bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Forest Fragmentation and Connectivity Using Fractal Dimension and Succolarity
Authors: Andronache Ion
Published: January 2024

Forests around the world, vital for ecological, economic, and social functions, are facing increasing threats such as deforestation and habitat fragmentation. This study introduces “succolarity” to analyse forest connectivity and fragmentation directionally in the Romanian Carpathians from 2000 to 2021. Besides traditional indices such as the fractal fragmentation index (FFI), the fractal fragmentation and disorder index (FFDI), the local connected fractal dimension (LCFD), and succolarity, two novel indices are proposed: potential succolarity and delta (Δ) succolarity, which provide nuanced insights into environmental changes and human interventions in forests worldwide. The succolarity tests showed invariance at the image scale and sensitivity to the obstacles in different image scenarios. The combined analysis of succolarity and fractal indices reveals dynamic patterns of connectivity, fragmentation, and spatial disturbance. The directional insights of succolarity highlight and enhance understanding of deforestation patterns. The FFI and FFDI show different levels of fragmentation across mountain groups, while the LCFD details local connectivity. The adaptability of the method makes it globally applicable, supporting biodiversity conservation and landscape management. In conclusion, the integration of succolarity and traditional fractal indices provides a robust methodology for the comprehensive analysis of forest fragmentation. This advancement not only supports the sustainable management of the Romanian Carpathians but also represents a versatile approach applicable to ecosystems worldwide, ensuring the long-term resilience of forested regions.
Validating Indigenous Farmers’ Practice in the Management of the Fall Armyworm Spodoptera frugiperda (J. E. Smith) in Maize Cropping Systems in Africa
Authors: Niassy Saliou , Omuse Evanson Rigan , Khang’ati John Emanuel , Bächinger Ines , Kupesa David Mfuti , Cheseto Xavier , Mbatha Benjamin W. , Copeland Robert S. , Mohamed Samira Abuelgasim , Gama Mphatso , Mitti Joyce Mulila , Belayneh Yeneneh , Delabays Nicolas , Lefort François , Ekesi Sunday , Subramanian Sevgan
Published: January 2024

Before the invasion of the fall armyworm (FAW) Spodoptera frugiperda into Africa, smallholder farmers had been using indigenous practices such as applying fish soup to plants to manage stemborer pests. Although farmers have since begun adapting this practice against FAW, no attempt has been made to scientifically evaluate this practice. Therefore, we assessed the efficacy of applying fish soup to maize plants that were artificially infested with FAW under semi-field conditions. Our results showed that foliar damage is inversely correlated with the concentration of a fish soup and sugar solution, with the highest (100%) concentration resulting in the lowest foliar damage and the highest plant recovery. The FAW foliar damage results for maize plants treated with 100%, 50%, 10% fish soup and sugar, and distilled water were 46.3 ± 5.6, 51.1 ± 5.0, 71.6 ± 5.2, and 99.4 ± 0.4%, respectively, whereas plant recovery results from the same treatments were 35.2 ± 3.7, 31.1 ± 5.4, 20.0 ± 4.6, and 0.0 ± 0.0%, respectively. A concentration of fish soup and sugar solution of at least 25.9% was required to achieve the lowest foliar damage of 17.8% and peak plant recovery of 73.6%. Fish soup and sugar solutions attracted a wide range of insects, including potential natural enemies (predators and parasitoids) of FAW, in a dose-dependent manner. Maize plants treated with fish soup and sugar showed higher chlorophyll content and better growth than the control did. Proximate and chemical analysis showed that fish soup contains essential plant growth nutrients (e.g., nitrogen, phosphorus, and calcium). Through GC-MS analyses, we identified 76 volatile organic compounds in fish soup, of which 16 have been reported as insect attractants, highlighting their potential ecological significance. Therefore, the indigenous pest management practices for FAW, such as the use of fish soup, deserve particular attention. These practices could contribute to food security and improve the livelihoods of vulnerable communities. Further field validation studies, economic analyses, product development, and optimisation are therefore required to optimise the use of fish soup based on fish waste.
First Cytogenetic Analysis of Hemidactylus mercatorius Gray, 1842 Provides Insights on Interspecific Chromosomal Diversification in the Genus Hemidactylus (Squamata: Gekkonidae)
Authors: Mezzasalma Marcello
Published: January 2024

This contribution provides the first karyotype description of Hemidactylus mercatorius and discusses the interspecific chromosome diversification in the genus. Chromosomal analysis was performed on samples from different Malagasy populations using standard karyotyping, Ag-NOR staining, and banding methods (sequential C-banding + Giemsa, + Chromomycin A3, +4′,6-diamidino-2-phenylindole). Irrespective of sex or sampling locality, H. mercatorius shows a karyotype of 2n = 42 with metacentric (1, 18–21), submetacentric (4), subtelocentric (5, 11), and acrocentric pairs (all the remaining pairs). There was no heteromorphic chromosome pair and no clear distinction between macro- and microchromosomes. NORs were localised close to the centromeres of a medium acrocentric pair (14). Heterochromatic blocks were identified on the telomeric and centromeric regions of most chromosome pairs. A comparison with the karyotype of H. mabouia highlights that the different morphology of several chromosome pairs clearly distinguishes the two species, contrasting the previously proposed synonymy. The differences between the karyotypes of H. mercatorius and H. mabouia concern the number of biarmed and acrocentric elements, suggesting the occurrence of several chromosome inversions. Considering all the available karyotype data on Hemidactylus and its sister genus Cyrtodactylus, it is possible to advance an evolutionary hypothesis on their chromosomal evolution, starting from a common ancestor with 2n = 48 and all acrocentric elements. From this ancestral condition, the karyotype diversification in the two genera has been prevalently characterised by a progressive accumulation of fusions and inversions which have reduced the total chromosome count and increased the number of biarmed chromosomes.
Characterization of the Complete Mitochondrial Genome of Wintersweet (Chimonanthus praecox) and Comparative Analysis within Magnoliids
Authors: Yu Xianxian , Feng Yanlei , Zhang Jie
Published: January 2024

