Hasil untuk "Evolution"

K. Tamura, D. Peterson, N. Peterson et al.

M. Price, Paramvir S. Dehal, A. Arkin

Background We recently described FastTree, a tool for inferring phylogenies for alignments with up to hundreds of thousands of sequences. Here, we describe improvements to FastTree that improve its accuracy without sacrificing scalability. Methodology/Principal Findings Where FastTree 1 used nearest-neighbor interchanges (NNIs) and the minimum-evolution criterion to improve the tree, FastTree 2 adds minimum-evolution subtree-pruning-regrafting (SPRs) and maximum-likelihood NNIs. FastTree 2 uses heuristics to restrict the search for better trees and estimates a rate of evolution for each site (the “CAT” approximation). Nevertheless, for both simulated and genuine alignments, FastTree 2 is slightly more accurate than a standard implementation of maximum-likelihood NNIs (PhyML 3 with default settings). Although FastTree 2 is not quite as accurate as methods that use maximum-likelihood SPRs, most of the splits that disagree are poorly supported, and for large alignments, FastTree 2 is 100–1,000 times faster. FastTree 2 inferred a topology and likelihood-based local support values for 237,882 distinct 16S ribosomal RNAs on a desktop computer in 22 hours and 5.8 gigabytes of memory. Conclusions/Significance FastTree 2 allows the inference of maximum-likelihood phylogenies for huge alignments. FastTree 2 is freely available at http://www.microbesonline.org/fasttree.

M. Nei

J. Felsenstein

J. Kennedy, R. Eberhart

A concept for the optimization of nonlinear functions using particle swarm methodology is introduced. The evolution of several paradigms is outlined, and an implementation of one of the paradigms is discussed. Benchmark testing of the paradigm is described, and applications, including nonlinear function optimization and neural network training, are proposed. The relationships between particle swarm optimization and both artificial life and genetic algorithms are described.

R. Kennicutt, Jr.

Observations of star formation rates (SFRs) in galaxies provide vital clues to the physical nature of the Hubble sequence and are key probes of the evolutionary histories of galaxies. The focus of this review is on the broad patterns in the star formation properties of galaxies along the Hubble sequence and their implications for understanding galaxy evolution and the physical processes that drive the evolution. Star formation in the disks and nuclear regions of galaxies are reviewed separately, then discussed within a common interpretive framework. The diagnostic methods used to measure SFRs are also reviewed, and a self-consistent set of SFR calibrations is presented as an aid to workers in the field. One of the most recognizable features of galaxies along the Hubble sequence is the wide range in young stellar content and star formation activity. This variation in stellar content is part of the basis of the Hubble classification itself (Hubble 1926), and understanding its physical nature and origins is fundamental to understanding galaxy evolution in its broader context. This review deals with the global star formation properties of galaxies, the systematics of those properties along the Hubble sequence, and their implications for galactic evolution. I interpret “Hubble sequence” in this context very loosely, to encompass not only morphological type but other properties such as gas content, mass, bar structure, and dynamical environment, which can strongly influence the largescale star formation rate (SFR).

J. Koza

D. Posada, K. Crandall

Gongxin Wang, Haiwei Zhang, Yuqing Shao et al.

Grasslands, covering over 40% of terrestrial land surfaces, play a critical role in regional water cycling through their greening processes. However, the decoupling mechanisms between grassland greening and water availability (WA) changes across the Northern Hemisphere, along with their future trajectories, remain poorly understood. Here, we integrated multi-source satellite observations with CMIP6 model ensembles to systematically assess the spatiotemporal evolution and trend divergence of leaf area index (LAI) and WA across Northern Hemisphere grasslands from 2000 to 2100. Our results showed that grassland LAI exhibited sustained growth during 2000–2020, with 55.28% of regions showing significant increasing trends. However, 73.67% of grassland regions experienced declining WA during the historical period, revealing widespread decoupling between grassland greening and water deficit. Future scenario projections indicated a reversal to increasing WA trends, with 57.51% of regions showing significant increases under SSP5–8.5. Furthermore, 61.87% of grasslands exhibited greening-driven drying (GDD) characteristics during the historical period, while greening-driven wetting (GDW) regions were projected to expand to 72.44% in the future. Analysis along aridity gradients revealed that humid zones contributed most prominently to LAI and WA changes. Mechanistic decomposition demonstrated that grassland WA changes shifted from precipitation-dominated control (53.60%) in the historical period toward a regime jointly governed by precipitation dominance and coupled precipitation–evapotranspiration drivers in the future. Concurrently, the dominant factor controlling grassland greening transitioned from vapor-pressure deficit (VPD) to temperature (TEM) control. Additionally, driving factors exhibited pronounced differentiation patterns along aridity gradients during the historical phase: arid zones were dominated by soil moisture (SM) and semi-arid zones displayed dual control by SM and VPD, while humid zones were governed by coupled TEM-VPD regulation. This study reveals the divergent trends between grassland greening and WA and unravels their driving mechanisms, offering important scientific evidence for formulating regionally differentiated ecological water resource management strategies.

