16 research outputs found

    The effect of functional unit and co-product handling methods on life cycle assessment of an algal biorefinery

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    Microalgae are a promising feedstock for sustainable fuel and nutritional products. To be economically viable, algal biorefineries will need to produce multiple products, such as nutraceuticals and animal feed, in addition to fuel. Life cycle assessment (LCA) has been applied widely to algal biorefineries, but results vary across studies. Here we address two methodological challenges that can lead to variability in LCAs of multi-product algal biorefineries: the choice of functional unit and the method used to handle co-products. LCA was conducted for an algal biorefinery that produces two representative products—fuel and animal feed—using three functional units: (1) 1 MJ fuel, (2) 1 kg animal feed, and (3) 1 ha of production area, coupled with the system expansion method. For the fuel-based functional unit, the system expansion method was compared to impact allocation based on mass, energy, and market value of the biorefinery products. The choice of functional unit affects the results for several environmental indicators. For ecosystem quality, the choice of functional unit can change the overall balance of environmental impacts from harmful to beneficial. The effect of functional unit on climate change depends on the boundary considered in the model—i.e., “well to gate” or “well to wheels”. When a fuel-based functional unit is used, the choice of co-product handling method (i.e., allocation versus the system expansion method) affects environmental impacts, such as ecosystem quality and climate change, differently. For LCAs that use a fuel-based functional unit to compare algal biofuel to other fuels, multiple co-product handling methods should be analyzed and presented to stakeholders. A land based functional unit coupled with the system expansion method can be used to improve LCAs that compare among multi-product algal biorefineries

    Prevalence of Listeria monocytogenes, Salmonella spp., Shiga toxin-producing Escherichia coli, and Campylobacter spp. in raw milk in the United States between 2000 and 2019: A systematic review and meta-analysis

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    Raw (unpasteurized) milk is available for sale and direct human consumption within some states in the United States (US); it cannot be sold or distributed in interstate commerce. Raw milk may contain pathogenic microorganisms that, when consumed, may cause illness and sometimes may result in death. No comprehensive review for prevalence and levels of the major bacterial pathogens in raw milk in the US exists. The objective of the present research was to systematically review the scientific literature published from 2000 to 2019 to estimate the prevalence and levels of Listeria monocytogenes, Salmonella spp., Shiga toxin-producing Escherichia coli (STEC), and Campylobacter spp. in raw milk in the US. Peer-reviewed studies were retrieved systematically from PubMed®, Embase®, and Web of ScienceTM. The unique complete nonduplicate references were uploaded into the Health Assessment Work Collaborative (HAWC). Based on the selection criteria, twenty studies were included in the systematic review and meta-analysis. Comprehensive Meta-Analysis (CMA) was used for statistical analyses, specifically, random effects meta-analyses were used to synthesize raw bulk tank milk (BTM) and milk filters (MF) data. Data from studies using culture and non–culture-based detection methods were included. Forest plots generated in CMA (Biostat, Englewood, NJ) were used to visualize the results. The average prevalence (event rate) of L. monocytogenes, Salmonella spp., STEC, and Campylobacter spp. in raw BTM in the US was estimated at 4.3% (95% confidence intervals [CIs], 2.8–6.5%), 3.6% (95% CIs, 2.0–6.2%), 4.3% (95% CIs, 2.4–7.4%), and 6.0% (95% CIs, 3.2–10.9%), respectively. Estimated prevalence was generally larger in MF than in BTM. There was not enough data to perform a meta-analysis for the prevalence or levels of pathogens in raw milk from retail establishments or other milk categories

    A global profile of germline gene expression in C. elegans

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    As a first step in determining the gene expression patterns that underlie the development of C. elegans, we have used DNA microarrays to identify genes whose expression is increased in the germline. The germline differs from somatic tissue in several ways. The germline is totipotent because it generates every tissue in an individual of the next generation. It is also immortal, since it perpetuates itself indefinitely by producing subsequent generations. In contrast, every cell in the soma differentiates into a particular type and survives only as long as the individual. The complete molecular depiction of germline gene expression generates an overview of all the biological processes in that tissue. In addition, th

    No-man's Land: Adoption Storied Through the Aotearoa/New Zealand Adoption Act 1955

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    © 2016 John Wiley & Sons, Ltd. The Aotearoa/New Zealand Adoption Act 1955 legislated and governed adoption practices from 1955 to 1985. Through an exploration of the historical, cultural and social assumptions underlying the Adoption Act 1955, this article questions how the social power relations complicit with adoption legislation and policy produce and reproduce subject positions for adoptees. In-depth narrative interviews were conducted with 12 adoptees from throughout Aotearoa/New Zealand. The researchers found the legal constitution of adoptees produces them as legitimate; however, they remain 'other' through dominant discourses of heteronormative blood kinship that reiterates their illegitimacy. The legal fiction of their legitimacy as if born to failed to secure them space within normative narratives of kinship and compromised adoptees' ability to take up responsibility as neoliberal citizens. Current New Zealand debate on adoption fails to take account of the experience of adoptees, focusing instead on the rights of married couples, including same-sex couples, to continue practices of adoption. Our analysis informs the critical importance of listening to how adoptees experience repeated exclusions and enduring loss represented by the metaphor of no-man's land
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