Free running period affected by network structures of suprachiasmatic nucleus neurons exposed to constant light

Exposed to the natural light-dark cycle,24 h rhythms exist in behavioral and physiological processes of living beings.Interestingly,under constant darkness or constant light,living beings can maintain a robust endogenous rhythm with a free running period(FRP)close to 24 h.In mammals,the circadian rhythm is coordinated by a master clock located in the suprachiasmatic nucleus(SCN)of the brain,which is composed of about twenty thousand self-oscillating neurons.These SCN neurons form a heterogenous network to output a robust rhythm.Thus far,the exact network topology of the SCN neurons is unknown.In this article,we examine the effect of the SCN network structure on the FRP when exposed to constant light by a Poincare model.Four typical network structures are considered,including a nearest-neighbor coupled network,a Newman-Watts small world network,an Erd¨os-Renyi random network and a Barabasi-Albert(BA)scale free network.The results show that the FRP is longest in the BA network,because the BA network is characterized by the most heterogeneous structure among these four types of networks.These findings are not affected by the average node degree of the SCN network or the value of relaxation rate of the SCN neuronal oscillators.Our findings contribute to the understanding of how the network structure of the SCN neurons influences the FRP.

Voluntary wheel running ameliorated the deleterious effects of high-fat diet on glucose metabolism,gut microbiota and microbial-associated metabolites

Exercise training is critical for the early prevention and treatment of obesity and diabetes mellitus.However,the mechanism with gut microbiota and fecal metabolites underlying the effects of voluntary wheel running on high-fat diet induced abnormal glucose metabolism has not been fully elaborated.C57BL/6 male mice were randomly assigned to 4 groups according to diets(fed with normal chow diet or high-fat diet)and running paradigm(housed in static cage or with voluntary running wheel).An integrative 16S rDNA sequencing and metabolites profiling was synchronously performed to characterize the effects of voluntary wheel running on gut microbiota and metabolites.It showed that voluntary wheel running prevented the detrimental effects of high-fat feeding on glucose metabolism 16S rDNA sequencing showed remarkable changes in Rikenella and Marvinbryantia genera.Metabolic profiling indicated multiple altered metabolites,which were enriched in secondary bile acid biosynthesis signaling.In conclusion,our study indicated that voluntary wheel running significantly improved glucose metabolism and counteracted the deleterious effects of high-fat feeding on body weight and glucose intolerance.We further found that voluntary wheel running could integratively program gut microbiota composition and fecal metabolites changes,and may regulate muricholic acid metabolism and secondary bile acid biosynthesis in high-fat fed mice.

Enhancement of motor functional recovery in thoracic spinal cord injury: voluntary wheel running versus forced treadmill exercise

Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery and morphological changes following thoracic contusive spinal cord injury. After a 7-day recovery period after spinal cord injury, mice were assigned to either a trained group(10 weeks of voluntary running wheel or forced treadmill exercise) or an untrained group. Bi-weekly assessments revealed that the exercise-trained group, particularly the voluntary wheel exercise subgroup, displayed significantly improved locomotor recovery, more plasticity of dopaminergic and serotonin modulation compared with the untrained group. Additionally, exercise interventions led to gait pattern restoration and enhanced transcranial magnetic motor-evoked potentials. Despite consistent injury areas across groups, exercise training promoted terminal innervation of descending axons. In summary, voluntary wheel exercise shows promise for enhancing outcomes after thoracic contusive spinal cord injury, emphasizing the role of exercise modality in promoting recovery and morphological changes in spinal cord injuries. Our findings will influence future strategies for rehabilitation exercises, restoring functional movement after spinal cord injury.

Acute effect of foot strike patterns on in vivo tibiotalar and subtalar joint kinematics during barefoot running

Background:Foot kinematics,such as excessive eversion and malalignment of the hindfoot,are believed to be associated with running-related injuries.The maj ority of studies to date show that different foot strike patterns influence these specific foot and ankle kinematics.However,technical deficiencies in traditional motion capture approaches limit knowledge of in vivo joint kinematics with respect to rearfoot and forefoot strike patterns(RFS and FFS,respectively).This study uses a high-speed dual fluoroscopic imaging system(DFIS)to determine the effects of different foot strike patterns on 3D in vivo tibiotalar and subtalar joints kinematics.Methods:Fifteen healthy male recreational runners underwent foot computed tomography scanning for the construction of 3-dimensional models.A high-speed DFIS(100 Hz)was used to collect 6 degrees of freedom kinematics for participants’tibiotalar and subtalar joints when they adopted RFS and FFS in barefoot condition.Results:Compared with RFS,FFS exhibited greater internal rotation at 0%-20%of the stance phase in the tibiotalar joint.The peak internal rotation angle of the tibiotalar joint under FFS was greater than under RFS(p<0.001,Cohen’s d=0.92).RFS showed more dorsiflexion at 0%-20%of the stance phase in the tibiotalar joint than FFS.RFS also presented a larger anterior translation(p<0.001,Cohen’s d=1.28)in the subtalar joint at i nitial contact than FFS.Conclusion:Running with acute barefoot FFS increases the internal rotation of the tibiotalar joint in the early stance.The use of high-speed DFIS to quantify the movement of the tibiotalar and subtalar joint was critical to revealing the effects of RF S and FFS during running.

