113 research outputs found

    A 3D measurement of the offset in paleoseismological studies

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    The slip rate of a seismogenic fault is a crucial parameter for establishing the contribution of the fault to the seismic hazard. It is calculated from measurements of the offset of linear landforms, such channels, produced by the fault combined with their age. The three-dimensional measurement of offset in buried paleochannels is subject to uncertainties that need to be quantitatively assessed and propagated into the slip rate. Here, we present a set of adapted scripts to calculate the net, lateral and vertical tectonic offset components caused by faults, together with their associated uncertainties. This technique is applied here to a buried channel identified in the stratigraphic record during a paleoseismological study at the El Saltador site (Alhama de Murcia fault, Iberian Peninsula). After defining and measuring the coordinates of the key points of a buried channel in the walls of eight trenches excavated parallel to the fault, we (a) adjusted a 3D straight line to these points and then extrapolated the tendency of this line onto a simplified fault plane; (b) repeated these two steps for the segment of the channel in the other side of the fault; and (c) measured the distance between the two resulting intersection points with the fault plane. In doing so, we avoided the near fault modification of the channel trace and obtained a three-dimensional measurement of offset and its uncertainty. This methodology is a substantial modification of previous procedures that require excavating progressively towards the fault, leading to possible underestimation of offset due to diffuse deformation near the fault. Combining the offset with numerical dating of the buried channel via U-series on soil carbonate, we calculated a maximum estimate of the net slip rate and its vertical and lateral components for the Alhama de Murcia fault. (C) 2016 Elsevier Ltd. All rights reserved

    Prospective study to assess progression of renal markers after interruption of tenofovir due to nephrotoxicity

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    Background. Prospective studies about the reversibility of tenofovir disoproxil fumarate- (TDF-) related renal impairment remain scarce. Methods. This is an observational prospective study including all patients that presented at our HIV Unit who interrupted TDF owing to nephrotoxicity. We assessed the evolution of renal parameters after discontinuation of this drug. Results. We included 59 patients, who were followed up for 72 weeks. Most were male (41, 69.5%), median (IQR) age was 53 (44; 58) years, and median time receiving TDF-containing regimens was 55.4 (28; 87.7) months. Most patients were receiving PI-based treatments (67%). At the final visit, most of the subjects showed complete recovery (35, 59.3%) or improvement (13 subjects, 22%). Significant improvements were observed in creatinine levels (from 84.9 [73.8; 97.5] to 78 [69.6; 91] mu mol/L, p = 0.013), estimated glomerular filtration rate (eGFR, CKD EPI equation, from 87.7 [67; 99] to 89.9 [73.6; 99.3] mL/min/1.73 m(2), p = 0.017), and number of patients with eGFR <60 mL/min/1.73 m(2) (from 9 [15.3%] to 1 [1.7%], p = 0.031). A trend toward significance was observed in abnormal urine proteinuria/creatinine ratio (from 22 [37%] to 8 [13.6%], p = 0.057). Conclusions. Our results corroborate the high frequency of complete or partial renal recovery in patients receiving TDF-containing regimens who discontinued therapy owing to nephrotoxicity.Peer ReviewedPostprint (published version

    Impact of protease inhibitors on the evolution of urinary markers: subanalyses from an observational cross-sectional study

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    Kidney injury (defined as the presence of albuminuria, proteinuria, glycosuria [without hyperglycemia], hematuria, and/or renal hypophosphatemia) is an emerging problem in human immunodeficiency virus (HIV)-infected patients, although few data are available on the role of protease inhibitors (PIs) in this condition. To determine the time to kidney injury in a cohort of HIV-infected patients receiving a PI-containing regimen. We report the results of a subanalysis of a published cross-sectional study. The subanalysis included only patients receiving PI-containing regimens for more than 6 months (377 of the overall 970 patients). We determined associated factors and constructed receiver operating characteristic curves to estimate time to kidney injury depending on the PI used. The percentage of patients with kidney injury was 27.7% for darunavir, 27.9% for lopinavir, and 30% for atazanavir. Time to kidney injury was as follows: 229 days for atazanavir/ritonavir (area under the curve [AUC], 0.639; sensitivity, 0.89; specificity, 0.41); 332 days for atazanavir/ritonavir plus tenofovir (AUC, 0.603; sensitivity, 0.75; and specificity, 0.29); 318 days for nonboosted atazanavir (AUC, 0.581; sensitivity, 0.89; and specificity, 0.29); 478 days for lopinavir/ritonavir (AUC, 0.566; sensitivity, 0.864; and specificity, 0.44); 1339 days for lopinavir/ritonavir plus tenofovir (AUC, 0.667; sensitivity, 0.86; and specificity, 0.77); 283 days for darunavir/ritonavir (AUC, 0.523; sensitivity, 0.80; and specificity, 0.261); and 286 days for darunavir/ritonavir plus tenofovir (AUC, 0.446; sensitivity, 0.789; and specificity, 0.245). The use of lopinavir/ritonavir without tenofovir was a protective factor (odds ratio = 1.772; 95% CI, 1.070-2.93; P = 0.026). For all PIs, the percentage of patients with kidney injury exceeded 27%, irrespective of tenofovir use. The longest time to kidney injury was recorded with lopinavir/ritonavir. These results demonstrate the need for renal monitoring, including urine samples, in patients receiving a PI-based regimen, even when tenofovir is not used concomitantly.Peer ReviewedPostprint (published version

