Metabolic and Stress Responses in Senegalese Soles (Solea senegalensis Kaup) Fed Tryptophan Supplements: E ects of Concentration and Feeding Period

The objective of this study was to assess the impact of di erent dietary Trp concentrations on the stress and metabolism response of juvenile Senegalese soles (Solea senegalensis). Fish (38.1 1.9 g) were fed di erent Trp-enriched feeds (0%, 1% and 2% Trp added) for two and eight days, and later exposed to air stress for three min. Samples were taken pre- and 1 h post-stress (condition). Plasma cortisol, lactate, glucose and proteins were significantly a ected by the sampling time, showing higher values at 1 h post-stress. Trp concentration in food also had significant e ects on lactate and glucose levels. However, the feeding period did not a ect these parameters. Post-stress values were higher than in the pre-stress condition for every plasma parameter, except for lactate in two days and 1% Trp treatment. Nevertheless, cortisol, glucose and lactate did not vary significantly between pre- and post-stress samplings in fish fed the 1% Trp-enriched diet for two days. The lack of variability in cortisol response was also due to the high pre-stress value, significantly superior to pre-stress control. The exposure time to Trp feeding did not significantly a ect any enzyme activity; however, Trp added and condition influenced protein-related enzyme activities. In spite of decreasing stress markers, Trp-enriched diets altered the protein metabolism

Calculation of multiple eigenvalues of the neutron diffusion equation discretized with a parallelized finite volume method

[EN] The spatial distribution of the neutron flux within the core of nuclear reactors is a key factor in nuclear safety. The easiest and fastest way to determine it is by solving the eigenvalue problem of the neutron diffusion equation, which only contains spatial derivatives. The approximation of these derivatives is performed by discretizing the geometry and using numerical methods. In this work, the authors used a finite volume method based on a polynomial expansion of the neutron flux. Once these terms are discretized, a set of matrix equations is obtained, which constitutes the eigenvalue problem. A very effective class of methods for the solution of eigenvalue problems are those based on projection onto a low-dimensional subspace, such as Krylov subspaces. Thus, the SLEPc library was used for solving the eigenvalue problem by means of the Krylov-Schur method, which also uses projection methods of PETSc for solving linear systems. This work includes a complete sensitivity analysis of different issues: mesh, polynomial terms, linear systems solvers and parallelization.This work has been partially supported by the Spanish Ministerio de Eduacion Cultura y Deporte under the grant FPU13/01009, the Spanish Ministerio de Ciencia e Innovacion under the project ENE2014-59442-P, the Spanish Ministerio de Economia y Competitividad and the European Fondo Europeo de Desarrollo Regional (FEDER) under the project ENE2015-68353-P (MINECO/FEDER), the Generalitat Valenciana under the project PROMETEOII/2014/008, and the Spanish Ministerio de Economia y Competitividad and the European Fondo Europeo de Desarrollo Regional (FEDER) under the project TIN2016-075985-P.Bernal-Garcia, A.; Roman, JE.; Miró Herrero, R.; Verdú Martín, GJ. (2018). Calculation of multiple eigenvalues of the neutron diffusion equation discretized with a parallelized finite volume method. Progress in Nuclear Energy. 105:271-278. https://doi.org/10.1016/j.pnucene.2018.02.006S27127810

Multigroup neutron diffusion equation with the finite volume method in reactors using MOX fuels

[EN] The use of mixed oxide (MOX) fuel to partially fill the cores of commercial light water reactors (LWRs) gives rise to a reduction of the radioactive waste and production of more energy. However, the use of MOX fuels in LWRs changes the physics characteristics of the reactor core, since the variation with energy of the cross sections for the plutonium isotopes is more complex than for the uranium isotopes. Although the neutron diffusion theory could be applied to reactors using MOX fuels, more emphasis on treatment of the energy discretization should be placed. This energy discretization could be typically 4¿8 energy groups, instead of the standard 2-energy group approach. In this work, the authors developed a finite volume method for discretizing the general multigroup neutron diffusion equation. This method solves the eigenvalue problem by using Krylov projection methods, in which the size of the vectors used for building the Krylov subspace does not depend on the number of energy groups, but it can solve the multigroup formulation with upscattering and fission production terms in several energy groups. The method was applied to MOX reactors for its validation. © 2017 Atomic Energy Society of Japan. All rights reserved.This work has been partially supported by the Spanish Ministerio de Eduacion Cultura y Deporte [grant number FPU13/01009]; the Spanish Ministerio de Ciencia e Innovacion [project ENE2014-59442-P]; the Spanish Ministerio de Economia y Competitividad and the European Fondo Europeo de Desarrollo Regional (MINECO/FEDER) [project ENE2015-68353-P]; the Generalitat Valenciana [project PROMETEOII/2014/008]; and the Spanish Ministerio de Economia y Competitividad [project TIN2016-75985-P].Bernal-Garcia, A.; Roman, JE.; Miró Herrero, R.; Verdú Martín, GJ. (2017). Multigroup neutron diffusion equation with the finite volume method in reactors using MOX fuels. Journal of Nuclear Science and Technology. 54(11):1251-1260. https://doi.org/10.1080/00223131.2017.1359120S12511260541

