Assessing the Multiple Pressure Source Hypothesis for the Sakurajima Volcano and Aira Caldera Magmatic System

Mapping Intimacies ◽

10.5194/egusphere-egu21-14799 ◽

2021 ◽

Author(s):

Robert Backhurst

Keyword(s):

Numerical Modelling ◽

Large Scale ◽

Numerical Study ◽

Deformation Source ◽

Geodetic Data ◽

Analytical Models ◽

Magmatic System ◽

Sakurajima Volcano ◽

Subsurface Heterogeneity ◽

Increased Risk

Sakurajima, located on the southern rim of Aira caldera, is one of the most active volcanoes in Japan. From long term deformation trends, the volcano is showing an increased risk of large-scale eruption, emphasizing the need to better understand the magmatic system.Deformation modelling, primarily using the Mogi method, has dominated the geodetic assessment history of Sakurajima. These methods, however, contain limitations, such as the assumption of a homogeneous crust, and have therefore not accurately depicted the magmatic system. Numerical modelling techniques have reduced this limitation by accounting for subsurface heterogeneity.Analytical modelling studies have suggested multiple magmatic sources beneath Aira caldera and Sakurajima volcano, whilst the only numerical study undertaken so far indicated a single source. Here, we test the multiple deformation source hypothesis, whilst also incorporating subsurface heterogeneity and topography, using Finite Element (FE) numerical modelling, and geodetic data from Sakurajima.Using a full 3D model geometry for Sakurajima and Aira caldera, preliminary forward modelling suggests a second deformation source produces our best fit to the measured geodetic data. Optimum results indicate a shallow prolate source 7-10 km below sea level (bsl), in addition to a deeper oblate source at ~13 km bsl. These preliminary findings produce greater shallow storage depths than the previous analytical models (3-6 km) and ties in with the trans-crustal magmatic system hypothesis.Increasing our understanding of the Sakurajima magmatic system will enable improved interpretations of geodetic data prior to eruptions and will inform models for a range of similar volcanoes world-wide.

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Variable inflation rate of a magmatic deformation source beneath Aira caldera after the 1914 eruption of Sakurajima volcano: Inferences from a linear Maxwell viscoelastic model constrained by geodetic data

Journal of Volcanology and Geothermal Research ◽

10.1016/j.jvolgeores.2021.107446 ◽

2021 ◽

pp. 107446

Author(s):

Tadashi Yamasaki ◽

Freysteinn Sigmundsson ◽

Masato Iguchi

Keyword(s):

Inflation Rate ◽

Viscoelastic Model ◽

Deformation Source ◽

Geodetic Data ◽

Sakurajima Volcano

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Study of Biochemical and Clinical Markers in Steatohepatitis Related to Obesity

Revista de Chimie ◽

10.37358/rc.18.6.6355 ◽

2018 ◽

Vol 69 (6) ◽

pp. 1501-1505

Author(s):

Roxana Maria Livadariu ◽

Radu Danila ◽

Lidia Ionescu ◽

Delia Ciobanu ◽

Daniel Timofte

Keyword(s):

