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241.
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Ricardo Polisaitis Oliveira Suzana Maria Ratusznei José Alberto Domingues Rodrigues Marcelo Zaiat Eugenio Foresti 《Journal of environmental management》2010,91(12):2499-2504
A mechanically stirred anaerobic sequencing batch reactor (ASBR) containing granular biomass was applied to the treatment of a wastewater simulating the effluent from a personal care industry. The ASBR was operated with cycle lengths (tC) of 8, 12 and 24 h and applied volumetric organic loads (AVOL) of 0.75, 0.50 and 0.25 gCOD/L.d, treating 2.0 L liquid medium per cycle. Stirring frequency was 150 rpm and the reactor was kept in an isothermal chamber at 30 °C. Increase in tC resulted in efficiency increase at constant AVOL, reaching 77% at tC of 24 h versus 69% at tC of 8 h. However, efficiency decreased when AVOL decreased as a function of increasing tC, due to the lack of substrate in the reaction medium. Moreover, replacing part of the wastewater by a chemically balanced synthetic one did not yield the expected effect and system efficiency dropped. 相似文献
244.
MarÍA JOSÉ Ruiz‐López Natalia Gañan José Antonio Godoy Ana Del Olmo Julian Garde Gerardo Espeso Astrid Vargas Fernando Martinez Eduardo R. S. Roldán Montserrat Gomendio 《Conservation biology》2012,26(6):1121-1129
The relation among inbreeding, heterozygosity, and fitness has been studied primarily among outbred populations, and little is known about these phenomena in endangered populations. Most researchers conclude that the relation between coefficient of inbreeding estimated from pedigrees and fitness traits (inbreeding‐fitness correlations) better reflects inbreeding depression than the relation between marker heterozygosity and fitness traits (heterozygosity‐fitness correlations). However, it has been suggested recently that heterozygosity‐fitness correlations should only be expected when inbreeding generates extensive identity disequilibrium (correlations in heterozygosity and homozygosity across loci throughout the genome). We tested this hypothesis in Mohor gazelle (Gazella dama mhorr) and Iberian lynx (Lynx pardinus). For Mohor gazelle, we calculated the inbreeding coefficient and measured heterozygosity at 17 microsatellite loci. For Iberian lynx, we measured heterozygosity at 36 microsatellite loci. In both species we estimated semen quality, a phenotypic trait directly related to fitness that is controlled by many loci and is affected by inbreeding depression. Both species showed evidence of extensive identity disequilibrium, and in both species heterozygosity was associated with semen quality. In the Iberian lynx the low proportion of normal sperm associated with low levels of heterozygosity was so extreme that it is likely to limit the fertility of males. In Mohor gazelle, although heterozygosity was associated with semen quality, inbreeding coefficient was not. This result suggests that when coefficient of inbreeding is calculated on the basis of a genealogy that begins after a long history of inbreeding, the coefficient of inbreeding fails to capture previous demographic information because it is a poor estimator of accumulated individual inbreeding. We conclude that among highly endangered species with extensive identity disequilibrium, examination of heterozygosity‐fitness correlations may be an effective way to detect inbreeding depression, whereas inbreeding‐fitness correlations may be poor indicators of inbreeding depression if the pedigree does not accurately reflect the history of inbreeding. Correlaciones Heterocigosidad‐ Adaptabilidad y Depresión Endogámica en Dos Especies de Mamíferos Críticamente en Peligro 相似文献
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246.
José Roberto Ferreira 《Ambio-人类环境杂志》2003,32(1):47-51
引言 莫日-瓜苏河位于纳斯吉拉斯州,海拔高1450m.流淌470km后,该河流注入圣保罗州的帕尔杜河.其流域总面积为1400km2,其中有86%位于圣保罗州,包括一个工业化地区[1]. 相似文献
247.
Electrochemical degradation of chlorophenoxy and chlorobenzoic herbicides in acidic aqueous medium by the peroxi-coagulation method 总被引:6,自引:0,他引:6
The degradation of 4-chlorophenoxyacetic acid (4-CPA), 4-chloro-2-methylphenoxyacetic acid (MCPA), 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as chlorophenoxy herbicides, as well as of 3,6-dichloro-2-methoxybenzoic acid (dicamba) as chlorobenzoic herbicide, has been studied by peroxi-coagulation. This electrochemical method yields a very effective depollution of all compounds in acidic aqueous medium of pH 3.0 working under pH regulation, since they are oxidized with hydroxyl radicals produced from Fenton's reaction between Fe(2+) and H(2)O(2) generated by the corresponding Fe anode and O(2)-diffusion cathode. Their products can then be removed by mineralization or coagulation with the Fe(OH)(3) precipitate formed. Both degradative paths compete at low currents, but coagulation predominates at high currents. The peroxi-coagulation process of dicamba at I>or=300 mA leads to more than 90% of coagulation, being much more efficient than its comparative electro-Fenton treatment with a Pt anode and 1 mM Fe(2+), where only mineralization takes place. For the chlorophenoxy compounds, electro-Fenton gives a slightly lower depollution than peroxi-coagulation, because more easily oxidable products are produced. Oxidation of chlorinated products during peroxi-coagulation is accompanied by the release of chloride ion to the solution. The efficiency of this method decreases with increasing electrolysis time and current. The decay of all herbicides follows a pseudo-first-order reaction, with a similar constant rate for 4-CPA, MCPA, 2,4-D and 2,4,5-T, and a higher value for dicamba. 相似文献
248.
