25949 research outputs found
Sort by
Evolution Enhances Kemp Eliminase Activity by Optimizing Oxyanion Stabilization and Conformational Flexibility
No full textThe base-promoted Kemp elimination reaction has been used as a model system for enzyme design. Among the multiple computationally designed and evolved Kemp eliminases generated along the years, the HG3-to-HG3.17 evolutionary trajectory is particularly interesting due to the high catalytic efficiency of HG3.17 and the debated role of glutamine 50 (Gln50) as potential oxyanion stabilizer. This study aims to elucidate the structural and dynamic changes along the evolutionary pathway from HG3 to HG3.17 that contribute to improved catalytic efficiency. In particular, we evaluate key variants along the HG3 evolutionary trajectory via molecular dynamics simulations coupled to non-covalent interactions and water analysis. Our computational study indicates that HG3.17 can adopt a catalytically competent conformation promoted by a water-mediated network of non-covalent interactions, in which aspartate 127 (Asp127) is properly positioned for proton abstraction and Gln50 and to some extent mutation cysteine 84 (Cys84) contribute to oxyanion stabilization. We find that HG3.17 exhibits a rather high flexibility of Gln50, which is regulated by the conformation adopted by the active site residue tryptophan 44 (Trp44). This interplay between Gln50 and Trp44 positioning induced by distal active site mutations affects the water-mediated network of non-covalent interactions, Gln50 preorganization, and water content of the active site pocket.Research funding: H2020 European Research Council. Grant Numbers: ERC-2015-StG-679001, ERC-2022-CoG-101088032, ERC-2022-POC-101112805, ERC-2023-POC-101158166; Ministerio de Ciencia e Innovación. Grant Numbers: PID2021-129034NB-I00, PDC2022-133950-I00, PRE2022-105114; Human Frontier Science Program Grants. Grant Number: RGP0054/2020 & Generalitat de Catalunya. Grant Number: SGR 2021 00487Open Access funding provided thanks to the CRUE-CSIC agreement with Wile
'Scuola Diffusa' y educación ampliada como práctica socio-educativa para la inclusión. Un estudio cualitativo = “Scuola Diffusa” and Widespread Education as a Socio-Educational Resilience Practice for Inclusion. A qualitative study
No full textIn Reggio Emilia, thanks to the "Officina Educativa", the educational department of the Reggio Emilia municipal government, 'Scuola Diffusa', a specific model of Widespread Education, emerged as a response tothe constraints resulting from the lockdown due to a health emergency situation. It shaped the educational ecosystem of the town, offering extensive educational opportunities for inclusion. It is based on deep alliances between different social, educational and community actors who co-design curricular projects that connect multiple contexts within a community and take the learners' everyday life interests and needs as a point of departure. In this study, and using qualitative methods to document the implementation of Widespread Education in the city of Reggio Emilia, we address the following question: What characteristics of Widespread Education facilitate inclusive practices?Three key conditions that seem to facilitate inclusive practices and experiences are identified in the educational model, namely: cooperative learning, learning from interests and real situations, as well as social support in small groups with the different professionals involved (teachersand educators). This requires training processes to address strategies and practices that allow different curricular units and objectives to be shared with areas of the territoryEn Reggio Emilia se ha consolidado un modelo educativo, «Scuola Diffusa», impulsado por la Oficina Educativa del Departamento de Educación del Gobierno Municipal de Reggio Emilia, que emergió como respuesta a las limitaciones derivadas del confinamiento producido por una emergencia sanitaria, y que ha modificado el ecosistema educativo de la ciudad ofreciendo amplias oportunidades educativas para la inclusión. Se basa en alianzas profundas entre diferentes actores sociales, educativos y comunitarios que codiseñan proyectos curriculares conectando múltiples contextos dentro de una comunidad, y que toman como punto de partida los intereses y necesidades de la vida cotidiana de los y las estudiantes. En este estudio, y utilizando métodos cualitativos para documentar la implementación del modelo en la ciudad de Reggio Emilia, abordamos la siguiente pregunta: ¿qué características del modelo “Scuola Diffusa” facilitan las prácticas inclusivas? Se identifican tres condiciones clave en el modelo educativo que parecen facilitar prácticas y experiencias inclusivas, a saber: el aprendizaje cooperativo, el aprendizaje a partir de intereses y situaciones reales, así como el apoyo social en pequeños grupos con diferentes profesionales involucrados. Ello requiere de procesos de formación para abordar estrategias y prácticas que permitan compartir distintas unidades y objetivos curriculares conjuntamente con agentes sociales y comunitarios del territori
