1,752 research outputs found

    Suplementação mineral e produtividade de cogumelo Shiitake em toros de eucalipto

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    As estimativas de produtividade do cogumelo Shiitake no Brasil em eucalipto são otimistas mas, na prática, a produção nessa madeira é baixa e inconstante. Visando aumentar a produtividade do Shiitake, estudaram-se as interações entre doses de suplementação mineral, em relação a três linhagens do cogumelo (Le 95/01, 96/17 e 96/18) inoculadas em toros de eucalipto de sétimo corte. A suplementação mineral foi realizada na água de imersão dos toros, no momento de cada indução da frutificação, nas seguintes concentrações: 0,00% (sem adição de suplementos), 0,05% (sulfato de amônio, com 18% de nitrogênio solúvel em água, na dosagem 0,35 g L-1 e superfosfato triplo, com 34% de fósforo solúvel em água, na dosagem 0,15 g L-1) e na concentração 0,50% (correspondendo à dosagem dez vezes maior que a anterior). Houve aumento de produtividade na linhagem Le 95/01. Toros inoculados com Le 96/17 foram mais produtivos apenas na dose de 0,05% e, para a linhagem Le 96/18 a produtividade diminuiu com a suplementação. A avaliação do crescimento radial com essas linhagens (meio de cultura de serragem com as mesmas concentrações salinas utilizadas no experimento em toros) evidenciou que todas responderam positivamente à suplementação e que, as respostas positivas da linhagem Le 95/01 e negativa da Le 96/18 obtidas no cultivo em toros de eucalipto de sétimo corte, são reflexos da maior competitividade da primeira linhagem em relação à segunda. A suplementação aumenta a produtividade desde que os toros estejam bem colonizados pelo Shiitake.Brazilian reports on Shiitake mushroom [Lentinula edodes (Berkeley) Pegler] productivity grown on Eucalyptus saligna (Sm.) logs are optimistic. The current production on this kind of wood is, however, low and variable. Aiming at increasing Shiitake mushroom productivity, the present work studied interactions among three concentrations of mineral supplement and three Shiitake strains (Le 95/01, 96/17 and 96/18) grown on seventh cut eucalyptus logs. Mineral fertilization was carried out when the logs were submerged in water to induce fruiting bodies, using the following saline concentrations: zero (no fertilizers added), 0.05% (equivalent to 0.35 g L-1 of ammonium sulfate with 18% nitrogen and 0.15 g L-1 of superphosphate with 34% phosphorus) and 0.50%. Fertilization of the Le 95/01 strain increased productivity, but logs inoculated with the Le 96/17 strain were more productive only at 0.05% concentration while in the Le 96/18 strain, mineral supplementation decreased in productivity. The radial growth of these Shiitake strains (in sawdust-agar medium and with the same saline concentrations used in the log experiment) showed that all strains reacted positively to fertilization and that positive results for the Le 95/01 strain and negative results for Le 96/18 on eucalyptus logs are due to the natural higher competitiveness of the first Le 95/01 in relation to the latter Le 96/18 strain. Mineral fertilization increases the productivity provided that the logs are well colonized by Shiitake mushrooms

    Caracterização morfomolecular de isolados de Pleurotus ostreatus (Jacq. Fr.) kummer em relação à luminosidade e temperatura de frutificação

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    A temperatura é um dos principais fatores que influenciam o desenvolvimento e a introdução de cogumelos em nova áreas. O efeito da temperatura (15ºC e 28ºC) e a luminosidade (120 e 900 lux) foram avaliados em oito isolados de P. ostreatus quanto à precocidade, eficiência biológica, área do pileus, padrão de formação das pencas, coloração e resistência ao manuseio. A variabilidade genética dos isolados foi analisada pelo método "Random Amplified Polymorphic DNA" ou DNA polimórfico amplificado ao acaso (RAPD). O isolado Pos 98/37 foi o único a produzir a 28ºC e 900 lux, apresentando píleo branco nessa temperatura e cinza a 15ºC e 120 lux. O isolado Pos 96/05, o mais tardio, apresentou píleo chumbo a 15ºC a 120 lux, assim como os demais isolados nesta temperatura. Os isolados cultivados a 15ºC não diferiram quanto à maior resistência ao manuseio, enquanto a 28ºC, os cogumelos obtidos foram mais frágeis. Quanto à eficiência biológica, o isolado Pos 98/38 foi mais eficiente. O isolado 98/37 a 28ºC, comparado com o mesmo isolado a 15ºC, foi mais eficiente e apresentou padrão de formação de pencas assimétrico. Entre os isolados cultivados a 15ºC, o padrão de formação de pencas foi similar exceto nos isolados Pos 97/15 e Pos 97/17. Na caracterização molecular, o isolado Pos 98/37 apresentou 30% de similaridade com os demais. A temperatura de frutificação e a intensidade luminosa influenciaram a indução e o desenvolvimento dos isolados.Temperature is one of the main factors affecting mushrooms development and introduction in new areas. Effects of temperature (15ºC and 28ºC) and luminosity (120 and 900 lux) were evaluated for eight P. ostreatus strains in relation to precocity, yield, pileus area, stalk formation pattern, coloration and handling resistance. Genetic variability of strains was analysed by the Random Amplified Polymorphic DNA (RAPD) method. The Pos 98/37 strain was the only to yield white pileus at 28ºC - 900 lux, and grey ones at 15ºC and 120 lux. The Pos 96/05 strain, the latest, produced lead-coloured pileus at 15ºC, as did the remaining strains at this temperature. Strains cultivated at 15ºC did not differ in relation to handling resistance. At 28ºC mushrooms were less resistant. In relation to yield, the Pos 98/38 strain was significantly more efficient. The Pos 98/37 strain, at 28ºC, as compared to the same strain at 15ºC, was more efficient and had an asymmetric stalk formation pattern. Among strains cultivated at 15ºC, the stalk formation pattern was symmetric, except for the Pos 97/15 and Pos 97/17 strains. Molecular characterization of the Pos 98/37 strain was 30% similar to the remaining strains. The temperature of fructification and luminosity influence the induction and development of the isolates

    Adolescent use of social media and associations with sleep patterns across 18 European and North American countries

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    Objective: Over the past decade, concurrent with increasing social media use (SMU), there has been a shift toward poorer sleep among adolescents in many countries. The purpose of this study was to examine the cross-national associations between adolescent SMU and sleep patterns, by comparing 4 different categories of SMU (nonactive, active, intense, and problematic use). Design, setting, and participants: Data were from 86,542 adolescents in 18 European and North American countries that participated in the 2017/18 Health Behaviour in School-aged study. Measurements: Mixed-effects linear regression models were used to examine cross-national associations between 4 SMU categories and adolescent sleep duration, bedtime and social jetlag derived from self-reported data. Results: For all countries combined, nonactive SMU was associated with longer sleep, earlier bedtimes, and less social jetlag, compared to active SMU, although the differences were minor. By comparison, intense and problematic SMU were associated with less sleep and later bedtimes on both school and nonschool days, and greater social jetlag, compared to active SMU. While findings were relatively consistent between countries, some differences were observed, suggesting that the national and cultural context may be important in interpreting results. Conclusions: These findings suggest that both intense and problematic SMU are associated with poorer sleep patterns in adolescents across most countries. Further research is needed to identify effective policies, programs, and messaging to promote the healthy use of social media and prevent potential negative impacts on adolescent sleep

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Search for stop and higgsino production using diphoton Higgs boson decays

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    Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

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    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe
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