BIOMECHANICAL ANALYSIS ON RUN-UP AND TAKE-OFF IN WOMEN’S POLE VAULT

Run-up, plant and take-off directly affect the aerodynamics and the bar clearance in the pole vault event. The purpose of this study was to show the biomechanical features of the last two strides of run-up and take-off performed by China’s elite women pole vault athletes. Two synchronized PEAK video cameras operating at 25 Hz were used to film the pole vaults of the subjects and films were digitized by an Engine 3D Video Analysis System. Kinematics data was obtained on change of length in two last strides, velocities of last foot in contact with ground, take-off parameters and body position during foot pushing-off ground. Comparing their performance with that of world elite athletes, all subjects in the study should improve the run-up velocities in order to be more successful. Based on the results from this study, it is suggested to increase the horizontal velocities during take-off and to reduce the take-off angle. In addition, the poles should be lowered earlier and the knee angles should be increased

BIOMECHANICAL ANALYSIS OF ELITE CHINESE FEMALE POLE VAULTERS’ TAKE-OFF TECHNIQUES

Takeoff is one of the most critical phases used to determine pole-vaulting performance. The purpose of this study was to study the takeoff in pole-vaulting of Chinese female athletes. A National M9500 video camera was used to record subjects’ performance at a frequency of 25 frames per second. The videos were digitized by stma10 video analysis system developed by Engine Body Information. Kinematics data including the take-off velocity, time, position and angle was calculated. Comparing the Chinese subjects with world elite athletes, all athletes that were studied, should increase horizontal absolute velocity and plant the pole at an earlier time. The take-off angle should be reduced to the proper value of 20°. Also, these athletes should limit the backward leap of the trunk in order to prevent the hip joint angle from becoming excessively large. Free takeoff technique should be adopted

THE EFFECTS OF SHOT WEIGHT ON THROWING POWER OUTPUT IN ELITE FEMALE SHOT PUTTTERS

INTRODUCTION: Sport specific strength development is one of the key factors of the efficient training for throwing athletes (Liu, 1996). Little research has been conducted to examine the appropriate weight of shot that could develop specific strength and promote maximum power output in shot put. The purpose of this study was to compare the power and strength output induced by different weight selected for shot-put exercise in elite female shot putters

ENVIRONMENTAL SURROUNDINGS AND PERSONAL WELL-BEING IN URBAN CHINA

We examine the relationship between atmospheric pollution, water pollution, traffic congestion, access to parkland and personal well-being using a survey administered across six Chinese cities in 2007. In contrast to existing studies of the determinants of well-being by economists, which have typically employed single item indicators to measure well-being, we use the Personal Well-Being Index (PWI). We also employ the Job Satisfaction Survey (JSS) to measure job satisfaction, which is one of the variables for which we control when examining the relationship between environmental surroundings and personal well-being. Previous research by psychologists has shown the PWI and JSS to have good psychometric properties in western and Chinese samples. A robust finding is that in cities with higher levels of atmospheric pollution and traffic congestion, respondents report lower levels of personal well-being ceteris paribus. We find that a one standard deviation increase in suspended particles or sulphur dioxide emissions is roughly equivalent to a 12-13 percent reduction in average monthly income in the six cities. This result suggests that the personal well-being of China's urban population can be enhanced if China were to pursue a more balanced growth path which curtailed atmospheric pollution.China, Environment, Pollution, Personal Well-Being.

ENVIRONMENTAL SURROUNDINGS AND PERSONAL WELL-BEING IN URBAN CHINA

We examine the relationship between atmospheric pollution, water pollution, traffic congestion, access to parkland and personal well-being using a survey administered across six Chinese cities in 2007. In contrast to existing studies of the determinants of well-being by economists, which have typically employed single item indicators to measure well-being, we use the Personal Well-Being Index (PWI). We also employ the Job Satisfaction Survey (JSS) to measure job satisfaction, which is one of the variables for which we control when examining the relationship between environmental surroundings and personal well-being. Previous research by psychologists has shown the PWI and JSS to have good psychometric properties in western and Chinese samples. A robust finding is that in cities with higher levels of atmospheric pollution and traffic congestion, respondents report lower levels of personal well-being ceteris paribus. Specifically, we find that a one standard deviation increase in suspended particles or sulphur dioxide emissions is roughly equivalent to a 12-13 per cent reduction in average monthly income in the six cities.China, Environment, Pollution, Personal Well-Being.