Modified DS np Chart Using Generalized Multiple Dependent State Sampling under Time Truncated Life Test

This study presents the design of a modified attributed control chart based on a double sampling(DS)np chart applied in combination with generalized multiple dependent state(GMDS)sampling to monitor the mean life of the product based on the time truncated life test employing theWeibull distribution.The control chart developed supports the examination of the mean lifespan variation for a particular product in the process of manufacturing.Three control limit levels are used:the warning control limit,inner control limit,and outer control limit.Together,they enhance the capability for variation detection.A genetic algorithm can be used for optimization during the in-control process,whereby the optimal parameters can be established for the proposed control chart.The control chart performance is assessed using the average run length,while the influence of the model parameters upon the control chart solution is assessed via sensitivity analysis based on an orthogonal experimental design withmultiple linear regression.A comparative study was conducted based on the out-of-control average run length,in which the developed control chart offered greater sensitivity in the detection of process shifts while making use of smaller samples on average than is the case for existing control charts.Finally,to exhibit the utility of the developed control chart,this paper presents its application using simulated data with parameters drawn from the real set of data.

SmartMicro Grid Energy System Management Based on Optimum Running Cost for Rural Communities in Rwanda

The governmental electric utility and the private sector are joining hands to meet the target of electrifying all households by 2024.However,the aforementioned goal is challenged by households that are scattered in remote areas.So far,Solar Home Systems(SHS)have mostly been applied to increase electricity access in rural areas.SHSs have continuous constraints to meet electricity demands and cannot run income-generating activities.The current research presents the feasibility study of electrifying Remera village with the smart microgrid as a case study.The renewable energy resources available in Remera are the key sources of electricity in that village.The generation capacity is estimated based on the load profile.The microgrid configurations are simulated with HOMER,and the genetic algorithm is used to analyze the optimum cost.By analyzing the impact of operation and maintenance costs,the results show that the absence of subsidies increases the levelized cost of electricity(COE)five times greater than the electricity price from the public utility.The microgrid made up of PV,diesel generator,and batteries proved to be the most viable solution and ensured continuous power supply to customers.By considering the subsidies,COE reaches 0.186$/kWh,a competitive price with electricity from public utilities in Rwanda.

Safety of the express freight train running over a long-span bridge

Purpose-Express freight transportation is in rapid development currently.Owing to the higher speed of express freight train,the deformation of the bridge deck worsens the railway line condition under the action of wind and train moving load when the train runs over a long-span bridge.Besides,the blunt car body of vehicle has poor aerodynamic characteristics,bringing a greater challenge on the running stability in the crosswind.Design/methodology/approach-In this study,the aerodynamic force coefficients of express freight vehicles on the bridge are measured by scale model wind tunnel test.The dynamic model of the train-long-span steel truss bridge coupling system is established,and the dynamic response as well as the running safety of vehicle are evaluated.Findings-The results show that wind speed has a significant influence on running safety,which is mainly reflected in the over-limitation of wheel unloading rate.The wind speed limit decreases with train speed,and it reduces to 18.83 m/s when the train speed is 160 km/h.Originality/value-This study deepens the theoretical understanding of the interaction between vehicles and bridges and proposes new methods for analyzing similar engineering problems.It also provides a new theoretical basis for the safety assessment of express freight trains.

Effect of Berm Width and Elevation on Irregular Wave Run-Up

This paper discusses the effect of berm width and elevation of composite slope on irregular wave run-up. Based on the data obtained from model tests, the formula and distribution of irregular wave run-up on composite slope are derived. The changing of wind speed, width and elevation of the berm are considered comprehensively. The wave run-up with various exceedance probability can be es-timated utilizing the distribution curves of irregular wave run-up.

The Effect of Body Pitching on Leg-Spring Behavior in Quadruped Running

In this paper we investigated how the running speed would affect the dynamics of body pitching, and whether body inertiais important for animals. Passive trotting of spring-mass model and passive bounding of spring-beam model were studied atdifferent speeds for different sets of body parameters respectively. Furthermore, different body inertias were used in bounding.We found that running speed exerts effect on leg performance by means of centrifugal force. The centrifugal force can be understoodas an enhancement to the natural frequency of the spring-mass system. The disadvantage of body pitching may beoffset by the great increase in centrifugal force at high speed. The results also reveal that body mass distribution might not be themain reason for the difference in maximal running speeds of different animals.

