Effects of ladder parameters on asymmetric patterns of force exertion during below-knee amputees climbing ladders

Different from walking, ladder climbing requires four-limb coordination and more energy exertion for below-knee amputees (BKAs). We hypothesized that functional deficiency of a disabled limb shall be compensated by the other three intact limbs, showing an asymmetry pattern among limbs. Hand and foot forces of six below-knee amputees and six able-bodied people were collected. Hand, foot and hand/foot sum force variances between groups (non-BKA, intact side and prosthetic side) were carefully examined. Our hypothesis was validated that there is asymmetry between prosthetic and intact side. Results further showed that the ipsilateral hand of the prosthetic leg is stronger than the hand on the intact side, compensating weakness of the prosthetic leg. Effects of ladder rung separations and ladder slant on asymmetric force distribution of BKAs were evaluated, indicating that rung separation has a more significant interactive effect on hand/foot force of BKAs than ladder slant.     

Influences of Microhabitat Constraints and Rock-Climbing Disturbance on Cliff-Face Vegetation Communities

Abstract:  Many researchers report that rock climbing has significant negative effects on cliff biota. Most work on climbing disturbance, however, has not controlled for variation in microsite characteristics when comparing areas with and without climbing presence. Additionally, some researchers do not identify the style or difficulty level of climbing routes sampled or select climbing routes that do not represent current trends in the sport. We solved these problems by sampling climbing areas used by advanced "sport" climbers and quantifying differences in microtopography between climbed and control cliffs. We determined whether differences in vegetation existed between pristine and sport-climbed cliff faces when microsite factors were not controlled. We then determined the relative influence of the presence of climbing, cliff-face microtopography, local physical factors, and regional geography on the richness, abundance, and community composition of cliff-face vascular plants, bryophytes, and lichens. When we did not control for microsite differences among cliffs, our results were consistent with the majority of prior work on impacts of climbing (i.e., sport-climbed cliff faces supported a lower mean richness of vascular plants and bryophytes and significantly different frequencies of individual species when compared with pristine cliff faces). When we investigated the relative influences of microtopography and climbing disturbance, however, the differences in vegetation were not related to climbing disturbance but rather to the selection by sport climbers of cliff faces with microsite characteristics that support less vegetation. Climbed sites had not diverged toward a separate vegetation community; instead, they supported a subset of the species found on pristine cliff faces. Prior management recommendations to restrict development of new climbing routes should be reevaluated based on our results.     

Increasing stair climbing in a train station: The effects of contextual variables and visibility

Accumulation of physical activity during daily living is a current public health target that is influenced by the layout of the built environment. This study reports how the layout of the environment may influence responsiveness to an intervention. Pedestrian choices between stairs and the adjacent escalators were monitored for 7 weeks in a train station (Birmingham, UK). After a 3.5 week baseline period, a stair riser banner intervention to increase stair climbing was installed on two staircases adjacent to escalators and monitoring continued for a further 3.5 weeks. Logistic regression analyses revealed that the visibility of the intervention, defined as the area of visibility in the horizontal plane opposite to the direction of travel (termed the isovist) had a major effect on success of the intervention. Only the largest isovist produced an increase in stair climbing. Additionally, stair climbing was more common during the morning rush hour and at higher levels of pedestrian traffic volume. The layout of the intervention site can influence responsiveness to point-of-choice interventions. Changes to the design of train stations may maximize the choice of the stairs at the expense of the escalator by pedestrians leaving the station.     

攀援型和矮生型四棱豆苯丙氨酸解氨酶活性和黄酮含量的研究

以攀援和矮生型四棱豆为研究对象,对不同部位苯丙氨酸解氨酶活性和总黄酮含量进行比较,结果表明：除嫩豆荚外,矮生型四棱豆不同部位的PAL活性均高于攀援型,其总黄酮含量亦高于攀援型。攀援型和矮生型四棱豆PAL活性均为种子最高,嫩豆荚最低;两者总黄酮含量均为叶最高,储藏器官块根最低。攀援型和矮生型的PAL活性和总黄酮含量之间均呈显著正相关。矮生型四棱豆不同部位的组织或器官PAL活性受外源因子影响小,类黄酮合成能力高于攀援型,具有更高的抗逆性。     

