油锯人机界面的优化研究

该文通过实验研究探讨了油锯人机界面几何参数对操作者主观施力及对其身体生理负荷的影响规律 .通过对实验数据的回归得出了高把油锯和矮把油锯的人机界面几何参数与评价指标 (最大有效扭矩、力损耗因子、肌肉收缩强度 )之间存在的定量化方程 .建立了油锯的人机界面几何参数优化的目标函数 ,并求出了高把油锯和矮把油锯的最佳几何参数 .高把油锯的最佳几何参数 :把手横轴距为 5 40mm ;把手与地面垂轴距为 6 88mm ;把手与油箱后部纵轴距为 186mm ;把手直径为 30mm ;把手倾角为 33° .矮把油锯的最佳几何参数 :把手横轴距为 14mm ;把手纵轴距为 40 0mm ;把手垂轴距为 5 0mm ;把手直径为 2 8mm ;把手倾角为 2 3     

Movements of Atlantic salmon migrating upstream through a fish-pass complex in Scotland

Abstract  – Movements of adult Atlantic salmon were tracked through a series of four fish passes and an impoundment on the River Conon system, Northern Scotland. Proportions of fish passing individual obstructions ranged from 63 to 100%. The cumulative effect was that only 4 of the 54 tagged fish reached the spawning areas. The fish were delayed for 1–41 days at a pool-and-overfall ladder and 1–52 days at a Borland fish lift. The fish swam through a 10 km long reservoir at 0.21–1.16 km·h⁻¹. A total of 13 fish negotiated a 2.5 km long, 3 m diameter diversion tunnel through a mountain to their home river. High levels of electromyogram (EMG) activity were recorded during ascent of a pool-and-overfall fish ladder, indicating that high energy demanding burst swimming was required.     

拖拉机驾驶员颈部疲劳的肌电评价

为了了解拖拉机驾驶员颈部疲劳状况,该文在模拟拖拉机倒车作业的基础上,对驾驶员颈部胸锁乳突肌的表面肌电信号进行了测试,选取积分肌电值、平均功率频率、小波分解系数等特征量对肌电信号进行时域、频域以及时频域分析。结果表明：拖拉机驾驶员颈部疲劳后胸锁乳突肌的积分肌电值、平均功率频率、小波分解系数都降低,疲劳前后各特征量存在显著性差异（P＜0.05）,这些特征量都可以有效评价拖拉机驾驶员的颈部疲劳。     

竞技武术套路中搬脚朝天蹬直立平衡动作下肢肌肉用力特征的表面肌电分析

运用表面肌电遥测和高速摄影同步测试技术,对竞技武术套路中搬脚朝天蹬直立平衡动作的下肢肌 肉用力特征进行测试。结果显示： 所测五名女子运动员的下肢六部位肌肉（胫骨前肌、臀中肌、臀大肌 、腓肠肌、股二头肌和股直肌）的放电大小顺序和先后顺序相似,即胫骨前肌最先放电且放电量最大、其 次是臀中肌和臀大肌几乎同时放电,而后依次是腓肠肌、股二头肌和股直肌。在完成动作过程中,运动员 的运动级别越高,其各部位肌肉的总积分肌电值却越低。武英级运动员与二级运动员在股直肌、股二头肌 、胫骨前肌、臀中肌上的均方根振幅(RMS)指标上存在显著性差异（P<0.05）。与二级运动员相比,武英 级运动员在完成该动作时肌肉间的配合更协调,总体更省力。     

Sex differences in metabolic rate and swimming performance in pink salmon (Oncorhynchus gorbuscha): the effect of male secondary sexual traits

Do secondary sexual traits, such as large dorsal hump and hooked snout, decrease the swimming efficiency of male pink salmon during freshwater migration? This is the first study to address the effects of secondary sexual traits in pink salmon on oxygen uptake and swimming capacity. We conducted a laboratory experiment using a swimming respirometer and a field study using electromyogram (EMG) telemetry in the Shibetsu River, Hokkaido, Japan. We compared the relationship between MO₂ (mg O₂·kg^?1·h^?1) and swimming velocity U (m·s^?1) in male and female fish, and also investigated the effects of morphological traits (secondary sexual characters) on the relationship between MO₂ (mg O₂·kg^?1·h^?1) and swimming velocity U (m·s^?1). Additionally, we compared energy costs and swimming behaviour during upstream migration between male and female pink salmon. The laboratory experiment revealed that MO₂ exponentially increased with increasing U; this increase was described by MO₂ = 167.9e^1.23U for males and 144.9e^1.14U for females. Linear mixed models found that hump height and the upper jaw length in males significantly and positively affected the relationship between MO₂ and U; no effect was found in females. The field study found that swimming velocity for both sexes estimated from EMG calibration was lower than optimal swimming velocity (U_opt) calculated from the laboratory experiment. We suggest that pink salmon in the Shibetsu River do not swim at the optimal swimming velocity because of the short migration distance involved (20 km).     

