Index Theory Research Articles

Atrial Topology for a Unified Understanding of Typical and Atypical Flutter.

Macroreentry stands as the predominant mechanism of typical and atypical flutter. Despite advances in mapping, many aspects of macroreentrant atrial tachycardia remain unsolved. In this translational study, we applied principles of topology to understand the activation patterns, entrainment characteristics, and ablation responses in a large clinical macroreentrant atrial tachycardia database. Because the atrium can be topologically seen as a closed sphere with holes, we used a computational fixed spherical mesh model with a finite number of holes to induce and analyze macroreentrant atrial tachycardia. The ensuing insights were used to interpret high-density activation maps, postpacing interval-tachycardia cycle length values (difference between postpacing interval and tachycardia cycle length), and ablation response in 131 cases of typical and atypical flutter (n=106 left atrium, n=25 right atrium). Modeling of macroreentrant atrial tachycardia revealed that reentry on closed surfaces consistently manifests itself as paired rotation and that an odd number of critical boundaries is mathematically impossible. Together with mathematical confirmation by the index theorem, this led to a unifying construct that could explain the number of loops, difference between postpacing interval and tachycardia cycle length values, and ablation outcomes (termination, no change, or prolongation in tachycardia cycle length) in all 131 cases. Combining topology with the index theorem offers a novel and cohesive framework for understanding and managing typical and atypical flutter.

A Study on Positive Solutions to Nonlinear Fractional Differential Equations

The purpose of this article concerns a type of nonlinear boundary value problem of fractional differential equations with the Caputo derivative. Using the fixed point index theory of condensing mapping in cones, the existence results of positive solutions for such a problem are obtained.

Adding gastrointestinal parasite resistance to the breeding objective in hair sheep: initial steps.

The U.S. Maternal Hair index was designed by the National Sheep Improvement Program (NSIP) to increase total weight of lamb weaned per ewe lambing (TW). Producers are interested in adding gastrointestinal nematode (GIN) resistance to this breeding objective since parasitism causes substantial economic losses. The NSIP provides producers with estimated breeding values (EBV) for post-weaning fecal egg count (PFEC), an indicator of GIN resistance. Our objective was to gauge the effects of including PFEC as another selection criterion and goal trait. Selection index theory was used to construct 11 indexes. First was a benchmark index with TW as the goal. Weaning weight, and number of lambs born and weaned, were selection criteria. An index was then designed with PFEC added as a selection criterion. In 9 more indices, PFEC was also included as a goal trait, where the economic value of TW was scaled relative to that of PFEC. PFEC received a scaled economic value of -1 with that of TW increasing from +1 to +5 at +0.5 increments. Selection criteria were modelled as EBV or phenotypes. Annual genetic responses in goal traits were predicted. The top 3% of males and 26% of females were selected. Breeding values and phenotypes were simulated for 200 lambs by Cholesky decomposition and used to generate index scores, with 100 replicates run. Concordances with the animals selected in the benchmark scenario were determined. Using EBV as selection criteria, TW increased by 1.46kg/yr in the benchmark scenario. However, unfavorably, PFEC increased by 2.24%/yr. When using phenotypic criteria, TW increased by 0.52kg/yr and PFEC by 0.28%/yr. Once added as a goal trait, PFEC decreased regardless of the scaled economic value of TW. However, responses in TW were also reduced, although less so as its scaled economic value increased. A scaled economic value of +3 for TW appeared reasonable over other choices with 79% of the emphasis placed on TW in the breeding objective. With EBV as selection criteria, PFEC declined by 7.96%/yr with 98% of the response in TW retained. Also, on average, 64% of males and 80% of females were chosen in common with the benchmark. With phenotypic selection criteria, PFEC declined by 5.13%/yr and 94% of the response in TW was retained; 61% of males and 80% of females were chosen in common with the benchmark. Implementing an index with scaled economic values of +3 for TW and -1 for PFEC would balance gains in TW with reductions in PFEC.

