4 resultados para Coco-da-Bahia

em Repositório Científico da Universidade de Évora - Portugal


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INTRODUCTION AND GOALS: Genus Bursaphelenchus includes several pests of the world importance for the rural economy, the most dangerous are the Bursaphelenchus xylophilus (the pinewood nematode caused decline of the pine trees in south Asia and in one spot area in Europe, Portugal, Peninsula de Setubal) and the Bursaphelenchus cocophilus, causing the decline of coco-palm plantations in Carribean and Latin American regions. The peculiarity of the host-parasite association of the genus that the nematode life cycle includes three trophic components: plant (mostly a tree), insect vector and a fungus. Goals of the presentation is to list all species of the world fauna and all efficient diagnostic characters, then create the identification tool and analyze the similarity of species and possible ways and causes of the host-parasite evolution of the group. RESULTS: Complete list of species with synonymy and a catalogue of all efficient diagnostic characters with their states, selected from papers of the most experienced taxonomists of the genus, are given for the genus Bursaphelenchus. List of known records of Bursaphelenchus species with names of natural vectors and plants and their families is given (for world pests the most important groups of trees and insects are listed). The tabular, traditional and computer-aided keys are presented. Dendrograms of species relationships (UPGMA, standard distance: mean character difference) based on all efficient taxonomic characters and separately on the spicule characters only, are given. Discussion whether the species groups are natural or purely diagnostic ones is based on the relationships dendrograms and the vector and associated plant ranges of Bursaphelenchus species; the xylophilus species group (B. xylophilus, B. abruptus, B. baujardi, B. conicaudatus, B. eroshenkii, B. fraudulentus, B. kolymensis, B. luxuriosae; B. mucronatus), the hunti group (B. hunti, B. seani, B. kevini and B. fungivorus) are probably the natural ones. CONCLUSIONS: The parasitic nematode association includes three trophic components: plant, insect vector and fungus. The initial insect-plant complex Scolytidae-Pinaceae is changeable and only in rare occasions the change of the preferred vector to Cerambycidae (the xylophilus group), Hymenoptera (the hunti group) led to formation of the natural species-groups. From the analysis it is clear that although the vector range is changeable it is comparatively more important for the evolution of the genus Bursaphelenchus than associations with plants at the family level. Data on the fungi species (3rd component in natural Bursaphelenchus associations) are insufficient for the detailed comparative analysis.

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The importance of student’s engagement has been recently pointed out in research. However, there has been a lack of engagement assessment instrument, pertaining psychometric qualities. Objective: This paper presents the Portuguese adaptation of the “Student’s Engagement in School International Scale” (SESIS), drawn up from a12 countries international study (Lam et al., 2012; Lam et al., in press). Method: Psychometric properties of this scale were examined with data from 685 students from different grades (6th, 7th, 9th and 10th), from both sexes, and different regions of the country. Results: Factorial analysis of the results, with varimax rotation, lead to three different factors which explain 50.88% of the variance. The scale integrates the original 33 items, and cognitive, affective and behavioural dimensions. For the external validity study, the relationship between student’s engagement in school results and other school variables — academic performance, self-concept — was considered, and significant relations were observed, as expected. Conclusion: The data presented highlights the qualities of SESIS, as well as its usefulness for research purposes. Suggestion: It is suggested the investigation of the extension of SESIS’s three-dimensionality, in future studiesKeywords: Innovation, technology, research projects, etc. [Arial 10-point, justified alignment].

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Students’ Engagement in School has been the focus of debate concerning academic success and school dropout, and pointed out as a mean to address the problems affecting our schools and their students, not only for having value in itself, but also for being an important mediator between several academic variables. This paper reviews the research and literature on this concept and its relations with personal and contextual variables, as well as with academic performance, with the aim of summarizing the main relationships found. Literature presents a significant number of studies which sustain that personal variables, such as self-efficacy and self-concept, as well as contextual - peers, school, family- are related with school engagement. The adoption of mastery goals, for instance, has a positive impact on school, as they are related with the use of cognitive and self-regulatory strategies by students. Positive relationships with peers, teachers support and the quality of family relations are associated with higher levels of engagement and academic performance, while negative experiences, such as bullying, are related with educational difficulties. Following this, we reflect about the relevance of studying engagement in school, in the context of widespread financial crisis, and emphasize the need to rethink educational institutions considering the paradigmatic changes that currently occur.

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The importance of student’s engagement has been recently pointed out in research. However, there has been a lack of engagement assessment instruments, showing psychometric qualities, such as reliability and validity. Objective: This paper presents the Portuguese adaptation of the “Student’s Engagement in Schools International Scale” (SESIS), drawn up from 12 countries international study (Lam et al., 2012; Lam et al., in press). Method: Psychometric properties of this scale were examined using data from 685 students, of both sexes, and from different grades (6th, 7th, 9th and 10th), and regions of the country. Results: Factorial analysis of the results, with varimax rotation, conducted to three different factors which explain 62,19% of the variance. The scale integrates the original 33 items, and cognitive, affective and behavioural dimensions. For the external validity study, the relationship between student’s engagement in school results and other school variables — academic performance, school conduct — was considered, and significant relations were observed, as expected. Conclusion: The data presented highlights the qualities of SESIS, as well as its usefulness for research purpose. Suggestion: It is suggested the investigation of the extension of SESIS’s three-dimensionality, in future studies