Numerical Investigation of Run-ups on Cylinder in Steep Regular Wave

The run-up on offshore structures induced by the steep regular wave is a highly nonlinear flow with a free surface. This article focuses on the investigation of the steep regular wave run-up on a single vertical cylinder by solving the Navier-Stokes equations. A numerical wave tank is established based on the open-source package to simulate the wave scattering induced by a vertical cylinder. The VOF method is applied to capture the large deformation and breaking of the free surface. The numerical model is validated by experimental results. The relative wave run-ups on the front face and the back face along the centerline of a cylinder are analyzed. The changes of the relative run-ups with the wave steepness, the relative diameter and the relative depth are studied. It is found that the relative run-ups on the front face and the back face of the cylinder depend mainly on the wave steepness and the relative diameter, while the dependence on the relative depth is weak. The empirical formulae are proposed to calculate the relative run-ups in terms of the wave steepness of incident regular waves and the relative diameter of a cylinder.

Impedance Analytical Method of Wave Run-up and Reflection from A Slotted-Wall Caisson Breakwater

An impedance analytical method （IAM） is developed to study the interaction of plane water wave with a slotted-wall caisson breakwater. The non-linear boundary condition at the slotted-wall is expressed in terms of flow resistance. A set of algebraic expressions are obtained for free surface elevation inside and outside chamber, and reflection coefficient. The prediction of the reflection coefficients shows that the relative widths of the chamber inducing the minimum reflection coefficient for a slotted-wall caisson breakwater are in a range of 0.10～0.20, which are smaller than that （0.15～0.25） for a perforated-wall caisson breakwater. The reflection coefficients and free surface elevation obtained by the present model are compared with that of laboratory experiments carried out by previous researchers.

Experimental Study on 2-D Focusing Wave Run-up on A Vertical Cylinder

In this paper,the focused wave groups with different parameters and their actions on a vertical cylinder are experimentally studied. The harmonic wave characteristics of the focusing waves are analyzed by the addition and subtraction of the crest and trough focusing waves. The analyzed results show that higher order harmonics can be generated because of the interaction of component waves. Nonlinearity increases with the inputted wave amplitude and the frequency width increment. Further, the wave run-up around the vertical circular cylinder is experimentally studied. It increases with the wave steepness and the relative cylinder diameter increase. However, the variations of wave run-up around the circular cylinder are different. The researches provide a reference for further numerical studies.

Wave Run-up on A Coaxial Perforated Circular Cylinder

This paper describes a plane regular wave interaction with a combined cylinder which consists of a solid inner column and a coaxial perforated outer cylinder. The outer perforated surface is a thin porous cylinder with an annular gap between it and the inner cylinder. The non-linear boundary condition at the perforated wall is a prime focus in the study; energy dissipation at the perforated wall occurs through the resistance to the fluid across the perforated wall. Explicit analytical formulae are presented to calculate the wave run-up on the outer and inner surfaces of the perforated cylinder and the surface of the inner column. The theoretical results of the wave run-up are compared with previous experimental data. Numerical results have also been obtained： when the ratio of the annular gap between the two cylinders to incident wavelength （b-a）/L≤0. 1, the wave run-up on the inner surface of the perforated cylinder and the surface of inner column can partially or completely exceed the incident wave height.

Metabolic cost of level,uphill,and downhill running in highly cushioned shoes with carbon-fiber plates

Background:Compared to conventional racing shoes,Nike Vaporfly 4% running shoes reduce the metabolic cost of level treadmill running by4%.The reduction is attributed to their lightweight,highly compliant,and resilient midsole foam and a midsole-embedded curved carbon-fiber plate.We investigated whether these shoes also could reduce the metabolic cost of moderate uphill(+3°) and downhill(-3°) grades.We tested the null hypothesis that,compared to conventional racing shoes,highly cushioned shoes with carbon-fiber plates would impart the same ~4%metabolic power(W/kg) savings during uphill and downhill running as they do during level running.Methods:After familiarization,16 competitive male runners performed six 5-min trials(2 shoes × 3 grades) in 2 Nike marathon racing-shoe models(Streak 6 and Vaporfly 4%) on a level,uphill(+3°),and downhill(-3°) treadmill at 13 km/h(3.61 m/s).We measured submaximal oxygen uptake and carbon dioxide production during Minutes 4-5 and calculated metabolic power(W/kg) for each shoe model and grade combination.Results:Compared to the conventional shoes(Streak 6),the metabolic power in the Vaporfly 4% shoes was 3.83%(level),2.82%(uphill),and2.70%(downhill)less(all p <0.001).The percent of change in metabolic power for uphill running was less compared to level running(p=0.04;effect size(ES)=0.561) but was not statistically different between downhill and level running(p=0.17;ES=0.356).Conclusion:On a running course with uphill and downhill sections,the metabolic savings and hence performance enhancement provided by Vaporfly 4% shoes would likely be slightly less overall,compared to the savings on a perfectly level race course.

