2,944 research outputs found
Cell sorting in a Petri dish controlled by computer vision.
Fluorescence-activated cell sorting (FACS) applying flow
cytometry to separate cells on a molecular basis is a widespread
method. We demonstrate that both fluorescent and unlabeled live
cells in a Petri dish observed with a microscope can be
automatically recognized by computer vision and picked up by a
computer-controlled micropipette. This method can be routinely
applied as a FACS down to the single cell level with a very
high selectivity. Sorting resolution, i.e., the minimum distance
between two cells from which one could be selectively removed
was 50-70 micrometers. Survival rate with a low number of 3T3
mouse fibroblasts and NE-4C neuroectodermal mouse stem cells was
66 +/- 12% and 88 +/- 16%, respectively. Purity of sorted
cultures and rate of survival using NE-4C/NE-GFP-4C co-cultures
were 95 +/- 2% and 62 +/- 7%, respectively. Hydrodynamic
simulations confirmed the experimental sorting efficiency and a
cell damage risk similar to that of normal FACS
Review: Synthetic Jets and their Cooling Applications
O objetivo deste artigo é apresentar uma revisão do estado da arte da aplicação de jatos sintéticos para resfriamento. A aplicação de jatos sintéticos representa uma técnica alternativa aos sistemas de resfriamento líquido, que busca aumentar a troca térmica mantendo-se o ar como fluido de trabalho. Para isso, é necessário primeiro discursar sobre as variações de dispositivos de geração, as principais características fluidodinâmicas dos jatos sintéticos e seus parâmetros adimensionais de avaliação de desempenho. Jatos sintéticos são formados em dispositivos geradores a partir de uma cavidade equipada com um pequeno orifício. A oscilação de uma membrana ou parede da cavidade induz uma movimentação periódica de fluido e produz um jato sintético na região externa ao orifício de saída. O jato sintético possui características de velocidade média semelhantes a um jato contínuo, mas com um nível de turbulência maior devido a sua natureza oscilatória. O resfriamento pode ser realizado em configurações de jato de impactação ou tangencial. Independente da configuração, a interação da turbulência do jato com uma superfície resulta em um aumento da troca térmica tanto em relação à convecção natural como convecção forçada de escoamentos de regime permanente.Palavras-chave: jato sintético, resfriamento, convecção forçadaThe objective of this paper is to present a review of the state of the art in cooling applications of synthetic jets. Cooling by means of synthetic jets represent an alternative technique to liquid cooling, in which air is still the working fluid. To this end, it is necessary first to present the varying types of synthetic jet generators, the fluid dynamic characteristics and the dimensionless performance parameters of the jets themselves. Synthetic jets are produced in generators that consist of a sealed cavity containing a small orifice. A boundary oscillation induces fluid movement in and out of the cavity through the orifice that, in the region external to the orifice, develops into a synthetic jet. The synthetic jet has average velocity properties similar to a steady jet albeit with a higher level of turbulence due to its oscillatory nature. Cooling applications of synthetic jets can occur in an impacting or tangential configuration. Regardless of the configuration used, several experimental and numerical studies have demonstrated that there is a significant increase in heat transfer compared to natural convection and forced convection with steady state turbulent flows.Keywords: synthetic jets, cooling, forced convectio
Measurement of the antineutrino neutral-current elastic differential cross section
arXiv:1309.7257v1 [hep-ex
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Molecular and Microbial Microenvironments in Chronically Diseased Lungs Associated with Cystic Fibrosis.
To visualize the personalized distributions of pathogens and chemical environments, including microbial metabolites, pharmaceuticals, and their metabolic products, within and between human lungs afflicted with cystic fibrosis (CF), we generated three-dimensional (3D) microbiome and metabolome maps of six explanted lungs from three cystic fibrosis patients. These 3D spatial maps revealed that the chemical environments differ between patients and within the lungs of each patient. Although the microbial ecosystems of the patients were defined by the dominant pathogen, their chemical diversity was not. Additionally, the chemical diversity between locales in the lungs of the same individual sometimes exceeded interindividual variation. Thus, the chemistry and microbiome of the explanted lungs appear to be not only personalized but also regiospecific. Previously undescribed analogs of microbial quinolones and antibiotic metabolites were also detected. Furthermore, mapping the chemical and microbial distributions allowed visualization of microbial community interactions, such as increased production of quorum sensing quinolones in locations where Pseudomonas was in contact with Staphylococcus and Granulicatella, consistent with in vitro observations of bacteria isolated from these patients. Visualization of microbe-metabolite associations within a host organ in early-stage CF disease in animal models will help elucidate the complex interplay between the presence of a given microbial structure, antibiotics, metabolism of antibiotics, microbial virulence factors, and host responses.IMPORTANCE Microbial infections are now recognized to be polymicrobial and personalized in nature. Comprehensive analysis and understanding of the factors underlying the polymicrobial and personalized nature of infections remain limited, especially in the context of the host. By visualizing microbiomes and metabolomes of diseased human lungs, we reveal how different the chemical environments are between hosts that are dominated by the same pathogen and how community interactions shape the chemical environment or vice versa. We highlight that three-dimensional organ mapping methods represent hypothesis-building tools that allow us to design mechanistic studies aimed at addressing microbial responses to other microbes, the host, and pharmaceutical drugs
SDRE APPLIED TO POSITION AND VIBRATION CONTROL OF A ROBOT MANIPULATOR WITH A FLEXIBLE LINK
This paper presents position and vibration control of a flexible robot composed of two rigid and one flexible links. Position is controlled by the current applied to the DC motor armature. To control vibrations of the flexible structure, Shape Memory Alloys (SMA) are used. Due to phase transformations, the SMA can change its stiffness through temperature variation, considering and taking advantage of this characteristic the vibration control is done. Control is achieved via the State Dependent Ricatti Equations (SDRE) technique, which uses suboptimal control and system local stability search. The simulation results show the feasibility of the proposed control for the considered system
Processos de Ensino e Aprendizagem de Biologia no Ensino Remoto Emergencial: Possibilidades de Inovação Pedagógica?