Automatic Segmentation of Sylvian Fissure in Brain Ultrasound Images of Pre-Term Infants Using Deep Learning Models
No full textObjective: Segmentation of brain sulci in pre-term infants is crucial for monitoring their development. While magnetic resonance imaging has been used for this purpose, cranial ultrasound (cUS) is the primary imaging technique used in clinical practice. Here, we present the first study aiming to automate brain sulci segmentation in pre-term infants using ultrasound images. Methods: Our study focused on segmentation of the Sylvian fissure in a single cUS plane (C3), although this approach could be extended to other sulci and planes. We evaluated the performance of deep learning models, specifically U-Net and ResU-Net, in automating the segmentation process in two scenarios. First, we conducted cross-validation on images acquired from the same ultrasound machine. Second, we applied fine-tuning techniques to adapt the models to images acquired from different vendors. Results: The ResU-Net approach achieved Dice and Sensitivity scores of 0.777 and 0.784, respectively, in the cross-validation experiment. When applied to external datasets, results varied based on similarity to the training images. Similar images yielded comparable results, while different images showed a drop in performance. Additionally, this study highlighted the advantages of ResU-Net over U-Net, suggesting that residual connections enhance the model's ability to learn and represent complex anatomical structures. Conclusion: This study demonstrated the feasibility of using deep learning models to automatically segment the Sylvian fissure in cUS images. Accurate sonographic characterisation of cerebral sulci can improve the understanding of brain development and aid in identifying infants with different developmental trajectories, potentially impacting later functional outcomesThis work was supported by grant no. PI18/00110 from the Instituto de Salud Carlos III, co-funded by the European Regional Development FundOpen Access funding provided thanks to the CRUE-CSIC agreement with Elsevie
The Sarcoplasmic/Endoplasmic Reticulum Ca2+-ATPase (SERCA) is present in pig sperm and modulates their physiology over liquid preservation
No full textLiquid storage is the primary preservation method in the swine breeding industry because of its advantages over cryopreservation. Calcium (Ca2+), a key regulator of cell physiology, plays a crucial role during liquid preservation. Sarcoplasmic/Endoplasmic Reticulum Ca2+ ATPases (SERCA) belong to a family of P-type ATPases that regulate Ca2+ homeostasis within cells and have been previously described to play a function in the sperm of various mammalian species. Herein, we hypothesized that SERCA2 is present in pig sperm and is involved in the resilience of this cell to liquid preservation at 17 °C. For this purpose, sperm were incubated with different concentrations of thapsigargin (Thg; 0, 5, 25, and 50 µM) and stored at 17 °C for ten days. The presence and localization of SERCA2 were evaluated using immunoblotting and immunofluorescence, respectively. On days 0, 4, and 10, sperm motility was assessed using a computer-assisted sperm analysis (CASA) system, and sperm viability, membrane lipid disorder, acrosome integrity, mitochondrial membrane potential (MMP), and intracellular levels of Ca2+, superoxides and total reactive oxygen species (ROS) were evaluated by flow cytometry. We localized SERCA2 in the acrosome and midpiece of pig sperm. Furthermore, inhibition of SERCA with Thg resulted in reduced sperm viability and membrane stability, and increased MMP, and Ca2+ and ROS levels. In conclusion, the activity of SERCA prevents the accumulation of intracellular Ca2+ in sperm, which is detrimental to sperm quality and function during liquid storage at 17 °C. We thus suggest that the function of SERCA is crucial for the preservation of pig semenThis study was supported by the Ministry of Science, Innovation and Universities, Spain (grants: PID2020-113320RB-I00 and PRE2021-098896), the European Union-Next Generation EU Funds (University of Murcia, Margarita Salas Scheme 181/MSJD/22), the Regional Government of Catalonia (2021-SGR-0900), and the Catalan Institution for Research and Advanced Studies (ICREA
Deliberación, función epistémica y establecimiento de hechos: Bases de una estructura metodológica para el Tribunal Penal