Liver Disease ◽

Liver Biopsy ◽

Large Scale ◽

Biological Data ◽

Obese Patients ◽

Clinical Markers ◽

Mean Values ◽

Nonalcoholic Fatty Liver ◽

Obstructive Sleep ◽

Increased Risk

Nonalcoholic fatty liver disease (NAFLD) is highly associated to obesity and comprises several liver diseases, from simple steatosis to steatohepatitis (NASH) with increased risk of developing progressive liver fibrosis, cirrhosis and hepatocellular carcinoma. Liver biopsy is the gold standard in diagnosing the disease, but it cannot be used in a large scale. The aim of the study was the assessment of some non-invasive clinical and biological markers in relation to the progressive forms of NAFLD. We performed a prospective study on 64 obese patients successively hospitalised for bariatric surgery in our Surgical Unit. Patients with history of alcohol consumption, chronic hepatitis B or C, other chronic liver disease or patients undergoing hepatotoxic drug use were excluded. All patients underwent liver biopsy during sleeve gastrectomy. NAFLD was present in 100% of the patients: hepatic steatosis (38%), NASH with the two forms: with fibrosis (31%) and without fibrosis (20%), cumulating 51%; 7 patients had NASH with vanished steatosis. NASH with fibrosis statistically correlated with metabolic syndrome (p = 0.036), DM II (p = 0.01) and obstructive sleep apnea (p = 0.02). Waist circumference was significantly higher in the steatohepatitis groups (both with and without fibrosis), each 10 cm increase increasing the risk of steatohepatitis (p = 0.007). The mean values of serum fibrinogen and CRP were significantly higher in patients having the progressive forms of NAFLD. Simple clinical and biological data available to the practitioner in medicine can be used to identify obese patients at high risk of NASH, aiming to direct them to specialized medical centers.

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Should all Hypertensive Patients be Screened for Primary Aldosteronism?

Current Hypertension Reviews ◽

10.2174/1573402114666180507153549 ◽

2019 ◽

Vol 15 (1) ◽

pp. 54-56

Author(s):

Stelina Alkagiet ◽

Konstantinos Tziomalos

Keyword(s):

Resistant Hypertension ◽

Primary Aldosteronism ◽

Large Scale ◽

Controlled Trial ◽

The Other ◽

Limited Data ◽

Hypertensive Patients ◽

Randomized Controlled ◽

Increased Risk ◽

Prospective Randomized Controlled Trial

Primary aldosteronism (PA) is not only a leading cause of secondary and resistant hypertension, but is also quite frequent in unselected hypertensive patients. Moreover, PA is associated with increased cardiovascular risk, which is disproportionate to BP levels. In addition, timely diagnosis of PA and prompt initiation of treatment attenuate this increased risk. On the other hand, there are limited data regarding the usefulness of screening for PA in all asymptomatic or normokalemic hypertensive patients. More importantly, until now, no well-organized, large-scale, prospective, randomized controlled trial has proved the effectiveness of screening for PA for improving clinical outcome. Accordingly, until more relevant data are available, screening for PA should be considered in hypertensive patients with spontaneous or diuretic-induced hypokalemia as well as in those with resistant hypertension. However, screening for PA in all hypertensive patients cannot be currently recommended.

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Interaction of Very Large Scale Motion of Coherent Structures with Sediment Particle Exposure

Water ◽

10.3390/w13030248 ◽

2021 ◽

Vol 13 (3) ◽

pp. 248

Author(s):

Sencer Yücesan ◽

Daniel Wildt ◽

Philipp Gmeiner ◽

Johannes Schobesberger ◽

Christoph Hauer ◽

...

Keyword(s):

Coherent Structures ◽

Large Scale ◽

Numerical Study ◽

Local Maximum ◽

Wave Number ◽

Exposure Level ◽

Sediment Particle ◽

High Wave Number ◽

Large Scale Motion ◽

Scale Motion

A systematic variation of the exposure level of a spherical particle in an array of multiple spheres in a high Reynolds number turbulent open-channel flow regime was investigated while using the Large Eddy Simulation method. Our numerical study analysed hydrodynamic conditions of a sediment particle based on three different channel configurations, from full exposure to zero exposure level. Premultiplied spectrum analysis revealed that the effect of very-large-scale motion of coherent structures on the lift force on a fully exposed particle resulted in a bi-modal distribution with a weak low wave number and a local maximum of a high wave number. Lower exposure levels were found to exhibit a uni-modal distribution.

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COVID-19 and Its Symptoms’ Panoply: A Case-Control Study of 919 Suspected Cases in Locked-Down Ovar, Portugal

Portuguese Journal of Public Health ◽

10.1159/000514925 ◽

2021 ◽

pp. 1-8

Author(s):

Regina Sá ◽

Tiago Pinho-Bandeira ◽

Guilherme Queiroz ◽

Joana Matos ◽

João Duarte Ferreira ◽

...

