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A influência da geometria do domínio sobre a existência de equilíbrios estáveis não-constantes para alguns sistemas parabólicos
(Universidade Federal de São Carlos, 2004-04-23) Madeira, Gustavo Ferron; Nascimento, Arnaldo Simal do; https://lattes.cnpq.br/6609243657130387
In this work we study the problem of existence of non-constant stable equilibria to some parabolic systems. Specifically, the Ginzburg-Landau system, the Landau-Lifshitz system and systems with skew-gradient structure. In all cases, we note that the geometry of the domain has a fundamental role in the problem above: if the domain has a smooth boundary and is convex, then there are no non-constant stable equilibrium solutions, that is, every non-constant equilibrium is unstable.
Privatização, mudança organizacional e novas relações de trabalho: um caso do setor de energia elétrica.
(Universidade Federal de São Carlos, 2004-04-23) Alves, Agda de Fátima; Grün, Roberto; https://lattes.cnpq.br/6028266827740491
This study analyses the process of organizational change and the new work relations decurrent of the privatization of eletric sector companies in São Paulo. The privatization of the State companies appears as an important mark in that process of change, because represent the necessity of to adapt the companies towards the new scenery occasioned by aperture of brazilian economy. The study focused on the point of view of an electric energy distributer company s employees, through twenty interviews with employees in various posts. These changes transformed the company organization and also brought consequences to the work relations and society. The centre of discussion was the appearing of new work relations, which was felt by workers as negative consequences, at least in this prime moment of adaptation to the new standard of life.
Aprendizagem observacional, formação e expansão de classes de equivalência.
(Universidade Federal de São Carlos, 2004-04-23) Piccolo, Adriana Aparecida Tambasco; Goyos, Antônio Celso de Noronha; https://lattes.cnpq.br/3407008711535651; https://lattes.cnpq.br/4282885195721660
Observational learning of conditional discrimination has been described in the literature, with results thus far yielding few conclusions. The present study investigated the conditions under which observational learning of conditional discrimination lead to the formation and expansion of equivalence classes in different populations. Served as participants in Experiments 1, 2 and 3, college students; in Experiment 4, preschool children and, in Experiment 5, children and adolescents with special education needs. Experiment 1 systematically replicated an earlier experiment carried out with mentally retarded adults with increased control over stimuli presentation and the demonstrators responses. The experimental stimuli were familiar pictures, and instructions for the participant to observe were introduced. First, BA relations were taught, followed by modeling of CA relations, and by tests of baseline and emergent relations. Finally, modeling of two new relations involving stimulus sets D and E and tests for expanded classes were introduced. All six participants learned the conditional discriminations, and showed equivalence class formation and only one of them did not show class expansion. Experiment 2 had an experimental design analogous to Experiment 1, but all the conditional relations were taught through modeling. Three of four participants learned the conditional discriminations and showed formation and expansion of classes. Experiment 3 extended the Experiment 1 results to three classes of abstract stimuli, all six participants learned the conditional discrimination and 5 of them showed formation and expansion of equivalence classes. In Experiment 4, eight preschool children were submitted to a similar procedure, but with familiar pictures were used as stimuli and tokens that could be exchanged for a gift at the end of the session, regardless of their performance. Six of eight participants learned relations BA and CA and showed equivalence class formation and two of them showed class expansion. In Experiment 5, children and adolescents with special needs were taught BA and CA relations only through modeling. The delay between the demonstrator s behavior and the participants response was manipulated as well as the reinforcement system, and seemed to be important for three out of six participants. The remaining three participants did not learn the relations even after protracted training. In general, observational learning occurred for all populations investigated. Further investigation, however, is necessary to clarify the role of the observational response, differential reinforcement and the delay between demonstration and response, the demonstrator as a conditioned reinforcer, and other reinforcement sources for the observer s behavior.
