A time series analysis of the relation between motor skill acquisition and sleep in infancy

To systematically examine the relation between motor milestone onset and disruption of night sleep in infancy, three families kept microgenetic, prospective, daily checklist diaries of their infants’ motor behavior and sleep (197-313 observation days; 19,000 diary entries). Process control and interrupted time series analyses examined whether deviations from the moving average for night wakings and evening sleep duration were temporally linked to motor skill onset and tested for meaningful differences in individual sleep patterns before and after skill onset. Model assumptions defined skill onset as first day of occurrence or as mastery and moving average windows as 3, 7, or 14 days. Changes in infants’ sleep patterns were associated with changing expertise for motor milestones. The temporal relation varied depending on infant and sleep parameter. Intensive longitudinal data collection may increase our understanding of micro-events in infant development.     

The effects of massage velocity on heart rate and heart rate variability in healthy infants: A randomized crossover study

BackgroundInfant massage, in which mothers stroke their infant’s skin slowly and gently, can cause pleasant sensations in the infant that can be affected by the velocity of massage. However, the massage velocity at which infants feel the most pleasant sensations remains unclear.ObjectiveTo investigate the effects of massage velocity on heart rate (HR) and HR variability (HRV) in healthy infants.MethodTwenty-two infant-mother dyads two to seven months of age were recruited. Mothers stroked their infant’s skin at three massage velocities (5.0, 7.5, and 10.0 cm/s) in a randomized order for 15 min. The rhythm of massage velocity was calculated according to the length of three body areas. The massage velocity of the mothers was regulated using a metronome. HR and HRV (high frequency [HF] and low frequency [LF]) were measured at rest and during massage for each velocity. The effects on pleasantness were evaluated using percent change in median baseline value compared with median values for the three massage velocities. Statistical analysis was performed using analysis of variance mixed effect models to exclude “period” and “carryover” effects during massage.ResultsWhen measuring HF, massage (7.5 cm/s) caused a significant increase in pleasantness compared with 10.0 cm/s (p = 0.04). The HR and LF/HF ratio were not significantly changed between velocities.ConclusionResults of this study suggested that a massage velocity of 7.5 cm/s was the most pleasant for infants. Future research should investigate the relationship between an infant massage by optimal velocity and infant development in longitudinal studies.     

Priming productive study strategies with preparatory quizzes in an engineering course

One approach to encourage productive study strategies is to incorporate preparatory quizzes (or pre‐quizzes) in which students are required to submit answers to questions before the underlying material is covered in class. In the present study, students took an introductory mechanical engineering class that either included pre‐quizzes (treatment group) or did not (control group). Students in the treatment group visited the online textbook more often and earlier in advance of deadlines, indicating better management of their study time—behaviors that have been shown to be productive study strategies. They also performed better in the course, indicating that techniques intended to prime productive study strategies can pay off. Finally, measures of productive learning strategies correlated with measures of course performance for both groups. These findings support the pretesting principle, which holds that students study more effectively and learn better when they take practice tests before a lesson.     

Effectiveness of the compensatory strategy adopted by older drivers: Difference between professional and non-professional drivers

It has been a controversial issue for the effect of ageing population on driving safety. Apparently, drivers’ physiological and cognitive performances deteriorate with age. However, older drivers may compensate for the elevated risk by adjusting their behaviors, known as compensatory strategy. Despite the extensive research on this topic, the compensatory strategy of older professional drivers is not well understood since many studies focused on the differences in compensatory behavior between older and young drivers. Professional drivers tend to be more skillful and able to cope with the unfavorable driving environments, thus presenting a higher capability to mitigate the risk. This study attempts to examine the compensatory behavior and its safety effect amongst older professional drivers, as compared to those of older non-professional drivers, using the driving simulator approach. In the driving simulator experiment, participants were asked to follow a leading vehicle for one hour, and two sudden brake events were presented. 41 (mid-aged and older) drivers completed the driving tests. Each participant was required to complete a car-following test, either under high or low traffic flow conditions. Performance indicators include driving capability (i.e. lateral control, longitudinal control, and brake reaction time) and compensatory behavior (i.e. average speed, and time headway). Additionally, two modified traffic conflict measures: time exposed time-to-collision (TET) and time integrated time-to-collision (TIT) are applied to indicate the traffic conflict risk. The random parameter Tobit models were estimated to measure the association between conflict risk and driver attributes, and random intercept models were used to assess other driving performance indicators. Results show that despite the impaired lateral control performance and longer brake reaction time of older drivers, the likelihood of severe traffic conflict of older drivers is lower than that of mid-aged drivers. Furthermore, though both older professional and older non-professional drivers adopted longer time headway, the reduction in the risk of severe traffic conflict is more profound among the older professional drivers. Such findings suggest that older professional drivers are more capable of mitigating the possible collision risk by adopting the compensatory strategy, as compared to older non-professional drivers. This justifies the existence of compound effect by the compensatory strategy of older driver and better driving skills of professional driver. This research provides useful insights into driver training and management strategies for employers, as older drivers would become a major cohort in the transportation industry.     

