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251.
252.
Joyce M Simpson Peter G Stroot Steve Gelman Inan Beydilli Sandra Dudley Daniel B Oerther 《Water environment research》2006,78(8):864-871
Molecular biology tools targeting 16S ribosomal RNA (16S rRNA) were used to identify a predominant bacterial population in a full-scale dairy wastewater activated sludge system suffering from poor biosolids separation. Gram and acridine orange staining indicated that viable, Gram-positive microorganisms were present in samples removed from the influent waste stream and represented approximately 50% of total cell counts in samples removed from the mixed liquor. Subsequently, the "full-cycle 16S rRNA approach" showed that phylogenetic relatives of Paenibacillus spp., a low guanine-plus-cytosine percent DNA-content, Gram-positive microorganism, represented up to 30% of total 4,6-diamidino-2-phenylindole (DAPI)-stained cell counts in samples of mixed liquor. Although fluorescent in situ hybridizations with 16S rRNA-targeted oligonucleotide hybridization probes identified Paenibacillus-like spp. in samples removed from the influent waste stream, their abundance was less than 10% of total stained cell counts. Results of this study suggest that Paenibacillus-like spp. were present in low abundance in the influent waste stream, increased in relative abundance within the treatment system, and should be examined further as a candidate bacterial population responsible for poor biosolids separation. This study demonstrates that the full-cycle 16S rRNA approach can be used to identify candidate bacterial populations that may be responsible for operational upsets in full-scale activated sludge systems without prior information from cultivation or microscopic analyses. 相似文献
253.
Defining Indicators and Standards for Tourism Impacts in Protected Areas: Cape Range National Park,Australia 总被引:2,自引:0,他引:2
Visitors’ perceptions of impacts and acceptable standards for environmental conditions can provide essential information for
the sustainable management of tourist destinations, especially protected areas. To this end, visitor surveys were administered
during the peak visitor season in Cape Range National Park, on the northwest coast of Western Australia and adjacent to the
iconic Ningaloo Reef. The central focus was visitors’ perceptions regarding environmental conditions and standards for potential
indicators. Conditions considered of greatest importance in determining visitors’ quality of experience included litter, inadequate
disposal of human waste, presence of wildlife, levels of noise, and access to beach and ocean. Standards were determined,
based on visitors’ perceptions, for a range of site-specific and non-site-specific indicators, with standards for facilities
(e.g., acceptable number of parking bays, signs) and for negative environmental impacts (e.g., levels of littering, erosion)
sought. The proposed standards varied significantly between sites for the facilities indicators; however, there was no significant
difference between sites for environmental impacts. For the facilities, the standards proposed by visitors were closely related
to the existing situation, suggesting that they were satisfied with the status quo. These results are considered in the context
of current research interest in the efficacy of visitor-derived standards as a basis for protected area management. 相似文献
254.
Septevani Athanasia Amanda Burhani Dian Sampora Yulianti Indriyati Shobih Rosa Erlyta Septa Sondari Dewi Margyaningsih Nur Ita Septiyani Melati Yurid Fitra Handayani Aniek Sri 《Journal of Polymers and the Environment》2022,30(9):3901-3913
Journal of Polymers and the Environment - Cellulose nanopaper (CNP) is a new potential candidate for flexible biopolymer substrate made of nanocellulose (NC). We systematically studied the effect... 相似文献
255.
Amanda K. Pettersen Ezequiel M. Marzinelli Peter D. Steinberg Melinda A. Coleman 《Conservation biology》2022,36(2):e13815
Preserving biodiversity over time is a pressing challenge for conservation science. A key goal of marine protected areas (MPAs) is to maintain stability in species composition, via reduced turnover, to support ecosystem function. Yet, this stability is rarely measured directly under different levels of protection. Rather, evaluations of MPA efficacy generally consist of static measures of abundance, species richness, and biomass, and rare measures of turnover are limited to short-term studies involving pairwise (beta diversity) comparisons. Zeta diversity is a recently developed metric of turnover that allows for measurement of compositional similarity across multiple assemblages and thus provides more comprehensive estimates of turnover. We evaluated the effectiveness of MPAs at preserving fish zeta diversity across a network of marine reserves over 10 years in Batemans Marine Park, Australia. Snorkel transect surveys were conducted across multiple replicated and spatially interspersed sites to record fish species occurrence through time. Protection provided by MPAs conferred greater stability in fish species turnover. Marine protected areas had significantly shallower decline in zeta diversity compared with partially protected and unprotected areas. The retention of harvested species was four to six times greater in MPAs compared with partially protected and unprotected areas, and the stabilizing effects of protection were observable within 4 years of park implementation. Conversely, partial protection offered little to no improvement in stability, compared with unprotected areas. These findings support the efficacy of MPAs for preserving temporal fish diversity stability. The implementation of MPAs helps stabilize fish diversity and may, therefore, support biodiversity resilience under ongoing environmental change. 相似文献
256.
Nicácio Pedro H. M. Severo Amanda M. C. Barros Ana B. S. Albuquerque Ananda K. C. Wellen Renate M. R. Koschek Katharina 《Journal of Polymers and the Environment》2022,30(9):3840-3851
Journal of Polymers and the Environment - Poly(lactic acid) (PLA) and PLA/5% Babassu compounds were molten mixed, afterwards aged at temperatures ranging from 50 to 90 °C during 15 to... 相似文献