A pressure index for the team batting second in T20I cricket

In sports, players usually undergo pressure situations in order to meet certain performance standards set by themselves or others. During the course of any competitive sporting event, players are often motivated to take calculated risks in attempts to secure a victory or to showcase their performance capabilities. However, quantifying the pressure experienced by players at any given stage of a game is quite a challenging and imposing task. This study discusses a method to compute the pressure experienced by batters when pursuing a target in a T20I cricket match. Diligent and extensive exploration of psychological pressures motivates us to formulate a differential equation, based on a set of reasonable assumptions, whose solution gives rise to a useful pressure index formula for quantifying the level of pressure experienced by the batters of the team batting second, i.e., the team chasing the target. This index takes into account two key assumptions: first, the rate of change of pressure on the batters at a given stage of the game depends on the pressure at that stage; and, second, the required run rate commensurate with available resources remaining at that stage of the game. The available data are used to fine-tune the parameter of the model. The applicability of the proposed pressure index is illustrated using data for T20I matches played by the major test playing countries during the years 2017, 2018, 2019, and 2021. Additionally, this pressure index can be used not only to predict the probability of winning at any given stage of the second innings, but also to quantify the contribution of each batter, taking into account the pressure situation in which they score runs.

Contributions to Generalized Oscillation Theory of Linear Hamiltonian Systems

In this paper we present several new contributions to the oscillation theory of linear differential equations, in particular of linear Hamiltonian systems, when the traditional Legendre condition is absent. Following our recent work (Discrete Contin. Dyn. Syst. 43(12):4139–4173, 2023), we introduce the multiplicity of a generalized right focal point and derive the corresponding local Sturmian separation theorem. We also examine the relation between the existence of finitely many generalized right focal points, or in the special case the nonexistence of generalized right focal points, with the Legendre condition. As the main tools we use new notions of the minimal multiplicities at a given point and the dual comparative index — an object from matrix analysis or differential geometry (Maslov index theory). Furthermore, we study local limit properties of the dual comparative index and the comparative index and apply them for deriving new oscillation results phrased in terms of the generalized right and left focal points. The investigation of the interplay between generalized right and left focal points leads to conditions characterizing the situation, when in the local Sturmian separation theorem the corresponding multiplicities attain the minimal possible value. This also provides a generalization of the concepts of the right and left proper focal point defined by Kratz (Analysis 23(2):163–183, 2003) and Wahrheit (Int. J. Differ. Equ. 2(2):221–244, 2007) to the setting, which does not impose the Legendre condition. The results are new even for completely controllable linear Hamiltonian systems, including the Sturm–Liouville differential equations of arbitrary even order.

Bi-TAM-Net framework: fault diagnosis for insulated bearing based on new noise-resistant time-series framework

Abstract Insulated bearings are extensively employed in wind turbines and other applications as essential core parts of high-power frequency control motors. However, the influence of the wind turbine structure makes it difficult to define the wind turbine insulated bearing fault signal extraction, and there is no distinctive index or qualitative formula to describe the bearing fault. In order to solve the above challenges, Bi-TAM-Net framework is developed to diagnose the insulated bearing fault signals and achieve accurate identification of bearing faults. Firstly, the temporal information feature fusion model is created by the Bi-TAM-Net framework using the time-series bearing dataset as the model data input with recursive and chain linking rules in the direction of time-series evolution. By virtue of its parallel approach and deep stacking structure, it comprehensively portrays the bearing fault data and temporally fuses the global feature information, which can effectively improve the classification performance of insulated bearing fault data. Then the self-attention mechanism is introduced into the structure of the designed temporal information fusion model for optimization, which can be modeled in sequences of arbitrary length, extracting the correlation between the features, isolating the unimportant noise information, and strengthening the extraction ability of the proposed framework for important information. Finally, in order to verify the accuracy and superiority of the developed Bi-TAM-Net framework for bearing faults, based on the same dataset, the Bi-TAM-Net framework is compared and analyzed with seven methods such as the advanced TAM-Net model, and the results show that the Bi-TAM-Net framework has better superiority. This study offers the analytical approach with engineering application value for the design and maintenance of insulated bearings used in wind turbines.

