Effect Of Local Environment Research Articles

(Epi)genomic adaptation driven by fine geographical scale environmental heterogeneity after recent biological invasions.

Elucidating processes and mechanisms involved in rapid local adaptation to varied environments is a poorly understood but crucial component in management of invasive species. Recent studies have proposed that genetic and epigenetic variation could both contribute to ecological adaptation, yet it remains unclear on the interplay between these two components underpinning rapid adaptation in wild animal populations. To assess their respective contributions to local adaptation, we explored epigenomic and genomic responses to environmental heterogeneity in eight recently colonized ascidian (Ciona intestinalis) populations at a relatively fine geographical scale. Based on MethylRADseq data, we detected strong patterns of local environment-driven DNA methylation divergence among populations, significant epigenetic isolation by environment (IBE), and a large number of local environment-associated epigenetic loci. Meanwhile, multiple genetic analyses based on single nucleotide polymorphisms (SNPs) showed genomic footprints of divergent selection. In addition, for five genetically similar populations, we detected significant methylation divergence and local environment-driven methylation patterns, indicating the strong effects of local environments on epigenetic variation. From a functional perspective, a majority of functional genes, Gene Ontology (GO) terms, and biological pathways were largely specific to one of these two types of variation, suggesting partial independence between epigenetic and genetic adaptation. The methylation quantitative trait loci (mQTL) analysis showed that the genetic variation explained only 18.67% of methylation variation, further confirming the autonomous relationship between these two types of variation. Altogether, we highlight the complementary interplay of genetic and epigenetic variation involved in local adaptation, which may jointly promote populations' rapid adaptive capacity and successful invasions in different environments. The findings here provide valuable insights into interactions between invaders and local environments to allow invasive species to rapidly spread, thus contributing to better prediction of invasion success and development of management strategies.

Real-time monitoring of residual strength in corroding steel reinforcement using ultrasonic-guided waves and multi-physics modelling

Corrosion-induced material strength degradation is a major threat to the service life of reinforced concrete (RC) structures. Continued mass loss and pit formation after the initiation of corrosion in reinforcing steel consequently results in strength degradation. In this study, a non-destructive structural health monitoring (SHM) approach using ultrasonic guided waves with multi-physics modelling to monitor and forecast strength degradation of corroding steel is presented. Surface-bonded piezoelectric wafer transducers (PWTs) are used for actuating and sensing of guided waves in order to correlate the group velocity and amplitude of flexural wave modes with the strength reduction. The major findings of the work are presented in the form of empirical relationships between guided wave characteristics with reduced yield, ultimate, and buckling strength of corroded steel. It is observed that for a rebar of 12 mm diameter having slenderness ratio between 8 and 10, a 10% increase in amplitude and 8.44% increase in group velocity of flexural mode for corroding steel indicates a corresponding reduction of 10.278% in yield strength, 10.277% in ultimate strength, and 4.45% in buckling strength in progression phase of corrosion. A multi-physics numerical model of corrosion in RC structures that considers the effect of local exposure and environment is then elucidated with deviation less than 6.34% from experimental results in order to forecast the mass loss. The presented data fusion strategy, which combines guided wave-based monitoring and multi-physics modelling finds valuable application in assessing the current state of degradation in structural performance and strength-based service life prediction.

Effects of Multiple Local Environments on Electron Energy Loss Spectra of Epitaxial Perovskite Interfaces.

The role of local chemical environments in the electron energy loss spectra of complex multiferroic oxides was studied using computational and experimental techniques. The evolution of the O K-edge across an interface between bismuth ferrite (BFO) and lanthanum strontium manganate (LSMO) was considered through spectral averaging over crystallographically equivalent positions to capture the periodicity of the local O environments. Computational techniques were used to investigate the contribution of individual atomic environments to the overall spectrum, and the role of doping and strain was considered. Chemical variation, even at the low level, was found to have a major impact on the spectral features, whereas strain only induced a small chemical shift to the edge onset energy. Through a combination of these methods, it was possible to explain experimentally observed effects such as spectral flattening near the interface as the combination of spectral responses from multiple local atomic environments.

