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CFD transient simulation of a breathing cycle in an oral-nasal extrathoracic model
Get PDFKnowledge of respiratory flow behaviour is important in many respiratory medical fields. The usefulness of numerical models in providing a better understanding of flow phenomena has made the Computational Fluid Dynamics (CFD) an indispensable research tool due to the difficulty of measuring in vivo data. In this research, the extrathoracic airways and the upper tracheobronchial region, trachea and main bronchus bifurcation were modelled. Oral and nasal breathing routes have been considered under steady and cyclic unsteady conditions. A realistic far boundary condition was imposed as the flow inlet. Different ventilation levels and frequencies were simulated. The model presented has been validated successfully by two parts: nasal and oral models. The airflow distributions through oral and nasal routes were determined, analysed and compared under different breathing conditions. The flow behaviour and respiratory effort during inhalation and exhalation phases change from rest to high activity; the flow can increase 40% with the same respiratory effort, opening the mouth during the inspiration. Significant differences in turbulent intensity contours in steady and unsteady cases have been observed. This study demonstrated the relevance of considering different breathing patterns and more realistic unsteady conditions
Analysis of arterial wall mechanics in right coronary artery obstructive disease: FSI modelling and non-invasive FFR validation
No full textCoronary artery disease remains one of the principal causes of mortality worldwide, motivating the development of patient-specific computational frameworks capable of accurately characterizing arterial wall mechanics in obstructive right coronary artery disease. In this study, a Fluid–Structure Interaction (FSI) modelling approach was employed to capture the dynamic interplay between pulsatile blood flow and vascular wall behaviour, with validation against invasive fractional flow reserve (FFR) measurements to ensure a faithful reproduction of patient-specific physiological conditions. Numerical simulations were performed using one-way coupled FSI on patient-specific right coronary artery geometries reconstructed from computed tomography angiography data. Blood rheology was described using the simplified Phan-Thien/Tanner (sPTT) viscoelastic model, while realistic physiological loading was achieved through patient-specific hyperemic conditions, Womersley velocity profiles prescribed at the inlet, and three-element Windkessel models applied at the outlets. The analysis focused on the spatial distribution and magnitude of arterial wall stresses and deformations. Results showed that regions of elevated mechanical response consistently co-located with areas of significant pressure drop and stenosis. Quantitatively, maximum wall deformation varied markedly across patients, ranging from approximately 0.14 mm–0.39 mm, while maximum equivalent stress values ranged from about 40 kPa to over 80 kPa, highlighting strong inter-patient variability driven by individual anatomy and stenosis severity. Statistical analyses confirmed that these differences were significant, indicating a link between functional severity and mechanical loading of the arterial wall. Four stress- and deformation-based metrics exhibited strong correlations with clinically measured FFR values, with absolute correlation coefficients exceeding 0.5. Overall, the proposed patient-specific FSI framework enables a physiologically grounded characterization of arterial wall mechanics in obstructive right coronary artery disease, providing mechanistic insight into patient-specific coronary pathology.Fundação para a Ciência e a Tecnologia | Ref. CADS-FACT – PTDC/EMD-EMD/0980/202
Evaluating the impact of historical climate and early human groups in the Araucaria Forest of eastern South America
Get PDFIt has been hypothesized that the Araucaria Forest in southern Brazil underwent expansions in the past, driven either by human groups or by climate fluctuations of the Holocene and Pleistocene. Fossil pollen records of the Paraná pine
Araucaria angustifolia
, a dominant tree in that forest, provide some insights into when those may have occurred. Still, the timing of those expansions has never been estimated. To infer past range shifts and shed light on their main drivers, we employed next‐generation DNA sequencing (ddRADseq), machine learning, and a comprehensive database of fossil pollen records into a study of historical demographic inference and paleo‐distribution modeling of the Paraná pine. We found that
A. angustifolia
comprises two populations expanding at different times: one in the Mantiqueira mountain chain, the other in the southern Brazilian plateau. The southern population began to expand during the Last Glacial Period ~ 70 kya, long before human arrival in South America. Still, genetic analyses support that humans later impacted this population, resulting in lower genetic diversity, higher inbreeding, and high levels of gene flow over large distances with a weak pattern of isolation‐by‐distance. It is possible this resulted from human influence on seed dispersal and germination on the southern Brazilian plateau. The Mantiqueira population, in contrast, expanded only recently (~ 3 kya). This timing coincides with Holocene climatic changes and human settlements established further south, although, to date, there is little archeological evidence of human impact in the Mantiqueira. In addition, multitemporal species distribution models built from a combination of present‐day and pollen records infer a range expansion of the Araucaria Forest during glacial times until the cold humid HS1 event (~ 16 kya), when the forest was most widespread, with no evidence of glacial refugia. The combination of genomic and spatial analyses suggests that both human and climatic controls played a role in the dynamics of the Araucaria Forest.National Science Foundation | Ref. 343578National Science Foundation | Ref. 1343612Xunta de GaliciaFundação de Amparo à Pesquisa do Estado de São Paulo | Ref. 2019/08308-
