Postnatal exposure to methyl mercury and neuropsychological development in 7-year-old urban inner-city children exposed to lead in the United States

Background: The most common route for general population exposure to methyl mercury (MeHg) is fish consumption. Recommendations to pregnant women about consuming fish contaminated with MeHg are also applied to children, but there are few studies available about the effects of low-level postnatal MeHg exposure in them.

Objectives: To investigate the association between postnatal methyl mercury exposure and neuropsychological development in a study of children also exposed to lead, both measured at 7 years.

Methods: We measured MeHg concentrations in blood samples from the Treatment of Lead-Exposed Children (TLC) trial in which 780 children with elevated concentrations of lead in blood were followed with neuropsychological tests from ages 12–33 months through 7 years. Here we examine blood MeHg concentration and neuropsychological test scores, both measured at age 7 years. We used a maximum likelihood method to estimate geometric mean MeHg concentration and generalized linear regression models to analyze MeHg and neuropsychological test scores.

Results: Geometric mean MeHg concentration was 0.56 (95% confidence interval: 0.52, 0.59) μg/L. A 1 μg/L increase in MeHg was associated with a 2.1 (95% confidence interval: 0.4, 3.8) point increase in Full-Scale IQ and 0.2 (95% confidence interval: 0.02, 0.4) point increase in Learning Slopeindex T-score on a test of verbal memory.

Conclusions: Our results suggest that the relatively low MeHg exposure in US school-aged children from this population has no detectable adverse effect on neuropsychological development. The positive associations observed between MeHg and neurodevelopment may indirectly reflect consumption of beneficial polyunsaturated fatty acids from seafood.     

Modeling Concordance Correlation Coefficient for Longitudinal Study Data

Measures of agreement are used in a wide range of behavioral, biomedical, psychosocial, and health-care related research to assess reliability of diagnostic test, psychometric properties of instrument, fidelity of psychosocial intervention, and accuracy of proxy outcome. The concordance correlation coefficient (CCC) is a popular measure of agreement for continuous outcomes. In modern-day applications, data are often clustered, making inference difficult to perform using existing methods. In addition, as longitudinal study designs become increasingly popular, missing data have become a serious issue, and the lack of methods to systematically address this problem has hampered the progress of research in the aforementioned fields. In this paper, we develop a novel approach to tackle the complexities involved in addressing missing data and other related issues for performing CCC analysis within a longitudinal data setting. The approach is illustrated with both real and simulated data.     

The effects of ageing and cognitive impairment on on‐line and off‐line motor learning

Skilled performance is a collective function of practice‐related experiences (online learning) and post‐practice memory consolidation during sleep (offline learning). This study examines the effects of ageing and cognitive impairment on the on‐ and offline learning of a point‐to‐point arm movement. In a 3‐day experiment, older adults (cognitively normal or impaired) and young adults (YAs) were randomly assigned to practice or no‐practice conditions. Changes in the dependent measures of movement time and timing error were analysed within and between conditions across days. The findings suggest that both age and cognitive function affect skill learning. YAs improved performance via both on‐ and offline learning whereas older adults with normal cognitive capacities appeared to learn the movement skill primarily in an online mode. Cognitive impairments were found to hinder both types of skill learning. Implications for motor skill acquisition and rehabilitation are briefly discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

PRL-3在宫颈鳞癌组织中的表达及临床意义

通过RT-PCR和Western blotting来检测45例宫颈鳞癌组织和20例正常宫颈组织中PRL-3的表达情况。RT-PCR和Western blotting结果均显示宫颈鳞癌组织中PRL-3的表达明显高于正常宫颈组织(P0.01),PRL-3的表达与宫颈鳞癌组织的分化程度及淋巴转移密切相关(P0.05),而与患者年龄、肿瘤直径无关(P0.05)。因此PRL-3可能参与了人类宫颈鳞癌的发生、发展,并与宫颈鳞癌的部分临床病理特征有关,将可能作为宫颈鳞癌靶向治疗的一个新的分子靶点。     

从达尔文医学看腋窝器官的形成——"臭"为什么在腋窝

应用达尔文医学的观点,结合腋窝体味及腋臭发生机制的现代研究进展,探讨了人体主要气味器官-腋窝器官形成的进化史原因.由于人体的上下对称性,腋窝很好地再现了腹股沟、会阴区域,在人类气味从胯下到腋下的转换过程中,出于机体设计方便的原因,腋窝被选中成为了人类的上部嗅腺器官.     

儿童心理理论对责任教育的启示

心理理论是指对自己和他人心理状态的认识,并由此对相应行为作出因果性的预测和解释。心理理论的发展不仅是儿童脱离自我中心、建立良好同伴关系的重要条件,而且还通过影响儿童的观点采择等心理机制影响儿童责任意识的形成与发展。这一理论对于当前的责任教育具有重要启示意义。     

阈下启动的恐惧和厌恶情绪对人际判断的影响

该研究通过两个实验,采用单因素的组间设计,探讨了阈下启动的恐惧情绪和厌恶情绪对人际判断的影响作用。研究结果显示:1)阈下呈现恐惧图片的情况下,被试认为随后的中性人物面孔图片表现出更多的攻击性和威胁性,相对于阈下呈现中性图片的条件;2)阈下呈现厌恶图片的情况下,被试认为人物随后的中性人物面孔图片表现出更多的无礼性和令人讨厌,相对于阈下呈现中性图片的条件。研究结果表明,在具体情绪的水平上,阈下情绪启动会影响被试随后的人际判断。     

《创世记》1-3章之历史批评法回眸

历史批评法研究《创世记》1-3章,通常以来源批评法、形式批评法、传统-历史批评法,以及编辑批评法等组成。这些方法之间,没有绝然的分野和对立。历史批评法诠释《创世记》1-3章,为读者揭示了两个创造故事。本文批判地回顾了学者对两个创造故事的来源、所使用的场景、传递的过程,以及编修的痕迹等方面的研究,认为尽管历史批评法受到许多质疑和挑战,但它仍然是研究希伯来圣经的基础方法。     

基于心理控制源视角的女公务员婚姻质量研究

目的:研究女公务员心理控制源和婚姻质量的关系。方法:采用《Olson婚姻质量问卷》和《控制圈量表》对551名女公务员进行调查。结果:不同职级的女公务员心理控制源差异显著,其婚姻质量差异不显著;不同年龄的女公务员心理控制源和婚姻质量差异不显著;影响女公务员婚姻满意度的主要因素是性生活、与亲友的关系、子女和婚姻、业余活动、信仰一致性、经济安排、夫妻交流、人际控制。结论:不同职级的女公务员心理控制源差异显著,其婚姻质量差异不显著;影响女公务员婚姻满意感的主要因素是婚际因素和外界因素,个人因素贡献不显著;基于控制源的视角,人际控制对女公务员婚姻满意度贡献显著,个人实力和社会政治控制对其婚姻满意度贡献不显著。