Outward Motion Research Articles

The impact of an educational program on some judo skills on developing motor balance

Introduction. Judo is a well-known Olympic sport and martial art that stresses the importance of mental and physical discipline. The goal is to controllably and safely submit an opponent using a range of techniques, like as throws, takedowns, joint locks, and chokes. By honing their agility, balance, and coordination, judokas also improve their strength, flexibility, and capacity for strategic thought. Judo is an all-encompassing system for personal and physical growth since it teaches respect, persistence, self-control, and other qualities in addition to physical skills. The purpose of this study was to examine the effect of a Judo-based instructional program on the development of motor balance in athletes between the ages of 15 and 18. Study participants and methods. The sample of the study consists of 15 junior players of the Bsira Sports Club for judo in Tafila/Jordan, who were selected in the manner deliberately, and the average weight 67,33, height 165,93, and age 16,60. The values of motor balance use the modified star flight test. The skills education program was applied for (8) 5 reasons per week for (60) minutes at a time (15 minutes for warm-up, 35 minutes for the central part, and 10 minutes to calm down). Statistical methods: athematic averages, standard deviations, T-test for pairs to compare pre and post-measurement, correlation coefficient, coefficient of variation, coefficient of convolution coefficient of Kurtosis. Results. On the whole, the motor balance variables showed statistically significant improvements. These included forward movement (mean: pre-63.93, post-66.00; T-value: 5.21), inner backward motion (mean: pre-66.93, post68.27; T-value: 4.39), and outward backward motion (mean: pre-61.47, post-62.20; T-value: 4.78). The results showed a considerable improvement in motor balance after training, as all T-values were significant at α < 0.05. These results provide credence to the idea that judo training improves stability and the function of the lower limbs via the development of motor balance. Conclusion. The findings demonstrate that the implementation of this program leads to improvements in equilibrium, coordination, and overall balance among participants. The study highlights the specific components of the program, such as balance exercises and proprioceptive training, that contribute to motor balance development. By targeting these areas, trainers can design effective training regimens for Judo athletes. Moreover, the study emphasizes the importance of introducing Judo training at a young age, as early intervention can have a lasting impact on motor balance. Overall, the study provides valuable insights for optimizing Judo training programs and enhancing performance outcomes. The importance of this study lies in the fact that it investigates the efficacy of certain exercises and drills designed for Judo in improving balance, stability, agility, and coordination. These enhancements help the participants physically and increase their Judo performance. The results of this study have important implications for improving Judo training programs and may also be applicable to other types of athletic training

The transient discharge circuit analysis of single-turn coil

Single-turn coil (STC) is a destructive pulse magnet aiming at a 100–300 T ultra-high magnetic field. A transient discharge circuit model considering the coupling of electromagnetic diffusion and conductor deformation is proposed, and the transient coil impedance characteristics are investigated. The results show that the coil resistance first decreases and then increases due to electromagnetic diffusion and temperature rise, respectively, while the coil inductance always increases because of the conductor’s outward motion. By comparison, the simulation results are consistent with the experimental data, and the correctness of the model is validated.

Shocks, clouds, and atomic outflows in active galactic nuclei hosting relativistic jets

Context. A number of observations have revealed atomic and/or molecular lines in active galaxies hosting jets and outflows. Line widths indicate outward motions of hundreds to a few thousands of kilometers per second. They appear to be associated with the presence of radio emission in Gigahert-peaked spectrum (GPS) and/or compact steep spectrum (CSS) sources, with linear sizes of ≤10 kpc. Numerical simulations have shown that the bow shocks triggered by relativistic jets in their host galaxies drive ionization and turbulence in the interstellar medium (ISM). However, the presence of atomic lines requires rapid recombination of ionized gas, which appears challenging to explain from the physical conditions revealed thus far based on numerical simulations of powerful jets. Aims. The aim of this paper is to provide a global framework to explain the presence of lines in terms of jet and shock evolution and to fix the parameter space where the atomic and molecular outflows might occur. Methods. This parameter space is inspired by numerical simulations and basic analytical models of jet evolution as a background. Results. Our results show that a plausible general explanation involves momentum transfer and heating to the interstellar medium gas by jet triggered shocks within the inner kiloparsecs. The presence of post-shock atomic gas is possible in the case of shocks interacting with dense clouds that remain relatively stable after the shock passage. Conclusions. According to our results, current numerical simulations cannot reproduce the physical conditions to explain the presence of atomic and molecular outflows in young radio sources. However, I show that these outflows might occur in low-power jets at all scales and I predict a trend towards powerful jets showing lines at CSS scales, when clouds have cooled to recombination temperatures.

