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561.
Russell J. Hall Susan D. Haseltine Paul H. Geissler 《Environmental monitoring and assessment》1989,13(1):11-19
Comparison of organochlorine residues in wildlife must often be made to regulatory standards or to values of known biological significance; this is difficult when dissimilar tissues are analyzed and results are expressed on different bases. To relate levels in the different tissues used for regulatory and monitoring purposes and for biological assessments, we exposed American black ducks to mixtures of three organochlorines. Differences in residue burdens among tissues were not statistically significant when levels were expressed on a lipid weight basis. Levels of heptachlor and Aroclor 1254 in one tissue can be accurately predicted from those in another; such predictions for endrin are less reliable. Lipid weight based residue concentrations in wings may be used to predict whether levels in fat exceed residue standards set for human health or approach those associated with effects on populations of species sampled. 相似文献
562.
Christine Susan Fagnant Liliana Margarita Sánchez-Gonzalez Nicolette A. Zhou Jill Christin Falman Michael Eisenstein Dylan Guelig Byron Ockerman Yifei Guan Alexandra Lynn Kossik Yarrow S. Linden Nicola Koren Beck Robyn Wilmouth Evans Komen Benlick Mwangi James Nyangao Jeffry H. Shirai Igor Novosselov Peter Borus David S. Boyle John Scott Meschke 《Food and environmental virology》2018,10(1):72-82
Environmental surveillance of poliovirus (PV) plays an important role in the global program for eradication of wild PV. The bag-mediated filtration system (BMFS) was first developed in 2014 and enhances PV surveillance when compared to the two-phase grab method currently recommended by the World Health Organization (WHO). In this study, the BMFS design was improved and tested for its usability in wastewater and wastewater-impacted surface waters in Nairobi, Kenya. Modifications made to the BMFS included the size, color, and shape of the collection bags, the filter housing used, and the device used to elute the samples from the filters. The modified BMFS concentrated 3–10 L down to 10 mL, which resulted in an effective volume assayed (900–3000 mL) that was 6–20 times greater than the effective volume assayed for samples processed by the WHO algorithm (150 mL). The system developed allows for sampling and in-field virus concentration, followed by transportation of the filter for further analysis with simpler logistics than the current methods. This may ultimately reduce the likelihood of false-negative samples by increasing the effective volume assayed compared to samples processed by the WHO algorithm, making the BMFS a valuable sampling system for wastewater and wastewater-impacted surface waters. 相似文献
563.
Smoldering Combustion (STAR) for the Treatment of Contaminated Soils: Examining Limitations and Defining Success 下载免费PDF全文
Gavin P. Grant David Major Grant C. Scholes John Horst Susan Hill Mark R. Klemmer James Neil Couch 《补救:环境净化治理成本、技术与工艺杂志》2016,26(3):27-51
Smoldering combustion, commercially available as the Self‐sustaining Treatment for Active Remediation (STAR) technology, is an innovative technique that has shown promise for the remediation of contaminant source zones. Smoldering combustion is an exothermic reaction (net energy producing) converting carbon compounds and an oxidant (e.g., oxygen in air) to carbon dioxide, water, and energy. Thus, following ignition, the smoldering combustion reaction can continue in a self‐sustaining manner (i.e., no external energy or added fuel input following ignition) as the heat generated by the reacting contaminants is used to preheat and initiate combustion of contaminants in adjacent areas, propagating a combustion front through the contaminated zone provided a sufficient flux of air is supplied. The STAR technology has applicability across a wide‐range of hydrocarbons in a variety of hydrogeologic settings; however, there are limitations to its use. Impacted soils must be permeable enough to allow a sufficient flux of air to the combustion front and there exists a minimum required concentration of contaminants such that the soils contain sufficient fuel for the reaction to proceed in a self‐sustaining manner. Further limitations, as well as lessons learned and methods to mitigate these limitations, are presented through a series of case studies. In summary, the successful implementation of STAR will result in >99 percent reduction in contaminant concentrations in treated areas, limited residual contaminant mass, reduced groundwater contaminant mass flux which can be addressed through monitored natural attenuation; and an enhanced site exit strategy, reduced lifecycle costs, and reduced risk. ©2016 Wiley Periodicals, Inc. 相似文献
564.
