Acute intraocular pressure changes during isometric exercise and recovery: The influence of exercise type and intensity,and participant´s sex

ABSTRACT

We assessed the intraocular pressure (IOP) behaviour during a 1-minute period of isometric physical effort and the immediate 1-minute of recovery in the mid-thigh clean pull and squat exercises at three different intensities. Twenty physically active individuals performed the isometric mid-thigh clean pull and squat exercises at three intensities (0% [low-intensity], 25% [medium-intensity] and 50% [high-intensity] of the maximum isometric force). IOP was semi-continuously measured by rebound tonometry. There was a statistically significant effect of exercise intensity on IOP (p < 0.001, ?_p² = 0.416), observing that IOP increments were positively associated with exercise intensity. The mid-thigh clean pull and squat exercises did not demonstrate differences (p = 0.510), and also, no differences were observed between men and women (p = 0.683). The IOP changes during the isometric physical effort showed a positive linear behaviour in all conditions (r = 0.70 to 0.96). IOP returned to baseline levels after 8 seconds of recovery. Our data showed a progressive and instantaneous IOP increment during isometric exercise, which was positively associated with exercise intensity. IOP changes were independent on the type of exercise and participant´s sex. After exercise, IOP rapidly (≈ 8 seconds) returned to baseline levels.     

Fractionated Reaction Time Responses to Auditory and Electrocutaneous Stimuli

Abstract

It is well documented that simple reaction time (RT) varies inversely with stimulus intensity, but there is disagreement as to which stimulus modality produces the fastest simple RT. An investigation was conducted to equate two stimulus modalities, auditory (A) and electrocutaneous (EC), using varying stimulus intensities in a simple RT protocol. A second investigation was then conducted to examine neuromotor characteristics of stimulus-evoked responses using previously equated A and EC stimuli of varying intensity from the first investigation. Results showed that RT, premotor time (PMT), and motor time (MT) were all inversely related to stimulus intensity, while maximum displacement (MAXD) was directly related to stimulus intensity, and movement time was not affected by stimulus intensity. We conclude that: (a) both central and peripheral components of RT are altered by varying stimulus intensities, and (b) rapid movements are enhanced by increasing stimulus intensity.     

我国能源强度与能源价格市场化关系研究

本文研究了能源价格波动性与能源强度之间的动态均衡关系,并进行了GARCH计量模型的实证检验以及两组估计结果的对比分析。研究发现,在市场化定价机制相对完善的情况下,能源价格与能源强度之间的负相关动态均衡关系才是存在的,如果国内缺乏市场化定价机制,能源价格提高非但不能降低能源强度,反而会因为能源替代而提高能源强度。     

一个新的等参数奇异单元

本文推导得到了一个新的等参数奇异单元,它仍然是四边形四分之一节点奇异元。数值实验表明,它要比常用的四边形四分之一节点奇异元精度更好,使用这种单元可以使断裂问题的有限元计算效果更好。在计算过程中还利用到改进等参变换。     

谈跑步运动的生理机制

本文从几个方面阐述了跑步对人体的益处,并说明了利用跑步进行锻炼及运动处方,并说明了跑步的注意事项.     

激光腔内单模场的强度和频率

本文用半经典理论研究激光腔内辐射场与原子的相互作用,得到了腔内单模场的强度随时间的变化关系以及频率牵引效应。     

学生课余体育锻炼应注意的几个问题

学生课余体育锻炼是学生体育课学习锻炼之外的自主学习行为,没有体育教师的参与和指导,锻炼活动还不够科学系统,锻炼环境、体育器材保障、医务救护监督等各方面条件也有所限制。本文就学生在课余体育锻炼如何做到科学合理,从而保证锻炼顺利进行并取得良好的锻炼效果做了探讨。     

论单位商品价值量下降规律——回应“成正比”争议的第2个命题

成正比的争议涉及两个命题:一是,一定长度的工作日总是表现为相同的价值产品。二是,劳动生产率提高,单位商品价值量下降。本文回应的是关于第二个命题的争议。在这个问题的争议中,认为在劳动生产率提高时,劳动生产率与单位商品价值量成反比的规律将不再成立的人,即主张"成正比"的人,其论证的主要依据是建立在劳动生产率等于劳动复杂程度和劳动强度的假设上的。然而这个假设是不成立的。社会劳动生产率的水平本身"表现为一个工人在一定时间内,以同样的劳动力强度使之转化为产品的生产资料的相对量。"其与劳动强度和劳动的复杂程度没有直接的关系,甚至在很大程度上劳动生产率与劳动复杂程度是成反比的。更为重要的是,市场竞争是通过使商品便宜而不是使商品昂贵来进行的。如果劳动生产率的提高使得单位商品价值提高从而使商品变得昂贵,那么,资本家就不会用提高劳动生产率的方法来进行竞争。显然,这不是事实。     

基于结构相似性的多源图像融合

对源图像进行小波分解,得到图像分解后的高频系数和低频系数,并且计算源图像的结构相似性。对于低频系数采用系数绝对值取大法进行融合;对于高频系数依据相似性大小对其进行融合,如果相似性大于设定阈值,则高频系数采用系数绝对值取大法,否则采用计算像素点边缘强度法进行融合,对融合后的系数进行小波逆变换得到融合图像。实验结果表明,该方法有效地综合了源图像中的重要信息,融合图像边界清晰,得到更好视觉效果和更优的评价指标,融合效果优于对比实验中的小波方法。     

应用系数法测定荧光灯的充气压强

阐述在不同检测温度下测得的荧光灯充气压强,比较与应用系数法反推出的荧光灯充气压强理论值之间的差异性。分析应用系数法检测的效果,以期为有关企业在荧光灯充气压强的实际检测中提供参考。