Keyword(s):

Large Scale ◽

Case Control Study ◽

Statistical Significance ◽

Case Control ◽

Case Definition ◽

Suspected Case ◽

Risk Characteristics ◽

Increased Risk ◽

Wide Range ◽

Control Study

Background: Ovar was the first Portuguese municipality to declare active community transmission of SARS-CoV-2, with total lockdown decreed on March 17, 2020. This context provided conditions for a large-scale testing strategy, allowing a referral system considering other symptoms besides the ones that were part of the case definition (fever, cough, and dyspnea). This study aims to identify other symptoms associated with COVID-19 since it may clarify the pre-test probability of the occurrence of the disease. Methods: This case-control study uses primary care registers between March 29 and May 10, 2020 in Ovar municipality. Pre-test clinical and exposure-risk characteristics, reported by physicians, were collected through a form, and linked with their laboratory result. Results: The study population included a total of 919 patients, of whom 226 (24.6%) were COVID-19 cases and 693 were negative for SARS-CoV-2. Only 27.1% of the patients reporting contact with a confirmed or suspected case tested positive. In the multivariate analysis, statistical significance was obtained for headaches (OR 0.558), odynophagia (OR 0.273), anosmia (OR 2.360), and other symptoms (OR 2.157). The interaction of anosmia and odynophagia appeared as possibly relevant with a borderline statistically significant OR of 3.375. Conclusion: COVID-19 has a wide range of symptoms. Of the myriad described, the present study highlights anosmia itself and calls for additional studies on the interaction between anosmia and odynophagia. Headaches and odynophagia by themselves are not associated with an increased risk for the disease. These findings may help clinicians in deciding when to test, especially when other diseases with similar symptoms are more prevalent, namely in winter.

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The association between XRCC3 rs1799794 polymorphism and cancer risk: a meta-analysis of 34 case–control studies

BMC Medical Genomics ◽

10.1186/s12920-021-00965-4 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Weiqing Liu ◽

Shumin Ma ◽

Lei Liang ◽

Zhiyong Kou ◽

Hongbin Zhang ◽

...

Keyword(s):

Breast Cancer ◽

Ovarian Cancer ◽

Thyroid Cancer ◽

Cancer Risk ◽

Large Scale ◽

Meta Analysis ◽

Cochrane Library ◽

Cancer Type ◽

Increased Risk ◽

Risk Of Cancer

Abstract Background Studies on the XRCC3 rs1799794 polymorphism show that this polymorphism is involved in a variety of cancers, but its specific relationships or effects are not consistent. The purpose of this meta-analysis was to investigate the association between rs1799794 polymorphism and susceptibility to cancer. Methods PubMed, Embase, the Cochrane Library, Web of Science, and Scopus were searched for eligible studies through June 11, 2019. All analyses were performed with Stata 14.0. Subgroup analyses were performed by cancer type, ethnicity, source of control, and detection method. A total of 37 studies with 23,537 cases and 30,649 controls were included in this meta-analysis. Results XRCC3 rs1799794 increased cancer risk in the dominant model and heterozygous model (GG + AG vs. AA: odds ratio [OR] = 1.04, 95% confidence interval [CI] = 1.00–1.08, P = 0.051; AG vs. AA: OR = 1.05, 95% CI = 1.00–1.01, P = 0.015). The existence of rs1799794 increased the risk of breast cancer and thyroid cancer, but reduced the risk of ovarian cancer. In addition, rs1799794 increased the risk of cancer in the Caucasian population. Conclusion This meta-analysis confirms that XRCC3 rs1799794 is related to cancer risk, especially increased risk for breast cancer and thyroid cancer and reduced risk for ovarian cancer. However, well-designed large-scale studies are required to further evaluate the results.

