Geophysical Imaging of the Critical Zone along the Eastern Betic Shear Zone (EBSZ), SE Iberian Peninsula

The geophysical data used in this study consisted of two datasets, namely electrical resistivity data and seismic data. Resistivity data were obtained from the Electrical Resistivity Tomography (ERT) method, while seismic data (Vp and Vs) were obtained from the multi-channel analysis of surface waves (MASW) and P-wave travel time tomography. The resistivity and seismic data used in this study were acquired within the INTER GEO research project, which was funded by the Spanish national research program.Funding: J.A. is funded by grant IJC2018-036074-I and by MCIN/AEI /10.13039/501100011033. I.P. is funded by the Spanish Government and the Universidad de Salamanca (Beatriz Galindo grant BEGAL 18/00090). This project was funded by Grant 2017SGR1022 (GREG) from the Generalitat de Catalunya (AGAUR); EU (H2020) 871121 (EPOS-SP); and EIT-RawMaterias 17024 from the European Institute of Technology (EIT) (SIT4ME).The critical zone (CZ) represents the most-shallow subsurface, where the bio-, hydro-, and geospheres interact with anthropogenic activity. To characterize the thickness and lateral variations of the CZ, here we focus on the Eastern Betic Shear Zone (EBSZ), one of the most tectonically active regions in the Iberian Peninsula. Within the EBSZ, the Guadalentín Depression is a highly populated area with intensive agricultural activity, where the characterization of the CZ would provide valuable assets for land use management and seismic hazard assessments. To achieve this, we have conducted an interdisciplinary geophysical study along the eastern border of the Guadalentín Depression to characterize the CZ and the architecture of the shallow subsurface. The datasets used include Electrical Resistivity Tomography (ERT), first-arrival travel time seismic tomography, and multichannel analysis of surface waves (MASW). The geophysical datasets combined help to constrain the high-resolution structure of the subsurface and image active fault systems along four transects. The resulting geophysical models have allowed us to interpret the first ~150 m of the subsurface and has revealed: (i) the variable thickness of the CZ; (ii) the CZ relationship between the fault zone and topographic slope; and (iii) the differences in CZ thickness associated with the geological units. Our results provide a method for studying the shallow subsurface of active faults, complementing previous geological models based on paleo-seismological trenches, and can be used to improve the CZ assessment of tectonically active regions.European Institute of Technology SIT4MEMCINSpanish national research programHorizon 2020 Framework Programme 871121, EIT-RawMaterias 17024European CommissionGeneralitat de CatalunyaAgència de Gestió d'Ajuts Universitaris i de RecercaAgencia Estatal de InvestigaciónUniversidad de Salamanca 2017SGR1022, BEGAL 18/0009

GPR Clutter Reflection Noise-Filtering through Singular Value Decomposition in the Bidimensional Spectral Domain

Usually, in ground-penetrating radar (GPR) datasets, the user defines the limits between the useful signal and the noise through standard filtering to isolate the effective signal as much as possible. However, there are true reflections that mask the coherent reflectors that can be considered noise. In archaeological sites these clutter reflections are caused by scattering with origin in subsurface elements (e.g., isolated masonry, ceramic objects, and archaeological collapses). Its elimination is difficult because the wavelet parameters similar to coherent reflections and there is a risk of creating artefacts. In this study, a procedure to filter the clutter reflection noise (CRN) from GPR datasets is presented. The CRN filter is a singular value decomposition-based method (SVD), applied in the 2D spectral domain. This CRN filtering was tested in a dataset obtained from a controlled laboratory environment, to establish a mathematical control of this algorithm. Additionally, it has been applied in a 3D-GPR dataset acquired in the Roman villa of Horta da Torre (Fronteira, Portugal), which is an uncontrolled environment. The results show an increase in the quality of archaeological GPR planimetry that was verified via archaeological excavation.Project “Innovación abierta e inteligente en la EUROACE” 0049_INNOACE_4_E - European Union (European Regional Development Fund) COMPETE 2020Portuguese Foundation for Science and Technology (FCT) projects UIDB/04683/2020-ICT (Institute of Earth Sciences) and SFRH/BSAB/143063/201

Increasing the Lateral Resolution of 3D-GPR Datasets through 2D-FFT Interpolation with Application to a Case Study of the Roman Villa of Horta da Torre (Fronteira, Portugal)

