19 research outputs found

    Low Energy Nuclear Reaction Aircraft- 2013 ARMD Seedling Fund Phase I Project

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    This report serves as the final written documentation for the Aeronautic Research Mission Directorate (ARMD) Seedling Fund's Low Energy Nuclear Reaction (LENR) Aircraft Phase I project. The findings presented include propulsion system concepts, synergistic missions, and aircraft concepts. LENR is a form of nuclear energy that potentially has over 4,000 times the energy density of chemical energy sources. It is not expected to have any harmful emissions or radiation which makes it extremely appealing. There is a lot of interest in LENR, but there are no proven theories. This report does not explore the feasibility of LENR. Instead, it assumes that a working system is available. A design space exploration shows that LENR can enable long range and high speed missions. Six propulsion concepts, six missions, and four aircraft concepts are presented. This report also includes discussion of several issues and concerns that were uncovered during the study and potential research areas to infuse LENR aircraft into NASA's aeronautics research

    A review of web-based support systems for students in higher education

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    Abstract Background Recent evidence suggests that there is an increasing need for accessible and anonymous services to support higher education (HE) students suffering from psychological and/or academic difficulties. Such difficulties can lead to several negative outcomes, including poor academic performance, sub-optimal mental health, reduced study satisfaction, and dropout from study. Currently, universities in the UK lack financial resources and the on-campus mental health services traditionally offered to students are increasingly economically unsustainable. Compounded by the perceived stigma of using such services, mental health providers have been driven to address the escalating needs of students through online services. Methods In this paper, we review online support systems identified through a literature search and a manual search of references in the identified papers. Further systems were identified through web searches, and systems still in development were identified by consultation with researchers in the field. We accessed systems online to extract relevant information, regarding the main difficulties addressed by the systems, the psychological techniques used and any relevant research evidence to support their effectiveness. Conclusion A large number of web-based support systems have been developed to support mental health and wellbeing, although few specifically target HE students. Further research is necessary to establish the effectiveness of such interventions in providing a cost-effective alternative to face-to-face therapy, particularly in certain settings such as HE institutions

    The Architecture Selection, Design, and Discharge Modeling of a Passive Compensation, Iron-Core, Two-Phase, Permanent Magnet Compulsator to Power a Small Railgun Platform

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    The goal of this project was to design and build a compensated pulsed alternator, or compulsator, to power the Cal Poly Electromagnetic Railgun Mark 1.1. This project examines the feasibility of implementing mechanical pulsed power supplies for repeatable use with a railgun load for orbital debris hypervelocity testing. The final system architecture chosen was a passively compensated, iron-core, 2-phase, permanent magnet compulsator. The Cal Poly Compulsator will be capable of storing 45 kJ of mechanical energy with a peak operating speed of 5,000 rpm at 190 V. Theoretical calculations resulted in the following predicted electrical performance values: a peak output current discharge of 33 kA, peak output power of 3.3 MW, and a pulse width of 4.3 ms. These values result in moving a 1 g projectile to a final velocity of 410 m/s. Experimental testing and comparison will occur once the system has been assembled. The architecture selection process, description of the mathematical modeling of the system, the mechanical design, and some of the manufacturing processes undertaken during this project are included in the discussion. This paper serves as a compilation of introductory information to assist individuals who are just starting their research into compulsators

    System Design Considerations and the Feasibility of Passively Compensated, Permanent Magnet, Iron-Core Compulsators to Power Small Railgun Platforms

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    This thesis provides insight into the different aspects of compulsator design for use with railgun systems. Specifically, the design space is explored for passively compensated, permanent magnet iron-core compulsators. Seven design parameters are varied within a compulsator model developed for the Cal Poly Compulsator (CPCPA). The Matlab code for this model is included within the appendix. Efforts were made to compare and validate this compulsator model to published data from existing systems. The compulsator model was found to match closely with discharge pulse length, but resulted in lower values for peak current and projectile velocity by 50% and 30% respectively when compared to published data

    Obituaries: M - Ma Folder

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    105 pages of subject files containing and related to Obituaries: M - M

