Glass Transition Behavior and Rheological Properties of Surfactants and Gluten‐Surfactant Mixtures

Diacetyltartaric acid esters of monoglycerides (DATEM) and sodium stearoyl lactylate (SSL) displayed thermal events corresponding to glass transition temperature (T_g) and melting of crystalline domains, while monoglycerides (MG) exhibited an endothermic peak corresponding to melting of crystalline structures when heated in a differential scanning calorimeter. The plasticizing effect of water on T_g of gluten exhibited little apparent change in the presence of DATEM, MG, or SSL (glutensurfactant 10:1), in the moisture range of 6.5–21.3% as shown by mechanical spectrometry and differential scanning calorimetry. Glutensurfactant mixtures showed higher G′ and apart from gluten‐SSL, which displayed higher tan δ (G″/G′) at ≤2.51 rad/sec, lower tan δ values than gluten in the frequency range of 0.1–100 rad/sec. DATEM and SSL softened the gluten network before cross‐linking reactions, while MG shifted the onset of cross‐linking reactions to higher temperatures at moisture contents of 30–40%. Complete vitrification of the gluten network occurred at higher temperatures, at the indicated moisture contents, in the presence of surfactants. Softening of the matrix and the delay in cross‐linking of gluten, in the presence of surfactants, might allow for greater expansion of doughs during baking with concomitant increase in loaf volumes.     

The distribution of <Emphasis Type="Italic">Obolodiplosis robiniae</Emphasis> on black locust in Slovakia

For the first time during October 2006, the occurrence of Obolodiplosis robiniae (Haldeman 1847) (Diptera: Cecidomyiidae) was recorded on the black locust (Robinia pseudoacacia L.) in Slovakia. During 2007, field surveys were undertaken to determine the distribution of the species and the infestation ratio at different locations. One year after its first discovery, O. robiniae was found throughout southern Slovakia. The gall midge was observed in 148 out of 161 checked locations. The infestation ratio of single leaves varied from 4 to 100%. The infestation ratio of the black locust tree was evaluated during May–June, July–August, and September–October, and accounted for 15–39, 9–53, and 6–49%, respectively. The most frequent infestation ratio fluctuated from 10 to 30% (115 locations). The highest infestation was recorded during July–August. Greater infestation was prevalent in the larger settlements than it was in the countryside. The gall midge was also recorded on R. viscosa Vent. Although the results show that O. robiniae is nowadays an usual insect with high potential to become an important pest of ornamental black locust or biological control agent against weedy black locust in southern Slovakia, the species do not appear to have reached pest status until now.     

Quantification of anthropogenic lead in Slovak forest and arable soils along a deposition gradient with stable lead isotope ratios

Isotope ratios of Pb may provide the opportunity to determine the contribution of Pb from a point source to Pb concentrations in soil. Our objective was to quantify the contribution of anthropogenic Pb to total Pb and chemical Pb fractions in contaminated soil profiles with the help of ²⁰⁶Pb/²⁰⁷Pb isotope ratios. We sampled 5 forest and 5 arable Cambisols along a transect from a Cu smelter and determined Pb concentrations and ²⁰⁶Pb/²⁰⁷Pb isotope ratios in total digests of all horizons and in 7 chemical fractions of the A horizons. In the organic layer under forest, Pb concentrations decreased from 2155 mg kg^—1 at 1.1 km distance from the smelter to 402 mg kg^—1 at 8 km distance; in the Ap horizons, it decreased from 126 to 72 mg kg^—1. In the total digests, ²⁰⁶Pb/²⁰⁷Pb isotope ratios could be explained by simple mixing of smelter‐ and background‐Pb as indicated by the correlation between the inverse of the Pb concentration and the ²⁰⁶Pb/²⁰⁷Pb ratio (r = 0.93). The mean proportion of smelter‐Pb in soil horizons decreased with depth from 87% (Oi) to 21% (C) under forest and from 64% (A) to 30% (B) in the arable soils. The smelter‐Pb proportions in the B horizons ranged from 6 to 66% and were independent of the distance from the smelter indicating variable leaching rates. The ²⁰⁶Pb/²⁰⁷Pb ratios in the chemical fractions could not be explained by a simple mixing model. Thus, the ²⁰⁶Pb/²⁰⁷Pb ratios may be used to determine the contribution of anthropogenic Pb in total digests but not in chemical Pb fractions.     

