233 research outputs found

    Three-dimensional Reconstruction of the Caspe Geological Structure (Spain) for Evaluation as a Potential CO2 Storage Site

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    The Caspe geological structure was formed by the convergence of the Iberian Range and the Catalonian Coastal Range, during the Tertiary compression. Traditionally, the Caspe structure has been interpreted from seismic profiles without considering surface structural data. The aim of this study is to build a 3D geological model taking into account the structural data from the geological map, stress fields and lineaments, and evaluate its possibility as potential CO2 storage site. Four surfaces have been modelled: Buntsandstein Top, Muschelkalk-I Top, Muschelkalk-II Top and Cenozoic Bottom. Considering the geometry and depth for storage the target reservoir was considered to be the Buntsandstein facies. The available seismic data indicate that the Buntsandstein facies top is at approximately 500 m depth and hosts a deep saline aquifer. The target reservoir series include the conglomerate and sandstone of the Hoz del Gallo and Cañizar Fms (Buntsandstein Facies) with an average thickness of 500 m and 21% porosity. The seal comprises the shales and silts of the Röt Fm with an average thickness of 100-150 m. The structure volume was calculated based on the -500 mbsl for the Buntsandstein top deepest closed contour lines. The estimated volume is 5, 800 Mm3 with most of CO2 in gaseous state

    Infrared and Millimetric Study of the Young Outflow Cepheus E

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    The Cepheus E outflow has been studied in the mid and far infrared using the ISO CAM and LWS instruments, and at millimetric wavelengths using OVRO. In the near and mid-IR, its morphology is similar to that expected for a jet driven outflow, where the leading bow shocks entrain and accelerate the surrounding molecular gas. As expected, fine structure atomic/ionic emission lines arise from the bow shocks, at both the Mach Disk and the stagnation tip, where J-shocks are dominant. The H2, H2O and CO molecular emission could arise further `downstream' at the bow shock wings where the shocks (v = 8-35 km/s) are oblique and more likely to be C-type. The 13CO emission arises from entrained molecular gas and a compact high velocity emission is observed, together with an extended low velocity component that almost coincides spatially with the H2 near-IR emission. The millimetric continuum emission shows two sources. We identify one of them with IRAS 23011+6126, postulating is the driver of the Cepheus E outflow; the other, also an embedded source, is likely to be driving one of other outflows observed in the region.Comment: 47 pages, 13 figure

    Statistical moments of scintillation light distribution analysis with dSiPMs and monolithic crystals

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    [Otros] Monolithic scintillation crystals offer the possibility to preserve the scintillation light distribution, specially when black painted. Furthermore, the statistical moments of that distribution can provide accurate information about the three spatial components. Nevertheless, for monolithic crystal the moments estimation has an associated error due to the symmetry truncation of the light distribution towards the crystal borders. For the 2-D impact coordinates determination, this error is called compression as it is accentuated near the edges. The computation of all centered moments is, therefore, affected by this error. Digital SiPMs (dSiPMs) can offer complete information about the light distribution, since all cells are purely digital detectors, so that other ways to obtain ¿-impact coordinates can be performed. In this work, a comparison between the statistical moments analysis and an alternative fitting the light distribution for each event to a theoretical distribution has been made. With the fitted approach, compression is avoided and an approximately constant spatial resolution is obtained for the entire photodetection area. Moreover, DOI information is improved and preserved all over the crystal.This work was supported by the Spanish Plan Nacional de Investigacion Científica, Desarrollo e Innovación Tecnologica (I+D+I) under Grant No. FIS2010-21216-CO2-01 and Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Conde, P.; González Martínez, AJ.; Hernández, L.; Bellido, P.; Crespo, E.; Iborra, A.; Moliner, L.... (2013). Statistical moments of scintillation light distribution analysis with dSiPMs and monolithic crystals. IEEE. 10-13. https://doi.org/10.1109/NSSMIC.2013.6829086S101

    Time reconstruction study using tubes of response backprojectors in List Mode algorithms, applied to amonolithic crystals based breast PET

