[en] This report summarizes the development of sensor particles for remote detection of trace chemical analytes over broad areas, e.g residual trinitrotoluene from buried landmines or other unexploded ordnance (UXO). We also describe the potential of the sensor particle approach for the detection of chemical warfare (CW) agents. The primary goal of this work has been the development of sensor particles that incorporate sample preconcentration, analyte molecular recognition, chemical signal amplification, and fluorescence signal transduction within a ''grain of sand''. Two approaches for particle-based chemical-to-fluorescence signal transduction are described: (1) enzyme-amplified immunoassays using biocompatible inorganic encapsulants, and (2) oxidative quenching of a unique fluorescent polymer by TNT

[en] The state of Mato Grosso, Brazil, has experienced rapid land use changes from the expansion of rain-fed agriculture (primarily soybean and pasture). This study presents changes to evapotranspiration contributions from terrestrial ecosystems in Mato Grosso over the 2000–9 period. Instead of focusing on land use change to infer hydrologic change, in this paper we assess hydrologic changes using remote sensing, meteorological and agricultural production data to determine the rainforest, crop and pasture components of total evapotranspiration. Humid tropical rainforest evapotranspiration represented half of the state’s total evapotranspiration in 2000 despite occupying only 40% of the total land area. Annual evapotranspiration fluxes from rainforest declined at a rate of 16.2 km³ y⁻¹ (R² = 0.82, p-value < 0.01) as a result of deforestation between 2000 and 2009, representing a 25% decline in rainforest evapotranspiration since 2000. By 2009, rainforest cover accounted for only 40% of total evapotranspiration. Over the same period, crop evapotranspiration doubled, but this increase was offset by a decline in pasture evapotranspiration. Pasture fluxes were at least five times larger than crop evapotranspiration fluxes in 2000–9, with increases spatially focused at the agricultural frontier. The results highlight the expanding appropriation of soil moisture stocks for use in Mato Grosso’s rain-fed agroecosystems. (letter)

[en] Mato Grosso has become the center of Brazil’s soybean industry, with production located across an agricultural frontier expanding into savanna and rainforest biomes. We present environmental footprints of soybean production in Mato Grosso and resource flows accompanying exports to China and Europe for the 2000s using five indicators: deforestation, land footprint (LF), carbon footprint (CF), water footprint (WF), and nutrient footprints. Soybean production was associated with 65% of the state’s deforestation, and 14–17% of total Brazilian land use change carbon emissions. The decade showed two distinct production systems illustrated by resources used in the first and second half of the decade. Deforestation and carbon footprint declined 70% while land, water, and nutrient footprints increased almost 30% between the two periods. These differences coincided with a shift in Mato Grosso’s export destination. Between 2006 and 2010, China surpassed Europe in soybean imports when production was associated with 97 m"2 deforestation yr"−"1 ton"−"1 of soybean, a LF of 0.34 ha yr"−"1 ton"−"1, a carbon footprint of 4.6 ton CO_2-eq yr"−"1 ton"−"1, a WF of 1908 m"3 yr"−"1 ton"−"1, and virtual phosphorous and potassium of 5.0 kg P yr"−"1 ton"−"1 and 0.0042 g K yr"−"1 ton"−"1. Mato Grosso constructs soil fertility via phosphorous and potassium fertilizer sourced from third party countries and imported into the region. Through the soybean produced, Mato Grosso then exports both water derived from its abundant, seasonal precipitation and nutrients obtained from fertilizer. In 2010, virtual water flows were 10.3 km"3 yr"−"1 to China and 4.1 km"3 yr"−"1 to Europe. The total embedded nutrient flows to China were 2.12 Mtons yr"−"1 and 2.85 Mtons yr"−"1 to Europe. As soybean production grows with global demand, the role of Mato Grosso’s resource use and production vulnerabilities highlight the challenges with meeting future international food security needs. (paper)

