Periodic Distribution Research Articles

Characterization of probiotic Bacillus sp. NP5 metabolites and its effect on female catfish broodstock rematuration

Probiotics are believed to contain active components that affect fish reproduction. This study aimed to evaluate the metabolite compounds contained in the probiotic Bacillus sp. NP5 and its effect on female catfish broodstock rematuration. The first step was to analyze the metabolite content of probiotic using liquid chromatography with tandem mass spectrometry LCMS/MS. Furthermore, feed supplementation was implemented with probiotic at concentrations of 106 CFU g-1 (P6), 108 CFU g-1 (P8), and control (C). Parameters observed included metabolite content of Bacillus sp. NP5, gonadosomatic index (GSI), hepatosomatic index (HSI), gonad histology, gonad maturity rate, fecundity, number of matured eggs, distribution of egg diameter, fertilization rate (FR), hatching rate (HR), larval survival (SR), rematuration period, and percentage of matured broodstock. The results showed that metabolites such as resveratrol (22.45%) and indoline (7.11%) are probably directly affecting reproduction. Other metabolites such as oxyresveratrol (22.95%) and vestitol (4.14%) are also thought to play an indirect role. Supplementation results showed the best reproductive performance in 108 CFU g-1 feed treatment with an increase in GSI (14.74%), HSI (1.65%), gonad maturity rate, percentage of mature eggs (86.00%), rematuration period (4 weeks), percentage of matured broodstock (100%), fecundity (243605.02 eggs/broodstock), FR (98.74%), HR (80.62%), and SR (87.31%). Application of probiotic Bacillus sp. NP5 can accelerate rematuration and improve reproductive performance of female catfish broodstock. Probiotics contain metabolites that have a positive effect on reproduction and can be an alternative in improving reproductive performance in female catfish broodstock. Keywords: Bacillus sp. NP5, female catfish, metabolites, probiotics, rematuration

On the Existence of Long-period Decayless Oscillations in Short Active Region Loops

Abstract Decayless kink oscillations, characterized by their lack of decay in amplitude, have been detected in coronal loops of varying scales in active regions, the quiet Sun, and coronal holes. Short-period (<50 s) decayless oscillations have been detected in short loops (< 50 Mm) within active regions. Nevertheless, long-period decayless oscillations in these loops remain relatively unexplored and crucial for understanding the wave modes and excitation mechanisms of decayless oscillations. We present the statistical analysis of decayless oscillations from two active regions observed by the Extreme Ultraviolet Imager onboard Solar Orbiter. The average loop length and period of the detected oscillations are 19 Mm and 151 s, respectively. We find 82 long-period and 23 short-period oscillations in these loops. We do not obtain a significant correlation between loop length and period. We discuss the possibility of different wave modes in short loops, although standing waves cannot be excluded from possible wave modes. Furthermore, a different branch exists for active region short loops in the loop length versus period relation, similar to decayless waves in short loops in the quiet Sun and coronal holes. The magnetic fields derived from MHD seismology, based on standing kink modes, show lower values for multiple oscillations compared to previous estimates for long loops in active regions. Additionally, the comparison of period distributions in short loops across different coronal regions indicates that different excitation mechanisms may trigger short-period kink oscillations in active regions compared to the quiet Sun and coronal holes.

Binary properties of the globular cluster 47 Tuc (NGC 104)

Spectroscopic observations of binary stars in globular clusters are essential to shed light on the poorly constrained period, eccentricity, and mass ratio distributions and to develop an understanding of the formation of peculiar stellar objects. 47 Tuc (NGC 104) is one of the most massive Galactic globular clusters, with a large population of blue stragglers and with many predicted but as-yet elusive stellar-mass black holes. This makes it an exciting candidate for binary searches. We present a multi-epoch spectroscopic survey of 47 Tuc with the VLT/MUSE integral field spectrograph to determine radial velocity variations for 21 699 stars. We find a total binary fraction in the cluster of (2.4 ± 1.0)%, consistent with previous photometric estimates, and an increased binary fraction among blue straggler stars, approximately three times higher than the cluster average. We find very few binaries with periods below three days, and none with massive dark companions. A comparison with predictions from state-of-the-art models shows that the absence of such short-period binaries and of binaries with massive companions is surprising, highlighting the need to improve our understanding of stellar and dynamical evolution in binary systems.

