Bravo/Nr-CAM Is Closely Related to the Cell Adhesion Molecules L1 and Ng-CAM and Has a Similar Heterodimer Structure

Diverse cell-surface molecules of the nervous system play an important role in specifying cell interactions during development. Using a method designed to generate mAbs against neural surface molecules of defined molecular weight, we have previously reported on the surface protein, Bravo, found in the developing avian retinotectal system. Bravo is immunologically detected on developing optic fibers in the retina, but absent from distal regions of the same fibers in the tectum. We have isolated cDNA clones encompassing the entire coding region of Bravo, including clones containing five alternative sequences of cDNA. These putative alternatively spliced sequences encode stretches of polypeptide ranging in length from 10-93 amino acids and are predicted to be both extra- and intracellular. The deduced primary structure of Bravo reveals that, like the cell adhesion molecules (CAMs) chicken Ng- CAM and mouse L1, Bravo is composed of six Ig-like domains, five fibronectin type III repeats, a transmembrane domain, and a short cytoplasmic region. Recently, the cDNA sequence of a related molecule, Nr-CAM, was reported and its possible identity with Bravo discussed (Grumet, M., V. Mauro, M. P. Burgoon, G. E. Edelman, and B. A. Cunningham. 1991. J. Cell Biol. 113:1399-1412). Here we confirm this identity and moreover show that Bravo is found on Muller glial processes and end-feet in the developing retina. In contrast to the single polypeptide chain structure of Nr-CAM reported previously, we show that Bravo has a heterodimer structure composed of an alpha chain of M(r) 140/130 and a beta chain of 60-80 kD. As with L1 and Ng-CAM, the two chains of Bravo are generated from an intact polypeptide by cleavage at identical locations and conserved sites within all three molecules (Ser-Arg/Lys-Arg). The similar domain composition and heterodimer structure, as well as the 40% amino acid sequence identity of these molecules, defines them as an evolutionarily related subgroup of CAMs. The relationship of Bravo to molecules known to be involved in cell adhesion and process outgrowth, combined with its pattern of expression and numerous potential isoforms, suggests a complex role for this molecule in cell interactions during neural development

Topologically Restricted Appearance in the Developing Chick Retinotectal System of Bravo, a Neural Surface Protein: Experimental Modulation by Environmental Cues

A novel neural surface protein, Bravo, shows a pattern of topological restriction in the embryonic chick retinotectal system. Bravo is present on the developing optic fibers in the retina; however, retinal axons in the tectum do not display Bravo. The appearance of Bravo in vitro is modulated by environmental cues. Axons growing out from retinal explants on retinal basal lamina, their natural substrate, express Bravo, whereas such axons growing on collagen do not. Retinal explants provide a valuable system to characterize the mechanism of Bravo restriction, as well as the cellular signals controlling it. Bravo was identified with monoclonal antibodies from a collection generated against exposed molecules isolated by using a selective cell surface biotinylation procedure. The NH2-terminal sequence of Bravo shows similarity with L1, a neural surface molecule which is a member of the immunoglobulin superfamily. This possible relationship to L1, together with its restricted appearance, suggests an involvement of Bravo in axonal growth and guidance

Large eddy simulations of solitons colliding with intrusions

The dynamics of lock-release Intrusive Gravity Currents (IGCs) generating Internal Solitary Waves (ISWs) are investigated by three-dimensional large eddy simulations. We set the numerical, laboratory-scale domain in order to release a uniform fluid in multi-layer, stratified ambient, exciting pycnocline displacements. By adopting different initial settings, we analyzed the influence of the ambient stratification on both IGCs and ISWs features. We present the main flow dynamics and the time evolution of IGC and ISW front and trough positions, respectively. During the simulations, the ISW is allowed to reach the vertical wall at the end of the domain, and it undergoes reflection. We then analyzed the interaction between the IGC and the reflected ISW: the wave is observed to accelerate as it is pushed upwards by the intrusion, which, in turns, flows below the ISW, decelerating. By analyzing instantaneous velocity fields and flow rates, we found that during this interaction, the ISW increases its celerity in response of the reduced area available for its propagation, partially occupied by the intrusion, and because the velocity field in the IGC interface surroundings acts to facilitate the ISW passage

Sensibility analysis of the Trace Transform on land coverage images

Aerial or satellital images may be used to produce terrain coverage maps, which in time are a very useful and important tool for decision-making in several fields including biodiversity, telecommunications and natural disaster management. The Trace Transform method can be used to process these images. This method extracts features from the images by applying a series of functionals to produce a numeric representation that will be used for classification later on. This model depends on several factors in order to have an efficient operation, among them, the frequency parameters of the traces, classifier type and land coverage. Experimentation on feature extraction time and precision rate revealed that the frequency parameters, specially Δτ, and the classifier type can affect both of them.AVIA,iDeTIC,Iko

Biomarker responses in caged carp (Cyprinuscarpio) and native collected fish (Leporinus obtusidens) in the Río de la Plata Estuary, Argentina