The effects of toxin and mutual interference among zooplankton on a diffusive plankton–fish model with Crowley–Martin functional response

A diffusive phytoplankton–zooplankton–fish model with toxin and Crowley–Martin functional response is considered. By the global bifurcation theorem and the fixed point index theory, the existence and multiplicity of coexistence states are discussed. Secondly, we investigate the bifurcation from a double eigenvalue by virtue of Lyapunov–Schmidt procedure and implicit function theorem. Then, the effect of large k, which measures the magnitude of interference among zooplankton, is studied by means of the combination of the perturbation theory and topological degree theory. The results indicate that if k is large enough, this system has only a unique asymptotically stable coexistence state provided that toxin is properly small and the maximal growth rates of phytoplankton and fish are suitably large. Furthermore, the extinction and permanence of the time-dependent system are determined by virtue of the comparison principle. Finally, we make some numerical simulations to validate and complement the theoretical analysis and exhibit the critical role of toxin, spatial diffusion and magnitude of interference among zooplankton in the dynamics. The findings suggest that the spatiotemporal dynamics of the systems with toxin and Crowley–Martin functional response are richer and more complex, and toxin and spatial diffusion have significant effects on the coexistence of phytoplankton–zooplankton–fish species.

Localizing Transitions via Interaction-Induced Flat Bands.

This Letter presents a theory of interaction-induced band-flattening in strongly correlated electron systems. We begin by illustrating an inherent connection between flat bands and index theorems, and presenting a generic prescription for constructing flat bands by periodically repeating local Hamiltonians with topological zero modes. Specifically, we demonstrate that a Dirac particle in an external, spatially periodic magnetic field can be cast in this form. We derive a condition on the field to produce perfectly flat bands and provide an exact analytical solution for the flat band wave functions. Furthermore, we explore an interacting model of Dirac fermions in a spatially inhomogeneous field. We show that certain Hubbard-Stratonovich configurations exist that "rectify" the field configuration, inducing band flattening. We present an explicit model where this localization scenario is energetically favorable-specifically in Dirac systems with nearly flat bands, where the energy cost of rectifying textures is quadratic in the order parameter, whereas the energy gain from flattening is linear. In conclusion, we discuss alternative symmetry-breaking channels, especially superconductivity, and propose that these interaction-induced band-flattening scenarios represent a generic nonperturbative mechanism for spontaneous symmetry breaking, pertinent to many strongly correlated electron systems.

From Spectral Characteristics to Index Bands: Utilizing UAV Hyperspectral Index Optimization on Algorithms for Estimating Canopy Nitrogen Concentration in Carya Cathayensis Sarg

Employing drones and hyperspectral imagers for large-scale, precise evaluation of nitrogen (N) concentration in Carya cathayensis Sarg canopies is crucial for accurately managing nitrogen fertilization in C. cathayensis Sarg cultivation. This study gathered five sets of hyperspectral imagery data from C. cathayensis Sarg plantations across four distinct locations with varying environmental stresses using drones. The research assessed the canopy nitrogen concentration of C. cathayensis Sarg trees both during singular growth periods and throughout their entire growth cycles. The objective was to explore the influence of band combinations and spectral index formula configurations on the predictive capability of the hyperspectral indices (HIs) for canopy N concentration (CNC), optimize the performance between HIs and machine learning approaches, and validate the efficacy of optimized HI algorithms. The findings revealed the following: (i) Optimized HIs demonstrated optimal predictive performance during both singular growth periods and the full growth cycles of C. cathayensis Sarg. The most effective HI model for singular growth periods was the optimized–modified–normalized difference vegetation index (opt-mNDVI), achieving an adjusted coefficient of determination (R2) of 0.96 and a root mean square error (RMSE) of 0.71. For the entire growth cycle, the HI model, also opt-mNDVI, attained an R2 of 0.75 and an RMSE of 2.11; (ii) optimized band combinations substantially enhanced HIs’ predictive performance by 16% to 71%, while the choice between three-band and two-band combinations influenced the predictive capacity of optimized HIs by 4% to 46%. Hence, utilizing optimized HIs combined with Unmanned Aerial Vehicle (UAV) hyperspectral imaging to evaluate nitrogen concentration in C. cathayensis Sarg trees under complex field conditions offers significant practical value.

