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Determinação de fontes de hidrocarbonetos policíclicos aromáticos e alifáticos em sedimentos de ambientes aquáticos
(Universidade Federal de São Carlos, 2006-04-20) Yamada, Thaís Mariana; Mozeto, Antonio Aparecido; https://lattes.cnpq.br/6594211224864538
Numerical values of polycyclic aromatic hydrocabons and n-alkanes distribution indexes of sediments are important tools to elucidate the origins of hydrocarbons mixtures. Polycyclic aromatic ratios are sensitive indicators of petrogenic and pyrogenic inputs, while n-alkanes distribution usualy discriminates biogenic from petrogenic sources. The study area of this work includes the Ibirité Reservoir and it´s tributaries, located in the Belo Horizonte metropolitan area, a site strongly affected by a petroleum refinary from Petrobras, but where an important industrial park is also present. Sampling was carried out in November 2005, at 12 stations located on Ibirité Reservoir, Pintados and Ibirité streams. The sediment samples were extracted in ultrasonic bath, purified in chromatographic columns and analysed by GC/MS. The studied compounds were polycyclic aromatic hydrocarbons, normal and isoprenoids alkanes. The total concentrations varied from 33.66 to 772.61 ng g-1. Despite of these low concentration values as compared to other aquatic environment, the Ibirité Reservoir showed strong inflluence from anthropic activities, reflected on petrogenic and pyrogenic hydrocarbons mixtures. The biogenic hydrocarbons, mainly derived from aquatic and terretrial higher plants, also showed its contribution as a result of algal blooms and extensive aquatic macrophyte banks typically found in the reservoir. Besides, the presence of unresolved complex mixtures in all chromatograms, points out to a significant contribution of petrogenic sources. Contamination of some sediment sample detectect in this study by polycyclic aromatic hydrocarbons migth suggest that occasional adverse effects to the organisms in this water body may occur. The sampling station of Taboões I stream was the only one site that petrogenic controbuition was not detected. However, the site that was considered as a reference site, showed that it suffers, already, influences from burned fossil fuel from industries and automobiles from the nearby Belo Horizonte metropolitan area.
Estudo das comunidades de macroinvertebrados bentônicos das Represas do Monjolinho e do Fazzari no campus da UFSCar, município de São Carlos, SP
(Universidade Federal de São Carlos, 2006-04-20) Fusari, Lívia Maria; Gessner, Alaíde Aparecida Fonseca; https://lattes.cnpq.br/8465752836529703
The objective of this study was to analyze the macroinvertebrate benthic communities in two small reservoirs, Monjolinho Reservoir and Fazzari Reservoir, both are localized in the campus of the Federal University of São Carlos, São Carlos city, São Paulo state, but they are on different anthropogenic disturbance. The samplings were carried out during the dry (April June) ant the wet (November December) seasons in 2004. In each dams the sampling were collected in 12 points random. At each site, three sampling units were taken with an Eckman-Birge sampler. Also were determinate more three sampling points at upstream in Monjolinho and Fazzari streams. Several physical and chemical variables were measured at each site and the means calculated to every season. Differents metrics were applied to compare the macroinvertebrate communities between the reservoirs. The analyses indicate that, overall, community persistent is correlated with the state environmental of each reservoir. The macroinvertebrate benthic community in Monjolinho reservoir was characterized by tolerant species dominant like Chironomus sp and Limnodrilus hoffmeisteri, they are very commons in trophic systems. In the other side in Fazzari reservoir, the no tolerant species (Chaoboridae and Campsurus sp) were dominants, this is an indication that the system is oligotrophic.
