Evaluación de la disposición de arenas de fundición en relación a la protección del recurso hídrico subterráneo. Programa I.W.E.M.

El modelo de evaluación de gestión de residuos industriales (IWEM) es una herramienta para la toma de decisión y prevención de la contaminación del recurso hídrico subterráneo. El objetivo del trabajo fue determinar la modalidad adecuada de disposición de arenas descartadas de fundición (ADF) al aplicar el software IWEM. Se utilizaron las concentraciones de Ag, Ba. Cd, Cr, Cu, Ni, Pb y Zn determinadas en 96 ADF sometidas al procedimiento de lixiviación EPA-1310B. Se corrieron en el IWEM las concentraciones bajo condiciones de clima húmedo, subhúmedo y seco. Este programa se corrió bajo determinadas condiciones hidrogeológicas de pH, permeabilidad, espesor y profundidad del nivel freático, y como carga contaminante se utilizó un relleno de 10.000 m3. Los resultados indican que en climas húmedos y subhúmedos los metales lixiviados no presentan un peligro para la calidad del recurso hídrico subterráneo a excepción de algunas ADFs que deben disponerse en rellenos con barrera compuesta debido a las concentraciones de Pb.The industrial waste management model (IWEM) is a tool used to prevent the pollution of groundwater re sources. The aim was to determine the appropriate mode of disposal of waste foundry sands (WFS) using the software IWEM. The concentration of Ba, Cd, Cr, Cu, Ni, Pb and Zn was analyzed in 96 WFS subjected to leaching procedure EPA 1310b. The concentrations were run in the IWEM taking into account humid, median tendency and dry weather conditions. The program was run with hydrogeological condition of pH, permeability, depth and thickness, and the landfilled area was a 10,000 m3. The results indicate that in humid and median tendency weather the leached metals do not present a danger to the quality of groundwater resources except for some WFS that It need to be disposed in landfills with composite barrier due to the Pb concentrations.Universidad Nacional de La Plat

Analysis of total metals in waste molding and core sands from ferrous and non-ferrous foundries

Waste molding and core sands from the foundry industry have been successfully used around the world as byproducts in geotechnical and agricultural applications. Although waste foundry sands (WFSs) are generally not considered hazardous in nature, relevant data are not available in Argentina. This study aimed to quantify metals in waste molding and core sands from foundries using a variety of metal-binder combinations. Metal concentrations in WFSs were compared to those in virgin silica sands (VSSs), surface soil and soil guidance levels according to hazardous waste law 24.051 from the Argentinean Secretariat of Environment and Sustainable Development. A total analysis for Ag, Al, Ba, Be, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Sb, Te, Tl, V, and Zn was conducted on 96 WFSs and 14 VSSs collected from 17 small and medium-sized foundries. The majority of WFSs analyzed, regardless of metal cast and binder type, contained elemental concentrations similar to those found in virgin sands and native soils. In several cases where alkyd urethane binder was used, Co and Pb concentrations were elevated in the waste sands. Elevated Cr, Mo, Ni, and Tl concentrations associated with the virgin sands should not be an issue since these elements are bound within the silica sand matrix. Because of the naturally low elemental concentrations found in most WFSs examined in this study, they should not be considered hazardous waste, thus making them available for encapsulated and unencapsulated beneficial use applications.Facultad de Ingenierí

Early satellite cell communication creates a permissive environment for long-term muscle growth

Using in vivo muscle stem cell (satellite cell)-specific extracellular vesicle (EV) tracking, satellite cell depletion, in vitro cell culture, and single-cell RNA sequencing, we show satellite cells communicate with other cells in skeletal muscle during mechanical overload. Early satellite cell EV communication primes the muscle milieu for proper long-term extracellular matrix (ECM) deposition and is sufficient to support sustained hypertrophy in adult mice, even in the absence of fusion to muscle fibers. Satellite cells modulate chemokine gene expression across cell types within the first few days of loading, and EV delivery of miR 206 to fibrogenic cells represses Wisp1 expression required for appropriate ECM remodeling. Late-stage communication from myogenic cells during loading is widespread but may be targeted toward endothelial cells. Satellite cells coordinate adaptation by influencing the phenotype of recipient cells, which extends our understanding of their role in muscle adaptation beyond regeneration and myonuclear donation

