RESUMO
Potato is an important crop worldwide and threatened by various environmental stresses, including elevated ozone (e[O3]). Here, we conducted a meta-analysis to quantify the effect of e[O3] on potato plants and how it varies depending upon different experimental conditions. Regarding plant growth and biomass, e[O3] significantly decreased shoot biomass by 18% and belowground biomass by 35%, while it increased the leaf area index by 19% and total number of injured leaves by 146%. As for yield, e[O3] significantly decreased the total tuber number by 21%. A relatively pronounced effect of e[O3] on the stomatal conductance was observed when exposure lasted 31-60 days, which was significantly greater than that after exposure lasted 96-311 days. The overall quantity of leaves was mainly decreased by higher (100-150 ppb) than lower (30-80 ppb) concentrations of e[O3] compared to ambient O3. The effect of e[O3] on the total tuber number was significant mainly when exposure lasted 31-90 days and was greater in plants grown in growth chambers than those planted in open-top chambers and glasshouses. The effect of e[O3] stress on physiology, growth, and yield varied among cultivars, with some cultivars showing marked tolerance relative to other cultivars. The findings can guide strategies to manage the negative impacts of e[O3] stress on potato production.
Assuntos
Ozônio , Folhas de Planta , Solanum tuberosum , Poluentes Atmosféricos/toxicidade , Ozônio/toxicidade , Fotossíntese , Estresse FisiológicoRESUMO
INTRODUCTION: College life is a challenging stage for students to transition from adolescence to early adulthood. College students need to adjust to various problems, including those related to learning, campus life, interpersonal relationships, career selection, emotions, and self. The aim of this study was to test the associations between different facets of mindfulness, resilience, and college adjustment, as well as the mediation effect of resilience between mindfulness and college adjustment among first-year college students. METHODS: This survey study recruited 765 first-year college students in China. The psychological variables were assessed by the Five Facet Mindfulness Questionnaire, the Connor-Davidson Resilience Scale, and the Chinese College Student Adjustment Scale. RESULTS: It has been showed in the current study that mindfulness and resilience were positively correlated with college adjustment. Resilience significantly mediated the associations between four dimensions of mindfulness (ie, describing, acting with awareness, observing and non-reactivity) and college adjustment. CONCLUSION: The findings support the potential importance of enhancing mindfulness and resilience to facilitate adjustment among first-year college students. Limitations and implications are discussed.
RESUMO
A simple and selective method was developed for the simultaneous determination of tetrandrine and fangchinoline in herbal medicine by HPLC with electrochemical detection (ECD) on a bare glassy carbon electrode. The HPLC separation and ECD conditions have been optimized. The separation was carried out on a WondaSil C18-WR column (4.6 mm × 250 mm, 5 µm), with the mobile phase of acetonitrile-ammonium acetate buffer (pH 6.5; 40 mM) (32:68, v/v) using an isocratic elution at the flow rate of 0.5 mL/min. The electrochemical detection potential was set at +0.9 V. The obtained LODs for tetrandrine and fangchinoline were 0.26 and 0.27 µmol/L, respectively. The method was successfully applied to the analysis of tetrandrine and fangchinoline contents in Stephania tetrandra S. Moore. It has been demonstrated that the LC-ECD method is an excellent technique for analysis of the herbal medicine. The mean recoveries were in the range of 95-105%, while the precision expressed as repetition of peak area was lower than 2.7%.