Efeitos do exercício físico moderado e da suplementação da dieta com vitamina C no crescimento e no metabolismo de matrinxã, Brycon cephalus (Günter, 1869) (Teleostei:Characidae)
(Universidade Federal de São Carlos, 2006-04-20) Oba, Eliane Tie; Rantin, Francisco Tadeu; https://lattes.cnpq.br/3546242299713690
Moderate exercise training is known to enhance fish appetite, feed conversion efficiency and growth rate. This type of exercise raises the hematocrit, thus blood hemoglobin concentration and the oxygen carrying capacity of the blood. This allows that less blood needed to be diverted away from the gut to supply aerobic metabolism in the muscles. Continuously swimming fish show lowered circulating levels of stress hormones (like cortisol) and this represents an energy saving and permits higher fish growth rate, with more homogenous body size. All aerobic living forms have defenses against reactive oxygen species. Oxygen consumption can increase with exercise training and this result in a higher production of reactive oxygen species. Antioxidants, like vitamin C, in the diet can reduce the disease risks and the oxidative damage by the reactive oxygen species. The aim of this study was to verify growth and oxidative metabolism of matrinxã, Brycon cephalus, after moderate and continuous exercise training (speed 1 2 BL.s-1) and after fed with vitamin C supplemented diet (432 mg AA.kg dieta-1). Matrinxãs were divided into four groups: Control (submitted to diet without vitamin C supplementation and to sedentarism), Vit.C (submitted to diet with vitamin C supplementation and to sedentarism), Exe (submitted to diet without vitamin C supplementation and to exercise training) and Vit.C+Exe (submitted to diet with vitamin C supplementation and to exercise training), during 60 and 90 days. After these treatments, matrinxãs were anesthetized and blood samples were collected with heparinized needles and syringes by caudal vein puncture. Fish were sacrificed by vertebral section, weighed and lengthened. Liver, white and red muscle and heart were collected for the biochemistry analysis. Plasma cortisol levels, liver vitamin C concentration, intermediary metabolite levels (glucose, glycogen, lactate, pyruvate and ammonia) and oxidative stress indicators (lipid hydroperoxide, superoxide dismutase and glutathione peroxidase) were measured. The exercise training increased growth rate of matrinxãs indicated by the condition factor and the maintenance of the liver glycogen levels and the higher muscle protein concentration. This moderate swimming exercise raised the hematocrit of matrinxãs and lowered the plasma cortisol levels. The vitamin C supplemented diet enhanced hepatic levels of this vitamin. This supplementation did not permit the increase of growth rate, however it reduced the lipid peroxidation levels. Exercise and vitamin C supplemented diet associated were responsible for the maintenance lipid peroxidation and antioxidants enzymes levels. After 90 days of experiment period, the group Vit.C+Exe showed similar growth and condition factor to the group Exe. The moderate exercise training with vitamin C supplemented diet increased the growth and the survive rates of matrinxãs, B. cephalus, due to the some alterations on the metabolism, improving the fish condition and favoring the fisheries production.
Ativação do subtipo de receptor 5-HT1A do núcleo paraventricular do hipotálamo sobre a ingestão de água e sódio
(Universidade Federal de São Carlos, 2006-04-20) Villa, Patrícia de Souza; Camargo, Luiz Antonio de Arruda; https://lattes.cnpq.br/9899442765636817
Hypothalamic paraventricular nucleus (PVN) has an important role in the hydroeletrolytic balance and it also participates in the regulation of water and sodium intake. Recent researches described the presence of 5-HT1 receptors in the central nervous system, standing out the subtypes 5-HT1A, 5-HT1B, 5-HT1C and 5-HT1D. The receptor 5-HT1A was one of the firsts to be identified and it is found in the somatodendritic and pos-synaptic forms. It has been showed the participation of PVN 5-HT1A receptor in the hydroeletrolytic balance. Therefore, the aim of this study was: a) To investigate the effects of bilateral injections of serotonin (5-HT) in the PVN about water intake induced by water deprivation and water and 1.8% NaCl intake induced by sodium depletion; b) To investigate the effects of 8-OH-DPAT injection, an 5-HT1A agonist, in the PVN about water intake induced by water deprivation and water and 1.8% NaCl intake induced by sodium depletion; c) To investigate the action of pMPPF, an 5-HT1A antagonist, into the PVN on the effects of 5-HT and 8-OH-DPAT on the water and 1.8% NaCl intake. Holtzman rats (280-320 g) were submitted to the implant of cannulas bilaterally in the PVN. For the implant, the animals were adapted to a stereotaxic apparatus. Using the bregma, introduction points of the stainless steel cannulas were identified according to the coordinates: 1.8 mm caudal to bregma, 0.6 mm lateral to the midline and 5.0 mm below dura mater. 