15 research outputs found

    Diagrama de manejo de densidad y su aplicación a raleo en bosques de segundo crecimiento de Drimys winteri en el sur de Chile

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    Stand density management (DMD) diagrams are graphical models of uniform stands at different ages that reflect the relationship among size, density, competition, site occupancy and self thinning. DMDs allow planning of thinnings through the definition of a target stand and the upper and lower limits of site occupancy. In this study we developed a DMD for Drimys winteri second-growth forests in southern Chile by using 300 sampling units with at least 70 % basal area of this species. The resulting DMD allowed the determination of the maximum density line, the volume and height isolines, and the evaluation of its use with information from permanent plots thinned 21 years ago. The results of the functions in the DMD present acceptable predictive power, and illustrate the usefulness and precision of this tool to plan silviculture activities. Results from applying the DMD suggest maintenance of site occupancy levels between the subutilization zone (30 % relative density index (RDI)) and the imminent mortality zone (45 % IDR), executing at least three thinnings to reach a target stand that will produce sawtimber and veneer at an age of at least 80 years for the study site. With this scheme the windfall risk is reduced and therefore so is the potential loss of production

    Sweet cherry production in South Patagonia

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    In South Patagonia, the total sweet cherry (Prunus avium L.) area has increased from 176 ha in 1997 to 507 ha in 2004, of which 232 ha are located in Los Antiguos (46°19¿ SL; 220 m elevation), 158 ha in the Lower Valley of Chubut River (LVCHR) (43°16¿ SL; 30 m elevation), 52 ha in Sarmiento (45°35¿ SL; 270 m elevation), 35 ha in Esquel (42°55¿ SL; 570 m elevation) and 30 ha in Comodoro Rivadavia (45°52¿ SL; 50 m elevation). The most common varieties are `Lapins¿, `Bing¿, `Newstar¿, `Sweetheart¿, `Stella¿, `Sunburst¿ and `Van¿ grafted on `Mahaleb¿, `Pontaleb¿, `SL 64¿, `Colt¿ or `Mazzard¿ rootstocks. Trees generally are drip-irrigated and planted at high densities, using training systems such as Tatura, central leader and modified vase (2700, 1100 and 1000 trees ha-1, respectively). Growers in Los Antiguos are more traditional, planting mainly as vase (400 to 1000 trees ha-1) or freestanding trees (280 trees ha-1) and irrigating by gravity (74% of the area). Only 4.4% of the area of Los Antiguos is frost protected, as growers rely strongly on the moderating effect of Lake Buenos Aires. Frost control systems are absent in Comodoro Rivadavia because the established orchards are located next to the sea, in an area with low risk of frost. The frost-protected area is 49% in Sarmiento, 35% in Esquel and 57% in LVCHR. Fruit are harvested from November (LVCHR) to the end of January (Los Antiguos and Esquel), and the harvest-only labour demand during the 2004/2005 season was 100,000 h. In that season, seven packinghouses exported 390 t (45% of the total production) to Europe. Most orchards have not yet reached their mature stage and new ones are being established. Therefore, fruit volumes will continue to increase and shortages of labour and packing facilities may become a constraint

    Top quark effects in composite vector pair production at the LHC

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    In the context of a strongly coupled Electroweak Symmetry Breaking, composite light scalar singlet and composite triplet of heavy vectors may arise from an unspecified strong dynamics and the interactions among themselves and with the Standard Model gauge bosons and fermions can be described by a SU(2)L×SU(2)R/SU(2)L+RSU(2)_L\times SU(2)_R/SU(2)_{L+R} Effective Chiral Lagrangian. In this framework, the production of the V+VV^{+}V^{-} and V0V0V^{0}V^{0} final states at the LHC by gluon fusion mechanism is studied in the region of parameter space consistent with the unitarity constraints in the elastic channel of longitudinal gauge boson scattering and in the inelastic scattering of two longitudinal Standard Model gauge bosons into Standard Model fermions pairs. The expected rates of same-sign di-lepton and tri-lepton events from the decay of the V0V0V^{0}V^{0} final state are computed and their corresponding backgrounds are estimated. It is of remarkable relevance that the V0V0V^{0}V^{0} final state can only be produced at the LHC via gluon fusion mechanism since this state is absent in the Drell-Yan process. It is also found that the V+VV^{+}V^{-} final state production cross section via gluon fusion mechanism is comparable with the V+VV^{+}V^{-} Drell-Yan production cross section. The comparison of the V0V0V^{0}V^{0} and V+VV^{+}V^{-} total cross sections will be crucial for distinguishing the different models since the vector pair production is sensitive to many couplings. This will also be useful to determine if the heavy vectors are only composite vectors or are gauge vectors of a spontaneously broken gauge symmetry.Comment: 18 pages, 5 tables, 6 figures. Missing figures added. Matches published versio

