tract, frequent and important, that causes pyrexia, nasal discharge and secretion of pus from lymph nodes. Often occur in young equines and is caused by Streptococcus equi â-hemolytic. Some times the strangles can promote results how sinusitis, guttural pouch empyema and distant abscess formation, main in the mesentery. The objective of this paper is study of timpany and empyema of guttural pouch associated with strangles, clinic and cirurgic, happened in a young horse.Garrotilho é uma doença infecto-contagiosa do trato respiratório superior dos eqüídeos, freqüente e importante, que causa pirexia, descarga nasal e abscedação dos linfonodos adjacentes. Acomete basicamente equídeos jovens, e é causada pelo Streptococcus equi â-hemolítico. Ocasionalmente, o garrotilho pode deixar seqüelas como sinusites, empiema das bolsas guturais e formação de abcessos à distância, principalmente no mesentério. O objetivo deste estudo é avaliar o timpanismo e empiema de bolsa gutural, clínico e cirúrgico, conseqüente a garrrotilho, ocorrido num eqüino jovem

Aplicação da estimulação magnética transcraniana de repetição no tratamento do transtorno obsessivo-compulsivo e outros transtornos de ansiedade

A estimulação magnética transcraniana de repetição (EMTr) vem sendo amplamente investigada como ferramenta terapêutica em transtornos psiquiátricos, especialmente a depressão. Neste trabalho, compilamos as informações provenientes de estudos que investigaram as aplicações da EMTr no tratamento dos transtornos de ansiedade: transtorno do pânico (TP), transtorno de estresse pós-taumático (TEPT), transtorno de ansiedade generalizada (TAG) e especialmente o transtorno obsessivo compulsivo (TOC). Três estudos foram publicados abordando o tratamento do TOC, sendo que utilizaram metodologias e parâmetros de aplicação extremamente diversos, dificultando a obtenção de informações conclusivas sobre a efetividade deste tratamento. Quatro estudos publicados sobre TEPT e EMTr também apresentam dados conflitantes e pouco comparáveis, mas destaca-se publicação recente com desenho duplo-cego e resultados positivos. Quanto ao TP e o TAG, apenas pequenas investigações iniciais foram realizadas. Conclusão: Apesar dos estudos citados, não há dados conclusivos sobre a eficácia terapêutica da EMTr nos transtornos de ansiedade. Isto se dá especialmente devido aos estudos com amostras pequenas e desenho aberto. Portanto, devem ser realizados estudos mais aprofundados para que possamos obter estas respostas.Repetitive transcranial magnetic stimulation (rTMS) have been widely studied as a therapeutic method in psychiatric disorders, specially in major depression. In this paper, we have compiled the information from studies concerning the use of rTMS as a therapeutic tool for anxiety disorders: panic disorder (PD), post-traumattic stress disorder (PTSD), generalized anxiety disorder (GAD) and mainly obsessive-compulsive disorder (OCD).Three studies have been published concerning treatment of OCD with rTMS, but they are very different in their methods and in the application parameters and location, making it difficult to draw any conclusion about the efficacy of rTMS in this cases. Four studies published on PTSD also showed very ambiguous and hardly comparable data, but a recent double-blind study with positive results is discussed. Very few inicial investigations are available concerning PD and GAD. Conclusion: Although many studies are mentioned, thete is no conclusive data about the therapeutic efficacy of rTMS in anxiety disorders. It is mainly due to a large number of open-labelled studies with small sample sizes. Therefore, studies with a deeper approach are needed to provide this answers

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

The role of natural science collections in the biomonitoring of environmental contaminants in apex predators in support of the EU's zero pollution ambition

The chemical industry is the leading sector in the EU in terms of added value. However, contaminants pose a major threat and significant costs to the environment and human health. While EU legislation and international conventions aim to reduce this threat, regulators struggle to assess and manage chemical risks, given the vast number of substances involved and the lack of data on exposure and hazards. The European Green Deal sets a 'zero pollution ambition for a toxic free environment' by 2050 and the EU Chemicals Strategy calls for increased monitoring of chemicals in the environment. Monitoring of contaminants in biota can, inter alia: provide regulators with early warning of bioaccumulation problems with chemicals of emerging concern; trigger risk assessment of persistent, bioaccumulative and toxic substances; enable risk assessment of chemical mixtures in biota; enable risk assessment of mixtures; and enable assessment of the effectiveness of risk management measures and of chemicals regulations overall. A number of these purposes are to be addressed under the recently launched European Partnership for Risk Assessment of Chemicals (PARC). Apex predators are of particular value to biomonitoring. Securing sufficient data at European scale implies large-scale, long-term monitoring and a steady supply of large numbers of fresh apex predator tissue samples from across Europe. Natural science collections are very well-placed to supply these. Pan-European monitoring requires effective coordination among field organisations, collections and analytical laboratories for the flow of required specimens, processing and storage of specimens and tissue samples, contaminant analyses delivering pan-European data sets, and provision of specimen and population contextual data. Collections are well-placed to coordinate this. The COST Action European Raptor Biomonitoring Facility provides a well-developed model showing how this can work, integrating a European Raptor Biomonitoring Scheme, Specimen Bank and Sampling Programme. Simultaneously, the EU-funded LIFE APEX has demonstrated a range of regulatory applications using cutting-edge analytical techniques. PARC plans to make best use of such sampling and biomonitoring programmes. Collections are poised to play a critical role in supporting PARC objectives and thereby contribute to delivery of the EU's zero-pollution ambition.Non peer reviewe

b-tagging in DELPHI at LEP

Abstract: The standard method used for tagging b-hadrons in the DELPHI experiment at the CERN LEP Collider is discussed in detail. The main ingredient of b-tagging is the impact parameters of tracks, which relies mostly on the vertex detector. Additional information, such as the mass of particles associated to a secondary vertex, significantly improves the selection efficiency and the background suppression. The paper describes various discriminating variables used for the tagging and the procedure of their combination. In addition, applications of b-tagging to some physics analyses, which depend crucially on the performance and reliability of b-tagging, are described briefly

Investigation of the splitting of quark and gluon jets

The splitting processes in identified quark and gluon jets are investigated using longitudinal and transverse observables. The jets are selected from symmetric three-jet events measured in Z decays with the Delphi detector in 1991-1994. Gluon jets are identified using heavy quark anti-tagging. Scaling violations in identified gluon jets are observed for the first time. The scale energy dependence of the gluon fragmentation function is found to be about two times larger than for the corresponding quark jets, consistent with the QCD expectation TeX . The primary splitting of gluons and quarks into subjets agrees with fragmentation models and, for specific regions of the jet resolution TeX , with NLLA calculations. The maximum of the ratio of the primary subjet splittings in quark and gluon jets is TeX . Due to non-perturbative effects, the data are below the expectation at small TeX . The transition from the perturbative to the non-perturbative domain appears at smaller TeX for quark jets than for gluon jets. Combined with the observed behaviour of the higher rank splittings, this explains the relatively small multiplicity ratio between gluon and quark jets