Isolation and identification of intermediates from biodegradation of low chlorinated biphenyls (Delor-103)

Microorganism Pseudomonas species P2 metabolizes polychlorinated biphenyls (PCBs) and biphenyl, producing the whole spectrum of intermediates, among them coloured intermediates, which are suitable for the monitoring of PCBs degradation by optical sensors. Knowledge of chemical structures and conditions of development of colour metabolites is necessary for application of optical analytical methods. The main goal of this work was the isolation and identification of intermediates from the biodegradation of the mixture of low chlorinated biphenyls (Delor-103), which is based on the solid phase extraction (SPE) of the whole mixture using LiChrolut EN cartridges, then silylation of the extract as one way to the identification of one part of intermediates by GC-MS, and acetylation of the extract as a way for the further concentration and analysis of more polar chlorobiphenylols and chlorobiphenyldiols. The combination of SPE and following acetylation allows to obtain chlorobiphenylols and chlorobiphenyldiols as an almost pure fraction. The acetylation method could be also used instead SPE procedure with the same final concentration effect. Using the simulation mass spectrometry program, two new compounds, dihydrodihydroxytrichloro- and tetrahydrodihydroxytrichlorobiphenyl, as silylderivatives, were identified.     

Photoinduced toxicity of fluoranthene on germination and early development of plant seedling

The influence of light on phytotoxicity of increased concentration (2, 5, 10 mg/l) of intact fluoranthene (FLT) and photomodified fluoranthene (phFLT) diluted in experimental solutions was investigated. The germination rate of lettuce (Lactuca sativa L.), onion (Allium cepa L.) and tomato (Lycopersicum esculentum L.) seeds and some parameters of seedlings primary growth of these plant species were used as laboratory indicators of phytotoxicity. Among them a length of root and shoot, their dry weight and a content of photosynthetic pigments in shoot were measured. The results demonstrated that the higher concentration (5 and 10 mg/l) of FLT and especially of phFLT significantly inhibited the germination rate of seeds and the length of root and shoot seedlings of all plant species. Decreased production of biomass expressed by dry weight of root and shoot was found in lettuce seedlings under the inhibitory effect of FLT and phFLT. An increased concentration of FLT and phFLT did not exhibit an unambiguous effect on the content of photosynthetic pigments in shoot of experimental plants. Only the highest concentration (10 mg/l) of FLT significantly increased content of chlorophylls a and b in lettuce, onion and tomato plants and content of carotenoids in lettuce and onion. Light intensified a significant inhibitory effect of phFLT in the most testified parameters of germination and seedling growth.     

Environmental risk assessment of metals contaminated soils at silvermines abandoned mine site,Co Tipperary,Ireland

A centuries long history of mining and mineral processing has resulted in elevated Cd, Pb and Zn soil concentrations in the vicinity of the Silvermines abandoned mine site (AMS), Co. Tipperary, Ireland. A process for preliminary evaluation of environmental risk was developed and implemented. Potential pathways of metal compound transport and deposition were mapped and used to optimise the subsequent site investigation. Elevated soil metals are shown to be predominantly in areas where metal deposition in soil is associated with water related pathways (surface runoff, seasonal groundwater seepage and floodplains). Extensive areas of soil in the surrounding district are classified as contaminated on the basis of Cd, Pb and Zn concentrations, both total and potential bioavailable (EDTA-extractable). The most affected areas, with metal concentrations in soil comparable with that within the AMS, were floodplains located 2–3 km downstream from the site. Assessment of the sequential effects on grass and grazing animals indicates that Pb poses the greatest risk due to its high toxicity and high concentrations in soil (more than 10 000 mg kg^–1). Within floodplain areas grazing cattle may intake a lethal dose of Pb. On the basis of the investigation an approach to risk assessment was developed which allowed quantified assessment of the risks related to individual metals, areas of contamination and contamination targets.     

Transformation of lead compounds in the soil-plant system under the influence of Bacillus and Azotobacter rhizobacteria

ABSTRACT

The study was aimed at the migration and transformation of lead compounds in the rhizosphere, its accumulation in plants under the influence of the rhizosphere bacteria. For experiment, soil samples of the technogenous ecosystem contaminated differently by lead have been selected for plant growing. The samples were subdivided into control soil and the soil, inoculated by Azotobacter and Bacillus rhizobacteria. Lead concentrations have been analysed in easily exchangeable, carbonate, organic and Fe hydroxide-associated fractions as well in chelate forms and fulvic and humic acids. In soils, inoculated by rhizobacteria, there is an increased mobilisation of lead due to its decrease in humic acids and increase in fulvic acids. On technogenic soil, rhizobacteria initiate the immobilisation of Fe-hydroxide-bound, chelate-bound lead in the rhizosphere as well as lead occurring in roots. As a results, there is a decreased lead uptake by upper parts of plants. There is also a correlation between increasing soil alkalinity and increasing Pb accumulation in the roots of plants. The results of the experiment helped to understand more about the mechanisms of Pb compound behaviour under the influence of rhizobacteria that can be used for developing biotechnologies related to soil bioremediation and crop production.     

