787 research outputs found

    Heuristically secure threshold lattice-based cryptography schemes

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    In public-key encryption, a long-term private key can be an easy target for hacking and deserves extra protection. One way to enhance its security is to share the long-term private key among multiple (say n) distributed servers; any threshold number (t, t ≤ n) of these servers are needed to collectively use the shared private key without reconstructing it. As a result, an attacker who has compromised less than t servers will still not be able to reconstruct the shared private key. In this thesis, we studied threshold decryption schemes for lattice-based public-key en- cryption, which is one of the most promising post-quantum public-key encryption schemes. We developed threshold decryption schemes for Stinson’s, the standard NTRU, and NTRU with Ring Learning with Errors (R-LWE) cryptosystems. Prototype implementations were developed for validating the functionality of these threshold decryption schemes. Our de- signs achieve heuristic security, and its security is supported by mechanisms similar to that of R-LWE

    Spectral Resting-State EEG (rsEEG) in Chronic Aphasia Is Reliable, Sensitive, and Correlates With Functional Behavior

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    We investigated spectral resting-state EEG in persons with chronic stroke-induced aphasia to determine its reliability, sensitivity, and relationship to functional behaviors. Resting-state EEG has not yet been characterized in this population and was selected given the demonstrated potential of resting-state investigations using other neuroimaging techniques to guide clinical decision-making. Controls and persons with chronic stroke-induced aphasia completed two EEG recording sessions, separated by approximately 1 month, as well as behavioral assessments of language, sensorimotor, and cognitive domains. Power in the classic frequency bands (delta, theta, alpha, and beta) was examined via spectral analysis of resting-state EEG data. Results suggest that power in the theta, alpha, and beta bands is reliable for use as a repeated measure. Significantly greater theta and lower beta power was observed in persons with aphasia (PWAs) than controls. Finally, in PWAs theta power negatively correlated with performance on a discourse informativeness measure, while alpha and beta power positively correlated with performance on the same measure. This indicates that spectral rsEEG slowing observed in PWAs in the chronic stage is pathological and suggests a possible avenue for directly altering brain activation to improve behavioral function. Taken together, these results suggest that spectral resting-state EEG holds promise for sensitive measurement of functioning and change in persons with chronic aphasia. Future studies investigating the utility of these measures as biomarkers of frank or latent aphasic deficits and treatment response in chronic stroke-induced aphasia are warranted

    Analysis of Lithium

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    The technology of lithium and its compounds was accorded little consideration a few years ago. Immediately following World War II fundamental knowledge of lithium began to be greatly expanded and its importance in industry has risen. Lithium and its compounds are used in porcelain enamels, and glazes; in air conditioning units; in greases, cosmetics and the like, just to cite a few examples. Lithium is the lightest of all the metals having an atomic weight of 6.94. The lithium ion has the smallest ionic radius of the alkalies and is approximately the same size as the magnesium ion. Its chemical properties frequently parallel those attributed to alkaline earths; this is the property which sets lithium apart from the other alkalies

    Tryptophan End-Tagging Confers Antifungal Activity on a Tick-Derived Peptide by Triggering Reactive Oxygen Species Production

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    WHO has identified several Candida species including Candida albicans as critical priority fungal pathogens due to greater infection prevalence and formation of recalcitrant biofilms. Novel antifungal agents are urgently needed, and antimicrobial peptides (AMPs) are being considered as potential alternatives, but inactivity in physiological salt environments, serum, and plasma often limits further therapeutic development. Tryptophan end-tagging is a strategy to overcome these limitations and is thought to selectively enhance membrane permeabilization in both fungal and bacterial plasma membranes. Here, we show that C-terminal tryptophan end-tagging of the tick-derived peptide Os-C transforms an inactive peptide into Os-C(W5), an antifungal peptide capable of preventing the formation of C. albicans biofilms. Mechanistic insight is provided by circular dichroism spectroscopy and molecular dynamics simulations, which demonstrate that tryptophan end-tagging alters the secondary structure of Os-C, while the latter reveals that end-tagging reduces interactions with, and insertion into, a model C. albicans membrane but promotes peptide aggregation on its surface. Interestingly, this leads to the induction of reactive oxygen species production rather than membrane permeabilization, and consequently, oxidative stress leads to cell wall damage. Os-C(W5) does not induce the hemolysis of human erythrocytes. Reduced cell adhesion and viability contribute to decreased biofilm extracellular matrix formation which, although reduced, is retained in the serum-containing medium. In this study, tryptophan end-tagging was identified as a promising strategy for enhancing the antifungal activity, including the biofilm inhibitory activity of Os-C against C. albicans in physiological salt environments.</p

    Redirection of SKN-1 abates the negative metabolic outcomes of a perceived pathogen infection

