Assessment of maximum likelihood PCA missing data imputation

Maximum likelihood principal component analysis (MLPCA) was originally proposed to incorporate measurement error variance information in principal component analysis (PCA) models. MLPCA can be used to fit PCA models in the presence of missing data, simply by assigning very large variances to the non-measured values. An assessment of maximum likelihood missing data imputation is performed in this paper, analysing the algorithm of MLPCA and adapting several methods for PCA model building with missing data to its maximum likelihood version. In this way, known data regression (KDR), KDR with principal component regression (PCR), KDR with partial least squares regression (PLS) and trimmed scores regression (TSR) methods are implemented within the MLPCA method to work as different imputation steps. Six data sets are analysed using several percentages of missing data, comparing the performance of the original algorithm, and its adapted regression-based methods, with other state-of-the-art methods.Research in this study was partially supported by the Spanish Ministry of Science and Innovation and FEDER funds from the European Union through grant DPI2011-28112-C04-02 and DPI2014-55276-C5-1R, and the Spanish Ministry of Economy and Competitiveness through grant ECO2013-43353-R.Folch Fortuny, A.; Arteaga Moreno, FJ.; Ferrer, A. (2016). Assessment of maximum likelihood PCA missing data imputation. Journal of Chemometrics. 30(7):386-393. https://doi.org/10.1002/cem.280438639330

Missing Data Imputation Toolbox for MATLAB

[EN] Here we introduce a graphical user-friendly interface to deal with missing values called Missing Data Imputation (MDI) Toolbox. This MATLAB toolbox allows imputing missing values, following missing completely at random patterns, exploiting the relationships among variables. In this way, principal component anal- ysis (PCA) models are fitted iteratively to impute the missing data until convergence. Different methods, using PCA internally, are included in the toolbox: trimmed scores regression (TSR), known data regres- sion (KDR), KDR with principal component regression (KDR-PCR), KDR with partial least squares regression (KDR-PLS), projection to the model plane (PMP), iterative algorithm (IA), modified nonlinear iterative partial least squares regression algorithm (NIPALS) and data augmentation (DA). MDI Toolbox presents a general procedure to impute missing data, thus can be used to infer PCA models with missing data, to estimate the covariance structure of incomplete data matrices, or to impute the missing values as a preprocessing step of other methodologies.Research in this study was partially supported by the Spanish Ministry of Science and Innovation and FEDER funds from the European Union through grant DPI2011-28112-C04-02 and DPI2014-55276-C5-1 R, and the Spanish Ministry of Economy and Competitiveness through grant ECO2013-43353-R.Folch Fortuny, A.; Arteaga Moreno, FJ.; Ferrer, A. (2016). Missing Data Imputation Toolbox for MATLAB. Chemometrics and Intelligent Laboratory Systems. 154:93-100. https://doi.org/10.1016/j.chemolab.2016.03.019S9310015

Investigación inter e intra-variable del valor percibido: un modelo causal de segundo orden y satisfacción cognitiva y afectiva

El valor percibido es axiomática y epistemológicamente clave para el Marketing. Su investigación es rica y profunda respecto a su dimensionalidad (análisis intra-variable) y a su relación con satisfacción y lealtad (inter-variable). Como contribución a la abundante literatura sobre medición del valor percibido en servicios turísticos, este trabajo propone un modelo causal que abarca las perspectivas inter e intra-variable, y propone el valor percibido como segundo orden y la cadena valor-satisfacción-lealtad, con una bifurcación de la satisfacción en afectiva y cognitiva. El modelo es testado con PLS sobre una muestra de 340 huéspedes de hotel en la Comunidad Valenciana, hallando contribuciones significativas de ocho dimensiones de valor (eficiencia, excelencia, estatus, estima, entretenimiento, estética, ética y escapismo) sobre el valor percibido como segundo orden. Aunque alguna dimensión contribuye más modestamente (ética y estatus), la riqueza de la variable valor queda refrendada, además de la dualidad cognitivo-afectiva en la cadena valor-satisfacción-lealtad.Value is axiomatically and epistemologically crucial for the Marketing thought. Accordingly, research on perceived value is rich and deep both in its multidimensionality (intra-variable perspective) and its relationships with other variables (inter-variable). For contributing to the abundant research on value in tourism, this works proposes a causal model encompassing both inter and intra-variable approaches, where value is a second order construct, and where satisfaction is bifurcated into cognitive and affective satisfaction, within the value-satisfaction-loyalty chain. The model is tested with PLS upon a sample of 340 hotel guests, in the Region of Valencia. Significant links are found between eight value dimensions (efficiency, excellence, status, esteem, entertainment, aesthetics, ethics and escapism) on the second-order value construct. Although some dimensions have lower effects (ethics and status), the richness of value dimensionality is proven, as well as the duality cognitive-affective of the value-satisfaction-loyalty chain

