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In the process of spectrum sensing applied to wireless communications, it is possible to build interference maps based on acquired power spectral values. This allows the characterization of spectral occupation, which is crucial to take management spectrum decisions. However, the amount of information both in the space and frequency domains that needs to be processed generates an enormous amount of data with high transmission delays and high memory requirements. Meanwhile, compressive sensing is a technique that allows the reconstruction of sparse or compressible signals using fewer samples than those required by the Nyquist criterion. This paper presents a new model that uses compressed multispectral sampling for spectrum sensing. The aim is to reduce the number of data required for the storage and the subsequent construction of power spectral maps with geo-referenced information in different frequency bands. This model is based on architectures that use compressive sensing to analyze multispectral images. The operation of a centralized manager is presented in order to select the power data of different sensors by binary patterns. These sensors are located in different geographical positions. The centralized manager reconstructs a data cube with the transmitted power and frequency of operation of all the sensors based on the samples taken and applying multispectral sensing techniques. The results show that this multispectral data cube can be built with 50% of the samples generated by the devices, and the spectrum cartography information can be stored using only 6.25% of the original data.

In the field of organic solar cells, organic semiconductors with Y6‐based chemical structure and their corresponding quinoxaline‐based assemblies are settled down as promising materials in the field of OSCs. However, the chemical structure of Y6 derivatives does not allow an expansion in the electron‐withdrawing central core, in contrast to their quinoxaline‐based analogues. For this reason, herein, two different quinoxaline‐based A–D–A′–D–A derivatives with 2D π‐extended cores endowed with electroactive rylenimide moieties, named as Y6‐1Napht and Y6‐1Pery, are designed and synthesized. These enlarged fused‐ring electron acceptors (FREAs) allow to study the influence of the length of the ryleneimide moiety on its structural, optical, electrochemical, and thermal properties as well as the tailoring of the frontier molecular orbitals. These results are also supported by quantum chemical calculations and photoluminescence measurements that provide additional information about their thermal stability and the microstructure of the films. Finally, as a proof of concept and to study the influence of these chemical modifications on the central core, solar cells based on these π‐conjugated nonfullerene acceptors are fabricated.

Associations between dyslipidemia and metabolic dysfunction-associated steatotic liver disease (MASLD) have been reported. Previous studies have shown that the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio may be a surrogate marker of MASLD, assessed by liver ultrasound. However, no studies have evaluated the utility of this ratio according to biopsy-proven MASLD and its stages. Therefore, our aim was to evaluate if the TG/HDL-C ratio allows for the identification of biopsy-proven MASLD in patients with obesity. We conducted a case-control study in 153 patients with obesity who underwent metabolic surgery and had a concomitant liver biopsy. Fifty-three patients were classified as no MASLD, 45 patients as metabolic dysfunction-associated steatotic liver—MASL, and 55 patients as metabolic dysfunction-associated steatohepatitis—MASH. A receiver operating characteristic (ROC) analysis was performed to assess the accuracy of the TG/HDL-C ratio to detect MASLD. We also compared the area under the curve (AUC) of the TG/HDL-C ratio, serum TG, and HDL-C. A higher TG/HDL-C ratio was observed among patients with MASLD, compared with patients without MASLD. No differences in the TG/HDL-C ratio were found between participants with MASL and MASH. The greatest AUC was observed for the TG/HDL-C ratio (AUC 0.747, p < 0.001) with a cut-off point of 3.7 for detecting MASLD (sensitivity = 70%; specificity = 74.5%). However, no statistically significant differences between the AUC of the TG/HDL-C ratio and TG or HDL-C were observed to detect MASLD. In conclusion, although an elevated TG/HDL-C ratio can be found in patients with MASLD, this marker did not improve the detection of MASLD in our study population, compared with either serum TG or HDL-C.

Abstract The development of n‐type organic semiconductors has evolved significantly slower in comparison to that of p‐type organic semiconductors mainly due to the lack of electron‐deficient building blocks with stability and processability. However, to realize a variety of organic optoelectronic devices, high‐performance n‐type polymer semiconductors are essential. Herein, conjugated microporous polymers (CMPs) comprising isoindigo acceptor units linked to benzene or pyrene donor units (BI and PI) showing n‐type semiconducting behavior are reported. In addition, considering the challenges of deposition of a continuous and homogeneous thin film of CMPs for accurate Hall measurements, a plasma‐assisted fabrication technique is developed to yield uniform thin films. The fully conjugated 2D networks in PI‐ and BI‐CMP films display high electron mobility of 6.6 and 3.5 cm2 V−1 s−1, respectively. The higher carrier concentration in PI results in high conductivity (5.3 mS cm−1). Both experimental and computational studies are adequately combined to investigate structure–property relations for this intriguing class of materials in the context of organic electronics.

