Evolutionary Models Research Articles

The ground beneath our feet: A critical reflection on 135 years of landscape evolution models for southern Africa

In his 1925 paper describing the Taung Child fossil, Dart makes various assertions about the landscape around Taung, inferring past climate dynamics, and the role these factors play in the evolution of our early prehuman relatives. He argues that this region of southern Africa is dry today and has been for much of the Cenozoic. This notion of long-term aridity and stability has dominated perspectives on southern African landscape evolution. Here, we present a review of this field, starting with the foundational studies from the late 1890s, which underpin Dart’s hypothesis. We examine the work of 20th-century researchers who developed models of landscape evolution; however, almost all of these models have been qualitative. With technological advancements, new quantitative techniques have emerged to provide evidence of landscape evolution events and to test previous models, and we present a brief overview of these methods. We call for reflection on the framing and languaging of many of these landscape models, specifically the ‘African land surface’ model. While the evidence of a homogeneous and stable landscape is continually being challenged through scientific advancement, this terminology is rooted in outdated colonial thinking. We also note that the key narratives that have driven research on landscape evolution have been largely shaped by selected prominent Western-based scientists. As we mark the centenary of the Taung discovery, we look toward a new era of landscape evolution research: one characterised by technological advancements and more diverse, local teams that will produce more quantitative, nuanced models for southern Africa and create richer, more dynamic backdrops for our own human evolution.

MINCE III. Detailed chemical analysis of the UVES sample

The Measuring at Intermediate Metallicity Neutron-Capture Elements (MINCE) project aims to provide high-quality neutron-capture abundances measurements for several hundred stars at an intermediate metallicity of -2.5 < Fe/H $<-1.5$. This project will shed light on the origin of the neutron-capture elements and the chemical enrichment of the Milky Way. The goal of this work is to chemically characterize the second sample of the MINCE project and compare the abundances with the galactic chemical evolution model at our disposal. We performed a standard abundance analysis based on one-dimensional (1D) local thermodynamic equilibrium (LTE) model atmospheres based on high-resolution and high-signal-to-noise-ratio (S/N) spectra from Ultraviolet and Visual Echelle Spectrograph (UVES) . We provide the kinematic classification (i.e., thin disk, thick disk, thin-to-thick disk, halo, Gaia Sausage Enceladus, Sequoia) of 99 stars and the atmospheric parameters for almost all stars. We derived the abundances for light elements (from Na to Zn) and neutron-capture elements (Rb, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, and Eu) for a subsample of 32 stars in the metallicity range of -2.5 < Fe/H $< -1.00$. In the subsample of 32 stars, we identified eight active stars exhibiting (inverse) P-Cygni profile and one Li-rich star, CD,28-11039. We find a general agreement between the chemical abundances and the stochastic model computed for the chemical evolution of the Milky Way halo for elements Mg, Ca, Si, Ti, Sc, Mn, Co, Ni, Zn, Rb, Sr, Y, Zr, Ba, La, and Eu . The MINCE project has already significantly increased the number of neutron-capture elements measurements in the intermediate metallicity range. The results from this sample are in perfect agreement with the previous MINCE sample. The good agreement between the chemical abundances and the chemical evolution model of the Galaxy supports the nucleosynthetic processes adopted to describe the origin of the n-capture elements.

