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Chilean soils degradation is a serious problem affecting directly the productivity of most of the crops. Some evidence indicates sewage sludge can improve soil physical properties, especially when combined with sawdust. The objective of this work was to evaluate the effect of different mixtures of sewage sludge (LU) and sawdust (RA) on water-stable aggregates and available water content of a degraded Alfisol cropped with hybrid ryegrass (Lolium x hybridum Hausskn.), under greenhouse conditions. The experimental design was a completely randomized with a factorial arrangement of 2 x 9 (ryegrass x rates of sludge and sawdust). Treatments were 25 and 50 Mg LU ha-1 mixed with 10, 25, and 50 Mg RA ha-1. Ratio mixtures of LU/RA were set in pots with hybrid ryegrass. Soil available water content (AW), percentage of macroaggregates (MA) and water-stable aggregates (AWD) were evaluated. Ryegrass aboveground biomass was also measured. Mixtures of LU/RA amended to the soil increased MA and AWD, an effect that was most evident at 50 Mg ha-1. The AW value was greater when LU was amended to 50 Mg ha-1 mixed with RA at doses of 10, 25, and 50 Mg ha-1. There was greater aboveground biomass of hybrid ryegrass, directly related to increasing doses of LU and RA in the mixtures. The addition to soil of both organic residues combined, LU and RA, improved the physical parameters studied, especially in the presence of hybrid ryegrass.La degradation de los suelos chilenos es un serio problema que afecta directamente la productividad de la mayoría de los cultivos. Los lodos urbanos pueden mejorar las propiedades físicas del suelo, sobre todo si van acompanadas con aserrín. El objetivo fue evaluar el efecto de distintas mezclas de lodo urbano (LU) y aserrín (RA) sobre los agregados estables al agua y el contenido de agua disponible en un Alfisol degradado y cultivado con ballica híbrida (Lolium x hybridum Hausskn.), bajo invernadero. El diseno experimental fue completamente al azar con un arreglo factorial 2 x 9 (ballica híbrida x dosis de lodo y aserrín). Los tratamientos fueron: 25 y 50 Mg ha-1 de LU en mezcla con 10, 25 y 50 Mg ha-1 de RA. Las mezclas LU/RA se enmendaron en macetas con ballica híbrida. Se evaluo el contenido de agua disponible (AW), el porcentaje de macroagregados (MA) y la estabilidad de los macroagregados al agua (AWD). También se midió la production de fitomasa aérea. Las mezclas de LU/ RA enmendadas al suelo aumentaron los MA y el AWD, efecto que fue más evidente a 50 Mg ha-1. El valor de AW fue mayor cuando se enmendó 50 Mg LU ha-1 en mezcla con RA a dosis de 10, 25 y 50 Mg ha-1. Hubo mayor biomasa aérea de ballica híbrida, en directa relación con el incremento de las dosis de LU y RA en las mezclas. La adición de LU y RA en mezclas combinadas al suelo mejoraron los parámetros físicos evaluados, especialmente en presencia de ballica híbrida.

There are few studies about the impact of sewage sludge on the biological properties in Alfisols of the Chilean Coastal Range drylands. Hence, the objective of this study was to evaluate its effect on the microbial respiration and enzymatic activities of a degraded Alfisol located in the Bío Bío Region (Chile) that was cropped with yellow serradela (Ornithopus compressus L.). Sludge was added to the soil at rates of 15, 30, and 60 t ha-1; he following treatments were defined: L15-P = 15 t ha-1 sludge + O. compressus; L30-P = 30 t ha-1 sludge + O. compressus; L60-P = 60 t ha-1 sludge + O. compressus; L15 = 15 t ha-1 sludge; L30 = 30 t ha-1 sludge; L60 = 60 t ha-1 sludge; CP = non-amended soil, cropped; and C = non-amended soil, no crop. Soil microorganism activity was evaluated by respirometry. Hydrolytic enzyme activity representative of soil C, N, and P cycles was determined. Crop phytomass development was also evaluated. The amount of C-CO2 produced by soil microorganisms was directly proportional to the dose of amended sludge (p ≤ 0.05). Similarly, greater β-glucosidase, urease, and acid phosphatase were more active at 60 t sludge ha-1. However, both respiratory and enzymatic activities were greater (p ≤ 0.05) in treatments with sludge-amended soil cropped with O. compressus. This greater activity was notorious when the legumes achieved greater phytomass development, thus highlighting the root’s stimulating effect on soil biological activity.