    Remote sensing and seismic data integration for the characterization of a rock slide and an artificially triggered rock fall

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    On May 5th, 2013 a planar rock slide (~450 m3) occurred in the village of La Riba (NE Spain), which forced the closure of the road C-240z for 6 months. This slide left a hanging block (~130 m3) suspended on the slope forcing a controlled blasting, followed by rock slope stabilization works. The volume of rock displaced during the both events was deduced from LiDAR and photogrammetry data following two approaches: subtracting pre- and post-event data and reconstructing the volume by fitting planes on the structural surfaces after a structural analysis of the slope. Information about the natural rock slide was obtained from the records of two permanent broadband seismic stations located 10 km from the site. From these seismic records, the existence of a rock slide was confirmed and its time of occurrence was determined, information that would be otherwise unknown. In addition, despite the small volume displaced during the event, its location was deduced from a single seismic station analysis. The blasting process was recorded with two high-definition (HD) video cameras and by two temporary seismic stations deployed close to the site (10 km). Partially, because only a part of the released energy is transmitted into the ground as seismic energy, and partially because the recorded seismic signal is highly dependent on the event characteristics and the geotechnical conditions of the ground materials. Nevertheless, seismic data is very well suited to detect and characterize in detail both rockfall events of different nature and size. Merging and integrating remote sensing techniques such as LiDAR or photogrammetry with seismic measurements should allow the implementation of rockfall early warning systems

    Minerales supergénicos de Hg de Almadén: Una forma natural de fijar mercurio

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    Como es conocido, la zona de Almadén constituye uno de los reservorios de mercurio más importantes del mundo (Higueras et al., 2006)

    Cross-sectional survey on the current role of clinical pharmacists among antimicrobial stewardship programmes in Catalonia: much ado about nothing

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    Background: Antimicrobial resistance killed 1.27 million people in 2019, so urgent actions are desperately needed. Antimicrobial stewardship programmes (ASPs) are essential to optimize antimicrobial use. The objective was to acknowledge the current role of clinical pharmacists engaged in ASP activities in Catalonia. Methods. This was a cross-sectional survey shared through the Catalan Infection Control Programme (VINCat). The survey consisted of four sections and was sent by e-mail. Results. A total of 69.0% of the centres answered. Pharmacists dedicated a median of 5.0 h per week (2.1 h/week/100 acute care beds), representing 0.15 full time equivalents. The ASP lacked information technology (IT) support, as only 16.3% of centres automatically calculated defined daily doses and days of therapy. Those with less than 15% of their time available for ASPs conducted fewer clinical activities, especially prospective audits and feedback. Those without official infectious diseases training also performed fewer clinical activities, but training was less determinant than IT support or time. Pharmacists performed interventions mostly through annotation in the medical records. Conclusions: Clinical pharmacists from Catalonia dedicated to ASPs present an important lack of time and IT support to perform clinical activities. Pharmacists should also improve their clinical skills and try to conduct clinical advice to prescribers, either by phone or face-to-face

    Refining seismic parameters in low seismicity areas by 3D trenching: The Alhama de Murcia fault, SE Iberia.