Melanocortin 4 Receptors Reciprocally Regulate Sympathetic and Parasympathetic Preganglionic Neurons

Melanocortin 4 receptors (MC4Rs) in the central nervous system are key regulators of energy and glucose homeostasis. Notably, obese patients with MC4R mutations are hyperinsulinemic and resistant to obesity-induced hypertension. Although these effects are likely dependent upon the activity of the autonomic nervous system, the cellular effects of MC4Rs on parasympathetic and sympathetic neurons remain undefined. Here, we show that MC4R agonists inhibit parasympathetic preganglionic neurons in the brainstem. In contrast, MC4R agonists activate sympathetic preganglionic neurons in the spinal cord. Deletion of MC4Rs in cholinergic neurons resulted in elevated levels of insulin. Furthermore, re-expression of MC4Rs specifically in cholinergic neurons (including sympathetic preganglionic neurons) restores obesity-associated hypertension in MC4R null mice. These findings provide a cellular correlate of the autonomic side effects associated with MC4R agonists and demonstrate a role for MC4Rs expressed in cholinergic neurons in the regulation of insulin levels and in the development of obesity-induced hypertension

Melanocortin 4 receptors in autonomic neurons regulate thermogenesis and glycemia

SUMMARY Melanocortin 4 receptors (Mc4rs) are expressed by extra-hypothalamic neurons including cholinergic autonomic pre-ganglionic neurons. However, whether Mc4rs in these neurons are required to control energy and glucose homeostasis is unclear. Here we report that Mc4rs in sympathetic, but not parasympathetic, pre-ganglionic neurons are required to regulate energy expenditure and body weight including brown and white adipose tissue thermogenic responses to diet and cold exposure. In addition, deletion of Mc4rs in both sympathetic and parasympathetic cholinergic neurons impairs glucose homeostasis

A study on diesel spray tip penetration and radial expansion under reacting conditions

The shape of Diesel spray was investigated at real engine conditions in a constant pressure combustion chamber. Schlieren imaging technique was used to make quantitative measurements of spray tip penetration and radial width stressing the impact that the fuel combustion and heat release have on the spray shape. The heat-release region and the Lift-off length were identified measuring OH* chem-iluminescence. The fuel (n-dodecane) as well as the operating conditions and the injector used (single axially-oriented hole, 89 mu m-diameter) were chosen following the guidelines of the Engine Combustion Network. The effects of different operating parameters on the axial and radial expansion were also investigated. According to the results the reacting spray can be divided into three parts: an inert part, a transient one, and a quasi-steady one that lays between the two other regions. A new method for evaluating this radial expansion of reacting spray was developed, which was evaluated under the different operating conditions. Results show that the radial expansion increases with increasing injection pressure and decreasing ambient temperature and ambient density. The oxygen concentration has no obvious effect on the radial expansion. (C) 2015 Elsevier Ltd. All rights reserved.Authors acknowledge that some equipment used in this work has been partially supported by FEDER project funds (FEDER-ICTS-2012-06), framed in the operational program of unique scientific and technical infrastructure of the Ministry of Science and Innovation of Spain.Payri, R.; García Oliver, JM.; Xuan, T.; Bardi, M. (2015). A study on diesel spray tip penetration and radial expansion under reacting conditions. Applied Thermal Engineering. 90:619-629. https://doi.org/10.1016/j.applthermaleng.2015.07.042S6196299

Qishen Yiqi dripping pills for chronic ischaemic heart failure:results of the CACT-IHF randomized clinical trial

10.1002/ehf2.12980ESC Heart Failure763881-389

Longitudinal Gut Bacterial Colonization and Its Influencing Factors of Low Birth Weight Infants During the First 3 Months of Life

Establishment of low birth weight (LBW) infant gut microbiota may have lifelong implications for the health of individuals. However, no longitudinal cohort studies have been conducted to characterize the gut microbial profiles of LBW infants and their influencing factors. Our objective was to understand how the gut bacterial community structure of LBW and normal birth weight (NBW) infants varies across the first 3 months of life and assess the influencing factors. In this observational cohort study, gut bacterial composition was identified with sequencing of the 16S rRNA gene in fecal samples of 69 LBW infants and 65 NBW controls at 0 day, 3 days, 2 weeks, 6 weeks, and 3 months (defined as stages 1–5) after birth. Alpha-diversity of both groups displayed a decreasing trend followed by slight variations. There were significant differences on the Shannon index of the two groups at stages 1 to 3 (P = 0.041, P = 0.032, and P = 0.014, respectively). The microbiota community structure of LBW infants were significantly different from NBW infants throughout the 3 months (all P < 0.05) but not at stage 2 (P = 0.054). There was a significant increase in abundance in Firmicutes while a decrease in Proteobacteria, and at genus level the abundance of Enterococcus, Klebsiella, and Streptococcus increased while it decreased for Haemophilus in LBW group. Birth weight was the main factor explaining the observed variation at all stages, except at stage 2. Delivery mode (4.78%) and antibiotic usage (3.50%) contributed to explain the observed variation at stage 3, and pregestational BMI (4.61%) partially explained the observed variation at stage 4. In conclusion, gut microbial communities differed in NBW and LBW infants from birth to 3 months of life, and were affected by birth weight, delivery mode, antibiotic treatment, and pregestational BMI