Diseño estadístico y análisis de datos

StatData

RESEARCH GROUP

Research Areas

  • Diseño de experimentos: clásico y óptimo
  • Modelización: Modelos lineales, lineales generalizados y no lineales; modelos mixtos; selección de variables; discriminación de modelos; modelos no paramétricos; modelos bayesianos; estadística espacio-temporal.
  • Muestreo; diseño, validación y análisis de encuentas.
  • Métodos cuantitativos en el tratamiento de datos experimentales.
  • Técnicas estadísticas de tratamiento de Big Data: Reducción de variables; modelos de clasificación; algoritmos heurísticos y meta-heurísticos de optimización, Machine Learning; aplicación del diseño de experimentos en la búsqueda de máxima información.

Keywords

  • Diseño de experimentos
  • Encuentas
  • Estadística Bayesiana
  • Machine Learning
  • Modelización
  • Muestreo
  • Tratamiento Estadístico de Big Data

Scientific Publications (since 2018)

  • Author: Íñigo Marco, Ignacio; Isturiz, J.; Fernández, M.; et al.
    Journal: ANNALS OF BIOMEDICAL ENGINEERING
    ISSN 0090-6964 Vol.49 N° 2 2021 pp. 746 - 756
    Abstract
    Imaging of small laboratory animals in clinical MRI scanners is feasible but challenging. Compared with dedicated preclinical systems, clinical scanners have relatively low B(0)field (1.5-3.0 T) and gradient strength (40-60 mT/m). This work explored the use of wireless inductively coupled coils (ICCs) combined with appropriate pulse sequence parameters to overcome these two drawbacks, with a special emphasis on the optimization of the coil passive detuning circuit for this application. A Bengal rose photothrombotic stroke model was used to induce cortical infarction in rats and mice. Animals were imaged in a 3T scanner using T2 and T1-weighted sequences. In all animals, the ICCs allowed acquisition of high-quality images of the infarcted brain at acute and chronic stages. Images obtained with the ICCs showed a substantial increase in SNR compared to clinical coils (by factors of 6 in the rat brain and 16-17 in the mouse brain), and the absence of wires made the animal preparation workflow straightforward.
  • Author: Solis-Barquero, S.; Echeverria-Chasco, R.; Calvo Imirizaldu, Marta; et al.
    Journal: FRONTIERS IN PHYSIOLOGY
    ISSN 1664-042X Vol.12 2021 pp. 621720
    Abstract
    A pseudocontinuous arterial spin labeling (PCASL) sequence combined with background suppression and single-shot accelerated 3D RARE stack-of-spirals was used to evaluate cerebrovascular reactivity (CVR) induced by breath-holding (BH) in ten healthy volunteers. Four different models designed using the measured change in PETCO2 induced by BH were compared, for CVR quantification. The objective of this comparison was to understand which regressor offered a better physiological model to characterize the cerebral blood flow response under BH. The BH task started with free breathing of 42 s, followed by interleaved end-expiration BHs of 21 s, for ten cycles. The total scan time was 12 min and 20 s. The accelerated readout allowed the acquisition of PCASL data with better temporal resolution than previously used, without compromising the post-labeling delay. Elevated CBF was observed in most cerebral regions under hypercapnia, which was delayed with respect to the BH challenge. Significant statistical differences in CVR were obtained between the different models in GM (p < 0.0001), with ramp models yielding higher values than boxcar models and between the two tissues, GM and WM, with higher values in GM, in all the models (p < 0.0001). The adjustment of the ramp amplitude during each BH cycle did not improve the results compared with a ramp model with a constant amplitude equal to the mean PETCO2 change during the experiment.
  • Author: Aramendia Vidaurreta, Verónica; Echeverria-Chasco, R. ; Vidorreta, M. ; et al.
    Journal: JOURNAL OF MAGNETIC RESONANCE IMAGING
    ISSN 1053-1807 Vol.53 N° 3 2021 pp. 777 - 788
    Abstract
    Background Myocardial perfusion is evaluated in first-pass MRI using a gadolinium-based contrast agent, which limits its repeatability and restricts its use in patients with abnormal kidney function. Arterial spin labeling (ASL) is a promising technique for measuring myocardial perfusion without contrast injection. The ratio of stress to rest perfusion, termed myocardial perfusion reserve (MPR), is an indicator of the severity of stenosis in patients with coronary artery disease (CAD). Purpose To quantify perfusion increases with pharmacological vasodilation, explore MPR differences between segments with and without perfusion defects, and examine the correlations between quantitative ASL and semiquantitative first-pass measurements. Study Type Prospective. Subjects Sixteen patients with suspected CAD: 10 classified as "healthy," having normal perfusion on first-pass and no enhancement on late gadolinium enhancement (LGE), and six as "nonhealthy," having hypoperfused segments including ischemic and infarcted. Field Strength/Sequence Flow-sensitive alternating inversion recovery (FAIR) rest-stress cardiac ASL with balanced steady-state free precession (bSSFP), rest-stress first-pass imaging using gradient-echo and LGE using a phase-sensitive inversion-recovery bSSFP at 1.5T. Assessment For healthy subjects, rest-stress perfusion data were compared in global, coronary artery territory, and segment regions of interest (ROIs). A segmental MPR comparison was performed between normal segments from healthy subjects and abnormal segments from nonhealthy subjects. Correlations between ASL and first-pass parameters were explored. Statistical Tests Wilcoxon-signed-rank test, nonparametric factorial analysis of variance (ANOVA), and Pearson's/Spearman's correlations. Results Perfusion increases were significant globally (P= 0.005), per coronary artery territory (P= 0.015), and per segment (P= 0.03 for all segments in ASL and first-pass, except anteroseptal in ASLP= 0.04). MPR differences between normal and abnormal segments were significant (P= 0.0028: ASL,P= 0.033: first-pass). ASL and first-pass measurements were correlated (MPR:r =0.64,P= 0.008 and perfusion:rho= 0.47,P= 0.007). Data Conclusion This study demonstrates the feasibility of ASL to detect hyperemia, the potential to differentiate segments with and without perfusion defects, and significant correlations between ASL and semiquantitative first-pass. Level of Evidence 2 Technical Efficacy Stage 1
  • Author: Aguilar, C.; Serna-Jiménez, J.; Benítez Sastoque, Edgar Ricardo; et al.
