Search Results (29)

Environmental DNA metabarcoding has proven to be a powerful tool for monitoring fish diversity, and has been widely used in both freshwater and marine ecosystems. Fish diversity is a critical indicator to assess ecosystem function and its health. In this study, we took 12 samples from four areas (Area 1 (LS1) is the edge of the seagrass field adjacent to oyster reefs; Area 3 (LS3) is the edge of the seagrass field adjacent to coral reefs; Area 2 (LS2) is situated between LS1 and LS3 where there is dense seagrass distribution around the sampling sites; and Area 4 (LS4) is located between LS1 and LS3; we sample in the places at least 4 m by 4 m on the beach where no seaweed is present, each with three replicates) from Li’an Bay to detect fish diversity across multi-habitat seagrass areas based on the environmental DNA metabarcoding. A total of 312 Amplicon Sequence Variants (ASVs) were detected from 12 samples, and 58 fish species were annotated, representing 21 orders, 32 families and 48 generas. In general, the mean of Simpson and Pielou’s evenness indices followed the pattern LS1 > LS4 > LS2 > LS3, while the mean of Shannon–Wiener Diversity Index is LS4 > LS1 > LS2 > LS3. A total of 35 functional entities were observed among the four areas, with functional redundancy (FR) values of 0.800, 0.657, 0.542, and 0.7 for LS1, LS2, LS3, and LS4, respectively. All FR values were below 1.5, suggesting low ecological niche overlap among species within each area. These findings provide fundamental insights into the ecological health and stability of seagrass beds in Li’an Bay and offer a scientific basis for future ecological restoration efforts. Full article

(1) Forest fragmentation and associated edge effects can strongly modify the diversity and distribution of soil invertebrates, yet their responses in temperate floodplain forests remain poorly understood. We investigated myriapod (centipede and millipede) assemblages in a fragmented forest mosaic in the protected landscape area Litovelské Pomoraví (Czech Republic), focusing on the role of stand age, ecotones and key microhabitat variables. (2) Myriapods were sampled continuously during two years using pitfall traps arranged along transects crossing four neighboring patches (clear-cut with seedlings, 10-year-old stand, 87-year-old and 127-year-old Querco–Ulmetum forests). Species diversity was quantified using the Shannon–Wiener index, and patterns were analyzed by t-tests, canonical correspondence analysis and generalized additive models. (3) We collected over six thousand individuals (10 centipede and 10 millipede species). Diversity peaked in old-growth stands and adjacent ecotones, and two of the three ecotones supported particularly high species abundances. Litter cover and thickness, stand age, and the structure of the herb and shrub layers were the most important predictors of species distributions. Dominant species (e.g., Glomeris tetrasticha Brandt, 1833, Lithobius mutabilis L. Koch, 1862, L. forficatus (Linnaeus, 1758)) showed contrasting habitat preferences, reflecting niche differentiation along microhabitat and stand-age gradients. (4) Our findings indicate that conserving a fine-grained mosaic of stand ages, together with structurally complex forest interiors and ecotones, is essential for maintaining myriapod diversity and the ecosystem functions they provide in Central European forests. Full article

Infrared remote sensing images are often degraded by blur and stripe noise caused by satellite attitude variations, optical distortions, and electronic interference, which significantly compromise image quality and target detection performance. Existing joint deblurring and destriping methods tend to over-smooth image edges and textures, failing to effectively preserve high-frequency details and sometimes misclassifying ringing artifacts as stripes. This paper proposes a variational framework for simultaneous deblurring and destriping of infrared remote sensing images. By leveraging an adaptive structure tensor model, the method exploits the sparsity and directionality of stripe noise, thereby enhancing edge and detail preservation. During blur kernel estimation, a fidelity term orthogonal to the stripe direction is introduced to suppress noise and residual stripes. In the image restoration stage, a WCOB (Non-blind restoration based on Wiener-Cosine composite filtering) model is proposed to effectively mitigate ringing artifacts and visual distortions. The overall optimization problem is efficiently solved using the alternating direction method of multipliers (ADMM). Extensive experiments on real infrared remote sensing datasets demonstrate that the proposed method achieves superior denoising and restoration performance, exhibiting strong robustness and practical applicability. Full article

