946 resultados para POSTEXERCISE OXYGEN-CONSUMPTION


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In India industrial pollution has become a subject of increasing concern.Incidents of industrial pollution have been reported from many parts of the country. Cochin, the collection site of the present study, being the industrial capital of Kerela is also a harbour, is vulnerable to pollution by trace metal contaminants. In the recent times, pollutants of greatest concern in the aquatic environment are those which are persistent such as toxic heavy metals and the chlorinated hydrocarbons which include insecticides and pesticides.The animals collected from the clam bed situated on the northern side af Cochin bermouth are subject to wide fluctuations in salinity both seasonal and tidal. also; salinity is considered as an important parameter influencing the.-physiological functioning of an organism. Hence, the salinity tolerance of the animal is worked out. Considering the potential vulnerability of Cochin backwaters to heavy metal pollution, the impact of heavy metal copper (II) on the bivalve Sunetta sripta was conceived. Static bioassays were conducted for the determination of the sublethal concentrations of the metal as a preliminary step towards the toxicity studies. Oxygen consumption and filtration rate which are considered as reliable sublethal toxicity indices were employed for investigating the toxic effects of the metal. Bioaccumulation, a physiological phenomenon which can be of importance from the public health point of view, and also in the assessment of environmental quality is also dealt with.

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In this thesis certain important aspects of heavy metal toxicity have been worked out. Recent studies have clearly shown that when experimental media contained more than one heavy metals, such metals could conspicuously influence the toxic reaction of the animals both in terms of quantity and nature. The experimental results available on individual metal toxicity show that, in majority of such results, unrealistically high concentrations of dissolved metals are involved. A remarkable number of factors have been shown to influence metal toxicity such as various environmental factors particularly temperature and salinity, the condition of the organism and the ability of some of the marine organisms to adapt to metallic contamination. Further, some of the more sensitive functions like embryonic and larval development, growth and fecundity, oxygen utilization and the function of various enzymes are found to be demonstrably sensitive in the presence of heavy metals. However, some of the above functions could be compensated for by adaptive process. If it is assumed that the presence of a single metal in higher concentrations could affect the life function of marine animals, more than one metal in the experimental media should manifest such effects in a greater scale. Commonly known as synergism or more than additivity, majority of heavy metals bring about synergistic reaction .The work presented in this thesis comprises lethal and sublethal toxicities of different salt forms of copper and silver on the brown mussel Perna indica. during the present investigation sublethal concentrations of copper and silver in their dent effects on survival, oxygen consumption, filtration, accumulation and depuration on Perna indica. The results are presented under different sections to make the presentation meaningful .

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Teredinids (shipworms), a group of wood boring bivalves occurring in the Cochin Harbour region have been taken up for the eco-physiological studies. On the ecological part, the occurrence, abunance and seasonal intensity of the teredinids in relation to hydrographic conditions have been studied. On the physiological part, salinity tolerance and oxygen consumption of the most commonly occurring shipworms, Nausitcra hedlgyi and Teredo furcifera have been investigated. The hydrographic factors studied are temperature, salinity, dissolved oxygen, phosphate, nitrite, silicate and pH. The variation in temperature is found to be comparatively narrow. But seasonal variation in salinity, dissolved oxygen, phosphate, nitrite and silicate has been observed, with the highest values during the monsoon period. In the case of pH, the minimum value has been obtained during the low saline period and the maximum value, during the high saline period. Of the various hydrographic factors studied, salinity has been found to be the most important fluctuating environmental parameter influencing the life of organisms in the habitat.

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The present study was undertaken with a view to understanding some aspects of the morphology, bionomics and physiology of the sea anemone A.nigrescens. This species was selected for the study since it is abundantly available along the coast throughout the year and can successfully reared in the laboratory without much effort. The present study deals with the following aspects of A.nigrescens. description of the species, habitat, food and feeding, digestion, studies on salinity tolerance, studies on oxygen consumption, studies on tolerance to desiccation, asexual reproduction and regeneration.

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Very little is known about the tolerance of the pensoid prawns in Indian waters under varying environment conditions ,except for a note on the salinityon The growth of the juvenile papacus indicus by sreekumaran nair and krishnankutty there seems to be no work on this aspect besides the oxygen consumption of metsponecus dobsoni which is a major constituent of prawn fishery in this region has not been studied so far.T he present work comprises studies on the occurrence and abudance of penacid prawnsin two major estuaries in Kerala the kayamkulam lake and cochin backwaters the salinity and tempeture tolerance the effect of salinity on the growth of three comercially important prawns of kerala namely pensecus indicus, ,metaponaeus dobsoni, M monoceros and the respiratory metabolism of M. dobsoni.