A Viscoplastic constitutive model with strain rate variables for asphalt mixtures’ numerical simulation

The study and development of recycling techniques for pavements is an increasing activity in engineering nowadays. This research line demands a more realistic characterization of the material properties with the aim of simulate the asphalt mixture’s response placed into a multilayered system over granular bases, under dynamic loads, considering also temperature variation or strenght reduction for cyclic loads. In order to improve the current formulations, a new viscoplastic model has been developed assuming the strain rate dependency of the material’s response observed in the experimental tests. The strain rate variable affects in a significant way the Young modulus and the viscosity parameter of the model. According to these hypothesis constitutive equations have been formulated. The mechanical variables involved have been calibrated according to experimental results, developing new expressions for the strain rate dependent parameters. The new viscoplastic model permit us to characterize the material’s response with a few mechanical values, easily obtained from standard laboratory tests. The results obtained show a good approximation to experimental laboratory curves for different rates of loading and temperatures. The model has been applied to simulate the response of a real flexible pavement structure conformed by two asphalt layers over two granular bases, that’s materials with different constitutive behaviors. Experimental tests in the recycled track have been made obtaining the horizontal strain evolution under dynamic load. Different loading rates and temperatures, as well as cracked and continuum pavement responses have been considered in the study. Strains were measured in the interface between the two asphalt layers and simulated using the here proposed model offering a fairly good approximation of the real response observed in the track, although the degree of variation even in the experimental curves is quite high. The results of this study represent a proper base for further developments in structural analysis of pavement layers, considering more complex phenomena, determinant in the long term material’s response, to develop a numerical tool for pavements’ design and lifetime prediction.Peer Reviewe

¿Cómo se evalúa por competencias? escuchando la opinión y percepción de los estudiantes

Resumen: Con el EEES hemos cambiado la forma de definir la educación: ahora ha de basarse en competencias. Esto debe significar un cambio en nuestra forma de trabajar y en nuestra forma de evaluar. Se presentan aquí resultados de una investigación sobre la evaluación por competencias. Se ha preguntado a directores de centros, profesores, empleadores y alumnos de 7 universidades y 4 titulaciones sobre la implantación de la enseñanza por competencias. Presentamos el análisis de cuál es la opinión de los estudiantes de ingeniería sobre cómo se les evalúa y la utilidad que dan a cada estrategia de evaluación. Comparamos estos resultados con los de otras titulaciones.Abstract: The EHEA made us change how we define education: now it must be based on competencies. This must change both our work in the classroom and our assessment methods. We present some results of a research project on assessment by competencies. We have asked administrators, professors, employers, and students of 7 Spanish universities in 4 degrees over the introduction of teaching with competencies. We show the analysis of the opinion of students of engineering over how they are assessed and the usefulness they award to different assessment strategies. We compare the results with students from other degrees

A Krylov-Schur solution of the eigenvalue problem for the neutron diffusion equation discretized with the Raviart-Thomas method