No full textThe epistemic function of deliberation and its relevance for the quality of probative reasoning, at least in Chile, has not been fully highlighted compared to the attention that the assessment and decision on the evidence and its justification in the sentence. Using the Chilean Oral Criminal Trial Court as a reference, we will show that, beyond certain established practices, a critical review is needed on the deliberation of the facts by professional judges and how they arrive at the reasoning synthetically expressed in the verdict. We intend demonstrate the usefulness of laying the foundations of a methodology and propose some guides that allows its organization, in order to improve debate and arguments in said collective spaceLa función epistémica de la deliberación y su relevancia para la calidad del razonamiento probatorio, al menos en Chile, no ha sido del todo destacada frente a la atención que sí ha tenido la valoración y decisión sobre la prueba y su justificación en la sentencia definitiva. Tomando como ejemplo el Tribunal de Juicio Oral en lo Penal chileno mostraremos que, más allá de ciertas prácti-cas establecidas, resulta necesaria una revisión crítica sobre la deliberación de los hechos por jueces profesionales y cómo estos arriban a las razones que sintéticamente se expresan en el veredicto, cimiento de la sentencia. Pretendemos demostrar la utilidad de sentar las bases de una metodología y proponer algunas guías que permitan organizarla, en orden a mejorar el debate y argumentos en dicho espacio colectivo1
Detrital zircon age distributions in Bayes-Hilbert spaces
No full textA growing number of researchers in the Earth Science community use the information provided by the U-Pb ages of detrital zircon in sedimentary environments, be these modern (sediments) or ancient (sedimentary or metasedimentary rocks). This information is key to understanding detritus's past and present flow on Earth and its attendant geological implications. An essential component of the investigation concerning detrital zircon age distributions (DZD) and their bearing on several sedimentological, tectonic, geodynamic, paleogeographic, or climatic issues is to compare DZD from different samples. Much theoretical and empirical research has been devoted to ascertaining how to best compare and measure the dissimilarity/distance between DZDs. This ongoing endeavour has generated a variety of metrics and statistical procedures to perform such tasks. In this contribution, a metric based on the Aitchison distance to measure the dissimilarity of any given set of DZD (samples represented by density functions) is presented. The Aitchison distance is used in the reference framework of the Bayes-Hilbert spaces, whose properties help to avoid some of the limitations of previously used metrics. The mathematical and methodological foundations are presented and illustrated with three geological examples taken from the recent literature, using both sedimentary rocks and recent sediments in different geological and geographical settings. The proposed approach results in a consistent statistical tool to determine whether a set of samples is likely to be derived from a common source or, at least, from indistinguishable sources based on DZD data aloneJJE and VPG were supported by the grants PID2021-123833OB-I00 and PID2021-125380OB-I00, funded by the Spanish Ministry of Science, Innovation and Universities (MICIU/AEI/10.13039/501100011033/) and ERDF A way of making Europe. JFS acknowledges financial support from project PID2020-112489GB-C21 funded by the Spanish Ministry of Science, Innovation and Universitie
Menstrual Cycle Matters in Host Attractiveness to Mosquitoes and Topical Repellent Protection
No full textHuman hosts exhibit remarkable variability in their attractiveness to mosquitoes, leading to differences in biting rates. It is essential to understand the factors behind this variability if we wish to develop more effective strategies for controlling the transmission of mosquito-borne diseases. While past studies have shed significant light on the forces shaping host attractiveness to mosquitoes, we continue to lack information about variation in attractiveness within individual hosts. For example, little attention has been paid to the potential impact of the menstrual cycle. Our study explored the relationship between the menstrual cycle, host attractiveness to mosquitoes, and the effectiveness of topical mosquito repellents. We found that mosquito landing rate was higher and repellent protection time was shorter during ovulation than during menstruation and the luteal phase. By beginning to clarify the intricate interplay between human physiology and mosquito behavior, our results contribute to the growing body of knowledge regarding the factors that affect within-individual variability in attractiveness to mosquitoes, which has implications for the efficacy of protection and disease prevention strategie
Fat-to-muscle ratio: exploring associations with motor competence and physical Fitness in 7-year-old children
