262 research outputs found

    Examination on total ozone column retrievals by Brewer spectrophotometry using different processing software

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    The availability of long-term records of the total ozone content (TOC) represents a valuable source of information for studies on the assessment of short-and long-term atmospheric changes and their impact on the terrestrial ecosystem. In particular, ground-based observations represent a valuable tool for validating satellite-derived products. To our knowledge, details about software packages for processing Brewer spectrophotometer measurements and for retrieving the TOC are seldom specified in studies using such datasets. The sources of the differences among retrieved TOCs from the Brewer instruments located at the Italian stations of Rome and Aosta, using three freely available codes (Brewer Processing Software, BPS; O3Brewer software; and European Brewer Network (EUBREWNET) level 1.5 products) are investigated here. Ground-based TOCs are also compared with Ozone Monitoring Instrument (OMI) TOC retrievals used as an independent dataset since no other instruments near the Brewer sites are available. The overall agreement of the BPS and O3Brewer TOC data with EUBREWNET data is within the estimated total uncertainty in the retrieval of total ozone from a Brewer spectrophotometer (1%). However, differences can be found depending on the software in use. Such differences become larger when the instrumental sensitivity exhibits a fast and dramatic drift which can affect the ozone retrievals significantly. Moreover, if daily mean values are directly generated by the software, differences can be observed due to the configuration set by the users to process single ozone measurement and the rejection rules applied to data to calculate the daily value. This work aims to provide useful information both for scientists engaged in ozone measurements with Brewer spectrophotometers and for stakeholders of the Brewer data products available on Web-based platforms

    Holocene Event Record of Aysen Fjord (Chilean Patagonia): An Interplay of Volcanic Eruptions and Crustal and Megathrust Earthquakes

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    In the first months of 2007, the Aysen region in southern Chile was affected by a crustal seismic swarm. Its largest earthquake (M-w 6.2) occurred in April and had its epicenter in Aysen Fjord. Seismic intensities became so high that hundreds of onshore mass movements were triggered, several of which entered into the fjord, resulting in mass transport deposits (MTDs) preserved at the fjord bottom. Here we present a Holocene record of paleo-earthquakes in the previously unstudied Patagonian fjordland based on MTD stratigraphy. High-resolution seismic data retrieved using two different seismic systems (sparker and TOPAS) reveal multiple older MTDs on different stratigraphic levels. Correlation of the seismic stratigraphy with sedimentological data obtained from a long Calypso core (MD07-3117) allows conclusion on the seismic origin of these deposits. Additionally, radiocarbon dating permits constructing an age model, validated by tephrochronology, providing an age for the different MTD levels. We thus present a highly detailed paleoseismological history of the Aysen region, including at least six major Holocene earthquakes, one of which is likely related to a known megathrust earthquake. Other earthquakes are related to activity of the Liquine-Ofqui Fault Zone (LOFZ), forming the main source of seismic hazard in the area. We can infer a general average recurrence time for LOFZ earthquakes of -2,100years in the vicinity of Aysen Fjord with clustered events during the early and late Holocene. Finally, we argue that cascading events (causal link between volcanic and seismic events) may be a frequent phenomenon along the LOFZ

    Review on Occupational Personal Solar UV Exposure Measurements

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    During leisure time, people can decide if they want to expose themselves to solar ultraviolet (UV) radiation and to which extent. During occupation, people do not have this choice. Outdoor workers are exposed to solar UV radiation (UVR) on a daily basis. This may hold a certain health risk, which can be estimated when the personal solar UVR exposure (PE) is known. During the past decades, a variety of studies was conducted to measure PE of outdoor workers and our knowledge on the PE of outdoor workers has remarkably increased. As shown by this review, studies clearly indicate that PE of most of outdoor workers exceeds the internationally proposed threshold limit value, which is comparable to 1.0 to 1.3 SED, respectively to 1.1 to 1.5 UV Index received over one hour. Besides working in a high UVR environment, monotonic workflow (limited movement, nearly static posture) is a risk factor. In such cases, PE can be higher than ambient UVR. In this review, we provide also a list of milestone, depicting the progress and the most important findings in this field during the past 45 years. However, in many respects our knowledge is still rudimentary, because of several reasons. Different measuring positions have been used so that measured PE is not comparable. Few studies were designed to enable extension of measured PE to other locations or dates. Although the importance of a proper calibration of the measuring devices in respect to the changing solar spectrum was pointed out from the beginning, this is often not performed, which leads to high uncertainties in the presented PE levels. At the end of our review, we provide some key points, which can be used to evaluate the quality of a study respectively to support the design of future studies

    Seismo‐turbidites in Aysén Fjord (Southern Chile) reveal a complex pattern of rupture modes along the 1960 megathrust earthquake segment

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    Grainsize analysis and end‐member modeling of a long sediment core from Aysén Fjord (southern Chile) allows to identify over 25 seismo‐turbidites in the last 9,000 years. Considering the shaking intensities required to trigger these turbidites (V½‐VI½), the majority can be related to megathrust earthquakes. Multiple studies in south‐central Chile have aimed at finding traces of giant, tsunamigenic megathrust earthquakes leading to the current 5,500‐year‐long paleoseismological record of the Valdivia segment. However, none of these cover the southern third of the segment. Aysén Fjord allows to fill this data gap and presents the first, crucial paleoseismic data to demonstrate that the 1960 event was not unique for the Valdivia segment, yielding a recurrence rate of 321 ± 116 years in the last two millennia. Moreover, the oldest identified events in Aysén Fjord date back to 9,000 cal years BP and, thus, also extend the regional paleoseismological record in time. We infer a large temporal variability in rupture modes, with successions of full‐segment ruptures alternating with partial and cascading ruptures. The latter seems to significantly postpone the occurrence of another full rupture when consecutively occurring in different parts of the segment. Additionally, one outstanding period of seismic quiescence ¿during which no megathrust earthquake evidence has been found at any paleoseismic site¿occurred after a full rupture in AD ~745 that presents an unusual uplift/subsidence pattern. Such variability makes it highly speculative to anticipate the rupture mode of the next megathrust earthquake along the Valdivia segment

