Topological and spectral properties of random digraphs

We investigate some topological and spectral properties of Erd\H{o}s-R\'{e}nyi (ER) random digraphs $D(n,p)$. In terms of topological properties, our primary focus lies in analyzing the number of non-isolated vertices $V_x(D)$ as well as two vertex-degree-based topological indices: the Randi\'c index $R(D)$ and sum-connectivity index $\chi(D)$. First, by performing a scaling analysis we show that the average degree $\langle k \rangle$ serves as scaling parameter for the average values of $V_x(D)$, $R(D)$ and $\chi(D)$. Then, we also state expressions relating the number of arcs, spectral radius, and closed walks of length 2 to $(n,p)$, the parameters of ER random digraphs. Concerning spectral properties, we compute six different graph energies on $D(n,p)$. We start by validating $\langle k \rangle$ as the scaling parameter of the graph energies. Additionally, we reformulate a set of bounds previously reported in the literature for these energies as a function $(n,p)$. Finally, we phenomenologically state relations between energies that allow us to extend previously known bounds

Transport studies in three-terminal microwave graphs with orthogonal, unitary, and symplectic symmetry

The Landauer-B\"uttiker formalism establishes an equivalence between the electrical conduction through a device, e.g., a quantum dot, and the transmission. Guided by this analogy we perform transmission measurements through three-port microwave graphs with orthogonal, unitary, and symplectic symmetry thus mimicking three-terminal voltage drop devices. One of the ports is placed as input and a second one as output, while a third port is used as a probe. Analytical predictions show good agreement with the measurements in the presence of orthogonal and unitary symmetries, provided that the absorption and the influence of the coupling port are taken into account. The symplectic symmetry is realized in specifically designed graphs mimicking spin 1/2 systems. Again a good agreement between experiment and theory is found. For the symplectic case the results are marginally sensitive to absorption and coupling strength of the port, in contrast to the orthogonal and unitary case.Comment: 6 pages, 6 figure

Estilo de vida y control metabólico en pacientes con diabetes mellitus tipo 2. Validación por constructo del IMEVID

ObjetivoEvaluar la validez de constructo de un instrumento para medir el estilo de vida en los pacientes con diabetes mellitus tipo 2 (cuestionario IMEVID)DiseñoEstudio observacional transversal comparativoEmplazamientoSeis unidades de medicina familiar (atención primaria)ParticipantesUn total de 412 adultos con diabetes mellitus tipo 2Mediciones principalesSe aplicó el IMEVID por autoadministración y se midió el índice de masa corporal (IMC), índice cintura/cadera (ICC), hemoglobina glucosilada (HbA1C), colesterol total (CT), triglicéridos (TG), presión arterial (PA) y glucemia en ayunas (GA). El constructo hipotético de prueba fue que las mayores calificaciones totales en el IMEVID (mejor estilo de vida) estarían asociadas a valores menores de estas variables clínicas. Se dividió a los sujetos en tres grupos según su calificación total: grupo uno (< cuartil 25), grupo dos (cuartil 25-75), grupo tres (> cuartil 75) y se buscaron diferencias intergrupo en los valores de los parámetros medidosResultadosCompletaron el estudio 389 sujetos, y un 69,2% eran mujeres. Siete dimensiones del IMEVID tuvieron correlaciones débiles al menos con dos de los ocho parámetros (r, –0,22 a 0,16; p≤0,05). La calificación total se correlacionó con seis de ocho parámetros (r, –0,18 a 0,10; p≤0,05). Los sujetos del grupo tres tuvieron valores menores de IMC, ICC, HbA1C, GA, CT y TGL que los del grupo 1 (p<0,05)ConclusionesEl IMEVID tiene validez de constructo para medir el estilo de vida en los sujetos con diabetes tipo 2. Su calificación total discrimina las características clínicamente relevantesObjectiveTo evaluate construct validity of an instrument to measure lifestyle in patients with type 2 diabetes mellitus (IMEVID questionnaire)DesignComparative cross-sectional studySettingSix family medicine units (primary care)Patients412 adults with type 2 diabetesMeasurementsThe IMEVID was applied by self-administration and the following metabolic control parameters values were measured: body mass index (BMI), waist/hip index (WHI), hemoglobin A1C (HbA1C), total cholesterol (TC), triglycerides (TG), systolic blood pressure (SBP), diastolic blood pressure (DBP), and the average of fasting plasma glucose in the last three months (FG). The test hypothetic construct was that higher total scores in the IMEVID (better lifestyle) would be associated with lower values in the metabolic control parameters. Three groups of subjects were formed based on the total score: group one (<cuartil 25), group two (among cuartil 25 and 75) and group three (>cuartil 75). Differences on these parameters between groups were researchedResults389 subjects completed the study, 69,2% were women. Seven IMEVID domains had weak correlations at least with two of eight parameters (r between –0.22 and 0.16; P≤.05). The total score had correlation with six of eight parameter (r between –0.18 and 0.10; P≤.05). The group three subjects had lower levels of BMI,WHI, HbA1C, FG,TC and TGL than group one subjects (P≤.05)ConclusionsIMEVID has construct validity to measure the lifestyle in subjects with DM2. Its total score discriminates outstanding clinical characteristics in these patient

