799 research outputs found

    Chain elongation in anaerobic reactor microbiomes to recover resources from waste

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    Different microbial pathways can elongate the carbon chains of molecules in open cultures of microbial populations (i.e. reactor microbiomes) under anaerobic conditions. Here, we discuss three such pathways: 1. homoacetogenesis to combine two carbon dioxide molecules into acetate; 2. succinate formation to elongate glycerol with one carbon from carbon dioxide; and 3. reverse ÎČ oxidation to elongate short-chain carboxylates with two carbons into medium-chain carboxylates, leading to more energy-dense and insoluble products (e.g. easier to separate from solution). The ability to use reactor microbiomes to treat complex substrates can simultaneously address two pressing issues: 1. providing proper waste management; and 2. producing renewable chemicals and fuels.The authors thank Wolfgang Bucket (MPI Marburg) for assistance with Figure 1. C.M.S. and L.T.A. were supported by the U. S. Army Research Laboratory and the U. S. Army Research Office under contract/grant number W911NF-12-1-0555. H.R. was supported for this work by the Cornell University Agricultural Experiment Station federal formula funds, Project No. NYC-123452 received from the National Institutes for Food and Agriculture (NIFA), U.S. Department of Agriculture. K.R. was supported by the European Research Council Starter Grant Electrotalk and the Multidisciplinary Research Partnership Ghent Bio-Economy. A.J.M.S. was supported by the Chemical Sciences division of the Netherlands Science Foundation (CW-TOP 700.55.343) and the European Research Council (ERC grant 323009)

    Metabarcoding assays for the detection of freshwater mussels (Unionida) with environmental DNA

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    Freshwater mussels of the order Unionida are a widely distributed taxon that are important in maintaining freshwater ecosystems and are also highly imperiled throughout the world. Monitoring of mussel populations with environmental DNA (eDNA) is an attractive alternative to traditional methods because it is noninvasive and requires less labor and taxonomic knowledge from field personnel. We developed eDNA metabarcoding assays specific to freshwater mussels and tested them at six sites in the Clinch River, located in the southeastern United States. Our objective was to determine the utility of eDNA metabarcoding for future monitoring of mussel populations and restoration efforts in this watershed. Two metabarcoding assays that target the mitochondrial DNA regions of the cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit (ND1) genes were developed and tested. Our assays appear to be order specific, amplifying members from the two families found in North America, Unionidae and Margaritiferidae, while not amplifying nontarget fish or other bivalve species. From the field collected samples, our assays together detected 19 species, eight of which are listed as federally endangered. The assays also detected 42%, 58%, and 54% of the species identified by recent quantitative visual mussel surveys at three sampling sites. Increased sampling effort by processing a greater water volume or number of samples will likely increase species detections. These eDNA metabarcoding assays may enable enhanced monitoring of freshwater mussel assemblages and subsequently inform conservation efforts

    Mapping City Visions: Integrating Mega- projects in Urban Development

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    This policy brief explores the mapping of city visions in fast-growing cities in several emerging economies (Brazil, South Africa, India, Peru). As cities have to deal increasingly with both complexity and uncertainty in their development, they are concerned with the future pathways their cities can take. City visions on urban development portray idealized situations as goals for the future, and the maps portraying them are strongly idealized. To get behind these idealized versions of reality, policy makers need to understand how such visions are developed, by whom, and whose realities they reflect

    Recent advances in environmental DNA-based biodiversity assessment and conservation

