University of Cádiz
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Uncovering biodiversity deficits: Experimental evidence for dispersal limitation of woody species in Mediterranean forest patches
No full textDeforestation and habitat disturbance are major drivers of local species extinctions within remnant forest patches. In plants, seed dispersal plays a key role in recolonising patches following disturbance. However, habitat fragmentation may hinder seed arrival to suitable but unoccupied patches, resulting in dispersal limitation and, thus, in prolonged biodiversity deficits. We assessed dispersal limitation in Mediterranean forest patches by experimentally introducing plant species from the regional pool. To do so, we sowed 61,000 seeds from 10 woody species and compared their establishment between occupied and unoccupied patches, assessing whether absences were driven by habitat unsuitability or dispersal limitation. We included five dry- and five fleshy-fruited species to test whether dispersal mechanisms influenced dispersal limitation. Additionally, we evaluated major biotic (vertebrate granivores and herbivores) and abiotic (soil properties and moisture) factors that could act as ecological filters in unoccupied areas. Finally, we planted saplings of four species to assess survival at later life stages and test the effectiveness of planting as a restoration strategy. On average, both dry- and fleshy-fruited species exhibited similar establishment rates in occupied and unoccupied patches, indicating that species absences were primarily due to dispersal limitation rather than to habitat unsuitability. Vertebrate antagonists had similar effects across patch occupancy levels, overall reducing establishment. Soil properties and moisture did not differ in ways that would limit establishment in unoccupied patches. Finally, planted saplings had similar or higher survival in unoccupied patches, indicating habitat suitability also in later life stages. Our experiments uncover diversity deficits of woody plants in forest patches driven by dispersal limitation, irrespective of the species' dispersal mechanisms. In general, neither biotic nor abiotic filters significantly constrained the establishment of introduced species in unoccupied patches more than in occupied ones. Synthesis and applications. Mediterranean forest patches in highly altered landscapes may harbour greater woody plant diversity than is currently observed due to dispersal limitation. Assisted colonisation through plant introductions can effectively restore such plant diversity deficits
Machine learning-assisted spectroscopic methods for detecting adulteration in Barrantes wine from Folla Redonda grapes
No full textThe present study explores the application of advanced machine learning algorithms combined with vis-NIRS and FTIR spectroscopy to detect and quantify adulteration in Barrantes wine, produced from the Folla Redonda grape, a variety exclusive to the Galicia region in Spain. Given the unique characteristics of Folla Redonda grapes, such as their distinctive phenolic profile and high antioxidant content, Barrantes wine is at risk of adulteration with lower-quality red wines. The study employs a variety of preprocessing techniques, including normalization and derivative transformations, and evaluates classification models such as Support Vector Machines (SVM), Partial Least Squares Discriminant Analysis (PLS-DA), and Random Forest (RF) for detecting adulteration at varying levels (10 % – 60 %). The findings show that SVM with SNV preprocessing provides the highest accuracy for vis-NIRS and FTIR data (100 %). Furthermore, regression models, particularly SVMRadial, were used to predict the level of adulteration with high precision (R2 > 0.95; RMSE <11 %). This research is pioneering in its field, as it is the first to optimize machine learning techniques for adulteration detection in wine. The findings provide a valuable tool for quality control in the agro-food sector, specifically for niche wines like Barrantes. The results of this study underscore the potential for rapid, precise, and non-destructive analysis through the integration of these approaches
Successive stressors alter microbiome composition and reduce resilience in the eelgrass Zostera marina
No full textSeagrass meadows are among the most threatened ecosystems worldwide, facing multiple anthropogenic stressors that often occur in succession. While plant-physiological responses to multiple stressors are well documented, the role of microbial symbionts in mediating consecutive stressors events remains poorly understood. Using a mesocosm experiment, Zostera marina (eelgrass) was exposed to sequential stressors: nutrient enriched sediments (NE; 70 mg of total N per 100 gDW sediment−1 for 28 days), followed by a simulated marine heatwave (MHW, 23.3 °C for 15 days) and subsequent storm event (25 cm/s flow, 12 days). Nutrient enrichment resulted in a microbiome shift, specifically a 49.2-fold enrichment of sulfur-oxidizing Arcobacteraceae and a 4.7-fold increase in Sulfurimonadaceae, suggesting possible microbiome-mediated responses mitigating sulfide toxicity. In contrast, warming responses were primarily physiological: aboveground biomass increased by 41.5 % and net production increased by 37.1 % (mg FW shoot−1 day−1), with synergistic effects under combined enrichment and heat stress (up to 175 % higher production), indicating that temperature outweighs nutrient stress. Storm exposure triggered a 114 % increase in belowground biomass via root elongation, which increases the resilience of these plants to higher flow velocities, but this acclimation was diminished by 51 % in plants previously exposed to the MHW, indicating environmental legacy effects. Our results demonstrate that eelgrass resilience depends critically on stressors sequence, where legacy effects alter both plant-microbe interactions and physiological responses. These findings emphasize the need to incorporate both a consecutive-stressor approach and microbiome dynamics into seagrass research and conservation strategies under climate change