Behaviour and physiology of mountain whitefish ( Prosopium williamsoni) relative to short‐term changes in river flow

Despite the growing recognition that river flow can have an effect on the growth, distribution and survival of fishes, little is known about the underlying mechanisms to explain this effect. Furthermore, there are few examples of integrated measures of behaviour and physiology to study the responses of fish to river hydrology. Here, axial swimming muscle electromyograms were logged as a sensitive indicator of activity from 19 mountain whitefish ( Prosopium williamsoni) across a large range of hourly discharge magnitudes (mean = 621 m³·s^?1, range = 0–1770 m³·s^?1) in a hydropeaking reach of the Columbia River, Canada. Hourly mean discharge had a significant positive effect on swimming muscle activity. However, a large amount of the variance was unexplained, possibly due to social interactions, feeding and/or flow‐refuging behaviours. Fluctuating flows were no more energetically costly than stable flows. Discharge magnitude had a significant positive effect on blood cortisol concentrations. Yet, cortisol concentrations were low overall (mean ± SD = 1.60 ± 0.09 ng·ml^?1), suggesting that the small observed response could be the result of routine physiological processes rather than a stress response per se. Based on low blood lactate concentrations, mountain whitefish were not swimming exhaustively (i.e., anaerobic burst‐type swimming) at high flows.     

Muscle activity as a key indicator of welfare in farmed European sea bass (Dicentrarchus labrax L. 1758)

Groups of adult sea bass were reared at either low (10 kg m^?3) or high (50 kg m^?3) stocking densities respectively for 84 and 116 days. To monitor the red muscle activity, about 20 fish from both densities were surgically implanted with EMG (Electromyograms) radio transmitters, after EMG calibration during exhaustive swimming exercise (U_crit test). Blood samples and morphometric measurements were also taken. EMG showed that the muscle activity of fish reared at 50 kg m^?3 was on average twofold higher than fish kept at lower density. Cortisol was significantly more elevated at higher density and haemoglobin, haematocrit and RBCC (red blood cells count) showed the same trend, while lysozyme decreased. Patterns for glucose and lactate were less clear. The results showed that the contemporary use of functional (EMG) and physiological (haematological and biochemical) profiles could give a more comprehensive view of the fish status validating the diagnosis of fish stress induced by culture practices.     

背负式林果采摘机的人机工程学评价

为了研究背负式林果采摘机的人机工程学特性, 通过林果采摘手臂疲劳实验, 建立了基于表面肌电信号的上肢肱二头肌疲劳评价模型, 并结合心率测试对比分析背负式林果采摘机和手持式采摘机的手臂疲劳特性。结果表明:操作背负式林果采摘机心率增加比小于手持式采摘机; 同时手臂疲劳程度也小于手持式采摘机。背负式林果采摘机较手持式采摘机更加省力, 能够有效地缓解肌肉疲劳。      

Antinociceptive effect of buprenorphine and evaluation of the nociceptive withdrawal reflex in foals

ObjectiveTo elicit and evaluate the NWR (nociceptive withdrawal reflex) in 2 and 11 day old foals, to investigate if buprenorphine causes antinociception and determine if the NWR response changes with increasing age. The effect of buprenorphine on behaviour was also evaluated.Study designProspective, experimental cross-over trial.AnimalsNine Norwegian Fjord research foals.MethodsBuprenorphine, 10 μg kg⁻¹ was administered intramuscularly (IM) to the same foal at 2 days and at 11 days of age. The NWR and the effect of buprenorphine were evaluated by electromyograms recorded from the left deltoid muscle following electrical stimulation of the left lateral palmar nerve at the level of the pastern. Mentation, locomotor activity and respiratory rate were recorded before and after buprenorphine administration.ResultsWe were able to evoke the NWR and temporal summation in foals using this model. Buprenorphine decreased the root mean square amplitude following single electrical stimulation (p < 0.001) in both age groups, and increased the NWR threshold following single electrical stimulation in 2 day old foals (p = 0.0012). Repeated electrical stimulation at 2 Hz was more effective to elicit temporal summation compared to 5 Hz (p < 0.001). No effect of age upon the NWR threshold was found (p = 0.34). Sedation when left undisturbed (11 occasions), increased locomotor activity when handled (9 occasions) and tachypnea (13 occasions) were common side-effects of buprenorphine.Conclusion and clinical relevanceThese findings indicate that buprenorphine has antinociceptive effect in foals. Opioid side effects often recognized in adult horses also occur in foals.