    Journal: ULTRASONICS SONOCHEMISTRY
    ISSN 1350-4177 Vol.72 2021 pp. 105415
    Abstract
    Raw meat emulsions may have natural, spoilage and pathogenic microorganisms due to the origin and characteristics of this food matrix. All of these microorganisms must be minimized during industrial processing to make food consumption safe and meet quality regulations. Therefore, in this research, the effect of probe ultrasound on the inactivation of three kinds of microorganisms in a raw meat emulsion is evaluated. The microorganisms are: natural microflora NAM, Listeria monocytogenes LIS, and Lactobacillus delbrueckii LAC. A high-intensity probe ultrasound system was used, during 1.0, 2.5, 5.0, 7.5 and 10 min, with pulsed waves of 0.0, 10, 20 and 30 seg, and 200, 250, 300, 350 and 400 W of power. The interrelation between time, wave pulse cycle, and power factors was assessed. The results showed a positive linear independence effect in the treatments without wave pulse for each microorganism, and a quadratic interaction with the time and the ultrasound power for the inactivation of the three kinds of microorganisms. Besides, the desirability function for the inactivation reached up to 60% of the microbial population with the probe ultrasound treatment, with 10 min, a 7.56 s wave pulse and 400 W of power. Thus, these results could be useful to decide the incorporation of mild and emerging technologies in a meat industry line process.
  • Author: Garcia-Rodenas, R. (Autor de correspondencia); Garcia-Garcia, J. C.; López Fidalgo, Jesús Fernando; et al.
    Journal: COMPUTATIONAL STATISTICS AND DATA ANALYSIS
    ISSN 0167-9473 Vol.144 2020 pp. 106844
    Abstract
    Several common general purpose optimization algorithms are compared for finding A- and D-optimal designs for different types of statistical models of varying complexity, including high dimensional models with five and more factors. The algorithms of interest include exact methods, such as the interior point method, the Nelder Mead method, the active set method, the sequential quadratic programming, and metaheuristic algorithms, such as particle swarm optimization, simulated annealing and genetic algorithms. Several simulations are performed, which provide general recommendations on the utility and performance of each method, including hybridized versions of metaheuristic algorithms for finding optimal experimental designs. A key result is that general-purpose optimization algorithms, both exact methods and metaheuristic algorithms, perform well for finding optimal approximate experimental designs. (C) 2019 Elsevier B.V. All rights reserved.
  • Author: Bueicheku, E.; Aznárez Sanado, Maite; Diez, I.; et al.
    Journal: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
    ISSN 0027-8424 Vol.117 N° 12 2020 pp. 6836 - 6843
    Abstract
    Visuomotor impairments characterize numerous neurological disorders and neurogenetic syndromes, such as autism spectrum disorder (ASD) and Dravet, Fragile X, Prader-Willi, Turner, and Williams syndromes. Despite recent advances in systems neuroscience, the biological basis underlying visuomotor functional impairments associated with these clinical conditions is poorly understood. In this study, we used neuroimaging connectomic approaches to map the visuomotor integration (VMI) system in the human brain and investigated the topology approximation of the VMI network to the Allen Human Brain Atlas, a whole-brain transcriptome-wide atlas of cortical genetic expression. We found the genetic expression of four genes-TBR1, SCN1A, MAGEL2, and CACNB4-to be prominently associated with visuomotor integrators in the human cortex. TBR1 gene transcripts, an ASD gene whose expression is related to neural development of the cortex and the hippocampus, showed a central spatial allocation within the VMI system. Our findings delineate gene expression traits underlying the VMI system in the human cortex, where specific genes, such as TBR1, are likely to play a central role in its neuronal organization, as well as on specific phenotypes of neurogenetic syndromes.
  • Author: López Fidalgo, Jesús Fernando; Amo-Salas, M. (Autor de correspondencia)
    Journal: RADIATION PHYSICS AND CHEMISTRY
    ISSN 0969-806X Vol.174 2020 pp. 108917
    Abstract
    In this paper, the tools provided by the theory of Optimal Experimental Design are applied to a nonlinear calibration model. This is motivated by the need of estimating radiation doses using radiochromic films for radiotherapy purposes. The calibration model is in this case nonlinear and the explanatory variable cannot be worked out explicitly from the model. In this case an experimental design has to be found on the dependent variable. For that, the inverse function theorem will be used to obtain an information matrix to be optimized. Optimal designs on the response variable are computed from two different perspectives, first for fitting the model and estimating each of the parameters and then for predicting the proper dose. While the first is a common point of view in a general context of the Optimal Experimental Design, the latter is actually the main objective of the calibration problem for the practitioners and algorithms for computing these optimal designs are also provided. The optimal designs obtained have just three different points in their support, but practitioners usually demand for more support points. Thus, a methodology for computing space-filling designs is also provided when the support points are forced to follow some mathematical rule, such as arithmetic or geometric sequences. Cross efficiencies of all these designs are computed in order to show their ability for different goals.
  • Author: Higueras, M. (Autor de correspondencia); Howes, A. ; López Fidalgo, Jesús Fernando
    Journal: INTERNATIONAL JOURNAL OF RADIATION BIOLOGY
    ISSN 0955-3002 Vol.96 N° 7 2020 pp. 894 - 902
    Abstract
    Purpose:To introduce optimal experimental design techniques in the cytogenetic biological dosimetry practice. This includes the development of a new optimality criterion for the calibration of radiation doses. Materials and methods:The most typical optimal design criterion and the one developed in this research are introduced and applied in an example from the literature. In another example from the literature, a simulation study has been performed to compare the standard error of the dose estimation using different experimental designs. An RStudio project and a GitHub project have been developed to reproduce these results. Results:In the paper, it is observed that the application of optimal experimental design techniques can reduce the standard error of biodosimetric dose estimations. Conclusions:Optimal experimental design techniques jointly with practitioners' requirements may be applied. This practice would not involve an additional laboratory work.
  • Author: Antony, Jiju; Viles Díez, Elisabeth; Fonseca, Alexandre; et al.
