Dynamical matrix for arbitrary quadratic fermionic bath Hamiltonians and non-Markovian dynamics of one and two qubits in an Ising model environment

We obtain the analytical expression for the Kraus decomposition of the quantum map of an environment modeled by an arbitrary quadratic fermionic Hamiltonian acting on one or two qubits, and derive simple functions to check the non-positivity of the intermediate map. These functions correspond to two different sufficient criteria for non-Markovianity. In the particular case of an environment represented by the Ising Hamiltonian, we discuss the two sources of non-Markovianity in the model, one due to the finite size of the lattice, and another due to the kind of interactions.Comment: 11 pages, 10 figure

Avaliação da depleção linfóide folicular da Bursa de Fabricius: uma metodologia alternativa utilizando análise digital de imagem e redes neurais artificiais

Fifty Bursa of Fabricius (BF) were examined by conventional optical microscopy and digital images were acquired and processed using Matlab® 6.5 software. The Artificial Neuronal Network (ANN) was generated using Neuroshell® Classifier software and the optical and digital data were compared. The ANN was able to make a comparable classification of digital and optical scores. The use of ANN was able to classify correctly the majority of the follicles, reaching sensibility and specificity of 89% and 96%, respectively. When the follicles were scored and grouped in a binary fashion the sensibility increased to 90% and obtained the maximum value for the specificity of 92%. These results demonstrate that the use of digital image analysis and ANN is a useful tool for the pathological classification of the BF lymphoid depletion. In addition it provides objective results that allow measuring the dimension of the error in the diagnosis and classification therefore making comparison between databases feasible.Cinquenta Bursa de Fabrícius (BF) foram examinadas através de microscopia óptica convencional e imagens digitais foram obtidas e processadas através do software Matlab® 6.5. Redes Neurais Artificiais (ANN) foram geradas com a utilização do software Neuroshell® Classifier, e os dados das análises óptica e digital foram comparados. A ANN classificou corretamente a maioria dos folículos, atingindo sensibilidade e especificidade de 89% e 96%, respectivamente. Quando os folículos foram agrupados de forma binária houve um aumento da sensibilidade para 90% e obteve-se um valor máximo para a especificidade de 92%. Estes resultados demonstram que o uso da análise digital de imagem associada à ANNé uma ferramenta bastante útil para a classificação patológica da depleção linfóide da BF. Além disso, fornece resultados objetivos que permitem medir a dimensão do erro classificatório, tornando possível a comparação entre distintos bancos de dados

Tympanic paragangliomas: case reports

Glomus tumors, also called paragangliomas, originate from nonchromaffin cells. The tumor is typically vascular and grows from capillary and pre-capillary vessels in-between epithelial cells. It is worth mentioning that the most common symptoms are pulsating tinnitus and hearing loss. Imaging studies (CT and MRI) are necessary for diagnosis. This paper shows five patients seen at the Hospital between 1995 and 2001 presenting glomus tympanicum. Women were most commonly affected, and the age ranged from 48 to 60 years (mean age of 50 years). The most common complaints were pulsating tinnitus and hearing loss. All patients were treated surgically.Os tumores glômicos, também chamados de paragangliomas, são formados por células não cromafins. O tumor é tipicamente vascular formado por vasos capilares e pré-capilares, interposto por células epiteliais. Para a sua abordagem inicial, deve-se ressaltar que os sintomas mais comumentes encontrados são o zumbido pulsátil e hipoacusia. A investigação através de imagem (tomografia computadorizada e ressonância magnética) se faz necessária. Apresentaremos neste trabalho 5 pacientes portadores de paragangliomas timpânicos atendidos no Hospital (de 1995 a 2001). O sexo predominante foi o feminino, a idade variou de 48 a 60 anos, com média de 50 anos. A queixa predominante foi o zumbido pulsátil e a hipoacusia. A conduta foi cirúrgica em todos os casos.Hospital Paulista de OtorrinolaringologiaUNIFESP-EPMUNIFESP, EPMSciEL

