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651.
Rien E. van Wijk Michael Schaub Steffen Hahn Natalia Juárez-García-Pelayo Björn Schäfer Lukáš Viktora Manuel Martín-Vivaldi Marko Zischewski Silke Bauer 《Die Naturwissenschaften》2018,105(7-8):42
The annual cycle of migrating birds is shaped by their seasonal movements between breeding and non-breeding sites. Studying how migratory populations are linked throughout the annual cycle—migratory connectivity, is crucial to understanding the population dynamics of migrating bird species. This requires the consideration not only of spatial scales as has been the main focus to date but also of temporal scales: only when both aspects are taken into account, the degree of migratory connectivity can be properly defined. We investigated the migration behaviour of hoopoes (Upupa epops) from four breeding populations across Europe and characterised migration routes to and from the breeding grounds, location of non-breeding sites and the timing of key migration events. Migration behaviour was found to vary both within and amongst populations, and even though the spatial migratory connectivity amongst the populations was weak, temporal connectivity was strong with differences in timing amongst populations, but consistent timing within populations. The combination of diverse migration routes within populations and co-occurrence on the non-breeding grounds between populations might promote exchange between breeding populations. As a result, it might make hoopoes and other migrating bird species with similar strategies more resilient to future habitat or climatic changes and stabilise population trends. 相似文献
652.
Reynaldo Mauricio Rodríguez Amaya Sandra Milena Becerra Pinto 《International journal of occupational safety and ergonomics》2016,22(1):152-158
Objective. The objective of this study was to learn about the health and safety strategies in a sample of taxi drivers in Bucaramanga, Colombia. Methods. A cross-sectional study was conducted among 138 taxi drivers. A survey was used to identify the socio-demographic and working characteristics, knowledge, attitudes and practices according to their occupational risk. Results. Eighty-five percent of the workers labored 9–15?h/day. Of those who suffered accidents, 27% were not affiliated to an occupational risk administrator (p = 0.028). Of the workers who had a work-related accident, 58% considered that the use of a cell phone while driving would not always reduce their attention, 50% always used their seat belt and 7% took active breaks and wore their seat belt (p = 0.01). Conclusions. Within this group of taxi drivers, having or believing to possess knowledge regarding an occupational risk did not ensure that they had a safe attitude or safe working practices. 相似文献
653.
Juggling work and family responsibilities when involuntarily working more from home: A multiwave study of financial sales professionals
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Laurent M. Lapierre Elianne F. van Steenbergen Maria C. W. Peeters Esther S. Kluwer 《组织行为杂志》2016,37(6):804-822
Using multiwave survey data collected among 251 financial sales professionals, we tested whether involuntarily working more from home (teleworking) was related to higher time‐based and strain‐based work‐to‐family conflict (WFC). Employees' boundary management strategy (integration vs. segmentation) and work–family balance self‐efficacy were considered as moderators of these relationships. Data were collected one month before, three months after, and 12 months after the implementation of a new cost‐saving policy that eliminated employees' access to office space in a centralized work location. The policy resulted in employees being forced to work more from home. A voluntary telework program had been in effect before the new policy, implying that working more from home as a result of the new policy was involuntary in nature. Results revealed that involuntarily working more from home was associated with higher strain‐based WFC but not higher time‐based WFC. However, moderator analyses revealed that the positive association between involuntarily working more from home and both types of WFC was significantly stronger among employees with weaker self‐efficacy in balancing work and family. Boundary management strategy had no detectable moderating effect. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
654.
B. Van der Bruggen H. Goossens P.A. Everard K. Stemgée W. Rogge 《Journal of environmental management》2009,90(2):541-549
Softening drinking water before distribution yields advantages with environmental impact, such as lower household products consumption, less scaling in piping and machines, and the avoidance of decentralized, domestic softeners. Central softening is under consideration in Flanders by the largest water supplier, VMW (Dutch acronym for “Flemish Company for Water Supply”), to deliver soft (15 °F) water to their customers. A case study is presented for a region with hard water (47 °F). The chosen technique is the pellet reactor, based on precipitation of CaCO3 by NaOH addition. This softening operation has possibly large impact on the environment and the water consumption pattern.A cost-benefit analysis has been made to estimate the added value of central softening, by investigating the impact on the drinking water company, on their customers, on employment, on environment, on health, etc. The analysis for the region of study revealed benefits for customers which were higher than the costs for the drinking water company. However, pricing of drinking water remains an important problem.A sensitivity analysis of these results has also been made, to evaluate the impact of important hypothesis, and to be able to expand this study to other regions. The conclusions for this part show that softening is beneficial if water hardness is to be decreased by at least 5 °F. 相似文献
655.
