Turn Angle Research Articles

Toxic effects of oxine-copper on development and behavior in the embryo-larval stages of zebrafish

Oxine-copper (OxCu) is generally used as an agricultural pesticide and induces harmful effects on ecosystems. In this study, zebrafish was used to assess the aquatic toxicity of OxCu. To detect the effects on development, embryos of 6 h post-fertilization (hpf) were exposed to 10 μg/L, 20 μg/L, 40 μg/L OxCu for 18 h; meanwhile, to evaluate the effects on the behavior, larval fish at 6 days post-fertilization (dpf) were exposed to the same concentrations for 24 h. Here, we show that there are embryonic developmental defects, including abnormalities of head and trunk, brain ventricle atrophy, reduced newborn neurons, disordered neurons, increased intercellular space, concentrated cytoplasm, decreased heart beat and blood flow velocity, and developmental delay of the vascular system; in addition, some embryos exposed to the high concentration of OxCu degraded from the tail. We also found that the spontaneous tail coiling frequency and AChE enzyme activity were reduced, while oxidative stress (free radical damage) and cell apoptosis were significantly increased. Moreover, the expression of genes involved in neurodevelopment, vascular development and apoptosis were dysregulated in the OxCu exposed embryos in a concentration-dependent manner. Finally, we found that after exposure to OxCu, larval locomotor activity was decreased and accompanied by Parkinson-like (increased absolute turn angle and sinuosity) and anxiety-like (preferred to the central area) behavior. These results indicate that OxCu induces developmental toxicity and behavioral alterations by affecting AChE enzyme activity and oxidative stress. Our data present new proofs of OxCu toxicity and a warning for its application.

Non-Euclidean navigation.

A basic set of navigation strategies supports navigational tasks ranging from homing to novel detours and shortcuts. To perform these last two tasks, it is generally thought that humans, mammals and perhaps some insects possess Euclidean cognitive maps, constructed on the basis of input from the path integration system. In this article, I review the rationale and behavioral evidence for this metric cognitive map hypothesis, and find it unpersuasive: in practice, there is little evidence for truly novel shortcuts in animals, and human performance is highly unreliable and biased by environmental features. I develop the alternative hypothesis that spatial knowledge is better characterized as a labeled graph: a network of paths between places augmented with local metric information. What distinguishes such a cognitive graph from a metric cognitive map is that this local information is not embedded in a global coordinate system, so spatial knowledge is often geometrically inconsistent. Human path integration appears to be better suited to piecewise measurements of path lengths and turn angles than to building a consistent map. In a series of experiments in immersive virtual reality, we tested human navigation in non-Euclidean environments and found that shortcuts manifest large violations of the metric postulates. The results are contrary to the Euclidean map hypothesis and support the cognitive graph hypothesis. Apparently Euclidean behavior, such as taking novel detours and approximate shortcuts, can be explained by the adaptive use of non-Euclidean strategies.

Predators and pastoralists: how anthropogenic pressures inside wildlife areas influence carnivore space use and movement behaviour

AbstractAcross the globe, wildlife populations and their behaviours are negatively impacted by people. Protected areas are believed to be an antidote to increasing human pressures but even they are not immune to the impact of anthropogenic activities. Areas that have been set aside for the protection of wildlife therefore warrant more attention when investigating the impact of anthropogenic pressures on wildlife. We use cheetahs Acinonyx jubatus as a case study to explore how a large carnivore responds to anthropogenic pressures inside wildlife areas. Using GPS‐collar data we investigate cheetah space use, both when moving and stationary, and movement parameters (speed and turn angles) in relation to human disturbance, distance to human settlement, livestock abundance and livestock site use inside wildlife areas. Space use was negatively influenced by human disturbance, resulting in habitat loss and fragmentation and potentially reducing landscape permeability between neighbouring wildlife areas. Cheetahs were also less likely to stop in areas where livestock numbers were high, but more likely to stop in areas that were frequently used by livestock. The latter could reflect that cheetahs are attracted to livestock however, cheetahs in the study area rarely predated on livestock. It is therefore more likely that areas that are frequently used by livestock attract wild herbivores, which in turn could influence cheetah space use. We did not find any effects of people and livestock on cheetahs’ speed and turn angles which might be related to the resolution of the data. We found that cheetahs are sensitive to human pressures and we believe that they could be an indicator species for other large carnivores facing similar challenges. We suggest that further research is needed to determine the levels of anthropogenic pressures needed to maintain ecological integrity, especially inside wildlife areas.

