Unstable manifold, Conley index and fixed points of flows

We study dynamical and topological properties of the unstable manifold of isolated invariant compacta of flows. We show that some parts of the unstable manifold admit sections carrying a considerable amount of information. These sections enable the construction of parallelizable structures which facilitate the study of the flow. From this fact, many nice consequences are derived, specially in the case of plane continua. For instance, we give an easy method of calculation of the Conley index provided we have some knowledge of the unstable manifold and, as a consequence, a relation between the Brouwer degree and the unstable manifold is established for smooth vector fields. We study the dynamics of non-saddle sets, properties of existence or non-existence of fixed points of flows and conditions under which attractors are fixed points, Morse decompositions, preservation of topological properties by continuation and classify the bifurcations taking place at a critical point

Hipertensión arterial emergente e inflamación en el ictus isquémico agudo

Se ha considerado que en la patogenia del ictus isquémico están implicados mecanismos inflamatorios. Durante la fase aguda de la isquemia cerebral se produce una cascada citotóxica que origina la liberación de factores quimiotácticos, lo cual desencadena una respuesta inflamatoria. También se ha sugerido que el incremento de la presión sanguínea puede ser un estímulo para la inflamación, y éste ser el posible mecanismo por el cual la hipertensión es un factor de riesgo para el desarrollo de aterosclerosis. La presión arterial desempeña una labor importante en la fase aguda del ictus, pero el mecanismo que justifica su elevación aun es desconocido

The relative age effect in the Spanish elite male handball

El nacimiento en diferentes trimestres del año conlleva diferencias entre los jugadores respecto al desarrollo madurativo, las cuales pueden influir en la selección, desarrollo y consolidación en el alto nivel en balonmano. El presente estudio pretendió analizar el efecto relativo de la edad en el balonmano de élite masculino en España. Para ello, fueron analizados los datos de nacimiento y puesto específico de los 586 jugadores participantes en la Liga ASOBAL en las temporadas comprendidas entre 2003-04 y 2008-09, realizándose comparaciones y estudiándose las diferencias mediante pruebas χ2 y Z. El análisis de resultados reveló la existencia de un mayor porcentaje de jugadores nacidos en el primer trimestre del año, constatándose diferencias significativas en función de la nacionalidad. Concretamente, se encontraron porcentajes muy elevados de jugadores nacidos en los primeros meses del año en los puestos específicos de la primera línea ofensiva y en el portero Por tanto, parece confirmarse un efecto relativo de la edad en los jugadores analizados, teniendo este relación con la nacionalidad y los puestos específicos.The birth in different quarters of the year involved differences regarding maturational development in handball players, which may influence the selection, development and consolidation in the elite in handball. This study sought to investigate the relative age effect in elite male handball players in Spain. To do this, data of birth and specific position of 586 players were analyzed, who participe in the League ASOBAL in seasons between 2003-04 and 2008-09. Comparisons and differences were studied by χ2 tests and Z. Analysis of results revealed a higher percentage of players born in the first quarter, significant differences were confirmed in spanish players. Specifically, the highest percentages of players born in the first months of the year were the specific positions of the first offensive line and the goalkeeper. In conclusion, the results seem to confirm a relative effect of age on the players analyzed. The nationality and specific positions have a significant relationship with this.peerReviewe

Charge ordering and dielectric properties in the near half-doped Pr0.79Na0.21MnO3 perovskite

[Abstract] The Pr0.79Na0.21MnO3 perovskite has been prepared in polycrystalline form by a ceramic method. We have carried out its structural characterization by synchrotron X-ray powder diffraction (SXRPD) at room temperature and at 150 K (T<TCO). In the charge ordering (CO) state, the SXRPD data can be refined both on the basis of the site-centred model and the bond-centred model proposed for half-doped manganites, without a clear advantage of one model over the other. From the dielectric point of view, at the CO temperature this manganite shows a maximum in the dielectric constant whose origin is intrinsic, and cannot be attributed to the presence of extrinsic factors. We relate this dielectric behaviour to the formation of polar entities at the temperature of charge condensation, due to an asymmetric charge distribution intermediate between site-centred and bond-centred type.Xunta de Galicia; PGIDIT06PXB103298PRMinisterio de Educación y Ciencia; Project FEDER MAT 2004-0513

Direct Access to Axially Substituted Subphthalocyanines from Trimethylsilyl-Protected Nucleophiles

A new synthetic one-step approach to perform the axial ligand exchange reaction in subphthalocyanines that employs trimethylsilyl-protected nucleophiles as starting materials is reported. Theoretical calculations indicate that the exchange reaction proceeds through a similar 4-centered σ-bond metathesis transition state as the substitution with phenols. This direct method allowed us to synthesize new axial derivatives of singular importance within the chemistry of subphthalocyanines, for which the reactivity and X-ray crystalline structure were studiedFinancial support from the MINECO, Spain (CTQ-2014-52869-P, T.T.; CTQ2014-57729-P, D.G.-R.), and the Comunidad de Madrid (S2013/MIT-2841 FOTOCARBON, T.T.) is acknowledged. M.Y. thank the MICINN (Spain) for the Project No.CTQ2012-35513-C02-0