El objetivo de esta investigación es evaluar la validez de contenido, de constructo y de criterio, así como la confiabilidad del cuestionario de la GRIII de la NOM-035-STPS-2018 en trabajadores de la actividad económica terciaria en la Ciudad de México. El método se planteó en tres fases: 1) validez de contenido: a partir de tablas de especificaciones basadas en la misma norma y su GRIII; 2) validez de constructo: con análisis factorial confirmatorio de los dominios, con una muestra de 1179 trabajadores; y 3) validez de criterio: con modelos de regresión lineal múltiple de los dominios sobre una medida de ansiedad, con una muestra de 432 trabajadores. Los resultados indican limitaciones de validez del cuestionario de la GRIII, lo que implica cuestionar su efectividad. Se plantea la recomendación a las autoridades correspondientes a reforzar el cuestionario o diseñar uno nuevo cuando se lleve a cabo la revisión de la norma.

In the last decades, obesity has reached epidemic proportions worldwide. Obesity is a chronic disease associated with a wide range of comorbidities, including insulin resistance and type 2 diabetes mellitus (T2D), which results in significant burden of disease and major consequences on health care systems. Of note, intricate interactions, including different signaling pathways, are necessary for the establishment and progression of these two closely related conditions. Altered cell-to-cell communication among the different players implicated in this equation leads to the perpetuation of a vicious circle associated with an increased risk for the development of obesity-related complications, such as T2D, which in turn contributes to the development of cardiovascular disease. In this regard, the dialogue between the adipocyte and pancreatic beta cells has been extensively studied, although some connections are yet to be fully elucidated. In this review, we explore the potential pathological mechanisms linking adipocyte dysfunction and pancreatic beta cell impairment/insulin resistance. In addition, we evaluate the role of emerging actors, such as the gut microbiome, in this complex crosstalk.

Type A insulin resistance (IR) syndrome is a very uncommon genetic disorder affecting the insulin receptor (INSR) gene, characterized by severe IR without the presence of obesity. Patients with this condition will eventually develop diabetes, presenting a variable response to insulin-sensitizers, such as metformin and thiazolidinediones, and high doses of insulin. We report for the first time the results of the use of combination therapy with a glucagon-like peptide-1 receptor agonist and a sodium-glucose cotransporter 2 inhibitor for the treatment of diabetes in the context of type A IR syndrome.

Abstract Background and objective Radiation pneumonitis (RP) could be a lethal complication of lung cancer treatment. No reliable predictors of RP severity have been recognized. This prospective pilot study was performed to identify early predictors of high grade lung toxicity and to evaluate clinical, biological or dosimetric features associated with different grades of toxicity. Method Sixteen patients with non-small cell lung cancer with indication of concurrent chemoradiotherapy using 60 Gy/2 Gy/fraction starting at cycle one of platinum based chemotherapy were included. Bronchoalveolar lavage (BAL), pulmonary function testing (PFT), and 18F-2-fluoro-2-deoxy-D-glucose positron-emission tomography was performed before radiotherapy (RT), after three weeks of treatment, and two months post-RT. For analysis, patients were grouped by grade (low [G1-G2] vs. high [G3-G5]). The two groups were compared to identify predictors of RP. Protein expression BAL and lung tissue metabolism was evaluated in two patients (RP-G1 vs. RP-G3). Categorical variables such as comorbidities, stages and locations were summarized as percentages. Radiation doses, pulmonary function values and time to RP were summarized by medians with ranges or as means with standard deviation. Longitudinal analysis PFT was performed by a T-test. Results All 16 patients developed RP, as follows: G1 (5 pts; 31.3%); G2 (5 pts; 31.3%); G3 (5 pts; 31.3%); and G5 (1 pts; 6.1%). Patients with high grade RP presented significant decrease (p = 0.02) in diffusing lung capacity for carbon monoxide (DLCO) after three weeks of RT. No correlation between dosimetric values and RP grades was observed. BAL analysis of the selected patients showed that CXCL-1, CD154, IL-1ra, IL-23, MIF, PAI-1 and IFN-γ were overexpressed in the lungs of the RP-G3 patient, even before treatment. The pre-RT SUVmax value in the RP-G3 patient was non-significantly higher than in the patient with RP-G1. Conclusions RT induces some degree of RP. Our data suggest that decrease in DLCO% is the most sensitive parameter for the early detection of RP. Moreover, we detect biological differences between the two grades of pneumonitis, highlighting the potential value of some cytokines as a prognostic marker for developing high grade lung toxicity. Further multicenter studies with larger sample size are essential to validate these findings.