El pilar dos de la OCDE sobre el impuesto mínimo global y su proyección en el ámbito de la UE. Incoherencias y cuestiones problemáticas desde la perspectiva del derecho de la UE
No full textActive yaw control strategy for a hybrid offshore wind farm under typical wind conditions
No full textThis paper proposes an active yaw control strategy for the hybrid offshore wind farms to enhance the offshore wind farm's total power generation. Firstly, a three-dimensional yawed wake model is applied for calculating the power output of different types of wind turbines under active yaw control and the whole offshore wind farm. Next, the architecture of the proposed active yaw control system is demonstrated, and an optimization model is formulated. To solve this optimization problem, the quantum genetic algorithm is employed. Simulation results on a simplified layout of three wind turbines in a row and the Guishan offshore wind farm under three typical wind conditions demonstrate that the proposed strategy can effectively mitigate the inner-array wake effect in hybrid offshore wind farms. The results also suggest that applying active yaw control in the non-dominant wind directions and for small wind turbines in a hybrid offshore wind farm should be prioritized which yields the most significant improvement of 24.89 % in overall offshore wind farm power output. Additionally, the quantum genetic algorithm is shown to be an efficient and robust optimization tool for solving the optimal active yaw control problem in hybrid offshore wind farms with computation time of 17.83 min, 20.12 min, and 19.30 min in the three test cases, respectively.National Natural Science Foundation of China | Ref. 52207111National Natural Science Foundation of China | Ref. 52577112Hong Kong Scholars Program | Ref. XJ2024024State Key Laboratory of Power System Operation and Control | Ref. 2449State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources | Ref. LAPS25013Jiangsu Key Laboratory of Power Transmission & Distribution Equipment Technology | Ref. 2025JSSPD0
Cell wall composition and ultrastructural immunolocalization of pectin and arabinogalactan protein during Olea europaea L. fruit abscission
No full textCell wall modification is integral to many plant developmental processes where cells need to separate, such as abscission. However, changes in cell wall composition during natural fruit abscission are poorly understood. In olive (Olea europaea L.), some cultivars such as ‘Picual’ undergo massive natural fruit abscission after fruit ripening. This study investigates the differences in cell wall polysaccharide composition and the localization of pectins and arabinogalactan protein (AGP) in the abscission zone (AZ) during cell separation to understand fruit abscission control in ‘Picual’ olive. To this end, immunogold labeling employing a suite of monoclonal antibodies to cell wall components (JIM13, LM5, LM6, LM19 and LM20) was investigated in olive fruit AZ. Cell wall polysaccharide extraction revealed that the AZ cell separation is related to the de-esterification and degradation of pectic polysaccharides. Moreover, ultrastructural localization showed that both esterified and unesterified homogalacturonans (HGs) localize mainly in the AZ cell walls, including the middle lamella and tricellular junction zones. Our results indicate that unesterified HGs are likely to contribute to cell separation in the olive fruit AZ. Similarly, immunogold labeling demonstrated a decrease in both galactose-rich and arabinose-rich pectins in AZ cell walls during ripe fruit abscission. In addition, AGPs were localized in the cell wall, plasma membrane and cytoplasm of AZ cells with lower levels of AGPs during ripe fruit abscission. This detailed temporal profile of the cell wall polysaccharide composition, and the pectins and AGP immunolocalization in the olive fruit AZ, offers new insights into cell wall remodeling during ripe fruit abscission.Ministerio de Economía y Competitividad | Ref. AGL2014-52194-RJunta de ExtremaduraFondo Europeo de Desarrollo Regiona
A new approach to assess canoe performance through functional electromechanical dynamometry
No full textThe aim of this study was to evaluate the predictive capacity of functional electromechanical dynamometry for sprint canoe performance. Twenty-one world-class sprint canoeists underwent two functional electromechanical dynamometry assessments (isometric and incremental load) in the sprint canoe-specific kneeling position. Race performance was assessed via official C1 500-m race times. Significant negative correlations were observed between 500-m race times and both the mean force (r=–0.72; p=0.001) and the peak force (r=–0.71; p=0.001) measured through the isometric dynamometric test. In the incremental test, a strong negative correlation was found between the race time and the number of strokes (Nreps; r=–0.85; p=0.001), as well as the absolute peak force (r=–0.80; p=0.001). These relationships remained significant when force values were adjusted for body mass. The strongest predictive model (R2 a=0.73) included the number of strokes from the incremental load test (C1 500-m race time=170.30–3.29 Nreps). These findings support the use of functional electromechanical dynamometry as a valid and sport-specific tool for assessing neuromuscular performance in elite sprint canoeists
Characterization of transcriptome dynamics during early fruit development in olive (Olea europaea L.)
