1,792 research outputs found

    Exploring the distilled realms: A study on whiskey and the travellers’ motivations

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    The study explores the impact of cultural alcoholic beverages, specifically whiskey, on travel motivations. Results from a quantitative research method indicate that both core cultural products and core whiskey products significantly influence the intention to participate in whiskey tourism. The findings suggest that promoting a destination’s reputation as a producer of high-quality cultural alcoholic beverages can enhance its appeal as a tourist destination, and whiskey as a cultural product can motivate tourism.info:eu-repo/semantics/publishedVersio

    Calibration of parameters in Dynamic Energy Budget models using Direct-Search methods

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    Dynamic Energy Budget (DEB) theory aims to capture the quantitative aspects of metabolism at the individual level, for all species. The parametrization of a DEB model is based on information obtained through the observation of natural populations and experimental research. Currently the DEB toolbox estimates these parameters using the Nelder–Mead Simplex method, a derivative-free direct-search method. However, this procedure presents some limitations regarding convergence and how to address constraints. Framed in the calibration of parameters in DEB theory, this work presents a numerical comparison between the Nelder–Mead Simplex method and the SID-PSM algorithm, a Directional Direct-Search method for which convergence can be established both for unconstrained and constrained problems. A hybrid version of the two methods, named as Simplex Directional Direct-Search, provides a robust and efficient algorithm, able to solve the constrained optimization problems resulting from the parametrization of the biological models.authorsversionpublishe

    A global hybrid derivative-free method for high-dimensional systems of nonlinear equations

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    Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) under the projects PTDC/MAT-APL/28400/2017 and UID/MAT/00297/2019. Marcia A. Gomes-Ruggiero: Partially supported by PRONEX-Optimization; CNPq (Grants 306220/2009-1 and 309733/2013-8); FAPESP (Grants 2013/05475-7 and 2013/07375-0) and CAPES.This work concerns the numerical solution of high-dimensional systems of nonlinear equations, when derivatives are not available for use, but assuming that all functions defining the problem are continuously differentiable. A hybrid approach is taken, based on a derivative-free iterative method, organized in two phases. The first phase is defined by derivative-free versions of a fixed-point method that employs spectral parameters to define the steplength along the residual direction. The second phase consists on a matrix-free inexact Newton method that employs the Generalized Minimal Residual algorithm to solve the linear system that computes the search direction. This second phase will only take place if the first one fails to find a better point after a predefined number of reductions in the step size. In all stages, the criterion to accept a new point considers a nonmonotone decrease condition upon a merit function. Convergence results are established and the numerical performance is assessed through experiments in a set of problems collected from the literature. Both the theoretical and the experimental analysis support the feasibility of the proposed hybrid strategy.authorsversionpublishe

    Holographic Principle bounds on Primordial Black Hole abundances

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    The generalized Second Law of thermodynamics and the Holographic Principle are combined to obtain the maximum mass of black holes formed inside a static spherical box of size RR filled with radiation at initial temperature TiT_{i}. The final temperature after the formation of black holes is evaluated, and we show that a critical threshold exists for the radiation to be fully consumed by the process. We next argue that if some form of Holographic Principle holds, upper bounds to the mass density of PBHs formed in the early universe may be obtained. The limits are worked out for inflationary and non-inflationary cosmological models. This method is independent of the known limits based on the background fluxes (from cosmic rays, radiation and other forms of energy) and applies to potentially important epochs of PBH formation, resulting in quite strong constraints to Ωpbh\Omega_{pbh}.Comment: Latex file, 2 .ps figures. To appear in Classical and Quantum Gravit

    A common deep source for upper-mantle upwellings below the Ibero-western Maghreb region from teleseismic P-wave travel-time tomography

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    Upper-mantle upwellings are often invoked as the cause of Cenozoic volcanism in the Ibero-western Maghreb region. However, their nature, geometry and origin are unclear. This study takes advantage of dense seismic networks, which cover an area extending from the Pyrenees in the north to the Canaries in the south, to provide a new high-resolution P-wave velocity model of the upper-mantle and topmost lower-mantle structure. Our images show three subvertical upper-mantle upwellings below the Canaries, the Atlas Ranges and the Gibraltar Arc, which appear to be rooted beneath the upper-mantle transition zone (MTZ). Two other mantle upwellings beneath the eastern Rif and eastern Betics surround the Gibraltar subduction zone. We propose a new geodynamic model in which narrow upper-mantle upwellings below the Canaries, the Atlas Ranges and the Gibraltar Arc rise from a laterally-propagating layer of material below the MTZ, which in turn is fed by a common deep source below the Canaries. In the Gibraltar region, the deeply rooted upwelling interacts with the Gibraltar slab. Quasi-toroidal flow driven by slab rollback induces the hot mantle material to flow around the slab, creating the two low-velocity anomalies below the eastern Betics and eastern Rif. Our results suggest that the Central Atlantic plume is a likely source of hot mantle material for upper-mantle upwellings in the Ibero-western Maghreb region

    Digestibilidade de gerações de perfilhos do capim Tanzânia.

