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17 pages, 2218 KiB  
Article
Application of GIS Technologies in Tourism Planning and Sustainable Development: A Case Study of Gelnica
by Marieta Šoltésová, Barbora Iannaccone, Ľubomír Štrba and Csaba Sidor
ISPRS Int. J. Geo-Inf. 2025, 14(3), 120; https://doi.org/10.3390/ijgi14030120 - 6 Mar 2025
Abstract
This study examines the application of Geographic Information Systems (GIS) in tourism planning and sustainable destination management, using Gelnica, Slovakia, as a case study. The research highlights a key challenge—the absence of systematic visitor data collection—which hinders tourism market analysis, demand assessment, and [...] Read more.
This study examines the application of Geographic Information Systems (GIS) in tourism planning and sustainable destination management, using Gelnica, Slovakia, as a case study. The research highlights a key challenge—the absence of systematic visitor data collection—which hinders tourism market analysis, demand assessment, and strategic decision-making. The study integrates alternative data sources, including the Google Places API, to address this gap to analyse Points of Interest (POIs) based on user-generated reviews, ratings, and spatial attributes. The methodological framework combines data acquisition, spatial analysis, and GIS-based visualisation, employing thematic and heat maps to assess tourism resources and visitor behaviour. The findings reveal critical spatial patterns and tourism dynamics, identifying high-demand zones and underutilised locations. Results underscore the potential of GIS to optimise tourism infrastructure, enhance visitor management, and inform evidence-based decision-making. This study advocates for systematically integrating GIS technologies with visitor monitoring and digital tools to improve destination competitiveness and sustainability. The proposed GIS-driven approach offers a scalable and transferable model for data-informed tourism planning in similar historic and environmentally sensitive regions. Full article
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<p>Administrative localisation of Gelnica at the macro level (1:2,000,000).</p>
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<p>Spatial distribution of primary and secondary tourism resources at the micro-level (1:25,000). 1—Mining Museum in Gelnica; 2—Gelnica Castle; 3—Jozef Shaft; 4—Turzov Lake; 5—Gloriet Viewpoint; 7—Church of the Assumption of the Virgin Mary; 8—Swing in Countryside; 9—Guesthouse Pod Hradom; 10—Turzov Guesthouse; 11—Private accommodation Biela Ruža; 12—Dino Apartments; 13—Viktória Cottage; 15—Bowling Pizzeria; 16—Culinarium Gelnica; 17—Mimóza Confectionery; 18—Morning Smile Café and Bistro; 19—Tatran Restaurant; 20—AB Caffe; 21—Restaurant Gelnické Mňamky; 22—Café Pod Lesom; 23—Restaurant Biergarten; 24—Emporio Casino Pizza Pub; 25—Bowling Bar; 27—Tourist Information Center.</p>
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<p>Heat map of primary and secondary tourism resources about the intersections of the shortest walkable paths with hiking trails and cycling paths (1:20 000).</p>
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14 pages, 7287 KiB  
Article
Genome and Pathogenicity Analysis of an NADC30-like PRRSV Strain in China’s Xinjiang Province
by Honghuan Li, Wei Zhang, Yanjie Qiao, Wenxing Wang, Wenxiang Zhang, Yueli Wang, Jihai Yi, Huan Zhang, Zhongchen Ma and Chuangfu Chen
Viruses 2025, 17(3), 379; https://doi.org/10.3390/v17030379 - 6 Mar 2025
Viewed by 44
Abstract
The porcine reproductive and respiratory syndrome virus (PRRSV) possesses an inherent ability to adapt to environmental transformations and undergo evolutionary changes, which has imposed significant economic pressure on the global pig industry. Given the potential for recombination among PRRSV genomes and variations in [...] Read more.
The porcine reproductive and respiratory syndrome virus (PRRSV) possesses an inherent ability to adapt to environmental transformations and undergo evolutionary changes, which has imposed significant economic pressure on the global pig industry. Given the potential for recombination among PRRSV genomes and variations in pathogenicity, newly emerging PRRSV isolates are of considerable clinical importance. In this study, we successfully isolated a novel strain named XJ-Z5 from PRRSV-positive samples collected in Xinjiang province in 2022. Through comprehensive genomic sequencing, phylogenetic analysis, and recombination analysis, we confirmed that this strain belongs to the NADC30-like recombinant PRRSV. During pathogenicity tests in piglets, this strain exhibited moderate virulence, causing symptoms such as reduced appetite, persistent fever, and weight loss; however, no mortality cases were observed. Tests conducted at various time points detected the presence of PRRSV nucleic acid in nasal swabs, rectal swabs, tissue samples, and blood, with the highest viral loads found in lung tissue and blood. Serum biochemical tests indicated significant impairment of liver and kidney function. PRRSV antibodies began to appear gradually after 10 days post infection. Hematoxylin and eosin staining revealed substantial pathological changes in lung tissue and lymph nodes. This study enhances our understanding of the epidemiology of PRRSV and underscores the importance of ongoing monitoring and research in light of the challenges posed by the continuous evolution of viral strains. Furthermore, the research emphasizes the urgency of the rapid genomic analysis of emerging viral strains. Through these comprehensive research and monitoring strategies, we aimed to curb the spread of PRRSV more effectively and thus reduce the huge economic losses it caused to the pig industry. Full article
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<p>Detection and isolation of PRRSV XJ-Z5 strain. (<b>A</b>) RT-PCR identification of PRRSV NSP2 specific primers; (<b>B</b>) PRRSV XJ-Z5 strain whole-genome segment primer identification map; (<b>C</b>) PRRSV XJ-Z5 strain was inoculated on PAM, Marc-145, NPTr, and MA-104. The area indicated by the red arrow shows cytopathic effect.</p>
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<p>Phylogenetic analysis based on ORF5 and whole-genome. Phylogenetic trees were constructed based on ORF5 (<b>A</b>) and the complete genome (<b>B</b>) of the PRRSV XJ-Z5 strains with 24 representative Chinese reference PRRSV strains. Phylogenetic trees were constructed using the distance-based neighbor-joining method with 1000 bootstrap replicates in MEGA7. The red font highlights the strain PRRSV XJ-Z5 used in this study.</p>
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<p>Recombination analysis. (<b>A</b>) Genomic diagram of the XJ-Z5 strain; (<b>B</b>) the crossover regions in the XJ-Z5 genome were further confirmed by Simplot 3.5.1. The crossover regions identified by Simplot were consistent with the results from the RDP5 analysis (<a href="#viruses-17-00379-t002" class="html-table">Table 2</a>). The <span class="html-italic">y</span>-axis shows the percentage of permutated trees employing a sliding window of 200 nucleotides (nt) and a step size of 30 nt. The other options, including the Kimura (2-parameter) distance model, 2.0 Ts/Tv ratio, neighbor-joining tree model, and 1000 bootstrap replicates were used.</p>
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<p>Pathogenicity results in piglets. (<b>A</b>) Animal challenge test procedure; (<b>B</b>) changes in body temperature after challenge; (<b>C</b>) changes in weight gain after challenge; (<b>D</b>–<b>F</b>) liver and kidney AST, GGT, and CRE biochemical indicators after challenge; (<b>G</b>) the viral load of heart, liver, spleen, lung, and kidney tissues after challenge; (<b>H</b>) the viral load of nasal swabs after challenge; (<b>I</b>) anal swab viral load after challenge; (<b>G</b>) viremia in the blood; (<b>K</b>) a PRRSV-specific antibody level was detected in each group during the challenge study.</p>
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<p>Lung autopsy and pathological sections after challenge infection. (<b>A</b>) Visual changes in lung anatomy; (<b>B</b>) results of lung hematoxylin–eosin staining. Scale bar = 100 µm. (<b>C</b>) Results of lymph node hematoxylin–eosin staining. The arrow indicates the characteristic area of the pathological changes. Scale bar = 100 µm and 20 µm.</p>
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13 pages, 828 KiB  
Article
Trajectories of Mental Distress and Resilience During the COVID-19 Pandemic Among Healthcare Workers
by Andreas M. Baranowski, Simone C. Tüttenberg, Anna C. Culmann, Julia-K. Matthias, Katja Maus, Rebecca Blank, Yesim Erim, Eva Morawa, Petra Beschoner, Lucia Jerg-Bretzke, Christian Albus, Kerstin Weidner, Lukas Radbruch, Cornelia Richter and Franziska Geiser
Healthcare 2025, 13(5), 574; https://doi.org/10.3390/healthcare13050574 - 6 Mar 2025
Viewed by 19
Abstract
Background/Objectives: The recent COVID-19 pandemic posed a significant psychological challenge for healthcare workers. Resilience and the extent of psychological stress varied across professional groups and individual circumstances. This study aims to longitudinally capture the trajectories of psychological stress and resilience among medical [...] Read more.