One of the most significant junctures in natural resource planning and management in recent years has been the emergence of community-based natural resource management (CBNRM). The central focus of CBNRM is the environment, of course. However, it explicitly considers the local economy and community as well. It is a highly participatory approach to local, place-based projects, programs and policies aimed simultaneously at environmental and community health. This paper is an attempt to shed light on what happens in the local economy and community as a result of pursuing a CBNRM strategy. Oregon has been in the vanguard in putting CBNRM into operation. A key example is the state's experience with local watershed councils and the state agency that supports them, the Oregon Watershed Enhancement Board (OWEB). Drawing from a larger study of Oregon's watershed councils, we ask and answer the questions: ‘What direct contribution do watershed councils make to the local economies of Oregon?’; ‘Do watershed councils contribute to ‘civic engagement’ in Oregon?’ and ‘Do they enhance individuals' and communities’ capacity to engage in public issues beyond watershed council activities?’ 相似文献
565.
Wet Strength and Water Resistance of Modified Soy Protein Adhesives and Effects of Drying Treatment 总被引:7,自引:0,他引:7
Zhikai Zhong X. Susan Sun Donghai Wang Jo A. Ratto 《Journal of Polymers and the Environment》2003,11(4):137-144
Soy protein isolate (SPI) was modified using sodium dodecyl sulfate (SDS) and guanidine hydrochloride (GuHCl). Adhesion performance of the modified SPI on fiberboard was studied. The Water-soluble mass of the modified SPI adhesives was examined following modified ASTM D5570. The SDS-modified SPI containing 91% protein had a water-soluble mass of 1.7%. To be considered a water-resistant adhesive, the water-soluble mass of adhesive should be less than 2%. The wet shear strength test showed 100% cohesive failure within fiberboard, indicating that the modified SPI has good water resistance. The effect of drying treatment on adhesion performance of the SDS-modified SPI on fiberboard was then investigated. Drying treatment significantly affected the final adhesion performance. Shear strength did not change much, but the percentage of cohesive failure within fiberboard increased markedly as drying temperature increased. All the unsoaked, soaked, and wet specimens glued by the adhesives treated at 70° or 90°C had 100% cohesive failure within fiberboard. Viscosity also increased greatly with an increase in drying temperature. This information will be useful in developing low-cost adhesive processing system in the future. 相似文献
566.
Martin M. Karpiscak Kennith E. Foster Susan B. Hopf John M. Bancroft Peter J. Warshall 《Journal of the American Water Resources Association》1994,30(2):219-227
ABSTRACT: Water hyacinth (Eichhornia crassipes L.) has shown to be effective in the treatment of municipal wastewater in a pilot study begun in January 1989 by the Pima County Wastewater Management Department and researchers associated with The University of Arizona's Office of Arid Lands Studies in the Sonoran Desert near Tucson. The influent pumped into the pilot facility's six raceways (ponds) typically has been treated secondary effluent diverted from a conventional treatment facility, although primary effluent from the same facility also has been treated. The Secondary Influent Treatment System has met the Arizona Department of Environmental Quality (ADEQ) tertiary standard for BOD5 and TSS of 10 mg/l for every month of its operation since March 1990; the Primary Influent Treatment System met the ADEQ secondary standard for BOD5 and TSS of 30 mg/1 for most of the 10 months it was in operation. 相似文献
567.
Ryoko Matsumoto Shigeru Suzuki Khisigjav Tsogtbaatar Susan E. Evans 《Die Naturwissenschaften》2009,96(2):233-242
New material of the enigmatic diapsid Khurendukhosaurus is described from the Mongolian type locality, Khuren Dukh, providing additional data on the vertebral column, pelvis, and
hind limb. It confirms the choristoderan status of the genus and permits a more detailed phylogenetic analysis that supports
a relationship between Khurendukhosaurus and the long-necked Asian Hyphalosauridae. The existence of tall caudal neural spines implies that Khurendukhosaurus was a deep-tailed swimmer. This and the open sacral costocentral sutures suggest a primarily aquatic lifestyle.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Institutional abbreviations MNHN BL, Museum National d’Histoire Naturelle, Paris, France; MPC, Mongolian Paleontological Center; PIN, Paleontologicheski
Institut, Akademii Nauk, Moscow; HMNS, Hayashibara Museum of Natural Sciences, Okayama, Japan. 相似文献
568.
