966 resultados para Peixos -- Poblacions -- Inform
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The dipeptide carnosine (β-alanyl-L-histidine) has contrasting but beneficial effects on cellular activity. It delays cellular senescence and rejuvenates cultured senescent mammalian cells. However, it also inhibits the growth of cultured tumour cells. Based on studies in several organisms, we speculate that carnosine exerts these apparently opposing actions by affecting energy metabolism and/or protein homeostasis (proteostasis). Specific effects on energy metabolism include the dipeptide's influence on cellular ATP concentrations. Carnosine's ability to reduce the formation of altered proteins (typically adducts of methylglyoxal) and enhance proteolysis of aberrant polypeptides is indicative of its influence on proteostasis. Furthermore these dual actions might provide a rationale for the use of carnosine in the treatment or prevention of diverse age-related conditions where energy metabolism or proteostasis are compromised. These include cancer, Alzheimer's disease, Parkinson's disease and the complications of type-2 diabetes (nephropathy, cataracts, stroke and pain), which might all benefit from knowledge of carnosine's mode of action on human cells. © 2013 Hipkiss et al.; licensee Chemistry Central Ltd.
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The UK's business R&D (BERD) to GDP ratio is low compared to other leading economies, and the ratio has declined over the 1990s. This paper uses data on 719 large UK firms to analyse the link between R&D and productivity during 1989-2000. The results indicate that UK returns to R&D are similar to returns in other leading economies and have been relatively stable over the 1990s. The analysis suggests that the low BERD to GDP ratio in the UK is unlikely to be due to direct financial or human capital constraints (as these imply finding relatively high rates of return). © Springer Science+Business Media, LLC 2009.
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Background: Emotional eating in children has been related to the consumption of energy-dense foods and obesity, but the development of emotional eating in young children is poorly understood. Objectives: We evaluated whether emotional eating can be induced in 5-7-y-old children in the laboratory and assessed whether parental use of overly controlling feeding practices at 3-5 y of age predicts a greater subsequent tendency for children to eat under conditions of mild stress at ages 5-7 y. Design: Forty-one parent-child dyads were recruited to participate in this longitudinal study, which involved parents and children being observed consuming a standard lunch, completing questionnaire measures of parental feeding practices, participating in a research procedure to induce child emotion (or a control procedure), and observing children's consumption of snack foods. Results: Children at ages 5-7 y who were exposed to a mild emotional stressor consumed significantly more calories from snack foods in the absence of hunger than did children in a control group. Parents who reported the use of more food as a reward and restriction of food for health reasons with their children at ages 3-5 y were more likely to have children who ate more under conditions of negative emotion at ages 5-7 y. Conclusions: Parents who overly control children's food intake may unintentionally teach children to rely on palatable foods to cope with negative emotions. Additional research is needed to evaluate the implications of these findings for children's food intake and weight outside of the laboratory setting. This trial was registered at clinicaltrials.gov as NCT01122290.
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Purpose: To investigate how initial HEMA and silicone-hydrogel (SiHy) contact lens fit on insertion, which informs prescribing decisions, reflect end of day fit. Methods: Thirty participants (aged 22.9. ±. 4.9 years) were fitted contralaterally with HEMA and SiHy contact lenses. Corneal topography and tear break-up time were assessed pre-lens wear. Centration, lag, post-blink movement during up-gaze and push-up recovery speed were recorded after 5,10,20. min and 8. h of contact lens wear by a digital slit-lamp biomicroscope camera, along with reported comfort. Lens fit metrics were analysed using bespoke software. Results: Comfort and centration were similar with the HEMA and SiHy lenses (p > 0.05), but comfort decreased with time (p <. 0.01) whereas centration remained stable (F = 0.036, p = 0.991). Movement-on-blink and lag were greater with the HEMA than the SiHy lens (p <. 0.01), but movement-on-blink decreased with time after insertion (F = 22.423, p <. 0.001) whereas lag remained stable (F = 1.967, p = 0.129). Push-up recovery speed was similar with the HEMA and the SiHy lens 5-20. min after insertion (p > 0.05), but was slower with SiHy after 8. h wear (p = 0.016). Lens movement on blink and push-up recovery speed was predictive of the movement after 8. h of wear after 10-20. min SiHy wear, but after 5 to 20. min of HEMA lens wear. Conclusions: A HEMA or SiHy contact lens with poor movement on blink/push-up after at least 10. min after insertion should be rejected.
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Funded by UK Government's Overseas Territories Environmental Programme (OTEP)
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Background: Since 2007, there has been an ongoing collaboration between Duke University and Mulago National Referral Hospital (NRH) in Kampala, Uganda to increase surgical capacity. This program is prepared to expand to other sites within Uganda to improve neurosurgery outside of Kampala as well. This study assessed the existing progress at Mulago NRH and the neurosurgical needs and assets at two potential sites for expansion. Methods: Three public hospitals were visited to assess needs and assets: Mulago NRH, Mbarara Regional Referral Hospital (RRH), and Gulu RRH. At each site, a surgical capacity tool was administered and healthcare workers were interviewed about perceived needs and assets. A total of 39 interviews were conducted between the three sites. Thematic analysis of the interviews was conducted to identify the reported needs and assets at each hospital. Results: Some improvements are needed to the Duke-Mulago Collaboration model prior to expansion; minor changes to the neurosurgery residency program as well as the method for supply donation and training provided during neurosurgery camps need to examined. Neurosurgery can be implemented at Mbarara RRH currently but the hospital needs a biomedical equipment technician on staff immediately. Gulu RRH is not well positioned for Neurosurgery until there is a CT Scanner somewhere in the Northern Region of Uganda or at the hospital. Conclusions: Neurosurgery is already present in Uganda on a small scale and needs rapid expansion to meet patient needs. This progression is possible with prudent allocation of resources on strategic equipment purchases, human resources including clinical staff and biomedical staff, and changes to the supply chain management system.
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Protected areas are the leading forest conservation policy for species and ecoservices goals and they may feature in climate policy if countries with tropical forest rely on familiar tools. For Brazil's Legal Amazon, we estimate the average impact of protection upon deforestation and show how protected areas' forest impacts vary significantly with development pressure. We use matching, i.e., comparisons that are apples-to-apples in observed land characteristics, to address the fact that protected areas (PAs) tend to be located on lands facing less pressure. Correcting for that location bias lowers our estimates of PAs' forest impacts by roughly half. Further, it reveals significant variation in PA impacts along development-related dimensions: for example, the PAs that are closer to roads and the PAs closer to cities have higher impact. Planners have multiple conservation and development goals, and are constrained by cost, yet still conservation planning should reflect what our results imply about future impacts of PAs.