分类: 心理学 >> 心理测量 提交时间: 2020-04-19
摘要: 及时性诊断反馈有助于学生和教师根据当前诊断结果及时调整后续学习和教学规划。针对当前纵向学习诊断模型采用的同时性估计策略无法提供及时性诊断反馈的问题,本研究提出一种新的马尔可夫估计策略,并通过模拟研究对比探究了同时性、马尔可夫、简单分离和锚题分离四种参数估计策略的表现。结果显示四者的表现具有较高一致性且呈现如下相对优劣顺序:同时性>马尔可夫>锚题分离≥简单分离。表明新策略在略微牺牲参数估计精度的前提下,可为实践者提供及时性诊断反馈,更符合“为学习而测评”的理念和形成性评价的需求。
分类: 生物学 >> 昆虫学 提交时间: 2020-04-19
摘要: Two mitogenomes of Cladiucha were newly reported and shown typical pattern of gene arrangement. The phylogenetic position of Cladiucha was obtained from tree reconstruction using various data treatment methods and substitution models. Significant heterogeneity in the nucleotide composition and mutational biases was found in the mitochondrial protein-coding genes, and the third codon position exhibited high levels of saturation. Therefore, 14 datasets were conducted under both site-homogeneous and site-heterogeneous models. The following conclusions were drawn from the phylogenetic analyses: (i) the monophyly of Tenthredinidae was confirmed, (ii) the monophyly of Allantinae + Tenthredininae + Megabelesinae was approved, and (iii) within the family, ((((Tenthredininae + Fenusinae) + Allantinae) + Megabelesinae) + Nematinae) is probably the most acceptable cladogram for the phylogeny of Tenthredinidae, which is also supported by the morphological analysis and a comparative study on the rRNA secondary structure. Divergence time estimation analyses indicated that diversification of the major superfamilies of the suborder Symphyta occurred around 232.9 Ma, and the splits of Tenthredinidae were dated to 146 Ma, which corresponding to the origin of the earliest lineages of flowering plants and major diversifications of core angiosperms, respectively. The Cladiucha arose in the Mid-Miocene; at that time, magnoliids are rapidly undergoing genus-species differentiation. "
分类: 心理学 >> 应用心理学 提交时间: 2020-04-19
摘要: 本研究探讨了新冠肺炎疫情爆发期民众的疫情风险感知和社会支持对其防护行为的影响,以及社会信任和应对效能在其间的中介作用。结果发现:(1)民众对新冠肺炎疫情的风险感知处于中等偏上水平,民众面对新冠肺炎疫情采取了积极主动的防护行为。(2)民众的情绪型风险感知和社会支持对其所采取的积极行动和计划解决防护行为具有直接的预测作用。(3)民众的社会信任和应对效能在情绪型风险感知与防护行为间起部分的中介作用,民众的社会信任和应对效能在认知型风险感知与防护行为间起完全的中介作用,民众的社会信任和应对效能在社会支持与防护行为间起部分的中介作用。
分类: 生物学 >> 病毒学 提交时间: 2020-04-19
摘要: The ongoing outbreak of Coronavirus Disease 2019 (COVID-19) has become a global pandemic and crisis. SARS-coronavirus-2 (SARS-CoV-2), the causative pathogen of COVID-19, is a positive-sense single-stranded RNA virus belonging to the family Coronaviridae. For RNA viruses, virus-encoded RNA helicases have long been recognized to play pivotal roles during viral life cycles by facilitating the correct folding and replication of viral RNAs. Here, our studies show that SARS-CoV-2-encoded nonstructural protein 13 (nsp13) possesses the nucleoside triphosphate hydrolase (NTPase) and RNA helicase activities that can hydrolyze all types of NTPs and unwind RNA helices dependently of the presence of NTP, and further characterize the biochemical characteristics of these two enzymatic activities associated with SARS-CoV-2 nsp13. Moreover, we found that some bismuth salts could effectively inhibit both the NTPase and RNA helicase activities of SARS-CoV-2 nsp13 in a dose-dependent manner. Thus, our findings demonstrate the NTPase and helicase activities of SARS-CoV-2 nsp13, which may play an important role in SARS-CoV-2 replication and serve as a target for antivirals.