    Preliminary Analysis of the Effects of Ad26.COV2.S Vaccination on CT Findings and High Intensive Care Admission Rates of COVID-19 Patients

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    On 27 February 2021, the Food and Drug Administration(FDA) authorized the administration of the adenovirus-based Ad26.COV2-S vaccine (J&J-Janssen) for the prevention of COVID-19, a viral pandemic that, to date, has killed more than 5.5 million people. Performed during the early phase of the COVID-19 4th wave, this retrospective observational study aims to report the computerized tomography (CT) findings and intensive care unit admission rates of Ad26.COV2-S-vaccinated vs. unvaccinated COVID-19 patients. From the 1st to the 23rd of December 2021, all confirmed COVID-19 patients that had been subjected to chest non-contrast CT scan analysis were enrolled in the study. These were divided into Ad26.COV2.S-vaccinated (group 1) and unvaccinated patients (group 2). The RSNA severity score was calculated for each patient and correlated to CT findings and type of admission to a healthcare setting after CT-i.e., home care, ordinary hospitalization, sub-intensive care, and intensive care. Descriptive and inference statistical analyses were performed by comparing the data from the two groups. Data from a total of 71 patients were collected: 10 patients in group 1 (4M, 6F, mean age 63.5 years, SD ± 4.2) and 61 patients in group 2 (32M, 29F, mean age 64.7 years, SD ± 3.7). Statistical analysis showed lower values of RSNA severity in group 1 compared to group 2 (mean value 14.1 vs. 15.7, p = 0.009, respectively). Furthermore, vaccinated patients were less frequently admitted to both sub-intensive and high-intensive care units than group 2, with an odds ratio of 0.45 [95%CI (0.01; 3.92)]. Ad26.COV2.S vaccination protects from severe COVID-19 based on CT severity scores. As a result, Ad26.COV2.S-vaccinated COVID-19 patients are more frequently admitted to home in comparison with unvaccinated patients

    First national intercomparison of solar ultraviolet radiometers in Italy

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    A blind intercomparison of ground-based ultraviolet (UV) instruments has been organized for the first time in Italy. The campaign was coordinated by the Environmental Protection Agency of Aosta Valley (ARPA Valle d'Aosta) and took place in Saint-Christophe (45.8 degrees N, 7.4 degrees E, 570 m a.s.l.), in the Alpine region, from 8 to 23 June 2010. It involved 8 institutions, 10 broadband radiometers, 2 filter radiometers and 2 spectroradiometers. Synchronized measurements of downward global solar UV irradiance at the ground were collected and the raw series were then individually processed by the respective operators on the base of their own procedures and calibration data. A radiative transfer model was successfully applied as an interpretative tool. The input parameters and output results are described in detail. The comparison was performed in terms of global solar UV Index and integrated UV-A irradiance against a well-calibrated double monochromator spectroradiometer as reference. An improved algorithm for comparing broadband data and spectra has been developed and is discussed in detail. For some instruments, we found average deviations ranging from -16% up to 20% relative to the reference and diurnal variations as large as 15% even in clear days. Remarkable deviations were found for the instruments calibrated in the manufacturers' facilities and never involved in field intercomparison. Finally, some recommendations to the UV operators based on the campaign results are proposed

    Clinicians' adherence versus non adherence to practice guidelines in the management of patients with sarcoma: a cost-effectiveness assessment in two European regions

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    International audienceABSTRACT: BACKGROUND: Although the management of sarcoma is improving, non adherence to clinical practice guidelines (CPGs) remains high, mainly because of the low incidence of the disease and the variety of histological subtypes. Since little is known about the health economics of sarcoma, we undertook a cost-effectiveness analysis (within the CONnective TIssue CAncer NETwork, CONTICANET) comparing costs and outcomes when clinicians adhered to CPGs and when they did not. METHODS: Patients studied had a histological diagnosis of sarcoma, were older than 15 years, and had been treated in the Rhone-Alpes region of France (in 2005/2006) or in the Veneto region of Italy (in 2007). Data collected retrospectively for the three years after diagnosis were used to determine relapse free survival and health costs (adopting the hospital's perspective and a microcosting approach). All costs were expressed in euros at their 2009 value. A 4% annual discount rate was applied to both costs and effects. The incremental cost-effectiveness ratio (ICER) was expressed as cost per relapse-free year gained when management was compliant with CPGs compared with when it was not. To capture uncertainty surrounding ICER, a probabilistic sensitivity analysis was performed based on a non-parametric bootstrap method. RESULTS: A total of 219 patients were included in the study. Compliance with CPGs was observed for 118 patients (54%). Average total costs reached 23,571 euros when treatment was in accordance with CPGs and 27,313 euros when it was not. In relation to relapse-free survival, compliance with CPGs strictly dominates non compliance, i.e. it is both less costly and more effective. Taking uncertainty into account, the probability that compliance with CPGs still strictly dominates was 75%. CONCLUSIONS: Our findings should encourage physicians to increase their compliance with CPGs and healthcare administrators to invest in the implementation of CPGs in the management of sarcoma

    Repositioning of the global epicentre of non-optimal cholesterol

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    High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe

    Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

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    Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks
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