J. Anandan, Y. Aharonov

E. Martins, T. Garland

Konan Yao Jean Rodrigue, Ta Bi Tra Dieudonné, Berté Djakaridja et al.

Vector control (VC) is one of the strategies employed to manage African trypanosomoses. This study aimed at assessing the effectiveness of a VC campaign against Glossina palpalis palpalis using tiny targets (TTs) impregnated with insecticide in an isolated, protected forest in Abidjan, Côte d’Ivoire, while considering ecological, genetic, and operational factors. Between January 2020 and September 2022, 2,712 TTs were deployed at 684 sites, covering a total area of 1.7 km2. VC monitoring was conducted using Vavoua traps during 12 evaluation surveys, between June 2020 and March 2023. Five months after the initial TT deployment, tsetse fly density had decreased by 98.53%. Although tsetse density remained low due to TT redeployment and reinforcement, there was a significant increase a few months after the last redeployment. VC appeared to have minimal impact on the genetic structuring of G. p. palpalis. This suggested recruitment of local surviving tsetse flies all along the VC campaign due to a low probability of tsetse coming into contact with TTs, or to the evolution of behavioral or physiological resistance to control efforts. The genetic study revealed that one of the microsatellite markers used, the GPCAG locus, exhibited a selection signature possibly in response to VC. This could partly explain the challenges encountered in eliminating a seemingly isolated tsetse population thriving in a particularly favorable habitat.

Junyu Chen, Yang Shan, Shuai Li et al.

Abstract The long-term mining of lead-zinc ore bodies in Suichang Gold Mine has formed a high-stage, long-span columnar goaf group above 500 m elevation, posing significant risks of roof collapse, slope fragmentation, and ground pressure disasters. These hazards threaten the safety of deep mining operations and surface stability. To address these challenges, this study integrates field investigations, laboratory rock mechanics experiments, and FLAC3D numerical simulations to analyze the stability evolution of goafs before and after filling. Key innovations include the application of disaster chain theory to interpret goaf failure mechanisms and the optimization of cement-sand ratios for targeted filling (1:20 for 260–610 m levels and 1:8 for 528–540 m levels). Results demonstrate that cemented filling reduces vertical displacement by 2–4 cm, alleviates stress concentration (maximum compressive stress decreased by 0.5–1.0 MPa), and minimizes plastic zone expansion. Furthermore, the proposed interval mining sequence (first mining 300–390 m, followed by 260–290 m and 420–500 m levels) ensures both production efficiency and operational safety. This research provides a systematic framework for goaf management in complex mining environments.

Szyszko Magdalena, Kliber Agata, Motuzka Olena

We use causal inference analysis with Bayesian structural time series modelling to identify the changes in the direction and amplitude of Ukrainian and Polish consumer and professional inflation expectations after the outbreak of war in Ukraine. The study spans January 2018–March 2024. The pre-invasion period is considered a training period. The most interesting finding of this study is about the behaviour of Ukrainian consumer who did not change their expectations during the war. As a reaction to the intervention, we reported an increase in expectations for Polish economic agents and Ukrainian professionals. This study provides the first empirical evidence of the evolution of expectations during the war in Ukraine and a neighbouring country.

Yingying Zheng, Yun Long, Min Liu et al.

