187 research outputs found

    Quantum mechanics on non commutative spaces and squeezed states: a functional approach

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    We review here the quantum mechanics of some noncommutative theories in which no state saturates simultaneously all the non trivial Heisenberg uncertainty relations. We show how the difference of structure between the Poisson brackets and the commutators in these theories generically leads to a harmonic oscillator whose positions and momenta mean values are not strictly equal to the ones predicted by classical mechanics. This raises the question of the nature of quasi classical states in these models. We propose an extension based on a variational principle. The action considered is the sum of the absolute values of the expressions associated to the non trivial Heisenberg uncertainty relations. We first verify that our proposal works in the usual theory i.e we recover the known Gaussian functions. Besides them, we find other states which can be expressed as products of Gaussians with specific hyper geometrics. We illustrate our construction in two models defined on a four dimensional phase space: a model endowed with a minimal length uncertainty and the non commutative plane. Our proposal leads to second order partial differential equations. We find analytical solutions in specific cases. We briefly discuss how our proposal may be applied to the fuzzy sphere and analyze its shortcomings.Comment: 15 pages revtex. The title has been modified,the paper shortened and misprints have been corrected. Version to appear in JHE

    TEORIAS DE ENFERMAGEM: IMPORTÂNCIA DA CORRETA APLICAÇÃO DOS CONCEITOS

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    Theoretical-reflexive research, whose aim is to analyze the clarity of concept stimulus in the Roy Model, for best comprehension in nursing practice. It was developed in three phases: 1- Search of studies that utilized the Roy Model; 2- Conducted reading for comprehension of the concept stimulus and 3- Analysis of clarity of the concept. The three studies were conducted at master level. The analysis of the studies shows deficiency in the clarity of the concept stimulus, being predominant the ambiguity in the classification and differentiation of the focal and contextual stimuli, without the existence of consistency and uniformity. The need arises to deepen the theories of nursing for adequate application in the areas of research: nursing education and practice, optimizing and improving its use, as well as, enabling the comprehension of determined concepts that are not sufficiently clear. The worries that arise among the nurses will provide a more profound approach to the study, enabling the advance of theories, as well as new findings, leading to necessary changes.  Investigación teórico-reflexiva cuyo objetivo fue analizar la claridad del concepto estímulo según el  modelo de Roy, para mayor comprensión en la práctica de enfermería. Desarrollada en tres etapas: 1ª- Levantamiento de estudios que utilizaron el Modelo de Roy; 2ª - Lectura dirigida hacia la comprensión del concepto estímulo y 3ª - Análisis de la claridad del concepto. Fueron utilizados tres estudios, a  nivel de maestrado. El análisis de los estudios demuestra deficiencia en la claridad del concepto estímulo, predominando ambigüedad en la clasificación y diferenciación de los estímulos focales y contextuales, sin consistencia y uniformidad. Se evidencia la necesidad de profundizar en las teorías de enfermería, para su aplicación adecuada en las áreas de investigación, enseñanza y práctica, optimizando y mejorando su uso, además de posibilitar la comprensión de determinados conceptos no suficientemente claros. Las inquietudes surgidas entre los enfermeros podrán motivar un abordaje más profundo de los estudios, posibilitando el avance de las teorías, así  como nuevos descubrimientos, dirigiendo los cambios necesariosPesquisa teórico-reflexiva, objetivando analisar a clareza do conceito estímulo no modelo de Roy, para maior compreensão na prática de enfermagem. Desenvolvido em três etapas: 1ª- Levantamento de estudos que utilizaram o Modelo de Roy; 2ª - Leitura dirigida para a compreensão do conceito estímulo e 3ª - Análise da clareza do conceito. Foram utilizados três estudos, em nível de mestrado. A análise dos estudos demonstra deficiência na clareza do conceito estímulo, predominando ambigüidade na classificação e diferenciação dos estímulos focais e contextuais, não existindo consistência e uniformidade. Evidencia-se a necessidade do aprofundamento nas teorias de enfermagem, para a aplicação adequada nas áreas de pesquisa, ensino e prática, otimizando e aprimorando seu uso, além de possibilitar a compreensão de determinados conceitos, não suficientemente claros. As inquietações surgidas entre os enfermeiros poderão proporcionar o aprofundamento nos estudos, possibilitando o avanço das teorias, assim como novos achados, direcionando as mudanças necessárias