    Journal: THE TQM JOURNAL
    ISSN 1754-2731 Vol.32 N° 6 2020 pp. 1159 - 1175
  • Author: Mendichovszky, I.; Pullens, P. ; Dekkers, I.; et al.
    Journal: MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE
    ISSN 0968-5243 Vol.33 N° 1 2020 pp. 131 - 140
    Abstract
    Purpose The potential of renal MRI biomarkers has been increasingly recognised, but clinical translation requires more standardisation. The PARENCHIMA consensus project aims to develop and apply a process for generating technical recommendations on renal MRI. Methods A task force was formed in July 2018 focused on five methods. A draft process for attaining consensus was distributed publicly for consultation and finalised at an open meeting (Prague, October 2018). Four expert panels completed surveys between October 2018 and March 2019, discussed results and refined the surveys at a face-to-face meeting (Aarhus, March 2019) and completed a second round (May 2019). Results A seven-stage process was defined: (1) formation of expert panels; (2) definition of the context of use; (3) literature review; (4) collection and comparison of MRI protocols; (5) consensus generation by an approximate Delphi method; (6) reporting of results in vendor-neutral and vendor-specific terms; (7) ongoing review and updating. Application of the process resulted in 166 consensus statements. Conclusion The process generated meaningful technical recommendations across very different MRI methods, while allowing for improvement and refinement as open issues are resolved. The results are likely to be widely supported by the renal MRI community and thereby promote more harmonisation.
  • Author: Beltrán, A. P.; Benítez Sastoque, Edgar Ricardo; Rondon, M.; et al.
    Journal: BREAST CANCER
    ISSN 1178-2234 Vol.14 2020 pp. UNSP 1178223420904939
    Abstract
    PURPOSE: Ubiquitin ligase genes can act as oncogenes or tumor suppressor genes. They play a role in various diseases, including development and progression of breast cancer; the objective of this study was to evaluate the association of common variants in the ductal-epithelium-associated RING chromosome 1 (DEAR1) gene with breast cancer risk in a sample of Colombian population. METHODS: We carried out a case-control study to investigate associations of variants in DEAR1 with breast cancer in women from Colombia. Single nucleotide polymorphisms (SNPs) rs584298, rs2927970, rs59983645, and rs599167 were genotyped in 1022 breast cancer cases and 1023 healthy controls using the iPLEX (R) and Kompetitive Allele Specific PCR ( polymerase chain reaction) (KASP) method. The associations between SNPs and breast cancer were examined by conditional logistic regression. The associations between SNPs and epidemiological/histopathological variables were examined by multinomial logistic regression. RESULTS : Associations were found between tag SNPs and breast cancer adjusted for the epidemiological risk factors rs584298 genotypes AG and GG (P =.048 and P =.004, respectively). The analysis of the disease characteristics showed that SNP rs584298 (genotype AG) (P =.015) shows association with progesterone receptor (PR) status and (genotype AA) (P =.048) shows association with human epidermal growth factor receptor 2 (HER2) status. CONCLUSIONS : The SNP rs584298 in DEAR1 showed associations with breast cancer and the expression of HER2 receptor; when this receptor is amplified, the result is aggressive tumoral subtype and expression of PR receptor that is associated with high-proliferative tumor grade. Validation of this SNP is important to establish whether this variant or the tagged variant is the cause for the risk association showed.
  • Author: Iriarte Redín, Concha (Autor de correspondencia); Ibarrola García, Sara; Aznárez Sanado, Maite
    Journal: REVISTA ESPAÑOLA DE PEDAGOGIA
    ISSN 0034-9461 Vol.78 N° 276 2020 pp. 309 - 326
    Abstract
    This study is part of a research project into coexistence and school mediation. Its aim is to develop a tool (short version) to measure moral, emotional, and socio-cognitive training and the socio-personal impact of mediation on mediating pupils and teachers and mediated pupils. The theoretical starting model on which the development of this tool is based is the Educational Model for Development of Competences through. Mediation (EMODESM). Methodology: the design is based on combining three previously-published questionnaires to create a single tool for evaluating mediation. The construct validity of this tool was studied in two phases. First, a sample of school students (n = 102) from Navarra (Spain) was evaluated, which gave rise to the revision of the tool. Second, the construct validity (confirmatory and exploratory factor analysis) and reliability (Cronbach's alpha [alpha]) of the revised tool were assessed with a new sample of school students (n = 140) from the Autonomous Community of Valencia. Results: we present a mediation assessment tool (MEQ) with 23 items and four dimensions: social impact, the interpersonal emotional area, the personal emotional area, and the moral cognition area. The reliability of the questionnaire showed appropriate values (alpha(Total) = 0.9497; alpha(Perception-SocialImpact) = 0.7896 ; alpha(EmotionalInterpersoal) = 0.7690; alpha(EmouonalPersonal) =0.8672; alpha(CognitiveMoral) = 0.9402). Discussion: the structure of factors shown by the MEQ
  • Author: Boer, A.; Villa, G.; Bane, O. ; et al.
    Journal: JOURNAL OF MAGNETIC RESONANCE IMAGING
    ISSN 1053-1807 2020
    Abstract
    Background Phase-contrast (PC) MRI is a feasible and valid noninvasive technique to measure renal artery blood flow, showing potential to support diagnosis and monitoring of renal diseases. However, the variability in measured renal blood flow values across studies is large, most likely due to differences in PC-MRI acquisition and processing. Standardized acquisition and processing protocols are therefore needed to minimize this variability and maximize the potential of renal PC-MRI as a clinically useful tool. Purpose To build technical recommendations for the acquisition, processing, and analysis of renal 2D PC-MRI data in human subjects to promote standardization of renal blood flow measurements and facilitate the comparability of results across scanners and in multicenter clinical studies. Study Type Systematic consensus process using a modified Delphi method. Population Not applicable. Sequence Field/Strength Renal fast gradient echo-based 2D PC-MRI. Assessment An international panel of 27 experts from Europe, the USA, Australia, and Japan with 6 (interquartile range 4-10) years of experience in 2D PC-MRI formulated consensus statements on renal 2D PC-MRI in two rounds of surveys. Starting from a recently published systematic review article, literature-based and data-driven statements regarding patient preparation, hardware, acquisition protocol, analysis steps, and data reporting were formulated. Statistical Tests Consensus was defined as >= 75% unanimity in response, and a clear preference was defined as 60-74% agreement among the experts. Results Among 60 statements, 57 (95%) achieved consensus after the second-round survey, while the remaining three showed a clear preference. Consensus statements resulted in specific recommendations for subject preparation, 2D renal PC-MRI data acquisition, processing, and reporting. Data Conclusion These recommendations might promote a widespread adoption of renal PC-MRI, and may help foster the set-up of multicenter studies aimed at defining reference values and building larger and more definitive evidence, and will facilitate clinical translation of PC-MRI. Level of Evidence 1 Technical Efficacy Stage 1
  • Author: Nery, F.; Buchanan, C. E. ; Harteveld, A. A. ; et al.