There are few studies about the impact of sewage sludge on the biological properties in Alfisols of the Chilean Coastal Range drylands. Hence, the objective of this study was to evaluate its effect on the microbial respiration and enzymatic activities of a degraded Alfisol located in the Bío Bío Region (Chile) that was cropped with yellow serradela (Ornithopus compressus L.). Sludge was added to the soil at rates of 15, 30, and 60 t ha-1; he following treatments were defined: L15-P = 15 t ha-1 sludge + O. compressus; L30-P = 30 t ha-1 sludge + O. compressus; L60-P = 60 t ha-1 sludge + O. compressus; L15 = 15 t ha-1 sludge; L30 = 30 t ha-1 sludge; L60 = 60 t ha-1 sludge; CP = non-amended soil, cropped; and C = non-amended soil, no crop. Soil microorganism activity was evaluated by respirometry. Hydrolytic enzyme activity representative of soil C, N, and P cycles was determined. Crop phytomass development was also evaluated. The amount of C-CO2 produced by soil microorganisms was directly proportional to the dose of amended sludge (p ≤ 0.05). Similarly, greater β-glucosidase, urease, and acid phosphatase were more active at 60 t sludge ha-1. However, both respiratory and enzymatic activities were greater (p ≤ 0.05) in treatments with sludge-amended soil cropped with O. compressus. This greater activity was notorious when the legumes achieved greater phytomass development, thus highlighting the root’s stimulating effect on soil biological activity.El impacto de los lodos urbanos sobre las propiedades biológicas en suelos Alfisoles del secano interior de la Cordillera de la Costa de Chile ha sido poco estudiado. El objetivo de este estudio fue evaluar el efecto de la aplicación de lodo urbano sobre las propiedades biológicas de un suelo Alfisol degradado de la Región del Bío Bío, Chile, cultivado con serradela amarilla (Ornithopus compressus L.). Se adicionó lodo al suelo a razón de 15, 30 y 60 t ha-1, a partir de lo cual se definieron los siguientes tratamientos: L15-P = 15 t ha-1 lodo + O. compressus; L30-P = 30 t ha-1 lodo + O. compressus; L60-P = 60 t ha-1 lodo + O. compressus; L15 = 15 t ha-1 lodo; L30 = 30 t ha-1 lodo; L60 = 60 t ha-1 lodo; CP = suelo sin enmendar, con cultivo; C = suelo sin enmendar, sin cultivo. Se evaluó la actividad de los microorganismos del suelo a través de pruebas de respirometría, se determinó la actividad de las enzimas hidrolíticas representativas de los ciclos del C, N y P en el suelo, y se evaluó el desarrollo de la fitomasa del cultivo. Se encontró un aumento (p ≤ 0,05) del C-CO2 respirado por los microorganismos del suelo en proporción directa con las dosis de lodo. Del mismo modo, hubo una mayor actividad de las enzimas β-glucosidasa, ureasa y fosfatasa ácida a 60 t ha-1 de lodo. Sin perjuicio de los anterior, tanto la actividad respiratoria como la actividad enzimática fueron superiores (p ≤ 0,05) en los tratamientos con suelo enmendado con lodo y cultivado con O. compressus. Esta mayor actividad fue más notoria cuando la leguminosa alcanzó el mayor desarrollo de su fitomasa, destacándose el efecto estimulante de las raíces en la actividad biológica del suelo.

