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Efeito de diferentes intensidades de perturbação na estrutura da comunidade de peixes de riachos
(Universidade Federal de São Carlos, 2009-06-10) Nassin, Fabiano Carneiro; Tanaka, Marcel Okamoto; https://lattes.cnpq.br/2768658925977757; https://lattes.cnpq.br/0961985340261125
Land use changes can impact aquatic communities, compromising water quality due to the physical and chemical degradation of the habitat. This study evaluated the hypothesis that stream fish communities differ relative to disturbance degree, determined by a habitat degradation gradient. Thus, the objectives of this project were: to survey streams not yet studied in central São Paulo State, located in a predominantly agricultural landscape; describe fish communities in streams subject to different degrees of habitat degradation and relate the fish communities to environmental variables. The study was conducted in low-order streams in the lower river Jacaré-Guaçu watershed, located in the Water Management Unit Tietê-Jacaré (UGRH-13). Twelve streams with different degrees of disturbance were assessed using a protocol for rapid assessment (PAR). In each 100m-reach, we estimated the PAR, and measured stream width and depth, physical and chemical variables of the water, and substrate diversity. Streams were classified in quality categories as preserved, altered and impacted, and fish communities were sampled with an electrofishing equipment. Most streams sampled were impacted or altered, with negative scores due to stream margin use, vegetation characteristics, sedimentation, water flow characteristics, velocity/depth regimes, temperature, pH, total dissolved solids and electrical conductivity. Fish communities presented low values of species richness and diversity, represented by a total of 20 species. Characiformes contributed with 40% of collected species, followed by Siluriformes (30%), and Perciformes, Gymnotiformes and Cyprinodontiformes (10% each). Representative species included Phalloceros caudimaculatus (41% of total abundance), Astyanax altiparanae (22%) and Poecilia reticulata (9%), whereas each of the other species contributed less than 5% of total abundance. Highest species diversity was found in streams classified as impacted, but there was a large variation, and relationship with PAR was found.. There is positive relationship of species richness with the increases in stream width, depth and electrical conductivity; evenness increased with stream width and pH, whereas diversity was positively related increases in stream depth and pH. Fish faunal composition did not differ among streams in different degradation classes identified by PAR, and were more influenced by stream physical characteristics and the presence of local impact factors, such as small barriers. Thus, although the habitat of most streams show evidence of degradation, fish communities did not reflect directly this result.
Respostas da frequência cardíaca durante o exercício isométrico de pacientes submetidos à reabilitação cardíaca fase III
(Universidade Federal de São Carlos, 2009-06-10) Leite, Poliana Hernandes; Catai, Aparecida Maria; https://lattes.cnpq.br/5801652590531684; https://lattes.cnpq.br/2346902876883219
Cardiovascular responses to different isometric contractions were evaluated in 12 patients (63 ± 11,6 years, mean ± dp) with coronary artery disease and/or risk factors, participants in the cardiac rehabilitation phase III. Heart rate variation (ΔHR) was evaluated during maximum (CVM, five and ten seconds in duration) and submaximal (CVSM, 30 and 60% of CVM-5, until muscle exhaustion) voluntary contraction, using a handgrip dynamometer. Additionally, the RMSSD (representative index of vagal modulation) was calculated at rest (precontraction), at the last 30 seconds of CVSM and recovery (post-contraction). ΔHR showed higher values in CVM CVM-10 vs-5 (17 ± 5,5 vs 12 ± 4,2 bpm, p <0.05) and the CVSM-60 vs CVSM -30 (19 ± 5,8 vs 15 ± 5,1 bpm, p <0.05). However, results for CVM-10 showed similar ΔHR compared to results for CVSM (p> 0.05). RMSSD at rest decreased (p <0.05) during CVSM-30 (30% = 28 ± 17 vs 13 ± 8 ms) and CVSM-60 (60% = 26 ± 18 vs 10 ± 4 ms), but returned to baseline values as the contraction was interrupted. In in patients with coronary artery disease and/or risk factors, low intensity isometric contraction, maintained over long periods of time, presents the same effect on the responses of HR, compared to a briefly high intensity or maximal isometric effort.