Dendritic mGluR2 and perisomatic Kv3 signaling regulate dendritic computation of mouse starburst amacrine cells

Dendritic mechanisms driving input-output transformation in starburst amacrine cells (SACs) are not fully understood. Here, we combine two-photon subcellular voltage and calcium imaging and electrophysiological recording to determine the computational architecture of mouse SAC dendrites. We found that the perisomatic region integrates motion signals over the entire dendritic field, providing a low-pass-filtered global depolarization to dendrites. Dendrites integrate local synaptic inputs with this global signal in a direction-selective manner. Coincidental local synaptic inputs and the global motion signal in the outward motion direction generate local suprathreshold calcium transients. Moreover, metabotropic glutamate receptor 2 (mGluR2) signaling in SACs modulates the initiation of calcium transients in dendrites but not at the soma. In contrast, voltage-gated potassium channel 3 (Kv3) dampens fast voltage transients at the soma. Together, complementary mGluR2 and Kv3 signaling in different subcellular regions leads to dendritic compartmentalization and direction selectivity, highlighting the importance of these mechanisms in dendritic computation.

A release of local subunit conformational heterogeneity underlies gating in a muscle nicotinic acetylcholine receptor

Synaptic receptors respond to neurotransmitters by opening an ion channel across the post-synaptic membrane to elicit a cellular response. Here we use recent Torpedo acetylcholine receptor structures and functional measurements to delineate a key feature underlying allosteric communication between the agonist-binding extracellular and channel-gating transmembrane domains. Extensive mutagenesis at this inter-domain interface re-affirms a critical energetically coupled role for the principal α subunit β1-β2 and M2-M3 loops, with agonist binding re-positioning a key β1-β2 glutamate/valine to facilitate the outward motions of a conserved M2-M3 proline to open the channel gate. Notably, the analogous structures in non-α subunits adopt a locally active-like conformation in the apo state even though each L9’ hydrophobic gate residue in each pore-lining M2 α-helix is closed. Agonist binding releases local conformational heterogeneity transitioning all five subunits into a conformationally symmetric open state. A release of conformational heterogeneity provides a framework for understanding allosteric communication in pentameric ligand-gated ion channels.

The relation between magnetic field inclination and the apparent motion of penumbral grains

Context. The bright heads of penumbral filaments, penumbral grains (PGs), show apparent horizontal motions inward, toward the umbra, or outward, away from the umbra. Aims. We aim to ascertain statistically whether the direction of PGs’ apparent motion is related to the inclination of the surrounding magnetic field. Methods. We used spectropolarimetric observations of five sunspot penumbrae to compare magnetic inclinations inside PGs with those in their surroundings. The data were taken by three observatories: the Hinode satellite, the Swedish Solar Telescope, and the GREGOR solar telescope. The direction of PGs’ motion was determined by feature tracking. The atmospheric conditions in PGs and their surroundings, including magnetic field information, were retrieved by means of height-stratified spectropolarimetric inversions. Results. Out of a sample of 444 inward-moving PGs and 269 outward-moving ones, we show that 43% of the inward-moving PGs have a magnetic inclination larger by 8° ±4° than the inclination in their surroundings and 51% of the outward-moving PGs have an inclination smaller by 13° ±7° than the surrounding one. The opposite relation of inclinations is observed in only one fifth of the inward- and outward-moving PGs. Conclusions. Rising hot plasma in PGs surrounded by a less inclined magnetic field may adapt its trajectory to be more vertical, causing an inward apparent motion of PGs. Conversely, it may be dragged by a more horizontal surrounding magnetic field such that an outward apparent motion is observed.

