The presence of vanadium in groundwater of southeastern extreme the pampean region Argentina Relationship with other chemical elements

Changes in the quality of groundwater resources are related to the presence and concentration of contaminants, especially trace elements such as arsenic, boron, fluoride and vanadium. Vanadium is a rare element naturally abundant, generally found in combination with other elements. Vanadium pentoxide is known to have aneugenic effects. Thus, a study was carried out to assess the presence of vanadium in the groundwater of the southeastern pampean region of Argentina, which constitutes the main water supply for the local population. Statistical and correlational analyses were applied to identify possible interrelationships between vanadium and another chemical elements. Vanadium was found in all groundwater samples. The minimum and maximum vanadium concentrations found were 0.05 mg/l and 2.47 mg/l, respectively. Vanadium is significantly correlated with other trace elements such as arsenic, fluoride and boron. The interrelationship between vanadium and the presence of volcanic glass in sediments is not significant as expected.     

A Comparative Study Between Technological Properties of Cashew Tree Gum and Arabic Gum

Arabic gum (AG) is the most common emulsifier used for beverage emulsions. Cashew tree gum (CG) is a biological macromolecule that has been proposed as a substitute for the AG, although their technological properties comparison is still necessary. The aim of this study was to evaluate an isolation method for CG, and then evaluate CG technological properties in comparison to AG. The CG isolation methodology was improved using a small solvent amount. CG zeta-potential ranged from +8.0 mV (pH 2) to ?9.7 mV (pH 5), while the electric charge in solution of AG ranged from ?2.7 mV (pH 2) to ?28.6 mV (pH 6). As compared to AG, the CG showed a 50 % higher swelling, a 36 % lower oil absorption capacity, a slightly lower (4–8 %) solubility and lower consistency. CG is a feasible polyelectrolyte, promotes lower consistency solutions, and exhibits good swelling property.     

Detection of human-induced environmental disturbances in a show cave

Purpose  

We investigated the effects of human-induced disruption in a subterranean stable environment containing valuable Palaeolithic paintings and engravings (Ardales Cave, Southern Spain) using a double analytical approach.     

Assessment of exposure to DDT and metabolites after indoor residual spraying through the analysis of thatch material from rural African dwellings

Introduction  

We report on the analysis of 4,4′-dichlorodiphenyltrichloroethane (4,4′-DDT) and its metabolites in thatch and branch samples constituting the wall materials of dwellings from South African subtropical areas. This approach was used to assess the exposure to DDT in the residents of the dwellings after indoor residual spraying (IRS) following recommended sanitation practices against malaria vectors.     

Chemosensory discrimination of familiar and unfamiliar conspecifics by lizards: implications of field spatial relationships between males

The ability of territorial lizards to discriminate between scents of neighbors and non-neighbors might contribute to decreasing the costs of aggressive interactions. To test this hypothesis, we conducted a field study to analyze the spatial relationships between male Iberian rock-lizards, Lacerta monticola. We then used the same individuals in a laboratory experiment to test whether male lizards can use chemical cues to discriminate between familiar conspecific males (those whose home ranges overlapped) and unfamiliar conspecific males (those whose home ranges did not overlap, and whose home range centers were at least 50 m apart). Differences in tongue-flick rates in the presence of chemical cues suggested that male L. monticola discriminated between odors of familiar and unfamiliar males. The behavioral responses were also dependent on relative differences in body size between the responding male and the unfamiliar male that donated the scent: There was a significant negative correlation between tongue-flick rates emitted in cages of unfamiliar males and the body size differences between males. In contrast, when the donor of the scent was a familiar male, the tongue-flick rate was not dependent on body size differences. These results are compatible with individual discrimination through chemical cues in male L. monticola.     

