Studies of an artificially generated electrode effect at ground level

International audienceThe outdoor experiments, using a metallic grid above the ground surface, have yielded well-defined vertical profiles of the space-charge density. The profiles showed strong evidence for the existence of an electrode effect, which could be named the artificial electrode effect and can serve as a very useful and well-controlled model for the study of atmospheric electric processes in the atmospheric surface layer. The build-up or break-down of an electrode-effect layer occurred in a time of the order of 10 s under the experimental conditions realized. The artificially generated electrode effect is dependent on the electrical field strength supplied, wind speed, turbulent mixing and ion mobilities. Wind speed and ion mobility seem to be the dominant factors, defining space-charge density profiles. A theoretical model for the artificial electrode effect has been developed, taking into account turbulent mixing of charged particles in the air flow with the logarithmic profile of the wind velocity. The numerical analysis of the boundary value problem for the two-dimensional equations for the light ion concentrations has been performed. The model presented shows a qualitative agreement of calculated space-charge profiles with measured ones, and explains the dependence of the artificial electrode effect on the dominant control parameters. The limiting conditions for the developed theory are discussed

A global atmospheric electricity monitoring network for climate and geophysical research

The Global atmospheric Electric Circuit (GEC) is a fundamental coupling network of the climate system connecting electrically disturbed weather regions with fair weather regions across the planet. The GEC sustains the fair weather electric field (or potential gradient, PG) which is present globally and can be measured routinely at the surface using durable instrumentation such as modern electric field mills, which are now widely deployed internationally. In contrast to lightning or magnetic fields, fair weather PG cannot be measured remotely. Despite the existence of many PG datasets (both contemporary and historical), few attempts have been made to coordinate and integrate these fragmented surface measurements within a global framework. Such a synthesis is important elvinin order to fully study major influences on the GEC such as climate variations and space weather effects, as well as more local atmospheric electrical processes such as cloud electrification, lightning initiation, and dust and aerosol charging. The GloCAEM (Global Coordination of Atmospheric Electricity Measurements) project has brought together experts in atmospheric electricity to make the first steps towards an effective global network for atmospheric electricity monitoring, which will provide data in near real time. Data from all sites are available in identically-formatted files, at both one second and one minute temporal resolution, along with meteorological data (wherever available) for ease of interpretation of electrical measurements. This work describes the details of the GloCAEM database and presents what is likely to be the largest single analysis of PG data performed from multiple datasets at geographically distinct locations. Analysis of the diurnal variation in PG from all 17 GloCAEM sites demonstrates that the majority of sites show two daily maxima, characteristic of local influences on the PG, such as the sunrise effect. Data analysis methods to minimise such effects are presented and recommendations provided on the most suitable GloCAEM sites for the study of various scientific phenomena. The use of the dataset for a further understanding of the GEC is also demonstrated, in particular for more detailed characterization of day-to-day global circuit variability. Such coordinated effort enables deeper insight into PG phenomenology which goes beyond single-location PG measurements, providing a simple measurement of global thunderstorm variability on a day-to-day timescale. The creation of the GloCAEM database is likely to enable much more effective study of atmospheric electricity variables than has ever been possible before, which will improve our understanding of the role of atmospheric electricity in the complex processes underlying weather and climate

Experimental study of diurnal and seasonal variations in the atmospheric electric field

In order to separate global and local effects of atmospheric electricity, measurements of the fair-weather electric field were performed in Nizhny Novgorod in 2013-2018. As a result of processing 139 diurnal records from four observation points spaced 6–8 km apart, diurnal variations in the fair-weather atmospheric electric field for different seasons and weekdays (working days and weekends) were studied. The curve of the local diurnal variation is shown to always have two maxima. The evening maximum of the diurnal variation (19:00–20:00 UT) coincides in time with the maximum of the Carnegie curve, which is a characteristic of the global electrical circuit. The highest values of the field amplitude are reached in the winter period. The field-intensity maximum in the first half of the day (09:00–11:00 LT) is characteristic of the urban environment and shows that local effects associated with the presence of aerosol particles in the air significantly contribute to the formation of diurnal variation, especially in summer. According to the 2013–2018 measurements, the seasonal variation in the monthly-average values of the atmospheric electric field is revealed and analyzed compared with the results of measurements of seasonal variation in other regions of the globe. The obtained results allow one to reveal the role of local effects in the formation of diurnal variation in the mid-latitude areas with temperate continental climate and provide a basis for developing a theory which can explain the physical mechanisms of local effects and suggest appropriate parametrization for finding the surface electric field in the weather and climate models

