248 resultados para Poisonous arthropoda


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Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

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As características dos artrópodes (insetos, crustáceos, aracnídeos, miriápodes) e conceitos a eles relacionados são conteúdos abordados pelas disciplinas de Ciências e Biologia, no ensino fundamental e médio. Neste contexto, considera-se relevante a elaboração de materiais que contribuam para os processos de ensino e aprendizagem desta temática e que incorporem a dimensão lúdica. Assim, a proposta desenvolvida teve como objetivos principais a elaboração e confecção de uma caixa contendo espécimes de artrópodes incrustados em resina, de modo a permitir o contato e a manipulação desses espécimes pelos alunos. Além disso, elaboramos um jogo didático, abordando as estruturas morfológicas dos artrópodes e suas funções, com o intuito de fixar o conhecimento adquirido em sala pelos alunos. Como complementação, desenvolvemos uma guia de orientação para o professor e um manual direcionado aos alunos, para os auxiliarem durante o desenvolvimento da aula. A elaboração deste trabalho foi uma maneira de tentar transmitir o tema proposto de forma dinâmica e agradável, tanto para o professor quanto para os alunos. O conteúdo fornecido neste trabalho foi baseado em livros didáticos específicos em zoologia de invertebrados, para possibilitar aulas com conteúdo adequado e para prevenir erros conceituais

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The physic nut (Jatropha curcas L.) (Euphorbiaceae) has emerged as a new option in cultivation aimed at biodiesel production. In order to provide information that may be useful to further develop management plans for that specific crop, samples of mites were collected from cultured and wild J. curcas plants in various regions of the country and from two other species of the same genus, Jatropha gossypiifolia L. and Jatropha mollissima (Pohl) Baill. in the northeastern region of Brazil. Altogether 31 species belonging to 10 families were recorded. The family Phytoseiidae presented the largest number of species (17). Polyphagotarsonemus latus Banks (Tarsonemidae) was the most abundant species (8,503 specimens). A dichotomous key was prepared to identify all the sampled species. At least four mite species of the samples deserve attention as showing potential for being pests in the crops of J. curcas, Brevipalpus phoenicis, Brevipalpus obovatus, Polyphagotarsonemus latus and Tetranychus bastosi, the latter two often found in great abundance.

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Eukaryotic ribosomal DNA constitutes a multi gene family organized in a cluster called nucleolar organizer region (NOR); this region is composed usually by hundreds to thousands of tandemly repeated units. Ribosomal genes, being repeated sequences, evolve following the typical pattern of concerted evolution. The autonomous retroelement R2 inserts in the ribosomal gene 28S, leading to defective 28S rDNA genes. R2 element, being a retrotransposon, performs its activity in the genome multiplying its copy number through a “copy and paste” mechanism called target primed reverse transcription. It consists in the retrotranscription of the element’s mRNA into DNA, then the DNA is integrated in the target site. Since the retrotranscription can be interrupted, but the integration will be carried out anyway, truncated copies of the element will also be present in the genome. The study of these truncated variants is a tool to examine the activity of the element. R2 phylogeny appears, in general, not consistent with that of its hosts, except some cases (e.g. Drosophila spp. and Reticulitermes spp.); moreover R2 is absent in some species (Fugu rubripes, human, mouse, etc.), while other species have more R2 lineages in their genome (the turtle Mauremys reevesii, the Japanese beetle Popilia japonica, etc). R2 elements here presented are isolated in 4 species of notostracan branchiopods and in two species of stick insects, whose reproductive strategies range from strict gonochorism to unisexuality. From sequencing data emerges that in Triops cancriformis (Spanish gonochoric population), in Lepidurus arcticus (two putatively unisexual populations from Iceland) and in Bacillus rossius (gonochoric population from Capalbio) the R2 elements are complete and encode functional proteins, reflecting the general features of this family of transposable elements. On the other hand, R2 from Italian and Austrian populations of T. cancriformis (respectively unisexual and hermaphroditic), Lepidurus lubbocki (two elements within the same Italian population, gonochoric but with unfunctional males) and Bacillus grandii grandii (gonochoric population from Ponte Manghisi) have sequences that encode incomplete or non-functional proteins in which it is possible to recognize only part of the characteristic domains. In Lepidurus couesii (Italian gonochoric populations) different elements were found as in L. lubbocki, and the sequencing is still in progress. Two hypothesis are given to explain the inconsistency of R2/host phylogeny: vertical inheritance of the element followed by extinction/diversification or horizontal transmission. My data support previous study that state the vertical transmission as the most likely explanation; nevertheless horizontal transfer events can’t be excluded. I also studied the element’s activity in Spanish populations of T. cancriformis, in L. lubbocki, in L. arcticus and in gonochoric and parthenogenetic populations of B. rossius. In gonochoric populations of T. cancriformis and B. rossius I found that each individual has its own private set of truncated variants. The situation is the opposite for the remaining hermaphroditic/parthenogenetic species and populations, all individuals sharing – in the so far analyzed samples - the majority of variants. This situation is very interesting, because it isn’t concordant with the Muller’s ratchet theory that hypothesizes the parthenogenetic populations being either devoided of transposable elements or TEs overloaded. My data suggest a possible epigenetic mechanism that can block the retrotransposon activity, and in this way deleterious mutations don’t accumulate.

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Species diversity is the most common variable reported in recent ecological research articles. Ecological processes, however, are driven by individuals. High abundances make arthropods, despite their small body sizes, important actors in food webs. We sampled arthropod assemblages in disturbed and undisturbed vegetation types along an elevation gradient of from 800 to 4550 m a.s.l. on the southern slopes of Mt. Kilimanjaro, Tanzania. In our analysis, we focused on 13 different lineages of arthropods that represented three major functional groups: predators, herbivores and decomposers. The samples were collected with pitfall traps on 59 (of 60) study sites within the framework of the KiLi-project (https://www.kilimanjaro.biozentrum.uni-wuerzburg.de/). In each of twelve vegetation types five sampling sites of 50 m x 50 m were established with a minimum distance of 300 m between the individual sites. On each of the 59 sites, ten pitfall traps were evenly spaced along two 50 m transects, with a distance of 10 m between individual traps and 20 m between the parallel transects. Pitfall traps were filled with 100-200 ml of a mixture of ethylenglycol and water (1:1) with a drop of liquid soap to break surface tension. Traps were exposed at 2 to 5 sampling events for seven days in both the dry and wet seasons between May 2011 and October 2012. The reported abundances per lineage were averaged twice: first over all samples per site for each sampling event (3-10 analyzed samples per site and sampling event), and then averaged over all sampling events for each site.

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Mode of access: Internet.

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Mode of access: Internet.

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Mode of access: Internet.