Topology and PT symmetry in a non-Hermitian Su–Schrieffer–Heeger chain with periodic hopping modulation

We study the effect of periodic hopping modulation in a Su-Schrieffer-Heeger (SSH) chain with an additional onsite staggered imaginary potential (of strengthγ). Such dissipative, non-Hermitian (NH) extension amply modifies the features of the topological trivial phase (TTP) and the topological nontrivial phase (TNP) of the SSH chain, more so with the periodic hopping distribution. Generally a weak NH potential can respect the parity-time (PT) symmetry keeping the energy eigenvalues real, while a strong potential breaksPTconservation leading to imaginary edge state and complex bulk state energies in the system. We find that the non-zero energy in-gap states, that appear due to periodic hopping modulations even in theγ = 0 limit, take purely real or purely imaginary eigenvalues depending on the strength of bothγand Δ (dimerization parameter). The localization of topological edge states (in-gap states) at the boundaries are investigated that reveals extended nature not only near topological transitions (further away from|Δ/t|=1) but also near the unmodulated limit ofΔ=0. Moreover, localization of the bulk states is observed at the maximally dimerized limit of|Δ/t|=1, which increases further withγ. These dissipative features can offer additional tunability in modulating the gain-loss contrast in optical systems or in designing various quantum information processing and storage devices.

Chronobiological variations of acute aortic dissection in a Northwest Chinese population

BackgroundThe prevalence of acute aortic dissection (AAD) has been gradually increasing in recent years. This study aimed to investigate the circadian variations of AAD onset in a northwest Chinese population and provide scientific insights for AAD prevention.MethodsThe clinical data of 1,145 AAD patients admitted to our hospital between January 2010 and December 2020 were retrospectively collected, and the periodic features of AAD were analyzed.ResultsStanford type A and type B AAD were present in 58.43% (669 cases) and 41.57% (476 cases) of the patients, respectively. The incidence rate was highest in the winter (358 cases, 31.27%) and lowest in the summer (225 cases, 19.65%). AAD occurred at the highest rate between 19:00–24:00 (321 cases, 28.03%) and the lowest rate between 1:00–6:00 (247 cases, 21.57%). Stanford type A AAD was most prevalent in the winter and the least prevalent in the spring, whereas Stanford type B AAD was most prevalent in the winter and the least prevalent in the summer. The difference between type A and type B in seasonal distribution was significant in spring (χ2 = 17.666, P < 0.001) and summer (χ2 = 6.228, P = 0.013). Stanford type A cases appeared most during 19:00–24:00 (236 cases, 35.28%) and least during 13:00–18:00 (73 cases, 10.91%), while Stanford type B cases appeared most during 13:00–18:00 (239 cases, 50.21%) and least during 1:00–6:00 (60 cases, 12.61%). The difference between type A and type B in period distribution was significant in all periods of time.ConclusionsAAD onset followed a chronobiological pattern in patients from northwest China, with winter and 19:00–24:00 being the peak season and time period of AAD occurrence, respectively.

Incorporating incubation period distributions to precisely estimate the association between rainfall and Legionella infection.

Multiple studies have shown a positive relationship between weather events and, 1 to 2 weeks later, Legionnaires' disease (LD) cases. Narrowing this time window of association can help determine whether the mechanism linking rainfall and relative humidity to sporadic LD is direct or indirect. Due to the large number of daily water interactions and low incidence of LD, we propose a new Bayesian modeling approach to disentangle the potential for a direct vs. indirect exposure to precipitation. Incubation period distributions were used to redistribute LD cases to their estimated day of exposure. Then Bayesian distributed lag models were fit to estimate cases per day of exposure with predictor variables for rainfall and absolute humidity. Sensitivity analyses explored the impact of relatively humidity, rainfall post-estimated date of exposure and randomized rainfall to validate our results. One standard deviation increase in rainfall 2 and 3 days prior to the date of estimated exposure was associated with an approximately 15% increase in LD risk (per day). When heavy rainfall occurred 0 to 3 days prior to estimated exposure, risk increased by more than 40%, peaking at a 51% increased risk of LD 2 days after heavy rainfall. Our findings of a 2- and 3-day lag between rainfall and the date of estimated exposure is consistent with an indirect link with rainfall, rather than a same-day exposure. Potential pathways that can indirectly link rainfall to LD cases include rainfall-mediated declines in public water supplies but greater environmental sampling research is needed.

