The Biomechanics of Movement of Horses Engaged in Jumping Over Different Obstacles in Competition and Training

There exist numerous scientific studies, which are evaluating the biomechanics of the jumping movement of horse and rider over different types of obstacles. The most important results of the kinematic and kinetic investigations are the takeoff position, the acceleration of the hind limbs at takeoff as well as the load of the fore limbs at landing. The starting position directly before takeoff is described by the angle of the trunk, the associated height of the center of gravity (CG), and by the distances of the hind limbs to the obstacle. The acceleration of the hind limbs at takeoff, which is expressed by the vertical and horizontal velocity of takeoff at CG, is a further important indicator for a successful overcoming of a given obstacle. Based on the landing, the load bearing of the fore limbs is an important factor with regard to a long-term health maintenance of horses tendons. From methodological point of view, the majority of investigations use a variety of visual methods in two dimensions. Occasionally, accelerometers and force plates were used to get further information. A combination of visual methods and accelerometer seems to be promising.     

Consequences of specialized breeding in the Swedish Warmblood horse population

In many European warmblood studbooks, clear specialization toward either jumping or dressage horses is evident. The Swedish Warmblood (SWB) is also undergoing such specialization, creating a possible need for separate breeding programs and a discipline-specific Young Horse Test (YHT). This study investigated how far specialization of the SWB breed has proceeded and the potential consequences. Individuals in a population of 122,054 SWB horses born between 1980 and 2020 were categorized according to pedigree as jumping (J), dressage (D), allround (AR), or thoroughbred (Th). Data on 8,713 J horses and 6,477 D horses assessed for eight traits in YHT 1999–2020 were used to estimate genetic parameters within and between J and D horses and between different periods. Future scenarios in which young horses are assessed for either jumping or dressage traits at YHT were also analyzed. More than 80% of horses born in 1980–1985 were found to be AR horses, while 92% of horses born in 2016–2020 belonged to a specialized category. The average relationship within J or D category was found to increase during the past decade, whereas the relationship between these categories decreased. Heritability estimates for gait traits were 0.42–0.56 for D horses and 0.25–0.38 for J horses. For jumping traits, heritability estimates were 0.17–0.26 for J horses and 0.10–0.18 for D horses. Genetic correlations between corresponding traits assessed in J and D horses were within the range 0.48–0.81, with a tendency to be lower in the late study period. In the future scenarios, heritability and genetic variance both decreased for traits that were not assessed in all horses, indicating that estimation of breeding value and genetic progress for these traits could be affected by a specialized YHT. However, ranking of sires based on estimated breeding values (EBVs) and accuracy of EBVs was only slightly altered for discipline-specific traits. With continued specialization in SWB, specialization of the YHT should thus be considered.     

由2006年切尔西花展看花园设计的新趋势

切尔西花展是世界最负盛名的花展,汇集了全世界最优秀的花卉园艺作品,代表着花卉园艺未来的发展趋势。其花园展览部分的作品,体现了花园设计的最高水平。本文通过介绍2006年切尔西花展的花园获奖作品,总结出本年度花园设计的特点及发展潮流,为我国的花园设计提供借鉴和启示。     

Possibility of selecting racehorses on jumping ability based on their steeplechase race results in France, the United Kingdom and Ireland

The aim of this study was to detect Thoroughbred mare families and sire lines, in France, in the United Kingdom and Ireland, whose offspring may be successful in steeplechase races and can be recommended therefore for sport horse breeding. Race results were collected from all steeplechase races in these countries between 1998 and 2003, which contained the results of 17,355 horses from 12,861 dams and 2452 sires. In France, non-Thoroughbred horses were also included in the analysis because they race and mate together with Thoroughbreds. Performance was measured with two criteria: earnings and ranks after mathematical transformation. The effects of year, sex, age and race were considered as fixed, animal, permanent environment and maternal environment as random. Precorrection for the effect of race was done to avoid computational difficulties. Maternal environmental components for ranks were 0.02 in France and zero in the United Kingdom and Ireland. Estimated heritabilities for the ranking criteria were 0.18 (repeatability 0.33) in France and 0.06 (repeatability 0.19) in the United Kingdom and Ireland. The high genetic correlation between the two criteria of measurement (0.94 and 0.97 respectively) gives the opportunity to choose the most suitable criteria for breeding value estimation. The ranking value, after statistical normalization has a great advantage for comparison between the countries.     

Post-buckling and mode jumping analysis of angle-ply composite laminates

The governing partial differential equations (PDEs) are deduced from the asymptotically correct, geometrically nonlinear theory to research the bucking and mode jumping behavior of biaxially antisymmetric angle-ply composite laminates. The PDEs are transformed into a system of nonlinear ordinary differential equations (ODEs) by using the generalized Galerkin method. Then, the post-buckling behavior is analyzed by using the solution extension software. At last, the paths of buckling mode jumping and critical loads for the composite laminates under the in-plane boundary condition of straight edge are determined. An example of 4-layer composite laminates shows that the numerical results in the primary post-buckling region from the present method agree with the finite element analysis (FEA); while the FEA may lose its convergence when solution comes close to the secondary bifurcation point, the analytic method has the capability to explore deeply into the post-secondary bucking realm and capture the mode jumping phenomenon.     

职业学校起步阶段“三难”现象分析

职业学校发展初期,教学设备、师资力量、生源质量都比较差,教学过程中出现“学习难”“教学难”“管理难”的现象。在对该现象分析后,提出新形势下班级管理的指导思想,引导学生提高培养自觉性与责任感,教师转变教学观念的一些看法,使教学活动达到乐教乐学、善教善学、会教会学的境界。     

浅谈沧州市首界迎春花卉展

首届沧州迎春花卉展以今年回家.公园看花为主题,取得了良好的社会效益,本文从花展前期筹备工作、采购情况、花展各展区的布置、各项策划内容的实施、后期管护工作等方面进行阐述。详细介绍了花展的情况,并进行分析总结,提出了改进意见。     

近48年大同市旱涝灾害对气候变化的响应

根据1960~2007年大同逐月平均气温和逐月降水资料,分析了近48 a大同市在全球增暖影响下气温和降水的变化;采用滑动t检验法和信噪比法分析了气温突变的时间点;在此基础上研究了大同市气温突变前后旱涝灾害的变化,并运用马尔可夫模型对未来5 a旱涝状况进行了预测。结果表明:近48 a来大同市气温呈明显的上升趋势;随着气温的升高,该市干旱灾害的比例增幅比较明显,特别是在气温突变后,干旱(4级和5级)的概率达到63.64%,2009~2012年处于"偏旱"的概率较大。     

2021年扬州世界园艺博览会深圳园“共生家园”

近年来,园林展在我国发展迅速。城市展园作为各级园林展的重要组成部分,在展示城市文化、地域特色方面具有重要作用。2021年扬州世园会深圳园占地面积2 500 m^(2),以“共生家园”为主题,设计理念强调突破对城市景观要素的提取与再现,通过地形空间优化、地域植物生境展示以及趣味化视听设计,塑造了一个双环结构的高品质开放空间,展现了深圳市开放包容、追求卓越的城市活力与魅力。