Background/Objectives: The recent COVID-19 pandemic posed a significant psychological challenge for healthcare workers. Resilience and the extent of psychological stress varied across professional groups and individual circumstances. This study aims to longitudinally capture the trajectories of psychological stress and resilience among medical personnel during the pandemic and identify various contributing factors. Methods: Over a period of three years, healthcare workers from five locations (Bonn, Cologne, Ulm, Erlangen, and Dresden) were surveyed regarding their psychological stress (PHQ-4) and other aspects of mental health. Data were collected at five different points during the pandemic. Using Growth Mixture Modeling (GMM), various stress trajectories during the crisis were modeled without initial adjustment for covariates to allow for an unbiased identification of latent classes. Differences in demographic and occupational factors (e.g., age, gender, profession) were analyzed across the identified trajectory groups in subsequent steps. Results: The application of GMM revealed three distinct profiles of psychological stress and resilience among the respondents, largely consistent with the literature. The largest group was the ‘resilience’ group (81%), followed by the ‘recovery’ (10%) and ‘delayed’ groups (9%). Group membership was consistent with self-reported trajectories over the course of the pandemic. It was not possible to predict individual trajectories based on the results of a short resilience questionnaire (RS-5). Conclusions: The COVID-19 pandemic had multiple psychological impacts on healthcare workers, manifesting in clearly differentiated group trajectories of distress over time. While a majority of respondents in this sample exhibited a stable trajectory with low distress, other groups showed varying stress responses over time. These findings highlight the necessity of longitudinal approaches to understand the complex interplay of stressors and coping mechanisms during prolonged crises. Full article
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<p>Trajectories of resilience among healthcare workers. All data and information pertain to Germany. Incidence rate and ICU bed occupancy rate are derived from the publicly available database of the Robert Koch Institute (<a href="http://www.rki.de" target="_blank">www.rki.de</a>). The cut-off value for the PHQ-4 is marked at 6 in the graph, with values above indicating major depressive and generalized anxiety disorder.</p>
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<p>Trajectories of resilience based on symptom burden (PHQ-4) and resilience (RS-5). Scores of the RS-5 from T1 to T5 for the three empirical trajectories of resilience. The dashed line shows the progression over the various measurement times. The solid line shows the respective empirical trajectory, measured using the PHQ-4, for clarification.</p>
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<p>Self-reported trajectories of stress at T5 across the three data-based resilience trajectory groups. Panels (<b>A</b>–<b>F</b>) depict the predefined stress trajectories that participants could select to best represent their experience. The <span class="html-italic">x</span>-axis represents the time course of the pandemic, while the <span class="html-italic">y</span>-axis indicates self-reported stress levels. The rightmost box indicates the proportion of participants who felt that none of the provided trajectories accurately reflected their experience. The bar chart below shows the percentage of participants within each data-based trajectory (‘Resilience,’ ‘Recovery,’ and ‘Delayed’) who selected each self-reported trajectory.</p>
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21 pages, 14388 KiB  
Article
Adaptive Matching of High-Frequency Infrared Sea Surface Images Using a Phase-Consistency Model
by Xiangyu Li, Jie Chen, Jianwei Li, Zhentao Yu and Yaxun Zhang
Sensors 2025, 25(5), 1607; https://doi.org/10.3390/s25051607 - 6 Mar 2025
Viewed by 117
Abstract
The sea surface displays dynamic characteristics, such as waves and various formations. As a result, images of the sea surface usually have few stable feature points, with a background that is often complex and variable. Moreover, the sea surface undergoes significant changes due [...] Read more.
The sea surface displays dynamic characteristics, such as waves and various formations. As a result, images of the sea surface usually have few stable feature points, with a background that is often complex and variable. Moreover, the sea surface undergoes significant changes due to variations in wind speed, lighting conditions, weather, and other environmental factors, resulting in considerable discrepancies between images. These variations present challenges for identification using traditional methods. This paper introduces an algorithm based on the phase-consistency model. We utilize image data collected from a specific maritime area with a high-frame-rate surface array infrared camera. By accurately detecting images with identical names, we focus on the subtle texture information of the sea surface and its rotational invariance, enhancing the accuracy and robustness of the matching algorithm. We begin by constructing a nonlinear scale space using a nonlinear diffusion method. Maximum and minimum moments are generated using an odd symmetric Log–Gabor filter within the two-dimensional phase-consistency model. Next, we identify extremum points in the anisotropic weighted moment space. We use the phase-consistency feature values as image gradient features and develop feature descriptors based on the Log–Gabor filter that are insensitive to scale and rotation. Finally, we employ Euclidean distance as the similarity measure for initial matching, align the feature descriptors, and remove false matches using the fast sample consensus (FSC) algorithm. Our findings indicate that the proposed algorithm significantly improves upon traditional feature-matching methods in overall efficacy. Specifically, the average number of matching points for long-wave infrared images is 1147, while for mid-wave infrared images, it increases to 8241. Additionally, the root mean square error (RMSE) fluctuations for both image types remain stable, averaging 1.5. The proposed algorithm also enhances the rotation invariance of image matching, achieving satisfactory results even at significant rotation angles. Full article
(This article belongs to the Section Remote Sensors)
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<p>Workflow of matching algorithm in this paper.</p>
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<p>The anisotropic weighted moment map: (<b>a</b>) Long-wave infrared image; (<b>b</b>) Medium-wave infrared image.</p>
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<p>Feature point detection results of anisotropic weighted moment diagram. (<b>a</b>) long-wave infrared image (<b>b</b>) medium-wave infrared image.</p>
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<p>Feature point detection results of the original image. (<b>a</b>) long-wave infrared image (<b>b</b>) medium-wave infrared image.</p>
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<p>Descriptor generation flowchart.</p>
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<p>Part of remote sensing images.</p>
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<p>Matching results of long-wave infrared images based on five methods. (<b>a</b>) SIFT; (<b>b</b>) SURF; (<b>c</b>) ORB; (<b>d</b>) HAPCG; (<b>e</b>) Textual algorithm.</p>
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<p>Matching results of medium-wave infrared images based on five methods. (<b>a</b>) SIFT; (<b>b</b>) SURF; (<b>c</b>) ORB; (<b>d</b>) HAPCG; (<b>e</b>) Textual algorithm.</p>
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<p>Matching results of long wave based on the textual algorithm.</p>
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<p>Matching results of medium wave based on the textual algorithm.</p>
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<p>Results of several indicators of long wave.</p>
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<p>Results of several indicators of medium wave.</p>
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<p>Matching results under different rotation differences of the textual algorithm. (<b>a</b>) 30 degrees; (<b>b</b>) 60 degrees; (<b>c</b>) 90 degrees; (<b>d</b>) 120 degrees; (<b>e</b>) 150 degrees; (<b>f</b>) 180 degrees; (<b>g</b>) 210 degrees; (<b>h</b>) 240 degrees; (<b>i</b>) 270 degrees; (<b>j</b>) 300 degrees.</p>
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<p>Result of NCM of the rotated image.</p>
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<p>Result of RMSE of the rotated image.</p>
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30 pages, 2413 KiB  
Review
Reviewing a Model of Metacognition for Application in Cognitive Architecture Design
by Teodor Ukov and Georgi Tsochev
Systems 2025, 13(3), 177; https://doi.org/10.3390/systems13030177 - 5 Mar 2025
Viewed by 217
Abstract
This systematic review answers questions about whether or not a model of metacognition is well accepted and if it can be used in cognitive architecture design. Self-planning, self-monitoring, and self-evaluation are the model concepts, which are viewed as metacognitive experiences. A newly formulated [...] Read more.
