50 research outputs found

    Residential Indoor and Outdoor PM Measured Using Low-cost Monitors during the Heating Season in Monroe County, NY

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    Continuous 1-minute indoor and outdoor PM concentrations (~PM2.5) were measured from November through April of 2015/16 and 2016/17 at 50 single family residences in Monroe County, NY (25 per season) using Speck (Airviz Inc., Pittsburgh, PA) low-cost monitors (LCMs). While the accuracy of LCMs is inconsistent and source dependent, the LCMs provided reasonable precision for estimating indoor/outdoor (I/O) ratios based on laboratory and field testing, understanding the relationship between indoor sources and concentration, and comparing PM concentrations across residences for the detected size range (0.5-3 mm). The indoor PM2.5 concentration pattern showed clear morning and evening peaks as well as higher indoor concentrations during the weekends when people are typically at home. The mean I/O PM2.5 ratio was 1.1 for all homes and increased to 1.7 when a combustion source was in use as indicated by an elevated CO concentration whereas most prior studies have found this ratio to be < 1. Increases in wood-burning appliance temperature and indoor CO concentrations were found to be associated with an overall moderate (mean value of 2.1 µg/m3) increase in indoor PM concentration averaged over the heating season. Short-term PM increases greater than 100 µg/m3 were periodically observed in homes with and without wood-burning appliances operating. This study provides an approach for exposure assessment in homes that can be utilized by employing appropriate calibration and quality assurance procedures for the LCMs

    Subclinical reactivation of varicella zoster virus after covid-19 as a possible cause of stroke in young patient

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    Previous studies have observed an association between Varicella Zoster Virus (VZV) infection and stroke. Here we discuss possible causes of Herpes Zoster (HZ) due to COVID-19. Reactivation of VZV caused by decline of cellular immune response has been noted during the convalescent period or after recovery from COVID-19. Whether s troke can be a late sequel of a COVID-19 due to different inflammatory and coagulation mechanisms is currently uncertain. We present the case of a young patient with acute ischemic stroke, two months after mild COVID19 infection associated with subclinical reactivation of VZV infection and discuss possible causes of stroke. Diffusio

    ПРОБЛЕМЫ ИНФОРМИРОВАНИЯ НАСЕЛЕНИЯ О ПОСЛЕДСТВИЯХ МИРНЫХ ЯДЕРНЫХ ВЗРЫВОВ

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    The paper provides the results of a study of the local public attitude to the problem of peaceful nuclear explosions (PNE) which were carried out in the Ivanovo, Murmansk and Perm regions and in the Republic of Sakha (Yakutia) in the last century. An estimate of the mass media information regarding consequences of the PNEs is given. The study shows that the local citizens are ready to deal with reliable sources of objective information about consequences of the PNEs. The recommendations on information of the general public about PNE are presented.В статье приводятся результаты изучения отношения местного населения к проблеме мирных ядерных взрывов (МЯВ), проведенных в прошлом веке на территории Ивановской и Мурманской областей, Пермского края и Республики Саха (Якутия). Дана оценка публикаций, имеющихся в средствах массовой информации по вопросам последствий МЯВ. Проведенное исследование показало, что население хочет и готово принять объективную информацию о последствиях МЯВ от источников, которым оно доверяет. Даны рекомендации по вопросам информирования населения о проблеме МЯВ

    Primary Versus Secondary Contributions to Particle Number Concentrations in the European Boundary Layer

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    It is important to understand the relative contribution of primary and secondary particles to regional and global aerosol so that models can attribute aerosol radiative forcing to different sources. In large-scale models, there is considerable uncertainty associated with treatments of particle formation (nucleation) in the boundary layer (BL) and in the size distribution of emitted primary particles, leading to uncertainties in predicted cloud condensation nuclei (CCN) concentrations. Here we quantify how primary particle emissions and secondary particle formation influence size-resolved particle number concentrations in the BL using a global aerosol microphysics model and aircraft and ground site observations made during the May 2008 campaign of the European Integrated Project on Aerosol Cloud Climate Air Quality Interactions (EUCAARI). We tested four different parameterisations for BL nucleation and two assumptions for the emission size distribution of anthropogenic and wildfire carbonaceous particles. When we emit carbonaceous particles at small sizes (as recommended by the Aerosol Intercomparison project, AEROCOM), the spatial distributions of campaign-mean number concentrations of particles with diameter >50 nm (N50) and >100 nm (N100) were well captured by the model (R2≥0.8) and the normalised mean bias (NMB) was also small (−18% for N50 and −1% for N100). Emission of carbonaceous particles at larger sizes, which we consider to be more realistic for low spatial resolution global models, results in equally good correlation but larger bias (R2≥0.8, NMB = −52% and −29%), which could be partly but not entirely compensated by BL nucleation. Within the uncertainty of the observations and accounting for the uncertainty in the size of emitted primary particles, BL nucleation makes a statistically significant contribution to CCN-sized particles at less than a quarter of the ground sites. Our results show that a major source of uncertainty in CCN-sized particles in polluted European air is the emitted size of primary carbonaceous particles. New information is required not just from direct observations, but also to determine the "effective emission size" and composition of primary particles appropriate for different resolution models.JRC.H.2-Air and Climat