Adverse effects of p-TSA-doped polypyrrole particulate exposure during zebrafish (Danio rerio) development.

Nanomaterials have been attracting attention due to the wide range of applications in nanomedicine. Polypyrrole (PPy), a conductive polymer, has been employed in the biomedical field due to its stimulus-responsive properties, although in vivo studies to assess its potential undesirable effects are limited. This study evaluated the effects of PPy doped with p-toluene sulfonic acid ((p-TSA); PPy/p-TSA) exposure (at 25, 100, 250 and 500 μg/mL) during six consecutive days on mortality, hatching, spontaneous movement, heart rate, morphology and locomotion behavior of zebrafish embryos/larvae. Additionally, PPy/p-TSA envelopment of developing embryo chorions and gene expression of a hypoxia-related marker in this context were also evaluated. No significant mortality was found; however, altered heart rate and early hatching was identified in all exposed groups at 48 hours post-fertilization (hpf). Surprisingly, with the 500 μg/mL dose, hatching initiated as early as 24 hpf. PPy/p-TSA adhered to and enveloped the chorion of embryos in a time- and dose-dependent fashion; morphological changes in body length and ocular distance were found with higher concentrations. PPy/p-TSA-exposed animals showed locomotor behavioral alterations compatible with hypoactivity. A significant increase in the turn angle with a concomitant reduction in meander was also verified at higher concentrations. Taken together, these results emphasize the adverse effects of PPy/p-TSA on zebrafish development and behavior. Some effects of PPy/p-TSA exposure were dose-dependent, and indicate specific adverse effects of PPy/p-TSA on zebrafish development and behavior.

Aesthetical cognitive perceptions of urban street form. Pedestrian preferences towards straight or curvy route shapes

ABSTRACTHuman perception of space is not purely metric. Route angularity and complexity-minimizing paths suggest that pedestrians, consciously or not, tend to reduce the number and the angle of turns when selecting routes. Decisions involving route selection are different when the main criterion is not the orientation but the aesthetics of urban forms. This paper indicates that 80% of a stratified random sample of 102 people stated to prefer, ceteris paribus and for continuous/legible routes, to walk throughout curvy paths instead of straight and felt the former as shorter too, to generically walk through a route, and to reach a destination.

Shape optimization of cold-formed steel beam-columns with practical and manufacturing constraints

This study aims to present a practical method for optimization of symmetric cold-formed steel (CFS) beam-column members using Genetic Algorithm (GA). To eliminate impractical cross-section shapes from the optimization results, a range of manufacturing and construction constraints are incorporated into the optimization process. Axial forces are applied with different eccentricities (0 to 30 mm) to cover the full spectrum of beam-column actions from pure axial compression to pure bending. The effect of element length on the optimization results is investigated by using short, intermediate and long beam-column members. A total of 132 beam-columns with different cross section shape complexity (4 to 12 rollers/nodes and 1 to 3 lips) are optimized. The compression and bending moment strengths are obtained based on direct strength method (DSM) using CUFSM software by accounting for local, distortional and global buckling modes. The results show that using more complex shapes does not necessarily lead to better design solutions. Increasing the eccentricity generally leads to more spread optimum sections particularly when distortional buckling is the predominant mode in short and intermediate-length beam-columns. In cases where local and global buckling modes govern the design, however, less spread sections with higher turn angles generally provide higher strength capacities. With the variation of eccentricity, the ultimate strength of optimum beam-column sections normalized by the strength of a reference lipped-channel are in the range of 110–163%, 128–194% and 160–222% for short, medium and long members, respectively. The results of this study, should prove useful in more efficient design of CFS beam-column elements in practice.

