963 resultados para Citologia e Biologia Celular


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Mangas 'Tommy Atkins' produzidas na região de Ibirá, São Paulo, foram pulverizadas na pré-colheita com cloreto de cálcio, nas concentrações de 0,0%, 2,5% e 5,0%, em três épocas de seu desenvolvimento (40; 60 e 90 dias após a floração) a fim de verificar a influência do cálcio na estrutura da parede celular destes frutos através de microscopia eletrônica de transmissão, imediatamente após a colheita e depois de 35 dias de armazenamento. Para fixar o material da polpa, utilizou-se metodologia descrita por Jacob e Gowanlock (1995). Nas condições experimentais, verificou-se que os frutos do tratamento-controle (sem cloreto de cálcio), no dia da colheita, já apresentavam desestruturação da parede celular e dissolução da lamela média (LM). A degradação da parede celular ocorre inicialmente na LM, levando à formação de espaços vazios bastante distintos, apresentando uma dissolução ainda maior, com o armazenamento prolongado (35 dias). Os frutos tratados com cloreto de cálcio a 5,0% apresentaram uma LM bem definida e ausência de espaços vazios, mesmo após o armazenamento, mostrando ser uma concentração efetiva na preservação da lamela média.

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This dissertation has the purpose to present a portable device named PlugData MG100G, equipped with a cellular module, to analyze the radiofrequency coverage in a GSM network situated in João Pessoa city, state of Paraíba, at four distinct regions. The equipment, originally, was developed to be used in fixed environments, so it was adapted so that it could be used in conditions of mobility. From the Mobile Measurement Reports (MMRs) RF coverage and the handover process are analyzed. The MMRs enable the identification of the serving cell and the list of the closest neighboring cells monitored by the mobile. This work analyses only data referent to the serving cell and the two closest neighboring cells. Inter-cell and intra-cell handovers are identified. The frequency planning and quality of service offered by the network related to the regions are discussed as well

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The development of wireless telecommunication in the last years has been great. It has been taking academics to conceive new ideas and techniques. Their aims are to increase the capacity and the quality of the system s services. Cells that are smaller every time, frequencies that are every time higher and environments that get more and more complex, all those facts deserve more accurate models the propagation prediction techniques are inserted in this context and results with a merger of error that is compatible with the next generations of communication systems. The objective of this Work is to present results of a propagation measurement campaign, aiming at pointing the characteristics of the mobile systems covering in the city of Natal (state of Rio Grande do Norte, Brazil). A mobile laboratory was set up, using the infra-structure available and frequently used by ANATEL. The measures were taken in three different areas: one characterized by high buildings, high relief, presence of trees and towers of different highs. These areas covered the city s central zone, a suburban / rural zone and a section of coast surrounded by sand dunes. It is important to highlight that the analysis was made taking into consideration the actual reality of cellular systems with covering ranges by reduced cells, with the intent of causing greater re-use of frequencies and greater capacity of telephone traffic. The predominance of telephone traffic by cell in the city of Natal occurs within a range inferior to 3 (three) km from the Radio-Base Station. The frequency band used was 800 MHz, corresponding to the control channels of the respective sites, which adopt the FSK modulation technique. This Dissertation starts by presenting a general vision of the models used for predicting propagation. Then, there is a description of the methodology used in the measuring, which were done using the same channels of control of the cellular system. The results obtained were compared with many existing prediction models, and some adaptations were developed by using regression techniques trying to obtain the most optimized solutions. Furthermore, according to regulations from the old Brazilian Holding Telebrás, a minimum covering of 90% of a determined previously area, in 90% of the time, must be obeyed when implanting cellular systems. For such value to be reached, considerations and studies involving the specific environment that is being covered are important. The objective of this work is contribute to this aspect

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The fly of the syrphid Microdon tigrinus is a specific social parasite of leaf-cutting ant, Acromyrmex coronatus. Six colonies of Acromyrmex coronatus were collected in plastic containers, which there was a layer of 1 cm of plaster, with the purpose of maintaining the humidity of fungus culture. Larvae of social parasite were separate for the establishment of instars number, through morphometric study. The data were measured of 165 larvae, using spiracle (length (Ls), width (Ws) and distance between spiracle (Ds)). After that, the morphometric data obtained for the larvae were submitted to cluster analysis by Wong's hybrid method, which produces the adequate number of groups through pseudo F-statistics and pseudo t-squared statistics. The three morphometric variables studied permitted grouping of larvae into the following three distinct groups: cluster 1 [long dash] consisting of 55 larvae (Ls=0.177[plus or minus]0.026, Ws=0.163[plus or minus]0.030, Ds=0.052[plus or minus]0.008 mm); cluster 2 - consisting of 20 larvae (Ls=0.631[plus or minus]0.065, Ws=0.630[plus or minus]0.049, Ds=0.065[plus or minus]0.018 mm); cluster 3 - consisting of 90 larvae (Ls=1.294[plus or minus]0.062, Ws=1.308[plus or minus]0.069, Ds=0.140[plus or minus]0.018 mm). of the all couples, only 1 obtained success in the mating, and the female, after 24 hours, began the oviposition. The female layed 76 eggs in a period of 6 days, after that, her death. The larvae emerged in the seventh day (incubation period [plus or minus] 7 days). From 76 eggs, 54 were viable, with a viability of 71.05%. This study contributes to the knowledge of Microdon tigrinus biology of, a social parasite poorly studied in Brazil.

