Grupos de Investigación

A Field‐Based Predictive Model for Evidence‐Based Classification in Male Footballers With Cerebral Palsy

2026-01-01T00:00:00Z

Over a 6-year research period, the classification of footballers with cerebral palsy (CP) has identified the best activity limitation tests that best capture the influence of eligible impairments on performance, leading to the implementation of a new classification system (i.e., FT1–FT3 sport classes). This study aimed to (i) assess the sensitivity of these tests to discriminate among sport classes; and (ii) estimate predictors of activity limitation outcomes to enhance accuracy in class allocation. A total of 177 international-level male CP footballers (25.90 ± 6.13 years.; 67.70 ± 11.49 kg; 173.90 ± 8.07 cm; 156 outfield players and 21 goalkeepers) completed 11 field-based tests assessing activity limitation, including balance, coordination, jumping, change of direction ability, and dribbling capacity, and a 2 versus 2 small-sided game. Classification and regression tree analysis were used to develop predictive models of sport classes with probabilities calculated at each node, considering a final number of 7 tests. Significant differences were observed between sport classes in all variables, except in one-leg stance acceleration. Specific activity limitation test outcomes for dribbling skills, inter-limb coordination, and static balance predict the sport class allocation with a success rate of 72.1% for a valid sample of 111 CP footballers, and 75.2% for a subsample of 101 players excluding goalkeepers. The dribbling speed test is relevant for classifying those with severe (FT1) and moderate forms of impairment (FT2), while the one-leg stance test better predicts the class allocation of those with less impairment (FT3). This study provides empirical support for classifiers' decision-making and suggests distinct patterns of sport-specific activity limitations across current CP football sport classes.

Analyzing the Associations Between Mediterranean Diet Adherence, Body Mass Index, and Physical Performance in Youth Handball Players: A Clustering Approach

2026-01-01T00:00:00Z

Background: Nutrition is a fundamental factor in the healthy growth and development of young athletes, as well as in supporting optimal sports performance. This study aimed to explore associations between Mediterranean diet adherence score, BMI and selected physical performance measures in youth handball players, by identifying distinct player profiles through a clustering approach. Methods: Thirty-five male youth handball players participated in the study. Mediterranean diet adherence was evaluated by means of a 16- item KIDMED questionnaire and total score, and physical performance was assessed using the countermovement jump (CMJ) test, the 505-change of direction test, linear straight sprints and isometric handgrip strength. Results: Cluster 1 goes more than one day a week to a fast-food restaurant, skips breakfast on more occasions and consumes sweets and candy more often. In addition, Cluster 2 showed better sprint (p = 0.019–0.053, ES = 0.39–0.47) and CMJ (p = 0.042; ES = 0.40) performance than Cluster 1. Conclusions: These findings present associations between dietary adherence, BMI, and selected physical performance measures in this specific cohort. Given the cross-sectional design and the small sample size, these findings should be interpreted with caution and do not allow causal inferences.

High-Load Strength Training Reduces Injury Incidence and Injury Burden and Improves Physical Fitness in Young Highly Trained Soccer Players

2026-01-01T00:00:00Z

Background: There is little available information on the reduction of injury incidence and injury burden after strength training programs. This study aimed to analyze the effects of a 12-week high-load strength training program on injury incidence, injury burden, and fitness in young, highly trained, soccer players. Hypothesis: It was hypothesized that well-targeted high-load training focused on the gluteal and hamstring musculature could aid in injury prevention and increase physical fitness. Study Design: A randomized controlled trial design was applied, which followed the CONSORT Statement. Level of Evidence: Level 2. Methods: Twenty players were assigned randomly to the experimental group (EG, n = 10 players), who performed a high-load strength training program, or to the control group (CG, n = 10 players), who performed only their usual soccer training. Injury incidence (injuries per 1000 hours exposure) and injury burden (days of absence per 1000 hours exposure) were recorded during the intervention, as well as the physical fitness attributes before and after the training program. Results: A significant (P < 0.05) lower injury incidence was observed in the EG (CG, 11.34 vs EG, 1.31 injuries per 1000 hours of exposure) and a significant (P < 0.001) lower injury burden in the EG (CG, 304.66 versus EG, 19.72 days of absence per 1000 h of exposure). The analysis of covariance model revealed significant between-group differences favoring the EG, showing significantly greater improvements in jumping, change of direction ability, sprinting, and imbalance strength tests (P < 0.001; effect size, 3.02 to −7.23). Conclusion: This study demonstrated the beneficial effects of a 12-week high-load strength training program on injury incidence, injury burden and physical fitness, in highly trained soccer players. Clinical Relevance: This study provides positive information for implementing this type of strength training in the daily training sessions of young soccer players for both performance enhancement and injury prevention.

