Heat transport with advection in fractured rock

In the transport of heat in porous media, diffusion generally dominates over advection due to slow fluid velocities imposed by low permeability. This is the reason why standard Galerkin formulation leading to extra non-symmetric matrix terms may be still used successfully. However, in the presence of fractures the situation may be different. Fractures constitute preferential flow paths where fluid velocities may be significant and advection may become dominant over diffusion (“large advection” with Péclet number >1). This paper focuses on the formulation, numerical implementation and verification of a model to solve the steady-state heat transport problem with large advection along geomechanical discontinuities represented by zero-thickness interface elements. The fluid velocity field is considered as known input data (no hydraulic coupling). The existing SUPG method is modified for its application to zero-thickness interface elements, and the resulting formulation is implemented in an existing FE geomechanical code. An example of application is presented with large advection along a discontinuity crossing a low permeability domain. The results show that the proposed approach leads to stable results, in contrast to standard Galerkin

Heat transport with advection in fractured rock

In the transport of heat in porous media, diffusion generally dominates over advection due to slow fluid velocities imposed by low permeability. This is the reason why standard Galerkin formulation leading to extra non-symmetric matrix terms may be still used successfully. However, in the presence of fractures the situation may be different. Fractures constitute preferential flow paths where fluid velocities may be significant and advection may become dominant over diffusion (“large advection” with Péclet number >1). This paper focuses on the formulation, numerical implementation and verification of a model to solve the steady-state heat transport problem with large advection along geomechanical discontinuities represented by zero-thickness interface elements. The fluid velocity field is considered as known input data (no hydraulic coupling). The existing SUPG method is modified for its application to zero-thickness interface elements, and the resulting formulation is implemented in an existing FE geomechanical code. An example of application is presented with large advection along a discontinuity crossing a low permeability domain. The results show that the proposed approach leads to stable results, in contrast to standard Galerkin.Postprint (published version

Transient large heat advection in fractured rock: a zero-thickness interface formulation

In a fractured rock mass, the existence of discontinuities may generate preferential paths where the hydraulic flow velocities are frequently much higher than in the porous medium and heat advection tends to dominate over heat diffusion. In these cases, the standard Galerkin FEM method leads to oscillatory results and requires the use of stabilization methods. Thus, the current paper introduces a 3-D formulation to solve the large advection problem for zero-thickness interface elements –which may be used to discretize fractures in a FEM context–, based on a pre-existent Characteristic method. A verification example is presented, showing that the formulation exhibits a good performance to represent the heat transport by the fluid along zero-thickness interface elements.This work was partially supported by research grant BIA2016-76543-R from MEC (Madrid), which includes European FEDER funds, and 2017SGR-1153 from Generalitat de Catalunya (Barcelona). The first author also acknowledges his FPU scholarship from MEC (Madrid).Postprint (published version

Abacavir/Lamivudine Versus Tenofovir/Emtricitabine in Virologically Suppressed Patients Switching from Ritonavir-Boosted Protease Inhibitors to Raltegravir

There are few clinical data on the combination abacavir/lamivudine plus raltegravir. We compared the outcomes of patients from the SPIRAL trial receiving either abacavir/lamivudine or tenofovir/emtricitabine at baseline who had taken at least one dose of either raltegravir or ritonavir-boosted protease inhibitors. For the purpose of this analysis, treatment failure was defined as virological failure (confirmed HIV-1 RNA ≥50 copies/ml) or discontinuation of abacavir/lamivudine or tenofovir/emtricitabine because of adverse events, consent withdrawal, or lost to follow-up. There were 143 (72.59%) patients with tenofovir/emtricitabine and 54 (27.41%) with abacavir/lamivudine. In the raltegravir group, there were three (11.11%) treatment failures with abacavir/lamivudine and eight (10.96%) with tenofovir/emtricitabine (estimated difference 0.15%; 95% CI -17.90 to 11.6). In the ritonavir-boosted protease inhibitor group, there were four (14.81%) treatment failures with abacavir/lamivudine and 12 (17.14%) with tenofovir/emtricitabine (estimated difference -2.33%; 95% CI -16.10 to 16.70). Triglycerides decreased and HDL cholesterol increased through the study more pronouncedly with abacavir/lamivudine than with tenofovir/emtricitabine and differences in the total-to-HDL cholesterol ratio between both combinations of nucleoside reverse transcriptase inhibitors (NRTIs) tended to be higher in the raltegravir group, although differences at 48 weeks were not significant. While no patient discontinued abacavir/lamivudine due to adverse events, four (2.80%) patients (all in the ritonavir-boosted protease inhibitor group) discontinued tenofovir/emtricitabine because of adverse events (p=0.2744). The results of this analysis do not suggest that outcomes of abacavir/lamivudine are worse than those of tenofovir/emtricitabine when combined with raltegravir in virologically suppressed HIV-infected adults

