Characteristics of stone moroko population dynamics at different stages of naturalization in lake- and steam-type Dnieper reservoirs

The probable source of stone moroko, Pseudorasbora parva (Temminck & Schlegel, 1846), populations in lake- and stream-type Dnieper reservoirs was revealed. The dynamics and specific growth rates of these populations over 20 years were analyzed. The dynamic phase portrait method was used to determine the timing of stages in the process of invader naturalization and the periods when its populations were in equilibrium. The potential growth rates of P. parva populations in the Kremenchug and Dneprodzerzhinsk reservoirs were estimated.     

Types of narrow-skulled vole (<Emphasis Type="Italic">Lasiopodomys gregalis</Emphasis>) colonies in Northern Kulunda and seasonal dynamics of their demographic composition

Demographic structure and its seasonal dynamics have been studied in colonies of narrow-skulled voles (Lasiopodomys gregalis Pall.) in Northern Kulunda. Three types of colonies have been distinguished: (I) true colonies (large, complex families), (II) simple families (nuclear or incomplete), and (III) all-male colonies. Changes in their sex, age, and functional composition (based on animal migration activity) during the breeding season have been analyzed.     

The city as a refuge for insect pollinators

Research on urban insect pollinators is changing views on the biological value and ecological importance of cities. The abundance and diversity of native bee species in urban landscapes that are absent in nearby rural lands evidence the biological value and ecological importance of cities and have implications for biodiversity conservation. Lagging behind this revised image of the city are urban conservation programs that historically have invested in education and outreach rather than programs designed to achieve high‐priority species conservation results. We synthesized research on urban bee species diversity and abundance to determine how urban conservation could be repositioned to better align with new views on the ecological importance of urban landscapes. Due to insect pollinators’ relatively small functional requirements—habitat range, life cycle, and nesting behavior—relative to larger mammals, we argue that pollinators put high‐priority and high‐impact urban conservation within reach. In a rapidly urbanizing world, transforming how environmental managers view the city can improve citizen engagement and contribute to the development of more sustainable urbanization.     

Recycling polymeric waste from electronic and automotive sectors into value added products

The environmentally sustainable disposal and recycling of ever increasing volumes of electronic waste has become a global waste management issue. The addition of up to 25% polymeric waste PCBs (printed circuit boards) as fillers in polypropylene (PP) composites was partially successful: while the tensile modulus, flexural strength and flexural modulus of composites were enhanced, the tensile and impact strengths were found to decrease. As a lowering of impact strength can significantly limit the application of PP based composites, it is necessary to incorporate impact modifying polymers such as rubbery particles in the mix. We report on a novel investigation on the simultaneous utilization of electronic and automotive rubber waste as fillers in PP composites. These composites were prepared by using 25 wt.% polymeric PCB powder, up to 9% of ethylene propylene rubber (EPR), and PP: balance. The influence of EPR on the structural, thermal, mechanical and rheological properties of PP/PCB/ EPR composites was investigated. While the addition of EPR caused the nucleation of the β crystalline phase of PP, the onset temperature for thermal degradation was found to decrease by 8%. The tensile modulus and strength decreased by 16% and 19%, respectively; and the elongation at break increased by ~71%. The impact strength showed a maximum increase of ~18% at 7 wt.%–9 wt.% EPR content. Various rheological properties were found to be well within the range of processing limits. This novel eco-friendly approach could help utilize significant amounts of polymeric electronic and automotive waste for fabricating valuable polymer composites.

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Bacterial toxicity testing and antibacterial activity of parabens

Parabens are used because of their antimicrobial effects, yet they have multiple adverse effects. The aim of this work was to evaluate the bactericidal activity and bacterial toxicity of the most common parabens: methylparaben, ethylparaben, propylparaben, isopropylparaben, butylparaben, isobutylparaben and phenylparaben. The bactericidal action was evaluated by means of the dilution-neutralization method against Escherichia coli and Staphylococcus aureus, and the biotest of inhibition of growth of E. coli was applied for the bacterial toxicity assay. Bactericidal concentrations were reached only for propylparaben, butylparaben and isobutylparaben. The toxicity study showed methylparaben to be the least toxic, whereas the most toxic one was phenylparaben. It can be concluded that the disinfectant activity of the parabens studied is insignificant against S. aureus and E. coli. Acute toxicity is very low, and the inhibitory effect is weak. Our results provide information about the risk–benefit balance of parabens use.     

Earth-tide-induced fluctuations in the salinity of an inland river,New South Wales,Australia: a short-term study

Wybong Creek discharges salts into the agriculturally and industrially important Hunter River in New South Wales, Australia. Abrupt increases in salinity occur periodically in the mid-Wybong Creek catchment. In order to understand the processes which cause these abrupt increases, changes in surface and groundwater were investigated. It is shown that salinity increases can be attributed to highly discrete groundwater discharge directly into the river from below. Hourly electrical conductivity data measured in the river showed regular, diurnal electrical conductivity fluctuations of up to 350 μS cm^?1. These fluctuations could not be attributed to barometric pressure, temperature, or evapotranspiration. Instead, a similar periodicity in surface water electrical conductivity and groundwater height in nearby groundwater wells was found. Fluctuations were of similar periodicity to the orthotides which cause fluctuations in surface water height and are induced by Earth tides. The geology in the mid-catchment area indicates conditions are optimal for Earth tides to impact groundwater. The reporting of orthotidal changes in water chemistry in this article is believed to be the first of its kind in the scientific literature, with the large fluctuations noted having important implications for water monitoring and management in the catchment. Further research investigating Earth-tide-induced phases of groundwater heights will better constrain the relationships between surface water chemistry and groundwater height.     