Nga Nguyen Russell C. Van Horn Susan C. Alberts Jeanne Altmann 《Behavioral ecology and sociobiology》2009,63(9):1331-1344
Close associations between adult males and lactating females and their dependent infants are not commonly described in non-monogamous
mammals. However, such associations [sometimes called “friendships” (Smuts 1985)] are regularly observed in several primate species in which females mate with multiple males during the fertile period.
The absence of mating exclusivity among “friends” suggests that males should invest little in infant care, raising questions
about the adaptive significance of friendship bonds. Using data from genetic paternity analyses, patterns of behavior, and
long-term demographic and reproductive records, we evaluated the extent to which friendships in four multi-male, multi-female
yellow baboon (Papio cynocephalus) groups in Amboseli, Kenya represent joint parental care of offspring or male mating effort. We found evidence that mothers
and infants benefited directly from friendships; friendships provided mother–infant dyads protection from harassment from
other adult and immature females. In addition, nearly half of all male friends were the genetic fathers of offspring and had
been observed mating with mothers during the days of most likely conception for those offspring. In contrast, nearly all friends
who were not fathers were also not observed to consort with the mother during the days of most likely conception, suggesting
that friendships between mothers and non-fathers did not result from paternity confusion. Finally, we found no evidence that
prior friendship increased a male’s chances of mating with a female in future reproductive cycles. Our results suggest that,
for many male–female pairs at Amboseli, friendships represented a form of biparental care of offspring. Males in the remaining
friendship dyads may be trading protection of infants in exchange for some resources or services not yet identified. Our study
is the first to find evidence that female primates gain social benefits from their early associations with adult males.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
569.
At small scales, areas with high native diversity are often resistant to invasion, while at large scales, areas with more native species harbor more exotic species, suggesting that different processes control the relationship between native and exotic species diversity at different spatial scales. Although the small-scale negative relationship between native and exotic diversity has a satisfactory explanation, we lack a mechanistic explanation for the change in relationship to positive at large scales. We investigated the native-exotic diversity relationship at three scales (range: 1-4000 km2) in California serpentine, a system with a wide range in the productivity of sites from harsh to lush. Native and exotic diversity were positively correlated at all three scales; it is rarer to detect a positive relationship at the small scales within which interactions between individuals occur. However, although positively correlated on average, the small-scale relationship between native and exotic diversity was positive at low-productivity sites and negative at high-productivity sites. Thus, the change in the relationship between native and exotic diversity does not depend on spatial scale per se, but occurs whenever environmental conditions change to promote species coexistence rather than competitive exclusion. This occurred within a single spatial scale when the environment shifted from being locally unproductive to productive. 相似文献
570.
Widespread contribution of methane-cycle bacteria to the diets of lake profundal chironomid larvae 总被引:1,自引:0,他引:1
Reports of unexpectedly 13C-depleted chironomid larvae in lakes have led to an hypothesis that significant transfer of detrital organic matter to chironomid larvae may occur via methane-cycle bacteria. However, to date little is known of how such transfer might vary across species and lakes. We gathered data from 87 lakes to determine how widespread this phenomenon might be and to define boundaries for its likely magnitude. Carbon stable isotope values of chironomid larvae varied greatly between taxa. Very marked 13C-depletion was evident only in certain taxa, especially Chironomus plumosus, C. anthracinus, and C. tenuistylus, all characteristic of eutrophic or dystrophic lakes and known to be tolerant of low oxygen conditions. Furthermore, marked 13C-depletion was only found in larvae from lakes in which late-summer hypolimnetic oxygen depletion near the sediment surface was below an apparent threshold concentration of 2-4 mg O2/L. Similarly, application of a two-source mixing model suggested that methanotrophic bacteria made the greatest contribution to profundal chironomid growth (0-70% of larval carbon) when the late-summer oxygen concentration dropped below approximately 2 mg O2/L. Our study demonstrates that methane-derived carbon is an important, but often neglected, contribution to the flux of carbon through the food webs of many productive or dystrophic lakes. 相似文献