Effect of local crystal field environment on luminous properties of Er3+/Yb3+-doped titanate upconversion luminescent materials

The upconversion luminescence performance is closely related to the local crystal field environment. However, it is challenging to achieve an ideal luminescence performance by local crystal structure engineering. In this work, four titanate upconversion luminescent materials with fixed elemental compositions were synthesized, which enabled systematic exploration effects of the local crystal field environment (local structure symmetry and interatomic distance) on the upconversion performance. When the effects of local structure symmetry and interatomic distance on upconversion performance were taken into account individually, it was not easy to precisely characterize how the local crystal field environment influenced the upconversion performance. Thus, to illustrate this issue, we established a mathematical model that can satisfactorily describe the variation trend of the red/green integrated intensity ratio in terms of the product of local crystal field intensity and interatomic distance. This finding provides an excellent theoretical basis for the design of luminescent materials with ideal upconversion performance.

Effect of Composition and Local Environment on CO2 Adsorption on Nickel and Magnesium Oxide Solid Solutions

CO2 adsorption energies on the (100) surfaces of a nickel oxide doped with Mg, magnesium oxide doped with Ni, and their 50:50 solid solution were calculated using density functional theory. The composition and atomic arrangement of the adsorption site were varied to understand how the local environment affects CO2 adsorption and the basicity of the surfaces at the atomic level. The dispersive and electronic contributions to the adsorption energies were quantified, and the results indicate that the variation of the adsorption energy with adsorption site configuration and metal composition is dominated by electronic interactions. Interestingly, for magnesium oxide doped with nickel, a single substitution can create stronger CO2 binding sites, which implies stronger basic sites, even though nickel oxide is less basic than magnesium oxide. The effect of double substitution at the binding site can be reasonably approximated by summing the effects of single substitutions. This work provides guidance for the preparation of metal oxides with tailored Lewis basicity.

Continuous Wavelet Analysis of Matter Clustering Using the Gaussian-derived Wavelet

Continuous wavelet analysis has been increasingly employed in various fields of science and engineering due to its remarkable ability to maintain optimal resolution in both space and scale. Here, we introduce wavelet-based statistics, including the wavelet power spectrum, wavelet cross correlation, and wavelet bicoherence, to analyze the large-scale clustering of matter. For this purpose, we perform wavelet transforms on the density distribution obtained from the one-dimensional Zel’dovich approximation and then measure the wavelet power spectra and wavelet bicoherences of this density distribution. Our results suggest that the wavelet power spectrum and wavelet bicoherence can identify the effects of local environments on the clustering at different scales. Moreover, we apply the statistics based on the three-dimensional isotropic wavelet to the IllustrisTNG simulation at z = 0, and investigate the environmental dependence of the matter clustering. We find that the clustering strength of the total matter increases with increasing local density except on the largest scales. Besides, we notice that the gas traces dark matter better than stars on large scales in all environments. On small scales, the cross correlation between the dark matter and gas first decreases and then increases with increasing density. This is related to the impacts of the active galactic nucleus feedback on the matter distribution, which also varies with the density environment in a similar trend to the cross correlation between dark matter and gas. Our findings are qualitatively consistent with previous studies on matter clustering.

Real-time two-photon interference from distinct molecules on the same chip

Scalability and miniaturization are hallmarks of solid-state platforms for photonic quantum technologies. Still a main challenge is two-photon interference from distinct emitters on chip. This requires local tuning, integration, and novel approaches to understand and tame noise processes. A promising platform is that of molecular single-photon sources. Thousands of molecules with optically tunable emission frequency can be easily isolated in solid matrices and triggered with pulsed excitation. We here discuss Hong–Ou–Mandel interference experiments using several couples of molecules within few tens of microns. Quantum interference is observed in real time, enabling the analysis of local environment effects at different time scales.

