Normal telomere length and chromosomal end capping in poly(ADP-ribose) polymerase–deficient mice and primary cells despite increased chromosomal instability

Poly(ADP-ribose) polymerase (PARP)-1, a detector of single-strand breaks, plays a key role in the cellular response to DNA damage. PARP-1–deficient mice are hypersensitive to genotoxic agents and display genomic instability due to a DNA repair defect in the base excision repair pathway. A previous report suggested that PARP-1–deficient mice also had a severe telomeric dysfunction consisting of telomere shortening and increased end-to-end fusions (d'Adda di Fagagna, F., M.P. Hande, W.-M. Tong, P.M. Lansdorp, Z.-Q. Wang, and S.P. Jackson. 1999. Nat. Genet. 23:76–80). In contrast to that, and using a panoply of techniques, including quantitative telomeric (Q)-FISH, we did not find significant differences in telomere length between wild-type and PARP-1−/− littermate mice or PARP-1−/− primary cells. Similarly, there were no differences in the length of the G-strand overhang. Q-FISH and spectral karyotyping analyses of primary PARP-1−/− cells showed a frequency of 2 end-to-end fusions per 100 metaphases, much lower than that described previously (d'Adda di Fagagna et al., 1999). This low frequency of end-to-end fusions in PARP-1−/− primary cells is accordant with the absence of severe proliferative defects in PARP-1−/− mice. The results presented here indicate that PARP-1 does not play a major role in regulating telomere length or in telomeric end capping, and the chromosomal instability of PARP-1−/− primary cells can be explained by the repair defect associated to PARP-1 deficiency. Finally, no interaction between PARP-1 and the telomerase reverse transcriptase subunit, Tert, was found using the two-hybrid assay

Determinación de las condiciones de germinación y el efecto de pretratamientos en semillas de Cuphea glutinosa (Lythraceae)

: Determination of germination conditions and the effect of pretreatments in Cuphea glutinosa seeds (Lythraceae). Cuphea glutinosa shows a high agronomic and agroindustrial potential. Germination conditions for this species are unknown. The objective of the work is to determine germination conditions, their impairments and the treatments to overcome them. There were utilized healthy seeds, complete and quite filled, gathered from a population of Sierra de los Padres, Buenos Aires province, Argentina. There were applied the following treatments, in six repetitions of 50 seeds, in a completely randomized design: blank, scarified, gibberellic acid, darkness, potassium nitrate, stratification and temperature alternation. The germination conditions after the pre-treatments were 24 °C (+/-1) under light, 100 µE.m-2.sec-1. The counts of emerged rootlets were performed at 6 and 12 days, except for the treatment with darkness, in which they were performed at 12 and 18 days. The effect of the treatments was evaluated by ANOVA and Tuckey tests (p = 0,05). The population showed 50 % of germination; positive response to light, to stratification, and to potassium nitrate. There was no effect with scarification neither with temperature alternation. The gibberellic acid showed a negative effect in the percentage of germination, and affected the carbon partition during the growing of seedlingsCuphea glutinosa presenta alto potencial agroindustrial y agronómico. Se desconocen las condiciones de germinación para la especie. El objetivo del trabajo es contribuir a determinar condiciones de germinación, impedimentos para la misma y tratamientos para superarlos. Se utilizaron semillas sanas, enteras y llenas, recolectadas de una población de Sierra de los Padres, provincia de Buenos Aires, Argentina. Se aplicaron los siguientes tratamientos en 6 repeticiones de 50 semillas, bajo un diseño completamente aleatorizado: testigo, escarificado, ácido giberélico, oscuridad, nitrato de potasio, estratificación y alternancia de temperaturas. Las condiciones de germinación después de los pre tratamientos fueron a 24 °C (+/-1) con luz, 100 µE.m-2.seg-1.Los recuentos de radículas emergidas fueron a los 6 y a los 12 días, excepto en el tratamiento oscuridad en el que fueron a los 12 y a los 18 días. El efecto de los tratamientos se evaluó mediante ANOVA y Tuckey (p = 0,05). La población mostró 50% de germinación; respuesta positiva a la luz, a la estratificación y al nitrato de potasio. No tuvieron efecto el escarificado ni las temperaturas alternas. El ácido giberélico tuvo un efecto negativo en el porcentaje de germinación y afectó la partición de carbono durante el crecimiento de las plántulas