Geospatial Clustering of GNSS Stations Using Unsupervised Learning: A Statistical Framework to Enhance Deformation Analysis for Environmental Risk Management
No full textThe global expansion of continuous GNSS networks has generated large-scale spatiotemporal
datasets whose analysis requires robust mathematical and statistical tools. This study
introduces a geospatial, multivariate statistical framework for classifying 21,548 GNSS
stations from the University of Nevada repository. The methodology integrates harmonic
regression, stochastic noise modeling, quality assessment, and slope estimation into a
unified feature space suitable for high-dimensional analysis. Using unsupervised learning
clustering computed with our custom-developed code, based entirely on free and
open-source software, we identify homogeneous station groups that reflect dominant signal
properties—periodicity, noise structure, data quality, and long-term velocity—together
with their spatial context. The resulting clusters exhibit strong mathematical coherence
and reveal continental-scale patterns driven by seasonal forcing, tectonic regime, climatic
variability, and monument stability. By grouping stations with similar statistical behavior,
the proposed framework improves reference-site selection, enhances deformation-field interpretation,
and supports the detection of anomalous or hazard-related behavior. Overall,
this approach provides a scalable, data-driven mathematical tool for analyzing complex
spatiotemporal signals and contributes to more reliable deformation modeling and environmental
risk assessment
Has the Spanish non-financial information regulation become a socially accepted norm?: Special emphasis on the road passenger transport sector
No full textThe main goal of this paper is to evaluate the impact of Spanish Non-Financial Information (NFI) regulation on the processes driving sustainability reporting (SR) in becoming a social norm in Spain. The focus is placed specifically on the road passenger transport sector.
We employ a qualitative approach by combining various data sources, primarily interviews and documents.
Our research indicates that the number of reporting companies from the Spanish road passenger transport sector has increased over time, primarily due to the coercive pressure exerted by the Spanish NFI regulation. However, we have found that this regulation does not conform to the prevailing practices and standards. Moreover, the socio-political context surrounding the law's launch hindered its effectiveness as an instrument of change in the SR activity. Consequently, the Spanish NFI regulation has not become a socially accepted norm in Spain, particularly among road passenger transport companies.
This paper makes several important contributions to the existing literature. First, it explores how socio-political, cultural, and historical factors impact SR activities. Second, it utilizes the concept of normativity, as developed by Bebbington et al. (2012), to provide deeper theoretical insights into the dynamic processes involved in the institutionalization of SR within a specific field
Total restrained coalitions in graphs
No full textA vertex set in a graph without isolated vertices is a total restrained dominating set (TRD-set) if it is dominating, induces a subgraph without isolated vertices, and the vertices not in the set also induce a subgraph without isolated vertices. Two vertex sets, which are not TRD-sets, form a total restrained coalition if their union is a TRD-set. A total restrained coalition partition is a partition where none of its elements are TRD-sets, but each forms a total restrained coalition with another element. The goal is to maximize the cardinality of such a partition, denoted C tr (G). We initiate the study of this concept by proving certain properties, extremal values, general bounds, and its relation to known structural parameters. Exact values for specific graph families are also provided
Co-creando con familias para movilizar el conocimiento, abordando qué estamos olvidando en la Educación Inclusiva
No full textEste trabajo se centra en la movilización del conocimiento con las familias. Se contextualiza en el caso de la Asociación Dislexia Cádiz (España), que participó en un micro-proyecto orientado a eliminar barreras al aprendizaje y a la participación del alumnado con dislexia y otras dificultades de aprendizaje. Se desplegó a través de una metodología de investigación inclusiva, siguiendo un diseño participativo. El trabajo muestra la co-construcción del proceso metodológico de movilización del conocimiento, así como sus resultados asociados, destacando un aumento significativo de la visibilización del trastorno, la apertura de espacios formales e informales y la emergencia de debates necesarios entre familias y profesionales.Este trabajo se adscribe al proyecto de I+D+i “¿Qué estamos olvidando en Educación Inclusiva? Una investigación participativa en Andalucía occidental” (PID2019-108775RB-C43), financiado por el Ministerio de Ciencia, Innovación y Universidades
Reading without Barriers: law, inclusion and critical thinking in young people with Down's Syndrome
No full textEl acceso a la lectura constituye un derecho fundamental de todas las personas. En esta investigación inclusiva, realizada con jóvenes con síndrome de Down, se utiliza una metodología cualitativa y de enfoque etnográfico. En ella se aborda la identificación de necesidades y el conocimiento que sobre los libros ilustrados de no ficcióny los de Lectura Fácil tienen los participantes. Se apuesta por el desarrollo del pensamiento crítico de jóvenes participantes desde el análisis contextual. Los resultados han permitido seleccionar cuarenta obras relacionadas con los ODS, vinculados a los temas que más interesan a los jóvenes. Esta selección conformará el corpus de lectura de un programa de dinamización lectora. Además de mostrar el interés por la lectura y el acceso al conocimiento, se ha detectado curiosidad por la propuesta y por recibir formación específica sobre este tipo de libros por parte de la comunidad educativa. Para finalizar, se ha identificado la necesidad de revitalizar la biblioteca del centro. En conclusión, los hallazgos destacan la relevancia de continuar con