    Cystatin F attenuates neuroinflammation and demyelination following murine coronavirus infection of the central nervous system

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    BackgroundCystatin F is a secreted lysosomal cysteine protease inhibitor that has been implicated in affecting the severity of demyelination and enhancing remyelination in pre-clinical models of immune-mediated demyelination. How cystatin F impacts neurologic disease severity following viral infection of the central nervous system (CNS) has not been well characterized and was the focus of this study. We used cystatin F null-mutant mice (Cst7-/-) with a well-established model of murine coronavirus-induced neurologic disease to evaluate the contributions of cystatin F in host defense, demyelination and remyelination.MethodsWildtype controls and Cst7-/- mice were intracranially (i.c.) infected with a sublethal dose of the neurotropic JHM strain of mouse hepatitis virus (JHMV), with disease progression and survival monitored daily. Viral plaque assays and qPCR were used to assess viral levels in CNS. Immune cell infiltration into the CNS and immune cell activation were determined by flow cytometry and 10X genomics chromium 3' single cell RNA sequencing (scRNA-seq). Spinal cord demyelination was determined by luxol fast blue (LFB) and Hematoxylin/Eosin (H&E) staining and axonal damage assessed by immunohistochemical staining for SMI-32. Remyelination was evaluated by electron microscopy (EM) and calculation of g-ratios.ResultsJHMV-infected Cst7-/- mice were able to control viral replication within the CNS, indicating that cystatin F is not essential for an effective Th1 anti-viral immune response. Infiltration of T cells into the spinal cords of JHMV-infected Cst7-/- mice was increased compared to infected controls, and this correlated with increased axonal damage and demyelination associated with impaired remyelination. Single-cell RNA-seq of CD45 + cells enriched from spinal cords of infected Cst7-/- and control mice revealed enhanced expression of transcripts encoding T cell chemoattractants, Cxcl9 and Cxcl10, combined with elevated expression of interferon-g (Ifng) and perforin (Prf1) transcripts in CD8 + T cells from Cst7-/- mice compared to controls.ConclusionsCystatin F is not required for immune-mediated control of JHMV replication within the CNS. However, JHMV-infected Cst7-/- mice exhibited more severe clinical disease associated with increased demyelination and impaired remyelination. The increase in disease severity was associated with elevated expression of T cell chemoattractant chemokines, concurrent with increased neuroinflammation. These findings support the idea that cystatin F influences expression of proinflammatory gene expression impacting neuroinflammation, T cell activation and/or glia cell responses ultimately impacting neuroinflammation and neurologic disease

    Arabidopsis thaliana AMY3 Is a Unique Redox-regulated Chloroplastic α-Amylase

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    α-Amylases are glucan hydrolases that cleave α-1,4-glucosidic bonds in starch. In vascular plants, α-amylases can be classified into three subfamilies. Arabidopsis has one member of each subfamily. Among them, only AtAMY3 is localized in the chloroplast. We expressed and purified AtAMY3 from Escherichia coli and carried out a biochemical characterization of the protein to find factors that regulate its activity. Recombinant AtAMY3 was active toward both insoluble starch granules and soluble substrates, with a strong preference for β-limit dextrin over amylopectin. Activity was shown to be dependent on a conserved aspartic acid residue (Asp(666)), identified as the catalytic nucleophile in other plant α-amylases such as the barley AMY1. AtAMY3 released small linear and branched glucans from Arabidopsis starch granules, and the proportion of branched glucans increased after the predigestion of starch with a β-amylase. Optimal rates of starch digestion in vitro was achieved when both AtAMY3 and β-amylase activities were present, suggesting that the two enzymes work synergistically at the granule surface. We also found that AtAMY3 has unique properties among other characterized plant α-amylases, with a pH optimum of 7.5-8, appropriate for activity in the chloroplast stroma. AtAMY3 is also redox-regulated, and the inactive oxidized form of AtAMY3 could be reactivated by reduced thioredoxins. Site-directed mutagenesis combined with mass spectrometry analysis showed that a disulfide bridge between Cys(499) and Cys(587) is central to this regulation. This work provides new insights into how α-amylase activity may be regulated in the chloroplast
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