    Key Points for Curbing Cardiopulmonary Bypass Inflammation

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    ABSTRACT PURPOSE: Cardiopulmonary bypass (CPB) procedures are thought to activate systemic inflammatory reaction syndrome (SIRS). Strategies to curb systemic inflammation have been previously described. However, none of them is adequate, since "curbing" the extent of the inflammatory response requires a multimodal approach. The aim of the present mini-review is to discuss the main key points about the main principles in cardiopulmonary bypass curbing inflammation. METHODS: No systematic literature search (MEDLINE) and extracted data from the accumulated experience of the authors. The preconceived idea of an association between severe inflammation and coagulation disorders is reviewed. Also, some fundamental concepts, CPB inflammatory biomarkers, the vasoplegic syndrome and the need forindividual CPB protocols for children, diabetes and old patients, are discussed. CONCLUSION: The ways in which surgical technique (atraumatic vein harvest, biocompatibility and shear resistance of the circuit, monitoring, minimizing organ ischemia, minimal cross-clamping trauma, and blood management) are thought to curb SIRS induced by CPB and affect positively the patient outcome.Improved patient outcomes are strongly associated with these modalities of care, more than single or combinatorial drug strategies (aprotinin, tranexamic acid, pentoxifylline) or CPB modalities (minicircuits, heparin-coated circuits, retrograde autologous prime)

    Early and Late Pathogenic Events of Newborn Mice Encephalitis Experimentally Induced by Itacaiunas and Curionópolis Bracorhabdoviruses Infection

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    In previous reports we proposed a new genus for Rhabdoviridae and described neurotropic preference and gross neuropathology in newborn albino Swiss mice after Curionopolis and Itacaiunas infections. In the present report a time-course study of experimental encephalitis induced by Itacaiunas and Curionopolis virus was conducted both in vivo and in vitro to investigate cellular targets and the sequence of neuroinvasion. We also investigate, after intranasal inoculation, clinical signs, histopathology and apoptosis in correlation with viral immunolabeling at different time points. Curionopolis and Itacaiunas viral antigens were first detected in the parenchyma of olfactory pathways at 2 and 3 days post-inoculation (dpi) and the first clinical signs were observed at 4 and 8 dpi, respectively. After Curionopolis infection, the mortality rate was 100% between 5 and 6 dpi, and 35% between 8 and 15 dpi after Itacaiunas infection. We identified CNS mice cell types both in vivo and in vitro and the temporal sequence of neuroanatomical olfactory areas infected by Itacaiunas and Curionopolis virus. Distinct virulences were reflected in the neuropathological changes including TUNEL immunolabeling and cytopathic effects, more intense and precocious after intracerebral or in vitro inoculations of Curionopolis than after Itacaiunas virus. In vitro studies revealed neuronal but not astrocyte or microglial cytopathic effects at 2 dpi, with monolayer destruction occurring at 5 and 7 dpi with Curionopolis and Itacaiunas virus, respectively. Ultrastructural changes included virus budding associated with interstitial and perivascular edema, endothelial hypertrophy, a reduced and/or collapsed small vessel luminal area, thickening of the capillary basement membrane, and presence of phagocytosed apoptotic bodies. Glial cells with viral budding similar to oligodendrocytes were infected with Itacaiunas virus but not with Curionopolis virus. Thus, Curionopolis and Itacaiunas viruses share many pathological and clinical features present in other rhabdoviruses but distinct virulence and glial targets in newborn albino Swiss mice brain