Pedosedimentary and climatic reconstruction of the last interglacial and early glacial loess–paleosol sequence in South Tadzhikistan

The thick loess–paleosol-sequences in Tadzhikistan, which indirectly record the environmental changes from the Upper Pliocene to the present-day, have been extensively described from a chronostratigraphical and archaeological point of view. The genesis of the soil-sedimentary complexes and their implications for palaeoenvironmental reconstruction in Tadzhikistan, however, have been considered only relatively recently [Bronger, A., Winter, R., Derevjanko, O., Aldag, S., 1993. Loess–paleosol sequences in Tadjikistan as a palaeoclimatic record of the Quaternary in Central Asia. Quaternary Proceedings 4, 69–81; Lomov, S.P., Tursina, T.V., Zhou, L.P., 1996. Magnetic susceptibility of soils: Micromorphology and possible reconstructions of climate. In: Soil micromorphology. Studies in Soil Diversity, Diagnostics, Dynamics, 10th International Working Meeting on Soil Micromorphology. Moscow, Russia, July 8–13, 1996, p. 145]. The pedocomplex of Last Interglacial and Early Glacial age (Oxygen Isotope Stage 5) in the Tagidjar and Darai Kalon sections near the town of Khovaling is represented by three major stages of soil formation. The soil characteristics have been micromorphologically analysed. The distinction between primary and secondary carbonates is of major importance to understand the soil forming processes. The relative distribution of needle fibre calcite (NFC), micritic infillings (M), hypocoatings (CHC), coarse calcitic grains (CCG) and calcified root cells (CRC) provides detailed insights into the environmental conditions prior, during and following pedogenesis. The abundance of coprolitic aggregates (CA) and pupal chambers gives a clear indication of the rate of biological activity which prevailed during the last two soil forming stages. Void pseudomorphs after gypsum crystals (gypsum pseudomorphs) are frequently observed beneath the Cca horizons of the paleosols. Using the present-day climate and soilscape as a reference base, the obtained pedosedimentary events detected in the Tadzhikistan sections provide a detailed palaeoenvironmental record. Indeed, glacial and interglacial climates and soils respond to contemporaneous climatic schemes and soil forming processes, which are still active in the region today. The amount and the seasonal variability of precipitation, mostly, are at the origin of the variable soils formed during glacial and interglacial ages.     

Distribution of Al and Heavy Metals in Bulk Soil and Aggregates at Three Sites Contaminated by the Emissions of a Central Slovak Al Smelter

Large spoils of metal-rich filtercake from the Port Kembla BHP steelworks were characterised by certain physical, chemical and biological parameters. The vegetation was assessed for potential metal hyperaccumulators and the presence of arbuscular mycorrhizae in the rhizospheres. Fresh filtercake (<2 yr old) was charcoal in colour and had a fine (clay loam) texture. Its composition was distinctly different to the older filtercake (3–4 yr) which was similar to the reference soil, being lighter in colour, loamy textured, more aggregated and with higher organic matter. Variability between the two filtercake types also occurred for electrical conductivity and pH. Total trace metal concentrations (Cd, Cu, Pb and Zn) were high and although only minor proportions were in bioavailable forms, the greater percentages in the older filtercake suggested temporal changes in metal speciation. Fresh filtercake was devoid of any plant life and fungal communities. The older material, however, was able to sustain a reasonable environment for plant, bacterial and fungal growth. The vegetation was dominated by Ricinus communis, along with species belonging to the families Asteraceae, Solanaceae, Malvaceae and Apiaceae. Rhizosphere of all these plants harboured mycorrhizae belonging to the Gigaspora and Glomus strains and while trace metal accumulation was observed no plant was a hyperaccumulator. The reference site was principally inhabited by certain Poaceae, Asteraceae and Verbenaceae species. All were mycorrhizal (principally Glomus strains), but no plant was represented on the contaminated site. Here also trace metal accumulation was taking place. The absence of hyperaccumulation in the filtercake was considered a consequence of low levels of bioavailable trace metals. However, as such metal forms may increase over time, particularly for copper and lead, cultivation of known hyperaccumulators could become worthwhile after prolonged exposure (>4 yr). Among the naturally colonising plants, Ricinus communis and Sonchus oleraceus are regarded the most suitable options for zinc and cadmium removal, respectively. Arbuscular mycorrhizal infection (particularly with Glomus and Gigaspora strains) should be promoted for optimum soil reclamation.     

