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For sessile organisms such as reef-building corals, differences in the degree of dispersion of individuals across a landscape may result from important differences in life-history strategies or may reflect patterns of habitat availability. Descriptions of spatial patterns can thus be useful not only for the identification of key biological and physical mechanisms structuring an ecosystem, but also by providing the data necessary to generate and test ecological theory. Here, we used an in situ imaging technique to create large-area photomosaics of 16 plots at Palmyra Atoll, central Pacific, each covering 100 m 2 of benthic habitat. We mapped the location of 44,008 coral colonies and identified each to the lowest taxonomic level possible. Using metrics of spatial dispersion, we tested for departures from spatial randomness. We also used targeted model fitting to explore candidate processes leading to differences in spatial patterns among taxa. Most taxa were clustered and the degree of clustering varied by taxon. A small number of taxa did not significantly depart from randomness and none revealed evidence of spatial uniformity. Importantly, taxa that readily fragment or tolerate stress through partial mortality were more clustered. With little exception, clustering patterns were consistent with models of fragmentation and dispersal limitation. In some taxa, dispersion was linearly related to abundance, suggesting density dependence of spatial patterning. The spatial patterns of stony corals are non-random and reflect fundamental life-history characteristics of the taxa, suggesting that the reef landscape may, in many cases, have important elements of spatial predictability.

A new nonlinear integrable fifth-order equation with temporal and spatial dispersion is investigated, which can be used to describe shallow water waves moving in both directions. By performing the singularity manifold analysis, we demonstrate that this generalized model is integrable in the sense of Painlevé for one set of parametric choices. The simplified Hirota method is employed to construct the one-, two-, three-soliton solutions with non-typical phase shifts. Subsequently, an extended projective Riccati expansion method is presented and abundant travelling wave solutions are constructed uniformly. Furthermore, several new interaction solutions between periodic waves and kinky waves are also derived via a direct method. The rich interactions including overtaking collision, head-on collision and periodic-soliton collision are analyzed by some graphs.

This study evaluates the emissions of volatile organic compounds (VOCs) from petroleum refinery operations, focusing on quantifying the VOCs emission inventory, analyzing their spatial distribution, and assessing their environmental impacts. Emission measurements identified storage tanks as the primary source of VOCs, with pentane, cyclopentane, and cyclohexane being the dominant species. The total VOCs emissions were estimated at 1132.1 tons per year. Spatial dispersion modeling revealed that storage tanks contributed significantly to VOCs concentrations at receptor sites, accounting for 64.5–88.1% of the total VOCs emissions, followed by contributions from the wastewater treatment unit and marketing terminal. Ambient VOCs concentrations were then used to calculate secondary organic aerosol (SOA) levels, with toluene identified as the primary contributor to SOA formation in the surrounding environment. This study underscores the critical importance of targeting VOCs emissions, particularly from storage tanks, as a strategy to mitigate both VOCs and SOA concentrations. The findings highlight the potential for improved management and control strategies to reduce the environmental and public health risks associated with these emissions.

To reduce the spatial simulation error generated by the finite difference method, previous researchers compute the optimal finite-difference weights always by minimizing the error of spatial dispersion relation. However, we prove that the spatial simulation error of the finite difference method is associated with the dot product of the spatial dispersion relation of the finite-difference weights and the spectrum of the seismic wavefield. Based on the dot product relation, we construct a L2 norm cost function to minimize spatial simulation error. For solving this optimization problem, the seismic wavefield information in wavenumber region is necessary. Nevertheless, the seismic wavefield is generally obtained by costly forward modeling techniques. To reduce the computational cost, we substitute the spectrum of the seismic wavelet for the spectrum of the seismic wavefield, as the seismic wavelet plays a key role in determining the seismic wavefield. In solving the optimization problem, we design an exhaustive search method to obtain the solution of the L2 norm optimization problem. After solving the optimization problem, we are able to achieve the finite-difference weights that minimize spatial simulation error. In theoretical error analyses, the finite-difference weights from the proposed method can output more accurate simulation results compared to those from previous optimization algorithms. Furthermore, we validate our method through numerical tests with synthetic models, which encompass homogenous/inhomogeneous media as well as isotropic and anisotropic media.