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    Early host responses toward pathogens are essential for defense against infection. In Caenorhabditis elegans, the transcription factor, SKN-1, regulates cellular defenses during xenobiotic intoxication and bacterial infection. However, constitutive activation of SKN-1 results in pleiotropic outcomes, including a redistribution of somatic lipids to the germline, which impairs health and shortens lifespan. Here, we show that exposing C. elegans to Pseudomonas aeruginosa similarly drives the rapid depletion of somatic, but not germline, lipid stores. Modulating the epigenetic landscape refines SKN-1 activity away from innate immunity targets, which alleviates negative metabolic outcomes. Similarly, exposure to oxidative stress redirects SKN-1 activity away from pathogen response genes while restoring somatic lipid distribution. In addition, activating p38/MAPK signaling in the absence of pathogens, is sufficient to drive SKN-1-dependent loss of somatic fat. These data define a SKN-1- and p38-dependent axis for coordinating pathogen responses, lipid homeostasis, and survival and identify transcriptional redirection, rather than inactivation, as a mechanism for counteracting the pleiotropic consequences of aberrant transcriptional activity

    Research Progress Reports, 1962. Fruit and Vegetable Processing and Technology Division, Department of Horticulture.

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    Tomato variety evaluation for processing, 1962 / W. A. Gould, J. R. Geisman and Wade Schulte -- Evaluation of snap bean varieties for processing, 1962 / Wilbur A. Gould -- Handling and holding studies of mechanically harvested tomatoes. 1. Processed product quality / W. A. Gould, W. D. Bash, J. R. Geisman, D. E. Yingst, G. A. Marlowe and W. N. Brown -- Handling and holding studies of mechanically harvested tomatoes. 2. Spore counts / Winston D. Bash and W. A. Gould -- Handling and holding studies of mechanically harvested tomatoes. 3. pH / Winston D. Bash and W. A. Gould -- Handling and holding studies of mechanically harvested tomatoes. 4. Chlorine residuals / Donald E. Yingst and W. A. Gould -- Removal of insects and residues from sweet corn by washing techniques / J. R. Geisman and W. A. Gould -- Removal of pesticides and radioactive fallout from fruits and vegetables / J. R. Geisman, R. P. Blackmore, R. W. Hirzel and W. S. Stinson -- The effect of apple variety and browning prevention treatments during preparation on the quality of frozen apple pies / D. Robert Davis and James F. Gallander -- Effect of three tomato peeling methods on efficiency and product quality / Wade A. Schulte and W. A. Gould -- Effects of cooling rates on vacuum of canned pumpkin / Winston D. Bash -- New flavors for sauerkraut / J. R. Geisman and Robert Reyda -- Flavor of tomato juice / Wilbur A. Gould, Natholyn Dalton and John Hal Johnson -- Fruit juice blends offer a promising new field for apple cider / D. Robert Davi

    Future challenges of occupational safety and health policy-making in the UK

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    Understanding the changing landscape of occupational safety and health (OSH) regulation and standards and its implications are of central importance for ensuring that OSH outcomes are not compromised and the needs of different types of organizations are met. It is also important for developing appropriate strategies to anticipate and deal with future challenges for OSH policy-making. This paper draws on findings from two qualitative studies with key OSH stakeholders in the UK that were conducted as part of a research programme funded the Institution of Occupational Safety & Health. The aim of the first study was to elicit the views of key stakeholders on changes in the current OSH landscape so as to understand the nature and implications of these changes. The second study explored stakeholder perspectives on how to secure the optimal OSH landscape in the UK by addressing key future challenges for OSH policy-making

    SP701-A-Growing and Harvesting Switchgrass for Ethanol Production in Tennessee

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    Switchgrass is a warm-season perennial grass native to North America. The plant can reach heights up to 10 feet with an extensive root system. Once established, switchgrass well-managed for biomass should have a productive life of 10-20 years. Within the stand, switchgrass is an extremely strong competitor. However, it is not considered an invasive plant. Switchgrass adapts well to a variety of soil and climatic conditions. It is most productive on moderately well to well-drained soils of medium fertility and a soil pH at 5.0 or above. The high cellulosic content of switchgrass makes it a favorable feedstock for ethanol production. It is anticipated that switchgrass can yield sufficient biomass to produce approximately 500 gallons of ethanol per acre. While the Tennessee Biofuels Initiative includes a demonstration plant to make ethanol from switchgrass, the market for switchgrass as an energy crop remains limited. Producers will likely need to be located within 30 to 50 miles of a cellulosic ethanol plant. Producing switchgrass for energy generally occurs under some form of contractual arrangement with the end-user. To reap potential benefits from using switchgrass for cellulosic ethanol production, the system of production must be profitable for farmers and energy producers, as well as cost effective for consumers
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