Comportamiento frente a la corrosión inducida por cloruros de armaduras de nuevos aceros inoxidables con bajo contenido en níquel

La utilización de armaduras de acero inoxidable, de los tipos austeníticos y dúplex, con el objetivo de prolongar la vida útil de las estructuras de hormigón, es una alternativa que está recibiendo cada vez más consideración. Los aceros inoxidables son aleaciones fundamentalmente de cromo y níquel, con muy alta resistencia a la corrosión, especialmente por cloruros. El elevado coste del níquel y sus grandes fluctuaciones en el mercado, han favorecido la aparición de nuevos aceros inoxidables con bajo contenido en dicha aleación y, por lo tanto, más económicos, que sin embargo presentan una resistencia a la corrosión similar a los tradicionales. En este trabajo se ha evaluado la resistencia a la corrosión por cloruros de dos nuevos aceros inoxidables de bajo contenido en níquel. Uno de los aceros es austenítico, de producción en forma de chapa, y el otro dúplex, que se comercializa como barra corrugada. La resistencia a la corrosión se ha evaluado, respectivamente, mediante ensayos electroquímicos de dichos aceros embebidos en solución simulada de poros de hormigón y en probetas de mortero contaminados con diferentes cuantías de cloruros. Los resultados de los ensayos se han comparado con los del acero austenítico tradicional AISI 304 y del acero al carbono B500SD

Comparación intraespecífica de la conducta antidepredatoria de la culebra Thamnophis melanogaster

Se explora la variación geográfica, ontogénica y sexual de la conducta antidepredatoria presentada en laboratorio de una culebra endémica de México. El diseño experimental no demostró que la conducta antidepredatoria fuera influida por la ontogenia, diferencias sexuales o geográficas, aunque el tamaño del cuerpo posiblemente sí la afecta. Se sugiere que la selección natural por depredación es similar en ambas poblaciones y entre sexos, pero posiblemente está sujeta a cambios ontogénicos en Cuitzeo, Michoacán.Se explora la variación geográÀca, ontogénica y sexual de la conducta antidepredatoria presentada en laboratorio de una culebra endémica de México. El diseño experimental no demostró que la conducta antidepredatoria fuera inÁuida por la ontogenia, diferencias sexuales o geográÀcas, aunque el tamaño del cuerpo posiblemente sí la afecta. Se sugiere que la selección natural por depredación es similar en ambas poblaciones y entre sexos, pero posiblemente está sujeta a cambios ontogénicos en Cuitzeo, Michoacán

A role for antizyme inhibitor 2 in the biosynthesis and content of serotonin and histamine in mouse mast cells

Polyamines (putrescine, spermidine and spermine; PAs) are essential for the majority of living cells. Antizymes and antizyme inhibitors are key regulatory proteins of PA levels by affecting ornithine decarboxylase and PA uptake. In addition to PAs, mast cells (MC) synthesize and store in their granules histamine (Hia) and serotonin (5-HT), which are critical for their function. Our previous studies have indicated a metabolic interplay among PAs, Hia and 5-HT in this cell type. For instance, we showed that PAs affect Hia synthesis during early stages of IL-3-induced bone marrow cell differentiation into bone marrow derived MCs (BMMCs) and demonstrated that PAs are present in MC secretory granules and are important for granule homeostasis, including Hia storage and 5-HT levels. A few years ago, a novel antizyme inhibitor (AZIN2) was described whose expression is restricted to a few tissues and cell types including brain, testis and MCs. In MCs, it was recently proposed that AZIN2 could act as a local regulator of PA biosynthesis in association with 5-HT-containing granules and with 5-HT release following MC activation. To gain insight into the role of AZIN2 in the biosynthesis and storage of 5-HT and also Hia, we have generated BMMCs from both wild-type and transgenic mice with severe Azin2 hypomorphism, and have analyzed the content of PAs, 5-HT and Hia, and some elements of their metabolisms. Spermine and 5-HT levels were reduced in Azin2 hypomorphic BMMCs compared with wild-type controls, whereas the amount of Hia was increased. Accordingly, the level of tryptophan hydroxylase 1 (the key enzyme for 5-HT biosynthesis) was reduced and the amount of enzymatic activity of histidine decarboxylase (the enzyme responsible for Hia biosynthesis) was increased in Azin2 hypomorphic BMMCs. Taken together, our results show evidence that AZIN2 has an important role in the regulation of 5-HT and Hia biosynthesis and storage in MCsUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This work was supported by SAF2011-26518 (MINECO, Spain) and P10-CVI-6585 and Bio-267 (Junta de Andalucia, Spain). CIBERER is an iniciative of Instituto de Salud Carlos III (Spain)