Impact of telomerase ablation on organismal viability, aging, and tumorigenesis in mice lacking the DNA repair proteins PARP-1, Ku86, or DNA-PKcs

The DNA repair proteins poly(ADP-ribose) polymerase-1 (PARP-1), Ku86, and catalytic subunit of DNA-PK (DNA-PKcs) have been involved in telomere metabolism. To genetically dissect the impact of these activities on telomere function, as well as organismal cancer and aging, we have generated mice doubly deficient for both telomerase and any of the mentioned DNA repair proteins, PARP-1, Ku86, or DNA-PKcs. First, we show that abrogation of PARP-1 in the absence of telomerase does not affect the rate of telomere shortening, telomere capping, or organismal viability compared with single telomerase-deficient controls. Thus, PARP-1 does not have a major role in telomere metabolism, not even in the context of telomerase deficiency. In contrast, mice doubly deficient for telomerase and either Ku86 or DNA-PKcs manifest accelerated loss of organismal viability compared with single telomerase-deficient mice. Interestingly, this loss of organismal viability correlates with proliferative defects and age-related pathologies, but not with increased incidence of cancer. These results support the notion that absence of telomerase and short telomeres in combination with DNA repair deficiencies accelerate the aging process without impacting on tumorigenesis

Chemical, Thermal and Spectroscopic Methods to Assess Biodegradation of Winery-Distillery Wastes during Composting

The objective of this work was to study the co-composting process of wastes from the winery and distillery industry with animal manures, using the classical chemical methods traditionally used in composting studies together with advanced instrumental methods (thermal analysis, FT-IR and CPMAS 13C NMR techniques), to evaluate the development of the process and the quality of the end-products obtained. For this, three piles were elaborated by the turning composting system, using as raw materials winery-distillery wastes (grape marc and exhausted grape marc) and animal manures (cattle manure and poultry manure). The classical analytical methods showed a suitable development of the process in all the piles, but these techniques were ineffective to study the humification process during the composting of this type of materials. However, their combination with the advanced instrumental techniques clearly provided more information regarding the turnover of the organic matter pools during the composting process of these materials. Thermal analysis allowed to estimate the degradability of the remaining material and to assess qualitatively the rate of OM stabilization and recalcitrant C in the compost samples, based on the energy required to achieve the same mass losses. FT-IR spectra mainly showed variations between piles and time of sampling in the bands associated to complex organic compounds (mainly at 1420 and 1540 cm-1) and to nitrate and inorganic components (at 875 and 1384 cm-1, respectively), indicating composted material stability and maturity; while CPMAS 13C NMR provided semi-quantitatively partition of C compounds and structures during the process, being especially interesting their variation to evaluate the biotransformation of each C pool, especially in the comparison of recalcitrant C vs labile C pools, such as Alkyl /O-Alkyl ratio.This work was supported by a contract to MABM, Spanish Ministry of Economy and Competitiveness (Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+i) 2008-2011), co-funded by the EU through the Social Funds (contract reference PTQ-12-05655)

Valorization of date palm (Phoenix dactylifera L.) pruning biomass by co-composting with urban and agri-food sludge

In the Mediterranean countries, there is an increasing production of date palm wastes (Phoenix dactylifera L.), not only due to the raising production of date palm fruits, but also derived from the maintenance of urban and peri-urban green areas, especially in those affected by red palm weevil (Rhynchophorus ferrugineus). The management of this increasing volume of green wastes usually concludes with a controlled disposal that implies an important loss of resources, in terms of organic matter, nutrients and energy. In addition, the rise of wastewater generation and the incentive of the wastewater treatment processes have derived in an increase of the amount of the sludge produced, which makes difficult its management. This work studies the feasibility of co-composting palm wastes with sludge from the urban and agri-food sectors as alternative treatment to manage these organic waste streams and to obtain added-value compost. For this, four mixtures (P1, P2, P3 and P4) were prepared using as main component palm leave waste (PL) mixed with different types of sludge. In the piles P1, P2 and P3, sewage sludge (SS) was used as co-composting agent, while agri-food sludge (AS) was used in P4. Throughout composting, the thermal profile of the composting piles was assessed, as were physical, chemical, physico-chemical and maturity parameters. In addition, the changes in water-soluble organic matter were assessed using chemical analytical methods and the excitation–emission matrix (EEM) fluorescence spectroscopy. The results obtained showed the viability of the co-composting process to obtain end-products with adequate maturity degree and physical characteristics for their potential use as substrates, except for the salt contents that can limit their use in some agricultural sectors.This work has been financed by the Spanish Ministry of Economy and Competitiveness and by European Regional Development Funds (ERDF, “Una manera de hacer Europa”), in the framework of the project “Development of new resources and bioproducts based on residues of palmaceous species oriented to carbon sequestration and mitigation strategies, Palmresource” (Project AGL2013-41612-R)