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Opportunistic Large Array Propagation Models: A Comprehensive Survey

Sensors ◽

10.3390/s21124206 ◽

2021 ◽

Vol 21 (12) ◽

pp. 4206

Author(s):

Farhan Nawaz ◽

Hemant Kumar ◽

Syed Ali Hassan ◽

Haejoon Jung

Keyword(s):

Energy Efficient ◽

Large Scale ◽

Performance Metrics ◽

Experimental Studies ◽

Cooperative Transmission ◽

Analytical Models ◽

Future Research ◽

Large Array ◽

Propagation Models ◽

Comprehensive Survey

Enabled by the fifth-generation (5G) and beyond 5G communications, large-scale deployments of Internet-of-Things (IoT) networks are expected in various application fields to handle massive machine-type communication (mMTC) services. Device-to-device (D2D) communications can be an effective solution in massive IoT networks to overcome the inherent hardware limitations of small devices. In such D2D scenarios, given that a receiver can benefit from the signal-to-noise-ratio (SNR) advantage through diversity and array gains, cooperative transmission (CT) can be employed, so that multiple IoT nodes can create a virtual antenna array. In particular, Opportunistic Large Array (OLA), which is one type of CT technique, is known to provide fast, energy-efficient, and reliable broadcasting and unicasting without prior coordination, which can be exploited in future mMTC applications. However, OLA-based protocol design and operation are subject to network models to characterize the propagation behavior and evaluate the performance. Further, it has been shown through some experimental studies that the most widely-used model in prior studies on OLA is not accurate for networks with networks with low node density. Therefore, stochastic models using quasi-stationary Markov chain are introduced, which are more complex but more exact to estimate the key performance metrics of the OLA transmissions in practice. Considering the fact that such propagation models should be selected carefully depending on system parameters such as network topology and channel environments, we provide a comprehensive survey on the analytical models and framework of the OLA propagation in the literature, which is not available in the existing survey papers on OLA protocols. In addition, we introduce energy-efficient OLA techniques, which are of paramount importance in energy-limited IoT networks. Furthermore, we discuss future research directions to combine OLA with emerging technologies.

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A numerical study of the transition of jet diffusion flames

Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences ◽

10.1098/rspa.1990.0132 ◽

1990 ◽

Vol 431 (1882) ◽

pp. 301-314 ◽

Cited By ~ 29

Keyword(s):

Reynolds Number ◽

Diffusion Coefficient ◽

Large Scale ◽

Numerical Study ◽

Small Scale ◽

Surface Model ◽

Flame Surface ◽

Transition Mechanism ◽

Air Stream ◽

Scale Fluctuation

A numerical study on the transition from laminar to turbulent of two-dimensional fuel jet flames developed in a co-flowing air stream was made by adopting the flame surface model of infinite chemical reaction rate and unit Lewis number. The time dependent compressible Navier–Stokes equation was solved numerically with the equation for coupling function by using a finite difference method. The temperature-dependence of viscosity and diffusion coefficient were taken into account so as to study effects of increases of these coefficients on the transition. The numerical calculation was done for the case when methane is injected into a co-flowing air stream with variable injection Reynolds number up to 2500. When the Reynolds number was smaller than 1000 the flame, as well as the flow, remained laminar in the calculated domain. As the Reynolds number was increased above this value, a transition point appeared along the flame, downstream of which the flame and flow began to fluctuate. Two kinds of fluctuations were observed, a small scale fluctuation near the jet axis and a large scale fluctuation outside the flame surface, both of the same origin, due to the Kelvin–Helmholtz instability. The radial distributions of density and transport coefficients were found to play dominant roles in this instability, and hence in the transition mechanism. The decreased density in the flame accelerated the instability, while the increase in viscosity had a stabilizing effect. However, the most important effect was the increase in diffusion coefficient. The increase shifted the flame surface, where the large density decrease occurs, outside the shear layer of the jet and produced a thick viscous layer surrounding the jet which effectively suppressed the instability.

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