BHK cells physiological response to spin-filter stress condition

Mammalian cells are the preferable platform for secreted pharmaceutical proteins due to the compatibility of posttranslational modifications performed by these cells with therapeutic applications. However, to obtain a desirable quantity of these proteins, high cell concentrations are also needed. Baby hamster kidney BHK-21/C13 cells, adapted to single-cell suspension culture growth were cultivated in batch mode in a Biostat B (Sartorius AG, Germany) bioreactor with a 1,5 L working volume vessel. The temperature was controlled at 37 ºC, pH at 7.2 with CO­2, agitation at 80 rpm and dissolved oxygen at 50% of air saturation. The culture medium used was IMDM/DMEM supplemented with Fetal Bovine Serum (5%), Pluronic F-68 as a shear protectant (2%) and L-glutamine 4 mM solution (2%). The bioreactor was inoculated with exponential-growing cells previously grown in T-25 and spinner flasks. Relevant data collected from this experiment is shown in Table 1. In order to achieve high cell concentration, the same BHK-21/C13 cells were cultivated in a perfusion set-up, with an internal polyester spin-filter BB-8808571 (Sartorius) with 10 µm diameter pore size attached to the impeller shaft as cell retention device. This set-up is different from the one previously used only by the presence of the internal spin-filter. To start the perfusion, before the feed and withdrawal pumps were turned on, the set-up was operated as a batch process until there were enough cells to start the continuous operation mode. Data collected from this phase was then compared with data obtained from the batch cultivation. Specific growth rates and exponential growth phase duration were similar for both experiments. However, the specific rates of glucose (qGLU) and glutamine (qGLN) consumption were 84% and 32% higher (Table 1), respectively, when compared to the batch cultivation. Similarly, the specific rates of lactate (qLAC) and ammonium (qNH4) formation were 78% and 102% higher, respectively. The specific rates of substrates consumption and of metabolites formation were calculated for the exponential growth phase. It is reported in literature the association of higher specific substrates consumption rates and metabolites production rates with stress factors, and we can associate the presence of the spin-filter with the physiological parameters findings, suggesting that BHK cells were exposed to a more stressful condition. The calculated value, obtained though CFD (computational fluid dynamics), for the wall shear stress of a filter rotating at 100 rpm vary from 1.57 to 1.67 Pa depending on the recirculation rate1. Despite being a small value, the system without the spin-filter already has its intrinsic shear stress value, so the stress caused by the filter must be added to and not considered as the absolute value. It was also reported that shear stress in the range from 0.75 to 1.0 Pa can affect both the viability and morphology of one BHK-21/C13 adherent cell line cultivated up to 24 hours2. Our data indicate that the presence of an internal spin-filter may be associated to cell stress

Análisis y desarrollo de una aplicación web de liquidación de Siniestros de Riesgos Varios

Con el avance de la tecnología cada vez son más las empresas que buscan automatizar los servicios que brinda, no sólo para ofrecer información más confiable sino también para mejorar el control sobre la empresa y apoyar la toma de decisiones. La compañía aseguradora donde trabajo, dispone de un sistema de administración de siniestros del ramo auto, moto vehículo y ART, sin embargo, no cuenta con una herramienta para administrar los siniestros de Riesgos varios, lo cual atrasa considerablemente la resolución de los casos de este tipo. El propósito de esta tesina es ampliar la aplicación web de Siniestros existente, con el previo análisis correspondiente. Esta ampliación permitirá a los liquidadores de Riesgos Varios gestionar todos los casos que le son derivados con información más amplia y ordenada. Además, le permitirá a la compañía tener un control de todos los casos gestionados a través de sus responsables internos y administradores.Director profesional: Víctor Gabriel Laferrara.Tesina Programa de Apoyo al Egreso de Profesionales en Actividad (PAEPA).Facultad de Informátic

Optical interferometric studies of a confined liquid free surface: meniscus-effect compensation and time evolution of the surface

A fruitful approach to the studies of a liquid free surface is demonstrated. Using optical interferential techniques, the free surface of nonvolatile and volatile confined liquids is analyzed. Various wall con tainer types are investigated. Besides the classical plane wall, experiments are performed by using cylindrical and toroidal walls. In these last cases, the meniscus effect that affects the free surface of the liquid is compensated. Then, it is possible to obtain completely flat free surfaces of liquids up to 80% of their total. Interferometric experiments are also described to measure the inclination of the site with respect to the local horizon, represented by the liquid flat free surface, and to follow the temporal evolution of such free surfaces affected by different conditions

