Farm Forestry.

17 p

Generalized Phase-Space Techniques to Explore Quantum Phase Transitions in Critical Quantum Spin Systems

We apply the generalized Wigner function formalism to detect and characterize a range of quantum phase transitions in several cyclic, finite-length, spin-$\frac{1}{2}$ one-dimensional spin-chain models, viz., the Ising and anisotropic $XY$ models in a transverse field, and the $XXZ$ anisotropic Heisenberg model. We make use of the finite system size to provide an exhaustive exploration of each system's single-site, bipartite and multi-partite correlation functions. In turn, we are able to demonstrate the utility of phase-space techniques in witnessing and characterizing first-, second- and infinite-order quantum phase transitions, while also enabling an in-depth analysis of the correlations present within critical systems. We also highlight the method's ability to capture other features of spin systems such as ground-state factorization and critical system scaling. Finally, we demonstrate the generalized Wigner function's utility for state verification by determining the state of each system and their constituent sub-systems at points of interest across the quantum phase transitions, enabling interesting features of critical systems to be intuitively analyzed.Comment: 20 pages, 8 figure

Levantamento da Realização de exames periódicos preventivos em funcionários do UniFOA e pacientes da Policlínica André Bianco

Os métodos de rastreamento permitem uma avaliação precoce dos estados fisiológicos e porventura patológicos de pacientes que não possuem indícios clínicos de doença e que se enquadrem na população de risco. Os mesmos são baseados em evidência, adotados por sistemas de saúde nacionais e internacionais com faixa da população que se submete a tais exames como preventivos do câncer de colo uterino, mamografia e próstata. Entretanto há questionamentos sobre qual parcela da população é candidata a estes métodos, principalmente no que tange a faixa etária, o conhecimento público da importância desta prática que se traduz pela não adesão e a verdadeira eficácia de cada exame. Objetiva-se verificar se existe algum fator preditivo para a adesão ou não dos candidatos a testes de rastreamento, um melhor compreendimento das razões pelas quais a procura pela medicina preventiva por parte do paciente não é ótima. A pesquisa, em andamento, é realizada em domínios do UniFOA, na cidade de Volta Redonda-RJ. Foram aplicados, até o presente momento, 211 questionários contendo perguntas a serem respondidas pelo pesquisado, mediante a assinatura de um Termo de Consentimento Livre e Esclarecido. Todos os questionários obtidos foram incluídos, uma vez que preenchiam os critérios de inclusão. Esta avaliação baseia-se em análise interina não planejada, após coleta de 18,11% do total de entrevistas intencionadas. O que se pode observar apesar de um “n” ainda pouco significativo é que o acesso a medicina privada através de planos ou seguros de saúde, aparenta ser um fator facilitador para a realização de exames preventivos ginecológicos, justificado pelo fato de 73% dos entrevistados que relataram dificuldade não serem possuidores dos mesmos. Este dado também é reproduzido entre indivíduos do sexo masculino, cerca de 20% que referem a não realização de exames preventivos contra o câncer de próstata por conta de dificuldade de acesso ao mesmo

Brownian Carnot engine

The Carnot cycle imposes a fundamental upper limit to the efficiency of a macroscopic motor operating between two thermal baths. However, this bound needs to be reinterpreted at microscopic scales, where molecular bio-motors and some artificial micro-engines operate. As described by stochastic thermodynamics, energy transfers in microscopic systems are random and thermal fluctuations induce transient decreases of entropy, allowing for possible violations of the Carnot limit. Despite its potential relevance for the development of a thermodynamics of small systems, an experimental study of microscopic Carnot engines is still lacking. Here we report on an experimental realization of a Carnot engine with a single optically trapped Brownian particle as working substance. We present an exhaustive study of the energetics of the engine and analyze the fluctuations of the finite-time efficiency, showing that the Carnot bound can be surpassed for a small number of non-equilibrium cycles. As its macroscopic counterpart, the energetics of our Carnot device exhibits basic properties that one would expect to observe in any microscopic energy transducer operating with baths at different temperatures. Our results characterize the sources of irreversibility in the engine and the statistical properties of the efficiency -an insight that could inspire novel strategies in the design of efficient nano-motors.Comment: 7 pages, 7 figure

Spatiotemporal expansion of primary progenitor zones in the developing human cerebellum

We present histological and molecular analyses of the developing human cerebellum from 30 days after conception to 9 months after birth. Differences in developmental patterns between humans and mice include spatiotemporal expansion of both ventricular and rhombic lip primary progenitor zones to include subventricular zones containing basal progenitors. The human rhombic lip persists longer through cerebellar development than in the mouse and undergoes morphological changes to form a progenitor pool in the posterior lobule, which is not seen in other organisms, not even in the nonhuman primate the macaque. Disruptions in human rhombic lip development are associated with posterior cerebellar vermis hypoplasia and Dandy-Walker malformation. The presence of these species-specific neural progenitor populations refines our insight into human cerebellar developmental disorders

Spatiotemporal expansion of primary progenitor zones in the developing human cerebellum

We present histological and molecular analyses of the developing human cerebellum from 30 days after conception to 9 months after birth. Differences in developmental patterns between humans and mice include spatiotemporal expansion of both ventricular and rhombic lip primary progenitor zones to include subventricular zones containing basal progenitors. The human rhombic lip persists longer through cerebellar development than in the mouse and undergoes morphological changes to form a progenitor pool in the posterior lobule, which is not seen in other organisms, not even in the nonhuman primate the macaque. Disruptions in human rhombic lip development are associated with posterior cerebellar vermis hypoplasia and Dandy-Walker malformation. The presence of these species-specific neural progenitor populations refines our insight into human cerebellar developmental disorders

Contesting the psychiatric framing of ME / CFS

ME/CFS is a medically contested illness and its understanding, framing and treatment has been the subject of heated debate. This paper examines why framing the condition as a psychiatric issue—what we refer to as ‘psychiatrisation’—has been so heavily contested by patients and activists. We argue that this contestation is not simply about stigmatising mental health conditions, as some have suggested, but relates to how people diagnosed with mental illness are treated in society, psychiatry and the law. We highlight the potentially harmful consequences of psychiatrisation which can lead to people’s experiential knowledge being discredited. This stems, in part, from a psychiatric-specific form of ‘epistemic injustice’ which can result in unhelpful, unwanted and forced treatments. This understanding helps explain why the psychiatrisation of ME/CFS has become the focus of such bitter debate and why psychiatry itself has become such a significant field of contention, for both ME/CFS patients and mental health service users/survivors. Notwithstanding important differences, both reject the way psychiatry denies patient explanations and understandings, and therefore share a collective struggle for justice and legitimation. Reasons why this shared struggle has not resulted in alliances between ME and mental health activists are noted