Numerical Homogenization of Orthotropic Functionally Graded Periodic Cellular Materials: Method Development and Implementation.

This study advances the state of the art by computing the macroscopic elastic properties of 2D periodic functionally graded microcellular materials, incorporating both isotropic and orthotropic solid phases, as seen in additively manufactured components. This is achieved through numerical homogenization and several novel MATLAB implementations (known in this study as Cellular_Solid, Homogenize_test, homogenize_ortho, and Homogenize_test_ortho_principal). The developed codes in the current work treat each cell as a material point, compute the corresponding cell elasticity tensor using numerical homogenization, and assign it to that specific point. This is conducted based on the principle of scale separation, which is a fundamental concept in homogenization theory. Then, by deriving a fit function that maps the entire material domain, the homogenized material properties are predicted at any desired point. It is shown that this method is very capable of capturing the effects of orthotropy during the solid phase of the material and that it effectively accounts for the influence of void geometry on the macroscopic anisotropies, since the obtained elasticity tensor has different E1 and E2 values. Also, it is revealed that the complexity of the void patterns and the intensity of the void size changes from one cell to another can significantly affect the overall error in terms of the predicted material properties. As the stochasticity in the void sizes increases, the error also tends to increase, since it becomes more challenging to interpolate the data accurately. Therefore, utilizing advanced computational techniques, such as more sophisticated fitting methods like the Fourier series, and implementing machine learning algorithms can significantly improve the overall accuracy of the results. Furthermore, the developed codes can easily be extended to accommodate the homogenization of composite materials incorporating multiple orthotropic phases. This implementation is limited to periodic void distributions and currently supports circular, rectangular, square, and hexagonal void shapes.

Modeling the generation and control of Bessel-like beams generated by annular patterns on a digital micromirror device

Bessel beams have been generated using different methods, such as Axicon lens, digital micromirror device (DMD), etc. Due to the infinite energy requirement of ideal Bessel beams in all space, the generated Bessel beams are more appropriately called Bessel-like beams in practice, which are approximations of the ideal Bessel beams. In this work, we theoretically investigated the generation of Bessel-like beams using annular patterns loaded on a DMD based on the scalar diffraction theory. The model predictions were compared and verified with our previous experimental results. For the first time, the theoretical study shows that the DMD-generated Bessel-like beams have an additional amplitude term depending on the annular radius, ring thickness, and incident angle compared with ideal Bessel beams. Furthermore, we modeled the superposition of two Generated Bessel-like beams using two coaxial annular patterns on a DMD, which revealed the periodic intensity distribution along the z axis as predicted previously based on the superposition of two ideal coaxial Bessel beams. Both the simulations and experiments give a similar periodic length that is close to the theoretical values. The modeling results show that the DMD-based method could not only generate a reasonable approximation of the ideal Bessel beams with good controllability and engineering applications but more importantly, provide explicit formulas to guide the design of the annular patterns on the DMD in order to generate and control Bessel-like beams for practical applications.

Asymptotic homogenization, domain decomposition and finite elements combined for calculating effective elastic properties of periodic fiber-reinforced composites with imperfect interfaces

A methodology is presented for calculating the effective elastic properties of periodic multi-phase composites made of an anisotropic linear elastic matrix reinforced with a periodical distribution of unidirectional fibers and exhibiting spring-type imperfect contacts at the interfaces. The periodicity cell contains any finite number of parallel fibers and exhibits arbitrary cross-section. Fibers also exhibit arbitrary cross-sections and are made of a different anisotropic linear elastic material each. The methodology uses asymptotic homogenization (AH) to obtain the mathematical expressions of the effective properties and to formulate the so-called local problems on the periodicity cell on whose solutions the effective properties depend on. In order to deal with the discontinuities arising from the spring-type interfaces, the local problems are then restated via domain decomposition (DD) in a way allowing for an iterative resolution scheme in which the solution of the problem to be solve in each iteration is obtained via finite elements (FE). Results in the examples are obtained via a computational implementation of the methodology based on the FreeFEM open-source software, which allows for the variational formulation of the iteration problem to be dealt with directly.

