195 research outputs found
Desenvolvimento profissional durante a implementação de inovações curriculares por professores do ensino secundário
Neste trabalho, apresentamos os primeiros resultados de uma pesquisa com cinco professores de fÃsica do ensino secundário que participaram de um projeto de inovação curricular na implementação de seqüências didáticas de ensino aprendizagem (Teaching and Learning Sequence) sobre FÃsica Moderna. Por meio de questionário e entrevista semi-estruturada, buscou-se a partir da análise relacionar as fases de desenvolvimento profissional dos professores. Percebemos nos casos estudados, que alguns professores apresentaram uma discordância entre as fases deste desenvolvimento. Os resultados parecem indicar que a participação de professores em grupos de projetos inovadores no Ensino de FÃsica, pode contribuir para consolidar seu desenvolvimento profissional na fase da experimentação ou diversificação
A Presence- and Performance-Driven Framework to Investigate Interactive Networked Music Learning Scenarios
Cooperative music making in networked environments has been subject of extensive research, scientific and artistic. Networked music performance (NMP) is attracting renewed interest thanks to the growing availability of effective technology and tools for computer-based communications, especially in the area of distance and blended learning applications. We propose a conceptual framework for NMP research and design in the context of classical chamber music practice and learning: presence-related constructs and objective quality metrics are used to problematize and systematize the many factors affecting the experience of studying and practicing music in a networked environment. To this end, a preliminary NMP experiment on the effect of latency on chamber music duos experience and quality of the performance is introduced. The degree of involvement, perceived coherence, and immersion of the NMP environment are here combined with measures on the networked performance, including tempo trends and misalignments from the shared score. Early results on the impact of temporal factors on NMP musical interaction are outlined, and their methodological implications for the design of pedagogical applications are discussed
Particle Shadow Tracking - Combining Magnetic Particle Manipulation with In-Situ Optical Detection in a CMOS Microsystem
We present a hybrid CMOS based microsystem where magnetic actuation of microparticles is combined with integrated optical detection via Single Photon Avalanche Diodes (SPADs). The system’s configuration permits the manipulation and detection of single magnetic particles having diameters of 1, 3 and 5 µm. We are able to show a size sensitivity of the particle detection, with a clear distinction between different particle diameters
Microparticle photometry in a CMOS microsystem combining magnetic actuation and in-situ optical detection
We present a hybrid CMOS-based microfluidic system that combines magnetic actuation of microparticles with in situ optical detection using single photon avalanche diodes (SPADs). The decoupling of the principles used for actuation and sensing permits a high sensitivity with respect to detection and particle handling. Single magnetic microparticles are transported within a glass micro-capillary positioned over an array of actuation coils and are detected upon passage over a SPAD, where they block incident light and thus lower the photon count. Use of the photometry method allows the determination of the particle size, which, in combination with a simultaneous measurement of the particle velocity, enables us to estimate further particle properties, such as their magnetization.We present the successful manipulation, detection and evaluation of magnetic particles with diameters ranging from 1 to 30 um
Microparticle photometry in a CMOS microsystem combining magnetic actuation and in situ optical detection
Essential versus accessory aspects of cell death: recommendations of the NCCD 2015
Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death
Lysosomal protease deficiency or substrate overload induces an oxidative-stress mediated STAT3-dependent pathway of lysosomal homeostasis
How cells regulate their lysosomal proteolytic capacity is only partly understood. Here, the authors show that lysosomal protease deficiency or substrate overload induces lysosomal stress leading to activation of a STAT3-dependent, TFEB-independent pathway of lysosomal hydrolase expression
Bacteriophage Lysin Mediates the Binding of Streptococcus mitis to Human Platelets through Interaction with Fibrinogen
The binding of bacteria to human platelets is a likely central mechanism in the pathogenesis of infective endocarditis. We have previously found that platelet binding by Streptococcus mitis SF100 is mediated by surface components encoded by a lysogenic bacteriophage, SM1. We now demonstrate that SM1-encoded lysin contributes to platelet binding via its direct interaction with fibrinogen. Far Western blotting of platelets revealed that fibrinogen was the major membrane-associated protein bound by lysin. Analysis of lysin binding with purified fibrinogen in vitro confirmed that these proteins could bind directly, and that this interaction was both saturable and inhibitable. Lysin bound both the Aα and Bβ chains of fibrinogen, but not the γ subunit. Binding of lysin to the Bβ chain was further localized to a region within the fibrinogen D fragment. Disruption of the SF100 lysin gene resulted in an 83±3.1% reduction (mean ± SD) in binding to immobilized fibrinogen by this mutant strain (PS1006). Preincubation of this isogenic mutant with purified lysin restored fibrinogen binding to wild type levels. When tested in a co-infection model of endocarditis, loss of lysin expression resulted in a significant reduction in virulence, as measured by achievable bacterial densities (CFU/g) within vegetations, kidneys, and spleens. These results indicate that bacteriophage-encoded lysin is a multifunctional protein, representing a new class of fibrinogen-binding proteins. Lysin appears to be cell wall-associated through its interaction with choline. Once on the bacterial surface, lysin can bind fibrinogen directly, which appears to be an important interaction for the pathogenesis of endocarditis
The interaction of bacterial pathogens with platelets.
In recent years, the frequency of serious cardiovascular infections such as endocarditis has increased, particularly in association with nosocomially acquired antibiotic-resistant pathogens. Growing evidence suggests a crucial role for the interaction of bacteria with human platelets in the pathogenesis of cardiovascular infections. Here, we review the nature of the interactions between platelets and bacteria, and the role of these interactions in the pathogenesis of endocarditis and other cardiovascular diseases
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