The effect of previous hamstring strain injuries on the change in eccentric hamstring strength during preseason training in elite Australian footballers

Background Hamstring strain injuries (HSIs) are the most common injury type in Australian football and the rate of recurrence has been consistently high for a number of years. Long lasting neuromuscular inhibition has been noted in previously injured athletes but it is not known if this influences athletes adaptive response to training. Purpose To determine if elite Australian footballers with a prior unilateral HSI (previously injured group) display lesser improvements in eccentric hamstring strength during pre-season training compared to athletes without a history of HSI (control group). Study design Prospective cohort study. Methods Ninety-nine elite Australian footballers participated (17 with a history of unilateral HSI in the previous 12 month period). Eccentric hamstring strength was assessed at the start and end of pre-season training using an instrumented Nordic hamstring device. Change in eccentric strength across preseason was determine in absolute terms and normalised to start of preseason strength. Start of preseason strength was used as a covariate to control for differences in starting strength. Results The left and right limbs in the control group showed no difference in absolute or relative change (left limb absolute change, 60.7±72.9N; relative change, 1.28±0.34; right limb absolute change, 48.6±83.8N; relative change, 1.24±0.43) . Similarly, the injured and uninjured limbs from the previously injured group showed no difference for either absolute or relative measures of change (injured limb absolute change, 13.1±57.7N; relative change, 1.07±0.18; uninjured limb absolute change, 14.7±54.0N; relative change, 1.07±0.22N). The previously injured group displayed a significantly lesser increase in eccentric hamstring strength across the preseason (absolute change, 13.9±55.0; relative change, 1.07±0.20) compared to the control group (absolute change, 54.6±78.5; relative change, 1.26±0.39) for both absolute and relative measures (p < 0.001), even after controlling for differences in start of pre-season eccentric hamstring strength, which had a significant effect on strength improvement. Conclusion Elite Australian footballers with a unilateral HSI history displayed lesser improvements in eccentric hamstring strength across preseason training. The smaller improvements were not restricted to the previously injured limb as the contralateral limb also displayed similarly small improvements in eccentric strength. Whether this is the cause of or the result of injury remains to be seen, but it has the potential to contribute to the risk of hamstring strain re-injury.

Socioeconomic Status, Occupational Factors and Lifestyle as Predictors of Hospitalisation for Back Disorders

The aim of this dissertation was to examine the determinants of severe back disorders leading to hospital admission in Finland. First, back-related hospitalisations were considered from the perspective of socioeconomic status, occupation, and industry. Secondly, the significance of psychosocial factors at work, sleep disturbances, and such lifestyle factors as smoking and overweight was studied as predictors of hospitalisation due to back disorders. Two sets of data were used: 1) the population-based data comprised all occupationally active Finns aged 25-64, and included hospitalisations due to back disorders in 1996 and 2) a cohort of employees followed up from 1973 to 2000 having been hospitalised due to back disorders. The results of the population-based study showed that people in physically strenuous industries and occupations, such as agriculture and manufacturing, were at an increased risk of being hospitalised for back disorders. The lowest hospitalisation rates were found in sedentary occupations. Occupational class and the level of formal education were independently associated with hospitalisation for back disorders. This stratification was fairly consistent across age-groups and genders. Men had a slightly higher risk of becoming hospitalised compared with women, and the risk increased with age among both genders. The results of the prospective cohort study showed that psychosocial factors at work such as low job control and low supervisor support predicted subsequent hospitalisation for back disorders even when adjustments were made for occupational class and physical workload history. However, psychosocial factors did not predict hospital admissions due to intervertebral disc disorders; only admissions due to other back disorders. Smoking and overweight predicted, instead, only hospitalisation for intervertebral disc disorders. These results suggest that the etiological factors of disc disorders and other back disorders differ from each other. The study concerning the association of sleep disturbances and other distress symptoms with hospitalisation for back disorders revealed that sleep disturbances predicted subsequent hospitalisation for all back disorders after adjustment for chronic back disorders and recurrent back symptoms at baseline, as well as for work-related load and lifestyle factors. Other distress symptoms were not predictive of hospitalisation.

固氮蓝藻的大量培养方法

<正> 固氮蓝藻能够利用空气中的游离氮素,合成氮素化合物,不断的释放出来,死亡分解之后,更可以释放出大量氮素化合物,作为其它植物的氮肥。过去国外的一些试验证明可以利用固氮蓝藻作为水稻的氮肥肥源;我们在1958年进行的固氮蓝藻对盆栽水稻的肥效试验和与湖北省农业科学研究所协作的田间施用固氮蓝藻水生686号和水生678号作为水稻追肥试验的结果,也证明固氮蓝藻可作为水稻田的氮肥新肥源。在我们的试验中,每亩稻田接入的固氮蓝藻数量是滤去培养液后的湿重5市斤,因此,大面积的稻田

Trade obstacles, inventory level of inputs, and internationalization of enterprise activities : a comparison between Southeast Asia and Latin America

This paper investigates the impact of trade barriers such as customs clearance, subjective trade obstacles (customs and trade regulations), and inventory of inputs on the internationalization of enterprises in Southeast Asia and Latin America, using the World Bank's enterprise surveys. Empirical results show a negative association between the internationalization of enterprises and subjective trade obstacles, while the impact of subjective trade obstacles is not significant on enterprises already internationalized. An international comparison between Southeast Asia and Latin America suggests that enterprises in Latin America face unfavorable conditions that discourage them from becoming more closely inserted into international production networks.

On the variety of Mexico's export goods

This paper examines the evolution of the variety of Mexico’s export goods using disaggregated trade data. Both the econometric estimation analyses using the raw data and the one using an improved version of Feenstra and Kee's (2004, 2007) methodology proposed in this paper show that NAFTA membership does not enhance the variety of Mexico's export goods. This finding contrasts with NAFTA's positive association with the increase in export variety found in the literature.