Recent theoretical studies have shown that gapped Dirac materials (such as gapped monolayer graphene) optically pumped with circularly polarized light can host edge-localized plasmon modes with nonreciprocal dispersions driven by valley population imbalance. Here, we extend this framework to Bernal-stacked bilayer graphene. Using the Wiener–Hopf method, we compute the exact edge plasmon dispersion, confinement length, and electric potential. Our results show that bilayer graphene exhibits stronger nonreciprocity in edge plasmons, requiring approximately one order of magnitude lower pump amplitude to achieve splitting compared with monolayer Dirac systems. Furthermore, the gate-tunable energy gap of bilayer graphene provides an additional degree of control, positioning optically pumped bilayer graphene as a versatile platform for magnet-free nonreciprocal plasmonics. Full article

Urban expansion fragments once-contiguous forest patches, generating pronounced edge gradients that modulate soil physicochemical properties and biodiversity. We quantified how fragmentation reshaped the soil microbiome continuum and its implications for soil carbon storage in a temperate urban mixed deciduous forest. A total of 18 plots were considered in this study, with six plots for each fragment type. Intact interior forest (F), internal forest path fragment (IF), and external forest path fragment (EF) soils were sampled at 0–15, 15–30, and 30–45 cm depths and profiled through phospholipid-derived fatty acid (PLFA) chemotyping and amino sugar proxies for living microbiome and microbial-derived necromass assessment, respectively. Carbon fractionation was performed through the chemical oxidation method. Diversity indices (Shannon–Wiener, Pielou evenness, Margalef richness, and Simpson dominance) were calculated based on the determined fatty acids derived from the phospholipid fraction. The microbial biomass ranged from 85.1 to 214.6 nmol g⁻¹ dry soil, with the surface layers of F exhibiting the highest values (p < 0.01). Shannon diversity declined systematically from F > IF > EF. The microbial necromass varied from 11.3 to 23.2 g⋅kg⁻¹. Fragmentation intensified the stratification of carbon pools, with organic carbon decreasing by approximately 14% from F to EF. Our results show that EFs possess a declining microbiome continuum that weakens their carbon sequestration capacity in urban forests. Full article

Understanding the characteristics of urban plant multidimensional diversity and urban green spaces (UGSs) landscape patterns is the central theme of urban ecology, providing theoretical support for UGSs management and biodiversity conservation. Taking Changchun, a provincial city, as an example, a total of 240 plots were surveyed using the stratified random sampling method. We studied the effects of the urban park construction period on plant multidimensional diversities, landscape patterns of green spaces, and their associations in Changchun City, Northeast China. The results indicated that total woody species and tree species diversity attributes were both the highest in the construction period of 2001–2020 and lowest in the construction period before 1940. However, shrub species diversity attributes were completely the opposite. Diameter at the breast height (DBH) diversity index (H_d) was the highest in the construction period before 1940 and lowest in the construction period of 2001–2020. However, the height diversity index (H_h) showed the opposite trend. Phylogenetic structures of total woody species and tree species showed divergent patterns in parks constructed before 1940 and 1940–2000 period, while that in 2001–2020 period could not be determined. In contrast, the phylogenetic structure of the shrub species clustered across all construction periods. Landscape pattern metrics varied significantly among different construction periods. Total Area (TA) was the highest in the construction period of 2001–2020. The structural equation model (SEM) revealed that construction periods exerted significant direct effects on both multidimensional diversities and landscape patterns of green spaces. Specifically, construction periods indirectly affected tree species diversity through structural diversity and influenced shrub species’ phylogenetic diversity through shrub species diversity. What is more, Patch Density (PD), Edge Density (ED), and Aggregation Index (AI) correlated with H_h, which had a direct effect on the Shannon–Wiener diversity index of tree species (H′_t). Overall, the results indicated that species diversity can be enhanced through regulating landscape patterns, rationally selecting tree species, and optimizing plant configuration. These above results can provide scientific references for the configuration of plant communities and selection of tree species in urban parks, and offer important guidance for urban biodiversity conservation and enhancement. Full article