Concurrent and Accurate Short Read Mapping on Multicore Processors

We introduce a parallel aligner with a work-flow organization for fast and accurate mapping of RNA sequences on servers equipped with multicore processors. Our software, HPG Aligner SA1, exploits a suffix array to rapidly map a large fraction of the RNA fragments (reads), as well as leverages the accuracy of the Smith-Waterman algorithm to deal with conflictive reads. The aligner is enhanced with a careful strategy to detect splice junctions based on an adaptive division of RNA reads into small segments (or seeds), which are then mapped onto a number of candidate alignment locations, providing crucial information for the successful alignment of the complete reads. The experimental results on a platform with Intel multicore technology report the parallel performance of HPG Aligner SA, on RNA reads of 100–400 nucleotides, which excels in execution time/sensitivity to state-of-the-art aligners such as TopHat 2+Bowtie 2, MapSplice, and STAR.This work has been supported by the Bull-CIPF Chair for Computational Genomics. The researchers from the Jaume I University were supported by project TIN2011-23283 and FEDER

Size dependent predation in piscivorous larval stages of three tuna species

The bluefin tuna (Thunnus thynnus) is a heavily fished temperate tuna that spawns in the Mediterranean Sea; the area off the Balearic Islands is a key spawning area. Other abundant tunas, including albacore (Thunnus alalunga) and the small bullet tuna (Auxis rochei) spawn in the same area. The three species temporally overlap during the summer spawning period of the adults. Because they are clearly piscivorous already at very early larval stages, we expect strong interactions both in terms of a direct predator–prey relationship and as competitors for food resources. In this study, we focus on understanding the size dependent trophic interactions among the three species at the different developmental larval stages. First, we describe the environmental and biological scenarios where different size stages of the three species co-occur through the application of generalized additive model (GAM) analyses to field data collected during cruise surveys in 2004–2005. We then develop an individual_based model (IBM) to evaluate inter- and intraspecific predation rates considering size structured prey and predator fields in the framework of piscivorous behaviour. The results demonstrate how predation mortality rates influence the spawning location of the three speci

Basement structure of the Hontomín CO2 Geological storage facility (Burgos, Spain): integration of microgravity & 3D seismic reflection data

The structure of the Hontomín CO2 geological storage research facility has been addressed combining 3D seismic reflection data, borehole information and microgravity data. The integrated interpretation constrains the basement structural setting geometry and that of the sedimentary succession. The study unravels the deep structure and topography of the basement and quantifies the thickness of the Triassic Keuper evaporites. We describe a half-graben setting filled with Keuper evaporites (up to 2000 m) forming an extensional forced fold. Three set of faults are identified with two main fault systems compartmentalizing the area into three differentiated blocks. These faults have been interpreted to be reactivated normal faults that have led to the formation of the Hontomín dome.The datasets in this work have been funded by Fundación Ciudad de la Energía (Spanish Government, www.ciuden.es) and by the European Union through the “European Energy Programme for Recovery” and the Compostilla OXYCFB300 project. Dr. Juan Alcalde is currently funded by NERC grant NE/M007251/1.Peer Reviewe

Basement structure of the Hontomín CO2 Geological storage facility (Burgos, Spain): integration of microgravity & 3D seismic reflection data

The structure of the Hontomín CO2 geological storage research facility has been addressed combining 3D seismic reflection data, borehole information and microgravity data. The integrated interpretation constrains the basement structural setting geometry and that of the sedimentary succession. The study unravels the deep structure and topography of the basement and quantifies the thickness of the Triassic Keuper evaporites. We describe a half-grabensetting filled with Keuper evaporites (up to 2000 m) forming an extensional forced fold. Three set of faults are identified with two main fault systems compartmentalizing the area into three differentiated blocks. These faults have been interpreted to be reactivated normal faults that have led to the formation of the Hontomín dome.The datasets in this work have been funded by Fundación Ciudad de la Energía (Spanish Government, www.ciuden.es) and by the European Union throughthe “European Energy Programme for Recovery” and the Compostilla OXYCFB300 project. Dr. Juan Alcalde is currently funded by NERC grant NE/M007251/1.Peer Reviewe

Cefalea y hemoptisis en varón joven

A 32-year-old male patient who visited the emergency room having headache for 5 days in a row along with cough, pleuritic pain and fever (hemoptysis in the last two days). He is wearing a piercing in his forehead. Anodyne physical exploration. Analytically PCR of 353 mg/L (3-10 mg/L), Leukocytes 21,000/ml (4800-10800/ml) with 81% neutrophils (40-70%). In the chest X-ray, there is condensed cavitation in the right upper lobe. So that, he enters at Pneumology department with suspected of having tuberculosis and empirical treatment with amoxicillin/clavulanic.Varón de 32 años que acude al Servicio de Urgencias por presentar un cuadro de 5 días de evolución de cefalea, tos, dolor pleurítico y febrícula (últimos 2 días episodios de hemoptisis). Portador de piercing a nivel frontal. Exploración física anodina. Analíticamente, PCR de 353 mg/L (3-10 mg/L), leucocitos 21.000/μL (4.800-10.800/μL) con 81% de neutrófilos (40-70%). En la radiografía de tórax se observa una condensación cavitada en lóbulo superior derecho. Ingresa en Neumología con sospecha de tuberculosis y tratamiento empírico con amoxicilina-clavulánico