Advancing the Construct of Self-Leadership: A Bibliometric Review

Self-leadership, or an individual's efforts to influence oneself to perform, ­is considered a prerequisite for leading others. Informed by Reichers and Schneider's (1990) 3-stage model of construct evolution, we leverage multiple bibliometric methods to map self-leadership's introduction, evaluation, and consolidation. This paper is guided by four research questions: RQA) What theories underlie self-leadership, and how is the construct elaborated over time? RQB) What is the nature of the current intellectual network, and who are the key conversants of self-leadership research? RQC) What are the past, present, and emerging trends in self-leadership research? RQD) What directions can researchers pursue to advance self-leadership firmly into the third stage of construct evolution based on Reichers and Schneiders’ model? To answer these questions, we critically examine the core theories underlying self-leadership and their elaboration through time (Stage 1; historiography) to uncover the strengths and gaps in the origination of the construct (RQA). We also reveal the dominating (and missing) perspectives of key conversants (e.g., co-authorship analysis; RQB). Moving through Stage 2 of construct evaluation and augmentation, we leverage a bibliographic coupling of 539 documents to identify and describe emergent research themes and a co-word analysis to contrast traditional and trending topics (RQC). We argue that the self-leadership construct has just progressed into Stage 3 (i.e., consolidation and accommodation) as self-leadership research remains somewhat isolated from the broader leadership and organizational studies literature. Finally, we detail future research strategies to integrate relevant theories, identify boundary conditions, and generalize self-leadership across contexts, demographics, and authors (RQD).

Responsive Magnetic Polymer Nanocomposites through Thermal-Induced Structural Reorganization.

Polymer nanocomposites (PNCs), which feature a hybrid network of soft polymers filled with nanoparticles, hold promise for application in soft robots due to their tunable physiochemical properties. Under certain environmental conditions, PNCs undergo stimuli-responsive structural rearrangement and transform the energy of the ambient environment into diverse uses, for example, repairing the injuries and reconfiguring the shapes of the materials. We develop PNCs with the ability of thermal-responsive restructuring by the stepwise assembly of functional components, including magnetite nanoparticles, silylated cellulose, and polydimethylsiloxane. We investigate the dynamic changes of the nano- and submicron structure of the magnetic PNCs upon the stimulation of heating based on a combined analytical approach: using dynamic mechanical analysis to interpret the viscoelastic properties of the PNC and in situ small-angle X-ray scattering to quantify the clustering of NPs. Based on these results, we formulate a structural model for the heating-induced evolution of the nano- to submicrometer assemblies in the magnetic PNC. Moreover, thermal-induced restructuring of magnetic PNCs leads to additional favorable functions, such as the abilities of healing, welding, reprocessing, and responses to photo and magneto stimuli. Our design provides a versatile means to develop responsive PNCs for applications in soft robots, sensors, and actuators.

Tractor Power Take-Off and Drawbar Pull Performance and Efficiency Evolution Analysis Methodology and Model: A Case Study

Previous studies on tractor performance and efficiency were conducted prior to the implementation of emission reduction technologies and the increased density and complexity of tractor portfolios. This study presents a robust methodology for forecasting specific fuel consumption based on public information, which incorporates physical attribute-based cohorts and technological generation groupings, alongside variables such as wheelbase, mass, and power take-off power. The proposed model significantly improves forecasting accuracy, enhancing the current R-squared (RSq) from 0.6091 to 0.8519 and reducing the root mean square error (RMSE) from 0.0098 to 0.0065. Additionally, the model provides accurate predictions of drawbar performance and efficiency. Its simplicity results in low cognitive and computational demands, making it accessible via widely available spreadsheet software on any computer or handheld device. This accessibility supports data-driven decision-making for tractor replacement strategies, ultimately promoting sustainable profitability in agricultural business operations.

Evolution of stakeholder behavior strategies under cap-and-trade of the benchmark method

This study establishes a carbon emission reduction supply chain mechanism for government-enterprise-consumer cooperation based on the cap-and-trade benchmark method that considers consumers’ willingness to pay, government regulation, and enterprise’ profit-driven motives. Then, in this research, a tripartite evolutionary game model of carbon emissions reduction between the government, high-emission enterprises, and low-emission enterprises is developed to examine the incentives for heterogeneous enterprises to reduce emissions in response to government subsidies, emission benchmark, carbon price and consumers’ carbon preferences. The results show that an increase in the government subsidy rate will effectively incentivize heterogeneous enterprises to reduce emissions and that differential subsidy rates should be set for heterogeneous enterprises. Making only emissions benchmark changes does not change the emission reduction decisions of heterogeneous enterprises. An increase in the price of carbon trading is the only factor that can incentivize both high- and low-emission enterprises to reduce emissions and innovate, as well as incentivize strict government regulation. An increase in the degree of consumer preference can effectively incentivize heterogeneous enterprises to reduce emissions.