Here, the single-target parameterization of alternatives to leading-edge noise is carried out using analytical models based on the Wiener–Hopf technique. Four leading-edge serration profiles with different frequencies, amplitudes, and phases are implemented to aid the understanding of sound suppression mechanisms. The effects of the serrated shape factor, wavelength, and amplitude are analyzed at tip-to-root ratios of 0.5, 1, and 2, respectively. An effective double-wavelength sinusoidal serration design can substantially reduce the noise emissions of 5.2 dB at $\overline{h}$ = 2. Additionally, compared to single-wavelength serrations, an additional 1.47 dB noise reduction effect can be obtained by double-wavelength serrations under the appropriate design parameters. The surface pressure and phase distribution of different spanwise-varying leading edges indicate that the phase interference effect affected by source-radiated noise reduction is enhanced by this serration at the hills for serrations with a small curvature, and noise emission in the low-frequency band is more effectively suppressed. The sharper the serration is, the more conducive it is to a reduction in high-frequency noise. Nevertheless, the effectiveness of serrations is usually partially limited by the non-negligible trailing-edge self-noise. The sound source intensity of the root is decreased by the ogee-shaped serrations with a large curvature transition. A secondary noise reduction mechanism with a local source cut-off effect caused by nonlinearity is demonstrated. Full article

This study utilized a remotely sensed dataset with a high spatial resolution of 3 m to predict species diversity in the Bobiri Forest Reserve (BFR), a moist semi-deciduous tropical forest in Ghana. We conducted a field campaign of tree species measurements to achieve this objective for species diversity estimation. Thirty-five field plots of 50 m × 20 m were established, and the most dominant tree species within the forest were identified. Other measurements, such as diameter at breast height (DBH ≥ 5 cm), tree height, and each plot’s GPS coordinates, were recorded. The following species diversity indices were estimated from the field measurements: Shannon–Wiener (H′), Simpson diversity index (D₂), species richness (S), and species evenness (J′). The PlanetScope surface reflectance data at 3 m spatial resolution was acquired and preprocessed for species diversity prediction. The spectral/pixel information of all bands, except the coastal band, was extracted for further processing. Vegetation indices (VIs) (NDVI—normalized difference vegetation index, EVI—enhanced vegetation index, SRI—simple ratio index, SAVI—soil adjusted vegetation index, and NDRE—normalized difference red edge index) were also calculated from the spectral bands and their pixel value extracted. A correlation analysis was then performed between the spectral bands and VIs with the species diversity index. The results showed that spectral bands 6 (red) and 2 (blue) significantly correlated with the two main species diversity indices (S and H′) due to their influence on vegetation properties, such as canopy biomass and leaf chlorophyll content. Furthermore, we conducted a stepwise regression analysis to investigate the most important spectral bands to consider when estimating species diversity from the PlanetScope satellite data. Like the correlation results, bands 6 (red) and 2 (blue) were the most important bands to be considered for predicting species diversity. The model equations from the stepwise regression were used to predict tree species diversity. Overall, the study’s findings emphasize the relevance of remotely sensed data in assessing the ecological condition of protected areas, a tool for decision-making in biodiversity conservation. Full article