This systematic review answers questions about whether or not a model of metacognition is well accepted and if it can be used in cognitive architecture design. Self-planning, self-monitoring, and self-evaluation are the model concepts, which are viewed as metacognitive experiences. A newly formulated theoretical approach named Attention as Action was targeted, as it is shown to be used in cognitive architecture design. In order to link the model to the theoretical approach, specific concepts like mental imagery and learning experience were researched. The method includes the statistical analysis of key phrases in articles that were collected based on a system of criteria. Data were retrieved from 91 scientific papers to allow statistical analysis of the relationship between the model of metacognition and the theoretical approach to cognitive architecture design. Several observations from the data show that the model is applicable for designing cognitive monitoring systems that depict experiences of metacognition. Furthermore, the results point out that the researched fields require explanations about the concepts defined in the theoretical approach of Attention as Action. Systematically formulated as types of internal attentional experiences, new relations are provided for researching cognitive and metacognitive concepts in terms of the cognitive cycle. Full article
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<p>Conceptual model that represents the theoretical idea for achieving the cognitive architecture design.</p>
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<p>Internal decision–making in terms of the cognitive cycle. The acronym AUP stands for automatic unconscious process.</p>
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<p>Basal guidelines for cognitive architecture design with the Attention as Action approach. Acronyms: AUP—automatic unconscious process; IA—internal action.</p>
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<p>Area chart showing how the reported articles are distributed in terms of publication year.</p>
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<p>These pie charts present the percentages of the occurrences of the model concept tokens: (<b>a</b>) general model keywords; (<b>b</b>) specific concepts that most exactly define the model.</p>
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<p>Pie chart of number of articles classified by the categorical variables.</p>
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<p>This graph shows how many of the linking concepts appear in articles that have the model occurrence phenomenon (the three model concepts mentioned together in a phrase). The abbreviation MOP corresponds to model occurrence phenomenon.</p>
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<p>General model of internal attention (GIMA). Abbreviations: IA: internal action; AUP: automatic unconscious process; SISI: stream of incoming sensory information; PAM: perceptual associative memory; and SMM: sensory motor memory.</p>
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<p>The GIMA model as a weighted bidirected graph. The twenty-eight weights are denominated with numbers between the internal action states.</p>
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<p>Design of a user interface applicable in a digital information system for critical decision-making that applies cognitive prompting via the GIMA model.</p>
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18 pages, 4938 KiB  
Study Protocol
Optimization of Control Point Layout for Orthophoto Generation of Indoor Murals
by Dingfei Yan and Yongming Yang
Sensors 2025, 25(5), 1588; https://doi.org/10.3390/s25051588 - 5 Mar 2025
Viewed by 64
Abstract
This study focuses on the preservation of indoor murals, which can be supported by combining RTK and total station technology to explore the optimization of image geometric accuracy based on a control points layout. The study involves placing varying numbers of control points [...] Read more.
This study focuses on the preservation of indoor murals, which can be supported by combining RTK and total station technology to explore the optimization of image geometric accuracy based on a control points layout. The study involves placing varying numbers of control points on the mural surface and processing the collected data using a spatial coordinate transformation model to assess the impact of different layouts on image accuracy. Some control points are used to ensure the spatial positioning accuracy of the images, while others serve as check points to validate the geometric precision of the images. After data processing, high-precision digital orthophotos are generated using Agisoft PhotoScan2.0.1 software, with accuracy verified by the check points. The experimental results show that as the number of control points increases, image accuracy improves gradually. When the number of control points reaches 24, the geometric accuracy of the images stabilizes, and further increases in the number of control points have a limited effect on improving accuracy. Therefore, the study proposes an optimal layout scheme: 24 control points for every 16 square meters. This scheme not only meets millimeter-level precision requirements but also effectively optimizes resource allocation and reduces time costs. The research provides reliable data support for the high-precision preservation and restoration of murals and offers important references for similar cultural heritage preservation projects. Full article
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<p>Experimental workflow.</p>
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<p>Control point distribution map. Note: Black pentagons represent the check points, and red triangles represent the control points.</p>
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<p>Schematic diagram of control point layout schemes. Note: Black pentagons represent the check points, and red triangles represent the control points.</p>
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<p>Before Y-axis rotation.</p>
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<p>After Y-axis rotation.</p>
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<p>Digital orthophoto generated with 24 control points.</p>
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<p>Total root mean square error distribution.</p>
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11 pages, 3295 KiB  
Article
Leontodon albanicus subsp. acroceraunicus (Asteraceae, Cichorieae): A New Subspecies from Southern Albania
by Fabio Conti, Luca Bracchetti, Marco Dorfner, Nadine Benda and Christoph Oberprieler
Biology 2025, 14(3), 259; https://doi.org/10.3390/biology14030259 - 4 Mar 2025
Viewed by 188
Abstract
Some plants belonging to the Leontodon sect. Asterothrix were collected from southern Albania. They were compared with the closest taxon (L. albanicus s.str.) from morphological and molecular (AFLPseq fingerprinting) points of view. Uni- and multivariate statistical analyses of morphological data revealed distinctive [...] Read more.
Some plants belonging to the Leontodon sect. Asterothrix were collected from southern Albania. They were compared with the closest taxon (L. albanicus s.str.) from morphological and molecular (AFLPseq fingerprinting) points of view. Uni- and multivariate statistical analyses of morphological data revealed distinctive discontinuities—especially in terms of the characteristics of the indumentum–that are paralleled by separation into two genetic clusters in AFLPseq fingerprinting. Following an integrated taxonomic approach based on morphological, genetic, and geographical sources of evidence, we show that the newly discovered population should be regarded as a new subspecies named Leontodon albanicus subsp. acroceraunicus. The new taxon is described and illustrated, and its relationship with L. albanicus subsp. albanicus is also discussed. We have no data to assess conservation status according to IUCN categories and criteria; however, considering that it is probably limited to the Acroceraunian Mountains, it deserves particular conservation interest. Full article
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<p>Scatter plot of Principal Component Analysis; accessions of the Ҫika population are on the left side (green triangles); accessions of the Nëmerçkë population of <span class="html-italic">L. albanicus</span> are on the right side (blue squares).</p>
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<p>Ordination of nine accessions of <span class="html-italic">Leontodon albanicus</span> on the first two axes of Principal Co-ordinate Analysis (PCoA) based on 9260 parsimony informative SNPs from AFLPseq fingerprinting with Jukes-Cantor distances as a measure of genetic similarity among accessions. Ҫika population is on the left (green triangles); Nëmerçkë population of <span class="html-italic">L. albanicus</span> is on the right (blue squares).</p>
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<p>Leaf hairs from a specimen of <span class="html-italic">L. albanicus</span> subsp. <span class="html-italic">albanicus</span> collected on Mt. Nëmerçkë.</p>
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<p>Leaf hairs from a specimen of <span class="html-italic">L. albanicus</span> subsp. acroceraunicus collected on Mt. Ҫika.</p>
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<p>Holotypus of <span class="html-italic">Leontodon albanicus</span> subsp. <span class="html-italic">acroceraunicus</span>.</p>
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<p>Distribution map of <span class="html-italic">Leontodon albanicus</span> according to the herbarium materials studied: subsp. <span class="html-italic">albanicus</span> (blue squares); subsp. <span class="html-italic">acroceraunicus</span> (green triangles).</p>
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28 pages, 8268 KiB  
Article
Selection of Landsat 8 OLI Levels, Monthly Phases, and Spectral Variables on Identifying Soil Salinity: A Study in the Yellow River Delta
by Guosheng Ni, Yang Guan, Xiaoguang Zhang, Yi Yang, Yu Li, Xinwei Liu, Ziguo Rong and Min Ju
Appl. Sci. 2025, 15(5), 2747; https://doi.org/10.3390/app15052747 - 4 Mar 2025
Viewed by 208
Abstract
Soil salinization is a significant threat to agricultural production, making accurate salinity prediction essential. This study addresses key challenges in the Yellow River Delta (YRD) soil salinity inversion, including (1) determining which Landsat 8 OLI level performs better, (2) identifying the most suitable [...] Read more.