Mitochondrial genome sequencing is a valuable tool for investigating mitogenome evolution, species phylogeny, and population genetics. Chimonanthus praecox (L.) Link, also known as “La Mei” in Chinese, is a famous ornamental and medical shrub belonging to the order Laurales of the Calycanthaceae family. Although the nuclear genomes and chloroplast genomes of certain Laurales representatives, such as Lindera glauca, Laurus nobilis, and Piper nigrum, have been sequenced, the mitochondrial genome of Laurales members remains unknown. Here, we reported the first complete mitogenome of C. praecox. The mitogenome was 972,347 bp in length and comprised 60 unique coding genes, including 40 protein-coding genes (PCGs), 17 tRNA genes, and three rRNA genes. The skewness of the PCGs showed that the AT skew (−0.0096233) was negative, while the GC skew (0.031656) was positive, indicating higher contents of T’s and G’s in the mitochondrial genome of C. praecox. The Ka/Ks ratio analysis showed that the Ka/Ks values of most genes were less than one, suggesting that these genes were under purifying selection. Furthermore, there is a substantial abundance of dispersed repeats in C. praecox, constituting 16.98% of the total mitochondrial genome. A total of 731 SSR repeats were identified in the mitogenome, the highest number among the eleven available magnoliids mitogenomes. The mitochondrial phylogenetic analysis based on 29 conserved PCGs placed the C. praecox in Lauraceae, and supported the sister relationship of Laurales with Magnoliales, which was congruent with the nuclear genome evidence. The present study enriches the mitogenome data of C. praecox and promotes further studies on phylogeny and plastid evolution.
Fabrication, Processing, Properties, and Applications of Closed-Cell Aluminum Foams: A Review
Authors: Fu Wensheng , Li Yanxiang
Published: January 2024

Closed-cell aluminum foams have many excellent properties, such as low density, high specific strength, great energy absorption, good sound absorption, electromagnetic shielding, heat and flame insulation, etc. As a new kind of material, closed-cell aluminum foams have been used in lightweight structures, traffic collision protections, sound absorption walls, building decorations, and many other places. In this paper, the recent progress of closed-cell aluminum foams, on fabrication techniques, including the melt foaming method, gas injection foaming method, and powder metallurgy foaming method, and on processing techniques, including powder metallurgy foaming process, two-step foaming process, cast foaming process, gas injection foaming process, mold pressing process, and integral foaming process, are summarized. Properties and applications of closed-cell aluminum foams are discussed based on the mechanical properties and physical properties separately. Special focuses are made on the newly developed cast-forming process for complex 3D parts and the improvement of mechanical properties by the development of small pore size foam fabrication and modification of cell wall microstructures.
Preparation and Characterization of Composites Based on ABS Modified with Polysiloxane Derivatives
Authors: Sztorch Bogna , Konieczna Roksana , Pakuła Daria , Frydrych Miłosz , Marciniec Bogdan , Przekop Robert E.
Published: January 2024

In this study, organosilicon compounds were used as modifiers of filaments constituting building materials for 3D printing technology. Polymethylhydrosiloxane underwent a hydrosilylation reaction with styrene, octadecene, and vinyltrimethoxysilane to produce new di- or tri-functional derivatives with varying ratios of olefins. These compounds were then mixed with silica and incorporated into the ABS matrix using standard processing methods. The resulting systems exhibited changes in their physicochemical and mechanical characteristics. Several of the obtained composites (e.g., modified with VT:6STYR) had an increase in the contact angle of over 20° resulting in a hydrophobic surface. The addition of modifiers also prevented a decrease in rheological parameters regardless of the amount of filler added. In addition, comprehensive tests of the thermal decomposition of the obtained composites were performed and an attempt was made to precisely characterize the decomposition of ABS using FT-IR and optical microscopy, which allowed us to determine the impact of individual groups on the thermal stability of the system.
Comparing Cyclic Fatigue Resistance and Free Recovery Transformation Temperature of NiTi Endodontic Single-File Systems Using a Novel Testing Setup
Authors: Youssef Emad , Jungbluth Holger , Jepsen Søren , Gruener Manfred , Bourauel Christoph
Published: January 2024

