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961.
Intake of many persistent organic pollutants (POPs) including dioxins, dibenzofurans and PCBs is almost exclusively from gastrointestinal ingestion of animal fats in the diet. With polybrominated diphenyl ether (PBDE) brominated flame retardants (BFRs), no consensus exists at present as to the extent of intake from food, from indoor dust or other routes of intake. Vegans, or pure vegetarians, were previously found to have low body burden of dioxins and dibenzofurans in blood. Data reported here for the first time show a trend towards lower PBDE levels with longer time periods without ingestion of food of animal origin in 8 adult residents of the United States. A stronger relationship between lower PBDE levels and time without meat, specifically, is consistent with substantial PBDE intake from meat relative to fish or dairy products in Americans. These vegans had somewhat lower PBDE levels with a range 12.4–127 and a median 23.9?ppb than published reports of US general population samples which had a range of 4–366 and median of 26?ppb. Our findings suggest that food of animal origin may be a major but not the sole contributor to human body burden of PBDEs. 相似文献
962.
Jérôme Lazard Hélène Rey-Valette Joël Aubin Syndhia Mathé Eduardo Chia Domenico Caruso 《国际发展与全球生态学杂志》2013,20(6):503-511
Little work dealing with the evaluation of aquaculture system sustainability has so far been undertaken on a global and comparative basis. Moreover, such work is mostly based on very unbalanced approaches in terms of the dimensions of sustainable development that are taken into account. The approach adopted in this article is designed to encompass all the dimensions of sustainability including the institutional one (governance). The taking into account of this latter, in particular, together with the role played by aquaculture in sustainability at the territorial level gives the approach its original and innovative nature. The process of establishing the checklist of sustainability indicators in aquaculture relies on a hierarchical nesting approach which makes it possible to link indicators with general sustainability criteria and principles. At once multidisciplinary and participatory, the approach compares several countries with highly differentiated types of aquaculture system. An original finding from this work is that the technically most intensive farming model scores better than more extensive systems, which might have been thought to be closer to natural systems in their environmental dimension and therefore intuitively more ‘sustainable’. This result suggests relating sustainability outcomes to the level of control and of devolved responsibilities. 相似文献
963.
Ploton P Pélissier R Proisy C Flavenot T Barbier N Rai SN Couteron P 《Ecological applications》2012,22(3):993-1003
Reducing Emissions from Deforestation and Forest Degradation (REDD) in efforts to combat climate change requires participating countries to periodically assess their forest resources on a national scale. Such a process is particularly challenging in the tropics because of technical difficulties related to large aboveground forest biomass stocks, restricted availability of affordable, appropriate remote-sensing images, and a lack of accurate forest inventory data. In this paper, we apply the Fourier-based FOTO method of canopy texture analysis to Google Earth's very-high-resolution images of the wet evergreen forests in the Western Ghats of India in order to (1) assess the predictive power of the method on aboveground biomass of tropical forests, (2) test the merits of free Google Earth images relative to their native commercial IKONOS counterparts and (3) highlight further research needs for affordable, accurate regional aboveground biomass estimations. We used the FOTO method to ordinate Fourier spectra of 1436 square canopy images (125 x 125 m) with respect to a canopy grain texture gradient (i.e., a combination of size distribution and spatial pattern of tree crowns), benchmarked against virtual canopy scenes simulated from a set of known forest structure parameters and a 3-D light interception model. We then used 15 1-ha ground plots to demonstrate that both texture gradients provided by Google Earth and IKONOS images strongly correlated with field-observed stand structure parameters such as the density of large trees, total basal area, and aboveground biomass estimated from a regional allometric model. Our results highlight the great potential of the FOTO method applied to Google Earth data for biomass retrieval because the texture-biomass relationship is only subject to 15% relative error, on average, and does not show obvious saturation trends at large biomass values. We also provide the first reliable map of tropical forest aboveground biomass predicted from free Google Earth images. 相似文献
964.
Atalay Sinan E. Bezci Betül Özdemir Burcu Göksu Yonca Alkan Ghanbari Abbas Jalali Amirjalal Nofar Mohammadreza 《Journal of Polymers and the Environment》2021,29(10):3412-3426
Journal of Polymers and the Environment - The degradation behaviors of an amorphous and a semicrystalline PLA (i.e., aPLA and cPLA) with similar molecular weights are compared at elevated... 相似文献
965.
