Stages Of Evolution Research Articles

Unique structural attributes of the PSI-NDH supercomplex in Physcomitrium patens.

Cyclic electron transport around photosystem I (PSI) is essential for the protection of the photosynthetic apparatus in plants under diverse light conditions. This process is primarily mediated by Proton Gradient Regulation 5 protein/Proton Gradient Regulation 5-like photosynthetic phenotype 1 protein (PGR5/PGRL1) and NADH dehydrogenase-like complex (NDH). In angiosperms, NDH interacts with two PSI complexes through distinct monomeric antennae, LHCA5 and LHCA6, which is crucial for its higher stability under variable light conditions. This interaction represents an advanced evolutionary stage and offers limited insight into the origin of the PSI-NDH supercomplex in evolutionarily older organisms. In contrast, the moss Physcomitrium patens (Pp), which retains the lhca5 gene but lacks the lhca6, offers a glimpse into an earlier evolutionary stage of the PSI-NDH supercomplex. Here we present structural evidence of the Pp PSI-NDH supercomplex formation by single particle electron microscopy, demonstrating the unique ability of Pp to bind a single PSI in two different configurations. One configuration closely resembles the angiosperm model, whereas the other exhibits a novel PSI orientation, rotated clockwise. This structural flexibility in Pp is presumably enabled by the variable incorporation of LHCA5 within PSI and is indicative of an early evolutionary adaptation that allowed for greater diversity at the PSI-NDH interface. Our findings suggest that this variability was reduced as the structural complexity of the NDH complex increased in vascular plants, primarily angiosperms. This study not only clarifies the evolutionary development of PSI-NDH supercomplexes but also highlights the dynamic nature of the adaptive mechanisms of plant photosynthesis.

Stacking and Analyzing MOSDEF Galaxies by Spectral Types: Implications for Dust Geometry and Galaxy Evolution

We examine star formation and dust properties for a sample of 660 galaxies at 1.37 ≤ z ≤ 2.61 in the MOSDEF survey by dividing them into groups with similarly shaped spectral energy distributions (SEDs). For each group, we combine the galaxy photometry into a finely sampled composite SED, and stack their spectra. This method enables the study of more complete galaxy samples, including galaxies with very faint emission lines. We fit these composite SEDs with Prospector to measure the stellar attenuation and SED-based star formation rates (SFRs). We also derive emission-line properties from the spectral stacks, including Balmer decrements, dust-corrected SFRs, and metallicities. We find that stellar attenuation correlates most strongly with mass, while nebular attenuation correlates strongly with both mass and SFR. Furthermore, the excess of nebular compared to stellar attenuation correlates most strongly with SFR. The highest SFR group has 2 mag of excess nebular attenuation. Our results are consistent with a model in which star-forming regions become more dusty as galaxy mass increases. To explain the increasing excess nebular attenuation, we require a progressively larger fraction of star formation to occur in highly obscured regions with increasing SFR. This highly obscured star formation could occur in dusty clumps or central starbursts. Additionally, as each galaxy group represents a different evolutionary stage, we study their locations on the UVJ and SFR-mass diagrams. As mass increases, metallicity and dust attenuation increase, while sSFR decreases. However, the most massive group moves towards the quiescent region of the UVJ diagram, while showing less obscuration, potentially indicating removal of dust.

Solar active region evolution and imminent flaring activity through color-coded visualization of photospheric vector magnetograms

Context. The emergence of magnetic flux, its transition to complex configurations, and the pre-eruptive state of active regions are probed using photospheric magnetograms. Aims. Our aim is to pinpoint different evolutionary stages in emerging active regions, explore their differences, and produce parameters that could advance flare prediction using color-coded maps of the photospheric magnetic field. Methods. The three components of the photospheric magnetic field vector are combined to create color-combined magnetograms (COCOMAGs). From these, the areas occupied by different color hues are extracted, creating appropriate time series (color curves). These COCOMAGs and color curves are used as proxies of the active region evolution and its complexity. Results. The morphology of COCOMAGs showcases typical features of active regions, such as sunspots, plages, and sheared polarity inversion lines. The color curves represent the area occupied by photospheric magnetic field of different orientation and contain information pertaining to the evolutionary stages of active regions. During emergence, most of the region area is dominated by horizontal or highly inclined magnetic field, which is gradually replaced by more vertical magnetic field. In complex regions, large parts are covered by highly inclined magnetic fields, appearing as abrupt color changes in COCOMAGs. The decay of a region is signified by a domination of vertical magnetic field, indicating a gradual relaxation of the magnetic field configuration. The color curves exhibit a varying degree of correlation with active region complexity. Particularly the red and magenta color curves, which represent strong, purely horizontal magnetic field, are good indicators of future flaring activity. Conclusions. Color-combined magnetograms facilitate a comprehensive view of the evolution of active regions and their complexity. They offer a framework for the treatment of complex observations and can be used in pattern recognition, feature extraction, and flare-prediction schemes.

