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Search Results: 1 - 10 of 10189 matches for " Castillo-Viveros Linda Valeria "
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Mycoplasmas detection in cells cultures
Rivera-Tapia José Antonio,Castillo-Viveros Linda Valeria,Sánchez-Hernández José Antonio
Revista Ciencias Biomédicas , 2010,
Abstract: INTRODUCTION. Cells cultures are widely used in both biomedical and biotechnological research centers and industry, as well as for diagnostic test in hospitals. Contaminations of cells cultures with microbial organisms as well as with virus or other eukaryotic cell lines are a major problem in cell culture related research.OBJECTIVE. Mycoplasmas detection in cells cultures came from biomedical laboratories.MATERIAL AND METHODS. The cells cultures screened for mycoplasmas by using of microbiological culture and PCR. Cells cultures were grown in the absence of antibiotics for 3-4 days. The identified based on alterations in the pH of the broth in the absence of turbidity, production of fried egg colonies. Comparison between microbiological and PCR were made using Student T test.RESULTS. Mycoplasmas were detected by culture in 9/20 (45%) of the cell culture samples and PCR revealed the presence of target DNA in 10/20 (50%) samples. Mycoplasmas detection between the microbiological culture and PCR showing not significant differences (P>0.05).CONCLUSION. Mycoplasmas detection in cell cultures must be strengthen with another technique to validate the results.RESUMENINTRODUCCIóN. Los cultivos celulares se utilizan frecuentemente en la investigación biomédica, en el área industrial y en pruebas diagnósticas en los hospitales. La contaminación de los cultivos celulares por microorganismos o por contaminación cruzada entre cultivos es uno de los principales problemas en la investigación.OBJETIVO. Detección de micoplasmas en cultivos celulares provenientes de diferentes laboratorios biomédicos.MATERIAL Y METODOS. Los cultivos celulares se evaluaron para detectar presencia de micoplasmas por medio de cultivo microbiológico y PCR. Los cultivos celulares fueron crecidos en ausencia de antibióticos durante 3-4 días. La identificación se presentó por el cambio en el indicador de pH y ausencia de turbidez en el caldo y por la presencia en agar de las colonias características a través de microscopia estereoscópica. La comparación de los resultados obtenidos entre el método microbiológico y PCR se realizó con la prueba de T de Student.RESULTADOS. Por el método microbiológico se detectó en 9/20 muestras (45%) presencia de micoplasmas en los cultivos celulares y por medio de la prueba de PCR resultaron positivas 10/20 muestras (50%) de cultivos celulares. El análisis estadístico mostró que no hay diferencia significativa (P>0.05) en la detección entre el método microbiológico y PCR.CONCLUSIONES. Es recomendable que la detección de micoplasmas en cultivos celulares debe refo
Evolución molecular y genómica en angiospermas
Eguiarte,Luis E; Castillo,Amanda; Souza,Valeria;
Interciencia , 2003,
Abstract: several aspects of the evolution of the genomes in angiosperms were reviewed, synthesized and compared. flowering plants have three genomes: chloroplast, mitochondrial and nuclear. the chloroplast genome has a largely conserved structure (120-217kb) including 110-113 genes. the mitochondrial genome is bigger (300-600kb), comprising about 60 genes, and is a very dynamic genome, losing and acquiring genes from the nucleus and chloroplast. nuclear genomes in angiosperms are among the largest known. in arabidopsis thaliana it is 125mb long with 25498 genes. from rice (oryza sativa) two varieties have been sequenced; its genome is almost 4 times larger than that of a. thaliana and includes 32000-55615 genes. maize (zea mays) has not been sequenced yet, but there is substantial genomic information, and it has been estimated that between 60 to 80% is composed of mobile elements. synonymous substitutions in chloroplast genes are 2 to 3 times faster than in mitochondria, and nuclear genes change in general 10 to 15 times faster than mitochondrial. nevertheless, substitution rates in non-synonymous sites are similar between chloroplast and mitochondria and only slightly higher in the nuclear genome. detailed studies of these 3 genomes allow the understanding of the complexities of the genetics and evolution of this group of plants.