Simultaneous Evolutionary Fits for Jupiter and Saturn Incorporating Fuzzy Cores

Abstract With the recent realization that there likely are stably stratified regions in the interiors of both Jupiter and Saturn, we construct new nonadiabatic, inhomogeneous evolutionary models with the same microphysics for each that result at the present time in respectable fits for all major bulk observables for both planets. These include the effective temperature, radius, atmospheric heavy-element and helium abundances (including helium rain), and the lower-order gravity moments J 2 and J 4. The models preserve from birth most of an extended “fuzzy” heavy-element core. Our predicted atmospheric helium mass fraction for Saturn is ∼0.2, close to some measured estimates but in disagreement with some published predictions. To preserve a fuzzy core from birth, the interiors of both planets must start out at lower entropies than would be used for traditional “hot start” adiabatic models, though the initial exterior mantle entropies can range from hot to warm start values. We do not see a helium ocean in Saturn’s interior, and both models have inner envelopes with significant Brunt–Väisälä frequencies; this region for Saturn at the current epoch is more extended, and in it, the Brunt is larger. The total heavy-element mass fraction in Jupiter and in Saturn is determined to be ∼14% and ∼26%, respectively, though there is some play in these determinations.

Carbon emissions reduction in shipping based on four-party evolutionary game

In order to realize a win-win situation between economic development and environmental benefits, this paper constructs a four-party evolutionary game model including the government, two homogeneous ports and shipping companies based on evolutionary game theory. By calculating the payoff matrices of the four parties and replicating the dynamic equations, according to the Jacobi matrix, we study and discuss the possible stabilization points of the model under five different scenarios. The game is simulated using MATLAB and the relevant parameters are selected for sensitivity analysis. The results show that the environmental benefits are maximized when the government does not implement the policy and the port and shipping companies use the shore electricty system (i.e., the stability point E12 (0,1,1,1)). Meanwhile, by analyzing the port size sensitivity, when t=1.116, the large-scale port evolution tends to 0, while the small-scale port fluctuates up and down, which leads to the conclusion that the small-scale ports have more potential to implement shore electricty and are able to gain benefits faster. This study provides theoretical support for the implementation of shore electricty systems, while pointing out the key role of the government in promoting the development of shore electricty. It provides a reference for effectively promoting the use of shore electricty in the context of carbon emission reduction, which is especially important for the implementation of shore electricty in small-scale ports and helps to maximize the environmental benefits of port operations.

Research on evolution of intellectual property collaborative governance strategies of multi-entities in open source community

ABSTRACT Open source community intellectual property governance is a collaborative activity among multiple entities. This paper starts from the perspective of multi-party collaborative governance, based on evolutionary game theory, using open source community foundations, community operators, and contributors as the game subjects, to construct an evolutionary game model for collaborative intellectual property governance strategy of open source community, digital technology innovation strategies as the core. The correctness of the theoretical analysis was verified through model derivation, calculation, and simulation. The simulation results indicate that digital technology innovation plays an important role in intellectual property governance, and factors such as initial willingness, reward and punishment mechanisms, contribution costs, and infringement risks have a significant impact on the evolution of strategies. Based on this, we propose specific implementation paths to improve the intellectual property governance capacity of open source communities and promote innovative development in open source communities. The research contribution of this paper lies in exploring the process of rule compliance and strategy evolution of multiple subjects in open source communities under the policies guidance and use of digital technology from the use of digital technology innovation, providing new governance tools and governance basis for intellectual property governance in open source communities.