The aim of this study was to assess the effect of body temperature (37 °C) on the cyclic fatigue resistance of three endodontic single-file systems using a new testing setup. One Shape® new generation (OS), WaveOne™ (WO) and WaveOne® GOLD (WOG), which are made from different NiTi alloys and operated in different motions (rotation/reciprocation), were evaluated. The study design included four groups. Each group comprised 30 files, 10 files of each of the three file systems, tested at 20 ± 2 °C (group 1 and 3) and at 37 ± 1 °C (group 2 and 4). All files were tested in a custom-made metal block with artificial canals of 60° angle, and a 5 mm and 3 mm radius of curvature, respectively. A heating element was attached to replicate a temperature of 37 °C. Files were introduced 18 mm into the canals and operated until failure. Transformation temperatures of five samples of each of the tested file systems were determined via the bend and free recovery (BFR) method. With the exception of WOG in canals with a 3 mm radius of curvature (p = 0.075), all the tested file systems showed statistically significantly less time needed to fracture when operated at 37 ± 1 °C compared to at 20 ± 2 °C in canals with a 5 mm and 3 mm radius of curvature using Mann–Whitney U test (p < 0.05). All file systems showed transformation temperatures below the body temperature. We concluded that body temperature directly affects the cyclic fatigue resistance of all tested file systems. Bend and free recovery can be suitable for the determination of austenite finish temperatures (Af) of endodontic instruments as it allows testing a longer portion of the instrument.
Unified Failure Criterion Based on Stress and Stress Gradient Conditions
Authors: Kwon Young W. , Markoff Emma K. , DeFisher Stanley
Published: January 2024

Specimens made of various materials with different geometric features were investigated to predict the failure loads using the recently proposed criterion comprised of both stress and stress gradient conditions. The notch types were cracks and holes, and the materials were brittle, ductile, isotropic, orthotropic, or fibrous composites. The predicted failure stresses or loads were compared to experimental results, and both experimental and theoretically predicted results agreed well for all the different cases. This suggests that the stress and stress-gradient-based failure criterion is both versatile and accurate in predicting the failure of various materials and geometric features.
Hydrothermal Synthesis of Cancrinite from Coal Gangue for the Immobilization of Sr
Authors: Wang Hao , Zhang Fujie , Ang Ran , Ren Ding
Published: January 2024

The primary objective of this study is to investigate and develop a rapid and effective method for the immobilization of Sr in the event of a nuclear leakage incident. Coal gangue, an underutilized form of solid waste from the coal industry, can be used as a raw material for curing Sr due to its high content of silica–alumina oxides. In the present study, Sr was successfully solidified in cancrinite synthesized using a hydrothermal method with coal gangue as raw material. A stable cancrinite phase was formed at a relative alkali concentration of more than 6 M. When the Sr/Al(Si) ratio was <1/6, cancrinite was the only stable phase that varied with the hydrothermal temperature and time. When the Sr/Al(Si) ratio increased to 1/2, the cancrinite phase completely disappeared, and a new strontium feldspar phase (SrAl2Si2O8) appeared. PCT leaching experiments showed that when Sr/Al(Si) < 1/6, the Sr leaching rate of Sr-cancrinite samples obtained by hydrothermal synthesis at 180 °C for 24 h was very low.
Engineered Nanocomposite Coatings: From Water-Soluble Polymer to Advanced Hydrophobic Performances
Authors: Jebali Syrine , Vayer Marylène , Belal Khaled , Sinturel Christophe
Published: January 2024

In this work, a water-soluble (hydrophilic) polymer was used to form a hydrophobic coating on silicon substrates (Si) in a two-step process comprising (i) the transformation of the polymer into an insoluble material and (ii) the structuring of this coating at nanometric and micrometric scales to achieve the desired hydrophobic behavior. Polyvinylpyrrolidone (PVP), a water-soluble commodity polymer, was crosslinked using benzophenone and UV irradiation to produce a water-insoluble PVP coating. The nanometric scale roughness of the coating was achieved by the addition of silica nanoparticles (NPs) in the coating. The micrometric scale roughness was achieved by forming vertical pillars of PVP/NP coating. To prepare these pillars, a perforated polystyrene (PS) template was filled with a PVP/NP suspension. Micrometer scale vertical pillars of PVP/silica NPs were produced by this method, which allowed us to tune the wettability of the surface, by combining the micrometric scale roughness of the pillars to the nanometric scale roughness provided by the nanoparticles at the surface. By adjusting the various experimental parameters, a hydrophobic PVP coating was prepared with a water contact angle of 110°, resulting in an improvement of more than 80% compared to the bare flat film with an equal amount of nanoparticles. This study paves the way for the development of a more simplified experimental approach, relying on a blend of polymers containing PVP and NPs, to form the micro/nano-structured PVP pillars directly after the deposition step and the selective etching of the sacrificial major phase.
The Removal of Strontium Ions from an Aqueous Solution Using Na-A Zeolites Synthesized from Kaolin
Authors: Lim Woo-Ri , Lee Chang-Han , Lee Chung-Mo
Published: January 2024

Sr2+ ions in an aqueous solution were removed using Na-A zeolites synthesized from kaolin, a natural mineral. Na-A zeolites with high crystallinity were synthesized using NaOH/kaolin mass ratios of 0.6 (ZK06) and 0.9 (ZK09). The adsorption reached equilibrium within 120 min. The adsorption data obtained from experiments for Sr2+ using ZK06 and ZK09 were appropriately analyzed with pseudo-second-order kinetic and Langmuir isotherm models. Comparing the maximum adsorption capacities (qm) of ZK06 and ZK09 for Sr2+, the highest values were obtained at 1.90 and 2.42 mmol/g, respectively. Consequently, the Na-A zeolites synthesized from kaolin can be evaluated as adsorbents with high adsorption capacities for the removal of Sr2+, proportional to the degree of their crystallinity.
Study on Influence of Rare Earth Ce on Micro and Macro Properties of U75V Steel
Authors: Feng Guangqian , Ren Lei , Yang Jichun
Published: January 2024

