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Abstract [Objective] The study aims to investigate the effects of drought stress on the photosynthetic characteristics and anatomical structure of turnip (Brassica rapa) leaves, and to provide a basis for the selection and breeding of drought-resistant germplasm and the development of cultivation measures. [Methods] Drought-resistant and drought-sensitive turnip seedlings were selected for normal water-supply and drought-stress potting experiments to analyze the changes in leaf photosynthetic characteristics and anatomical structures. [Results] Drought stress reduced chlorophyll a, chlorophyll b, and total chlorophyll contents, net photosynthetic rate, stomatal conductance, transpiration rate, stomatal limiting values, as well as maximal fluorescence, variable fluorescence, maximal photochemical efficiency, and photochemical potential activity of turnip leaves, while the inter-cellular CO2 concentration, water-use efficiency, and initial fluorescence were increased, with greater variations in drought-sensitive germplasm. Drought also reduced leaf stomatal length, width, openness, density, and tissue laxity, while leaf thickness was increased. Drought also caused swelling of chloroplasts, blurring of basal lamellae, the appearance of cavities, and an increase in osmiophilic and amylopectin granules, while mitochondria were swollen and their internal cristae blurring, while the drought-sensitive germplasm was severely damaged. [Conclusion] Drought stress reduces stomatal opening and tissue structure laxity, increases leaf thickness, impaires the morphological structure of chloroplasts and mitochondria, and reduces the chlorophyll content and photosynthetic efficiency. The drought-resistant germplasm has stronger adaptive regulation to drought stress.

Aimed at the staring imaging requirements of the low earth orbit (LEO) satellite array camera for aerial dynamic targets, a method for target position estimation and staring attitude planning based on image miss-distance of the satellite platform is proposed. Based on the prior knowledge of the flying altitude of the aerial dynamic target, taking the latitude and longitude change rate of the target geography as the state quantity and the central pixel value of the target as the observation, an extended Kalman filter (EKF) is designed to realize the accurate smooth estimation and prediction of the geographical latitude and longitude of the target. On this basis, the attitude and angular velocity of the satellite are planned, the influence of target pixel noise and delay on attitude stability is avoided, and the position estimation of a single satellite to target is realized. The effectiveness of the proposed method is illustrated by a numerical simulation.

Chevrel-type superatoms refer to the ligated transition metal chalcogenide clusters M6E8L6, where the octahedral M6 is face-capped with cubic chalcogen E8 (E = S/Se/Te). Most transition metals can form such superatoms and many organic and inorganic ligands can be substituted in solution reactions, which allows these atomic precision species to be easily functionalized and their properties to be tunable. No test was reported for substituting the chalcogens with pnicogens in this class of materials. In this article, we try to discover if such substitutions are possible. Combining different transition metals and ligands, theoretical computations show that [M6Q8(CN)6]2− (Q = P, As, Sb) for M = Co, Rh, Ir, and Ni, Pd, Pt have closed electronic shells and possess enhanced thermal and chemical stabilities. Analyses of the electronic structures indicate high similarity between the M–M and M–Q/M–S interactions in these species. [ABSTRACT FROM AUTHOR]

Objective: Limited research exists on the use of electroconvulsive therapy (ECT) for adolescents with major depressive disorder (MDD). This study investigates the effects of ECT on inflammatory markers in adolescents aged 13-18 suffering from severe MDD, evaluating its efficacy in modulating cellular inflammatory markers and ameliorating depressive symptoms. Methods: A cohort of 38 adolescents with severe MDD received standard antidepressant therapy along with 6-8 ECT sessions spanning two weeks. A control group of 29 age-matched, healthy individuals was also assessed for comparative purposes. The investigation measured variations in depressive symptomatology and inflammatory marker levels (IL-1β, IL-6, IL-10) pre- and post-intervention. Results: Post-ECT, a substantial decrease in pro-inflammatory cytokines (IL-1β and IL-6) and an increase in the anti-inflammatory cytokine (IL-10) were noted. Participants who responded to the treatment showed a significant decline in HAMD-17 scores, which accentuates ECT's therapeutic potential. Comparative analysis indicated a significant correlation between post-treatment inflammatory marker alterations and clinical improvement, implying that shifts in inflammatory state might serve as predictors of treatment response. Moreover, the mitigation of depressive symptoms exhibited a moderate correlation with post-treatment decrements in IL-1β and IL-6 levels, underscoring MDD's intricacy and ECT's comprehensive impact. Conclusion: While initial inflammatory marker levels did not predict the response to ECT, the post-treatment measures appeared to be linked to clinical improvement. These findings suggest ECT's potential effectiveness in treating severe MDD in adolescents and point to the possible predictive value of inflammatory markers in therapeutic outcomes. The study contributes to our understanding of the biopsychosocial framework of MDD and indicates that ECT may be a viable treatment option for this population. [ABSTRACT FROM AUTHOR]

Research has found that contact with a second language (L2), L2 motivation and foreign language anxiety are important variables affecting L2 learning. Nevertheless, not much research has explored the relationships among these variables and their interactive effects on L2 learning outcomes. The present large-scale survey study examined the relationships between English learning motivation, English classroom anxiety and use of English, as well as their predictive effects on Chinese university students' English achievement. A total of 439 randomly sampled students from two Chinese universities in Beijing answered the background information questionnaire, the 8-item English Classroom Anxiety Scale and the 35-item English Learning Motivation Questionnaire. The major findings were as follows: (a) English learning motivation, English classroom anxiety and use of English were significantly correlated with one another, and (b) English classroom anxiety, use of English and English learning motivation generally significantly predicted the students' English achievements. These findings confirm the importance of L2 motivation, foreign language anxiety and contact with the L2 for second language learners. Hence, specific suggestions (e.g., reading and listening to more of a second language, creating a supportive and relaxed L2 classroom environment, etc.) are discussed regarding how to enhance L2 learning motivation, reduce foreign language anxiety and increase contact with the L2 in second language learning, so as to ensure sustainable development in second language learning. [ABSTRACT FROM AUTHOR]

The present study examined how undergraduate students from a prestigious Chinese university perceived the teaching and learning of English for general academic purposes (EGAP) reading and writing courses. Analyses of 951 questionnaires revealed that most participants generally (strongly) believed that learning general academic English was closely related to their major study, reported being motivated to learn general academic English, and expected to improve their academic English reading, writing, listening and speaking skills from EGAP courses. The study also showed that they had consensus about the requirements and teaching and learning foci of general academic English in spite of their concerns about academic English, and that students of more demanding and more academic EGAP courses tended to have a better understanding of general academic English. Based on the findings, some suggestions are discussed.