Development of organic fertilizers from food market waste and urban gardening by composting in Ecuador

Currently, the management of urban waste streams in developing countries is not optimized yet, and in many cases these wastes are disposed untreated in open dumps. This fact causes serious environmental and health problems due to the presence of contaminants and pathogens. Frequently, the use of specific low-cost strategies reduces the total amount of wastes. These strategies are mainly associated to the identification, separate collection and composting of specific organic waste streams, such as vegetable and fruit refuses from food markets and urban gardening activities. Concretely, in the Chimborazo Region (Ecuador), more than 80% of municipal solid waste is dumped into environment due to the lack of an efficient waste management strategy. Therefore, the aim of this study was to develop a demonstration project at field scale in this region to evaluate the feasibility of implanting the composting technology not only for the management of the organic waste fluxes from food market and gardening activities to be scaled-up in other developing regions, but also to obtain an end-product with a commercial value as organic fertilizer. Three co-composting mixtures were prepared using market wastes mixed with pruning of trees and ornamental palms as bulking agents. Two piles were created using different proportions of market waste and prunings of trees and ornamental palms: pile 1 (50:33:17) with a C/N ratio 25; pile 2: (60:30:10) with C/N ratio 24 and pile 3 (75:0:25) with C/N ratio 33), prepared with market waste and prunings of ornamental palm. Throughout the process, the temperature of the mixtures was monitored and organic matter evolution was determined using thermogravimetric and chemical techniques. Additionally, physico-chemical, chemical and agronomic parameters were determined to evaluate compost quality. The results obtained indicated that all the piles showed a suitable development of the composting process, with a significant organic matter decomposition, reached in a shorter period of time in pile 3. At the end of the process, all the composts showed absence of phytotoxicity and suitable agronomic properties for their use as organic fertilizers. This reflects the viability of the proposed alternative to be scaled-up in developing areas, not only to manage and recycle urban waste fluxes, but also to obtain organic fertilizers, including added value in economic terms related to nutrient contents.This work was supported by a PhD scholarship to JJS of the National Secretary of Higher Education, Science, Technology and Innovation SENESCYT of Ecuador and it was also developed in the framework of the project of the Spanish Ministry of Economy and Competitiveness co-funded by the EU through the Social Funds (ref. AGL2013-41612-R)

Mapping the ecosystem service of food associated with fishing in inland wetlands of Colombia