Hybrid control of aerofoil self-noise by coupling air blowing and trailing-edge serration

Active and passive control methods have been extensively studied and employed for reducing turbulent-boundary-layer (TBL) trailing-edge (TE) noise of aerofoils, for example air blowing and TE serration. To further explore the potential of noise reduction, this paper proposes a hybrid method coupling blowing and serration at the trailing edge, and investigates the effects of air blowing, TE serration, and the hybrid blowing-serration (HBS) on the TBL TE noise of a NACA0012 aerofoil at a Reynolds number of Rec=4×105. Large eddy simulation and Ffowcs Williams–Hawkings acoustic analogy were used to analyse these effects and the respective noise reduction mechanisms. The numerical results show that the HBS method exhibits superior acoustic performance to the blowing and serration methods, with a maximum reduction of 20.5 dB in broadband noise and 5.7 dB in overall sound pressure level. It is revealed that the HBS method functions primarily through three noise reduction mechanisms. Firstly, blowing eliminates the outward flow motion at the serration root and tip, resulting in a forced flow alignment. Secondly, it weakens the turbulence energy in the near wake as for air blowing. Finally, this method mitigates spanwise coherence at the trailing edge, thereby causing destructive interference of noise sources, similar to the effect of TE serration.

Vortex dynamics in rotating Rayleigh–Bénard convection

We investigate the spatial distribution and dynamics of the vortices in rotating Rayleigh–Bénard convection in a reduced Rayleigh number range $1.3\le Ra/Ra_{c}\le 83.1$ . Under slow rotations ( $Ra\approx 80\,Ra_{c}$ ), the vortices are distributed randomly, which is manifested by the size distribution of the Voronoi cells of the vortex centres being a standard $\varGamma$ distribution. The vortices exhibit Brownian-type horizontal motion in the parameter range $Ra\gtrsim 10\,Ra_{c}$ . The probability density functions of the vortex displacements are, however, non-Gaussian at short time scales. At modest rotating rates ( $4\,Ra_{c}\le Ra\lesssim 10\,Ra_{c}$ ), the centrifugal force leads to radial vortex motions, i.e. warm cyclones (cold anticyclones) moving towards (outwards from) the rotation axis. The horizontal scale of the vortices decreases with decreasing $Ra/Ra_c$ , and the size distribution of their Voronoi cells deviates from the $\varGamma$ distribution. In the rapidly rotating regime ( $1.6\,Ra_{c}\le Ra\le 4\,Ra_{c}$ ), the vortices are densely distributed. The hydrodynamic interaction of neighbouring vortices results in the formation of vortex clusters. Within clusters, cyclones exhibit inverse-centrifugal motion as they submit to the outward motion of the strong anticyclones, and the radial velocity of the anticyclones is enhanced. The radial mobility of isolated vortices, scaled by their vorticity strength, is shown to be a simple power function of the Froude number. For all flow regimes studied, we show that the number of vortices with a lifespan greater than $t$ decreases exponentially as $\exp ({-t/{\tau }})$ for large time, where $\tau$ represents the characteristic lifetime of long-lived vortices.

Cracking and associated volumetric expansion of NMC811 secondary particles

Secondary particles comprising a large number of nickel-rich single crystal primary particles are extensively used as storage particles in cathodes of lithium-ion batteries. It is well-established that crack formation in secondary particles is an important degradation mode that contributes to decline in battery performance. Recent X-ray tomographic observations suggest that, at very low C-rates, concentration gradients of lithium within an NMC811 secondary particle are negligible yet cracking still occurs. Additionally, during delithiation the primary particles shrink yet a volumetric expansion of the secondary particle occurs. These observations are explained by a numerical model of distributed cracking due to the extreme anisotropy of lithiation strain of primary particles. The incompatible deformation from grain to grain induces large self-stresses even in the absence of spatial gradients in the lithium concentration. The stress state is sufficient to drive a dynamic catastrophic fracture event, and the associated kinetic energy acquired by the primary particles moves them apart (akin to an explosive event) with the carbon and binder domain surrounding each secondary particle restricting the outward motion of the primary particles. It is predicted that a volume expansion of the secondary particles on the order of 20 % accompanies cracking, in agreement with recently reported observations.

