6 resultados para Pepino

em Universidade Federal do Rio Grande do Norte(UFRN)


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The fruit fly Ceratitis capitata is considered the most destructive pest of the world fruitculture. Many pest management practices, mainly based on agrochemicals, have been developed to allow the world-wide commerce of fruit. Solutions to decrease the use of synthetic insecticides in agriculture are based on the development of new target-specific compounds which cause less damage to the environment, especially vegetal proteins with insecticidal effects. The aim of this work was to evaluate the deleterious effect of a purified vicilin of E. velutina (EvV) seeds to C. capitata larvae and adult insects and to investigate the mechanisms involved in these effects. EvV was purified, characterized and its deleterious effect was tested in bioassay systems. EvV mechanism of action was determined by immunodetection techniques and fluorescence localization in chitin structures that are present in C. capitata digestory system. EvV is a glycoprotein with affinity to chitin. Its molecular weight, of 216,57 kDa, was determined by gel filtration chromatography in FPLC system. Using SDS-PAGE, it was possible to observe EvV dissociation in two main subunits of 54,8 and 50,8 kDa. When it was submitted to eletrophoresis in native conditions, EvV presented only one band of acid characteristic. The WD50 and LD50 values found in the bioassays were 0,13% and 0,14% (w/w), respectively for the larvae. EvV deleterious effects were related to the binding to chitin structures presented in peritrophic membrane and gut epithelial cells, associated with its low digestibility in C. capitata digestive tract. The results described herein are the first demonstration of the larvicidal effects of plant protein on C. capitata larvae. EvV may be part of the pest management programs, in the toxic bait composition, or an alternative in plant improvement program

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Shrimp farming is one of the activities that contribute most to the growth of global aquaculture. However, this business has undergone significant economic losses due to the onset of viral diseases such as Infectious Myonecrosis (IMN). The IMN is already widespread throughout Northeastern Brazil and affects other countries such as Indonesia, Thailand and China. The main symptom of disease is myonecrosis, which consists of necrosis of striated muscles of the abdomen and cephalothorax of shrimp. The IMN is caused by infectious myonecrosis virus (IMNV), a non-enveloped virus which has protrusions along its capsid. The viral genome consists of a single molecule of double-stranded RNA and has two Open Reading Frames (ORFs). The ORF1 encodes the major capsid protein (MCP) and a potential RNA binding protein (RBP). ORF2 encodes a probable RNA-dependent RNA polymerase (RdRp) and classifies IMNV in Totiviridae family. Thus, the objective of this research was study the IMNV complete genome and encoded proteins in order to develop a system differentiate virus isolates based on polymorphisms presence. The phylogenetic relationship among some totivirus was investigated and showed a new group to IMNV within Totiviridae family. Two new genomes were sequenced, analyzed and compared to two other genomes already deposited in GenBank. The new genomes were more similar to each other than those already described. Conserved and variable regions of the genome were identified through similarity graphs and alignments using the four IMNV sequences. This analyze allowed mapping of polymorphic sites and revealed that the most variable region of the genome is in the first half of ORF1, which coincides with the regions that possibly encode the viral protrusion, while the most stable regions of the genome were found in conserved domains of proteins that interact with RNA. Moreover, secondary structures were predicted for all proteins using various softwares and protein structural models were calculated using threading and ab initio modeling approaches. From these analyses was possible to observe that the IMNV proteins have motifs and shapes similar to proteins of other totiviruses and new possible protein functions have been proposed. The genome and proteins study was essential for development of a PCR-based detection system able to discriminate the four IMNV isolates based on the presence of polymorphic sites

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The study Teacher work and education in the municipal schools of Natal objectifies the analysis of the education and work conditions of the teachers in the municipal schools of Natal, placing them within the scenario of the public policies outlined for Basic Education (2005-2010). The thesis is based on the perspective that the educational reforms implemented by the Brazilian government in an attempt to answer to the new contextual demands originated from the world of work and globalization, demanding increasingly higher levels of qualification and constant extension of the teaching functions in school from the teachers, have been configured withal as a strategy for intensifying the teacher s work. The empirical field of study was constituded by thirteen municipal schools that offer basic education. Four hundred and seventeen teacher subjects that work in the municipal school system of Natal, two representatives of the Secretaria Municipal de Educação de Natal (SME)1 that work in the pedagogical team and one representative of the Sindicato dos Trabalhadores em Educação do Rio Grande do Norte2 took part in the study. The procedures/instruments used in the research were: bibliographic review, document research, questionnaires and recording of information in a field journal. The study confirmed that the majority of the teachers that work in the municipal school system were admitted by means of public entry exams, therefore meeting the requirements set by Law 9.394/96. Most of the teachers have the initial education demanded to work in basic education, although with some limitations due to the fact that they do not correspond to the needs of the educational system. The SME has a plan for continued training of the teachers in accordance to the current ideas defended by researchers of this field. There is, although, a disconnection between the purpose of the plan and the training strategies, because, in truth, predominate repetitive and specific actions that do not contemplate the training needs of the teachers, nor the demands of the system. Although the work conditions are evaluated, by the teachers, as relatively good, limits in relation to the physical structure of the schools are observed (dirty walls with holes in them, broken ceiling fans, old chairs and desks, old and stained black boards, inadequate restroom installations, poor maintenance of the computers, amongst other items). It was also verified the an increase in the functions of the teachers and an intensification of their work, materialized through an overburden of activities undertaken daily at school (and outside of it) and through the demand in taking part in activities that go beyond those inherent to the teaching process, such as the elaboration of political-pedagogical projects, participation in collegiate, registration of student information solicited by the SME and the participation in commissions, has been happening

