Statistical Modeling of the Partitioning of Nonylphenol in Soil

Partition coefficients K _P of nonylphenol (NP) in soil were determined for 193 soil samples which differed widely in content of soil organic carbon (SOC), hydrogen activity, clay content, and in the content of dissolved organic carbon (DOC). By means of multiple linear regression analysis (MLR), pedotransfer functions were derived to predict partition coefficients from soil data. SOC and pH affected the sorption, though the latter was in a range significantly below the pK_a of NP. Quality of soil organic matter presumably plays an important but yet not quantified role in sorption of NP. For soil samples with SOC values less than 3 g kg^?1, model prediction became uncertain with this linear approach. We suggest that using only SOC and pH data results in good prediction of NP sorption in soils with SOC higher than 3 g kg^?1. Considering the varying validity of the linear model for different ranges of the most sensitive parameter SOC, a more flexible, nonlinear approach was tested. The application of an artificial neuronal network (ANN) to predict sorption of NP in soils showed a sigmoidal relation between K _P and SOC. The nonlinear ANN approach provided good results compared to the MLR approach and represents an alternative tool for prediction of NP partitioning coefficients.     

Screening of mango (Mangifera indica L.) cultivars for their contents of flavonol O- and xanthone C-glycosides, anthocyanins, and pectin

With respect to their browning potential and in consideration of a combined recovery of pectin and phenolic compounds, peels of 14 cultivars and the flesh of nine cultivars of mango (Mangifera indica L.) fruits were analyzed for their contents of flavonol O- and xanthone C-glycosides by high-performance liquid chromatography (HPLC)-diode array detection-electrospray ionization mass spectrometry (ESI-MS). While total amounts of up to 4860 mg/kg dry matter demonstrated the peels to be a rich source of phenolic compounds, only traces could be detected in the flesh. The profile of flavonol glycosides of the peels proved to be highly characteristic and may therefore serve as a tool for authenticity control of mango puree concentrate, which is often produced from unpeeled fruits and represents an important intermediate for the production of mango nectars. Two compounds were isolated by preparative HPLC, and their structures were elucidated on the basis of ESI-MS as well as NMR spectroscopy, establishing the two compounds as rhamnetin 3-O-beta-galactopyranoside and rhamnetin 3-O-beta-glucopyranoside, respectively. In the peels of red-colored cultivars, cyanidin 3-O-galactoside and an anthocyanidin hexoside so far not reported in mango could tentatively be identified. The contents and degrees of esterification of pectins extracted from the lyophilized peels ranged from 12.2 to 21.2% and from 56.3 to 65.6%, respectively, suggesting mango peels also as a promising source of high-quality pectin.     

Effects on Motile Factors and Cell Growth of Euglena gracilis After Exposure to Wood Ash Solution; Assessment of Toxicity, Nutrient Availability and pH-Dependency

Wood ash application (WAA) to the forest has been suggested as a resource of nutrients for trees and for restoration of acidified soils and surface waters. However, studies of the effects of WAA on aquatic systems are few. This study investigated the effects of wood ash (1–25 g L^?1) on the unicellular flagellate Euglena gracilis, which has been proved to be a sensitive test organism for assessing environmental change. Long-term (7 days) growth studies and short-term (direct, 24 and 48 h) studies of different motile factors, using the automatic biological test system Ecotox, were conducted. The results show no indication of biotoxic effects due to wood ash (adjusted to neutral) treatments. However, when no adjustments of pH in wood ash solutions were made, inhibitory effects on motile factors and cell growth were observed at higher concentrations of wood ash (10–25 g L^?1) due to high pH (> 8). In tests with pH adjusted to neutral, enhanced motility was observed. These results indicate that high concentration of WAA could affect freshwater environments.     

Detection of phloridzin in strawberries (Fragaria x ananassa Duch.) by HPLC-PDA-MS/MS and NMR spectroscopy

The phenolic profile of strawberry fruits (Fragaria x ananassa Duch., Rosaceae) was investigated by high-performance liquid chromatography with photodiode array detection. A peak displaying retention time and UV spectral data identical to those of phloridzin (phloretin 2'-O-beta-d-glucoside), a dihydrochalcone glucoside so far considered characteristic of apples, was monitored. For further characterization, crude extracts of strawberries were purified on polyamide, and the target compound was isolated by preparative and analytical HPLC. Structure elucidation was performed on the basis of APCI- and ESI-MS in the negative ion mode as well as by 1D and 2D NMR spectroscopy using authentic phloridzin for comparison. The d-configuration of the sugar moiety was established by HPLC analysis of the corresponding acyclic 1-deoxy-1-(N-acetyl-alpha-methylbenzylamino)alditol acetate. Apart from its chemotaxonomic relevance, this first report on the occurrence of phloridzin in strawberries is of particular interest for the authenticity control of strawberry products such as juices, jams, and fruit preparations since phloridzin has so far been used for the detection of fraudulent admixtures.     

