Strong solar flare events can occur even during the decay phase of the solar cycle. During these events concurrent increases in the X‐ray and Enhanced UV (EUV) fluxes and solar radio bursts (SRBs) ...can be observed. The SRBs cover a large range of frequencies including the L band, giving rise to signal fades in the GNSS carrier‐to‐noise ratio and fluctuations in its amplitude and phase. The increases in the X‐ray, UV, and EUV fluxes cause increase in the ionospheric D, E, and F region electron densities. The aim of this work is to analyze the effects in the GNSS signal, in the ionosphere and in the magnetic field H component of the X9.3 and X1.3 solar flares that occurred on 06 and 07 September 2017, respectively. Data from a network of six GNSS receivers, two magnetometers, and four Digisondes are used in the analysis. Fades of about 5 and 10 dB were observed in the signals of GNSS L1 and L2/L5 frequencies, respectively. Significant positioning errors, were observed for the strongest X9.3 flare. A sudden increase in Total Electron Content with the rates of 2.5–5.0 TECU/min was observed. An increase in the E layer density gave origin to an increase in the Equatorial Electrojet intensity, whose signatures were observed in the H component of two magnetometers. Another observed effect was the ionospheric D region density increase that caused disruption in the Digisonde signal. As a consequence of the described effects, GNSS receivers may fail to produce accurate navigation solution.
Key Points
Effects in the GNSS signal, in the ionosphere and in the magnetic field H component of the September 2017 X9.3 and X1.3 solar flares
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
MicroRNAs (miRNAs) recently emerged with a key role in multiple myeloma (MM) pathophysiology and are considered important regulators of MM cell growth and survival. Since miRNAs can act either as ...oncogenes or tumour suppressors, the potential of targeting the miRNA network arises as a novel therapeutic approach for human cancer. Potential strategies based on miRNA therapeutics basically rely on miRNA inhibition or miRNA replacement approaches and take benefit respectively from the use of antagomirs or synthetic miRNAs as well as from lipid-based nanoparticles which allow an efficient miRNA-delivery. The availability of experimental in vivo platforms which recapitulate the growth of MM cells within the specific human bone marrow microenvironment in immunocompromised mice (SCID-hu and SCID-synth-hu) provides powerful systems for development of miRNA-based therapeutics in MM. Preliminary findings on the anti-MM activity of synthetic miRNAs in such experimental models offer a proof-of-principle that miRNA therapeutics is a promising opportunity for this still incurable disease representing the rationale for a new venue of investigation in this specific field.
The availability of computer tools able to describe the behavior of pyroclastic density currents (PDCs) with uncertainty quantification is of primary importance for the assessment of volcanic hazard. ...A common strategy to assess the intrinsic variability of these phenomena is based on the analysis of large sets of numerical simulations with variable input parameters. The use of models fast enough to allow for a large number of simulations, such as the so-called kinetic energy models, is thus advantageous. Due to the sensitivity of kinetic energy models to poorly constrained input parameters, the definition of their variation ranges is a critical step in the construction of hazard maps and a numerical calibration becomes necessary. We present a set of reproducible and structured calibration procedures of numerical models based either on a reference deposit or on the distribution of runout distance or inundation area of documented PDCs. In the first case, various metrics can be adopted to compare the model results with the reference PDC deposit (root mean square distance, Hausdorff distance, and Jaccard index), facilitating the development of scenario-based hazard assessments. Calibrations based on the distribution of runout distance or inundation area allow the construction of probabilistic hazard maps that are not conditioned on the occurrence of a specific scenario, but rather reflect the variability of the documented PDCs during the time window considered. Importantly, our calibration strategies allow one to set the input parameters considering their potential statistical dependence. These procedures have been implemented on the user-friendly versions of two kinetic energy models: ECMapProb 2.0 and BoxMapProb 2.0, whose functionalities are presented for the first time in this paper. The different calibration strategies and the functionalities of the two programs are illustrated by considering three case studies: El Misti (Peru), Merapi (Indonesia), and Campi Flegrei (Italy).
Highlights
• We present a set of structured and reproducible strategies to calibrate PDC numerical models.
• We implement these calibration strategies on two user-friendly kinetic energy models: ECMapProb 2.0 and BoxMapProb 2.0.
