Athletes trained using stable compared to unstable surfaces exhibit distinct postural control profiles when assessed by traditional and nonlinear measures

Athletes are assumed to exhibit better balance than non-athletes; however, few studies have examined the role of different types of sports on balance measures. Two athlete groups that experience divergent sport-specific balance training are stable- (i.e. basketball) and unstable-surface athletes (i.e. surfers). The purpose of this study was to quantify the effect of stable- compared to unstable-surface sports on postural stability.MethodsEight non-athletes (NON), eight stable-surface athletes (SSA) and eight unstable-surface athletes (USA) performed five 20-s quiet standing trials while ground reaction forces were recorded. Approximate entropy (ApEn), total excursion and root mean square distances (RMS) of the center of pressure position were calculated. Univariate ANOVAs with post hoc tests were conducted for each variable.ResultsApEn values were lower in SSA compared to NON in the ML direction (p = 0.012) and USA had lower ApEn values compared to SSA in the AP direction (p = 0.036). The USA had smaller AP RMS compared to SSA (p = 0.002) while the USA had greater ML RMS (p = 0.008) and resultant RMS values compared to SSA (p = 0.025).DiscussionThese data suggest that USA and SSA may exhibit direction-specific differences in balance strategy due to feedback paradigm.     

Social Context and the Dynamics of Cooperative Choice

Recent work using decontextualized economic games suggests that cooperation is a dynamic decision‐making process: Automatic responses typically support cooperation on average, while deliberation leads to increased selfishness. Here, we performed two studies examining how these temporal effects generalize to games with richer social context cues. Study 1 found that time pressure increased cooperation to a similar extent in games played with in‐group members and out‐group members. Study 2 found that time pressure increased cooperation to a similar extent in games described as competitions and games described as collaborations. These results show that previous positive effects of time pressure on cooperation are not unique to neutrally framed games devoid of social context and are not driven by implicit assumptions of shared group membership or cooperative norms. In doing so, our findings provide further insight into the cognitive underpinnings of cooperative decision making. Copyright © 2014 John Wiley & Sons, Ltd.     

Hemodynamic responses to active and passive coping tasks and the prediction of future blood pressure in Thai participants: A preliminary prospective cohort study

Cardiovascular responses to mental stress tests have been related to future blood pressure (BP) levels. However, most studies have been completed in North America and Europe; only one study has been conducted in Asia. Therefore, the study explored whether cardiovascular responses to mental stress predict future resting BP in Thailand. Hemodynamic measures were obtained from 101 healthy adults before, during and after mental arithmetic, a speech task, and a cold pressor task. A follow‐up assessment of resting BP was undertaken 1 year later. Results showed that Thais responded to standardized mental stress tasks with large and significant cardiovascular reactivity. Regression analyses indicated that, after adjustment for baseline BP and traditional risk factors, heightened systolic blood pressure (SBP) responses to mental arithmetic were associated with increased future SBP (ΔR² = .045). These findings suggest that BP reactivity predicts future BP and may play a role in the development of hypertension. In addition, Thais displayed large cardiovascular responses to standardized mental stress tasks, of a similar magnitude to previous studies of North Americans and Europeans.     

Magnitude of cerebral asymmetry at rest: covariation with baseline cardiovascular activity

The cerebral regulation of cardiovascular functioning varies along both a lateral and a longitudinal axis. The parasympathetic and sympathetic nervous systems are lateralized to the left and right cerebral hemispheres, respectively. Further, the frontal lobes are known to be inhibitory in nature, whereas the temporal lobes are excitatory. However, no systematic investigation has been conducted to determine the nature and strength of the relationship between the left and right frontal and temporal lobes in regulating cardiovascular activity. The present investigation sought to examine these relationships by testing the hypothesis that negative correlations would be found between baseline heart rate and blood pressure and asymmetry of alpha magnitude across the frontal lobes. Further, positive correlations were hypothesized to exist across the temporal lobes. A total of 20 women were asked to relax with their eyes closed while heart rate and blood pressure as well as quantitative electroencephalography data were obtained. The results indicated that, as hypothesized, significant negative correlations existed across the frontal lobes and significant positive correlations existed across the temporal lobes. The results provide further support for a division of responsibility between the left and right frontal and temporal lobes in the regulation of heart rate and blood pressure.     

大连某医院体检人群血脂四项的调查分析

对大连地区健康成人血清总胆固醇（TC）、血清甘油三脂（TG）、高密度脂蛋白胆固醇（HDL-C）和低密度脂蛋白胆固醇（LDL-C）进行调查研究.选取2009年4月至2010年12月大连地区16 052名健康体检者,并按性别和年龄分组.早晨空腹,采集所有调查对象3ml肝素抗凝血,用日立7060全自动生化分析仪检测血清TC、TG、HDL-C和LDL-C的结果.结果大连地区健康成人血脂水平比2007年发表的中国成人血脂异常防治指南所确定的正常参考区间偏高,因此,我们对大连地区人们的血脂水平必须引起高度重视,以预防和减少高脂血症及其相关疾病的发生.     