la intervención en la asociación para, paulatinamente, mejorar la calidad de vida de sus usuarios.Access to reading is a fundamental right for all people. This inclusive research, carried out with young people with Down’s syndrome, uses a qualitative methodology and an ethnographic approach. It addresses the identification of needs and the participants’ knowledge of non-fiction illustrated books and easy-to-read books. It is committed to developing the critical thinking of young participants through contextual analysis. The results have made possible to select forty works related to the SDGs, linked to the topics that most interest young people. This selection will form the reading corpus of a reading promotion program. In addition, it has been detected an interest in reading, access to knowledge and curiosity in the proporsal and in receiving specific training on this type of book by the educational community. Finally, the need to revitalize the school library has been identified. In conclusion, the findings highlight the relevance of continuing with the intervention in the association to gradually improve the quality of life of its users.Ayuda para la Formación de Profesorado Universitario (FPU) otorgada por el Ministerio de Universidades del Gobierno de España (FPU22/04158)
Optimal control strategy based on differential evolution algorithm for seamless transition between islanded and grid-connected operation modes in microgrid clusters
Get PDFThe increasing integration of renewable energy sources and distributed energy resources is accelerating the transformation of traditional power systems into smart grids. This transformation relies heavily on the deployment of microgrids (MGs), which offer enhanced flexibility, resilience, and sustainability. However, ensuring the stable and efficient synchronization of MGs, especially during transitions between islanded and grid-connected modes, remains a critical and unresolved challenge. This challenge is further amplified in MG clusters (MGCs), where coordinated operation is essential to maintain power quality and system reliability. Driven by the need to address this challenge, this study proposes a real-time synchronization control method to enhance the dynamic performance and operational reliability of MGCs. The main objective is to design and validate an optimal control strategy capable of minimizing frequency deviations and improving power sharing during the synchronization process. To achieve this, an optimal seamless synchronization control based on a differential evolution (DE) algorithm is developed. This controller optimizes a frequency error control objective function in real time and is tested on an MGC architecture combining grid-forming (GFM) and grid-feeding (GFD) inverters. This work addresses the lack of robust, fast, and quantifiable synchronization methods for hybrid inverter-based MGCs, a gap that this study aims to fill. The proposed method enables accurate optimization of the transition between islanded and grid-connected modes. Simulation results demonstrate substantial performance gains: a 66.33% reduction in the ITSE compared to a synchronization strategy based on the fmincon optimization algorithm, and a 37.91% improvement over a conventional approach that adjusts synchronization by modifying the droop control coefficients. Furthermore, a comparative analysis with the particle swarm optimization (PSO) algorithm demonstrated that the DE-based approach reduces computation time by 20.29%, highlighting its superior efficiency and suitability for real-time embedded implementation. A sensitivity analysis involving 500 different scenarios, including evaluations under fault conditions, confirms the robustness of the approach. The average ITSE for these 500 simulations was 0.2459, with a standard deviation of 0.041, demonstrating consistent and reliable performance under varying load conditions. Moreover, a second sensitivity analysis, conducted over 250 simulations, identified the optimal DE parameters, enabling the selection of an effective combination of population size, mutation factor, and crossover rate. Finally, experimental validation using a Hardware-in-the-Loop setup, with an OPAL-RT4512 unit and a dSPACE MicroLabBox, verifies the effectiveness and real-time performance of the proposed control strategy
Agreement-Based Validation of ISOMETRO for Upper-Limb Isometric Tension Measurements
No full textMuscular fitness is a key component of health and athletic performance, and isometric strength is a widely used indicator. This study reports an agreement-based validation of the Isometric Strength Measurement Device (ISOMETRO) for upper-limb isometric tension measurements under controlled laboratory conditions. Twenty-one healthy young amateur rock climbers (11 men and 10 women) performed four upper-limb tensile tests (shoulder adduction at 90°, shoulder adduction at 60°, shoulder extension at 90°, and elbow extension at 90°). Agreement with an independent criterion device was evaluated using a force plate, while a series-connected load cell was used as an internal consistency check of the measurement chain. Linear mixed-effects models showed that ISOMETRO strongly predicted force plate values (β = 0.999, SE = 0.002, p 0.99. Bland–Altman analysis indicated negligible bias (−0.08 N) and narrow limits of agreement (−4.97 to 4.81 N), and concordance was excellent (CCC ≥ 0.996). The series-connected load cell comparison also showed near-unity agreement (β = 0.998, SE = 0.003, p < 0.001), supporting internal measurement chain integrity. These findings support excellent agreement between ISOMETRO and force plate measurements for upper-limb tensile isometric testing along the vertical axis in young amateur rock climbers under controlled laboratory conditions. However, given the specific sample characteristics and the strictly vertical laboratory configuration, these results should not be generalized to other populations, joint angles, force directions, or non-laboratory environments without further validation. Further studies are needed to confirm performance in more diverse contexts and to establish reliability for repeated-measurement applications