595 research outputs found

    Development of wind resource assessment methods and application to the Waterloo region

    Get PDF
    A wind resource assessment of two sites in the Waterloo region, WRESTRC and RIM Park, was conducted using wind speed, wind direction, temperature and pressure data collected from meteorological towers for over two years. The study was undertaken as part of the W3 Wind Energy Project, and the equipment was purchased from NRG Systems and R. M. Young Company. The data was filtered to reduce the effect of icing and tower shadow, and was analyzed using MATLAB software. Based on the mean wind speeds, small wind turbines less than 50 kW in capacity would be appropriate at both sites. Wind speeds tended to be stronger during the winter than the summer, and during the afternoon than the rest of the day. Both sites also exhibited a strong dominant wind direction -- from the northwest. Due to the terrain, the wind shear and turbulence intensity at WRESTRC were moderate when the wind flowed from the dominant direction, but very high from other directions. The wind shear and turbulence intensity at RIM Park were consistently moderate in all directions. Although the terrain seems more complex at WRESTRC, the wind speed distribution and estimated annual energy production were higher at WRESTRC than at RIM Park, which indicates that it is a more viable site. The estimated capacity factors ranged from 9.4% to 22% depending on the hub height, which is not nearly high enough to suggest a commercial wind farm would be viable at either site. A small 5 kW to 15 kW wind turbine in the Waterloo region could offset the electricity usage of an average home. A two-parameter power law model of wind shear was explored and compared with the standard one-parameter model. In terms of goodness-of-fit, the two-parameter model did perform better. But in terms of accuracy of extrapolation, it was not conclusively better or worse than a one-parameter model forced through the known data point closest to the prediction height. The relationship between turbulence intensity and measurement interval was examined. Since atmospheric flow is unsteady, they are not independent. The perceived turbulence intensity was found to increase exponentially with time intervals under 24 hours. Two linear regression-based Measure-Correlate-Predict methods were evaluated using long-term data from a weather station also at WRESTRC. The ordinary least squares method was considered the baseline given its simplicity. The variance ratio method improved upon it by ensuring that the variance of the wind speed distribution at the target site was preserved

    Humans and Nature in the Loop: Integrating occupants & natural conditioning into advanced controls for high performance buildings

    Get PDF
    Post Occupancy Evaluation plus Measurements (POE+M) has revealed that thermal, visual, acoustic and even air quality standards derived through controlled experimentation alone does not ensure comfort or health in buildings. Introducing human input into environmental standards and into user centric controls is critically needed for a sustainable future. For over a decade, CMUā€™s Center for Building Performance & Diagnostics has been gathering POE+M data from over 1500 workstations around the world and testing the benefits on innovative environmental control systems. The separation of ambient and task conditioning, the provision of task controls, the introduction of occupant voting and bio-signal inputs into ambient and task set-points, offers major gains in comfort, task performance, energy savings, as well as health and wellness

    Ca2+ signaling modulates cytolytic T lymphocyte effector functions

    Get PDF
    Cytolytic T cells use two mechanisms to kill virally infected cells, tumor cells, or other potentially autoreactive T cells in short-term in vitro assays. The perforin/granule exocytosis mechanism uses preformed cytolytic granules that are delivered to the target cell to induce apoptosis and eventual lysis. FasL/Fas (CD95 ligand/CD95)ā€“mediated cytolysis requires de novo protein synthesis of FasL by the CTL and the presence of the death receptor Fas on the target cell to induce apoptosis. Using a CD8+ CTL clone that kills via both the perforin/granule exocytosis and FasL/Fas mechanisms, and a clone that kills via the FasL/Fas mechanism only, we have examined the requirement of intra- and extracellular Ca2+ in TCR-triggered cytolytic effector function. These two clones, a panel of Ca2+ antagonists, and agonists were used to determine that a large biphasic increase in intracellular calcium concentration, characterized by release of Ca2+ from intracellular stores followed by a sustained influx of extracellular Ca2+, is required for perforin/granule exocytosis. Only the sustained influx of extracellular Ca2+ is required for FasL induction and killing. Thapsigargin, at low concentrations, induces this small but sustained increase in [Ca2+]i and selectively induces FasL/Fas-mediated cytolysis but not granule exocytosis. These results further define the role of Ca2+ in perforin and FasL/Fas killing and demonstrate that differential Ca2+ signaling can modulate T cell effector functions

