Evolutionary Patterns Research Articles

Integrating historical patterns and future trends for ecological management zone identification and validation: A case study in Beijing, China

Ecological management zones (EMZs) are pivotal in improving the management of ecosystem services (ESs) and promoting sustainable regional development. In this study, we developed a comprehensive framework aimed at identifying EMZs and substantiating their efficacy through the amalgamation of historical evolutionary patterns and future trends. We applied this framework to Beijing, China, and selected five vital ESs for the study area namely, water yield (WY), carbon sequestration (CS), habitat quality (HQ), soil conservation (SC) and water purification (WP). The framework involves two key components. Firstly, the identification of EMZs is based on the historical evolution of five types of ESs and the dynamic assessment of ES bundles. Subsequently, it enables a simulation of various scenarios to predict future alterations in land use and ESs, thereby validating the effectiveness of the identified EMZs. Our findings reveal notable spatial heterogeneity among different ESs, and that CS, HQ, SC, and WP exhibited synergies, while WY and showed trade-offs with the remaining four types of ESs. Based on an analysis of ES bundle evolution trajectories, we identified four types of EMZs: ecological conservation zone, ecological restoration zone, ecological transition zone and sustainable construction zone. Through strategic EMZ planning, it becomes possible to augment the area of forestland and grassland, alleviate the contradiction between arable land and construction land, and enhance the supply of various ESs. The proposed framework not only offers a novel perspective on the scientific management of ESs but also furnishes decision-makers and planners with an intuitive understanding of the tangible benefits associated with EMZ planning.

A state estimation method based on CNN-LSTM for ball screw

Ball screw is widely used in the engineering field, and accurate estimation of their state is crucial for the reliability of system operation. However, existing methods often overlook the time series characteristics and spatial correlation of vibration signals, unable to provide complete degradation information and divide the degradation process, resulting in limited prediction accuracy. Therefore, a state estimation method for ball screw based on Convolutional Neural Networks (CNN) and Long Short-Term Memory Neural Networks (LSTM) is proposed. An experiment of ball screw transmission equipment was conducted to collect vibration signals throughout the entire life cycle and verify the proposed method. Firstly, the frequency domain amplitude signal of the transformed ball screw is normalized to eliminate scale differences, which serves as the input for CNN feature extraction. Then, these deep features are input into the LSTM network to capture the fault evolution patterns that reveal the degradation of ball screw performance, and achieve accurate estimation of ball screw state. The final prediction accuracy was 97.87%, verifying the effectiveness of the proposed method.

Exploring evolutionary trajectories in ovarian cancer patients by longitudinal analysis of ctDNA.

We analysed whether temporal heterogeneity of ctDNA encodes evolutionary patterns in ovarian cancer. Targeted sequencing of 275 cancer-associated genes was performed in a primary tumor biopsy and in ctDNA of six longitudinal plasma samples from 15 patients, using the Illumina platform. While there was low overall concordance between the mutational spectrum of the primary tumor biopsies vs. ctDNA, TP53 variants were the most commonly shared somatic alterations. Up to three variant clusters were detected in each tumor biopsy, likely representing predominant clones of the primary tumor, most of them harbouring a TP53 variant. By tracing these clusters in ctDNA, we propose that liquid biopsy may allow to assess the contribution of ancestral clones of the tumor to relapsed abdominal masses, revealing two evolutionary patterns. In pattern#1, clusters detected in the primary tumor biopsy were likely relapse seeding clones, as they contributed a major share to ctDNA at relapse. In pattern#2, similar clusters were present in tumors and ctDNA; however, they were entirely cleared from liquid biopsy after chemotherapy and were undetectable at relapse. ctDNA private variants were present among both patterns, with some of them mirroring subclonal expansions after chemotherapy. We demonstrate that tracing the temporal heterogeneity of ctDNA, even below exome scale resolution, deciphers evolutionary trajectories in ovarian cancer. Furthermore, we describe two evolutionary patterns that may help to identify relapse seeding clones for targeted therapy.

