Arsenic Mining Waste in the Catchment Area of the Madrid Detrital Aquifer (Spain)

In recent years, elevated arsenic concentrations in groundwater used for drinking water supplies have been recognised in the Madrid Tertiary detrital aquifer. Although only natural causes have been suggested as the source of arsenic, this study aims to highlight that the anthropogenic contribution cannot be disregarded. During the sub-catchment??s areas sampling, we found many geographical sites where natural arsenopyrite [FeAsS] originally encapsulated in pegmatite bodies and quartz veins, was artificially outcropped and dumped out, since mining wastes were scattered and exposed to weathering. Several mineral and ground specimens were collected to analyse its mineralogical and chemical composition by X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) spectrometry and by Environmental Scanning Electron Microscope (ESEM). Both, the abundant existence of secondary phases, such as scorodite [FeAsO₄?2H₂O] and jarosite [KFe₃(SO₄)₂(OH)₆], much more soluble than arsenopyrite, and the lixiviation experiments of arsenopyrite in acidic media to simulate acid mine drainage (AMD) conditions, usually found in old mining districts, point to a potential risk of arsenic contamination of surface water bodies, which operate as recharged waters of the aquifer in the studied area. The elemental determination of heavy metals present in ground samples by XRF analyses, reaching up to 1,173 mg kg^?C1 of copper, 347 mg kg^?C1 of lead and 113,702 mg kg^?C1 of arsenic; and the physicochemical and arsenic fractionation studies of soil samples, led us to classify the soil as Spolic Technosol (Toxic). The contamination of the area due to old mining activities could release arsenic to Madrid water supplies; accordingly, additional decontamination studies should be performed.     

A Geochemical and Geophysical Characterization of Sulfide Mine Ponds at the Iberian Pyrite Belt (Spain)

This work presents the results of a geochemical and geophysical characterization of the Monte Romero and La Naya mine ponds, belonging to the Cueva de la Mora and Riotinto mine districts, respectively, based on mineralogical, geochemical and geophysical techniques. In order to obtain a representative environmental characterization, two deposits showing different mineralogies, physico-chemical parameters, chemical compositions of tailings and pond conditions were selected. Monte Romero mine tailings showed an upper level mainly composed of silicates and a deeper level mainly composed of sulfides and barite. The toxic metal content was different in both levels but high enough to exceed the regional legal concentration limits for agricultural soils. An electrical resistivity tomography survey revealed a homogeneous upper unit (3?m thickness), which displayed low resistivity values, corresponding to water-saturated silt and clay materials with an abundance of sulfides which was interpreted as the pond infilling. The La Naya mine pond presented a homogeneous mineralogical composition made up of quartz as the main mineral and chlorite-smectite and jarosite as accessory phases. The absence of sulfide phases and the low contents of metal elements are directly related to the reworking processes of the sludge dumped in this pond. The geophysical survey revealed that the pond infilling did not have a constant thickness, but ranged between 15 and 20?m. An inner groundwater flow in the infilling was recognized. The low resistivity values allowed the presence of acid waters and related subsurface flows to be identified in both mine ponds, but no acid water drainage occurred across their vessels. When compared to the Aznalc??llar tailings spill, the La Naya pond is large enough to release a similar amount of sludge, but of a very low metal content. The Monte Romero sludge displays a similar, potentially toxic metal content to the Aznalc??llar sludge, but its size is significantly smaller.     

Microwave l-band (1730 MHz) accurately estimates the relative water content in poplar leaves. A comparison with a near infrared water index (R1300/R1450)

In this study the estimation of reflectivity at 1730 MHz (l-band), measured with a microwave digital cordless telephony (DCT) patch antenna, is presented as an easy-to-handle and non-destructive new method to assess the relative water content (RWC) of poplar leaves and filter discs at different levels of dehydration. The accuracy of this new method has been contrasted with the R₁₃₀₀/R₁₄₅₀ index, determined by a portable near infrared (NIR) spectrometer. The close correlations found between RWC and the reflectivity at a frequency of 1730 MHz, both for filters and leaves, indicate that microwave determinations are rather independent of the physical properties of the material analysed. On the contrary, the differences found between poplar leaves and leaf filters in the relationships established between RWC and the R₁₃₀₀/R₁₄₅₀ index demonstrate a strong influence of the properties of the material in NIR reflectance measurements, specifically as they relate to changes in leaf thickness during dehydration. It should be noted that the amount of energy received by the leaf for the microwave technique (0.1 mW) was much lower than that received for the measuring of the R₁₃₀₀/R₁₄₅₀ index (2.5 W). Moreover, R-square coefficients were higher for microwaves than for the R₁₃₀₀/R₁₄₅₀ index. The use of a technologically simple, low cost and portable device, based on a microwave DCT patch antenna, could yield a solid support for the development of a commercial apparatus enabling the determination of plant water status under field conditions.     

