Endogenous longevity, biological deterioration and economic growth

The identification of the types of bidirectional interactions that take place between longevity and economic growth in the long-run is carried out by means of the integration of human capital accumulation, innovation in medical technology, a health goods sector, and individual decisions on health and longevity in a dynamic general equilibrium set-up. In this context, in which individual agents decide not only on their “quality” of life but also on its “quantity”, the mere process of biological deterioration, that is to say, the continuous loss of health goods effectiveness in maintaining a given level of health as individuals age, provides the reason for an additional, and new, engine of growth.Biological deterioration; Health; Health goods; Endogenous longevity; Endogenous growth

La deterioración de las piedras de la Catedral de Oviedo. 2° Parte: Formas y Fenómenos de Alteración

The different forms of superficial alteration that appear on the stones of the Oviedo Cathedral are described and localed, in this part of the paper. The more common phenomena of deterioration of the monument are also defined, stressing on the crusts.En esta parte del trabajo, se describen y localizan las diversas formas de alteración superficial observadas sobre las piedras de la Catedral. Asimismo se concretan los fenómenos de deterioración más generalizados en el monumento, haciendo especial énfasis en el análisis de las costras

Estudios experimentales sobre la consolidación y protección de los materiales calcáreos de la Catedral de Oviedo. 1.ª parte

The suitability of some consolidating and protecting products, to be applied to the deteriorated calcareous stones of the Cathedral of Oviedo, is presented. A proposed procedure and methodology for evaluating that suitability is also described. The studied stones, limestones and dolomites, have been experimentally subjected in laboratory to some treatment products: ethyl silicate, oligomeric silane and silicon resin. Some physical properties of those stones were evaluated before and after the treatments with the mentioned products. Those properties (porosity, water absorption, compressive strength and deformability, mechanical microfissuration threshold, acoustic emission, etc.) were selected according to the significative role they play on the process of stone alteration or in supporting the proposed conclusions.Se presenta una metodología de trabajo encaminada a evaluar la idoneidad de ciertos productos consolidantes y protectores aplicados a piedras monumentales deterioradas. Para ello, en esta 1.ª parte, se determinan una serie de propiedades físicas, antes y después de aplicar los tratamientos. Dichas propiedades han sido seleccionadas por su incidencia en los mecanismos de alteración. Las piedras ensayadas proceden de la Catedral de Oviedo, son rocas calcáreas: calizas y dolomías. Los productos de tratamiento empleados han sido: silicato de etilo, silano oligomérico y resina silicónica. Se concluye con la comparación de las variaciones en las propiedades determinadas, antes y después del tratamiento, según el producto empleado

STENOSTOMUM LEUCOPS DUGÈS, 1828 (PLATYHELMINTHES, CATENULIDA): A PUTATIVE SPECIES COMPLEX WITH PHENOTYPIC PLASTICITY

RESUMO Stenostomum são pequenos vermes que vivem em água doce e normalmente se reproduzem assexualmente por paratomia. Eles estão na base da filogenia dos platelmintes. Por mais de um século, espécies desse gênero, especialmente S. leucops, vêm sendo empregadas em estudos biológicos, principalmente sobre regeneração. Entretanto, alguns aspectos básicos da biologia destes vermes são ainda pobremente conhecidos. Neste estudo, caracterizamos uma linhagem que vem sendo mantida no laboratório por cinco anos. O tempo necessário para reprodução assexuada e completa formação de zoóides, a 28°C, é de aproximadamente 42,5 horas. O número de células nos zoóides, logo após a paratomia, é de aproximadamente 2.500. O número de zoóides presentes nos vermes é uma característica variável e depende das condições de cultivo. Em alguns procedimentos de cultivo de S. leucops, apenas cadeias com dois zoóides são formadas. No entanto, em outras condições de cultivo, cadeias de até cinco zoóides podem ser observadas. Análise filogenética empregando sequência do gene de Citocromo C Oxidase (COI) mostrou que S. leucops e S. grande constituem um complexo de espécies cujas linhagens mostram altas divergências intraespecíficas.ABSTRACT Species of Stenostomum are small flatworms that live in freshwater and normally reproduce asexually by paratomy. They are basal in the phylogeny of Platyhelminthes. For more than a century, species of this genus, especially S. leucops, have been used in regeneration and other biological studies. However, some basic aspects of their biology are poorly known. Here, we characterized a strain of S. leucops that has been maintained in the laboratory for five years and a recent strain of S. grande. The time required for complete formation of zooids of S. leucops by asexual reproduction is approximately 42.5 hours at 28°C. The number of cells in the zooids, soon after paratomy, is approximately 2,500. The number of zooids formed in the chain is a plastic characteristic and is dependent on the conditions for cultivation. In some cultivation conditions of S. leucops, only worms with two zooids are formed. However, in other conditions, worms with up to five zooids are observed. Phylogenetic analyses of a fragment of the Cytochrome C Oxidase I (COI) sequence showed S. leucops and S. grande species constitute a species complex, the lineages of which having high intraspecific divergences