Understanding the Ries impact structure subsurface from high-resolution seismic data

Abstract The Ries impact structure (southern Germany) formed ca. 15 Ma and is 22–26 km in diameter, making it one of the youngest and best-preserved mid-size terrestrial impact craters, yet the subsurface has not been studied with modern geophysics. We present the first high-resolution seismic profiles of the Ries impact structure; the profiles show discontinuous intra-basement reflectors and a central crater floor without a significant central topographic high. The inner crystalline ring sits adjacent to, not on top of, the crater terrace zone. These morphologies indicate that during the crater modification stage, the rebounding central uplift at Ries rose and then collapsed without the continued outward motion required to form a fully developed peak ring. The Ries impact structure may be best considered a transitional complex crater form between a central-peak crater and a peak-ring crater as documented on the Moon and other rocky planets. A series of high-amplitude, discontinuous, topographically influenced reflectors overlying the basement implies that the suevite within the crater basin was emplaced via lateral transport.

Water maser distributions and their internal motions in the Sagittarius B2 complex

Abstract We conducted a multi-epoch very long baseline interferometry (VLBI) observation of 22 GHz H2O maser sources, which are associated with the Sagittarius B2 (Sgr B2) complex, one of the most active star-forming regions in the Galactic center. Using the VLBI exploration of radio astrometry (VERA) array, we detected 29, 90, and seven maser features in Sgr B2(North), (Main), and (South), respectively. We also discovered two H2O maser features in Sgr B2 (Mid-North). Moreover, we successfully measured spatial distributions and internal motions of the H2O maser sources in Sgr B2(M). We then discovered that the H2O maser features in Sgr B2(M) are located at the outer edge of H ii regions detected by using the centimeter radio continuum emission, and observationally demonstrated that they have outward motions from the two H ii regions separated by 1′. We obtained an absolute proper motion of (μαcos δ, μδ) = (−2.17 ± 0.03, −2.63 ± 0.06) mas yr−1 and marginally detected a parallax of Sgr B2, which is consistent with other measurements. The absolute proper motion corrected by the internal motions of the H2O maser features implies that the Sgr B2 complex is located at the near side of the Galactic center and is moving toward the positive galactic longitude. We estimate that Sgr B2 is at 160 ± 10 pc in front of Sgr A* by assuming a simple circular orbit of the central molecular zone (CMZ).

Multi-joint Assessment of Proprioception Impairments Poststroke

ObjectivesTo investigate shoulder, elbow and wrist proprioception impairment poststroke. DesignProprioceptive acuity in terms of the threshold detection to passive motion at the shoulder, elbow and wrist joints was evaluated using an exoskeleton robot to the individual joints slowly in either inward or outward direction. SettingA university research laboratory. ParticipantsSeventeen stroke survivors and 17 healthy controls (N=34). Inclusion criteria of stroke survivors were (1) a single stroke; (2) stroke duration <1 year; and (3) cognitive ability to follow simple instructions. InterventionsNot applicable. Main Outcome MeasuresThreshold detection to passive motion and detection error at the shoulder, elbow and wrist. ResultsThere was significant impairment of proprioceptive acuity in stroke survivors as compared to healthy group at all 3 joints and in both the inward (shoulder horizontal adduction, elbow and wrist flexion, P<.01) and outward (P<.01) motion. Furthermore, the distal wrist joint showed more severe impairment in proprioception than the proximal shoulder and elbow joints poststroke (P<.01) in inward motion. Stroke survivors showed significantly larger detection error in identifying the individual joint in motion (P<.01) and the movement direction (P<.01) as compared to the healthy group. There were significant correlations among the proprioception acuity across the shoulder, elbow and wrist joints and 2 movement directions poststroke. ConclusionsThere were significant proprioceptive sensory impairments across the shoulder, elbow and wrist joints poststroke, especially at the distal wrist joint. Accurate evaluations of multi-joint proprioception deficit may help guide more focused rehabilitation.

Evolution behavior of cavitation bubble in pure Sn liquid medium with narrow gap under low-amplitude ultrasound

In this study, a numerical model of cavitation bubble in the narrow-gap pure Sn liquid medium was established by two-dimensional compressible multiphase flow simulation. The effects of the pressure amplitude and the gap size on the shape, size and position of the cavitation bubble were investigated. The calculation results showed that the cavitation bubble in the narrow-gap soldering seam could exist stably after experiencing two stages of the nonlinear oscillation and the near-wall oscillation with the low-amplitude ultrasound and moved directionally on the metal substrate surface. When the pressure amplitude increased or the gap size decreased, the directional motion rate of the cavitation bubble increased and the shape of the bubble was elliptical due to the confinement effect of the substrate wall. The ultrasonic degassing mechanism of the narrow-gap soldering seam under the action of exponential decay ultrasonic vibration was analyzed by comparing the fluid pressure and velocity field variations. The flow field in the center of the soldering seam vibrated stronger than that of the peripheral regions, which could promote the outward motion of the cavitation bubble. Within the calculation time of 0.002 s, the maximum horizontal motion distance of bubble in the narrow-gap soldering seam was 1.13 mm.