HPLC-DAD-ESI-MS/MS characterization of pyranoanthocyanins pigments formed in model wine

Formation of wine pyranoanthocyanins in model wine was monitored by HPLC-DAD-ESI-MS/MS, using red grape skin extracts and wine fermentation metabolites (acetaldehyde, pyruvic and acetoacetic acids, and diacetyl) and also hydroxycinnamic acids (p-coumaric, caffeic, ferulic, and sinapic acids). Pyruvic acid and acetaldehyde reacted fast, the first reaching high product yield and the second inducing mainly pigment polymerization. In contrast, acetoacetic acid and diacetyl reacted slowly with poor product yields. Hydroxycinnamic acids progressively reacted without apparent formation of polymeric pigments, the reaction rate and yield increasing as the number of hydroxy/methoxy groups did. Substituent at C-10 strongly affected the visible maximum absorbance wavelength, whereas B-ring substitution pattern or sugar acylation exerted little effect. The 10-methylpyranoanthocyanins formed from acetoacetic acid were also found as side products in the formation of 10-carboxypyranoanthocyanins. Finally, we report for the first time on UV-vis and MS spectral data of 10-acetylpyranoanthocyanins formed from diacetyl, and their occurrence in commercial red wines is suggested.     

Influence of energy supplementation on dietary nitrogen utilization and milk production in cows fed foliage of Leucaena leucocephala

Tropical Animal Health and Production - The aim of the study was to assess the effect of four energy supplements (two highly fermentable; two starch-based carbohydrates) on blood urea nitrogen...     

A New Micromonospora Strain with Antibiotic Activity Isolated from the Microbiome of a Mid-Atlantic Deep-Sea Sponge

To tackle the growing problem of antibiotic resistance, it is essential to identify new bioactive compounds that are effective against resistant microbes and safe to use. Natural products and their derivatives are, and will continue to be, an important source of these molecules. Sea sponges harbour a diverse microbiome that co-exists with the sponge, and these bacterial communities produce a rich array of bioactive metabolites for protection and resource competition. For these reasons, the sponge microbiota constitutes a potential source of clinically relevant natural products. To date, efforts in bioprospecting for these compounds have focused predominantly on sponge specimens isolated from shallow water, with much still to be learned about samples from the deep sea. Here we report the isolation of a new Micromonospora strain, designated 28ISP2-46^T, recovered from the microbiome of a mid-Atlantic deep-sea sponge. Whole-genome sequencing reveals the capacity of this bacterium to produce a diverse array of natural products, including kosinostatin and isoquinocycline B, which exhibit both antibiotic and antitumour properties. Both compounds were isolated from 28ISP2-46^T fermentation broths and were found to be effective against a plethora of multidrug-resistant clinical isolates. This study suggests that the marine production of isoquinocyclines may be more widespread than previously supposed and demonstrates the value of targeting the deep-sea sponge microbiome as a source of novel microbial life with exploitable biosynthetic potential.     

Soil erosion modelling of burned and mulched soils following a Mediterranean forest wildfire

Soil erosion modelling applied to burned forests in different global regions can be unreliable because of a lack of verification data. Here, we evaluated the following three erosion models: (1) Water Erosion Prediction Project (WEPP), (2) Morgan-Morgan-Finney (MMF) and (3) Universal Soil Loss Equation-Modified (USLE-M). Using field plots that were either untreated or mulched with straw, this study involved observations of soil loss at the event scale at a burned pine forest in Central Eastern Spain. The erosion predictions of the three models were analysed for goodness-of-fit. Optimization of the MMF model with a new procedure to estimate the C-factor resulted in a satisfactory erosion prediction capacity in burned plots with or without the mulching treatment. The WEPP model underestimated erosion in the unburned areas and largely overestimated the soil loss in burned areas. The accuracy of soil loss estimation by the USLE-M model was also poor. Calibration of the curve numbers and C-factors did not improve the USLE-M model estimation. Therefore, we conclude that an optimized MMF model was the most accurate way to estimate soil loss and recommend this approach for in Mediterranean burned forests with or without postfire mulching. This study gives land managers insight about the choice of the most suitable model for erosion predictions in burned forests.     