A pesquisa em políticas públicas e Educação Ambiental

Este artigo desenvolve as discussões realizadas no Grupo de Discussão dePesquisas em Políticas Públicas e Educação Ambiental durante o V Encontro dePesquisa em Educação Ambiental. Afirma a importância desse campo emergentelevantando questões pertinentes ao desenvolvimento de pesquisas na área

A pesquisa em políticas públicas e educação ambiental

This article builds on the discussions carried out in the Public Policy and Environmental Education Research Discussion Group during the V Research Meeting on Environmental Education. It affirms the importance of this emerging field by raising issues relevant to research in the area.Este artigo desenvolve as discussões realizadas no Grupo de Discussão de Pesquisas em Políticas Públicas e Educação Ambiental durante o V Encontro de Pesquisa em Educação Ambiental. Afirma a importância desse campo emergente levantando questões pertinentes ao desenvolvimento de pesquisas na área

Contribuição ao estudo das ondas geradas pela ruptura de barragens

Orientador: Marcos Jose TozziDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Curso de Pós-Graduação em Engenharia HidráulicaInclui referências: p. 109-117Resumo: Este trabalho apresenta uma revisão bibliográfica sobre os temas ruptura de barragem e escoamento não permanente em canais. Apresenta, também, dois programas de computador para cálculo da onda gerada pela ruptura de uma barragem: um para ruptura considerada ideal e outro para ruptura em canal retangular de largura, declividade longitudinal e rugosidade constantes ao longo do desenvolvimento do canal. O modelo computacional proposto é aplicado a (e comparado com) dois casos constantes na literatura sobre ruptura de barragens e a um caso hipotético. Nesses exemplos de aplicação são avaliados, também, o efeito que alterações em diversas características do problema (rugosidade, velocidade inicial, largura do Canal, entre outras) apresentam no resultado final da dissipação da onda

Engineering Education Research

This chapter describes several aspects of engineering education research with an emphasis on how they might relate to computing education research. We briefly summarize the history of engineering education as a scholarly field, and we describe the current structures that support engineering education research: academic departments, scholarly journals, annual conferences, and professional societies. We identify the theories that often inform engineering education research studies, including theories of cognition, motivation, and identity. We explain how quantitative, qualitative, and mixed methods have been used. We summarize the results of an illustrative selection of empirical studies across a broad range of topics, including instructional methods, student development, faculty teaching practices, diversity, and assessment. Finally, we outline some similarities and differences between computing education research and engineering education research. Engineering education research has a longer history of research in professional development and assessment but an arguably shorter history in pre-college education and less international integration than computing education research

Biodegradation of the herbicide mecoprop-p with soil depth and its relationship with class III tfdA genes

Mecoprop-p [(R)-2-(4-chloro-2-methylphenoxy) propanoic acid) is widely used 37 in agriculture and poses an environmental concern because of its susceptibility to leach 38 from soil to water. We investigated the effect of soil depth on mecoprop-p 39 biodegradation and its relationship with the number and diversity of tfdA related genes, 40 which are the most widely known genes involved in degradation of the 41 phenoxyalkanoic acid group of herbicides by bacteria. Mecoprop-p half-life (DT50) was 42 approximately 12 days in soil sampled from <30 cm depth, and increased progressively 43 with soil depth, reaching over 84 days at 70-80 cm. In sub-soil there was a lag period of 44 between 23 and 34 days prior to a phase of rapid degradation. No lag phase occurred in 45 top-soil samples prior to the onset of degradation. The maximum degradation rate was 46 the same in top-soil and sub-soil samples. Although diverse tfdAα and tfdA genes were 47 present prior to mecoprop-p degradation, real time PCR revealed that degradation was 48 associated with proliferation of tfdA genes. The number of tfdA genes and the most 49 probable number of mecoprop-p degrading organisms in soil prior to mecoprop-p 50 addition were below the limit of quantification and detection respectively. Melting 51 curves from the real time PCR analysis showed that prior to mecoprop-p degradation 52 both class I and class III tfdA genes were present in top- and sub-soil samples. However 53 at all soil depths only tfdA class III genes proliferated during degradation. Denaturing 54 gradient gel electrophoresis confirmed that class III tfdA genes were associated with 55 mecoprop-p degradation. Degradation was not associated with the induction of novel 56 tfdA genes in top- or sub-soil samples, and there were no apparent differences in tfdA 57 gene diversity with soil depth prior to or following degradation