Universal insulating-to-metallic crossover in tight-binding random geometric graphs

Within the scattering matrix approach to electronic transport, the scattering and transport properties of tight-binding random graphs are analyzed. In particular, we compute the scattering matrix elements, the transmission, the channel-to-channel transmission distributions (including the total transmission distribution), the shot noise power, and the elastic enhancement factor. Two graph models are considered: random geometric graphs and bipartite random geometric graphs. The results show an insulating to a metallic crossover in the scattering and transport properties by increasing the average degree of the graphs from small to large values. Also, the scattering and transport properties are shown to be invariant under a scaling parameter depending on the average degree and the graph size. Furthermore, for large connectivity and in the perfect coupling regime, the scattering and transport properties of both graph models are well described by the random matrix theory predictions of electronic transport, except for bipartite graphs in particular scattering setups.Comment: 13 pages, 16 figure

Competencia global y educación literaria: fundamentos teóricos y aportes críticos

E El objetivo de este trabajo es presentar los resultados de una revisión teórica sistemática de alcance internacional sobre la noción emergente de competencia global, identificando su potencial para la educación literaria. Las fuentes revisadas son artículos y trabajos de investigación publicados en los últimos quince años, y seleccionados en bases de datos especializadas. El estudio revela cómo la competencia global se configura desde la movilización de dimensiones como comprender múltiples perspectivas, comunicar eficazmente con audiencias diversas, indagar sobre el mundo y emprender acciones éticamente responsables, junto con componentes como la conciencia intercultural y la alfabetización crítica. En este escenario educativo, se analiza el papel que debe desempeñar una educación literaria que conecte al alumnado con el mundo, acompañándole en el descubrimiento, análisis e interpretación de cuestiones globales y multiculturales, desde la literatura infantil y juvenil. Como conclusión, se afirma que esta perspectiva implica la revisión del canon literario y la aplicación de propuestas metodológicas de mediación que focalicen la gestión del aula y las estrategias de interacción comunicativa a partir de los textos

Competencia global y educación literaria: fundamentos teóricos y aportes críticos

E El objetivo de este trabajo es presentar los resultados de una revisión teórica sistemática de alcance internacional sobre la noción emergente de competencia global, identificando su potencial para la educación literaria. Las fuentes revisadas son artículos y trabajos de investigación publicados en los últimos quince años, y seleccionados en bases de datos especializadas. El estudio revela cómo la competencia global se configura desde la movilización de dimensiones como comprender múltiples perspectivas, comunicar eficazmente con audiencias diversas, indagar sobre el mundo y emprender acciones éticamente responsables, junto con componentes como la conciencia intercultural y la alfabetización crítica. En este escenario educativo, se analiza el papel que debe desempeñar una educación literaria que conecte al alumnado con el mundo, acompañándole en el descubrimiento, análisis e interpretación de cuestiones globales y multiculturales, desde la literatura infantil y juvenil. Como conclusión, se afirma que esta perspectiva implica la revisión del canon literario y la aplicación de propuestas metodológicas de mediación que focalicen la gestión del aula y las estrategias de interacción comunicativa a partir de los textos

