Octopamine Signaling Via Oamb is Essential for A Well-Orchestrated Climbing Performance of Adult Drosophila Melanogaster

The biogenic amine octopamine (OA) orchestrates many behavioural processes in insects. OA mediates its function by binding to OA receptors belonging to the G protein-coupled receptors superfamily. Despite the potential relevance of OA for controlling locomotion, our knowledge about the role of each octopaminergic receptor still limited. In this study, RNA interference (RNAi) was used to knockdown each OA receptor type in almost all Drosophila melanogaster tissues using a tubP-GAL4 driver to investigate the loss of which receptor affects the climbing ability of adult flies. The results demonstrated that oamb-deficient flies had impaired climbing ability more than those deficient in other receptors receptive for OA. Targeted RNAi-mediated kockdown of oamb in the nervous system or muscular system decreased the climbing ability, indicating that within Drosophila legs, OA through oamb orchestrated the nervous system control and muscular tissue responses. Oamb-deficient adult males showed morphometric changes in the length and width of leg parts. Transmission electron microscopy revealed that the leg muscles oamb-deficient flies have severe ultrastructural changes compared to those of control flies. The severe impairment in the climbing performance of oamb-deficient flies correlates well with the completely distorted leg muscle ultrastructure in these flies. Taken together, we could conclude that OA via oamb plays an important role in the locomotor activity of Drosophila.

Obstacle Capability of an Air-Ground Amphibious Reconnaissance Robot with a Planetary Wheel-Leg Type Structure

According to the requirements of the reconnaissance robot for the ability to adapt to a complex environment and the in-depth study of the obstacle climbing mechanisms, a planetary wheel-leg-combined mechanism capable of adapting to complex terrains is proposed. According to the proposed planetary wheel-leg-combined mechanism, the land part of the air-ground amphibious reconnaissance robot is designed. Considering the obstacle and fast marching performance, four groups of combined wheel-leg mechanisms are adopted in the land bank. Under the action of three kinds of obstacles, the stability and the movement ability of the robot are analyzed by using the static method. The parameter model of the reconnaissance robot is built by a virtual prototype dynamics software MSC.ADMAS. The kinematic characteristic curves of each component and the whole prototype are obtained, which provides a theoretical basis for the design and numerical calculation of the robot structure. Finally, the climbing ability tests of the reconnaissance robot prototype verify the reliability and practicability of the body structure of the reconnaissance robot.

Reliability of stair-climbing speed in two cohorts of older adults

Background/Aims The ability to climb stairs is an important prerequisite for activities of daily living and social participation in older adults, and is therefore an important part of rehabilitation. However, there is no consensus on how to measure stair-climbing ability. The aim of this study was to investigate the test–retest reliability of the measurement of stair-climbing speed (steps per second) as a parameter for functional ability in older adults. Methods A total of 57 participants who were in hospital and 56 participants who were community-dwelling and did not have any limitations in activities in daily living, all aged 60 years and over, ascended and descended a set of 13 stairs twice. The halfway point of the staircase was marked in order to split the time required for both the ascending and the descending actions. Additional measurements consisted of the Functional Reach Test, the Timed Up and Go Test, walking ability using the GAITRite walkway system and the isometric strength of four muscle groups of the lower extremities using a handheld dynamometer. Results Test–retest reliability of the first and second half of the stair-climbing for both ascending and descending showed excellent results for the group of hospitalised participants (intraclass correlation coefficient, [ICC] 0.87, 95% confidence interval [CI] 0.79–0.93 to 0.94, 95% CI 0.9 – 0.97 for comparison of first vs second half of stair climbing; ICC 0.9, 95% CI 0.83-0.94 to ICC 0.95, 95% CI 0.92–0.97 for comparing first vs second measurement)) and moderate to excellent results for the group of community-dwelling participants with no limitations (ICC 0.58, 95% CI 0.37–0.73 to ICC 0.76, 95% 95% CI 0.63-0.85 for comparison of first vs second half of stair climbing; ICC 0.82, 95% CI 0.71-0.89 to 0.92, 95% CI 0.87–0.95 for comparing first vs second measurement). As expected, hospitalised participants took significantly longer descending than ascending stairs (t(56)=6.98, P<0.001, d=0.93). A general and significant trend of increasing speed while descending could be observed in both groups (performing paired sample t-tests). Conclusions The results indicate that stair-climbing speed is not constant and that different patterns exist in older adults who have no limitations and in those who are hospitalised. The use of stair-climbing speed as an assessment tool should include both stair ascent and descent, because differences in these speeds seem to be indicators of stair-climbing ability.