Center of Gravity Motions and Ankle Joint Stiffness Control in Upright Undisturbed Stance Modeled Through a Fractional Brownian Motion Framework

The authors modeled the center of gravity vertical projection (CG_V) and the difference, CP - CG_V, which, combined, constitute the center of pressure (CP) trajectory, as fractional Brownian motion in order to investigate their relative contributions and t heir spatiotemporal articulation. The results demonstrated that CG_V and CP - CG_V motions are both endowed in complementary tashion with strong stochastic and part-deterministic behaviors. In addition, if the temporal coordinates remain similar for all 3 trajectories by definition, the switch between the successive control mechanisms appears for shorter displacements for CP - CG_V and CG_V than for CP trajectories. Results deduced from both input (CG,) and muscular stiffness (CP - CG_V) thus provide insight into the way the central nervous system regulates stance control and in particular how CG and CP - CG are controlled.     

Age-Related Changes in Distance From Center of Mass to Center of Pressure During One-Leg Standing

ABSTRACT. The purpose of this study was to clarify the age-related effects of distances from the center of pressure (COP) to the center of mass (COM) (COP-COM distances) during one-leg standing (OLS) task. Healthy old and young adults (n = 11 each) participated in this study. The authors divided the task into 3 phases (accelerated, decelerated, and steady) based on the relationship between COM and COP. COP-COM distances in the older group were significantly reduced during the accelerated phase, then significantly increased during the decelerated and steady phases. Furthermore, distances during these phases correlated inversely with OLS time. The authors conclude that OLS time is shortened by the larger braking response to COM shifts just after leg-lifting, and the production of larger inertial forces to maintain COM position during the OLS in older individuals.     

Evaluating the Safety and Effectiveness of the Weighted Blanket With Adults During an Inpatient Mental Health Hospitalization

The weighted blanket (WB) is a modality used to self-comfort, rest, sleep, and decrease anxiety. This exploratory, pilot study investigates the safety and effectiveness of the standardized use of the 30-pound WB with 30 adults during an acute inpatient mental health hospitalization. Safety measures include blood pressure, pulse rate, and pulse oximetry monitoring, with and without the 30-pound WB. The State Trait Anxiety Inventory-10 (STAI-10), a self-rating 0–10 anxiety scale, and electrodermal activity (EDA) readings measure effectiveness for anxiety reduction. No statistical differences in vital signs indicate WB safety. The STAI-10 and self-ratings indicate 60% had a significant reduction in anxiety using the WB. EDA readings were inconclusive.     

Increased forefoot loading is associated with an increased plantar flexion moment

The aim of this study was to identify the cascade of effects leading from alterations in force generation around the ankle joint to increased plantar pressures under the forefoot. Gait analysis including plantar pressure measurement was performed at an individually preferred and a standardized, imposed gait velocity in diabetic subjects with polyneuropathy (n = 94), without polyneuropathy (n = 39) and healthy elderly (n = 19). The plantar flexion moment at 40% of the stance phase was negatively correlated with the displacement rate of center of pressure (r = ?.749, p < .001 at the imposed, and r = ?.693, p < .001 at the preferred gait velocity). Displacement rate of center of pressure was strongly correlated with forefoot loading (r = ?.837, p < .001 at the imposed, and r = ?.731, p < .001 at the preferred gait velocity). People with a relatively high plantar flexion moment at 40% of the stance phase, have a faster forward transfer of center of pressure and consequently higher loading of the forefoot. This indicates that interventions aimed at increasing the control of the roll-off of the foot may contribute to a better plantar pressure distribution.     

Positive Social Pressure and Prosocial Motivation: Evidence from a Large‐Scale Field Experiment on Voter Mobilization

Political scientists are increasingly exploring the psychological underpinnings of voting behavior using field experimental techniques. Research in psychology demonstrates that positive reinforcement—what I describe as positive social pressure—motivates prosocial behavior. A distinctive feature of the current study is the focus on key subgroups of voters, namely unmarried women and minorities. Attention to these voter subgroups allows us to build upon findings reported in previous studies that leave questions about the generalizability of the reported effects of positive social pressure to key demographic subgroups of voters largely unanswered. This article reports the results of a large‐scale randomized field experiment designed to investigate the impact of positive social pressure on voter turnout. The experiment was conducted during the November 2009 gubernatorial election in New Jersey, and the results suggest positive social pressure mobilizes voters. Moreover, the effects appear to be robust across subgroups of voters, including minorities and unmarried women, and both lower‐ and higher‐propensity voters.