    Journal: MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE
    ISSN 0968-5243 Vol.33 N° 1 2020 pp. 141 - 161
    Abstract
    Objectives This study aimed at developing technical recommendations for the acquisition, processing and analysis of renal ASL data in the human kidney at 1.5 T and 3 T field strengths that can promote standardization of renal perfusion measurements and facilitate the comparability of results across scanners and in multi-centre clinical studies. Methods An international panel of 23 renal ASL experts followed a modified Delphi process, including on-line surveys and two in-person meetings, to formulate a series of consensus statements regarding patient preparation, hardware, acquisition protocol, analysis steps and data reporting. Results Fifty-nine statements achieved consensus, while agreement could not be reached on two statements related to patient preparation. As a default protocol, the panel recommends pseudo-continuous (PCASL) or flow-sensitive alternating inversion recovery (FAIR) labelling with a single-slice spin-echo EPI readout with background suppression and a simple but robust quantification model. Discussion This approach is considered robust and reproducible and can provide renal perfusion images of adequate quality and SNR for most applications. If extended kidney coverage is desirable, a 2D multislice readout is recommended. These recommendations are based on current available evidence and expert opinion. Nonetheless they are expected to be updated as more data become available, since the renal ASL literature is rapidly expanding.
  • Author: Lleo De Nalda, Álvaro (Autor de correspondencia); Viles Díez, Elisabeth; Jurburg, D. ; et al.
    Journal: INTERNATIONAL JOURNAL OF QUALITY AND SERVICE SCIENCES
    ISSN 1756-669X Vol.12 N° 3 2020 pp. 229 - 245
    Abstract
    Purpose This paper aims to identify key middle manager trustworthy behaviours that encourage employees' participation in continuous improvement activities in industrial contexts. Design/methodology/approach The list of behaviours has been developed in two different phases. First, the authors conducted two concept mappings with operators and middle managers and, subsequently, the authors combined and integrated both points of view. Second, the authors developed an expert panel with researchers, consultants and experienced practitioners of industrial management for debugging and reducing the results, presenting the final list of behaviours. Findings This work presents 55 different middle manager trustworthy behaviours divided into four different categories: human qualities; training and development; technical and managerial competencies; and team building. Research limitations/implications This paper contributes to existing literature about sustainable continuous improvement systems highlighting the role of middle managers and proposes a set of specific middle manager trustworthy behaviours for increasing supervisors' influence on operator participation. Originality/value After extracting the knowledge of different stakeholders, the list of behaviours identified can serve as a useful tool for recruiting, training, evaluating and developing a supervisors' managerial style that enhances operator participation in continuous improvement activities.
  • Author: Pereira-Sanchez, V. ; Franco, A.; de Castro Manglano, María Pilar; et al.
    Journal: BIOLOGICAL PSYCHIATRY
    ISSN 0006-3223 Vol.87 N° 9 2020 pp. S19 - S20
  • Author: Englund, E. K.; Fernández Seara, María Asunción; Rodriguez-Soto, A. E.; et al.
    Journal: JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM
    ISSN 0271-678X 2019
    Abstract
    Functional MRI (fMRI) can identify active foci in response to stimuli through BOLD signal fluctuations, which represent a complex interplay between blood flow and cerebral metabolic rate of oxygen (CMRO2) changes. Calibrated fMRI can disentangle the underlying contributions, allowing quantification of the CMRO2 response. Here, whole-brain venous oxygen saturation (Y-v ) was computed alongside ASL-measured CBF and BOLD-weighted data to derive the calibration constant, M, using the proposed Y-v -based calibration. Data were collected from 10 subjects at 3T with a three-part interleaved sequence comprising background-suppressed 3D-pCASL, 2D BOLD-weighted, and single-slice dual-echo GRE (to measure Y (v) via susceptometry-based oximetry) acquisitions while subjects breathed normocapnic/normoxic, hyperoxic, and hypercapnic gases, and during a motor task. M was computed via Y-v -based calibration from both hypercapnia and hyperoxia stimulus data, and results were compared to conventional hypercapnia or hyperoxia calibration methods. Mean M in gray matter did not significantly differ between calibration methods, ranging from 8.5 +/- 2.8% (conventional hyperoxia calibration) to 11.7 +/- 4.5% (Y-v-based calibration in response to hyperoxia), with hypercapnia-based M values between (p = 0.56). Relative CMRO2 changes from finger tapping were computed from each M map. CMRO2 increased by similar to 20% in the motor cortex, and good agreement was observed between the conventional and proposed calibration methods.
  • Author: Zazpe García, Itzíar; Santiago Neri, Susana; de la Fuente Arrillaga, María del Carmen; et al.
    Journal: JMIR PUBLIC HEALTH AND SURVEILLANCE
    ISSN 2369-2960 Vol.5 N° 4 2019 pp. e11997
    Abstract
    Web-based questionnaires allow collecting data quickly, with minimal costs from large sample groups and through Web-based self-administered forms. Until recently, there has been a lack of evidence from large-scale epidemiological studies and nutrition surveys that have evaluated the comparison between traditional and new technologies to measure dietary intake.
  • Author: Portilla Manjón, Idoia
    Journal: NUEVAS TENDENCIAS
    ISSN 1139-8124 Vol.102 2019 pp. 10 - 16
    Abstract
    En la era del Big Data las empresas se enfrentan al reto de manejar datos que puedan permitir la identificación del sujeto. La legislación no nos impide acumular información pero, si se trata de datos personales, nos exige protegerlos adecuadamente.
