Single magnetic impurities in the Kane-Mele model

The realization of the spin-Hall effect in quantum wells has led to a plethora of studies regarding the properties of the edge states of a 2D topological insulator. These edge states constitute a class of one-dimensional liquids, called the helical liquid, where an electron's spin quantization axis is tied to its momentum. In contrast to one dimensional conductors, magnetic impurities - below the Kondo temperature - cannot block transport and one expects the current to circumvent the impurity. To study this phenomenon, we consider the single impurity Anderson model embedded into an edge of a Kane-Mele ribbon with up to 512x80 sites and use the numerically exact continuous time QMC method to study the Kondo effect. We present results on the temperature dependence of the spectral properties of the impurity and the bulk system that show the behaviour of the system in the various regimes of the Anderson model. A view complementary to the single particle spectral functions can be obtained using the spatial behaviour of the spin-spin correlation functions. Here we show the characteristic, algebraic decay in the edge channel near the impurity.Comment: 14 pages, 14 Figures, submitted to PR

Revisiting the Hybrid Quantum Monte Carlo Method for Hubbard and Electron-Phonon Models

A unique feature of the hybrid quantum Monte Carlo (HQMC) method is the potential to simulate negative sign free lattice fermion models with subcubic scaling in system size. Here we will revisit the algorithm for various models. We will show that for the Hubbard model the HQMC suffers from ergodicity issues and unbounded forces in the effective action. Solutions to these issues can be found in terms of a complexification of the auxiliary fields. This implementation of the HQMC that does not attempt to regularize the fermionic matrix so as to circumvent the aforementioned singularities does not outperform single spin flip determinantal methods with cubic scaling. On the other hand we will argue that there is a set of models for which the HQMC is very efficient. This class is characterized by effective actions free of singularities. Using the Majorana representation, we show that models such as the Su-Schrieffer-Heeger Hamiltonian at half filling and on a bipartite lattice belong to this class. For this specific model sub-cubic scaling is achieved

Identity development in adolescents with mental problems

Background: In the revision of the Diagnostic and Statistical Manual (DSM-5), "Identity" is an essential diagnostic criterion for personality disorders (self-related personality functioning) in the alternative approach to the diagnosis of personality disorders in Section III of DSM-5. Integrating a broad range of established identity concepts, AIDA (Assessment of Identity Development in Adolescence) is a new questionnaire to assess pathology-related identity development in healthy and disturbed adolescents aged 12 to 18 years. Aim of the present study is to investigate differences in identity development between adolescents with different psychiatric diagnoses. Methods: Participants were 86 adolescent psychiatric in- and outpatients aged 12 to 18 years. The test set includes the questionnaire AIDA and two semi-structured psychiatric interviews (SCID-II, K-DIPS). The patients were assigned to three diagnostic groups (personality disorders, internalizing disorders, externalizing disorders). Differences were analyzed by multivariate analysis of variance MANOVA. Results: In line with our hypotheses, patients with personality disorders showed the highest scores in all AIDA scales with T>70. Patients with externalizing disorders showed scores in an average range compared to population norms, while patients with internalizing disorders lay in between with scores around T=60. The AIDA total score was highly significant between the groups with a remarkable effect size of f= 0.44. Conclusion: Impairment of identity development differs between adolescent patients with different forms of mental disorders. The AIDA questionnaire is able to discriminate between these groups. This may help to improve assessment and treatment of adolescents with severe psychiatric problems

Uso de la ciclosporina en el tratamiento de las fístulas perianales caninas a propósito de cuatro casos clínicos

Se describen los resultados del tratamiento con ciclosporina en cuatro casos clínicos (tres machos y una hembra) de perros Pastores Alemanes afectados de fístulas perianales. La evolución a largo plazo y los escasos efectos secundarios observados en los pacientes tratados nos permiten considerar a esta droga como una muy buena opción en el tratamiento de esta patología.

Araucariácea nativa de argentina : estado de conservación y características del recurso forestal Araucaria araucana (Molina) K. Koch

La familia Araucariáceas está representada en Argentina por el género Araucaria; A. araucana se encuentra distribuida naturalmente al sur restringida a un clima extremo y aunque ha encontrado condiciones agroclimáticas únicas para prosperar, el grave estado de conservación en que se encuentran, peligra la perpetuidad no solo de ella sino también del ecosistema que la alberga, ya que contribuye a mantener un equilibrio ecológico único. El presente trabajo describe las características ecológicas de la especie y resume los aspectos más relevantes del estado de conservación y hábitat de este representante nativo de un género tan emblemático, ya que solo a través del conocimiento del patrimonio que poseemos es posible implementar acciones para su conservación, protección e integración de las comunidades locales en dicha actividades.The Araucariaceae family in Argentina is represented by the genus Araucaria; A. araucana is naturally distributed to the south restricted to extreme weather and although it has found unique growing conditions to thrive, severe condition they are in, endangered the perpetuity not only her but also the ecosystem that houses it, as it helps to maintain a unique ecological balance. This paper describes the ecological characteristics of the species and summarizes the most relevant aspects of the conservation status and habitat of this native representative of as emblematic genre; because only through knowledge of the heritage we have is possible to implement actions for their conservation, protection and integration of local communities in such activities.Fil: Goth, Silvia A.. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; ArgentinaFil: Fontana, María Laura. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); ArgentinaFil: Luna, Claudia Verónica. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentin