Caracterización de la madera de Salix, 2: Relaciones entre propiedades ópticas y otros atributos del leño

The objective of this study was to establish relationships between some characteristics of the wood of Salix and their possible influence on its optical properties. In both willow clones, the presence of stains caused the decrease of brightness, L*, and b*. This effect was intensified in the more deteriorated areas. Tyloses increased with the presence of such stains. The whiter wood showed the highest values of L*, being more yellow and less red, except for the "dark zone" in the American willow, and the "brown stains" and the "blue stain" in the hybrid willow, in which the parameters a* and b* correlated positively. The presence of defects in the wood was related to the decrease of density in both clones, except for the "dark-brown stain" in the American willow, which caused the increase of disks density when presenThe content of insoluble and total lignin correlated negatively with brightness and L* in American willow, and with basic density in the hybrid. In the last clone, the extractives in hot water and alcohol-benzene, correlated with the alkalisoluble substances content (frequently used as a measure of decay degree), and also played an important role in determining the tendency to blue color in the stains of the wood.Se analizaron posibles relaciones entre algunas características de la madera de sauces (Salix) y se determinó su influencia sobre las propiedades ópticas de la madera. En los dos sauces estudiados, la presencia de manchas en la madera ocasionó disminuciones de blancura, L* y b*, acentuándose a medida que aumenta la superficie deteriorada y un incremento en el contenido de tilosis. La madera más blanca presentó los mayores valores de L*, siendo también más amarilla y menos roja, exceptuando la zona oscurecida en sauce americano y las manchas castañas y azul en sauce híbrido, donde los parámetros a* y b* correlacionaron positivamente. La presencia de deterioro en la madera se relacionó con disminuciones de densidad en ambos clones, exceptuando la mancha castaño oscuro de sauce americano, que provocó aumentos de densidad en las rodajas que la presentan. Las manchas de la madera afectaron su composición química. En sauce americano la madera más oscura presentó más lignina insoluble y total. En el híbrido, los extractivos en agua caliente y en alcohol-benceno se relacionaron con la mancha azulada y con los solubles en NaOH, medida utilizada generalmente como indicadora del grado de deterioro de la madera

Caracterización de la madera de Salix, 1: Influencia del sitio, clon, edad y altura de muestreo

The wood of two Salix clones cultivated in the Delta of Paraná River in Argentina was characterized according to their optical properties, chemical composition, basic density, tyloses content and health condition, analysing variations in terms of site, clone, age and sampling heighAmerican willow showed more cellulose content, higher density and less lignin, extractives and tyloses than the 131/27 hybrid. The wood of the last one had the smallest damaged area in the disks and the highest brightness values. The most appropriate site for both clones was the one less affected by flood. Brightness, L* and basic density increased, whereas deteriorated area decreased from bottom to tip within each tree. The tyloses percentage also decreased, both in vertical and horizontal directions. Six different types of wood were defined. Between them, "grey-coloured rings", result of flood, and "dark zone", may be considered similar to "healthy wood". Three types of stains were responsible for the main changes in the wood analysed. The "brown stains" showed low brightness and high tyloses, but the darkest one showed high lignin and low cellulose contents. The "light-brown stain" had the highest alkali-soluble substances contenThe "blue stain" showed low brightness and high extractives content.Se caracterizó la madera de dos clones de sauces (Salix) implantados en el Delta del río Paraná, Argentina, según sus propiedades ópticas, composición química, densidad básica, tilosis y estado sanitario, analizando las variaciones en las características anteriores de acuerdo al sitio, clon, edad y altura de muestreo. El sauce americano presentó promedios más altos de celulosa y densidad y menores porcentajes de lignina, extractivos y tilosis. El híbrido 131/27 tuvo la madera más blanca y con menos superficie deteriorada. El sitio más adecuado para ambos clones fue el menos inundable. La blancura, L* y la densidad básica se incrementaron, mientras la superficie con defectos y el porcentaje de tilosis decrecieron en sentido base-ápice dentro de cada individuo. Dicho porcentaje también disminuyó transversalmente de médula a corteza. De los 6 tipos de madera descriptos, los anillos grises y la zona oscura resultaron similares a la madera sana. Las manchas castañas se caracterizaron por su baja blancura y elevada tilosis, si bien la más oscura fue rica en lignina y pobre en celulosa, mientras que la más clara tuvo el más alto porcentaje de solubles en NaOH al 1%. La mancha azul se caracterizó por su elevado tenor de extractivos y escasa blancura

The endogenous caspase-8 inhibitor c-FLIPL regulates ER morphology and crosstalk with mitochondria

Components of the death receptors-mediated pathways like caspase-8 have been identified in complexes at intracellular membranes to spatially restrict the processing of local targets. In this study, we report that the long isoform of the cellular FLICE-inhibitory protein (c-FLIPL), a well- known inhibitor of the extrinsic cell death initiator caspase-8, localizes at the endoplasmic reticulum (ER) and mitochondria-associated membranes (MAMs). ER morphology was disrupted and ER Ca2+-release as well as ER-mitochondria tethering were decreased in c-FLIP-/- mouse embryonic fibroblasts (MEFs). Mechanistically, c-FLIP ablation resulted in enhanced basal caspase-8 activation and in caspase-mediated processing of the ER-shaping protein reticulon-4 (RTN4) that was corrected by re-introduction of c-FLIPL and caspase inhibition, resulting in the recovery of a normal ER morphology and ER-mitochondria juxtaposition. Thus, the caspase-8 inhibitor c-FLIPL emerges as a component of the MAMs signaling platforms, where caspases appear to regulate ER morphology and ER-mitochondria crosstalk by impinging on ER-shaping proteins like the RTN4