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The present work comprises studies on the salinity tolerance and respiratory metabolism of a mood-boring sphaeromid, Sphaeroma annandalei, Stabbing and two free living,foulers of the family Cirolanidae, Cirolana fluviatilis Stabbing and C. uilleyi Stabbing. Except for the systematic accounts and general observations by Pillai (1961) and the preliminary studies on the salinity tolerance and respiration of C. fluviatilis by Nagabhushanam and Gopalakrishnamurthy (1965, 1965a) very little is known about these isopods From Indian waters. Studies by John (1968) on the habits, structure, and development of Sphaeroma terebrans and by Cheriyan (1973) on the eoéphysiology of the same are the recent major contributions on this interesting group of animals. 5. annandalei is closely related to S. terebrans and has been reported to occur on timber along with the latter (Pillai, 1951). s. gggandalei is a serious pest attacking wood along the Kerala coast, but detailed works on this species have not been undertaken so Far

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This thesis is an attempt by the author to assess the suitability of Metapenaeus dobsoni (Miers), an economically important crustacean species as a sentinel organism of trace metal pollution. The results of detailed investigations on seasonal variation, bioassay, accumulation and depuration of three metals viz., mercury, copper and zinc are presented and discussed. The importance of trace metals in the aquatic environment and their present status in the study area - Cochin backwaters, the significance of crustacean fisheries, the species M. dobsoni and the objectives of the present studies are described in Chapter 1. The methodology adopted during the investigation is given in Chapter 2. Chapter 3 delineates the seasonal variation of Hg, Cu and Zn in the edible and non-edible parts of M. dobsoni collected from Cochin backwaters for a period of one year (June 1984-May 1985). The results of bioassay experiments are given in Chapter 4. Kinetics of accumulation ,retention and depuration of trace metals, their biological half-life, the influence of size group and environmental factors are given in Chapter 5. The effect of these metals on the physiological response of M. dobsoni viz. oxygen consumption is included in Chapter 6. A summary and list of references are also appended.

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Los bomberos aeronáuticos son los encargados de atender todas las emergencias en los aeropuertos y sus cercanías. Estas emergencias incluyen emergencias aéreas, en tierra, eventos con materiales peligros e incendios, entre otros. Su trabajo tiene como características la realización de actividades durante periodos largos de baja intensidad y periodos cortos de alta intensidad. De acuerdo con estas características, es necesario que los bomberos aeronáuticos tengan una buena condición física. El consumo máximo de oxígeno (VO2 máx) como indicador de capacidad aeróbica resulta indispensable para conocer el desempeño de los bomberos en su trabajo. El objetivo de este estudio es determinar la capacidad aeróbica de los bomberos aeronáuticos y sus factores determinantes. Por tanto se desarrolló un estudio transversal de tipo descriptivo en una muestra de 23 hombres bomberos aeronáuticos. Se obtuvo información acerca de sus variables socio-demográficas, se determinó el VO2 máx y umbral ventilatorio mediante análisis de gases espirados durante un protocolo de ejercicio máximo sobre tapiz rodante, se evaluó la composición corporal mediante adipometría y se determinó el nivel de actividad física mediante el cuestionario internacional de actividad física IPAQ. Se encontró que la muestra tenia una edad de 32,6 ± 4,8 años, peso de 78,4 ± 9,8 kg, porcentaje de grasa de 14,8 ± 3,8 %, índice de masa corporal de 25,7 ± 2,7 y VO2máx de 44,6 ± 6. No se encontraron cambios significativos del VO2máx con la edad, pero si con la actividad física, porcentaje de grasa e índice de masa corporal. Se sugiere que el entrenamiento de los bomberos aeronáuticos durante su jornada laboral sea de intervalos de alta intensidad y que se monitorice su nivel de actividad física y composición corporal.

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Este estudio presenta los efectos de la implementación de un programa de ejercicio como terapia complementaria del tratamiento del cáncer próstata. El diseño del estudio es casi-experimental con una muestra de 33 pacientes en fase de tratamiento. En la metodología del programa se utiliza la guía de la American College Sports Medicine Position Stand (ACSM, 2009). Se estudian las variables antropométricas, la fuerza-resistencia, el consumo máximo de oxígeno (VO2 Máx), la percepción subjetiva del esfuerzo, la incontinencia, el dolor y la Calidad de Vida (CdV). Al finalizar 24 semanas de programa, se observa una mejora significativa de la CdV del enfermo. Los resultados demuestran que la mejoría en la CdV viene mediada por la mejora de la capacidad física, funcional y psico-emocional del enfermo. El modelo de adherencia integrado al programa de ejercicio consigue mejorar la calidad y cantidad de ejercicio necesario para la práctica autónoma en el hogar

