Prevalence and predictors of exposure to multiple metals in preschool children from Montevideo, Uruguay

The extent of children's exposure to multiple toxic metals is not well described in many developing countries. We examined metal exposures in young children (6-37 months) from Montevideo, Uruguay and their mothers (15-47 years) participating in a community-based study. Hair samples collected from 180 children and their mothers were analyzed for: lead (Pb), cadmium (Cd), manganese (Mn), and arsenic (As) concentration using inductively coupled plasma-mass spectrometry (ICP-MS). Median metal levels (μg/g) were: Pb 13.69, Mn 1.45, Cd 0.17, and As 0.09 for children and Pb 4.27, Mn 1.42, Cd 0.08, and As 0.02 for mothers. Of the child and maternal samples, 1.7% and 2.9% were below the limit of detection (LOD) for Cd, and 21.3% and 38.5% were below the LOD for As, respectively. Correlations between maternal and child levels ranged 0.38-0.55 (p < 0.01). Maternal hair metal levels were the strongest predictors of metal concentrations in children's hair. Girls had significantly lower As levels than boys (p < 0.01) but did not differ on other metals. In addition, in bivariate logistic regressions predicting the likelihood that the child would be exposed to multiple metals, hemoglobin < 10.5 g/dL (OR = 2.12, p < 0.05), blood lead (OR = 1.17, p < 0.01), and the mother being exposed to two or more metals (OR = 3.34, p < 0.01) were identified as significant predictors of increased likelihood of multiple metal exposure. Older child age (OR = 0.96, p < 0.05), higher maternal education (OR = 0.35, p < 0.01), and higher number of household possessions (OR = 0.83, p < 0.01) were significantly associated with decreased likelihood of multiple metal exposure. Preschool children in Uruguay are exposed to multiple metals at levels that in other studies have been associated with cognitive and behavioral deficits. Sources of exposure, as well as cognitive and behavioral consequences of multiple metal exposure, should be investigated in this population.     

Nitrous oxide emissions from an Uruguayan argiudoll under different tillage and rotation treatments

Lack of local data limits estimation of nitrous oxide (N₂O) emissions from different land uses of Uruguay. As a first step towards obtaining local information, we measured from August 2003 to September 2004 N₂O fluxes from a rotation-by-tillage experiment established in 1993 and from a nearby natural pasture (NP). Nitrous oxide emission rates were measured on an event-driven basis by using the closed chamber technique with six replicates per treatment. Fluxes varied considerably with time and the higher rates (more than 30 g N ha⁻¹ day⁻¹) were generally associated with periods of high soil water content, high temperature, and/or decreasing soil nitrate. We could not identify, however, any statistically significant correlation between flux and these variables. Throughout the evaluation period, fluxes from crops or cultivated pastures tended to be higher than those from NP, but the effects of tillage (no-till and conventional tillage) or rotation (continuous tillage and rotation with pasture) were not consistent. The application of 112 kg N ha⁻¹ to barley did not increase N₂O fluxes probably due to a high fertilizer use efficiency caused by the recommended three-split application and by the lack of rain during this period. The annual cumulative flows of different treatments compared well with those estimated using IPCC methodology, but the high spatial and temporal variability observed in this one-year study indicate that further research is needed to obtain reliable data on N₂O fluxes from agricultural soils of Uruguay.     

乌拉圭主要金属矿床研究现状综述

乌拉圭盛产石灰石、大理石、紫水晶、玛瑙等矿产资源,但一直被认为缺乏金属矿产。随着近年来矿产资源勘查开发力度的增大,陆续发现了一批金、铁、锰等矿床,金已成为其主要矿产资源。乌拉圭地质工作程度较低[3],可供研究地质资料较少,本文在系统分析已有乌拉圭地质背景、地质矿产等资料的基础上对其主要金属矿床现状进行了综合研究。     

Classification of the floral origin of Uruguayan honeys by chemical and physical characteristics combined with chemometrics