Investigating 39 Galactic Wolf-Rayet stars with VLTI/GRAVITY

Context. Wolf-Rayet stars (WRs) represent one of the final evolutionary stages of massive stars and are thought to be the immediate progenitors of stellar-mass black holes. Their multiplicity characteristics form an important anchor point in single and binary population models for predicting gravitational-wave progenitors. Recent spectroscopic campaigns have suggested incompatible multiplicity fractions and period distributions for N- and C-rich Galactic WRs (WNs and WCs) at both short and long orbital periods, in contradiction with evolutionary model predictions. Aims. In this work, we employed long-baseline infrared interferometry to investigate the multiplicity of WRs at long periods and explored the nature of their companions. We present a magnitude-limited (K &lt; 9; V &lt; 14) survey of 39 Galactic WRs, including 11 WN, 15 WC, and 13 H-rich WN (WNh) stars. Methods. We used the K-band instrument GRAVITY at the Very Large Telescope Interferometer (VLTI) in Chile. The sensitivity of GRAVITY at spatial scales of ∼1 to 200 milliarcseconds and flux contrast of 1% allowed an exploration of periods in the range 102 − 105 d and companions down to ∼5 M⊙. We carried out a companion search for all our targets, with the aim of either finding wide companions or calculating detection limits. We also explored the rich GRAVITY dataset beyond a multiplicity search to look for other interesting properties of the WR sample. Results. We detected wide companions with VLTI/GRAVITY for only four stars in our sample: WR 48, WR 89, WR 93, and WR 115. Combining our results with spectroscopic studies, we arrived at observed multiplicity fractions of fobsWN = 0.55 ± 0.15, fobsWC = 0.40 ± 0.13, and fobsWNh = 0.23 ± 0.12. The multiplicity fractions and period distributions of WNs and WCs are consistent in our sample. For single WRs, we placed upper limits on the mass of potential companions down to ∼5 M⊙ for WNs and WCs, and ∼7 M⊙ for WNh stars. In addition, we also found other features in the GRAVITY dataset, such as (i) a diffuse extended component contributing significantly to the K-band flux in over half the WR sample; (ii) five known spectroscopic binaries resolved in differential phase data, which constitutes an alternative detection method for close binaries; and (iii) spatially resolved winds in four stars: WR 16, WR 31a, WR 78, and WR 110. Conclusions. Our survey reveals a lack of intermediate- (a few hundred days) and long- (a few years to decades) period WR systems. The 200d peak in the period distributions of WR+OB and BH+OB binaries predicted by Case B mass-transfer binary evolution models is not seen in our data. The rich companionship of their O-type progenitors in this separation range suggests that the WR progenitor stars expand and interact with their companions, most likely through unstable mass transfer, resulting in either a short-period system or a merger.

Novel chirped nonautonomous periodic waves in inhomogeneous spin-1/2 Bose-Einstein condensates with pair-transition effects

We present the first analytical demonstration of the existence and propagating characteristics of chirped nonautonomous periodic waves with constant background in an inhomogeneous spin-1/2 Bose-Einstein condensate system with temporally varying pair-transition effects and gain or loss. We find that such periodic waveforms can exist in cn-cn, sn-sn as well as in dn-dn configurations with background, which can transform into new kinds of nonautonomous solitons on a continuous-wave background in the long-wave limit. A key characteristic is that the amplitude, phase and width of obtained periodic waves change significantly with changes in the chirping and system parameters. As a very physically interesting application, we study the propagation dynamics of the newly found nonautonomous waves in the diffraction periodic distribution and decreasing systems.

Constructing the Joint Probability Spatial Distribution of Different Levels of Drought Risk Based on Copula Functions: A Case Study in the Yellow River Basin