• These calibration strategies reduce the biases derived from user choices in the construction of hazard maps.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this paper a commutative watermarking and ciphering scheme for digital images is presented. The commutative property of the proposed method allows to cipher a watermarked image without interfering ...with the embedded signal or to watermark an encrypted image still allowing a perfect deciphering. Both operations are performed on a parametric transform domain: the Tree Structured Haar transform. The key dependence of the adopted transform domain increases the security of the overall system. In fact, without the knowledge of the generating key it is not possible to extract any useful information from the ciphered-watermarked image. Experimental results show the effectiveness of the proposed scheme.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Radon exposure is the second leading risk factor for lung cancer among smokers and the leading risk factor among non‐smokers. Radon concentrated in lower levels of homes/buildings can be reduced if ...found, thus lowering lung cancer risk. The objective of this study was to measure radon knowledge in diverse populations, with varying radon‐related laws, to inform radon‐related cancer control practices and activities. A survey was mailed to 3000 homebuyers who purchased single‐family homes; 995 responses (33%) were received. Overall, 86% of respondents heard of radon‐related health issues. Real estate agents (69%) or home inspectors (65%) were the most common sources of information. Respondents were more likely to test their home for radon if they reported previously hearing of radon‐related health issues or understanding of how radon‐related health issues affect the home‐buying process. Respondents in states with notification policies were twice as likely as those without policies to have heard about radon‐related health issues (OR 2.01, 95% CI: 1.27‐3.17). This study provides useful information for cancer control activities including that education is positively associated with home testing for radon. It also suggests partnering with real estate agents to further radon education and testing efforts to reduce radon exposure and lung cancer risk.
Full text
Available for:
DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Explosive volcanic eruptions comprise a complex series of processes involving withdrawal from the magma chamber, magma ascent along the conduit and eruption column dynamics. Numerous studies have ...modeled the different sub-domains of a volcanic system, but their interplay has seldom been analyzed. To this end, we developed C3 (C-cubed, that stands for Chamber, Conduit and Column), a new integrated model that describes the dynamics of an explosive eruption as a series of steady state regimes and as a function of geometry and initial conditions of the magma reservoir. We used Global Sensitivity Analysis to quantify the role of the relevant model parameters and describe the interplay between the different volcanic sub-domains. In particular, we analyzed the evolution of a sustained explosive eruption in order to identify the conditions for buoyant, super-buoyant and collapsing columns. Input data were based on field reconstructions of Quaternary explosive eruptions in the Vulsini Volcanic District (Roman Province, central Italy). Model results show that: 1) the column regime, although affected by complex interactions among several factors, mostly depends on the conduit radius, the volatile content (i.e. supersaturation concentration at the top of the chamber) and length of the conduit, in decreasing level of importance; 2) the amount of mass erupted is independent of the conduit radius and depends mostly on volatile supersaturation, the radius of the magma chamber, the length of the conduit and the overpressure at the conduit inlet; 3) the mass flow-rate, column height and duration of the eruption are largely controlled by the conduit radius; 4) the flow pressure and density at the conduit exit are mostly controlled by the conduit inlet overpressure at the onset of the eruption, and by the length of the conduit at the end of the eruption; 5) the exit velocity from the conduit is mostly controlled by the volatile content, the length of the conduit and the inlet overpressure. In this model framework, and with specific reference to selected Plinian events of the Vulsini Volcanic District, simulation results show that column collapse is not achieved for reasonable eruption durations (order of hours) and conduit widths (tens of meters). This is consistent with field reconstructions suggesting that column collapse did not likely occur and that pyroclastic flows were therefore generated by independent mechanisms from ring fissures and/or multiple vents concomitant to caldera collapse.
•We present a newly developed code, C3 (C-cubed) of the entire volcanic system.•We analyze the model's sensitivity to the different system input parameters.•We present an application to explosive eruptions of the Vulsini Volcanic District.•Results show that column collapse is not achieved for reasonable conditions.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Background
Prevalence of frailty is significant in Latin America. However, no previous study evaluated mortality prediction using the two most used frailty models in Brazil.
Objectives
The aim of the ...present study was to compare the frailty phenotype and the frailty index with regard to accuracy in the prediction of mortality among community-dwelling older adults.
Methods
A cohort study was conducted involving 674 older adults. Thirty-five variables (signs, symptoms, chronic diseases and disabilities) were used for the construction of the frailty index (FI). The frailty phenotype index (FPI) was defined based on the criteria proposed in the Cardiovascular Health Study. Periodic verifications were performed in the databank of the Mortality Information System. Cox regression was used to estimate the relative risk (RR) of mortality and Kaplan-Meier survival curves were used in the analysis.
Results
The prevalence of frailty was greater based using the FI (16.3%) compared to the FPI (5.34%). Older adults classified as frail by the FPI had a greater risk of death (RR: 10.03; 95% CI: 4.43–22.74) that those classified as frail by the FI (RR: 0.87; 95% CI: 0.25–3.00). The lowest survival rate was found in the group of older adults classified as frail based on the FPI and classified as pre-frail and robust based on the FI.
Conclusion
The FPI demonstrated greater accuracy in predicting the risk of mortality among Brazilian older adults than the FI. The validation of frailty measures is fundamental to the identification of older adults who are more vulnerable to adverse health events.
Cast iron street furniture: A historical review Soffritti, C.; Calzolari, L.; Chicca, M. ...
Endeavour (New series),
September 2020, 2020-Sep, 2020-09-00, 20200901, Volume:
44, Issue:
3
Journal Article
Peer reviewed
•Street furniture in cast iron for improving the quality of life in urban settlements.•Diffusion of street furniture in relation to the First Industrial Revolution.•Artistic, aesthetic and ethical ...issues, and historical catalogues.•Local aspects of street furniture in United Kingdom, France and Italy.•Production technique and preservation of street furniture.
