Carbon and Nitrogen Mineralization of Lead Treated Soils in the Eastern Mediterranean Region,Turkey

The aim of this study was to determine the first effect of lead on microbial activity in soil. The study was carried out in the soil samples from four different radish (Raphanus sativus L. var. radicula, Brassicaceae) fields along the highway in a district (Kadirli, Osmaniye) of the Eastern Mediterranean Region, Turkey. After the calculation of Pb contents, the Pb amounts of the soil samples were brought up to 50 and 100 mg Pb kg^?1 by treatment with Pb(NO ₃ ) ₂ , and the samples for the carbon and the nitrogen mineralization were incubated under controlled conditions (28°C, constant moist). The carbon mineralization was determined by a CO ₂ respiration method for 30 days. The nitrogen mineralization was observed in vitro for 6 weeks. The untreated group was statistically different from the 50 and 100 mg Pb kg^?1 treatments in the aspect of the C(CO ₂ ) outlet during mineralization (P ≤ 0.05), but difference between the 50 and 100 mg Pb kg^?1 treatments was not significant. NH ₄ -N and NO ₃ -N contents of each soil were shown differences between across treatments. Based on these results, it is possible to conclude that the addition of 50 and 100 mg Pb kg^?1 provided a toxic effect threshold for the microbial activity into 30 days.     

Incidence of mycoflora and mycotoxins in some edible fruits and seeds of forest origin

Twelve fungi namelyAlternaria alternata, Aspergillus flavus, A niger, A ochraceus, Actinomucor repens, Capnodoium spp., Curvularia lunata, Fusarium pallidoroseum, F solani, F verticillioides, Penicillium citrinum and Rhizopus stolonifer were recorded from samples ofAegle marmelos, Aesculus indica, Buchanania lanzan andPinus gerardiana. In case ofPrunus amygdalus only Rstolonifer was recorded. A significant variation in pattern of mycoflora incidence was observed in terms of source and season. Fungal infestation in most of the substrates was found to be highest during monsoon. Aflatoxins were the most common mycotoxins elaborated by different isolates ofA flavus obtained fromA marmelos, B lanzan andP gerardiana. The amount of aflatoxins produced by the toxigenic isolates ofA flavus was in the range of traces to 0.9–26.0 μg/ml inA marmelos, 0.8–17.5 μg/ml inP gerardiana and 0.65–13.2 μg/ml inB lanzan. The percentage toxigenicity was comparatively lower in the isolates of other mycotoxigenic fungi. Aflatoxins were detected almost in all the samples analyzed for mycotoxin contamination. However, traces of zearalenone were detected inA marmelos. The concentration of aflatoxin B₁ was in the range of 0.13–0.75 μg/g inA marmelos, 0.09–0.60 μg/g inP gerardiana and 0.01–0.20 ug/g inB lanzan. Mycotoxins were not detected inAesculus indica andPrunus amygdalus.     

Synthesis and Utilization of Trialkylammonium‐Substituted Cyclodextrins as Water‐Soluble Chiral NMR Solvating Agents for Anionic Compounds

Cationic trialkylammonium‐substituted α‐, β‐, and γ‐cyclodextrins containing trimethyl‐, triethyl‐, and tri‐n‐propylammonium substituent groups were synthesized and analyzed for utility as water‐soluble chiral nuclear magnetic resonance (NMR) solvating agents. Racemic and enantiomerically pure (3‐chloro‐2‐hydroxypropyl)trimethyl‐, triethyl‐, and tri‐n‐propyl ammonium chloride were synthesized from the corresponding trialkyl amine hydrochloride and either racemic or enantiomerically pure epichlorohydrin. The ammonium salts were then reacted with α‐, β‐, and γ‐cyclodextrins at basic pH to provide the corresponding randomly substituted cationic cyclodextrins. The ¹H NMR spectra of a range of anionic, aromatic compounds was recorded with the cationic cyclodextrins. Cyclodextrins with a single stereochemistry at the hydroxy group on the (2‐hydroxypropyl)trialkylammonium chloride substituent were often but not always more effective than the corresponding cyclodextrin in which the C‐2 position was racemic. In several cases, the larger triethyl or tri‐n‐propyl derivatives were more effective than the corresponding trimethyl derivative at causing enantiomeric differentiation. None of the cyclodextrin derivatives were consistently the most effective for all of the anionic compounds studied. Chirality 28:299–305, 2016. © 2016 Wiley Periodicals, Inc.     

Molecular evidence of the survival of subterranean amphipods (Arthropoda) during Ice Age underneath glaciers in Iceland

Two endemic groundwater arthropod crustacean species, Crangonyx islandicus and Crymostygius thingvallensis, were recently discovered on the mid‐Atlantic volcanic island of Iceland. The extent of morphological differences from closest relatives, endemism, along with the geographic isolation of Iceland and its complete coverage by glaciers 21 000 years ago, suggests that these two species have survived glaciation periods in sub‐glacial refugia. Here we provide strong support for this hypothesis by an analysis of mitochondrial genetic variation within Crangonyx islandicus. Our results show that the species is divided into several distinct monophyletic groups that are found along the volcanic zone in Iceland, which have been separated by 0.5 to around 5 million years. The genetic divergence between groups reflects geographic distances between sampling sites, indicating that divergence occurred after the colonization of Iceland. The genetic patterns, as well as the dependency of genetic variation on distances from the tectonic plate boundary and altitude, points to recent expansion from several refugia within Iceland. This presents the first genetic evidence of multicellular organisms as complex as crustacean amphipods which have survived glaciations beneath an ice sheet. This survival may be explained by geothermal heat linked to volcanic activities, which may have maintained favourable habitats in fissures along the tectonic plate boundary in Iceland during glaciations.     

Low incidence of DNA sequence variation in human induced pluripotent stem cells generated by nonintegrating plasmid expression

The utility of induced pluripotent stem cells (iPSCs) as models to study diseases and as sources for cell therapy depends on the integrity of their genomes. Despite recent publications of DNA sequence variations in the iPSCs, the true scope of such changes for the entire genome is not clear. Here we report the whole-genome sequencing of three human iPSC lines derived from two cell types of an adult donor by episomal vectors. The vector sequence was undetectable in the deeply sequenced iPSC lines. We identified 1,058-1,808 heterozygous single-nucleotide variants (SNVs), but no copy-number variants, in each iPSC line. Six to twelve of these SNVs were within coding regions in each iPSC line, but ~50% of them are synonymous changes and the remaining are not selectively enriched for known genes associated with cancers. Our data thus suggest that episome-mediated reprogramming is not inherently mutagenic during integration-free iPSC induction.