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    [Otros] The LM-EM algorithm has the advantage to calculate the emission probabilities needed for the reconstruction process on the fly, without the need of a pre-calculated system matrix. The reconstruction time for this algorithm strongly depends on the used backprojector and the available statistics. This algorithm when implemented in systems using monolithic crystals to detect gamma radiation allows one to extensively exploit the virtual pixilation feature, not available for systems based on pixilated crystals. In this work we present a backprojector for LM-EM, the TOR method, which achieves a tradeoff between computational efficiency and image quality. Its temporal subset algorithm optimization (LM-OS) has also been implemented in order to achieve real-time reconstructions. To evaluate the performances of LM-OS algorithm with the TOR method backprojector and only with one iteration on the datasets, studies based on the system spatial resolution, uniformity, and contrast coefficients were carried out and they were compared with those obtained with LM-EM and MLEM algorithms using twelve iteration. Finally, a study on reconstruction time using LM-OS has been performed with breast patients dataProject funded by the Spanish Ministry of Economy and Competitiveness and co-funded with FEDER's funds within the INNPACTO 2011 program. This work was supported by the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+i) under Grant No. FIS2010-21216-CO2-01 and the Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Moliner, L.; Correcher, C.; González Martínez, AJ.; Conde, P.; Crespo, E.; Hernandez, L.; Rigla, JP.... (2013). Time reconstruction study using tubes of response backprojectors in List Mode algorithms, applied to amonolithic crystals based breast PET. IEEE. 14-18. https://doi.org/10.1109/NSSMIC.2013.6829372S141

    P. falciparum In Vitro Killing Rates Allow to Discriminate between Different Antimalarial Mode-of-Action

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    Chemotherapy is still the cornerstone for malaria control. Developing drugs against Plasmodium parasites and monitoring their efficacy requires methods to accurately determine the parasite killing rate in response to treatment. Commonly used techniques essentially measure metabolic activity as a proxy for parasite viability. However, these approaches are susceptible to artefacts, as viability and metabolism are two parameters that are coupled during the parasite life cycle but can be differentially affected in response to drug actions. Moreover, traditional techniques do not allow to measure the speed-of-action of compounds on parasite viability, which is an essential efficacy determinant. We present here a comprehensive methodology to measure in vitro the direct effect of antimalarial compounds over the parasite viability, which is based on limiting serial dilution of treated parasites and re-growth monitoring. This methodology allows to precisely determine the killing rate of antimalarial compounds, which can be quantified by the parasite reduction ratio and parasite clearance time, which are key mode-of-action parameters. Importantly, we demonstrate that this technique readily permits to determine compound killing activities that might be otherwise missed by traditional, metabolism-based techniques. The analysis of a large set of antimalarial drugs reveals that this viability-based assay allows to discriminate compounds based on their antimalarial mode-of-action. This approach has been adapted to perform medium throughput screening, facilitating the identification of fast-acting antimalarial compounds, which are crucially needed for the control and possibly the eradication of malaria

    Performance Evaluation of the Dual Ring MAMMI breast PET

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    [Otros] MAMMI is a dedicated breast positron emission tomograph (PET) based on monolythic LYSO crystals, with a transaxial field of view (FOV) of 170 mm. It has been upgraded by adding a second ring of detectors that extends the axial FOV from 40 mm to 94.4 mm, in order to improve its sensitivity and reduce the acquisition time. In this work we present the performance evaluation of the dual ring MAMMI breast PET and a discussion about the contribution of the addition of a second ring of detectors, the compensation of the detector blur and the increase of the scintillator thickness. Experimental measurements suggested on NEMA NU 4-2008 and NEMA NU 2-2007 have been conveniently adapted to the dimensions of the MAMMI. The addition of the second ring of detectors leads to a rise of the sensitivity from 1.8% to 3.6%. The spatial resolution at one-fourth of the axial FOV (1.5 mm axial, 1.6 mm tangential, 1.7 mm radial) is slightly better than that measured at the axial center (1.9 mm axial, 1.8 mm tangential and radial), because of the 14 mm gap in between detection rings. The results obtained after the evaluation reflect a substantial performance improvement, specially in the absolute sensitivity, because of the changes introduced in the MAMMI PET.This work was supported in part bythe Spanish Plan Nacional de Investigacion Científica, Desarrollo e Innovación Tecnologica (I+D+I) under Grant No. FIS2010-21216-CO2-01 and Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Soriano, A.; Sánchez, F.; Carrilero, V.; Pardo, A.; Vidal San Sebastian, LF.; Vazquez, C.; Barbera, J.... (2013). Performance Evaluation of the Dual Ring MAMMI breast PET. IEEE. 1-4. https://doi.org/10.1109/NSSMIC.2013.6829103S1

