208 research outputs found

    Mapping long-period soil resonances in the Kathmandu basin using microtremors

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    This study reports the geostatistical analysis of a set of 40 single-station horizontal-to-vertical spectral ratio (HVSR) passive seismic survey data collected in the Kathmandu basin (Nepal). The Kathmandu basin is characterized by a heterogeneous sedimentary cover and by a complex geo-structural setting, inducing a high spatial variability of the bedrock depth. Due to the complex geological setting, the interpretation and analysis of soil resonance periods derived from the HVSR surveys is challenging, both from the perspective of bedrock depth estimation as well as of seismic-site effects characterization. To exploit the available information, the HVSR data are analyzed by means of a geostatistical approach. First, the spatial continuity structure of HVSR data is investigated and interpreted taking into consideration the geological setting and available stratigraphic and seismic information. Then, the exploitation of potential auxiliary variables, based on surface morphology and distance from outcropping bedrock, is evaluated. Finally, the mapping of HVSR resonance periods, together with the evaluation of interpolation uncertainty, is obtained by means of kriging with external drift interpolation. This work contributes to the characterization of local seismic response of the Kathmandu basin. The resulting map of soil resonance periods is compatible with the results of preceding studies and it is characterized by a high spatial variability, even in areas with a deep bedrock and long resonance periods

    Nuova formulazione delle procedure per la stima dell’intensità macrosismica da dati epicentrali o da risentimenti in zone vicine

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    Vengono presentate nuove relazioni empiriche, definite per il territorio italiano, per la stima dell’intensità in un dato sito a partire da informazioni epicentrali o relative a località vicine. Queste relazioni, espresse in forma probabilistica e quindi direttamente utilizzabili per la stima della pericolosità sismica, condividono la stessa formalizzazione e la medesima base informativa. In particolare, sono state seguite tre diverse strategie: le prime due hanno portato alla definizione di una relazione di attenuazione per la stima dell’intensità al sito da dati epicentrali utilizzando una forma parametrica rispettivamente Gaussiana e Binomiale; la terza analisi è stata invece mirata a definire le modalità di “correzione” del valore locale di intensità, dedotto dalle informazioni epicentrali, con dati di risentimenti osservati in località vicine al sito in esame

    In Search of New Imaging For Historical Earthquakes: A New Geophysical Survey Offshore Western Calabria (Southern Tyrrhenian Sea, Italy)

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    During the summer of 2010 we carried out a survey to acquire a multidisciplinary dataset within the Gulf of Sant'Eufemia (SE Tyrrhenian sea, Italy), with the aim of studying the active tectonics affecting the region, including that potentially responsible for key, elusive earthquakes such as the to-date unexplained 8 September 1905 (Mw 7 - 7.5) earthquake. The data here analysed highlight the presence of several tectonic and morphologic features characterizing the investigated area. We have recognized the Angitola Channel, a deep and wide canyon showing a straight trend in its coastward segment, and a meandering trend in the seaward segment. Based on morpho-structural elements, we maintain that the Angitola Channel could be tectonically controlled. Moreover, several gravitational instabilities as slumps and collapses affect the flanks of the morpho-structural high, detected offshore Capo Vaticano. Very high resolution seismic data have unveiled the presence of numerous fluid escape features and several mud volcanoes straddling the sector from the coastline to seaward.INOGS (RIMA Department) supported the acquisition of the entire dataset.Published385-4013.2. Tettonica attivaJCR Journalrestricte

    Rapid COVID-19 screening based on self-reported symptoms: Psychometric assessment and validation of the EPICOVID19 short diagnostic scale