Integrando marketing experiencial y service dominant logic: creación de un índice de co-creación de valor interactivo y contextual

El Valor Percibido es crucial para dos aproximaciones claves en Marketing: el Marketing Experiencial y el Service Dominant Logic (SDL), Sin embargo, la segunda no parece haber integrado toda la riqueza de la primera. Por ello, este trabajo, tras revisar la aproximación al Valor Experiencial (en general, y según Holbrook) y el SDL y la noción de co-creación de Valor, propone ejes argumentales de relación y un modelo conceptual integrador de sendas propuestas. El estudio empírico plantea un índice de co-creación de Valor, soportado por un modelo estructural de orden jerárquico. que es testado con PLS en 240 huéspedes de hotel. Los resultados permiten refrendar que la co-creación de Valor es a) interactiva al reagrupar recursos (empresa, empleados y consumidores), y b) contextual al variar con el nivel de estudios (inversamente) y con la frecuencia viajera. Todo ello ayuda a concluir sobre las posibilidades inexploradas de integración del Valor experiencial y el SDL.Value is a notion crucial for both Experiential Marketing and Service Dominant Logic, although the latter has not always entirely integrated the former. This work revises both perspectives: namely, Experiential Value in general, and more precisely through Holbrook; and SDL alongside with the notion of value co-creation, and finds conceptual axes around which to build a conceptual Model of integration of both frameworks. Based on this, empirically, a value-based index of co-creation is built, upon a higher order structural model, and tested among 340 leisure tourist at hotels. Results show that cocreation is a) interactive as regrouping three origin of resources (the firm, the employees and the consumer) and b) contextual, as it varies by subjects and circumstances (by education level (reversely) and travelling frequency). Conclusions address the potential of conceptual and methodological integration of both Experiential Value and SDL

Desarrollo y validación de una escala formativa de grado de avance tecnológico en hoteles desde la perspectiva del huésped

La rápida evolución de las Tecnologías de la Información y de la Comunicación (TIC) ha supuesto un cambio radical en las condiciones de mercado para las empresas turísticas, ofreciendo nuevos instrumentos para la gestión y para añadir valor a la experiencia del cliente en el establecimiento. Sin embargo, el desarrollo de escalas para la medición del grado de avance tecnológico de la empresa turística ha recibido escasa atención en la investigación académica. Por ello, el objetivo del presente trabajo es, por una parte, realizar una revisión de las principales propuestas conceptuales para el estudio de las TIC en las empresas turísticas, y por otra, desarrollar y validar una escala formativa para la medición del grado de desarrollo de las TIC en hoteles, a partir de las percepciones de una muestra de huéspedes de hoteles españoles.The rapid evolution of Information and Communication Technologies (ICT) has involved a radical change in the market conditions for tourism companies, offering new tools for management and adding value to the customer experience in the establishment. However, the development of scales for measuring the degree of technological advancement of tourism companies has received scant attention in academic research. Therefore, the objective of the present work is, first, to carry out a review of the main conceptual proposals for the study of ICT in tourism companies, and second, to develop and validate a formative scale for the measurement of the degree of development of ICT in hotels, based on the perceptions of a sample of Spanish hotel guests.Ministerio de Educación y Ciencia ECO2013-43353-RMinisterio de Educación y Ciencia ECO2016-76553-

Social Vulnerability and COVID-19 Vaccine in Spain

Different analyses show that the design of vaccination policies should especially protect the most vulnerable social groups, since the level of acceptance is determined by the population’s knowledge, attitude and concerns about the safety and efficacy of vaccines. The objective of this work will be to detect the most socially vulnerable groups with respect to COVID-19 and to analyze the factors that influence predisposition to vaccination. This is a cross-sectional study using data from the Centro de Investigaciones Sociológicas (CIS) on the Effects and Consequences of Coronavirus (Study 3346 of December 2021). Sociodemographic variables (sex, age, employment status, studies and subjective class identification) were extracted, as well as the answers to the questions indicating the attitude towards vaccination, corresponding to questions 7,8,10 and 11 of the study. The most vulnerable group was lower class women (self-perceived), under 45 years of age with lower educational level, unemployed or performing unpaid work in the home. Most of them are not predisposed to vaccinate only because of the obligation to do so, mainly due to lack of belief in the power and efficacy of vaccines, as well as fear of health risks/collateral side effects. The lower vaccine uptake in this vulnerable population group may be due to a lack of awareness and lower trust in the authorities, as well as the benefits of the vaccine, which could be related to a lack of policy targeting the most socially vulnerable populations.The results of this article are part of a project funded by the Centro de Investigaciones Sociológicas (CIS) through the call “Subvenciones para formación e investigación en materias de interés para el organismo para el año 2022”. Call code: BDNS: 609943.Psicologí

