Cooperative cell motility during tandem locomotion of amoeboid cells.

Streams of migratory cells are initiated by the formation of tandem pairs of cells connected head to tail to which other cells subsequently adhere. The mechanisms regulating the transition from single to streaming cell migration remain elusive, although several molecules have been suggested to be involved. In this work, we investigate the mechanics of the locomotion ofDictyosteliumtandem pairs by analyzing the spatiotemporal evolution of their traction adhesions (TAs). We find that in migrating wild-type tandem pairs, each cell exerts traction forces on stationary sites (∼80% of the time), and the trailing cell reuses the location of the TAs of the leading cell. Both leading and trailing cells form contractile dipoles and synchronize the formation of new frontal TAs with ∼54-s time delay. Cells not expressing the lectin discoidin I or moving on discoidin I-coated substrata form fewer tandems, but the trailing cell still reuses the locations of the TAs of the leading cell, suggesting that discoidin I is not responsible for a possible chemically driven synchronization process. The migration dynamics of the tandems indicate that their TAs' reuse results from the mechanical synchronization of the leading and trailing cells' protrusions and retractions (motility cycles) aided by the cell-cell adhesions

Perfil d’activitat durant el joc en futbolistes infantils

Al futbol, el patró d’activitat dels jugadors adults, tant masculins com femenins, ha estat estudiat àmpliament, però són escassos els estudis que han centrat l’atenció en l’anàlisi dels desplaçaments dels jugadors de categories infantils. Un coneixement més gran de les demandes d’aquest esport en les etapes inicials permetria la confecció de programes d’entrenament més concordes amb les característiques dels nois d’aquestes edats. L’objectiu del nostre estudi va ser quantificar dels desplaçaments en jugadors de futbol de categoria infantil (12,2 ± 0,6 anys; 156 ± 0,8 cm i 51 ± 5,2 kg) que pertanyien a la selecció de la ciutat autònoma de Melilla, mitjançant l’aplicació de dispositius basats en tecnologia GPS. Els resultats obtinguts certifiquen que el futbol infantil és una especialitat esportiva intermitent en la qual s’intercalen activitats d’alta intensitat amb situacions del joc que permeten que el jugador recuperi estant aturat, caminant o amb una velocitat de carrera molt baixa. La taxa treball-descans va ser d’1:3,5 i la distància mitjana recorreguda per minut va ser aproximadament de 100 m. Aquesta distància varia i disminueix de forma lineal en el transcurs del partit: hi ha diferències significatives entre l’inici i el final del joc, la qual cosa indicaria l’aparició de la fatiga. Els esforços d’alta intensitat que es realitzen impliquen el 6,1 % del temps de joc i el 16,3 % de la distància recorreguda; efectuen un esprint màxim d’entre 10 i 15 m de mitjana, cada 141 segons. L’aplicació de tasques que reprodueixin la intensitat del joc durant curts períodes de temps (no superiors a 10 minuts) asseguraria una elevada intensitat de treball durant els entrenaments

Perfil de actividad durante el juego en futbolistas infantiles

En fútbol, el patrón de actividad de jugadores adultos, tanto masculinos como femeninos, ha sido ampliamente estudiado, pero son escasos los estudios que han centrado su atención en el análisis de los desplazamientos de los jugadores de categorías infantiles. Un mayor conocimiento de las demandas de este deporte en las etapas iniciales permitiría la confección de programas de entrenamiento más acordes con las características de los chicos de estas edades. El objetivo del presente estudio fue cuantificar de los desplazamientos en jugadores de fútbol de categoría infantil (12,2 ± 0,6 años; 156 ± 0,8 cm y 51 ± 5,2 kg) que pertenecían a la selección de la ciudad autónoma de Melilla, mediante la aplicación de dispositivos basados en tecnología GPS. Los resultados obtenidos certifican que el fútbol infantil es una especialidad deportiva intermitente en la que se intercalan actividades de alta intensidad con situaciones del juego que permiten que el jugador recupere estando parado, andando o con una velocidad de carrera muy baja. La tasa trabajo-descanso fue de 1:3,5 y la distancia media recorrida por minuto fue aproximadamente de 100 m. Esta distancia varía disminuyendo de forma lineal conforme transcurre el partido, existiendo diferencias significativas entre el inicio y el final del juego, lo que indicaría la aparición de la fatiga. Los esfuerzos de alta intensidad que se realizan implican el 6,1% del tiempo de juego y el 16,3 % de la distancia recorrida, efectuando un sprint máximo de entre 10 y 15 m de media, cada 141 segundos. La aplicación de tareas que reproduzcan la intensidad del juego durante cortos periodos de tiempo (no superiores a 10 minutos) aseguraría una elevada intensidad de trabajo durante los entrenamientos

TiO2-Low Band Gap Semiconductor Heterostructures for Water Treatment Using Sunlight-Driven Photocatalysis