El propósito de este artículo es doble: en primer lugar, analizar los procedimientos contables que utilizaba el Colegio de la Compañía de Jesús de Cádiz para controlar los fondos que se empleaban en el cultivo de la viña que tenía en Jerez y, sobre todo, para gestionar los flujos de la bodega en la que se almacenaban los vinos procedentes de aquella y, en segundo lugar, a partir de la información procedente de la documentación primaria utilizada — los libros 613 y 1.919 de la Sección Clero del Archivo Histórico Nacional (Madrid) — reconstruir las magnitudes básicas y el funcionamiento de la bodega, entre mediados del siglo XVII y mediados del siglo XVIII. El estudio de estos libros nos ha permitido conocer aspectos fundamentales del funcionamiento de la bodega del Colegio, entre los que destacamos: la ausencia de libros específicos de bodega; las dificultades existentes para gestionar las entradas y salidas de caldos, por tratarse de mostos y de vinos, respectivamente y la preocupación por garantizar la calidad de la producción mediante el establecimiento de varios trasiegos al año y a través de la utilización de prácticas enológicas que, con toda prudencia, anticipan el sistema de criaderas y soleras, término éste que se utiliza ya en algunos apuntes contables de finales del siglo XVII.

En este trabajo se analiza el rol que ocupan los conceptos indeterminados o abiertos en el Derecho Constitucional. Para tal efecto se revisan las constituciones de Estados Unidos, Alemania, España y Chile, y se hace una somera revisión de lo que la literatura jurídica ha dicho sobre la incorporación de esta clase de cláusulas en esos sistemas constitucionales. Asimismo, se plantean y analizan las consecuencias y riesgos que implican el uso de estos conceptos, y se revisa el problema adicional que surge a partir de la transformación de conceptos ciertos y determinados, en conceptos controvertidos.

Resumen: Introducción: El hiperparatiroidismo primario (HPTP) es un trastorno endocrino frecuente, caracterizado por hipercalcemia y elevación de la parathormona. La disminución del filtrado glomerular ( 11,2 mg/dl (27%), litiasis renal (13%), baja masa ósea (12%), edad 60 ml/min (creatinina sérica basal 0,77 mg/dl vs. creatinina sérica al año 0,81 mg/dl, p 11.2 mg/dl (27%), nephrolithiasis (13%), low bone mass (12%), age 60 ml/min (baseline serum creatinine levels 0.77 mg/dl vs serum creatinine levels after one year 0.81 mg/dl, P

Introduction: Primary hyperparathyroidism (PHPT) is a common endocrine disorder characterised by hypercalcaemia and parathormone increase. Decreased glomerular filtration rate (11.2 mg/dl (27%), nephrolithiasis (13%), low bone mass (12%), age 60 ml/min (baseline serum creatinine levels 0.77 mg/dl vs serum creatinine levels after one year 0.81 mg/dl, p 11,2 mg/dl (27%), litiasis renal (13%), baja masa ósea (12%), edad 60 ml/min (creatinina sérica basal 0,77 mg/dl vs. creatinina sérica al año 0,81 mg/dl, p

Zinc-α2 glycoprotein (ZAG) is an adipokine involved in adipocyte metabolism with potential implications in the pathogenesis of metabolic disorders. Our aim was to evaluate the relationship between visceral (VAT) and subcutaneous adipose tissue (SAT) ZAG expression and metabolic parameters in patients with class III obesity, along with the impact of basal ZAG expression on short- and medium-term outcomes related to bariatric surgery. 41 patients with class III obesity who underwent bariatric surgery were included in this study. ZAG gene expression was quantified in SAT and VAT. Patients were classified into two groups according to SAT and VAT ZAG percentile. Anthropometric and biochemical variables were obtained before and 15 days, 45 days, and 1 year after surgery. The lower basal SAT ZAG expression percentile was associated with higher weight and waist circumference, while the lower basal VAT ZAG expression percentile was associated with higher weight, waist circumference, insulin, insulin resistance, and the presence of metabolic syndrome. Basal SAT ZAG expression was inversely related to weight loss at 45 days after surgery, whereas no associations were found between basal VAT ZAG expression and weight loss after surgery. Additionally, a negative association was observed between basal SAT and VAT ZAG expression and the decrease of gamma-glutamyl transferase after bariatric surgery. Therefore, lower SAT and VAT ZAG expression levels were associated with an adverse metabolic profile. However, this fact did not seem to confer worse bariatric surgery-related outcomes. Further research is needed to assess the clinical significance of the role of ZAG expression levels in the dynamics of hepatic enzymes after bariatric surgery.