A Gradient-Enhanced Thermo-Poro-Elastoplastic Finite-Element Model for Stimulated Volume Evolution in Porous Media

A Gradient-Enhanced Thermo-Poro-Elastoplastic Finite-Element Model for Stimulated Volume Evolution in Porous Media

Global sensitivity analysis of reactive transport modelling for the geochemical evolution of a high-level radioactive waste repository

Global sensitivity analysis of reactive transport modelling for the geochemical evolution of a high-level radioactive waste repository

Improved Reservoir Porosity Estimation Using an Enhanced Group Method of Data Handling with Differential Evolution Model and Explainable Artificial Intelligence

Summary Reservoir characterization is critical to the oil and gas industry, influencing field development, production optimization, hydraulic fracturing, and reserves estimation decisions. Accurately estimating porosity is crucial for reservoir characterization, well planning, and production optimization in the oil and gas industry. Traditional porosity determination methods, such as porosimetry, geostatistical, and core analysis, often involve complex geological and geophysical models, which are expensive and time-consuming. This study used the integrated machine learning and optimization model of differential evolution (DE) with group method of data handling (GMDH-DE) to estimate the porosity using integrated well log and core data from the Mpyo oil field, Uganda. The GMDH-DE demonstrates superior performance compared with conventional GMDH, support vector regression (SVR), and random forest (RF), achieving a coefficient of determination (R2) of 0.9925 and a root mean square error (RMSE) of 0.0017 during training, an R² of 0.9845 with an RMSE of 0.0121 during testing, and when validated the R2 was 0.9825 with RMSE of 0.00018. A key novelty of this work is the integration of Shapley additive explanations (SHAP), which provides an interpretable analysis of the model’s input features. SHAP reveals that bulk density (RHOB) and neutron porosity (NPHI) are the most critical parameters for porosity estimation, offering valuable insight into features importance. The proposed GMDH-DE model and SHAP analysis represent a novel and independent approach for accurate porosity estimation and interpretability, significantly enhancing the efficiency and reliability of hydrocarbon exploration and development.

Spatial temporal modelling of air traffic network evolution and resilience enhancement in response to the dynamic coupling of propagation outbreaks

Spatial temporal modelling of air traffic network evolution and resilience enhancement in response to the dynamic coupling of propagation outbreaks

Examining the value realization of ecological agricultural products in China: A tripartite evolutionary game analysis.

Agricultural products are essential for nutrition and food security, particularly in China where agricultural production capacity is growing steadily. Despite the benefits of Ecological Agricultural (EA) products, including environmental protection and enhanced consumer utility, their widespread adoption and maximization of value are impeded by various factors. This study explores the intricate tripartite relationship - government, agribusiness, and consumer, in the value realization of EA products in China by establishing an evolutionary game model. The purpose is to illuminate the evolution of system equilibrium strategies across various scenarios and examine how significant external factors influence these strategies, thereby summarizing the evolutionary process of EA products' value realization and providing guidance for stakeholders' decision-making processes. The results indicate that with increased government regulatory efforts, technological advancements, and scale expansion in agribusiness, as well as the refinement of market mechanisms, the production cost of EA products decreases, leading to a steady rise in EA product prices and economic benefits for consumers purchasing them. Ultimately, the value of EA products was primarily realized through market forces. Simulation analysis using Matlab further validated the model's effectiveness and precision, highlighting the influence of government regulatory measures, consumer green sensitivity and preferences, and product base value on system equilibrium strategies. These conclusions provide insights for policymakers to facilitate the realization of EA product value and promote green and low-carbon agricultural development.

Did Along-Strike Changes in Continental Subduction Styles Occur in the Dabie-Sulu Orogenic Belt?

