Bone Morphogenetic Protein and its Option as an Alveolar Cleft Treatment

Indexación: Scopus; Scielo.Bone morphogenetic protein (BMP) is an endogenous protein that has shown significant effects in the promotion of bone formation. BMP also has been described in the reconstruction of traumatic and pathological bone defects, including alveolar cleft, alveolar ridge augmentation, maxillary sinus elevation, and applications in post-extraction alveolus graft, and peri-implant surgery among others. Despite the advantages associated with the use of BMP, currently is applied in combination with collagen matrices, which has certain properties such as low mechanical resistance and a high burst initial release that diminish its effectiveness in bone formation. In this context, the development of novel systems with greater mechanical resistance and prolonged release of BMP, that lead to chemotaxis of mesenchymal cells, following by its differentiation to osteoblasts represents a major challenge that holds outstanding clinical potential for the stimulation of bone formation. In this paper, we describe the use of BMP for the reconstruction of alveolar clefts, and its advantages being administrated in polymeric microparticles as sustain release system with promising applications in the stimulation of bone formation.http://ref.scielo.org/ps5w6

A Fuzzy Syllogistic Reasoning Schema for Generalized Quantifiers

In this paper, a new approximate syllogistic reasoning schema is described that expands some of the approaches expounded in the literature into two ways: (i) a number of different types of quantifiers (logical, absolute, proportional, comparative and exception) taken from Theory of Generalized Quantifiers and similarity quantifiers, taken from statistics, are considered and (ii) any number of premises can be taken into account within the reasoning process. Furthermore, a systematic reasoning procedure to solve the syllogism is also proposed, interpreting it as an equivalent mathematical optimization problem, where the premises constitute the constraints of the searching space for the quantifier in the conclusion.Comment: 22 pages, 6 figures, journal pape

Measuring the physical imprints of gas flows in galaxies I: Accretion rate histories

Galaxies are expected to accrete pristine gas from their surroundings to sustain their star formation over cosmic timescales. Its lower abundance affects the metallicity of the ISM in which stars are born, leaving chemical imprints in the stellar populations. We measure the amount of pristine gas that galaxies accrete during their lifetime, using information on the ages and abundances of their stellar populations and a chemical evolution model. We also aim to determine the efficiency of star formation over time. We derived star formation histories and metallicity histories for a sample of 8523 galaxies from the MaNGA survey. We use the former to predict the evolution of the metallicity in a closed-box scenario, and estimate for each epoch the gas accretion rate required to match these predictions with the measured stellar metallicity. Using only chemical parameters, we find that the history of gas accretion depends on the mass of galaxies. More massive galaxies accrete more gas and at higher redshifts than less massive galaxies, which accrete their gas over longer periods. We also find that galaxies with a higher star formation rate at z = 0 have a more persistent accretion history for a given mass. The star formation efficiency shows similar correlations: early-type galaxies and higher-mass galaxies had a higher efficiency in the past, and it declined such that they are less efficient in the present. Our analysis of individual galaxies shows that compactness affects the peak star formation efficiency that galaxies reach, and that the slope of the efficiency history of galaxies with current star formation is flat. Our results support the hypothesis that a steady and substantial supply of pristine gas is required for persistent star formation in galaxies. Once they lose access to this gas supply, star formation comes to a halt.Comment: 17 pages, 11 figures. Accepted at A&

The Onfp Class in the Magellanic Clouds

The Onfp class of rotationally broadened, hot spectra was defined some time ago in the Galaxy, where its membership to date numbers only eight. The principal defining characteristic is a broad, centrally reversed He II $\lambda$4686 emission profile; other emission and absorption lines are also rotationally broadened. Recent surveys in the Magellanic Clouds (MCs) have brought the class membership there, including some related spectra, to 28. We present a survey of the spectral morphology and rotational velocities, as a first step toward elucidating the nature of this class. Evolved, rapidly rotating hot stars are not expected theoretically, because the stellar winds should brake the rotation. Luminosity classification of these spectra is not possible, because the principal criterion (He II $\lambda$4686) is peculiar; however, the MCs provide reliable absolute magnitudes, which show that they span the entire range from dwarfs to supergiants. The Onfp line-broadening distribution is distinct and shifted toward larger values from those of normal O dwarfs and supergiants with >99.99% confidence. All cases with multiple observations show line-profile variations, which even remove some objects from the class temporarily. Some of them are spectroscopic binaries; it is possible that the peculiar profiles may have multiple causes among different objects. The origin and future of these stars are intriguing; for instance, they could be stellar mergers and/or gamma-ray-burst progenitors.Comment: 27 pages, 8 figures, 2 tables; AJ accepte

Análisis observacional del discurso docente del profesorado de educación física en formación a través de patrones comunicativos

El marco teórico socioconstructivista concede una gran importanciaal papel del lenguaje como un poderoso instrumento para la construcciónde significados compartidos sobre los contenidos escolares entreprofesorado y alumnado. Este trabajo aborda el análisis observacional delas estrategias discursivas empleadas por una maestra en un curso mixto de19 estudiantes de primero y segundo de Educación Primaria en dos unidadesdidácticas, una antes y otra después de su participación en un procesode investigación-acción centrado en el empleo de las estrategias discursivascomo recurso metodológico en Educación Física. Para ello se ha utilizadoun instrumento de observación ad hoc que combina formato de campo ysistema de categorías, y como instrumento de registro el programa Atlas.ti, 7.1.8. Los datos han sido analizados aplicando la técnica analítica Tpatternspor medio del programa Theme v.6, cuyo algoritmo nos permitedesvelar patrones discursivos que subyacen en la conducta verbal de formano directamente perceptible. Los resultados revelan la aparición recurrentede un patrón comunicativo formado por la combinación de demandas deinformación (preguntas) con incorporación literal de las aportaciones delalumnado al discurso del profesor, que se mantiene en las dos fases, lo quepone de manifiesto una preocupación por generar momentos de reflexiónsobre los contenidos desarrollados, además de hacer partícipe al alumnadoen el proceso de enseñanza-aprendizaje, pieza clave en la construcción delconocimiento desde una perspectiva socioconstructivista. El resto de estrategiasdiscursivas aparecen en menor medida antes del proceso de investigación-acción, con un aumento importante después de su desarrollo