This study reports both the chemical and physical characterization of honey samples produced in Uruguay and the classification of honeys by floral origin using chemometrics. Moisture (M), pH, electric conductivity (EC), hydroxymethyl-2-furaldehyde and colour composition were analysed. As well as composition, classification of honey samples from different floral origins namely pasture (n=6), Eucalyptus spp. (n=6), Citrus spp. (n=5), Baccharis spp. (n=5), multifloral (n=2) and others (n=6) was attempted using principal component analysis and linear discriminant analysis. All the honey samples were found to meet the international specifications for the chemical parameters evaluated. The EC, M and pH were the variables that explain the classification of honey samples according to floral origin. More than 80% of the samples belonging to pasture, Citrus spp. and Baccharis spp. honeys were correctly classified according to its floral origin. Further studies are needed in order to investigate the effect of other floral and geographical (region) to provide a robust model to classify honey samples.     

Growth,carcass traits and palatability: Can the influence of the feeding regimes explain the variability found on those attributes in different Uruguayan genotypes?

It is well known what genetic and nutritional factors affect growth and meat quality, but there is less information related to interactive importance of them during the productive process. These systems are mainly based on rangelands affecting animal growth in early stages of life thus producing smaller cattle and reduced retail yield comparing with well grown calves. During the last ten years, Uruguayan livestock production systems have been intensified using improved pastures, concentrates and better genetic. The main breeds in Uruguay are Hereford, Angus and their crosses. These British breeds are under genetic evaluation programs which consider carcass trait parameters. It is important for beef industry to know if interactions between genotype and nutrition during growth and fattening phases are influencing production, efficiency, carcass weight and meat quality attributes. The aim of this article is to present information obtained under different feeding strategies during the post weaning and fattening and their influence on those attributes.     

Transboundary groundwater governance in the Guarani Aquifer System: reflections from a survey of global and regional experts

To understand transboundary groundwater governance in the South American Guarani Aquifer System, we surveyed global and regional experts about the region’s groundwater quantity and quality, ownership and rights, and regulation and administration. Respondents (1) perceived groundwater quality and withdrawal as under-regulated, and relevant information and data as inadequate; (2) suggested that contamination and overdrafting remain mostly incipient and localized along international borders; and (3) viewed groundwater as a shared resource administered by the state for the public, rather than as private property. Respondents suggested that while there is progress towards implementing a formal transboundary aquifer agreement, local-to-national-scale governance is important.     

The formation of country wineries networks for internationalization: an analysis of two new world wines regions

The objective of this study is to understand the characteristics of winemakers' networks and their effect on the internationalization process of the wine industry. Case studies in two emerging wine export countries were developed and analyzed. The Brazilian network, Integrated Sector Project Wines from Brazil, and the Uruguayan network, Wines of Uruguay, were both analyzed. The purpose of these networks is to promote those countries' wineries in international markets and to develop a common organizational structure shared by all the network members; however, local influences, such as market size and antecedent characteristics, result in different network roles. In each case, the network acts as an aggregate in the internationalization process of affiliate companies and assists in establishing the image of each country as a wine producer. The formation of a winemakers' network has a positive effect on the internationalization of the winemaking industry. Moreover, public policies to support internationalization demonstrate to improve the international competitiveness of wine companies. This study improves the understanding of the benefits winemakers' networks provide New World wines and the impact those networks have on the internationalization process. The results provide insights for advancing winemakers' internationalization strategy and the industrial policies affecting wine.     

Temporary and Mobile Protected Areas for the Conservation of a Palm Tree Landscape in Uruguay

The Butia capitata woodlands in southeastern Uruguay have a density and dimension that makes them unique in the world. This complex ecosystem, situated in prairie and grasslands, is dominated by Butia capitata palms and associated with a low herb stratum, some shrubs and trees, seasonal flooded areas and small ponds. The presence of cattle has inhibited recruitment for approximately 300 years, and the palm trees are therefore typically of this age. To date, no action has been taken to protect this magnificent landscape, which is under risk of disappearing due to the senescence of the palm trees and lack of recruitment. The pros and cons of using a novel system of temporary and mobile protected areas for landscape conservation are explored. It is concluded that temporary and mobile protected areas should be considered as a tool in a region where almost 100% of the land is privately owned, and the state has very limited funds.