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Politics of Continued Formation of Tachers: settings, directives and pratices is constituted in a study from politics of continued formation of teachers materialized for the actual government. It has for purpose to analyse aspects of experience of continued formation in techers service that work at initial levels of fundamental education desenvolved in Natal through Program Management of School Learning (GESTAR) at the period from 2002 to 2005. The empiric field of study privileged the experience of formation in service developed by GESTAR in a school located at the procedures that materialized the search, we can point out: bibliographic review of literature that analyses the new demands for education in view of occurred transformations at the word setting and studies about the thematic continued formation of teachers; documentary search about the politics of continue formation of teachers and the GESTAR program from municipal net of study of Natal, four teachers and pedagogic coordinater of searched school. The study established a positive evaluation by the teachers that took part at the program in Natal and they pointed out that politics strategy of continued formation in service made possible the study of contents of Portuguese Language and Mathernatics associated to a new form for working them in the classroom, understanding of certain contents that they had difficulties before, understanding that activitus realized should have meaning for the student, favouring the understanding of subject studied. Among some limits noticed, we can point out: absence of reading of the material by the teachers, difficulty of the teachers in reconcile the diary activities wiht the individual studies at distance, no realization of a systematic following of the pedagogic practical of teachers use the exam how the only instrument of evaluation used by the teachers and difficulties of them in going on with the pedagogic proposal of GESTAR after the end of this program

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The fruit fly Ceratitis capitata is considered the most destructive pest of the world fruitculture. Many pest management practices, mainly based on agrochemicals, have been developed to allow the world-wide commerce of fruit. Solutions to decrease the use of synthetic insecticides in agriculture are based on the development of new target-specific compounds which cause less damage to the environment, especially vegetal proteins with insecticidal effects. The aim of this work was to evaluate the deleterious effect of a purified vicilin of E. velutina (EvV) seeds to C. capitata larvae and adult insects and to investigate the mechanisms involved in these effects. EvV was purified, characterized and its deleterious effect was tested in bioassay systems. EvV mechanism of action was determined by immunodetection techniques and fluorescence localization in chitin structures that are present in C. capitata digestory system. EvV is a glycoprotein with affinity to chitin. Its molecular weight, of 216,57 kDa, was determined by gel filtration chromatography in FPLC system. Using SDS-PAGE, it was possible to observe EvV dissociation in two main subunits of 54,8 and 50,8 kDa. When it was submitted to eletrophoresis in native conditions, EvV presented only one band of acid characteristic. The WD50 and LD50 values found in the bioassays were 0,13% and 0,14% (w/w), respectively for the larvae. EvV deleterious effects were related to the binding to chitin structures presented in peritrophic membrane and gut epithelial cells, associated with its low digestibility in C. capitata digestive tract. The results described herein are the first demonstration of the larvicidal effects of plant protein on C. capitata larvae. EvV may be part of the pest management programs, in the toxic bait composition, or an alternative in plant improvement program

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Shrimp farming is one of the activities that contribute most to the growth of global aquaculture. However, this business has undergone significant economic losses due to the onset of viral diseases such as Infectious Myonecrosis (IMN). The IMN is already widespread throughout Northeastern Brazil and affects other countries such as Indonesia, Thailand and China. The main symptom of disease is myonecrosis, which consists of necrosis of striated muscles of the abdomen and cephalothorax of shrimp. The IMN is caused by infectious myonecrosis virus (IMNV), a non-enveloped virus which has protrusions along its capsid. The viral genome consists of a single molecule of double-stranded RNA and has two Open Reading Frames (ORFs). The ORF1 encodes the major capsid protein (MCP) and a potential RNA binding protein (RBP). ORF2 encodes a probable RNA-dependent RNA polymerase (RdRp) and classifies IMNV in Totiviridae family. Thus, the objective of this research was study the IMNV complete genome and encoded proteins in order to develop a system differentiate virus isolates based on polymorphisms presence. The phylogenetic relationship among some totivirus was investigated and showed a new group to IMNV within Totiviridae family. Two new genomes were sequenced, analyzed and compared to two other genomes already deposited in GenBank. The new genomes were more similar to each other than those already described. Conserved and variable regions of the genome were identified through similarity graphs and alignments using the four IMNV sequences. This analyze allowed mapping of polymorphic sites and revealed that the most variable region of the genome is in the first half of ORF1, which coincides with the regions that possibly encode the viral protrusion, while the most stable regions of the genome were found in conserved domains of proteins that interact with RNA. Moreover, secondary structures were predicted for all proteins using various softwares and protein structural models were calculated using threading and ab initio modeling approaches. From these analyses was possible to observe that the IMNV proteins have motifs and shapes similar to proteins of other totiviruses and new possible protein functions have been proposed. The genome and proteins study was essential for development of a PCR-based detection system able to discriminate the four IMNV isolates based on the presence of polymorphic sites