Soil salinization is a significant threat to agricultural production, making accurate salinity prediction essential. This study addresses key challenges in the Yellow River Delta (YRD) soil salinity inversion, including (1) determining which Landsat 8 OLI level performs better, (2) identifying the most suitable month for salinity inversion, and (3) improving model performance and identifying important variables in modeling. Thus Landsat 8 OLI images (Level-1 and Level-2) for 12 months were collected, then images having less than 10% cloud cover were selected and processed to extract spectral values. A total of 86 sampled points were processed to measure soil salinity. Using Pearson correlation and expert insights, January 15 and August 26 were identified as suitable dates for inversion. Then, seven original bands, 29 spectral indicators, and 39 derived variables which created through six mathematical transformations, were used to construct the following three models: partial least squares regression (PLSR), random forest (RF), and backpropagation neural network (BPNN). The results showed the following: (1) The Level-1 data, after FLAASH atmospheric correction, outperforms Level-2 data. (2) January is optimal for salinity inversion. (3) Among the three models, RF outperformed the others, achieving test set R2 = 0.55, RMSE = 3.4, suggesting that the combination of spectral indicators and mathematically transformed variables can effectively enhance model accuracy for predicting soil salinity in the YRD. Furthermore, SWIR1, SWIR2, CLEX, second-order difference of SWIR1, and first-order difference of SWIR2 along with NIR played a key role in modeling. Full article
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<p>Location of the study area and 86 sampling points. Red dots mean the sampled points. The data sources were Landsat 8 OLI Collection 2 Level-2 image taken on 15 January 2016 from the United States Geological Survey ©, <a href="https://earthexplorer.usgs.gov/" target="_blank">https://earthexplorer.usgs.gov/</a> (accessed on 20 October 2024).</p>
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<p>The top images are Level-1, and the bottom images are Level-2. From left to right, the dates are January 15, February 16, March 3, August 26, and December 16. Different colors of images mean the different situation of ground.</p>
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<p>RF flowchart.</p>
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<p>BPNN flowchart.</p>
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<p>Workflow of this research.</p>
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<p>The correlation of each band. * represents the <span class="html-italic">p</span>-value &lt; 0.05 and ** represents the <span class="html-italic">p</span>-value &lt; 0.01.</p>
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<p>The performance of PLSR for January 15 (<b>left</b>) and August 26 (<b>right</b>).</p>
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<p>The performance of RF for January 15 (<b>left</b>) and August 26 (<b>right</b>).</p>
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<p>The performance of BPNN for January 15 (<b>left</b>) and August 26 (<b>right</b>).</p>
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<p>Summary of the performance of the three models for January 15.</p>
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<p>Summary of the performance of the three models for August 26. The darker the color in the R<sup>2</sup> area, the higher the R<sup>2</sup> value; the lighter the color, the lower the R<sup>2</sup> value.</p>
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<p>Prediction of soil salinity in Yellow River Delta.</p>
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<p>(<b>a</b>) Sentinel-2 10 m resolution land use data are from <a href="https://viewer.esa-worldcover.org/worldcover/" target="_blank">https://viewer.esa-worldcover.org/worldcover/</a> (accessed on 28 October 2024) (<b>b</b>) Soil type classification is from the Natural Resources Network <a href="https://www.resdc.cn/data.aspx?DATAID=145" target="_blank">https://www.resdc.cn/data.aspx?DATAID=145</a> (accessed on 28 October 2024).</p>
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<p>Top 20 important variables in RF. The red words indicate variables retained after a correlation analysis in <a href="#applsci-15-02747-f015" class="html-fig">Figure 15</a>, which filtered out variables with high correlation, then used to construct a new RF model.</p>
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<p>The correlation heatmap of selected 20 features. * represents the <span class="html-italic">p</span>-value &lt; 0.05 and ** represents the <span class="html-italic">p</span>-value &lt; 0.01.</p>
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<p>The performance of RF constructed by 15 features.</p>
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15 pages, 4153 KiB  
Article
Highly Branched Poly(Adipic Anhydride-Co-Mannitol Adipate): Synthesis, Characterization, and Thermal Properties
by Mahir A. Jalal, Einas A. Abood, Zainab J. Sweah, Hadi S. Al-Lami, Alyaa Abdulhasan Abdulkarem and Haider Abdulelah
Polymers 2025, 17(5), 684; https://doi.org/10.3390/polym17050684 - 4 Mar 2025
Viewed by 116
Abstract
In this study, modification of poly(adipic anhydride) through branching its chains was carried out via melt condensation polymerization with D-mannitol. The percentage of mannitol was varied (3, 4, 5, 10, 15, and 20 Wt.%) and the resulting copolymers were purified and characterized by [...] Read more.
In this study, modification of poly(adipic anhydride) through branching its chains was carried out via melt condensation polymerization with D-mannitol. The percentage of mannitol was varied (3, 4, 5, 10, 15, and 20 Wt.%) and the resulting copolymers were purified and characterized by FT-IR and 13C-NMR. These analyses indicated that linear chains of poly(adipic anhydride) can react with strong nucleophiles and dissociate to produce highly branched poly(adipic anhydride-co-mannitol adipate) which confirms the validity of the proposed mechanism. The copolymer’s molecular weight characteristics have been also examined using GPC analysis. Thermal properties of copolymers were also investigated using TGA, DTG, and DCS analyses. TGA/DTG revealed that the thermal degradation of copolymers proceeds in multi-stage decomposition, whereas the shift and pattern change of the melting point peak of DSC curves can identify the weight percentage of mannitol for homogenous copolymers. Two non-isothermal models, the Flynn–Wall–Ozawa and Kissinger methods, have been also employed to analyze thermogravimetric data collected from the thermal decomposition of the copolymers and found that Flynn–Wall–Ozawa method provides better results with R2 correlation up to 99.3%. The activation energy in the region of Tmax was determined and found that an increase in mannitol contents in copolymer has a positive impact on its thermal stability. Full article
(This article belongs to the Section Polymer Analysis and Characterization)
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<p>FT-IR of PAA and highly branched PAA-<span class="html-italic">co</span>-M copolymers.</p>
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<p><sup>13</sup>C NMR of (<b>a</b>) PAA and (<b>b</b>) PAA-<span class="html-italic">co</span>-M(10%). The blue scale represents to the chemical shift (ppm).</p>
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<p>TGA curves of PAA and PAA-<span class="html-italic">co</span>-M copolymers (<span class="html-italic">β</span> = 30 °C/min).</p>
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<p>DTG curves of PAA and PAA-<span class="html-italic">co</span>-M copolymers (<span class="html-italic">β</span> = 30 °C/min).</p>
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<p>DSC curves of copolymers at the region of their melting points.</p>
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<p>A plot of ln(<span class="html-italic">β</span>/<span class="html-italic">T<sub>p</sub></span><sup>2</sup>) versus the reciprocal of the peak temperature 1/<span class="html-italic">T<sub>p</sub></span> (Kissinger method) to estimate <span class="html-italic">E<sub>a</sub></span> for the thermal decomposition of copolymers.</p>
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<p>F-W-O plots for thermal degradation of PAA and PAA-<span class="html-italic">co</span>-M copolymers (<b>a</b>) first DTG peak and (<b>b</b>) second DTG peak.</p>
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<p>Steps of copolymer synthesis (<b>a</b>) polymerization of adipic acid and (<b>b</b>) chemical reaction of synthesis highly branched PAA-<span class="html-italic">co</span>-M.</p>
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18 pages, 6652 KiB  
Article
Tensile Strength Predictive Modeling of Natural-Fiber-Reinforced Recycled Aggregate Concrete Using Explainable Gradient Boosting Models
by Celal Cakiroglu, Farnaz Ahadian, Gebrail Bekdaş and Zong Woo Geem
J. Compos. Sci. 2025, 9(3), 119; https://doi.org/10.3390/jcs9030119 - 4 Mar 2025
Viewed by 70
Abstract
Natural fiber composites have gained significant attention in recent years due to their environmental benefits and unique mechanical properties. These materials combine natural fibers with polymer matrices to create sustainable alternatives to traditional synthetic composites. In addition to natural fiber reinforcement, the usage [...] Read more.