Impact of training regimens on small-sided soccer games: a scoping review

2026-01-01T00:00:00Z

This scoping review aimed to map and summarise the literature examining how different small-sided games (SSG) training regimens affect physical, psychophysiological, technical, and tactical outcomes in soccer players. The methodology followed the PRISMA-ScR guidelines, where three databases were searched. Eligible studies directly compared at least two SSG regimens (continuous vs intermittent; intermittent formats with differing work durations; or intermittent formats with differing rest durations). In total, 30 studies were included. Across the comparison types assessed, continuous vs intermittent regimens were the most studied, particularly for physiological measures (n = 15), followed by intermittent comparisons manipulating bout duration (n = 15 for physiological, n = 11 for physical outcomes). Studies focusing on rest/density manipulations were fewer, especially for technical outcomes (n = 3). Most studies clustered around mid-sized SSG formats (3v3–5v5), with 4v4 particularly dominant in continuous–intermittent contrasts (n = 9). In contrast, very small-sided formats (1v1, 2v2) and larger-sided formats (6v6, 7v7) were rarely explored under these regimen conditions. Shorter bouts tended to increase external intensity per unit time and total distance, while fractionating continuous play into sets generally raised per-minute intensity and high-speed actions but reduced total volume. In small formats, continuous play tended to elicit higher heart rate, lactate, and enjoyment, though one study suggested females preferred intermittent, whereas males reported greater enjoyment and load with continuous play. Rest duration also appeared to modulate outcomes, with very short recoveries linked to reduced passing success and longer rests enabling better ball actions. In conclusion, current evidence is largely focused on physical and psychophysiological responses, while technical and especially tactical domains remain underexplored. To better inform training design, future research should aim to incorporate objective assessments of technical and tactical outcomes – using objective tools – while also extending to female players, elite levels, and longitudinal designs. These steps would help determine whether the acute responses mapped here translate into consistent adaptations across contexts.

Los inventarios de bienes de don Juan de Austria: mentalidad, gusto y vida material

2000-01-01T00:00:00Z

Los inventarios de bienes de don Juan de Austria: mentalidad, gusto y vida material

El pobre Lázaro

2024-01-01T00:00:00Z

Escultura del siglo XVII del Museo Catedralicio de Ávila

Implementation of a motion estimation algorithm for Intel FPGAs using OpenCL

2023-01-01T00:00:00Z

Motion Estimation is one of the main tasks behind any video encoder. It is a computationally costly task; therefore, it is usually delegated to specific or reconfigurable hardware, such as FPGAs. Over the years, multiple FPGA implementations have been developed, mainly using hardware description languages such as Verilog or VHDL. Since programming using hardware description languages is a complex task, it is desirable to use higher-level languages to develop FPGA applications.The aim of this work is to evaluate OpenCL, in terms of expressiveness, as a tool for developing this kind of FPGA applications. To do so, we present and evaluate a parallel implementation of the Block Matching Motion Estimation process using OpenCL for Intel FPGAs, usable and tested on an Intel Stratix 10 FPGA. The implementation efficiently processes Full HD frames completely inside the FPGA. In this work, we show the resource utilization when synthesizing the code on an Intel Stratix 10 FPGA, as well as a performance comparison with multiple CPU implementations with varying levels of optimization and vectorization capabilities. We also compare the proposed OpenCL implementation, in terms of resource utilization and performance, with estimations obtained from an equivalent VHDL implementation.

DDFU-Net: A Deep Decoder-Focused U-Net Model for Retinal Lesion Segmentation

2026-01-01T00:00:00Z

Early detection of retinal lesions helps to avoid visual loss or blindness. The main lesions associated with eye diseases include soft exudates, hard exudates, microaneurysms, and hemorrhages. However, the segmentation of these four kinds of lesions is difficult and time-consuming due to their uncertainty in size, contrast, and high inter-class similarity. To address these issues, this study presents Deep Decoder-Focused U-Net (DDFU-Net), an asymmetric dense U-Net model for automatic and accurate multi-lesion segmentation using fundus images. Our approach simultaneously segments all four kinds of retinal lesions after proving that multi-task learning yields better results than single-task learning. DDFU-Net incorporates an asymmetric design with five dense blocks in the encoder and seven dense blocks in the decoder. This design enhances feature extraction while ensuring a more refined reconstruction of lesion boundaries, particularly for small and complex structures. By allocating more layers to the decoder, the model improves segmentation accuracy by gradually restoring spatial details lost during down-sampling, mitigating over-compression, and enhancing fine-grained feature preservation. Comprehensive experiments on IDRiD and DDR datasets well demonstrate the superiority of our approach, which outperforms state-of-the-art segmentation methods. Specifically, DDFU-Net achieved a mean Area Under the Precision-Recall Curve of 54.86%, a mean Intersection Over Union of 36.96%, and mean Dice scores of 52.24% on the DDR test set. On the IDRiD test set, it achieved 66.69%, 57.31%, and 69.93%, respectively. The asymmetric structure outperforms traditional symmetric U-Nets by capturing more detailed features during encoding while reducing complexity during decoding. The proposed method can be useful to aid in the diagnosis of eye diseases, reducing the workload of specialists and improving the attention to patients.