A 3D view of multiple populations’ kinematics in Galactic globular clusters

We present the first 3D kinematic analysis of multiple stellar populations (MPs) in a representative sample of 16 Galactic globular clusters (GCs). For each GC in the sample, we studied the MP line-of-sight, plane-of-the-sky and 3D rotation, and velocity distribution anisotropy. The differences between first-population (FP) and second-population (SP) kinematic patterns were constrained by means of parameters specifically defined to provide a global measure of the relevant physical quantities and to enable a meaningful comparison among different clusters. Our analysis provides the first observational description of the MP kinematic properties and of the path they follow during their long-term dynamical evolution. In particular, we find evidence of differences between the rotation of MPs along all velocity components with the SP preferentially rotating faster than the FP. The difference between the rotation strength of MPs is anticorrelated with the cluster dynamical age. We also observe that FPs are characterized by isotropic velocity distributions at any dynamical age probed by our sample. On the contrary, the velocity distribution of SP stars is found to be radially anisotropic in dynamically young clusters and isotropic at later evolutionary stages. The comparison with a set of numerical simulations shows that these observational results are consistent with the long-term evolution of clusters forming with an initially more centrally concentrated and more rapidly rotating SP subsystem. We discuss the possible implications these findings have on our understanding of MP formation and early evolution.

Morphosedimentary evolution of the Belgica Mound Drift: Controls on contourite depositional system development in association with cold-water coral mounds

Small-scale contourite drift is an important component of continental margins that can record information about complex oceanographic processes. The Belgica Mound Drift is one example of a small-scale contourite drift. It is formed under the influence of cold-water coral (CWC) mounds and represents one of the most distal contouritic expressions influenced by the Mediterranean Outflow Water (MOW) in the NE Atlantic Ocean. Three distinct evolutionary stages have been identified from new high-resolution pseudo-3D reflection seismic data, each associated with a significant change in paleoceanography, affecting both bottom-current intensity and sediment input. The pre-drift stage (Pliocene–Early Pleistocene) corresponds to the regional RD1 erosive event, which was caused by the reintroduction of the MOW in the Porcupine Seabight, creating a distinct paleotopography that will influence all ensuing sedimentary processes. The second stage (Early Pleistocene–Middle Pleistocene) is the contourite drift inception in two distinct centres of growth, strongly steered by topographic obstacles such as the CWC mounds. During the third and final stage (Middle Pleistocene–present day), the contourite drift is developed under a more stable but less dynamic environment, characterised by more continuous and mounded aggradational stratification. The final stage of the contourite drift is related to the Middle Pleistocene Transition, with a spatially variable reduction in the MOW-related bottom currents and sediment input. The spatial and temporal evolution of this drift shows that its present-day morphology is controlled by the location of initial growth. Evolving moat morphology indicates that the intensity of the bottom currents generally increases during the drift evolution.This research presents a crucial paradigm for advancing our knowledge of elucidating the complexities of smaller-sized contourite systems in diverse oceanic environments.