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    Background: Confirmed COVID-19 cases have been registered in more than 200 countries, and as of July 28, 2020, over 16 million cases have been reported to the World Health Organization. This study was conducted during the epidemic peak of COVID-19 in Italy. The early identification of individuals with suspected COVID-19 is critical in immediately quarantining such individuals. Although surveys are widely used for identifying COVID-19 cases, outcomes, and associated risks, no validated epidemiological tool exists for surveying SARS-CoV-2 infection in the general population. Objective: We evaluated the capability of self-reported symptoms in discriminating COVID-19 to identify individuals who need to undergo instrumental measurements. We defined and validated a method for identifying a cutoff score. Methods: Our study is phase II of the EPICOVID19 Italian national survey, which launched in April 2020 and included a convenience sample of 201,121 adults who completed the EPICOVID19 questionnaire. The Phase II questionnaire, which focused on the results of nasopharyngeal swab (NPS) and serological tests, was mailed to all subjects who previously underwent NPS tests. Results: Of 2703 subjects who completed the Phase II questionnaire, 694 (25.7%) were NPS positive. Of the 472 subjects who underwent the immunoglobulin G (IgG) test and 421 who underwent the immunoglobulin M test, 22.9% (108/472) and 11.6% (49/421) tested positive, respectively. Compared to NPS-negative subjects, NPS-positive subjects had a higher incidence of fever (421/694, 60.7% vs 391/2009, 19.5%; P<.001), loss of taste and smell (365/694, 52.6% vs 239/2009, 11.9%; P<.001), and cough (352/694, 50.7% vs 580/2009, 28.9%; P<.001). With regard to subjects who underwent serological tests, IgG-positive subjects had a higher incidence of fever (65/108, 60.2% vs 43/364, 11.8%; P<.001) and pain in muscles/bones/joints (73/108, 67.6% vs 71/364, 19.5%; P<.001) than IgG-negative subjects. An analysis of self-reported COVID-19 symptom items revealed a 1-factor solution, the EPICOVID19 diagnostic scale. The following optimal scores were identified: 1.03 for respiratory problems, 1.07 for chest pain, 0.97 for loss of taste and smell 0.97, and 1.05 for tachycardia (ie, heart palpitations). These were the most important symptoms. For adults aged 18-84 years, the cutoff score was 2.56 (sensitivity: 76.56%; specificity: 68.24%) for NPS-positive subjects and 2.59 (sensitivity: 80.37%; specificity: 80.17%) for IgG-positive subjects. For subjects aged ≥60 years, the cutoff score was 1.28, and accuracy based on the presence of IgG antibodies improved (sensitivity: 88.00%; specificity: 89.58%). Conclusions: We developed a short diagnostic scale to detect subjects with symptoms that were potentially associated with COVID-19 from a wide population. Our results support the potential of self-reported symptoms in identifying individuals who require immediate clinical evaluations. Although these results come from the Italian pandemic period, this short diagnostic scale could be optimized and tested as a screening tool for future similar pandemics

    Self-reported symptoms of SARS-CoV-2 infection in a non-hospitalized population : results from the large Italian web-based EPICOVID19 cross-sectional survey. (Preprint)