  • Author: Ángel-Rendón, S. V.; Filomena-Ambrosio, A.; Cordon-Díaz, S.; et al.
    Journal: INTERNATIONAL JOURNAL OF GASTRONOMY AND FOOD SCIENCE
    ISSN 1878-450X Vol.17 2019 pp. 100164
    Abstract
    Ohmic heating is a novel technique that, until the past two decades, had been underutilized in the industry, particularly because of limitations in the development of applied devices. In recent years, ohmic heating applications have been studied in different varieties of food processing (i.e.: pork, beef, turkey, rice). This technique potentially represents an innovative application for the gastronomic sector. In this research, the aim was to evaluate the application of ohmic cooking regarding water holding capacity, cooking loss and pork short shank colour. Ohmic cooking was used for 2, 2.5, and 3 min at an electric field strength of 21 +/- 1 V/cm, and the results were compared to pan cooking for 13 min. There were no significant differences between the cooking methods regarding cooking loss; however, significant differences concerning water holding capacity and change in colour (Delta E) were found for ohmic cooking treatments at 2 min and 2.5 min, respectively. It was found that for the ohmic cooking process of pork meat samples brined with saltwater concentrations below 2.1% (w/w NaCl), the electrical conductivity values are generally low, and are not sufficient for the cooking of meat samples at these conditions. Thus, ohmic heating of short shank compared to pan cooking represents an advantage with respect to cooking time for the gastronomic sector.
  • Author: Echarri-Iribarren, V. (Autor de correspondencia); Echarri Iribarren, Fernando; Rizo-Maestre, C.
    Journal: APPLIED ENERGY
    ISSN 0306-2619 Vol.233 - 234 2019 pp. 959 - 974
    Abstract
    In the field of architecture, there is a growing awareness as to the relevance of using building materials that are produced in same geographical area as the buildings to be constructed. Important implications of these projects include environmental impact reductions deriving from less energy needed for transporting the materials, as well as the activation of the regional economy by promoting local materials. Effects are all the more significant in the case of emblematic buildings with repercussions in the media, in which aesthetic criteria are often placed before functional ones. This study examines the case of the Museu de Bellas Artes de Castellon (the Fine Arts Museum in Castellon, Spain). Cast aluminium recycled panels were used for the facade's finishing material. Based on life cycle analysis (LCA), a comparison with the scenario of having used large-format ceramic panels, produced in the region in which the building is located, is given. A new evaluation methodology, Life Cycle Construction Assessment of Envelopes (LCCA-e) was applied, introducing the analysis of constructive improvements derived from the application of new facade materials. The reduction of derived environmental impacts was evaluated, obtaining 65.6% and 67.7% of the GER and GWP indicators in the production phase and a reduction of these indicators by 87.1% and 86.8% respectively in the complete LCA. This was also due to the reduction of energy needed for transport, as well as a reduction in annual energy demand by 8.55%, evaluated by monitoring, calibration and simulation using EnergyPlus.
  • Author: Galera Peral, Francisco; García del Barrio, Pedro; Mendi Güemes, Pedro (Autor de correspondencia)
    Journal: JOURNAL OF REGULATORY ECONOMICS
    ISSN 0922-680X Vol.55 N° 1 2019 pp. 33 - 45
    Abstract
    A well-known result with important policy implications is that an output increase is a necessary condition for social welfare to increase with third-degree price discrimination. In this paper, we explore the robustness of this result to the introduction of an assumption that is different than the conventional approach, namely preferences not being quasilinear. We show that in the presence of income differences among consumers, the aggregate utility of consumers may increase with price discrimination while total output remains constant. This result questions the general policy recommendation that third-degree price discrimination should be disapproved because it reduces welfare unless output increases. Our result highlights the crucial role of the assumption of quasilinear preferences in standard welfare calculations. In the presence of income differences, consumer surplus may be a biased welfare measure, thus potentially leading to incorrect conclusions when assessing the impact of specific policies.
  • Author: López Fidalgo, Jesús Fernando (Autor de correspondencia); Sánchez, J. G.
    Journal: STOCHASTIC ENVIRONMENTAL RESEARCH AND RISK ASSESSMENT
    ISSN 1436-3240 Vol.33 N° 3 2019 pp. 905 - 914
    Abstract
    Bioassays are applied to workers and other people exposed to radiation through routine or accidental intake of radioactive isotopes. The quantity of the isotope intake by an individual can be estimated from the measured quantities in the bioassays using the corresponding retention or excretion function. A retention (excretion) function represents the predicted activity of a radionuclide in the body, organ, or tissue or in a 24-h excreta at a particular time after the intake. The International Commission on Radiological Protection provides these biokinetic models. We have used these functions to compute optimal experimental designs for estimating the intake quantity in workers following radionuclide inhalation or ingestion. In particular, we have considered the case where the individual is exposed to a constant intake during some periods followed by other periods without intakes, which we called multiple constant intakes. The main aim of this work is finding the best times where the bioassay samples should be obtained in order to estimate optimally the actual intake of the last period. The problem is also extended to compute the next two or more bioassays to be performed. Measurements on the same worker are modeled through a correlation structure. The outline of the problem is established for a general case and results are given for a typical case as a real example. The methodology given in the paper can be applied to other cases with multiple constant intakes, e.g. in medical treatments where the patient is exposed to successive doses during particular periods.
  • Author: Vargas, D.; López, C.; Acero, E.; et al.