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A broca do pedúnculo floral do coqueiro, Homalinotus coriaceus (Gyllenhal), é uma praga limitante à produção de coco no Brasil, provocando a queda das flores e dos frutos imaturos. Sua biologia é pouco conhecida o que tem dificultado a seu manejo adequado no campo. Dessa forma, foi realizado o estudo da biologia desse inseto no Laboratório de Entomologia da Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Tabuleiros Costeiros - CPATC, em Aracaju, SE, à temperatura de 25 ± 2°C, umidade relativa de 70% e fotofase de 12h. Para alimentação e oviposição dos adultos coletados no campo foram utilizados toletes de cana-de-açúcar como substrato, nos quais as fêmeas colocaram ovos individualizados, cujo período de incubação variou de seis a 14 dias. As larvas foram criadas no mesocarpo de coco, desenvolvendo-se em 144 dias em média, passando por cinco a sete ínstares. O período pupal médio foi de 31 dias. A longevidade do adulto variou de 303 a 695 dias para fêmeas e de 246 a 635 dias para machos, sendo o ciclo de ovo a adulto de 181,9 dias para fêmeas e 188,5 para machos. Foram observadas diferenças morfológicas nas pupas e nos adultos, que podem ser utilizadas para separação dos sexos. Ao contrário dos machos, as fêmeas apresentam, na fase de pupa, duas estruturas arredondadas e elevadas situadas na face ventral e final do abdome e, na fase adulta, o penúltimo tergito abdominal projeta-se sobre o último.

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Visando conhecer a relação parasito hospedeiro de M. enterolobii em plantas com resistência a nematoides das galhas, estudos comparativos da biologia de M. enterolobii e M. javanica em tomateiros com o gene Mi foram conduzidos. O experimento foi conduzido em esquema fatorial 2x2, composto de dois porta-enxertos de tomateiro ('Magnet' e 'Helper M') e duas espécies de nematoides das galhas (M. enterolobii e M. javanica) com cinco repetições. As plantas foram inoculadas com 500 juvenis infectantes (J2) de M. enterolobii ou M. javanica. As raízes foram coletadas aos 3, 10, 17, 24 e 31 dias após a inoculação, coloridas com fucsina ácida, e dissecadas sob microscópio estereoscópico para a localização e contagem dos diferentes estádios de desenvolvimento dos nematoides. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de probabilidade. Os resultados obtidos mostraram que, embora ambas as espécies tenham sido capazes de penetrar as raízes dos porta-enxertos de tomateiro, somente M. enterolobii conseguiu desenvolver-se normalmente, com as fêmeas maduras realizando suas posturas, a partir de 24 dias após a inoculação.

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Escherichia coli has been one of the most widely used hosts in recombinant protein production, in both laboratory and industrial scale since the advent of recombinant DNA technology. Despite the substantial progress of studies on the molecular biology and immunology of infections, there is currently no medication-based prophylaxis capable of preventing leishmaniasis. As such, there is a great need to identify specific antigens for the development of vaccines and diagnostic kits against visceral leishmaniasis. Thus, the primary goal of the present study is to assess the influence of cultivation conditions on the production of Leishmania chagasi antigens, carried out in a rotating incubator and bioreactor. To that end, several assays were conducted to evaluate the kinetic behavior of antigens (648, 503) of Leishmania. i. chagasi in two different compositions of media (2xTY, TB), with and without an inducer. In order to improve expression, assays were performed in a benchtop bioreactor using the best conditions obtained in a rotating incubator, in addition to assessing the influence of stirring speed. Results show that high complexity of the cultivation medium favored kinetic growth of clones (648, 503). However, in assays submitted to induction by IPTG, this elevated complexity did not promote the expression of recombinant proteins. Expression of antigens 648 and 503 exhibited behavior associated with growth and, in terms of location, proteins 648 and 503 are intracellularly stored. Lactose may be the most adequate inducer in protein expression, when considering factors, cost, toxicity and stability. Elevated stirring may increase cell growth in clone 53, although it may not result in high concentrations for the protein of interest. On the other hand, positive results were obtained for all recombinant clones (648, 503) tested, confirmed by the electrophoretic profile

