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One of the critical aspects in modelling soil organic carbon (SOC) predictions is the lack of access to soil information which is usually concentrated in regions of high agricultural interest. In Chile, most soil and SOC data to date is highly concentrated in 25 % of the territory that has intensive agricultural or forestry use. Vast areas beyond those forms of land use have few or no soil data available. Here, we present a new database of SOC for the country, which is the result of an unprecedented national effort under the frame of the Global Soil Partnership that help to build the largest database on SOC to date in Chile named “CHLSOC" comprising 13,612 data points. This dataset is the product of the compilation from numerous sources including unpublished and difficult to access data, allowing to fill numerous spatial gaps where no SOC estimates were publicly available before. The values of SOC compiled in CHLSOC range from 6×10−5 to 83.3 percent, reflecting the variety of ecosystems that exists in Chile. Profiting from the richness of geochemical, topographic and climatic variability in Chile, the dataset has the potential to inform and test models trying to predict SOC stocks and dynamics at larger spatial scales. [ABSTRACT FROM AUTHOR]

High arsenic (As), cadmium (Cd), lead (Pb), and nitrate (NO3−) concentrations in soil pose a risk for the human population and compromise food safety. The goal of this study was to obtain preliminary approximations for the expected mean values of As, Cd, Pb, and N-NO3in three leafy vegetables (lettuce, spinach, and chard) grown in the central farming regions of Chile. Representative samples (n = 148) of these crops were collected from the Coquimbo, Valparaíso, and Metropolitana Regions. Water extraction and an ion-selective electrode were used to determine NO3−contents, while total As, Cd, and Pb contents were determined by atomic absorption spectroscopy. The recorded values were 23.8%, 59.2%, and 97.9% below detection limits for As, Cd, and Pb, respectively. Furthermore, As and Cd intake by leafy vegetables reached 0.26 and 2.30% of the daily intake levels estimated by Chilean authorities. The daily NO3−intake by leafy vegetables was 0.44 mg per kg of bodyweight per day (kgbw−1day−1), or 12% of the WHO-recommended intake. No analyses were performed for Pb due to highly left-censored data. While the recorded NO3−, As, and Cd concentrations in lettuce, spinach, and chard do not apparently pose a health risk, further detailed studies are suggested. [ABSTRACT FROM PUBLISHER]

Objective: To study how to identify patients with "triple negative" sporadic breast cancers (BCs) having BRCA1 silenced or down-regulated due to epigenetic BRCA1 inactivation., Study Design: We selected, from our database, patients diagnosed with BC between 1995 and 2001 with tumors exhibiting the "triple negative" phenotype. "Triple positive" tumors were used as controls. BRCA1 protein expression was determined by immunohistochemistry. Methylation specific polymerase chain reaction (PCR) and bisulfite sequencing on genomic DNA were used to assess BRCA1 promoter methylation. BRCA1 m-RNA expression analysis was conducted by real-time PCR., Results: Forty-four triple negative and 68 controls (triple positive) were eligible for our analysis. BRCA1 promoter methylation was present in 31.8% of triple negative and in 20.6% of triple positive cases. BRCA1 was inactivated (absent BRCA1 m-RNA expression and lack of BRCA1 protein) in 21.4% of tumors with BRCA1 promoter methylation, as compared with 6% of non-methylated ones (p = 0.0453)., Conclusion: BRCA1 inactivation due to promoter methylation could play an important role in some sporadic BC cases. Patients with this signature could represent the basis for prospective studies aiming to compare clinical response to different drugs.