Prediction models of CO, SPM and SO2 concentrations in the Campo de Gibraltar Region, Spain: a multiple comparison strategy

The 'Campo de Gibraltar' region is a very industrialized area where very few air pollution studies have been carried out. Up to date, no model has been developed in order to predict air pollutant levels in the different towns spread in the region. Carbon monoxide (CO), Sulphur dioxide (SO(2)) and suspended particulate matter (SPM) series have been investigated (years 1999-2000-2001). Multilayer perceptron models (MLPs) with backpropagation learning rule have been used. A resampling strategy with two-fold crossvalidation allowed the statistical comparison of the different models considered in this study. Artificial neural networks (ANN) models were compared with Persistence and ARIMA models and also with models based on standard Multiple Linear Regression (MLR) over test sets with data that had not been used in the training stage. The models based on ANNs showed better capability of generalization than those based on MLR. The designed procedure of random resampling permits an adequate and robust multiple comparison of the tested models. Principal component analysis (PCA) is used to reduce the dimensionality of data and to transform exogenous variables into significant and independent components. Short-term predictions were better than medium-term predictions in the case of CO and SO(2) series. Conversely, medium-term predictions were better in the case of SPM concentrations. The predictions are significantly promising (e.g., d (SPM 24-ahead) = 0.906, d (CO 1-ahead) = 0.891, d (SO2 1-ahead) = 0.851).     

Goose barnacle Pollicipes pollicipes as biomonitor of metal contamination in the northwest coast of Portugal

The main objective of this work was to assess the potential use of goose barnacle Pollicipes pollicipes as biomonitor of metal contamination in northwest (NW) coast of Portugal. The concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Zn were determined in coastal seawaters and tissues of P. pollicipes, which allowed establishing correlations between metals in coastal seawaters and P. pollicipes and calculating metal bioaccumulation factors (BAFs). The results of this study showed that P. pollicipes soft tissues can be used for monitoring metal contamination in these coastal seawaters: (1) there were significant correlations (p??0.05); (2) soft tissues were sensitive to spatial variations of metal bioavailabilities and their concentrations ranged 0.70-2.22?mg?Cd?kg(-1), 0.49-1.40?mg?Cr?kg(-1), 1.37-2.07?mg?Ni?kg(-1), 2.4-3.3?mg?Cu?kg(-1), 5-59?mg?Mn?kg(-1), 134-578?mg?Fe?kg(-1)and 728-1,854?mg?Zn?kg(-1); (3) mean logarithmic bioaccumulation factors (log BAF) of Fe, Cd and Zn were higher, 5.57, 5.47 and 4.41, respectively, than mean log BAFs of Cr, Mn, Cu and Ni, 4.18, 4.14, 3.98 and 3.51, respectively. In contrary, P. pollicipes shell plates were not considered ideal material to monitor metal bioavailabilities in these coastal seawaters. Regarding the very high concentrations of Zn obtained in the coastal seawaters and P. pollicipes soft tissues, the NW coast of Portugal should be classified as "Class III/IV - Remarkably/Highly Polluted".     

The influence of the operational environment on the efficiency of water utilities

Adjusting for the operational environment in studies of performance measurement is very important, otherwise the analysis may lead to unrealistic scores, especially when its influence on costs is high, such as in the water utilities. In this paper, we study the influence of exogenous variables on the water utilities performance by applying conditional efficiency measures based on the order-m method and its probabilistic formulation. We use a sample of 66 water utilities operating between 2002 and 2008, representing about 70% of the Portuguese population. Our research suggests that inefficiency of Portuguese water utilities is substantial for some utilities: several exogenous variables might influence it considerably. For example, regulation has a positive influence on efficiency but when drinking water supply and wastewater services are provided by the same utility or when the wholesale and retail activities are provided together, the performance is lower. The effect of ownership is inconclusive and the variables residential customers, water source, peak factor, and density of customers have a mixed influence on performance which varies according to their scores.     

Investing in fertilizer–mining companies in times of food scarcity

The primary goal of the paper is to show the validity of investing capital in fertilizer–mining companies, both from a market return perspective for individual or institutional investors, or from a hedging standpoint for insurance companies and other economic actors exposed to inflation risk and high agricultural commodity prices. After providing some elements on the fertilizer market and describing the joint dynamics of corn, wheat and fertilizer prices over the last decade, we analyze an exhaustive sample of listed fertilizer producing companies over the years January 2004–December 2012. We show that their shares generated quite good returns over the whole period and extremely high ones during the years January 2004–December 2007, both in absolute terms and compared to their betas. We also exhibit that these returns display higher sensitivities to major agricultural indexes than to the World Bank Fertilizer Index, making the hedging argument quite compelling.     

Searching for Networks: Ecological Connectivity for Amphibians Under Climate Change

Environmental Management - Ecological connectivity depends on key elements within the landscape, which can support ecological fluxes, species richness and long-term viability of a biological...