Estructura espacial de un ecotono bosque subalpino-pastos alpinos en los Estanys de la Pera (Pirineos orientales) formado por manchas de árboles

Se describe la estructura y el patrón espacial de un ecotono bosque subalpino-pastos alpinos dominado por Pinus uncinata Ram. (Pirineos Orientales, Cerdanya, Estanys de la Pera). La historia de perturbaciones de la zona sugiere que el patrón espacial del ecotono puede haber sido afectado recientemente por el pastoreo. Se situó una parcela rectangular (30 x 100 m) cruzando el ecotono con su lado mayor paralelo a la pendiente. Para cada individuo de P. uncinata dentro de la parcela se midió: su localización (coordenadas x, y), y diversas variables estructurales (diámetros basal y a 1,3 m de altura, altura, radios de las copas, número de cohortes de acículas, edad estimada -número de internodos del tronco). Los individuos vivos de P. uncinata se clasificaron según su tamaño (adultos, jóvenes, vástagos y plántulas) y forma de crecimiento (krummholz -individuos arbustivos policórmicos-). Se describieron cuantitativamente el tipo de sustrato (roca, materia orgánica, suelo) y la cobertura de herbáceas, arbustos y P. uncinata usando transectos paralelos a la pendiente. La estructura del ecotono se describió mediante: (i) los análisis del patrón de puntos (K de Ripley, casos uni- y bivariante) y (ii) del patrón de superficies (correlogramas omni- y unidireccionales de Moran). El ecotono estudiado mostró una distribución de individuos de P. uncinata en agregados, predominando los vástagos. Los análisis espaciales mostraron la existencia y el tamaño de agregados con valores similares para ciertas variables de los árboles situados dentro del bosque (p. ej. 8-10 m para la edad estimada). La edad estimada de los individuos jóvenes (60 años <) estaba positivamente correlacionada con la altura y el diámetro basal. La regeneración reciente presentó dos máximos (1965-67, 1973-77). Apareció una posible cohorte de individuos más viejos (1941-57). A partir de 1975, la regeneración declinó de forma exponencial. El establecimiento...

La sucesión en los bosques de Pinus uncinata del Pirineo. De los anillos de crecimiento a la historia del bosque

El patrón de sucesión a largo plazo en los bosques subalpinos de Pinus uncinata y su relación con el régimen de perturbaciones al que se ven sometidos se analizan aquí, tomando como referencia el modelo de sucesión de PEET & CHRISTENSEN (1987). Por métodos dendrocronológicos, utilizando datos de árboles vivos y muertos, se han reconstruido los últimos 140-220 años de la historia de tres bosques suficientemente viejos y poco alterados, al menos recientemente, por el hombre. Los resultados ponen de manifiesto ciertas regularidades importantes en la secuencia y en la duración de las fases de la sucesión observadas en la escala espacial que nos permite el muestreo realizado (un transecto lineal de 280-350 metros. De una larga fase de iniciación (110140 años) se pasa casi directamente a una fase de transición, con escasa evidencia de una fase intermedia de exclusión. Este patrón de sucesión, causado por la lentitud y la heterogeneidad espacial de la fase de iniciación y por un régimen de pequeñas perturbaciones dispersas y frecuentes que aparecen muy pronto, es similar al observado en otros bosques subalpinos y ambientes extremos y representa una desviación respecto del modelo de referencia. La tasa media de mortalidad natural de los áboles adultos durante las últimas 4-6 décadas ha sido, respectivamente para los tres bosques, de 6,2, 1,4 y 5,7% por década. Estas tasas son lo sufientemente bajas como para permitir una larga persistencia en la fase de transición de la cohorte dominante - la instalada durante la fase de iniciación -, en declive pero al mismo tiempo inhibiendo la aparición masiva de regeneración. Ello hace previsible una dinámica de la estructura y la funcionalidad del bosque muy fluctuante a largo plazo en la escala espacial estudiada, aunque en su origen puede encontrarse la mano del hombre a través de una perturbación inicial homogeneizadora

