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

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.

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.

Coherent control of the efficient ladder-type population transfer by four-color harmonic laser pulses

The ladder-type population transfer of the HF molecule steered by four-color harmonic laser pulses (HLPs) is investigated using the time-dependent quantum wave packet method. It is found that although there exist large background excitations and many (resonant) transition pathways during the driving, nearly 100% of the population could be transferred to the target state. In particular, such a process could be coherently controlled by changing the phases of the four HLPs, especially the phases of the fundamental and second HLPs, which can be accounted for in large part by the combined effects of the corresponding transition pathways and the maximal amplitude of the total electric field. However, for manipulating the phases of the third and fourth HLPs, both the changes in the maximal electric field amplitude and the asymmetry size fail to guide the variation of the target-state population because of the correlated effects of all these transition pathways, particularly the ones that do not contain the third and fourth HLP excitations. Importantly, our results also denote that the variation of the maximal electric field amplitude may give a well qualitative prediction about the phase-controlled population when the manipulated phase is directly related to all the transition pathways, which is the general case in the widely used two-color scheme. In addition, the maximal amplitude of the total electric field tends to play a more important role than its asymmetry size in the phase-controlled population transfer process.

Controlling bulk electrostatics in electrolytes by surface polarization

The benchmark theory of hydration forces that relies on the phenomenological expressions developed by Marčelja and Radić (MR) has recently been revived by experimental, computational, and theoretical advances. Here, we consider the effect of surface polarization on electrolytes in a slab geometry by combining the MR approach to polarization with Poisson–Boltzmann theory. Due to the coupling of bulk and surface fields, not only is the electrostatics modified by polarization, but maybe even more importantly, vice versa: a finite polarization at the wall is sufficient to generate a finite electrostatic potential even in the absence of net charges on the wall. We determine the polarization and electrostatic potential profiles and the free energy of the system. Our results show that the presence of surface polarization alone suffices to imprint the bulk structural properties on the electrostatic field in an electrolyte.

Assessing the performance of coupled-trajectory schemes on full-dimensional two-state linear vibronic coupling models

We investigate the performance of coupled-trajectory methods for nonadiabatic molecular dynamics in simulating the photodynamics of 4-(dimethylamino)benzonitrile (DMABN) and fulvene, with electronic structure provided by linear vibrational coupling models. We focus on the coupled-trajectory mixed quantum-classical (CTMQC) algorithm and on the (combined) coupled-trajectory Tully surface hopping [(C)CTTSH] in comparison to independent-trajectory approaches, such as multi-trajectory Ehrenfest and Tully surface hopping. Our analysis includes not only electronic populations but also additional electronic and nuclear properties in position and momentum space. For both DMABN and fulvene, the recently developed CCTTSH algorithm successfully resolves the internal inconsistencies of coupled-trajectory Tully surface hopping. Instead, we find that DMABN highlights a significant weakness of CTMQC, which arises when the trajectories remain for a long time in the vicinity of a region of strong nonadiabaticity.

Numerically stable resonating Hartree–Fock

The simulation of excited states at low computational cost remains an open challenge for electronic structure (ES) methods. While much attention has been given to orthogonal ES methods, relatively little work has been done to develop nonorthogonal ES methods for excited states, particularly those involving nonorthogonal orbital optimization. We present here a numerically stable formulation of the Resonating Hartree–Fock (ResHF) method that uses the matrix adjugate to remove numerical instabilities arising from nearly orthogonal orbitals, and as a result, we demonstrate improvements to ResHF wavefunction optimization. We then benchmark the performance of ResHF against complete active space self-consistent field in the avoided crossing of LiF, the torsional rotation of ethene, and the singlet–triplet energy gaps of a selection of small molecules. ResHF is a promising excited state method because it incorporates the orbital relaxation of state-specific methods, while retaining the correct state crossings of state-averaged approaches. Our open-source ResHF implementation, yucca, is available on GitLab.

Stereodynamics of cold HD and D2 collisions with He

We present a comprehensive quantum mechanical study of stereodynamic control of HD + He and D2 + He collisions that have been probed experimentally by Perreault et al. [J. Phys. Chem. Lett. 13, 10912 (2022)] using Stark-induced adiabatic Raman passage (SARP) techniques. Our calculations utilize a highly accurate full-dimensional H2 + He interaction potential with diagonal Born–Oppenheimer correction appropriate for HD and D2 isotopomers. The results show that rotational quenching of HD from j = 2 → j′ = 0 in v = 2, j = 2 → j′ = 1 in v = 2 and v = 4, and j = 4 → j′ = 3 in v = 4 is dominated by an l = 1 shape resonance located between 0.1 and 1.0 cm−1. For collision energies less than 0.1 cm−1, isotropic scattering prevails. An l = 1 resonance centered around 0.02 cm−1 is also found to dominate the j = 2 → j′ = 0 and j = 4 → j′ = 2 transitions in v = 4 for He–D2 collisions consistent with our prior studies of Δj = −2 transition in He + D2(v = 2, j = 2) collisions. Our analysis does not support the hypothesis of Perreault et al. [J. Phys. Chem. Lett. 13, 10912 (2022)] that a strong l = 2 resonance controls the angular distribution for Δj = −2 transition for both systems. Despite improvements in the development of the potential energy surface, a good agreement with SARP experiments for v = 2 is achieved only when contributions from collision energies less than 1.0 cm−1 were excluded in the computation of velocity averaged differential rate coefficients for both systems. This could be due to some uncertainties in the velocity spread in the experiment that employs co-propagation of the collision partners and possibly, the neglect of transverse velocities in the simulation of the experiment.

Hamiltonian replica-exchange method α-REMD for ring spearing elimination in polymers

Accurate prediction of polymer properties using molecular dynamics (MD) simulations requires a properly relaxed starting structure. Polymer models built from scratch by specialized algorithms (self-avoiding random walk, Monte Carlo, etc.) are far from relaxed and, moreover, often possess a large number of structural defects: close contacts between atoms, wrong bond distances, voids, unfavorable molecular conformations or packing, etc. This is especially problematic for ring-containing polymers whose initial structures also include ring spearing (bonds passing through cycles, including benzene rings). All these defects must be eliminated before running an MD simulation to correctly predict polymer properties. Short MD simulations can be enough to remove close contacts; however, ring spearing elimination and general structure relaxation cannot be achieved this way. In this work, we propose α-Replica Exchange MD (α-REMD)–a Hamiltonian replica-exchange MD protocol that reliably eliminates ring spearing defects and performs a general relaxation of the system. Its efficiency is demonstrated on five polyethersulfones whose initial geometries contained numerous ring intersections that were completely removed by α-REMD.