    Planck 2013 results. XX. Cosmology from Sunyaev-Zeldovich cluster counts

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    We present constraints on cosmological parameters using number counts as a function of redshift for a sub-sample of 189 galaxy clusters from the Planck SZ (PSZ) catalogue. The PSZ is selected through the signature of the Sunyaev--Zeldovich (SZ) effect, and the sub-sample used here has a signal-to-noise threshold of seven, with each object confirmed as a cluster and all but one with a redshift estimate. We discuss the completeness of the sample and our construction of a likelihood analysis. Using a relation between mass MM and SZ signal YY calibrated to X-ray measurements, we derive constraints on the power spectrum amplitude σ8\sigma_8 and matter density parameter Ωm\Omega_{\mathrm{m}} in a flat Λ\LambdaCDM model. We test the robustness of our estimates and find that possible biases in the YY--MM relation and the halo mass function are larger than the statistical uncertainties from the cluster sample. Assuming the X-ray determined mass to be biased low relative to the true mass by between zero and 30%, motivated by comparison of the observed mass scaling relations to those from a set of numerical simulations, we find that σ8=0.75±0.03\sigma_8=0.75\pm 0.03, Ωm=0.29±0.02\Omega_{\mathrm{m}}=0.29\pm 0.02, and σ8(Ωm/0.27)0.3=0.764±0.025\sigma_8(\Omega_{\mathrm{m}}/0.27)^{0.3} = 0.764 \pm 0.025. The value of σ8\sigma_8 is degenerate with the mass bias; if the latter is fixed to a value of 20% we find σ8(Ωm/0.27)0.3=0.78±0.01\sigma_8(\Omega_{\mathrm{m}}/0.27)^{0.3}=0.78\pm 0.01 and a tighter one-dimensional range σ8=0.77±0.02\sigma_8=0.77\pm 0.02. We find that the larger values of σ8\sigma_8 and Ωm\Omega_{\mathrm{m}} preferred by Planck's measurements of the primary CMB anisotropies can be accommodated by a mass bias of about 40%. Alternatively, consistency with the primary CMB constraints can be achieved by inclusion of processes that suppress power on small scales relative to the Λ\LambdaCDM model, such as a component of massive neutrinos (abridged).Comment: 20 pages, accepted for publication by A&

    Planck 2013 results. XXIX. Planck catalogue of Sunyaev-Zeldovich sources

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    We describe the all-sky Planck catalogue of clusters and cluster candidates derived from Sunyaev-Zeldovich (SZ) effect detections using the first 15.5 months of Planck satellite observations. The catalogue contains 1227 entries, making it over six times the size of the Planck Early SZ (ESZ) sample and the largest SZ-selected catalogue to date. It contains 861 confirmed clusters, of which 178 have been confirmed as clusters, mostly through follow-up observations, and a further 683 are previously-known clusters. The remaining 366 have the status of cluster candidates, and we divide them into three classes according to the quality of evidence that they are likely to be true clusters. The Planck SZ catalogue is the deepest all-sky cluster catalogue, with redshifts up to about one, and spans the broadest cluster mass range from (0.1 to 1.6) × 1015 M⊙. Confirmation of cluster candidates through comparison with existing surveys or cluster catalogues is extensively described, as is the statistical characterization of the catalogue in terms of completeness and statistical reliability. The outputs of the validation process are provided as additional information. This gives, in particular, an ensemble of 813 cluster redshifts, and for all these Planck clusters we also include a mass estimated from a newly-proposed SZ-mass proxy. A refined measure of the SZ Compton parameter for the clusters with X-ray counter-parts is provided, as is an X-ray flux for all the Planck clusters not previously detected in X-ray surveys.The development of Planck has been supported by: ESA; CNES and CNRS/INSU-IN2P3-INP (France); ASI, CNR, and INAF (Italy); NASA and DoE (USA); STFC and UKSA (UK); CSIC, MICINN and JA (Spain); Tekes, AoF and CSC (Finland); DLR and MPG (Germany); CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); SFI (Ireland); FCT/MCTES (Portugal); and PRACE (EU).Peer Reviewe

    2 nd Brazilian Consensus on Chagas Disease, 2015

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    Abstract Chagas disease is a neglected chronic condition with a high burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. It is hoped that this document will strengthen the development of integrated actions against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research
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