Acute hypoxia/reoxygenation affects muscle mitochondrial respiration and redox state as well as swimming endurance in zebrafish.

Rapid fluctuations of the oxygen content of both natural and anthropogenic origin are relatively common in freshwater environments. Fish adaptation to these conditions implies tolerance of both low levels of oxygen availability and reoxygenation. Hypoxia tolerance in fish has been widely studied, but the involvement of mitochondria in the response of fish to rapid hypoxia/reoxygenation stress is less known. Zebrafish, a floodplain species, is likely facing significant changes in dissolved oxygen in its natural environment and displays a moderate ability to tolerate hypoxia. In the present study, we report the effects of an acute hypoxia/reoxygenation stress (H/R) protocol on mitochondrial functionality (respiration, complex activities, rate of H2O2 release) and redox state (level of HPs and protein oxidation) of muscle tissue. In parallel, the animal metabolic performance (routine metabolism, nitrogen excretion and swimming performance) was measured. Additionally, the recovery from H/R was tested 20 h after treatment. A significant stimulation by H/R of muscle mitochondrial respiration and H2O2 release was observed, which was only in part counteracted by stimulation of the antioxidant system, resulting in an increased level of lipid peroxides and protein carbonyls. In parallel, H/R increased the animal oxygen consumption and urea excretion rate and reduced routine activity. A significant strong reduction of endurance at 80% Ucrit was also observed. Most of the altered parameter did not recover 20 h after reoxygenation. These data indicate a significant alteration of zebrafish muscle mitochondrial state after acute H/R, associated with changes in tissue redox state and locomotor performance.

Effects on crops of irrigation with treated municipal wastewaters.

The fertilizing potential of treated municipal wastewater (oxidation ditch) and crop sanitary acceptability for direct human consumption were evaluated in Mendoza, Argentina. Two experiments were performed on a pilot plot planted with garlic (1998) and onions (1999) using furrow irrigation with three types of water in 10 random blocks: treated effluent (2.5 x 10(3) MPN Escherichia coli/100 ml, 3 helminth eggs/l, and Salmonella (positive); and well water (free of microorganisms), with and without fertilizer. Two responses were evaluated: (1) crop yield, and (2) crop microbiological quality for human consumption at different times after harvest. Crop yields were compared using Variance analysis. Crops' sanitary acceptability was assessed using a two-class sampling program for Salmonella (n=10; c=0), and a three-class program for E. coli (n=5, c=2, M=10(3) and m=10 MPN/g) as proposed by the International Commission on Microbiological Specifications for Foods (ICMSF) for fresh vegetables. Wastewater irrigation acted as well water with fertilizer, increasing garlic and onion yields by 10% and 15%, respectively, compared to irrigation with well water with no fertilizer. Wastewater-irrigated garlic reached sanitary acceptability 90 days after harvest, once attached roots and soil were removed. Onions, which were cleaned immediately after harvest, met this qualification earlier than garlic (55 days). Neither the wastewater-irrigated crops nor the control crops were microbiologically acceptable for consumption raw at harvest.

Domestic wastewater treatment in waste stabilization ponds for irrigation in Mendoza, Argentina: policies and challenges.

Arid areas call for imaginative water management solutions to avoid the dangers of water shortages. Growing demands of water for domestic and industrial uses decrease the availability of water for agriculture. It therefore becomes necessary to set up a policy for the use of domestic effluents. For the province of Mendoza, Argentina, with 1,500,000 inhabitants, a master plan was designed as of 1991 for the treatment of domestic effluents and subsequent disposal for irrigation. The guidelines set up by WHO for the use of wastewater in agricultural applications were taken into consideration. At present, the Province of Mendoza has available projects which are either complete, in execution or in the bidding process, entailing secondary treatment capacity with reuse of 320,000 cubic metres/day and an estimated possible irrigation area of 10,000 hectares. With this infrastructure, some strategic lines of action are recommended to establish a policy for the agricultural use of wastewater: (a) to program the use of treated wastewater to avoid discharges to irrigation flows; (b) to develop an institutional scheme for the efficient and safe use of these waters; and (c) develop scientific and technologic know-how to accompany the updated policies.