Steroid pulse -therapy in patients With coronAvirus Pneumonia (COVID-19), sYstemic inFlammation And Risk of vEnous thRombosis and thromboembolism (WAYFARER Study)

Introduction: Coronavirus pneumonia not only severely affects the lung tissue but is also associated with systemic autoimmune inflammation, rapid overactivation of cytokines and chemokines known as “cytokine storm”, and a high risk of thrombosis and thromboembolism. Since there is no specific therapy for this new coronavirus infection (COVID-19), searching for an effective and safe anti-inflammatory therapy is critical.Materials and Methods: This study evaluated efficacy and safety of pulse therapy with high doses of glucocorticosteroids (GCS), methylprednisolone 1,000 mg for 3 days plus dexamethasone 8 mg for another 3-5 days, in 17 patients with severe coronavirus pneumonia as a part of retrospective comparative analysis (17 patients in control group). The study primary endpoint was the aggregate dynamics of patients’ condition as evaluated by an original CCS-COVID scale, which included, in addition to the clinical status, assessments of changes in the inflammation marker, C-reactive protein (CRP); the thrombus formation marker, D-dimer; and the extent of lung injury evaluated by computed tomography (CT). Patients had signs of lung injury (53.2 % and 25.6 %), increases in CRP 27 and 19 times, and a more than doubled level of D-dimer (to 1.41 µg/ml and 1.15 µg/ml) in the active therapy and the control groups, respectively. The GCS treatment group had a more severe condition at baseline.Results: The GCS pulse therapy proved effective and significantly decreased the CCS-COVID scores. Median score difference was 5.00 compared to the control group (р=0.011). Shortness of breath considerably decreased; oxygen saturation increased, and the NEWS-2 clinical status scale scores decreased. In the GCS group, concentration of CRP significantly decreased from 134 mg/dl to 41.8 mg/dl (р=0.009) but at the same time, D-dimer level significantly increased from 1.41 µg/ml to 1.98 µg/ml (р=0.044). In the control group, the changes were nonsignificant. The dynamics of lung injury by CT was better in the treatment group but the difference did not reach a statistical significance (р=0.062). Following the GCS treatment, neutrophilia increased (р=0.0001) with persisting lymphopenia, and the neutrophil/lymphocyte (N/L) ratio, a marker of chronic inflammation, increased 2.5 times (р=0.006). The changes in the N/L ratio and D-dimer were found to correlate in the GCS pulse therapy group (r =0.49, p=0.04), which underlined the relationship of chronic autoimmune inflammation with thrombus formation in COVID-19. No significant changes were observed in the control group. In result, four patients developed venous thromboembolic complications (two of them had pulmonary artery thromboembolism) after the GCS pulse therapy despite the concomitant antiplatelet treatment at therapeutic doses. Recovery was slower in the hormone treatment group (median stay in the hospital was 26 days vs 18 days in the control group, р=0.001).Conclusion: Pulse therapy with high doses of GCS exerted a rapid anti-inflammatory effect but at the same time, increased the N/L ratio and the D-dimer level, which increased the risk of thromboembolism

Patients with a Combination of Atrial Fibrillation and Chronic Heart Failure in Clinical Practice: Comorbidities, Drug Treatment and Outcomes