Mapping AGN winds: A connection between radio-mode AGNs and the AGN feedback cycle

We present a kinematic analysis based on the large integral field spectroscopy (IFS) dataset of SDSS-IV MaNGA (Sloan Digital Sky Survey/Mapping Nearby Galaxies at Apache Point Observatory; ∼10 000 galaxies). We have compiled a diverse sample of 594 unique active galactic nuclei (AGNs), identified through a variety of independent selection techniques, encompassing radio (1.4 GHz) observations, optical emission-line diagnostics (BPT), broad Balmer emission lines, mid-infrared colors, and hard X-ray emission. We investigated how ionized gas kinematics behave in these different AGN populations through stacked radial profiles of the [O III] 5007 emission-line width across each AGN population. We contrasted AGN populations against each other (and non-AGN galaxies) by matching samples by stellar mass, [O III] 5007 luminosity, morphology, and redshift. We find similar kinematics between AGNs selected by BPT diagnostics compared to broad-line-selected AGNs. We also identify a population of non-AGNs with similar radial profiles as AGNs, indicative of the presence of remnant outflows (or fossil outflows) of past AGN activity. We find that purely radio-selected AGNs display enhanced ionized gas line widths across all radii. This suggests that our radio-selection technique is sensitive to a population in which AGN-driven kinematic perturbations have been active for longer durations (potentially due to recurrent activity) than in purely optically selected AGNs. This connection between radio activity and extended ionized gas outflow signatures is consistent with recent evidence that suggests radio emission (expected to be diffuse) originated due to shocks from outflows. We conclude that different selection techniques can trace different AGN populations not only in terms of energetics but also in terms of AGN evolutionary stages. Our results are important in the context of the AGN duty cycle and highlight integral field unit data’s potential to deepen our knowledge of AGNs and galaxy evolution.

S-process nucleosynthesis in chemically peculiar binaries

Context. Around half of the heavy elements in the Universe are formed through the slow neutron capture (s-) process, which takes place in thermally pulsing asymptotic giant branch (AGB) stars with masses of 1 − 6 M⊙. The nucleosynthetic imprint of the s-process can be studied by observing the material on the surface of binary barium (Ba), carbon (C), CH, and carbon-enhanced metal-poor (CEMP) stars. Aims. We study the s-process by observing the luminous components of binary systems polluted by a previous AGB companion. Our radial velocity (RV) monitoring program establishes an ongoing collection of binary stars exhibiting enrichment in s-process material for the study of elemental abundances, the production of s-process material, and binary mass transfer. Methods. From high-resolution optical spectra, we measured RVs for 350 stars and derived stellar parameters for approximately 150 stars using ATHOS. For a subsample of 24 chemically interesting stars, we refined our atmospheric parameters using ionization and excitation balance with the Xiru program. We used the MOOG code to compute one-dimensional local thermodynamic equilibrium (1D-LTE) abundances of carbon, magnesium, s-process elements (Sr, Y, Zr, Mo, Ba, La, Ce, Nd, Pb), and Eu to investigate neutron capture events and stellar chemical composition. We estimated dynamical stellar masses via orbital optimization using Markov chain Monte Carlo techniques in the ELC program, and we compared our results with low-mass AGB models in the FUll-Network Repository of Updated Isotopic Tables & Yields (FRUITY) database. Results. In our abundance subsample, we find enhancements in s-process material in spectroscopic binaries, a signature of AGB mass transfer. We add the element Mo to the abundance patterns, and for 12 stars we add Pb detections or upper limits, as these are not known in the literature. Computed abundances are in general agreement with the literature. Comparing our abundances to dilution-modified FRUITY yields, we find correlations in s-process enrichment and AGB mass, which are supported by dynamical modeling from RVs. Conclusions. From our high-resolution observations, we expand heavy element abundance patterns and highlight binarity in our chemically interesting systems. We find trends in s-process element enhancement from AGB stars, and agreement between theoretical and dynamically modeled masses. We investigate evolutionary stages for a small subset of our stars.

Narratives of growth of formative technological innovation systems based on a knowledge perspective: the case of medical devices