Joint multivariate distribution and calculation of return period are essential in enhancing drought risk assessment and promoting the sustainable development of water resources. Aiming to address the increasingly serious drought situation in the Yellow River Basin, this study first utilized the Soil and Water Assessment Tool (SWAT) distributed hydrological model combined with the Standardized Precipitation Evapotranspiration Index (SPEI), the Standardized Soil Moisture Index (SSMI), and the Standard Water Yield Index (SWYI); the duration, peak, and severity of meteorological, agricultural, and hydrological droughts were analyzed. Based on the selected copula function, a three-dimensional joint distribution of drought duration (D), drought severity (S), and maximum severity (M) was constructed. The corresponding copula joint probability was calculated, leading to the three-dimensional joint return period and concurrent return period of meteorological drought, agricultural drought, and hydrological drought. The findings reveal several key trends: (1) Meteorological drought intensifies over time. Although drought areas eased after the 1990s, the overall drought trend continues to rise. Agricultural drought has intensified in arid regions but eased in semi-humid areas after the 2000s. Hydrological drought was severe in the upstream regions during the 1990s but eased in the 2000s, while it was particularly severe in the midstream and downstream regions during the 2000s. (2) Meteorological droughts are more severe in arid and semi-arid temperate regions and milder in semi-humid cold temperate regions. Agricultural droughts are extreme in arid and semi-arid cold temperate regions. Hydrological drought events are fewer but more severe in semi-arid temperate regions and have the lowest probability of occurrence in semi-humid cold temperate regions. (3) The overall probability of the occurrence of meteorological drought is between 55.7% and 69%; that of agricultural drought is between 73.1% and 91.7%, and that of hydrological drought is between 66.9% and 84%. Drought risk assessment provides scientific references for the analysis of the uncertainty of water supply in the basin and the formulation of effective risk management strategies.

High-temperature stability and decoding of large field-of-view observable color codes prepared by femtosecond laser on titanium alloy

This study reported on the large field-of-view observable color code obtained by femtosecond laser-induced oxidation on titanium alloy. The simulation results showed that simultaneous roughening of the oxide layer and metal layer could effectively increase the color rendering range of the structural colors. Based on the diffraction effect of the diaphragm, the laser energy was periodically distributed. In addition, the simultaneous formation of the oxide layer and the micro/nano structures was attributed to the periodic distribution of laser energy. Compared to the substrate, the increase in oxygen content of the colored area ranged from 5 % to 11 %, indicating that the infiltration of oxygen inside the material was increased. Additionally, the surface chemical composition of the upper oxide layer of the colored areas was TiO2. XRD analysis showed that laser-induced surface coloring did not affect the phase composition of the alloy except for the generation of a small amount of carbon. Moreover, different scanning numbers affected the color difference ΔE∗ ab of adjacent scanning speeds. High-temperature experiments showed that the color code prepared by femtosecond laser-induced oxidization of titanium alloy was reliable in use at less than 100 °C. Since the color code could still be clearly obtained at a field angle of 77.3°, the angle insensitivity of the color code could be effectively improved by selective roughening of the oxide layer prepared by femtosecond laser. Furthermore, the decoding of color code was the inverse encoding process. Therefore, the angle insensitivity of the color code was improved and the temperature range of the structural color was clarified.

Exploring the extensive movements and home range of one of North America’s most mobile fish: the freshwater drum (Aplodinotus grunniens)

Freshwater drum Aplodinotus grunniens are a unique and ubiquitous freshwater species of the family Sciaenidae. Despite the species’ wide distribution and unique biogeography, life history, and behavior, surprisingly little is known about freshwater drum movement ecology. In this study, we use passive acoustic telemetry tags and a broad-scale gridded receiver array to track the interannual and seasonal movement of freshwater drum tagged in tributaries of the North and South Basins of Lake Winnipeg (Manitoba, Canada). First, tagged freshwater drum had lower survival in the south basin where higher fishing pressure is thought to be a cause of mortality. We found that freshwater drum in Lake Winnipeg are remarkably mobile, with mean monthly movement rates among the highest on record for any freshwater fish. In the spring, fish entered rivers prior to spawning. A few weeks later, most individuals moved into lake habitat where they made extensive lateral movements. Home range and hotspot analysis revealed seasonal and population-specific patterns of occupancy, with elevated densities in lake habitat during the ice-on period and dispersed distributions during open water. Both populations remained almost exclusively in their respective rivers and basins. Homing and site fidelity were apparent, with nearly all fish returning to their original tagging river during each successive spawning season. The results bolster the existing information on freshwater drum movement ecology and may help enhance conservation and management strategies, particularly toward addressing commercial bycatch.