Fast Radio Bursts in the disks of Active Galactic Nuclei

Abstract Fast radio bursts (FRBs) are luminous millisecond-duration radio pulses with extragalactic origin, which were discovered more than a decade ago. Despite the numerous samples, the physical origin of FRBs remains poorly understood. FRBs have been thought to originate from young magnetars or accreting compact objects (COs). Massive stars or COs are predicted to be embedded in the accretion disks of active galactic nuclei (AGNs). The dense disk absorbs FRBs severely, making them difficult to observe. However, progenitors’ ejecta or outflow feedback from the accreting COs interact with the disk material to form a cavity. The existence of the cavity can reduce the absorption by the dense disk materials, making FRBs escape. Here we investigate the production and propagation of FRBs in AGN disks and find that the AGN environments lead to the following unique observational properties, which can be verified in future observation. First, the dense material in the disk can cause large dispersion measure (DM) and rotation measure (RM). Second, the toroidal magnetic field in the AGN disk can cause Faraday conversion. Third, during the shock breakout, DM and RM show non-power-law evolution patterns over time. Fourth, for accreting-powered models, higher accretion rates lead to more bright bursts in AGN disks, accounting for up to 1 % of total bright repeating FRBs.

Museum skins enable identification of introgression associated with cytonuclear discordance.

Increased sampling of genomes and populations across closely related species has revealed that levels of genetic exchange during and after speciation are higher than previously thought. One obvious manifestation of such exchange is strong cytonuclear discordance, where the divergence in mitochondrial DNA (mtDNA) differs from that for nuclear genes more (or less) than expected from differences between mtDNA and nuclear DNA (nDNA) in population size and mutation rate. Given genome-scale datasets and coalescent modelling, we can now confidently identify cases of strong discordance and test specifically for historical or recent introgression as the cause. Using population sampling, combining exon capture data from historical museum specimens and recently collected tissues we showcase how genomic tools can resolve complex evolutionary histories in the brachyotis group of rock-wallabies (Petrogale). In particular, applying population and phylogenomic approaches we can assess the role of demographic processes in driving complex evolutionary patterns and assess a role of ancient introgression and hybridisation. We find that described species are well supported as monophyletic taxa for nDNA genes, but not for mtDNA, with cytonuclear discordance involving at least four operational taxonomic units (OTUs) across four species which diverged 183-278 kya. ABC modelling of nDNA gene trees supports introgression during or after speciation for some taxon pairs with cytonuclear discordance. Given substantial differences in body size between the species involved, this evidence for gene flow is surprising. Heterogenous patterns of introgression were identified but do not appear to be associated with chromosome differences between species. These and previous results suggest that dynamic past climates across the monsoonal tropics could have promoted reticulation among related species.

Study on the evolution of permeability properties of limestone under different stress paths

Abstract Stress path change has a great relationship with the effect of deformation and strength of rock. However, the underground rock body is in the engineering environment where the stress field, seepage field, and other fields are coupled to change, the law of fluid flow in the rock body is complex and variable. The change in the stress field has an important effect on the seepage characteristics of rock body; therefore, it is necessary to study the pattern of rock permeability evolution pattern by different stress paths. This study is based on the study of limestone, conducting triaxial unloading seepage mechanics experiments, the evolution of permeability properties of limestone specimens was analyzed based on the test results. The results show that in the conventional triaxial loading seepage test, the permeability of the limestone decreases before the rock stress reaches the peak intensity and increases after that. Increasing axial pressure unloading surrounding pressure compression section, permeability loss rate and effective stress are in line with the changing law of Gaussian distribution function. Under the action of constant axial pressure unloading surrounding pressure, with the increase in unloading amount, the permeability rate of change appears to increase slowly, and in the late stage of unloading section, the permeability rate of change appears to surge. Unloading section permeability change rate and cumulative unloading amount are in line with the law of change of the exponential function. Creep unloading pressure seepage test found that unloading pressure stage strain-time and permeability-time evolution characteristics are in line with the exponential rule of change. The experimental results of this study can provide an important experimental and theoretical basis for the permeability analysis of low-permeability rock body under complex stress conditions in underground engineering.

How do learners’ content network characteristics evolve in cMOOC from the perspective of clustering and comparing learners?