Heterogeneous photocatalysis is a promising advanced oxidation process for water purification, given its potential to fully oxidize organic pollutants and to inactivate microorganisms. Due to its versatility and high performance in a broad range of conditions, titanium dioxide (TiO2)-based photocatalysis has been systematically used at laboratory scale to treat water of different quality. Even though TiO2 is an exceptional photocatalyst, its broad band gap value (3.2 eV) makes necessary the use of UV light to achieve the photoactivation. This results in the underutilization of the material in sunlight-driven photocatalysis schemes. In order to overcome this handicap, the synthesis of heterostructures using low band gap semiconductors coupled with TiO2 has brought exceptional materials for visible light-driven photocatalysis. In this chapter, the fundamentals of the synthesis and photoactivation of TiO2-low band gap semiconductor heterostructures are explored. The mechanisms leading to the increase of the photocatalytic activity of such heterostructures are described. A summary of the available data on the photocatalytic performance of TiO2-based heterostructures is presented, in terms of degradation of organic pollutants in water using visible light and sunlight. A comparison of the depuration performance of powdered and thin film heterostructures is given at the end of the chapter

Models for the Assessment of Treatment Improvement: The Ideal and the Feasible

Comparisons of different treatments or production processes are the goals of a significant fraction of applied research. Unsurprisingly, two sample problems play a main role in statistics through natural questions such as. Is the the new treatment significantly better than the old. However, this is only partially answered by some of the usual statistical tools for this task. More importantly, often practitioners are not aware of the real meaning behind these statistical procedures. We analyze these troubles from the point of view of the order between distributions, the stochastic order, showing evidence of the limitations of the usual approaches, paying special attention to the classical comparison of means under the normal model. We discuss the unfeasibility of statistically proving stochastic dominance, but show that it is possible, instead, to gather statistical evidence to conclude that slightly relaxed versions of stochastic dominance hold.Research partially supported by the Spanish Ministerio de Economía y Competitividad y fondos FEDER, grants MTM2014-56235-C2-1-P and MTM2014-56235-C2-2, and by Consejería de Educación de la Junta de Castilla y León, grant VA212U13

Investigation of Coulomb dipole polarization effects on reactions involving exotic nuclei

We have analyzed elastic scattering angular distributions and total reaction cross sections of the exotic nuclei Li9,11 on Pb208, at energies below and above the Coulomb barrier. For this purpose, we have used an optical potential with no adjustable parameters, composed by the nuclear São Paulo potential, derived from the nonlocal nature of the interaction, and the Coulomb dipole polarization potential, derived from the semiclassical theory of Coulomb excitation. Within this formalism, we identified an unusual long-range absorption for the Li11+Pb208 system, which is dominated by the Coulomb interaction. We compare it to the absorption mechanisms observed for He6+Pb208 which, unlike those of Li11+Pb208, take place at small interacting distances, where both Coulomb and nuclear interactions are important. The proposed approach shows to be a fundamental basis to study reactions involving exotic nuclei

Connections between the facial and trigeminal nerves: Anatomical basis for facial muscle proprioception

Proprioception is a quality of sensibility that originates in specialized sensory organs (proprioceptors) that inform the central nervous system about static and dynamic conditions of muscles and joints. The facial muscles are innervated by efferent motor nerve fibers and typically lack proprioceptors. However, facial proprioception plays a key role in the regulation and coordination of the facial musculature and diverse reflexes. Thus, facial muscles must be necessarily supplied also for afferent sensory nerve fibers provided by other cranial nerves, especially the trigeminal nerve. Importantly, neuroanatomical studies have demonstrated that facial proprioceptive impulses are conveyed through branches of the trigeminal nerve to the central nervous system. The multiple communications between the facial and the trigeminal nerves are at the basis of these functional characteristics. Here we review the literature regarding the facial (superficial) communications between the facial and the trigeminal nerves, update the current knowledge about proprioception in the facial muscles, and hypothesize future research in facial proprioception

Biodiesel production from waste cooking oil in an oscillatory flow reactor. Performance as a fuel on a TDI diesel engine

This paper describes the biodiesel production from waste cooking oil (50% (v/v) olive oil/sunflower oil) in an oscillatory flow reactor (OFR) in batch mode. We mainly focused on the characteristics of the biodiesel and its performance as a fuel. First at all, we verified that biodiesel yield in OFR was higher than in stirred tank reactor (STR) under the same experimental conditions, and that composition and properties of the resulting biofuel did not depend on reactor type. Besides, biodiesel production in OFR took half the time than in STR. Subsequently, we modify some OFR operational parameters to assess their influence on biodiesel yield. The most suitable conditions were found to be 6:1 methanol to waste cooking oil molar ratio, 0.67 Hz oscillation frequency and 30 min reaction time. Finally, the biofuel obtained was tested in a 2.0 TDI 140 hp EURO4 engine installed on an engine test bench. Specific fuel consumption, particle size distribution and concentration of exhaust gas sample pollutants and were analysed running with commercial diesel, 50% (v/v) diesel/biodiesel blend (B50) and biodiesel (B100) in order to ensure the viability of using this biofuel in vehicle engines.Fondos de la Unión Europea - LIFE 13-Bioseville ENV/111