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641.
Jörn Germer Michael Yongha Boh Marie Schoeffler Philip Amoah 《Waste management (New York, N.Y.)》2010,30(2):185-191
Small scale co-composting of faecal matter from dry toilet systems with shredded plant material and food waste was investigated in respect to heat development and deactivation of faecal indicators under tropical semiarid conditions. Open (uncovered) co-composting of faecal matter with shredded plant material alone did not generate temperatures high enough (<55 °C) to reduce the indicators sufficiently. The addition of food waste and confinement in chambers, built of concrete bricks and wooden boards, improved the composting process significantly. Under these conditions peak temperatures of up to 70 °C were achieved and temperatures above 55 °C were maintained over 2 weeks. This temperature and time is sufficient to comply with international composting regulations. The reduction of Escherichia coli, Enterococcus faecalis and Salmonella senftenberg in test containment systems placed in the core of the compost piles was very efficient, exceeding 5 log10-units in all cases, but recolonisation from the cooler outer layers appeared to interfere with the sanitisation efficiency of the substrate itself. The addition of a stabilisation period by extending the composting process to over 4 months ensured that the load of E. coli was reduced to less than 103 cfu?g and salmonella were undetectable. 相似文献
642.
Drawing from the social cognitive theory of self‐regulation, we develop a model linking experienced incivility to emotional exhaustion and supportive behaviors via self‐blame, with observed incivility experienced by coworkers as a first‐stage moderator and trait emotional control as a second‐stage moderator. We contend that employees will experience self‐blame if they perceive themselves to be distinct targets of incivility (i.e., observed incivility experienced by others is low). Self‐blame can potentially trigger prosocial responses for improving the situation, but self‐blaming targets rarely respond in a prosocial manner because rational attempts to do so are thwarted by deleterious negative emotions accompanying self‐blame. We argue that trait emotional control provides resources for managing these negative emotions to unleash a bright side of self‐blame, such that the relation of self‐blame with prosocial responses (i.e., being supportive to coworkers) will be more positive and the relation of self‐blame with emotional exhaustion will be less positive for individuals with high (vs. low) trait emotional control. Multiwave data collected from a sample of 220 police officers largely support our hypotheses, indicating that the indirect relation of experienced incivility with supportive behaviors via self‐blame is strongest at lower levels of observed incivility and higher levels of emotional control. 相似文献
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J. Russell Finley János D. Pintér Mysore G. Satish 《Environmental Modeling and Assessment》1998,3(1-2):117-126
This paper summarizes a study aimed at the application of global optimization techniques for the purpose of quantitative characterization of the Wolfville formation located in Nova Scotia, Canada. Aquifer parameters (transmissivity, storativity, areal recharge and boundary flux) are calibrated in order to yield the best possible match with the available field observations. The calibration is accomplished using a global approach to the inverse procedure in “black box” systems optimization which makes possible the simultaneous fitting of several tens of parameters. This study indicates that, even for a limited number of optimized parameters, a global search procedure should be considered. Numerical results are presented and discussed to show the validity of the approach. 相似文献
646.
In many temperate estuarine areas, ongoing climatic changes are expected to lead to higher seawater temperatures, to increased inflow of freshwater and nutrients (due to increased rainfall) and to altered light conditions. During the last two decades, several winters have been unusually mild in southern Finland, and the subsequent springs have been early. This may have consequences for the seasonality of many species, including the bladder-wrack, Fucus vesiculosus, whose reproductive cycle may be especially sensitive. In the present study, F. vesiculosus receptacles from the field were weighed regularly during three warm (early) springs and compared with receptacles from three cold (late) springs. On average, the first sign of receptacle growth in the field occurred 5–6?weeks earlier and receptacles probably matured 2–3?weeks earlier during the warm springs than during the cold springs. This may be due to differences in seawater temperatures among years, but significantly heavier receptacles at 0.8?m compared to at 3.1?m further suggests the importance of light for receptacle growth as a measure of maturation, since there were no depth-related differences in seawater temperatures. Also, when plotting receptacle wet weights against seawater temperatures, the importance of light can be seen as different regression relationships (slopes and intercepts). In an outdoor aquarium experiment, the effects of temperature and light on receptacle growth were also tested, and there were significant differences between shallow and deep specimens, but temperature and light had no effects, except on initial receptacle growth. Since oogonian development, and thereby the time for zygote release, followed the receptacle growth curve, this could mean a mismatch between the timing of F. vesiculosus zygote settlement and the cover of competing filamentous algae, but such species interactions require further investigations in order to better understand their possible consequences. 相似文献
647.
S. Clemente J. C. Hernández G. Montaño-Moctezuma M. P. Russell T. A. Ebert 《Marine Biology》2013,160(3):579-590
We evaluated the effects of potential predators from intertidal habitats on Strongylocentrotus purpuratus survival using laboratory experiments and assessed abundances of main predatory species along the Pacific coast of North America. The interactive effects of urchins’ and predators’ sizes in mediating predation were quantified. Habitat complexity (substrate pits, adult spine canopy) was manipulated to examine its effects on predation of most susceptible individuals (<14 mm). Pachygrapsus crassipes was identified as a major predator of urchins up to ≈30 mm. A positive effect of predator size on consumption of progressively larger urchins was detected, probably due to a mechanical limitation on crabs’ ability to consume large prey. Larger claws of males with respect to females of comparable sizes facilitated the handling of larger prey. Substrate refuges significantly reduced mortality on juvenile urchins. These results show that crab predation may be important in organizing intertidal communities, despite multiple ecological mechanisms promoting sea urchin survival. 相似文献
648.
Gregor Kalinkat Juliano S. Cabral William Darwall G. Francesco Ficetola Judith L. Fisher Darren P. Giling Marie‐Pierre Gosselin Hans‐Peter Grossart Sonja C. Jähnig Jonathan M. Jeschke Klaus Knopf Stefano Larsen Gabriela Onandia Marlene Pätzig Wolf‐Christian Saul Gabriel Singer Erik Sperfeld Ivan Jarić 《Conservation biology》2017,31(2):481-485
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Marie Maud Bear Valérie Langlois Daniel Robic Richard Bourbouze Philippe Guerin 《Journal of Polymers and the Environment》1999,7(3):127-134
Design of optically active polymeric materials for temporary therapeutic and environmental applications requires the working-out of functionalized polymers with structures and properties adjusted to the considered applications. Biocompatibility of selected polymers is a required property in regard to the interactions between living organisms and macromolecular systems. It is therefore important to prepare highly optically active monomers and their corresponding hydrolyzable and biocompatible polymers. Bacterium Clostridium tetanomorphum is an useful source of enzymes for bioconversion and particularly in the chemoenzyrnatic route to optically active alkylmalolactonic acid esters and their optically pure stereoisomers. 3-Methylaspartase, involved in the glutamate fermentation pathway, is a very interesting enzyme, which can provide chiral precursors with high optically purity. This chemoenzymatic strategy can be used to prepare the four stereoisomers of 3-methylmalolaconic acid esters, by enzymatic resolution of natural and artificial stereoisomers of 3-methylaspartic acid. A series of 3-alkymalolactonic acid esters with alkyl equal to ethyl or isopropyl, have been also synthesized and transformed into corresponding optically active polyesters. 相似文献