The effect of humic acid in chronic deoxynivalenol intoxication

Environmental Science and Pollution Research - The most common mycotoxin found in European foodstuffs, especially unprocessed grains, is deoxynivalenol (DON), which inhibits proteosynthesis and...     

Assessment of the Streptomyces-plant system to mitigate the impact of Cr(VI) and lindane in experimental soils

Environmental Science and Pollution Research - Phytoremediation techniques have been proposed as ecological methods to clean up contaminated sites. This study is aimed to evaluate the effect of the...     

Surface lipids of queen-laid eggs do not regulate queen production in a fission-performing ant

In animal societies, most collective and individual decision making depends on the presence of reproductive individuals. The efficient transmission of information among reproductive and non-reproductive individuals is therefore a determinant of colony organization. In social insects, the presence of a queen modulates multiple colonial activities. In many species, it negatively affects worker reproduction and the development of diploid larvae into future queens. The queen mostly signals her presence through pheromone emission, but the means by which these chemicals are distributed in the colony are still unclear. In several ant species, queen-laid eggs are the vehicle of the queen signal. The aim of this study was to investigate whether queen-laid eggs of the ant Aphaenogaster senilis possess queen-specific cuticular hydrocarbons and/or Dufour or poison gland compounds, and whether the presence of eggs inhibited larval development into queens. Our results show that the queen- and worker-laid eggs shared cuticular and Dufour hydrocarbons with the adults; however, their poison gland compounds were not similar. Queen-laid eggs had more dimethylalkanes and possessed a queen-specific mixture of cuticular hydrocarbons composed of 3,11?+?3,9?+?3,7-dimethylnonacosane, in higher proportions than did worker-laid eggs. Even though the queen-laid eggs were biochemically similar to the queen, their addition to experimentally queenless groups did not prevent the development of new queens. More studies are needed on the means by which queen ant pheromones are transmitted in the colony, and how these mechanisms correlates with life history traits.     

ISO 14001 certification and financial performance: selection-effect versus treatment-effect

The paper explores the bi-directional relationship between ISO 14001 certification and financial performance with the aim of shedding light on whether better performance is due to the beneficial effects of ISO 14001 or due to selection-effects where better performance precedes accreditation. The study uses a five year longitudinal analysis to compare the financial performance of firms in Spain before and after certification. The results of a multivariate panel data analysis find that firms with better than average performance have a greater propensity to pursue accreditation but there is no evidence that improvements in performance follow certification. This suggests that the inference that environmental variables cause improved financial performance may be unwise in research studies that can only measure association.     

Presence, biotransformation and effects of sulfophenylcarboxylic acids in the benthic fish Solea senegalensis

The presence of linear alkylbenzene sulfonates (LAS) and their degradation intermediates, sulfophenylcarboxylic acids (SPCs), with concentrations up to 100 ppb has been found in surface waters taken from the estuary of the river Guadalete (Cádiz, SW of Spain). Higher concentrations were found at the sampling site located adjacent to the discharge outlet of a wastewater treatment plant (WWTP). The concentrations decreased downstream to a few ppb as a result of dilution, sorption, and degradation processes, which were taking place along the estuary. Once the presence of both xenobiotics was confirmed in the environment, an in vivo assay was conducted to study their biotransformation and effects in the benthic fish Solea senegalensis. A flow-through system was employed, consisting of an exposure phase (120 h) with environmental levels of the surfactant (200, 500 and 800 microg/L of 2?C(10)LAS), followed by a depuration stage (72 h). The generation of SPCs has been quantified during these phases in both water and fish, with LAS biotransformation shown in all cases. The antioxidant enzymes catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), the phase II enzyme glutathione S-transferase (GST), and the phase III acid and alkaline phosphatases (AcP, ALP) were also estimated and utilized as biomarkers.     