Effects of acetochlor on neurogenesis and behaviour in zebrafish at early developmental stages

The herbicide acetochlor is used in most parts of the world and is frequently detected in agricultural land and surface water; however, knowledge on the neurotoxicity of acetochlor is limited. Here, to test the effects of acetochlor on zebrafish development and behaviour, zebrafish embryos were exposed to acetochlor from 6 h post-fertilization (hpf) to 24 hpf, and larvae at 6 days post-fertilization (dpf) were exposed to acetochlor for 24 h. Both were exposed to 5, 10, or 20 mg/L acetochlor. We found that acetochlor induced developmental abnormalities, locomotion variations and changes in the physiology and gene expression in the embryos and larvae. The abnormalities included spinal curvature, brain abnormalities, and the decreased formation of newborn neurons. Larval locomotion was decreased with increases in the absolute turn angle and sinuosity. Acetylcholinesterase activity reduced in both embryos and larvae, and the expression of genes that are involved in neurodevelopment and the neurotransmitter system altered. Acetochlor increased the production of ROS and the accumulation of MDA but decreased CAT activity in the embryonic brain. Additionally, acetochlor induced cell death in the brain and tail spinal cord, and the expression of the apoptosis-related genes Bcl2 and caspase 3 were significantly upregulated. Collectively, this is the first study to examine the molecular and physiological effects of acetochlor on neuronal development, and the potential mechanisms appear to be associated with oxidative stress and decreased AChE activity, which disrupt the expression of nervous system genes and apoptosis-related genes and finally lead to apoptosis and morphological malformations.

The results of experimental research of the parameters of methane capturing by local degassing wells in the undermining area

The article is devoted to the analysis of the results of the mine instrumental measurements of the local degassing system of the m3 seam on the horizon of 1100 m of the mine named. V.M. Bazhanov to establish the basic rational parameters with the subsequent application of the biotechnological method of reducing the concentration of methane. As a result of mine instrumental measurements (vacuum-gas surveys at the borehole heads), the parameters of the degassing process (methane flow rate at the borehole heads and the average vacuum on them), technological parameters (angle of turn and tilt of wells, their length), well flow rate efficiency from the distance to the bottom of the longwall and the displacement of the undermined rocks. Establishing the basic parameters of degassing will allow you to quickly manage the flow rate of wells and underpressure at their mouths, taking into account the specific mining and geological and mining conditions. The use of biofilters allows controlling the concentration of methane in the atmosphere of mine roadway by methanotrophic bacteria.

Management of duane retraction syndrome

Background Duane retraction syndrome (DRS) is a congenital ocular motility disorder most commonly characterized by the inability of the eye to abduct, sometimes limitation of adduction, and globe retraction with palpebral fissure narrowing on adduction. Aim To study the clinical features, management, and outcome of DRS. Patients and methods A prospective, nonrandomized study was carried out on patients attending the Outpatient Clinic of Ophthalmology in Menoufia University Hospital during the period of study from June 2017 to July 2019. This study was conducted on 51 patients with DRS. Ocular and systemic features were studied. Surgery was done when indicated to eliminate upshoot or downshoot, face turn with a horizontal deviation, and globe retraction. Preoperative and postoperative ocular deviation, angle of head turn, and severity of limitation in abduction and adduction were detected and analyzed. Results Type I DRS was more common (70.6%), with female preponderance (52.9%) and a predilection for the left eye (70.6%). Twenty-one (41.2%) cases were operated, by recessing MR and/or lateral rectus (LR) muscles and/or Y-splitting and acceptable improvement was detected. Mean esotropic DRS improved from 18±4.02 to 3±2.8 (P Conclusion Proper diagnosis of patients with DRS and proper plan for surgical management can reduce several complications with satisfactory postoperative outcomes.