Innovative development indices for the national economies: on the way to the “ideal” assessment of innovation processes in the countries of the world

Purpose: is to develop recommendations for the construction of new indices of innovative development designed for cross-country comparisons.Methods: the conventional general scientific methods were used in the article, such as the ones of description, comparison, system analysis and historical comparison. The study was based on the documents describing calculation methods of the economic indices and scientific publications covering the history, specifics and problems of the practical application of those indices.Results: it is shown that since the 1930s, when the creation of economic indices drew attention of economic science, indices have evolved from the relatively simple statistical indicators to the complex tools with sophisticated calculation methods. Using several of the most famous or remarkable indices as an example, the principal methods currently used in assessing the level of innovative development are revealed. Basing on the conducted research, the major requirements for composing innovative development indices are stipulated.Conclusions and Relevance: it has been found out that in order to achieve the maximum objectivity in compiling indices of innovative development, the widest possible range of significant indicators should be used and a pool of experts should be engaged in their selection. It is also advisable to engage the pool in compiling the index formula, in particular the indicators weights. Data normalization should be used to ensure comparability of incommensurable indicators, and statistical outliers are advised to be neutralized through standardization techniques. It is also necessary to take into account the goals of the index compiled. At the same time, in the future it is necessary to take into account relationships between the actors of national innovation systems and between different innovation systems, effects of scale and, when possible, sectoral specialization of countries and other national specifics.

GTDI: a game-theory-based integrated drought index implying hazard-causing and hazard-bearing impact change

Abstract. Developing an effective and reliable integrated drought index is crucial for tracking and identifying droughts. The study employs game theory to create a spatially variable weight drought index (game-theory-based drought index, GTDI) by combining two single-type indices: an agricultural drought index (standardized soil moisture index, SSMI), which implies drought hazard-bearing conditions, and a meteorological drought index (standardized precipitation evapotranspiration index, SPEI), which implies drought hazard-causing conditions. In addition, the entropy-theory-based drought index (ETDI) is introduced to incorporate a spatial comparison with GTDI to illustrate the rationality of gaming weight integration, as both entropy theory and game theory belong to linear combination methods in the development of the integrated drought index and entropy theory has been applied in related research. Leaf area index (LAI) data are employed to confirm the reliability of GTDI in identifying drought by comparing it with SPEI, SSMI, and ETDI. Furthermore, a comparative analysis is conducted on the temporal trajectories and spatial evolution of the GTDI-identified drought to discuss GTDI's level of advancement in monitoring changes in hazard-causing and hazard-bearing impacts. The results show that GTDI has a very high correlation with single-type drought indices (SPEI and SSMI), and its gaming weight integration is more logical and trustworthy than that of ETDI. As a result, it outperforms ETDI, SPEI, and SSMI in recognizing drought spatiotemporally and is projected to replace single-type drought indices to provide a more accurate picture of actual drought. Additionally, GTDI exhibits the gaming feature, indicating a distinct benefit in monitoring changes in hazard-causing and hazard-bearing impacts. The case studies show that drought events in the Wei River basin are dominated by a lack of precipitation. The hazard-causing index, SPEI, dominates the early stages of a drought event, whereas the hazard-bearing index, SSMI, dominates the later stages. This study surely serves as a helpful reference for the development of integrated drought indices as well as regional drought prevention and monitoring.

