Is There a Calcification Factor Common to All Calcifying Matrices?

This paper reviews the principal morphological findings pertinent to the early phases of the calcification process and explores the possibility that there may be a calcification factor common to all calcifying matrices. Three structures have a main role in calcification: collagen fibrils, matrix vesicles, and crystal ghosts. Only crystal ghosts are present in all calcified tissues, so that only they can be taken into consideration as a common calcification factor. They are organic molecules which have the same morphology as that of the inorganic structures present in the calcified matrix, which means that they can be considered as templates for those structures. Early calcification might be initiated by the binding of calcium and phosphate ions to the unmasked reactive groups of the crystal ghosts which are probably contained not only in the matrix, but also in the holes of the collagen fibrils and in matrix vesicles. The available data suggest that crystal ghosts share many of the properties of crystal bound proteins . The involvement of alkaline phosphatase in their composition may account for their calcium-and phosphate-binding activity

Anti-oxidant and anti-inflammatory activity of ketogenic diet. New perspectives for neuroprotection in alzheimer’s disease

The ketogenic diet, originally developed for the treatment of epilepsy in non-responder children, is spreading to be used in the treatment of many diseases, including Alzheimer’s disease. The main activity of the ketogenic diet has been related to improved mitochondrial function and decreased oxidative stress. B-Hydroxybutyrate, the most studied ketone body, has been shown to reduce the production of reactive oxygen species (ROS), improving mitochondrial respiration: it stimulates the cellular endogenous antioxidant system with the activation of nuclear factor erythroid-derived 2-related factor 2 (Nrf2), it modulates the ratio between the oxidized and reduced forms of nicotinamide adenine dinucleotide (NAD+/NADH) and it increases the efficiency of electron transport chain through the expression of uncoupling proteins. Furthermore, the ketogenic diet performs anti-inflammatory activity by inhibiting nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) activation and nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome as well as inhibiting histone deacetylases (HDACs), improving memory encoding. The underlying mechanisms and the perspectives for the treatment of Alzheimer’s disease are discussed

Characterization of the Stellar / Substellar Boundary

The aim of this dissertation is to address the topic of distinguishing very low mass stars from brown dwarfs through observational means. To that end, we seek to better characterize both populations and establish mechanisms that facilitate establishing an individual object\u27s membership in either the very low mass star or the brown dwarf populations. The dissertation is composed of three separate observational studies. In the first study we report on our analysis of HST/NICMOS snapshot high resolution images of 255 stars in 201 systems within ~10 parsecs of the Sun. We establish magnitude and separation limits for which companions can be ruled out for each star in the sample, and then perform a comprehensive sensitivity and completeness analysis for the subsample of 138 M dwarfs in 126 systems. We calculate a multiplicity fraction of $0.0-0.0+3.5$2.3-0.7+5.0% for L and T companions to M dwarfs in the separation range of 10 to 70 AU. Considering these results and results from several other studies, we argue that the so-called brown dwarf desert extends to binary systems with low mass primaries and is largely independent of primary mass, mass ratio, and separation. In the second study we construct a Hertzsprung-Russell diagram for the stellar/substellar boundary based on a sample of 63 objects ranging in spectral type from M6V to L4. We report new VRI photometry for 63 objects and new trigonometric parallaxes for 37 objects. We employ a novel SED fitting algorithm to determine effective temperatures, bolometric luminosities, and radii. We find evidence for the local minimum in the radius-temperature and radius-luminosity trends that may indicate the end of the stellar main sequence and the start of the brown dwarf sequence at $Teff ~2075K, log(L/Lsun) ~ -3.9, and (R/Rsun) ~ 0.086. The third study is a pilot study for future work and part of a long term search for astrometric binaries that have the potential to yield dynamical masses. We report the discovery of five new multiple systems and discuss their potential for determining dynamical masses: LHS 2071AB, GJ 1215 ABC, LTT 7434 AB, LHS 501 AC, and LHS 3738 AB

Measurement techniques in a transonic wind tunnel. Total temperature and turbulence characterization.

A new refrigeration solution for high by-pass ratio engines is the main objective of the Intelligent Cooling System project. This study is based on a surface integrated air-oil heat exchanger placed at the location of the air separator nose within the bypass flow of a turbofan. The aim is to help the cooling of the oil circuit without disturbing the air stream and decreasing the overall efficiency of the engine. The present work focuses on the aerodynamic characterization of the interaction between the three dimensional bypass flow and different configurations of finned heat exchangers. This research is done in von Karman Institute in a new blowdown wind tunnel characterized by an helicoidal test section specifically design within this project in order to reproduce the engine bypass flow in the region of interest. This report presents the work performed for the calibration and implementation of the thermocouples and hot wire anemometers used for total temperature and turbulence measurements, as well as part of the flow results, with the relative postprocessing methodology. Finally the uncertainties analysis was done in order to estimate the goodness of the results and to identify the major sources of errors

Structural and Functional Consequences Induced by Post-Translational Modifications in α-Defensins

HNP-1 is an antimicrobial peptide that undergoes proteolytic cleavage to become a mature peptide. This process represents the mechanism commonly used by the cells to obtain a fully active antimicrobial peptide. In addition, it has been recently described that HNP-1 is recognized as substrate by the arginine-specific ADP-ribosyltransferase-1. Arginine-specific mono-ADP-ribosylation is an enzyme-catalyzed post-translational modification in which NAD+ serves as donor of the ADP-ribose moiety, which is transferred to the guanidino group of arginines in target proteins. While the arginine carries one positive charge, the ADP-ribose is negatively charged at the phosphate moieties at physiological pH. Therefore, the attachment of one or more ADP-ribose units results in a marked change of cationicity. ADP-ribosylation of HNP-1 drastically reduces its cytotoxic and antibacterial activities. While the chemotactic activity of HNP-1 remains unaltered, its ability to induce interleukin-8 production is enhanced. The arginine 14 of HNP-1 modified by the ADP-ribose is in some cases processed into ornithine, perhaps representing a different modality in the regulation of HNP-1 activities

El orgullo del primer número de la revista Science of Human Action

Para una Institución de Educación Superior es vital la consolidación del proceso investigativo, pues es éste el motor que retroalimenta y dinamiza a la docencia y la extensión universitaria. No puede concebirse a la universidad sin la investigación. Ahora bien, la investigación debe ser sometida a la evaluación de expertos y debe estar disponible para la comunidad en general, con la finalidad no sólo de cumplir un requisito académico, sino de compartir y hacer extensivo el conocimiento generado por medio de la investigación. Por eso el nacimiento de una revista científica debe celebrarse, ya que es otra forma de extender la universida

Análise e dimensionamento de estacas sujeitas a compressão axial : aplicações na região administrativa especial de Macau

Tese de mestrado. Estruturas de Engenharia Civil. Faculdade de Engenharia. Universidade do Porto, Laboratório de Engenharia Civil de Macau. 200