Formación del anillo de crecimiento y clima: un ejemplo de modelos para Pinus uncinata Ram. y Pinus sylvestris L. en los Pirineos Centrales

En este trabajo, describimos el desarrollo y la estructura del anillo de crecimiento de Pinus uncinata Ram. y de Pinus sylvestris L. en un gradiente altitudinal en los Pirineos centralese

Insulin-Like growth-factor 1 myocardial expression decreases in chronic alcohol consumption

Background Chronic alcohol ingestion may cause severe biochemical and pathophysiological derangements to skeletal muscle. Unfortunately, these alcohol-induced events may also prime skeletal muscle for worsened, delayed, or possibly incomplete repair following acute injury. As alcoholics may be at increased risk for skeletal muscle injury, our goals were to identify the effects of chronic alcohol ingestion on components of skeletal muscle regeneration. To accomplish this, age- and gender-matched C57Bl/6 mice were provided normal drinking water or water that contained 20% alcohol (v/v) for 1820 wk. Subgroups of mice were injected with a 1.2% barium chloride (BaCl2) solution into the tibialis anterior (TA) muscle to initiate degeneration and regeneration processes. Body weights and voluntary wheel running distances were recorded during the course of recovery. Muscles were harvested at 2, 7 or 14 days post-injection and assessed for markers of inflammation and oxidant stress, fiber cross-sectional areas, levels of growth and fibrotic factors, and fibrosis. Results Body weights of injured, alcohol-fed mice were reduced during the first week of recovery. These mice also ran significantly shorter distances over the two weeks following injury compared to uninjured, alcoholics. Injured TA muscles from alcohol-fed mice had increased TNFα and IL6 gene levels compared to controls 2 days after injury. Total protein oxidant stress and alterations to glutathione homeostasis were also evident at 7 and 14 days after injury. Ciliary neurotrophic factor (CNTF) induction was delayed in injured muscles from alcohol-fed mice which may explain, in part, why fiber cross-sectional area failed to normalize 14 days following injury. Gene levels of TGFβ1 were induced early following injury before normalizing in muscle from alcohol-fed mice compared to controls. However, TGFβ1 protein content was consistently elevated in injured muscle regardless of diet. Fibrosis was increased in injured, muscle from alcohol-fed mice at 7 and 14 days of recovery compared to injured controls. Conclusions Chronic alcohol ingestion appears to delay the normal regenerative response following significant skeletal muscle injury. This is evidenced by reduced cross-sectional areas of regenerated fibers, increased fibrosis, and altered temporal expression of well-described growth and fibrotic factors.

Ensenyar a escriure textos acadèmics a la Universitat : el guiatge i la revisió col·laborativa del projecte de recerca en els estudis de psicologia

En aquest article es recull una intervenció per ensenyar a escriure el projecte de recerca als estudis de Psicologia de la Facultat de Psicologia, Ciències de l’Educació i l’Esport Blanquerna. La proposta tenia com a objectiu general ajudar als estudiants a utilitzar els mecanismes discursius que els permetessin fer visible la seva veu en els textos acadèmics i desenvolupar la seva identitat com a autors mitjançant el guaitge i la revisió col·laborativa. En aquest article es focalitza especialment en la presentació dels pressupòsits teòrics de la intervenció i en el seu impacte en el coneixement i les representacions dels estudiants. Els resultats evidencies que els estudiants van desenvolupar el coneixement necessari per a produir textos acadèmics, gràcies a l’apropiació dels recursos discursius vinculats al posicionament de l’autor, al diàleg intertextual amb d’altres autors i a l’organització de la informació. Tanmateix, també van posar de manifest dificultats pel que fa a la seva comprensió del concepte d’objectivitat i la seva relació amb la veu del autor en els textos cientifico-acadèmics.

