Quadriceps muscle blood flow and oxygen availability during repetitive bouts of isometric exercise in simulated sailing

In this study, we wished to determine whether the observed reduction in quadriceps muscle oxygen availability, reported during repetitive bouts of isometric exercise in simulated sailing efforts (i.e. hiking), is because of restricted muscle blood flow. Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3-min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts. The blood flow index (BFI) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye, while cardiac output was determined from impedance cardiography. At equivalent cardiac outputs (ranging from 10.3±0.5 to 14.8±0.86 L · min(-1)), the increase from baseline in vastus lateralis BFI across the three hiking bouts (from 1.1±0.2 to 3.1±0.6 nM · s(-1)) was lower (P = 0.036) than that seen during the three cycling bouts (from 1.1±0.2 to 7.2±1.4 nM · s(-1)) (Cohen's d: 3.80 nM · s(-1)), whereas the increase from baseline in deoxygenated haemoglobin (by ～17.0±2.9 μM) (an index of tissue oxygen extraction) was greater (P = 0.006) during hiking than cycling (by ～5.3±2.7 μM) (Cohen's d: 4.17 μM). The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles.     

The effect of patellar taping on EMG activity of vasti muscles during squatting in individuals with patellofemoral pain syndrome

Although patellar taping has been shown to reduce pain in participants with patellofemoral pain syndrome, the mechanisms of pain reduction have not completely been established following its application. The purpose of this study was to evaluate EMG activity of vastus medialis and vastus lateralis following the application of patellar taping during a functional single leg squat. Both vastus medialis obliquus-vastus lateralis onset and vastus medialis obliquus/vastus lateralis amplitude of 18 participants with patellofemoral pain syndrome and 18 healthy participants as controls were measured using an EMG unit. This procedure was performed on the affected knee of participants with patellofemoral pain syndrome, before, during, and after patellar taping during unilateral squatting. The same procedure was also performed on the unaffected knees of both groups. The mean values of vastus medialis obliquus-vastus lateralis onset prior to taping (2.54 ms, s = 4.35) were decreased significantly following an immediate application of tape (-3.22 ms, s = 3.45) and after a prolonged period of taping (-6.00 ms, s = 3.40 s) (P < 0.05). There was also a significant difference between the mean values of vastus medialis obliquus-vastus lateralis onset among controls (-2.03 ms, s = 6.04) and participants with patellofemoral pain syndrome prior to taping (P < 0.05). However, there were no significant difference between the ranked values of vastus medialis obliquus/vastus lateralis amplitude of the affected and unaffected knees of participants with patellofemoral pain syndrome and controls during different conditions of taping (P > 0.05). Decreased values of vastus medialis obliquus-vastus lateralis onset may contribute to patellar realignment and explain the mechanism of pain reduction following patellar taping in participants with patellofemoral pain syndrome.     

体育教学中如何培养大学生的创新意识

创新教育是素质教育的灵魂,是当今教育改革的主旋律。在体育教学中实施创新教育,既能培养学生的创新意识、创新精神和创新能力,又能提高体育教学质量,培养社会需要的全面发展的高素质人才,推动高校体育改革不断向前发展。     

Experimental study on dispersion coefficient of dredger fill in reclamation region

In order to satisfy the demand of land use, reclamation engineering has been undertaken in coastal cities for a long time. To study the contaminant transport in the reclamation districts, robust and accurate estimation of dispersion coefficient is essential. In this study, the continuous sodium chloride （NaC1） solution with constant concentration was introduced into the column filled with the dredger fill to get the breakthrough curves （BTCs）. Inverse error function method （IEFM） and CXTFIT program were used for estimating dispersion coefficient. Results showed that the difference between the dispersion coefficients estimated by IEFM and CXTFIT program was slight. The main reason was that the BTC was not strictly linear. IEFM performed poorly in the nonlinear area, while the CXTFIT performed well over the entire BTCs. Moreover, the dispersion coefficient of dredger fill was small. The dispersion property of dredger fill would result in the slow migration of contaminants in the dredger fill.     

《公民韦尔斯》——又一部韦尔斯传发表

人们仍然怀念已故的奥森·韦尔斯。他曾是一位活跃于舞台、银幕和广播电台的明星,也是一位无论是他的失败或成功都受到人们关注的自视颇高的天才。在漫长而渐渐衰微的艺术生涯中,他表演过各种各样的节目:从古典作品到商业广告。老一代人依然记得他演出过有争议的新编莎士比亚戏剧,也记得他演播的广播剧《星际战争》,这部广播剧曾使千千万万听众相信火星人曾经入侵新泽西州。     

七彩年华

雨后,大自然送给人间一件别致的礼物——七彩虹,清晰地折射出阳光那迷人的颜色,青春则犹如这雨后的彩虹,充满了丰富的色彩。赤、橙、黄、绿、青、蓝、紫亦如青春的音符,谱奏着生命中最美丽的旋律。     

阿旃陀洞穴的宝藏

隐藏在印度农村,距孟买东约200英里的30座阿旃陀洞穴,堪与世界七大奇迹并列。这些面积广大的佛教寺院均为2200—1300年以前从险峻的玄武岩悬崖上用凿斧和錾子挖掘而成的。印度其他1000个宗教山洞都无法与阿旃陀洞内那些激动人心的壁画相比,可以说这些阿旃陀洞穴的创     

非洲国家学校教学中的民族语

尽管非洲国家在发展教育中取得了显著成绩,但是在那里有效的教育系统直到现在还是不完备的。这首先表现为由于学生被淘汰和留级造成学校失去质量水平。为了找到解决教育质量问题的方法,非洲国家正在致力于把课程引导到使教育具有非洲特征的轨道上来。而实现这个任务与用地方语翻译教材、用地方语编写教材和教学参考书紧密相关。人们注意到对多数学生用他们所不熟悉的欧洲语言授课是教育质量低、淘汰人数多的原     

短距离爬泳的耐力

专项耐力是指机体用一定速度和强度持续完成该专项的工作能力.当运动员参加短距离项目比赛时,我们认为专项耐力显得更重要.然而,如果认为在赛前专项耐力的训练是起压倒一切的作用,那么这种看法就值得怀疑了.同样,从重要性来说,运动员应该制订大强度短距离游(25,50和100米)的训练和竞赛计划,所要创造的条件,类似他在比赛中所遇到的条件.