During the hydraulic performance experiment, significant vibration and noise were observed in the mixed-flow pump operating in the hump region. Cavitation occurrence in the impeller flow channels was confirmed through the transparent chamber. To analyze cavitation flow structure evolution in the mixed-flow pump, this paper integrates numerical and experimental approaches, capturing cavitation flow structures under the valley condition through high-speed photography technology. During the various stages of cavitation development, the cavitation forms are mostly vortex cavitation, cloud cavitation, and perpendicular vortex cavitation. Impeller rotation induces downstream transport of shedding cloud cavitation shedding structures. Flow blockage occurs when cavitation vortexes obstruct specific passages, accelerating cavitation growth that culminates in head reduction through energy dissipation mechanisms. Vortex evolution analysis revealed enhanced density of small-scale vortex structures with stronger localized core intensity in the impeller and diffuser. Despite larger individual vortex scales, reduced core intensity persists throughout the full flow domain. Concurrently, velocity profile characteristics across flow rates and blade sections (spanwise from tip to root) indicate heightened predisposition to flow separation, recirculation zones, and low-velocity regions during off-design operation. This study provides scientific guidance for enhancing anti-cavitation performance in the hump region.

Weiying KONG, Yizhuo LIU, Sichun DONG et al.

ObjectiveIn the contemporary global context, urban areas are increasingly confronted with the dual pressures of global climate change and rapid urbanization. These pressures have led to a significant rise in urban temperature, thereby amplifying the importance of blue-green spaces in mitigating the urban heat island (UHI) effect. Blue-green spaces, which include natural water bodies, parks, green corridors, and other vegetated areas, play a crucial role in regulating urban microclimates. As cities enter an era of stock development, where the focus shifts from expansion to optimization of existing resources, the strategic configuration of these spaces has become a cornerstone for enhancing urban thermal environments. Understanding the cooling mechanisms of blue-green spaces at various spatial scales is essential for improving urban thermal comfort and guiding the planning and construction of urban blue-green infrastructure.MethodsThis research focuses on the central urban area of Xi’an, a city that has experienced substantial urban growth over the past decade. By employing a combination of spatial autocorrelation analysis and a multi-scale geographically weighted regression (MGWR) model, the research examines the change characteristics of blue-green spaces and their impact on land surface temperature from 2013 to 2023. The findings reveal the spatial heterogeneity of cooling effects and offer tailored optimization strategies for blue-green spaces across diverse urban contexts. The research methodology involves selecting six representative landscape indices to evaluate the changes in blue-green space patterns in the central urban area of Xi’an. These indices are carefully chosen to capture the nuances of spatial configuration, fragmentation, and connectivity of blue-green spaces. Spatial autocorrelation analysis is utilized to identify spatial clustering and patterns extracted from the data collected, while the MGWR model is adopted for a more granular examination of the relationship between landscape indices and land surface temperature levels. This integrated approach not only reveals the factors influencing the cooling effects of blue-green spaces but also highlights their spatial variability across the urban landscape.ResultsThe results of the research are both revealing and instructive. 1) The blue-green space patterns in the central urban area of Xi’an underwent significant changes over the research period, reflecting the dynamic interplay between urban development and environmental management. 2) The spatial distribution of land surface temperature exhibits a distinct pattern of being “high in the north and low in the south”. The central area, characterized by dense urban fabric, shows minimal fluctuations in land surface temperature, whereas low-temperature zones are predominantly concentrated in the southern part of Baqiao District. This uneven thermal distribution underscores the complexity of urban heat dynamics and the need for targeted interventions. 3) The relationship between landscape indices and land surface temperature changes displays notable spatial heterogeneity. In high-density urban areas, small and complex blue-green patches demonstrate stronger cooling effects, emphasizing the importance of intricate designs in densely built environments where space is limited but the need for effective cooling is significant. In contrast, suburban areas benefit from avoiding the aggregation of large blue-green patches, which may otherwise hinder effective cooling due to reduced air circulation and increased shading. Near large water bodies, regularly shaped and highly connected blue-green patches are found to be particularly effective in reducing land surface temperature, highlighting the synergistic effects of water and vegetation in enhancing cooling performance and suggesting that integrated blue-green networks can maximize thermal benefits.ConclusionThe research concludes that the relationship between temperature changes and blue-green space changes in the central urban area of Xi’an is significant and characterized by strong spatial heterogeneity during the period from 2013 to 2023, with the cooling effects of blue-green spaces found varying by their spatial attributes and the characteristics of the surrounding urban environment. These findings highlight the necessity for region-specific optimization strategies to maximize the cooling potential of blue-green spaces. By integrating spatial analysis and regression modeling, the research provides a detailed understanding of the cooling mechanisms of blue-green spaces across diverse urban contexts. The results emphasize the importance of tailoring blue-green space designs to local conditions, considering factors such as urban density, proximity to water bodies, and regional climatic characteristics. This approach enhances the effectiveness of blue-green spaces in mitigating the urban heat island effect and contributes to the creation of more sustainable and thermally comfortable urban environments. The research advocates a holistic and adaptive urban planning strategy, where blue-green spaces are strategically designed and managed to address the unique thermal challenges of different urban areas. This research offers valuable guidance for policymakers and urban planners aiming to optimize blue-green infrastructure and improve urban resilience in the face of climate change and urbanization.

