Female relative age effects and the second-quartile phenomenon in young female ice hockey players

ObjectivesRelative age effects exist across sports and cultures (Cobley, Baker, Wattie, & McKenna, 2009), though a recent, unusual trend is females born in the second quartile of the selection year are most over-represented on elite teams. The first purpose of this study was to test the hypothesis that the second-quartile phenomenon was the result of first-quartile female athletes registering to play male sport. Due to the nature of the collected data, a secondary purpose was to examine relative age effects across female age divisions.DesignCross-sectional, with multiple chi-square analyses.MethodPlayers included 29,924 female ice hockey players (ages 7–17 years) from the Ontario Hockey Federation. Birthdates were converted into quartiles following the Hockey Canada selection year.ResultsRelative age effects (with the second quartile most over-represented) existed for the entire sample (χ² [3, 29923] = 401.95, p < 0.001), those registered for female ice hockey (χ² [3, 24984] = 369.90, p < 0.001) and those registered for male ice hockey (χ² [3, 4938] = 37.88, p < 0.001). The strength of the effect lessened as athletes aged.ConclusionIt appears the second-quartile phenomenon cannot be explained by athletes’ choice to play male sport. Further, female relative age effects appear strongest at younger ages. The discussion includes integration of results with previous literature, along with plausible explanations.     

The illusion of the perfect alibi: Establishing the base rate of non‐offenders' alibis

The present study was designed to establish the base rate of alibis and supportive evidence for alibis of non‐offenders. That is important because the presence and lack of an alibi are often seen as a clear indicator of innocence and guilt, respectively, of a suspect. A large sample of laypersons (N  = 841) was randomly assigned to one of 32 conditions in which they were asked to generate a true alibi after they were falsely accused of being the perpetrator of a mock robbery. Each condition consisted of either a Tuesday or a Saturday and one of 16 timeframes. In general, the majority of the participants had an alibi (99.5%) and supportive evidence for their alibis (92.4%). The supportive evidence often consisted of a combination of supportive evidence rather than one distinct form of supportive evidence (33.3%). Although it is widely assumed that the alibi believability is determined based on the strength of the supportive evidence, our results show that the type of evidence that can be presented by laypeople depends upon the day and the timeframe wherein the crime has been committed. The results of the study therefore imply that determining alibi believability solely on the strength of the supportive evidence is not a fair measure. We suggest that the believability should also be based on the base rate of alibis and its supportive evidence.     

上海市大学城学生网瘾调查报告

本调查使用大学生网络成瘾量表,调查了上海市大学城里1286名大学生.调查结果显示:大学城学生不同性别和年级在因特网成瘾障碍量表各维度上的差异不显著,其脱瘾综合症状明显.大学城学生不同性别和年级网络成瘾的发生率有显著差异.上海市大学城学生网瘾发牛率在总体、男生、大二、大四维度上显著低于全市大学生网瘾发生率.     

就业危机形势下——大学生就业心理问题分析及对策研究

在当前就业危机的严峻形势下,大学生就业是一个社会热点和难点问题。大学生的就业压力越来越大,由此导致大学生出现了自卑、不平衡、自负等一系列的就业心理问题。本文就大学生就业心理问题的表现、产生就业心理问题的原因以及应采取的措施作以分析。     

剖宫产率上升探析

剖宫产作为产科分娩的干预手段,既可以挽救孕妇和胎儿的生命,又会对孕妇和胎儿带来某些预料不到的危险。近年来,许多国家的剖宫产率随着剖宫产术的推广不断上升,引起了社会各界的广泛关注。本文概述了国内外剖宫产率变化的主要特征,综述了导致剖宫产率上升的主要因素及社会各界对剖宫产率上升的不同看法。     