The approach presented in this work uses an interpolation methodology to densify 3D-GPR datasets to sharpen the results obtained in GPR surveys carried out in an archaeological environment. It allows the estimation of missing data from the combined use of mathematical transforms, such as the Fourier and curvelet transforms, and predictive filters. This technique makes it possible to calculate the missing signal simply by meeting two requirements: the data in the frequency domain must be limited in a range of values and must be able to be represented by a distribution of Fourier coefficients (verified conditions). The INT-FFT algorithm uses an open-access routine (Suinterp, Seismic Unix) to interpolate the GPR B-scans based on seismic trace interpolation. This process uses automatic event identification routines by calculating spatial derivatives to identify discontinuities in space by detecting very subtle changes in the signal, thus allowing for more efficient interpolation without artifacts or signal deterioration. We successfully tested the approach using GPR datasets from the Roman villa of Horta da Torre (Fronteira, Portugal). The results showed an increase in the geometric sharpness of the GPR reflectors and did not produce any numerical artifacts. The tests performed to apply the methodology to GPR-3D data allowed for assessing the interpolation efficiency, the level of estimation of missing data, and the level of information lost when we chose to increase the distance between B-scans in the acquisition stage.research project "Innovacion abierta e inteligente en la EUROACE" 0049_INNOACE_4_EEuropean Commission COMPETE 2020Portuguese Foundation for Science and Technology UIDB/04683/2020 SFRH/BSAB/143063/201

High resolution seismic tomography using an elastic wave generator

Several seismic surveys were carried out in the urban Palmela region (Azeitão), using 48 channel seismograph and single geophone per channel. The scope was mainly to test the efficiency and reliability of seismic source, an elastic wave generator using an accelerated hammer drop, to produce shallow velocity models with high resolution. A 300 m profile was acquired and the position based on constant topography and neighbouring the wells location previously drilled for aquifers delineation. Despite the presence of significant urban and coherent noise, the seismic source revealed effective to sum several shots and enhancing the ratio signal/noise. First arrivals processing illustrate clearly the geological structures until 60 m depth. A preliminary stack section did not support the findings in the first arrivals study. To resolve the difference, the field reflection data are being reprocessed to provide more details about the layering and lateral structures already observed in the refraction data

Exploration of the One-Bead One-Compound Methodology for the Design of Prolyl Oligopeptidase Substrates

Here we describe the design, synthesis and evaluation of the first solid-phase substrates for prolyl oligopeptidase (POP), a cytosolic serine peptidase associated with schizophrenia, bipolar affective disorder and related neuropsychiatric disorders. This study seeks to contribute to the future design of a one-bead one-compound (OBOC) peptide library of POP substrates, based on an intramolecular energy transfer substrate. Unexpectedly, the enzymatic evaluation of the substrates attached on solid-phase by means of the HMBA linker were cleaved through the ester bond, thereby suggesting an unknown esterase activity of POP, in addition to its known peptidase activity. By performing multiple activity assays, we have confirmed the esterase activity of this enzyme and its capacity to process the substrates on solid-phase. Finally, we tested a new linker, compatible with both the solid-phase peptide-synthesis used and the enzymatic assay, for application in the future design of an OBOC library

5-Hydroxymethylfurfural content in foodstuffs determined by micellar electrokinetic chromatography

Micellar electrokinetic chromatography (MEKC) has been applied for the determination of 5-hydroxymethylfurfural in several foodstuffs. A 75 mM phosphate buffer solution at pH 8.0 containing 100 mM sodium dodecylsulfate was used as background electrolyte (BGE), and the separation was performed by applying +25 kV in a 50 µm I.D. uncoated fused-silica capillary. Good linearity over the range 2.5-250 mg kg-1 (r2 ≥ 0.999) and run-to-run and day-to-day precisions at low and medium concentration levels were obtained. Sample limit of detection (0.7 mg kg-1) and limit of quantification (2.5 mg kg-1) were established by preparing the standards in blank matrix. The procedure was validated by comparing the results with those obtained with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Levels of HMF in 45 different foodstuffs such as breakfast cereals, toasts, honey, orange juice, apple juice, jam, coffee, chocolate and biscuits were determined

Estudios de liberación de plata a partir de nanocompuestos de interés alimentario para producción animal

El trabajo se basa en la importancia de las nanopartículas de plata como alternativa al uso de antibióticos en la producción animal, debido a sus propiedades antimicrobianas. Se realizan estudios con un tipo de nanomaterial denominado C3 que es un sistema caolín-plata. Esta muestra contiene nanopartículas de plata y plata iónica. Se determina el contenido total de plata en la muestra. Asimismo se estudia la posible liberación de plata en distintos medios acuosos y celulares, para conocer la cantidad de plata que puede llegar a los animales al ser suministrada en su alimentación. Los estudios de lixiviación se llevan a cabo a distintos tiempos para comprobar cuánto tarda la plata en ser liberada en el interior del animal. Además se aplican procesos de ultrafiltración para separar las distintas especies de plata. Se utiliza la Espectroscopía de Absorción Atómica en Llama (FAAS) como sistema de detección. Los resultados indican que la mayor parte de la plata presente se encuentra en forma iónica, que el contenido de plata total es de 0,84% y que la cantidad de plata liberada en agua es de alrededor de un 44%.<br /