P. Van Tienderen

Xu‐Sheng Chen, Ran Hu, Chen‐Xing Zhou et al.

Abstract Salt precipitation is a crucial process occurring during CO2 injection into saline aquifers. It significantly alters the porous space, leading to reduced permeability and impaired injectivity. While the dynamics of precipitation have been studied within porous media, our understanding of precipitation patterns and permeability evolution within rough fractures remains inadequate. Here, we conduct flow‐visualization experiments on salt precipitation, wherein dry air invades brine‐filled rough fractures under various flow rate conditions. Our observations reveal that the precipitation pattern shifts from ex situ precipitation to homogeneous form as the flow rate (capillary number Ca) increases. Through real‐time imaging of the salt precipitation process, we determine that ex situ precipitation is due to capillary‐driven backflow. This backflow phenomenon occurs when previously precipitated salt, acting as a hydrophilic porous medium, attracts the brine flow backward. As a result, precipitation occurs at a location different from the original site. We further show that the impact of capillary‐driven backflow is significant at low flow rates and is gradually suppressed as the flow rate increases. We provide a theoretical estimation for the critical Ca for the occurrence of capillary‐driven backflow. As Ca is smaller than this critical value, backflow‐precipitation positive feedback causes fracture voids to become completely clogged, thereby leading to a more substantial permeability reduction. In contrast, a homogeneous precipitation pattern tends to only partially clog the fracture voids, causing a relatively smaller permeability reduction. This study enhances our understanding of the role of capillary‐driven backflow in controlling salt precipitation and permeability reduction in fractures.

Yunfan ZHAO, Xinyi TAN, Xiaoyun CHEN et al.

Abstract. Narrative medicine has gained significant attention in recent decades. The similarities between “parallel charts” and “medical cases” in traditional Chinese medicine (TCM) primarily lie in their authenticity. However, they differ in structure and narrative methods. Furthermore, medical case teaching is a prevalent pedagogical approach in TCM education that practitioners must master. This study explores the connection between TCM medical case teaching and narrative medicine, and concludes that the evolution of modern TCM case teaching aligns with the international standards of narrative medicine while integrating key TCM characteristics to enhance its value. This approach is essential for fostering humanistic sentiments, empathy, and reflective capabilities among future well-rounded TCM practitioners.

Marin Kneib, Catriona L. Fyffe, Evan S. Miles et al.

Abstract Ice cliff distribution plays a major role in determining the melt of debris‐covered glaciers but its controls are largely unknown. We assembled a data set of 37,537 ice cliffs and determined their characteristics across 86 debris‐covered glaciers within High Mountain Asia (HMA). We find that 38.9% of the cliffs are stream‐influenced, 19.5% pond‐influenced and 19.7% are crevasse‐originated. Surface velocity is the main predictor of cliff distribution at both local and glacier scale, indicating its dependence on the dynamic state and hence evolution stage of debris‐covered glacier tongues. Supraglacial ponds contribute to maintaining cliffs in areas of thicker debris, but this is only possible if water accumulates at the surface. Overall, total cliff density decreases exponentially with debris thickness as soon as the debris layer reaches a thickness of over 10 cm.