[EN] Mixed-dual formulations of the finite element method were successfully applied to the neutron diffusion equation, such as the Raviart¿Thomas method in Cartesian geometry and the Raviart¿Thomas¿Schneider in hexagonal geometry. Both methods obtain system matrices which are suitable for solving the eigenvalue problem with the preconditioned power method. This method is very fast and optimized, but only for the calculation of the fundamental mode. However, the determination of non-fundamental modes is important for modal analysis, instabilities, and fluctuations of nuclear reactors. So, effective and fast methods are required for solving eigenvalue problems. The most effective methods are those based on Krylov subspaces projection combined with restart, such as Krylov¿Schur. In this work, a Krylov¿Schur method has been applied to the neutron diffusion equation, discretized with the Raviart¿Thomas and Raviart¿Thomas¿Schneider methods.This work has been partially supported by the Spanish Ministerio de Eduacion Cultura y Deporte [grant number FPU13/01009]; Spanish Ministerio de Ciencia e Innovacion [project number ENE2014-59442-P]; Spanish Ministerio de Economia y Competitividad and the European Fondo Europeo de Desarrollo Regional (FEDER) [project number ENE2015-68353-P (MINECO/FEDER)]; Generalitat Valenciana [project number PROMETEOII/2014/008]; Universitat Politecnica de Valencia [project number UPPTE/2012/118]; Spanish Ministerio de Economia y Competitividad [project number TIN2016-75985-P].Bernal-Garcia, A.; Hébert, A.; Roman, JE.; Miró Herrero, R.; Verdú Martín, GJ. (2017). A Krylov-Schur solution of the eigenvalue problem for the neutron diffusion equation discretized with the Raviart-Thomas method. Journal of Nuclear Science and Technology. 54(10):1085-1094. https://doi.org/10.1080/00223131.2017.1344577S108510945410Hébert, A. (1993). Application of a dual variational formulation to finite element reactor calculations. Annals of Nuclear Energy, 20(12), 823-845. doi:10.1016/0306-4549(93)90076-2Hébert, A. (2008). A Raviart–Thomas–Schneider solution of the diffusion equation in hexagonal geometry. Annals of Nuclear Energy, 35(3), 363-376. doi:10.1016/j.anucene.2007.07.016Hébert, A. (1986). Preconditioning the Power Method for Reactor Calculations. Nuclear Science and Engineering, 94(1), 1-11. doi:10.13182/nse86-a17111Verdú, G., Ginestar, D., Vidal, V., & Muñoz-Cobo, J. L. (1994). 3D λ-modes of the neutron-diffusion equation. Annals of Nuclear Energy, 21(7), 405-421. doi:10.1016/0306-4549(94)90041-8Miró, R., Ginestar, D., Verdú, G., & Hennig, D. (2002). A nodal modal method for the neutron diffusion equation. Application to BWR instabilities analysis. Annals of Nuclear Energy, 29(10), 1171-1194. doi:10.1016/s0306-4549(01)00103-7Hébert A. Applied reactor physics. 2nd ed. Montréal: Presses Internationales Polytechnique; 2016. p. 368–369.Döring, M. G., Kalkkuhl, J. C., & Schröder, W. (1993). Subspace Iteration for Nonsymmetric Eigenvalue Problems Applied to the λ-Eigenvalue Problem. Nuclear Science and Engineering, 115(3), 244-252. doi:10.13182/nse93-a24053Modak, R. S., & Jain, V. K. (1996). Sub-space iteration scheme for the evaluation of λ-modes of finite-differenced multi-group neutron diffusion equations. Annals of Nuclear Energy, 23(3), 229-237. doi:10.1016/0306-4549(95)00015-6Singh, K. P., Modak, R. S., Degweker, S. B., & Singh, K. (2009). Iterative schemes for obtaining dominant alpha-modes of the neutron diffusion equation. Annals of Nuclear Energy, 36(8), 1086-1092. doi:10.1016/j.anucene.2009.05.006Gupta, A., & Modak, R. S. (2011). Evaluation of dominant time-eigenvalues of neutron transport equation by Meyer’s sub-space iterations. Annals of Nuclear Energy, 38(7), 1680-1686. doi:10.1016/j.anucene.2011.02.016Kópházi, J., & Lathouwers, D. (2012). Three-dimensional transport calculation of multiple alpha modes in subcritical systems. Annals of Nuclear Energy, 50, 167-174. doi:10.1016/j.anucene.2012.06.021VERDÚ, G., GINESTAR, D., ROMÁN, J., & VIDAL, V. (2010). 3D Alpha Modes of a Nuclear Power Reactor. Journal of Nuclear Science and Technology, 47(5), 501-514. doi:10.1080/18811248.2010.9711641Lathouwers, D. (2003). Iterative computation of time-eigenvalues of the neutron transport equation. Annals of Nuclear Energy, 30(17), 1793-1806. doi:10.1016/s0306-4549(03)00151-8Warsa, J. S., Wareing, T. A., Morel, J. E., McGhee, J. M., & Lehoucq, R. B. (2004). Krylov Subspace Iterations for Deterministick-Eigenvalue Calculations. Nuclear Science and Engineering, 147(1), 26-42. doi:10.13182/nse04-1Verdu, G., Miro, R., Ginestar, D., & Vidal, V. (1999). The implicit restarted Arnoldi method, an efficient alternative to solve the neutron diffusion equation. Annals of Nuclear Energy, 26(7), 579-593. doi:10.1016/s0306-4549(98)00077-2Lehoucq, R. B., Sorensen, D. C., & Yang, C. (1998). ARPACK Users’ Guide. doi:10.1137/1.9780898719628Boer, B., Lathouwers, D., Kloosterman, J. L., Van Der Hagen, T. H. J. J., & Strydom, G. (2010). Validation of the DALTON-THERMIX Code System with Transient Analyses of the HTR-10 and Application to the PBMR. Nuclear Technology, 170(2), 306-321. doi:10.13182/nt10-a9485Hernandez, V., Roman, J. E., & Vidal, V. (2005). SLEPc. ACM Transactions on Mathematical Software, 31(3), 351-362. doi:10.1145/1089014.1089019Hernández, V., Román, J. E., & Vidal, V. (2003). SLEPc: Scalable Library for Eigenvalue Problem Computations. High Performance Computing for Computational Science — VECPAR 2002, 377-391. doi:10.1007/3-540-36569-9_25Stewart, G. W. (2002). A Krylov--Schur Algorithm for Large Eigenproblems. SIAM Journal on Matrix Analysis and Applications, 23(3), 601-614. doi:10.1137/s0895479800371529Chao, Y. A., & Shatilla, Y. A. (1995). Conformal Mapping and Hexagonal Nodal Methods —II: Implementation in the ANC-H Code. Nuclear Science and Engineering, 121(2), 210-225. doi:10.13182/nse95-a2855

