Browse Articles

Optimized hybrid machine learning framework for early diabetes prediction using electrogastrograms

The Polish version of the Ethical Climate Questionnaire

Abstract Ethical organizational climate is a pivotal topic in business ethics, influencing employees’ well-being and attitude toward the organization. In Poland, there is a lack of measures dedicated to verifying organizational climate. Our research aimed to examine the psychometrical properties of the Ethical Climate Questionnaire (ECQ) in Polish business conditions. Studies conducted on two samples confirmed the original structure of the Polish version of the ECQ and its better psychometric properties compared to the original version. Confirmatory factor analysis (CFA) confirmed good construct validity and internal consistency of the ECQ, with Cronbach’s alpha coefficients in the range of 0.74–0.81, depending on the type of ethical climate. Bagozzi and Heatherton’s criteria of the magnitude of factor loadings, average variance extracted, and composite reliability showed good convergent validity of the tool. The value of the heterotrait–monotrait ratio of correlations indicated good discriminant validity of the ECQ. Also, the criterion validity of this measure was confirmed. In conclusion, the Polish version of the ECQ is a measure that can be used to study the ethical climate in Polish organizations.

Dynamics and conditions for inhibitory synaptic current to induce bursting and spreading depolarization in pyramidal neurons

Melatonin alleviates ferroptosis triggered by cadmium via regulating ferritinophagy and iron metabolism in spermatogonia

Exploring farmers’ psychological perspectives on multimedia-based agro-advisory services

Indigenous farming methods and crop management practices used by local farmers in Madibeng local municipality, South Africa

Abstract This study investigated indigenous farming methods, practices, and crop management strategies used by farmers in local communities within the North West Province, South Africa. A survey was conducted using semi-structured interview guide with 49 participants recruited through the snowball sampling technique. Data were analysed using ethnobotanical indices, including frequency of citation (FC), use value (UV), and relative frequency of citation (RFC). The participants identified four distinct soil types, along with different ways for soil preparation. Five soil fertilisation materials were mentioned with mixed cropping (intercropping) (95.9%) and crop rotation (93.8%) being the most used farming systems. Additionally, we identified 10 plant species belonging to seven families that were used to manage crop pests and diseases. The plant with the highest RFC was Allium dregeanum Kunth (RFC = 0.88) while Tulbaghia violacea Harv. had the second highest RFC (0.73) and the highest UV (0.10). The families with the highest number of plant species were Fabaceae (3 plants) and Alliaceae (2 plants). In terms of plant parts used, bark was the most cited (53%), followed by whole plant (32%) and fruit (10%). Overall, this study underscores the importance of indigenous crop farming methods and practices towards household food security and general well-being.

Probabilistic analysis of active earth pressures in spatially variable soils using machine learning and confidence intervals

Stable hippocampal correlates of high episodic memory function across adulthood

Abstract Some older adults show high episodic memory performance compared to same-age peers. It is not known whether their high function is caused by special brain features in aging, or whether superior memory has the same brain foundation throughout adult life. To address this, we measured hippocampal volume and atrophy, microstructural integrity by diffusion tensor imaging, and activity during an episodic memory encoding and retrieval task in cognitively healthy adults ( n = 277, age 20.1–81.5 years). Atrophy was quantified by repeated MRIs (2–7 examinations, mean max follow-up time 9.3 years). Superior memory was associated with higher retrieval activity in the anterior hippocampus and less hippocampal atrophy. There were no significant age-interactions, suggesting stable correlates of superior memory function. Age-memory performance curves across the full age-range were similar for participants with high memory performance compared to those with normal and low performance. These trajectories were based on cross-sectional data but did not indicate preserved memory among the superior functioning older adults. In conclusion, the results confirm that aspects of hippocampal structure and function are related to superior memory, without evidence to suggest that the best performing older adults are characterized by special hippocampal features compared to their younger counterparts.