El recurso pesquero enfrenta grandes amenazas a nivel mundial, por lo que es de vital importancia analizar su dinámica como alimento y su conservación, como parte integral de la evaluación de un servicio ecosistémico (SE). En los humedales interiores de Colombia, la pesca continental es una actividad de importancia cultural y económica pues ~26% del país está cubierto por humedales. Este trabajo identifica y mapea, a partir de la actividad pesquera continental, los beneficiarios y la dinámica espacial del SE de alimento asociado a la pesca, ofrecido por los humedales interiores de Colombia. Se caracterizan: i) riqueza de las especies asociadas a la pesca, ii) áreas de suministro del SE, iii) áreas de beneficiarios del SE, iv) flujos del SE, y v) estado de amenaza de las especies que componen el recurso pesquero. Este método permite identificar de manera espacialmente explícita las áreas donde se configura el SE, que merecen atención especial en los procesos de gestión del territorio. Se identificaron 138 especies que las comunidades consumen como recurso pesquero. Las cuencas del Orinoco y Amazonas fueron las áreas con mayor riqueza de recursos pesqueros, mientras que las cuencas del Magdalena-Cauca fueron las de mayor suministro del SE. Por su parte, varios municipios de la región andina y amazónica fueron identificados como los principales beneficiarios directos del SE (autoconsumo), en tanto que ciudades principales, seguidas de numerosos municipios vecinos, fueron identificadas como áreas de beneficiarios indirectos (comercialización de la pesca). La espacialización y visualización de estos aspectos permitió analizar los diferentes factores que determinan y afectan el SE en los humedales del país y realizar sugerencias sobre acciones de manejo y gestión del recurso pesquero.The fishery resource faces great threats worldwide, so it is vital to make an analysis of its dynamics as food and its conservation as an integrated part of the evaluation of an ecosystem service (SE). In the inland wetlands of Colombia, fishing is an activity of cultural and economic importance since about 26% of the national territory is covered by wetlands. This work identifies and maps, from the continental fishing activity, the beneficiaries and the spatial dynamics of the ES of food associated with fishing offered by inland wetlands of Colombia.We describe: i) species richness associated with fishing, ii) areas supplying the ES, iii) areas with the beneficiaries of the ES, iv) flow of the ES, and v) the endangered status of the species within the fishery resource. We identified 138 fish species were consumed by communities. The Orinoco and Amazon basins were identified as the richest areas of fishery resources species, whereas the Magdalena-Cauca’s basins were identified as the areas with more supply of the ES. On the other hand, several communities in the Andean and Amazonian region were identified as the main direct beneficiaries of ES (self-consumption), while main cities, followed by numerous neighboring municipalities, were identified as areas of indirect beneficiaries (marketing of fishery). Spatialization and visualization of these aspects allowed to analyze the different factors that determine and affect the ES in the country’s wetlands and make suggestions on management actions for the fishery resource

Diseño de itinerarios de aprendizaje sobre Moodle para asignaturas de redes de computadores basados en virtualización mediante software libre

El diseño de recursos educacionales y materiales didácticos vía on-line permite mejorar el aprendizaje autónomo y a distancia (o no presencial). El proceso de convergencia Europea del Espacio de Educación Superior determina que el empleo de este tipo de recursos dota al estudiante de más flexibilidad, aunque la metodología de educación dominante sea la tradicional (es decir, las clases presenciales). Los recursos educacionales on-line juegan un rol importante en este contexto. En trabajos previos se ha experimentado diseñando cursos con ayuda de un LCMS (Learning Content Management System) como el Moodle corporativo de la UA, incorporando documentos SCORM para diseñar lecciones de autoevaluación, con laboratorios virtuales y otras herramientas de simulación de diseño propio (KIVANS, applets KIVANS+EJS). En esta nueva red se pretende generar nuevos recursos didácticos basados en software libre. Ninguno de los laboratorios virtuales desarrollados hasta ahora permiten a los alumnos poner en práctica los desarrollos de las clases presenciales a distancia. Para ello, usando el software de libre distribución GNS3, y teniendo como base la configuración de la red del laboratorio L24 de la EPS, se pretende construir un entorno virtual que simule las posibilidades reales de este laboratorio

Virtualización de Redes de Computadores con GNS3: Evaluación de soluciones para el aprendizaje a distancia

El diseño de los recursos educativos permite a los estudiantes modificar su proceso de aprendizaje. En particular, los recursos educativos on-line descargables han sido utilizados con éxito en la educación en ingeniería en los últimos años. Por lo general, estos recursos son gratuitos y accesibles desde la web. Además, son diseñados y desarrollados por profesores y usados por sus estudiantes. Pero, rara vez se desarrollan por los estudiantes con el fin de ser utilizados por otros estudiantes. En este artículo, profesores y estudiantes trabajan juntos para implementar recursos educativos de libre distribución, que puedan ser utilizados por los estudiantes para mejorar el proceso de aprendizaje de redes de computadores en los estudios de ingeniería. En particular, se virtualizan topologías de red para modelar redes LAN (Local Area Network) y MAN (Metropolitan Area Network) con el fin de simular el comportamiento de los enlaces y nodos cuando están interconectados con diferente diseño físico y lógico. Para ello, usando el software de libre distribución GNS3, y teniendo como base la configuración de la red del laboratorio L24 de la EPS, se construye un entorno virtual que simula las posibilidades reales de este laboratorio