Annekatrin Wagner Stephan Hülsmann Lothar Paul Rüdiger J. Paul Thomas Petzoldt René Sachse Thomas Schiller Bettina Zeis Jürgen Benndorf Thomas U. Berendonk 《Marine Biology》2012,159(11):2543-2559
To predict the coherence in local responses to large-scale climatic forcing among aquatic systems, we developed a generalized approach to compare long-term data of dimictic water bodies based on phenomenologically defined hydrographic events. These climate-sensitive phases (inverse stratification, spring overturn, early thermal stratification, summer stagnation) were classified in a dual code (cold/warm) based on threshold temperatures. Accounting for a latitudinal gradient in seasonal timing of phases derived from gradients in cumulative irradiation (2.2?days per degree latitude), we found a high spatial and temporal coherence in warm–cold patterns for six lakes (84?%) and the Baltic Sea (78?%), even when using the same thresholds for all sites. Similarity to CW-codes for the North Sea still was up to 72?%. The approach allows prediction of phase-specific warming trends and resulting instantaneous or time-delayed ecological responses. Exemplarily, we show that warming during early thermal stratification controls food-web-mediated effects on key species during summer. 相似文献
249.
Effects of paternal care on reproductive success in the polygynous spotless starling Sturnus unicolor 总被引:2,自引:0,他引:2
J. Moreno José P. Veiga Pedro J. Cordero Eduardo Mínguez 《Behavioral ecology and sociobiology》1999,47(1-2):47-53
For males of socially polygynous avian species like the spotless starling, there may exist a trade-off between investing in
paternal care and controlling several nests. To determine how the intensity of paternal care affects reproductive success
per brood sired or expressed as the total number of young raised in all nests controlled by the same male, it is necessary
to manipulate paternal care. Testosterone (T) has been shown to depress the tendency for males to care for their young, and
induces them to acquire more mates. The effects of paternal care on reproductive success were studied by treating certain
male starlings with exogenous T and others with the antiandrogen cyproterone acetate (CA), and comparing the parental behavior
of T- and CA-males throughout the breeding season with that of controls. CA-males fed their chicks more during the first week
after hatching than T-males, with controls feeding at intermediate rates, both on a per nest basis and as total effort for
all nests controlled by the same male. Paternal feeding rates during the first week of chick life had a significant positive
effect on the number of fledged young. The hormone treatment significantly affected the number of chicks raised per nest,
CA-males having a higher breeding success per nest than T-males, and controls showing intermediate levels of success. There
was no significant effect of treatment on total reproductive success attained by males throughout the season. In the polygonous
spotless starling, the intensity of paternal care of young affects reproductive success per nest positively but not on a seasonal
basis.
Received: 6 February 1999 / Received in revised form: 30 June 1999 / Accepted: 11 July 1999 相似文献
250.
Mobilization of soil organic matter by complexing agents and implications for polycyclic aromatic hydrocarbon desorption 总被引:10,自引:0,他引:10
Complexing agents are frequently used in treatment technologies to remediate soils, sediments and wastes contaminated with toxic metals. The present study reports results that indicate that the rate and extent of soil organic matter (SOM) as represented by dissolved natural organic carbon (DNOC) and polycyclic aromatic hydrocarbon (PAH) desorption from a contaminated soil from a manufactured gas plant (MGP) site can be significantly enhanced with the aid of complexing agents. Desorption of DNOC and PAH compounds was pH dependent, with minimal release occurring at pH 2-3 and maximal release at pH 7-8. At pH-6, chelate solutions were shown to dissolve large amounts of humic substances from the soil compared to controls. The complexing agents mobilized polyvalent metal ions, particularly Fe and Al from the soil. Metal ion chelation may disrupt humic (metal ion)-mineral linkages, resulting in mobilization of SOM and accompanying PAH molecules into the aqueous phase; and/or reduce the degree of cross-linking in the soil organic matter phase, which could accelerate PAH diffusion. 相似文献