19 research outputs found

    Electricity Distribution Networks: Investment and Regulation, and Uncertain Demand

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    Electricity distribution networks are capital intensive systems and timely investments are crucial for long-term reliability of their service. In coming years, in the UK, and elsewhere in Europe, many networks are in need of extensive investments in their aging assets. Also, aspects of energy policy concerning climate change, renewable energy, energy efficiency, demand side management (DSM), network energy loss reduction, quality of service standards, and security of supply require active, flexible, and smart networks that can be achieved through investments. This paper is a chapter in the forthcoming book "Jamasb T. and Pollitt, M. G. (2011) Eds., The Future of Electricity Demand: Customers, Citizens and Loads, Cambridge University Press: Cambridge" and describes a network investment assessment model developed as a tool to identify and assess the investment requirements of distribution networks. A broadening of the scope of network investments to include demand-related measures that can reduce the need for investments

    The relationship between vitamin D status and muscle strength in young healthy adults from sunny climate countries currently living in the northeast of Scotland

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    Summary: The current study examined the relationship between vitamin D status and muscle strength in young healthy adults: residents (>6 months) and newcomers (0–3 months), originally from sunny climate countries but currently living in the northeast of Scotland. Our longitudinal data found a positive, albeit small, relationship between vitamin D status and knee extensor isometric strength.  Introduction: Vitamin D has been suggested to play a role in muscle health and function, but studies so far have been primarily in older populations for falls prevention and subsequent risk of fractures.  Methods: Vitamin D status was assessed in a healthy young adults from sunny climate countries (n = 71, aged 19–42 years) with 56% seen within 3 months of arriving in Aberdeen [newcomers; median (range) time living in the UK = 2 months (9–105 days)] and the remainder resident for >6 months [residents; 23 months (6–121 months)]. Participants attended visits every 3 months for 15 months. At each visit, fasted blood samples were collected for analysis of serum 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), carboxy-terminal collagen crosslinks (CTX) and N-terminal propeptide of type I collagen (P1NP). Maximal voluntary contractions (MVC) were performed for grip strength (both arms) and for maximal isometric strength of the knee extensors (right knee).  Results: There were small seasonal variations in 25(OH)D concentrations within the newcomers and residents, but no seasonal variation in bone turnover markers. There was a positive, albeit small, association between 25(OH)D and knee extensor maximal isometric strength. Mixed modelling predicted that for each 1 nmol/L increase in 25(OH)D, peak torque would increase by 1 Nm (p = 0.04).  Conclusions: This study suggests that vitamin D may be important for muscle health in young adults migrating from sunnier climates to high latitudes, yet the potential effect is small

    25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 exert distinct effects on human skeletal muscle function and gene expression

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    Age-associated decline in muscle function represents a significant public health burden. Vitamin D-deficiency is also prevalent in aging subjects, and has been linked to loss of muscle mass and strength (sarcopenia), but the precise role of specific vitamin D metabolites in determining muscle phenotype and function is still unclear. To address this we quantified serum concentrations of multiple vitamin D metabolites, and assessed the impact of these metabolites on body composition/muscle function parameters, and muscle biopsy gene expression in a retrospective study of a cohort of healthy volunteers. Active serum 1,25-dihydroxyvitamin D3 (1α,25(OH)2D3), but not inactive 25-hydroxyvitamin D3 (25OHD3), correlated positively with measures of lower limb strength including power (rho = 0.42, p = 0.02), velocity (Vmax, rho = 0.40, p = 0.02) and jump height (rho = 0.36, p = 0.04). Lean mass correlated positively with 1α,25(OH)2D3 (rho = 0.47, p = 0.02), in women. Serum 25OHD3 and inactive 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) had an inverse relationship with body fat (rho = -0.30, p = 0.02 and rho = -0.33, p = 0.01, respectively). Serum 25OHD3 and 24,25(OH)2D3 were also correlated with urinary steroid metabolites, suggesting a link with glucocorticoid metabolism. PCR array analysis of 92 muscle genes identified vitamin D receptor (VDR) mRNA in all muscle biopsies, with this expression being negatively correlated with serum 25OHD3, and Vmax, and positively correlated with fat mass. Of the other 91 muscle genes analysed by PCR array, 24 were positively correlated with 25OHD3, but only 4 were correlated with active 1α,25(OH)2D3. These data show that although 25OHD3 has potent actions on muscle gene expression, the circulating concentrations of this metabolite are more closely linked to body fat mass, suggesting that 25OHD3 can influence muscle function via indirect effects on adipose tissue. By contrast, serum 1α,25(OH)2D3 has limited effects on muscle gene expression, but is associated with increased muscle strength and lean mass in women. These pleiotropic effects of the vitamin D ‘metabolome’ on muscle function indicate that future supplementation studies should not be restricted to conventional analysis of the major circulating form of vitamin D, 25OHD3