5-HT injections (10, 20, 40 and 50 µg/ 0,2 µl) in the PVN reduced the water intake (13.4±2.0; 12.6±1.3; 12.9±1.0 and 9.0±2.9 ml/ 30 min vs. sal: 18.4±0.8 ml/ 30 min, respectively, n = 6-8) and the doses 10 and 20 µg/ 0.2 µl reduced the 1.8% NaCl intake (7.9 ± 3.0 and 9.0 ± 2.1 ml/ 30 min, respectively, vs. sal: 17.7 ± 1.8 ml/ 30 min, n = 7). 8-OH-DPAT injections (1.0, 2.5 and 5.0 µg/ 0.2 µl) in the PVN reduced the water intake (15.4 ± 1.3; 14.8 ± 1.2 and 14.2 ± 0.9 ml/ 120 min vs. sal: 19.1 ± 1.0 ml/ 120 min, n = 10) and the doses 2.5 µg and 5 µg also reduced 1.8% NaCl intake (12.4 ± 2.7 ml/ 60 min vs. sal: 19.3 ± 1.0 ml/ 60 min; 12.2 ± 1.8 ml/ 120 min vs. sal: 20.0 ± 1.0 ml/ 120 min, respectively, n = 9). pMPPF bilateral injections (5-HT1A antagonist) preview to 8-OH-DPAT injections have completely blocked the inhibitory effect over water intake (sal + DPAT: 13.8 ± 1.1 ml/ 90 min vs. pMPPF + DPAT: 16.4 ± 1.1 ml/ 90 min, n = 12) and 1.8% NaCl (sal + DPAT: 11.4 ± 2.9 ml/ 30 min vs. pMPPF + DPAT: 17.6 ± 1.7 ml/ 30 min, n = 8). 5-HT1A antagonist partially reduced the inhibitory effect of 5-HT on water intake induced by water deprivation (sal+5-HT: 5.9±1.6 ml/ 30 min vs. pMPPF+5-HT: 12.3±1.1 ml/ 30 min, n=12) as well as on sodium intake induced by sodium depletion (sal+5-HT: 2.8±1.3 ml/ 30 min vs. pMPPF+5-HT: 12.3±1.9 ml/ 30 min, n=15). Our results demonstrate the presence of serotonergic mechanisms in PVN inhibiting water and sodium intake and also the participation of pos-synaptic 5-HT1A receptors on water intake control induced by water deprivation and on sodium intake induced by sodium depletion, and that this receptor doesn t have a tonic inhibitory effect. This work also showed others subtypes serotonergic PVN receptors participating in the dipsogenesis and natriorexigenesis control.
Preparação e aplicação de óxidos tipo perovskita La1-xCexNiO3 e La1-xCaxNiO3 para obtenção de gás de síntese a partir do metano
(Universidade Federal de São Carlos, 2006-04-20) Lima, Sania Maria de; Assaf, José Mansur; https://lattes.cnpq.br/9563312407691130
Catalysts precursors with perovskite structure like La1-xCexNiO3 ( x = 0, 0.03, 0.05, 0.1, 0.4 ,0.7) and La1-xCaxNiO3 (x = 0, 0.05, 0.1, 0.3, 0.5, 0.8) have been prepared by three different methods: precipitation, citrate and citrate with successive additions. The loss of mass and structure transformations during the calcination were studied by thermogravimetric and thermodifferential analysis; the calcined samples were characterized by X-ray diffraction, specific surface area measurements (BET method), temperature-programmed reduction, thermogravimetric analysis in H2 atmosphere, temperature-programmed desorption of oxygen, X-ray photoelectron spectroscopy and sequential pulse experiments with CH4/O2/CH4. The catalysts were tested in CO2 reforming and partial oxidation of methane. After the tests, the catalysts surface was studied by scanning electron microscopy and thermogravimetric analysis in oxidant atmosphere. Small quantities of NiO were observed together the perovskite structure even for x = 0 in the solids prepared by all the synthesis methods. In the Ce-La series with x ≥ 0.05 were also identified CeO2 and La2NiO4; the perovskite structure formation for x = 0.7 was not observed. For the samples containing Ca with x ≥ 0.1, in addition to the perovskite structure, was observed NiO and La2NiO4; when x ≥ 0.3 an additional CaO phase was identified. However, in these samples, the perovskite structure was still observed even with high Ca contents. The reaction results of CO2 reforming of methane showed that the Cecatalysts prepared by citrate route presented Ni particles smaller and with better dispersion than the catalysts obtained by precipitation. This was evidenced by the higher resistance to carbon formation. Among these catalysts, the La0.95Ce0.05NiO3 was the most promising because it was the most active and resistant to carbon formation. This carbon deposition resistance was due to the predominance of perovskite structure that resulted in higher dispersion of nickel particles and also to the presence of the incorporated cerium that increased its stability. The Ce containing catalysts obtained by the two citrate methods deactivated during the partial oxidation of methane due to the oxidation of active Ni fractions. These oxide sites favored the CO2 formation via the combustion of methane reaction. In the other hand, the catalysts obtained by precipitation were highly active to CO formation, and the most promising were those with x = 0 and x = 0.05. The Ca content influenced the carbon deposition resistance and the conversion levels in the CO2 reforming of methane. In partial oxidation of methane, for some contents of calcium, the reactants conversion levels have decreased due to the oxidation of active Ni fractions, but there was no carbon formation for all the catalysts.