1,387 research outputs found

    Reflective Efficiencies of Materials for Applications of Bifacial Solar Cells

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    The bifacial solar cell is superior to its monofacial predecessor due to its ability to convert both incident light on top and reflected light from below into energy. The scattering of the reflected light is affected by the property of the material on which it is interacting. To date, little work has been contributed to studying the properties of these materials to determine optimal quantities for bifacial solar cells. In the first experiment, reflective efficiencies compared to the angle of reflection were explored for different grit of sandpaper in order to develop an understanding of how surface texture impacts reflectivity. Then materials that would typically be used in construction are explored using the same techniques. As the world becomes more energy efficient, it is important to understand what building materials should be used to increase solar cell efficiencies

    Protein for Life: Towards a focussed dietary framework for healthy ageing

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    ‘Ageing well’ has been highlighted as an important research area by the World Health Organization. In the UK, healthy ageing has been identified as a priority research area by multiple Research Councils and is a key NHS priority. Sarcopaenia, the decline of muscle mass/strength and a key component of healthy ageing, can have a major impact on quality of life and is associated with premature mortality. Increasing protein intake at all stages of the life course may help to reduce the rate of muscle decline and the onset of associated health conditions. However, there is a lack of understanding of the social, demographic and psychological drivers of food choices surrounding protein intake. This report describes the multidisciplinary approach that has been adopted by the Protein for Life project to create a framework for the development of palatable, cost-effective higher-protein foods suitable for an ageing population

    Quantifying Bromocarbon Emissions from Seaweed Aquaculture in California

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    Feeding ruminant livestock seaweed rich in bromoform (CHBr3) is an emerging strategy to reduce methane emissions from the livestock sector to meet climate targets. Consequently, there is a strong interest in farming bromoform rich seaweeds (e.g., Asparagopsis taxiformis) on a large scale which may impact the atmospheric inventory of bromine and in return induce catalytic ozone destruction. However, to date, only three studies have measured bromoform emission rates from Asparagopsis seaweeds which vary by order of magnitude. To fill this gap, the most comprehensive data set of bromocarbon emissions from A. taxiformis, a leading candidate for enteric methane reduction in cattle, was collected from Santa Catalina Island (California) under natural conditions, where the measured emissions were found to be five to twenty times higher than previously reported values. Bromocarbon emission data were also collected from Gracilaria parvispora, which has methanogenic reduction potential and is part of the globally cultivated Gracilara genus. Light intensity and water temperature most affected bromocarbon emission rates for both seaweed species. A comparison of emissions rates between aquaculture tanks (380 L) and bottle incubations (0.5 L) suggests that bottle incubations can represent of aquaculture settings. Finally, this study suggests that mass-producing A. taxiformis for approximately 50% of Californai cattle at a 1% inclusion rate (dry weight) is unlikely to significantly increase annual global bromocarbon emissions, whereas mass producing A. taxiformis for approximately 26% of all United States cattle may significantly increase global bromocarbon emissions

    Lifelong exercise, but not short-term high-intensity interval training, increases GDF11, a marker of successful aging: a preliminary investigation

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    Lifelong exercise is associated with regulation of skeletal mass and function, reductions in frailty, and successful aging. Yet, the influence of exercise on myostatin and myostatin-interacting factors is relatively under examined in older males. Therefore, we investigated whether serum total myostatin, free myostatin, follistatin, and growth and differentiation factor 11 (GDF11) were altered following high-intensity interval training (HIIT) in a group of 13 lifelong sedentary (SED; 64 [6] years) and 11 lifelong exercising (LEX; 62 [6] years) older males. SED follistatin was moderately greater than LEX pre-HIIT (Cohen's d = 0.66), and was largely greater post-HIIT (Cohen's d = 1.22). The HIIT-induced increase in follistatin was large in SED (Cohen's d = 0.82) and absent in LEX (Cohen's d = 0.03). GDF11 was higher in LEX pre-HIIT (Cohen's d = 0.49) and post-HIIT (Cohen's d = 0.63) compared to SED. HIIT resulted in no change to GDF11 in LEX or SED (Cohen's d = 0.00–0.03). Peak power output and GDF11 were correlated (r = 0.603), independent of grouping. Differences in GDF11 with lifelong exercise training, paired with the correlation between GDF11 and peak power output, suggested that GDF11 may be a relevant myostatin-interacting peptide to successful aging in humans, and strategies to maintain this need to be further explored

    Muscle strength mediates the relationship between mitochondrial energetics and walking performance