Qualidade de pêssegos cultivares Granada e Maciel colhidos em diferentes graus de maturidade em armazenamento refrigerado

In this study the effects of ripening stages on the quality of peaches cultivars Granada and Macielduring cold storage were evaluated. Peaches of both cultivars at ripening stages: green, semi-green, semi-ripen and ripen, were kept during 30 days (‘Granada’) or 40 days (‘Maciel’) in a cold room, at 0 ± 0,5oC cold storage temperature and 85% to 90% relative humidity. At every-ten-days period fruits were taken out of the cold room and after three days under room temperature, the following variables were evaluated: weight loss; color, firmness;total soluble solids (TSS); total titratable acidity (TTA); decay; internal browning; mealiness; polyphenoloxidase activity; phenols and sensorial aspects. It was concluded that for regular cold storage, peaches of ‘Granada’should be harvested at the semi-green stage and cold stored for up to 30 days; harvested at the semi-ripen stage and cold stored for up to 20 days; harvested at the ripen stage for immediate marketing. Peaches of the ‘Maciel’should be harvested at the semi-green ripening stage and cold stored for up to 20 days; harvested at the semiripen stage and cold stored for up to ten days and or harvested at the ripen stage for immediate marketing.Nesse estudo foi avaliado o efeito do grau de maturação na qualidade pós-colheita de pêssegoscultivares Granada e Maciel, durante o armazenamento refrigerado. As frutas foram selecionadas nos estádiosde maturação verde, meio-verde, meio-maduro e maduro, sendo armazenadas por até 30 dias as da cultivarGranada e até 40 dias as da cultivar Maciel, em temperatura de 0 ± 0,5oC e 85% a 90% de umidade relativa. A cadadez dias as frutas foram retiradas da câmara, e após três dias em temperatura de 20 ± 0,5oC avaliou-se a perdade peso, a firmeza de polpa, os sólidos solúveis totais (SST), a acidez total titulável (ATT), as porcentagens depodridões, o escurecimento interno, a farinosidade, a atividade da polifenoloxidase, os fenóis e característicassensoriais. A partir dos resultados, pode-se concluir que pêssegos ‘Granada’, colhidos nos estádios de maturaçãomeio-verde e meio-maduro são conservados com qualidade comercial, durante 30 e 20 dias, respectivamente; eos pêssegos ‘Maciel’, durante 20 dias, quando colhidos no estádio de maturação meio-verde e por dez dias no estádiomeio-maduro

XPR1 mediates the pancreatic B-cell phosphate flush

Glucose-stimulated insulin secretion is the hallmark of the pancreatic β-cell, a critical player in the regulation of blood glucose concentration. In 1974, the remarkable observation was made that an efflux of intracellular inorganic phosphate (P ) accompanied the events of stimulated insulin secretion. The mechanism behind this "phosphate flush," its association with insulin secretion, and its regulation have since then remained a mystery. We recapitulated the phosphate flush in the MIN6m9 β-cell line and pseudoislets. We demonstrated that knockdown of XPR1, a phosphate transporter present in MIN6m9 cells and pancreatic islets, prevented this flush. Concomitantly, XPR1 silencing led to intracellular P accumulation and a potential impact on Ca signaling. XPR1 knockdown slightly blunted first-phase glucose-stimulated insulin secretion in MIN6m9 cells, but had no significant impact on pseudoislet secretion. In keeping with other cell types, basal P efflux was stimulated by inositol pyrophosphates, and basal intracellular P accumulated following knockdown of inositol hexakisphosphate kinases. However, the glucose-driven phosphate flush occurred despite inositol pyrophosphate depletion. Finally, while it is unlikely that XPR1 directly affects exocytosis, it may protect Ca signaling. Thus, we have revealed XPR1 as the missing mediator of the phosphate flush, shedding light on a 45-year-old mystery