Spatial and Temporal Variations in SO 2 and PM 2.5 Levels Around Kīlauea Volcano, Hawai'i During 2007–2018

Among the hazards posed by volcanoes are the emissions of gases and particles that can affect air quality and damage agriculture and infrastructure. A recent intense episode of volcanic degassing associated with severe impacts on air quality accompanied the 2018 lower East Rift Zone (LERZ) eruption of Kīlauea volcano, Hawai'i. This resulted in a major increase in gas emission rates with respect to usual emission values for this volcano, along with a shift in the source of the dominant plume to a populated area on the lower flank of the volcano. This led to reduced air quality in downwind communities. We analyse open-access data from the permanent air quality monitoring networks operated by the Hawai'i Department of Health (HDOH) and National Park Service (NPS), and report on measurements of atmospheric sulfur dioxide (SO2) between 2007 and 2018 and PM2.5 (aerosol particulate matter with diameter <2.5 μm) between 2010 and 2018. Additional air quality data were collected through a community-operated network of low-cost PM2.5 sensors during the 2018 LERZ eruption. From 2007 to 2018 the two most significant escalations in Kīlauea's volcanic emissions were: the summit eruption that began in 2008 (Kīlauea emissions averaged 5–6 kt/day SO2 from 2008 until summit activity decreased in May 2018) and the LERZ eruption in 2018 when SO2 emission rates reached a monthly average of 200 kt/day during June. In this paper we focus on characterizing the airborne pollutants arising from the 2018 LERZ eruption and the spatial distribution and severity of volcanic air pollution events across the Island of Hawai'i. The LERZ eruption caused the most frequent and severe exceedances of the Environmental Protection Agency (EPA) PM2.5 air quality threshold (35 μg/m3 as a daily average) in Hawai'i in the period 2010–2018. In Kona, for example, the maximum 24-h-mean mass concentration of PM2.5 was recorded as 59 μg/m3 on the twenty-ninth of May 2018, which was one of eight recorded exceedances of the EPA air quality threshold during the 2018 LERZ eruption, where there had been no exceedances in the previous 8 years as measured by the HDOH and NPS networks. SO2 air pollution during the LERZ eruption was most severe in communities in the south and west of the island, as measured by selected HDOH and NPS stations in this study, with a maximum 24-h-mean mass concentration of 728 μg/m3 recorded in Ocean View (100 km west of the LERZ emission source) in May 2018. Data from the low-cost sensor network correlated well with data from the HDOH PM2.5 instruments, confirming that these low-cost sensors provide a robust means to augment reference-grade instrument networks

Probing the Inner Jet of the Quasar PKS 1510-089 with Multi-waveband Monitoring during Strong Gamma-ray Activity

We present results from monitoring the multi-waveband flux, linear polarization, and parsec-scale structure of the quasar PKS 1510-089, concentrating on eight major gamma-ray flares that occurred during the interval 2009.0-2009.5. The gamma-ray peaks were essentially simultaneous with maxima at optical wavelengths, although the flux ratio of the two wavebands varied by an order of magnitude. The optical polarization vector rotated by 720 degrees during a 5-day period encompassing six of these flares. This culminated in a very bright, roughly 1 day, optical and gamma-ray flare as a bright knot of emission passed through the highest-intensity, stationary feature (the "core") seen in 43 GHz Very Long Baseline Array images. The knot continued to propagate down the jet at an apparent speed of 22c and emit strongly at gamma-ray energies as a months-long X-ray/radio outburst intensified. We interpret these events as the result of the knot following a spiral path through a mainly toroidal magnetic field pattern in the acceleration and collimation zone of the jet, after which it passes through a standing shock in the 43 GHz core and then continues downstream. In this picture, the rapid gamma-ray flares result from scattering of infrared seed photons from a relatively slow sheath of the jet as well as from optical synchrotron radiation in the faster spine. The 2006-2009.7 radio and X-ray flux variations are correlated at very high significance; we conclude that the X-rays are mainly from inverse Compton scattering of infrared seed photons by 20-40 MeV electrons.Comment: 10 pages of text + 5 figures, to be published in Astrophysical Journal Letters in 201