[en] Metal ions can regulate various cell processes being first, second or third messengers, and some of them, especially transition metal ions, take part in catalysis in many enzymes. As an intracellular ion, Ca²⁺ is involved in many cellular functions from fertilization and contraction, cell differentiation and proliferation, to apoptosis and cancer. Here, we have identified and described two novel calcium recognition environments in proteins: the calcium blade zone and the EF-hand zone, common to 12 and 8 different protein families, respectively. Each of the two environments contains three distinct structural elements: (a) the well-known characteristic Dx[DN]xDG motif; (b) an adjacent structurally identical segment, which binds metal ion in the same way between the calcium blade zone and the EF-hand zone; and (c) the following structurally variable segment, which distinguishes the calcium blade zone from the EF-hand zone. Both zones have sequence insertions between the last residue of the zone and calcium-binding residues in positions V or VI. The long insertion often connects the active and the calcium-binding sites in proteins. Using the structurally identical segments as an anchor, we were able to construct the classical calmodulin type EF-hand calcium-binding site out of two different calcium-binding motifs from two unrelated proteins.

[en] Starting with conformations of calcium-binding sites in parvalbumin and integrin (representative structures of EF-hand and calcium blade zones, respectively) we introduce four new different local Ca²⁺-recognition units in proteins: a one-residue unit type I (ORI); a three-residue unit type I (TRI); a one-residue unit type II (ORII) and a three-residue unit type II (TRII). Based on the amount and nature of variable atoms, the type I and II units theoretically can have four and twelve variants, respectively. Analysis of known “Ca²⁺-bound functional niches” in proteins revealed presence of almost all possible variants of Ca²⁺-recognition units in actual structures. Parvalbumin, integrin alpha-IIb and sixteen other proteins with different Ca²⁺-bound functional niches contain various consecutively joined combinations of OR(I/II) and TR(I/II) units. Such a OR(I/II)+TR(I/II) joint unit forms a tripeptide, which uses three main-chain atoms for metal binding: nitrogen_n (Donor), oxygen_n (Acceptor) and nitrogen_n+2 (Donor). Thus, taken together, the described ORI, TRI, ORII and TRII units can serve as elementary blocks to construct more complex calcium recognizing substructures in a variety of calcium binding sites of unrelated proteins.

[en] The compound 2-amino-4,6-dinitrotoluene (2A-DNT) was evaluated under laboratory conditions in the Western fence lizard (Sceloporus occidentalis) to assess the potential for reptile toxicity. Oral LD₅₀ values were 1406 and 1867 mg/kg for male and female lizards, respectively. Based on responses from a 14-day subacute study, a 60-day subchronic experiment followed where lizards were orally dosed at 0, 5, 15, 20, 25, 30 mg/kg-d. At day 60, number of days and survivors, food consumption, and change in body weight were inversely related to dose. Signs of toxicity were characterized by anorexia and generalized cachexia. Significant adverse histopathology was observed in hepatic tissue at ≥15 mg/kg-d, consistent with hepatocellular transdifferentiation. Based on survival, loss of body weight, diminished food intake, changes in liver, kidney, and testes, and increased blood urea nitrogen, these data suggest a LOAEL of 15 mg/kg-d and a NOAEL of 5 mg/kg-d in S. occidentalis. - Research highlights: → Oral LD₅₀ (mg/kg) values were 1406 for male and 1867 for female lizards. → Dose-dependent hepatocellular transdifferentiation was observed at ≥5 mg/kg-d. → Chromaturia in 2A-DNT and the parent TNT suggest biomarkers of exposure and effect. → Health effects of metabolites support comprehensive ecological risk assessments. - The Western fence lizard (Sceloporus occidentalis) is a suitable reptile model for assessing the toxicity of energetic compounds and their metabolites.