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    Special issue Environmental DNA‐based biodiversity assessment and conservation management in the Anthropocene.-- 4 pagesKnowledge of species distribution across space and time is critical to ecological conservation and environmental management at the local, regional and global scales (Albert et al., 2021). Traditional morphology-based surveys on either single-celled protists or larger animals and plants are time-consuming and largely expert-dependent (Baird & Hajibabaei, 2012; Liu et al., 2017; Yang et al., 2017). Recently, there has been considerable interest in the detection of environmental DNA (eDNA) fragments to allow species identification and monitoring within different environments, including soil, sediment, water, snow or air (Abdullah et al., 2021; Rees et al., 2014; Xie et al., 2018). The eDNA analysis can be used to detect common, endangered, invasive or rare species (Liu et al., 2019; Sepulveda et al., 2020), and provide a potent tool for elucidating mechanistic insights into ecological and evolutionary processes (Baird & Hajibabaei, 2012; Bohmann et al., 2014; Pawlowski et al., 2021). In past decades, eDNA metabarcoding has been increasingly used to study the present and past biodiversity from population to community levels, and eDNA-based surveys have revolutionized studies in ecology and biodiversity sciences, particularly in aquatic ecosystems (Euclide et al., 2021; Valentini et al., 2016). The significance of various human activities has resulted in multiple interacting environmental stressors in all types of ecosystems (Pukk et al., 2021; Yang et al., 2022). Such stressors, including global climate change, invasive species, chemical pollution and habitat loss, have led to biodiversity crises and threatened the human sustainability and ecosystem health (Osathanunkul & Minamoto, 2021; Yang et al., 2017). Comprehensive biodiversity assessment and conservation management are prerequisites for addressing these significant challenges in the Anthropocene (Mace et al., 2012; Sepulveda et al., 2020). Indeed, effective biodiversity assessment and conservation management require a deep understanding of organisms’ geographical distributions and their respective roles in ecosystem processes and services (Mo et al., 2021; West et al., 2021). However, researchers and conservation managers have encountered numerous obstacles in answering these fundamental and applied research questions at the local, regional and global scales. The aim of this special issue—Environmental DNA-based biodiversity assessment and conservation—was to provide a selection of studies that highlight the utility and diversity of eDNA-based research for biodiversity assessment and conservation management within marine and freshwater ecosystems. This special issue includes 12 articles that advance our knowledge of eDNA. Together, these studies deliver compelling evidence for successful applications of eDNA-based surveys in aquatic ecosystems in the AnthropoceneThis work was supported by the National Natural Science Foundation of China (91851104) and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA23040302)With the institutional support of the ‘Severo OchoaCentre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

    Loss of fibrinogen in zebrafish results in an asymptomatic embryonic hemostatic defect and synthetic lethality with thrombocytopenia

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148369/1/jth14391.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148369/2/jth14391-sup-0001-Supinfo.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148369/3/jth14391_am.pd

    Understanding young people's transitions in university halls through space and time

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    This article contributes to the theoretical discussion about young people's transitions through space and time. Space and time are complex overarching concepts that have creative potential in deepening understanding of transition. The focus of this research is young people's experiences of communal living in university halls. It is argued that particular space-time concepts draw attention to different facets of experience and in combination deepen the understanding of young people's individual and collective transitions. The focus of the article is the uses of the space-time concepts 'routine', 'representation', 'rhythm' and 'ritual' to research young people's experiences. The article draws on research findings from two studies in the North of England. © 2010 SAGE Publications

    Immunoarchitecture of the Regenerating Rat Spleen: Effects of Partial Splenectomy and Heterotopic Autotransplantation

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    To investigate the microstructure of in situ (eutopic) and autotransplanted (ectopic) splenic remnants, adult Sprague-Dawley rats were studied 60 days after 1) subtotal (~80%) splenectomy, 2) total splenectomy followed by single or multiple remnant intraperitoneal autotransplantation, or 3) sham operation. Total nucleated cell counts were determined in excised splenic remnants, and immunohistochemical staining using monoclonal antibodies to rat B-and T-cell antigens was performed in serial tissue sections. Immunoarchitecture of eutopic remnants was indistinguishable from that of intact spleens and total nucleated cell counts remained proportional to weight. In contrast, ectopic remnants showed sparsity and abnormal mixing of B and T lymphocyte subpopulations with widespread loss of follicles and periarteriolar lymphoid sheaths in addition to lower density and marked reduction of total nucleated cells. These findings provide immunohistologic evidence that preservation of intact vasculature is critical to splenic architecture, which may account in part for the demonstrable functional inferiority of ectopic remnants

    Estradiol and Bisphenol A Stimulate Androgen Receptor and Estrogen Receptor Gene Expression in Fetal Mouse Prostate Mesenchyme Cells

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    doi:10.1289/ehp.9804Hormonal alterations during development have lifelong effects on the prostate gland. Endogenous estrogens, including 17ÎČ-estradiol (E2), and synthetic estrogenic endocrine disruptors, such as bisphenol A (BPA), have similar effects on prostate development. Increasing exposure to estrogens within the low-dose, physiologic range results in permanent increases in the size and androgen responsiveness of the prostate, whereas exposure within the high-dose, pharmacologic range has the opposite effects
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