Contribution to the study of Normandina pulchella: a cytological approach

A cytological study was undertaken on Normandina pulchella (Borr.) Nyl. in order to contribute to a better knowledge of the structure of the lichen and to acquire useful information on its taxonomic arrangement. Micro- and submicroscopic observations revealed that the tallus is heteromerous, with a medullary "tissue" composed of a network of hyaline fungal threads surrounding small clumps of algal cells. These were thick-walled and exhibited a single lobate chloroplast in which a conspicuous rnetameric pyrenoid, small starch granules and lipophilic plastoglobuli were frequently present. The mycobiont had hyphae with simple perforated septa with associated Woronin bodies. The relationship between the two partners was merely of very close proximity of their cell walls and involved no fungal penetration into algal cells. The presence of Woronin bodies, exclusive of the Ascomycetes and of plastoglobuli, that were described only in the Chlorococcales phycobionts in ascolichens, indicates that in all likelyhood Normandina is a member of the ascolichens and not of basidiolichens, as previously reported by some workers.Contribución al estudio de Normandina pulchella: aproximación citológica. Para contribuir a un mejor conocimiento de la estructura de Normandina pulchella (Borr.) Nyl. y para obtener informaciones útiles para su correcta colocación taxonómica, se ha emprendido un estudio citológico sobre el liquen. Observaciones al microscopio Óptico y electrónico han revelado que el tallo del liquen es heterómero, con un tejido medular compuesto por un entrelazamiento de hifas hialinas de hongos, que rodean pequeños grupos de células algales. Éstas presentaban una pared gruesa y un cloroplast lobulado simple, en el cua1 frecuentemente estaban presentes un voluminoso pirenoide metamérico, pequeños granos de almidón y plastoglóbulos lipófilos. El micobionte tenía hifas con septos simples y corpúsculos de Woronin asociados. La relación entre los dos componentes consistia en una simple y densa aproximación de sus paredes, sin una penetración del hongo en las células algales. La presencia de los corpúsculos de Woronin, exclusivos de 10s Ascomicetes y de 10s plastoglóbulos, que han sido descritos solo en los clorococales ficobiontes de 10s ascolíquenes indica que, con toda probabilidad, Normandina es un miembro de los ascolíquenes y no de los basidiolíquenes, como había sido previamente afirmado por algunos autores

Biological effects of PAHs and heavy metals in Mytilus galloprovincialis: Assessment of the petrochemical industry in the Sicilian Coast, Italy

The use of biomarkers to analyze the effects of exposure to chemical contaminants in the aquatic environment is more extended nowadays. Mussels are sedentary filter-feeding organisms which may be exposed to large amounts of chemical pollutants. Mussels are prone to bioaccumulation and magnification of contaminants. In the present work, biological effects of environmental pollution were evaluated, mainly related to presence of PAHs and heavy metals, through several antioxidants and detoxification biomarkers in mussels (Mytilus galloprovincialis) from three areas located in the Eastern coastline of Sicily (Italy), previously transplanted (active biomonitoring). One of these three areas corresponds to the industrial harbour area between Augusta and Priolo, considered one of the most extensive areas of petrochemical industrial activity in Europe, severely contaminated by PAHs and heavy metals; a second point is located in Brucoli, littoral zone where the presence of xenobiotics in the environment is considered negligible; and a third point (reference site) from which proceed the pristine population of M. galloprovincialis. Changes at molecular and biochemical level in the tissue of the digestive gland were quantified. The results showed a significant increase (p<0.05) in the activity of the antioxidant enzyme catalase, the activity and expression of the detoxifying enzyme glutathione-S-transferase, and malondialdehyde levels, as a marker of lipid peroxidation, in mussels from the area of Priolo. The metallothioneins (MTs) gene expression was significantly induced in mussels (p<0.05) from Priolo when compared to those from the reference site. AChE was negatively affected by pollutants evidencing a decreased activity in Priolo (p<0.05). No significant differences were observed between the three sampling sites in the expression of the CYP3A1. In conclusion, the observed results demonstrate that the pollution associated with petrochemical industrial area (mainly of PAHs and heavy metals) causes the activation of the detoxification and antioxidant defence systems in the digestive gland of the mussels M. galloprovincialis, indicative of oxidative stress. This study provides further evidence of the criticality representing harbour areas, due to the presence of xenobiotics in high concentrations, which can accumulate in sediments and in living organisms due to the limited hydrodynamic inside harbour

Necesidad de calefacción en la región centro oeste del país, según la dirección de los vientos