Punta Lara is located in the Río de la Plata estuary near industrial areas contaminated mainly by organic pollutants. In this work, the responses and status of hepatic biomarkers were studied in juvenile carp (Cyprinus carpio) by means of a 21-day field exposure in cages and collection of juvenile native fish (Leporinus obtusidens) at Punta Lara. The analyzed hepatic biomarkers were: enzymatic activity of glutathione-S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD), lipid peroxidation level using the thiobarbituric acid reaction (TBARS), and CYP1A protein expression, condition factor (CF) and liver somatic (LSI) index. Taking into account oxidative stress responses, SOD activity was increased in both species, while CAT was increased in C. carpio and decreased in L. obtusidens; TBARS levels indicated that oxidative damage was possibly exerted only in L. obtusidens. Biotransformation responses mediated by CYP1A were observed in both species, while GST activity was induced mainly in carps. Considering morphometric indices, CF and LSI were significantly increased in carps while CF decreased in native species. The anthropogenic pollution detected in this study in Punta Lara was associated with differences in biomarkers on both fish species, although a different pattern of response was observed.Fil: Scarcia, Paola Inés. Universidad Nacional de Luján. Departamento de Ciencias Básicas. Programa de Ecofisiología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Calamante, Gabriela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de la Torre, Fernando Roman. Universidad Nacional de Luján. Departamento de Ciencias Básicas. Programa de Ecofisiología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Estudio del comportamiento y los habitos de compra de los clientes de una multitienda, mediante el uso de tecnicas de mineria de datos

133 p.La industria del Retail en Chile ha experimentado un significativo crecimiento durante los últimos años, posicionándose en un mercado atractivo y competitivo en donde tiendas por departamento como Multihogar, buscan la diferenciación en Curicó. Para lograr este objetivo, herramientas propias de Minería de Datos son utilizadas para el desarrollo de tres estudios, que en base a información transaccional de los años 2006 y 2007, pretenden la identificación de productos complementarios ofrecidos en la tienda, con el objetivo de reconocer los hábitos de compra de los consumidores. Además, se genera un modelo de migración del cliente con el propósito de detectar de manera anticipada, que clientes son propensos a terminar su relación con la empresa, pronosticándose que un 10,7% de los clientes abandonan la tienda al cabo de 3 meses. Finalmente, se desarrolla un estudio para determinar el Valor de Vida del Cliente, para el cual se establece que los consumidores que visitan la tienda más de dos veces y realizan compras de $ 123.000 mensuales en promedio, corresponden a los clientes más rentables para la empresa. Posteriormente los modelos generados son validados en base a información transaccional del año 2008 para luego presentar conclusiones que permitan a la empresa tomar medidas futuras en base al conocimiento adquirido

Co-exposure of the organic nanomaterial fullerene C60 with benzo[a]pyrene in Danio rerio (zebrafish) hepatocytes: Evidence of toxicological interactions

Compounds from the nanotechnology industry, such as carbon-based nanomaterials, are strong candidates to contaminate aquatic environments because their production and disposal have exponentially grown in a few years. Previous evidence shows that fullerene C60, a carbon nanomaterial, can facilitate the intake of metals or PAHs both in vivo and in vitro, potentially amplifying the deleterious effects of these toxicants in organisms. The present work aimed to investigate the effects of fullerene C60 in a Danio rerio (zebrafish) hepatocyte cell lineage exposed to benzo[a]pyrene (BaP) in terms of cell viability, oxidative stress parameters and BaP intracellular accumulation. Additionally, a computational docking was performed to investigate the interaction of the fullerene C60 molecule with the detoxificatory and antioxidant enzyme πGST. Fullerene C60 provoked a significant (p 0.05) alter the enzyme activity when added to GST purified extracts from the zebrafish hepatocyte cells. These results show that fullerene C60 can increase the intake of BaP into the cells, decreasing cell viability and impairing the detoxificatory response by phase II enzymes, such as GST, and this latter effect should be occurring at the transcriptional level.Fil: Ribas Ferreira, Josencler L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lonné, María Noelia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: França, Thiago A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Maximilla, Naiana R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lugokenski, Thiago H.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: Costa, Patrícia G.. Universidade Federal do Rio Grande do Sul; BrasilFil: Fillmann, Gilberto. Universidade Federal do Rio Grande do Sul; BrasilFil: Soares, Félix A.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: de la Torre, Fernando Roman. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Monserrat, José María. Universidade Federal do Rio Grande do Sul; Brasil. Instituto Nacional de Ciência e Tecnologia de Nanomateriais de Carbono; Brasi

Influencia de la Capacitación en el Teletrabajo en el Sector Salud.

El presente trabajo de investigación pretende determinar en qué medida la capacitación del manejo tecnológico es relacionado con el teletrabajo en el sector salud, a través del estudio realizado con el personal de salud del sector Salud en la ciudad de Lima en el año 2021, mediante el análisis de comparativo entre el trabajo convencional y el teletrabajo a partir de un programa de capacitación en el manejo tecnológico; con el uso de las variables como la capacitación en el manejo tecnológico y el teletrabajo. Esta investigación presenta un método mixto de técnicas cualitativas y cuantitativas con un diseño de investigación no experimental transversal, de subtipo descriptivo y correlacional, usando como instrumento de recolección la encuesta con preguntas cerradas según Likert. El análisis comparativo demuestra que la capacitación en el manejo tecnológico para ejecutar el teletrabajo tiene relación significativa con los teletrabajadores como trabajo flexible, desempeño laboral y las tecnologías de información y comunicación (TIC’s), presentando una mayor competitividad y calidad de vida de los trabajadores, esto se corrobora en los resultados de las pruebas de las hipótesis con un nivel de confianza del 99% y un nivel de significación del 1% a través de la prueba estadística del Coeficiente de correlación de Spearman con un resultado de 0.803, 0.811 y 0.823 respectivamente para las tres hipótesis específicas y con una significancia de 0.000, lo que demuestra que la capacitación del manejo tecnológico se relaciona con el teletrabajo en el sector salud