二苯基-15-冠-5加速钠离子和钾离子在微米管支撑的微-水/1,2-二氯乙烷界面上的转移反应

玻璃微米管针尖可用于支撑微米级的水/1,2-二氯乙烷（W/DCE）界面,并用来研究二苯基-15-冠-5（DB15C5）加速钠离子和钾离子转移反应的机理和求算其络合物的稳定常数.在两种极限情况下,即水相中金属离子浓度远大于有机相中DB15C5的浓度（DB15C5扩散控制过程）和有机相中DB15C5的浓度远大于水相中金属离子浓度（金属离子扩散控制过程）,循环伏安研究表明,加速钠离子转移反应均发生1∶1（金属离子:载体）的界面络合转移过程,相应的一级络合常数分别为logβ1=8.97±0.05和logβ1=8.63±0.03.而对于加速钾离子转移反应,当 DB15C5扩散控制时发生的是一个1:2的界面络合转移过程,当钾离子扩散控制时,在电位窗内却观察到两个过程:一个较低电位的1∶2的界面络合转移过程和一个较高电位的1∶1界面络合转移过程.两种极限条件下所求算的钾离子和DB15C5的二级络合常数分别为logβ1=13.64±0.03和logβ2=11.34±0.24.

SYNTHESIS AND STRUCTURE OF (ETA-5-C5H5)2YB.DME

(eta-5-C5H5)2YbCl.THF reacts with an equivalent molecular quantity of K(2,4-C7H11) (2,4-dimethyl pentadienyl potassium), and treatment of the product with DME yields (eta-5-C5H5)2Yb.DME. The crystal of (eta-5-C5H5)2Yb.DME belongs to the orthorhombic space group Fdd2 with a = 13.678(4) angstrom, b = 23.255(6) angstrom, c = 9.192(2) angstrom and Z = 8. The crystal parameters are found to differ from previously reported data.

Informe del trigésimo quinto Período de Sesiones de la CEPAL. Lima, 5 a 9 de mayo

Asistencia y organización de los trabajos .-- Temario .-- Desarrollo de la reunión.-- Resoluciones aprobadas por la CEPAL en su Trigésimo Quinto Período de Sesiones. 676(XXXV) Calendario de conferencias de la CEPAL para el período 2015-2016 .-- 677(XXXV) Conferencia Regional sobre la Mujer de América Latina y el Caribe .-- 678(XXXV) Conferencia Estadística de las Américas de la Comisión Económica para América Latina y el Caribe .-- 679(XXXV) Respaldo a la labor del Instituto Latinoamericano y del Caribe de Planificación Económica y Social (ILPES) .-- 680(XXXV) Comité de Desarrollo y Cooperación del Caribe .-- 681(XXXV) Conferencia Regional sobre Población y Desarrollo de América Latina y el Caribe .-- 682(XXXV) Establecimiento de la Conferencia Regional sobre Desarrollo Social de América Latina y el Caribe .-- 683(XXXV) Admisión de San Martín como miembro asociado de la Comisión Económica para América Latina y el Caribe .-- 684(XXXV) Prioridades y Programa de Trabajo de la Comisión Económica para América Latina y el Caribe para el bienio 2016-2017 .-- 685(XXXV) Actividades de la Comisión Económica para América Latina y el Caribe en relación con el seguimiento de los Objetivos de Desarrollo del Milenio y la aplicación de los resultados de las grandes conferencias y cumbres de las Naciones Unidas en las esferas económica y social y esferas conexas .-- 686(XXXV) Aplicación del Principio 10 de la Declaración de Río sobre el Medio Ambiente y el Desarrollo en América Latina y el Caribe .-- 687(XXXV) Dimensión regional de la agenda para el desarrollo después de 2015 .-- 688(XXXV) Comité de Cooperación Sur-Sur .-- 689(XXXV) Lugar del próximo período de sesiones.

Report of the thirty-fifth session. Lima, 5-9 May 2014

Attendance and organization of work .-- Agenda .-- Summary of proceedings .-- Resolutions adopted at the Thirty-Fifth Session of the Commission: 676(XXXV) ECLAC calendar of conferences for the period 2015-2016 .-- 677(XXXV) Regional Conference on Women in Latin America and the Caribbean .-- 678(XXXV) Statistical Conference of the Americas of the Economic Commission for Latin America and the Caribbean .-- 679(XXXV) Support for the work of the Latin American and Caribbean Institute for Economic and Social Planning .-- 680(XXXV) Caribbean Development and Cooperation Committee .-- 681(XXXV) Regional Conference on Population and Development in Latin America and the Caribbean .-- 682(XXXV) Establishment of the Regional Conference on Social Development in Latin America and the Caribbean .-- 683(XXXV) Admission of Sint Maarten as an associate member of the Economic Commission for Latin America and the Caribbean .-- 684(XXXV) Programme of Work and priorities of the Economic Commission for Latin America and the Caribbean for the 2016-2017 biennium .-- 685(XXXV) Activities of the Economic Commission for Latin America and the Caribbean in relation to follow-up to the Millennium Development Goals and implementation of the outcomes of the major United Nations conferences and summits in the economic, social and related fields .-- 686(XXXV) Application of Principle 10 of the Rio Declaration on Environment and Development in Latin America and the Caribbean .-- 687(XXXV) The regional dimension of the post-2015 development agenda .-- 688(XXXV) South-South Cooperation .-- 689(XXXV) Place of the next session .-- 690(XXXV) Lima Resolution .-- 691(XXXV) Ministerial Conference on the Information Society in Latin America and the Caribbean.