Effect of the local chemical environment on oxidation resistance mechanisms in AlNbTiZr refractory high entropy alloys: A first-principles study

The present study is dedicated to the effect of local chemical environment on structure and properties of oxygen adsorption on AlNbTiZr surface from first-principle investigation. The adsorption energy results illustrate that the most stable adsorption sites are those with high content Ti, mainly due to its highest t 2g states near Fermi level. The stronger O-Al than O-Ti interaction will cause outward diffusion of Al, which explains the high concentration Al in oxide layer of AlNbTiZr experimentally. More importantly, Ti atom weakens the O-Al interaction, and thereby may weaken the stability of Al-containing oxides. Consequently, it is necessary to control experimentally by different processing methods to decrease the occurrence of Ti-Ti arrangement on the surface to improve oxidation resistance of AlNbTiZr.

Discriminating ecological processes affecting different dimensions of α- and β-diversity in desert plant communities.

Understanding the spatial distribution of plant diversity and its drivers are major challenges in biogeography and conservation biology. Integrating multiple facets of biodiversity (e.g., taxonomic, phylogenetic, and functional biodiversity) may advance our understanding on how community assembly processes drive the distribution of biodiversity. In this study, plant communities in 60 sampling plots in desert ecosystems were investigated. The effects of local environment and spatial factors on the species, functional, and phylogenetic α‐ and β‐diversity (including turnover and nestedness components) of desert plant communities were investigated. The results showed that functional and phylogenetic α‐diversity were negatively correlated with species richness, and were significantly positively correlated with each other. Environmental filtering mainly influenced species richness and Rao quadratic entropy; phylogenetic α‐diversity was mainly influenced by dispersal limitation. Species and phylogenetic β‐diversity were mainly consisted of turnover component. The functional β‐diversity and its turnover component were mainly influenced by environmental factors, while dispersal limitation dominantly effected species and phylogenetic β‐diversity and their turnover component of species and phylogenetic β‐diversity. Soil organic carbon and soil pH significantly influenced different dimensions of α‐diversity, and soil moisture, salinity, organic carbon, and total nitrogen significantly influenced different dimensions of α‐ and β‐diversity and their components. Overall, it appeared that the relative influence of environmental and spatial factors on taxonomic, functional, and phylogenetic diversity differed at the α and β scales. Quantifying α‐ and β‐diversity at different biodiversity dimensions can help researchers to more accurately assess patterns of diversity and community assembly.

Metal-Coordinating Single-Boron Sites Confined in Antiperovskite Borides for N2-to-NH3 Catalytic Conversion

The concept of single-atom catalysts (SACs) takes our understanding of active sites of heterogeneous catalysts to greater heights. While the knowledge about the SACs containing isolated metal centers has rapidly enriched over the last decade, a few examples of the SACs that feature single-nonmetal centers are studied, and their application potentials are also poorly explored. Herein, we report a family of 358 model surfaces featuring metal-coordinated single-boron sites for investigating the effects of boron-centered local environment on N2-to-NH3 catalytic conversion. We demonstrate these model surfaces with (001) surfaces of antiperovskite borides (M3M′B, M, and M′ represent different metal atoms), where the surface-isolated boron atoms are spacially separated by M atoms, but they do not directly bond to M′ atoms. The surface-isolated boron atoms are found to be necessary for the adsorption and activation of dinitrogen, and the types of M atoms determine dinitrogen adsorption configurations. When M atoms are the late transition metals (e.g., Ni), dinitrogen prefers to adsorb on the top-site of the surface B atom with an end-on configuration; when M atoms are alkaline-earth metals, early transition metals and lanthanide elements (e.g., Sr, Zr, and La) and dinitrogen bonds to M–B–M three-center site with a side-on configuration. Additionally, during the catalytic conversion of dinitrogen to ammonia, the M atoms cooperate with the isolated boron atom to costabilize NxHy intermediates (x = 1, 2; y = 0–4), and the M′ atoms finely regulate the electronic structure of B–M ensembles and thereby tune the adsorption property and catalytic activity. Furthermore, the adsorption free energy of *N is found to be applied as a descriptor of the limiting potential of dinitrogen reduction reaction, and its value is correlated with orbital hybridization between M and B atoms apart from the inherent electronic properties of M and B atoms. Finally, we predict Rh3GeB, Rh3SbB, and Ni3LiB to be promising ammonia synthesis catalysts with high activity that exceed that of the stepped Ru(0001) surface, a prominent benchmarking surface for ammonia synthesis.