DNA and chromosomal damage induced in fish (Anguilla anguilla L.) by aminomethylphosphonic acid (AMPA)—the major environmental breakdown product of glyphosate

The assessment of the direct impact of breakdown products of pesticide components on aquatic wildlife is ecotoxicologically relevant, but frequently disregarded. In this context, the evaluation of the genotoxic hazard posed by aminomethylphosphonic acid (AMPA—the major natural degradation product of glyphosate) to fish emerges as a critical but unexplored issue. Hence, the main goal of the present research was to assess the AMPA genotoxic potential to fish following short-term exposures (1 and 3 days) to environmentally realistic concentrations (11.8 and 23.6 μg L^?1), using the comet and erythrocytic nuclear abnormalities (ENA) assays, as reflecting different levels of damage, i.e. DNA and chromosomal damage, respectively. Overall, the present findings pointed out the genotoxic hazard of AMPA to fish and, subsequently, the importance of including it in future studies concerning the risk assessment of glyphosate-based herbicides in the water systems.     

Permeability of hair to cadmium,copper and lead in five species of terrestrial mammals and implications in biomonitoring

The capacity of mammal hair to absorb toxic metals and its utility in biomonitoring has been broadly studied. Though these metal-binding properties has generally been attributed to the sulphur contained in cysteine, an amino acid that forms part of keratin, there are not many experimental studies that analyze the role of sulphur in the external deposition of potentially toxic metallic elements in order to better understand the potential of hair in biomonitoring and generate better tools for differentiating between internal and external deposition of contaminants. In this study, an experimental analysis is carried out using a scanning electron microscope on hairs of five terrestrial mammal species (Peromyscus furvus, P. maniculatus, Glossophaga soricina, Artibeus jamaicensis and Marmosa mexicana) treated with cadmium, copper and lead salts. We quantified absorbed metals as well as natural elements of the hair by energy dispersive X-ray spectroscopy (EDS) to analyze using simple statistics the role of sulphur in the absorption Cd, Cu and Pb. Given the lack of studies comparing the mechanisms of deposition of metal elements among different orders of Class Mammalia, external morphology was considered to be an important factor in the deposition of metallic particles of Cd, Cu and Pb. Bat species (Glossophaga soricina, Artibeus jamaicensis) showed a high concentration of particles in their scales, however, no between-species differences in metal absorption were observed, and during the exogenous deposition metal particles do not permeate the medulla. These results suggest that the sulphur in hair itself cannot bind metals to hair cuticle and that hair absorption capacity depends on a variety of factors such as aspects of hair morphology.     

Characterization of EVA/PLA Blends When Exposed to Different Environments

EVA/PLA blends compatibilized with EVA-g-PLA grafted copolymers synthesized by reactive extrusion, through transesterification reaction between ethylene-vinyl-acetate (EVA) and polylactide (PLA) using titanium propoxide (Ti(OPr)₄) as catalyst, were characterized when exposed to different environments. Stability to UV radiation was assessed exposing the samples to a Xenon lamp, which simulates the sun UV spectrum and the biodegradability was evaluated by biochemical oxygen demand (BOD) in a closed respirometer. Exposed samples were removed periodically and analyzed by several analytical techniques, such as, FTIR, DSC, rheology and tensile tests. The results obtained evidenced that UV radiation induces structural modifications, which affect substantially rheological and mechanical properties. Moreover, the blend with higher amount of copolymer exhibits lower photo durability and greater biodegradability. From the environmental point of view, these new materials are very promising for application with short lifetime, like packaging.     

Identification and source apportionment of polycyclic aromatic hydrocarbons in ambient air particulate matter of Riyadh, Saudi Arabia

In an effort to assess the occurrence and sources of polycyclic aromatic hydrocarbons (PAHs) in the ambient air of Riyadh, Saudi Arabia, PM₁₀ samples were collected during December 2010. Diagnostic PAH concentration ratios were used as a tool to identify and characterize the PAH sources. The results reflect high PM₁₀ and PAH concentrations (particulate matter (PM)?=?270–1,270 μg/m³). The corresponding average PAH concentrations were in the range of 18?±?8 to 1,003?±?597 ng/m³ and the total concentrations (total PAHs (TPAHs) of 17 compounds) varied from 1,383 to 13,470 ng/m³ with an average of 5,871?±?2,830 ng/m³. The detection and quantification limits were 1–3 and 1–10 ng/ml, respectively, with a recovery range of 42–80 %. The ratio of the sum of the concentrations of the nine major non-alkylated compounds to the total (CPAHs/TPAHs) was 0.87?±?0.10, and other ratios were determined to apportion the PM sources. The PAHs found are characteristic for emissions from traffic with diesel being a predominant source.