Purpose This study aims to analyze the narratives of growth during the initial stages of development of the medical device technological innovation system (TIS). This paper used micro/nanofluidic-based point-of-care testing (mnPOCT), a breakthrough technology in the health-care sector. Design/methodology/approach This study presents a framework that includes measures of knowledge breadth and sharing mechanisms based on cognitive and actor-based networks. The framework integrates bibliometric, network and statistics-based approaches with a focus on the first decade of mnPOCT development. Findings In addition to the typical patterns of technological emergence, the mnPOCT sector exhibits distinctive characteristics. This paper observed significant scientific content and a high geographic concentration. Although small- and medium-sized enterprises, particularly startups, detonate knowledge development, large companies play a subtle yet impactful role as innovation mediators. Interfirm alliances are sparse, reflecting the complementarities between startups and large firms throughout the innovation value chain. These alliances show a significant correlation with SME knowledge creation. Research limitations/implications This study provides researchers and practitioners with guidelines for assessing the dynamics of the growth of technologies in the earliest stages of growth through knowledge and implications for research strategy toward the development and deployment of effective system interventions. Originality/value The study of formative TISs presents challenges because of the nascent characteristics and uncertainties surrounding emerging technologies. Current discussions on the narratives of growth of emerging TISs are limited to broad descriptions, which hinder understanding of these formative stages. This study offers a unique approach to assessing the initial stages of technological evolution. Moreover, it contributes to the existing literature by providing guidelines for managing new technologies for R&D researchers and practitioners.

NH3 (1,1) hyperfine intensity anomalies in infall sources

Identifying infall motions is crucial for our understanding of accretion processes in regions of star formation. The NH3 (1,1) hyperfine intensity anomaly (HIA) has been proposed to be a readily usable tracer for such infall motions in star-forming regions harboring young stellar objects at very early evolutionary stages. In this paper, we seek to study the HIA toward 15 infall candidate regions in order to assess its reliability as an infall tracer. Using deep observations of the NH3 (1, 1) transition with the Effelsberg 100 m telescope, we identified HIAs toward all 15 targets. Of the 15 sources, 14 exhibit anomalous intensities in either the inner or outer satellite lines. All the derived HIAs conform to the framework of the existing two models, namely hyperfine selective trapping (HST) and systematic contraction or expansion motion (CE) models. In our sample of infall candidates, the majority of the HIAs remain consistent with the HST model. Only in three targets are the HIAs consistent with infall motions under the CE model. Thus, the HIA could indeed be used as an infall tracer, but does not appear to be highly sensitive to infall motions in our single-dish data. Nevertheless, the emission could be blended with emission from outflow activities. HIAs consistent with the HST model show stronger anomalies with increasing kinetic temperatures (TK), which is expected based on the HST model. On the other hand, HIAs consistent with infall motions show little dependence on Tk . Therefore, HIAs may preferably trace the infall of cold gas.

First map of D2H+ emission revealing the true centre of a prestellar core: Further insights into deuterium chemistry

Context. IRAS 16293E is a rare case of a prestellar core being subjected to the effects of at least one outflow. Aims. We want to disentangle the actual structure of the core from the outflow impact and evaluate the evolutionary stage of the core. Methods. Prestellar cores being cold and depleted, the best tracers of their central regions are the two isotopologues of the trihydrogen cation that are observable from the ground: ortho-H2D+ and para-D2H+. We used the Atacama Pathfinder EXperiment (APEX) telescope to map the para-D2H+ emission in IRAS 16293E and collected James Clerk Maxwell Telescope (JCMT) archival data of ortho-H2D+. We compared their emission to that of other tracers, including dust emission, and analysed their abundance with the help of a 1D radiative transfer tool. The ratio of the abundances of ortho-H2D+ to para-D2H+ can be used to estimate the stage of the chemical evolution of the core. Results. We have obtained the first complete map of para-D2H+ emission in a prestellar core. We compare it to a map of ortho-H2D+ and show their partial anti-correlation. This reveals a strongly evolved core with a para-D2H+/ortho-H2D+ abundance ratio towards the centre for which we obtain a conservative lower limit from 3.9 (at 12 K) to 8.3 (at 8 K), while the high extinction of the core is indicative of a central temperature below 10 K. This ratio is higher than predicted by the known chemical models found in the literature. Para-D2H+ (and indirectly ortho-H2D+) is the only species that reveals the true centre of this core, while the emission of other molecular tracers and dust are biased by the temperature structure that results from the impact of the outflow. Conclusions. This study is an invitation to reconsider the analysis of previous observations of this source and possibly questions the validity of the deuteration chemical models or of the reaction and inelastic collisional rate coefficients of the H+3 isotopologue family. This could impact the deuteration clock predictions for all sources.