Manipulating the oxygen reduction reaction pathway on Pt-coordinated motifs

Electrochemical oxygen reduction could proceed via either 4e−-pathway toward maximum chemical-to-electric energy conversion or 2e−-pathway toward onsite H2O2 production. Bulk Pt catalysts are known as the best monometallic materials catalyzing O2-to-H2O conversion, however, controversies on the reduction product selectivity are noted for atomic dispersed Pt catalysts. Here, we prepare a series of carbon supported Pt single atom catalyst with varied neighboring dopants and Pt site densities to investigate the local coordination environment effect on branching oxygen reduction pathway. Manipulation of 2e− or 4e− reduction pathways is demonstrated through modification of the Pt coordination environment from Pt-C to Pt-N-C and Pt-S-C, giving rise to a controlled H2O2 selectivity from 23.3% to 81.4% and a turnover frequency ratio of H2O2/H2O from 0.30 to 2.67 at 0.4 V versus reversible hydrogen electrode. Energetic analysis suggests both 2e− and 4e− pathways share a common intermediate of *OOH, Pt-C motif favors its dissociative reduction while Pt-S and Pt-N motifs prefer its direct protonation into H2O2. By taking the Pt-N-C catalyst as a stereotype, we further demonstrate that the maximum H2O2 selectivity can be manipulated from 70 to 20% with increasing Pt site density, providing hints for regulating the stepwise oxygen reduction in different application scenarios.

Ab initio prediction of vacancy energetics in HCP Al-Hf-Sc-Ti-Zr high entropy alloys and the subsystems

We perform ab initio density-functional-theory (DFT) calculations to investigate the vacancy formation and migration energies in HCP Al-Hf-Sc-Ti-Zr high entropy alloys (HEAs) and their subsystems from binaries to quinaries. For the vacancy formation properties, we utilize the special quasi-random structure approach in conjunction with a statistical analysis, from which temperature-dependent formation Gibbs energies as well as averaged atomic environments can be extracted. We show that the temperature-dependent vacancy formation Gibbs energy due to configurational excitations has a negative configurational entropy contribution. For the vacancy migration barriers, obtained from the nudged elastic band method, we apply the local cluster expansion technique to the kinetically resolved activation barriers to explore extended vacancy migration phase spaces. The local chemical environment effect and general trends in terms of the “high entropy” effect are analyzed.

Cosolvent and Local Environment Effects of Vanadium Incorporation on MCM-41 Catalysts for Selective Oxidation Reactions

Cosolvent and Local Environment Effects of Vanadium Incorporation on MCM-41 Catalysts for Selective Oxidation Reactions

Engineering Electrochemical Surface for Efficient Carbon Dioxide Upgrade

AbstractElectrochemical CO2 conversion offers an attractive route for recycling CO2 with economic and environmental benefits, while the catalytic materials and electrode structures still require further improvements for scale‐up application. Electrocatalytic surface and near‐surface engineering (ESE) has great potential to advance CO2 reduction reactions (CO2RR) with improved activity, selectivity, energetic efficiency, stability, and reduced overpotentials. This review initially provides a panorama of ESE effects to give a clear perspective and leverage their advantages, including surface electronic effects, ensemble effects, strain effects, and local environment effects. Additionally, relevant in situ spectroscopic characterization techniques to detect, and theoretical computational approaches to reveal these ESE effects are presented. Typical ESE strategies are also summarized, e.g., in situ surface reconstruction, surface morphology control, surface modifications, etc. Rational manipulations of specific ESE approaches or combinations of them are critical to designing composite catalysts and electrodes, consequently promoting sustainable development and steadily increasing the prosperity of this field.

