On the connected component of compact composition operators on the Hardy space

We show that there exist non-compact composition operators in the connected component of the compact ones on the classical Hardy space $H^2$ on the unit disc. This answers a question posed by Shapiro and Sundberg in 1990. We also establish an improved version of a theorem of MacCluer, giving a lower bound for the essential norm of a difference of composition operators in terms of the angular derivatives of their symbols. As a main tool we use Aleksandrov-Clark measures.Comment: 16 page

Band-diagonal operators on Banach lattices: matrix dynamics and invariant subspaces

We address the existence of non-trivial closed invariant ideals for positive operators defined on Banach lattices whose order is induced by an unconditional basis. In particular, for band-diagonal positive operators such existence is characterized whenever their matrix representations meet a positiveness criteria. For more general classes of positive operators, sufficient conditions are derived proving, particularly, the sharpness of such results from the standpoint of view of the matrix representations. The whole approach is based on studying the behavior of the dynamics of infinite matrices and the localization of the non-zero entries. Finally, we generalize a theorem of Grivaux regarding the existence of non-trivial closed invariant subspaces for positive tridiagonal operators to a more general class of band-diagonal operators showing, in particular, that a large subclass of them have non-trivial closed invariant subspaces but lack non-trivial closed invariant ideals.Depto. de Análisis Matemático y Matemática AplicadaFac. de Ciencias MatemáticasTRUEMinisterio de Ciencia e Innovacióninpres

El paisaje eólico de la llanura aluvial de San Juan (Llanura Manchega Central)

[Resumen] El campo dunar de la Llanura aluvial de San Juan, esta caracterizado por la presencia dedunas arcillosas, limosas o limo-arcillosas. Morfologicamente, son dunas de tipo parabólico y otras con aspecto "cónico", "transverso" o "longitudinal", construidas por paleovientos efectivos que provenían del W y SW. Finalmente, se discute la edad y origen de estos complejos dunares.[Abstract] The dunes of the San Juan alluvial plain consists most characteristically of clayey, silty, and clayeysilty dunes, which morphologically are most commonly of parabolic type , but dome-shaped, transverse and linear dunes are present as well. These were built up by effective winds coming from the Wand SW. Finally, both the age and genesis of these dunes is discússed

First approach to understanding riparian wetlands in the Middle Ebro River floodplain (NE, Spain) : structural characteristics and functional dynamics

In Spring of 2005, the relationships between the physical and chemical characteristics of the aquatic and benthic environments and macroinvertebrate assemblages in seven wetlands representative of the floodplain of the Middle Ebro River (NE Spain), were analyzed. The selected wetlands differed in their hydrological connectivity, local environmental conditions and anthropic influence. Through multivariate analyses, two environmental gradients and three main wetland groups were detected. The hydrological connectivity differences generate a heterogenous landscape of structurally and functionally different wetlands in the Ebro Middle floodplain. Confined wetlands, such as older ox bow lakes, showed higher salt and organic matter contents and lower macroinvertebrates' density and biodiversity than did the other wetlands. This suggests that confinement and lack of disturbance events have led to water salinization and eutrophication, habitat homogenization and natural succession of the communities towards more adapted structures with lower biodiversity. Wetlands that still maintain some functional relationship with the river, such as newer ox bow lakes, constructed wetlands, and backwaters, show a higher inorganic nutrient concentration and suspended solids. They also show higher taxa richness and evenness, which suggests that higher disturbance frequencies enhance habitat's heterogeneity and resource availability, and therefore primary and secondary production that allow adapted and opportunistic species to coexist. The progressive flow regulation tends to homogenise this complex system, endangering its conservation. Therefore, the key processes identified here should be taken under consideration for the planning and execution of ecological monitoring, management and restoration.En primavera de 2005 se analizaron las relaciones entre las características físicas y químicas de los medios acuático y bentónico, y la comunidad de macroinvertebrados de 7 humedales representativos de la llanura de inundación del río Ebro (NE de España) en su tramo medio. Los humedales seleccionados se diferenciaron por su grado de conectividad hídrica, condiciones ambientales locales e influencia antrópica. Mediante análisis multivariante, se localizaron dos gradientes ambientales y tres tipos de humedales principales. Las diferencias de conectividad hidrológica generan un mosaico heterogéneo de humedales con diferente estructura y función en la llanura de inundación del Ebro Medio. Los humedales confinados -como los meandros abandonados más antiguos- mostraron mayor contenido de sales y materia orgánica, y menor densidad y diversidad de macroinvertebrados que el resto de humedales. Esto sugiere que el confinamiento y la falta de eventos de perturbación han conducido a la salinización y eutrofización del agua, la homogeneización del hábitat y la sucesión natural de las comunidades hacia estructuras más adaptadas y de menor diversidad. Los humedales que todavía mantienen cierta relación funcional con el río -como los meandros abandonados más recientes, humedales artificiales y "madres"- muestran una mayor concentración de nutrientes inorgánicos y sólidos en suspensión, además de una mayor riqueza de taxones y equitatividad, lo que sugiere que la mayor frecuencia de perturbación favorece la heterogeneidad de hábitat y de recursos, y por tanto la producción primaria y secundaria permitiendo la coexistencia de especies oportunistas y adaptadas. La progresiva regulación de caudales tiende a homogeneizar este complejo sistema poniendo en peligro su conservación. Por tanto, los procesos principales identificados en este estudio deben ser tenidos en cuenta en el diseño de planes de monitoreo, gestión y restauración ecológicas