ABSTRACT The content network of cMOOC learners reflects the interactions between learners and valuable external information, and the learners in connectivist learning are diverse. Therefore, it's necessary to make a clear understanding of learners' participation types and content network characteristics. This study proposed a content network characteristics analysis model that included five indexes and corresponding computing methods. 251 learners were included and their interaction data were analyzed through cluster analysis, natural language processing and complex network analysis. The results demonstrated that there were four types of learners, namely “Connecters”, “Followers”, “Likers”, and “Commentators”. There were differences in the content network characteristics among the four types of learners, and the evolution patterns varied. Overall, the values of content network characteristics of Connectors were greatest, and the values of Likers were the lowest. Except for Likers, the content network characteristics of the other three types of learners all exhibited periodic evolution patterns accompanied by the key teaching events, but they varied in evolution trends, specifically manifesting as a spiral upwards trend for Connecters, a gradual trend for Followers, and a steady trend for Commentators. Finally, this study provides valuable suggestions for cMOOC designers and facilitators to support different types of cMOOC learners.

Investigation into the seamless construction for hundred-meter scale super-length raft structure based on magnesia expansive agent concrete

This research introduces an innovative construction method based on magnesia expansive agent concrete for the seamless construction of hundred-meter scale super-length raft structures, corroborated by the on-site test. The basic principle of this construction method is to use the pre compression stress generated by magnesia expansive agent to offset temperature and shrinkage stress. A temperature-strain monitoring system was employed to gather data, affirming the technique’s applicability and safety. Through the examination of temperature and strain dispersion trends in super-length raft structure, recommendations for the configuration of temperature-strain sensors have been put forth. Through the scrutiny of the temporal evolution pattern of temperature, the specific temporal and spatial coordinates that warrant particular vigilance during the surveillance of the raft’s inner-surface temperature difference were identified. Upon evaluating the correlation between strain dispersion and strain-temperature differential in the raft’s thickness dimension, a novel temperature control index (the bottom-surface temperature difference) was introduced. The threshold for this metric was established at 30°C, derived from empirical test outcomes conducted on-site. Furthermore, the critical regions for monitoring the bottom-surface temperature difference were specified.

Numerical study on the critical characteristics of internal short-circuit hot spot in lithium-ion batteries

High current density resulting from internal short circuit (ISC) in lithium-ion batteries leads to rapid local temperature rise, forming a hot spot. This study quantitatively characterized the critical properties of ISC hot spot in batteries. ISC hot spot in batteries exhibit two different evolution patterns. When the short circuit resistance approaches the internal resistance of the battery, the hot spot temperature reaches its peak at 1165 K. The thermal runaway characteristics of batteries vary depending on the short circuit resistance, with the hot spot growing and spreading rapidly when the resistance value is 30 mΩ. In addition, a modeling study was conducted to examine the critical characteristics of short circuit resistance. At a hot spot radius of 2 mm, the critical resistance was determined to be 281 mΩ, accompanied by a critical hot spot temperature of 562 K. Under subcritical conditions, the SEI film decomposes completely, while the electrolyte undergoes minimal decomposition. Interestingly, it was observed that the critical resistance and critical hot spot temperature decrease as the hot spot radius increases. Finally, the study quantified the effects of hot spot thermal conductivity, convective heat transfer coefficient, and hot spot position on the critical threshold of hot spots. These findings provide valuable references for the design of batteries with high critical thresholds.

Detecting Shoreline Changes on the Beaches of Hainan Island (China) for the Period 2013–2023 Using Multi-Source Data

This study presents an in-depth analysis of the dynamic beach landscapes of Hainan Island, which is located at the southernmost tip of China. Home to over a hundred natural and predominantly sandy beaches, Hainan Island confronts significant challenges posed by frequent marine natural disasters and human activities. Addressing the urgent need for long-term studies of beach dynamics, this research involved the use of CoastSat to extract and analyze shoreline data from 20 representative beaches and calculate the slopes of 119 sandy beaches around the island for the period from 2013 to 2023. The objective was to delineate the patterns of beach evolution that contribute to the prevention of sediment loss, the mitigation of coastal hazards, and the promotion of sustainable coastal zone management. By employing multi-source remote sensing imagery and the CoastSat tool, this investigation validated slope measurements across selected beaches, demonstrating consistency between the calculated and actual distances despite minor anomalies. The effective use of the finite element solution (FES) in the 2014 global tidal model for tidal corrections further aligned the coastlines with the mean shoreline, underscoring CoastSat’s utility in enabling precise coastal studies. The analysis revealed significant seasonal variations in shoreline positions, with approximately half of the monitored sites showing a seaward progression in summer and a retreat in winter, which were linked to variations in wave height. The southern beaches exhibited distinct seasonal variations, which contrasted with the general trend due to differing wave impacts. The western and southern shores showed erosion, while the northern and eastern shores displayed accretion. The calculated slopes across the island indicated that the southern beaches had steeper slopes, while the northern areas exhibited more pronounced slope variations due to wave and tidal impacts. These findings highlight the critical role of integrated coastal management and erosion control strategies in safeguarding Hainan Island’s beaches. By understanding the mechanisms driving seasonal and regional shoreline changes, effective measures can be developed to mitigate the impacts of erosion and enhance the resilience of coastal ecosystems amidst changing environmental conditions. This research provides a foundational basis for future efforts aimed at the sustainable development and utilization of coastal resources on Hainan Island.