Prognosis of iron chlorosis in apple trees by floral analysis

In populations of apple trees (Malus pumila Mill) affected by iron (Fe) chlorosis, the floral analyses permit to establish relationships between the Fe concentration in flowers and the chlorophyll content in leaves at 60 and 120 days after full bloom. The relationships between both parameters were highly significant with correlation coefficients of 0.603*** and 0.872***, respectively. As from previous research with peach trees, these high correlations permitted us to predict at a very early stage, the appearance of the Fe deficiency and its intensity. In our experimental conditions, the first visual symptoms of the Fe chlorosis appear in apple leaves with floral Fe concentrations below 310 ppm in dry matter.     

Coniferous afforestation increases soil carbon in maritime sand dunes

Afforestation of grasslands can increase C sequestration and provide additional economic and environmental benefits. Pine plantations, however, have often been found to deplete soil organic C and trigger detrimental effects on soils. We examined soil characteristics under a 45-year-old Pinus radiata stand and under adjacent grassland on maritime dunes in temperate Argentina. Soil under the pine plantation had greater soil organic C (+93%), total N (+55%) and available P (+100%) concentrations than under grassland. Carbon was stored under the pinestand at an estimated mean accretion rate of 0.64 Mg ha^?1 y^?1. At 0- to 25-cm depth, soil C amounted to 61 Mg ha^?1 under pine and 27 Mg ha^?1 under grassland. Soil C accumulated more on dune slopes (35 Mg ha^?1 y^?1) than on ridges(29 Mg ha^?1 y^?1) and bottoms (12 Mg ha^?1 y^?1). Compared with the grassland, soil acidity, cation-exchange capacity, base losses (K > Ca = Mg) and C/N ratio increased under pine. Spatial heterogeneity in soil characteristics was greater under pine than under grassland. Such variability was non-systematic and did not support the ‘single-tree influence circle’ concept. Afforestation increased C in soil, forest floor and tree biomass in dunes with ustic climate regime.     

Colored plastic mulches affect soil temperature and tuber production of potato

Abstract

The main crops on which plastic mulch is widely used in Mexico include tomato, bell pepper, eggplant, melons, watermelons, and strawberry; however, very little research has been performed on potato. One of the main benefits associated with plastic mulching is the modification of the microclimate around the plant. To obtain a positive microclimate modification studies are required to understand how plastic mulch affects growth and yield of a given species. Previous field research assessing the response to colored plastic mulching in potato shows no consistent results on yield, maybe because it has been performed under different geographical latitudes. Potato in Mexico is conventionally cultivated on bare soil combined with various irrigation systems. The objective of the present study was to examine the effect of colored plastic mulches on soil temperature, growth, yield and photosynthetic response of potato plants. The experiment was conducted in Northeast Mexico and the treatments included were: black plastic mulch (BPM); white-on-black plastic mulch (W/B), silver-on-black (SPM), aluminum-on-black plastic mulch (APM) and a control that consisted of bare soil cultivated plants. Treatments were arranged in a randomized complete block design with four replications. Results suggest that average daily mean soil temperature was linearly and negatively correlated with total yield and yield of first-quality tubers. Total yield and yield of first-quality tubers of plants mulched with W/B, SPM and APM was significantly higher (p≤0.05) than those of control plants. Leaf area and shoot dry weight were increased when soil temperatures were higher due to the effect of radiation transmission to the soil, however, this decrease was associated with a decrease in tuber production. The results of our study indicate that plants grown under BPM, which induced the highest soil temperature, showed marginal difference in yield compared with control plants, suggesting that colored plastic mulches have a positive effect on yield through decreased rise in soil temperature.