Introducción. En población adulta, las fracturas de clavícula constituyen el 2.6% de todas las fracturas y el 35% de todas las lesiones del hombro. Existen varias técnicas quirúrgicas para el tratamiento de estas fracturas, entre ellas la fijación con placa antero-inferior y con placa superior. Objetivo. Determinar cuál es la técnica quirúrgica más efectiva y segura para el tratamiento de fracturas del tercio medio de la clavícula: fijación con placa superior o con placa antero-inferior. Materiales y métodos. Estudio observacional analítico de cohorte realizado en 96 pacientes con fracturas del tercio medio de la clavícula tratadas mediante una de estas dos técnicas quirúrgicas en un hospital de segundo nivel de Huila, Colombia. Se midieron distintos desenlaces de interés para cada técnica. El grado de satisfacción y el resultado funcional fueron evaluados mediante los cuestionarios DASH y Constant Score, respectivamente. Además, se realizó un análisis univariado, uno bivariado, y uno multivariado para caracterizar la relación entre los desenlaces medidos. Resultados. la técnica de fijación de placa superior se utilizó en 52 pacientes, y la de placa antero-inferior, en 44. Los desenlaces de interés medidos se comportaron como factor protector para el método de placa antero-inferior: sangrado intraoperatorio (RR 0.60), tiempo quirúrgico (RR 0.53), tiempo de consolidación (RR 0.56, irritación del material de osteosíntesis (RR 0.12) y retiro del material (RR 0.25). Las diferencias respecto a resultados funcionales y grado de satisfacción también fueron estadísticamente significativas (Constant Score, p=0.000; DASH, p=0.000, respectivamente). Conclusión. La técnica de fijación con placa antero-inferior demostró ser más segura y efectiva para el tratamiento de estas fracturas, logrando un mejor resultado funcional y grado de satisfacción, por lo que se recomienda su uso en estos pacientes.

The moderate consumption of beer has been associated with positive effects on health, and these benefits are driven, in part, by the antioxidant properties of phenolic compounds found in this beverage. However, the potential impact of beer polyphenols on the human gut microbiome and their consequences are yet to be elucidated. In this study, our aim was to evaluate the effect of three different phenolic-content beers on the gut microbiome and the potential role of the induced shifts in the antioxidant capacity of beer polyphenols. In total, 20 subjects (10 healthy volunteers and 10 individuals with metabolic syndrome) were randomly assigned in a crossover design to consume each of the different beers (alcohol-free, lager or dark beer) during a 2-week intervention. Significant changes in the relative abundance of Streptococcaceae and Streptococcus were found after beer consumption. An increased abundance of Streptococcaceae and Streptococcus was observed after the consumption of dark beer, with no detected differences between baseline and alcohol-free/lager beer intervention. Moreover, some of the detected differences appeared to be related to the metabolic status. Finally, a decrease in porphyrin metabolism and heme biosynthesis was found after the intervention, especially after the consumption of dark beer. These results show that the antioxidant capacity of beer polyphenols may induce positive shifts in gut microbiota composition, and some of the observed changes may also boost the antioxidant capacity of these compounds.

This work contributes to enlightening the opportunities of the anisotropic scheme of non-covalent interactions present in supramolecular materials. It provides a top-down approach based on their selective disruption that herein has been employed to process a conventional microcrystalline material to a nanofibrillar porous material. The developed bulk microcrystalline material contains uracil-1-propionic acid (UPrOH) nucleobase as a molecular recognition capable building block. Its crystal structure consists of discrete [Cu(UPrO)2 (4,4′-bipy)2 (H2 O)] (4,4′-bipy=4,4′-bipyridine) entities held together through a highly anisotropic scheme of non-covalent interactions in which strong hydrogen bonds involving coordinated water molecules provide 1D supramolecular chains interacting between them by weaker interactions. The sonication of this microcrystalline material and heating at 45 °C in acetic acid–methanol allows partial reversible solubilization/recrystallization processes that promote the cross-linking of particles into an interlocked platelet-like micro-particles metal–organic gel, but during CO2 supercritical drying, the microcrystalline particles undergo a complete morphological change towards highly anisotropic nanofibers. This unprecedented top-down microstructural conversion provides a nanofibrillar material bearing the same crystal structure but with a highly increased surface area. Its usefulness has been tested for HPLC separation purposes observing the expected nucleobase complementarity-based separation.