ПЕРЕДУМОВИ СИНХРОНІЗАЦІЇ КОЛЕКТИВНОГО РУХУ АВТОТРАНСПОРТНИХ ПОТОКІВ НА ДІЛЯНКАХ СЕРПАНТИНУ (У ШПИЛЬКАХ) АВТОМОБІЛЬНИХ ДОРІГ

Synchronization of the collective movement of vehicles in the composition of flows in special sections of motor vehicles is one of the most pressing problems in the context of increasing intensity of motor traffic. The aim of the study is to increase the levels of safety of transport and technological processes on sections of serpentine (studs) of the road network by synchronizing the collective movement of vehicles in traffic. According to the stated goal the following tasks are defined: to develop a topological form of auxiliary curves of the highway route on the sections of serpentines of the 1st and 2nd kind; determine the topological dimensions of the minimum permissible distance of the contour of the obverse side of the shrubbery gas-dustprotective forest belt to the axis of the carriageway on the serpentine sections. The researches were carried out on the basis of methods of analytical geometry on a plane and taking into account the topological features of algebraic functions, which described the trajectories of the gradients of the movement of flows of "wide moving clusters" of vehicles. It was established a priori that, according to the theory of the three phases of motor traffic, proposed by B. Kerner, the desynchronization of the collective movement of vehicles in the composition of traffic flows at sections with special traffic conditions leads to a violation of the coherence of these flows. The synchronized traffic flow is transformed into a “wide moving vehicle cluster”. Such desynchronization not only breaks the stability of the modes of transport and technological process, but also causes a decrease in the levels of traffic safety and intensification of the emission of aerosols of gas-dust emissions produced by the flows of vehicles. According to the results of researches, topological parameters and a two-dimensional graphical model of a possible variant of transport and technological optimization of the road network in "studs" of serpentines were developed. The design distance of the contour of the obverse side of the wood-bush gas-dust lane to the axis of the carriageway is determined depending on the angle of turn of the highway. Accordingly, the proposed optimization of the design parameters of the road network in the "studs" of serpentines provides for the possibility of synchronization of collective traffic of vehicles in the composition of traffic flows, which provides stabilization of the implementation of transport and technological operations and, as a consequence, increases the overall level of safety of the motor complex. Further research should be aimed at ensuring the safe transport and technological modes of operation of the motor transport complex in the conditions of growth of the share of autonomous robotic unmanned vehicles in the composition of motor transport flows

Animal movement tools (amt): R package for managing tracking data and conducting habitat selection analyses.

Advances in tracking technology have led to an exponential increase in animal location data, greatly enhancing our ability to address interesting questions in movement ecology, but also presenting new challenges related to data management and analysis. Step‐selection functions (SSFs) are commonly used to link environmental covariates to animal location data collected at fine temporal resolution. SSFs are estimated by comparing observed steps connecting successive animal locations to random steps, using a likelihood equivalent of a Cox proportional hazards model. By using common statistical distributions to model step length and turn angle distributions, and including habitat‐ and movement‐related covariates (functions of distances between points, angular deviations), it is possible to make inference regarding habitat selection and movement processes or to control one process while investigating the other. The fitted model can also be used to estimate utilization distributions and mechanistic home ranges. Here, we present the R package amt (animal movement tools) that allows users to fit SSFs to data and to simulate space use of animals from fitted models. The amt package also provides tools for managing telemetry data. Using fisher (Pekania pennanti) data as a case study, we illustrate a four‐step approach to the analysis of animal movement data, consisting of data management, exploratory data analysis, fitting of models, and simulating from fitted models.