Natural fiber composites have gained significant attention in recent years due to their environmental benefits and unique mechanical properties. These materials combine natural fibers with polymer matrices to create sustainable alternatives to traditional synthetic composites. In addition to natural fiber reinforcement, the usage of recycled aggregates in concrete has been proposed as a remedy to combat the rapidly increasing amount of construction and demolition waste in recent years. However, the accurate prediction of the structural performance metrics, such as tensile strength, remains a challenge for concrete composites reinforced with natural fibers and containing recycled aggregates. This study aims to develop predictive models of natural-fiber-reinforced recycled aggregate concrete based on experimental results collected from the literature. The models have been trained on a dataset consisting of 482 data points. Each data point consists of the amounts of cement, fine and coarse aggregate, water-to-binder ratio, percentages of recycled coarse aggregate and natural fiber, and the fiber length. The output feature of the dataset is the splitting tensile strength of the concrete. Extreme gradient boosting (XGBoost), light gradient boosting machine (LightGBM) and extra trees regressor models were trained to predict the tensile strength of the specimens. For optimum performance, the hyperparameters of these models were optimized using the blended search strategy (BlendSearch) and cost-related frugal optimization (CFO). The tensile strength could be predicted with a coefficient of determination greater than 0.95 by the XGBoost model. To make the predictive models accessible, an online graphical user interface was also made available on the Streamlit platform. A feature importance analysis was carried out using the Shapley additive explanations (SHAP) approach. Full article
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<p>(<b>a</b>) Coir [<a href="#B30-jcs-09-00119" class="html-bibr">30</a>], (<b>b</b>) ramie [<a href="#B16-jcs-09-00119" class="html-bibr">16</a>], (<b>c</b>) jute [<a href="#B31-jcs-09-00119" class="html-bibr">31</a>] fibers.</p>
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<p>Distribution of the input and output features.</p>
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<p>Parallel coordinates’ plot of the dataset.</p>
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<p>Isolation of data points.</p>
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<p>Predictive model development and interpretation.</p>
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<p>Explained variance ratios.</p>
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<p>Outliers for (<b>a</b>) contamination = 0.1, (<b>b</b>) contamination = 0.06, (<b>c</b>) contamination = 0.02, (<b>d</b>) contamination = 0.01.</p>
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<p>Model performances with respect to contamination.</p>
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<p>Extra trees model performance fluctuations on the test set.</p>
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<p>Hyperparameter optimization steps.</p>
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<p>Predicted and true values for (<b>a</b>) extra trees, (<b>b</b>) LightGBM, (<b>c</b>) XGBoost.</p>
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<p>Online graphical user interface.</p>
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<p>SHAP feature importances.</p>
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<p>SHAP summary plot.</p>
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<p>SHAP heatmap plot.</p>
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16 pages, 4367 KiB  
Article
Gut Mycobiome Changes During COVID-19 Disease
by Danil V. Krivonos, Dmitry E. Fedorov, Ksenia M. Klimina, Vladimir A. Veselovsky, Svetlana N. Kovalchuk, Alexander V. Pavlenko, Oleg O. Yanushevich, Dmitry N. Andreev, Filipp S. Sokolov, Aleksey K. Fomenko, Mikhail K. Devkota, Nikolai G. Andreev, Andrey V. Zaborovsky, Sergei V. Tsaregorodtsev, Vladimir V. Evdokimov, Natella I. Krikheli, Petr A. Bely, Oleg V. Levchenko, Igor V. Maev, Vadim M. Govorun and Elena N. Ilinaadd Show full author list remove Hide full author list
J. Fungi 2025, 11(3), 194; https://doi.org/10.3390/jof11030194 - 3 Mar 2025
Viewed by 189
Abstract
The majority of metagenomic studies are based on the study of bacterial biota. At the same time, the COVID-19 pandemic has prompted interest in the study of both individual fungal pathogens and fungal communities (i.e., the mycobiome) as a whole. Here, in this [...] Read more.
The majority of metagenomic studies are based on the study of bacterial biota. At the same time, the COVID-19 pandemic has prompted interest in the study of both individual fungal pathogens and fungal communities (i.e., the mycobiome) as a whole. Here, in this work, we investigated the human gut mycobiome during COVID-19. Stool samples were collected from patients at two time points: at the time of admission to the hospital (the first time point) and at the time of discharge from the hospital (the second time point). The results of this study revealed that Geotrichum sp. is more represented in a group of patients with COVID-19. Therefore, Geotrichum sp. is elevated in patients at the time of admission to the hospital and underestimated at the time of discharge. Additionally, the influence of factors associated with the diversity of fungal gut microbiota was separately studied, including disease severity and age factors. Full article
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<p>Phylogenetic tree for assembled ASVs. Bootstrap support visualized with light blue color. Mean relative abundance was illustrated for each group separately (F1—1st time point; F2—2nd time point). The tree was rooted in the midpoint.</p>
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<p>Presentation of metadata for patients. CT is computed tomography score (CT1—less than 25–50% of the lungs are affected; CT2—moderate pneumonia, 25–50% of the lungs are affected; CT3—50–75% of the lungs are affected; CT4 is a severe form of pneumonia, affecting &gt;75%). The who1 score is the WHO performance score at admission to the hospital. The severity group is a combined score of disease severity according to CT and the WHO performance score scale.</p>
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<p>PERMANOVA results for different patient factors (*—<span class="html-italic">p</span>-value ≤ 0.05, **—<span class="html-italic">p</span>-value ≤ 0.01, ***—<span class="html-italic">p</span>-value ≤ 0.001). CT is computed tomography score (CT1—less than 25–50% of the lungs are affected; CT2—moderate pneumonia, 25–50% of the lungs are affected; CT3—50–75% of the lungs are affected; CT4 is a severe form of pneumonia, affecting &gt;75%). The who1 score is the WHO performance score at admission to the hospital. The severity group is a combined score of disease severity according to CT and the WHO scale.</p>
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<p>(<b>A</b>) Alpha diversity for different time points for ASV level (Mann–Whitney U-test results: **—<span class="html-italic">p</span>-value ≤ 0.01, ***—<span class="html-italic">p</span>-value ≤ 0.001). (<b>B</b>) PCoA plot with Atchenson distance for samples from different time points (NS.—<span class="html-italic">p</span>-value &gt; 0.05, ***—<span class="html-italic">p</span>-value ≤ 0.001).</p>
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<p>Results of differential abundance analysis obtained via DESeq2. (<b>A</b>) ASV level; (<b>B</b>) species level (****—<span class="html-italic">p</span>-value ≤ 0.0001).</p>
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<p>Changes in the trend of alpha diversity depending on the severity of the disease (species level). CT is computed tomography score (CT1—less than 25–50% of the lungs are affected; CT2—moderate pneumonia, 25–50% of the lungs are affected; CT3—50–75% of the lungs are affected; CT4 is a severe form of pneumonia, affecting &gt;75%). The who1 score is the WHO performance score at admission to the hospital. The severity group is a combined score of disease severity according to CT and the WHO scale.</p>
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<p>Changes in the trend of alpha diversity depending on age group (*—<span class="html-italic">p</span>-value &lt; 0.05).</p>
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17 pages, 1245 KiB  
Article
Dynamic Changes in Rumen Microbial Diversity and Community Composition Within Rumen Fluid in Response to Various Storage Temperatures and Preservation Times
by Chang Liu, Jin Cheng, Yunong Xie, Kehui Ouyang, Mingren Qu, Ke Pan and Qinghua Qiu
Vet. Sci. 2025, 12(3), 234; https://doi.org/10.3390/vetsci12030234 - 3 Mar 2025
Viewed by 190
Abstract
The aim of this study was to investigate the effects of storage temperature and preservation time on the microbial diversity and community composition of rumen fluid. Rumen fluid samples were collected from six Hu sheep fed on a high-forage diet and stored at [...] Read more.