    Phenomenology of ultrafine particle concentrations and size distribution across urban Europe

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    The 2017-2019 hourly particle number size distributions (PNSD) from 26 sites in Europe and 1 in the US were evaluated focusing on 16 urban background (UB) and 6 traffic (TR) sites in the framework of Research Infrastructures services reinforcing air quality monitoring capacities in European URBAN & industrial areaS (RI-URBANS) project. The main objective was to describe the phenomenology of urban ultrafine particles (UFP) in Europe with a significant air quality focus. The varying lower size detection limits made it difficult to compare PN concentrations (PNC), particularly PN10-25, from different cities. PNCs follow a TR > UB > Suburban (SUB) order. PNC and Black Carbon (BC) progressively increase from Northern Europe to Southern Europe and from Western to Eastern Europe. At the UB sites, typical traffic rush hour PNC peaks are evident, many also showing midday-morning PNC peaks anti-correlated with BC. These peaks result from increased PN10-25, suggesting significant PNC contributions from nucleation, fumigation and shipping. Site types to be identified by daily and seasonal PNC and BC patterns are: (i) PNC mainly driven by traffic emissions, with marked correlations with BC on different time scales; (ii) marked midday/morning PNC peaks and a seasonal anti-correlation with PNC/BC; (iii) both traffic peaks and midday peaks without marked seasonal patterns. Groups (ii) and (iii) included cities with high insolation. PNC, especially PN25-800, was positively correlated with BC, NO2, CO and PM for several sites. The variable correlation of PNSD with different urban pollutants demonstrates that these do not reflect the variability of UFP in urban environments. Specific monitoring of PNSD is needed if nanoparticles and their associated health impacts are to be assessed. Implementation of the CEN-ACTRIS recommendations for PNSD measurements would provide comparable measurements, and measurements of <10 nm PNC are needed for full evaluation of the health effects of this size fraction

    The F0F1-ATP Synthase Complex Contains Novel Subunits and Is Essential for Procyclic Trypanosoma brucei

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    The mitochondrial F0F1 ATP synthase is an essential multi-subunit protein complex in the vast majority of eukaryotes but little is known about its composition and role in Trypanosoma brucei, an early diverged eukaryotic pathogen. We purified the F0F1 ATP synthase by a combination of affinity purification, immunoprecipitation and blue-native gel electrophoresis and characterized its composition and function. We identified 22 proteins of which five are related to F1 subunits, three to F0 subunits, and 14 which have no obvious homology to proteins outside the kinetoplastids. RNAi silencing of expression of the F1 α subunit or either of the two novel proteins showed that they are each essential for the viability of procyclic (insect stage) cells and are important for the structural integrity of the F0F1-ATP synthase complex. We also observed a dramatic decrease in ATP production by oxidative phosphorylation after silencing expression of each of these proteins while substrate phosphorylation was not severely affected. Our procyclic T. brucei cells were sensitive to the ATP synthase inhibitor oligomycin even in the presence of glucose contrary to earlier reports. Hence, the two novel proteins appear essential for the structural organization of the functional complex and regulation of mitochondrial energy generation in these organisms is more complicated than previously thought

    Highly Divergent Mitochondrial ATP Synthase Complexes in Tetrahymena thermophila

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    Tetrahymena ATP synthase, an evolutionarily divergent protein complex, has a very unusual structure and protein composition including a unique Fo subunit a and at least 13 proteins with no orthologs outside of the ciliate lineage

    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

    Get PDF
    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
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