The term “street furniture” indicates objects mostly made of cast iron alloys and aimed to improve the quality of life in urban settlements, such as street lamps, fountains and gazebos. These objects are often ancient and relevant as cultural heritage. Despite the constant presence of street furniture in urban settlements, studies of its evolution along centuries are limited. Since functional aspects have been often considered prevalent against artistic and historical values, many objects have been considered obsolete, thus replaced or re-melted. Street furniture rarely received attention by scholars, and studies on this topic have been often incomplete.
This study reviews the history of street furniture made of cast iron (CI street furniture), first examining the reasons behind the choice of this material, closely related to its diffusion during the First Industrial Revolution. The review discusses the relationship between CI street furniture and cultural heritage based on artistic, aesthetic and ethical issues, also examining historical catalogs. The development of CI street furniture in United Kingdom, France and Italy is reported, together with their local aspects. The production technique is discussed and the importance of preservation of CI street furniture is highlighted, emphasizing the need for globally planned interventions in this field.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The dynamics of effusive events is controlled by the interplay between conduit geometry and source conditions. Dyke‐like geometries have been traditionally assumed for describing conduits during ...effusive eruptions, but their depth‐dependent and temporal modifications are largely unknown. We present a novel model which describes the evolution of conduit geometry during effusive eruptions by using a quasi steady state approach based on a 1‐D conduit model and appropriate criteria for describing fluid shear stress and elastic deformation. This approach provides time‐dependent trends for effusion rate, conduit geometry, exit velocity, and gas flow. Fluid shear stress leads to upward widening conduits, whereas elastic deformation becomes relevant only during final phases of effusive eruptions. Simulations can reproduce different trends of effusion rate, showing the effect of magma source conditions and country rock properties on the eruptive dynamics. This model can be potentially applied for data inversion in order to study specific case studies.
Plain Language Summary
The dynamics of effusive eruptions is controlled by the interplay between the feeding conduit geometry and magma chamber conditions. Dyke‐like geometries have been traditionally assumed for describing conduits of effusive eruptions, but their depth‐dependent and temporal modifications are largely unknown. Conduit geometry is controlled by fluid shear stress and pressure‐driven elastic deformation, which depend on magma and host rock properties. Here we present a novel model for studying the temporal evolution of effusive eruptions, using a steady‐state conduit model and appropriate criteria for describing the temporal evolution of conduit geometry. Model inputs are related to host rock properties, magma source conditions, and some additional equations for describing the ascending magma behavior. The model provides time‐dependent trends for effusion rate, conduit geometry, exit velocity, and gas flow. Because of the typical magma viscosity and velocity profiles along the conduit, they tend to produce higher erosion rates near the vent, giving place to upward widening conduits. Simulations are compatible with the erosion rates estimated for natural cases and are able to reproduce different curves of effusion rate. This model can be potentially applied for data inversion in order to study magma reservoir dynamics and conduit geometry evolution during specific case studies.
Key Points
Temporal evolution of conduit geometry is modeled by the effects of fluid shear stress and elastic deformation
Numerical modeling of conduit dynamics is coupled with appropriate criteria for addressing the temporal variations of the feeding system
We study the controlling factors of effusion rate curves during basaltic effusive eruptions
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this paper a new integral mathematical model for volcanic plumes, named PLUME-MoM, is presented. The model describes the steady-state dynamics of a plume in a 3-D coordinate system, accounting for ...continuous variability in particle size distribution of the pyroclastic mixture ejected at the vent. Volcanic plumes are composed of pyroclastic particles of many different sizes ranging from a few microns up to several centimeters and more. A proper description of such a multi-particle nature is crucial when quantifying changes in grain-size distribution along the plume and, therefore, for better characterization of source conditions of ash dispersal models. The new model is based on the method of moments, which allows for a description of the pyroclastic mixture dynamics not only in the spatial domain but also in the space of parameters of the continuous size distribution of the particles. This is achieved by formulation of fundamental transport equations for the multi-particle mixture with respect to the different moments of the grain-size distribution. Different formulations, in terms of the distribution of the particle number, as well as of the mass distribution expressed in terms of the Krumbein log scale, are also derived. Comparison between the new moments-based formulation and the classical approach, based on the discretization of the mixture in N discrete phases, shows that the new model allows for the same results to be obtained with a significantly lower computational cost (particularly when a large number of discrete phases is adopted). Application of the new model, coupled with uncertainty quantification and global sensitivity analyses, enables the investigation of the response of four key output variables (mean and standard deviation of the grain-size distribution at the top of the plume, plume height and amount of mass lost by the plume during the ascent) to changes in the main input parameters (mean and standard deviation) characterizing the pyroclastic mixture at the base of the plume. Results show that, for the range of parameters investigated and without considering interparticle processes such as aggregation or comminution, the grain-size distribution at the top of the plume is remarkably similar to that at the base and that the plume height is only weakly affected by the parameters of the grain distribution. The adopted approach can be potentially extended to the consideration of key particle–particle effects occurring in the plume including particle aggregation and fragmentation.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
PDF