Formulación de alimentos para celíacos con base en mezclas de harinas de quínoa, cereales y almidones
Del Castillo,Valeria; Lescano,Gerardo; Armada,Margarita;
Archivos Latinoamericanos de Nutrición , 2009,
Abstract: gluten free food for people with celiac disease based on quinoa, rice and corn flours and starches, were formulated. an informatic tool (alim v 1.0) developed by the authors, was used for the formulation of these foods. the obtained products were pancakes, scons, precooked pizza and bread which were analyzed in their chemical composition (protein, fat, fiber, moisture, ash and carbohydrates). water activity (aw), acceptability and texture parameters (hardness, gumminess, chewiness, adhesiveness and cohesiveness) were also determined. commercial products (c) were taken as reference and were performed the same analysis to formulated products (f). significant differences were found in protein, fat moisture, ash and fiber content and in most of the texture parameters studied in both food groups (pw of products (f) and (c), gave values similar to the data cited on bibliography for analogous products. the formulations more acceptable (values over 80%) were scones and pancakes. overall, the formulated products provide good quality proteins, have good textural characteristics and adequate percentages of acceptability to be used in the feeding of celiac patients.
Metabolic transcription analysis of engineered Escherichia coli strains that overproduce L-phenylalanine
José Báez-Viveros, Noemí Flores, Katy Juárez, Patricia Castillo-Espa?a, Francisco Bolivar, Guillermo Gosset
Microbial Cell Factories , 2007, DOI: 10.1186/1475-2859-6-30
Abstract: MTA revealed that a set of genes encoding carbohydrate transporters (galP, mglB), gluconeogenic (ppsA, pckA) and fermentative enzymes (ldhA) were significantly induced, while some others were down-regulated such as ppc, pflB, pta and ackA, as a consequence of PTS inactivation. One of the most relevant findings was the coordinated up-regulation of several genes that are exclusively gluconeogenic (fbp, ppsA, pckA, maeB, sfcA, and glyoxylate shunt) in the best PTS- L-Phe overproducing strain (PB12-ev2). Furthermore, it was noticeable that most of the TCA genes showed a strong up-regulation in the presence of multicopy plasmids by an unknown mechanism. A group of genes exhibited transcriptional responses to both PTS inactivation and the presence of plasmids. For instance, acs-ackA, sucABCD, and sdhABCD operons were up-regulated in PB12 (PTS mutant that carries an arcB- mutation). The induction of these operons was further increased by the presence of plasmids in PB12-ev2. Some genes involved in the shikimate and specific aromatic amino acid pathways showed down-regulation in the L-Phe overproducing strains, might cause possible metabolic limitations in the shikimate pathway.The identification of potential rate-limiting steps and the detection of transcriptional responses in overproducing microorganisms may suggest "reverse engineering" strategies for the further improvement of L-Phe production strains.Metabolic engineering is the specific modification of the metabolic pathways or the introduction of new ones within the host organism by means of genetic engineering techniques [1]. In the context of L-phenylalanine (L-Phe) production, the challenge to design and construct L-Phe overproducing strains has been approached by using several genetic strategies: 1) the deregulation and overexpression of key enzymes. For example 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthase and chorismate-mutase prefenate-dehydratase (CM-PDT), are two essential steps to overcome the
A Psychological Profile of Acculturation, Ethnic Identity and Teaching Efficacy among Latino In-service Teachers
Fuhui Tong,Linda G. Castillo,Aida E. Pérez
International Education Studies , 2010, DOI: 10.5539/ies.v3n3p41
Abstract: This study examined psychological constructs of acculturation, ethnic identity, and teaching efficacy among 89 Latino in-service teachers serving minority students. Results showed significant differences in these constructs in relation to certification, program taught, and years of teaching. First, bilingual teachers were less likely to be assimilated to White-American culture compared to traditionally/alternatively prepared ESL teachers. Second, traditionally certified ESL teachers were more efficacious in controlling disruptive behavior than alternatively prepared ESL teachers. Finally, higher acculturated teachers were associated with university route and ESL program while low acculturation individuals were more likely to hold alternative certification and teach in bilingual program. Educational implications were discussed.