The aim of this study was to investigate the effects of storage temperature and preservation time on the microbial diversity and community composition of rumen fluid. Rumen fluid samples were collected from six Hu sheep fed on a high-forage diet and stored at −80 °C and −20 °C for intervals of 0, 7, 14, 30, 60, 120, and 240 days. DNA was extracted at each time point for 16S rRNA gene sequencing to evaluate the rumen microbial diversity and community composition. The results showed that storage temperature affected only the relative abundance of Proteobacteria, with no substantial impact on alpha-diversity or other microbial groups (p > 0.05), and no significant interaction effects were observed between storage temperature and preservation time (p > 0.05). Alpha-diversity indices such as Chao1, observed species, and PD whole tree showed dynamic changes after 7 days of storage, while the relative abundances of Verrucomicrobiota and Christensenellaceae R-7 group, as well as the energy metabolism metabolic pathway, exhibited significant alterations after 14 days of storage (p < 0.05). Notably, Patescibacteria, Rikenellaceae RC9 gut group, and Veillonellaceae UCG-001 abundances demonstrated significant changes after 240 days of storage (p < 0.05). Both principal coordinates analysis (PCoA) and non-metric multidimensional scaling (NMDS) showed distinct overlaps. This study suggests that storing rumen fluid at −80 °C and −20 °C does not influence rumen microbial diversity and community composition, whereas the storage time significantly impacts these factors, with most differences emerging after 14 days of preservation. Consequently, it is advised that the analysis of microbial diversity and community composition in rumen fluid samples be conducted within 14 days post-collection. Full article
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<p>Principal coordinates analysis (PCoA, (<b>a</b>)) and non-metric multidimensional scaling (NMDS, (<b>b</b>)) of rumen bacterial community within rumen fluid from various preservation times and storage temperatures.</p>
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<p>Effect of preservation time and storage temperature on the discriminative bacterial communities across various taxonomic levels in rumen fluid is illustrated by (<b>a</b>) linear discriminant analysis and (<b>b</b>) cladogram.</p>
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13 pages, 2376 KiB  
Article
Wave-like Behavior in the Source–Detector Resonance
by Ioannis Contopoulos
Particles 2025, 8(1), 24; https://doi.org/10.3390/particles8010024 - 3 Mar 2025
Viewed by 199
Abstract
We consider a particular model of a Source of independent particles and a macroscopic Detector that are both tuned to the same resonance frequency ν01/P. Particles are emitted by the Source at exact multiples of the resonance [...] Read more.
We consider a particular model of a Source of independent particles and a macroscopic Detector that are both tuned to the same resonance frequency ν01/P. Particles are emitted by the Source at exact multiples of the resonance period P, and the Detector absorbs them with a certain probability at any one of its points. The Detector may also announce the detection of the absorbed particle. Any particle that is not absorbed at a certain point passes through to a deeper layer in the interior of the Detector. Eventually, all particles will be absorbed, i.e., detected. We calculate the probability of detection for two particle time series generated by the same Source reaching the Detector with a time delay of δt and show that it manifests the illusion of collective (wave-like) interference with particle number conservation. We conclude that wave phenomena may reflect the nature of detectors rather than fundamental laws of physics. Full article
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<p>A <span class="html-italic">Source</span> contains a macroscopic oscillator of resonance frequency <math display="inline"><semantics> <msub> <mi>ν</mi> <mn>0</mn> </msub> </semantics></math> that releases elementary particles of mass <span class="html-italic">m</span> with the same velocity <span class="html-italic">v</span> every resonance period <math display="inline"><semantics> <mrow> <mi>P</mi> <mo>=</mo> <mn>1</mn> <mo>/</mo> <msub> <mi>ν</mi> <mn>0</mn> </msub> </mrow> </semantics></math>. <span class="html-italic">M</span> is the oscillating mass, and <math display="inline"><semantics> <msub> <mi>L</mi> <mn>0</mn> </msub> </semantics></math> is the equilibrium position.</p>
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<p>Top–bottom rows of panels: Time series and corresponding spectra of particles emitted continuously and intermittently <math display="inline"><semantics> <mrow> <mn>80</mn> <mo>%</mo> <mo>,</mo> <mo> </mo> <mn>50</mn> <mo>%</mo> <mo>,</mo> <mo> </mo> <mn>20</mn> <mo>%</mo> </mrow> </semantics></math> with fixed period <span class="html-italic">P</span> by the Source (from top left to bottom right, respectively).</p>
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<p>The <span class="html-italic">Resonant Oscillator</span> is tuned to the same resonance frequency <math display="inline"><semantics> <msub> <mi>ν</mi> <mn>0</mn> </msub> </semantics></math> as the Source. A stream of elementary particles reaches it, but the Resonant Oscillator absorbs them only if they reach it at its resonance frequency. The Resonant Oscillator absorbs particles with a certain probability given by Equation (<a href="#FD6-particles-08-00024" class="html-disp-formula">6</a>). If a particle is not absorbed, it continues its motion unimpeded downstream from the Resonant Oscillator.</p>
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<p>Sketch of interference between two different streams of particles that originate at the same Source and have a time delay of <math display="inline"><semantics> <mrow> <mi>δ</mi> <mi>t</mi> <mo>=</mo> <mo>(</mo> <msub> <mi>L</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>L</mi> <mn>2</mn> </msub> <mo>)</mo> <mo>/</mo> <mi>v</mi> </mrow> </semantics></math> between themselves. Such superposition manifests interference characteristics at the Detector.</p>
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<p>Top–bottom rows of panels: The superposition of two equal-power time series of particles emitted intermittently by the Source with fixed period <span class="html-italic">P</span> and a time delay between them equal to <math display="inline"><semantics> <mrow> <mi>δ</mi> <mi>t</mi> <mo>=</mo> <mn>0</mn> <mo>,</mo> <mo> </mo> <mn>0.1</mn> <mo>,</mo> <mo> </mo> <mn>0.2</mn> <mo>,</mo> <mo> </mo> <mn>0.3</mn> <mo>,</mo> <mo> </mo> <mn>0.4</mn> <mo>,</mo> <mo> </mo> <mn>0.5</mn> </mrow> </semantics></math> times the period <span class="html-italic">P</span> (plus an integer multiple of <span class="html-italic">P</span>) from top left to bottom right respectively. These time series of particles are collected by the Resonant Oscillator/Detector. The corresponding spectra are also shown. We see very clearly that when <math display="inline"><semantics> <mrow> <mi>δ</mi> <mi>t</mi> <mo>=</mo> <mn>0.5</mn> <mi>P</mi> </mrow> </semantics></math>, the spectrum power at resonance vanishes.</p>