Effect of Wall Oscillation Period on Fluid Flow in Branched Channel with a Moving Indentation

The numerical simulation of two-dimensional fluid flow in T-shaped and Y-shaped channels having a single moving indented wall is performed by the finite element method in the Arbitrary Lagrangian-Eulerian frame. The motion of the indented wall is defined as a hyperbolic function, and it is located at a small segment at the bottom wall in the parent channel. The smallest value of the wall oscillation period causes the waviest core flow in the main channel, resulting in bigger vortices and greater flow separation region in the branches, especially during the outward indentation motion. This flow disturbance pattern is found more severe in T-channel as compared to that of in Y-channel.

Analytical Model of Foreshock Ion Interaction With a Discontinuity: A Statistical Study

AbstractWhen a solar wind discontinuity interacts with foreshock ions, foreshock transients such as hot flow anomalies and foreshock bubbles can form. These create significant dynamic pressure perturbations disturbing the bow shock, magnetopause, and magnetosphere‐ionosphere system. However, presently these phenomena are not predictable. In the accompanying paper, we derived analytical equations of foreshock ion partial gyration around a discontinuity and the resultant current density. In this study, we utilize the derived current density strength to model the energy conversion from the foreshock ions, which drives the outward motion or expansion of the solar wind plasma away from the discontinuity. We show that the model expansion speeds match those from local hybrid simulations for varying foreshock ion parameters. Using MMS, we conduct a statistical study showing that the model expansion speeds are moderately correlated with the magnetic field strength variations and the dynamic pressure decreases around discontinuities with correlation coefficients larger than 0.5. We use conjunctions between ARTEMIS and MMS to show that the model expansion speeds are typically large for those already‐formed foreshock transients. Our results show that our model can be reasonably successful in predicting significant dynamic pressure disturbances caused by foreshock ion‐discontinuity interactions. We discuss ways to improve the model in the future.

On The Partially Reacted Boundary Layer in Rate Sticks

Using our temperature dependent reactive rate (TDRR) reactive flow model to simulate detonation in a rate stick, we observe that a partially reacted layer (PRL) is being formed near the boundary. We are not aware that such a PRL has been observed in tests, and this is why we regarded it in the past as a numerical artifact. Assuming that such an artifact may be caused by the finite rise time of the detonation shock, we showed in [1] how it can be eliminated by delaying the outward boundary motion for a length of time comparable with the shock rise time. Here we revisit the PRL problem. We first show that it is not a numerical artifact but a real phenomenon. We do this by repeating the reactive flow run with a finer mesh. By looking at the PRL structure, we see that doubling the resolution affects the PRL only slightly. We then conjecture that the PRL formation has to do with the finite duration of the reaction process (or the finite extent of the reaction zone). By the time the boundary rarefaction reaches a cell near the boundary, it may still be only partially reacted, and its reaction process may be therefore cut off. To establish our conjecture, we show how the PRL structure changes with the reaction duration.

Can radial motions in the stellar halo constrain the rate of change of mass in the Galaxy?

ABSTRACT A change in the mass of the Galaxy with time will leave its imprint on the motions of the stars, with stars having radially outward (mass-loss) or inward (mass accretion) bulk motions. Here, we test the feasibility of using the mean radial motion of stars in the stellar halo to constrain the rate of change of mass in the Galaxy, e.g. due to decay of dark matter. In the lambda cold dark matter (ΛCDM) paradigm, the stellar halo is formed by accretion of satellites on to the host galaxy and its mean radial motion 〈VR〉 is eventually expected to be close to zero. But due to incomplete mixing most haloes have substructures and this can lead to non-zero 〈VR〉 in them. Using simulations, we measure the mean radial motion of stars in 13 ΛCDM stellar haloes lying in a spherical shell of radius 30 kpc. For most haloes, the shell motion is quite small, with 75 per cent of haloes having $\langle V_\text{R}\rangle \lesssim 1.2 \:{\rm km}\, {\rm s}^{-1}$. When substructures are removed by using a clustering algorithm, 〈VR〉 is reduced even further, with 75 per cent of haloes having $\langle V_\text{R}\rangle \lesssim 0.6 \:{\rm km}\, {\rm s}^{-1}$. A value of $\langle V_\text{R}\rangle \approx 0.6 \:{\rm km}\, {\rm s}^{-1}$ can be attained corresponding to a galactic mass-loss rate of 2 per cent per Gyr. We show that this can place constraints on dark matter decay parameters such as the decay lifetime and the kick velocity that is imparted to the daughter particle. The advent of all-sky stellar surveys involving millions to billions of stars is encouraging for detecting signatures of dark matter decay.