The Gullele Botanic Garden was established to preserve and safeguard indigenous, rare, endemic, endangered, and economically important plant species. The objective of this study was to identify and map the exotic, invasive, and potentially invasive plant species that are present in the garden’s various land use types, such as natural vegetation, plantations, roadsides and garden edges. The research involved laying plots at different distances in each land use type and collecting vegetation data with geo-location information. Sorensen’s similarity index was used to measure the floristic similarity between the sampled land use types. Data on species density and abundance were analyzed using the corresponding formula. The Shannon–Wiener diversity index and evenness were used to compute the diversity of the species in each land use type using R packages. ArcGIS version 10.5 was used to track the geographical distribution and map the exotic, invasive, and potentially invasive species that exist in all land use types of the garden. A total of 80 plant species belonging to 70 genera in 44 families were recorded in the garden. Asteraceae, Myrtaceae, and Fabaceae comprised the highest number of species. Acacia decurrens, Acacia melanoxylon, Cuscuta campestris, Galinsoga parviflora, Nerium oleander, and Cyathula uncinulata were the most prevalent invasive and potentially invasive species. The study found that the roadside and garden edge land use types had the most diverse exotic and invasive plants. The total density of exotic species was 2.36 plants/m². The potential possibility of these plants in displacing the native plant species is quite high unless the introduction of exotic plant species is inspected and appropriate management strategies for invasive species are put in place. Full article

A set of one-dimensional (as well as one two-dimensional) Fredholm integral equations (IEs) of the first kind of convolution type is solved. The task for solving these equations is ill-posed (first of all, unstable); therefore, the Wiener parametric filtering method (WPFM) and the Tikhonov regularization method (TRM) are used to solve them. The variant is considered when a kernel of the integral equation (IE) is unknown or known inaccurately, which generates a significant error in the solution of IE. The so-called “spectral method” is being developed to determine the kernel of an integral equation based on the Fourier spectrum, which leads to a decrease of the error in solving the IE and image improvement. Moreover, the authors also propose a method for diffusing the solution edges to suppress the possible Gibbs effect (ringing-type distortions). As applications, the problems for processing distorted (smeared, defocused, noisy, and with the Gibbs effect) images are considered. Numerical examples are given to illustrate the use of the “spectral method” to enhance the accuracy and stability of processing distorted images through their mathematical and computer processing. Full article

The Wiener process was used to explore the (2 + 1)-dimensional chiral nonlinear Schrödinger equation (CNLSE). This model outlines the energy characteristics of quantum physics’ fractional Hall effect edge states. The sine-Gordon expansion technique (SGET) was implemented to extract stochastic solutions for the CNLSE through multiplicative noise effects. This method accurately described a variety of solitary behaviors, including bright solitons, dark periodic envelopes, solitonic forms, and dissipative and dissipative–soliton-like waves, showing how the solutions changed as the values of the studied system’s physical parameters were changed. The stochastic parameter was shown to affect the damping, growth, and conversion effects on the bright (dark) envelope and shock-forced oscillatory wave energy, amplitudes, and frequencies. In addition, the intensity of noise resulted in enormous periodic envelope stochastic structures and shock-forced oscillatory behaviors. The proposed technique is applicable to various energy equations in the nonlinear applied sciences. Full article

Background and Objectives: Brain Tumor Fusion-based Segments and Classification-Non-enhancing tumor (BTFSC-Net) is a hybrid system for classifying brain tumors that combine medical image fusion, segmentation, feature extraction, and classification procedures. Materials and Methods: to reduce noise from medical images, the hybrid probabilistic wiener filter (HPWF) is first applied as a preprocessing step. Then, to combine robust edge analysis (REA) properties in magnetic resonance imaging (MRI) and computed tomography (CT) medical images, a fusion network based on deep learning convolutional neural networks (DLCNN) is developed. Here, the brain images’ slopes and borders are detected using REA. To separate the sick region from the color image, adaptive fuzzy c-means integrated k-means (HFCMIK) clustering is then implemented. To extract hybrid features from the fused image, low-level features based on the redundant discrete wavelet transform (RDWT), empirical color features, and texture characteristics based on the gray-level cooccurrence matrix (GLCM) are also used. Finally, to distinguish between benign and malignant tumors, a deep learning probabilistic neural network (DLPNN) is deployed. Results: according to the findings, the suggested BTFSC-Net model performed better than more traditional preprocessing, fusion, segmentation, and classification techniques. Additionally, 99.21% segmentation accuracy and 99.46% classification accuracy were reached using the proposed BTFSC-Net model. Conclusions: earlier approaches have not performed as well as our presented method for image fusion, segmentation, feature extraction, classification operations, and brain tumor classification. These results illustrate that the designed approach performed more effectively in terms of enhanced quantitative evaluation with better accuracy as well as visual performance. Full article