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<p>Top-Bottom rows of panels: The superposition of two unequal time series of particles emitted intermittently by the Source with fixed period <span class="html-italic">P</span> and a time delay between them equal to <math display="inline"><semantics> <mrow> <mi>δ</mi> <mi>t</mi> <mo>=</mo> <mn>0</mn> <mo>,</mo> <mn>0.1</mn> <mo>,</mo> <mo> </mo> <mn>0.2</mn> <mo>,</mo> <mo> </mo> <mn>0.3</mn> <mo>,</mo> <mo> </mo> <mn>0.4</mn> <mo>,</mo> <mo> </mo> <mn>0.5</mn> </mrow> </semantics></math> times the period <span class="html-italic">P</span> (plus an integer multiple of <span class="html-italic">P</span>) from top left to bottom right respectively. The first time series contains only <math display="inline"><semantics> <mrow> <mn>20</mn> <mo>%</mo> </mrow> </semantics></math> of the particles of the continuous time series of the tope left panel of <a href="#particles-08-00024-f002" class="html-fig">Figure 2</a>, and the second only <math display="inline"><semantics> <mrow> <mn>50</mn> <mo>%</mo> </mrow> </semantics></math>. These time series of particles are collected by the Resonant Oscillator/Detector. The corresponding spectra are also shown. We see very clearly that when <math display="inline"><semantics> <mrow> <mi>δ</mi> <mi>t</mi> <mo>=</mo> <mn>0.5</mn> <mi>P</mi> </mrow> </semantics></math>, the spectrum power at resonance does not vanish. The ratio of the number of particles and resonance over the total number of particles emitted by the Source is given by Equation (<a href="#FD7-particles-08-00024" class="html-disp-formula">7</a>).</p>
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<p>Distribution of the square of the ratio of the PSD at resonance over the PSD at zero frequency as a function of the time delay <math display="inline"><semantics> <mrow> <mi>δ</mi> <mi>t</mi> </mrow> </semantics></math>. We consider here the combination of two power time series with <math display="inline"><semantics> <mrow> <mo>(</mo> <mi>α</mi> <mo>,</mo> <mi>β</mi> <mo>)</mo> <mo>=</mo> <mo>(</mo> <mn>0.8</mn> <mo>,</mo> <mn>0.8</mn> <mo>)</mo> <mo>/</mo> <mo>(</mo> <mn>0.8</mn> <mo>,</mo> <mn>0.6</mn> <mo>)</mo> <mo>/</mo> <mo>(</mo> <mn>0.8</mn> <mo>,</mo> <mn>0.4</mn> <mo>)</mo> <mo>/</mo> <mo>(</mo> <mn>0.8</mn> <mo>,</mo> <mn>0.2</mn> <mo>/</mo> <mo>(</mo> <mn>0.8</mn> <mo>,</mo> <mn>0.1</mn> <mo>)</mo> <mo>/</mo> <mo>(</mo> <mn>0.8</mn> <mo>,</mo> <mn>0.05</mn> <mo>)</mo> <mo>)</mo> </mrow> </semantics></math> from top left to bottom right, respectively. The fits to the expression of Equation (<a href="#FD7-particles-08-00024" class="html-disp-formula">7</a>) for the correponding values of <math display="inline"><semantics> <mi>α</mi> </semantics></math> and <math display="inline"><semantics> <mi>β</mi> </semantics></math> are also shown. Except for the case of zero time delay <math display="inline"><semantics> <mrow> <mi>δ</mi> <mi>t</mi> </mrow> </semantics></math>, this distribution leaves a fraction <math display="inline"><semantics> <mrow> <mo>(</mo> <mn>1</mn> <mo>−</mo> <msub> <mi>Prob</mi> <mi>abs</mi> </msub> <mo>)</mo> </mrow> </semantics></math> of particles undetected. Clearly, when either one of <math display="inline"><semantics> <mi>α</mi> </semantics></math> or <math display="inline"><semantics> <mi>β</mi> </semantics></math> is equal to zero (i.e., if we have only one and not two combined particle time series), the detection probability <math display="inline"><semantics> <msub> <mi>Prob</mi> <mi>abs</mi> </msub> </semantics></math> is equal to unity.</p>
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<p>Sketch of a double-slit experiment. Two particle streams from the two slits that reach the surface of the <span class="html-italic">Detector</span> with <math display="inline"><semantics> <mrow> <mi>δ</mi> <mi>t</mi> <mo>=</mo> <mn>0</mn> </mrow> </semantics></math> (plus an integer multiple of the period <span class="html-italic">P</span>) are directly absorbed. Double particle streams with <math display="inline"><semantics> <mrow> <mi>δ</mi> <mi>t</mi> <mo>=</mo> <mi>P</mi> <mo>/</mo> <mn>2</mn> </mrow> </semantics></math> plus an integer multiple of <span class="html-italic">P</span> are not immediately absorbed, and their individual particle streams continue unimpeded in the interior of the Detector. It is clear that all such particles will be gradually absorbed within a certain depth inside the Detector as they reach positions with <math display="inline"><semantics> <mrow> <mn>0</mn> <mo>≤</mo> <mi>δ</mi> <mi>t</mi> <mo>&lt;</mo> <mi>P</mi> <mo>/</mo> <mn>2</mn> </mrow> </semantics></math> (plus an integer multiple of the period <span class="html-italic">P</span>). The Detector thus announces the same number of particles as those that reached it through the two slits.</p>
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<p>Upper plot: <math display="inline"><semantics> <mrow> <mi>x</mi> <mo>=</mo> <mi>x</mi> <mo>(</mo> <mi>t</mi> <mo>)</mo> </mrow> </semantics></math> for the Source oscillator described by Equation (<a href="#FD9-particles-08-00024" class="html-disp-formula">A2</a>). <math display="inline"><semantics> <mrow> <mi>x</mi> <mrow> <mo>(</mo> <mn>0</mn> <mo>)</mo> </mrow> <mo>=</mo> <mn>2</mn> <msub> <mi>L</mi> <mn>0</mn> </msub> </mrow> </semantics></math>. <math display="inline"><semantics> <mrow> <mover accent="true"> <mi>x</mi> <mo>˙</mo> </mover> <mrow> <mo>(</mo> <mn>0</mn> <mo>)</mo> </mrow> <mo>=</mo> <mn>0</mn> </mrow> </semantics></math>. Initial oscillator energy <math display="inline"><semantics> <mrow> <mo>≫</mo> <mi>h</mi> <msub> <mi>ν</mi> <mn>0</mn> </msub> </mrow> </semantics></math>. Time in units of the oscillator period <span class="html-italic">P</span>. Lower plot: Evolution of the oscillator energy (blue/orange/green lines: kinetic/potential/total energy respectively).</p>
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22 pages, 1394 KiB  
Article
Dealing with Urban Biodiversity Through Butterfly Gardens: A Project-Based Learning Proposal for Pre-Service Teachers Training
by Zoel Salvadó and Maite Novo
Sustainability 2025, 17(5), 2195; https://doi.org/10.3390/su17052195 - 3 Mar 2025
Viewed by 208
Abstract
Research in environmental education points out the need for an improvement in pre-service teacher education training in this area. This proposal follows PBL methodology and focuses on the development of an environmental education project whose final product is the organization of a science [...] Read more.
