Neuroanatomy Learning: Augmented Reality vs. Cross-Sections

Neuroanatomy education is a challenging field which could benefit from modern innovations, such as augmented reality (AR) applications. This study investigates the differences on test scores, cognitive load, and motivation after neuroanatomy learning using AR applications or using cross-sections of the brain. Prior to two practical assignments, a pretest (extended matching questions, double-choice questions and a test on cross-sectional anatomy) and a mental rotation test (MRT) were completed. Sex and MRT scores were used to stratify students over the two groups. The two practical assignments were designed to study (1) general brain anatomy and (2) subcortical structures. Subsequently, participants completed a posttest similar to the pretest and a motivational questionnaire. Finally, a focus group interview was conducted to appraise participants’ perceptions. Medical and biomedical students (n = 31); 19 males (61.3%) and 12 females (38.7%), mean age 19.2 ± 1.7 years participated in this experiment. Students who worked with cross-sections (n = 16) showed significantly more improvement on test scores than students who worked with GreyMapp-AR (P = 0.035) (n = 15). Further analysis showed that this difference was primarily caused by significant improvement on the cross-sectional questions. Students in the cross-section group, moreover, experienced a significantly higher germane (P = 0.009) and extraneous cognitive load (P = 0.016) than students in the GreyMapp-AR group. No significant differences were found in motivational scores. To conclude, this study suggests that AR applications can play a role in future anatomy education as an add-on educational tool, especially in learning three-dimensional relations of anatomical structures.     

聋生心理健康状况的初步调查

为了探查聋生的心理健康状况,本研究采用《心理健康诊断测验》(MHT)对重庆市180名聋生进行了测量。结果发现:聋生的心理健康总体状况良好;男生的心理健康状况优于女生,城市学生的心理健康状况优于乡村学生,从五年级到高二聋生的心理健康水平呈M状发展;聋生的学习焦虑和过敏倾向较普通学生为轻,而孤独倾向较普通学生为重。     

中国股票市场多因素定价模型研究与实证分析

本文以APT理论为基本架构,提出影响股票收益率的包括成长因子、价值因子、盈利因子、动量因子、风险因子、规模因子的多因素定价模型,并对中国股票市场进行实证分析,得出结论以流通市值、净市值比、换手率、动量、价格波动率、主营业务收入增长率、主营业务利润率、主营业务毛利率、净资产收益、流通股比例、市盈率以及每股公积金比股价为代表的风险因子能够很好的解释股票的超额收益。     

高中生应对方式的调查研究

目的 了解高中生应对方式的特征，为培养其积极应对方式、开展心理健康教育提供依据。方法 采用简易应对方式量表（SCSQ）对755名高中生进行问卷调查。结果（1）高中生与全国常模相比在积极应对和消极应对两个维度上均差异显著；（2）高中生在积极应对和消极应对两个维度上不存在性别、是否独生子女、城乡等差异，但文、理科学生在消极应对维度上存在差异，文科的均分高于理科；（3）高中生在积极应对和消极应对两个维度上存在年级差异。结论 根据不同年级特点，加强高中学生心理健康教育。培养积极应对方式。     

Relationship between Achilles tendon properties and foot strike patterns in long-distance runners

The purpose of this study was to investigate the relationship between Achilles tendon properties and foot strike patterns in long-distance runners. Forty-one highly trained male long-distance runners participated in this study. Elongation of the Achilles tendon and aponeurosis of the medial gastrocnemius muscle were measured using ultrasonography, while the participants performed ramp isometric plantar flexion up to the voluntary maximum. The relationship between the estimated muscle force and tendon elongation during the ascending phase was fit to a linear regression, the slope of which was defined as stiffness. In addition, the cross-sectional area of the Achilles tendon was measured using ultrasonography. Foot strike patterns (forefoot, midfoot and rearfoot) during running were determined at submaximal velocity (18 km · h^?1) on a treadmill. The number of each foot strike runner was 12 for the forefoot (29.3%), 12 for the midfoot (29.3%) and 17 for the rearfoot (41.5%). No significant differences were observed in the variables measured for the Achilles tendon among the three groups. These results suggested that the foot strike pattern during running did not affect the morphological or mechanical properties of the Achilles tendon in long-distance runners.     