Extending Teach and Repeat to Pivoting Wheelchairs
Guillermo Del Castillo,Steven B. Skaar,Linda Fehr
Journal of Systemics, Cybernetics and Informatics , 2003,
Abstract: The paper extends the teach-and-repeat paradigm that has been successful for the control of holonomic robots to nonholonomic wheelchairs which may undergo pivoting action over the course of their taught movement. Due to the nonholonomic nature of the vehicle kinematics, estimation is required -- in the example given herein, based upon video detection of wall-mounted cues -- both in the teaching and the tracking events. In order to accommodate motion that approaches pivoting action as well as motion that approaches straight-line action, the estimation equations of the Extended Kalman Filter and the control equations are formulated using two different definitions of a nontemporal independent variable. The paper motivates the need for pivoting action in real-life settings by reporting extensively on the abilities and limitations of estimation-based teach-and-repeat action where pivoting and near-pivoting action is disallowed. Following formulation of the equations in the near-pivot mode, the paper reports upon experiments where taught trajectories which entail a seamless mix of near-straight and near-pivot action are tracked.
Un corpo di donna per fare la guerra. Lettura della Ifigenia in Aulide di Euripide
Valeria Andò
Storia delle Donne , 2009,
Abstract: This paper analyzes Euripides’s Iphigenia in Aulis from a perspective that highlights the relationship between three different levels - the sacred, the political and the private -intersected as they are by the opposition male/female. In the course of the tragedy we assist at the gradual domination of the two spheres of “public” and “political”, while the sphere of “sacred” provides only a ritual frame. On the other hand, from the overall structure of the tragedy it also results that the sphere of “private” relationships and loves is a loser. Iphigenia, who takes upon herself the political and patriotic values of war, peculiar to the male, allows the execution of the sacrificial ritual and hence leads to the apparent triumph of the sacred final. Nevertheless, by resetting the other plans, she attains to upset oppositions and dichotomies and thus questions the prevalence of the sphere of “political” and, paradoxically, even her own reasons. The tragedy not only denounces war and politics as meaningless categories, but even erodes the religious value of sacrifice: in the final part of the tragedy, violence is actually rejected, but the refusal of human sacrifice does not involve a new political tension, and what remains is nothing but the beauty of poetry.
Políticas de sexualidad juvenil y diferencias étnico-raciales en Colombia: reflexiones a partir de un estudio de caso
Viveros Vigoya, Mara;
Revista Estudos Feministas , 2006, DOI: 10.1590/S0104-026X2006000100009
Abstract: this article analyzes the particular modes of governance of adolescent sexuality that emerge from the educational activities carried out by sexual and reproductive health programs for young colombians. it also analyzes their effects on the production of adolescent subjectivities. in addition, it examines the perception of those who carry out the pedagogic activities related to sexuality with adolescents and the way these perceptions are marked by ethnic/racial differences, as well as their influence on their professional performance. field data are based on observation of two pilot programs on sexual and reproductive health among adolescent high school students in bogotá, and on interviews with workshop coordinators and male and female counselors.
Discriminación racial, intervención social y subjetividad: Reflexiones a partir de un estudio de caso en Bogotá
Viveros Vigoya,Mara;
Revista de Estudios Sociales , 2007,
Abstract: based on a case study in one of bogotá?s poorest neighborhoods, this article contributes to the ongoing analysis of discourses of racial discrimination in colombia. it does not examine the experiences of people who are supposed to be the victims of discrimination, but focuses rather on some of the social agents implicated in its regulation: the officials who develop and implement the government?s social policies and programs in the aforementioned neighborhood. the article first describes the officials interviewed for the study, as well as the programs in which they are engaged. second, it examines how these social agents perceive, name, and experience their relationship with the "afro-colombian" residents of the neighborhood. and third, it analyzes their views on whether or not these people suffer from racial discrimination, and how the interviewees, as government officials, respond to their demands. the purpose of this article is to relate these different perceptions with their daily work experience and the philosophy behind the programs in which they work.
Una experiencia didáctica en torno a la brevedad y su versión en TIC
David Jacobo Viveros Granja
Folios , 2009,
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