Variability of the radius growth at 25 years old Pinus uncinata Miller ex Mirbel in the North-East Spanish Pyrenees

It has been studied the variability of stem radial growth in four radius orientations at the age of 25 years old trees. The species was Pinus uncinata. The sampling sites, located in the North East Spanish Pyrenees belong to different plant communities. An ANOVA analysis was performed in order to find out which factors, the radio orientation, plant community of the site and tree itself are significative or have some kind of influence on the tree radial growth.

Polymorphisms in DNA-repair genes in a cohort of prostate cancer patients from different areas in Spain: heterogeneity between populations as a confounding factor in association studies

Background: Differences in the distribution of genotypes between individuals of the same ethnicity are an important confounder factor commonly undervalued in typical association studies conducted in radiogenomics. Objective: To evaluate the genotypic distribution of SNPs in a wide set of Spanish prostate cancer patients for determine the homogeneity of the population and to disclose potential bias. Design, Setting, and Participants: A total of 601 prostate cancer patients from Andalusia, Basque Country, Canary and Catalonia were genotyped for 10 SNPs located in 6 different genes associated to DNA repair: XRCC1 (rs25487, rs25489, rs1799782), ERCC2 (rs13181), ERCC1 (rs11615), LIG4 (rs1805388, rs1805386), ATM (rs17503908, rs1800057) and P53 (rs1042522). The SNP genotyping was made in a Biotrove OpenArrayH NT Cycler. Outcome Measurements and Statistical Analysis: Comparisons of genotypic and allelic frequencies among populations, as well as haplotype analyses were determined using the web-based environment SNPator. Principal component analysis was made using the SnpMatrix and XSnpMatrix classes and methods implemented as an R package. Non-supervised hierarchical cluster of SNP was made using MultiExperiment Viewer. Results and Limitations: We observed that genotype distribution of 4 out 10 SNPs was statistically different among the studied populations, showing the greatest differences between Andalusia and Catalonia. These observations were confirmed in cluster analysis, principal component analysis and in the differential distribution of haplotypes among the populations. Because tumor characteristics have not been taken into account, it is possible that some polymorphisms may influence tumor characteristics in the same way that it may pose a risk factor for other disease characteristics. Conclusion: Differences in distribution of genotypes within different populations of the same ethnicity could be an important confounding factor responsible for the lack of validation of SNPs associated with radiation-induced toxicity, especially when extensive meta-analysis with subjects from different countries are carried out.

Anàlisis antropològica de les restes neolítiques de la Caserna de Sant Pau (Biometria, Dentició, ADN i Microestriació Dentària).

Les restes esquelètiques analitzades corresponen tant al nivell neolític (n=26) com a l"època del bronze (n=2), encara que aquí es presenten tan sols els resultats de la població neolítica (taula 1). En tots els casos les sepultures són individuals, amb l"única excepció de la sepultura 20, on s"han recuperat les restes corresponents a un individu femení adult (CSP201) i un fetus (CSP202) (taula 1). Per tal de caracteritzar biomètricament la població s"ha emprat la metodologia proposada per Martin i Saller (1959), Brothwell (1981) i Bass (1971). La determinació del sexe s"ha realitzat a través dels caràcters sexuals secundaris del crani i de la pelvis, i se"n pot trobar una descripció més detallada a Estebaranz et alii (2007). En el cas específic de les paleopatologies es van seguir les recomanacions de Campillo (Campillo, 1977).