Depression screening and treatment among uninsured populations in Primary Care

Uninsured populations have poor treatment engagement and are less likely to receive evidence-based interventions for depression. The objective of the current study was to retrospectively examine depression screening, diagnosis, and treatment patterns among uninsured patients in primary care. Study sample included all patients (N = 11,803) seen in nine community-based clinics. Key variables included depression screener and/or a depression diagnosis, anti-depressant initiation, behavioral health visits, and patient follow up measures. Treatment patterns from the subsample of patients diagnosed with depression were analyzed by collecting the number of behavioral health visits and antidepressant use six months (180 days) following the diagnosis. Utilization of the depression screening tool was high (67%, n = 7,935) and 24% (n = 2,789) of the patients had a diagnosis of depression, however, more than half of the patients with a depression diagnosis did not have a recorded treatment plan (n = 1,474). The odds of anti-depressant use and behavioral visits for Hispanic patients were significantly greater than for Non-Hispanic patients. Universal screening with brief measures in primary care is improving, however, guideline-concordant depression treatment remains elusive for uninsured populations.     

Active school travel is associated with fewer suicide attempts among adolescents from low-and middle-income countries

Background/Objective: This study explored the association between active school travel (AST) and suicide attempts among adolescents in low- and middle-income countries (LMICs). Method: We used the data from the Global School-based Health Survey, including 127,097 adolescents aged 13-17 years from 34 LMICs. A self-reported survey was used to collect data on AST and suicide attempts as well as some variables. Multivariable logistic regression was performed to assess the association between AST and suicide attempts. A meta-analysis with random effects was undertaken to identify the difference in the association between AST and suicide attempts. Results: Across all the adolescents, the prevalence of AST was 37% and the prevalence of suicide attempts was 11.60%. Adolescents who engaged in AST were less likely to have suicide attempts irrespective of gender. The country-wise analysis indicated a large inconsistency in the association between AST and suicide attempt across the countries. Conclusions: AST would appear to be a protective factor for reducing suicide attempts among adolescents. However, the association between AST and suicide attempts varied greatly across the countries. Future studies should confirm the association between AST and suicide attempts.     

Social status and friendship in peer victimization trajectories

Background/Objective: Most studies have evaluated victimization at a single time point, making it difficult to determine the impact of the time during which an individual is victimized. This longitudinal study aims to examine the differences in the levels of social status (social preference and perceived popularity) and friendship in peer victimization trajectories, and to analyse if there were changes over time in the levels of social status and friendship in each trajectory. Method: The final sample was composed of 1,239 students (49% girls) with ages between 9 and 18 (M = 12.23, SD = 1.73), from 22 schools in southern Spain. Peer nominations were collected. Results: The General Linear Model results associated the highest levels of social preference, perceived popularity and friendship with the sporadic victimization profile and the lowest levels of these dimensions with the stable profile. Conclusions:The results are discussed based on important personal aspects of stable victimization that confirms social rejection, unpopularity, and the low social support that victimization causes. This contribution is discussed in terms of health and social welfare in adolescence.     

廖平的《左传》研究

随着今文经学的复兴,晚清学术在今古文学的激烈冲突中展开。在这一过程中,《左传》研究一直是核心的内容。晚清《左传》研究主要呈现出刘逢禄、康有为为代表的今文学与章太炎为代表的古文学两大学派争论的态势。廖平的《左传》研究,与两派的学术路径既有联系,有呈现出不同的学术特色,在晚清学术研究中独树一帜,值得关注。     

淄潍河流域商周文化东渐历史背景之考古学观察

商周文化东渐是山东地区商周考古的一个重要课题,淄潍河流域则是山东地区商周考古的一个关键性区域,随着考古资料的日益丰富,从考古学角度探讨淄潍河流域商周文化东渐及其历史背景已成为可能。     

Anger and aggression in women: Influence of sports choice and testosterone administration

We report on two studies of anger and aggression in women. One study concerns an experimental study of anger induction in aggressive and non-aggressive sportswomen. It was found that sports choice in itself, contrary to expectation, does not predict anger arousal and aggressive behavior in the laboratory. However, at an individual level the anger proneness of the subject, as measured by a questionnaire we developed, was related to the intensity of aggressive behavior and subjectively reported anger. The second study concerns the activating effects of androgens on aggression and anger proneness. In a group of 22 female-to-male transsexuals, a battery of anger proneness and aggression questionnaires was administered twice: shortly before and 3 months after the start of androgen treatment. Administration of androgens was clearly associated with an increaese in anger proneness, although there were no changes in several aspects of overt aggressive behavior. © 1994 Wiley-Liss, Inc.