Exercise-induced changes in climbing performance

Exercise is recommended to promote health and prevent a range of diseases. However, how exercise precipitates these benefits is unclear, nor do we understand why exercise responses differ so widely between individuals. We investigate how climbing ability in Drosophila melanogaster changes in response to an exercise treatment. We find extensive variation in baseline climbing ability and exercise-induced changes ranging from −13% to +20% in climbing ability. Climbing ability, and its exercise-induced change, is sex- and genotype-dependent. GWASs implicate ‘cell–cell signalling’ genes in the control of climbing ability. We also find that animal activity does not predict climbing ability and that the exercise-induced climbing ability change cannot be predicted from the activity level induced by the exercise treatment. These results provide promising new avenues for further research into the molecular pathways controlling climbing activity and illustrate the complexities involved in trying to predict individual responses to exercise.

Static Gait Scheme for Horizontal Posture Slope Climbing with Quadruped Robot

With a view to expanding serviceability in different applications, the slope climbing ability of a quadruped robot is important. In this paper, a gait scheme i.e. walking algorithm for slope climbing is proposed. It differs from the previous studies in terms of the posture of the robot while climbing. The presented scheme is designed such a way that the body of the robot maintains horizontal posture with positive static stability which can be used for carrying a load and disabled while climbing the slope. For this proposed scheme, different parameters of gait are shown. The algorithm is tested with a multibody simulation and based on the results of transformation of the inertial frame about the world frame; it is proven to be steady.

Mini Review: Comparison of Bio-Inspired Adhesive Feet of Climbing Robots on Smooth Vertical Surfaces

Developing climbing robots for smooth vertical surfaces (e.g., glass) is one of the most challenging problems in robotics. Here, the adequate functioning of an adhesive foot is an essential factor for successful locomotion performance. Among the various technologies (such as dry adhesion, wet adhesion, magnetic adhesion, and pneumatic adhesion), bio-inspired dry adhesion has been actively studied and successfully applied to climbing robots. Thus, this review focuses on the characteristics of two different types of foot microstructures, namely spatula-shaped and mushroom-shaped, capable of generating such adhesion. These are the most used types of foot microstructures in climbing robots for smooth vertical surfaces. Moreover, this review shows that the spatula-shaped feet are particularly suitable for massive and one-directional climbing robots, whereas mushroom-shaped feet are primarily suitable for light and all-directional climbing robots. Consequently, this study can guide roboticists in selecting the right adhesive foot to achieve the best climbing ability for future robot developments.

Utility of TPP-manufactured biophysical restrictions to probe multiscale cellular dynamics

Biophysical restrictions regulate protein diffusion, nucleus deformation, and cell migration, which are all universal and important processes for cells to perform their biological functions. However, current technologies addressing these multiscale questions are extremely limited. Herein, through two-photon polymerization (TPP), we present the precise, low-cost, and multiscale microstructures (micro-fences) as a versatile investigating platform. With nanometer-scale printing resolution and multiscale scanning capacity, TPP is capable of generating micro-fences with sizes of 0.5–1000 μm. These micro-fences are utilized as biophysical restrictions to determine the fluidity of supported lipid bilayers (SLB), to investigate the restricted diffusion of Src family kinase protein Lck on SLB, and also to reveal the mechanical bending of cell nucleus and T cell climbing ability. Taken together, the proposed versatile and low-cost micro-fences have great potential in probing the restricted dynamics of molecules, organelles, and cells to understand the basics of physical biology. Graphic abstract

Energy and nutritional inadequacies in a group of recreational adult Spanish climbers

Introduction: Although nutrition is determinant in the performance of athletes, few publications on this topic are available for climbers. Objectives: To measure body composition and dietary intake in a group of recreational Spanish climbers. Material and method: For body composition data we performed the measurements included in the ISAK anthropometric restricted- profile. Daily dietary intake was self-recorded on 3 days of the week: a non-climbing day, a climbing-gym training day and a rock- climbing day. Results were compared to Spanish nutritional recommendations. Results: 61 climbers (44 men, 17 women), aged 34 ± 8 years, volunteered. Body fat % was 8.1 ± 1.5% in men and 15.7 ± 3.0% in women. A negative correlation was found between body fat % and climbing ability (P<0.0005). Intake of energy and carbohydrates was 40% below estimated targets and that of proteins was 20-25% below. Moreover, macronutrient contribution to energy was unbalanced (protein: fat: CHO: alcohol was 17: 38: 42: 3%). We observed an elevated intake of SFA and sugars and low consumption of MUFA and fiber. Micronutrient intakes were acceptable except for iodine, zinc and vitamin D in both genders and iron and folate in women. Mean Adequacy Ratio of diet was higher in advanced/elite climbers compared with those in the intermediate level showing a possible relationship between climbing ability and diet quality. Conclusions: This study evidences there is a need of nutritional recommendations targeted to climbers. Our findings can contribute to the design of evidence-based food guides to help climbers optimise health and performance outcomes.