    Journal: PLOS ONE
    ISSN 1932-6203 Vol.13 N° 3 2019 pp. e0194269
    Abstract
    The anatomical location of adipose tissue might have direct implications for its functionality and risk of cardiovascular disease. Adipose tissue surrounding blood vessels may be thermogenically more active in specific areas of the body, releasing substances that regulate vascular metabolism. In humans, the phenotypic characteristics of adipose tissue surrounding the aorta and the cardiovascular disease risk that it might entail remain largely unknown. Here, we compared thermogenesis-related molecular features of human periaortic adipose tissue samples with those of subcutaneous adipose tissue, obtained by sternotomy from 42 patients undergoing cardiovascular surgery. To determine the expression of genes related to energy expenditure and the levels of some adipokines, histological examinations, quantitative PCR, and protein expression measurements in adipocyte precursor cells were performed. Periaortic adipocytes were smaller than those from subcutaneous tissue. Moreover, weight gain induced periaortic adipocyte hypertrophy (r = -0.91, p<0.01). Compared to subcutaneous tissue, adiponectin, FABP4, IL-4 and IL-6 was decreased in periaortic adipocytes, whereas FGF21, UCP-1, PGC-1a, CITED1, Omentin and TFAM (Mitochondrial protein) increased. Upon analyzing patients' clinical conditions, it emerged that the levels of PGC-1a both in male (r = -0.48 p<0.04) and female (r = -0.61, p<0.05) and TFAM in male (r = -0.72, p<0.0008) and female (r = -0.86, p<0.002) decreased significantly with progressive weight gain. However, no differences were observed in patients with diabetes mellitus 2 or Hyperlipidemia. Adipocytes surrounding the ascending aorta present markers of major thermogenic activity than those in subcutaneous tissue. Nevertheless, this characteristic might change, due to unfavorable metabolic conditions such as obesity, which is a risk factor for cardiovascular disease.
  • Author: Odudu, A. ; Nery, F. ; Harteveld, A. A. ; et al.
    Journal: NEPHROLOGY DIALYSIS TRANSPLANTATION
    ISSN 0931-0509 Vol.33 N° Suppl. 2 2018 pp. ii15 - ii21
    Abstract
    Renal perfusion provides the driving pressure for glomerular filtration and delivers the oxygen and nutrients to fuel solute reabsorption. Renal ischaemia is a major mechanism in acute kidney injury and may promote the progression of chronic kidney disease. Thus, quantifying renal tissue perfusion is critically important for both clinicians and physiologists. Current reference techniques for assessing renal tissue perfusion have significant limitations. Arterial spin labelling (ASL) is a magnetic resonance imaging (MRI) technique that uses magnetic labelling of water in arterial blood as an endogenous tracer to generate maps of absolute regional perfusion without requiring exogenous contrast. The technique holds enormous potential for clinical use but remains restricted to research settings. This statement paper from the PARENCHIMA network briefly outlines the ASL technique and reviews renal perfusion data in 53 studies published in English through January 2018. Renal perfusion by ASL has been validated against reference methods and has good reproducibility. Renal perfusion by ASL reduces with age and excretory function. Technical advancements mean that a renal ASL study can acquire a whole kidney perfusion measurement in less than 5-10¿min. The short acquisition time permits combination with other MRI techniques that might inform drug mechanisms and renal physiology. The flexibility of renal ASL has yielded several variants of the technique, but there are limited data comparing these approaches. We make recommendations for acquiring and reporting renal ASL data and outline the knowledge gaps that future research should address.
  • Author: Bulto, R. (Autor de correspondencia); Viles Díez, Elisabeth; Mateo Dueñas, Ricardo
    Journal: PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE
    ISSN 0954-4054 Vol.232 N° 5 2018 pp. 755 - 765
    Abstract
    The automotive sector, along with many others, has been subject to two key trends in recent times. The first relates to globalization, in other words, the incorporation of new markets and a growing demand that needs to be satisfied. The second concerns the high expectations of customers regarding quality and the on-going renovation of products. The incorporation of new markets results in the expansion of new production centres all over the world, making it necessary to synchronize launches in different parts of the globe. Furthermore, customers' new demands cause shorter product life cycles. Time is seen as the main factor in the success of any new product launch. Particularly, the period that begins when the production has started in a production plant and continues until the planned production rate has been attained (the ramp-up curve). Because launches have become more frequent, the specific importance given to the life of the model is greater. This article has the following objective: provide a thorough review of the literature, focusing on this specific phase in the life cycle of a model in order to identify, compile and extract any relevant information that will enable us to build a theoretical framework for the ramp-up curve. The article begins by analysing the different interpretations of the phases of the launch stage of a new product that exist in the literature, and it concludes with the evidence that ramp-up curves are an item of scientific interest, where the 21% of the papers relating to this item are focused on the automotive sector, where planning and management are the most recurrent themes. Finally, two themes that remain open for further research are detected: the lack of structured organization during the ramp-up phase and knowledge transfer between different launches of the same product in different places.
  • Author: Jurburg, D.; Viles Díez, Elisabeth; Tanco Rainusso, Martín; et al.
    Journal: TOTAL QUALITY MANAGEMENT AND BUSINESS EXCELLENCE
    ISSN 1478-3363 Vol.29 N° 7-8 2018 pp. 817 - 833
    Abstract
    Continuous improvement (CI) systems still have room for improvement due to the difficulty in sustaining the system and attaining a high level of employee participation. This study looks to analyse the level of implementation in manufacturing companies of 16 CI routines, and how these routines foster CI and employee participation. Based on a general survey of CI managers from Spain which yielded 147 valid responses, a Cluster Analysis (CA) and a Factorial Analysis were performed in order to group both responses and the variables used into more comprehensive categories. Statistical tests were run to test for significant relationships. This paper introduces a new perspective on the issue of CI maturity levels by using CA to group companies into three categories based on the score of a set of 16 CI enablers, which were in turn reduced to four factors using Factor Analysis, allowing for the identification of improvement challenges depending on the maturity stage of each company. Three different maturity groups of companies were identified, named as Leaders, Followers and Laggards. Results show that companies with better scores on these factors believe to have more sustainable CI systems and a higher level of employee participation.
  • Author: Charitopoulou, E.; García Manglano, Javier
    Journal: JOURNAL OF ETHNIC AND MIGRATION STUDIES
    ISSN 1369-183X Vol.44 N° 5 2018 pp. 849 - 869
    Abstract
    In this paper, we examine the association between contact with migrant populations and support for the populist radical right (PRR) in Switzerland. Building on group threat and intergroup contact theories, which offer opposing predictions, and drawing on Appadurai¿s thesis of the `fear of small numbers¿, we propose a new theoretical framework to explain this association. We predict that the relationship between the size of the migrant populations and PRR voting is nonlinear: a small but noticeable minority triggers the formation of anti-immigrant attitudes, which soften as the minority grows and people start having meaningful interactions with foreigners. To test these theories, we combine individual-level data with municipality-level information. Mixed-effects multilevel models confirm that individuals in municipalities with a moderate proportion of foreigners are more likely than those with fewer or a greater number of migrants to cast their vote in support of PRR parties; this is particularly so for certain stigmatised minorities. We further explore the effect of perceived immigrant threat in moderating these relationships.