Stakeholders self‐organization and adaptive governance in social enterprises: Membership representation, worker control and client orientation

AbstractThe article uses elements of complexity theory, social systems theory, and new institutionalism to analyse stakeholder self‐organization in Italian non‐profit social enterprises. Organizational development goes through an evolutionary process of trial and error, in which stakeholder self‐organization produces governance rules and routines to achieve adaptation and resilience in a changing socioeconomic environment. Survey data regarding social cooperatives, which are prevalent in Italy as a form of social enterprise, display how diverse stakeholders engage in self‐organization and self‐positioning within key governance bodies of membership and board of directors. The results demonstrate that in the absence of investor ownership, producers, especially paid staff but also volunteer workers, assume the main responsibility for decision‐making and control. Client orientation, the production of economic and social value in favour of customers and users, is achieved in a context of high relational intensity through participation in the co‐production and co‐creation of services, as well as the pooling of non‐commercial resources and favourable price discrimination, less through participation in decision‐making and control. This emerging evolutionary pattern can support the development of new organizational and business models for social enterprises.

Incorporating historical information into the multi-type ant colony optimization model to optimize patch-level land use allocation

Land use optimization is a crucial approach for promoting sustainable development. However, current land use optimization models usually ignore the temporal pattern of land use evolution. Research on how to quantify and incorporate historical information into land use optimization process is scarce, and worth exploring. This study proposed a historical-information-based patch-level multi-type ant colony optimization (HI-PMACO) model to examine the effect of incorporating historical information into the optimization model from both macro and local perspectives. Specifically, we (1) constructed five machine learning models to explore the transition potentials and used the SHAP algorithm to visualize the non-linear effects of spatial variables; (2) introduced a size-adaptive neighborhood strategy to quantify the local land use evolution preference; (3) designed an evolution preference-weighted roulette wheel mechanism to incorporate the extracted historical information into the biomimetic intelligent algorithm; and (4) verified the effect of the HI-PMACO model. Results demonstrated that the proposed HI-PMACO model exhibited better performance in improving economic benefit and transition potential objectives with smaller land use change costs, and the local details were highly in line with relevant planning policies. This study contributes to spatio-temporal land use optimization modeling in methodology and land use management considering temporal evolution patterns.

Hydrological control of the surging behaviour of the Ghujerab River Head Glacier, Karakoram (2019–2023): Insights from high-temporal-resolution remote sensing monitoring

Study regionThe northern region of the Karakoram Range. Study focusKarakoram is a region in High Mountain Asia with many surge-type glaciers. This study employed over 200 high-temporal-resolution remote sensing images and investigated the variations in elevation and velocity of the Ghujerab River Head Glacier (GRHG) from 2019 to 2023. Furthermore, we elucidated the potential controlling mechanisms. New hydrological insights for the regionOur findings revealed that the GRHG, akin to typical surge-type glaciers in Karakoram, started to surge in the spring and finished surging in the summer, with a duration of less than two years. Throughout the surging process, the glacier transferred a mass of 0.11±0.003 km³ from the reservoir area to the receiving area, resulting in a thickening of 91.59±1.04 m at the glacier terminus and thinning of 11.78±1.04 m in the upper glacier. By analysing the mass balance and glacier surface albedo during surging, we proposed that climatic disturbances in the glacier region provided essential material inputs for the surge. Additionally, based on the seasonal evolution pattern of glacier flow velocity, we inferred a close correlation between surging and variations in subglacial hydrology. The duration of acceleration and deceleration during glacier surging, as well as a comparison with existing studies, further support our conclusion. Future research integrating multi-source remote sensing and onsite observations can support numerical simulations to quantitatively reveal the key processes occurring beneath and within glaciers during surge events.