Bioadhesión sobre Alúmina. Propiedades superficiales

La alúmina es uno de los materiales cerámicos de mayor relevancia en usos biomédicos. Así, este trabajo hace una completa caracterización de su superficie a través de propiedades que son de especial importancia en aquellos procesos de interacción con superficies biológicas como son células y microorganismos. Tensión superficial, potencial zeta y rugosidad superficial se analizan utilizando métodos diversos. La tensión superficial se muestra en torno a 35 mJ m-2 aunque los valores dependen en muchos casos de la aproximación escogida y de los grupos de líquidos prueba necesarios para su determinación. El punto isoeléctrico aparece a pH = 4,6 lo que indica una carga superficial negativa cuando la alúmina se encuentre inmersa en líquidos fisiológicos (pH = 7). Los accidentes topográficos responsables de la macrorugosidad pueden considerarse de periodicidad en torno a 25um presentando alta variabilidad a escalas inferiores, por ello, es importante determinar la rugosidad a escalas próximas al tamaño de las células que intervienen en el proceso de adhesión

Serum proteomics of active tuberculosis patients and contacts reveals unique processes activated during Mycobacterium tuberculosis infection.

Tuberculosis (TB) is the most lethal infection among infectious diseases. The specific aim of this study was to establish panels of serum protein biomarkers representative of active TB patients and their household contacts who were either infected (LTBI) or uninfected (EMI-TB Discovery Cohort, Pontevedra Region, Spain). A TMT (Tamdem mass tags) 10plex-based quantitative proteomics study was performed in quintuplicate containing a total of 15 individual serum samples per group. Peptides were analyzed in an LC-Orbitrap Elite platform, and raw data were processed using Proteome Discoverer 2.1. A total of 418 proteins were quantified. The specific protein signature of active TB patients was characterized by an accumulation of proteins related to complement activation, inflammation and modulation of immune response and also by a decrease of a small subset of proteins, including apolipoprotein A and serotransferrin, indicating the importance of lipid transport and iron assimilation in the progression of the disease. This signature was verified by the targeted measurement of selected candidates in a second cohort (EMI-TB Verification Cohort, Maputo Region, Mozambique) by ELISA and nephelometry techniques. These findings will aid our understanding of the complex metabolic processes associated with TB progression from LTBI to active disease

Hilbert-Schmidt composition operators on Dirichlet spaces

In this note we show that analytic self-maps phi of the unit disk inducing Hilbert-Schmidt composition operators C-phi on the weighted Dirichlet space D-alpha satisfy that the set E-phi = {e(itheta) is an element of partial derivativeD : |phi(e(itheta))| = 1} has zero alpha-capacity

Phase coexistence in highly deuterated ferroelectric triglycine selenate: Landau description

The phase transition in a 90% deuterated sample of TGSe has been investigated by calorimetric and dielectric measurements. As a consequence of the presence of an internal crack in the sample, the transition takes place in two stages separated by an interval where the paraelectric and the ferroelectric phases coexist without latent heat contribution. From the latent heat, the specific heat excess and the Curie law for the dielectric constant, it is shown that the transition follows a 2-4-6 Landau potential, whose coefficients are determined. This potential describes completely all the data, including those corresponding to the coexistence interval.Dirección General de Investigación Científica y Técnica (DGICYT) FIS2005-0244

Opinion of handball players, trainers and referees using the handball/futsal goalpost anti-tip system “tutigool” for a safe game: 2019 four nations international handball junior tournament

[EN] Problem Statement:Athletes and especially children die around the world due to sports accidents. In this regard, changes in the federal sports regulations are not only aimed at favoring the game, but also to improve the safety of athletes. In handball, the goal is an essential piece of equipment and the anti-tip system used is fundamental to prevent accidents. Purpose:The objective of the present study was to know the opinion of different sports agents about the use of the Tutigool anti-tip system in the goals. Methods:The sample consisted of 60 subjects (players (51 ± 0.72), trainers (5 ± 14.01), and referees (4 ± 2.5)), of which, 96.7% were men and 3.3% women. A modified Likert-scale questionnaire was filled out (1 = strongly disagree to 7 = strongly agree) by the participants of the Four Nations International Tournament in January 2019 in the male U21 category, held in Santander (Spain). The questionnaire consisted of 18 items. Results: The most relevant results affirm that the system is appropriate for the handball game at the municipal and school level at 5.35 and for high level sports at 4.10. The average satisfaction with this system is 4.34. By agents, the coaches obtained 5.4, the referees 4.5 and the players 4.22. The Kruskal-Wallis test was carried out, which showed no significant differences in the mean scores (p> 0.05) given by players, trainers and referees in different aspects related to the anti-tip system. Conclusions:These results allow making a deep reflection and a change in handball regulations with the aim of adapting them and guaranteeing a safer practice, not only for athletes and amateur users, but also for sports facilities technicians who are responsible for the maintenance and handling of sports equipment.S