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171.
脓毒症多呈现典型的促炎效应和抗炎反应,并与获得性免疫功能障碍同时出现,且免疫细胞中超过80%的基因表达发生改变。由于单核/巨噬细胞细胞因子谱的改变、主要组织相容性复合体Ⅱ类抗原(MHCⅡ)及共刺激分子表达下降以及树突状细胞的凋亡,诱发细胞免疫功能下降;中性粒细胞活性降低和补体系统的激活,又增加感染易感性。T淋巴细胞表现...  相似文献   
172.
采用记忆更新任务,实验1要求被试分别更新3个和4个记忆项目,并设置不转换、控制转换和抑制转换条件,考察记忆集对注意焦点转换及其返回抑制的影响;实验2操纵两次更新同一记忆项目之间对其它记忆项目更新的次数(2次、3次及3次以上),在实验1基础上,考察返回抑制中项目抑制状态的消退过程.结论:随记忆集增加,转换代价增大,而返回抑制效应消失;当注意焦点对其它记忆项目更新2次时,之前被抑制项目的抑制状态可完全消退.  相似文献   
173.
Strong associations between target stimuli and responses usually facilitate fast and effortless reactions. The present study investigated whether long-term associations between distractor stimuli and responses modulate behavior. In particular, distractor stimuli can affect behavior due to distractor-based stimulus-response retrieval, a phenomenon called distractor-response binding: An ignored stimulus becomes temporarily associated with a response and retrieves it at stimulus repetition. In a flanker task, participants ignored left and right pointing arrows and responded to a target letter either with left and right (strongly associated) responses or with upper and lower (weakly associated) responses. Binding effects were modulated in dependence of the long-term association strength between distractors and responses. If the association was strong (arrows pointing left and right with left and right responses), binding effects emerged but only in case of compatible responses. If the long-term association between distractors and responses was weak (arrows pointing left and right with upper and lower responses), binding was weaker and not modulated by compatibility. In contrast, sequential compatibility effects were not modulated by association strength between distractor and response. The results indicate that existing long-term associations between stimuli responses may modulate the impact of an ignored stimulus on action control.  相似文献   
174.
Reading fluency is necessary for reading comprehension, but approximately 40% of U.S. fourth-grade students have inadequate reading fluency skills. Because small-group (SG) instruction is often used as a first line of intervention for struggling readers, SG instruction targeting deficiencies in text reading fluency ought to be part of every school's intervention toolbox. The authors summarize the existing research on instruction and interventions that specifically targets reading fluency and is implemented by an adult with 3 or more students at once. Key findings revealed that most studies used a single-case design, nearly all studies were rated positively in terms of methodological quality, and the majority of participants significantly improved as a result of receiving SG intervention. Furthermore, of the five studies examining comparable SG and 1-on-1 interventions, 79% of the students performed equally well from both interventions. Implications and several recommendations for future research are discussed.  相似文献   
175.
This article investigates how test-takers change their strategies to handle increased test difficulty. An adult sample reported their test-taking strategies immediately after completing the tasks in a reading test. Data were analyzed using structural equation modeling specifying a measurement-invariant, ability-moderated, latent transition analysis in Mplus (Muthén & Asparouhov, 2011). It was found that almost half of the test-takers (47%) changed their strategies when encountering increased task-difficulty. The changes were characterized by augmenting comprehending-meaning strategies with score-maximizing and test-wiseness strategies. Moreover, test-takers' ability was the driving influence that facilitated and/or buffered the changes. The test outcomes, when reviewed in light of adjusted test-taking strategies, demonstrated a form of process-based validity evidence.  相似文献   
176.
研究以150名五、六年级的学生为被试,考察儿童版特里尔社会应激测试(TSST-C)对儿童客观生理反应(唾液皮质醇和唾液α-淀粉酶)和主观情绪反应的影响。结果发现,TSST-C引起了儿童显著的应激反应,包括皮质醇和唾液α-淀粉酶水平的升高,以及主观消极情绪(如焦虑和紧张)的增加,这表明TSST-C在中国儿童中的适用情况良好,能够有效诱发儿童的应激反应。同时,研究也发现,皮质醇反应和唾液α-淀粉酶反应不存在相关,生理反应和情绪反应之间也不存在相关。  相似文献   
177.
采用康春花、孙小坚和曾平飞(2016)提出的等级反应多水平侧面模型探讨了评分者人数和项目个数对被试能力估计准确性的影响。模拟研究的结果表明:(1)随着项目个数的增加,估计值与真值之间的相关也不断增加;(2)评分者人数和项目个数在平均绝对偏差(MAB)和误差均方根(RMSE)上的主效应均显著,两者间的交互效应也显著;(3)简单效应分析发现,当项目较少时,3个评分者条件下的能力估计准确性最好; 随着项目个数的增加,4个评分者的估计误差迅速下降,且表现变为最好。  相似文献   
178.
Background and objectives: Developmental theorists posit that temperament contributes to preadolescent’s stress response styles. Findings from empirical studies, however, have yielded mixed results, thus indicating a need to consider moderators of this relation. Utilizing an analytic framework guided by resiliency theory [Zimmerman, M. A. (2013). Resiliency theory: A strengths-based approach to research and practice for adolescent health. Health Education &; Behavior, 40, 381–383], this study examined achievement goal orientation as a moderator of the relation between temperament and stress response styles.

Methods: 96 preadolescent–parent dyads (Mage?=?10.30 years, range?=?9–12 years) participated in the study. Preadolescents reported on their achievement goal orientation, coping and involuntary stress responses (ISRs) styles and a parent reported on children’s temperament.

Results: Multiple regressions revealed that effortful control positively predicted preadolescent’s predominant use of engagement coping and negatively predicted predominance of ISRs, but only for children with a predominant mastery goal orientation. For preadolescents with a predominant performance goal orientation, effortful control negatively predicted the predominant use of engagement coping and positively predicted predominance of ISRs. Negative affectivity and its interaction with goal orientation did not predict coping or ISR styles.

Conclusions: Findings suggest that a predominant mastery goal orientation may function as a promotive factor by enhancing the contribution of effortful control to engagement coping styles and buffering against unmanaged reactivity.  相似文献   
179.
There have been few previous attempts to assess the development of early markers of executive function in infants born preterm despite well-established deficits reported for older preterm children that have been closely linked to poorer academic functioning. The present study investigates early attention control development in healthy 12-month-old age-corrected pre-term infants who were born less than 30 weeks and compares their performance to full-term infants. Eye-tracking methodology was used to measure attention control. Preterm Infants spent less time focused on the target and were slower to fixate attention, with lower gestational age associated with poorer target fixation and slower processing speed. There were no significant group differences observed for inhibition of return or interference control. These findings suggest that specific emerging deficits in attention control may be observed using eye tracking methodology in very preterm infants at this early stage of development, despite scores within the average range on the Bayley Scales of Infant Development.  相似文献   
180.
本研究开发了两种新的适用于多级评分项目的多维计算机化自适应测验(PMCAT)的选题策略——修正的连续熵(RCEM)和修正的后验期望KL信息(MKB)方法,并与以往PMCAT的选题策略进行了对比研究。Monte Carlo实验结果表明:两种新开发的选题策略比原方法估计精度更高,并且RCEM方法在所有选题策略中曝光率最低。新开发的选题策略具有较理想的估计精度和曝光控制效果,为PMCAT在实践中的应用提供了新的方法支持。  相似文献   
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