Developmental Features of Rapid Aiming Arm Movements Across the Lifespan

Using a lifespan approach, the authors investigated developmental features of the control of ballistic aiming arm movements by manipulating movement complexity, response uncertainty, and the use of precues. Four different age groups of participants (6- and 9-year-old boys and girls and 24- and 73-year- old men and women, 20 participants in each age group) performed 7 types of rapid aiming arm movements on the surface of a digitizer. Their movement characteristics such as movement velocity, normalized jerk, relative timing, movement linearity, and intersegment intervals were profiled. Analyses of variance with repeated measures were conducted on age and task effects in varying movement complexity (Study 1), response uncertainty (Study 2), and precue use (Study 3) conditions. Young children and senior adults had slower, more variant, less smooth, and less linear arm movements than older children and young adults. Increasing the number of movement segments resulted in slower and more variant responses. Movement accuracy demands or response uncertainty interacted with age so that the 6- and 74-year-old participants had poorer performances but responded similarly to the varying treatments. Even though older children and young adults had better performances than young children and senior adults, their arm movement performance declined when response uncertainty increased. The analyses suggested that young children's and senior adults' performances are poorer because less of their movement is under central control, and they therefore use on-line adjustments. In addition, older children and young adults use a valid precue more effectively to prepare for subsequent movements than do young children and senior adults, suggesting that older children and young adults are more capable of organizing motor responses than arc young children and senior adults.     

Maternal Socialization Goals,Parenting Styles,and Social-Emotional Adjustment Among Chinese and European American Young Adults: Testing a Mediation Model

The authors compared the associations among perceived maternal socialization goals (self-development, filial piety, and collectivism), perceived maternal parenting styles (authoritative, authoritarian, and training), and the social-emotional adjustment (self-esteem, academic self-efficacy, and depression) between Chinese and European American young adults. The mediation processes in which socialization goals relate to young adults’ adjustment outcomes through parenting styles were examined. Results showed that European American participants perceived higher maternal self-development socialization goals, whereas Chinese participants perceived higher maternal collectivism socialization goals as well as more authoritarian parenting. Cross-cultural similarities were found in the associations between perceived maternal authoritative parenting and socioemotional adjustment (e.g., higher self-esteem and higher academic self-efficacy) across the two cultural groups. However, perceived maternal authoritarian and training parenting styles were found only to be related to Chinese participants’ adjustment (e.g., higher academic self-efficacy and lower depression). The mediation analyses showed that authoritative parenting significantly mediated the positive associations between the self-development and collectivism goal and socioemotional adjustment for both cultural groups. Additionally, training parenting significantly mediated the positive association between the filial piety goal and young adults’ academic self-efficacy for the Chinese group only. Findings of this study highlight the importance of examining parental socialization goals in cross-cultural parenting research.     

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。     

关注幽门螺杆菌治疗中的实际问题

我国对Hp感染诊断和治疗有自己的标准,也有很多成熟的经验,但在根除HP治疗过程中,存在诸多问题,如过度医疗、适应证掌握不严格、第一次根除失败后再次治疗不规范等。我们应共同关注这些问题,提高Hp根除率,降低治疗中的副作用,对HP的许多未知问题从不认识到认识。     

医学实验设计的几点思考

通过分析医学实验设计中常见的问题,思考其原因,提出了解决这些问题的初浅体会:针对研究主题,全面考量研究环节;重视知识积累,合理预知"未知"的结果;对他人和自己的研究行不间断反思;在研究活动持有客观的态度。     

医学实验设计的几点思考

通过分析医学实验设计中常见的问题,思考其原因,提出了解决这些问题的初浅体会:针对研究主题,全面考量研究环节;重视知识积累,合理预知"未知"的结果;对他人和自己的研究行不间断反思;在研究活动持有客观的态度.