Evaluación de Cepas Fermentativas en la Hidrólisis y Fermentación Simultáneas (SSF) de Cascarilla de Arroz para la Producción de Bioetanol

La disminución en las reservas de petróleo a nivel mundial y los problemas medioambientales ocasionados por su utilización, propician la búsqueda de nuevas alternativas renovables y menos contaminantes. En este trabajo se estudió el comportamiento de enzimas celulasas y celobiosas, junto con cepas de Saccharomyces cerevisiae, Candida kefyr, Candida tropicalis y Candida guilliermondii en el proceso de hidrólisis y fermentación simultánea (SSF) conducido a 35°C para la producción de bioetanol, a partir de los carbohidratos presentes en cascarilla de arroz. Este proceso busca hidrolizar la celulosa y aprovechar de inmediato los azúcares fermentables, atravesando la dificultad de la diferencia entre la temperatura óptima para el desempeño de enzimas (50°C) y la de levaduras (25°C a 35°C). La cascarilla fue pretratada con una secuencia ácido-alcalina para la separación de los carbohidratos. Los mayores % de bioetanol se obtuvieron con Saccharomyces cerevisiae (68%) y Candida kefyr (75%)

The making of a mammalian peroxisome, version 2.0: mitochondria get into the mix

This is the author accepted manuscript. The final version is available from Nature Publishing Group via the DOI in this record.A recent report from the laboratory of Heidi McBride (McGill University) presents a role for mitochondria in the de novo biogenesis of peroxisomes in mammalian cells (1). Peroxisomes are essential organelles responsible for a wide variety of biochemical functions, from the generation of bile, to plasmalogen synthesis, reduction of peroxides, and the oxidation of very long chain fatty acids (2). Like mitochondria, peroxisomes proliferate primarily through growth and division of pre-existing peroxisomes (3-6). However, unlike mitochondria, peroxisomes do not fuse (5,7); further, and perhaps most importantly, they can also be born de novo, a process thought to occur through the generation of pre-peroxisomal vesicles that originate from the endoplasmic reticulum (reviewed in (8,9). De novo peroxisome biogenesis has been extensively studies in yeast, with a major focus on the role of the ER in this process. Comprehensive studies in mammalian cells are, however, scarce (5,10-12). By exploiting patient cells lacking mature peroxisomes, Sugiura et al. (1) now assign a role to ER and mitochondria in de novo mammalian peroxisome biogenesis by showing that the formation of immature preperoxisomes occurs through the fusion of Pex3- / Pex14-containing mitochondriaderived vesicles with Pex16-containing ER-derived vesicles

Aboriginal-mainstream partnerships: Exploring the challenges and enhancers of a collaborative service arrangement for Aboriginal clients with substance use issues

Background: Partnerships between different health services are integral to addressing the complex health needs of vulnerable populations. In Australia, partnerships between Aboriginal community controlled and mainstream services can extend health care options and improve the cultural safety of services. However, although government funding supports such collaborations, many factors can cause these arrangements to be tenuous, impacting the quality of health care received. Research was undertaken to explore the challenges and enhancers of a government initiated service partnership between an Aboriginal Community Controlled alcohol and drug service and three mainstream alcohol rehabilitation and support services. Methods. Sixteen staff including senior managers (n=5), clinical team leaders (n=5) and counsellors (n=6) from the four services were purposively recruited and interviewed. Interviews were semi-structured and explored staff experience of the partnership including the client intake and referral process, shared client care, inter-service communication and ways of working. Results & discussion. Communication issues, partner unfamiliarity, 'mainstreaming' of Aboriginal funding, divergent views regarding staff competencies, client referral issues, staff turnover and different ways of working emerged as issues, emphasizing the challenges of working with a population with complex issues in a persistent climate of limited resourcing. Factors enhancing the partnership included adding a richness and diversity to treatment possibilities and opportunities to explore different, more culturally appropriate ways of working. Conclusion: While the literature strongly advises partnerships be suitably mature before commencing service delivery, the reality of funding cycles may require partnerships become operational before relationships are adequately consolidated. Allowing sufficient time and funding for both the operation and relational aspects of a partnership is critical, with support for partners to regularly meet and workshop arrangements. Documentation that makes clear and embeds working arrangements between partners is important to ameliorate many of the issues that can arise. Given the historical undercurrents, flexible approaches are required to focus on strengths that contribute to progress, even if incremental, rather than on weaknesses which can undermine efforts. This research offers important lessons to assist other services collaborating in post-colonial settings to offer treatment pathways for vulnerable populations. © 2013 Taylor et al.; licensee BioMed Central Ltd