Morphological Transformation and Star Formation Quenching of Massive Galaxies at 0.5 ≤ z ≤ 2.5 in 3D-HST/CANDELS

Abstract To figure out the effect of stellar mass and local environment on morphological transformation and star formation quenching in galaxies, we use the massive (M * ≥ 1010 M ⊙) galaxies at 0.5 ≤ z ≤ 2.5 in five fields of 3D-HST/CANDELS. Based on the UVJ diagnosis and the possibility of possessing a spheroid, our sample of massive galaxies is classified into four populations: quiescent early-type galaxies (qEs), quiescent late-type galaxies (qLs), star-forming early-type galaxies (sEs), and star-forming late-type galaxies (sLs). It is found that the quiescent fraction is significantly elevated at the high ends of mass and local environmental overdensity, which suggests a clear dependence of quenching on both mass and local environment. Over cosmic time, the mass dependence of galaxy quiescence decreases while the local environment dependence increases. The early-type fraction is found to be larger only at the high-mass end, indicating an evident mass dependence of morphological transformation. This mass dependence becomes more significant at lower redshifts. Among the four populations, the fraction of active galactic nuclei (AGNs) in the qLs peaks at 2 < z ≤ 2.5, and rapidly declines with cosmic time. The sEs are found to have higher AGN fractions of 20%–30% at 0.5 ≤ z < 2 . The redshift evolution of AGN fractions in the qLs and sEs suggests that AGN feedback could have played important roles in the formation of the qLs and sEs.

Role of Pigment–Protein Coupling in the Energy Transport Dynamics in the Fenna–Matthews–Olson Complex

The role of pigment-protein coupling in the dynamics of photosynthetic energy transport in chromophoric complexes has not been fully understood. The excitation energy transfer in the photosynthetic system is tremendously efficient. In particular, we investigate the excitation energy transport in the Fenna-Matthews-Olson (FMO) complex. The exciton dynamics and excitation energy transfer (EET) depend on the interaction between the excited chromophores and their environment. Most theoretical models believe that all bacteriochlorophyll-a (BChla) sites are surrounded by the same local protein environment, which is contradicted by the structural analysis of the FMO complex. Based on different values of pigment-protein coupling for different sites, measured in the adiabatic limit, we have theoretically investigated the effect of the heterogeneous local protein environment on the EET process. By the realistic and site-dependent model of the system-bath couplings, the results show that this interaction may have a critical value for the coherent energy-transfer process. Furthermore, we verify that the two transport pathways are coherent and stable to the important parameter reorganization energy of environmental interactions. The quantum dynamical simulations show that the correlation fluctuation keeps the oscillation of the coherent excitation on a long timescale. In addition, due to the inhomogeneous pigment-protein coupling, different BChl sites have asymmetric excitation oscillation timescales.

Effects of local matrix environment on the spectroscopic properties of ensemble to single-particle level carbon dots

Carbon dots (CDs), because of their unique properties, are being rapidly developed as important luminescent materials for imaging, sensing, and use in photonic devices. However, most of the reported fundamental properties of the CDs are results of investigations conducted in the solution state, which may be completely different from those conducted in the solid state. In this work, we study the luminescence properties, photostability, and the dynamics of CDs in different matrix environments, from ensemble to the single-particle level. We observed that the properties associated with the emission centers and photostability of CDs were extremely sensitive to the local chemical environment. A better understanding of the dependence of the spectroscopic properties of CDs on the complex local chemical environment is an important step toward finding new ways of controlling the optical properties of CDs and optimizing their use in various applications.

Effects of Heme Electronic Structure and Local Heme Environment on Catalytic Activity of a Peroxidase-Mimicking Heme-DNAzyme.

