Selenocianato alílico, processo de obtenção e usos do mesmo e composição de enxaguatório bucal

Universidade Federal de Santa CatarinaUniversidade Federal do Rio Grande do SulQuímicaFarmáciaDepositad

A global experiment on motivating social distancing during the COVID-19 pandemic

Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

Modelling lucerne (Medicago sativa L.) crop response to light regimes in an agroforestry system

The general goal of this research was to understand the agronomic and physiological changes of a lucerne crop in distinct physical radiation environments and to verify the potential of lucerne to grow under shaded conditions. To achieve this, the research was conducted in four main steps: (i) firstly, experimental data collection in the field using two artificial shade materials (shade cloth and wooden slats) under inigated and non-irrigated conditions; (ii) a second experiment with data collection in a typical temperate dryland agroforestry area under non-irrigated conditions; (iii) generation of a light interception sub-model suitable for shaded crops and (iv) a linkage between the light interception sub-model and a canopy photosynthesis model for agroforestry use. In experiments 1 and 2, lucerne crop was exposed to 6 different light regimes: full sunlight (FS), shade cloth (FS+CL), wooden slats (FS+SL), trees (T), trees+cloth (T +CL) and trees+slats (T+SL). The FS+SL structure produced a physical radiation environment (radiation transmission, radiation periodicity and spectral composition) that was similar to that observed in the agroforestry site (f). The mean annual photosynthetic photon flux density (PPFD) was 41 % under the FS+CL, 44% under FS+SL and 48% under T compared with FS in clear sky conditions. Plants were exposed to an intermittent (sun/shade) regime under both FS+SL and T, whereas under FS+CL the shaded light regime was continuous. The red to far-red (RIFR) ratio measured during the shade period under the slats was 0.74 and under the trees was 0.64. However, R/FR ratio increased to 1.26 and 1.23 during the illuminated period under FS+SL and T, respectively, and these were equivalent to the ratio of 1.28 observed under the FS+CL and 1.31 in FS. The radiation use efficiency (RUE) of shoots increased under the 5 shaded treatments compared with full sunlight. The pattern of radiation interception was unchanged by radiation flux, periodicity and spectral composition and all treatments had a mean extinction coefficient of 0.82. However, the magnitude of the decrease in canopy growth was less than those in PPFD transmissivity. The mean lucerne annual dry matter (DM) yield was 17.5 t ha⁻¹ in FS and 10 t ha⁻¹ under the FS+CL, FS+SL and T regimes. This declined to 3.4 t DM ha⁻¹ under T+CL (22% PPFD transmissvity) and 4.1 t DM ha⁻¹ under T+SL (23% transmissivity). A similar pattern of response was observed for leaf net photosynthesis (Pn) rates under the shade treatments compared with full sun. In addition, spectral changes observed under the trees and slats affected plant motphology by increasing the number of long stems, stem height and internode length compared with full sunlight. Thus, there were two main explanations for the increase in RUE under shade compared with full sun: (i) preferential partition of assimilates to shoot rather than root growth and/or (ii) leaves under shade were still operating at an efficient part of the photosynthetic light curve. The changes proposed for the canopy Pn model were appropriate to simulate the radiation environment of an agroforestry system. However, the model underestimated DM yields under the continuous and intermittent shade regimes. These were considered to be mainly associated with plant factors, such as overestimation in maintenance respiration and partitioning between shoots and roots in shade and the intermittency light effect on leaf Pn rates. Further investigation in these topics must be addressed to accurately predict crop yield in agroforestry areas. Overall, the lucerne crop responded typically as a sun-adapted plant under shade. It was concluded that lucerne yield potential to grow under intermediate shade was superior to most of C3 pastures previously promoted in the literature

Comparação da variabilidade temporal do NDVI para cereais de inverno destinados à produção de grãos e para pastagem no Planalto Meridional do Rio Grande do Sul

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Comparação da variabilidade temporal do NDVI para cereais de inverno destinados à produção de grãos e para pastagem no Planalto Meridional do Rio Grande do Sul

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Use of Cattle and Sheep as Agents to Control the Growth of Native Vegetation underneath of Three Eucalyptus Populations

O objetivo deste trabalho foi avaliar cinco sistemas de controle da vegetação nativa e os danos provocados por bovinos e ovinos em três populações de eucalipto. O delineamento experimental foi em parcelas subdivididas, com dois blocos completos. Os tratamentos foram: a) três densidades de Eucalyptus saligna Smith. (204, 400 e 816 árvores/ha) nas parcelas principais e b) cinco sistemas de controle da vegetação nativa (sem controle, herbicida pré-emergente, herbicidas pré e pós-emergentes, pastejo com bovinos e com ovinos) nas subparcelas. O pastejo com bovinos ou ovinos foi mais eficiente na redução da vegetação nativa que nos demais tratamentos. Os bovinos danificaram mais as árvores que os ovinos. Existe estreita relação entre a altura das mudas de eucalipto e os danos causados pelos bovinos e ovinos no momento da introdução destes animais no sub-bosque.The objective of this work was to evaluate five control systems of native vegetation and the damages caused by cattle and sheep to trees of three eucalyptus populations. A split-plot experimental design in two randomized complete blocks was used. Treatments were a) three populations of Eucalyptus saligna Smith. (204, 400 and 816 plants/ha) as the main plots; b) five control systems of the native vegetation (without control, pre-emergent herbicide, pre and post-emergent herbicides, cattle grazing or sheep grazing) as subplots. The cattle and sheep grazing were the most efficient than any other treatments. The cattle caused more damage to the trees than sheep did. There is a close relation between tree height and damages caused by cattle and sheep at the moment of the introduction of these animals in the underneath forest

Uso de bovinos e de ovinos como agentes de controle da vegetação nativa sob três populações de eucalipto

O objetivo deste trabalho foi avaliar cinco sistemas de controle da vegetação nativa e os danos provocados por bovinos e ovinos em três populações de eucalipto. O delineamento experimental foi em parcelas subdivididas, com dois blocos completos. Os tratamentos foram: a) três densidades de Eucalyptus saligna Smith. (204, 400 e 816 árvores/ha) nas parcelas principais e b) cinco sistemas de controle da vegetação nativa (sem controle, herbicida pré-emergente, herbicidas pré e pós-emergentes, pastejo com bovinos e com ovinos) nas subparcelas. O pastejo com bovinos ou ovinos foi mais eficiente na redução da vegetação nativa que nos demais tratamentos. Os bovinos danificaram mais as árvores que os ovinos. Existe estreita relação entre a altura das mudas de eucalipto e os danos causados pelos bovinos e ovinos no momento da introdução destes animais no sub-bosque