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121.
Assessment of metal availability to vegetation (Betula pendula) in Pb-Zn ore concentrate residues with different features 总被引:1,自引:0,他引:1
Marguí E Queralt I Carvalho ML Hidalgo M 《Environmental pollution (Barking, Essex : 1987)》2007,145(1):179-184
In this work, characterisation of several ore concentrate remains from an abandoned Pb-Zn mining factory was performed determining chemical and physical properties such as pH, organic carbon content, particle size distribution, total heavy metal content (Pb, Zn, Cu, As and Cd) as well as mineralogical composition which showed, in most cases, the oxidization of the parent ore material (mostly galena: PbS and sphalerite: ZnS) to more mobile fractions as anglesite (PbSO(4)) and goslarite (ZnSO(4)). Moreover, two operational defined extraction procedures commonly used in soil and sediment studies (first and second steps of BCR procedure and DTPA extraction protocol) were applied in the different mining wastes in order to study Pb and Zn mobility and likely bioavailability to Betula pendula growing on the same mining spoils, which presents lead and zinc contents in leaves over ten times background values. 相似文献
122.
There is little experience in Portugal with the separate collection of the biodegradable fraction of municipal solid waste (MSW). Therefore, it is relevant to evaluate how this process could economically affect the actual practices of MSW collection in small municipalities. This article simulates the costs of collection by means of a fixed container system and a transfer station, using values from a municipality with a population of 28,000 inhabitants. The main goal of this exercise is to compare the economic effects of three alternative scenarios: (i) the traditional, unsorted collection; (ii) the separate collection of whole biowaste; and (iii) the separate collection of biowaste generated in the major urban communities, while setting aside the other biowaste for home composting. The input data are from 2001, and include waste quantities, travel times, work crew composition, crew time shifts, vehicles, and containers. Calculations of the proposed mathematical method were carried out using the Microsoft Excel software. This study concludes that the global cost for separate collection of biowaste (alternative ii) need not necessarily be higher than the corresponding cost of the traditional, unsorted method of collection (alternative i). Furthermore, the global cost for collection with separated biowaste and home composting (alternative iii) could also be lower than the corresponding cost of the traditional, unsorted method of collection. 相似文献
123.
R. R. Valle F. M. Carvalho J. A. P. C. Muniz C. L. V. Leal M. García-Herreros 《Die Naturwissenschaften》2013,100(10):923-933
The aim of this study was to develop an objective method to determine the incidence of pleiomorphisms and its influence on the distribution of sperm morphometric subpopulations in ejaculates of howling monkeys (Alouatta caraya) by using a combination of computerized analysis system (ASMA) and principal component analysis (PCA) methods. Ejaculates were collected by electroejaculation methods on a regular basis from five individuals maintained under identical captive environmental, nutritional, and management conditions. Each sperm head was measured for dimensional parameters (Area [A, (square micrometers)], Perimeter [P, (micrometers)], Length [L, (micrometers)], and Width [W, (micrometers)]) and shape-derived parameters (Ellipticity [(L/W)], Elongation [(L???W)/(L?+?W)], and Rugosity [(4лA/P 2)]). PCA revealed two principal components explaining more than the 96 % of the variance. Clustering methods and discriminant analyzes were performed and seven separate subpopulations were identified. There were differences (P?<?0.001) in the distribution of the seven subpopulations as well as in the incidence of abnormal pleiomorphisms (58.6 %, 49.8 %, 35.1 %, 66.4 %, and 55.1 %, P?<?0.05) among the five donors tested. Our results indicated that differences among individuals related to the incidence of pleiomorphisms, and sperm subpopulational structure was not related to the captivity conditions or the sperm collection method, since all individuals were studied under identical conditions. In conclusion, the combination of ASMA and PCA is a useful clinical diagnostic resource for detecting deficiencies in sperm morphology and sperm subpopulations in A. caraya ejaculates that could be used in ex situ conservation programs of threatened species in Alouatta genus or even other endangered neotropical primate species. 相似文献
124.