Daptomycin Plus Fosfomycin Versus Daptomycin Alone for Methicillin-resistant Staphylococcus aureus Bacteremia and Endocarditis: A Randomized Clinical Trial

Bacteremia; Daptomycin; FosfomycinBacterièmia; Daptomicina; FosfomicinaBacteriemia; Daptomicina; FosfomicinaBackground We aimed to determine whether daptomycin plus fosfomycin provides higher treatment success than daptomycin alone for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and endocarditis. Methods A randomized (1:1) phase 3 superiority, open-label, and parallel group clinical trial of adult inpatients with MRSA bacteremia was conducted at 18 Spanish hospitals. Patients were randomly assigned to receive either 10 mg/kg of daptomycin intravenously daily plus 2 g of fosfomycin intravenously every 6 hours, or 10 mg/kg of daptomycin intravenously daily. Primary endpoint was treatment success 6 weeks after the end of therapy. Results Of 167 patients randomized, 155 completed the trial and were assessed for the primary endpoint. Treatment success at 6 weeks after the end of therapy was achieved in 40 of 74 patients who received daptomycin plus fosfomycin and in 34 of 81 patients who were given daptomycin alone (54.1% vs 42.0%; relative risk, 1.29 [95% confidence interval, .93–1.8]; P = .135). At 6 weeks, daptomycin plus fosfomycin was associated with lower microbiologic failure (0 vs 9 patients; P = .003) and lower complicated bacteremia (16.2% vs 32.1%; P = .022). Adverse events leading to treatment discontinuation occurred in 13 of 74 patients (17.6%) receiving daptomycin plus fosfomycin, and in 4 of 81 patients (4.9%) receiving daptomycin alone (P = .018). Conclusions Daptomycin plus fosfomycin provided 12% higher rate of treatment success than daptomycin alone, but this difference did not reach statistical significance. This antibiotic combination prevented microbiological failure and complicated bacteremia, but it was more often associated with adverse events.This work was supported by the Spanish Ministry of Science, Innovation and Universities (PI12/01907); Spanish Network for Research in Infectious Diseases (RD16/0016/0005); Instituto de Salud Carlos III (ISCIII); and Spanish Ministry of Economy, Industry and Competitiveness. This work was also supported by the European Development Regional Fund “A way to achieve Europe,” Operational Programme Intelligent Growth 2014–2020; Spanish Clinical Research Network (SCReN), co-financed by the Plan Nacional de I+D and ISCIII, Subdirección General de Evaluación y Fomento de la Investigación (PT13/0002/0007); and the Grupo de Estudio de la Infección Relacionada con la Asistencia Sanitaria. J. M.-M. received a personal 80:20 research grant from the Institut d’Investigacions Biomèdiques Agust Pi i Sunyer, Barcelona, Spain, during 2017–2021

Predictors of Global Non-Motor Symptoms Burden Progression in Parkinson's Disease. Results from the COPPADIS Cohort at 2-Year Follow-Up