Influências de substâncias húmicas nas características bionômicas, toxicocidade e bioacumulação de cobre por Ceriodaphnia silvestrii Daday (Crustacea, Cladocera)
(Universidade Federal de São Carlos, 2004-04-23) Santos, Maria Alice Penna Firme dos; Melão, Maria da Graça Gama; https://lattes.cnpq.br/8342306603661310
Effects of different food sources and culture medium on life history traits of Ceriodaphnia silvestrii were studied under controlled conditions. Animals were submitted to five different treatments: (1) autoclaved natural water filtered through plankton net of 20µm mesh size, supplied with Chlorella lacustris as food source; (2) autoclaved natural water filtered through plankton net of 20µm mesh size, supplied with Scenedesmus bijugus; (3) soft reconstituted water supplied with S. bijugus; (4) soft reconstituted water supplied with S. bijugus plus humic substances (20mg L-1); and (5) hard reconstituted water supplied with S. bijugus. Observations were performed at 12 hours intervals from organism birth until its natural death. All treatments were kept in a 25±1 ºC temperature. Instantaneous rate of population increase (r) was calculated for all treatments. Body length-dry weight relationship was also established. Results showed longer longevity in C. lacustris treatment, and better fecundity on treatment with natural water and S. bijugus. In the treatment with artificial medium, fecundity and growing parameters were lower than in natural water treatment. Increased hardness did not affect reproduction and growth values. Humic substances addition resulted in greater fecundity and survival values. Copper acute toxicity to Ceriodaphnia silvestrii (Cladocera, Daphnidae), was also studied in the absence and presence of humic substances (HS). Groups of 20 adult females of similar sizes were exposed to copper (total concentration range from 10-8 to 10-5 M) for a period of 24h. LC50 was estimated by the Trimmed Spearman-Karber method. It revealed that humic substances altered LC50 from 4.4 x 10-8 M without humic substances to 1.1x10-6 M with 20mg HS L-1 in the medium. Free copper ions were determined in test media and it showed that humic substances reduced Cu2+ concentration. LC50 values based on total copper concentration varied significantly between the two treatments. However, when lethality was estimated based on free ion concentrations, the values were similar: 3.3 x 10-8 M without humic substances, and 2.8 x 10-8 M when HS were present in the medium. Moreover, C. silvestrii is capable of regulating its body copper levels over a range of copper availabilities, as so many other crustaceans. As also reported, humic substances did not influence copper bioaccumulation by C. silvestrii.
Subclonagem e expressão do domínio catalítico da jararagina: estudo do efeito das modificações pós-traducionais na atividade hemorrágica
(Universidade Federal de São Carlos, 2004-04-23) Sánchez, Liliana Torcoroma García; Araújo, Heloísa Sobreiro Selistre de; https://lattes.cnpq.br/4065824911933203
Metalloproteases are Zn++-dependent peptidase enzymes, richly found in Crotalidae and Viperidae snake venoms. Most snake venom metalloproteases (svMPs) are active on extracellular matrix components and this effect is thought to result in bleeding as a consequence of the basement membrane disruption in capillaries. Jararhagin is a hemorrhagic svMP from Bothrops jararaca venom. This enzyme has proteolytic activity on fibrinogen and fibronectin and inhibits collagen-induced platelet-aggregation in vitro. Its amino acid sequence corresponds to a N-terminal metalloprotease domain, a disintegrin-like and a C-terminal Cysteine-rich, being classified as a P-III snake venom metalloprotease (svMP). This work describes the expression, purification and successful refolding of the recombinant catalytic domain of jararhagin. The heterologous protein was produced in E.coli, an in vivo expression system that does not make post-translational modifications. The recombinant refolded protein did not show any hemorrhagic activity in mice skin, as well as, the native deglycosylated jararhagin. However, they preserved their proteolytic activity on fibrinogen and fibronectin. It seems that the hemorrhagic properties of these hemorrhagins are dependent on post-translational modifications, whereas their proteolytic activity is not completely dependent on such modifications.