Enhanced soil sorption of methidathion using sewage sludge and surfactants

Batch experiments were carried out to examine the partitioning of an organophosphorus insecticide, methidathion, in non-amended agricultural soil and soil amended with urban sewage sludge and/or different types of surfactant. Kinetic data showed that sewage sludge significantly reduced adsorption rate, whereas amendment of the soil with the cationic surfactant tetradecyltrimethylammonium bromide (TDTMA) at 10 x CMC (critical micellar concentration) increased the adsorption rate by a factor of 10. The adsorption isotherms were evaluated using the Freundlich model. The soil adsorption capacity for methidathion was enhanced by amendment with sewage sludge and even more significantly with TDTMA at 10 x CMC or combined with sewage sludge. TDTMA conferred a high hydrophobic character to the soil, enhancing the adsorption capacity of the rather hydrophobic methidathion. The amendment of soil both with sewage sludge and TDTMA combines the increased hydrophobicity with a higher surfactant retention by organic matter, due to an increase in cation exchange capacity, which promotes even more the adsorption capacity for the insecticide. An anionic surfactant, linear alkylbenzene sulfonate, and the non-ionic Tween 80 only induced a slight modification in the kinetics and adsorption of methidathion.     

Vaccination against Taenia solium cysticercosis in underfed rustic pigs of México: roles of age, genetic background and antibody response

Vaccination of pigs of mixed genetic make-up, raised as rustically as done in rural Mexico, resulted in effective protection to experimental challenge against Taenia solium cysticercosis. Maximum protection was achieved if pigs were immunized at 70 days of age. There was large variation of viable parasite load within vaccinated pigs and controls, which is suggestive of significant genetic factors influencing susceptibility, besides immunization. Our results strengthen the advisability of pig vaccination for control of T. solium cysticercosis, since it lowers the number of viable cysticerci capable of transforming into tapeworms.     

Silicon‐induced cadmium resistance in rice (Oryza sativa)

Silicon (Si)‐induced cadmium (Cd) tolerance in rice (Oryza sativa L.) was investigated by analyzing Cd uptake, growth, and physiological parameters. Silicon treatments (0.0, 0.2, or 0.6 mM) were added to 6 d–old seedlings, and Cd treatments (0.0 or 5.0 μM) were added to 20 d–old seedlings. Parameters determined included: maximum net CO₂ assimilation (A_max), stomatal conductance (g_smax), and transpiration (E_max) rates at varying intercellular CO₂ concentrations (C_i). Also measured were chlorophyll fluorescence, growth, and Cd‐uptake parameters. Results showed a Si‐induced inhibition of Cd uptake. However, 0.2 mM or 0.6 mM Si treatment concentrations did not differentially inhibit Cd uptake or differentially alleviate Cd‐induced growth inhibition, despite a significant increase in tissue Si concentration due to 0.6 mM Si treatment compared to 0.2 mM Si treatment. Additionally, photosynthesis and chlorophyll‐fluorescence analysis showed that treatment with Cd significantly inhibited photosynthetic efficiency. Interestingly, the addition of 0.2 mM Si, more so than the addition of 0.6 mM Si, significantly alleviated the inhibitory effects of Cd toxicity on photosynthesis and chlorophyll‐fluorescence parameters. Our results suggest that 0.2 mM Si could be close to an optimum Si‐dose requirement for the alleviation of toxicity symptoms mediated by moderate (5 μM) Cd exposure.     

Short‐term effect of the inoculation of probiotics in mature bioflocs: Water quality parameters and abundance of heterotrophic and ammonia‐oxidizing bacteria

The aim of this study was to evaluate the short‐term effect of probiotic inoculation on the abundance of heterotrophic and ammonia‐oxidizing bacteria in mature biofloc, as well as on total suspended solids (TSS), chlorophyll‐a and nitrogenous compounds in water. A completely randomized design consisting of five treatments (three commercial probiotics, one native consortia and one control) was performed. At the beginning of the experiment (day 1), each treatment was inoculated with the respective probiotic: PondPlus^® (PP), Efinol^® PT (EF) and Epicin^® ponds (EP), native consortia UE, whereas the control was not inoculated. Water parameters and bacterial abundance were evaluated at 0, 2, 4, 6 and 8 days. The addition of probiotics, either native or commercial, did not show any significant effect on the TSS, Chl‐a and colony‐forming unit (CFU) of heterotrophic bacteria when they were added to the systems containing mature biofloc. A significant increase in ammonium oxidizing bacteria was registered with the probiotics PP and EP, although the levels of total ammonia nitrogen, NO₃‐N and NO₂‐N were statistically similar among all treatments. Modifications on most of the parameters measured were associated with the factor of time, rather than the inclusion of probiotics. Results suggest that the bacterial conglomerates in mature stage contain well‐established bacterial communities that are difficult to be affected by the addition of probiotics.     