In the modern era, mathematical modeling consisting of graph theoretic parameters or invariants applied to solve the problems existing in various disciplines of physical sciences like computer sciences, physics, and chemistry. Topological indices (TIs) are one of the graph invariants which are frequently used to identify the different physicochemical and structural properties of molecular graphs. Wiener index is the first distance-based TI that is used to compute the boiling points of the paraffine. For a graph F, the recently developed Gutman Connection (GC) index is defined on all the unordered pairs of vertices as the sum of the multiplications of the connection numbers and the distance between them. In this note, the $GC$ index of the operation-based symmetric networks called by first derived graph $D_1\left(F\right)$ (subdivision graph), second derived graph $D_2\left(F\right)$ (vertex-semitotal graph), third derived graph $D_3\left(F\right)$ (edge-semitotal graph) and fourth derived graph $D_4\left(F\right)$ (total graph) are computed in their general expressions consisting of various TIs of the parent graph F, where these operation-based symmetric graphs are obtained by applying the operations of subdivision, vertex semitotal, edge semitotal and the total on the graph F respectively. Full article

The advent of fuzzy sets, and consequently fuzzy graphs, has solved many problems in ambiguous and uncertain contexts. It is interesting and necessary to study the Wiener index in a cubic fuzzy graph that employs both fuzzy membership and interval-valued fuzzy membership at the same time. In this paper, the Wiener index in a cubic fuzzy graph is introduced as a cubic fuzzy number and some related results are described. The comparison between connectivity index and Wiener index, changes in Wiener index through deleting a node or an edge, and determining the Wiener index in some specific cubic fuzzy graphs have been the other topics studied in this research. In addition, the Wiener index is determined by mentioning concepts of the saturated cubic fuzzy cycle. In this review, the Wiener index is shown as a combination of classical and interval numbers. The results indicate that when some vertices are removed, the Wiener index may change. However, this change will not be exclusively related to both values. Finally, an application of the Wiener index is presented in the study of the properties of some monomer molecules. Full article

A topological index is a number derived from a molecular structure (i.e., a graph) that represents the fundamental structural characteristics of a suggested molecule. Various topological indices, including the atom-bond connectivity index, the geometric–arithmetic index, and the Randić index, can be utilized to determine various characteristics, such as physicochemical activity, chemical activity, and thermodynamic properties. Meanwhile, the non-commuting graph ${\mathrm{\Gamma }}_{\mathcal{G}}$ of a finite group $\mathcal{G}$ is a graph where non-central elements of $\mathcal{G}$ are its vertex set, while two different elements are edge connected when they do not commute in $\mathcal{G}$. In this article, we investigate several topological properties of non-commuting graphs of finite groups, such as the Harary index, the harmonic index, the Randić index, reciprocal Wiener index, atomic-bond connectivity index, and the geometric–arithmetic index. In addition, we analyze the Hosoya characteristics, such as the Hosoya polynomial and the reciprocal status Hosoya polynomial of the non-commuting graphs over finite subgroups of $SL(2,\mathbb{C})$. We then calculate the Hosoya index for non-commuting graphs of binary dihedral groups. Full article