The social fabric of leadership. A study of teachers’ collaboration networks in primary schools

Este artículo analizará la red social que configura el profesorado en seis centros de educación primaria andaluces, así como la modalidad de distribución del liderazgo que aparece en cada una de las redes. Nuestro propósito al utilizar la metodología de Análisis de Redes Sociales (ARS) en el marco de un proyecto más amplio sobre alcance y patrones de distribución del liderazgo en los centros escolares era conocer mejor la trama de relaciones sociales que sustenta al liderazgo escolar. Para ello elaboramos y administramos al profesorado participante un Cuestionario sobre la Red Social del Centro Escolar (CURSO) en el que se indaga sobre las relaciones docentes en cuatro ámbitos: enseñanza, gestión escolar, convivencia y apoyo individual. Los datos fueron analizados mediante el programa UCINET. El análisis se realizó a partir del grado de centralidad de los actores implicados en cada red, así como de varias propiedades estructurales de las mismas como su densidad, centralización y número y composición de los cliques o grupos participantes. Los resultados nos permitieron identificar diversas configuraciones relevantes del liderazgo escolar: focalizado, múltiple, alternativo y sin-liderazgo. Finalmente se aportan algunas conclusiones sobre la relevancia de la metodología de análisis de redes sociales para el estudio del liderazgoThis paper will analyse the social network emerging from teachers’ relationships in six Andalusian primary schools, and will identify the leadership distribution pattern of each network. Our aim using Social Network Analysis methodology in the framework of a wider research project about patterns and scope of school leadership distribution was to better know the web of social relationships that sustain school leadership. To do this, a School Social Network Questionnaire was designed and administered to the whole staff of the participating schools. The questionnaire included questions regarding four areas: teaching, school management, social relationships and personal support. Data collected were analysed by means of UCINET software. The analysis focused both on the actors’ centrality degree and several structural properties of the networks, such as their density, centralisation, and the number and composition of the cliques or groups participants. The results allowed the research team to identify some relevant patterns of school leadership: focused, multiple, alternative, and leadership void. Finally some conclusions are presented about the relevance of social network analysis in leadership studie

Apparent colossal dielectric constants in nanoporous Metal Organic Frameworks

[Abstract] In this work, we show that the hybrid material Co2(1,4-bdc)2(dabco)•[4DMF•1H2O], shows an apparent colossal dielectric constant at room temperature (r5000 at 300 K for =100 Hz). Nevertheless, such response does not imply colossal polarizability processes, as its dielectric constant is not purely intrinsic, but is greatly enhanced by the activation of extrinsic dielectric effects close to room temperature associated to the diffusion of numerous guest molecules through the channels. If such extrinsic contributions are eliminated or reduced, the values of the dielectric constant turn to be much smaller, as observed in the closely related Co2(1,4-bdc-NH2)2(dabco)•[7/2DMF•1H2O], Co2(1,4-ndc)2(dabco) •[3DMF•2H2O] and Ni2(1,4-bdc)2(dabco)•[3DMF•1/2H2O] compounds. Therefore, we warn about the imperious necessity of distinguishing between intrinsic and extrinsic effects in electrically inhomogenous MOF materials that display a certain conductivity in order to adequately interpret their dielectric behaviorMinisterio de Economía y Competitividad; MAT2010-21342-C02-01Xunta de Galicia; PGIDIT10PXB103272P