All over the world people are witnessing a new form of social behavior, in this sense, the work strategies and, mainly, the teaching work has been affected. Faced with this scenario, education, in a time of facing COVID-19, comes to understand technology even more as an instrument of solution, adaptation, but also of inequalities. In this context, remote teaching came to replace face-to-face classes, while the pandemic situation lasts. Legislations were modified, ordinances were created, so that teachers could continue with teaching. This work sought to map the elements of innovation in pedagogical practices, carried out by different teachers, during the remote period, which aim to ensure the teaching and learning processes in Biology. To operationalize this study, Grounded Theory was used. The results indicate that, in the view of the research participants, remote teaching is harmful to the teaching and learning processes in Biology, being pointed out as aggravating spatio-temporal, technological and socio-emotional factors. Thus, the data point to remote teaching as a way to meet the need for school contact, but which does not provide significant learning and innovative teaching and learning spaces-times, since pedagogical practices for teaching Biology are not promoting student protagonism, nor guaranteeing the right to learn for students.
Keywords: Meaningful learning. Remote teaching emergency. Pedagogical innovation. Grounded theory. No mundo, todas pessoas estão presenciando uma nova forma de comportamento social, nesse sentido, as estratégias de trabalho e, principalmente, o trabalho docente foi afetado. Frente a este cenário, a educação, em época de enfrentamento à COVID-19, passa a entender ainda mais a tecnologia como um instrumento de solução, adaptação, mas também de desigualdades. Assim, o ensino remoto veio para substituir as aulas presenciais, enquanto durar a situação de pandemia. Legislações foram modificadas, portarias foram criadas, para que os professores prosseguissem com o ensino. Este trabalho buscou mapear os elementos de inovação nas práticas pedagógicas, executadas por diferentes professoras, durante o período remoto, que se propõem a assegurar os processos de ensino e aprendizagem de conteúdos na área de Biologia. Para operacionalizar este estudo utilizou-se da Teoria Fundamentada nos Dados. Os resultados apontam que, na visão dos participantes da pesquisa, o ensino remoto é prejudicial aos processos de ensino e aprendizagem em Biologia, sendo apontados como agravantes fatores espaço-temporais, tecnológicos e socioemocionais. Deste modo, os dados apontam o ensino remoto como uma forma de suprir a necessidade de contato escolar, mas que não proporciona aprendizagens significativas e espaços-tempos de ensino e aprendizagem inovadores, visto que as práticas pedagógicas para o ensino de Biologia não estão promovendo o protagonismo estudantil, tampouco garantindo o direito à aprendizagem dos estudantes.
Palavras-chave: Aprendizagem significativa. Ensino remoto emergencial. Inovação pedagógica. Teoria fundamentada nos dados
Niche partitioning of a pathogenic microbiome driven by chemical gradients
© 2018 The Authors, some rights reserved. Environmental microbial communities are stratified by chemical gradients that shape the structure and function of these systems. Similar chemical gradients exist in the human body, but how they influence these microbial systems is more poorly understood. Understanding these effects can be particularly important for dysbiotic shifts in microbiome structure that are often associated with disease. We show that pH and oxygen strongly partition the microbial community from a diseased human lung into two mutually exclusive communities of pathogens and anaerobes. Antimicrobial treatment disrupted this chemical partitioning, causing complex death, survival, and resistance outcomes that were highly dependent on the individual microorganism and on community stratification. These effects were mathematically modeled, enabling a predictive understanding of this complex polymicrobial system. Harnessing the power of these chemical gradients could be a drug-free method of shaping microbial communities in the human body from undesirable dysbiotic states
Percepção de atendentes de farmácias sobre os riscos da automedicação
Introdução: A automedicação é uma realidade para uma grande parcela da população. O atendente de farmácia é um profissional que, embora participe diretamente dessa prática, não costuma ser considerado em estudos que avaliam a automedicação no Brasil. Como resultado, pouco se sabe sobre o entendimento dos atendentes de farmácia quanto aos riscos dessa prática. Objetivo: O objetivo do presente trabalho foi avaliar o uso da automedicação pelos balconistas da cidade de Pelotas, no Rio Grande do Sul, além de seus conhecimentos sobre os riscos que envolvem essa prática. Método: Foi realizado um estudo transversal por meio de questionário estruturado enviado ao e-mail profissional dos atendentes. Resultados: 41,6% dos atendentes entrevistados afirmaram que se automedicam pelos menos uma vez por mês e 66,3% que realizam indicação de medicamentos isentos de prescrição para clientes da farmácia. 30,7% dos participantes afirmaram que já foram incentivados a indicar medicamentos, porém 75,2% não se consideram preparados para auxiliar os clientes na automedicação. Conclusão A automedicação e o auxílio à automedicação de pacientes é uma prática comum entre os atendentes de farmácia. Diante disso, cabe ao farmacêutico assumir a responsabilidade pelo treinamento desses profissionais para minimizar os riscos da automedicação para os pacientes e atendentes
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