Kinetics and kinematics of the horse comparing left and right rising trot

Reasons for performing study: At rising trot the rider sits alternately down on one diagonal pair of limbs and rises up on the other. The possible effects on asymmetry of locomotion induced by rising trot have rarely been studied. Objectives: To demonstrate whether, and if so to what extent, rising trot causes asymmetrical loading in the vertical ground reaction force (VGRF) and/or asymmetrical effects on the locomotion pattern, comparing left and right side. Methods: Seven elite horses were ridden in left and right rising trot on a treadmill, while VGRF and kinematics were measured, with the horses' neck raised, the poll high and the bridge of the nose slightly in front of the vertical. Results: Force loading was generally increased in the limbs of the sitting diagonal. The lumbar back was lower between mid‐stances of the sitting and nonsitting stance, pelvic roll was limited and the tuber coxae heights were lower on the sitting side. Maximal hindlimb protraction was decreased. Forelimb retraction was increased and the T6 height decreased. Conclusion: The rider movement induces an uneven biphasic load that affects the back, pelvis and limb kinematics and VGRF. Potential relevance: The generally advocated technique of alternating limbs when riding in rising trot is supported. The VGRF changes between rising on the left or right diagonal were distinct, but minor in absolute terms and therefore unlikely to have direct impact on the occurrence of locomotor injuries. Knowledge of an increase of asymmetry in rising trot is potentially useful for riders/trainers.     

Factors impacting hunter access to private lands in southeast Minnesota

White-tailed deer (Odocoileus virginianus) have important socioeconomic and ecological impacts in the United States. Hunting is considered to be important for the effective management of deer and relies on access to privately owned lands. In 2013, we surveyed nonindustrial private landowners in southeast Minnesota and created two logit models to examine factors that impact landowners’ decision to (a) allow public hunting access and (b) post private property. Parcel characteristics were found to impact landowner decisions to allow hunting access, particularly the size of the property and whether it was posted. Hunting access to small properties was more likely to be restricted to family, friends, and neighbors (83%) compared to medium (74%) or large properties (60%). Hunter concerns (e.g., liability) and knowledge about deer management was significant in both models, suggesting there are opportunities to educate landowners about the importance of allowing public hunting access and available liability protections.     

氮肥减量后移对土壤氮素供应和夏玉米氮素吸收利用的影响

采用田间试验研究了氮肥减量后移对土壤氮素供应和夏玉米氮素吸收利用的影响。结果表明,与农民习惯施肥（N 240 kg/hm2,基肥和大喇叭口追肥为1∶2）相比,氮肥减量后移（N 168 kg/hm2,基肥、大喇叭口肥和吐丝肥为1∶3∶1）处理的产量、植株干物质积累量、植株氮积累量和积累速率均没有降低,而氮肥利用率显著增加。氮肥减量后移可使耕层无机氮供应较好地与作物吸收同步,降低收获期0—100 cm土层硝态氮积累,减少氮素的田间表观损失。基于夏玉米不同生育阶段的氮素吸收特征进行氮肥减量后移可节省氮肥30%,是较为理想的氮素施用方式。     

津郊潮土磷素组成及其演变规律的定位研究

１９７９～１９９３年研究了长期定位施肥对天津郊区潮土磷素组成及其演变规律的影响。结果表明，潮土磷素组成以无机磷为主，其中又以磷酸钙盐最多，其次是闭蓄态磷酸盐，而磷酸铝盐和铁盐所占比例很少。长期定位施肥对潮土速效磷影响显著，变幅也最大，其中化肥的影响高于有机肥，平均每施入２８ｋｇ／ｈｍ２或亏缺磷素４５ｋｇ／ｈｍ２，土壤速效磷约升或降１ｍｇ／ｋｇ。潮土速效磷的累积与下降呈现阶段性，开始１～２年变幅大，其后６～８年时间保持稳定变化，当速效磷升降到某一定值时，变幅显著降低。小麦、夏玉米连作年产在１１１９８ｋｇ／ｈｍ２水平下，平均每生产１００ｋｇ籽实，施磷１．２ｋｇ，在１４年中可保持土壤磷素平衡     

蚯蚓堆肥在污泥处理中的应用

概述了利用蚯蚓处理污泥技术的基本原理、生活污泥和工业污泥蚯蚓堆肥研究的历史和现状,介绍了国内外的应用实例。蚯蚓污泥堆肥技术具有设备简单、操作方便、费用低廉等特点,能处理多种类型的污泥;处理后污泥无害化、稳定化和减量化,可资源化利用;该技术应用前景可观,尤其适合城镇小型污水厂的污泥处理。