Multi-frame cloud prediction in all-sky images from RGB images and segmented masks

2026-01-01T00:00:00Z

This paper presents a comparative study on the impact of input representation on deterministic artificial intelligence models for short-term multi-frame prediction in all-sky images. This work compares a model operating on 8-bit RGB all-sky images with a model that shares the same backbone, but operates directly on semantically segmented masks that encode cloud-related classes. Using an available sky segmentation model, predictions are evaluated in the segmentation label space using segmenter-derived masks as a proxy reference. Within this evaluation framework, the use of semantic masks as input for short-term prediction leads to improved temporal stability and higher agreement across standard segmentation metrics such as intersection over union, Dice coefficient, and categorical cross-entropy. While these results suggest potential relevance for weather and solar energy nowcasting applications, further validation against physical irradiance measurements is required.

Design rules for Sb and bi porphyrin capsules: Para-substitution effects and pnictogen bond conformational control

2026-01-01T00:00:00Z

Herein, we investigate the interplay between the heavy pnictogen bridgehead atom (E) in the tris(3-pyridyl) linkers E(3-py)3 (E = Sb (1), Bi (2)), and meso-aryl substituents on the metalloporphyrin scaffolds MTPPX (M = Zn, Mg; TPPX = substituted tetraphenylporphyrin) with respect to capsule formation and conformational control. Coordination of 1 and 2 to para-substituted zinc porphyrins ZnTPPOMe and ZnTPPBr yielded partially encapsulated semicapsules {[E(3-py)3]·(ZnTPPX)2}, while MgTPPBr produced oligomeric structures, showing that relatively bulky para-substituents disfavor complete 1:3 capsule formation. In contrast, coordination of 1 and 2 to perfluorinated ZnTPPF5 promotes the formation of full 1:3 capsules {[E(3-py)3]·(ZnTPPF5)3}, stabilized by three intramolecular E···F pnictogen bonds (PnBs) that give rise to a unique “blocked” conformation. DFT calculations indicate that distal porphyrin coordination enhances Lewis acidity at E, deepening its σ-holes and strengthening E···F interactions, thus overcoming the negative cooperativity typically associated with multiple PnBs. This remote coordination effect offers a new supramolecular strategy to fine-tune σ-hole depth and Lewis acidity. The steric shielding of the bridgehead in this conformation markedly affects reactivity, as shown by the inhibition of Sb-catalyzed α-hydroxyketone oxidation. These studies illustrate the crucial role of PnBs in stabilizing capsules of this type and modulating their reactivity through conformational control.

Supercritical water valorization of chitin in a continuous reaction system: Chitin nano-particles.

2023-01-01T00:00:00Z

Chitin is an abundant biopolymer of [-1,4-poly(n-acetyl-D-glucosamine)] units, produced by crustaceans, mollusks, insects, and fungi. Nowadays, chitin is discarded in massive amounts (6–8 million tons/year) as waste from the seafood industry, being underexploited as biomass resource[1]. Chitin is of great interest as a biocompatible and biodegradable material, gaining importance in the formulation of phytosanitary products, thanks to its elicitor activity in plants[2]. It is also considered as a source of oligosaccharides and biologically active monomers, N-acetylglucosamine (depolymerization) and glucosamine (deacetylation). Several studies have shown that chitin, like cellulose, can be dissolved and hydrolyzed in supercritical water (SCW) due to the change in its properties (water density and ionic product, among others); however, due to the high chitin crystallinity, this process occurs less easily[3]. The present work aims to investigate the mechanisms of chitin transformation in SCW medium (400°C and 25MPa), using ultrafast sudden expansion microreactors (SEMR) in a continuous system (residence time 0.1s - 2s).

Valorization of crustacean shell residues: Fractionation of proteins by microwave-extraction and applications of the residual solid.