Compact object populations over cosmic time II. Compact object merger rates and masses over redshift from varying initial conditions

ABSTRACT We perform a first study of the impact of varying two components of the initial conditions in binary population synthesis of compact binary mergers – the initial mass function, which is made metallicity- and star formation rate-dependent, and the orbital parameter (orbital period, mass ratio, and eccentricity) distributions, which are assumed to be correlated – within a larger grid of initial condition models also including alternatives for the primary mass-dependent binary fraction and the metallicity-specific cosmic star formation history. We generate the initial populations with the sampling code bossa and evolve them with the rapid population synthesis code compas. We find strong suggestions that the main role of initial conditions models is to set the relative weights of key features defined by the evolution models. In the two models we compare, black hole–black hole (BHBH) mergers are the most strongly affected, which we connect to a shift from the common envelope to the stable Roche lobe overflow formation channels with decreasing redshift. We also characterize variations in the black hole–neutron star (BHNS) and neutron star–neutron star (NSNS) final parameter distributions. We obtain the merger rate evolution for BHBH, BHNS, and NSNS mergers up to $z=10$, and find a variation by a factor of $\sim 50\textnormal {--}60$ in the local BHBH and BHNS merger rates, suggesting a more important contribution from initial conditions than previously thought, and calling for a complete exploration of the initial conditions model permutations.

Analyzing AIS and wave hindcast data for global wave scatter diagrams with seasonality

Global scatter diagrams are used to estimate possible ship motions in a specified route and are required for comprehensive cargo-loading considerations of merchant ships. This study aims to update global wave scatter diagrams using the latest wave hindcast and Automatic Identification System (AIS) data. The AIS data for over 7500 merchant ships were collected between 2015 and 2022. The wave hindcast data ECMWF Reanalysis v.5 (ERA5), preferred for its recent coverage, were adjusted based on CCI satellite data. The duration of the AIS data is much shorter than the design lifetime of merchant ships, which is generally 25 years. This study found almost linear relationships between the maximum significant wave heights in storms and the generalized extreme value (GEV) parameters representing the distribution of encountered significant wave heights, with adjustments made for seasonality and tropical cyclones. By simulating the parameters based on these relationships and the wave hindcast data over 25 years, the encountered significant wave height distributions over 25 years were obtained. The results indicated a reduction in extremely significant wave heights compared with the BMT-GWS, in agreement with previous studies. This study also found that the difference in the wave period distribution between natural and encountered sea states was small in most sea areas for all significant wave height levels. Taking advantage of the abundant data volume of ERA5, this study adopted an empirical distribution of the wave period conditioned by the significant wave height. The novelty of this study is that we obtained wave scatter diagrams globally by month to consider the seasonal effect in detail and evaluated the confidence interval of the encountered wave height in its probability tail. In addition, this study quantifies the uncertainty of the wave height distribution by Monte Carlo simulation, which is not within the scope of previous studies on wave scatter diagrams based on the significant wave heights encountered by merchant ships around the world.

Analysis of the air gap magnetic field in cylindrical magnetic couplings based on mathematical and finite element approach

The air gap magnetic field of a magnetic coupling plays a crucial role in the examination of its static torque and eddy current losses. Precise characterization of the air gap magnetic field is essential for ensuring the accuracy of performance assessments of the magnetic coupling. This study focuses on the cylindrical magnetic coupling as the subject of investigation, employing mathematical analysis and finite element methods to evaluate and quantify the magnetic field properties. The study establishes a mathematical model of the magnetic field of a magnetic coupling based on electromagnetic field principles and the superposition theorem. An analytical formula for the magnetic flux density distribution of the air-gap magnetic field is derived. Subsequently, a three-dimensional magnetic field finite element model is created using the finite element method to numerically calculate the air gap magnetic field and validate the analytical formula. The research also explores the periodic distribution characteristics of the magnetic field in the air gap, analyzing axial differences in magnetic flux density value and direction distribution influenced by end effects.