Uterine cavity lavage: Adding fish to conventional cytogenetics for embryonic sexing and diagnosing common chromosomal aberrations

This study was undertaken to examine the efficacy for early prenatal diagnosis of uterine cavity lavage at the level of the internal os and to assess the rate of maternal contamination. In phase I, uterine cavity lavage was performed in 38 women scheduled for pregnancy termination between 6 and 12 weeks. In addition to short- and long-term cultures, one-colour FISH (fluorescence in situ hybridization) with Y and X probes was used for fetal sexing. Two-colour FISH was used in all known male fetuses for the assessment of maternal contamination. In phase II, lavage was performed on 16 women. Fetal sex was diagnosed with direct labelled X and Y probes and common numerical chromosomal aberration was attempted with 18 and 21 direct labelled probes. Fetal sexing was successful in all cases in phases I and II. Out of 34 patients in which tissue was obtained, only FISH was done in six. Long-term cell cultures were successful in the other 28 cases, but complete karyotyping in 19 (56 per cent). No chromosomal aberration was found with the direct labelled probes 18 and 21 in FISH. Maternal contamination was assessed to be 5–10 per cent. This simple and easy-to-master technique is very effective in obtaining fetal cells early in pregnancy for genetic diagnosis, especially by FISH. However, the safety of the procedure must be tested in ongoing pregnancies.     

Navigating uneven terrain: The roles of political skill and LMX differentiation in prediction of work relationship quality and work outcomes

Drawing from social/political influence, leader–member exchange (LMX), and social comparison theories, the present two‐study investigation examines three levels of LMX differentiation (i.e., individual‐level, meso‐level, and group‐level LMX differentiation) and further tests a model of the joint effects of political skill and LMX differentiation on LMX, relative LMX, and employee work outcomes. In Study 1, we used data from 231 employees and found support for the interactive effect of political skill and individual perceptions of LMX differentiation on LMX quality. We also found partial support for the moderating role of individual‐level LMX differentiation on the indirect effects of political skill on self‐rated task performance and job satisfaction via LMX. In Study 2, we used data from 185 supervisor–subordinate dyads and examined both meso‐level and group‐level LMX differentiation via a multilevel moderated mediation model. Results supported the moderating role of group‐level LMX differentiation and group mean LMX on the indirect effects of political skill on supervisor‐rated task performance and contextual performance/citizenship behavior as well as job satisfaction via relative LMX. Overall, the results suggest that politically skilled employees reap the benefits of LMX differentiation, as they enjoy higher absolute LMX and relative (i.e., to their peers) LMX quality. Copyright © 2016 John Wiley & Sons, Ltd.     

Using electrical resistivity tomography to assess the effectiveness of managed aquifer recharge in a salinized coastal aquifer

Over 40 years, the detrital aquifer of the Plana de Castellón (Spanish Mediterranean coast) has been subjected to seawater intrusion because of long dry periods combined with intensive groundwater exploitation. Against this backdrop, a managed artificial recharge (MAR) scheme was implemented to improve the groundwater quality. The large difference between the electrical conductivity (EC) of the ambient groundwater (brackish water due to marine intrusion) and the recharge water (freshwater) meant that there was a strong contrast between the resistivities of the brackish water saturated zone and the freshwater saturated zone. Electrical resistivity tomography (ERT) can be used for surveying similar settings to evaluate the effectiveness of artificial recharge schemes. By integrating geophysical data with lithological information, EC logs from boreholes, and hydrochemical data, we can interpret electrical resistivity (ER) with groundwater EC values and so identify freshwater saturated zones. Using this approach, ERT images provided a high-resolution spatial characterization and an accurate picture of the shape and extent of the recharge plume of the MAR site. After 5 months of injection, a freshwater plume with an EC of 400–600 μS/cm had formed that extended 400 m in the W-E direction, 250 m in the N-S direction, and to a depth of 40 m below piezometric level. This study also provides correlations between ER values with different lithologies and groundwater EC values that can be used to support other studies.     

Foraging behavior and habitat use by the Southern Giant Petrel on the Patagonian Shelf

We explored the at-sea behavior and marine habitat use of the Southern Giant Petrel breeding in Patagonia, Argentina by means of satellite telemetry. Adult breeders showed a wide distribution over the Patagonian Shelf, using 74% of its surface. The maximum distance traveled from the colonies was 683 km, but on average birds moved no more than 200 km further away from their colony. Important marine areas were located in the shelf break, middle shelf and coastal waters. Areas of activity by sex overlap between 35 and 94%. Females foraged primarily away from the coast and males mainly on coastal areas. Both sexes were capable of flying up to 4,000 km but most of the foraging trips were of less than 200 km. Our results emphasize the importance of the Patagonian Shelf as foraging habitat for pelagic seabirds and contribute to international efforts to identify and protect a network of marine sites.