Open cast mining — a predominant method of coal production in India (94.46% of total coal production) — has been found to be a major factor which is responsible for the emission of dust particles and gaseous pollutants, leading to the deterioration of air quality in the coal mining area. Considering the health concerns and environmental impacts of these pollutants, the inhabited villages of Ib valley coalfield area of Orisha, India, were selected for this study. In this regard, various researchers have performed the analysis of air quality data and modeling for the dispersion of pollutants. However, a long-term study on spatial and seasonal variations of air pollutants and their relationship with meteorological parameters were missing in the literature. Accordingly, the spatial and seasonal variations of air pollutants in the area were assessed for a period of six years (2014 – 2020), and concentrations of PM 2.5 , PM 10 , and SPM were found to be above the annual national ambient air quality standards (NAAQS) for all the three seasons. The overall mean concentrations of NO x , PM 10 , PM 2.5 , SPM, and SO 2 during this period were found to be 17.2 ± 9.28, 152.5 ± 99.7, 53.27 ± 37.70, 268.5 ± 158.2, and 12.58 ± 7.47 μg/m 3 , respectively. The analysis of meteorological parameters showed a strong and significant negative correlation of relative humidity with PM 2.5 ( r  =  − 0.30, p -value = 5.659 × 10 −10 ), PM 10 ( r  =  − 0.36, p -value = 1.97 × 10 −13 ), and SPM ( r  =  − 0.45, p -value = 2.2 × 10 −16 ). Furthermore, the spatial distribution of pollutants was performed using the geographic information system (GIS) and inverse distance weighting (IDW) method, wherein the seasonal distribution of pollutants was shown through the bivariate polar plots. Therefore, the analyses and recommendations provided in this study can help the policymakers in developing a long-term air quality improvement strategy around a coal mining area, including the spatial and seasonal variations of air pollutants and their relationship with meteorological parameters.

Noise-normalization has been shown to partly compensate for the localization bias towards superficial sources in minimum norm estimation. However, it has been argued that in order to make inferences for the case of multiple sources, localization properties alone are insufficient. Instead, multiple measures of resolution should be applied to both point-spread and cross-talk functions (PSFs and CTFs). Here, we demonstrate that noise-normalization affects the shapes of PSFs, but not of CTFs. We evaluated PSFs and CTFs for the MNE, dSPM and sLORETA inverse operators, on the metrics dipole localization error (DLE), spatial dispersion (SD) and overall amplitude (OA). We used 306-channel MEG configurations obtained from 17 subjects in a real experiment, including individual noise covariance matrices and head geometries. We confirmed that for PSFs DLE improved after noise normalization, and is zero for sLORETA. However, SD was generally lower for the unnormalized MNE. OA distributions were similar for all three methods, indicating that all three methods may greatly underestimate some sources relative to others. The reliability of differences between methods across subjects was demonstrated using distributions of standard deviations and p-values from paired t-tests. As predicted, the shapes of CTFs were the same for all methods, reflecting the general resolution limits of the inverse problem. This means that noise-normalization is of no consequence where linear estimation procedures are used as “spatial filters.” While low DLE is advantageous for the localization of a single source, or possibly a few spatially distinct sources, the benefit for the case of complex source distributions is not obvious. We suggest that software packages for source estimation should include comprehensive tools for evaluating the performance of different methods. ►Noise-normalization of inverse estimators affects the shapes of PSFs, but not CTFs. ►Spatial resolution of EEG/MEG should be assessed using multiple resolution metrics. ►Resolution metrics should describe localization, spatial extent and amplitude. ►dSPM and sLORETA have lower localization error than MNE, but larger spatial extent. ►The benefit of dSPM/sLORETA over MNE for complex source distributions is not clear.