Comparison between magnetic anomalies and GPR images. North of La Alcudia site, Elche (Alicante)

When an archaeological site is extensive and the structures are supposed to be superficial (above of 3 metres), the most advisable geophysical prospection method is magnetic pseudo-gradient. To be explored, the North Alcudia zone was divided into 21 square sectors of 20 m by 20 m, and a potassium vapour magnetometer (GSMP-40) which absolute precision is 0.1 nT, was used. In each sector, the established distance between profiles was 1 m and the data acquisition was performed in a way, such it was obtained a sample each 10 cm (approximately). The aspects that influence the most in the interpretation of a magnetic anomalies map are the distinction between the two magnetic types (induced and remanent) materials, and the fact that the wide of these anomalies are always much bigger than the wide of the objects which produce that anomalies. In order to evaluate the detection grade provided by this kind of magnetograms, once they were obtained they, we was defined a group of areas to prospect in with GRP (SIR 200); with a 400 MHz antenna. Each area was acquired with 3D reflection methodology; that is with parallel profiles separated by 0.5 m and taking one sample each 2 cm. This work present a comparison between the results obtained with both techniques

DETECTION OF HYDRAULIC ROMAN STRUCTURES BY MEANS OF GEOPHYSICAL METHODS. THE ARCHAEOLOGICAL AREA OF MAJADAIGLESIA, EL GUIJO (CÓRDOBA)

La Zona Arqueológica  de Majadaiglesia  está situada  en la comarca  de Los Pedroches,  en el término municipal de El Guijo, al norte de la provincia de Córdoba. Los abundantes restos arqueológicos y epigráf icos de la misma llevan  a plantear la hipótesis de que Majadaiglesia pueda ser Solia, un  asentamiento multicultural totalmente romanizado en el último cuarto del siglo I. En este vasto yacimiento de unas 19 ha se observan los restos de una muralla, numerosas estructuras hidráulicas y una necrópolis de época romana. Con vistas a futuras actuaciones arqueológicas 3,7 ha del yacimiento fueron investigadas mediante prospecciones geofísicas, donde 1,3 ha corresponden  a la meseta del Cortijo de Majadaiglesia y son las que constituyen el objeto de este estudio. Los trabajos de exploración geofísica seguidos han consistido en un levantamiento topográf ico de la zona de estudio, una prospección magnética y una prospección con rádar del subsuelo (3D) en los sectores donde  la prospección magnética había señalado anomalías de interés. Mediante la combinación de ambos  métodos se han detectado una serie de estructuras soterradas que han permitido establecer que la mayor parte de las estructuras están relacionadas con construcciones hidráulicas. Asimismo, el buen contraste dieléctrico entre los cuerpos soterrados y el material encajante ha favorecido la aplicación de tratamiento ref inado a una de las estructuras detectadas con georrádar, de modo que se han podido generar imágenes con  sufciente  calidad  para  hacer  plausible su  interpretación  arqueológica, basada  en  la comparación con estructuras similares excavadas en otros lugares.The  Archaeological  Area  of  Majadaiglesia  is  located  in  the  comarca  of  Pedroches,  in  the municipal term of El Guijo, to the north of the province of Córdoba. The abundant archaeological and  epigraphic remains lead to the hypothesis that Majadaiglesia can be Solia, a completely romanized multicultural settlement in the last quarter of the  first century. In this  vast site  of about 19 ha the  remains of a  wall, many hydraulic structures and a necropolis  from Roman times are observed. With view to future archaeological activities 3.7  ha  site  were  investigated  by  geophysical  surveys,  which  1.3  ha  correspond  to  plateau Cortijo  Majadaiglesia,  and  are  forming  the  subject  of this  study. Geophysical exploration work consisted of a topographic survey of the study area, a magnetic survey,  and  a  survey  with  subsurface  radar  (3D)  in sectors  where  the magnetic  survey  had identified  anomalies  of  interest. By combining both methods have been identif ied a number of underground structures that have established  that most of the structures  are linked to hydraulic  constructions.  Moreover, the good  dielectric contrast between the buried bodies and the enveloping material it has favored  the  application  of a ref ined  treatment  to one  of the  structures  detected  with  GPR, so have been able to generate  images  with suff icient  quality  for its archaeological  interpretation, based on comparison with similar structures excavated elsewhere