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    Skeletal muscle mitochondrial oxidative capacity declines with age and negatively affects walking performance, but the mechanism for this association is not fully clear. We tested the hypothesis that impaired oxidative capacity affects muscle performance and, through this mechanism, has a negative effect on walking speed. Muscle mitochondrial oxidative capacity was measured by in vivo phosphorus magnetic resonance spectroscopy as the postexercise phosphocreatine resynthesis rate, kPCr , in 326 participants (154 men), aged 24-97 years (mean 71), in the Baltimore Longitudinal Study of Aging. Muscle strength and quality were determined by knee extension isokinetic strength, and the ratio of knee extension strength to thigh muscle cross-sectional area derived from computed topography, respectively. Four walking tasks were evaluated: a usual pace over 6 m and for 150 s, and a rapid pace over 6 m and 400 m. In multivariate linear regression analyses, kPCr was associated with muscle strength (β = 0.140, P = 0.007) and muscle quality (β = 0.127, P = 0.022), independent of age, sex, height, and weight; muscle strength was also a significant independent correlate of walking speed (P < 0.02 for all tasks) and in a formal mediation analysis significantly attenuated the association between kPCr and three of four walking tasks (18-29% reduction in β for kPCr ). This is the first demonstration in human adults that mitochondrial function affects muscle strength and that inefficiency in muscle bioenergetics partially accounts for differences in mobility through this mechanism

    Activin subfamily peptides predict chronological age in humans

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    Loss of muscle mass and function are a well‐defined aspect of human aging from the 3rd decade of life, which result in reduced independence and increased mortality. The activin family of peptides contains several endocrine factors (activin A, myostatin, growth and differentiation factor 11 [GDF11]) that may play roles in changes in muscle mass and the aging process, however, it may be simplistic to consider aging as a result of a single peptides changes. Thus, we aimed to examine changes in activin family members across a cohort of healthy individuals of various ages, hypothesizing that these would aid predictive models of age and functional measures of age. Healthy participants (n = 88) were recruited and resting metabolic rate, body composition, grip strength, walking speed, and circulating plasma concentrations of myostatin (total and free), activin A, follistatin‐like binding protein (FLRG), and GDF11 quantified. Simple regressions between circulating factors and chronological age, grip strength, and walking speed were examined. Multiple stepwise regressions for age, grip strength, and walking speed are also reported. Age negatively correlated with total myostatin (P = 0.032, r2 = 0.053), grip strength positively with activin A (P = 0.046, r2 = 0.048), whereas walking speed showed no simple regression relationships. Stepwise regressions suggested a role of total myostatin and activin A in models of age, whereas GDF11 contributed to the model of grip strength. Here we suggest a role for myostatin, activin A, and GDF11 in normal human aging that mirrors animal studies to date. Further interventional studies are required to elicitate the physiological role of these changes in the normal human aging process, and indeed if offsetting these changes can promote successful aging

    Serum albumin and muscle strength: a longitudinal study in older men and women

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    OBJECTIVES: To examine whether low serum albumin is associated with low muscle strength and future decline in muscle strength in community-dwelling older men and women. DESIGN: Population-based cohort study. SETTING: The Longitudinal Aging Study Amsterdam. PARTICIPANTS: Six hundred seventy-six women and 644 men aged 65 to 88. MEASUREMENTS: Serum albumin was determined at baseline. Muscle strength was assessed using grip strength at baseline, after 3 (n = 1,009), and 6 (n = 741) years. The outcomes were continuous baseline muscle strength, 3- and 6-year change in muscle strength, and a dichotomous indicator for substantial decline (a decrease if ≥1 standard deviations for women = 11 kg, for men = 12 kg) in muscle strength. RESULTS: Mean serum albumin concentration ± standard deviation was 45.0 ± 3.3 g/L for women and 45.2 ± 3.2 g/L for men. At baseline, adjusting for age, lifestyle factors, and chronic conditions, lower serum albumin was cross-sectionally associated with weaker muscle strength (P < .001) in women and men. After 3 years of follow-up, mean decline in muscle strength was -5.6 ± 10.9 kg in women and -9.6 ± 11.9 kg in men. After adjustment for potential confounders, lower serum albumin was associated with muscle strength decline over 3 years (P < .01) in women and men (β = 0.57, standard error (SE) = 0.18; β = 0.37, SE = 0.16, respectively). Lower serum albumin was also associated with substantial decline in muscle strength in women (per unit albumin (g/L) adjusted odds ratio (OR) = 1.14, one-sided 95% confidence limit (CL) = 1.07) and men (per unit albumin (g/L) adjusted OR = 1.14, 95% CL = 1.08). Similar but slightly weaker associations were found between serum albumin and 6-year change in muscle strength (P < .05). CONCLUSION: These results suggest that low serum albumin, even within the normal range, is independently associated with weaker muscle strength and future decline in muscle strength in older women and men. © 2005 by the American Geriatrics Society