Observational studies of S-bearing molecules in massive star-forming regions

S-bearing molecules are powerful tools for determining the physical conditions inside a massive star-forming region. The abundances of S-bearing molecules, including H$_ $S, H$_ $CS, and HCS$^ $, are highly dependent on physical and chemical changes, which means that they are good tracers of the evolutionary stage of massive star formation. We present observational results of H$_ $S 1$_ $, H$_ $34S 1$_ $, H$_ $CS 5$_ $, HCS$^ $ 4-3, SiO 4-3, HC$_ $N 19-18, and C18O 1-0 toward a sample of 51 late-stage massive star-forming regions, and study the relationships between H$_ $S, H$_ $CS, HCS$^ $, and SiO in hot cores. We discuss the chemical connections of these S-bearing molecules based on the relations between the relative abundances in our sources. H$_ $34S 1$_ $, as the isotopic line of H$_ $S 1$_ $, was used to correct the optical depths of H$_ $S 1$_ $. Beam-averaged column densities of all molecules were calculated, as were the abundances of H$_ $S, H$_ $CS, and HCS$^ $ relative to H$_ $, which were derived from C18O. Results from a chemical model that included gas, dust grain surface, and icy mantle phases, were compared with the observed abundances of H$_2$S, H$_2$CS, and HCS$^+$ molecules. H$_ $S 1$_ $, H$_ $34S 1$_ $, H$_ $CS 5$_ $, HCS$^ $ 4-3, and HC$_ $N 19-18 were detected in 50 of the 51 sources, SiO 4-3 was detected in 46 sources, and C18O 1-0 was detected in all sources. The Pearson correlation coefficients between H$_ $CS and HCS$^+$ normalized by H$_ $ and H$_ $S are 0.94 and 0.87, respectively, and a tight linear relationship with a slope of 1.00 and 1.09 is found; this relationship is 0.77 and 0.98 between H$_ $S and H$_ $CS and 0.76 and 0.97 between H$_ $S and HCS$^ $. The full widths at half maxima of H$_ $34S 1$_ $, H$_ $CS 5$_ $, HCS$^ $ 4-3, and HC$_ $N 19-18 in each source are similar to each other, which indicates that they may trace similar regions. By comparing the observed abundance with model results, we see that there is one possible time (2-3times 105 yr) a which each source in the model matches the measured abundances of H$_ $S, H$_ $CS, and HCS$^ $. The abundances of HCS$^ $, H$_ $CS, and H$_ $S increase with the SiO abundance in these sources, which implies that shock chemistry may be playing a large role. The close abundance relation of H$_2$S, H$_2$CS, and HCS$^+$ and the similar line widths in observational results indicate that these three molecules could be chemically linked, with HCS$^+$ and H$_2$CS the most correlated. The comparison of the observational results with chemical models shows that the abundances can be reproduced for almost all the sources at a specific time. The observational results, including the abundances in these sources need to be considered in further modeling of H$_ $S, H$_ $CS, and HCS$^ $ in hot cores with shock chemistry.

The Possible Factors that Influence the Stability of Binary Star System

Binary star systems are a crucial subject in astrophysics, as they provide insights into stellar formation, evolution, and dynamics. Despite extensive research, there remains a gap in understanding the factors influencing the longterm stability of such systems. This paper discusses the factors that may affect the stability of binary star systems by analyzing and exploring the physical laws and formulas of the operation of binary star systems and using the operation data of specific binary star systems as evidence. It can be concluded that the factors affecting the stability of a binary star system may be as follows: 1. Mass ratio of two stars, 2. Stellar spacing, 3. Orbital eccentricity, 4. Influence of stellar evolution stage, 5. The influence of external bodies. Future research should further explore the combined effects of these factors in more complex systems to better understand binary star stability in various astrophysical environments. Additionally, understanding how these factors interact in multi-body systems could provide deeper insights into the evolution of complex stellar systems.