Predicting heavy metal transfer from soil to plant: potential use of Freundlich‐type functions

Soil‐plant transfer of metals is a nonlinear process. We therefore aimed at evaluating the potential of Freundlich‐type functions (c_Plant = b × c_Soil^a) to predict Cd, Cu, Pb, and Zn concentrations in wheat (Triticum aestivum L.) grain and leaf (c_Plant) from soil concentrations (c_Soil). Wheat plants and soil A horizons, mainly developed from Holocene sediments, were sampled at 54 agricultural sites in Slovakia. Metals were extracted from soils with 0.025 M EDTA at pH 4.6 and concentrated HNO₃/HClO₄ (3:1); plant samples were digested with concentrated HNO₃. Total metal concentrations of soil samples were 0.07—25 mg Cd kg^—1, 9.3—220 mg Cu kg^—1, 14—1827 mg Pb kg^—1, and 34—1454 mg Zn kg^—1. On average, between 20 % (Zn) and 80 % (Cd) of the total concentrations were EDTA‐extractable. The total metal concentrations of grain samples were < 0.01—1.3 mg Cd kg^—1, 1.3—6.6 mg Cu kg^—1, < 0.05—0.30 mg Pb kg^—1, and 8—104 mg Zn kg^—1. The leaves contained up to 3.2 mg Cd kg^—1, 111 mg Cu kg^—1, 4.3 mg Pb kg^—1, and 177 mg Zn kg^—1. Linear regression without data transformation was precluded because of the nonnormal data distribution. The Freundlich‐type function was suitable to predict Cd (grain: r = 0.71, leaf: 0.86 for the log‐transformed data) and Zn concentrations (grain: 0.69, leaf: 0.68) in wheat grain and leaf from the EDTA‐extractable metal concentrations. The prediction of Cu and Pb concentrations in grain (Cu: r = 0.44, Pb: 0.41) was poorer and in leaf only possible for Pb (0.50). We suggest to use the Freundlich‐type function for defining threshold values instead of linear regression because it is more appropriate to simulate the nonlinear uptake processes and because it offers interpretation potential. The results suggest that the coefficient b of the Freundlich‐type function depends on the intensity of metal uptake, while the coefficient a reflects the plants' capability to control the heavy metal uptake. The latter is also sensitive to metal translocation in plants and atmospheric deposition.<?show $6#>     

Physiological Aspects of Cadmium and Nickel Toxicity in the Lichens Peltigera rufescens and Cladina arbuscula Subsp. mitis

This study was undertaken with the aim of investigating the effect of Cd²⁺ and Ni²⁺ containing solutions on selected physiological parameters (metal uptake, chlorophyll a fluorescence, assimilation pigment composition, thiobarbituric acid-reactive substance production, and ergosterol content) in the lichens Peltigera rufescens and Cladina arbuscula subsp. mitis growing on historic copper mine-spoil heaps at ?ubietová-Podlipa, Slovakia. Physiological measurements did not confirm significantly higher sensitivity to Cd and Ni of the cyanolichen P. rurescens compared to the green-algal lichen C. arbuscula subsp. mitis. Under natural conditions, C. arbuscula subsp. mitis is able to grow directly on copper mine heaps of Central Slovakia, while P. rufescens grows only on their margins. A crucial factor for this limited distribution of P. rufescens may be, at least in part, the higher intracellular accumulation of metals. Although lichen photobionts are generally regarded as key elements of lichen sensitivity, further research is necessary to elucidate this point since the higher levels of intracellular Cd and Ni do not allow to regard cyanobacterial photobionts of P. rufescens as more sensitive than the eukaryotic ones of C. arbuscula subsp. mitis.     