Non-metallic inclusions in steel have great influence on the continuity of the steel matrix and the mechanical properties of steel. The precipitation sequence of Ce inclusions in molten steel is predicted by thermodynamic calculations. The results show that Ce content will affect the precipitation sequence of rare earth inclusions in molten steel, and the formation of CeO2, Ce2O3 and CeAlO3 will be inhibited with the increase in Ce content. Our laboratory smelted the test steel without rare earth additive and the test steel with rare earth Ce additive (0.0008%, 0.0013%, 0.0032%, 0.0042%). It was found that the MnS inclusions and inclusions containing Al, Ca, Mg and Si oxides or sulfides in the steel after rare earth addition were modified into complex inclusions containing CeAlO3 and Ce2O2S. The size of inclusion in steel was reduced and the aspect ratio of inclusion was improved. The addition of Ce also improved the grain size of U75V steel and significantly refined the pearlite lamellar spacing. After mechanical property testing of the test steel, it was found that when Ce is increased within 0.0042%, the tensile and impact properties of U75V steel are also improved.
Negative Thermal Quenching of Photoluminescence: An Evaluation from the Macroscopic Viewpoint
Authors: Yan Shirun
Published: January 2024

Negative thermal quenching (NTQ) denotes that the integral emission spectral intensity of a given phosphor increases continuously with increasing temperature up to a certain elevated temperature. NTQ has been the subject of intensive investigations in recent years, and a large number of phosphors are reported to have exhibited NTQ. In this paper, a collection of results in the archival literature about NTQ of specific phosphors is discussed from a macroscopic viewpoint, focusing on the following three aspects: (1) Could the NTQ of a given phosphor be reproducible? (2) Could the associated data for a given phosphor exhibiting NTQ be in line with the law of the conservation of energy? (3) Could the NTQ of a given phosphor be demonstrated in a prototype WLED device? By analyzing typical cases based on common sense, we hope to increase awareness of the issues with papers reporting the NTQ of specific phosphors based on spectral intensity, along with the importance of maintaining stable and consistent measurement conditions in temperature-dependent spectral intensity measurement, which is a prerequisite for the validity of the measurement results.
Low-Dimensional Vanadium-Based High-Voltage Cathode Materials for Promising Rechargeable Alkali-Ion Batteries
Authors: Ni Wei
Published: January 2024

Owing to their rich structural chemistry and unique electrochemical properties, vanadium-based materials, especially the low-dimensional ones, are showing promising applications in energy storage and conversion. In this invited review, low-dimensional vanadium-based materials (including 0D, 1D, and 2D nanostructures of vanadium-containing oxides, polyanions, and mixed-polyanions) and their emerging applications in advanced alkali-metal-ion batteries (e.g., Li-ion, Na-ion, and K-ion batteries) are systematically summarized. Future development trends, challenges, solutions, and perspectives are discussed and proposed. Mechanisms and new insights are also given for the development of advanced vanadium-based materials in high-performance energy storage and conversion.
Design, Testing, and Sensitivity Analysis of a Torsional Cyclic Test Adapter
Authors: Gaber Klara , Škrlec Andrej , Klemenc Jernej , Šeruga Domen
Published: January 2024

In this article, a torsional adapter is designed and evaluated through the comparison of analytical, numerical, and experimental tools. The adapter converts a conventional tension–compression test machine for cyclic loading to a modified application of both force-controlled and displacement-controlled torsional loading. The mechanism ensures a uniform distribution of loading application on both sides of the specimen. The determination of the durability curve can therefore be consistently carried out by acknowledging the geometric relation between the displacement of the test rig and the strain on the specimen. However, friction and clearance in the mechanism joints can cause energy dissipation; therefore, a detailed evaluation of this effect is mandatory before the use of the adapter. Here, it is shown that, using the current version of the adapter, the energy dissipation during torsional testing can be measured and later successfully considered during the determination of the torsional cyclic curve. Future improvements of the adapter will involve the reduction of the friction between the components of the mechanism.
Realization of a Human-like Gait for a Bipedal Robot Based on Gait Analysis
Authors: Yamano Junsei , Kurokawa Masaki , Sakai Yuki , Hashimoto Kenji
Published: January 2024

There are many studies analyzing human motion. However, we do not yet fully understand the mechanisms of our own bodies. We believe that mimicking human motion and function using a robot will help us to deepen our understanding of humans. Therefore, we focus on the characteristics of the human gait, and the goal is to realize a human-like bipedal gait that lands on its heels and takes off from its toes. In this study, we focus on kinematic synergy (planar covariation) in the lower limbs as a characteristic gait seen in humans. Planar covariation is that elevation angles at the thigh, shank, and foot in the sagittal plane are plotted on one plane when the angular data are plotted on the three axes. We propose this feature as a reward for reinforcement learning. By introducing this reward, the bipedal robot achieved a human-like bipedal gait in which the robot lands on its heels and takes off from its toes. We also compared the learning results with those obtained when this feature was not used. The results suggest that planar covariation is one factor that characterizes a human-like gait.
On Unicyclic Graphs with Minimum Graovac–Ghorbani Index
Authors: Majstorović Ergotić Snježana
Published: January 2024