    Short-Term Exercise Training Inconsistently Influences Basel Testosterone in Older Men: A Systematic Review and Meta-Analysis

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    Background The age-associated decrease in testosterone is one mechanism suggested to accelerate the aging process in males. Therefore, approaches to increase endogenous testosterone may be of benefit. The aim of this paper was to undertake a Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)-accordant meta-analysis concerning the effect of exercise on total (TT), bioavailable (bio-T), free (free-T), and salivary (sal-T) testosterone in older males. Methods Databases were searched up to and including 20th February 2018 for the terms ‘testosterone AND exercise AND aging AND males’, ‘testosterone AND exercise AND old AND males’, ‘testosterone AND training AND aging AND males’ and ‘testosterone AND training AND old AND males’. From 1259 originally identified titles, 22 studies (randomized controlled trials; RCTs; n=9, and uncontrolled trials; UCTs; n=13) were included which had a training component, participants ≥60 years of age, and salivary or serum testosterone as an outcome measure. Meta-analyses were conducted on change to testosterone following training using standardised difference in means (SDM) and random effects models. Results The overall SDM for endurance training, resistance training, and interval training was 0.398 (95% CI = 0.034 – 0.761; P = 0.010), -0.003 (95% CI = -0.330 – 0.324; P = 0.986), and 0.283 (95% CI = 0.030 – 0.535; P = 0.028) respectively. Resistance training exhibited a qualitative effect of hormone fraction whereby free-T resulted in the greatest SDM (0.253; 95% CI = -0.043 – 0.549; P = 0.094), followed by TT (0.028; 95% CI = -0.204 – 0.260; P = 0.813), and resistance training negatively influenced bio-T (-0.373; 95% CI = -0.789 – 0.042; P = 0.078). Due to the small number of studies, subgroup analysis was not possible for endurance training and interval training studies. Conclusions Data from the present investigation suggests that resistance training does not significantly influence basal testosterone in older men. Magnitude of effect was influenced by hormone fraction, even within the same investigation. Aerobic training and interval training did result in small, significant increases in basal testosterone. The magnitude of effect is small but the existing data are encouraging and may be an avenue for further research

    Novel nano-composite biomaterials that respond to light

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    Composites of nanoparticles and polymers are finding wide applications to alter material properties, conductivity, and utility. Here, we show that nano-composites can be designed to heat in the presence of near infrared light. This process is useful in transitioning materials through a transition temperature for a range of applications. For example, shape-memory materials (including polymers, metals, and ceramics) are those that are processed into a temporary shape and respond to some external stimuli (e.g., temperature) to undergo a transition back to a permanent shape and may be useful in a range of applications from aerospace to fabrics, to biomedical devices and microsystem components. In this work, we formulated composites of gold nanorods (\u3c1% by volume) and biodegradable networks, where exposure to infrared light induced heating and consequently, shape transitions. The heating is repeatable and tunable based on nanorod concentration and light intensity

    Locally advanced duodenal gangliocytic paraganglioma treated with adjuvant radiation therapy: case report and review of the literature

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    BACKGROUND: Gangliocytic paraganglioma are rare neoplasms that predominantly arise in periampulary region. Though considered benign the disease can spread to regional lymphatics. CASE PRESENTATION: A 49 year old woman presented with melena and was found to have a periampullary mass. Endoscopic evaluation and biopsy demonstrated a periampullary paraganglioma. The tumor was resected with pylorus-preserving pancreaticoduodenectomy and was found to represent a gangliocytic paraganglioma associated with nodal metastases. In a controversial decision, the patient was treated with adjuvant external beam radiation therapy. She is alive and well one year following resection. The authors have reviewed the current literature pertaining to this entity and have discussed the biologic behavior of the tumor as well as the rationale for treatment strategies employed. CONCLUSION: Paraganglioma is a rare tumor that typically resides in the gastrointestinal tract and demonstrates low malignant potential. Due to rarity of the disease there is no consensus on the adjuvant treatment even though nearly 5% of the lesions demonstrate the malignant potential
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