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O presente artigo apresenta os resultados de uma pesquisa cujo objetivo foi identificar as percepções dos professores de Biologia do município de Piracicaba, SP, e dos alunos concluintes de um curso de licenciatura em Ciências Biológicas em relação à presença da Educação Ambiental em sua formação inicial, a fim de discutir a inserção da temática na universidade em geral e, especificamente, na licenciatura em Ciências Biológicas. Os resultados indicam que o professor de Biologia ainda necessita de uma formação mais crítica em relação à educação ambiental e que, numa perspectiva complexa, essa formação necessita ser tratada de forma mais rigorosa na universidade e nas licenciaturas em Ciências Biológicas para que os profissionais formados possam atuar, efetivamente, na formação cidadã para uma sociedade mais sustentável.

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La práctica educativa en espacios no formales es un recurso didáctico catalizador de motivación e interese, tanto para alumnos como para los profesores. El crecimiento de los espacios no formales coincide con los cambios recientes en el mundo en los campos sociales, políticos, económicos y culturales. Como una de las consecuencias de esos cambios, tenemos el crecimiento de otras instancias difusoras de conocimientos rompiendo, así, la hegemonía de la escuela. De esa forma, en este trabajo busqué investigar la frecuencia y las formas de utilización de los espacios de educación no formal por profesores de biología, de la enseñanza media, de la Ciudad de Natal (RN). Procuré también, identificar cuales son los espacios de educación no-formal que son utilizados; describir los recursos y las acciones desarrolladas en eses espacios; identificar la existencia o no de interese y la importancia que atribuyen a los espacios para la enseñanza de biología, además de divulgar los espacios utilizados como recursos didácticos. Para alcanzar estos objetivos fueron hechas observaciones de los espacios, aplicados cuestionarios y realizadas entrevistas con los profesores que realizan actividades junto a tales instituciones. Para el análisis de los datos se utilizó tanto el abordaje cuantitativo como cualitativa. Nos basamos en referenciales teóricos de autores que buscan establecer las relaciones entre diferentes modalidades de educación para mejor comprender lo que es la educación no-formal y su trayectoria histórica. Constaté que los profesores utilizan los espacios de educación no-formales, aun la cantidad de visitas al año sea reducida, en virtud de varias dificultades por ellos apuntadas, tales como el transporte, la falta de recursos financieros y de apoyo para viabilizar la visita, entre otros. Verifiqué también que los profesores demostraron un alto interese por los espacios no-formales y apuntaron como principales justificativas para considerarlos importantes para la enseñanza de la biología la posibilidad de establecer conexiones entre la teoría y la practica, además de la complementariedad

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Recent research has revealed that the majority of Biology teachers believe the practice of experimental activities as a didactical means would be the solution for the improvement of the Biology teaching-learning process. There are, however, studies which signal the lack of efficiency in such practice lessons as far as building scientific knowledge is concerned. It is also said that despite the enthusiasm on the teachers‟ part, such classes are rarely taught in high school. Several studies point pedagogical difficulties as well as nonexistence of a minimal infrastructure needed in laboratories as cause of low frequency in experimental activities. The poor teacher performance in terms of planning and development of classes; the large number of students per class; lack of financial stimulus for teachers are other reasons to be taken into account among others, in which can also be included difficulties of epistemological nature. That means an unfavorable eye of the teacher towards experimental activities. Our study aimed to clarify if such scenario is generalized in high schools throughout the state of Rio Grande do Norte Brazil. During our investigation a sample of twenty teaching institutions were used. They were divided in two groups: in the first group, five IFRN- Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte schools. Two of those in Natal, and the other three from the country side. The second group is represented by fifteen state schools belonging to the Natal metropolitan area. The objectives of the research were to label schools concerning laboratory facilities; to identify difficulties pointed by teachers when performing experiment classes, and to become familiar with the conceptions of the teachers in regarding biology experiment classes. To perform such task, a questionnaire was used as instrument of data collecting. It contained multiple choice, essay questions and a semi-structured interview with the assistance of a voice recorder. The data analysis and the in loco observation allowed the conclusion that the federal schools do present better facilities for the practice of experimental activities when compared to state schools. Another aspect pointed is the fact that teachers of federal schools have more time available for planning the experiments; they are also better paid and are given access a career development, which leads to better salaries. All those advantages however, do not show a significantly higher frequency regarding the development of experiments when compared to state school teachers. Both teachers of federal and state schools pointed infra-structure problems such as the availability of reactants, equipments and consumption supplies as main obstacle to the practice of experiments in biology classes. Such fact leads us to conclude that maybe there are other problems not covered by the questionnaire such as poor ability to plan and execute experimental activities. As far as conceptions about experimental activities, it was verified in the majority of the interviewees a inductive-empiric point of view of science possibly inherited during their academic formation and such point of view reflected on the way they plan and execute experiments with students