In discrete mathematics, graph theory is the study of graphs, which are mathematical structures used to model pairwise relations between objects. Chemical graph theory is concerned with non-trivial applications of graph theory to the solution of molecular problems. Its main goal is to use numerical invariants to reduce the topological structure of a molecule to a single number that characterizes its properties. Topological indices are numerical invariants associated with the chemical constitution, for the purpose of the correlation of chemical structures with various physical properties, chemical reactivity, or biological activity. They have found important application in predicting the behavior of chemical substances. The Graovac–Ghorbani (ABCGG) index is a topological descriptor that has improved predictive potential compared to analogous descriptors. It is used to model both the boiling point and melting point of molecules and is applied in the pharmaceutical industry. In the recent years, the number of publications on its mathematical properties has increased. The aim of this work is to partially solve an open problem, namely to find the structure of unicyclic graphs that minimize the ABCGG index. We characterize unicyclic graphs with even girth that minimize the ABCGG index, while we also present partial results for odd girths. As an auxiliary result, we compare the ABCGG indices of paths and cycles with an odd number of vertices.
A Conceptual Framework for Quantifying the Robustness of a Regression-Based Causal Inference in Observational Study
Authors: Li Tenglong , Frank Kenneth A. , Chen Mingming
Published: January 2024

The internal validity of a causal inference made based on an observational study is often subject to debate. The potential outcomes framework of causal inference stipulates that causal inference is essentially a missing data problem, and we follow this spirit to define the ideal sample as the combination of the observed data and the missing/counterfactual data for regression models. The robustness of a causal inference can be quantified by the probability of a robust inference for internal validity in regression, i.e., the PIVR, which is the probability of rejecting the null hypothesis again for the ideal sample provided the same null hypothesis has been already rejected for the observed sample. Drawing on the relationship between the PIVR and the mean counterfactual outcomes, we formalize a conceptual framework of quantifying the robustness of a regression-based causal inference based on a joint distribution about the mean counterfactual outcomes, holding the observed sample fixed. Interpretatively, the PIVR is the statistical power of the null hypothesis significance testing that is thought to be built on the ideal sample. We demonstrate the conceptual framework of quantifying the robustness of a regression-based causal inference with an empirical example.
Detection of Current Transformer Saturation Based on Machine Learning
Authors: Odinaev Ismoil , Pazderin Andrey , Safaraliev Murodbek , Kamalov Firuz , Senyuk Mihail , Gubin Pavel Y.
Published: January 2024

One of the tasks in the operation of electric power systems is the correct functioning of the protection system and emergency automation algorithms. Instrument voltage and current transformers, operating in accordance with the laws of electromagnetism, are most often used for information support of the protection system and emergency automation algorithms. Magnetic core saturation of the specified current transformers can occur during faults. As a result, the correct functioning of the protection system and emergency automation algorithms is compromised. The consequences of current transformers saturation are mostly reflected in the main protections of network elements operating on a differential principle. This work aims to consider the analysis of current transformer saturation detection methods. The problem of identifying current transformer saturation is reduced to binary classification, and methods for solving the problem based on artificial neural networks, support vector machine, and decision tree algorithms are proposed. Computational experiments were performed, and their results were analyzed with imbalanced (dominance of the number of current transformer saturation modes over the number of modes with its normal operation) and balanced classes 0 (no current transformer saturation) and 1 (current transformer saturation).
Ridge-Type Pretest and Shrinkage Estimation Strategies in Spatial Error Models with an Application to a Real Data Example
Authors: Al-Momani Marwan , Arashi Mohammad
Published: January 2024

Spatial regression models are widely available across several disciplines, such as functional magnetic resonance imaging analysis, econometrics, and house price analysis. In nature, sparsity occurs when a limited number of factors strongly impact overall variation. Sparse covariance structures are common in spatial regression models. The spatial error model is a significant spatial regression model that focuses on the geographical dependence present in the error terms rather than the response variable. This study proposes an effective approach using the pretest and shrinkage ridge estimators for estimating the vector of regression coefficients in the spatial error mode, considering insignificant coefficients and multicollinearity among regressors. The study compares the performance of the proposed estimators with the maximum likelihood estimator and assesses their efficacy using real-world data and bootstrapping techniques for comparison purposes.
Velocity Field due to a Vertical Deformation of the Bottom of a Laminar Free-Surface Fluid Flow
Authors: González Rodrigo , Tamburrino Aldo
Published: January 2024

This article investigates the velocity field of a free-surface flow subjected to harmonic deformation of the channel bottom, progressing asymptotically from a flat initial state to a maximum amplitude. Assuming a uniform main flow with the primary velocity component transverse to the bed undulation, analytical solutions are obtained for the three velocity components and free surface distortion using the method of perturbations. The perturbation components of the velocity field, streamlines, and surface deformation depend on a dimensionless parameter that reflects the fluid inertia induced by bed deformation relative to viscous resistance. When viscous effects dominate, a monotonic decay of the perturbations from the bed to the free surface is observed. In contrast, when inertia dominates, the perturbations can exhibit an oscillatory behavior and introduce circulation cells in the plane normal to the main flow. The interplay between inertia and viscosity reveals scenarios where surface and bed deformations are either in or out of phase, influencing vertical velocity components. Figures illustrate these phenomena, providing insights into the complex dynamics of free-surface flows with harmonic bed deformation in the direction normal to the main flow, and amplitude growing with time. The results are limited to small deformations of the channel bottom, as imposed by the linearization of the momentum equations. Even so, to the best of the authors’ knowledge, this problem has not been addressed before.
Fish By-Product Collagen Extraction Using Different Methods and Their Application
Authors: Gaikwad Sunita , Kim Mi Jeong
Published: January 2024