  • Author: Portilla Manjón, Idoia
    Journal: INVESTIGACION Y MARKETING
    ISSN 1131-6144 Vol.Especial 50 aniversario N° Abril 2018 pp. 66 - 68
  • Author: Portilla Manjón, Idoia
    Journal: OBSERVATORIO
    ISSN 1646-5954 Vol.12 N° 3 2018 pp. 66 - 82
  • Author: Montoro Gurich, Carolina
    Journal: FINISTERRA
    ISSN 0430-5027 Vol.53 N° 109 2018 pp. 71-93
    Abstract
    This paper explores the relationship between immigration and health status variation among Moroccan immigrants from a gender perspective, using data from a cross-sectional ethnographic survey conducted in the Spanish region of Navarre. Results show, against the literature, that women have a better health status variation than men, probably because men have a higher age profile and a longer stay in Spain. The binary logistic regression reveals important differences in social determinants by gender. Paid employment is the most positive, significant factor for health among women. Close social ties with compatriots, living in an inexpensive old house and, to a lesser extent, having a secondary level of educational achievement are the key factors for men. The economic implications of daily life have an impact on the health of Moroccan immigrants of both sexes.
  • Author: Sempere Souvannavong, Juan-David; Montoro Gurich, Carolina; Parreño Castellano, Juan Manuel; et al.
    Books: Población y territorio: España tras la crisis de 2008
    ISSN 978-84-9045-911-9 2020 pp. 1 - 10
  • Author: Pons Izquierdo, Juan José; Montoro Gurich, Carolina
    Books: Población y territorio: España tras la crisis de 2008
    ISSN 978-84-9045-911-9 2020 pp. 175 - 190
    Abstract
    El envejecimiento demográfico es una cuestión preocupante desde muchos puntos de vista, incluyendo la localización espacial de los mayores. Y si bien este fenómeno afecta preferentemente al mundo rural, son cada vez más frecuentes los barrios de las ciudades cuya población se encuentran en un avanzado estado de envejecimiento. De todo ello se derivan evidentes consecuencias sociales, de movilidad, asistenciales, etc. Y, por eso, siempre se considera este aspecto a la hora de analizar la vulnerabilidad de las diferentes zonas urbanas. Desde esta perspectiva, el presente trabajo tiene por objetivos (1) establecer una metodología adecuada para la delimitación de lo que hoy en día puede considerarse un barrio envejecido y (2) mostrar como resultado la situación de este fenómeno por áreas urbanas, utilizando los últimos datos padronales disponibles (2017), a escala de sección censal.
  • Author: Montoro Gurich, Carolina
    Books: Studium, magisterium et amicitia: homenaje al profesor Agustín González Enciso
    ISSN 978-84-7768-350-6 2018 pp. 625 - 636
  • Author: López Fidalgo, Jesús Fernando; Tommasi, C.
    Books: The mathematics of the uncertain. A tribute to Pedro Gil
    ISSN 978-3-319-73847-5 2018 pp. 253 - 263
    Abstract
    Model selection is a core topic in modern Statistics. This is a review of what has been researched on optimal experimental design for model selection. The aim is to find good designs for increasing the test power for discriminating between rival models. This topic has a special impact nowadays in the area of experimental design.

Projects (since 2018)

  • Title: Desarrollo y validación de una herramienta digital basada en inteligencia artificial para la detección de publicaciones científicas relevantes en la toma de decisiones relacionadas con la Covid-19 Proyecto "Covid Content Curation".
    Project reference: 011-3638-2020-000001
    Principal Investigator: JORGE MARIA NUÑEZ CORDOBA.
    Funding organisation: GOBIERNO DE NAVARRA. DEPARTAMENTO DE SALUD
    Programme/Call: 2020 GN Proyectos de Investigación en salud
    Starting date: 01-01-2021
    Ending date: 31-12-2021
    Amount awarded: 20.700,00 €
    FEDER Funds: NO
  • Title: Binge-drinking: peor calidad de vida, riesgo de cáncer y de envejecimiento no saludable.
    Project reference:
    Principal Investigator: ALFREDO GEA SANCHEZ.
    Funding organisation: MINISTERIO DE SANIDAD, SERVICIOS SOCIALES E IGUALDAD
    Programme/Call: 2020 MSanidad Investigación en Drogodependencias
    Starting date: 01-01-2021
    Ending date: 31-12-2023
    Amount awarded: 45.509,38 €
    FEDER Funds: NO
  • Title: Desarrollo y evaluación de una técnica de imagen por resonancia magnética multiparamétrica para predecir de forma precoz la disfunción del injerto renal tras el trasplante,. RM-RENAL.
    Project reference: 0011-1383-2020-000010 PC181 UNAV RM-RENAL
    Principal Investigator: MARIA ASUNCION FERNANDEZ SEARA.
    Funding organisation: GOBIERNO DE NAVARRA
    Programme/Call: 2020 GN Proyectos Colaborativos
    Starting date: 01-01-2020
    Ending date: 30-11-2022
    Amount awarded: 164.349,50 €
    FEDER Funds: NO
  • Title: Solicitud ayuda movilidad Senior
    Project reference: PRX18/00339
    Principal Investigator: JESUS FERNANDO LOPEZ FIDALGO.
    Funding organisation: MINISTERIO DE EDUCACION , CULTURA Y DEPORTE
    Programme/Call: 2018 MECD SENIOR
    Starting date: 01-07-2019
    Ending date: 30-09-2019
    Amount awarded: 9.981,00 €
    FEDER Funds: NO
  • Title: De la arquitectura de la escucha a la huella social: buenas prácticas en la producción de contenidos
    Project reference: RTI2018-101124-B-I00
    Principal Investigator: MARIA DE LAS MERCEDES MEDINA LAVERON.