Endothelial Dysfunction: Associations with Exposure to Ambient Fine Particles in Diabetic Individuals

BACKGROUND: Exposure to fine airborne particulate matter [<= 2.5 mu m in aerodynamic diameter (PM2.5)] has been associated with cardiovascular and hematologic effects, especially in older people with cardiovascular disease. Some epidemiologic studies suggest that adults with diabetes also may be a particularly susceptible population. OBJECTIVES: The purpose of this study was to analyze the short-term effects of ambient PM2.5 on markers of endothelial function in diabetic volunteers.METHODS: We conducted a prospective panel study in 22 people with type 2 diabetes mellitus in Chapel Hill, North Carolina (USA), from November 2004 to December 2005. We acquired daily measurements of PM2.5 and meteorologic data at central monitoring sites. On 4 consecutive days, we measured endothelial function by brachial artery ultrasound in all participants and by pulsewave measurements in a subgroup. Data were analyzed using additive mixed models with a random participant effect and adjusted for season, day of the week, and meteorology. RESULTS: Flow-mediated dilatation decreased in association with PM2.5 during the first 24 hr, whereas small-artery elasticity index decreased with a delay of 1 and 3 days. These PM2.5-associated decrements in endothelial function were greater among participants with a high body mass index, high glycosylated hemoglobin Ale, low adiponectin, or the null polymorphism of glutathione S-transferase M1. However, high levels of myeloperoxidase on the examination day led to strongest effects on endothelial dysfunction. CONCLUSIONS: These data demonstrate that PM2.5 exposure may cause immediate endothelial dysfunction. Clinical characteristics associated with insulin resistance were associated with enhanced effects of PM on endothelial function. In addition, participants with greater oxidative potential seem to be more susceptible

Nutritional and environmental effects on ammonia emissions from dairy cattle housing: A meta-analysis

Nitrogen (N) excreted in urine by dairy cows can be potentially transformed to ammonia (NH3) and emitted to the atmosphere. Dairy production contributes to NH3 emission, which can create human respiratory problems and odor issues, reduces manure quality, and is an indirect source of nitrous oxide (N2O). The objective of this study was to (i) investigate environmental factors and measurement method that influence NH3 from dairy housing, and (ii) identify key explanatory variables in the prediction of NH3 emissions from dairy barns using a meta-analytical approach. Data from 25 studies were used for the preliminary analysis and data from 10 studies reporting 87 treatment means were used for the meta-analysis. Season, flooring type, manure handling and housing type and system significantly affected NH3 emission rates as well as the measurement method used to quantify the NH3 emission. Ammonia emissions rates from open-lot and scrape systems were considerably greater and those from deep pit systems lower compared to U.S. Environmental Protection Agency (USEPA) estimates used in national inventory calculations. For nutritional effect analysis, the between-study variability (heterogeneity) of the mean emission was estimated using random-effect models and had a significant effect (P < 0.01). Therefore, random-effect models were extended to mixed-effect models to explain heterogeneity. Available dietary and animal variables were included as fixed effects in the mixed-effect models. The final mixed-effect model included dietary crude protein, milk yield and dry matter intake, explaining 45.5% of the heterogeneity in NH3 emissions. A unit increase in milk yield (kg/d) resulted in 4.9 g cow/d reduction in NH3 emissions, and a unit increase in diet crude protein content (%) and dry matter intake (kg/d) resulted in 10.2 and 16.3 g cow/d increase in NH3 emissions, respectively. Ammonia emissions from dairy barns are driven by several factors including housing system, season and diet. Crude protein content of the diet, dry matter intake and milk production are important animal related factors that significantly affect ammonia emission from dairy facilities