This study extends efforts to incorporate spatial dispersion into Biot-Allard’s theory, with a focus on poroelastic media with intricate microgeometries where spatial dispersion effects play a significant role. While preserving Biot’s small-scale quasi-“en-bloc” frame motion to keep the structure of Biot-Allard’s theory intact, the paper challenges Biot’s quasi-incompressibility of fluid motion at that scale by introducing structurations in the form of Helmholtz’s resonators. Consequently, Biot-Allard’s theory undergoes a significant augmentation, marked by the arising of non-local dynamic tortuosity and compliability, which are associated with potentially resonant fluid behavior. Building on an acoustic-electromagnetic analogy, the study defines these non-local responses and suggests simplifying them into pseudo-local ones, now potentially resonant and reminiscent of Veselago-type phenomena. In the high-frequency limit of small boundary layers and as an extension of the classical Johnson-Allard’s findings, simple field-averaged formulas are demonstrated for pseudo-local ideal-fluid tortuosity and compliability (complex frequency-dependent) and viscous and thermal characteristic lengths (positive frequency-dependent). These formulations are grounded in the Umov-Heaviside-Poynting thermodynamic macroscopic acoustic stress concept, suggested by the analogy. Future computational investigations, spanning various fundamental microgeometries, are planned to assess assumed pseudo-local simplifications, encompass low- and intermediate frequencies, and unveil potential behavioral outcomes resulting from the incorporation of spatial dispersion effects.

The level of energy green consumption is an essential factor influencing China’s economy’s high-quality development. In this paper, we select relevant panel data from 2010 to 2019 for 28 cities in Beijing-Tianjin-Hebei and surrounding areas, and use the DPSIR model and spatial econometric model to analyze the spatial divergence characteristics and driving factors of the energy green consumption index based on the construction of the energy green consumption level evaluation index system and index measurement. The results of this research are as follows: (1) The energy green consumption index has a distribution pattern of “high in the east and low in the west, high in the north, and low in the south,” and the driving force (D) and response force (I) are the key factors influencing the spatial variation of the energy green consumption index. (2) The measurement results show that GDP per capita and built-up green coverage have a considerable positive effect on the energy green consumption index, whereas non-domestic energy structure has a significant inhibitory effect. (3) In terms of spatial spillover effects, greening coverage of built-up areas, industrial structure, and domestic energy structure, all have positive effects on neighboring regions’ energy green consumption indexes, with positive spatial spillover effects, whereas GDP per capita, urbanization level, and non-domestic energy structure, all have negative spatial spillover effects. In light of the issues at hand, this paper suggests making good efforts to create and put into practice laws and policy norms, cultivate green energy-saving markets, vigorously promote the use and promotion of energy-saving technologies, and lower energy consumption in secondary industry and domestic consumption. The study’s findings can help advance the modernization of the region’s industrial structure and the growth of a green economy by providing the local government with a reference point for timely policy adjustments.

The floodplain forests of the Danube Delta are among the important European biotopes and are protected in Slovakia under Natura 2000. In order to preserve these biotopes, their restoration is underway, which also restores the original fauna. These biotopes are sensitive to environmental and ecological changes, which is also reflected in the spatial distribution of epigeic arthropods. Between the years 2020 and 2023, we investigated the impact of floodplain restoration on the population structure of epigeic arthropods in eight study areas (two control study areas and six study areas with ongoing biotope restoration). We placed five pitfall traps in a transect for each biotope. In total, we recorded 66,771 individuals belonging to 15 arthropod taxa. We found differences in the taxonomic structures between forest stands with management and forest stands without management (larger number of taxa) using spatial modelling. We also confirmed interannual changes in the taxa composition of epigeic arthropods and their abundance. Over the years of restoration, the number of individual epigeic arthropods decreased. In the years following revitalization, when succession took place, it subsequently increased. Overall, the restoration management of floodplain forests had a positive effect on epigeic arthropods, as well as on their number of individuals, which is important for the preservation of these important habitats in Europe.

— Asymptotic calculations are provided for the effective magnetic permeability of a random ensemble of spherical particles in three cases where the material of the particles possesses high conductivity or a large positive or negative real part of the permittivity. Silicon was chosen for numerical calculations because it exhibits the described dielectric properties at different wavelengths of electromagnetic radiation. If silicon’s permittivity has a negative real part, a random ensemble of Si particles exhibits a negative efficient magnetic permeability once the packing factor exceeds 0.1. As the packing factor increases, the effective magnetic permeability approaches zero on both the negative and positive sides for particles with high conductivity and negative real part of dielectric permittivity, respectively.