The Triassic collision between the North China Block (NCB) and the South China Block (SCB) formed the Dabie-Sulu orogenic belt, renowned for its extensive ultra-high-pressure metamorphic rocks and the prominent Tan-Lu Fault. Geological and geophysical data reveal significant along-strike differences in both shallow and deep structures within the belt, raising a critical question: What tectonic processes drive these structural variations? Considering that the Triassic collision involved pre-collisional accreted microcontinents and along-strike variations in convergence velocities, this study investigates the influence of microcontinental width, convergence rate, and initial Moho temperature on continental subduction styles using numerical modeling. The models incorporate pre-collisional accreted microcontinent(s) and reveal a two-stage subduction evolution: an initial transition from one-sided to two-sided continental subduction, followed by subduction polarity reversal. High initial Moho temperatures, rapid convergence rates, and wide accreted microcontinents promote the development of two-sided subduction, characterized by an initially vertical interface that gradually inclines towards the pro-plate as convergence progresses. These subduction styles significantly influence crustal suture migration. One-sided subduction results in minimal horizontal displacement, whereas two-sided subduction and polarity reversal lead to substantial horizontal shifts. Based on the modeling results, this study proposes a new evolutionary model for the Dabie-Sulu orogenic belt during the NCB-SCB collision. The model effectively explains along-strike structural differences, such as the inconsistent tectonic trends on either side of the Tan-Lu Fault and the opposite dipping directions of high-velocity mantle anomalies observed in geophysical profiles. Furthermore, the proposed model sheds light on the formation and evolution of the Tan-Lu Fault.

Premises for digital twins reporting on Atlantic salmon wellbeing.

Many species of fish, birds and mammals commonly live in human captivity; Atlantic salmon Salmo salar is one of them. The international legal status of the welfare of captive animals is slowly developing and still requires rigorous specification. For example, even though fish have complex cognition and elements of sentience, The United Nations' animal welfare principles still take a functional health-centred perspective overlooking the cognitive-affective component. Wellbeing problems remain a major source of slow growth and high mortality in intensive aquaculture of Atlantic salmon. The value system for decision making in vertebrates is based on expectations of emotional wellbeing for the options available and is linked with the individual's assessment of its future. We propose a new approach for monitoring and improving the welfare of salmon (or any other captive or wild vertebrate) based on modelling the salmon's wellbeing system by digital twins, which are simulation models that implement major bodily mechanisms of the organism. Indeed, predictions on boredom, stress and wellbeing can all be captured by a computational evolutionary model of the factors underlying behaviour. We explain how such an agent-based model of salmon digital twins can be constructed by modelling a salmon's subjective wellbeing experience along with prediction of its near future and allostasis (the bodily preparation for the expected near future). We attempt to identify the building blocks required in digital twin models to deliver early warnings about escalating issues that could eventually lead to negative effects on salmon health in aquaculture. These models would provide critical insights for optimizing production processes and could significantly reduce the reliance on animal experiments. Overall, reports of a population of digital twins could support the implementation of 3Rs - replacement, reduction, refinement - by offering actionable information to fish farmers as well as consumers, voters, politicians and regulators on relevant issues as well as guide experimental work on animal wellbeing across species.

High-Precision computational solutions for nonlinear evolution models in graphene sheets

This study investigates the analytical solutions of a nonlinear evolution model governing the dynamics of graphene sheets, a material renowned for its exceptional electronic properties and versatile applications in nanotechnology. Three advanced analytical approaches-the Khater II (Khat II) method, the Khater III (Khat III) method, and the Generalized Rational (GRat) approach-are employed to derive exact solutions for this model with high precision. The accuracy and reliability of these solutions are validated by comparing them to numerical results obtained via He’s Variational Iteration (HVI) method, which serves as a benchmark for numerical verification. The analysis reveals a remarkable agreement between the analytical and numerical solutions, highlighting the robustness and effectiveness of the proposed methodologies. Furthermore, this study provides new insights into the nonlinear dynamics and physical properties of graphene sheets, while also identifying connections to other prominent nonlinear evolution equations. The innovative use of these analytical techniques offers practical frameworks for addressing complex nonlinear models in mathematical physics, thus advancing solution methodologies for such equations. This research contributes significantly to applied mathematics, material science, and nanotechnology by delivering accurate solutions and enhancing our understanding of graphene’s nonlinear behavior. Finally, the findings have far-reaching implications, offering potential applications in designing advanced materials with tailored properties to support technological advancements, thereby pushing the boundaries of nanotechnology and materials engineering.