Structural and functional interaction between polyamine related molecules and biological membranes

La comunicación describe el conocimiento actual sobre las interacciones de biomoléculas relacionadas con el metabolismo de poliaminas con las estructuras y funciones de las membranas biológicasChanges induced by PA on nucleic acid (NA) conformation and synthesis is proven to be a major reason for PA essentiality (1-3). However, PA interactions with other polyanions, for instance polyanionic membrane lipid bilayers and glyosaminoglycans have received less attention (3-4). The functional importance of these interactions still is an obscure but interesting area of cell and molecular biology, especially in mammalian cells for which specific PA transport systems are not fully characterized (5). In mammals, activity and turnover of the polyamine (PA) synthesis key enzyme is controlled by a set of proteins: Antizymes (OAZ1-3) and antizyme inhibitors (AZIN1 and 2). It is demonstrated that AOZ modulate polyamine uptake (6), and that PA transport to mitochondria is linked to the respiratory chain state and modulates mitochondrial permeability transition (7). Antizyme expression variants have been located in mitochondria, being proposed as a proapoptotic factor (7-8). AZIN 2 is only expressed in a reduced set of tissues that includes mast cells, where it is associated to mast cell granules membrane (9). This fact, together to the abnormalities observed in bone marrow derived mast cell granules when they are differentiated under restricted PA synthesis conditions (10 and unpublished results), point out to important roles of PA and their related proteins in structure and function of mast cell granules. We will also present novel biophysical results on tripartite interactions of PA that remark the interest of the characterization of PA interactions with lipid bilayers for biomedicine and biotechnology. Thus, the information reported in this paper integrates previously reported information with our still unpublished results, all indicating that PA and their related proteins also are important factors for structure and dynamics of biological membranes and their associated functions essential in human physiology; for instance, solute interchange with the environment (uptake and secretion), oxidative metabolism and apoptosis. The importance of these involved processes for human homeostasis claim for further research efforts. 1. Ruiz-Chica J, Medina MA, Sánchez-Jiménez F and Ramírez FJ (2001) Fourier Transform Raman study of the structural specificities on the interaction between DNA and biogenic polyamines. Biophysical J. 80:443-454. 2. Lightfoot HL, Hall J (2014) Endogenous polyamine function--the RNA perspective. Nucleic Acids Res. 42:11275-11290. 3. Igarashi K, Kashiwagi K (2010) Modulation of cellular function by polyamines. Int J Biochem Cell Biol. 42:39-51. 4. Finger S, Schwieger C, Arouri A, Kerth A, Blume A (2014) Interaction of linear polyamines with negatively charged phospholipids: the effect of polyamine charge distance. Biol Chem. 395:769-778. 5. Poulin R, Casero RA, Soulet D. (2012) Recent advances in the molecular biology of metazoan polyamine transport. Amino Acids. 42:711-723. 6. Kahana C (2009) Regulation of cellular polyamine levels and cellular proliferation by antizyme and antizyme inhibitor. Essays Biochem. 4:47-61. 7. Agostinelli E, Marques MP, Calheiros R, Gil FP, Tempera G, Viceconte N, Battaglia V, Grancara S, Toninello A (2010) Polyamines: fundamental characters in chemistry and biology. Amino Acids 38:393-403. 8. Liu GY, Liao YF, Hsu PC, Chang WH, Hsieh MC, Lin CY, Hour TC, Kao MC, Tsay GJ, Hung HC (2006) Antizyme, a natural ornithine decarboxylase inhibitor, induces apoptosis of haematopoietic cells through mitochondrial membrane depolarization and caspases' cascade. Apoptosis 11:1773-1788. 9. Kanerva K, Lappalainen J, Mäkitie LT, Virolainen S, Kovanen PT, Andersson LC (2009). Expression of antizyme inhibitor 2 in mast cells and role of polyamines as selective regulators of serotonin secretion. PLoS One 31:e6858. 10. García-Faroldi G, Rodríguez CE, Urdiales JL, Pérez-Pomares JM, Dávila JC, Pejler G, Sánchez-Jiménez F, Fajardo I (2010) Polyamines are present in mast cell secretory granules and are important for granule homeostasis. PLoS One 30:e15071.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Comportamiento frente a la corrosión de armaduras de acero inoxidable