656.
Kurt Haerens Edward Matthijs Andrzej Chmielarz Bart Van der Bruggen 《Journal of environmental management》2009,90(11):3245-3252
Ionic liquids are studied intensively for different applications. They tend to be denoted as “green solvents”, largely because of their low vapour pressure. In recent years toxicity and biotoxicity of ionic liquids have also been investigated, which proved that not all of these are “green”. In this paper the use of ionic liquids based on choline chloride and ethylene glycol in electrochemistry is discussed in the context of their use as green solvents. Due to their low toxicity and ready biodegradability, these deep eutectic solvents are promising for the electrodeposition of metals. The influence of the use of these liquids as metal deposition baths on the waste water is investigated. Drag-out was found to be the most influencing parameter on the environmental impact of the process, as it is three times higher compared to classical solutions due to the higher viscosity of the ionic liquid. There are no major changes needed in the rinsing configuration of classic electroplating plants, and ion exchange to remove the metal out of the waste water was not hindered by the presence of the ionic liquid. The formation of by-products during the deposition of metals has to be further investigated and evaluated in consideration of the environmental impact. 相似文献
657.
Michael G. Zemanek Simon J. Pollard Sandra L. Kenefick Steve E. Hrudey 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1250-1258
Abstract Microtox and Ames bioassays were employed to assess acute toxicity and mutagenicity of water soluble components of class–fractionated oils extracted from one creosote–and four petroleum–contaminated soils. Microtox results revealed that potential acute toxicity resides mainly in the polar class fractions at three sites and indicated potential synergistic and antagonistic effects between compounds in the total extracts at two sites. Ames Salmonella/microsome testing indicated that the polyaromatic fractions at two sites exhibit weak mutagenicity with enzymatic activation, while the polar fractions at two sites are weakly mutagenic without enzyme activation. Further chemical characterization of the polar and polyaromatic fractions is required to fully assess the potential of health and ecological risks at the creosote–and petroleum–contaminated sites exhibiting these toxic responses. 相似文献
658.
659.
Manzetti Sergio Hadi Behzadi Andersen Otto David van der Spoel 《Environmental Chemistry Letters》2013,11(2):105-118
Nanotechnology globally represents a new direction within scientific development, where the atomic and electronic properties of molecules are used in a unique fashion to produce and construct new and exotic materials and products. Fullerenes (Bucky balls, C60) constitute a particular group within the field of nanotechnology. Fullerenes find applications in medicine, industrial chemistry and electronics. However, there are several unanswered questions about fullerenes and their toxicological properties. Most toxicological studies on fullerenes evolve around the in vitro and in vivo aspects of pristine C60 along with chemically modified C60 molecules. We reviewed toxicology reports on C60. We bring a critical and challenging evaluation of the electronic and quantum properties of C60 molecules in context with the implications on cellular factors and metabolites. The evaluation shows that the reactivity and quantum chemical properties of C60 can have unexpected effects in the cell, by principally absorbing metabolites, such as OH? and H+ ions and alter its reactivity. We thus challenge the present view of C60 solely based on empirical studies, based on the electronic properties of C60 that vary considerably with their size and reaction path. A further example of this is the absorption of divalent zinc ions, which shows an increase in reactivity of the C60 that presents an important pattern of chemical state, reactivity and toxicological potential. The results evaluate the toxicological potential of C60 from a different angle than conventional, by applying a blend of critical review of the findings on C60 toxicity, their chemical and electronic properties. 相似文献
660.
Frank von der Kammer 《Environmental pollution (Barking, Essex : 1987)》2010,158(12):3472-10052
Assessment of the behavior and fate of engineered nanoparticles (ENPs) in natural aquatic media is crucial for the identification of environmentally critical properties of the ENPs. Here we present a methodology for testing the dispersion stability, ζ-potential and particle size of engineered nanoparticles as a function of pH and water composition. The results obtained from already widely used titanium dioxide nanoparticles (Evonik P25 and Hombikat UV-100) serve as a proof-of-concept for the proposed testing scheme. In most cases the behavior of the particles in the tested settings follows the expectations derived from classical DLVO theory for metal oxide particles with variable charge and an isoelectric point at around pH 5, but deviations also occur. Regardless of a 5-fold difference in BET specific surface area particles composed of the same core material behave in an overall comparable manner. The presented methodology can act as a basis for the development of standardised methods for comparing the behavior of different nanoparticles within aquatic systems. 相似文献