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    Background: Understanding the occurrence of Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2)-like symptoms in a large non-hospitalized population, when the epidemic peak was occurring in Italy, is of paramount importance but data are scarce. Objective: Aims of this study were to evaluate the association of self-reported symptoms with SARS-CoV-2 nasopharyngeal swab (NPS) test in non-hospitalized individuals and to estimate the occurrence of COVID-19-like symptoms in a larger non-tested population. Methods: This is an Italian countrywide self-administered cross-sectional web-based survey on voluntary adults who completed an anonymous questionnaire in the period 13-21 April 2020. The associations between symptoms potentially related to SARS-CoV-2 infection and NPS results were calculated as adjusted odds ratios with 95% confidence intervals (aOR, 95%CI) by means of multiple logistic regression analysis controlling for age, sex, education, smoking habits, and the number of co-morbidities. Thereafter, for each symptom and for their combination, we calculated sensitivity, specificity, accuracy and AUC in a ROC analysis to estimate the occurrence of COVID-19-like infections in the non-tested population. Results: A total of 171,310 responded to the survey (59.9% females, mean age 47.4 years). Out of the 4,785 respondents with known NPS test result, 4,392 were not hospitalized. Among them, the NPS positive respondents (n=856) most frequently reported myalgia (61.6%), olfactory and/or taste disorders (OTDs, 59.2%), cough (54.4%), and fever (51.9%) whereas 7.7% were asymptomatic. Multiple regression analysis showed that OTDs (aOR 10.3, [95%CI 8.4-12.7]), fever (2.5, 95%CI 2.0-3.1), myalgia (1.5, 95%CI 1.2-1.8), and cough (1.3, 95%CI 1.0-1.6) were associated with NPS positivity. Having two to four of these symptoms increased the aOR from 7.4 (95%CI, 5.6-9.7) to 35.5 (95%CI, 24.6-52.2). The combination of the four symptoms showed an AUC of 0.810 (95%CI 0.795-0.825) in classifying NPS-P, and was applied to the non-hospitalized and non-tested sample (n=165,782). We found that from 4.4% to 12.1% of respondents had experienced symptoms suggestive of COVID-19 infection. Conclusions: Our results suggest that self-reported symptoms may be reliable indicators of SARS-CoV-2 infection in a pandemic context. A not negligible part (up to 12.1%) of the symptomatic respondents were left undiagnosed and potentially contributed to the spread of the infection

    Assessment of the application for renewal of the authorisation of PHYZYME® XP 10000 TPT/L (6-phytase) as a feed additive for all avian species and all swine species

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    PHYZYME\uae XP 10000 TPT/L is a feed additive that contains 6-phytase produced by a genetically modified strain of Schizosaccharomyces pombe. The applicant requested for the renewal of the authorisation for PHYZYME\uae XP 10000 TPT and L to be used as a feed additive for avian species for fattening/laying, weaned piglets, pigs for fattening and sows and for an extension of use to avian species reared for laying/breeding, suckling piglets and minor porcine species. To support the request or the renewal of the authorisation, the applicant provided evidence that the additive in the market complies with the conditions of the authorisation. According to the information provided by the applicant, no new evidence has been identified that would make the FEEDAP Panel reconsider the previous conclusions regarding the safety for the target species, consumer, user and environment. The application for renewal of the authorisation did not include a proposal for amending the conditions of use in those species for which an authorisation exists that would have an impact on the efficacy of the additive. Therefore, there was no need for assessing the efficacy of the additive in the context of the renewal of the authorisation. Regarding the new species/categories, the Panel concluded that the additive is safe and has a potential to be efficacious in avian species reared for laying/breeding at 250 FTU/kg feed and for suckling piglets and minor porcine species at 500 FTU/kg feed

    Safety and efficacy of a feed additive consisting of β-mannanase produced by Aspergillus niger CBS 120604 (Nutrixtend Optim) for use in all poultry for fattening (Kerry Ingredients & Flavours Ltd)

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    Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of a product containing beta-mannanase produced by a non-genetically modified strain of Aspergillus niger (CBS 120604). The commercial name is Nutrixtend Optim and it is intended to be used as a zootechnical feed additive for all poultry for fattening. Based on a tolerance trial in chickens for fattening and the no observed adverse effect level identified in a subchronic oral toxicity study in rats, the additive was considered safe for all poultry for fattening. The Panel concluded that the use of the product as a feed additive does not give rise to concerns for consumers and the environment. The additive is considered an irritant to skin and eyes and a dermal sensitiser. Due to the proteinaceous nature of the active substance, it is also considered a respiratory sensitiser. The Panel concludes that the additive has the potential to be efficacious as a zootechnical additive at the level of inclusion in feed of chickens for fattening of 30 U beta-mannanase/kg complete feed. This conclusion was extrapolated to all poultry for fattening. (c) 2023 European Food Safety Authority. EFSA Journal published by Wiley-VCH GmbH on behalf of European Food Safety Authority
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