Get PDFIn the olive (Olea europaea L.), an economically leading oil crop worldwide, fruit size and yield are determined by the early stages of fruit development. However, few detailed analyses of this stage of fruit development are available. This study offers an extensive characterization of the various processes involved in early olive fruit growth (cell division, cell cycle regulation, and cell expansion). For this, cytological, hormonal, and transcriptional changes characterizing the phases of early fruit development were analyzed in olive fruit of the cv. ‘Picual’. First, the surface area and mitotic activity (by flow cytometry) of fruit cells were investigated during early olive fruit development, from 0 to 42 days post-anthesis (DPA). The results demonstrate that the cell division phase extends up to 21 DPA, during which the maximal proportion of 4C cells in olive fruits was reached at 14 DPA, indicating that intensive cell division was activated in olive fruits at that time. Subsequently, fruit cell expansion lasted as long as 3 weeks more before endocarp lignification. Finally, the molecular mechanisms controlling the early fruit development were investigated by analyzing the transcriptome of olive flowers at anthesis (fruit set) as well as olive fruits at 14 DPA (cell division phase) and at 28 DPA (cell expansion phase). Sequential induction of the cell cycle regulating genes is associated with the upregulation of genes involved in cell wall remodeling and ion fluxes, and with a shift in plant hormone metabolism and signaling genes during early olive fruit development. This occurs together with transcriptional activity of subtilisin-like protease proteins together with transcription factors potentially involved in early fruit growth signaling. This gene expression profile, together with hormonal regulators, offers new insights for understanding the processes that regulate cell division and expansion, and ultimately fruit yield and olive size.Agencia Estatal de Investigación | Ref. RTI2018-097244-B-I00Junta de ExtremaduraFondo Europeo de Desarrollo Regiona
Mar Caldas. O mundo patas arriba
No full textObras de Mar Caldas no catálogo da exposición celebrada no Museo Manuel Torres, Marín, Pontevedra, do 26 octubre ao 26 noviembre: O mundo patas arriba, 2009. Imágenes impresas y laminadas sobre PVC -100 x 84 cm - Mar Caldas. O mundo patas arriba, 2009. Imágenes impresas sobre papel 176 x 120 cm Obra instalada en MUPI, ubicada en Avenida de Ourense, nº
Nordic walking for overweight and obese people: a systematic review and meta-analysis
No full textBackground
: Nordic walking (NW) is a potentially beneficial exercise strategy for overweight and obese people. To date, no reviews have synthesized the existing scientific evidence regarding the effects of NW on this population. This systematic review and meta-analysis aimed to identify the characteristics, methodological quality, and results of the investigations that have studied the effects of NW in overweight and obese individuals.
Methods
: Six electronic databases were searched up to June 2019 for studies that examined the effects of NW on people with a body mass index ≥ 25 kg/m
2
. The methodological quality of the included randomized controlled trials was retrieved from the physiotherapy evidence database or evaluated using the physiotherapy evidence database scale.
Results
: Twelve studies were included in the review. The investigations were mostly good-to-fair methodological quality. NW groups had a significant improvement on parameters such as fasting plasma glucose, abdominal adiposity, and body fat compared with the baseline, but no significant improvements were found when compared with control groups.
Conclusions
: NW can potentially lead to improvements in parameters related to major health outcomes in overweight and obese people. The lack of control for confounding variables in the analyzed studies prevents further elaboration on its potential benefits