The catalytic cycle of a peroxidase-mimicking heme-DNAzyme involves an iron(IV)oxo porphyrin π-cation radical intermediate known as compound I formed through heterolytic O-O bond cleavage of an Fe3+-bound hydroperoxo ligand (Fe-OOH) in compound 0, like that of a heme enzyme such as horseradish peroxidase (HRP). Peroxidase assaying of complexes composed of chemically modified hemes possessing various electron densities of the heme iron atom (ρFe) and parallel-stranded tetrameric G-quadruplex DNAs of oligonucleotides d(TTAGGG), d(TTAGGGT), and d(TTAGGGA) was performed to elucidate the effects of the heme electronic structure and local heme environment on the catalytic activity of the heme-DNAzyme. The study revealed that the DNAzyme activity is enhanced through an increase in the ρFe and general base catalysis of the adenine base adjacent to the heme, which are reminiscent of the "push" and "pull" mechanisms in the catalytic cycle of HRP, respectively, and that the activity of the heme-DNAzyme can be independently controlled through the heme electronic structure and local heme environment. These findings allow a deeper understanding of the structure-function relationship of the peroxidase-mimicking heme-DNAzyme.

Unraveling the roles of genotype and environment in the expression of plant defense phenotypes.

Phenotypic variability results from interactions between genotype and environment and is a major driver of ecological and evolutionary interactions. Measuring the relative contributions of genetic variation, the environment, and their interaction to phenotypic variation remains a fundamental goal of evolutionary ecology.In this study, we assess the question: How do genetic variation and local environmental conditions interact to influence phenotype within a single population? We explored this question using seed from a single population of common milkweed, Asclepias syriaca, in northern Michigan. We first measured resistance and resistance traits of 14 maternal lines in two common garden experiments (field and greenhouse) to detect genetic variation within the population. We carried out a reciprocal transplant experiment with three of these maternal lines to assess effects of local environment on phenotype. Finally, we compared the phenotypic traits measured in our experiments with the phenotypic traits of the naturally growing maternal genets to be able to compare relative effect of genetic and environmental variation on naturally occurring phenotypic variation. We measured defoliation levels, arthropod abundances, foliar cardenolide concentrations, foliar latex exudation, foliar carbon and nitrogen concentrations, and plant growth.We found a striking lack of correlation in trait expression of the maternal lines between the common gardens, or between the common gardens and the naturally growing maternal genets, suggesting that environment plays a larger role in phenotypic trait variation of this population. We found evidence of significant genotype‐by‐environment interactions for all traits except foliar concentrations of nitrogen and cardenolide. Milkweed resistance to chewing herbivores was associated more strongly with the growing environment. We observed no variation in foliar cardenolide concentrations among maternal lines but did observe variation among maternal lines in foliar latex exudation.Overall, our data reveal powerful genotype‐by‐environment interactions on the expression of most resistance traits in milkweed.

Contrasting effects of local environment and grazing pressure on the genetic diversity and structure of Artemisia frigida

Drylands count among the most globally extensive biomes, and while many desert and dry rangeland ecosystems are under threat, genetic structures of dryland species are still rarely studied. Artemisia frigida is one of the most widely distributed plant species in the temperate rangelands of Eurasia and North America, and it also dominates in many habitats of Mongolia due to its tolerance to low temperatures, drought and disturbance. Local environmental conditions and grazing pressure can influence species performance and affect spatial patterns of genetic diversity in contrasting ways, and our study set out to evaluate such effects on the genetic diversity and structure of A. frigida. We first developed new species-specific Simple Sequence Repeats (SSRs) markers using whole genome sequencing. We then analysed 11 populations of A. frigida that had been sampled along a large climatic gradient in Mongolia, which were sub-structured according to three levels of grazing intensity. Estimates of genetic diversity at the population level were high (HO = 0.56, HE = 0.73) and tended to increase with higher precipitation and soil nutrient availability. Grazing had no effect on genetic diversity, however, a high number of grazing-specific indicator alleles was found at grazed sites. Genetic differentiation among populations was extremely low (global GST = 0.034). Analysis of Molecular Variance revealed 5% variance between populations along the climatic gradient, with 3% of the variance being partitioned among different grazing intensity levels. We found no relationship between geographic and genetic distances, and thus no isolation by distance in this widely distributed species. The relatively low genetic structuring suggests that considerable gene flow exists among A. frigida populations across the rangelands of Mongolia, in spite of the pervasive grazing in the region.