Normative face recognition ability test scores vary across online participant pools

Multi-modal emotion recognition in conversation based on prompt learning with text-audio fusion features

DNA in honey could describe the changes in flower visits and microbe encounters of honey bees over decades

Abstract Recent environmental changes due to land-use and climate change threaten biodiversity and the ecosystem services it provides. Understanding the true scope of these changes is complicated by the lack of historical baselines for many of the interactions underpinning ecosystem services, such as pollination, or disservices, such as disease spreading. To assess changes in such services, it is vital to find ways of comparing past and current interactions between species. Here, we focus on interactions between honey bees – one of the world’s most important agricultural pollinators, the plants they visit, and the microbes they encounter in the environment. DNA in honey offers insights into the contemporary interactions of honey bees. Old honey samples could serve to describe honey bees’ interactions in previous decades, providing a baseline against which to assess changes in interactions over time. By identifying the taxonomic origin of plant, bacterial and fungal DNA in fifty-year-old honey samples, we show that plant DNA can reveal which plants honey bees visited in the past. Likewise, microbe DNA records the microbes, including pollinator and plant pathogens, honey bees encountered and possibly spread. However, some differences in the DNA recovered between old and new honey suggest that differences in DNA degradation of different microbes could bias naive comparisons between samples. Like other types of ancient samples, old honey may be most useful for identifying interactions that historically occurred and should not be taken as proof that an interaction did not occur. Keeping these limits of the data in mind, time series of honey may offer unique information about how honey bees’ associations with flowers and microbes have changed during decades of environmental change.

Parrot optimizer with multiple search strategies for parameters estimation of proton exchange membrane fuel cells model

Topological valley-locked waveguide transport in opto-heterostructures

In this paper, an opto-heterostructure based on light-responsive liquid crystal elastomers (LCEs) is presented to realize topological valley-locked waveguide transport. First, the opto-deformation mode of the LCE gear-like cell is investigated. Then, the effects of light intensity and geometric parameters on degeneracy in the dispersion relation and the topological valley Hall phase transition are clarified. The existence of topological valley-locked waveguide states (TVWSs) in the heterostructures is theoretically analyzed and numerically simulated, and their robustness under varying conditions is verified. Finally, design schemes for high-throughput beam splitters and topological energy concentrators are proposed, and optically selective waveguides are implemented through the adjustment of the light intensity. The results illustrate that flexible control on the waveguide path and frequency selection is achieved through tuning the illumination pattern and the light intensity, which provide a new strategy for the design of TVWS opto-metamaterials.

Plasmonics and optical metastructures

Plasmonics and optical metastructures represent cutting-edge frontiers in nanophotonics, enabling on-demand control of light at the subwavelength scale. This special topic of the Journal of Applied Physics highlights the recent advancements and synergy of the two fields, delving into the fundamental physics governing plasmonic phenomena and showcasing innovative metastructures that hold significant potential for diverse applications, including sensing, optical manipulation, wireless communication, optical computing, and beyond.

A plausible heating in ferroelectric ultra-thin films during uniform polarization reversal

We formulate the heat generated during the homogeneous polarization reversal at the coercive field of a ferroelectric thin film with a second-order transition. The developed formalism is applied to ultra-thin films, where ferroelectric polarization may exhibit a homogeneous reversal mechanism, as reported in recent studies. Heat involved in such a process, if contained within the film, causes a temperature increase similar to that following an exothermic reaction, namely, the flame temperature. It is analytically shown that this temperature change strongly depends on the initial temperature of the system and reaches a maximal value before the ferroelectric–paraelectric transition for a given compressive misfit strain.

Singular value decomposition for deconvolution and physical insight into reflectance anisotropy in zincblende semiconductors

Reflectance Anisotropy Spectroscopy (RAS), also known as Reflectance Difference Spectroscopy (RDS), is an optical probe with high surface specificity for cubic semiconductors. In this paper, we demonstrate the use of Singular Value Decomposition (SVD) for the deconvolution of the RA spectrum of GaAs(001) surfaces with an As-rich reconstruction into its constitutive spectral components. SVD analysis allows the decomposition of the RA spectrum in terms of a small number of linearly independent spectra, which in turn allows the determination of their physical origin. We identify three main components: a first component that is associated with the upper atomic layers, a second component that originates from the subsurface layer that is orthorhombically strained by the reconstruction of the GaAs surface, and a third component associated with the surface roughness due to the surface steps. Moreover, these obtained SVD components are well compared with both first-principles calculations and experimental reflectance anisotropy spectra reported in the literature. The results presented here are relevant for the use of RAS/RDS as a surface probe for cubic semiconductors. In particular, for the real-time in situ monitoring of epitaxial growth of zincblende semiconductors.