SYNTHESIS OF FRACTIONAL ORDER CONTROLLERS FOR MULTI-LUPP CONTROL STRUCTURE OF FIRE LIFT BASKET TURNING

Introduction. The attempt to get the best dynamic and static characteristics of the basket turn angle complicates the tasks performed by the automatic control system (ACS) basket turn drive. The ACS of the basket turn should meet the following requirements: high speed, smooth acceleration and breaking of the motor, static and dynamic accuracy of the reproduction of tasks trajectories, no overregulation in transition modes, required stability reserve, low sensitivity to coordinate and parametric disturbances, etc. A number of fundamentally different ACSs and methods for their synthesis have been analyzed to provide these requirements. As a result of the analysis, there has been selected a two-loop feedback control system (FCS) of the basket turn with regard to the elastic properties of the arrow, which is synthesized by the method of the generalized characteristic polynomial. Studies have shown that this system allows to provide an aperiodic transition process of the basket turn angle with a given speed and low sensitivity in steady state to the perturbation effect. However, the synthesized FCS transfer functions of the controllers of angular velocity of the motor and the basket have a high order and turned out to be quite complicated in terms of practical implementation.
 Purpose. In the article it is proposed to replace these controllers, by approximating them through evolutionary methods, with more compact fractional PІλDμ-controllers or fractional order controllers.
 Results. The studies carried out in this work have shown that fractional order controllers are quite advantageous in comparison with the over classical ones, particularly in the case of their application for optimization of electromechanical systems with the following features of their control objects: two masses, including those with the presence of impact; backlash viscosity of the drive friction; nonlinear load and so on.
 Replacement of the high-order motor and basket angular speed controllers with more compact PІλDμcontrollers or fractional order controllers has been performed using Optimization Toolbox optimization package in the MATLAB package. This software has been developed for approximation of classical parts with high-order transfer functions by fractional order parts, using a genetic algorithm or a particle swarm optimization for their transition functions.
 Conclusion. The conducted research on digital models has confirmed the efficiency of the replacement of high-order motor and basket angular velocity controllers with PІλDμ-controllers or fractional order controllers, whose transfer functions are determined by approximating the transition functions of the controllers by the genetic algorithm method.

Protocatechuic acid ameliorates neurobehavioral deficits via suppression of oxidative damage, inflammation, caspase-3 and acetylcholinesterase activities in diabetic rats

Clinical and experimental data have demonstrated that diabetes is associated with neurological complications. Protocatechuic acid (PCA) is a phenolic phytochemical widely reported to possess antidiabetic property. However, there is no scientific information on the influence of PCA on diabetes-induced neurotoxicity. The present study aimed at investigating the neuroprotective mechanism of PCA in streptozotozin (STZ)-induced type 1 diabetic rats orally treated with PCA (50 mg/kg body weight) or glibenclamide (5 mg/kg body weight) for 45 consecutive days. Locomotor behavior was analyzed using video-tracking software during the 8-min trial in a novel environment whereas the pancreas, cerebrum and cerebellum of the rats were processed for biochemical analyses. Results showed that treatment of diabetic rats with PCA at 50 mg/kg significantly (p < 0.05) improved the locomotor and motor activities including the average speed, total time mobile, distance travelled, body rotation, turn angle, forelimb grip and grooming when compared with untreated diabetic rats. Moreover, the prevention of diabetes-mediated increase in acetylcholinesterase activity, biomarkers of inflammatory and oxidative stress as well as caspase 3 activity by PCA treatment was accompanied by improved pancreatic, cerebral and cerebellar architectures. Collectively, the neuroprotective mechanisms of PCA is related to its antioxidant, anti-inflammatory and anti-apoptotic activities.