Evaluating Source, Scale Risk, and Corrosion Risk of the Produced Water Samples from the Appalachian Basin Based on a Geochemical Database

Summary Statistically, oil and gas production can generate up to 20 times the oil equivalent of produced water. The composition of produced water samples reflects its source, its interactions with reservoir rocks, and downhole (DH) facilities, which are critical for basin evolution, water source determination, and the monitoring, management, and optimization of oil and gas production. For example, scale and corrosion, two of the most severe flow assurance issues accompanied by produced water, can lead to billions of dollars lost every year. However, few studies have developed a standard protocol to extract such valuable information from produced water compositions due to a lack of data and professional models. Using produced water geochemical data from the Appalachian Basin, one of the largest natural gas producers in the US, from the United States Geological Survey (USGS) Produced Waters Geochemical Database (PWGD), we developed a standard protocol to investigate the produced water source, evolution history, and scale and corrosion risks under both DH and surface conditions by means of incorporating the professional models for water-rock interaction and corrosion. The results show that the produced water from the Appalachian Basin possibly evolves from seawater evaporation following a typical evolution pattern of ion concentration and water isotopes, while a group of time-elapsed samples indicates that such an evolution pattern can also be due to the mixture of the injected water and reservoir water. In addition, most produced water samples show obvious risks of mineral scaling (e.g., calcite, barite, and siderite) and CO2 corrosion with corresponding mitigation strategies recommended. This study not only developed a reliable data processing and analysis protocol but also showed the valuable information a systematic analysis of produced water samples can provide for actual oil and gas production.

Multiplex vortex instability in the flow of non-Newtonian fluids through microcavity arrays

Complex fluids always possess obvious non-Newtonian properties that facilitate the occurrence and development of vortex instability in porous media, which is of critical significance in many natural and industrial processes. It is widely known that this flow instability is regulated by both fluid flow and solid structure. However, the quantitative understanding of how structural characteristics of porous space affect the evolution of vortex instability is still nascent, especially in the case of fluids with varying rheological properties. Herein, the flow of polymer solutions with distinct non-Newtonian properties through microcavity arrays is experimentally studied, by which we systematically explore the effect of structural parameters of the cavity array on vortex instability. We find that, for both Newtonian and shear-thinning fluids with negligible elasticity, the vortex evolution behavior in each cavity of the cavity array is identical to those in an isolated cavity. In contrast, for viscoelastic fluids, the vortex instability is visibly affected by cavity number and cavity–cavity interval, and this effect exhibits different forms when the fluid shear-thinning participates or not. Multiplex vortex instabilities are observed under these tested conditions. By multiplex, we mean the vortex formation dynamics and evolution patterns are diversified. These unusual evolution phenomena are then interpreted in terms of the interplay between the elongation and relaxation of polymers as they navigate among neighboring cavities. These results can help us to further understand the flow instability of complex fluids in porous media and evoke new strategies for microfluidic applications of efficient mixing.

Influences of the Hard Rock Proportion Coefficient on the Evolution Pattern and Fractal Characteristics of Mining Fractures in a Composite Roof

Influences of the Hard Rock Proportion Coefficient on the Evolution Pattern and Fractal Characteristics of Mining Fractures in a Composite Roof

Micromechanical modeling of hollow cylinder torsional shear test on sand using discrete element method

Previous studies on the hollow cylinder torsional shear test (HCTST) have mainly focused on the macroscopic behavior, while the micromechanical responses in soil specimens with shaped particles have rarely been investigated. This paper develops a numerical model of the HCTST using the discrete element method (DEM). The method of bonded spheres in a hexagonal arrangement is proposed to generate flexible boundaries that can achieve real-time adjustment of the internal and external cell pressures and capture the inhomogeneous deformation in the radial direction during shearing. Representative angular particles are selected from Toyoura sand and reproduced in this model to approximate real sand particles. The model is then validated by comparing numerical and experimental results of HCTSTs on Toyoura sand with different major principal stress directions. Next, a series of HCTSTs with different combinations of major principal stress direction (α) and intermediate principal stress ratio (b) is simulated to quantitatively characterize the sand behavior under different shear conditions. The results show that the shaped particles are horizontally distributed before shearing, and the initial anisotropic packing structure further results in different stress–strain curves in cases with different α and b values. The distribution of force chains is affected by both α and b during the shear process, together with the formation of the shear bands in different patterns. The contact normal anisotropy and contact force anisotropy show different evolution patterns when either α or b varies, resulting in the differences in the non-coaxiality and other macroscopic responses. This study improves the understanding of the macroscopic response of sand from a microscopic perspective and provides valuable insights for the constitutive modeling of sand.