Computational Insights into the Allosteric Modulation of a Phthalate-Degrading Hydrolase by Distal Mutations.

Phthalate esters (PAEs) are a ubiquitous kind of environmental endocrine that disrupt chemicals, causing environmental and health issues. EstJ6 is an effective phthalate-degrading hydrolase, and its mutant with a combination of three non-conservative distal mutations has an improved activity against PAEs with unknown molecular mechanisms. Herein, we attempt to fill the significant gap between distal mutations and the activity of this enzyme using computational approaches. We found that mutations resulted in a redistribution of the enzyme's preexisting conformational states and dynamic changes of key functional regions, especially the lid over the active site. The outward motion of the lid upon the mutations made it easier for substrates or products to enter or exit. Additionally, a stronger substrate binding affinity and conformational rearrangements of catalytic reaction-associated residues in the mutant, accompanied by the strengthened communication within the protein, could synergistically contribute to the elevated catalytic efficiency. Finally, an attempt was made to improve the thermostability of EstJ6 upon introducing a distal disulfide bond between residues A23 and A29, and the simulation results were as expected. Together, our work explored the allosteric effects caused by distal mutations, which could provide insights into the rational design of esterases for industrial applications in the future.

Collective vortical motion and vorticity reversals of self-propelled particles on circularly patterned substrates.

The collective behavior of self-propelled particles (SPPs) under the combined effects of a circularly patterned substrate and circular confinement is investigated through coarse-grained molecular dynamics simulations of polarized and disjoint ring polymers. The study is performed over a wide range of values of the SPPs packing fraction ϕ[over ¯], motility force F_{D}, and area fraction of the patterned region. At low packing fractions, the SPPs are excluded from the system's center and exhibit a vortical motion that is dominated by the substrate at intermediate values of F_{D}. This exclusion zone is due to the coupling between the driving force and torque induced by the substrate, which induces an outward spiral motion of the SPPs. For high values of F_{D}, the SPPs exclusion from the center is dominated by the confining boundary. At high values of ϕ[over ¯], the substrate pattern leads to reversals in the vorticity, which become quasiperiodic with increasing ϕ[over ¯]. We also found that the substrate pattern is able to separate SPPs based on their motilities.

Effects of turbulent diffusion and back-reaction on the dust distribution around two resonant planets

ABSTRACT In evolved and dusty circumstellar discs, two planets with masses comparable to Jupiter and Saturn that migrate outwards while maintaining an orbital resonance can produce distinctive features in the dust distribution. Dust accumulates at the outer edge of the common gas gap, which behaves as a dust trap, where the local dust concentration is significantly enhanced by the planets’ outward motion. Concurrently, an expanding cavity forms in the dust distribution inside the planets’ orbits, because dust does not filter through the common gaseous gap and grain depletion in the region continues via inward drifting. There is no cavity in the gas distribution because gas can filter through the gap, although ongoing gas accretion on the planets can reduce the gas density in the inner disc. Such behaviour was demonstrated by means of simulations neglecting the effects of dust diffusion due to turbulence and of dust backreaction on the gas. Both effects may alter the formation of the dust peak at the gap outer edge and of the inner dust cavity, by letting grains filter through the dust trap. We performed high-resolution hydrodynamical simulations of the coupled evolution of gas and dust species, the latter treated as pressureless fluids, in the presence of two giant planets. We show that diffusion and backreaction can change some morphological aspects of the dust distribution but do not alter some main features, such as the outer peak and the expanding inner cavity. These findings are confirmed for different parametrizations of gas viscosity.