[en] The expansion of cattle in central western Brazil has been under scrutiny because of the region’s historic reliance on Amazon and Cerrado deforestation for cropland and pastureland expansion. In this study, we determined the volumetric water footprint (VWF) and the land footprint (LF) of cattle in Mato Grosso state for the years 2000, 2005, 2010 and 2014 using official statistics and remote sensing imagery. We found the average VWF of cattle for the time period to be 265–270 l kg⁻¹ LW⁻¹ (LW as live weight of cattle) and a LF which decreased from 71 to 47 m² kg⁻¹ LW⁻¹. The largest contribution to VWF came from farm impoundments whose total area increased from roughly 46 000 to 51 000 ha between 2000 and 2014, leading to a total evaporation as high as 7.31 × 10¹¹ l yr⁻¹ in 2014. Analysis at the municipality level showed a tendency towards greater density of cattle with respect to both pasture area and impoundments. While cattle intensification on current pastureland is commonly viewed as a means to prevent further deforestation and greenhouse gas emissions, we stress the need to also consider the increasing demand for water associated with a growing cattle herd and the potential appropriation of additional resources for feed for feedlot finishing. Land and water resource management need to be considered together for future planning of cattle intensification at the Brazilian agricultural frontier as illustrated by the footprints reported here. (letter)

[en] Dinitrotoluenes are used as propellants and in explosives by the military and as such have been found at relatively high concentrations in the soil. To determine whether concentrations of 2,4-dinitrotoluene (2,4-DNT) in soil are toxic to amphibians, 100 red-backed salamanders (Plethodon cinereus) were exposed to either 1500, 800, 200, 75 or 0 mg 2,4-DNT/kg soil for 28 days and evaluated for indicators of toxicity. Concentrations of 2,4-DNT were less than targets and varied with time. Most salamanders exposed to concentrations exceeding 1050 mg/kg died or were moribund within the first week. Salamanders exposed to soil concentrations exceeding 345 mg/kg lost >6% of their body mass though no mortality occurred. Overt effects included a reduction in feed consumption and an increase in bucco-pharyngeal oscillations in salamanders. These results suggest that only high soil concentrations of 2,4-DNT have the potential to cause overtly toxic effects in terrestrial salamanders. - Exposures of 2,4-dinitrotoluene in soil exceeding 345 mg/kg causes toxicity to P. cinereus

[en] Landscape characteristics and access type may exert a strong influence on groundwater quality, thereby adversely affecting human health. The aim of this study was to evaluate groundwater quality in springs and shallow wells of rural areas in terms of hydrochemical properties and different water quality indexes by comparing distinct microregions, groundwater sources (springs and shallow wells), and surrounding properties (e.g., presence of livestock, presence of fences, other protection structures, and restrictions on human access). Physical–chemical, chemical, and microbiological parameters were analyzed over 12 months between 2013 and 2014 in the Marombas River basin located in Santa Catarina State, Southern Brazil. Land use and landforms played an important role in controlling groundwater hydrochemistry in rural areas. The type of groundwater source (springs or shallow wells) did not influence water quality, although springs tended to be more susceptible to bacterial contamination, especially in areas with livestock in the surroundings. Chemical relationships allowed classifying these waters as predominantly calcium–magnesium bicarbonate or calcium–magnesium chloride, the latter being the most common in the study region. Groundwater was acidic, with low dissolved salt content, large range in dissolved oxygen concentrations, low turbidity, and presence of fecal coliforms in most studied months. Results indicate that water might be affected by septic tank leakage associated with wastewater and output from agricultural fields, given precarious installation and conservation conditions of springs and shallow wells in this region. When comparing the results with drinking water standards established by Brazilian Health Ministry, 70% of springs and shallow wells were found not suitable for consumption, especially due to organoleptic properties, high aluminum concentrations, and presence of fecal coliforms. Water quality indexes demonstrated that groundwater is suitable for agricultural uses (irrigation, livestock, and fish farming) and drinking, if treated via disinfection, filtering, or boiling before consumption. Nevertheless, use of this water resource, especially without any treatment—as is currently common among users—raises concerns related to its susceptibility to spread waterborne diseases, and lack of information among water users regarding procedures to improve water quality.