Marson Eduardo O. Paniagua Cleiseano E.S. Costa-Serge Nayara M. Sousa Raquel M.F. Silva Gizele D. Becker Raquel W. Sirtori Carla Starling Maria Clara V. M. Carvalho Solidônio R. Trovó Alam G. 《Environmental science and pollution research international》2021,28(19):23582-23594
Environmental Science and Pollution Research - As the presence of antibiotics in environmental waters enhances antimicrobial resistance, photolysis and heterogeneous photocatalysis of... 相似文献
125.
126.
The integration of socio-economic and environmental objectives is a major challenge in developing strategies for sustainable landscapes. We investigated associations between socio-economic variables, landscape metrics and measures of forest condition in the context of Portugal. The main goals of the study were to 1) investigate relationships between forest conditions and measures of socio-economic development at national and regional scales, 2) test the hypothesis that a systematic variation in forest landscape metrics occurs according to the stage of socio-economic development and, 3) assess the extent to which landscape metrics can inform strategies to enhance forest sustainability. A ranking approach and statistical techniques such as Principal Component Analysis were used to achieve these objectives. Relationships between socio-economic characteristics, landscape metrics and measures of forest condition were only significant in the regional analysis of municipalities in Northern Portugal. Landscape metrics for different tree species displayed significant variations across socio-economic groups of municipalities and these differences were consistent with changes in characteristics suggested by the forest transition model. The use of metrics also helped inform place-specific strategies to improve forest management, though it was also apparent that further work was required to better incorporate differences in forest functions into sustainability planning. 相似文献
127.
128.
Mariane de Fátima Yukie Maeda Maria de Lourdes Brizot Maria Augusta Bento Cicaroni Gibelli Silvia Maria Ibidi Werther Brunow de Carvalho Mara Sandra Hoshida Clarisse Martins Machado Ester Cerdeira Sabino Lea Campos de Oliveira da Silva Thomas Jaenisch Maria Cássia Jacintho Mendes-Correa Philippe Mayaud Rossana Pulcinelli Vieira Francisco HC-FMUSP-Obstetric COVID Study Group 《黑龙江环境通报》2021,41(8):998-1008
129.
Reproduction of Asterina stellifera was studied in two populations from the Cabo Frio region, southeastern Brazil. One was located in an intertidal seagrass
flat at Japonês Island (1994–1995); the second was on a sublittoral rocky shore at Pontal beaches (1999–2000). Reproductive
cycle was studied at monthly intervals by organ indices and histological examinations of gonads. Although these two populations
were studied in different habitats and at different times, the periodicity of the annual reproductive cycle was very similar
for the two populations. The highest gonad index (GI) values were found in August/September (late winter), followed by a drop
in GI values, indicating spawning. The GI and pyloric caeca index (PCI) tended to have an inverse relationship in both populations,
but it was only statistically significant in the rocky-shore population. Gametogenesis in the two populations was described
and roughly confirmed the reproductive cycles determined by GIs.
Published online: 9 August 2002 相似文献
130.
M. H. B. Carvalho M. L. Brizot L. M. Lopes C. H. Chiba S. Miyadahira M. Zugaib 《黑龙江环境通报》2002,22(1):1-4
The aim of this study was to evaluate the detection of fetal structural abnormalities by the 11–14 week scan. 2853 pregnant women were submitted to a routine ultrasound scan between the 11th and 14th week and the fetal skull, brain, spine, abdominal wall, limbs, stomach and bladder were examined. Following the scans the patientes were examined in the second or third trimester of pregnancy. An isolated increased nuchal translucency was not considered an abnormality. However, these patients had an early echocardiography assessment. Fetal structural abnormalities were classified as major or minor and of early or late onset. A total of 130 (4.6%) defects were identified and 29 (22.3%) of these were diagnosed at the 11–14 week scan, including nine cardiac defects associated with increased nuchal translucency. The antenatal ultrasound detection rate was 71.5%, and 31.2% were detected in the first-trimester assessment. 78.8% of the major defects were diagnosed by the prenatal scan and 37.8% by the 11–14 week scan. Fetal structural abnormalities at the 11–14 week scan were detected in approximately 22.3% of the cases, therefore, a second-trimester anomaly scan is important in routine antenatal care to increase the prenatal detection of fetal defects. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献