Blocking between landmarks during 2-D (touchscreen) and 3-D (ARENA) search tasks with pigeons

Many studies investigating cue competition have focused on the blocking effect. We investigated the blocking effect with pigeons using a landmark-based spatial search task in both a touchscreen preparation (Exp. 1a) and an automated remote environmental navigation apparatus (Exp. 1b). In Phase 1, two landmarks (LMs: A and Z) appeared on separate trials as colored circles among a row of eight (touchscreen) or six (ARENA) identical response units. Subjects were rewarded for pecking at a target response unit to the right of LM A and to the left of an extraneous LM, Z. During the blocking trials in Phase 2, LM X was presented in compound with a second LM (A) that had been previously trained. On control trials, LM Y was presented in compound with LM B and a target in the same manner as in the trials of AX, except that neither landmark had previously been trained with the target. All subjects were then tested with separate trials of A, X, B, and Y. Testing revealed poor spatial control by X relative to A and Y. We report the first evidence for a spatial-blocking effect in pigeons and additional support for associative effects (e.g., blocking) occurring under similar conditions (e.g., training sessions, spatial relationships, etc.) in 3-D and 2-D search tasks.     

中国传统武术发展的方向

从中西体育文化交流的特点和变化的视角,对中国传统武术发展的方向提出3条意见:中国传统武术应坚持社会化的发展方向;中国传统武术的发展应坚持走大众化的道路;中国传统武术的发展应首先把太极拳、散手推向世界.     

Injury rates in professional soccer players during Ramadan

Many of the socio-cultural lifestyle and dietary changes that take place during Ramadan may affect the risk of injury in athletes, but little evidence is available. The aim of the present study was to examine the effects over two consecutive years of the holy month of Ramadan on injury rates in 42 professional players of a Tunisian top-level professional soccer team. Players were retrospectively organized into fasting and non-fasting groups and monitored for 3 months: 4 weeks before Ramadan, during the month of Ramadan (4 weeks), and 4 weeks after Ramadan each year. During Ramadan, training started at 22.00 h. The circumstances (training/match) and mechanism of injury (traumatic/overuse) were recorded. No significant differences between the three periods were observed for weekly mean training load, training strain, training duration, and Hooper's Index (quality of sleep, and quantities of stress, delayed-onset muscle soreness, and fatigue). Compared with non-fasting players, fasters had a lower (P < 0.05) Hooper's Index and stress during and after Ramadan. No significant difference in injury rates was observed between fasting and non-fasting players. Nevertheless, the rates of non-contact (6.8 vs. 0.6 and 1.1) and training overuse (5.6 vs. 0.6 and 0.5) injuries were significantly higher in fasting players during the month of Ramadan than before or after Ramadan. In conclusion, Ramadan, along with the corresponding changes in nutritional habits, sleeping schedule, and socio-cultural and religious events, significantly increased overuse and non-contact injuries in fasting players despite the fact that the training load, strain, and duration were maintained.     

绍-江古陆对接带深成杂岩厘定及其成因环境判别

绍-江对接带位处华夏-扬子古陆对接碰撞带北东敛合端,其间保留有俯冲混杂堆积岩,是仅存可见的元古碰撞造山带的根部,是判析古大洋壳岩石学演进及俯冲消减动力学过程的天然实验室,自然也是当前中国南方古板块构造格局厘定及元古造山带研究的核心问题。本文重点阐述绍江对接碰撞带系列岩石学组成及其地球化学特征,探索成因环境、论证元古南华洋的存在,追溯其消减造山的历史过程。     

正视英语口语教学 积极思考相关对策

由于新课改和时代的要求,口语教学越显重要。文章就英语口语教学中存在的问题及困难,提出对策,从而达到提高英语口语教学效果的目的。     

Growth behavior of publications and patents: A comparative study on selected Asian economies

This study attempts to model the growth behavior of the number of publications and patents of South Korea, Taiwan, Japan and Malaysia. Three competing growth functions, namely, simple logistic growth function, bi-logistic growth function and logistic function within a dynamic carrying capacity were considered. The findings provide insight to the diffusion process of science and technology, often measured by the number of publications and patents, respectively. The function that provides the best fit to the observed data was opted for explaining the diffusion process. The function with the best fit is the bi-logistic growth function for the number of publications as well as the number of patents of South Korea and Taiwan, the logistic growth function within a dynamic carrying capacity (LGDCC) for the number of publications and the bi-logistic growth function for the number of patents of Japan, and the LGDCC for the number of publications and simple growth function for the number of patents of Malaysia. The results suggest a dynamic self-propagating growth for the science and technology, and thereby a transition from science and technology-push to market-pull growth for South Korea and Taiwan. While a similar transition was observed for the technology of Japan, the growth in science had entered a maturity stage. On the other hand, the growth potential in science is dynamic for Malaysia, but its technological advancement is relatively lower and static compared to the other economies.     

Book Reviews

Rational choice models of teenage sexual behaviour lead to radically different predictions than do models that assume such behaviour is random. Existing empirical evidence has not been able to distinguish conclusively between these competing models. I use regional data from England between 1998 and 2001 to examine the impact of recent increases in access to family planning on teenage pregnancy and sexually transmitted infection diagnosis rates. I find consistent evidence that access to family planning services is not associated with reductions in teenage pregnancy rates. I also find consistent evidence that increased promotion of emergency birth control in youth family planning clinics has not affected the relationship between clinic services and teenage pregnancy rates, but has significantly worsened the relationship between clinic services and teenage sexually transmitted infection diagnosis rates. Most of the observed relationships are inconsistent, with teenage sexual behaviour being the result of a random decision‐making process.     

A Two-Stage Approach to Synthesizing Covariance Matrices in Meta-Analytic Structural Equation Modeling

A great obstacle for wider use of structural equation modeling (SEM) has been the difficulty in handling categorical variables. Two data sets with known structure between 2 related binary outcomes and 4 independent binary variables were generated. Four SEM strategies and resulting apparent validity were tested: robust maximum likelihood (ML), tetrachoric correlation matrix input followed by SEM ML analysis, SEM ML estimation for the sum of squares and cross-products (SSCP) matrix input obtained by the log-linear model that treated all variables as dependent, and asymptotic distribution-free (ADF) SEM estimation. SEM based on the SSCP matrix obtained by the log-linear model and SEM using robust ML estimation correctly identified the structural relation between the variables. SEM using ADF added an extra parameter. SEM based on tetrachoric correlation input did not specify the data generating process correctly. Apparent validity was similar for all models presented. Data transformation used in log-linear modeling can serve as an input for SEM.