A new Dasypodini armadillo (Xenarthra: Cingulata) from San Gregorio Formation,Pliocene of Venezuela: affinities and biogeographic interpretations

We describe Pliodasypus vergelianus gen. et sp. nov., a Dasypodini armadillo from the middle Pliocene of Venezuela (Vergel Member, San Gregorio Formation). Although scarce, the remains are remarkable because of their geochronologic proximity to the main phase of Great American Biotic Interchange (GABI). The cladistic analysis conducted reveals that Pliodasypus groups with Dasypus and both are sister taxa of Propraopus, whereas Anadasypus is at a basal position. With respect to the records of tribe Dasypodini, after its oldest representative (Anadasypus, middle and late Miocene), the chronologically subsequent form is Pl. vergelianus (middle Pliocene), followed by Dasypus bellus in higher northern latitudes (late Pliocene), and then by widespread occurrences in the Pleistocene of North America (D. bellus) and South America (Propraopus, Dasypus punctatus, and Dasypus novemcinctus). Thus, we infer that Dasypus differentiated in the late Pliocene at low latitudes in the northern South America. It leads to two alternative hypotheses of dispersal: (a) some early Dasypus remained cryptically in South America until the Pleistocene, whereas others dispersed to North America between 2.2 and 2.7 Ma, or (b) they dispersed to North America subsequently to the emersion of the Panamanian isthmus and D. bellus differentiated there; later, during the Pleistocene, D. bellus entered South America and experienced speciation. The same process of re-ingression has been proposed to other xenarthrans, breaking with the traditional assumption that the GABI was unidirectional.     

Distribution and dietary regulation of an associated facultative Rhizobiales-related bacterium in the omnivorous giant tropical ant,Paraponera clavata

We document a facultative Bartonella-like Rhizobiales bacterium in the giant tropical ant, Paraponera clavata. In a lowland tropical rainforest in Costa Rica, 59 colonies were assayed for the prevalence of the Bartonella-like bacterium (BLB), 14 of which were positive. We addressed three questions: First, how does the prevalence of BLB within colonies vary with environmental conditions? Second, how does diet affect the prevalence of BLB in P. clavata? Third, how does the distribution of BLB among colonies reflect ambient differences in food resources and foraging habits? A variety of environmental variables that may be predictive of the presence of BLB were measured, and diet manipulations were conducted to test whether the prevalence of BLB responded to supplemental carbohydrate or prey. The ambient frequency of BLB is much higher in young secondary forests, but is nearly absent from older secondary forests. The prevalence of BLB inside field colonies increased over the duration of a 2-week carbohydrate supplementation; however, water and prey supplementation did not alter the prevalence of BLB. The diets of the colonies located in young secondary forest, compared to other habitats, have a diet richer in carbohydrates and lower in prey. The abundance of carbohydrate, or the relative lack of N, in a colony’s diet influences the occurrence of the BLB microbe in P. clavata. As experimental diet manipulations can affect the facultative presence of an N-cycling microbe, a consistent diet shift in diet may facilitate the emergence of tighter symbioses.     

Zinc removal from synthetic waters using magnetite/graphene oxide composites

The removal of heavy metals from wastewater has become a global challenge, which demands the continuous study of efficient and low-cost treatment alternatives such as adsorption. In this research, the removal of zinc was evaluated using batch adsorption processes with nonconventional materials such as graphene oxide (GO), magnetite (MG), and their composites (GO:MG), formulated with three weight ratios (2:1, 1:1, and 1:2). Graphene was synthesized by the modified Marcano method, using pencil lead graphite as a precursor. MG and the composites were synthesized by chemical coprecipitation of ferrous sulfate and ferric chloride. The materials were characterized by Raman and Fourier transform infrared spectroscopies, scanning electron microscopy, X-ray diffraction, and the Brunauer–Emmett–Teller method to determine the functional groups, microstructural and morphological characteristics, and specific surface area. Batch adsorption tests were carried out to optimize the adsorbent dose and contact time with zinc solutions of 10 ppm. Zinc adsorption reached equilibrium at 2 h, with an optimal dose between 0.25 and 1.0 g/L. The maximum zinc removal efficiencies/adsorption capacities were 98.6%/165.6, 83.4%/47.6, 83.5%/21.9, 72.8%/19.9, and 82.2%/9.25 mg/g using GO, 2GO:1MG, 1GO:1MG, 1GO:2MG, and MG, respectively. Furthermore, the analysis of the isotherm and adsorption kinetics models determined that the adsorption processes using MG and the composites fit the Sips and pseudo-second-order models.     

Application of life cycle assessment of system solution scenarios for municipal solid waste management in Turkey

Journal of Material Cycles and Waste Management - In this study, an average waste composition was determined using the Provincial Environmental Status Reports of 81 provinces in Turkey for 2019,...