STENOSTOMUM LEUCOPS DUGÈS, 1828 (PLATYHELMINTHES, CATENULIDA): A PUTATIVE SPECIES COMPLEX WITH PHENOTYPIC PLASTICITY

RESUMO Stenostomum são pequenos vermes que vivem em água doce e normalmente se reproduzem assexualmente por paratomia. Eles estão na base da filogenia dos platelmintes. Por mais de um século, espécies desse gênero, especialmente S. leucops, vêm sendo empregadas em estudos biológicos, principalmente sobre regeneração. Entretanto, alguns aspectos básicos da biologia destes vermes são ainda pobremente conhecidos. Neste estudo, caracterizamos uma linhagem que vem sendo mantida no laboratório por cinco anos. O tempo necessário para reprodução assexuada e completa formação de zoóides, a 28°C, é de aproximadamente 42,5 horas. O número de células nos zoóides, logo após a paratomia, é de aproximadamente 2.500. O número de zoóides presentes nos vermes é uma característica variável e depende das condições de cultivo. Em alguns procedimentos de cultivo de S. leucops, apenas cadeias com dois zoóides são formadas. No entanto, em outras condições de cultivo, cadeias de até cinco zoóides podem ser observadas. Análise filogenética empregando sequência do gene de Citocromo C Oxidase (COI) mostrou que S. leucops e S. grande constituem um complexo de espécies cujas linhagens mostram altas divergências intraespecíficas.ABSTRACT Species of Stenostomum are small flatworms that live in freshwater and normally reproduce asexually by paratomy. They are basal in the phylogeny of Platyhelminthes. For more than a century, species of this genus, especially S. leucops, have been used in regeneration and other biological studies. However, some basic aspects of their biology are poorly known. Here, we characterized a strain of S. leucops that has been maintained in the laboratory for five years and a recent strain of S. grande. The time required for complete formation of zooids of S. leucops by asexual reproduction is approximately 42.5 hours at 28°C. The number of cells in the zooids, soon after paratomy, is approximately 2,500. The number of zooids formed in the chain is a plastic characteristic and is dependent on the conditions for cultivation. In some cultivation conditions of S. leucops, only worms with two zooids are formed. However, in other conditions, worms with up to five zooids are observed. Phylogenetic analyses of a fragment of the Cytochrome C Oxidase I (COI) sequence showed S. leucops and S. grande species constitute a species complex, the lineages of which having high intraspecific divergences

Liquid mixtures involving hydrogenated and fluorinated alcohols: thermodynamics, spectroscopy, and simulation

This article reports a combined thermodynamic, spectroscopic, and Computational study on the interactions and structure of binary mixtures of hydrogenated and fluorinated substances that simultaneously interact through strong hydrogen bonding. Four binary mixtures of hydrogenated and fluorinated alcohols have been studied, namely, (ethanol + 2,2,2-trifluoroethanol (TFE)), (ethanol + 2,2,3,3,4,4,4-heptafluoro-1-butanol), (1-butanol (BuOH) + TFE), and (BuOH + 2,23,4,4,4-heptafluoto-1-butanol). Excess molar volumes and vibrational spectra of all four binary mixtures have been measured as a function of composition at 298 K, and molecular dynamics simulations have been performed. The systems display a complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The combined analysis of the results from different approaches indicates that this results from a balance between preferential hydrogen bonding between the hydrogenated and fluorinated alcohols and the unfavorable dispersion forces between the hydrogenated and fluorinated chains. As the chain length increases, the contribution of dispersion increases and overcomes the contribution of H-bonds. In terms of the liquid structure, the simulations suggest the possibility of segregation between the hydrogenated and fluorinated segments, a hypothesis corroborated by the spectroscopic results. Furthermore, a quantitative analysis of the infrared spectra reveals that the presence of fluorinated groups induces conformational changes in the hydrogenated chains from the usually preferred all-trans to more globular arrangements involving gauche conformations. Conformational rearrangements at the CCOH dihedral angle upon mixing are also disclosed by the spectra

AMPK activation by oncogenesis is required to maintain cancer cell proliferation in astrocytic tumors

5'-AMP-activated protein kinase (AMPK) is an energy sensor that controls cell metabolism, and it has been related to apoptosis and cell-cycle arrest. Although its role in metabolic homeostasis is well documented, its function in cancer is much less clear. In this study, we examined the role of AMPK in a mouse model of astrocytoma driven by oncogenic H-Ras(V12) and/or with PTEN deletion based on the common constitutive activation of the Raf/MEK/ERK and PI3K/AKT cascades in human astrocytomas. We also evaluated the activity and role of AMPK in human glioblastoma cells and xenografts. AMPK was constitutively activated in astrocytes expressing oncogenic H-Ras(V12) in parallel with high cell division rates. Genetic deletion of AMPK or attenuation of its activity in these cells was sufficient to reduce cell proliferation. The levels of pAMK were always related to the levels of phosphorylated retinoblastoma (Rb) at Ser804, which may indicate an AMPK-mediated phosphorylation of Rb. We confirmed this AMPK-Rb relationship in human glioblastoma cell lines and xenografts. In clinical specimens of human glioblastoma, elevated levels of activated AMPK appeared especially in areas of high proliferation surrounding the blood vessels. Together, our findings indicate that the initiation and progression of astrocytic tumors relies upon AMPK-dependent control of the cell cycle, thereby identifying AMPK as a candidate therapeutic target in this setting