Degradation of IF1 controls energy metabolism during osteogenic differentiation of stem cells

Differentiation of human mesenchymal stem cells (hMSCs) requires the rewiring of energy metabolism. Herein, we demonstrate that the ATPase inhibitory factor 1 (IF1) is expressed in hMSCs and in prostate and colon stem cells but is not expressed in the differentiated cells. IF1 inhibits oxidative phosphorylation and regulates the activity of aerobic glycolysis in hMSCs. Silencing of IF1 in hMSCs mimics the metabolic changes observed in osteocytes and accelerates cellular differentiation. Activation of IF1 degradation acts as the switch that regulates energy metabolism during differentiation. We conclude that IF1 is a stemness marker important for maintaining the quiescence stateThis work was supported by grants from the Ministerio de Educación y Ciencia (BFU2010-18903), the Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, and Comunidad de Madrid (S2011/BMD-2402), Spai

Peripheral Inflammatory Parameters in Late-Life Depression: A Systematic Review

Depressive disorders appear relatively frequently in older patients, and therefore represent an important disease burden worldwide. Given the high levels of inflammatory parameters found in depressed elderly patients, the "inflammaging" hypothesis is gaining strength. In this systematic review, we summarize current evidence regarding the relationship between inflammatory parameters and late-life depression, with a unique focus on longitudinal studies to guarantee temporality. According to the data summarized in this review, the levels of some proinflammatory parameters-especially interleukin (IL)-8, IL-6, and tumor necrosis factor (TNF)-α-could serve as biomarkers for the future development of depressive symptoms in elderly patients. Proinflammatory cytokines seem to be associated with the future development of clinically significant depression, irrespective of baseline scores, thus indicating that inflammation temporally precedes and increases depression risk. As insufficient research has been conducted in this field, further prospective studies are clearly warranted.This study was funded by grants from Research Network Center of Mental Health-CIBERSAM (2010-P-02); the Government of Spain “Health Research Fund” FEDER (PI08-1213, PI11-01977, PI14-01900, PI08-0873; PI10-01746; PS09/02002; PI12/02077; PI15-00789; PI13/00451); Ministry of Health and Social Equality (20111064) Policy; Local funding from the Department of Education, Language Policy and Culture of the Basque Government (200911147, 2013111162, 2010111170, SAIO10-PC10BF01); European Comission funds (UE/2012/FI-STAR). We appreciate the support of the University of the Basque Country (GIC10/80, GIC12/84) and the Basque Foundation for Health Innovation and Research-BIOEF. The Psychiatry Research Unit of the University Hospital of Álava-Santiago is supported by the “Stanley Research Foundation” (03-RC-003). John O’Brien is supported by the NIHR Cambridge Biomedical Research Centre awarded to the University of Cambridge, Cambridge University Hospitals NHS Trust and Cambridgeshire and Peterborough NHS Trust

Caracterización Mineralógica de Cálculos Salivales y Nasales

Dos rinolitos y dos cálculos salivales se han estudiado por diversas técnicas. El análisis por fluorescencia de Rayos-X revela la presencia de Calcio y Fósforo como elementos mayoritarios e impurezas de varios elementos (Na, Mg, Al, Si, S, Cl, K, Ti, Cr, Mn, Fe, Co, Cu y Zn). La difracción de rayos-X indica que las especies mineralógicas más frecuentes en los cálculos son fosfato tricálcico y apatitos. Un estudio paralelo por espectroscopia infrarroja entre los cálculos y sus productos calcinados también se ha llevado a cabo.Two rhinoliths and two salivary calculi were studied. X-ray fluorescence analysis reveals the presence of Ca and P as majority elements and several impurities in the specimens (Na, Mg, Al, Si, S, CI, K, Ti, Cr, Mn, Fe, Co, Cu & Zn). The X-ray powder patterns of the samples, show mainly tric\acium phosphate hydrate and apatites as mineralogical species. A comparative infrared study between the unheated and calcinated samples is shown