Toxicity and repellence of aqueous and ethanolic extracts from Schinus molle on elm leaf beetle Xanthogaleruca luteola

Extracts of leaves of Schinus molle Rev L. (Anacardiaceae) obtained with water or ethanol as solvents were evaluated in the laboratory for their insecticidal effect on adults of the elm leaf beetle, Xanthogaleruca luteola Müller (Coleoptera: Chrysomelidae), at 2.5, 3.0, 4.3, and 5.6% w/v for the aqueous extracts and, 2.0, 2.5, 3.5, 4.3, and 4.7% w/v for the ethanol extracts. The extracts were applied onto leaves of elm trees (Ulmus sp., Ulmaceae) to observe the feeding of adults, and later their effectiveness and to obtain the LC₅₀. Both extracts were effective and caused mortalities greater than 97% with the ethanol extract at the two highest concentrations (4.3 and 4.7% w/v), and near 27% with water at 4.3 and 5.6% w/v. The LC₅₀ of the ethanol extract, calculated through Probit analysis, was 1.88% w/v on the 2nd day, lower than the LC₅₀ of 8.52% w/v on the 4^th day achieved by the aqueous extract. Additionally, the antifeeding effect of both extracts on adults was determined. The aqueous extract inhibited feeding completely (100%), whereas the ethanol extract did not cause any antifeeding effect.     

<Emphasis Type="Italic">Lupinus luteus</Emphasis>, a new host of <Emphasis Type="Italic">Phytophthora cinnamomi</Emphasis> in Spanish oak-rangeland ecosystems

Phytophthora cinnamomi is an aggressive pathogen on Lupinus luteus (yellow lupin), causing root rot, wilting and death of this crop, common in oak-rangeland ecosystems ('dehesas') in south-western Spain. The oomycete, the main cause of Quercus decline in the region, was isolated from roots of wilted lupins in the field. Artificial inoculations on four cultivars of L. luteus reproduced the symptoms of the disease, both in pre- and post-emergence stages, recovering the pathogen from necrotic roots. These results suggest the potential of yellow lupin as inoculum reservoir for the infection of Quercus roots. This is the first report of P. cinnamomi as root pathogen of L. luteus.     

Evolution of Chemical Characteristics of Technosols in an Afforested Coal Mine Dump over a 20‐year Period

Coal mining in areas containing pyritic materials frequently leads to a remarkable impact on the environment because of sulphide oxidation. We studied the evolution of chemical characteristics of Technosols derived from sterile materials, in a lignite mine located in As Pontes (northwest Spain), over a 20‐year period. Three plots, which had different management practices, were selected. The mine spoil was deposited randomly in two of the plots (CSP with low S concentration and CSA with high S concentration), while it was selectively managed in the other one (P206). Twenty years after the first sampling, CSA continued to show the highest acidity (pH_water 3∙7–3∙9), whereas the lowest acidity was that of P206 (pH_water 5∙0). Regarding the surface layer, C increased 1∙1% in P206, 0∙3% in CSP and 0∙2% in CSA. Nitrogen increased 1% in P206. The C/N ratio increased in all plots. Phosphorus, Ca, Mg, K and effective cation exchange capacity decreased in 2002 and experienced a slight increase in 2012. Exchangeable Al and Al saturation increased in CSP and P206 and decreased in CSA. Electric conductivity levels of Ca, Mg, Na, Al and SO₄²⁻ concentrations decreased in the soil solution in all plots during the 20‐year period. Twenty years after the first monitoring, the plots that were built based on selective management of the mine spoil showed lower acidity and acidity‐derived consequences. These facts confirm the necessity of an appropriate selection of sterile materials, avoiding the placement of pyrite‐rich spoils on the surface or near‐surface zones, which is essential to facilitate proper restoration of this kind of dumping areas. Copyright © 2015 John Wiley & Sons, Ltd.     

The Interdependence of Deformational and Thermal Processes in Mountain Belts

Crustal temperatures within collisional orogens are anomalously high compared with temperatures at comparable depths in stable continents, which is evidence of thermal processes that are fundamental to orogenesis. These temperatures can be explained by the redistribution of crust enriched in heat-producing elements through the accretion of crust from the down-going plate to the upper plate and surface erosion. With the use of geologically reasonable rates, the model results predict high temperatures (over 600°C) and inverted upper-plate geotherms (about 100°C over 20 kilometers) at shallow depths (20 to 40 kilometers) by 25 to 35 million years after collision. This study emphasizes the interdependence of deformational, surficial, and thermal processes.