7 research outputs found

    Mesh motion methods for numerical aerodynamic design of lift and control surfaces

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    In this work, moving mesh methods based on the solution of pseudo structural and fluid problems are developed. Mesh motion methods are necessary features for numerical aerodynamic design and test of lift and control surfaces of UAVs. Here a particular moving mesh method based on a pseudo Stokes problem is compared to different well known moving mesh approaches such as techniques by solving diffusion and pseudo structural problems with prescribed velocity and displacement fields, respectively. The benchmark test for this comparison is an airfoil with a fully meshed domain, including the far field and boundary layer, over which is imposed a rotation velocity boundary condition. In order to distinguish the mesh motion methods, several mesh quality criteria are employed to determine a mesh quality mapping to identify critical regions with poor mesh quality and to access the performance of each mesh motion approach. In order to illustrate the mesh motion technology, this paper also presents results of the numerical simulation of a laminar flow over a NACA 0012 airfoil by using a numerical code based on a finite element projection method augmented with mesh motion capabilities

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Trends in Glaucoma Surgical Procedures in Portugal: A 16-Year Nationwide Study (2000-2015)

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    PURPOSE: Glaucoma leads as the first cause of irreversible blindness. The number of patients will greatly increase in upcoming years and changes will have to be accomplished to cope with those numbers. As such, data are important to understand the effect of new policies introduced in glaucoma management. Only few countries have described their glaucoma surgical profile and, in Europe, only the United Kingdom described the last 15 years. The aim of this study is to assess the glaucoma surgical profile and its changes in mainland Portugal from 2000 to 2015. METHODS: Retrospective database analysis of inpatient and surgical outpatients' episodes of all public hospitals in mainland Portugal was performed. The annual absolute numbers of ophthalmic procedures, as well as their surgical rate (per 100,000 inhabitants) were calculated. RESULTS: Glaucoma patients undergoing glaucoma procedures were 67±14 years old and 50% were female. During the study period there was an increase in the number and surgical rate of glaucoma procedures. Trabeculectomy showed a stable surgical rate (7 per 100,000 inhabitants) despite a reduction in terms of relative weight among glaucoma procedures. At the same time, the surgical rate of glaucoma drainage devices and cyclophotoablation increased, while remaining stable for cyclocryoablation. CONCLUSIONS: In Portugal, trabeculectomy had a stable surgical rate throughout the study period, being the most performed glaucoma surgical procedure. Other surgeries, like glaucoma drainage devices and cyclophotoablation are gaining ground among glaucoma specialists. Our results match what has been published by other countries worldwide and can be used to achieve a better health planning.status: publishe

    Global urban environmental change drives adaptation in white clover

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    Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale

    Mitochondrial physiology: Gnaiger Erich et al ― MitoEAGLE Task Group

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    Characteristics and outcomes of an international cohort of 600 000 hospitalized patients with COVID-19

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    Background: We describe demographic features, treatments and clinical outcomes in the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) COVID-19 cohort, one of the world’s largest international, standardized data sets concerning hospitalized patients. Methods: The data set analysed includes COVID-19 patients hospitalized between January 2020 and January 2022 in 52 countries. We investigated how symptoms on admission, co-morbidities, risk factors and treatments varied by age, sex and other characteristics. We used Cox regression models to investigate associations between demographics, symptoms, co-morbidities and other factors with risk of death, admission to an intensive care unit (ICU) and invasive mechanical ventilation (IMV). Results: Data were available for 689 572 patients with laboratory-confirmed (91.1%) or clinically diagnosed (8.9%) SARS-CoV-2 infection from 52 countries. Age [adjusted hazard ratio per 10 years 1.49 (95% CI 1.48, 1.49)] and male sex [1.23 (1.21, 1.24)] were associated with a higher risk of death. Rates of admission to an ICU and use of IMV increased with age up to age 60 years then dropped. Symptoms, co-morbidities and treatments varied by age and had varied associations with clinical outcomes. The case-fatality ratio varied by country partly due to differences in the clinical characteristics of recruited patients and was on average 21.5%. Conclusions: Age was the strongest determinant of risk of death, with a ~30-fold difference between the oldest and youngest groups; each of the co-morbidities included was associated with up to an almost 2-fold increase in risk. Smoking and obesity were also associated with a higher risk of death. The size of our international database and the standardized data collection method make this study a comprehensive international description of COVID-19 clinical features. Our findings may inform strategies that involve prioritization of patients hospitalized with COVID-19 who have a higher risk of death
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