Chilean soils degradation is a serious problem affecting directly the productivity of most of the crops. Some evidence indicates sewage sludge can improve soil physical properties, especially when combined with sawdust. The objective of this work was to evaluate the effect of different mixtures of sewage sludge (LU) and sawdust (RA) on water-stable aggregates and available water content of a degraded Alfisol cropped with hybrid ryegrass (Lolium x hybridum Hausskn.), under greenhouse conditions. The experimental design was a completely randomized with a factorial arrangement of 2 x 9 (ryegrass x rates of sludge and sawdust). Treatments were 25 and 50 Mg LU ha-1 mixed with 10, 25, and 50 Mg RA ha-1. Ratio mixtures of LU/RA were set in pots with hybrid ryegrass. Soil available water content (AW), percentage of macroaggregates (MA) and water-stable aggregates (AWD) were evaluated. Ryegrass aboveground biomass was also measured. Mixtures of LU/RA amended to the soil increased MA and AWD, an effect that was most evident at 50 Mg ha-1. The AW value was greater when LU was amended to 50 Mg ha-1 mixed with RA at doses of 10, 25, and 50 Mg ha-1. There was greater aboveground biomass of hybrid ryegrass, directly related to increasing doses of LU and RA in the mixtures. The addition to soil of both organic residues combined, LU and RA, improved the physical parameters studied, especially in the presence of hybrid ryegrass. La degradation de los suelos chilenos es un serio problema que afecta directamente la productividad de la mayoría de los cultivos. Los lodos urbanos pueden mejorar las propiedades físicas del suelo, sobre todo si van acompanadas con aserrín. El objetivo fue evaluar el efecto de distintas mezclas de lodo urbano (LU) y aserrín (RA) sobre los agregados estables al agua y el contenido de agua disponible en un Alfisol degradado y cultivado con ballica híbrida (Lolium x hybridum Hausskn.), bajo invernadero. El diseno experimental fue completamente al azar con un arreglo factorial 2 x 9 (ballica híbrida x dosis de lodo y aserrín). Los tratamientos fueron: 25 y 50 Mg ha-1 de LU en mezcla con 10, 25 y 50 Mg ha-1 de RA. Las mezclas LU/RA se enmendaron en macetas con ballica híbrida. Se evaluo el contenido de agua disponible (AW), el porcentaje de macroagregados (MA) y la estabilidad de los macroagregados al agua (AWD). También se midió la production de fitomasa aérea. Las mezclas de LU/ RA enmendadas al suelo aumentaron los MA y el AWD, efecto que fue más evidente a 50 Mg ha-1. El valor de AW fue mayor cuando se enmendó 50 Mg LU ha-1 en mezcla con RA a dosis de 10, 25 y 50 Mg ha-1. Hubo mayor biomasa aérea de ballica híbrida, en directa relación con el incremento de las dosis de LU y RA en las mezclas. La adición de LU y RA en mezclas combinadas al suelo mejoraron los parámetros físicos evaluados, especialmente en presencia de ballica híbrida.

Chilean soils degradation is a serious problem affecting directly the productivity of most of the crops. Some evidence indicates sewage sludge can improve soil physical properties, especially when combined with sawdust. The objective of this work was to evaluate the effect of different mixtures of sewage sludge (LU) and sawdust (RA) on water-stable aggregates and available water content of a degraded Alfisol cropped with hybrid ryegrass (Lolium x hybridum Hausskn.), under greenhouse conditions. The experimental design was a completely randomized with a factorial arrangement of 2 x 9 (ryegrass x rates of sludge and sawdust). Treatments were 25 and 50 Mg LU ha-1 mixed with 10, 25, and 50 Mg RA ha-1. Ratio mixtures of LU/RA were set in pots with hybrid ryegrass. Soil available water content (AW), percentage of macroaggregates (MA) and water-stable aggregates (AWD) were evaluated. Ryegrass aboveground biomass was also measured. Mixtures of LU/RA amended to the soil increased MA and AWD, an effect that was most evident at 50 Mg ha-1. The AW value was greater when LU was amended to 50 Mg ha-1 mixed with RA at doses of 10, 25, and 50 Mg ha-1. There was greater aboveground biomass of hybrid ryegrass, directly related to increasing doses of LU and RA in the mixtures. The addition to soil of both organic residues combined, LU and RA, improved the physical parameters studied, especially in the presence of hybrid ryegrass.

