155 research outputs found

    Development of Oxidative Lime Pretreatment and Shock Treatment to Produce Highly Digestible Lignocellulose for Biofuel and Ruminant Feed Applications

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    At present, the United States generates biofuels (ethanol) from corn grain. Unfortunately, low crop yields and limited growth regions result in limited availability. Furthermore, the use of staple food crops for ethanol production has generated a highly controversial food vs. fuel debate. Because of its high abundance and relatively low cost, lignocellulosic biomass is a promising alternative feedstock for biofuel production; however, structural features of lignocellulose limit accessibility of enzymes or microorganisms. These structural barriers include high lignin content, acetyl groups on hemicellulose, high cellulose crystallinity, cellulose degree of polymerization, and small pore volume. To overcome these barriers, a variety of pretreatment processes (chemical and mechanical) have been developed. Oxidative-lime pretreatment (OLP) is highly effective at reducing lignin content and removing acetyl groups from hemicellulose. Combining OLP with a mechanical treatment process greatly enhances the enzymatic digestibility of lignocellulose. Recommended OLP conditions were determined for Dacotah (120 °C, 6.89-bar O2, 240 min) and Alamo (110 °C, 6-89-bar O2, 240 min) switchgrass. Using recommended conditions, 72-h glucan digestibilities (g glucan hydrolyzed/100 g glucan in raw biomass; 15 filter paper units/g raw glucan) of 85.2 and 88.5 were achieved for Dacotah and Alamo, respectively. Adding ball milling to OLP further enhanced glucan digestibility to 91.1 (Dacotah) and 90.0 (Alamo). In previous studies, shock treatment achieved promising results, but was often inconsistent. This work refined shock treatment with a focus on using consistent procedures and performance analysis. The combination of OLP and shock treatment enhanced the 72-h glucan digestibility of several promising biomass feedstocks: bagasse (74.0), corn stover (92.0), poplar wood (94.0), sorghum (71.8), and switchgrass (89.0). Highly digestible lignocellulose can also be used as ruminant animal feed. Shock treatment plus OLP increased the total digestible nutrients (TDNN; g nutrients digested/100 g organic matter) of corn stover from 51.9 (untreated) to 72.6. Adding in pre-washed corn stover solubles to produce a combined feed (17.8 percent corn stover solubles and 82.2 percent shock OLP corn stover) increased TDNN to 74.9. Mixing in enough solubilized protein to match the crude protein content of corn grain further improved TDNN to 75.5, only 12.6 less than corn grain

    1998 Fine Art Graduation Exhibition Catalogue

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    Fine Art ProgramFanshawe College McIntosh GalleryUniversity of Western Ontario April 16th to May 3rd., 1998 Guest Speaker: Michael P. Gibson Director: Michael Gibson Galleryhttps://first.fanshawec.ca/famd_design_fineart_gradcatalogues/1009/thumbnail.jp

    The Drosophila phenotype ontology

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    BACKGROUND: Phenotype ontologies are queryable classifications of phenotypes. They provide a widely-used means for annotating phenotypes in a form that is human-readable, programatically accessible and that can be used to group annotations in biologically meaningful ways. Accurate manual annotation requires clear textual definitions for terms. Accurate grouping and fruitful programatic usage require high-quality formal definitions that can be used to automate classification. The Drosophila phenotype ontology (DPO) has been used to annotate over 159,000 phenotypes in FlyBase to date, but until recently lacked textual or formal definitions. RESULTS: We have composed textual definitions for all DPO terms and formal definitions for 77% of them. Formal definitions reference terms from a range of widely-used ontologies including the Phenotype and Trait Ontology (PATO), the Gene Ontology (GO) and the Cell Ontology (CL). We also describe a generally applicable system, devised for the DPO, for recording and reasoning about the timing of death in populations. As a result of the new formalisations, 85% of classifications in the DPO are now inferred rather than asserted, with much of this classification leveraging the structure of the GO. This work has significantly improved the accuracy and completeness of classification and made further development of the DPO more sustainable. CONCLUSIONS: The DPO provides a set of well-defined terms for annotating Drosophila phenotypes and for grouping and querying the resulting annotation sets in biologically meaningful ways. Such queries have already resulted in successful function predictions from phenotype annotation. Moreover, such formalisations make extended queries possible, including cross-species queries via the external ontologies used in formal definitions. The DPO is openly available under an open source license in both OBO and OWL formats. There is good potential for it to be used more broadly by the Drosophila community, which may ultimately result in its extension to cover a broader range of phenotypes

    Technical Data Interoperability (TDI) Pathfinder Via Emerging Standards

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    The TDI project (TDI) investigates trending technical data standards for applicability to NASA vehicles, space stations, payloads, facilities, and equipment. TDI tested COTS software compatible with a certain suite of related industry standards for capabilities of individual benefits and interoperability. These standards not only esnable Information Technology (IT) efficiencies, but also address efficient structures and standard content for business processes. We used source data from generic industry samples as well as NASA and European Space Agency (ESA) data from space systems

    Critical reflections on asymptotically safe gravity

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    Asymptotic safety is a theoretical proposal for the ultraviolet completion of quantum field theories, in particular for quantum gravity. Significant progress on this program has led to a first characterization of the Reuter fixed point. Further advancement in our understanding of the nature of quantumspacetime requires addressing a number of open questions and challenges. Here, we aim at providing a critical reflection on the state of the art in the asymptotic safety program, specifying and elaborating on open questions of both technical and conceptual nature. We also point out systematic pathways, in various stages of practical implementation, toward answering them. Finally, we also take the opportunity to clarify some common misunderstandings regarding the program

    FlyBase at 25: looking to the future.

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    Since 1992, FlyBase (flybase.org) has been an essential online resource for the Drosophila research community. Concentrating on the most extensively studied species, Drosophila melanogaster, FlyBase includes information on genes (molecular and genetic), transgenic constructs, phenotypes, genetic and physical interactions, and reagents such as stocks and cDNAs. Access to data is provided through a number of tools, reports, and bulk-data downloads. Looking to the future, FlyBase is expanding its focus to serve a broader scientific community. In this update, we describe new features, datasets, reagent collections, and data presentations that address this goal, including enhanced orthology data, Human Disease Model Reports, protein domain search and visualization, concise gene summaries, a portal for external resources, video tutorials and the FlyBase Community Advisory Group

    Novel retrotransposed imprinted locus identified at human 6p25

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    Differentially methylated regions (DMRs) are stable epigenetic features within or in proximity to imprinted genes. We used this feature to identify candidate human imprinted loci by quantitative DNA methylation analysis. We discovered a unique DMR at the 5′-end of FAM50B at 6p25.2. We determined that sense transcripts originating from the FAM50B locus are expressed from the paternal allele in all human tissues investigated except for ovary, in which expression is biallelic. Furthermore, an antisense transcript, FAM50B-AS, was identified to be monoallelically expressed from the paternal allele in a variety of tissues. Comparative phylogenetic analysis showed that FAM50B orthologs are absent in chicken and platypus, but are present and biallelically expressed in opossum and mouse. These findings indicate that FAM50B originated in Therians after divergence from Prototherians via retrotransposition of a gene on the X chromosome. Moreover, our data are consistent with acquisition of imprinting during Eutherian evolution after divergence of Glires from the Euarchonta mammals. FAM50B expression is deregulated in testicular germ cell tumors, and loss of imprinting occurs frequently in testicular seminomas, suggesting an important role for FAM50B in spermatogenesis and tumorigenesis. These results also underscore the importance of accounting for parental origin in understanding the mechanism of 6p25-related diseases
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