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La eliminación biológica de nitrógeno amoniacal se ha llevado a cabo, habitualmente, a través del proceso convencional de nitrificación-desnitrificación. Sin embargo, los lixiviados generados en los depósitos controlados de residuos sólidos urbanos contienen elevadas cantidades de amonio y bajas concentraciones de materia orgánica biodegradable, así como una elevada salinidad. En este caso, para reducir el elevado coste económico que supone aplicar los procesos convencionales en este tipo de efluentes es conveniente desarrollar sistemas alternativos. Uno de estos nuevos procesos biológicos se basa en el proceso anammox (acrónimo en inglés de anaerobic ammonium oxidation) previa nitritación parcial de amonio a nitrito. El proceso anammox es un proceso autotrófico que realiza la conversión de amonio y nitrito a nitrógeno gas bajo condiciones anaerobias. El menor consumo de oxígeno durante el proceso de nitritación parcial y la no necesidad de adicionar materia orgánica para desnitrificar representan un importante ahorro económico respecto a los tratamientos convencionales

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Considerando que a prática de exercício físico com uma intensidade pelo menos moderada melhora a capacidade funcional (Maines et al., 1997; Clara et al., 2002; Olney et al., 2006), a qualidade de vida (Leal et al., 2005; Azevedo & Leal, 2009; Flynn et al., 2009) e diminui os fatores de risco coronários (Maines et al., 1997; Squires & Hamm, 2007; Perk, 2009; Pimenta, 2010), propõe-se com o presente estudo analisar o efeito do exercício físico supervisionado, em fase ambulatório precoce, realizada na comunidade, ao nível da recuperação de doentes cardíacos. Método: Aplicar-se-á um estudo experimental, em doentes cardíacos de ambos os sexos, entre os 28 e os 80 anos. Atribuir-se-á particular ênfase às alterações induzidas pela aplicação do programa de exercício físico nos parâmetros bioquímicos (colesterol total, C-LDL, C-HDL, triglicéridos e glicose), na composição corporal (peso, índice de massa corporal, perímetro da cintura), na capacidade funcional (consumo de oxigénio pico –V02 pico, equivalente metabólico, duplo produto), no nível de atividade física, na ingestão alimentar e na qualidade de vida. O estudo terá uma duração superior a três meses, comparando dois grupos, um grupo submetido ao exercício físico supervisionado (ES) e outro aos cuidados usuais (CU), os quais serão alvo de duas avaliações (inicial e final), avaliando-se a média e o desvio-padrão para todas as variáveis em estudo e recorrendo-se aos testes não paramétricos e paramétricos, para um nível de significância de p< .05. Resultados: Foram elegidos 52 doentes, sendo que 22 participaram no grupo cuidados usuais (CU) e 30 no grupo exercício físico supervisionado (ES), observando-se que o grupo ES apresentou melhorias mais acentuadas quando comparadas com o grupo CU, ao nível dos seguintes indicadores: dispêndio de kcal/semana (+697.22% vs +320.20%); PC (-3.19% vs +5.85%); CT (-23.92% vs -9.29%), C-LDL (-32.52% vs -8.92%); total de kcal/dia ingeridas (-33,31% vs -2.58%); VO2 pico (+30.88% vs -3.57%); qualidade de vida geral (+53.86% vs +2.96%). Conclusão: Concluindo que o exercício físico multicomponente, inserido na fase de ambulatório precoce na comunidade, potencia a recuperação de doentes cardíacos influenciando positivamente os fatores de risco de progressão da doença coronária, a capacidade funcional e a qualidade de vida fundamentais para que o doente possa, pelos seus próprios meios, retomar a sua vida na comunidade.

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Blood flow and net nutrient fluxes for portal-drained viscera (PDV) and liver ( total splanchnic tissues) were measured at 19 and 9 d prepartum and at 11, 21, 33, and 83 d in milk ( DIM) in 5 multiparous Holstein-Friesian cows. Cows were fed a grass silage-based gestation ration initially and a corn silage-based lactation ration peripartum and postpartum. Meals were fed at 8-h intervals and hourly (n = 8) measures of splanchnic metabolism were started before ( 0730 h and 0830 h) feeding at 0830 h. Dry matter intakes (DMI) at 19 and 9 d prepartum were not different. Metabolism changes measured from 19 to 9 d prepartum were lower arterial insulin and acetate, higher arterial nonesterified fatty acids and increased net liver removal of glycerol. After calving, PDV and liver blood flow and oxygen consumption more than doubled as DMI and milk yield increased, but 85 and 93% of the respective increases in PDV and liver blood flow at 83 DIM had occurred by 11 DIM. Therefore, factors additional to DMI must also contribute to increased blood flow in early lactation. Most postpartum changes in net PDV and liver metabolism could be attributed to increases in DMI and digestion or increased milk yield and tissue energy loss. Glucose release was increasingly greater than calculated requirements as DIM increased, presumably as tissue energy balance increased. Potential contributions of lactate, alanine, and glycerol to liver glucose synthesis were greatest at 11 DIM but decreased by 83 DIM. Excluding alanine, there was no evidence of an increased contribution of amino acids to liver glucose synthesis is required in early lactation. Increased net liver removal of propionate (69%), lactate (20%), alanine (8%), and glycerol (4%) can account for increased liver glucose release in transition cows from 9 d before to 11 d after calving.