There are few studies about the impact of sewage sludge on the biological properties in Alfisols of the Chilean Coastal Range drylands. Hence, the objective of this study was to evaluate its effect on the microbial respiration and enzymatic activities of a degraded Alfisol located in the Bío Bío Region (Chile) that was cropped with yellow serradela (Ornithopus compressus L.). Sludge was added to the soil at rates of 15, 30, and 60 t ha-1; he following treatments were defined: L15-P = 15 t ha-1 sludge + O. compressus; L30-P = 30 t ha-1 sludge + O. compressus; L60-P = 60 t ha-1 sludge + O. compressus; L15 = 15 t ha-1 sludge; L30 = 30 t ha-1 sludge; L60 = 60 t ha-1 sludge; CP = non-amended soil, cropped; and C = non-amended soil, no crop. Soil microorganism activity was evaluated by respirometry. Hydrolytic enzyme activity representative of soil C, N, and P cycles was determined. Crop phytomass development was also evaluated. The amount of C-CO2 produced by soil microorganisms was directly proportional to the dose of amended sludge (p ≤ 0.05). Similarly, greater β-glucosidase, urease, and acid phosphatase were more active at 60 t sludge ha-1. However, both respiratory and enzymatic activities were greater (p ≤ 0.05) in treatments with sludge-amended soil cropped with O. compressus. This greater activity was notorious when the legumes achieved greater phytomass development, thus highlighting the root’s stimulating effect on soil biological activity. El impacto de los lodos urbanos sobre las propiedades biológicas en suelos Alfisoles del secano interior de la Cordillera de la Costa de Chile ha sido poco estudiado. El objetivo de este estudio fue evaluar el efecto de la aplicación de lodo urbano sobre las propiedades biológicas de un suelo Alfisol degradado de la Región del Bío Bío, Chile, cultivado con serradela amarilla (Ornithopus compressus L.). Se adicionó lodo al suelo a razón de 15, 30 y 60 t ha-1, a partir de lo cual se definieron los siguientes tratamientos: L15-P = 15 t ha-1 lodo + O. compressus; L30-P = 30 t ha-1 lodo + O. compressus; L60-P = 60 t ha-1 lodo + O. compressus; L15 = 15 t ha-1 lodo; L30 = 30 t ha-1 lodo; L60 = 60 t ha-1 lodo; CP = suelo sin enmendar, con cultivo; C = suelo sin enmendar, sin cultivo. Se evaluó la actividad de los microorganismos del suelo a través de pruebas de respirometría, se determinó la actividad de las enzimas hidrolíticas representativas de los ciclos del C, N y P en el suelo, y se evaluó el desarrollo de la fitomasa del cultivo. Se encontró un aumento (p ≤ 0,05) del C-CO2 respirado por los microorganismos del suelo en proporción directa con las dosis de lodo. Del mismo modo, hubo una mayor actividad de las enzimas β-glucosidasa, ureasa y fosfatasa ácida a 60 t ha-1 de lodo. Sin perjuicio de los anterior, tanto la actividad respiratoria como la actividad enzimática fueron superiores (p ≤ 0,05) en los tratamientos con suelo enmendado con lodo y cultivado con O. compressus. Esta mayor actividad fue más notoria cuando la leguminosa alcanzó el mayor desarrollo de su fitomasa, destacándose el efecto estimulante de las raíces en la actividad biológica del suelo.