RECOGNITION OF DURICRUST GEOMORPHIC SURFACES USING A RELIEF DISSECTION MATRIX

Landforms can orientate the hydrodynamics and distribution of materials on the ground, producing flattened and/or lowered geomorphic surfaces given the evolutionary characteristics from climatic, morphogenetic and pedogenetic factors. This work aims to demonstrate the compartmentalization and association of geomorphic surfaces covered by ferruginous duricrusts in Savannah areas in Brazil according to a relief dissection matrix. This matrix indicates the vertical cutting of the valleys and the interfluvial horizontal dimension of the hills through landform measurements in radar images, classification in alphanumeric codes and statistical correlations. The results indicated details in the compartmentalization of the surface according to the landform roughness, making it possible to link, through data from the dissection matrix and the statistical correlation, the association between the compartments according to summit positions and remaining depressed areas. Despite the fact that more robust measurements obtained from high-precision mappings can point out further landform evolutionary stages, it is understood that a dissection matrix and its statistical correlations can not only compartmentalize the landscape and provide an initial overview of the landscape’s evolution, but also indicate geomorphic surfaces that could have been worked at the same time. In this sense, the recognition of geomorphic surfaces, occurrence of duricrusts and landforms in this work allowed a certain morphogenetic correspondence that can contribute to geomorphological studies, although the results must be observed with caution when verified from the tropical perspective of relief evolution. Keywords: Valley Cutting; Interfluvial Dimension; Dissection Matrix; Geomorphic Surfaces; Duricrusts

Collagen VI and endotrophin: potential extracellular matrix targets to attenuate adverse cardiac remodeling post-infarction

Abstract Background The extracellular matrix (ECM) is a key component of cardiac repair after myocardial infarction (post-MI). After tissue damage following myocardial ischaemia, the ECM becomes enriched in proteases that are known to induce partial enzymatic cleavage and fragmentation of native structural and fibrillar macromolecules such as collagens. While some of the resulting protein fragments (matrikines) may have beneficial effects by mediating an active scar formation, other such as the collagen VI (COL6) proteolytic component "endothrophin" has been related to deleterious evolution and fibrosis, particularly in the presence of cardiovascular risk factors. Purpose We aimed to investigate the collagen profile in the structural fraction of ECM (enriched in fibrillar and structural proteins) of post-MI hearts at late evolution stages after MI. Methods The ECM protein profile was investigated in the ischemic (ISCH) and non-ischemic (NISCH) zones of the post-MI myocardium in pigs. MI was induced by closed-chest balloon occlusion of the LAD for 90 minutes. Studies were performed in normo- and hypercholesterolemic (diet induced) animals. Myocardial tissue was obtained 30d after MI. ECM proteins were selectively extracted, identified by LC/MS-MS and validated by Western Blot. Plasma levels of endothrophin were quantified by ELISA. Myocardial tissue from the same areas was characterized by immunohistochemistry. Results The ECM in the ISCH zone showed a differential signature of 39 proteins (14 upregulated / 25 downregulated) 30 days after MI compared to the NISCH area of the same animals. In the ISCH region, significant changes in collagen referring to COL6A3 and COL6A1 (increase) and COL6A2 and COL6A6 (decrease) were detected. COL6A3 protein content was 1.8fold higher (p=0.01) in the ISCH-ECM. A similar increase was found in normo- and hypercholesterolemic animals. A higher trend in COL6A3 levels was found in the ISCH- vs, the NISCH-zone in the myocardial cellular fraction suggesting that the COL6 ECM-related increase in ISCH is produced at a transcript level. Importantly, the COL6A3 found in the ECM did not contain the protein peptide (C5 domain) corresponding to endotrophin matrikine, suggesting its cleavage and release. Using a specific ELISA, hypercholesterolemic animals showed significantly higher endothrophin plasma levels than normolipemic controls (p=0.003) even in the absence of MI. Conclusion Our results evidence an increase in COL6A3 content in the ECM of the ischemic myocardium at 30 days post-MI. COL6A3 is depleted in a peptide of the C5 domain corresponding to endotrophin, found to be enhanced in hypercholesterolemia. These findings support a role for collagen type VI in adverse cardiac remodeling post-MI.