Se presentan los resultados de la exposición a la corrosión por cloruros durante dos años de tres tipos de armaduras de acero inoxidable embebidas en probetas de mortero

A role for antizyme inhibitor 2 in the biosynthesis and content of histamine and serotonin in mouse mast cells

Polyamines (putrescine, spermidine and spermine; PAs) are required for the survival of the majority of living cells. Antizymes and antizyme inhibitors are key regulatory proteins of PA levels by affecting ornithine decarboxylase, the rate-limiting biosynthetic enzyme, and PA uptake. In addition to PA, mast cells (MC) synthesize and store in their granules the biogenically active amines histamine (Hia) and serotonin (5-HT), which are of critical importance for their function. Previously, we have performed several studies in this cell type regarding the interplay between the metabolisms of PAs and Hia and 5-HT. Our results showed that PAs affect Hia synthesis during early stages of IL-3-induced bone marrow cell differentiation into bone marrow derived MCs (BMMCs) and demonstrated that PAs are present in MC secretory granules and are important for granule homeostasis, including Hia storage and 5-HT levels. A few years ago, a novel antizyme inhibitor (AZIN2) was described. In contrast to AZIN1, AZIN2 expression is restricted to a few tissues and cell types including brain, testis and MCs. In MCs, it was recently described that AZIN2 could act as a local regulator of PA biosynthesis in association with the 5-HT granule content and release. At present, our aim is to gain further insight into the role of AZIN2 in the biosynthesis, storage and release of both Hia and 5-HT. In this study, we have generated BMMCs from both wild-type and transgenic mice with severe Azin2 hypomorphism, and have analyzed the content of PAs, Hia and 5-HT, and some elements of their metabolisms. Both PAs and 5-HT levels were reduced in Azin2 hypomorphic BMMCs compared with wild-type controls, whereas the amount of Hia was increased. Accordingly, the level of tryptophan hydroxylase 1 (the key enzyme for 5-HT biosynthesis) was reduced and the amount of enzymatic activity of histidine decarboxylase (the enzyme responsible for histamine biosynthesis) was increased in Azin2 hypomorphic BMMCs. Taken together, our results show evidence that AZIN2 has an important role in the regulation of Hia and 5-HT biosynthesis and storage in MCs. Department of Molecular Biology and Biochemistry, and CIBER de Enfermedades Raras (CIBER-ER), Faculty of Sciences, University of Málaga, Málaga 29071, Spain. Corresponding author: I. Fajardo ([email protected]) This work was supported by SAF2011-26518 (MINECO, Spain) and P10-CVI-6585 and Bio-267 (Junta de Andalucia, Spain). CIBERER is an iniciative of Instituto de Salud Carlos III (Spain).Universidad de Málaga. Campus de Excelencia Internacional Andalucía-Tech. SAF2011-26518 (MINECO, Spain) and P10-CVI-6585 and Bio-267 (Junta de Andalucia, Spain. CIBERER is an iniciative of Instituto de Salud Carlos III (Spain)