Pocos estudios se han llevado a cabo en ciudades intermedias latinoamericanas a fin de determinar sus niveles de contaminación atmosférica. A través de un análisis de la contaminación urbana de la ciudad de Chillán (Chile), el artículo demuestra que la atmósfera respirable en la ciudad de Chillán debe ser considerada como un problema de origen antropogénico durante otoño e invierno. Esto se explica mayormente debido al uso masivo de la madera como combustible para la calefacción residencial dentro de las áreas urbanas de la ciudad. Este abatimiento se puede alcanzar junto con regulaciones públicas del transporte y de la industria, tales como definir nuevas maneras de evitar tráfico vehicular a través del centro de la ciudad, y prohibiendo el uso de taxibuses contaminantes que han sido retirados de circulación en Santiago. Sólo así se facilitará el desarrollo sustentable de ciudades latinoamericanas intermedias como Chillán, que no necesariamente deben repetir los graves problemas de contaminación de las grandes urbes Few studies have been carried out in middle-sized Latin American cities in order to determine their levels of atmospheric contamination. Through an analysis of the urban contamination of the city of Chillán (Chile), it has been demonstrated that the breathable atmosphere in the city of Chillán must be considered as a problem of anthropathogenic origin during autumn and winter. This is explained mainly due to the massive use of firewood for residential heating in urban areas of the city. The reduction in use of wood heating can be achieved, along with public regulation of transport and industry. The latter can be accomplished by defining new ways of avoiding cross town traffic as well as restricting the use of contaminant buses that have been retired from circulation in Santiago. Only in this way will the sustainable development of medium-sized Latin-American cities such as Chillán be assured, without necessarily repeating the serious problems of the large polluted metropolitan cities

OBJECTIVES: To compare clinic and ambulatory blood pressure measurement and the reproducibility of these measurements in older patients with isolated systolic hypertension.PATIENTS: A total of 477 patients aged/= 60 years with isolated systolic hypertension on clinic measurement were monitored during the placebo run-in phase of the Syst-Eur trial. METHODS: The time-weighted 24 h blood pressure, clock time day and night blood pressure, the cumulative sum-derived crest and trough blood pressure and the high and low blood pressure levels of the square-wave model were computed. The daily alteration between the high and low blood pressure spans was quantified using the clock time day-night difference, the cumulative sum-derived circadian alteration magnitude, the Fourier amplitude and the difference between the high and low blood pressure levels of the square-wave model. RESULTS: The daytime ambulatory systolic blood pressure was, on average, 21 mmHg lower than the clinic blood pressure, whereasthe diastolic blood pressure was, on average, similar with both techniques of measurement. In the 132 patients who underwent repeat measurements, clinic blood pressure levels and the parameters describing the difference betgween the daily high and low blood pressure spans were equally reproducible. However, both were less reproducible than the ambulatory blood pressure levels. The repeatability coefficients, expressed as percentages of near maximum variation, were 50 and 51% for the clinic systolic and diastolic blood pressures, 30 and 33% for the mean 24 h systolic and diastolic blood pressures and between 44 and 54% for the parameters describing the daily alteration between the high and low blood pressure spans. CONCLUSION: In older patients with isolated systolic hypertension, clinic and ambulatory systolic blood pressure may differ greatly; the prognostic significance of this difference remains to be elucidated. Furthermore, the level of blood pressure in these patients is more reproducible by ambulatory measurement than it is by clinic measurement.

In order to determine whether alterations in membrane lipids affect transmembrane cationic transport systems in erythrocytes and platelets, cationic fluxes and intracellular cationic concentrations were measured in hypercholesterolaemic patients before and during administration of an inhibitor of 3-hydroxy-3-methlglutaryl coenzyme A reductase.After a 1-month run-in placebo period on a lipid-lowering diet the patients were treated, in a double-blind manner, with either placebo (n = 25) or pravastatin (n = 25) for 6 months. Placebo or pravastatin (10 mg during the first month, 20 mg during the second month and 40 mg during the remaining 4 months) was administered once a day in the evening.Compared with the placebo group, the erythrocyte and platelet membrane cholesterol content was reduced in the patients treated with pravastatin. The intra-erythrocyte and intraplatelet Na+ concentration was reduced during pravastatin administration, whereas the activity of the erythrocyte and platelet Na(+)-K+ pump was increased. However, the intra-erythrocyte and intraplatelet K+, Mg2+ and cytosolic Ca2+ concentrations, and water content, as well as the activities of the erythrocyte Na(+)-Li+ countertransporter and Na+,K+ cotransporter, and Na+ and K+ leakage, were not changed during pravastatin treatment.The present data show that cholesterol lowering in hypercholesterolaemic patients may result in a significant decrease in erythrocyte and platelet membrane cholesterol content. These changes in membrane cholesterol are accompanied by an increase in activity of the Na(+)-K+ pump and a decrease in intra-erythrocyte and intraplatelet Na+ concentrations.