243 research outputs found

    Investigation of a decentralised control strategy for grid frequency support from DC microgrids

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    DC microgrids are capable of integrating and coordinating distributed energy resources into power systems, along with providing services to the wider system e.g. balancing, frequency support, demand response, etc. This paper investigates the capability of DC microgrids providing grid frequency support, for the GB Enhanced Frequency Response service. In this study, photovoltaic generation, energy storage, and load, form the DC microgrids. The control strategy is a decentralised scheme, based on conventional droop control for active power sharing and grid frequency support. Droop control is also used within the DC microgrid for power sharing amongst generation and load. Scenarios are conducted to evaluate the effectiveness of the control strategy and verified by MATLAB/Simulink simulations

    Elite mountain bike enduro competition: a study of rider hand-arm vibration exposure

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    Limited information is currently available regarding the hand-arm vibration (HAV) exposure 5 for professional off-road cyclists. Previous reports have suggested that commuting and 6 recreational cyclists are at risk of exceeding exposure limit values (ELV) in a single ride. 7 Therefore, further investigation of HAV exposure in competitive mountain biking is 8 warranted. Partial and total eight hour exposure data (Ai(8), A(8), ms⁻²) were computed for a 9 national level mountain bike enduro competitions. Hand-arm vibrations were measured using 10 a tri-axial accelerometer recording at a frequency of 3.2 kHz mounted on the handlebar and 11 accelerations were quantified after frequency weighting filters were applied (Wh). The data 12 presented shows that HAV exposure during one day of competitive enduro mountain bike 13 racing exceeds ELV (mean race exposure = 5.84 ms⁻² , minimum = 5.47ms⁻² , maximum = 14 6.61ms⁻²) and is greater than the HAV exposure observed in recreational cycling. This 15 suggests that further work is required to determine the exposure associated with changes in 16 equipment, technique and international racing events in professional athletes

    Ex Vivo treatment of coronary artery endothelial cells with serum post-exercise training offers limited protection against in vitro exposure to FEC-T chemotherapy

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    Background: Chemotherapy treatment for breast cancer associates with well-documented cardiovascular detriments. Exercise has shown promise as a potentially protective intervention against cardiac toxicity. However, there is a paucity of evidence for the benefits of exercise on the vasculature. Objectives: This study aimed to determine the effects of chemotherapy on the vascular endothelium; and if there are protective effects of serological alterations elicited by an exercise training intervention. Methods and Results: 15 women participated in a 12-week home-based exercise intervention consisting of three high-intensity interval sessions per week. Human coronary artery endothelial cells (HCAEC) were exposed to physiological concentrations of 5-fluorouracil, epirubicin, cyclophosphamide (FEC) and docetaxel to determine a dose-response. Twenty-4 hours prior to FEC and docetaxel exposure, HCAECs were preconditioned with serum collected pre- and post-training. Annexin V binding and cleaved caspase-3 were assessed using flow cytometry and wound repair by scratch assays. Chemotherapy exposure increased HCAEC Annexin V binding, cleaved caspase-3 expression in a dose-dependent manner; and inhibited wound repair. Compared to pre-training serum, conditioning HCAECs with post-training serum, reduced Annexin V binding (42% vs. 30%, p = 0.01) when exposed to FEC. For docetaxel, there were no within-group differences (pre-vs post-exercise) for Annexin V binding or cleaved caspase-3 expression. There was a protective effect of post-training serum on wound repair for 5-flurouracil (p = 0.03) only. Conclusion: FEC-T chemotherapy drugs cause significant damage and dysfunction of endothelial cells. Preconditioning with serum collected after an exercise training intervention, elicited some protection against the usual toxicity of FEC-T, when compared to control serum

    Ex Vivo treatment of coronary artery endothelial cells with serum post-exercise training offers limited protection against in vitro exposure to FEC-T chemotherapy

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    Background: Chemotherapy treatment for breast cancer associates with well-documented cardiovascular detriments. Exercise has shown promise as a potentially protective intervention against cardiac toxicity. However, there is a paucity of evidence for the benefits of exercise on the vasculature. Objectives: This study aimed to determine the effects of chemotherapy on the vascular endothelium; and if there are protective effects of serological alterations elicited by an exercise training intervention. Methods and Results: 15 women participated in a 12-week home-based exercise intervention consisting of three high-intensity interval sessions per week. Human coronary artery endothelial cells (HCAEC) were exposed to physiological concentrations of 5-fluorouracil, epirubicin, cyclophosphamide (FEC) and docetaxel to determine a dose-response. Twenty-4 hours prior to FEC and docetaxel exposure, HCAECs were preconditioned with serum collected pre- and post-training. Annexin V binding and cleaved caspase-3 were assessed using flow cytometry and wound repair by scratch assays. Chemotherapy exposure increased HCAEC Annexin V binding, cleaved caspase-3 expression in a dose-dependent manner; and inhibited wound repair. Compared to pre-training serum, conditioning HCAECs with post-training serum, reduced Annexin V binding (42% vs. 30%, p = 0.01) when exposed to FEC. For docetaxel, there were no within-group differences (pre-vs post-exercise) for Annexin V binding or cleaved caspase-3 expression. There was a protective effect of post-training serum on wound repair for 5-flurouracil (p = 0.03) only. Conclusion: FEC-T chemotherapy drugs cause significant damage and dysfunction of endothelial cells. Preconditioning with serum collected after an exercise training intervention, elicited some protection against the usual toxicity of FEC-T, when compared to control serum

    Influence of country and city images on students’ perception of host universities and their satisfaction with the assigned destination for their exchange programmes

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    ABSTRACT: This research focuses on the effect that country image, city image and university image has on students’ a priori satisfaction with the assigned destination for their international exchange programme (Bachelor and Master). In particular, this study establishes six hypotheses related to the causal relationships among the different typologies of image and their effects on students’ satisfaction with the assigned destination to study at least one semester in a host university. In order to contrast these hypotheses, a quantitative research was carried out in the Spanish city of Santander (Spain), by obtaining a sample of 245 international students who participated in an exchange programme at the University of Cantabria. The research findings are: (1) students’ satisfaction with the assigned destination is positively influenced by the university image; (2) the university image is positively influenced by the city image; and (3) the city image is positively influenced by the country image

    Globalization and the Transmission of Social Values: The Case of Tolerance

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    Quasi-Experimental Analysis of Targeted Economic Development Programs: Lessons from Florida

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    The authors highlight three sources of endogeneity bias that typically haunt analyses of local government policies, and offer an empirical methodology for estimating program impacts given such concerns. They investigate Florida’s experience with implementing two common targeted economic development policies, community redevelopment areas (CRAs) and enterprise zones (EZs). Developing a simple application decision model as a guide, they find significant differences in policy implementation for small cities compared with larger cities. Florida’s small-city program implementation offers a unique opportunity to compare areas that received state-level approval for the programs with all areas that qualified for but did not receive designation using a quasi-experimental framework. In so doing, the authors explicitly address the potential for endogeneity bias caused by programrationing on the part of administrators and by nonrandom targeting of distressed areas. Consistent with existing research, they do not find evidence validating the efficacy of targeted development programs for small cities.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Expanded access study of patients with advanced basal cell carcinoma treated with the Hedgehog pathway inhibitor, vismodegib

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    Background: Vismodegib, a first-in-class Hedgehog pathway inhibitor, was US Food and Drug Administration (FDA) approved for advanced basal cell carcinomas (BCCs) based on a single, nonrandomized, phase-II trial. Consequently, additional clinical data are critical to confirm the efficacy and safety of vismodegib
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