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Schumann resonances' statistical parameters vary over time, which gives way to analyze them as a stochastic process. By splitting the Schumann resonance's records into segments and obtaining their empirical distribution function, the differences can be evaluated by calculating the Kolmogorov–Smirnov distance between them. The analysis' results allow for the characterization of the Schumann resonance's variations, along with the typical values it reaches under the chosen metric. It is shown how divergence is mitigated through sample averaging, and also how divergent samples impact on the Fast Fourier Transform algorithm. Divergence quantification adds a layer of information for data processing. Knowing the changes experienced over time in Schumann resonances gives a way to know what kind of mathematical procedures can be applied to the signal. Quantification of signal variations over time can identify error sources in specific procedures, filter out samples unfit under certain analyses, or serve as a stop criteria for cumulative analyses. • Schumann Resonances' temporal segments compared with Kolmogorov–Smirnov distance. • Flexible methodology to compare segments of different duration allowing overlap. • Methodology tested over real data, showing relationship with lightning activity. • Kolmogorov–Smirnov distance as support for further analysis procedures discussed. [ABSTRACT FROM AUTHOR]

The frequencies between the ELF, ULF and VLF bands are widely used as indicators of the electrical activity in the atmosphere, as precursors of seismic activity and are of interest in the study of geophysical phenomena. These signal methods of analysis are varied, and among them, we find a method of averaged periodograms, which is based on the Fast Fourier Transform (FFT). In this type of analysis, the optimal number of segments to be averaged must be determined; however, there seems to be no satisfactory method for choosing them. In this paper, we provide a method that will allow us to select the optimal number of segments to be averaged. [ABSTRACT FROM AUTHOR]

The South Shetland Islands archipelago is dynamically complex due to its tectonic surroundings. Most islands are part of a formerly active volcanic arc, although Deception, Penguin and Bridgeman Islands, as well as several submarine volcanoes, are characterized by active back-arc volcanism. Geodetic benchmarks were deployed and the movement of the lithosphere to which they were fixed measured to provide geodynamic insight for the South Shetland Islands, Bransfield Basin and Antarctic Peninsula area based on surface deformation. These benchmarks' data add spatial and temporal coverage to previous results. The results reveal two different geodynamic patterns, each confined to a distinct part of the South Shetland Islands archipelago. The inferred absolute horizontal velocity vectors for the benchmarks in the northeastern part of the archipelago are consistent with the opening of the Bransfield Basin, while benchmark vectors in the southwestern part of the archipelago are similar to those of the benchmarks on the Antarctic Peninsula. In between, Snow, Deception and Livingston Islands represent a transition zone. In this area, the horizontal velocity vectors relative to the Antarctic plate shift northeastwards from N to NW. Furthermore, the South Shetland Islands benchmarks, except for that at Gibbs (Elephant) Islands, indicate subsidence, which might be a consequence of the slab roll-back at the South Shetland Trench. In contrast, the uplift revealed by the Antarctic Peninsula benchmarks suggests glacial isostatic adjustment after the Larson B ice-shelf breakup. [ABSTRACT FROM AUTHOR]

Background Post-treatment contralateral hemiliver hypertrophy has created an interest in lobar liver radioembolization (RE) as a pre-surgery tool. Methods Liver and spleen volumes and function were studied in 83 patients submitted to partial liver volume RE at 4-8 weeks ( T1), 10-26 weeks ( T2), and >26 weeks ( T3) after RE. Results More than half of the patients had cirrhosis with hepatocellular carcinoma. The main finding was a progressive increase in the volume of the spared hemiliver (mean absolute increase at T3: 230 ml). The percentage of patients in whom the baseline ratio of spared volume to total liver volume was <40% dropped from 56.6% at baseline to 29.4% at T2 ( P < 0.001). A significant and progressive increase in spleen volume but not in portal vein diameter was also observed. A small percentage of patients developed hypersplenism, mostly those without cirrhosis (16.0% at T2). Six patients (five with portal vein thrombosis, cirrhosis or both) developed signs of portal hypertension by T2. Conclusions The present results warrant further studies to better elucidate the mechanism underlying this phenomenon of spared hemiliver hypertrophy and to investigate its role as an alternative to portal vein embolization in the management of patients with potentially resectable liver tumours. [ABSTRACT FROM AUTHOR]