    Funding organisation: MINISTERIO DE CIENCIA E INNOVACIÓN
    Programme/Call: 2018 AEI - MCIU - Retos Investigación
    Starting date: 01-01-2019
    Ending date: 31-12-2021
    Amount awarded: 30.250,00 €
    FEDER Funds: SI
  • Title: Desarrollo de técnicas de mapeado de la reactividad cerebrovascular. Aplicaciones en la cirugía de tumores cerebrales.
    Project reference: PI18/00084
    Principal Investigator: MARIA ASUNCION FERNANDEZ SEARA.
    Funding organisation: INSTITUTO DE SALUD CARLOS III
    Programme/Call: AES2018 PI
    Starting date: 01-01-2019
    Ending date: 31-12-2021
    Amount awarded: 62.920,00 €
    FEDER Funds: SI
  • Title: USO DE FORMULACIONES POLIMÉRICAS MUCOADHESIVAS PARA LA ERRADICACIÓN DE HELICOBACTER PYLORI
    Project reference: RTC-2017-6643-1
    Principal Investigator: RAMON JESUS ANGOS MUSGO.
    Funding organisation: MINISTERIO DE CIENCIA E INNOVACIÓN
    Programme/Call: 2017 MINECO RETOS COLABORACIÓN
    Starting date: 01-07-2018
    Ending date: 31-12-2021
    Amount awarded: 148.104,00 €
    FEDER Funds: SI
  • Title: Estudio de la obesidad como factor de riesgo de mortalidad y su prevención mediante recomendaciones dietéticas: Análisis longitudinal de la cohorte SUN.
    Project reference: PI17/01795
    Principal Investigator: MAIRA BES RASTROLLO.
    Funding organisation: INSTITUTO DE SALUD CARLOS III
    Programme/Call: AES2017 PROYECTOS DE INVESTIGACIÓN
    Starting date: 01-01-2018
    Ending date: 30-06-2021
    Amount awarded: 93.170,00 €
    FEDER Funds: SI
  • Title: Devaluación en la toma de decisiones en adultos con TDAH: asociación con estilos de vida y efecto de la medicación
    Project reference: PSI2017-86763-P
    Principal Investigator: JAVIER BERNACER MARIA, GONZALO ARRONDO OSTIZ.
    Funding organisation: MINISTERIO DE CIENCIA E INNOVACIÓN
    Programme/Call: 2017 MINECO EXCELENCIA
    Starting date: 01-01-2018
    Ending date: 30-09-2021
    Amount awarded: 54.813,00 €
    FEDER Funds: SI
  • Title: PLATAFORMA DE UNIDADES DE INVESTIGACION CLINICA Y ENSAYOS CLINICOS Spanish Clinical Research Network (SCReN)
    Project reference: PT17/0017/0014
    Principal Investigator: JOSE RAMON AZANZA PEREA.
    Funding organisation: INSTITUTO DE SALUD CARLOS III
    Programme/Call: AES2017 PLATAFORMAS
    Starting date: 01-01-2018
    Ending date: 31-12-2020
    Amount awarded: 102.300,00 €
    FEDER Funds: SI
  • Title: Juan de la Cierva Formación - JM García Manglano
    Project reference: IJCI-2015-26327
    Principal Investigator: LUIS RAVINA BOHORQUEZ.
    Funding organisation: MINISTERIO DE CIENCIA E INNOVACIÓN
    Programme/Call: 2015 MINECO JUAN DE LA CIERVA INCORPORACION
    Starting date: 26-06-2017
    Ending date: 25-06-2019
    Amount awarded: 64.000,00 €
    FEDER Funds: SI
  • Title: Nuevo Sistema Inalámbrico de Antenas de Resonancia Magnética para Imagen de Animales de Laboratorio en Escáners Clínicos
    Project reference: 0011-1365-2017-000106
    Principal Investigator: MARIA ASUNCION FERNANDEZ SEARA.
    Funding organisation: GOBIERNO DE NAVARRA
    Programme/Call: 2017 GN I+D
    Starting date: 04-05-2017
    Ending date: 30-04-2019
    Amount awarded: 86.879,86 €
    FEDER Funds: NO
  • Title: Ayudas para la Incorporacion de doctores 2017 (I3)
    Project reference: IEDI-2017-00826
    Principal Investigator: MARIA ASUNCION FERNANDEZ SEARA.
    Funding organisation: MINISTERIO DE EDUCACION , CULTURA Y DEPORTE
    Programme/Call: 2017 MINECO I3
    Starting date: 01-01-2017
    Ending date: 31-12-2019
    Amount awarded: 100.000,00 €
    FEDER Funds: SI
  • Title: Ensayo aleatorizado de prevención con dieta mediterránea de arritmias recurrentes (estudio predimar) en pacientes con fibrilación auricular
    Project reference: 46/2016
    Principal Investigator: MIGUEL RUIZ-CANELA LOPEZ.
    Funding organisation: GOBIERNO DE NAVARRA
    Programme/Call: 2016 GN SALUD
    Starting date: 08-12-2016
    Ending date: 08-12-2019
    Amount awarded: 47.385,16 €
    FEDER Funds: NO
  • Title: Determinantes nutricionales del Cáncer de mama
    Project reference: 41/2016
    Principal Investigator: ESTEFANIA AINHOA TOLEDO ATUCHA.
    Funding organisation: GOBIERNO DE NAVARRA
    Programme/Call: 2016 GN SALUD
    Starting date: 08-12-2016
    Ending date: 08-12-2020
    Amount awarded: 47.004,31 €
    FEDER Funds: NO
  • Title: Evaluación de la perfusión cerebral y la conectividad funcional en la enfermedad de Alzheimer: Dos marcadores emergentes para un idagnostico temprano.
    Project reference: SAF2014-56330-R
    Principal Investigator: MARIA ASUNCION FERNANDEZ SEARA.
    Funding organisation: MINISTERIO DE CIENCIA E INNOVACIÓN
    Programme/Call: 2014 - PROYECTOS DE I+D RETOS
    Starting date: 01-01-2015
    Ending date: 30-06-2018
    Amount awarded: 90.750,00 €
    FEDER Funds: SI