Ecology and Chronic Wasting Disease Epidemiology Shape Prion Protein Gene Variation in Rocky Mountain Elk (Cervus elaphus nelsoni).

As chronic wasting disease (CWD) continues to spread across North America, the relationship between CWD and host genetics has become of interest. In Rocky Mountain elk (Cervus elaphus nelsoni), one or two copies of a leucine allele at codon 132 of the prion protein gene (132L*) has been shown to prolong the incubation period of CWD. Our study examined the relationship between CWD epidemiology and codon 132 evolution in elk from Wyoming, USA, from 2011 to 2018. Using PCR and Sanger sequencing, we genotyped 997 elk and assessed the relationship between genotype and CWD prevalence estimated from surveillance data. Using logistic regression, we showed that each 1% increase in CWD prevalence is associated with a 9.6% increase in the odds that an elk would have at least one copy of leucine at codon 132. In some regions, however, 132L* variants were found in the absence of CWD, indicating that evolutionary and epidemiologic patterns can be heterogeneous across space and time. We also provide evidence that naturally occurring CWD is not rare in 132L* elk, which merits the study of shedding kinetics in 132L* elk and the influence of genotype on CWD strain diversity. The management implications of cervid adaptations to CWD are difficult to predict. Studies that investigate the degree to which evolutionary outcomes are shaped by host spatial structure can provide useful epidemiologic insight, which can in turn aid management by informing scale and extent of mitigation actions.

Effect of fluid–structure interaction on the oblique water entry of the projectile under the influence of floating ice structure

The water entry of a projectile constrained by polar floating ice presents a unique cross-media challenge. This paper investigates the dynamics of oblique water entry for a projectile influenced by floating ice using the fluid–structure interaction (FSI) method. The validity of the numerical method has been confirmed through experimental validation. The water entry process of a projectile from the side of the floating ice is examined. The evolution of the cavity and the movement patterns of objects as the distance between the projectile and the floating ice decreases toward collision are investigated. The influence of water on the critical collision distance between the projectile and the floating ice during oblique water entry is analyzed. Additionally, the physical mechanism of floating ice deflection through collision is investigated based on the theory of cavity dynamics. Subsequently, the study focuses on the oblique water entry process of a projectile colliding with the upper surface of the floating ice. Different entry angles determine the collision mode between the projectile and the floating ice surface. This study also examines how varying entry angles influence cavity evolution and object movement patterns during oblique collisions. Different collision modes between the projectile and the floating ice lead to asymmetric cavity evolution and various modes of object deflection motion. Finally, changes in the flow field and vortex structure during oblique collisions are studied to examine the influence of the FSI process between the projectile and the floating ice on the flow field.

Light conditions and the evolution of the visual system in birds.

Despite vision is an essential sense for many animals, the intuitively appealing notion that the visual system has been shaped by environmental light conditions is backed by insufficient evidence. Based on a comprehensive phylogenetic comparative analysis of birds, we investigate if exposure to different light conditions might have triggered evolutionary divergence in the visual system through pressures on light sensitivity, visual acuity, and neural processing capacity. Our analyses suggest that birds that have adopted nocturnal habits evolved eyes with larger corneal diameters and, to a lesser extent, longer axial length than diurnal species. However, we found no evidence that sensing and processing organs were selected together, as observed in diurnal birds. Rather than enlarging the processing centers, we found a tendency among nocturnal species to either reduce or maintain the size of the two main brain centers involved in vision -the optic tectum and the wulst. These results suggest a mosaic pattern of evolution, wherein optimization of the eye optics for efficient light capture in nocturnal species may have compromised visual acuity and central processing capacity.