Older Adults and Positive Mental Health during the Second and Sixth COVID-19 Waves in Spain

The spread of the COVID-19 virus was a worldwide phenomenon, which was unprecedented in modern times. The restriction measures can be perceived as a heavy burden for mental health during this period, particularly for some groups. The aim of this study is to examine a positive mental health model across ages, where a moderated mediation model is proposed involving sex differences and confidence in coping with COVID-19. Two independent samples were studied during the second and sixth waves in Spain: n = 2861 and n = 2462, respectively. The main conclusions can be described as follows: (i) while age was not related to mental health during the second wave, a positive relationship was found between it and the sixth one; (ii) age was positively related to the confidence in coping with COVID-19 during both of the waves; (iii) women showed worse scores for the variables in the study than the men did during the second wave, but this pattern was reversed in the sixth one; (iv) after a moderated mediation model on the relationship between age and positive mental health in terms of confidence in coping with COVID-19 and sex, an interaction was found for the second wave but not for the sixth one. These results suggest that older adults and women would develop more strategies and resources for a positive mental health across time.The results of this article are part of a project funded by the Centro de Investigaciones Sociológicas (CIS) through the call “Subvenciones para formación e investigación en materias de interés para el organismo para el año 2022”. Call code: BDNS: 609943.Educació

Cardiopulmonary resuscitation training for odontologists.

La formación en procedimientos de resucitación cardiopulmonar es cada vez más necesaria en ámbitos extrahospitalarios como son los gabinetes de odonto-estomatología. El presente artículo muestra un estudio observacional sobre la evaluación teórica, práctica y el control de calidad en un curso de reanimación cardiopulmonar instrumental impartido en el conjunto de la programación del Máster universitario y oficial para odontólogos, de la Universidad Católica de Valencia San Vicente Mártir. Se concluye que la adquisición del conocimiento y de las habilidades psicomotoras necesarias para abordar con eficacia situaciones de paro cardiorrespiratorio, se pueden conseguir con escaso coste económico y de consumo de tiempo por los profesionales de odontología en activo; se evidencia, de forma objetiva, la adquisición de un elevado nivel de conocimientos teóricos y prácticos en todos los participantes, así como el haber conseguido un elevado nivel de seguridad y confianza para abordar situaciones futuras de paro cardiorrespiratorio.Training in cardiopulmonary resuscitation procedures is increasingly necessary in extra-hospital settings, such as cabinets of stomatology. This article presents an observational study on the theoretical, practical assessment and quality control, in a course of cardio pulmonary resuscitation instrumental given in the whole programming University Master for dentists, Catholic University of Valencia. Concluding that the acquisition of knowledge and psychomotor skills necessary to effectively address situations of cardio respiratory arrest can be achieved with little cost and time consumption by dental professionals active; objectively demonstrating the acquisition of a high level of knowledge and skills of all participants; as well as having achieved a high level of security and confidence among all participants to address future situations of cardio respiratory arrest.Medicin

Laparoscopic vs. Open Approach in Emergent Inguinal Hernia: Our Experience and Review of Literature

There is currently no consensus or homogeneous recommendation about the role of the laparoscopic approach in emergent inguinal hernia surgery. The aim of this manuscript is showing our experience and results of laparoscopic approach for emergent groin hernia repair comparing with open approach. A retrospective review of a prospectively maintained database between January 2011 and December 2021 of acute incarcerated groin hernia that were operated at Virgen del Rocio University Hospital. In this period, they were identified 463 patients with groin hernia that required an emergency repair. 454 patients underwent open surgery (group 1) and 36 patients underwent laparoscopic approach (TAPP procedure) (group 2). Median length stay was 1 day in lap group and 2 days in open approach. Reintervention was necessary in 20 cases (4.40%) from group 1 and one (2.27%) from group 2. In laparoscopic approach, no mortality was described but in open approach, 10 patients (2.20%) died. Globally, 58 cases (12.77%) from group 1 and six patients (16.66%) from group 2 presented any complication. Wound infection was higher in group of open repairs (5.94% vs. 2.77%). Non-surgical complications were higher in open approach (19 vs. 0). There is no statistical significance in any of these items. Laparoscopic approach is a safe, feasible and effective therapeutic option for the treatment of incarcerated groin hernia that require emergency surgery, but prospective and randomized comparative studies are needed to establish the best approach

Impact of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients: A nationwide study in Spain

Objective To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain. Settings The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied. Participants This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020. Interventions An exploratory factorial analysis was performed to select the most relevant variables of the sample. Primary and secondary outcome measures Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection. Results Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/10 5 people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade =3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/10 5 people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated. Conclusions Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/10 5 people/week) was a statistically independent predictor of mortality. Trial registration number CEIM 20/217