762 research outputs found

    Is supplemental stocking of brown trout (Salmo trutta) worthwhile in low productive streams?

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    The effect of trout stocking was evaluated in two headstreams located in northern Portugal in order to assess the impact on wild trout (Salmo trutta L.) and to analyze the success of this operation. The results obtained exhibited the limitation of stocking: 1) the clumped character of the release fishes created a high mortality and limited the increasing of salmonid population to a few weeks; 2) because density-dependent factors seem to prevail in the regulation of salmonid populations, stocking is beneficial only if a population has became scarce, otherwise, the autochthonous fish may be strongly impacted; 3) the relative vulnerability of each age class of the native trout may vary according with the site

    Estudo da humidade e actividade de água de pranchas de cortiça durante o processo de fabrico de rolhas de cortiça - resultados preliminares

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    The main goal of this work was to make evidence of the applicability in the cork stopper industry of a control method along the cork slabs maturing stage after boiling, aiming to ensure the adequate conditions for Chrysonilia sitophila colonisation of cork slabs during that period, avoiding the development of other fungi. Cork humidity and water activity (wa) were used as indicators. Comparing the drying rate of the outer and the inner parts of the bark it could be observed, under the assay conditions, that to attain 0.9 wa, (the critical point for C. sitophila development), 39.8h were necessary in the case of outer bark while inner bark only need 20.4h. As the visible part of the cork slabs corresponds more to its outer part, the time of 40h can be taken as a good visible indicator to limit the cork slabs maturing period after boiling. Moreover it could be observed that under that period of time the evident prevailing fungus on the cork slabs was C. sitophila so probably assuring low probabilities of ‘cork taint’ occurrence, under the conditions propose on this study

    Effect of chronic infusion of leptin and nutrition on sexual maturation of zebu heifers

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    The amount of fat in the carcass has been proposed as a regulator of initiation of puberty in cattle. To test if changes in energy intake and in circulating leptin concentration are each capable of altering age, BW, and body composition at puberty, 36 prepubertal Nellore heifers, 18 to 20 mo old, 275.8 ± 17.2kg BW, and BCS of 5 ± 0.5 (1 to 9 scale), were randomly assigned to each of 3 treatments (n = 12): High (high energy diet), Low (low energy diet), and LL [low energy diet + ovine leptin (oLeptin)]. Diets were formulated to promote BW gain of 0.4 kg/d (groups Low and LL) or 1.2 kg/d (High group). After 14 d of adjustment to diet, heifers in LL group received subcutaneous injections of oLeptin at 4.8 μg/kg BW twice a day for 56 d. Groups High and Low received similar injections of 2 mL saline solution. Age at puberty was considered to be the age on first detection of a corpus luteum, confirmed by plasma concentrations of progesterone of >1 ng/mL. Heifers were slaughtered on the second day after first corpus luteum detection. Expression of leptin gene was quantified by real-time PCR using ribosomal protein-L19 (RPL19) as a control gene. Leptin administration increased (P = 0.04) leptin serum concentration but had no effect (P > 0.05) on age, BW, or BCS at puberty. High energy intake increased (P < 0.01) leptin concentration, accelerated (P = 0.02) puberty, and increased (P < 0.01) BCS at puberty, without altering (P = 0.17) BW at puberty. High energy intake also accelerated (P = 0.04) follicular development. Leptin administration caused a significant (P < 0.05) but transient increase in follicular development, which was similar to the transient increase in leptin serum concentration. Results from leptin gene expression demonstrated that high energy intake increased (P < 0.01) and leptin administration decreased (P < 0.01) leptin expression in 3 adipose tissues. The observed decrease in leptin gene expression after administration of leptin could explain the reduction in leptin serum concentration after 30 d of treatment and consequently the failure of leptin to accelerate puberty. Our findings did not support the hypothesis that reduced serum concentration of leptin is an important hindrance for puberty onset in malnourished zebu heifers. Although exogenous administration of leptin temporarily enhanced rate of follicular growth, it did not accelerate puberty

    Ordering Quantiles through Confidence Statements

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    Ranking variables according to their relevance to predict an outcome is an important task in biomedicine. For instance, such ranking can be used for selecting a smaller number of genes for then applying other sophisticated experiments only on genes identified as important. A nonparametric method called Quor is designed to provide a confidence value for the order of arbitrary quantiles of different populations using independent samples. This confidence may provide insights about possible differences among groups and yields a ranking of importance for the variables. Computations are efficient and use exact distributions with no need for asymptotic considerations. Experiments with simulated data and with multiple real -omics data sets are performed, and they show advantages and disadvantages of the method. Quor has no assumptions but independence of samples, thus it might be a better option when assumptions of other methods cannot be asserted. The software is publicly available on CRAN