Efeito do alimento contaminado com cobre sobre o ciclo de vida e produção secundária de Daphnia laevis
(Universidade Federal de São Carlos, 2009-06-10) Rocha, Giseli Swerts; Melão, Maria da Graça Gama; https://lattes.cnpq.br/8342306603661310; https://lattes.cnpq.br/9522932409165588
With the advance of industrialization, there was an increase in the quantity of substances discharged in nature without treatment. Many of these substances are toxic and can cause adverse effects to aquatic biota, and may affect the rest of the food chain, including humans. For better understanding of the effects of contamination, there is a growing progress in the study of exposure of organisms of different trophic levels of the contaminant and monitoring changes in their development and reproduction. Copper, an essential element at low concentrations, can cause adverse effects in higher concentrations. The aim of this study was to evaluate changes in a zooplankton species, Daphnia laevis (Crustacea, Cladocera) fed with algae (Pseudokirchneriella subcapitata) previously exposed to different concentrations of copper. The accumulation of metal was measured both in algae and in cladoceran. The animals were monitored throughout its life cycle through the testing of chronic toxicity and through bionomic parameters and calculation of their secondary production, the treatments were compared to a control. The results suggest that exposure to contaminated food directly influence the reproduction of animals, and found significant statistical differences (p <0.05) in the total number of eggs and neonates produced over the life of the animal. Another parameter that was affected significantly was the secondary production of animals, where changes were observed mainly in the investment to reproduction, affecting the total secondary production. Through the results, consider the importance of the capture of copper through the food and how the secondary production, although very important, is not explored in ecotoxicological studies.
Toxicidade aguda e respostas metabólicas e hematológicas do bagre do canal (Ictalurus punctatus, Rafinesque, 1818) exposto a concentração sub-letal de fenol e recuperação
(Universidade Federal de São Carlos, 2009-06-10) Moraes, Fernanda Dias de; Moraes, Gilberto; https://lattes.cnpq.br/4427903557163246; https://lattes.cnpq.br/6686160677282539
Phenol and its derivates are aromatic organic compounds and there are present in the mill, domestic waste and cropscience. Moreover, phenol could induce toxicity in both freshwater and seawater fish and other animals. The aim of this work was evaluating hematological features, intermediary metabolism and muscular and cerebral acetylcholinesterase enzyme activity in juveniles channel catfish Ictalurus punctatus exposed to 1.5 mg L-1 of phenol (10% LC50) for 96 h and after 7 or 14 days of recovery. Ammonia, lactate, piruvate, glucose, amino acids, protein, triglycerides and fatty acids concentrations were measured in liver, muscle and plasma. Glycogen concentration was determined in liver and muscle. Aspartate aminostransferase (ASAT), alanine aminotransferase (ALAT), lactate desidrogenase (LDH), alkaline phosphatase (FALC) and acid phosphatase (FAC) enzymes activities were assayed in liver and muscle. Acetylcholinesterase activity was assayed in white muscle and brain. Hematological features were analyzed through hematocrit, haemoglobin concentration, red cell count (RBC), mean corpuscular volume (VCM), mean corpuscular haemoglobin (HCM) and mean corpuscular haemoglobin concentration (CHCM). Hematological alterations were observed after 7 days of recovery. After 96 h, ALAT and ASAT activities and protein concentration indicated proteolysis liver and muscle. The triglycerides and fatty acids concentration suggested lipolysis in muscle. The results also indicated gluconeogenesis in liver. Gluconeogenesis follows over 7 days of recovery and glycemia was kept constant. After 7 days of recovery, the results suggested proteolysis and lipolysis in liver. After 14 days of recovery, the results indicated glycogenolysis and muscle and liver. Reductions of protein and amino acid concentrations plus ASAT activity rising in muscle, also suggested proteolysis. Alterations in FAC and FALC activities in muscle and liver were observed. These results suggest membrane cell damage. Reduction in cerebral AChE activity was observed after 14 days recovery. In other hand, an increase of muscular AChE was observed after 7 and 14 days recovery. In conclusion, the alterations observed in this work seem to be due to increased metabolic demand and other mechanisms that respond to homeostasis in fish.