Flaring Behavior of the Quasar 3C~454.3 across the Electromagnetic Spectrum

We analyze the behavior of the parsec-scale jet of the quasar 3C~454.3 during pronounced flaring activity in 2005-2008. Three major disturbances propagated down the jet along different trajectories with Lorentz factors $\Gamma>$10. The disturbances show a clear connection with millimeter-wave outbursts, in 2005 May/June, 2007 July, and 2007 December. High-amplitude optical events in the $R$-band light curve precede peaks of the millimeter-wave outbursts by 15-50 days. Each optical outburst is accompanied by an increase in X-ray activity. We associate the optical outbursts with propagation of the superluminal knots and derive the location of sites of energy dissipation in the form of radiation. The most prominent and long-lasting of these, in 2005 May, occurred closer to the black hole, while the outbursts with a shorter duration in 2005 Autumn and in 2007 might be connected with the passage of a disturbance through the millimeter-wave core of the jet. The optical outbursts, which coincide with the passage of superluminal radio knots through the core, are accompanied by systematic rotation of the position angle of optical linear polarization. Such rotation appears to be a common feature during the early stages of flares in blazars. We find correlations between optical variations and those at X-ray and $\gamma$-ray energies. We conclude that the emergence of a superluminal knot from the core yields a series of optical and high-energy outbursts, and that the mm-wave core lies at the end of the jet's acceleration and collimation zone.Comment: 57 pages, 23 figures, 8 tables (submitted to ApJ

Understanding the environmental impacts of large fissure eruptions: Aerosol and gas emissions from the 2014-2015 Holuhraun eruption (Iceland)

The 2014-2015 Holuhraun eruption in Iceland, emitted ~11 Tg of SO2 into the troposphere over 6 months, and caused one of the most intense and widespread volcanogenic air pollution events in centuries. This study provides a number of source terms for characterisation of plumes in large fissure eruptions, in Iceland and elsewhere. We characterised the chemistry of aerosol particle matter (PM) and gas in the Holuhraun plume, and its evolution as the plume dispersed, both via measurements and modelling. The plume was sampled at the eruptive vent, and in two populated areas in Iceland. The plume caused repeated air pollution events, exceeding hourly air quality standards (350 µg/m3) for SO2 on 88 occasions in Reykjahlíð town (100 km distance), and 34 occasions in Reykjavík capital area (250 km distance). Average daily concentration of volcanogenic PM sulphate exceeded 5 µg/m3 on 30 days in Reykjavík capital area, which is the maximum concentration measured during non-eruptive background interval. There are currently no established air quality standards for sulphate. Combining the results from direct sampling and dispersion modelling, we identified two types of plume impacting the downwind populated areas. The first type was characterised by high concentrations of both SO2 and S-bearing PM, with a high Sgas/SPM mass ratio (SO2(g)/SO42-(PM) >10). The second type had a low Sgas/SPM ratio (<10). We suggest that this second type was a mature plume where sulphur had undergone significant gas-to-aerosol conversion in the atmosphere. Both types of plume were rich in fine aerosol (predominantly PM1 and PM2.5), sulphate (on average ~90% of the PM mass) and various trace species, including heavy metals. The fine size of the volcanic PM mass (75-80% in PM2.5), and the high environmental lability of its chemical components have potential adverse implications for environmental and health impacts. However, only the dispersion of volcanic SO2 was forecast in public warnings and operationally monitored during the eruption. We make a recommendation that sulphur gas-to-aerosol conversion processes, and a sufficiently large model domain to contain the transport of a tropospheric plume on the timescale of days be utilized for public health and environmental impact forecasting in future eruptions in Iceland and elsewhere in the world

Unique establishment of procephalic head segments is supported by the identification of cis-regulatory elements driving segment-specific segment polarity gene expression in Drosophila

Anterior head segmentation is governed by different regulatory mechanisms than those that control trunk segmentation in Drosophila. For segment polarity genes, both initial mode of activation as well as cross-regulatory interactions among them differ from the typical genetic circuitry in the trunk and are unique for each of the procephalic segments. In order to better understand the segment-specific gene network responsible for the procephalic expression of the earliest active segment polarity genes wingless and hedgehog, we started to identify and analyze cis-regulatory DNA elements of these genes. For hedgehog, we could identify a cis-regulatory element, ic-CRE, that mediates expression specifically in the posterior part of the intercalary segment and requires promoter-specific interaction for its function. The intercalary stripe is the last part of the metameric hedgehog expression pattern that appears during embryonic development, which probably reflects the late and distinct establishment of this segment. The identification of a cis-regulatory element that is specific for one head segment supports the mutant-based observation that the expression of segment polarity genes is governed by a unique gene network in each of the procephalic segments. This provides further indication that the anterior-most head segments represent primary segments, which are set up independently, in contrast to the secondary segments of the trunk, which resemble true repetitive units