No full textFeatured Application: This study demonstrates that compartmental bioimpedance analysis, through the fat-to-muscle ratio, provides a simple and non-invasive method for identifying individuals at risk of exercise deficit disorder related to motor competence and physical fitness, as well as subsequent health risks. Consequently, it could be used to individualize physical exercise programs or physical education classes focusing on MC mastery and PF improvements based on muscle coordination and strength. Abstract: This study aimed (1) to explore the association between body composition [fat-tomuscle ratio (FMR), waist circumference (WC), and body mass index (BMI)] with motor competence (MC) and physical fitness (PFI) in 7-year-old children; (2) to ascertain whether FMR modifies the associations between MC and PF. A total of 164 children (7 yr) were included. Anthropometric (fat and muscle mass were calculated with TANITA), motor competence (CAMSA test), and physical fitness (1/2 mile run, handgrip strength, 10 × 5, standing long jump, and sit and reach tests) variables were collected. FMR, WC, and BMI correlated negatively with MC (all between r ≤ −0.333 and −0.183 and p < 0.05) and PFI (all between r ≤ −0.410 and −0.246 and p < 0.05) in all children. However, the associations were stronger for FMR. Only FMR was independently and negatively associated with MC and PFI in linear regression analyses, explaining 12.6% and 20.9% of its variance, respectively. Positive correlations between PFI and MC existed. Also, the association was not modified by FMR levels, since in both groups (above and below FMR median), the associations were maintained (p < 0.0001). However, the t-test showed that children with higher FMRs have lower levels of MC (p = 0.005) and PFI (p < 0.0001). FMR may be the best body composition parameter related to MC and PFI. Furthermore, the association between FMR does not modulate MC and PFI but children with higher FMRs show lower levels of MC and PF
Mechanosynthesis of Nanocrystalline Biphasic Ni-Fe Alloy Powders by Mechanical Alloying and Their Structural and Thermal Characterization
No full textAn equiatomic Ni-Fe alloy was synthesized through mechanosynthesis, under an argon atmosphere using a planetary ball mill, after 100 h. To assess the phase stability, the alloy was subsequently annealed at 923.15 K for 2 h. At the end of mechanosynthesis, X-ray diffraction analysis revealed the formation of two distinct solid phases, FCC γ-NiFe (wt% = 90.3%) and BCC α-FeNi (wt% = 9.7%). The lattice parameter of the FCC phase stabilized at 3.5748 Å, whereas the BCC phase exhibited a lattice parameter of 2.6608 Å. The average crystallite size was determined to be around 7 nm with the lattice strains quantified as 0.48% for both phases. This significant refinement of microstructure indicates extensive plastic deformation within the grains. Scanning electron microscopy revealed an angular particle morphology with an average particle size of 8.15 µm. Differential scanning calorimetry (DSC) analysis identified an exothermic transition at 623.15 K, corresponding to the Curie temperature of nickel, and another one at 873.15 K, attributed to the Curie temperature of Ni3Fe. These results demonstrate the efficiency of mechanosynthesis in producing biphasic Ni-Fe nanomaterials with tailored properties, characterized by a dominant FCC phase with a highly deformed nanocrystalline structure. These findings highlight the great influence of mechanical milling on the structural properties of the Ni-Fe alloy in terms of a high density of stored crystalline defectsThis research was funded by University of Girona, project2024-1
Evaluation of Motiv-ARCHE in the Santa Clara Museum
No full textCurrently, heritage sites, such as museums, have focused on the preservation and conservation of heritage elements for present and future generations. However, when displaying their content, they often do not consider different types of visitors, their preferences regarding the type and format of content, their interests, or their information needs (the same content is always presented). All of this can reduce the number of visits and the motivation of visitors. To address this issue, Motiv-ARCHE was developed as an application designed to enhance motivation in learning about cultural and natural heritage using augmented reality (AR). Motiv-ARCHE was implemented using the design-based research (DBR) methodology, an iterative approach that allows user feedback. In this article, we concentrate on presenting an experiment conducted at the Santa Clara Museum (Bogotá) in which a group of 44 participants used Motiv-ARCHE to access content associated with 10 cultural heritage elements that had been previously co-created with heritage experts from the museum itself. To evaluate the experiment, motivation and technology acceptance tests were applied, along with a demographic questionnaire, to statistically analyze whether the examined variables influence motivation for learning about cultural and natural heritage. Among the results, it is noteworthy that users with greater knowledge of AR, cultural and natural heritage, and a higher frequency of using this type of application felt more motivated to learn about heritage element