5,879 research outputs found

    Botanicals

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    Master's Project (M.F.A.) University of Alaska Fairbanks, 2022Botanicals is an exhibit of extremely close-up color photographs of flowers and plant materials which were created without the use of a camera. The 31 framed works reference the historical memento mori art movement intended to remind the viewer of the fragility of life. The work explores the details of a world unseen by the naked eye. The images were all made using a flatbed scanner at extremely high resolution but often seem more three-dimensional than would usually be expected from that process. There is something unusual about the lighting in these images but it’s hard to put one’s finger on quite what unless you are aware of the process

    Do glucocorticoids predict fitness? Linking environmental conditions, corticosterone and reproductive success in the blue tit, Cyanistes caeruleus

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    Glucocorticoids, including corticosterone (CORT), have been suggested to provide a physiological link between ecological conditions and fitness. Specifically, CORT, which is elevated in response to harsh conditions, is predicted to be correlated with reduced fitness. Yet, empirical studies show that CORT can be non-significantly, positively and negatively linked with fitness. Divergent environmental conditions between years or study systems may influence whether CORT is linked to fitness. To test this, we monitored free-living blue tits ( Cyanistes caeruleus ) during breeding over 3 years. We quantified foraging conditions during brood rearing, and examined whether they were correlated with parental baseline CORT and reproductive success. We then tested whether CORT predicted fitness. Elevated parental CORT was associated with lower temperatures, greater rainfall and lower territory-scale oak density. Whereas asynchrony with the caterpillar food peak was correlated with reduced nestling mass and fledging success, but not parental CORT. Only low temperatures were associated with both reduced nestling mass and elevated parental CORT. Despite this, parents with elevated CORT had lighter offspring in all years. Contrarily, in 2009 parental CORT was positively correlated with the number fledged. The absence of a direct link between the foraging conditions that reduce nestling quality and elevate parental CORT suggests that parental CORT may provide a holistic measure of conditions where parents are working harder to meet the demands of developing young. As the positive correlation between parental CORT and fledging success differed between years, this suggests that contrasting conditions between years can influence correlations between parental CORT and fitness. Ultimately, as CORT concentrations are intrinsically variable and linked to the prevalent conditions, studies that incorporate environmental harshness will improve our understanding of evolutionary endocrinology. </jats:p

    Hopping dynamics for localized Lyapunov vectors in many-hard-disk systems

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    The dynamics of the localized region of the Lyapunov vector for the largest Lyapunov exponent is discussed in quasi-one-dimensional hard-disk systems at low density. We introduce a hopping rate to quantitatively describe the movement of the localized region of this Lyapunov vector, and show that it is a decreasing function of hopping distance, implying spatial correlation of the localized regions. This behavior is explained quantitatively by a brick accumulation model derived from hard-disk dynamics in the low density limit, in which hopping of the localized Lyapunov vector is represented as the movement of the highest brick position. We also give an analytical expression for the hopping rate, which is obtained us a sum of probability distributions for brick height configurations between two separated highest brick sites. The results of these simple models are in good agreement with the simulation results for hard-disk systems.Comment: 28 pages, 13 figure

    Training peers to treat Ebola centre workers with anxiety and depression in Sierra Leone

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    Background: Following the 2014 Ebola virus disease (EVD) outbreak in West Africa, the UK Department for International Development funded South London and Maudsley National Health Service (NHS) to develop a psychological intervention that ex-Ebola Treatment Centre (ETC) staff could be trained to deliver to their peers to improve mental health in Sierra Leone. / Aim: The two key aims were to assess the feasibility of training a national team to deliver a cognitive behavioural therapy (CBT)–based group intervention, and to evaluate the effectiveness of the overall intervention within this population. / Methods: UK clinicians travelled to Sierra Leone to train a small team of ex-ETC staff in a three-phased CBT-based intervention. Standardised clinical measures, as well as bespoke measures, were applied with participants through the intervention to assess changes in mental health symptomology, and the effectiveness of the intervention. / Results: The results found improvements across all factors of mental health in the bespoke measure from phase 1 to phase 3. Additionally, the majority of standardised clinical measures showed improvements between phase 2 and the start of phase 3, and pre- and post-phase 3. / Conclusion: Overall, the findings suggest that it is possible to train staff from ETCs to deliver effective CBT interventions to peers. The implications of these results are discussed, including suggestions for future research and clinical intervention implementation within this population. The limitations of this research are also addressed