Antioxidant capacity changes and phenolic profile of Echinacea purpurea, nettle (Urtica dioica L.), and dandelion (Taraxacum officinale) after application of polyamine and phenolic biosynthesis regulators

The changes of the antioxidant (AOA) and antiradical activities (ARA) and the total contents of phenolics, anthocyanins, flavonols, and hydroxybenzoic acid in roots and different aerial sections of Echinacea purpurea, nettle, and dandelion, after treatment with ornithine decarboxylase inhibitor, a polyamine inhibitor (O-phosphoethanolamine, KF), and a phenol biosynthesis stimulator (carboxymethyl chitin glucan, CCHG) were analyzed spectrophotometrically; hydroxycinnamic acids content was analyzed by RP-HPLC with UV detection. Both regulators increased the AOA measured as inhibition of peroxidation (IP) in all herb sections, with the exception of Echinacea stems after treatment with KF. In root tissues IP was dramatically elevated mainly after CCHG application: 8.5-fold in Echinacea, 4.14-fold in nettle, and 2.08-fold in dandelion. ARA decrease of Echinacea leaves treated with regulators was in direct relation only with cichoric acid and caftaric acid contents. Both regulators uphold the formation of cinnamic acid conjugates, the most expressive being that of cichoric acid after treatment with CCHG in Echinacea roots from 2.71 to 20.92 mg g(-1). There was a strong relationship between increase of the total phenolics in all sections of Echinacea, as well as in the studied sections of dandelion, and the anthocyanin content.     

The effect of an experimentally induced acute mastitis on the test results of an Ostertagia ostertagi milk ELISA

Antibody levels against Ostertagia ostertagi in the milk are a promising parameter to identify dairy cows or herds with production losses due to gastrointestinal nematodes. However, milk antibody levels can be influenced by udder-related factors. In this study, the effect of an experimentally induced mastitis on the test results (ODR) of a milk O. ostertagi ELISA was investigated. Twenty-five cows that were naturally infected with gastrointestinal nematodes, were inoculated in their left udder quarters with Escherichia coli P4:O32 and quarter milk samples were collected at several intervals from 24 h before until 144 h after experimental infection. The effect of the contribution of milk from one or more infected quarters on the bulk tank milk ODR was estimated, based on a titration experiment. The mean O. ostertagi antibody levels of the infected udder quarters were significantly (P < 0.001) higher than those of the uninfected udder quarters at each sampling time post-infection. The largest difference was observed at 24 h post-infection with a mean difference of 0.251 ODR (95%CI: 0.172; 0.330). There was also a significant increase (P < 0.001) in total IgG levels with the largest difference being observed at 24 h post-infection. Highly significant (P < 0.005) correlation coefficients were observed between O. ostertagi ODR, total IgG ODR, Na+ and Cl- ion concentration and log transformed somatic cell counts at 24 h post-infection. The results demonstrate that an acute mastitis causes a flow of specific and non-specific antibodies from serum to milk with a subsequent increase in the O. ostertagi ODR values. The effect of the contribution of milk from infected quarters on the bulk tank milk O. ostertagi ODR was estimated to be minor if the relative number of infected quarters is small (< 3%).     

Mental notes in tracking BVDV carriers

The detection and elimination of animals persistently infected with bovine viral diarrhoea virus (BVDV) is the key to BVD control. This method has proven to be very efficient in eradicating BVDV in a herd. Several pitfalls in the detection procedure can make that some persistently infected (PI) animals do not get identified or are removed too late, supporting the assumption that circulation of the virus could be possible in absence of PI animals. Furthermore the risk of reintroduction is high since the prevalence of BVD is high in the Netherlands and Belgium. Based on both practical experience and literature, here we review critical control points in order to minimise the risk of a false negative BVDV screening.