Nutrient Availability to Corn From Dairy Manures and Fertilizer in a Calcareous Soil

Abstract: The expansion of the dairy industry in southern Idaho has led to increased application of manures to meet crop nutrient demands that can alter the uptake pattern of both macronutrients and micronutrients. A greenhouse study was conducted to determine the effects of dairy manure, composted dairy manure, and fertilizer (monoammonium phosphate) application on soil test phosphorus (P), microbial activity, and nutrient uptake by silage corn (Zea mays). Two Portneuf soils, having either a low or high soil test P concentration, were amended with the three treatments at four application rates (25, 50, 100, and 200 mg P kg j1 ) with four replications of each treatment in a randomized complete design. Treatments were incubated for 2 weeks, then planted with corn grown for approximately 3 weeks. Soil samples were analyzed before planting, whereas plant samples were analyzed at the end of the growing period. Increases in Olsen P from P additions were greatest in the monoammonium phosphate and least in the manure-treated soils. Plant dry matter production and tissue P concentration did not differ with treatment. Tissue K increased with manure and compost addition, whereas tissue Ca decreased; there was also a decrease in tissue Mg with compost application. Tissue Zn increased with manure applications, whereas tissue Mn decreased with manure and compost application on the low-P soil. It is important to consider plant nutrient interactions when applying manure and compost to forage crops as imbalances in K, Ca, and Mg can have a negative impact on animal health

Nutritional and Environmental Effects on Ammonia Emissions from Dairy Cattle Housing: A Meta-Analysis.

Nitrogen excreted in dairy manure can be potentially transformed and emitted as NH, which can create livestock and human respiratory problems and be an indirect source of NO. The objectives of this study were to: (i) investigate environmental factors influencing NH emissions from dairy housing; and (ii) identify key explanatory variables in the NH emissions prediction from dairy housing using a meta-analytical approach. Data from 25 studies were used for the preliminary analysis, and data from 10 studies reporting 87 treatment means were used for the meta-analysis. Season and flooring type significantly affected NH emissions. For nutritional effect analysis, the between-study variability (heterogeneity) of mean NH emission was estimated using random-effect models and had a significant effect ( &lt; 0.01). Therefore, random-effect models were extended to mixed-effect models to explain heterogeneity regarding the available dietary and animal variables. The final mixed-effect model included milk yield, dietary crude protein, and dry matter intake separately, explaining 45.5% of NH emissions heterogeneity. A unit increase in milk yield (kg d) resulted in a 4.9 g cow d reduction in NH emissions, and a unit increase in dietary crude protein content (%) and dry matter intake (kg d) resulted in 10.2 and 16.3 g cow d increases in NH emissions, respectively, in the scope of this study. These results can be further used to help identify mitigation strategies to reduce NH emissions from dairy housing by developing predictive models that could determine variables with strong association with NH emissions

Altered response to metabolic challenges in mice with genetically targeted deletions of galanin-like peptide

Galanin-like peptide (GALP) is expressed in the arcuate nucleus and is implicated in the neuroendocrine regulation of metabolism and reproduction. To investigate the physiological significance of GALP, we generated and characterized a strain of mice with a genetically targeted deletion in the GALP gene [GALP knockout (KO) mice]. We report that GALP KO mice have a subtle, but notable, metabolic phenotype that becomes apparent during adaptation to changes in nutrition. GALP KO mice are indistinguishable from wild-type (WT) controls in virtually all aspects of growth, sexual development, body weight, food and water consumption, and motor behaviors, when they are allowed unlimited access to standard rodent chow. However, GALP KO mice have an altered response to changes in diet. 1) Male GALP KO mice consumed less food during refeeding after a fast than WT controls (P < 0.01). 2) GALP KO mice of both sexes gained less weight on a high-fat diet than WT controls (P < 0.01), despite both genotypes having consumed equal amounts of food. We conclude that although GALP signaling may not be essential for the maintenance of energy homeostasis under steady-state nutritional conditions, GALP may play a role in readjusting energy balance under changing nutritional circumstances