940 resultados para C sequestration rate
Resumo:
The objective of this work was to evaluate some aspects of the populational ecology of Chrysomya megacephala, analyzing demographic aspects of adults kept under experimental conditions. Cages of C. megacephala adults were prepared with four different larval densities (100, 200, 400 and 800). For each cage, two tables were made: one with demographic parameters for the life expectancy estimate at the initial age (eo), and another with the reproductive rate and average reproduction age estimates. Populational parameters such as the intrinsic growth rate (i) and thefinite growth rate (lambda) were calculated as well.
Resumo:
Jararhagin is a metalloproteinase from Bothrops jararaca responsible for hemorrhage, inflammation, necrosis and edema. Effects of low doses of the toxin were analyzed on the energy metabolism of mice as well as its physiological implications. Measures of O-2 consumption (VO2) were quantified after 4 and 24 h of the jarathagin administration during four weeks. Hematocrit and histology of the lungs were also analyzed after the end of the treatment. Results showed that animals that received subcutaneous doses of jararhagin had significant increase in VO2 from second (120 ng) and third weeks (60 ng) after 4 and 24 h, comparing to control, as well as in the number of erythrocytes after four weeks. Histology of the lungs showed interstitial edema within the alveolar septum. Results suggest that the jararhagin toxin caused an increase in VO2 and edema of intra-alveolar septum. The increase of the erythrocytes could be a physiological response to adjust the higher necessity of oxygen, due to diffusional abnormalities caused by the edema. Thus, low doses of jararhagin promote endothelial edema which lead to changes in several physiological conditions. (c) 2006 Elsevier Ltd. All rights reserved.
Resumo:
Oxygen consumption rate was measured continuously in young tegu lizards Tupinambis merianae exposed to 4 d at 25 degrees C followed by 7-10 d at 17 degrees C in constant dark at five different times of the year. Under these conditions, circadian rhythms in the rate of oxygen consumption persisted for anywhere from 1 d to the entire 2 wk in different individuals in all seasons except the winter. We also saw a progressive decline in standard oxygen consumption rate (at highly variable rates in different individuals) to a very low rate that was seasonally independent (ranging from 19.1 +/- 6.2 to 27.7 +/- 0.2 mL kg(-1) h(-1) across seasons). Although this degree of reduction appeared to take longer to invoke when starting from higher metabolic rates, tegu lizards reduced their metabolism to the low rates seen in winter dormancy at all times of the year when given sufficient time in the cold and dark. In the spring and summer, tegus reduced their standard metabolic rate (SMR) by 80%-90% over the experimental run, but only roughly 20%-30% of the total fall was due to the reduction in temperature; 70%-80% of the total fall occurred at constant temperature. By autumn, when the starting SMR on the first night at 25 degrees C was already reduced by 59%-81% (early and late autumn, respectively) from peak summer values, virtually all of the fall (63%-83%) in metabolism was due to the reduction in temperature. This suggests that the temperature-independent reduction of metabolism was already in place by autumn before the tegus had entered winter dormancy.
Resumo:
This study examined how the standard metabolic rate of tegu lizards, a species that undergoes large ontogenetic changes in body weight with associated changes in life-history traits, is affected by changes in body mass, body temperature, season, and life-history traits. We measured rates of oxygen consumption ((V) over dot o(2)) in 90 individuals ranging in body mass from 10.4. g to 3.75 kg at three experimental temperatures ( 17 degrees, 25 degrees, and 30 degrees C) over the four seasons. We found that standard metabolic rate scaled to the power of 0.84 of body mass at all experimental temperatures in all seasons and that thermal sensitivity of metabolism was relatively low (Q(10) approximate to 2.0-2.5) over the range from 17 degrees to 30 degrees C regardless of body size or season. Metabolic rates did vary seasonally, being higher in spring and summer than in autumn and winter at the same temperatures, and this was true regardless of animal size. Finally, in this study, the changes in life-history traits that occurred ontogenetically were not accompanied by significant changes in metabolic rate.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Estudou-se, sob condições de casa de vegetação, o efeito da aplicação de reguladores e estimulantes vegetais no desenvolvimento do milho cultivar Cargill -525. Os reguladores e estimulantes utilizados foram: giberelina 100 ppm, ethephon 600 ppm, Agrostemin 0,8 g/l e Triacontanol 0,5 mg/l; aplicados por pulverização 34 dias após a semeadura, além do controle, foram determinados os parâmetros relativos a altura da planta, número de folhas, área foliar e peso da materia seca de raiz, caule e folhas. A partir dos dados de área foliar e peso da matéria seca total obtidos em 4coletas realizadas com intervalos de 14 dias, foram calculadas a taxa assimilatória líquida (TAL), taxa de crescimento relativo (TCR) e razão de área foliar (RAF). Giberelina 100 ppm aumentou inicialmente a altura das plantas de milho, sendo que ethephon 600 ppm reduziu a altura média do milho. 0 número de folhas foi diminuído nas plantas tratadas com giberelina, tendendo a aumentar no tratamento com ethephon. Giberelina reduziu o peso da matéria seca das plantas de milho, sendo que ethephon incrementou o peso de raízes, colmo e folhos. Triacontanol promoveu redução na TAL e na TCR do milho 'Cargill - 525' . Giberelina e ethephon tenderam a diminuir a RAF das plantas de Zea mays L.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
The rate coefficients for the formation of carbon monophosphide (CP) and silicon monophosphide (SiP) by radiative association are estimated for temperatures ranging from 300 to 14 100 K. In this temperature range, the radiative association rate coefficients are found to vary from 1.14 x 10(-18) to 1.62 x 10(-18) cm(3) s(-1) and from 3.73 x 10(-20) to 7.03 x 10(-20) cm(3) s(-1) for CP and SiP, respectively. In both cases, rate coefficients increase slowly with the increase in temperature.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
This investigation reports the results of a study realized in areas related to the development of sand mining activities, which belong to CRS-Mineragao Industria e Comercio Ltd. and Sibelco Mineracao Ltd. Both areas are located around Analandia municipality, nearly in the center of São Paulo State, Brazil. Flow rate and hydrochemical analyses were realized over different periods of time, with the aim of evaluating the possibility of release of several constituents to the liquid phase, which may be a source of pollution of the surface hydrological resources. This is because some tributaries from the Corumbatai River may be suffering contamination, implying on the impoverishment of the water quality that is a very important resource in the region, as it is extensively used for drinking purposes, among others.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)