DYNAMICS OF CHOICE: RELATIVE RATE AND AMOUNT AFFECT LOCAL PREFERENCE AT THREE DIFFERENT TIME SCALES

To examine extended control over local choice, the present study investigated preference in transition as food‐rate ratio provided by two levers changed across seven components within daily sessions, and food‐amount ratio changed across phases. Phase 1 arranged a food‐amount ratio of 4:1 (i.e., the left lever delivered four pellets and the right lever one pellet); Phase 2 reversed the food‐amount ratio to 1:4, and in Phase 3 the food‐amount ratio was 3:2. At a relatively extended time scale, preference was described well by a linear relation between log response ratio and log rate ratio (the generalized matching law). A small amount of carryover occurred from one rate ratio to the next but disappeared after four food deliveries. Estimates of sensitivity to food‐amount ratio were around 1.0 and were independent of rate ratio. Analysis across food deliveries within rate‐ratio components showed that the effect of a small amount was diminished by the presence of a large amount—that is, when a larger amount was present in the situation (three or four pellets), the value of a small amount (one or two pellets) became paltry. More local analysis of visits to the levers between food deliveries showed that postfood visits following a large amount were disproportionately longer than following a small amount. Continuing food deliveries from the same source tended to make visits less dependent on relative amount, but a discontinuation (i.e., food from the other lever) reinstated dependence on relative amount. Analysis at a still smaller time scale revealed preference pulses following food deliveries that confirmed the tendency toward dependence on absolute amount with continuing deliveries, and toward dependence on relative amount following discontinuations. A mathematical model based on a linear‐operator equation accounts for many of the results. The larger and longer preference following a switch to a larger amount is consistent with the idea that local preference depends on relatively extended variables even on short time scales.     

儿童内包量概念发展的实验研究

以2～5年级学生为被试．系统探讨了儿童速度、浓度内包量概念的发展。研究发现：(1)儿童的内包量概念发展要经历四个阶段;(2)儿童速度概念的形成早于其浓度概念的形成;(3)凋整任务在儿童解决速度内包量问题中优于比较任务;(4)儿童解决内包量概念问题的策略经历从单维向双维、从比差的加法法则向乘法法则的转变。     

Age-related changes of phasic heart rate responses to affective pictures

This study examined age differences in phasic heart rate in response to neutral, negative and positive pictures. Heart rate changes and subjective ratings were analyzed in 22 middle-aged (40-55 years) and 30 older (56-78 years) participants. The effects of valence on the HR pattern across time were similar to that obtained by Bradley and co-workers. Conversely to previous studies, we did not report any age-related reduction in cardiac reactivity. Instead, when viewing positive pictures, the triphasic wave form appeared in the group of older adults, but for younger participants, it was replaced by a sustained deceleration. These results were interpreted in the light of the socioemotional selectivity theory.     

Using heart rate as a physical activity metric

Physical activity (PA) is critical for a healthy lifestyle. The current study assessed heart rate (HR) as a primary measure of moderate and vigorous PA with four typically developing children. First, individualized HR assessments were conducted to determine moderate and vigorous HR zones. Next, participants engaged in various exercises at a local YMCA facility (i.e., biking, elliptical, basketball, and exergame boxing) to determine how HR during these activities aligned with their individualized HR zones. During exercise bouts, HR was typically above moderate, but below vigorous HR zones for all participants. Additionally, exercises that restricted range of motion (i.e., biking and elliptical) engendered generally lower HR than exercises with greater range of motion. Vocal instructions to exercise at vigorous levels were effective at increasing HR to vigorous levels for one participant. The advantages of using HR as a metric of PA during assessment and intervention are discussed.     

Response rate correlates with indifference points in a delay‐discounting procedure

To study how effort affects reward value, we replicated Fortes, Vasconcelos and Machado's (2015) study using an adjusting‐delay task. Nine pigeons chose between a standard alternative that gave access to 4 s of food, after a 10 s delay, and an adjusting‐delay alternative that gave access to 12 s of food after a delay that changed dynamically with the pigeons' choices, decreasing when they preferred the standard alternative, and increasing when they preferred the adjusting alternative. The delay value at which preference stabilized defined the indifference point, a measure of reward value. To manipulate effort across phases, we varied the response rate required during the delay of the standard alternative. Results showed that a) the indifference point increased in the higher‐response‐rate phases, suggesting that reward value decreased with effort, and b) in the higher‐response‐rate phases, response rate in the standard alternative was linearly related to the indifference point. We advance several conceptions of how effort may change perceived delay or amount and thereby affect reward value.