DETECTION OF WANDERING BEHAVIORS USING A BODY-WORN INERTIAL SENSOR IN PATIENTS WITH COGNITIVE IMPAIRMENT: RESULTS OF A PILOT TRIAL

Patients with Alzheimer’s disease and related dementias (ADRD) often experience wandering behavior, characterized by aimless or purposeless movement. Wandering has been associated with falls, caregiver burden, and nursing home placement. Despite the substantial clinical consequences of wandering, there is currently no standardized approach to objectively quantify wandering behavior. In this pilot study, we used a lightweight inertial sensor to examine at-home mobility characteristics of a small group of older adults with ADRD and mild cognitive impairment. Participants wore the sensor for ≥4 days, and turning frequency and direction changes were measured given that frequent turns and direction changes during walking are seen in patients who wander. We found that all 12 patients were able to wear the sensor yielding quantitative turn data including #turns/time, mean turn duration, mean turn speed, and mean turn angle. We compare these data to similar data obtained in healthy older adults, and discuss future directions.

Flight path optimization with application to in-flight replanning to changing destinations

PurposeThe purpose of this paper is to present a new approach for finding a minimum-length trajectory for an autonomous unmanned air vehicle or a long-range missile from a release point with specified release conditions to a destination with specified approach conditions. The trajectory has to avoid obstacles and no-fly zones and must take into account the kinematic constraints of the air vehicle.Design/methodology/approachA discrete routing model is proposed that represents the airspace by a sophisticated network. The problem is then solved by applying standard shortest-path algorithms.FindingsIn contrast to the most widely used grids, the generated networks allow arbitrary flight directions and turn angles, as well as maneuvers of different strengths, thus fully exploiting the flight capabilities of the aircraft. Moreover, the networks are resolution-independent and provide high flexibility by the option to adapt density.Practical implicationsAs an application, a concept for in-flight replanning of flight paths to changing destinations is proposed. All computationally intensive tasks are performed in a pre-flight planning prior to the launch of the mission. The in-flight planning is based entirely on precalculated data, which are stored in the onboard computer of the air vehicle. In particular, no path finding algorithms with high or unpredictable running time and uncertain outcome have to be applied during flight.Originality/valueThe paper presents a new network-based algorithm for flight path optimization that overcomes weaknesses of grid-based approaches and allows high-quality solutions. The method can be applied for quick in-flight replanning of flight paths.

Diphenyl diselenide abrogates brain oxidative injury and neurobehavioural deficits associated with pesticide chlorpyrifos exposure in rats

Exposure to pesticide chlorpyrifos (CPF) is associated with neurodevelopmental toxicity both in humans and animals. Diphenyl diselenide (DPDS) is a simple synthetic organoselenium well reported to possess antioxidant, anti-inflammatory and neuroprotective effects. However, there is paucity of information on the beneficial effects of DPDS on CPF-mediated brain injury and neurobehavioural deficits. The present study investigated the neuroprotective mechanism of DPDS in rats sub-chronically treated with CPF alone at 5 mg/kg body weight or orally co-treated with DPDS at 2.5 and 5 mg/kg body weight for 35 consecutive days. Endpoint analyses using video-tracking software in a novel environment revealed that co-treatment with DPDS significantly (p < 0.05) protected against CPF-mediated locomotor and motor deficits precisely the decrease in maximum speed, total distance travelled, body rotation, absolute turn angle, forelimb grip strength as well as the increase in negative geotaxis and incidence of fecal pellets. The enhancement in the neurobehavioral activities of rats co-treated with DPDS was verified by track plot analyses. Besides, DPDS assuaged CPF-induced decrease in acetylcholinesterase and antioxidant enzymes activities and the increase in myeloperoxidase activity and lipid peroxidation level in the mid-brain, cerebral cortex and cerebellum of the rats. Histologically, DPDS co-treatment abrogated CPF-mediated neuronal degeneration in the cerebral cortex, dentate gyrus and cornu ammonis3 in the treated rats. In conclusion, the neuroprotective mechanisms of DPDS is related to the prevention of oxidative stress, enhancement of redox status and acetylcholinesterase activity in brain regions of the rats. DPDS may be a promising chemotherapeutic agent against brain injury resulting from CPF exposure.