    SHIP Represses the Generation of Alternatively Activated Macrophages

    Get PDF
    SummaryWe recently reported that SHIP restrains LPS-induced classical (M1) activation of in vitro differentiated, bone marrow-derived macrophages (BMMĪ¦s) and that SHIP upregulation is essential for endotoxin tolerance. Herein, we show that in vivo differentiated SHIPāˆ’/āˆ’ peritoneal (PMĪ¦s) and alveolar (AMĪ¦s) macrophages, unlike their wild-type counterparts, are profoundly M2 skewed (alternatively activated), possessing constitutively high arginase I (ArgI) and Ym1 levels and impaired LPS-induced NO production. Consistent with this, SHIPāˆ’/āˆ’ mice display M2-mediated lung pathology and enhanced tumor implant growth. Interestingly, BMMĪ¦s from SHIPāˆ’/āˆ’ mice do not display this M2 phenotype unless exposed to TGFĪ² within normal mouse plasma (MP) during in vitro differentiation. Our results suggest that SHIP functions in vivo to repress M2 skewing and that macrophage polarization can occur during differentiation in response to TGFĪ² if progenitors have elevated PIP3

    Using Chinese Version of MYMOP in Chinese Medicine Evaluation: Validity, Responsiveness and Minimally Important Change

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Measure Yourself Medical Outcome Profile (MYMOP) is a patient generated outcome instrument applicable in the evaluation of both allopathic and complementary medicine treatment. This study aims to adapt MYMOP into Chinese, and to assess its validity, responsiveness and minimally important change values in a sample of patients using Chinese medicine (CM) services.</p> <p>Methods</p> <p>A Chinese version of MYMOP (CMYMOP) is developed by forward-backward-forward translation strategy, expert panel assessment and pilot testing amongst patients. 272 patients aged 18 or above with subjective symptoms in the past 2 weeks were recruited at a CM clinic, and were invited to complete a set of questionnaire containing CMYMOP and SF-36. Follow ups were performed at 2<sup>nd </sup>and 4<sup>th </sup>week after consultation, using the same set of questionnaire plus a global rating of change question. Criterion validity of CMYMOP was assessed by its correlation with SF-36 at baseline, and responsiveness was evaluated by calculating the Cohen effect size (ES) of change at two follow ups. Minimally important difference (MID) values were estimated via anchor based method, while minimally detectable difference (MDC) figures were calculated by distribution based method.</p> <p>Results</p> <p>Criterion validity of CMYMOP was demonstrated by negative correlation between CMYMOP Profile scores and all SF-36 domain and summary scores at baseline. For responsiveness between baseline and 4<sup>th </sup>week follow up, ES of CMYMOP Symptom 1, Activity and Profile reached the moderate change threshold (ES>0.5), while Symptom 2 and Wellbeing reached the weak change threshold (ES>0.2). None of the SF-36 scores reached the moderate change threshold, implying CMYMOP's stronger responsiveness in CM setting. At 2<sup>nd </sup>week follow up, MID values for Symptom 1, Symptom 2, Wellbeing and Profile items were 0.894, 0.580, 0.263 and 0.516 respectively. For Activity item, MDC figure of 0.808 was adopted to estimate MID.</p> <p>Conclusions</p> <p>The findings support the validity and responsiveness of CMYMOP for capturing patient centred clinical changes within 2 weeks in a CM clinical setting. Further researches are warranted (1) to estimate Activity item MID, (2) to assess the test-retest reliability of CMYMOP, and (3) to perform further MID evaluation using multiple, item specific anchor questions.</p

    The role of SHIP in the development and activation of mouse mucosal and connective tissue mast cells

    Get PDF
    Although SHIP is a well-established suppressor of IgE plus Ag-induced degranulation and cytokine production in bone marrow-derived mast cells (BMMCs), little is known about its role in connective tissue (CTMCs) or mucosal (MMCs) mast cells. In this study, we compared SHIP's role in the development as well as the IgE plus Ag and TLR-induced activation of CTMCs, MMCs, and BMMCs and found that SHIP delays the maturation of all three mast cell subsets and, surprisingly, that it is a positive regulator of IgE-induced BMMC survival. We also found that SHIP represses IgE plus Ag-induced degranulation of all three mast cell subsets and that TLR agonists do not trigger their degranulation, whether SHIP is present or not, nor do they enhance IgE plus Ag-induced degranulation. In terms of cytokine production, we found that in MMCs and BMMCs, which are poor producers of TLR-induced cytokines, SHIP is a potent negative regulator of IgE plus Ag-induced IL-6 and TNF-Ī± production. Surprisingly, however, in splenic or peritoneal derived CTMCs, which are poor producers of IgE plus Ag-induced cytokines, SHIP is a potent positive regulator of TLR-induced cytokine production. Lastly, cell signaling and cytokine production studies with and without LY294002, wortmannin, and PI3KĪ± inhibitor-2, as well as with PI3K p85Ī±(-/-) BMMCs and CTMCs, are consistent with SHIP positively regulating TLR-induced cytokine production via an adaptor-mediated pathway while negatively regulating IgE plus Ag-induced cytokine production by repressing the PI3K pathway