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    Three-dimensional paleoseismology in strike-slip faults with slip rates less than 1 mm per year involves a great methodological challenge. We adapted 3D trenching to track buried channels offset by the Alhama de Murcia seismogenic left-lateral strike-slip fault (SE Iberia). A fault net slip of 0.9 +/- 0.1 mm/yr was determined using statistical analysis of piercing lines for one buried channel, whose age is constrained between 15.2 +/- 1.1 ka and 21.9-22.3 cal BP. This value is larger and more accurate than the previously published slip rates for this fault: The minimum number of five paleo-earthquakes identified since the deposition of dated layers suggests a maximum average recurrence interval of approximately 5 ka. The combination of both seismic parameters yields a maximum slip per event between 53 and 63 m. We show that accurately planned trenching strategies and data processing may be key to obtaining robust paleoseismic parameters in low seismicity areas. (C) 2016 Elsevier B.V. All rights reserved

    Mompa project: actuation protocols based on satellite radar interferometry (INSAR) monitoring

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    [EN] The objective of the POCTEFA - MOMPA project (Monitoring of Ground Movements and Action Protocol) is to provide a useful technical-operational tool for the prevention and management of risks due to slope movements, at a cross-border level, based on the satellite monitoring technique InSAR (Synthetic Aperture Radar Inteferometry). The tool includes two main elements: the risk evaluation, and the integration of the technique in an action protocol for the administrations in charge of Civil Protection. The study area covers around 4,000 km2 and includes a part of the eastern Pyrenees, including the countries of Spain, France, and Andorra. The project deals with risk assessment based on the ground displacement map at an interregional scale and on the detected Active Deformation Areas (ADA), to select movements with potential risk where it will then focus on an analysis at a local scale using traditional methods (photo interpretation and field work). Both the free medium-resolution data, acquired by the Sentinel-1 satellite, as well as the high-resolution data acquired by COSMO-SkyMed are used. In addition, the project focuses on the landslide event of “la Portalada” (in Andorra) that occurred in 2019. Today the slope shows a slow movement that could affect a main road located at the bottom of the valley. The Government of Andorra is implementing measures to monitor and characterize the current movement of the slope. Therefore, nine artificial reflectors were installed along this forested slope. The data obtained will be integrated into the risk prevention protocol. Here, the project and the first results obtained through satellite interferometry are presented.[ES] El objetivo del proyecto POCTEFA - MOMPA (MOnitorización de Movimientos del terreno y Protocolo de Actuación) es proporcionar una herramienta técnico-operativa útil para la prevención y la gestión de los riesgos ocasionados por movimientos de ladera, a nivel transfronterizo, basada en la técnica de seguimiento satelital InSAR. (Interferometría Radar a Apertura Sintética) La herramienta incluye dos elementos principales: la evaluación del riesgo; y la integración de la técnica en un protocolo de actuación para las administraciones encargadas de la Protección Civil. El área de estudio cubre alrededor de 4.000 km2 e incluye una parte de los Pirineos orientales, incluyendo los países España, Francia y Andorra. El proyecto trata la evaluación de riesgos a partir del mapa de movimientos del terreno a escala interregional y de las Áreas de Deformación Activa (ADA), para seleccionar movimientos con riesgo potencial donde luego se enfocará en un análisis a escala local mediante el uso de métodos tradicionales (básicamente fotointerpretación y trabajo de campo). Se utilizan tanto los datos libres y gratuitos de resolución media, adquiridos por el satélite Sentinel-1, como los datos de alta resolución adquiridos por COSMO-SkyMed. Además, el proyecto centra su atención en el caso particular del deslizamiento de “la Portalada” (Andorra) ocurrido en 2019. En la actualidad, la ladera presenta un movimiento lento que podría afectar el eje principal de comunicación entre Andorra y España ubicado en el fondo del valle. El Gobierno de Andorra está implementando medidas para monitorear y caracterizar el movimiento actual de la ladera. Por tanto, nueve reflectores artificiales se instalaron a lo largo de esta ladera ocupada por un bosque. Los datos obtenidos se integrarán en el protocolo de prevención de riesgos. En este trabajo se presentan el proyecto y los primeros resultados obtenidos mediante interferometría satelital.Este trabajo ha sido co-financiado por el Fondo Europeo de Desarrollo Regional (“European Regional Development Fund”) a través de Interreg V-A España, Francia y Andorra (POCTEFA 2014-2020), proyecto EFA295/19. En el caso de la Portalada, los autores agradecen a la administración local de La Portalada, el Comú de Sant Julià de Lòria, por permitir la implementación de los reflectores, y al Ministerio de Ordenación Territorial del Gobierno de Andorra por facilitar su gestión. La obra de implementación de los reflectores fue contratada a la empresa INACCÉS.Barra, A.; Colell, X.; Echeverria, A.; Trapero, L.; Marturia, J.; Fabregat, I.; Gao, Q.... (2021). El proyecto Mompa: protocolos de actuación basados en el monitoreo mediante interferometría satelital radar (INSAR). En Proceedings 3rd Congress in Geomatics Engineering. Editorial Universitat Politècnica de València. 118-126. https://doi.org/10.4995/CiGeo2021.2021.12709OCS11812