Research in environmental education points out the need for an improvement in pre-service teacher education training in this area. This proposal follows PBL methodology and focuses on the development of an environmental education project whose final product is the organization of a science fair for elementary school students. The 5-week project addresses the topic of urban biodiversity decline and uses the butterfly garden as an initiative to mitigate it. Four months after the program ended, a survey was administered to the 86 participating pre-service teachers. A mixed-methods approach was used, collecting quantitative data on perceptions of urban biodiversity decline, the One Health concept, and environmental education, along with qualitative keyword responses to open-ended questions about the butterfly garden’s impact and the project’s value for self-learning and professional development. Participants reported positive perceptions regarding butterfly gardens after participating in our environmental program, recognizing them as both a valuable educational resource and an effective initiative to mitigate urban biodiversity decline. Respondents showed a strong pro-environmental attitude, taking seriously their role in transmitting environmental values. Using a butterfly garden for teaching purposes offers insight into environmental literacy, connection with nature, and improvements in well-being and is a powerful platform for deep and meaningful pedagogical learning. Full article
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<p>Workflow of the PBL program Butterfly Garden Science Fair. Adapted from [<a href="#B30-sustainability-17-02195" class="html-bibr">30</a>]. Detailed information on the PBL methodology and Need to know list [<a href="#B30-sustainability-17-02195" class="html-bibr">30</a>], Word Café Conversation technique [<a href="#B40-sustainability-17-02195" class="html-bibr">40</a>] and Feedback sandwich technique [<a href="#B41-sustainability-17-02195" class="html-bibr">41</a>] can be found in the original references.</p>
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<p>Butterfly garden of Universitat Rovira I Virgili during different editions of the Butterfly Garden Science Fair: (<b>a</b>) first edition of the Butterfly Garden Science Fair, 2018; (<b>b</b>) most recent edition of the Butterfly Garden Science Fair, 2024.</p>
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11 pages, 2514 KiB  
Article
Intrinsic Defect-Induced Local Semiconducting-to-Metallic Regions Within Monolayer 1T-TiS2 Displayed by First-Principles Calculations and Scanning Tunneling Microscopy
by P. J. Keeney, P. M. Coelho and J. T. Haraldsen
Crystals 2025, 15(3), 243; https://doi.org/10.3390/cryst15030243 - 3 Mar 2025
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Abstract
Using density functional theory (DFT) and scanning tunneling microscopy (STM), the intrinsic point defects, formation energy, and electronic structure of 1T-TiS2 were investigated. Defect systems include single-atom vacancies, interstitial and adatom additions, and direct atomic substitution. Using a collective approach for analyzing [...] Read more.
Using density functional theory (DFT) and scanning tunneling microscopy (STM), the intrinsic point defects, formation energy, and electronic structure of 1T-TiS2 were investigated. Defect systems include single-atom vacancies, interstitial and adatom additions, and direct atomic substitution. Using a collective approach for analyzing realistic systems for point defect investigation, we provide a more straightforward comparison to the experimental measurements, reproducing more realistic environmental conditions related to thin film growth. STM images are compared to computationally simulated electron density images to identify specific geometries that result from favorable point defects. DFT suggests that titanium interstitials are the most energetically favorable intrinsic defect, and sulfur vacancies are more likely to form than titanium vacancies within this realistic analysis, which is in agreement with STM data. A pristine, stoichiometric monolayer system is calculated to have a direct band gap of 0.422 eV, which varies based on local point defects. Local semiconducting-to-metallic electronic transitions are predicted to occur based on the presence of Ti interstitials. Full article
(This article belongs to the Section Materials for Energy Applications)
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<p>(<b>a</b>) A side view of 1T and 2H structures displays the polyhedron containing the transition-metal atoms within the middle hexagonal sheet. (<b>b</b>) The Brillouin zone for a monolayer TiS<sub>2</sub> crystallographic system with points of high symmetry and the Brillouin zone analysis route used for band structure calculations.</p>
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<p>Respective lattices for each point defect system of interest before and after geometry optimization. After optimization, the initial configuration of 1S-Interstitial settles at an adatom position (in green), demonstrating that it is energetically unfavorable for sulfur to settle within the lattice. This optimized system will be referred to as 1S-Adatom<sub>1</sub> throughout this paper, with the subscript <sub>1</sub> referring to an initial state of the respective initial atom (titanium (blue) or sulfur (yellow)) located at a traditional interstitial site. 1Ti-Adatom (red) settles closer to the lattice, sitting right above the top sulfur plane, versus its original adatom position. This optimized system will be referred to as 1Ti-Interstitial<sub>2</sub>, with subscript <sub>2</sub> indicating the initial state with the respective initial atom located at a traditional adatom site. Further analysis is addressed within the Density Functional Calculations section.</p>
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<p>Band structures for (<b>a</b>) a pristine 3 × 3 × 1 monolayer cell, indicating a semiconducting system with a band gap of 0.422 eV, (<b>b</b>) the 3 × 3 × 1 cell with an additional titanium atom shifts the cell to a metallic electronic ground state, and (<b>c</b>) a 3 × 3 × 1 cell with a sulfur vacancy that corresponds to a similar metallic shift; however, there are fewer bands present at the Fermi level.</p>
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<p><b>Top</b>-to-<b>Bottom</b>: geometry-optimized lattice, local density of states, partial density of states displaying sulfur 2p orbital contributions, and partial density of states displaying titanium 3d orbital contributions. Left-to-right: pristine TiS<sub>2</sub> cell, pristine cell with one additional titanium atom, and pristine cell with one sulfur vacancy. The orbital angular momentum (<span class="html-italic">l</span>) and magnetic (<span class="html-italic">m</span>) quantum numbers are displayed within the legends. <math display="inline"><semantics> <mrow> <mi>l</mi> <mo>=</mo> <mn>1</mn> </mrow> </semantics></math> corresponds to the p orbital, with <math display="inline"><semantics> <mrow> <mi>l</mi> <mo>=</mo> <mn>2</mn> </mrow> </semantics></math> corresponding to the d orbital. Respectively, <math display="inline"><semantics> <mrow> <mi>m</mi> <mo>=</mo> <mo>−</mo> <mn>1</mn> <mo>,</mo> <mn>0</mn> <mo>,</mo> <mn>1</mn> </mrow> </semantics></math> correspond to <math display="inline"><semantics> <mrow> <msub> <mi>p</mi> <mi>y</mi> </msub> <mo>,</mo> <msub> <mi>p</mi> <mi>z</mi> </msub> <mo>,</mo> <msub> <mi>p</mi> <mi>x</mi> </msub> </mrow> </semantics></math> for the sulfur-2p partial DoS, and <math display="inline"><semantics> <mrow> <mi>m</mi> <mo>=</mo> <mo>−</mo> <mn>2</mn> <mo>,</mo> <mo>−</mo> <mn>1</mn> <mo>,</mo> <mn>0</mn> <mo>,</mo> <mn>1</mn> <mo>,</mo> <mn>2</mn> </mrow> </semantics></math> correspond to <math display="inline"><semantics> <mrow> <msub> <mi>d</mi> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> <mo>,</mo> <msub> <mi>d</mi> <mrow> <mi>y</mi> <mi>z</mi> </mrow> </msub> <mo>,</mo> <msub> <mi>d</mi> <msup> <mi>z</mi> <mn>2</mn> </msup> </msub> <mo>,</mo> <msub> <mi>d</mi> <mrow> <mi>x</mi> <mi>z</mi> </mrow> </msub> <mo>,</mo> <msub> <mi>d</mi> <mrow> <msup> <mi>x</mi> <mn>2</mn> </msup> <mo>−</mo> <msup> <mi>y</mi> <mn>2</mn> </msup> </mrow> </msub> </mrow> </semantics></math>, respectively, for the titanium-3d partial DoS. Notably, the DoS contributions are stacked rather than overlapping.</p>
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<p>STM images demonstrating the surface of a bulk TiS<sub>2</sub> crystal with a sulfur vacancy (<b>a</b>) and an additional titanium interstitial atom (<b>b</b>). Scans were taken with bias voltage <math display="inline"><semantics> <mrow> <msub> <mi>V</mi> <mi>b</mi> </msub> <mo>=</mo> <mn>200</mn> </mrow> </semantics></math> mV and tunneling current <math display="inline"><semantics> <mrow> <msub> <mi>I</mi> <mi>t</mi> </msub> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math> nA. These are overlaid with a DFT-based computational electron density mapping of the surface of a monolayer of TiS<sub>2</sub> with respective point defects, specifically a single sulfur vacancy and a single additional titanium interstitial atom.</p>
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