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    O objetivo do presente experimento foi determinar o efeito da intensidade e do ciclo de pastejo sobre a digestibilidade in vitro da matéria orgânica de gerações de perfilhos de capim Tanzânia. O delineamento experimental foi de blocos completos ao acaso com três tratamentos (intensidade de pastejo alta, média e baixa) e quatro repetições. As gerações de perfilhos eram identificadas com fios de arame coloridos. Um dia antes de cada pastejo duas amostras eram cortadas por parcela e a digestibilidade in vitro da matéria orgânica de cada geração determinada. A digestibilidade das gerações de perfilhos foi maior nas áreas submetidas a elevada intensidade de pastejo e decresceu com o avanço da idade (redução de 3 a 6 pontos percentuais de digestibilidade por ciclo) .Os efeitos negativos do florescimento sobre o valor nutritivo da forragem podem ser reduzidos através de práticas de manejo que promovam uma maior renovação de perfilhos

    Pain Intensity and Time to Death of Cancer Patients Referred to Palliative Care

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    Introdução: A dor é uma experiência frequente nos doentes com cancro, especialmente naqueles em fase final de vida. Com este estudo, pretendemos estudar a intensidade de dor nos doentes com cancro avançado, referenciados aos cuidados paliativos, analisar os factores associados à ocorrência de dor moderada ou intensa e avaliar a sua relação com o tempo até à morte destes doentes. Material e Métodos: Estudo prospectivo observacional que incluiu consecutivamente todos os doentes referenciados aos cuidados paliativos com tumores sólidos metastizados e sem tratamento oncológico específico. Foi considerada a intensidade de dor da escala de Edmonton, de acordo com a graduação zero a 10, onde 0 = ausência de dor e 10 = máxima dor possível. Resultados: Entre outubro de 2012 e junho de 2015, foram incluídos 301 doentes, com idade mediana de 69 anos (37 - 94), 57% homens e 64,8% dos doentes com performance status 3/4. Aproximadamente 42% dos doentes apresentaram dor ≥ 4 e cerca de 74,4% estavam medicados com analgesia opióide. A intensidade de dor esteve associada ao performance status dos doentes, de acordo com a análise multivariável (OR: 1,7; IC 95%: 1,0 - 2,7; p = 0,045). A mediana do tempo de sobrevivência foi de 37 dias (IC 95%: 28 - 46), tendo os doentes com dor moderada ou intensa (intensidade de dor ≥ 4) uma mediana de sobrevivência de 29 dias (IC 95%: 21 - 37), comparada com os 49 dias (IC 95%: 35 - 63) para os doentes sem dor ou dor ligeira (p = 0,022). Discussão: O performance status, para além de ter estado associado a uma maior intensidade de dor, esteve associado a um menor tempo até à morte dos doentes com cancro avançado referenciados aos cuidados paliativos. Também o internamento, a presença de metastização intra-abdominal e a analgesia opióide estiveram associados de forma negativa ao tempo até à morte destes doentes. Conclusão: A dor oncológica continua a ser um problema clinicamente relevante nos doentes com cancro avançado

    Toxic effects of Ricinus communis non-protein trypsin inhibitor on Spodoptera frugiperda (J. E. Smith) (Lepidoptera:Noctuidae)

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    In the study reported herein, we aimed to isolate a trypsin inhibitor from Ricinus communis leaves through chromatographic and spectrometric techniques and evaluate its toxic effects on the development of Spodoptera frugiperda larvae. Plant extracts were submitted to fractionation in adsorption column. The fraction 10, which showed the highest inhibitory activity, were incorporated into an artificial diet at the concentrations of 0, 0.06, 0.12, 0.25 and 0.5%, and offered to S. frugiperda larvae. Fresh weight of larvae, food consumed and weight of eliminated faeces were registered. Based on these parameters the following nutritional index were calculated: Relative Consumption Rate (RCR), Relative Metabolic Rate (RMR), Relative Growth Rate (RGR), Approximated Digestibility (AD), Efficiency of Ingested Food Conversion (EIC), Efficiency of Digested Food Conversion (EDC) and the Metabolic Cost (100 - EDC). The inhibitor at 0.5% concentration was deleterious to S. frugiperda, extending the larval stage in 11 days, with higher RCR and ECD, and lower RGR, ECI and ECD. Therefore, the trypsin inhibitor from leaves of R. communis affected the S. frugiperda larval development, being promising in studies of alternative and sustainable control methods for lepidopteran pest species.Keywords: Castor beans, enzymatic inhibition, integrated pest management, plant defense against herbivor

    Role of physical activity and diet in incidence of hypertension: a population-based study in Portuguese adults

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    Background/Objectives: To evaluate longitudinally the role of physical activity (PA) (type and intensity) and diet (measured using DASH score, nutrients and food intake) in hypertension incidence. Subjects/Methods: As part of the EPIPorto study, 549 participants (X40 years), resident in Porto, Portugal, at risk of developing hypertension, were evaluated. Blood pressure (BP) measurements were obtained twice (1999–2003 and 2005–2008), with a median interval of 3.8 years. Hypertension was defined as systolic BP>=140mmHg and/or diastolic BP>=90mmHg, and/or if the subjects were under anti-hypertensive therapy. Validated questionnaires were used to assess usual PA and dietary intake during the previous year. Poisson regression was used to calculate the incident rate ratios (IRRs) and respective 95% confidence intervals (95% CIs). Results: In our population, the crude incidence rate (95% confidence interval (CI)) per 100 person-years of hypertension was 6.23 (5.26–7.20). After adjustment for several confounders, an inverse, though not significant, association was found across increasing tertiles of leisure-time PA and IRR (95% CI): 1 (reference); 0.77 (0.51–1.16); and 0.74 (0.48–1.11). No significant associations between the DASH score and hypertension incidence were observed. However, potassium intake (mg/1000 kcal) was shown to be inversely associated with hypertension development (upper tertile: >1863.0 for women and >1657.2 for men) vs first tertile (IRR=0.65 (0.44–0.96), P for trend=0.025). Additionally, in multivariate analysis, a significantly inverse association between the consumption of fruits/vegetables/pulses and hypertension incidence was found (upper vs first tertile: IRR=0.61 (0.40–0.93), P for trend=0.024). Conclusions: In Portuguese adults, after adjustment for several confounders, the development of hypertension was inversely associated with potassium and fruits/vegetables/pulses intake. A dose–response is inherent to these inverse associations
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