Different fatty acid metabolism effects of (−)-epigallocatechin-3-gallate and C75 in adenocarcinoma lung cancer

Background Fatty acid synthase (FASN) is overexpressed and hyperactivated in several human carcinomas, including lung cancer. We characterize and compare the anti-cancer effects of the FASN inhibitors C75 and (−)-epigallocatechin-3-gallate (EGCG) in a lung cancer model. Methods We evaluated in vitro the effects of C75 and EGCG on fatty acid metabolism (FASN and CPT enzymes), cellular proliferation, apoptosis and cell signaling (EGFR, ERK1/2, AKT and mTOR) in human A549 lung carcinoma cells. In vivo, we evaluated their anti-tumour activity and their effect on body weight in a mice model of human adenocarcinoma xenograft. Results C75 and EGCG had comparable effects in blocking FASN activity (96,9% and 89,3% of inhibition, respectively). In contrast, EGCG had either no significant effect in CPT activity, the rate-limiting enzyme of fatty acid β-oxidation, while C75 stimulated CPT up to 130%. Treating lung cancer cells with EGCG or C75 induced apoptosis and affected EGFR-signaling. While EGCG abolished p-EGFR, p-AKT, p-ERK1/2 and p-mTOR, C75 was less active in decreasing the levels of EGFR and p-AKT. In vivo, EGCG and C75 blocked the growth of lung cancer xenografts but C75 treatment, not EGCG, caused a marked animal weight loss. Conclusions In lung cancer, inhibition of FASN using EGCG can be achieved without parallel stimulation of fatty acid oxidation and this effect is related mainly to EGFR signaling pathway. EGCG reduce the growth of adenocarcinoma human lung cancer xenografts without inducing body weight loss. Taken together, EGCG may be a candidate for future pre-clinical development.

pH Sensitive surfactants from lysine: assessment of their cytotoxicity and environmental behavior

The toxicity and environmental behavior of new pH-sensitive surfactants from lysine are presented. Three different chemical structures are studied: surfactants with one amino acid and one alkyl chain, surfactants with two amino acids on the polar head and one alkyl chain, and gemini surfactants. The pH sensitivity of these compounds can be tuned by modifying their chemical structures. Cytotoxicity has been evaluated using erythrocytes and fibroblast cells. The toxic effects against these cells depend on the hydrophobicity of the molecules as well as their cationic charge density. The effect of hydrophobicity and cationic charge density on toxicity is different for each type of cells. For erythrocytes, the toxicity increases as hydrophobicity and charge density increases. Nevertheless, for fibroblasts cationic charge density affects cytotoxicity in the opposite way: the higher charge density, the lower the toxicity. The effect of the pH on hemolysis has been evaluated in detail. The aquatic toxicity was established using Daphnia magna. All surfactants yielded EC50 values considerably higher than that reported for cationic surfactants based on quaternary ammonium groups. Finally, their biodegradability was evaluated using the CO2 headspace test (ISO 14593). These lysine derivatives showed high levels of biodegradation under aerobic conditions and can be classified as"readily biodegradable compounds".

Análisis de la productividad de miera entre diferentes métodos de resinación en un monte de la Serranía Baja de Cuenca

Aquest treball, desenvolupat en una forest de la serralada de Cuenca, durant el primer any de resinació, ofereix resultats de producció obtinguts en funció de variables dendromètriques dels peus, qualitat d'estació, mida de la ferida i considerant els factors: (i) eina, manual o mecanitzada, i (ii) sentit d'avanç de les piques, ascendent o descendent. Així, el diàmetre dels pins, la qualitat d'estació i la superfície foliar, apareixen més determinants sobre la producció que la superfície de la ferida practicada. El mètode descendent s'evidencia millor que l'oposat, mentre que l'eina utilitzada va resultar indiferent.