An indicator can be considered any measure – quantitative or qualitative – that seeks to produce information on an issue of interest. Safety indicators can play a key role in providing information on organizational performance, motivating people to work on safety and increasing organizational potential for safety. We will describe the challenges of monitoring and driving system safety. Currently, the same lead indicators are used – explicitly or implicitly – for both purposes. The fact that the selection and use of safety performance indicators is always based on a certain understanding (a model) of the sociotechnical system and safety is often forgotten. We present a theoretical framework for utilizing safety performance indicators in safety–critical organizations that incorporates three types of safety performance indicators – outcome, monitor and drive indicators. We provide examples of each type of indicator and discuss the application of the framework in organizational safety management. We argue that outcome indicators are lag indicators since outcomes always follow something; they are the consequences arising from multiple other situational and contextual factors. Monitor and drive indicators are lead indicators. The main function of the drive indicators is to direct the sociotechnical activity in the organization by motivating certain safety-related activities. Monitor indicators provide a view on the dynamics of the organization: the practices, abilities, skills and motivation of the personnel – the organizational potential for safety. We conclude that organizations should better acknowledge the significance of monitor and drive indicators in safety management. 相似文献
966.
Non-parametric statistical tests are commonly used in the behavioral sciences. Researchers need to be aware that non-parameteric
methods involving ranks can perform unreliably as a result of very small amounts of noise added in the storage and manipulation
of values by computers, causing spurious reduction in the number of ties. In order to avoid this problem, researchers should
round values to an appropriate number of decimal places prior to the ranking procedure to ensure that data points whose values
cannot be separated according to the precision of their measurement are recorded as having identical rank. We also recommend
exact rather than asymptotic evaluation of p values in non-parametric statistical tests. 相似文献
967.
Bent Barman Skaare Morten Schaanning Pål Tore Mørkved 《Environmental Chemistry Letters》2009,7(2):183-189
This paper demonstrates how stable carbon isotopes can be utilized to identify the source of oil-based drill cuttings discharges
and estimate the time of their deposition. The base-oil used in drilling mud systems may be biodegraded by seabed microflora.
Effects of such processes make it difficult to identify sources of discharges based on the oil’s molecular structure. However,
the stable isotope fingerprint of the base oil may vary for each batch of base-oil. Because carbon isotopic ratios in compounds
with more than ten carbons are resistant to fractionation during biodegradation, this may be used as a tool to identify the
source of drill cuttings discharges. 相似文献
968.
Different uptake routes of contaminants were analysed with focus on particle-bound pollutants. Bioavailability of cadmium was determined with quantitative mRNA-analysis using the expression of the “cadmium responsive gene” cdr- in Caenorhabditis elegans. Comparable experiments were performed with fluoranthene as organic pollutant. The exposure in medium was compared with and without bacteria as food particles. Both bioaccumulation and toxic effects were most influenced via the food exposure. Inorganic particles increased also the uptake of cadmium, but significantly less than food or mixtures of food and inorganic particles. The exposure of fluoranthene reduced the reproduction of the nematodes, if a gene expression threshold was exceeded. However, bioavailabilty of fluoranthene via food particles caused a faster response of the cyp-expression. Thus means, the internal availability is crucial influenced by the uptake route. 相似文献
969.
The genetic structure of benthic marine invertebrates is often described as “chaotic” when genetic structure cannot be explained and barriers to dispersal and gene flow cannot be identified. Here, chaotic patterns of genetic structure for the polychaete Pygospio elegans (Claparède) sampled at 16 locations from the heterogeneous Isefjord–Roskilde Fjord estuary complex in Denmark were found. There was no isolation by distance, and the geography of the estuary complex did not seem to pose a barrier to dispersal and gene flow in this species. We investigated whether characteristics of the environment could be related to the genetic structure and possibly restrict gene flow in this species. Additionally, since P. elegans is poecilogonous, producing larvae with different pelagic developmental periods, we investigated whether observed developmental modes in the samples might clarify the genetic patterns. None of the tested factors explained the population genetic structure. However, a high degree of relatedness among individuals in almost all samples was found. Samples with a larger percentage of young individuals had more related individuals, suggesting that different cohorts could be comprised of individuals with different degrees of relatedness. Relatedness within a site could be increased by limited larval dispersal, collective dispersal of related larvae, sweepstakes reproductive success, or asexual reproduction, but distinguishing between these requires further study. Using a “seascape genetics” approach allowed us to investigate some of the numerous potential factors that could influence population genetic structure in a poecilogonous species. 相似文献
970.
Häring Ivo Fehling-Kaschek Mirjam Miller Natalie Faist Katja Ganter Sebastian Srivastava Kushal Jain Aishvarya Kumar Fischer Georg Fischer Kai Finger Jörg Stolz Alexander Leismann Tobias Hiermaier Stefan Carli Marco Battisti Federica Makri Rodoula Celozzi Giuseppe Belesioti Maria Sfakianakis Evangelos Agrafioti Evita Chalkidou Anastasia Papadakis George Fuggini Clemente Bolletta Fabio Neri Alberto Giunta Guiseppe Scheithauer Hermann Höflinger Fabian Schott Dominik J. Schindelhauer Christian Köhler Sven Linkov Igor 《The Environmentalist》2021,41(2):286-329
Environment Systems and Decisions - Organizational and technical approaches have proven successful in increasing the performance and preventing risks at socio-technical systems at all scales.... 相似文献