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The deployment of master professionals in Mathematics and Science Teaching by CAPES provided an interesting perspective, involving institutional incentive to upgrade teacher training in this modality. In this sense, the objective was to map the profile of the candidates in the Graduate School of Natural Sciences and Mathematics UFRN (PPGECNM), develop a database with specific descriptors for dissertations and research the group creation biology research and dissertations produced by graduate students in the Master course. This thesis has three threads, where the first is entitled: "The teaching of science as part of research: emergency, improvement and current reflections", giving a brief description of the creation of graduate studies and the emergence of Brazil in Science education. The second topic: "Professional Masters in Teaching of Natural Sciences and Mathematics-UFRN: candidate profile the biological ', shows the general characteristics of PPGECNM-UFRN and who are the candidates seeking the biological area of the Graduate Program. The third topic. "The construction and consolidation of the research group in biology education in PPGECNM-UFRN", a survey was made of data on the creation of the research group in biology education from the analysis of academic productions of teachers and masters graduates this Masters course, for those involved, some additional interviews about the experience in training in biology education. Data used in these investigations related to these students correspond to the technical product to be used in other studies profile teachers /dissertations from the PPGECNM / UFRN. Research shows that: the existence of a larger number of postgraduate courses in the field of Science Education provides greater productivity in academic research on the subject, the emergence of a research group on education in biology, tied to a post degree in education, is an attraction to strengthen lines of research in science education by teachers researchers in other disciplines, the candidates seeking permanent area for research in biology education signals the importance of this investment because if shows the need to search for the continuing education of practicing teachers, demands with interests in investigations from real problems from school

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El trabajo práctico experimental en la educación en Ciencias y en el contexto de la enseñanza de la Biología es un objetivo clave. Teniendo en cuenta la influencia de los libros de texto en la actividad profesional de docentes, interesado en este estudio para caracterizar la orientación de este tipo de materiales, para el trabajo práctico experimental y el uso de la medición en esta actividad. Para ello analizaron las ocho colecciones de libros de Biología aprobado en PNLD en 2012. La investigación es de naturaleza descriptiva e interpretativa y de recogida de datos ha sido elegida por el método de análisis de contenido (BARDIN, 2002). El análisis de los trabajos práctico experimentales buscó caracterizar su naturaleza epistemológica, concepción de la ciencia implícita, conceptual, tipología, contenido conceptual de Biología utilizado, cuántos implican medidas, y cómo se utiliza en este contexto según el procedimiento general para medir propuesto por Núñez y Silva (2008). Los trabajo práctico experimental ha sugerido una epistemología de la enseñanza conceptual, carácter racionalista en su mayoría y dominada por las actividades del tipo de ejercicio práctico, a necesidad de medir está presente en una minoría de estos y se se utiliza el procedimiento general de medición de forma parcial e implícito en la mayoría de los trabajos prático experimentales. Por lo tanto, proponemos en este actividades de estudio a desarrollar una guía de análisis de los trabajo práctico experimentales propuesto en los libros de texto de Biología

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Normally initial teacher training has not been sufficient to provide all the tools for an updated and efficient teaching practice. It is presented here one of the ways of working the completion of the initial training through a course of continuing education. This course is based on inquiry teaching which is considered an important teaching strategy for science education. This kind of teaching enables improvement of students reasoning and cognitive skills, the cooperation among them, the understanding of the nature of scientific work, and the motivation to think about the relationship between science, technology, society and environment. For this dissertation a course of continuing education based on this approach was followed in order to evaluate which contributions it can bring to the teaching practice. The course was followed based on three stages: on the first there was a questionnaire and an informal interview; next it happened through participant observation with audio and visual aid; the third stage happened through semi structured interview. The collected information was analyzed based on Content Analysis. An inquiry teaching pedagogical material was produced for the course including some examples and applications of this approach. The aim of the material is that it can be a support for the teachers after de course. The results allowed seeing that the course was very useful, different from the traditional and the teachers that put the approach to use found it to be very positive. Thus it can be said that some of the teachers who participated will try again to apply it, try to contextualize more the teaching situations with the students day to day life, as well make them more active and critic. We can also gather from the study, that the inquiry teaching is a very different tool from what the teacher was taught and is accustomed to use and the theoretical comprehension, acceptance and practice change is a complicated process and demands time

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)