Subjects: Biology >> Botany >> Applied botany submitted time 2023-09-20 Cooperative journals: 《广西植物》
Abstract： Flowers of Rhododendron have unique poricidal dehiscence anther, but the formation of the dehiscence pore and the mechanism of pollen releasing are not known. The purpose of this research was to study the anther development of Rh. × pulchrum Sweet through microdissection and paraffin section to find out how the dehiscence pore develops and what tissues are involved in its development. The results were as follows: (1) The tissue forming the apical pore and the main body of the anther diverged from the very beginning of the stamen development. The dehiscence pore is formed by breaking down of parenchyma tissue, which is derived from the apical meristem of stamen primordium. The body part of the anther comes from the archesporial cells and they develop into regular pollen sacs with multi-layered anther walls. (2) The anther wall is fully differentiated at the stages from microspore mother cell to microspore tetrad and it consists of 6-7 layers: 1 layer of epidermis, 2-3 layers of endothecia, 1-2 layers of middle layers and 1 layer of tapetum. The middle layers soon break down after completion of microspore tetrads and the tapetum disappears before the pollen tetrads are fully mature. The epidermis and 2~3 layers of endothecia remain to the end; (3) Unlike those of longitudinal dehiscent anthers, the endothecia of Rh. × pulchrum are not fibrous at maturation. Instead, they are persistent and somewhat elastic through accumulation of polysaccharide granules in cells; (4) The four microspores produced by one microspore mother cell do not separate from each other and the pollens are released as tetrads, with viscous threads between pollens and among tetrads. The authors assume that the thickened multi-layer endothecia reduced the inner volume of the pollen sacs, therefore the pollen tetrads at the top are “squeezed out” from the dehiscence pore, and the viscous threads allow the pollen tetrads to be pulled out in clumps by pollinators.
Subjects: Psychology >> Social Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： Reward processing abnormalities are prominent in the clinical presentation of patients with major depression, bipolar disorder and schizophrenia. Reward processing comprises a dynamic set of cognitive component processes that may occur temporally adjacent to each other. Event-related potentials (ERPs), as one of the most commonly used tools to assess cognitive processing with a high temporal resolution, is a useful method to investigate complex, multifaceted constructs composed of the substages of reward processing. However, ERP research in psychiatric conditions has typically focused on a single component of reward processing rather than capturing the dynamics of reward processing. Reward processing can be decomposed into two temporally distinct stages: reward-anticipation and outcome-evaluation, each of which is associated with different ERP components (i.e., reward-anticipation: cue-related N2 and P3, stimulus-preceding negativity or SPN and contingent-negative variation or CNV; outcome-evaluation: feedback-related negativity or FRN/reward positive or RewP, feedback-related P3 or FB-P3 and the late positive potential or FB-LPP), and abnormal activities of these ERPs are closely related to transdiagnostic psychiatric symptoms. Attenuated cue-related N2 (associated with conflict detection) and cue-related P3 (associated with attention allocation) during reward-anticipation stage and blunted FRN/RewP (an initial reactivity to receipt of feedback) and FB-LPP (a sustained processing of motivationally salient stimuli) during outcome-evaluation stage could be found in patients with major depression compared to healthy controls, suggesting a reduced reward sensitivity in patients with depression. For CNV (associated with motor preparation), SPN (associated with anticipation feedback), and FB-P3 (associated with the evaluation of feedback), no consistent findings emerge in previous depression studies. Patients with schizophrenia exhibit abnormal activities of cue-related N2, cue-related P3 and SPN during reward-anticipation stage, and evidences of abnormal ERPs activities are inconclusive during outcome-evaluation stage. Currently few studies have investigated the reward-related ERP components in patients with bipolar disorder. Preliminary findings suggest that patients with bipolar disorder might have enhanced FRN activities during different stages of disease development. Further research should carefully consider some factors which might have an influence on the results, such as small samples, different experimental paradigms and data analysis methods, and the disease state of patients. In conclusion, utilizing multistage experimental designs and implementing multicomponent analyses hold great promise to investigate neurophysiological abnormalities during different stages of reward processing in psychiatric disorders.
Subjects: Psychology >> Medical Psychology submitted time 2022-10-20
Abstract： Abstract: Reward processing abnormalities are prominent in the clinical presentation of patients with major depression, bipolar disorder and schizophrenia. Reward processing comprises a dynamic set of cognitive component processes that may occur temporally adjacent to each other. Eventrelated potentials (ERPs), as one of the most commonly used tools to assess cognitive processing with a high temporal resolution, is a useful method to investigate complex, multifaceted construct composed of the substages of reward processing. However, ERP research in psychiatric conditions has typically focused on a single component of reward processing rather than capturing the dynamics of reward processing. Reward processing can be decomposed into two temporally distinct stages: reward-anticipation and outcome-evaluation, each of which is associated with different ERP components (i.e., reward-anticipation: cue-related N2 and P3, stimulus-preceding negativity or SPN and contingent-negative variation or CNV; outcome-evaluation: feedback-related negativity or FRN/reward positive or RewP, feedback-related P3 or FB-P3 and the late positive potential or FBLPP), and abnormal activities of these ERPs are closely related to transdiagnostic psychiatric symptoms. Utilizing multistage experimental designs and implementing multicomponent analyses hold great promise to investigate neurophysiological abnormalities during different stages of reward processing and enhance treatment development in psychiatric disorders.
Peer Review Status:
Awaiting Review
Subjects: Biology >> Ecology submitted time 2017-03-22 Cooperative journals: 《生态学报》
Abstract：本试验主要以秦岭山脉锐齿栎（Quercus aliena var. acutidentata）、油松（Pinus tabuliformis）、华山松（Pinus armandii）、云杉（Picea asperata）4种典型林分为对象，利用BIOLOG微孔板法研究4种林分夏、秋两季根际与非根际土壤微生物群落代谢多样性。研究表明：（1）夏、秋季土壤根际与非根际的平均颜色变化率（AWCD）值截然不同，除秋季云杉外，其余处理均表现为非根际>根际，且AWCD明显受到季节的影响。（2）夏秋两季4种林分根际与非根际土壤微生物功能多样性之间差异显著，其中锐齿栎林夏秋两季均表现为根际小于非根际，而其它3种针叶林则是夏季根际小于非根际，秋季根际大于非根际；锐齿栎林根际与非根际均为秋季低于夏季，其他3种针叶林则是非根际土秋季低于夏季，而根际土秋季高于夏季。（3）主成分分析显示各土壤微生物功能多样性具有显著差异，且4种林分夏秋两季根际与非根际主成分综合得分也有所不同，4种林分非根际土综合得分锐齿栎最高，其次是华山松和云杉，油松最低；根际土夏秋规律不同，夏季华山松和油松较高，云杉最低，秋季油松和云杉较高，锐齿栎最低，且综合得分与多样性指数达到显著或极显著的正相关。（4）冗余分析表明土壤理化性质的综合作用对土壤微生物群落功能多样性有显著影响。
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