Anisotropic tidal dissipation in misaligned planetary systems

Context. Tides are the main driving force behind the long-term evolution of planetary systems. The associated energy dissipation and momentum exchanges are commonly described by Love numbers, which relate the exciting potential to the tidally perturbed potential. These transfer functions are generally assumed to depend solely on tidal frequency and body rheology, following the isotropic assumption, which presumes invariance of properties by rotation about the centre of mass. Aims. We examine the limitations of the isotropic assumption for fluid bodies, in which Coriolis acceleration breaks spherical symmetry, resulting in rotational scattering and complex tidal responses. Methods. Using angular momentum theory, we derived a new formalism to calculate the tidal rates of energy and momentum transfers in non-isotropic cases. We applied this formalism to the Earth-Moon system to assess the effects of anisotropy in planet-satellite systems with misaligned spin and orbital angular momenta. Results. Our findings indicate that the isotropic assumption can introduce significant errors in planetary evolution models, particularly in the dynamical tide regime. These errors stem from forced wave resonances, with inaccuracies in energy dissipation scaling in proportion to resonance amplification factors.

The ALPINE-ALMA [CII] Survey: Unveiling the baryon evolution in the interstellar medium of z ∼ 5 star-forming galaxies

Context. Recent observations suggest a significant and rapid buildup of dust in galaxies at high redshift (z > 4); this presents new challenges to our understanding of galaxy formation in the early Universe. Although our understanding of the physics of dust production and destruction in a galaxy’s interstellar medium (ISM) is improving, investigating the baryonic processes in the early universe remains a complex task owing to the inherent degeneracies in cosmological simulations and chemical evolution models. Aims. In this work we characterized the evolution of 98 z ∼ 5 star-forming galaxies observed as part of the ALMA Large Program ALPINE by constraining the physical processes underpinning the gas and dust production, consumption, and destruction in their ISM. Methods. We made use of chemical evolution models to simultaneously reproduce the observed dust and gas content of our galaxies, obtained respectively from spectral energy distribution (SED) fitting and ionized carbon measurements. For each galaxy we constrained the initial gas mass, gas inflows and outflows, and efficiencies of dust growth and destruction. We tested these models with both the canonical Chabrier and a top-heavy initial mass function (IMF); the latter allowed rapid dust production on shorter timescales. Results. We successfully reproduced the gas and dust content in most of the older galaxies (≳600 Myr) regardless of the assumed IMF, predicting dust production primarily through Type II supernovae (SNe) and no dust growth in the ISM, as well as moderate inflow of primordial gas. In the case of intermediate-age galaxies (300−600 Myr), we reproduced the gas and dust content through Type II SNe and dust growth in ISM, though we observed an overprediction of dust mass in older galaxies, potentially indicating an unaccounted dust destruction mechanism and/or an overestimation of the observed dust masses. The number of young galaxies (≲300 Myr) reproduced, increases for models assuming top-heavy IMF but with maximal prescriptions of dust production. Galactic outflows are required (up to a mass-loading factor of 2) to reproduce the observed gas and dust mass, and to recover the decreasing trend of gas and dust over stellar mass with age. Assuming the Chabrier IMF, models are able to reproduce ∼65% of the total sample, while with top-heavy IMF the fraction increases to ∼93%, alleviating the tension between the observations and the models. Observations from the James Webb Space Telescope (JWST) will allow us to remove degeneracies in the diverse intrinsic properties of these galaxies (e.g., star formation histories and metallicity), thereby refining our models.

Establishment of strength evolution model and life prediction for diatomite-modified concrete under freeze-thaw conditions

Establishment of strength evolution model and life prediction for diatomite-modified concrete under freeze-thaw conditions