An adaptive differential evolution algorithm driven by multiple probabilistic mutation strategies for influence maximization in social networks

Influence maximization is a critical research topic of social network analysis, particularly with the increasing involvement of individuals in the global networked society. The purpose of the problem is to identify k influential nodes from the social network and activate them initially to maximize the expected number of influenced nodes at the end of the spreading process. Although some meta-heuristics based on swarm intelligence or biological evolution have been proposed to tackle this intractable problem, further investigation is required to refine the exploration and exploitation operations based on the iterative information from the evolutionary process. In this paper, an adaptive differential evolution algorithm driven by multiple probabilistic mutation strategies is proposed for the influence maximization problem. In order to enhance the evolutionary capability of the later stages of the discrete differential evolution, the mutation in the framework, consisting of three policies, namely comprehensive learning particle swarm mutation strategy, differential mutation strategy, and perturbation strategy, is implied based on different probabilistic models. An adaptive local search strategy is presented to improve the local optimum results based on a potential alternative library consisting of structural hole nodes, which guides the differential evolution to find a more optimal solution. Experimental results on six real-world social networks demonstrate the competitive performance of the proposed algorithm in terms of both efficacy and efficiency compared to state-of-the-art algorithms.

Variations of flare energy release behaviour and magnetic loop characteristics versus absolute stellar parameters

ABSTRACT In this paper, we examine how stellar flare activity varies with evolution stage, rotation period, and spectral type. To do this, we examine the distributions of the flare equivalent duration on a logarithmic scale, which we consider as an indicator of the maximum energy level that a star can reach in white-light flares. We conduct these analyses using two distinct statistical models of data obtained from white-light flare patrols of 33 stars. These models are the one-phase exponential association (OPEA) and cumulative flare frequency models. The results show that the value of the OPEA model parameter Plateau has a linear relationship with the stellar B – V colour index and the rotation period. In addition, it is shown that flare time-scales, and therefore the maximum magnetic loop height that stars can have, vary according to the evolutionary stage of the star. Finally, it is concluded that the cumulative flare frequency parameters of the stars are not as effective as the OPEA parameters at exhibiting these variations.

Property of Quark-Gluon Plasma

During the nascent stages of the universe's evolution, matter existed in the form of quarkgluon plasma (QGP), characterized by its presence under conditions of exceedingly high temperature andpressure. Presently, the ability to replicate the QGP state has been attained through relativistic heavy.ion collision experiments, Key indicators of QGP generation encompass the initial collision configurationwhich exerts a discernible infuence on the subsequent momentum and scattering angles of emitted hadronsThis study endeavors to recapitulate the findings of the CMS XeXe collision experiment by meticulouslyscrutinizing data stemming from PbPb collisions at a center-of-mass energy of s = 5.02 TeV. Specificallyour focus centers on an exhaustive analysis of the transverse momentum (pt), azimuthal angle (), ancpseudorapidity () of scattered particles. 'Through this comprehensive approach, we aim to corroborate theimplications drawn from the ClMS XeXe experiment, thereby contributing to a deeper understanding of themechanisms underlying quark-gluon plasma creation and behavior

Neoproterozoic Tectonics of the Arabian-Nubian Shield: Insights from U–Pb Zircon Geochronology, Sr–Nd–Hf Isotopes, and Geochemistry of the Deki Amhare Complex Granitoids, Central Eritrea

The Deki Amhare complex is located in central Eritrea, within the Arabian–Nubian Shield (ANS). It consists of an inner core of monzogranite porphyry and diorite enclaves (MMEs), surrounded outwardly by granodiorite and quartz diorite. The zircon U–Pb ages, whole-rock geochemistry, and Sr–Nd–Hf isotopic compositions of the Deki Amhare complex granitoids were used to discuss the Neoproterozoic tectonics of the ANS. The Late Tonian granodiorite and quartz diorite are metaluminous and calc-alkaline to slightly high-K calc-alkaline I-type plutons, with ages of 811.2 ± 4.8 Ma and 811.6 ± 5.7 Ma, respectively. They exhibit positive εHf(t) (7.6–9.5) and εNd(t) (3.9–4.7) values and relatively low (87Sr/86Sr)i ratios (0.70374–0.70463), indicating that they derived from the partial melting of a metasomatized mantle wedge during intra-oceanic subduction. The Ediacaran monzogranite porphyry and MMEs are subalkaline to alkaline A2-type granitoids with ages of 620.0 ± 4.3 Ma and 614.8 ± 3.9 Ma. These display positive εHf(t) (5.3–8.7) and εNd(t) (4.2–4.7) values, as well as low (87Sr/86Sr)i ratios (0.70310–0.70480), implying that they formed through crust–mantle magma mixing related to post-collisional slab break-off. Based on these data, three stages of regional tectonic evolution can be described: (1) from ~1200 Ma to ~875 Ma, the mafic oceanic crust was derived from depleted mantle during the opening of the Mozambique Ocean; (2) from ~875 Ma to ~630 Ma, intra-oceanic subduction and arc formation occurred with the development of I-type batholiths; and (3) from ~630 Ma to ~600 Ma, crustal and lithospheric reworking took place post-collision, leading to the formation of A2-type granitoids.