Unsteady slip pulses under spatially-varying prestress

It has been recently established that self-healing slip pulses under uniform background/ambient stress (prestress) τb are intrinsically unstable frictional rupture modes, i.e., they either slowly expand or decay with time t. Furthermore, their spatiotemporal dynamics have been shown to follow a reduced-dimensionality description corresponding to a special one-dimensional curve L(c), parameterized by τb, in a plane defined by the pulse propagation velocity c(t) and size L(t). Yet, uniform prestress is rather the exception than the rule in natural faults. Here, we study the effects of a spatially-varying prestress τb(x) (in the fault direction x) on 2D slip pulses, initially generated under a uniform τb along a rate-and-state friction fault. We consider both periodic and constant-gradient prestress distributions τb(x) around the reference uniform τb. For a periodic τb(x), pulses either sustain and form quasi-limit cycles in the L−c plane or decay predominantly monotonically along the L(c) curve depending on the instability index of the initial pulse and the properties of the periodic τb(x). For a constant-gradient τb(x), expanding and decaying pulses closely follow the L(c) curve, with small systematic shifts determined by the sign and magnitude of the gradient. We also find that a spatially-varying τb(x) can revert the expanding/decaying nature of the initial reference pulse. Finally, we show that a constant-gradient τb(x), of sufficient magnitude and specific sign, can lead to the nucleation of a back-propagating rupture at the healing tail of the initial pulse, generating a bilateral crack-like rupture. This pulse-to-crack transition, along with the above-described effects, demonstrates that rather rich rupture dynamics can emerge from a simple, spatially-varying prestress. Furthermore, our results show that as long as pulses exist, their spatiotemporal dynamics are related to the special L(c) curve, providing an effective, reduced-dimensionality description of unsteady slip pulses under spatially-varying prestress.

Implementation of Human Resource Management at SMAIT Al-Fityan School Gowa, Gowa Regency

This study aims to analyze the planning, implementation, and supervision of Human Resource Management (HRM) at SMAIT Al-Fityan School Gowa, Gowa Regency. A qualitative approach with phenomenological methods is used to collect data through interviews, observations, and documentation from related parties. The results of the study show that MSDM planning involves several stages, such as recruitment through meetings, distribution of pamphlets, file collection, interviews, probationary periods, and announcements. The selection is carried out in two stages: administration and interview. Orientation lasts from a probationary period to basic and advanced training for six months. The placement of educators is adjusted to their expertise in teaching, communicating, mastering technology, and management. Training and development are divided into general and religious training. The implementation of MSDM in this school runs systematically and structured, especially in recruitment, selection, orientation, placement, as well as training and development of educators. Supervision is carried out by school principals, directors, education offices, and international supervisors (intertek). The implication of this study is the importance of more attention from the foundation, especially on continuous professional training and development, to improve competence and innovation in teaching methods. Thus, educators can increase competence, job satisfaction, and better career development opportunities

The Galactic population of canonical pulsar. II. Taking into account several evolutionary paths: Interstellar medium interaction, Galactic potential, and a death valley

Pulsars are highly magnetised rotating neutron stars, emitting in a broad electromagnetic energy range. These objects were discovered more than 55 years ago and are astrophysical laboratories for studying physics at extreme conditions. Reproducing the observed pulsar population helps refine our understanding of their formation and evolution scenarios, as well as their radiation processes and geometry. In this paper, we improve our previous population synthesis by focusing on both the radio and gamma -ray pulsar populations, investigating the impact of the Galactic gravitational potential and of the radio emission death line. To elucidate the necessity of a death line, we implemented our refined initial distributions of the spin period and spacial position at birth. This approach allowed us to elevate the sophistication of our simulations to the most recent state-of-the-art approaches. The motion of each individual pulsar was tracked in the Galactic potential by a fourth-order symplectic integration scheme. Our pulsar population synthesis took into account the secular evolution of the force-free magnetosphere and magnetic field decay simultaneously and self-consistently. Each pulsar was evolved from birth to the present time. The radio and gamma -ray emission locations were modelled by the polar cap geometry and striped wind model, respectively. By simulating ten million pulsars, we found that including a death line allows us to better reproduce the observational trend. However, when simulating one million pulsars, we obtained an even more realistic $P- P $ diagram, whether or not a death line was included. This suggests that the ages of the detected pulsars might be overestimated and so, it sets the need for a death line in pulsar population studies into question. Kolmogorov-Smirnov tests confirm the statistical similarity between the observed and simulated $P- P $ diagram. Additionally, simulations with increased gamma -ray telescope sensitivities hint at a significant contribution coming from the gamma -ray pulsars to the GeV excess in the Galactic centre.