五爪金龙不同部位化感作用可塑性变化

为探讨五爪金龙化感作用可塑性,利用生物检测法研究了五爪金龙不同部分水提液对莴苣种子萌发的影响,结果表明:经过长期的适应和进化,五爪金龙不同部位化感作用变化幅度具有不同程度的差异;随水提液质量浓度的增加,五爪金龙植株整体化感作用变化范围增加,不同部位之间化感作用变化幅度差异加大。五爪金龙不同部位化感综合效应的质量浓度敏感性大小与其化感作用效率有关。五爪金龙不同部位化感综合效应平均值大小与其95%置信区间不存在协变关系,但其化感综合效应平均值的95%置信区间大小可以表征化感可塑性变化范围。五爪金龙较高的化感作用可塑性有利于增强其种间竞争能力。     

Elevator availability and its impact on stair use in a workplace

Consistent success in encouraging stair climbing on public access staircases contrasts with equivocal evidence for effectiveness in worksites. This paper tests whether contextual factors may affect stair/elevator choice. The study investigated the impact of elevator availability, pedestrian traffic (number using the elevator and stairs per minute), building occupancy (total individuals in the building) and time of day on stair ascent and descent in a workplace. Stair and elevator choices were monitored by automatic counters every weekday during two phases. In a natural experiment, days with four available elevators were compared with days when three elevators were available. Stair use increased for three elevators compared to four. Increasing building occupancy was associated with increased stair use, whilst increasing pedestrian traffic and time of day was associated with reduced stair use. A follow-up study revealed complimentary effects of building occupancy and time of day on elevator waiting times, indicating that increased stair use by contextual factors reflects increased elevator waiting times. In contrast, shorter waiting times are likely when momentary pedestrian traffic is high and later in the day. Crucially, the magnitude of the effects of these contextual factors was ten times larger than previously reported effects of stair climbing interventions.     

无井架附壁式爬模法在烟囱施工中的安全措施

附壁式爬模法在烟囱施工的安装、提升操作、高空拆除过程中的安全技术措施。     

基于生理指标的建筑工人攀登作业疲劳实验研究

为研究攀登作业建筑工人生理疲劳状态的评测指标,提出1种基于生理指标的建筑工人攀登作业疲劳测度实验方法。首先,设计实验测量建筑工人的心率、皮肤温度、舒张压、收缩压4项生理指标,结合Brog’s RPE主观疲劳程度量表研究建筑工人生理疲劳的变化;其次,提取上述4项指标的平均值和标准差作为生理指标特征值,利用静息状态下生理指标特征值和疲劳状态下生理指标特征值进行方差分析、球形检验、T检验筛选出与疲劳相关的特征值;最后,利用支持向量机构建疲劳检测模型。研究结果表明：上述8项生理指标特征值与攀登作业工人疲劳具有显著相关性,疲劳检测模型的准确率为96.875%,研究结果可对攀登作业人员疲劳评估和疲劳预警具有实践性意义。     

Rock climbers' attitudes toward management of climbing and the use of bolts

The purpose of this research was to verify that various segments of the rock climbing community have different attitudes toward resource management and to aid in the understanding of attitudinal differences that can affect rock-climbing management. Respondents were given an on-site questionnaire; 400 usable surveys were collected from 13 different locations in the United States. Respondents identified themselves according to the type of climbing they participated in (e.g., traditional climbing, sport climbing, and hybrid climbing). Factor analysis identified five usable factors: bolt placement/use, need for management, reservations about management, appropriateness of bolts, and climbers' self-perception. A repeated-measures analysis of variance identified significant differences among responses from traditional and sport climbers on four of the five scales used to measures attitudes. The variance among the climbing subgroups indicated that various climbing groups had significantly different attitudes toward management. All climbers surveyed had reservations about the management process. Results from the analysis indicated that climbers from all three groups (traditional, sport, and hybrid) felt that managers did not adequately understand the activity of climbing, climbers did not adequately understand the management process, climbing was not treated fairly in the management process in comparison to other activities, and climbing was micromanaged.