In the last decades, the global prevalence of non-alcoholic fatty liver disease (NAFLD) has reached pandemic proportions with derived major health and socioeconomic consequences; this tendency is expected to be further aggravated in the coming years. Obesity, insulin resistance/type 2 diabetes mellitus, sedentary lifestyle, increased caloric intake and genetic predisposition constitute the main risk factors associated with the development and progression of the disease. Importantly, the interaction between the inherited genetic background and some unhealthy dietary patterns has been postulated to have an essential role in the pathogenesis of NAFLD. Weight loss through lifestyle modifications is considered the cornerstone of the treatment for NAFLD and the inter-individual variability in the response to some dietary approaches may be conditioned by the presence of different single nucleotide polymorphisms. In this review, we summarize the current evidence on the influence of the association between genetic susceptibility and dietary habits in NAFLD pathophysiology, as well as the role of gene polymorphism in the response to lifestyle interventions and the potential interaction between nutritional genomics and other emerging therapies for NAFLD, such as bariatric surgery and several pharmacologic agents.

La Vitamina D ha adquirido importancia no solo por su conocido papel en el mantenimiento de la masa ósea, sino por la evidencia reciente que vincula su deficiencia con patologías cardiovasculares, metabólicas, gineco-obstétricas, oncológicas e infecciosas entre otras. Se han considerado normales niveles por encima de 30 ng/mL y hay una relación inversamente proporcional entre los niveles de Vitamina D y la presencia de patologías diversas, entre las cuales se destacan las osteomusculares que ofrecen más contundencia de la relación en la evidencia. Por eso, la evaluación de los niveles de Vitamina D en población de alto riesgo y el tratamiento de la hipovitaminosis constituyen medidas que el personal de salud debe realizar. La identificación de esta población y la revisión de los esquemas de suplementación representan los objetivos primordiales de este consenso. En forma de sugerencias y recomendaciones, pensando en el impacto que el documento pueda tener en la salud pública, se presenta el Consenso colombiano de Vitamina D que contó con la participación de especialistas de siete ramas de la medicina y la implementación de la técnica Delphi, técnica mundialmente aceptada para este tipo de ejercicios académicos.

Non-alcoholic fatty liver disease (NAFLD), which approximately affects a quarter of the world’s population, has become a major public health concern. Although usually associated with excess body weight, it may also affect normal-weight individuals, a condition termed as lean/non-obese NAFLD. The prevalence of lean/non-obese NAFLD is around 20% within the NAFLD population, and 5% within the general population. Recent data suggest that individuals with lean NAFLD, despite the absence of obesity, exhibit similar cardiovascular- and cancer-related mortality compared to obese NAFLD individuals and increased all-cause mortality risk. Lean and obese NAFLD individuals share several metabolic abnormalities, but present dissimilarities in genetic predisposition, body composition, gut microbiota, and susceptibility to environmental factors. Current treatment of lean NAFLD is aimed at improving overall fitness and decreasing visceral adiposity, with weight loss strategies being the cornerstone of treatment. Moreover, several drugs including PPAR agonists, SGLT2 inhibitors, or GLP-1 receptor agonists could also be useful in the management of lean NAFLD. Although there has been an increase in research regarding lean NAFLD, there are still more questions than answers. There are several potential drugs for NAFLD therapy, but clinical trials are needed to evaluate their efficacy in lean individuals.

The Recent benthic foraminiferal families Bolivinidae, Buliminidae and Uvigerinidae from 34 core top samples were studied in order to analyze their geographic distribution and possible environmental controls in the Panama Basin. A cluster analysis defined five assemblages based on the percentage abundance of 33 species. The Bolivinidae and Buliminidae have a homogeneous distribution along the basin, in comparison to the Uvigerinidae, which has its largest proportion over the western flank of the Cocos Ridge and over the north-western flank of the Carnegie Ridge. A canonical correspondence analysis (CCA) over 26 species suggests that the Bolivinidae and Buliminidae are related to bottom temperature, in comparison to the Uvigerinidae, which has a more complex relation with depth, salinity and dissolved O2 content.