Is erythrocyte size a strategy to avoid hypoxia in Wiegmann’s Torquate Lizards (Sceloporus torquatus)? Field evidence

This study examined changes in certain hematological parameters in a reptilian model naturally exposed to altitude-associated hypoxia. Four populations of the Mexican lizard Sceloporus torquatus Wiegmann, 1828 (Wiegmann’s Torquate Lizard) from different altitudes were sampled to evaluate erythrocyte count (Erc), hematocrit (Hct), mean corpuscular hemoglobin concentration (MCHC), and erythrocyte size (Ers). Blood was also assayed to determine hemoglobin ([Hb]), glucose, lactate, and electrolyte concentrations. Erc was performed using a Neubauer hemocytometer. Hct was calculated as percentage of packed cell volume by centrifuging blood samples. [Hb] was determined using a Bausch and Lomb Spectronic colorimeter. MCHC was calculated with the formula 100 × [Hb]/Hct. Ers was calculated from blood smear microphotographs analyzed with the Sigma Scan Pro software. Values of serum electrolytes (sodium (Na+), potassium (K+), and calcium (Ca2+)), pH, glucose, and lactate from blood samples were obtained through a blood electrolyte analyzer. Highland populations of S. torquatus exhibited a significant increase in Erc, Hct, Ers, and [Hb]. In contrast, MCHC showed no correlation with altitude. Additionally, significant differences in lactate, Na+, K+, and Ca2+ were observed in highland populations. In general, we found that most hematological parameters were significantly different among lizard populations from different altitudes. This is the first study to report changes in Ers in relation to altitude, which could be a physiological response to hypoxia.CONACYT 17872

Optimización de la red privada del banco de Machala:

Este proyecto esta dirigido hacia una optimización adecuada de la red de Telecomunicaciones del Banco de Machala, que maximize los recursos de la misma para el año 2000. Se hace una revisión general de como está estructurada la red de datos del Banco de Machala a nivel nacional, así como la arquitectura y protocolos utilizados en la misma, además de presentar las justificaciones para la optimización de la red. Se presenta además una descripción de los equipos tanto en software como en hardware, que se plantean como solución en el nuevo diseño de la red del Banco de Machala y se describen los enlaces de comunicación para el diseño; se detallan las consideraciones tomadas en el diseño, se muestra el diagrama de bloques para la nueva configuración y se dan a conocer los diferentes beneficios y desventajas que se presentarían en el nuevo diseño, así como los costos que implicarían ejecutarlo

Who do you refer to? How young students with mild intellectual disability confront anaphoric ambiguities in texts and sentences

Along 2 experiments we tested the anaphoric pronoun resolution abilities of readers with intellectual disability in comparison with chronological and reading age-matched groups. In Experiment 1, the anaphor test of Elosúa, Carriedo, and García-Madruga (2009) confirmed that readers with intellectual disability (ID) are slower than control readers resolving clitic anaphoric pronouns, especially when the use of morphological cues (e.g. gender) is necessary. In order to test if the poor performance could be due to low levels of metacognitive skills during reading, an inconsistency detection task combined with eye tracking was designed in Experiment 2. Participants read short texts with an anaphoric pronoun in the fifth sentence, either morphologically (gender) consistent or not with the information provided in the second sentence. The scores in the anaphor comprehension questions presented after the text confirmed that readers with ID are affected by the gender inconsistency but they are unable to explicitly report it and recover from it, as the number of re-fixations after reading the critical sentence suggests. As their answers to the explicit detection questions showed, the adults control group did not show any preference for morphosyntax or semantics in spite of being aware of the inconsistency. In sum, both groups of readers with and without ID are affected by inconsistencies, but ID readers do not have appropriate metacognitive skills to explicitly identify the source of the inconsistency and fix it