289 research outputs found

    "One card to rule them all:" Towards a Critical Understanding of New Fare Collection Technology

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    Payments for public transit are changing, as agencies adapt to the near-ubiquity of smartphones as well as credit- and debit-cards in order to secure fare revenues. These developments have enabled many transit agencies in the U.S. to implement new fare collection technology (NFC). Previous forms of fare collection, which relied on paper tickets, tokens and magnetic-striped cards, are giving way to “automated” and “smart” modes of payment via smartcards and mobile apps. In their roll-out of these technologies, transit agencies typically claim that they will operationalize “convenient” and “seamless” forms of mobility through their chosen mode of fare collection. However, these technologies serve instead as a “fix” for transit agencies, which employ light infrastructure investments that support a market for private mobility services. While NFC technology shapes public transit to serve capitalist imperatives, it also must contend with the social infrastructures which also shape urban mobility

    Metabolic Fingerprint Analysis of Cytochrome b5-producing E. coli N4830-1 Using FT-IR Spectroscopy

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    Optimization of recombinant protein expression in bacteria is an important task in order to increase protein yield while maintaining the structural fidelity of the product. In this study, we employ Fourier transform infrared (FT-IR) spectroscopy as a high throughput metabolic fingerprinting approach to optimize and monitor cytochrome b 5 (CYT b 5) production in Escherichia coli N4830-1, as the heterologous host. Cyt b5 was introduced as a plasmid with between 0 and 6 copies under a strong promoter. The FT-IR spectroscopy results combined with multivariate chemometric analysis illustrated discriminations among culture conditions as well as revealing features that correlated to the different cytb 5 gene copy numbers. The second derivative of the FT-IR spectral data allowed for the quantitative detection of Cyt b5 directly inside the intact cells without the need for extraction, and highlighted changes in protein secondary structure that was directly correlated to the cytb 5 gene copy number and protein content, and was in complete agreement with quantitative findings of standard traditional techniques such as SDS-PAGE and western blot analysis

    Metaphylogenomic and Potential Functionality of the Limpet <i>Patella pellucida</i>’s Gastrointestinal Tract Microbiome

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    This study investigated the microbial diversity associated with the digestive tract of the seaweed grazing marine limpet Patella pellucida. Using a modified indirect DNA extraction protocol and performing metagenomic profiling based on specific prokaryotic marker genes, the abundance of bacterial groups was identified from the analyzed metagenome. The members of three significantly abundant phyla of Proteobacteria, Firmicutes and Bacteroidetes were characterized through the literature and their predicted functions towards the host, as well as potential applications in the industrial environment assessed

    Gasification of Miscanthus x giganteus Pellets in a Fixed bed Pilot-scale Unit

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    Gasification of Miscanthus x giganteus (Mxgig), is highly promising due to the high efficiency of the process and the many advantageous properties of this crop. Pilot-scale, fixed bed gasification studies were performed utilizing this fuel at three temperatures (750, 850, and 950 degrees C) to determine the process effects of temperature on gas quality and tar yields. Simple thermodynamic equilibrium modeling was successfully applied to the pilot-scale gasification process. The Mxgig crop performed well, with best process stability reached at temperatures of 800 degrees C or higher. Average calorific values of the product gases were highest at around 850 degrees C at 5.2 MJ.m(-3). Tar yields gradually increased with increasing temperature and dropped after 900 degrees C. The presented thermodynamic equilibrium model conformed well with experimental results, deviating little in terms of O-2, CO2, H-2, and CH4 and no more than 8.1% in the case of CO. This indicates that simple modeling methods can be utilized to predict gas compositions for the pilot-scale.Web of Science6art. no. UNSP 9

    Task 28: Web Accessible APIs in the Cloud Trade Study

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    This study explored three candidate architectures for serving NASA Earth Science Hierarchical Data Format Version 5 (HDF5) data via Hyrax running on Amazon Web Services (AWS). We studied the cost and performance for each architecture using several representative Use-Cases. The objectives of the project are: Conduct a trade study to identify one or more high performance integrated solutions for storing and retrieving NASA HDF5 and Network Common Data Format Version 4 (netCDF4) data in a cloud (web object store) environment. The target environment is Amazon Web Services (AWS) Simple Storage Service (S3).Conduct needed level of software development to properly evaluate solutions in the trade study and to obtain required benchmarking metrics for input into government decision of potential follow-on prototyping. Develop a cloud cost model for the preferred data storage solution (or solutions) that accounts for different granulation and aggregation schemes as well as cost and performance trades

    Fructan synthesis, accumulation, and polymer traits I:Festulolium chromosome substitution lines

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    The fructans found as storage carbohydrates in temperate forage grasses have a physiological role in regrowth and stress tolerance. They are also important for the nutritional value of fresh and preserved livestock feeds, and are potentially useful as feedstocks for biorefining. Seasonal variation in fructan content and the capacity for de novo fructan synthesis have been examined in a Festulolium monosomic substitution line family to investigate variation in the polymers produced by grasses in the ryegrass-fescue complex. There were significant differences between ryegrass and fescue. Fescue had low polymeric fructan content and a high oligomer/polymer ratio; synthesis of polymers longer than degree of polymerisation 6 (DP6) from oligomers was slow. However, extension of polymer length from DP10/DP20 upwards appeared to occur relatively freely, and, unlike ryegrass, fescue had a relatively even spread of polymer chain lengths above DP20. This included the presence of some very large polymers. Additionally fescue retained high concentrations of fructan, both polymeric and oligomeric, during conditions of low source/high sink demand. There were indications that major genes involved in the control of some of these traits might be located on fescue chromosome 3 opening the possibility to develop grasses optimised for specific applications
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