    Cost-effectiveness analysis of left atrial appendage occlusion compared with pharmacological strategies for stroke prevention in atrial fibrillation

    Get PDF
    Background Transcatheter left atrial appendage occlusion (LAAO) is a promising therapy for stroke prophylaxis in non-valvular atrial fibrillation (NVAF) but its cost-effectiveness remains understudied. This study evaluated the cost- effectiveness of LAAO for stroke prophylaxis in NVAF. Methods A Markov decision analytic model was used to compare the cost-effectiveness of LAAO with 7 pharmacological strategies: aspirin alone, clopidogrel plus aspirin, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban. Outcome measures included quality-adjusted life years (QALYs), lifetime costs and incremental cost-effectiveness ratios (ICERs). Base-case data were derived from ACTIVE, RE-LY, ARISTOTLE, ROCKET-AF, PROTECT-AF and PREVAIL trials. One- way sensitivity analysis varied by CHADS2 score, HAS-BLED score, time horizons, and LAAO costs; and probabilistic sensitivity analysis using 10,000 Monte Carlo simulations was conducted to assess parameter uncertainty. Results LAAO was considered cost-effective compared with aspirin, clopidogrel plus aspirin, and warfarin, with ICER of US5,115,5,115, 2,447, and 6,298perQALYgained,respectively.LAAOwasdominant(i.e.lesscostlybutmoreeffective)comparedtootherstrategies.SensitivityanalysisdemonstratedfavorableICERsofLAAOagainstotherstrategiesinvariedCHADS2score,HASāˆ’BLEDscore,timehorizons(5to15years)andLAAOcosts.LAAOwascostāˆ’effectivein86.246,298 per QALY gained, respectively. LAAO was dominant (i.e. less costly but more effective) compared to other strategies. Sensitivity analysis demonstrated favorable ICERs of LAAO against other strategies in varied CHADS2 score, HAS-BLED score, time horizons (5 to 15 years) and LAAO costs. LAAO was cost-effective in 86.24 % of 10,000 simulations using a threshold of US50,000/QALY. Conclusions Transcatheter LAAO is cost-effective for prevention of stroke in NVAF compared with 7 pharmacological strategies. Condensed abstract The transcatheter left atrial appendage occlusion (LAAO) is considered cost-effective against the standard 7 oral pharmacological strategies including acetylsalicylic acid (ASA) alone, clopidogrel plus ASA, warfarin, dabigatran 110 mg, dabigatran 150 mg, apixaban, and rivaroxaban for stroke prophylaxis in non-valvular atrial fibrillation management

    Lgr5 and Col22a1 mark progenitor cells in the lineage toward juvenile articular chondrocytes

    Get PDF
    The synovial joint forms from a pool of progenitor cells in the future region of the joint, the interzone. Expression of Gdf5 and Wnt9a has been used to mark the earliest cellular processes in the formation of the interzone and the progenitor cells. However, lineage specification and progression toward the different tissues of the joint are not well understood. Here, by lineage-tracing studies we identify a population of Lgr5+ interzone cells that contribute to the formation of cruciate ligaments, synovial membrane, and articular chondrocytes of the joint. This finding is supported by single-cell transcriptome analyses. We show that Col22a1, a marker of early articular chondrocytes, is co-expressed with Lgr5+ cells prior to cavitation as an important lineage marker specifying the progression toward articular chondrocytes. Lgr5+ cells contribute to the repair of a joint defect with the re-establishment of a Col22a1-expressing superficial layer

    MeSH Up: effective MeSH text classification for improved document retrieval

    Get PDF
    Motivation: Controlled vocabularies such as the Medical Subject Headings (MeSH) thesaurus and the Gene Ontology (GO) provide an efficient way of accessing and organizing biomedical information by reducing the ambiguity inherent to free-text data. Different methods of automating the assignment of MeSH concepts have been proposed to replace manual annotation, but they are either limited to a small subset of MeSH or have only been compared with a limited number of other systems
    • ā€¦
    corecore