Topological Levinson’s theorem in presence of embedded thresholds and discontinuities of the scattering matrix: A quasi-1D example

A family of quasi-[Formula: see text]D Schrödinger operators is investigated through scattering theory. The continuous spectrum of these operators exhibits changes of multiplicity, and some of these operators possess resonances at thresholds. It is shown that the corresponding wave operators belong to an explicitly constructed [Formula: see text]-algebra. The quotient of this algebra by the ideal of compact operators is studied, and an index theorem is deduced from these investigations. This result corresponds to a topological version of Levinson’s theorem in the presence of embedded thresholds, resonances, and changes of multiplicity of the scattering matrices. In the last two sections of the paper, the [Formula: see text]-theory of the main [Formula: see text]-algebra and the dependence on an external parameter are carefully analyzed. In particular, a surface of resonances is exhibited, probably for the first time. The contents of these two sections are of independent interest, and the main result does not depend on them.

Investigating the Correlation Between Cognitive Function and Fasting Blood Sugar, Fasting Insulin Level and Insulin Sensitivity in Patients With Multiple Sclerosis.

There has been a surge in interest in identifying the factors that impact cognitive impairment (CI) in patients with multiple sclerosis (MS). The purpose of our study was to examine the correlation between fasting blood sugar (FBS), fasting insulin level, as well as insulin sensitivity and cognitive function in patients with MS. A total of 85 patients with MS enrolled in this cross-sectional study. Insulin sensitivity (IS) was determined using the quantitative insulin sensitivity check index (Quicki) formula. Cognitive function was evaluated using the Persian version of the Brief International Cognitive Assessment for MS (BICAMS). Spearman correlation test was employed to examine the correlation between cognition and FBS, insulin and IS. The mean ± SD age of the participants was 39.4 ± 10.2 years, and 62 (72.9%) were female. The participants had a FBS level of 87.05 ± 11.73 mg/dL, insulin level of 10.14 ± 7.57 μU/mL and a Quicki index of 0.36 ± 0.05. A higher score on the BVMT-R and BVMT-R-Delayed subtests showed a significant negative correlation with FBS (r: -0.32; p: 0.003 and r: -0.31; p: 0.004, respectively). Conversely, a significant negative correlation (r: -0.24; p: 0.031) was observed between higher fasting insulin levels and the CVLT_II score. IS showed a positive correlation with the CVLT-II (r: 0.24; p: 0.027) and BVMT_R (r: 0.21; p: 0.054) subtests. Our data indicate that elevated fasting glucose, developed fasting insulin levels and reduced insulin sensitivity may serve as potential predictors for CI in patients with MS.

Readability Level of Spanish Language Online Health Information: A Systematic Review.

Introduction: Because there is limited online health information in Spanish and it is critical to raise health literacy among Spanish-speaking people, it is essential to assess the readability level of Spanish material. Method: This systematic review included all articles published up to January 3, 2024, and used the CINAHL, MEDLINE, and PubMed databases. The objective was to include the body of knowledge on published articles on the readability levels of Spanish-language, web-based health information intended for lay audiences. Results: There were 27 articles in the final review. Within these articles, 11 tools were used in the Spanish language text. Of the tools, INFLESZ was the most frequently used and the FRY formula, Flesch-Szigriszt Index, and Flesch Formula Index were least used. Most materials (85.2%) reported readability levels of online Spanish information above the 8th grade reading level. Conclusions: The findings show the lack of internet-based Spanish language health information and materials at a recommended (e.g., 5th to 8th grade) reading level. More research is needed to determine which readability tests are more accurate for calculating the readability of Spanish web health information.