Wave Run-up on A Vertical Seawall Protected by An Offshore Submerged Barrier

Submerged barriers are constructed in coastal zones for shoreline or harbor protection or to prevent the beach erosion. In the present study, the wave run-up on a vertical seawall protected by a submerged barrier is analyzed. The physical configurations include a rigid barrier and a long channel of finite depth. For linear water waves, by matching the velocity along the barrier and along the gap, the systems of linear equations about the velocity potentials are obtained. The wave rim-up is further analyzed for various settings of barrier height and distance between the barrier and the wall, i.e. the chamber length. For nonlinear waves and random sea waves, a numerical model is extended to investigate the effect parameters of the barrier on the wave rim-up against the seawall. Not only the numerical simulations, but also the analytical results illustrate that the wave run-up on the seawall depends very much on the distance between the barrier and the vertical seawall.

Application of artificial neural network to calculation of solitary wave run-up

The prediction of solitary wave run-up has important practical significance in coastal and ocean engineering, but the calculation precision is limited in the existing models. For improving the calculation precision, a solitary wave run-up calculation model was established based on artificial neural networks in this study. A back-propagation （BP） network with one hidden layer was adopted and modified with the additional momentum method and the auto-adjusting learning factor. The model was applied to calculation of solitary wave run-up. The correlation coefficients between the neural network model results and the experimental values was 0.996 5. By comparison with the correlation coefficient of 0.963 5, between the Synolakis formula calculation results and the experimental values, it is concluded that the neural network model is an effective method for calculation and analysis of solitary wave ran-up.

Critical Factors for Run-up and Impact of the Tohoku Earthquake Tsunami

The earthquake of March 11 of magnitude 9 offshore Tohoku, Japan, was followed by a tsunami wave with particularly destructive impact, over a coastal area extending approx. 850km along the Pacific Coast of Honshu Island. First arrival times and measurements and maximum height were recorded by the Japanese monitoring system (wherever there was no failure of the equipment). The maximum run-up is well evident in satellite images available through USGS, Google and other institutes. Moreover, personal observations of Prof. Lekkas were made during a field survey in March 2011. The results of the study of the tsunami impact and run-up show the variety of factors affecting the run-up, creating zones with similar phenomena, but also specific locations where run-up exceeds by far the run-up zone maximum values. This differentiation, observed also in the past by other authors, is here attributed to the general orientation of the coast, the distance from the tsunami generation area, bathymetry offshore, the coastline morphology and land geomorphology. In certain cases that funnelling and reflection effects in narrow gulfs parallel to the tsunami propagation vector were combined with narrow valleys onshore, peak run-up exceeded 20m, or even 40 m (Miyagi coastline, Ogatsu, Onagawa, etc).

Run-Up Flow of a Maxwell Fluid through a Parallel Plate Channel

We consider the flow of an incompressible viscous Maxwell fluid between two parallel plates, initially induced by a constant pressure gradient. The pressure gradient is withdrawn and the upper plate moves with a uniform velocity while the lower plate continues to be at rest. The arising flow is referred to as run-up flow. The unsteady governing equations are solved as initial value problem using Laplace transform technique. The expression for velocity, shear stresses on both plates and discharge are obtained. The behavior of the velocity, shear stresses and mass flux has been discussed in detail with respect to variations in different governing flow parameters and is presented through graphs.

Energy Dissipation Within the Wave Run-Up at Stepped Revetments

To understand the processes and energy dissipation performance caused by turbulence during the wave run-up over a stepped revetment,hydraulic model tests with steady flow conditions are conducted and correlated with unsteady flow conditions of the wave run-up within a short time frame.Under irregular waves,the run-up reduction over a stepped revetment is dependent on the Iribarren number and decreases for decreasing Iribarren numbers.Velocity gradients are found to be similar in a steady and unsteady flow regime near the pseudo-bottom.

Running Coupling Constants in N-N Interaction

The scalar and vector running coupling constants are derived using the renormalization group method in the σ-ω model. The numerical values of the two running coupling constants are obtained and the physical meaning of the result is discussed.