    Developing methods to compare tablet formulations of atorvastatin

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    Atorvastatin (ATV) is an antilipemic drug of great interest to the pharmaceutical industry. ATV does not appear in the monographs of Brazilian pharmacopoeia, and analytical methodologies for its determination have been validated. The chromatographic conditions used included: RP-18 column-octadecylsilane (250 x 4.6 mm, 5 mm), detection at 238 nm, mobile phase containing 0.1% phosphoric acid and acetonitrile (35:65% v/v), flow at 1.5 mL min-1, oven temperature at 30ºC, and injection volume of 10 mL. ATV is classified as a class II product, according to the biopharmaceutical classification system. As such, a dissolution test was proposed to evaluate pharmaceutical formulations on the market today, under the following conditions: water as a dissolution medium, 1000 mL as a volume, paddle apparatus at a rotation speed of 50 rpm, 80% (Q) in 15 minutes with UV spectrophotometer readings at 238 nm. In the pattern condition proposed as the ideal dissolution test, which appropriately differentiates amongst formulations, the generic product was not considered pharmaceutically equivalent; however, in other less differential dissolution methods, which also fall within appropriate legal parameters, this product could come to be regarded as generic.Atorvastatina (ATV) é um fármaco antilipêmico de grande interesse para a indústria farmacêutica. ATV não apresenta monografia na Farmacopéia Brasileira e metodologias analíticas para sua determinação foram validadas. As condições cromatográficas utilizadas foram: coluna RP-18-octadecilsilano (250 x 4.6 mm, 5 mm), detecção em 238 nm, fase móvel contendo ácido fosfórico 0,1% e acetonitrila (35:65% v/v), fluxo de 1,5 mL min-1, temperatura do forno de 30 ºC e volume de injeção de 10 mL. ATV é classificada como um fármaco de classe II, de acordo com o sistema de classificação biofarmacêutica (SCB). Como tal, um teste de dissolução foi proposto para avaliar as formulações farmacêuticas do mercado atual, sob as seguintes condições: água como meio de dissolução, volume de 1000 mL, aparato pá, velocidade de rotação de 50 rpm, 80% (Q) em 15 minutos com leituras espectrofotômetro UV a 238 nm. Na condição padrão proposta para o teste de dissolução, o qual seria capaz de diferenciar apropriadamente as formulações farmacêuticas, o produto genérico não foi considerado equivalente farmacêutico. No entanto, em outros métodos de dissolução menos discriminativos, que também seriam considerados apropriados pelos parâmetros legais, este produto pode vir a ser considerado como genérico

    The Psychological Science Accelerator’s COVID-19 rapid-response dataset

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    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    The Psychological Science Accelerator’s COVID-19 rapid-response dataset

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    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    Ocorrência de Spalangia endius Walker, 1839 (Hymenoptera, Pteromalidae) em pupas de Musca domestica L. e Stomoxys calcitrans L. (Diptera, Muscidae) no sul do Rio Grande do Sul

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    It was reported the occurrence of Spalangia endius Walker, 1839 (Hymenoptera, Pteromalidae) as a parasitoid of pupae of Musca domestica Linnaeus, 1758 (Diptera, Muscidae) and Stomoxys calcitrans Linnaeus, 1758 (Diptera, Muscidae) in the extreme Southern of Brazil. The collection of pupae was performed in January and February, 2008. The pupae of M. domestica and S. calcitrans were collected from bovine feces using the flotation method. The pupae were individualized in glass tubes and maintained in acclimatized chamber at 27±2ºC with relative air humidity > 70% until the emergence of the flies or the parasitoids. The referred occurrence consists in the first report to Rio Grande do Sul
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