    Antioxidant and anti-inflammatory properties of red, white and pink globe amaranth hydromethanolic extracts

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    Medicinal plants have been playing a vital role on human health and healing, representing one of the major sources of drugs in modem and traditional medicine [1]. Plants synthesize and preserve a variety of biochemical products that can be used as pharmaceutical compounds [2], and recently there has been an increasing interest in the therapeutic potential of plants as antioxidants and anti-inflammatories [3]. Oxidative stress and inflammation play critical roles in the pathogenesis of many diseases, such as cancer, cardiovascular disease, arthritis and obesity [4], among others. Thus, the aim of this study was to explore the bioactivity of red, white and pink globe amaranth (different cultivars of Gomphrena globosa L.) hydromethanolic extracts, namely the antioxidant and anti-inflammatory activities. The antioxidant activity was tested through radicals scavenging capacity, reducing power, and lipid peroxidation inhibition, whereas the anti-inflammatory activity was assessed by monitoring the inhibition of nitric oxide (NO) release in the mouse macrophage-like cell line RAW 264.7. The absence of toxicity of the extracts was also confirmed by the sulphorodamine B (SRB) assay applied to a porcine liver primary culture (PLP2) established by the authors. Among the three studied samples, pink globe amaranth showed the highest antioxidant activity, with the lowest ECso values (0.25 to 1.02 mg/mL), followed by red (0.41 to 1.30 mg/mL) and white (0.57 to 1.47 mg/mL) globe amaranth. Regarding the anti-inflammatory activity, pink and red globe amaranth also revealed the lowest ECso values (133 and 136 pg/mL, respectively), with white globe amaranth revealing an ECso value of 198pg/mL. None of the extracts presented cytotoxicity in PLP2 cells up to 400 pg/mL. From the results obtained, we can conclude that the extracts of these plants can be considered good sources of antioxidants and can also be used for anti-inflammatory purposes

    Governança de TI: Métodos Científicos nas Publicações de Tecnologia da Informação em Administração

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    O objetivo da pesquisa foi verificar a conformidade entre objetivos apresentados e suas conclusões, além dos métodos científicos utilizados nas pesquisas em Governança e Gestão de Tecnologia da Informação nas duas primeiras edições do ENANPAD. Foi desenvolvida uma pesquisa qualitativa/quantitativa, dividida em duas fases, onde se avaliou 179 artigos em periódicos nacionais e um estudo censitário com avaliação quali-quanti de 17 artigos apresentados nos dois primeiros anos do tema citado (2009-2010). Foi observado a predominância do paradigma positivista, trabalhos quantitativos, e método hipotético-dedutivo, além de ter sido identificada a predominância da análise fatorial, e no qualitativo, o estudo de caso único. Conformidade entre objetivo e conclusões

    Natural food colorants and preservatives: a review, a demand, and a challenge

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    The looming urgency of feeding the growing world population along with the increasing consumers’ awareness and expectations have driven the evolution of food production systems and the processes and products applied in the food industry. Although substantial progress has been made on food additives, the controversy in which some of them are still shrouded has encouraged research on safer and healthier next generations. These additives can come from natural sources and confer numerous benefits for health, beyond serving the purpose of coloring or preserving, among others. As limiting factors, these additives are often related to stability, sustainability, and cost-effectiveness issues, which justify the need for innovative solutions. In this context, and with the advances witnessed in computers and computational methodologies for in silico experimental aid, the development of new safer and more efficient natural additives with dual functionality (colorant and preservative), for instance by the copigmentation phenomena, may be achieved more efficiently, circumventing the current difficulties.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (Grant UIDB/00690/2020); national funding by F.C.T. and P.I., through the Institutional Scientific Employment Program-Contract for C.P. and L.B. contracts and C.N. (Grant 2021.05369.BD) and A.K.M. (Grant 2020.06231.BD) Ph.D. grants. The authors acknowledge the FEDER-Interreg España-Portugal Programme for financial support through the Project TRANSCoLAB 0612_TRANS_CO_LAB_2_P; to ERDF through the Regional Operational Program North 2020, within the scope of Project Mobilizador Norte-01-0247-FEDER-024479: Valor- Natural. The GIP-USAL is financially supported by the Spanish “Ministerio de Ciencia and Innovación” (Grant PID2019-106167RB-I00) and “Junta de Castilla y León” (Grants SA093P20 and CLU-2018-04).info:eu-repo/semantics/publishedVersio
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