    Electricity distribution networks: Investment, regulation and uncertain demand

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    Electricity Distribution Networks: Investment and Regulation, and Uncertain Demand

    No full text
    Electricity distribution networks are capital intensive systems and timely investments are crucial for long-term reliability of their service. In coming years, in the UK, and elsewhere in Europe, many networks are in need of extensive investments in their aging assets. Also, aspects of energy policy concerning climate change, renewable energy, energy efficiency, demand side management (DSM), network energy loss reduction, quality of service standards, and security of supply require active, flexible, and smart networks that can be achieved through investments. This paper is a chapter in the forthcoming book "Jamasb T. and Pollitt, M. G. (2011) Eds., The Future of Electricity Demand: Customers, Citizens and Loads, Cambridge University Press: Cambridge" and describes a network investment assessment model developed as a tool to identify and assess the investment requirements of distribution networks. A broadening of the scope of network investments to include demand-related measures that can reduce the need for investments.Electricity networks, regulation, investment

    Radiotherapy-related toxicity for localized prostate cancer: meta-analysis comparing conventional or moderately hypofractionated vs. ultrahypofractionated protocols

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    Background To compare toxicities in relation to standard radiation treatments [conventional fractionation RT (CRT) and moderate hypofractionated RT (MRT)] with ultrahypofractionated RT (URT) in the treatment of patients with localized PCa. Methods A searched was performed in Medline, Embase, Cochrane CENTRAL, and LILACS to January 2020 for studies comparing URT to CRT and/or MRT in relation to genitourinary (GU) and gastrointestinal (GI) toxicity in the treatment of patients with localized PCa. URT, MRT and CRT were defined as protocols delivering a daily dose of >= 5 Gy, 2.4-4.9 Gy, and <2.4 Gy per fractions regardless total dose, respectively. Results Eight studies with 2929 patients with localized PCa were included in the analysis. These eight studies did not find any difference between URT and MRT/CRT groups in relation to acute GU toxicity (21.0% x 23.8%, RD -0.04; 95% CI -0.13, 0.06; p = 0.46; I-2 = 89%) and acute GI toxicity (4.9% x 6.9%, RD -0.03; 95% CI -0.07, 0.01; p = 0.21; I-2 = 79%). Six studies did not find any difference between URT and MRT/CRT groups in relation to late GU toxicity (3.9% x 4.7%, RD -0.01; 95% CI -0.03, 0.00; p = 0.16; I-2 = 19%) and late GI toxicity (2.1% x 3.5%, RD -0.01; 95% CI -0.03, 0.00; p = 0.05; I-2 = 22%). Conclusion The present study suggests that acute GU/GI and late GU/GI toxicity are similar between URT and standard protocols. More studies with longer follow-ups directed to oncology outcomes are warranted before any recommendation on this topic

    Vitamin D supplementation and muscle strength in pre-sarcopenic elderly Lebanese people: a randomized controlled trial

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    Previous studies have shown that improving vitamin D status among the elderly may lead to an improvement in muscle mass and muscle strength. In our study, vitamin D supplementation showed significant improvements in vitamin D concentrations as well as appendicular muscle mass in pre-sarcopenic older Lebanese people. However, we found no significant effect on muscle strength. INTRODUCTION: Improving vitamin D status might improve muscle function and muscle mass that lead to sarcopenia in older subjects. The aim of this randomized, controlled, double-blind study was to examine the effect of vitamin D supplementation on handgrip strength and appendicular skeletal muscle mass in pre-sarcopenic older Lebanese subjects. We also examined whether this effect differs in normal vs. obese subjects. METHODS: Participants (n = 128; 62 men and 66 women) deficient in vitamin D (25(OH)D = 12.92 +/- 4.3 ng/ml) were recruited from Saint Charles Hospital, Beirut, Lebanon. The participants were given a supplement of 10,000 IU of cholecalciferol (vitamin D group; n = 64) to be taken three times a week or a placebo tablet (placebo group; n = 64) for 6 months. One hundred fifteen subjects completed the study: 59 had normal weight, while 56 were obese. Strength and functional assessment and biochemical analysis were performed at the start and after 6 months. RESULTS: Compared to placebo, the vitamin D supplemented group showed significant improvements in appendicular skeletal muscle mass (ASMM) (P < 0.001) but not in handgrip strength (P = 0.2901). ANCOVA for ASMM adjusting for obesity and including the interaction between obesity and vitamin D showed a significant interaction. The increase in ASMM with vitamin D in normal-weight subjects was higher than that of obese subjects (B = 35.09 vs. B = 2.19). CONCLUSION: Treatment with vitamin D showed beneficial effects on appendicular muscle mass in pre-sarcopenic older Lebanese men and women. However, it had no effect on muscle strength relative to placebo. This trial was registered at isrctn.org as ISRCTN16665940
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