Controls on regional sulphate distribution in shallow groundwater in the western Canadian Interior Plains

Sulphate (SO4), predominantly derived from sulphur (S)-bearing glacial sediments distributed widely across the Canadian Interior Plains, contributes to high groundwater salinity and can be detrimental to riparian and dry-land ecosystems, agricultural production, and water use. While previous researchers investigated SO4 distribution and dynamics in shallow groundwater at local scales (<1500 km2), we examine SO4 occurrence in groundwater at larger scales, and to depths of ~150 m, considering variations in geology, glacial history, climate, and geochemical and hydrogeological settings in the Canadian province of Alberta. Sulphate concentrations in groundwater vary considerably, with 15 % of 139,130 samples above the 500 mg/L Canadian drinking water aesthetic objective. Analysis of δ34SSO4 and δ18OSO4 from 179 wells throughout Alberta shows SO4 is dominantly derived from oxidation of S-bearing material. At this large scale, marine shale bedrock subcrops, glacial ice flow directions, and climate control SO4 distribution. Groundwater contains less SO4 (<200 mg/L) in western Alberta compared to the east due to a lack of S-bearing bedrock, higher groundwater recharge rates, thinner glacial sediments, and increased groundwater circulation. Focusing on a region in south-central Alberta (Red Deer area), hydrogeological characteristics relating to SO4 formation, recharge, permeability, hydraulic gradient, and travel time are included in a principal component analysis to identify six groundwater groups at varying stages of evolution and SO4 concentrations depending on their hydrogeological setting. Low SO4 concentrations are associated with areas of high recharge, where SO4 has been leached from the sediments, or with more evolved bedrock groundwater where SO4 has been reduced or was recharged in pre-glacial times. High SO4 concentrations are found in areas of lower recharge and permeability, where flushing occurs more slowly. Combining the Red Deer area and province-wide analyses, we identify seven regions across Alberta with characteristic distribution and controls on SO4 occurrence in shallow groundwater.

Structures of Forest Stands in Monospecific Reforestations Based on Tectona grandis Lf. (Verbenaceae) in the Sangoué Classified Forest in Côte d’Ivoire

Teak-based reforestation poses the challenge of sustainable development in terms of meeting economic, social and environmental needs. In order to meet the needs of populations for timber and contain anthropogenic pressures on flora, reforestation based on Tectona grandis is initiated in the Sangoué Classified Forest. Therefore, a diagnostic study is therefore essential to assess the effects of this practice on the environment. This study assessed the consequences of planting Tectona grandis on the conservation and restoration of the Sangoué classified forest. For this, the structural and floristic characteristics of teak stands at different stages of evolution were compared. The results showed that young plots have more plant species, are more diverse and more evenly distributed. Older plots have the highest densities and basal areas of stems, with an inverted J-shaped distribution. Young plots have the lowest densities and basal areas, as well as a more regular horizontal structure. The woody species introduced into reforestation are Tectona grandis, Gmelina arborea and Cedrela odorata. In the 33-year-old block, the total basal area value is 18.07 m² per hectare, then 13.72 m² per hectare in the 30-year-old block. As for the 25- and 28-year-old blocks, the basal area values per hectare are 12.61 m2 and 9.39 m2 respectively. Young plots promote natural regeneration and floristic diversity, while older plots present low floristic diversity with reduced structural balance. Introduced species have benefited more from teak planting than native ones. Teak planting may lead to profit, but it presents challenges for biodiversity. The impact of teak planting on the Sangoué classified forest differs depending on the stage of evolution of the stands. Therefore, it has advantages and disadvantages for forest restoration and conservation. The teak plantation needs to be adjusted to forest management.