The processing of fishery resources results in the production of a growing quantity of byproducts, including heads, skins, viscera, intestines, frames, and fillet cutoffs. These byproducts are either wasted or utilized for the production of low-value items and fish oil. Typically, fish processing industries use only 25%, while the remaining 75% is considered as waste by-products. This review presents a comprehensive review on the extraction of collagen from fish byproducts, highlighting numerous techniques including acid-soluble collagen (ASC), enzyme-soluble collagen (ESC), ultrasound extraction, deep eutectic solvent (DES) extraction, and supercritical fluid extraction (SFE). A detailed explanation of various extraction parameters such as time, temperature, solid to liquid (S/L) ratio, and solvent/pepsin concentration is provided, which needs to be considered to optimize the collagen yield. Moreover, this review extends its focus to a detailed investigation of fish collagen applications in the biomedical sector, food sector, and in cosmetics. The comprehensive review explaining the extraction methods, extraction parameters, and the diverse applications of fish collagen provides a basis for the complete understanding of the potential of fish-derived collagen. The review concludes with a discussion of the current research and a perspective on the future development in this research field.
Carneusones A-F, Benzophenone Derivatives from Sponge-Derived Fungus Aspergillus carneus GXIMD00543
Authors: Lu Chun-Ju , Liang Li-Fen , Zhang Geng-Si , Li Hai-Yan , Fu Chun-Qing , Yu Qin , Zhou Dong-Mei , Su Zhi-Wei , Liu Kai , Gao Cheng-Hai , Xu Xin-Ya , Liu Yong-Hong
Published: January 2024

Six benzophenone derivatives, carneusones A-F (1–6), along with seven known compounds (7–13) were isolated from a strain of sponge-derived marine fungus Aspergillus carneus GXIMD00543. Their chemical structures were elucidated by detailed spectroscopic data and quantum chemical calculations. Compounds 5, 6, and 8 exhibited moderate anti-inflammatory activity on NO secretion using lipopolysaccharide (LPS)-induced RAW 264.7 cells with EC50 values of 34.6 ± 0.9, 20.2 ± 1.8, and 26.8 ± 1.7 μM, while 11 showed potent effect with an EC50 value of 2.9 ± 0.1 μM.
Human Coronary Artery Endothelial Cell Response to Porphyromonas gingivalis W83 in a Collagen Three-Dimensional Culture Model
Authors: Cardona-Mendoza Andrés , Roa Molina Nelly Stella , Castillo Diana Marcela , Lafaurie Gloria Inés , Gualtero Escobar Diego Fernando
Published: January 2024

P. gingivalis has been reported to be an endothelial cell inflammatory response inducer that can lead to endothelial dysfunction processes related to atherosclerosis; however, these studies have been carried out in vitro in cell culture models on two-dimensional (2D) plastic surfaces that do not simulate the natural environment where pathology develops. This work aimed to evaluate the pro-inflammatory response of human coronary artery endothelial cells (HCAECs) to P. gingivalis in a 3D cell culture model compared with a 2D cell culture. HCAECs were cultured for 7 days on type I collagen matrices in both cultures and were stimulated at an MOI of 1 or 100 with live P. gingivalis W83 for 24 h. The expression of the genes COX-2, eNOS, and vWF and the levels of the pro-inflammatory cytokines thromboxane A2 (TXA-2) and prostaglandin I2 (PGI2) were evaluated. P. gingivalis W83 in the 2D cell culture increased IL-8 levels at MOI 100 and decreased MCP-1 levels at both MOI 100 and MOI 1. In contrast, the 3D cell culture induced an increased gene expression of COX-2 at both MOIs and reduced MCP-1 levels at MOI 100, whereas the gene expression of eNOS, vWF, and IL-8 and the levels of TXA2 and PGI2 showed no significant changes. These data suggest that in the collagen 3D culture model, P. gingivalis W83 induces a weak endothelial inflammatory response.
Systematic Review: Strategies for Improving HIV Testing and Detection Rates in European Hospitals
Authors: Vliegenthart-Jongbloed Klaske J. , Vasylyev Marta , Jordans Carlijn C. E. , Bernardino Jose I. , Nozza Silvia , Psomas Christina K. , Voit Florian , Barber Tristan J. , Skrzat-Klapaczyńska Agata , Săndulescu Oana , Rokx Casper
Published: January 2024

Undiagnosed HIV infection is a prominent clinical issue throughout Europe that requires the continuous attention of all healthcare professionals and policymakers to prevent missed testing opportunities and late diagnosis. This systematic review aimed to evaluate interventions to increase HIV testing rates and case detection in European hospitals. Out of 4598 articles identified, 29 studies fulfilled the selection criteria. Most of the studies were conducted in single Western European capital cities, and only one study was from Eastern Europe. The main interventions investigated were test-all and indicator-condition-based testing strategies. Overall, the prevalence of undiagnosed HIV was well above 0.1%. The studied interventions increased the HIV testing rate and the case detection rate. The highest prevalence of undiagnosed HIV was found with the indicator-condition-driven testing strategy, whereas the test-all strategy had the most profound impact on the proportion of late diagnoses. Nevertheless, the HIV testing rates and case-finding varied considerably across studies. In conclusion, effective strategies to promote HIV testing in European hospitals are available, but relevant knowledge gaps regarding generalizability and sustainability remain. These gaps require the promotion of adherence to HIV testing guidelines, as well as additional larger studies representing all European regions.
Comparative Metagenomic Analysis of Bacteriophages and Prophages in Gnotobiotic Mouse Models
Authors: Ishola Oluwaseun A. , Kublik Susanne , Durai Raj Abilash Chakravarthy , Ohnmacht Caspar , Schulz Stefanie , Foesel Bärbel U. , Schloter Michael
Published: January 2024