L'avaluació, tria i eliminació de fons fotogràfics digitals. Estudi de cas del fons del fotògraf Efren Montoya a l'Arxiu Històric de Sabadell

Durant la última dècada hem viscut l’explosió de la fotografia digital. Les possibilitats de captar imatges s’ha multiplicat de manera gairebé infinita sense implicar costos afegits pel fotògraf. Això ens obliga a replantejar-nos la necessitat d’establir uns criteris ben definits per avaluar, triar i eliminar les fotografies que ingressen als nostres arxius. El treball que es presenta aquí té com a objectiu establir uns protocols per tal de poder aplicar aquests procediments al nous fons que passin a formar part del nostre patrimoni documental. Finalment, s’ha dut a terme l’experiència d’entregar al productor d’un fons part de la seva documentació per tal que ell l’avalués i després comparar els resultats amb l’avaluació duta a terme des de l’arxiu. Paraules clau: avaluació, tria, eliminació, fotografia born-digital, ingrés, metadades, arxiu digital, formats de preservació

Reduction of oxidative cellular damage by overexpression of the thioredoxin TRX2 gene improves yield and quality of wine yeast dry active biomass

Background: Wine Saccharomyces cerevisiae strains, adapted to anaerobic must fermentations, suffer oxidative stress when they are grown under aerobic conditions for biomass propagation in the industrial process of active dry yeast production. Oxidative metabolism of sugars favors high biomass yields but also causes increased oxidation damage of cell components. The overexpression of the TRX2 gene, coding for a thioredoxin, enhances oxidative stress resistance in a wine yeast strain model. The thioredoxin and also the glutathione/glutaredoxin system constitute the most important defense against oxidation. Trx2p is also involved in the regulation of Yap1p-driven transcriptional response against some reactive oxygen species. Results: Laboratory scale simulations of the industrial active dry biomass production process demonstrate that TRX2 overexpression increases the wine yeast final biomass yield and also its fermentative capacity both after the batch and fed-batch phases. Microvinifications carried out with the modified strain show a fast start phenotype derived from its enhanced fermentative capacity and also increased content of beneficial aroma compounds. The modified strain displays an increased transcriptional response of Yap1p regulated genes and other oxidative stress related genes. Activities of antioxidant enzymes like Sod1p, Sod2p and catalase are also enhanced. Consequently, diminished oxidation of lipids and proteins is observed in the modified strain, which can explain the improved performance of the thioredoxin overexpressing strain. Conclusions: We report several beneficial effects of overexpressing the thioredoxin gene TRX2 in a wine yeast strain. We show that this strain presents an enhanced redox defense. Increased yield of biomass production process in TRX2 overexpressing strain can be of special interest for several industrial applications.

Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation

Background: In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation. Results: In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p). Bidimensional electrophoresis and carbonylated protein identification from TRX-deficient and TRX-overexpressing cells revealed that glycolysis and fermentation-related proteins are specific targets of Trx2p protection. Indeed, the TRX2 overexpressing strain presented increased activity of the central carbon metabolism enzymes. Interestingly, Trx2p specifically preserved alcohol dehydrogenase I (Adh1p) from carbonylation, decreased oligomer aggregates and increased its enzymatic activity. Conclusions: The identified proteins suggest that the fermentative capacity detriment observed under industrial conditions in T73 wine commercial strain results from the oxidative carbonylation of specific glycolytic and fermentation enzymes. Indeed, increased thioredoxin levels enhance the performance of key fermentation enzymes such as Adh1p, which consequently increases fermentative capacity.

Dendrochronological study of the avalanche path Canal del Roc Roig: first results of the ALUDEX Project in the Pyrenees

Historical data about ancient avalanches are scarce in the Pyrenees. Dendrochronology can provide new data about past avalanches and their return period, but up to now little research has been carried out with this purpose. The Aludex project aims to obtain information about the frequency and extent of extreme avalanches, using a dendrochronological and a nivo-meteorological approach. In this paper, we present the results of a dendrochronological study of the Canal del Roc Roig avalanche path which was affected by two extreme avalanches in February 1996. This first dendrochronological study has permitted us to assess the tree-ring signals due to avalanche events in 53 out of 132 dated trees. The trees presented a variety of responses to the 1996 avalanche events. It is shown that the type of tree-ring signal depends on tree age. The methodology has proved successful in detecting the 1996 and 1972 documented avalanche events, and provided outstanding evidence of undocumented past events such as one in 1930.