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Myostatin (Mstn) participates in the regulation of skeletal muscle size and has emerged as a regulator of muscle metabolism. Here, we hypothesized that lack of myostatin profoundly depresses oxidative phosphorylation-dependent muscle function. Toward this end, we explored Mstn/ mice as a model for the constitutive absence of myostatin and AAV-mediated overexpression of myostatin propeptide as a model of myostatin blockade in adult wild-type mice. We show that muscles from Mstn/ mice, although larger and stronger, fatigue extremely rapidly. Myostatin deficiency shifts muscle from aerobic toward anaerobic energy metabolism, as evidenced by decreased mitochondrial respiration, reduced expression of PPAR transcriptional regulators, increased enolase activity, and exercise-induced lactic acidosis. As a consequence, constitutively reduced myostatin signaling diminishes exercise capacity, while the hypermuscular state of Mstn/ mice increases oxygen consumption and the energy cost of running. We wondered whether these results are the mere consequence of the congenital fiber-type switch toward a glycolytic phenotype of constitutive Mstn/ mice. Hence, we overexpressed myostatin propeptide in adult mice, which did not affect fiber-type distribution, while nonetheless causing increased muscle fatigability, diminished exercise capacity, and decreased Pparb/d and Pgc1a expression. In conclusion, our results suggest that myostatin endows skeletal muscle with high oxidative capacity and low fatigability, thus regulating the delicate balance between muscle mass, muscle force, energy metabolism, and endurance capacity.

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Although seasonal metabolic variation in ectothermic tetrapods has been investigated primarily in the context of species showing some level of metabolic depression during winter, but several species of anurans maintain their activity patterns throughout the year in tropical and subtropical areas. The tree-frog Hypsiboas prasinus occurs in the subtropical Atlantic Forest and remains reproductively active during winter, at temperatures below 10 degrees C. We compared males calling in summer and winter, and found that males of H. prasinus exhibit seasonal adjustments in metabolic and morphometric variables. Individuals calling during winter were larger and showed higher resting metabolic rates than those calling during summer. Calling rates were not affected by season. Winter animals showed lower liver and heart activity level of citrate synthase (CS), partially compensated by larger liver mass. Winter individuals also showed higher activity Of pyruvate kinase (PK) and lower activity of CS in trunk muscles, and higher activity of CS in leg muscles. Winter metabolic adjustments seem to be achieved by both compensatory mechanisms to the lower environmental temperature and a seasonally oriented aerobic depression of several organs. The impact of seasonal metabolic changes on calling performance and the capacity of subtropical anurans for metabolic thermal acclimatization are also discussed. (C) 2008 Elsevier Inc. All rights reserved.

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Virtually every mammalian cell, including cardiomyocytes, possesses an intrinsic circadian clock. The role of this transcriptionally based molecular mechanism in cardiovascular biology is poorly understood. We hypothesized that the circadian clock within the cardiomyocyte influences diurnal variations in myocardial biology. We, therefore, generated a cardiomyocyte-specific circadian clock mutant (CCM) mouse to test this hypothesis. At 12 wk of age, CCM mice exhibit normal myocardial contractile function in vivo, as assessed by echocardiography. Radiotelemetry studies reveal attenuation of heart rate diurnal variations and bradycardia in CCM mice (in the absence of conduction system abnormalities). Reduced heart rate persisted in CCM hearts perfused ex vivo in the working mode, highlighting the intrinsic nature of this phenotype. Wild-type, but not CCM, hearts exhibited a marked diurnal variation in responsiveness to an elevation in workload (80 mmHg plus 1 mu M epinephrine) ex vivo, with a greater increase in cardiac power and efficiency during the dark (active) phase vs. the light (inactive) phase. Moreover, myocardial oxygen consumption and fatty acid oxidation rates were increased, whereas cardiac efficiency was decreased, in CCM hearts. These observations were associated with no alterations in mitochondrial content or structure and modest mitochondrial dysfunction in CCM hearts. Gene expression microarray analysis identified 548 and 176 genes in atria and ventricles, respectively, whose normal diurnal expression patterns were altered in CCM mice. These studies suggest that the cardiomyocyte circadian clock influences myocardial contractile function, metabolism, and gene expression.