Este estudio indaga si la edad, la consciencia y la interiorización del ideal corporal predicen la insatisfacción corporal y las conductas alimentarias anómalas, en una muestra de 144 mujeres y 138 hombres, en dos grupos de diferentes edades (9-12 y 13-15 años). Para tal fin se aplicaron tres cuestionarios: Cuestionario de Imagen Corporal, Test Infantil de Actitudes Alimentarias y Cuestionario de Actitudes Socioculturales hacia la Apariencia. Mediante un modelo hipotético, que se probó a través de un path análisis, se concluye que la edad es un predictor directo de la insatisfacción corporal y las conductas alimentarias anómalas en los hombres, mientras que la interiorización del ideal corporal es el principal predictor de la insatisfacción corporal en ambos sexos.

Neither the exchanges through Jamaica, which had been seized from Spain in 1655, nor the privileges enjoyed by the South Sea Company as the result of the Tratado del Asiento from 1713 onwards entailed the decadence of the British merchant colony at Cadiz in the late seventeenth and early eighteenth centuries. In order to explain this apparent paradox, the article analyses the contribution of the Cadiz Factory to British imperial and commercial expansion in a period characterised by the strengthening of the ties between the Atlantic, Mediterranean and Asian worlds.Ni los intercambios realizados a través de Jamaica, conquistada a España en 1655, ni los privilegios disfrutados por la Compañía del Mar del Sur en virtud del Tratado del Asiento a partir de 1713 conllevaron la decadencia de la colonia mercantil británica de Cádiz a finales del siglo XVII y comienzos del siglo XVIII. Con objeto de explicar esta aparente paradoja, el artículo analiza la forma en que la Cadiz Factory contribuyó a la expansión comercial e imperial británica en un periodo caracterizado por el reforzamiento de los lazos entre los mundos atlántico, mediterráneo y asiático.

Este artículo analiza el proceso de integración de la economía malagueña en el comercio internacional en el siglo XVII, un proceso en el que los mercaderes ingleses y las relaciones mercantiles con Inglaterra desempeñaron un papel fundamental. A partir de fuentes primarias se reconstruyen el tamaño de la colonia mercantil inglesa de Málaga en distintos momentos del periodo, la cuantía y composición de los productos intercambiados y los factores institucionales que hicieron posible que Málaga se convirtiera en un puerto inglés en la España del Seiscientos. Se subraya también la extraordinaria importancia de las exportaciones malagueñas, especialmente de las pasas, en los intercambios españoles con Inglaterra.

Ni los intercambios realizados a través de Jamaica, conquistada a España en 1655, ni los privilegios disfrutados por la Compañía del Mar del Sur en virtud del Tratado del Asiento a partir de 1713 conllevaron la decadencia de la colonia mercantil británica de Cádiz a finales del siglo XVII y comienzos del siglo XVIII. Con objeto de explicar esta aparente paradoja, el artículo analiza la forma en que la Cadiz Factory contribuyó a la expansión comercial e imperial británica en un periodo caracterizado por el reforzamiento de los lazos entre los mundos atlántico, mediterráneo y asiático.

En el presente trabajo se analizará una cuestión de gran relevancia en la teoría de los derechos fundamentales, que no es otra que la problemática de sus límites. Los derechos y libertades constitucionales no son ilimitados, a pesar que algunos de ellos son absolutos. Y esto no es un contrasentido, pues ambas cosas tienen distinta significación, según se verá. Pero a su vez, no son iguales los límites de los derechos y libertades clásicos que los de los derechos sociales, lo que en gran medida se debe precisamente a que unos son absolutos y otros no. Todas estas cuestiones serán tratadas a continuación.

Various studies have pointed to the importance of interaction between the actors (teacher-student) in virtual learning environments. In this paper our objective is to evaluate the dimensions of interaction of distance-learning students in virtual learning environments. A Scale of Interaction in Virtual Learning Environments was constructed, based on Barberà, Badia and Monimó’s (2001) interaction typology. Assessment by expert judges was used to improve content validity. Subsequently the scale was applied to a sample of distance-learning high school students in order to identify psychometric properties. The scale had a reliability coefficient of .93 and the following factorial structure: Factor I) Learning support interactions with the advisor; Factor II) Interactions with the virtual environment learning materials; and Factor III) Dialogic interaction with peers. This measurement model was evaluated by means of CFA, which demonstrated adequate goodness-of-fit indices.