Finely tuned energy gaps in host-guest complexes: Insights from belt[14]pyridine and fullerene-based nano-Saturn systems

Over the past few decades, doping, physisorption and chemisorption remained some of the commonly utilized methods to modify the energy gaps and electronic properties of materials. Yet, achieving precise control over tuning the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels within these systems persisted as a remarkable challenge. Therefore, there is a growing need for systems that facilitate exact adjustments of energy gaps and HOMO/LUMO levels. Here, in this research work, the nano-Saturn host-guest complex systems are designed based on belt[14]pyridine as a host and fullerene nanocages (C20, C32, C34 and C36) as guests. The greater thermodynamic stability of the complexes is revealed by the higher values of interaction energies (Eint) for these complexes, ranging from −45.50 to −56.81 kcal/mol. The frontier molecular orbital (FMO) analysis revealed the contribution of HOMO of fullerenes and LUMO of belt[14]pyridine towards the HOMO and LUMO of the designed complexes, respectively. The energy gaps of the complexes also decrease compared to the constituents, with the least Egap of 0.52 eV observed for C20@N-belt. Moreover, the charge transfer from the host towards the guests is predicted and confirmed via natural bond orbital (NBO) and electron density difference (EDD) analyses. The non-covalent interaction index (NCI) and quantum theory of atoms in molecules (QTAIM) analyses determine the nature and strength of interactions in the host-guest complexes. Moreover, it is noticed through the UV–vis analysis that the bare fullerenes show the maximum absorption in ultraviolet (UV) region, but after complexation, maximum absorption is observed in visible and near infrared (NIR) regions, with highest λmax of 927 nm for C36@N-belt. These findings highlight the successful development of nano-Saturn host-guest complexes with precise control over HOMO-LUMO levels and energy gaps. This work aims to address the challenges in fine-tuning the electronic properties and demonstrates potential applications in optoelectronics, photovoltaics, and NIR-based sensors. Moreover, the ability to tune the electronic properties can guide future material design strategies for advanced energy storage and photonic devices.

Compound Poisson distributions for random dynamical systems using probabilistic approximations

We obtain quenched hitting distributions to be compound Poissonian for a certain class of random dynamical systems. The theory is general and designed to accommodate non-uniformly expanding behavior and targets that do not overlap much with the region where uniformity breaks. Based on annealed and quenched polynomial decay of correlations, our quenched result adopts annealed Kac-type time-normalization and finds limits to be noise-independent. The technique involves a probabilistic block-approximation where the quenched hit-counting function up to annealed Kac-normalized time is split into equally sized blocks which are mimicked by an independency of random variables distributed just like each of them. The theory is made operational due to a result that allows certain hitting quantities to be recovered from return quantities. Our application is to a class of random piecewise expanding one-dimensional systems, casting new light on the well-known deterministic dichotomy between periodic and aperiodic points, their usual extremal index formula EI=1−1/JTp(x0), and recovering the Polya-Aeppli case for general Bernoulli-driven systems, but distinct behavior otherwise.

Analysis, Geometry and Topology of Positive Scalar Curvature Metrics

Riemannian metrics with positive scalar curvature play an important role in differential geometry and general relativity. To investigate these metrics, it is necessary to employ concepts and techniques from global analysis, geometric topology, metric geometry, index theory, and general relativity. This workshop brought together researchers from a variety of backgrounds to combine their expertise and promote cross-disciplinary exchange.

Nondestructive Detection of Corky Disease in Symptomless 'Akizuki' Pears via Raman Spectroscopy.

'Akizuki' pear (Pyrus pyrifolia Nakai) corky disease is a physiological disease that strongly affects the fruit quality of 'Akizuki' pear and its economic value. In this study, Raman spectroscopy was employed to develop an early diagnosis model by integrating support vector machine (SVM), random forest (RF), gradient boosting decision tree (GBDT), extreme gradient boosting (XGBoost), and convolutional neural network (CNN) modeling techniques. The effects of various pretreatment methods and combinations of methods on modeling results were studied. The relative optimal index formula was utilized to identify the SG and SG+WT as the most effective preprocessing methods. Following the optimal preprocessing method, the performance of the majority of the models was markedly enhanced through the process of model reconditioning, among which XGBoost achieved 80% accuracy under SG+WT pretreatment, and F1 and kappa both performed best. The results show that RF, GBDT, and XGBoost are more sensitive to the pretreatment method, whereas SVM and CNN are more dependent on internal parameter tuning. The results of this study indicate that the early detection of Raman spectroscopy represents a novel approach for the nondestructive identification of asymptomatic 'Akizuki' pear corky disease, which is of paramount importance for the realization of large-scale detection across orchards.

