Life cycle assessments for waste, part I: Overview, methodology and scoping process

Part I (from three parts) of the series “LCAs for Waste” describes the Dutch hazardous waste management structure, and the goal and scope definition step for a chain-oriented Environmental Impact Assessment (EIA). For about 7 waste sectors, no change in existing policy was foreseen and Dutch legislation required no comparative assertion. For 7 others, a lack of inventory data or methodological problems did not allow for the performance of a meaningful quantitative LCA. For the remaining 7 sectors, LCAs were performed to deal with 12 technology choices. They were based on primary data for the central processes, and literature data for background processes. A slightly adapted approach of the 1992 CML manual was used. System enlargement appeared to be slightly preferable as an allocation method.     

The relationship between ribosomal repeat length and genome size in Vicia

The organization of the ribosomal RNA genes was examined in several species of Vicia in an attempt to determine whether a relationship exists between genome size and ribosomal repeat length. Species within this genus exhibit a sevenfold variation in haploid DNA content. Our data suggest that species with an intermediate genome size maintain one predominant Eco RI class of ribosomal repeat of about 9 kilobases (kb). In contrast, the smallest and largest genomes of Vicia possess one major and several minor classes. The possible relationship between repeat classes among species is discussed. We examined the species with the smallest (V. villosa) and largest (V. faba) genomes in closer detail by R-loop analysis of a satellite DNA from Hoechst 33258 dye-CsCl gradients. Heterogeneity was found in the length of the ribosomal repeat for both species, but no appreciable difference was observed in the distribution of these lengths, which averaged 11–12 kb. This heterogeneity is associated with the nontranscribed spacer region. Intervening sequences were not found in either the 25S or 18S coding regions of the ribosomal repeat of either of these two plants. A putative ribosomal RNA precursor of 7 kb was identified for both species.     

Jack bean meal as biocatalyst for urea biosensors

Summary The construction and response of a novel biosensor for urea are described. This sensor utilizes a layer of jack bean meal immobilized at the surface of an ammonia gassensing probe. The resulting sensor is found to be a viable alternative to the enzyme-based sensor.Visiting from the Department of Chemistry, Otterbein College, Westerville, Ohio as a University of Iowa, Department of Chemistry 1983 Summer Undergraduate Research Fellow.     

A new variety of Draba oreibata (Brassicaceae) from Nevada,U.S.A.

A new variety ofDraba oreibata, var.serpentina, is described, illustrated, and discussed.     

Impact of vaginal microbiome communities on HIV antiretroviral-based pre-exposure prophylaxis (PrEP) drug metabolism

Despite the efficacy of antiretroviral-based pre-exposure prophylactics (PrEP) in men who have sex with men, studies in women have produced widely varying outcomes. Recent evidence demonstrates that vaginal microbial communities are associated with increased HIV acquisition risk and may impact PrEP efficacy. Here, we investigate the mechanisms underlying how vaginal bacteria alter PrEP drug levels and impact HIV infection rates ex vivo. Using cervicovaginal lavages (CVLs) from women with or without bacterial vaginosis (BV), we identified microbial metabolism of PrEP drugs in BV samples through LC-MS/MS analysis of soluble drug levels and metabolite formation in dual T-cell cultures. CVL samples were assessed for microbiome analysis using sequencing of bacterial 16S rRNA genes. We also observed non-Lactobacillus bacteria that are associated with BV may potentially impact PrEP efficacy through increased HIV infection rates in co-cultures containing Lactobacillus or BV bacteria, PrEP drugs, CEM-GFP cells, and HIV-1_LAI virus. Finally, we used these data to develop a novel predictive mathematical simulation modeling system to predict these drug interactions for future trials. These studies demonstrate how dysbiotic vaginal microbiota may impact PrEP drugs and provides evidence linking vaginal bacteria to PrEP efficacy in women.     

Use of monetary wetland value estimates by EPA Clean Water Act Section 404 regulators

U.S. Environmental Protection Agency wetland regulators appear to use monetary estimates of the societal value of wetlands relatively infrequently in Section 404 permit review, enforcement, and compensatory mitigation-related activities. While 52 % of surveyed EPA regulators had used such estimates at least once, only 3 % reported using them frequently. Forty-eight percent said they never used them. Survey respondents indicated that their use of such estimates is inhibited by a lack of relevant information, uncertainty about the scientific validity of estimates, and concerns about the scientific and legal defensibility of estimate use. Respondents said they would be more apt to use estimates in regulatory activities if they perceived agency approval for such use and had access to training and best practices. The barriers and inducements EPA regulators cited largely accord with the literature on the science-policy divide and with the argument that regulatory use of valuation estimates may be inappropriate because research in this arena is not sufficiently advanced.