Onset of three-dimensionality in supersonic flow over a slender double wedge

An investigation shows that laminar supersonic flow on a 2D compression corner can destabilize to become 3D beyond a critical turn angle. This compressible instability resides in the recirculating flow, producing spiral wall flow patterns postseparation and wall temperature streaks downstream.

Dietary co-exposure to methylmercury and monosodium glutamate disrupts cellular and behavioral responses in the lobster cockroach, Nauphoeta cinerea model

The present study aims to investigate the effect of monosodium glutamate (MSG) both separately and combined with a low dose of methylmercury (MeHg) on behavioral and biochemical parameters in Nauphoeta cinerea (lobster cockroach). Cockroaches were fed with the basal diet alone, basal diet + 2% NaCl, basal diet + 2% MSG; basal diet + 0.125 mg/g MeHg, basal diet + 0.125 mg/g MeHg + 2% NaCl; and basal diet + 0.125 mg/g MeHg + 2% MSG for 21 days. Behavioral parameters such as distance traveled, immobility and turn angle were automatically measured using ANY-maze video tracking software (Stoelting, CO, USA). Biochemical end-points such as acetylcholinesterase (AChE), glutathione-S-transferase (GST), total thiol and TBARS were also evaluated. Results show that MeHg + NaCl, increased distance traveled while MeHg + MSG increased time immobile. AChE activity was significantly reduced in cockroaches across all the groups when compared to the control. There was no significant alteration in GST activity and total thiol levels. It could be that both NaCl and MSG potentiates the neurotoxic effect of MeHg in cockroaches.

Enhanced water removal performance of a slope turn in the serpentine flow channel for proton exchange membrane fuel cells

Aim to effectively improve the removal and transport of liquid water in the flow channel in a proton exchange membrane fuel cell (PEMFC), we designed a slope turn in the serpentine flow channel and conducted numerical simulations using volume-of-fluid method to investigate the water behavior in it. To optimize the slope turn, the effects of the sectional area and slope angle of the slope turn and the wettability of channel wall on the transport and dynamics of water were investigated. Besides, cases with different sizes of single water droplet and the interactions between multiple droplets were also considered. For single droplet, the results suggest that with the designed slope turn, water droplet can be effectively removed from the surface of membrane electrode assembly (MEA) though the channel walls are hydrophobic. Without slope turn, the water droplet is transported downstream, always being attached on the MEA surface. The designed slope turn is also applicable for the case of multiple droplets to enhance water removal from the MEA surface.

Energy expenditure associated with walking speed and angle of turn in children

PurposeRecent studies have suggested that turning is power intensive. Given the sporadic and irregular movement patterns of children, such findings have important implications for the assessment of true energy expenditure associated with habitual physical activity. The purpose of this study was to investigate the influence of walking speed and angle, and their interaction, on the energy expenditure of healthy children.Methods20 children (10.1 ± 0.5 years; 10 boys) participated in the study. On two separate days, participants completed a turning protocol involving 3-min bouts of walking at one of the 16 speed (2.5, 3.5, 4.5, and 5.5 km h− 1) and angle (0°, 45°, 90°, and 180°) combinations, interspersed by 3 min seated rest. The movement involved 5 m straight walking interspaced with prescribed turns with speed dictated by a digital, auditory metronome. Breath-by-breath gas exchange was measured, in addition to tri-axial acceleration and magnetic field intensity recorded at 100 Hz.ResultsMixed models revealed a significant main effect for speed (p < 0.006) and angle (p < 0.006), with no significant interaction between speed and angle (p > 0.006). Significant differences to straight-line walking energy expenditure within speed were established for 3.5 and 5.5 km h− 1 for 180° turns (~ 13% and ~ 30% increase, respectively).ConclusionThese findings highlight the importance of accounting for the magnitude and frequency of turns completed when estimating children’s habitual physical activity and have significant implications for the assessment of daily energy expenditure.