Gnotobiotic murine models are important to understand microbiota–host interactions. Despite the role of bacteriophages as drivers for microbiome structure and function, there is no information about the structure and function of the gut virome in gnotobiotic models and the link between bacterial and bacteriophage/prophage diversity. We studied the virome of gnotobiotic murine Oligo-MM12 (12 bacterial species) and reduced Altered Schaedler Flora (ASF, three bacterial species). As reference, the virome of Specific Pathogen-Free (SPF) mice was investigated. A metagenomic approach was used to assess prophages and bacteriophages in the guts of 6-week-old female mice. We identified a positive correlation between bacteria diversity, and bacteriophages and prophages. Caudoviricetes (82.4%) were the most prominent class of phages in all samples with differing relative abundance. However, the host specificity of bacteriophages belonging to class Caudoviricetes differed depending on model bacterial diversity. We further studied the role of bacteriophages in horizontal gene transfer and microbial adaptation to the host’s environment. Analysis of mobile genetic elements showed the contribution of bacteriophages to the adaptation of bacterial amino acid metabolism. Overall, our results implicate virome “dark matter” and interactions with the host system as factors for microbial community structure and function which determine host health. Taking the importance of the virome in the microbiome diversity and horizontal gene transfer, reductions in the virome might be an important factor driving losses of microbial biodiversity and the subsequent dysbiosis of the gut microbiome.
Electrochemical Characterization of Two Gut Microbial Strains Cooperatively Promoting Multiple Sclerosis Pathogenesis
Authors: Naradasu Divya , Miran Waheed , Okamoto Akihiro
Published: January 2024

In this study, we explored the extracellular electron transfer (EET) capabilities of two bacterial strains, OTU0001 and OTU0002, which are demonstrated in biofilm formation in mouse gut and the induction of autoimmune diseases like multiple sclerosis. OTU0002 displayed significant electrogenic behaviour, producing microbial current on an indium tin-doped oxide electrode surface, particularly in the presence of glucose, with a current density of 60 nA/cm2. The presence of cell-surface redox substrate potentially mediating EET was revealed by the redox-based staining method and electrochemical voltammetry assay. However, medium swapping analyses and the addition of flavins, a model redox mediator, suggest that the current production is dominated by soluble endogenous redox substrates in OTU0002. Given redox substrates were detected at the cell surface, the secreted redox molecule may interact with the cellular surface of OTU0002. In contrast to OTU0002, OTU0001 did not exhibit notable electrochemical activity, lacking cell-surface redox molecules. Further, the mixture of the two strains did not increase the current production from OTU0001, suggesting that OTU0001 does not support the EET mechanism of OTU0002. The present work revealed the coexistence of EET and non-EET capable pathogens in multi-species biofilm.
Bacillus sp. G2112 Detoxifies Phenazine-1-carboxylic Acid by N5 Glucosylation
Authors: Iloabuchi Kenechukwu , Spiteller Dieter
Published: January 2024

Microbial symbionts of plants constitute promising sources of biocontrol organisms to fight plant pathogens. Bacillus sp. G2112 and Pseudomonas sp. G124 isolated from cucumber (Cucumis sativus) leaves inhibited the plant pathogens Erwinia and Fusarium. When Bacillus sp. G2112 and Pseudomonas sp. G124 were co-cultivated, a red halo appeared around Bacillus sp. G2112 colonies. Metabolite profiling using liquid chromatography coupled to UV and mass spectrometry revealed that the antibiotic phenazine-1-carboxylic acid (PCA) released by Pseudomonas sp. G124 was transformed by Bacillus sp. G2112 to red pigments. In the presence of PCA (>40 µg/mL), Bacillus sp. G2112 could not grow. However, already-grown Bacillus sp. G2112 (OD600 > 1.0) survived PCA treatment, converting it to red pigments. These pigments were purified by reverse-phase chromatography, and identified by high-resolution mass spectrometry, NMR, and chemical degradation as unprecedented 5N-glucosylated phenazine derivatives: 7-imino-5N-(1′β-D-glucopyranosyl)-5,7-dihydrophenazine-1-carboxylic acid and 3-imino-5N-(1′β-D-glucopyranosyl)-3,5-dihydrophenazine-1-carboxylic acid. 3-imino-5N-(1′β-D-glucopyranosyl)-3,5-dihydrophenazine-1-carboxylic acid did not inhibit Bacillus sp. G2112, proving that the observed modification constitutes a resistance mechanism. The coexistence of microorganisms—especially under natural/field conditions—calls for such adaptations, such as PCA inactivation, but these can weaken the potential of the producing organism against pathogens and should be considered during the development of biocontrol strategies.
The Effect of Salvia tomentosa Miller Extracts, Rich in Rosmarinic, Salvianolic and Lithospermic Acids, on Bacteria Causing Opportunistic Infections
Authors: Piątczak Ewelina , Kolniak-Ostek Joanna , Gonciarz Weronika , Lisiecki Paweł , Kalinowska-Lis Urszula , Szemraj Magdalena , Chmiela Magdalena , Zielińska Sylwia
Published: January 2024