    Simulation study of random sequential adsorption of mixtures on a triangular lattice

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    Random sequential adsorption of binary mixtures of extended objects on a two-dimensional triangular lattice is studied numerically by means of Monte Carlo simulations. The depositing objects are formed by self-avoiding random walks on the lattice. We concentrate here on the influence of the symmetry properties of the shapes on the kinetics of the deposition processes in two-component mixtures. Approach to the jamming limit in the case of mixtures is found to be exponential, of the form: θ(t)θjamΔθexp(t/σ),\theta(t) \sim \theta_{jam}-\Delta\theta \exp (-t/\sigma), and the values of the parameter σ\sigma are determined by the order of symmetry of the less symmetric object in the mixture. Depending on the local geometry of the objects making the mixture, jamming coverage of a mixture can be either greater than both single-component jamming coverages or it can be in between these values. Results of the simulations for various fractional concentrations of the objects in the mixture are also presented.Comment: 11 figures, 2 table

    Effect of varying the concentrations of carbohydrate and milk protein in rehydration solutions ingested after exercise in the heat

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    The present study investigated the relationship between the milk protein content of a rehydration solution and fluid balance after exercise-induced dehydration. On three occasions, eight healthy males were dehydrated to an identical degree of body mass loss (BML, approximately 1.8 %) by intermittent cycling in the heat, rehydrating with 150 % of their BML over 1 h with either a 60 g/l carbohydrate solution (C), a 40 g/l carbohydrate, 20 g/l milk protein solution (CP20) or a 20 g/l carbohydrate, 40 g/l milk protein solution (CP40). Urine samples were collected pre-exercise, post-exercise, post-rehydration and for a further 4 h. Subjects produced less urine after ingesting the CP20 or CP40 drink compared with the C drink (P<0.01), and at the end of the study, more of the CP20 (59 (SD 12) %) and CP40 (64 (SD 6) %) drinks had been retained compared with the C drink (46 (SD 9) %) (P,0.01). At the end of the study, whole-body net fluid balance was more negative for trial C (2470 (SD 154) ml) compared with both trials CP20 (2181 (SD 280) ml) and CP40 (2107 (SD 126) ml) (P<0.01). At 2 and 3 h after drink ingestion, urine osmolality was greater for trials CP20 and CP40 compared with trial C (P<0.05). The present study further demonstrates that after exercise-induced dehydration, a carbohydrate–milk protein solution is better retained than a carbohydrate solution. The results also suggest that high concentrations of milk protein are not more beneficial in terms of fluid retention than low concentrations of milk protein following exercise-induced dehydration

    A sodium drink enhances fluid retention during 3 hours of post-exercise recovery when ingested with a standard meal

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    The purpose of this study was to examine the efficacy of water and a 50 mmol/L NaCl solution on post-exercise rehydration when a standard meal was consumed during rehydration. Eight healthy participants took part in two experimental trials during which they lost 1.5 ± 0.4 % of initial body mass via intermittent exercise in the heat. Participants then rehydrated over a 60 minute period with water or a 50 mmol/L NaCl solution in a volume equivalent to 150% of their body mass loss during exercise. In addition, a standard meal was ingested during this time which was equivalent to 30% of participants predicted daily energy expenditure. Urine samples were collected before and after exercise and for three hours after rehydration. Cumulative urine volume (981 ± 458 mL and 577 ± 345 mL; P = 0.035) was greater, whilst percentage fluid retained (50 ± 20% and 70 ± 21 %; P = 0.017) was lower during the water compared to the NaCl trial respectively. A high degree of variability in results was observed with one participant producing 28% more urine and others ranging from 18 – 83% reduction in urine output during the NaCl trial. The results of this study suggest that after exercise induced dehydration, the ingestion of a 50 mmol/L NaCl solution leads to greater fluid retention compared with water, even when a meal is consumed post-exercise. Furthermore, ingestion of plain water may be effective for maintenance of fluid balance when food is consumed in the rehydration period
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