Aim. To assess in clinical practice the structure of multimorbidity, cardiovascular pharmacotherapy and outcomes in patients with a combination of atrial fibrillation (AF) and chronic heart failure (CHF) based on prospective registries of patients with cardiovascular diseases (CVD).Materials and Methods. The data of 3795 patients with atrial fibrillation (AF) were analyzed within the registries RECVASA (Ryazan), RECVASA FP (Moscow, Kursk, Tula, Yaroslavl), REGION-PO and REGION-LD (Ryazan), REGION-Moscow, REGATA (Ryazan). The comparison groups consisted of 3016 (79.5%) patients with AF in combination with CHF and 779 (29.5%) patients with AF without CHF. The duration of prospective observation is from 2 to 6 years.Results. Patients with a combination of AF and CHF (n=3016, age was 72.0±10.3 years; 41.8% of men) compared with patients with AF without CHF (n=779, age was 70.3±12.0 years; 43.5% of men) had a higher risk of thromboembolic complications (CHA2DS2-VASc – 4.68±1.59 and 3.10±1.50; p<0.001) and hemorrhagic complications (HAS-BLED – 1.59±0.77 and 1.33±0.76; p<0.05). Patients with a combination of AF and CHF significantly more often (p<0.001) than in the absence of CHF were diagnosed with arterial hypertension (93.9% and 83.8%), coronary heart disease (87.9% and 53,5%), myocardial infarction (28.4% and 14.0%), diabetes mellitus (22.4% and 7.7%), chronic kidney disease (24.8% and 16.2%), as well as respiratory diseases (20.1% and 15.3%; p=0.002). Patients with AF in the presence of CHF, compared with patients without CHF, were more often diagnosed with a permanent form of arrhythmia (49.3% and 32.9%; p<0.001) and less often paroxysmal (22.5% and 46.2%; p<0.001) form  of  arrhythmia.  Ejection  fraction  ≤40%  (9.3%  and  1.2%;  p<0.001),  heart  rate  ≥90/min  (23.7% and 19.3%; p=0.008) and blood pressure ≥140/90 mm Hg (59.9% and 52.2%; p<0.001) were recorded with AF in the presence of CHF more often than in the absence of CHF. The frequency of proper cardiovascular pharmacotherapy was higher, albeit insufficient, in the presence of CHF (64.9%) than in the absence of it (56.1%), but anticoagulants were prescribed less frequently when AF and CHF were combined (38.8% and  49, 0%; p<0.001). The frequency of unreasonable prescription of antiplatelet agents instead of anticoagulants was 52.5% and 33.3% (p<0.001) in the combination of AF, CHF and coronary heart disease, as well as in the combination of AF with coronary heart disease but without CHF. Patients with AF and CHF during the observation period compared with those without CHF had higher mortality from all causes (37.6% and 30.3%; p=0.001), the frequency of non-fatal cerebral stroke (8.2% and 5.4%; p=0.032) and myocardial infarction (4.7% and 2.5%; p=0.036), hospitalizations for CVD (22.8% and 15.5%; p<0.001).Conclusion. Patients with a combination of AF and CHF, compared with the group of patients with AF without CHF, were older, had a higher risk of thromboembolic and hemorrhagic complications, they were more often diagnosed with other concomitant cardiovascular and chronic noncardiac diseases, decreased left ventricular ejection fraction, tachysystole, failure to achieve the target blood pressure level in the presence of arterial hypertension. The frequency of prescribing proper cardiovascular pharmacotherapy was higher, albeit insufficient, in the presence of CHF, while the frequency of prescribing anticoagulants was less. The  incidence of mortality from all causes, the development of non-fatal myocardial infarction   and cerebral stroke, as well as the incidence of hospitalizations for CVDs were higher in AF associated with CHF

Pan-Eurasian Experiment (PEEX): Towards a holistic understanding of the feedbacks and interactions in the land-Atmosphere-ocean-society continuum in the northern Eurasian region

The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic-boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (https://www.atm.helsinki.fi/peex/). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land-Atmosphere-Aquatic-society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context