大学生主观幸福感和生活事件之关系

目的研究大学生主观幸福感和生活事件的关系。方法运用主观幸福感问卷和青少年生活事件量表,整体随机抽样,对769名大学生进行测试。结果大学生主观幸福感处于中等偏上水平。主观幸福感和生活事件均存在性别差异、年级差异、城乡差异;生活事件分别可以解释总体主观幸福感、生活满意度、正性情感及负性情感变异的5.1%、3.7%、1.3%、17.3%。不喜欢上学、学习负担重、受人歧视冷遇、亲友死亡、与老师关系紧张、考试失败或不理想、受批评或处分、长期远离家人不能团聚、被盗或丢失东西、家庭经济困难、与人打架、家庭施加学习压力是影响大学生主观幸福感的主要生活事件,可以不同程度地解释总体主观幸福感、生活满意度、正性情感及负性情感变异的14.8%、13.9%、8.4%、30.0%。结论主观幸福感和生活事件均存在性别差异、年级差异、城乡差异,生活事件对大学生主观幸福感有显著影响。     

Modeling Unobserved Heterogeneity Using Latent Profile Analysis: A Monte Carlo Simulation

Latent profile analysis (LPA) has become a popular statistical method for modeling unobserved population heterogeneity in cross-sectionally sampled data, but very few empirical studies have examined the question of how well enumeration indexes accurately identify the correct number of latent profiles present. This Monte Carlo simulation study examined the ability of several classes of enumeration indexes to correctly identify the number of latent population profiles present under 3 different research design conditions: sample size, the number of observed variables used for LPA, and the separation distance among the latent profiles measured in Mahalanobis D units. Results showed that, for the homogeneous population (i.e., the population has k = 1 latent profile) conditions, many of the enumeration indexes used in LPA were able to correctly identify the single latent profile if variances and covariances were freely estimated. However, for a heterogeneous population (i.e., the population has k = 3 distinct latent profiles), the correct identification rate for the enumeration indexes in the k = 3 latent profile conditions was typically very low. These results are compared with the previous cross-sectional mixture modeling studies, and the limitations of this study, as well as future cross-sectional mixture modeling and enumeration index research possibilities, are discussed.     

Nonlongitudinal Estimation of Growth Curve Parameters: The Cohort Growth Model

The cohort growth model (CGM) is a method for estimating the parameters of a latent growth model (LGM) based on cross-sectional data. The CGM models the interindividual differences in the growth rate, and it models how subjects’ growth rate is related to their initial status. We derive model identification for the CGM and illustrate, in a simulation study, that the CGM provides unbiased parameter estimates in most simulation conditions. Based on empirical data we compare the estimates of the CGM with the estimates of the LGM. The results were comparable for both models. Although the estimates of the (co)-variances were different, the estimates of both models led to similar conclusions on the developmental change. Finally, we discuss the advantages and limitations of the CGM, and we provide recommendations for its use in empirical research.     

A Hands-On Organ-Slicing Activity to Teach the Cross-Sectional Anatomy

The presentation of pre-sliced specimens is a frequently used method in the laboratory teaching of cross-sectional anatomy. In the present study, a new teaching method based on a hands-on slicing activity was introduced into the teaching of brain, heart, and liver cross-sectional anatomy. A randomized, controlled trial was performed. A total of 182 third-year medical students were randomized into a control group taught with the prosection mode (pre-sliced organ viewing) and an experimental group taught with the dissection mode (hands-on organ slicing). These teaching methods were assessed by testing the students' knowledge of cross-sectional specimens and cross-sectional radiological images, and analyzing students' feedback. Using a specimen test on three organs (brain, heart, and liver), significant differences were observed in the mean scores of the control and experimental groups: for brain 59.6% (±14.2) vs. 70.1% (±15.5), (P < 0.001, Cohen's d = 0.17); for heart: 57.6% (±12.5) vs. 75.6% (±15.3), (P < 0.001, d = 0.30); and for liver: 60.4% (±14.5) vs. 81.7% (±14.2), (P < 0.001, d = 0.46). In a cross-sectional radiological image test, better performance was also found in the experimental group (P < 0.001). The mean scores of the control vs. experimental groups were as follows: for brain imaging 63.9% (±15.1) vs. 71.1% (±16.1); for heart imaging 64.7% (±14.5) vs. 75.2% (±15.5); and for liver imaging 61.1% (±15.5) vs. 81.2% (±14.6), respectively. The effect sizes (Cohen's d) were 0.05, 0.23, and 0.52, respectively. Students in the lower tertile benefited the most from the slicing experiences. Students' feedback was generally positive. Hands-on slicing activity can increase the effectiveness of anatomy teaching and increase students' ability to interpret radiological images.