Random Forest-Based Prediction of Stroke Outcome

[Abstract] We research into the clinical, biochemical and neuroimaging factors associated with the outcome of stroke patients to generate a predictive model using machine learning techniques for prediction of mortality and morbidity 3-months after admission. The dataset consisted of patients with ischemic stroke (IS) and non-traumatic intracerebral hemorrhage (ICH) admitted to Stroke Unit of a European Tertiary Hospital prospectively registered. We identified the main variables for machine learning Random Forest (RF), generating a predictive model that can estimate patient mortality/morbidity according to the following groups: (1) IS + ICH, (2) IS, and (3) ICH. A total of 6022 patients were included: 4922 (mean age 71.9 ± 13.8 years) with IS and 1100 (mean age 73.3 ± 13.1 years) with ICH. NIHSS at 24, 48 h and axillary temperature at admission were the most important variables to consider for evolution of patients at 3-months. IS + ICH group was the most stable for mortality prediction [0.904 ± 0.025 of area under the receiver operating characteristics curve (AUC)]. IS group presented similar results, although variability between experiments was slightly higher (0.909 ± 0.032 of AUC). ICH group was the one in which RF had more problems to make adequate predictions (0.9837 vs. 0.7104 of AUC). There were no major differences between IS and IS + ICH groups according to morbidity prediction (0.738 and 0.755 of AUC) but, after checking normality with a Shapiro Wilk test with the null hypothesis that the data follow a normal distribution, it was rejected with W = 0.93546 (p-value < 2.2e−16). Conditions required for a parametric test do not hold, and we performed a paired Wilcoxon Test assuming the null hypothesis that all the groups have the same performance. The null hypothesis was rejected with a value < 2.2e−16, so there are statistical differences between IS and ICH groups. In conclusion, machine learning algorithms RF can be effectively used in stroke patients for long-term outcome prediction of mortality and morbidity.This study was partially supported by grants from the Spanish Ministry of Science and Innovation (SAF2017-84267-R), Xunta de Galicia (Axencia Galega de Innovación (GAIN): IN607A2018/3), Instituto de Salud Carlos III (ISCIII) (PI17/00540, PI17/01103), Spanish Research Network on Cerebrovascular Diseases RETICS-INVICTUS PLUS (RD16/0019) and by the European Union FEDER program. T. Sobrino (CPII17/00027), F. Campos (CPII19/00020) are recipients of research contracts from the Miguel Servet Program (Instituto de Salud Carlos III). General Directorate of Culture, Education and University Management of Xunta de Galicia (ED431G/01,252 ED431D 2017/16), “Galician Network for Colorectal Cancer Research" (Ref. ED431D 2017/23), Competitive Reference Groups (ED431C 2018/49), Spanish Ministry of Economy and Competitiveness via funding of the unique installation BIOCAI (UNLC08-1E-002, UNLC13-13–3503), European Regional Development Funds (FEDER).Xunta de Galicia; IN607A2018/3Xunta de Galicia; ED431G/01,252Xunta de Galicia; ED431D 2017/1

Interleukin-10 facilitates the selection of patients for systemic thrombolysis

Background: Clinical-Diffusion mismatch (CDM; NIHSS score ≥8 & DWI lesion volume ≤25 mL) and Perfusion-Diffusion mismatch (PDM; difference >20% between initial DWI and MTT lesion volumes) have been proposed as surrogates for ischemic brains that are at risk of infarction. However, their utility to improve the selection of patients for thrombolytic treatment remains controversial. Our aim was to identify molecular biomarkers that can be used with neuroimaging to facilitate the selection of ischemic stroke patients for systemic thrombolysis. Methods: We prospectively studied 595 patients with ischemic stroke within 12 h of the stroke onset. A total of 184 patients received thrombolytic treatment according to the SITS-MOST criteria. DWI and MTT volumes were measured at admission. The main outcome variable was good functional outcome at 3 months (modified Rankin scale <3). Serum levels of glutamate (Glu), IL-10, TNF-α, IL-6, NSE, and active MMP-9 also were determined at admission. Results: Patients treated with t-PA who presented with PDM had higher IL-10 levels at admission (p < 0.0001). In contrast, patients with CDM had higher levels of IL-10 (p < 0.0001) as well as Glu and TNF-α (all p < 0.05) and lower levels of NSE and active MMP-9 (all p < 0.0001). IL-10 ≥ 30 pg/mL predicts good functional outcome at 3 months with a specificity of 88% and a sensitibity of 86%. IL-10 levels ≥30 pg/mL independently in both patients with PDM (OR, 18.9) and CDM (OR, 7.5), after an adjustment for covariates. Conclusions: Serum levels of IL-10 facilitate the selection of ischemic stroke patients with CDM and PDM for systemic thrombolysis

Influence of Sex on Stroke Prognosis: A Demographic, Clinical, and Molecular Analysis

Identifying the complexities of the effect of sex on stroke risk, etiology, and lesion progression may lead to advances in the treatment and care of ischemic stroke (IS) and non-traumatic intracerebral hemorrhage patients (ICH). We studied the sex-related discrepancies on the clinical course of patients with IS and ICH, and we also evaluated possible molecular mechanisms involved. The study's main variable was the patient's functional outcome at 3-months. Logistic regression models were used in order to study the influence of sex on different inflammatory, endothelial and atrial dysfunction markers. We recruited 5,021 patients; 4,060 IS (54.8% male, 45.2% female) and 961 ICH (57.1% male, 42.9% female). Women were on average 5.7 years older than men (6.4 years in IS, 5.1 years in ICH), and more likely to have previous poor functional status, to suffer atrial fibrillation and to be on anticoagulants. IS patients showed sex-related differences at 3-months regarding poorer outcome (55.6% women, 43.6% men, p &lt; 0.0001), but this relationship was not found in ICH (56.8% vs. 61.9%, p = 0.127). In IS, women had higher levels of NT-proBNP and 3-months worse outcome in both cardioembolic and non-cardioembolic stroke patients. Stroke patients showed sex-related differences in pre-hospital data, clinical variables and molecular markers, but only IS patients presented independent sex-related differences in 3-months poor outcome and mortality. There was a relationship between the molecular marker of atrial dysfunction NT-proBNP and worse functional outcome in women, resulting in a possible indicator of increased dysfunction