    Palaeoenvironmental changes in the Iberian central system during the Late-glacial and Holocene as inferred from geochemical data: A case study of the Navamuño depression in western Spain

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    The Iberian Central System (ICS) is a clue region to reveal Mediterranean/Atlantic inferences over Iberia. We present a multidisciplinary study from western Spain conducted in the Navamuno ˜ depression (ND), covering the last 16.8 ka (cal BP). A reconstruction of the palaeotemperature from the resulting geochemical data highlights four cold and dry intervals, namely, the Oldest Dryas, Older Dryas, Intra-Allerød Cold Period (IACP), and the Younger Dryas, along with warmer intervals: the Bølling (14.7–14 ka) and the Allerød (12.9–12.6 ka); however, the Greenland Interstadial GI-1c (13.4–13.1 ka) is barely distinguishable in the ND. Despite the shortage of biomass to sustain fire, the earliest charcoals are from ~14.4–13.8 ka. Evidence of ash/dust events overprinting the geochemical background starts at ~13.8–12.8 ka. Significant fire activity in the Early Holocene at ~11.7–10.6 ka affected the ND, matching the westernmost ICS data. This period includes short oceanic spells inferred from Cl peaks at ~10.9–10.2 ka and three cold intervals at 11.4, 9.3, and 8.2 ka disrupted the progressive temperature increase. The Mid-Holocene showed a continuously increasing trend towards an arid climate, peaking at 4.2 ka under a pervasive dust influx from North Africa, which has prevailed since almost ~7.9 ka. A prominent volcanic event at ~6.8–5.8 ka is in Navamuno ˜ and Ronanzas ˜ (Asturias, N Spain; Gallego et al., 2013) identified from heavy metal-rich layer, synchronous with the last known eruption of the Calatrava volcanic field (South-Central Spain; Poblete-Piedrabuena et al., 2019). This volcanic eruption could affect many other regions half north of Iberia. The pervasive presence of oceanic aerosols in the last three millennia (2.8 ka ~ ) allowed the formation of a Cl-rich peat layer during the Ibero-Roman humid period ~2.1 ka, before a changing around ~0.4 ka toward colder and drier conditions at the Little Ice Age (LIA) periodThis study was funded by the LATESICE-CGL2016-78380-P, FINICES- PID2020-117685 GB-I00 and MED-REFUGIA-RTI2018-101714-BI00 (Plan Nacional I + D + I, Spanish Ministry of Science, Innovation and Universities) projects

    Changing Trends in the Global Consumption of Treatments Used in Hospitalized Patients for COVID-19: A Time Series Multicentre Study

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    Aim: To analyze trends in the prescription of COVID-19 treatments for hospitalized patients during the pandemic. Methods: Multicenter, ecological, time-series study of aggregate data for all adult patients with COVID-19 treated in five acute-care hospitals in Barcelona, Spain, between March 2020 and May 2021. Trends in the monthly prevalence of drugs used against COVID-19 were analyzed by the Mantel-Haenszel test. Results: The participating hospitals admitted 22,277 patients with COVID-19 during the study period, reporting an overall mortality of 10.8%. In the first months of the pandemic, lopinavir/ritonavir and hydroxychloroquine were the most frequently used antivirals, but these fell into disuse and were replaced by remdesivir in July 2020. By contrast, the trend in tocilizumab use varied, first peaking in April and May 2020, declining until January 2021, and showing a discrete upward trend thereafter. Regarding corticosteroid use, we observed a notable upward trend in the use of dexamethasone 6 mg per day from July 2020. Finally, there was a high prevalence of antibiotics use, especially azithromycin, in the first three months, but this decreased thereafter. Conclusions: Treatment for patients hospitalized with COVID-19 evolved with the changing scientific evidence during the pandemic. Initially, multiple drugs were empirically used that subsequently could not demonstrate clinical benefit. In future pandemics, stakeholders should strive to promote the early implementation of adaptive randomized clinical trials
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