2023-01-01T00:00:00Z

The fishing and food industry generates large amounts of crustacean shells as waste from their processes. These shells contain 20-30% of chitin, 30-50% of minerals (mainly calcium carbonate - CaCO3), 30-40% of proteins and other compounds in smaller amounts, such as lipids and pigments. Chitin and its derivative, chitosan, are highly demanded products due to their interesting applications. Global valorization of crustacean shells may include protein recovery and development of applications for minerals. In the conventional process for the separation of chitin and its subsequent purification from the crustacean shells, three chemical processes are necessary: deproteinization, demineralization and decolorization, and chemical reagents potentially harmful to the environment are used for each of these steps. To avoid the drawbacks realated to chemicals, development of greener and more efficient processes are under development for the valorization of this waste biomass. In this context, this project aims to develop a biorefining process for the valorization of shrimp molting shells, by sequential fractionation with non-conventional techniques to obtain two differenciated products: 1) a protein concentrate and 2) a chitin-calcium carbonate composite that will be used as platform material for catalyst development and films production.

Understanding the behavior of chitin in Subcritical and Supercritical Water in a continuous reaction system.

2023-01-01T00:00:00Z

Chitin ((1,4)-β-N-acetylglucosamine) is the second most widespread bio-polymer worldwide. Its high crystallinity and low solubility limit the exploitation of its antimicrobial, non-toxic and biodegradable properties, among others. So far, batch reactors and residence times longer than 1min with sub-and supercritical water have been tested to depolymerize chitin. In this work, we investigate the influence of temperature and residence time on chitin transformation in sub- and supercritical water (25MPa, 350 °C to 385 °C), using ultrafast continuous reactors (0.3s to 12s). Within the range studied, chitin gasification above 30% was detected when operating at high temperature (T≥376 °C) and a long residence time (t≥5s). At these conditions, mean particle size of water-insoluble fraction was also reduced to ca. 280 nm. By-products such as glycolaldehyde, acetic acid and 5-HMF were identified in the water-soluble fraction, indicating the presence of side reactions.

Microwave extraction of proteins from Litopenaeus vannamei molt shell using only water as a solvent

2023-01-01T00:00:00Z

This study aimed to apply microwave technique for the extraction of proteins from shrimp molt shell using water as the only solvent. The variables temperature, isothermal time, particle size, solid-liquid ratio (S/F) and stirring rate were studied to understand if they are significant variables. By varying the process parameters, it was possible to obtain an extraction yield of 16-31g/100g dry molt shell, extracted proteins of 3-7 g/100g of dry molt shell, and extracted amino acids of 0.5-3 g/100 g dry molt shell. In addition, isothermal time was found to be the variable with the highest influence on the extracted protein content. The obtained results indicated the variables temperature, isothermal time, and S/F as significant variables for protein extraction, within the selected range.

Microwave pretreatment for supercritical carbon dioxide extraction of lipid fraction of shrimp shell

2023-01-01T00:00:00Z

According to the Food and Agriculture Organization of the United Nations, by the year 2022, crustacean production represented 10% of all global production from fisheries and aquaculture. The shell of the shrimp represents approximately 47% (w/w) of the animal2. It is therefore a potential source of pollution in the production (aquaculture) or processing (food industry) process, when not properly disposed. Currently, shrimp shell is partially used to produce chitin and chitosan by harsh acid and alkaline treatments, however, they pose an environmental threat and avoid the valorization of other compounds of industrial interest, such as the liposoluble compounds, with emphasis on carotenoids2. The application of the supercritical fluid extraction technique with the cooking and conventional drying of shrimp shells as a pretreatment for the extraction of carotenoids has already been studied. Despite the advantages shown by this pretreatment to increase the extracted carotenoids by breaking their association with macromolecules, the process has the disadvantage of requiring long processing time and high energy consumption. However, for sustainable biorefining processes, faster and more efficient pretreatment processes are required. The microwave technique for pretreatment of the sample to increase the extraction yield has already been proven in the literature for other raw materials with shorter processing time compared to conventional methods4. Within this context, this work aimed to study the efficiency of the MW pretreatment for the combined cooking and drying process in relation to the conventional method.

Microwave aqueous extraction of shrimp shell proteins.

2023-01-01T00:00:00Z

Shrimp production generates the exoskeleton as one of the waste products due to the moulting process of the arthropods1. This shell can be valorised by the recovery of chitin, but it also has a high protein content (20-40%)2 with interest to be isolated. During the conventional chitin extraction process, these obtained proteins cannot be reused, due to the use of inorganic alkaline solvents3. In this context, this study aimed to use water as solvent for the extraction of proteins from shrimp molt shells by microwave assisted extraction. The variables temperature (T: 175 and 225 °C), isothermal time (t: 0 and 10), and solvent-feed ratio (S/F: 10, 20 and 40 mL/g) were studied to understand their effects in the extraction of the proteins and co-extraction of other compounds