Investigating older adults users' willingness to adopt wearable devices by integrating the technology acceptance model (UTAUT2) and the Technology Readiness Index theory.

With the continuous advancement of wearable technology, smart wearable devices are increasingly recognized for their value in health monitoring, assessment, and intervention for the older adults, thus promoting intelligent older adults care. This study, based on the theoretical framework of the Unified Theory of Acceptance and Use of Technology 2 (UTAUT2) and the Technology Readiness Index (TRI) model, aims to identify and explore the key factors influencing older adults consumers' willingness to adopt smart wearable devices and their impact mechanisms. A questionnaire survey was conducted to collect valid data from 389 older adults respondents. Empirical analysis validated the model's applicability and explored the key factors influencing acceptance. Factors influencing the use of smart wearable devices by the older adults include performance expectancy (β = 0.152, p < 0.001), effort expectancy (β = 0.154, p < 0.001), social influence (β = 0.135, p < 0.05), facilitating conditions (β = 0.126, p < 0.05), hedonic motivation (β = 0.166, p < 0.001), price value (β = 0.182, p < 0.001), and digital health literacy (β = 0.189, p < 0.001). Additionally, optimism (β = 0.208, p < 0.001), innovativeness (β = 0.218, p < 0.001), and discomfort (β = -0.245, p < 0.001) significantly positively influenced performance expectancy, while optimism (β = 0.282, p < 0.001), innovativeness (β = 0.144, p < 0.01), discomfort (β = -0.239, p < 0.001), and insecurity (β = -0.117, p < 0.05) significantly positively influenced effort expectancy. Insecurity did not significantly influence performance expectancy. Performance expectancy and effort expectancy partially mediated the relationship between personality traits (optimism, innovativeness, discomfort, and insecurity) and behavioral intention. Digital health literacy significantly negatively moderated the relationship between performance expectancy and behavioral intention, as well as between effort expectancy and behavioral intention. The study confirms that integrating the UTAUT2 model and TRI theory effectively explains the acceptance of smart wearable devices among older adults consumers, emphasizing the importance of enhancing digital health literacy in the design and promotion of smart health devices. The findings provide guidance for developers, increasing the acceptance and usage rate of these devices among the older adults.

Analysis of the Interrelation and Seasonal Variation Characteristics of the Spatial Niche of Dominant Fishery Species-A Case Study of the East China Sea.

The spatial niche has garnered significant attention in ecological research, particularly regarding species distribution patterns. The East China Sea, known for its favorable natural conditions and abundant fishery resources, exhibits diverse spatial distribution patterns among species, shaped by their seasonal physiological needs. This study utilized a habitat suitability index model to explore the spatial distribution patterns of key fishery resources in the East China Sea across four seasons and their interactions. Two methodologies were employed to identify key environmental factors and assess the ecological niche overlap among different species and seasons. Results indicated that the initial method identified water temperature as the critical factor for hairtail, while the subsequent method emphasized water temperature and salinity for hairtail, salinity for small yellow croaker, and water depth for Bombay duck. The main spatial habitat overlap was observed between paired species, likely driven by predator-prey interactions. During summer and autumn, increased overlap among multiple species was primarily influenced by synchronized life cycles. An overlap index formula quantified the seasonal species overlap, showing an increase from spring to winter, reflecting changes in convergent habitat preferences. The peak overlap occurred in winter, driven by overwintering, reduced food competition, and enhanced coexistence potential, while the lowest overlap was noted in spring as overwintering ended and predation and competition intensified.