    Effect of noise in CT image reconstruction using QR- Decomposition algorithm

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    [EN] The QR-Decomposition algorithm for CT 3D image reconstruction uses a linear system of equations to model the CT system response. Linear systems have a condition number that can be used to estimate the image noise. In this work the number of projections and the number of pixels in the detector have been studied to characterize the CT and the linear system of equations. The condition number of the system is estimated for the previous parameters used to generate the CT model with the aim of characterizing how these parameters affect the condition number and therefore bound the image noise level. It is shown that the condition number mainly depends on the size of pixels of the detector rather than the number of projections and this algorithm can be applied to low dose CT 3D image reconstruction without compromising image qualityThis work was supported by the Spanish Plan Nacional de Investigacion Científica, Desarrollo e Innovación Tecnológica (I+D+I) under Grant No. FIS2010-21216-CO2-01 and Valencian Local Government under Grants PROMETEOII/2013/010 and ISIC 2011/013Iborra, A.; Rodríguez-Álvarez, MJ.; Soriano, A.; Sánchez, F.; Bellido, P.; Conde, P.; Crespo, E.... (2013). Effect of noise in CT image reconstruction using QR- Decomposition algorithm. IEEE. 5-9. http://hdl.handle.net/10251/167122S5

    Differential body composition effects of protease inhibitors recommended for initial treatment of HIV infection: A randomized clinical trial

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    This article has been accepted for publication in Clinical Infectious Diseases ©2014 The Authors .Published by Oxford University Press on Clinical Infectious Disease 60.5. DOI: 10.1093/cid/ciu898Background. It is unclear whether metabolic or body composition effects may differ between protease inhibitor-based regimens recommended for initial treatment of HIV infection. Methods. ATADAR is a phase IV, open-label, multicenter randomized clinical trial. Stable antiretroviral-naive HIV-infected adults were randomly assigned to atazanavir/ritonavir 300/100 mg or darunavir/ritonavir 800/100 mg in combination with tenofovir/emtricitabine daily. Pre-defined end-points were treatment or virological failure, drug discontinuation due to adverse effects, and laboratory and body composition changes at 96 weeks. Results. At 96 weeks, 56 (62%) atazanavir/ritonavir and 62 (71%) darunavir/ritonavir patients remained free of treatment failure (estimated difference 8.2%; 95%CI -0.6 to 21.6); and 71 (79%) atazanavir/ritonavir and 75 (85%) darunavir/ritonavir patients remained free of virological failure (estimated difference 6.3%; 95%CI -0.5 to 17.6). Seven vs. five patients discontinued atazanavir/ritonavir or darunavir/ritonavir due to adverse effects. Total and HDL cholesterol similarly increased in both arms, but triglycerides increased more in atazanavir/ritonavir arm. At 96 weeks, body fat (estimated difference 2862.2 gr; 95%CI 726.7 to 4997.7; P=0.0090), limb fat (estimated difference 1403.3 gr; 95%CI 388.4 to 2418.2; P=0.0071), and subcutaneous abdominal adipose tissue (estimated difference 28.4 cm2; 95%CI 1.9 to 55.0; P=0.0362) increased more in atazanavir/ritonavir than in darunavir/ritonavir arm. Body fat changes in atazanavir/ritonavir arm were associated with higher insulin resistance. Conclusions. We found no major differences between atazanavir/ritonavir and darunavir/ritonavir in efficacy, clinically-relevant side effects, or plasma cholesterol fractions. However, atazanavir/ritonavir led to higher triglycerides and total and subcutaneous fat than darunavir/ritonavir and fat gains with atazanavir/ritonavir were associated with insulin resistanceThis is an Investigator Sponsored Research study. It was supported in part by research grants from Bristol‐Myers Squibb and Janssen‐Cilag; Instituto de Salud Carlos III (PI12/01217) and Red Temática Cooperativa de Investigación en SIDA G03/173 (RIS‐EST11), Ministerio de Ciencia e Innovación, Spain. (Registration number: NCT01274780; registry name: ATADAR; EUDRACT; 2010‐021002‐38)
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