Mechanistic insights into hole spin dynamics in colloidal Ag+-doped CdSe nanosheets: Interplay between two counteracting surface effects

We present a mechanistic study of hole spin dynamics in colloidal cadmium selenide (CdSe) nanosheets, aiming to gain insights into the elusive interplay between two counteracting surface effects, i.e., hole-trapping interaction [between the valence-band heavy-hole (HH) state and its nearby localized surface trap (LST) state] vs spin-exchange interaction [between the HH spin state and the surface dangling-bond spin (DBS) state]. Differently from our previous work adopting a strategy of ligand engineering [see Wu et al., Adv. Opt. Mater. 12, 2400583 (2024)], we here implement an alternative strategy of element doping to regulate the LST and DBS states in the Ag+-doped CdSe nanosystem. It is observed that the hole spin-flip lifetime is shortened when the Ag+-doping level is elevated, demonstrating that the hole–DBS exchange interaction can effectively compete against the coexisting hole–LST trapping interaction, mainly due to the doping-induced increase in the density of the DBS state. Markedly, this observation is contrary to that in the ligand-engineering case, where the hole-trapping interaction plays a predominant role due to the strong ligand/CdSe orbital hybridization. This work elucidates the interplay between the two surface effects and enriches the understanding about the subtle DBS-related effect, providing valuable mechanistic information for rational design and optimization of spintronic applications based on colloidal nanostructures.

Broadband low-to-mid-range frequency sound absorption using a micro-perforated panel with variable-depth parallel U-shaped cavities

This study proposes a microperforated panel (MPP) supported by four U-shaped cavities with different depths arranged in parallel, referred to as MPPU. A theoretical model was developed using the electro-acoustic analogy to calculate the normalized surface acoustic impedance expressions and the normal incidence sound absorption coefficient (SAC). The broadband sound absorption mechanism is explained using finite element analysis simulations. The performance of the MPPU was compared with both simulation and theoretical results to that of a microperforated panel supported by a straight cavity (MPPS) with similar geometric parameters. The MPPU outperformed the MPPS, achieving an average sound absorption coefficient (SAC) of 20% higher across the 300–1200 Hz frequency range. Theoretical and numerical modeling was successfully validated after printing the sample using additive manufacturing and testing the MPPU sample in an impedance tube for normal incidence sound absorption. The experimental results demonstrated that 69% of the incident sound energy was absorbed in the 300–1200 Hz frequency range and 89% in the 600–1200 Hz octave band. The tunability of the resonant frequency of the proposed MPPU structure was analyzed by changing the boundary condition, such as placing an impervious solid plate on one side of each U-shaped cavity and modifying the geometrical parameters on one side while keeping them fixed on the other. By doing this, the proposed structure can attenuate sound in the broadband spectrum while the overall sample thickness remains the same.

Molecular insights into odorant recognition: Rotational and docking studies of 3-methylcyclopentane-1,2-dione and its monohydrate

The binding behavior of 3-methylcyclopentane-1,2-dione, a cyclic α-diketone with a caramel-like aroma, was investigated to elucidate molecular mechanisms of olfactory recognition. Using Fourier-transform microwave spectroscopy complemented with quantum chemical calculations, the structures of 3-methylcyclopentane-1,2-dione and its monohydrate were determined, revealing the preferred conformation of the monomer and structural changes upon complexation with water. Intramolecular hydrogen bond weakening was observed, indicating significant rearrangements, as further supported by non-covalent interaction and quantum theory analyses. Molecular docking demonstrates how these structural adaptations facilitate ligand–protein interactions, providing a microscopic framework for understanding diketone binding within odorant-binding proteins.

Development of regular vertical p-n junction on nanocrystalline PbTe film

Polycrystalline nanograined p-type PbTe films were obtained by electron gun-assisted vapor deposition on 100 μm thick amorphous substrates. This part of the study included the establishment and tuning of fabrication technology regimes in terms of the films' composition and crystallites arrangement optimal for having best structural properties, such as dominant texture, tiny-sized or absent voids, and small surface roughness. For this synthesis, we used components' composition Pb0.999Te1.001 bearing in mind that any excess Te builds up an acceptor center. Then, from the thus prepared p-type films, their n-type counterparts were obtained by ion implantation of zinc. At suitable conditions of the implantation process, the inversion of p-type to overall n-type material was experimentally shown and qualitatively explained. The structural and transport properties of both types of films were investigated, demonstrating their high integrity and a moderate effect of grain boundaries. Vertical p-n junction structures were prepared in the p-type films by a combination of proper masking and ion implantation. An electron beam-induced current technique was applied to directly portray the transition between p-and n-sides of the film and to assess the diffusion length of the minority charge carriers. The transition proves rather sharp spatially, which points to a well-defined p-n junction. Increasing the diffusion length of charge carriers of these structures compared to that in epitaxial films was discovered. A possible explanation of this effect and device applications of the developed structure are suggested.