Se determina para siete localidades del centro oeste del país las necesidades de calefacción en función de las direcciones de los vientos y las calmas para los meses de abril a setiembre, a partir de los datos climáticos de la década 1981-1990 generados por el Servicio Meteorológico Nacional. Se emplean para los cálculos dos procedimientos: Mediante uno de éstos, se calculan los grados días de calefacción , GDC y el otro empleando el programa Psicro, que permite chequear los resultados obtenidos.Tema: Uso racional de la energía.Asociación Argentina de Energía Sola

Necesidad de calefacción en la región centro oeste del país, según la dirección de los vientos

Se determina para siete localidades del centro oeste del país las necesidades de calefacción en función de las direcciones de los vientos y las calmas para los meses de abril a setiembre, a partir de los datos climáticos de la década 1981-1990 generados por el Servicio Meteorológico Nacional. Se emplean para los cálculos dos procedimientos: Mediante uno de éstos, se calculan los grados días de calefacción , GDC y el otro empleando el programa Psicro, que permite chequear los resultados obtenidos.Tema: Uso racional de la energía.Asociación Argentina de Energía Sola

Necesidad de calefacción en la región centro oeste del país, según la dirección de los vientos

Se determina para siete localidades del centro oeste del país las necesidades de calefacción en función de las direcciones de los vientos y las calmas para los meses de abril a setiembre, a partir de los datos climáticos de la década 1981-1990 generados por el Servicio Meteorológico Nacional. Se emplean para los cálculos dos procedimientos: Mediante uno de éstos, se calculan los grados días de calefacción , GDC y el otro empleando el programa Psicro, que permite chequear los resultados obtenidos.Tema: Uso racional de la energía.Asociación Argentina de Energía Sola

Broken and mended

A considerable amount of literature highlights the importance of membership in recovery-oriented groups (e.g. Best, Bamber, Battersby, Gilman, Groshkova, Honeor & White, 2010; Zywiak, Neighbors, Martin, Johnson, Eaton & Rosenhow, 2009), while identifying the lack of research and understanding of group processes and mechanisms of change in treatment. This chapter aims to capture the mechanisms and processes of recovery and desistance and the experiences, contextual and personal factors that take place during an inprison drug treatment group. We analyse narratives of men with histories of substance use attending an in-prison treatment programme while serving a life sentence and focus on elements that contribute to personal constructions of change and factors that facilitate or hinder recovery within the context of imprisonment

Analysis of X.500 Distributed Directory Refresh Strategies

Distributed database directory refresh strategies, commonly recommended for the X.500 standard, are defined and analytically modeled for variations on push/pull and total/differential under idealistic asynchronous control conditions. The models are implemented in a HyperCard-based tool called DirMod (for "directory model"). Experimental test results show important elapsed time performance tradeoff among the different strategies, and live test data contribute to the verification of the models.http://deepblue.lib.umich.edu/bitstream/2027.42/107872/1/citi-tr-90-6.pd

Apoptosis, cell proliferation and serotonin immunoreactivity in gut of Liza aurata from natural heavy metal polluted environments: preliminary observations.

In the present paper, the effect of natural environment nonlethal heavy metal concentration on cell renewal of Liza aurata intestinal epithelium, was studied by the TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling) method and anti-PCNA (proliferating cell nuclear antigen) immunohistochemistry, in order to detect, respectively, apoptosis and cell proliferation. In addition, the presence and distribution of the cell renewal regulator, serotonin, was immunohistochemically investigated. In order to reduce variability, only immature specimens were considered. The results indicated that in the control specimens from non-polluted areas, the PCNA immunoreactive nuclei of the proximal intestinal epithelium were only located at the bottom of the intestinal folds, together with a few TUNEL-positive nuclei, and goblet mucous differentiated cells. In the specimens from polluted areas, the number of PCNA immunoreactive cells was greatly enhanced, and they extended along the mid portion of the intestinal folds; the number of TUNEL-positive nuclei was enhanced as well, but they were almost exclusively detected in the third apical portion of the intestinal folds. Serotonin immunoreactive nerve elements were more frequently detected in the intestinal wall of L. aurata specimens from polluted areas, and besides that, some serotonin immunoreactive endocrine cells were also present. Variations in distribution and frequency of TUNEL-positive nuclei, PCNA immunoreactive nuclei, and serotonin immunoreactivity put in evidence an alteration of cell renewal with an enhancement of cell proliferation, probably leading to morphological intestinal fold changes