Malaltia de Parkinson; Símptomes no motors; ProgressióEnfermedad de Parkinson; Sintomas no motores; ProgresiónParkinson’s disease; Non-motor symptoms; ProgressionBackground and Objective: Non-motor symptoms (NMS) progress in different ways between Parkinson’s disease (PD) patients. The aim of the present study was to (1) analyze the change in global NMS burden in a PD cohort after a 2-year follow-up, (2) to compare the changes with a control group, and (3) to identify predictors of global NMS burden progression in the PD group. Material and Methods: PD patients and controls, recruited from 35 centers of Spain from the COPPADIS cohort from January 2016 to November 2017, were followed-up with after 2 years. The Non-Motor Symptoms Scale (NMSS) was administered at baseline (V0) and at 24 months ± 1 month (V2). Linear regression models were used for determining predictive factors of global NMS burden progression (NMSS total score change from V0 to V2 as dependent variable). Results: After the 2-year follow-up, the mean NMS burden (NMSS total score) significantly increased in PD patients by 18.8% (from 45.08 ± 37.62 to 53.55 ± 42.28; p < 0.0001; N = 501; 60.2% males, mean age 62.59 ± 8.91) compared to no change observed in controls (from 14.74 ± 18.72 to 14.65 ± 21.82; p = 0.428; N = 122; 49.5% males, mean age 60.99 ± 8.32) (p < 0.0001). NMSS total score at baseline (β = −0.52), change from V0 to V2 in PDSS (Parkinson’s Disease Sleep Scale) (β = −0.34), and change from V0 to V2 in NPI (Neuropsychiatric Inventory) (β = 0.25) provided the highest contributions to the model (adjusted R-squared 0.41; Durbin-Watson test = 1.865). Conclusions: Global NMS burden demonstrates short-term progression in PD patients but not in controls and identifies worsening sleep problems and neuropsychiatric symptoms as significant independent predictors of this NMS progression.This research was funded by Fundación Española de Ayuda a la Investigación en Parkinson y otras Enfermedades Neuro-degenerativa

Predictors of clinically significant quality of life impairment in Parkinson’s disease

Parkinson's disease; Quality of lifeEnfermedad de Parkinson; Calidad de vidaMalaltia de Parkinson; Qualitat de vidaQuality of life (QOL) plays an important role in independent living in Parkinson’s disease (PD) patients, being crucial to know what factors impact QoL throughout the course of the disease. Here we identified predictors of QoL impairment in PD patients from a Spanish cohort. PD patients recruited from 35 centers of Spain from the COPPADIS cohort from January 2016, to November 2017, were followed up during 2 years. Health-related QoL (HRQoL) and global QoL (GQoL) were assessed with the 39-item Parkinson’s disease Questionnaire (PDQ-39) and the EUROHIS-QOL 8-item index (EUROHIS-QOL8), respectively, at baseline (V0) and at 24 months ± 1 month (V2). Clinically significant QoL impairment was defined as presenting an increase (PDQ-39SI) or decrement (EUROHIS-QOL8) at V2 ≥ 10% of the score at baseline (V0). A comparison with a control group was conducted for GQoL. GQoL did not change significantly in PD patients (N = 507; p = 0.686) or in the control group (N = 119; p = 0.192). The mean PDQ-39SI was significantly increased in PD patients (62.7 ± 8.5 years old; 58.8% males; N = 500) by 21.6% (from 16.7 ± 13 to 20.3 ± 16.4; p < 0.0001) at V2. Ninety-three patients (18.6%) presented a clinically significant HRQoL impairment at V2. To be younger (OR = 0.896; 95% CI 0.829–0.968; p = 0.006), to be a female (OR = 4.181; 95% CI 1.422–12.290; p = 0.009), and to have a greater increase in BDI-II (Beck Depression Inventory-II) (OR = 1.139; 95% CI 1.053–1.231; p = 0.001) and NMSS (Non-Motor Symptoms Scale) (OR = 1.052; 95% CI 1.027–1.113; p < 0.0001) total scores from V0 to V2 were associated with clinically significant HRQoL impairment at the 2-year follow-up (Hosmer–Lemeshow test, p = 0.665; R 2 = 0.655). An increase in ≥5 and ≥10 points of BDI-II and NMSS total score at V2 multiplied the probability of presenting clinically significant HRQoL impairment by 5 (OR = 5.453; 95% CI 1.663–17.876; p = 0.005) and 8 (OR = 8.217; 95% CI, 2.975–22.696; p = 0.002), respectively. In conclusion, age, gender, mood, and non-motor impairment were associated with clinically significant HRQoL impairment after the 2-year follow-up in PD patients