ИНФАРКТ МИОКАРДА ВТОРОГО ТИПА: СОВРЕМЕННЫЕ ОСОБЕННОСТИ ДИАГНОСТИКИ И ЛЕЧЕНИЯ

Aim. To determine the frequency of detection of patients with myocardial infarction (MI) type 2 and their features in real clinical practice.Methods. A prospective study of 204 patients diagnosed with acute coronary syndrome (ACS) was performed. Diagnosis of ACS at admission followed by a confirmed diagnosis of MI during the hospital period according to the Fourth Universal Definition of MI. The following were analyzed: anthropometric parameters, clinical and anamnestic characteristics of patients, results of laboratory research methods, determination of biochemical markers of myocardial necrosis, results of instrumental diagnostic methods and coronary angiography. The annual follow-up stage was carried out in the form of a telephone survey of patients with a follow-up of dynamic features during the year after ACS (presence of endpoints: repeated coronary events, death, repeated hospitalizations, adherence to medical recommendations, therapy taken by the patient).Results. Type 2 MI was diagnosed in 22 (10.8%) cases. The results of coronary angiography demonstrated the absence of coronary artery (CA) in 16 (72.7%) patients of this group or the presence of stenoses of less than 50% without indications of the presence of thrombosis. Chronic occlusion of the infarct-unrelated coronary artery was found in 6 (27.3%) patients. Patients with type 2 MI were comparable in age with the group of patients with type 1 MI. Differences were female predominance (p = 0.029), fewer smokers (p = 0.037) and more frequent history of atrial fibrillation (AF) (p = 0.003). The most frequent provoking factors of type 2 MI were determined: sinus tachycardia in 3 (13.6%) patients, flutter paroxysm or AF with tachysystole for the ventricles in 4 cases (18.2%).Conclusion. A less favorable course of the disease was found in patients with type 1 MI. A feature of the post-infarction period in this case was the greatest number of recurrent MI and deaths during the year compared with patients after type 2 MI, which were characterized by a predominance of women, a smaller number of smokers and people with dyslipidemia, as well as a more frequent indication of the presence of AF.Основные положенияВыявлены особенности отдаленного постинфарктного периода у больных инфарктом миокарда 2-го типа в виде благоприятного течения при сравнении с больными ИМ 1-го типа. Определены различия клинико-анамнестических данных пациентов с ИМ 1-го и 2-го типа. Аннотация:Цель. Определить частоту выявления пациентов с инфарктом миокарда (ИМ) 2-го типа и их особенностей в реальной клинической практике.Материалы и методы. Проведено проспективное исследование 204 пациентов с диагнозом «острый коронарный синдром (ОКС)». В исследование вошли лица с установленным при поступлении ОКС и последующим диагнозом ИМ, подтвержденным в госпитальном периоде согласно Четвертому универсальному определению ИМ. Проанализированы антропометрические показатели, клинико-анамнестические характеристики пациентов, результаты лабораторных методов исследования, биохимические маркеры некроза миокарда, результаты инструментальных методов диагностики и коронароангиографии. Годовой этап наблюдения осуществлялся в виде телефонного опроса пациентов с целью отслеживания динамических особенностей в течение года после перенесенного ОКС (наличия конечных точек: повторных коронарных событий, летального исхода, повторных госпитализаций по причине кардиальных и внекардиальных событий; приверженности врачебным рекомендациям и принимаемой терапии).Результаты. Диагноз ИМ 2-го типа установлен в 22 (10,8%) случаях. Результаты коронарографии продемонстрировали отсутствие поражения коронарных артерий у 16 (72,7%) больных этой группы или наличие стенозов менее 50% без указаний на тромбоз. Хроническая окклюзия инфаркт-несвязанной коронарной артерии обнаружена у 6 (27,3%) пациентов. Пациенты с ИМ 2-го типа оказались сопоставимы по возрасту с группой больных ИМ 1-го типа. Отличия заключались в преобладании лиц женского пола (p = 0,029), меньшем количестве курящих пациентов (p = 0,037) и более частом указании на наличие фибрилляции предсердий в анамнезе (p = 0,003). Определены факторы, наиболее часто провоцирующие ИМ 2-го типа: синусовая тахикардия – у 3 (13,6%) пациентов, пароксизм трепетания или фибрилляции предсердий с тахисистолией желудочков – в 4 (18,2%) случаях.Заключение. Выявлено менее благоприятное течение заболевания у пациентов, перенесших ИМ 1-го типа. Особенностью постинфарктного периода в данном случае стало наибольшее количество повторных ИМ и летальных исходов в течение года по сравнению с пациентами после ИМ 2-го типа, которые характеризовались преобладанием женщин, меньшим количеством курящих и лиц, имеющих дислипидемию, а также более частым указанием на наличие фибрилляции предсердий