Methanolic-aqueous extracts of Salvia tomentosa Miller roots, aerial parts, and inflorescences were examined for their content of polyphenolic derivatives and the antimicrobial and cytotoxic effect. In the polyphenolic-rich profile, rosmarinic, salvianolic, and lithospermic acids along with various derivatives were predominant. A total of twenty phenolic compounds were identified using the UPLC/DAD/qTOF-MS technique. These were caffeic acid, rosmarinic acid derivatives, lithospermic acid derivatives, salvianolic acids B, F, and K derivatives, as well as sagerinic acid, although rosmarinic acid (426–525 mg/100 g of dry weight—D.W.) and salvianolic acid B (83–346.5 mg/100 g D.W.) were significantly predominant in the metabolic profile. Strong antibacterial activity of S. tomentosa extracts was observed against Staphylococcus epidermidis (MIC/MBC = 0.625 mg/mL) and Bacillus cereus (MIC = 0.312–1.25 mg/mL). The extracts showed low cytotoxicity towards the reference murine fibroblasts L929 and strong cytotoxicity to human AGS gastric adenocarcinoma epithelial cells in the MTT reduction assay. The observed cytotoxic effect in cancer cells was strongest for the roots of 2-year-old plant extracts.
Dietary Supplementation with 23-Hydroxy Ursolic Acid Reduces the Severity and Incidence of Acute Experimental Autoimmune Encephalomyelitis (EAE) in a Murine Model of Multiple Sclerosis
Authors: Asmis Reto , Medrano Megan , Chase Huizar Carol , Griffith Wendell , Forsthuber Thomas
Published: January 2024

23-Hydroxy ursolic acid (23-OH UA) is a potent atheroprotective and anti-obesogenic phytochemical, with anti-inflammatory and inflammation-resolving properties. In this study, we examined whether dietary 23-OH UA protects mice against the acute onset and progression of experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS). Female C57BL/6 mice were fed either a defined low-calorie maintenance diet (MD) or an MD supplemented with 0.2% wgt/wgt 23-OH UA for 5 weeks prior to actively inducing EAE and during the 30 days post-immunization. We observed no difference in the onset of EAE between the groups of mice, but ataxia and EAE disease severity were suppressed by 52% and 48%, respectively, and disease incidence was reduced by over 49% in mice that received 23-OH UA in their diet. Furthermore, disease-associated weight loss was strikingly ameliorated in 23-OH UA-fed mice. ELISPOT analysis showed no significant differences in frequencies of T cells producing IL-17 or IFN-γ between 23-OH UA-fed mice and control mice, suggesting that 23-OH UA does not appear to regulate peripheral T cell responses. In summary, our findings in EAE mice strongly suggest that dietary 23-OH UA may represent an effective oral adjunct therapy for the prevention and treatment of relapsing–remitting MS.
The Relationship between Mushroom Intake and Cognitive Performance: An Epidemiological Study in the European Investigation of Cancer—Norfolk Cohort (EPIC-Norfolk)
Authors: Cha Sara , Bell Lynne , Williams Claire M.
Published: January 2024

The previous literature suggests that regular consumption of edible mushrooms may confer neuroprotective cognitive health benefits. To further investigate the possible association between mushrooms and brain function during ageing, data from a population-based study of diet and chronic disease (EPIC-Norfolk cohort) were analysed. Changes in mushroom intake were measured using a food frequency questionnaire at three health check (HC) points over an 18-year period, with participants categorised based on their consumption frequency. Cognitive performance was assessed at the final health check (3HC) via a battery of validated tests assessing a range of different cognitive domains. The findings revealed a significant reduction in mushroom intake over time, with 4.12% of the cohort giving up mushrooms after previously consuming them. At 3HC, mushroom consumers displayed better cognitive performance than non-consumers across multiple cognitive domains. This relationship was observed to be dose-dependent, with those consuming 1 or more portions per week showing the highest cognitive scores. These findings suggest that regular mushroom consumption may be beneficial for cognitive function during aging. Further randomised controlled trials will be needed to confirm any potential benefits of mushrooms on long-term cognitive health, alongside public health initiatives to promote mushroom consumption in this older-adult demographic.
The NLRP3 Inflammasome Is Dispensable in Methicillin-Resistant Staphylococcus aureus Urinary Tract Infection
Authors: Paudel Santosh , Kumar Rahul , Rogers Kenneth A. , Saini Yogesh , Patial Sonika , Kulkarni Ritwij
Published: January 2024

The NLRP3 inflammasome is a cytoplasmic complex that senses molecular patterns from pathogens or damaged cells to trigger an innate immune defense response marked by the production of proinflammatory cytokines IL-1β and IL-18 and an inflammatory death called pyroptosis. The NLRP3 inflammasome is activated in the urinary tract by a variety of infectious and non-infectious insults. In this study, we investigated the role of the NLRP3 inflammasome by comparing the pathophysiology of methicillin-resistant Staphylococcus aureus (MRSA) ascending UTI in wild-type (WT) and Nlrp3−/− mice. The difference in the bacterial burden detected in the urinary tracts of MRSA-infected WT and Nlrp3−/− was not statistically significant at 6, 24, and 72 h post-infection (hpi). The levels of pro-inflammatory cytokines and chemokines as well as the numbers of granulocytes recruited to bladder and kidney tissues at 24 hpi were also similar between Nlrp3−/− and WT mice. The histopathological analysis of MRSA-infected bladder and kidney sections from Nlrp3−/− and WT mice showed similar inflammation. Overall, these results suggest that MRSA-induced urinary NLRP3 activity does not play a role in the pathophysiology of the ascending UTI.