80 resultados para Character interdependence
Resumo:
The squat lobster Pleuroncodes monodon is one of the most common and abundant galatheid species in the deepwater fishery of Pacific coast of America. In contrast with Peru and Chile, the red squat lobster is not commercially exploited in Costa Rica. Here we estimated the size of sexual maturity and analysed egg production in P. monodon from the Pacific of Costa Rica; the results might be important for an adequate management strategy when initiating a sustainable fishery of this resource in Costa Rica. Analyses of allometric growth revealed that females and males reached their morphological sexual maturity at 26.9 and 30.4 mm CL. respectively. The percentage of immature females captured in the present study (54%) suggests that almost half of females are able to reproduce before they are caught. Egg production was positively correlated with body size; females that measured between 24.1 and 29.0 mm CL contributed roughly 90% to the offspring production of the population. Females from Costa Rica had a considerably lower average egg volume (0.039 mm(3)) and higher fecundity (9810) than females from Chile. In comparison to other American galatheids P. monodon from Costa Rica produces numerous but small eggs, a typical strategy of species with a prolonged larval development. An analysis between our results and information published about P. monodon from Chile also revealed differences in the size-frequency distribution shape of both populations. The non-exploited character of the Costa Rican P. monodon population and a latitudinal (temperature-related) cline in body size might be associated with these differences. (C) 2010 Elsevier B.V. All rights reserved.
Resumo:
The genus Simothraulopsis contains three described species, one of which occurs in Brazil. The new species Simothraulopsis diamantinensis sp. n. and Simothraulopsis janae sp. n. are figured and described from male imagines. The main discriminating character of these two new species from their congeners is the fused forceps socket. The material was collected in Bahia State in northeastern Brazil.
Resumo:
This work reports on the synthesis, characterization and applications of the new cerium(III) beta-diketonate Ce(hdacac)(3)(Hhdacac)(3)center dot 2H(2)O (where hdacac and Hhdacac denote, respectively, the hexadecylpentane-2,4-dionate and hexadecylpentane-2,4-dione ligands) as catalyst for the reduction of automotive emissions. Due to its amphiphilic character, this complex can be solubilized in non-polar fuels, thus generating cerium(IV) oxide particles, which efficiently catalyze the oxidation of diesel/biodiesel soot. The synthesized complex was characterized by microanalysis (C, H), thermal analysis, and infrared spectroscopy. Scanning electron microscopy, X-ray diffractometry, and specific surface area measurements attested that the complex can act as a soluble precursor of homogeneous CeO(2) spherical nanoparticles. The efficiency of this compound as catalyst for the reduction of soot emission was evaluated through static studies (comprising carbon black oxidation), which confirmed that increasing concentrations of the complex result in lower carbon black oxidation temperatures and lower activation Gibbs free energies. Dynamic studies, which embraced the combustion of diesel/biodiesel blends containing different amounts of the solubilized complex in a stationary motor, allowed a comparative evaluation of the soot emission through diffuse reflectance spectroscopy. These analyses provided very emphatic evidences of the efficiency of this new cerium complex for the control of soot emission in diesel/biodiesel motors. (c) 2009 Published by Elsevier B.V.
Resumo:
Tipulomorpha (craneflies) comprise one of the largest subgroups of Diptera, but its phylogeny at different levels has been poorly explored. This study presents the most comprehensive cladistic analysis of the group ever made, with emphasis on the genera and subgenera of the subfamily Limnophilinae (Limoniidae), assumed to include some of the earliest lineages of Tipulomorpha sensu stricto and therefore important for the understanding of the early patterns in the evolution of the craneflies. Eighty-eight characters of the male imago were scored for 104 exemplar species. The most parsimonious trees were searched using implied weighting, in the framework of a sensitivity analysis with different values of k (2 to 6). The dataset based on the characters of adult male morphology showed high levels of homoplasy and yielded very incongruent and unstable phylogenetic results, which are very sensitive to changes in analytical parameters. In the preferred and most parsimonious phylogenetic hypothesis, the Pediciidae is the sister-group of all other Tipulomorpha sensu stricto. The results indicate the paraphyly of the Limoniidae with respect to the Cylindrotomidae and Tipulidae, which are considered sister-groups. The Limoniidae subfamilies Limnophilinae, Limoniinae and Chioneinae are considered non-monophyletic. The study allowed a reconstruction of the possible ground plan condition of selected features of the adult male morphology of craneflies. The genera/subgenera Epiphragma (Epiphragma), Acantholimnophila, Shannonomyia, Limnophila (Arctolimnophila), Eloeophila, Conosia, Polymera, Polymera (Polymerodes), Prionolabis, Eutonia, Phylidorea (Phylidorea), Metalimnophila, Gynoplistia (Cerozodia), Gynoplistia (Dirhipis), Nothophila, Pseudolimnophila (Pseudolimnophila), Pilaria and Ulomorpha are considered monophyletic, but in general are defined by combinations of very homoplastic character states. Two Temperate Gondwanan clades, (Tonnoirella + (Edwardsomyia + (Tinemyia + (Rhamphophila + (Nothophila))))) and ((Notholimnophila + Bergrothomyia) + (Mesolimnophila + (Chilelimnophila + Ctenolimnophila))) are recovered. The genera Limnophila, Neolimnomyia, Gynoplistia (sensu lato) and Hexatoma (sensu lato) are considered non-monophyletic. The systematic position and some morphological characters of `problematic` taxa, such as Dactylolabis, Elephantomyia, Helius and Atarba are discussed on the light of the proposed phylogeny and the analysis of the characters. Character states are richly illustrated. A detailed study of the morphology of the male genitalia is made, and several genera and species have the morphology of the male genitalia illustrated for the first time.
Resumo:
In this article, the authors analyze the relationship between labor sociology and trade unionism in Brazil by focusing on its three key phases. Against the backdrop of successive political and economical scenarios, the authors go from the first generation of labor sociologists to the most recent period, trying to identify the transition points in this trajectory. This study develops the hypothesis that labor sociology in Brazil was first characterized by a search for affirmation and professionalization (1950-1960). Later, it developed a strong political-social engagement, and assumed a public character, by claiming particular social identities (1970-1980). Finally, it flowed toward policy sociology (1990-2000).