Riego con efluentes tratados: potencial fertilizante para un cultivo de ajo

Se realizó un ensayo a campo en Mendoza, Argentina, para evaluar el potencial fertilizante de aguas residuales tratadas, en un cultivo de ajo. Se compararon dos variedades de ajo y tres fuentes de agua para riego: efluente tratado en zanjas de oxidación, agua de perforación sin fertilizantes y agua de perforación con fertilizantes. El efluente se comportó como una fertilización nitrogenada y mejoró la calidad del ajo y aumentando su rendimiento en un 10

con respecto al cultivo regado con agua de perforación sin fertilizantes

Riego con efluentes tratados: aceptabilidad sanitaria para un cultivo de ajo

Se realizó un trabajo en parcelas experimentales para determinar el momento a partir de la cosecha, en el que los ajos adquieren aceptabilidad para ser consumidos tras ser regados efluentes domésticos tratados. En la experiencia realizada en Mendoza, Argentina, se compararon dos cultivos: uno fue regado con efluentes tratados, y otro como testigo. Se encontró que a los 90 días de la cosecha, luego de la limpieza de la tierra y raíces, los ajos regados con efluentes tratados presentaban aceptabilidad para el consumo

Riego con efluentes tratados: potencial fertilizante para un cultivo de ajo

Se realizó un ensayo a campo en Mendoza, Argentina, para evaluar el potencial fertilizante de aguas residuales tratadas, en un cultivo de ajo. Se compararon dos variedades de ajo y tres fuentes de agua para riego: efluente tratado en zanjas de oxidación, agua de perforación sin fertilizantes y agua de perforación con fertilizantes. El efluente se comportó como una fertilización nitrogenada y mejoró la calidad del ajo y aumentando su rendimiento en un 10 con respecto al cultivo regado con agua de perforación sin fertilizantes

[A new mini-invasive technique for the treatment of sleep breathing disorders: preliminary results of a clinical experience]. / Nuova tecnica mini-invasiva per il trattamento dei disturbi respiratori del sonno (DRS). Risultati preliminari della nostra esperienza clinica.

The REPOSE system is a new, mini-invasive technique with which the base of the tongue is suspended to treat sleep breathing disorders (SBD) induced by hypertrophy of the base of the tongue. The surgical technique calls for the intra-oral insertion of a small titanium screw in the anterior portion of the mandible. Two polypropylene threads are attached to the screw and these are passed through the base of the tongue and then tied at the point where it is inserted in the floor of the mouth, thus effectively suspending the base of the tongue. 10 patients with SBD due to hypertrophy of the base of the tongue underwent this procedure. Only one major complication was found: an infection requiring sectioning of the suspension thread. For an average 7 to 30 days all patients showed signs of odinophagia, bilateral otalgia, dysphagia and dislalia. In all patients snoring either disappeared altogether or was significantly reduced. Statistical analysis of the pre- and post-operative polysonnograph data showed a significant reduction in the apnea index (AI), the respiratory distress index (RDI) (p = 0.009) as well as a significant improvement in the degree of oxygen saturation (SaO2) (p = 0.008). The results were independent from the body mass since the patients did not lose weight during the follow-up period.

Evaluación de impactos ambientales de uso de efluentes domiciliarios para riego: el caso del Gran Mendoza

En el análisis realizado en este trabajo se aportan elementos económicos para decidir con respecto al problema de contaminación hídrica provocado por el uso desordenado y clandestino de los efluentes domésticos del gran Mendoza, en el riego de cultivos. La evaluación de impactos ambientales resulta, para un horizonte de 20 años y una tasa de costo de oportunidad del capital del 10

de alrededor $900.000.-, por lo que la rentabilidad del proyecto es muy satisfactoria

Una metodología de evaluación de impactos ambientales de proyectos de saneamiento; aplicación al caso de Palmira, Mendoza

Este estudio se realiza para identificar, prevenir e intepretar las consecuencias al bienestar humano y al entorno con el objeto de asegurar las inversiones que se lleven a cabo prevengan, controlen y/o mitiguen los efectos negativos sobre los recursos naturales y el bienestar de las personas