Q–Str2–Models is an opensource application developed in Python (PyQGIS) and integrated into QGIS that provides us with several tools for creating Stress–Strain models in geodynamically active areas, from the calculation of the horizontal velocities of many points from a temporal or permanent GNSS network. This software generates the results of the maximum geodetic deformation, shear deformation, rotation and dilatation of the points, which are later translated into graphic products; heatmaps, displacement vectors and Stress–Strain tensors. In this article we show the results of the application of Q–Str2–Models for the analysis of 65 GNSS stations of SPINA (South of the Iberian Peninsula and North Africa) network to know the geodynamic behavior of the Andalusian region and its surroundings. • The Q–Str2–Models software helps us to obtain various geodynamic parameters of a point from its horizontal velocities. • This software generates geodynamic deformation models using various interpolation methods. • It is an opensource application for QGIS that can be modified according to the user's needs. • It allows us to know the Stress–Strain tensors of a geodynamically active area. • It is a tool that helps to mitigate possible risks in the face of geological phenomena. [ABSTRACT FROM AUTHOR]

Abstract: Establishment of a geodetic network in Tenerife is the starting point for the use of GPS and other precise geodetic techniques in the support of the study of kinematics and their relation with island volcanic activity. This paper is focused on the characterization of volcanotectonic activity of Tenerife, to determine the geodynamic framework for volcanic surveillance. TEGETEIDE network, set up in 2005 and re-observed each year, is composed of seven GNSS–GPS stations scattered throughout the island. A horizontal deformation model is presented in order to explain the observed island displacement pattern in the geodynamic context of the Nubian plate. According to the models obtained, the most important geologic structures, such as the volcanic rifts and the caldera, determine the current deformation pattern of Tenerife. The geodynamics of the most stable areas of the island behave similarly to that observed from the permanent GNSS–GPS reference stations located in La Palma and Gran Canaria Islands. Anomalous geodynamic behaviour has been detected in two zones of Tenerife, which configure an NW–SE axis crossing the central sector of the island, related with the volcanotectonic activity of the island and its surroundings. [ABSTRACT FROM AUTHOR]

In this paper, a real-time monitoring system is presented to be used for environmental parameters measurement in tourist caves that can be employed for getting a sustainable tourism. The system allows the registration of a lot of metadata (temperature, relative humidity, wind speed and direction, CO2, atmospheric pressure, rain, presence and visitor count) and it shows them via the Internet in real time anywhere. The system reports the data registered and stored as metadata in a database online. In the ”El Soplao” Cave in the North of Spain, this system, permits a high level of control and security of the influence of visitors on a day to day and the temporal evolution to medium and long term. These measurements allow developing a sustainable and profitable system where heritage management and tourism exploitation acquire a subordinate commitment to the welfare of the natural asset (Cave-Mine “El Soplao”); the alteration of the fragile microclimate inside the cave can damage or destroy the specific geologic formations that make the touristic cave. After the visits, the company managing the cave takes in charge monitoring the environmental parameters of the cave to regulate future visits. The temperature in the cave has ranges between 11 and 13.5 °C, a seasonal quasi-periodic maximum variation of ± 0.5 °C and depending on the temperature outside the cave and number of visitors; it is difficult to associate one with another because both happen in the same month. The relative humidity is around 70–95%, it has no correlation with the number of visitors accessing the cavity. The CO2 concentration in air is around 400–1000 ppm; it has a clear correlation with the number of visitors and cave area (the deepest present's higher level CO2). In conclusion, a cave is visited as long as its microclimate is maintained, thus the real-time system developed has been conceptualized for monitoring over time the relationship between the cave environment and a sustainable tourism. Monitoring can help to preserve the specific geologic formation and therefore to keep the touristic interest of the cave. [ABSTRACT FROM AUTHOR]

Abstract: When establishing the relative distance between two GNSS–GPS stations with sub-centimeter accuracy, it is necessary to have auxiliary data, some of which can only be collected some time after the moment of measurement. However, for monitoring highly-active geodynamic areas, such as volcanoes and landslides, data precision is not as essential as rapid availability, processing of data in real-time, and fast interpretation of the results. This paper describes the development of an integrated automatic system for monitoring volcanic deformation in quasi real-time, applied to the Deception volcano (Antarctica). This experimental system integrates two independent modules that enable researchers to monitor and control the status of the GNSS–GPS stations, and to determine a surface deformation parameter. It comprises three permanent stations, one of which serves as the reference for assessing the relative distance in relation to the other two. The availability of GNSS–GPS data in quasi real-time is achieved by means of a WiFi infrastructure and automated data processing. This system provides, in quasi real-time, a time series of varying distances that tells us the extent to which any ground deformation is taking place. [Copyright &y& Elsevier]