The Importance of Precedent Hydro-climatological Conditions for the Mass Transfer of Pollutants in Separated Sewer Systems and Corresponding Tributaries During Storm Events

Runoff events were analysed in separated sewer systems in the town of Luxembourg. The relationships between Event Mean Concentrations of different pollutants and runoff patterns were evaluated. In addition, the inter-storm and intra-storm variability of the material transport were determined. Primarily, the variations in pollutant concentrations and loads are determined by the antecedent weather conditions. The presence of illicit sanitary inputs in one of the sewers produced a significant first flush effect as well as higher Event Mean Concentrations for pollutants. Furthermore, near the town of Trier 40 storms were analyzed in a small natural basin mainly influenced by runoff from a separated sewer system. Natural and artificial storm events were investigated in order to estimate the relationship between the pollutant sources in the channel and from the separated sewer system. Just like in the canalization of Luxembourg City the pollutant dynamics during natural storms are strongly influenced by pre-event hydrological conditions. The artificial storms behave differently. Despite little pre-rain, the maximum concentrations of toxic substances are comparatively low. A resuspension of sediment only occurs in the natural channel system, without the introduction of fines from the sewer system.     

Effects of oligosaccharides on functional parameters of the intestinal tract of growing pigs.

Feeding experiments were carried out in growing pigs using topinambur powder or inactivated yeasts as prebiotic additives with an application period of at least 3 weeks. At the end of the experimental periods the animals were killed and segments of the intestinal tract were used for measuring transport physiological parameters and for mucin histochemistry. Jejunal epithelia were mounted in Ussing chambers for measuring electrical tissue parameters, paracellular permeability and short circuit current response to mucosal glucose. Both prebiotics had no effects on basal or forskolin stimulated short circuit currents. Total tissue conductances tended to be higher in response to both prebiotics. Topinambur increased mucosal-to-serosal fluxes of mannitol in the proximal and distal jejunum, which could only be demonstrated for the distal jejunum when inactivated yeasts were fed. Mucosal application of glucose induced higher current responses in jejunal tissues. From histochemistry it could be demonstrated that both prebiotics increased the number of ileal goblet cells and the thickness of the colonic mucosa.     

The persistence of spray droplets above two vegetation canopies

Droplets were released from an ‘instantaneous line source’ perpendicular to the wind at heights of 4 and 7 m above the ground. Droplets were collected by rotating samplers at three heights; sets of samplers were positioned in a line parallel to the wind, downwind of the line source. Trials were carried out in moderately unstable conditions during the day, and under stable conditions shortly after dark, both over short rough stubble and over mature cotton. A substantial proportion of the small droplets were found to travel as far as 500 m over cotton; over grass, few of even the smallest droplets were collected 250 and 500 m downwind of the line source. Collection at the distant samplers was on average slightly, but not significantly, more when the spray was released at the greater height.     

Chemical control of the heartwater vectors

This paper reviews available literature on the efficacy of acaricides against Amblyomma hebraeum and other tick species, and presents information on tests done with registered chemicals in the laboratory. Little published information is available on the efficacy of chemicals specifically against A. hebraeum. A host of formulations are registered for use as acaricides on cattle, sheep, and goats in South Africa and thus, by implication, against this species. Resistance has only been described to arsenic and toxaphene in Southern Africa; the other registered products are generally considered to be effective. In contrast, many efficacy tests of various chemicals in different formulations against other Amblyomma spp. have been described. These publications have mainly emanated from the USA, where bite-wounds of these ticks serve as oviposition sites for screwworm flies. In this paper, Amblyomma maculatum and Amblyomma variegatum are included as potential heartwater vectors. The acaricidal efficacy of a number of compounds, representative of different chemical classes, was tested in South Africa against an arsenic and organochlorine resistant strain of A. hebraeum. The engorged adult female immersion method was used. A disconcerting discovery was that several of these registered products failed to control this tick when used at their recommended concentrations. It is concluded that many chemicals which fail against A. hebraeum on cattle do so because of insufficient persistence. Exposure of this tick to lower levels of existing chemicals, but for longer periods, ought to provide satisfactory control for many years.     

Ileal digestibility of amino acids in pigs fed barleys differing in protein content

The apparent digestibility of nitrogen and amino acids was measured by the ileal and faecal methods in pigs fed nine barleys differing in nitrogen content (from 1.73 to 2.16 per cent/DM). A positive (r = 0.87) and significant relationship was found between the apparent nitrogen digestibility at the end of the ileum and the crude protein content of barley. Generally, the higher the protein of the grain, the higher the ileal digestibilities of the amino acids. For most amino acids the faecal values were greater than the ileal ones. This being specially so for threonine, tryptophan, histidine and cystine belonging to the nutritionally important amino acid group. When the relationship between the amino acid and nitrogen digestibilities at the level of ileum is considered, the values were found to be similar to that of nitrogen in the case of tryptophan, higher for isoleucine, valine (both 2-3 units), cystine, histidine, leucine, methionine (all 5-6 units) and phenylalanine (10 units) and lower only for lysine and threonine (7-8 dig. units).