Importance of chlorogenic acid on the oxidative potential of potato tubers of two German cultivars

Summary Two German cultivars differing in blackspot susceptibility were grown in pots in 1998 and 1999 under control and water stress conditions. Blackspot susceptibility of the tubers was defined as oxidative potential. The effect of free tyrosine, cysteine, phenylalanine, chlorogenic and ascorbic acid on the oxidative potential was analyzed. A high concentration of ascorbic acid led to a decrease in the oxidative potential after harvesting in 1998. No correlation was found between oxidative potential and free tyrosine, phenylalanine or cysteine, respectively. Chlorogenic acid content increased during storage and gave a significant correlation with discoloration, showing that it can have an effect on the oxidative potential of the tuber greater than previously thought. Supplementing freeze-dried potato samples with pure chlorogenic acid increased the oxidative potential. Oxidative potential seems to depend on a series of chemical compounds, and their content is affected by factors including annual variations, cultivar, water availability and storage.     

Electron solvation in two dimensions

Ultrafast two-photon photoemission has been used to study electron solvation at two-dimensional metal/polar-adsorbate interfaces. The molecular motion that causes the excess electron solvation is manifested as a dynamic shift in the electronic energy. Although the initially excited electron is delocalized in the plane of the interface, interactions with the adsorbate can lead to its localization. A method for determining the spatial extent of the localized electron in the plane of the interface has been developed. This spatial extent was measured to be on the order of a single adsorbate molecule.     

Über den Metabolismus von Endrin,Heptachlor und Telodrin

Zusammenfassung Im Rahmen der Untersuchungen über den Metabolismus insektizider Chlorkohlenwasserstoffe mit Hilfe¹⁴C-markierter Verbindungen wird über den Abbau von Endrin, Heptachlor und Telodrin in Warmblütern, Pflanzen und Mikroorganismen berichtet; die entstandenen Metaboliten wurden zum Teil als Hydroxyl-Derivate der Insektizide identifiziert.Nach oraler Applikation von radioaktiv markiertem Endrin an Ratten — Endrin weist von allen diesen Insektiziden gegenüber Warmblütern die höchste Toxizität auf — wird die Radioaktivität sehr schnell ausgeschieden (Speicherung nach 13 Tagen, bei täglicher Applikation, 14% der Gesamtaktivität; drei Tage nach letzter Endrindosis 5,3%). Als Ausscheidungsprodukte treten, hauptsächlich in den Faeces, neben geringen Mengen Endrin zwei hydrophile Metaboliten auf.20 Tage nach Besprühen von Pflanzen (Brassica oleracea) mit Endrin-¹⁴C enthalten die Wurzeln größere Mengen eines hydrophilen Metaboliten, der auch in Stengeln, Blättern und im Erdreich nachgewiesen wurde.

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Summary In the context of investigations of the metabolism of insecticidal chlorinated hydrocarbons by means of¹⁴C-labelled compounds this report deals with the degradation of endrin, heptachlor and telodrin in warm-blooded animals, plants and micro-organisms. The resulting metabolites were identified partly as hydroxyl derivatives of the insecticides.After oral application of radioactively labelled endrin in rats — endrin shows the highest toxicity among all insecticides towards warm-blooded animals — the radioactivity was very quickly eliminated (accumulation after 13 days' application was 14% of the total activity; 5,3% remained three days after the last dose of endrin). The waste products, appearing mainly in the faeces, were found to be, beside small quantities of endrin, two hydrophilic metabolites.20 days after plants(Brassica oleracea) were sprayed with endrin-¹⁴C the roots contained considerable amounts of a hydrophilous metabolite. The latter was also found in stems, leaves and in the soil.

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Resumé Dans le cadre de recherches sur le métabolisme des insecticides à base d'hydrocarbures chlorés, effectuées à l'aide de composés marqués à¹⁴C, on expose les modalités de dégradation de l'endrine, de l'heptachlore et de la télodrine chez les animaux à sang chaud, chez les plantes et les micro-organismes; on a identifié une partie des métabolites obtenus comme dérivés hydroxyles des insecticides.Après l'administration par voie buccale à des rats d'endrine marquée, qui a, de tous ces insecticides, la plus grande toxicité pour les animaux à sang chaud, la radioactivité était très vite éliminée. L'activité résiduelle totale était de 14% après qu'on leur avait administré une dose quotidienne d'endrine pendant 13 jours et de 5,3% trois jours après la dernière administration. Parmi les produits éliminés, surtout dans les fèces, il faut citer, à côté de quantités réduites d'endrine, deux métabolites hydrophiles.20 jours après la pulvérisation des plantes(Brassica oleracea L) avec de l'endrine-¹⁴C, les racines contenaient des quantités appréciables d'un métabolite hydrophile, que l'on a aussi détecté dans les tiges, les feuilles et le sol.

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mit 11 Fig.     

THE EFFECTS OF HEAVY DRESSINGS OF POTASH APPLIED TO THE SEEDBED OF A LEY COMPARED WITH ANNUAL DRESSINGS

Two experiments were established to compare the effect on the yield of continuously cut herbage of varying amounts of potassium fertilizer applied either in one large dose to the seedbed, or as 3 equal dressings applied to the seedbed and in the summer of the 2 following years. Responses in dry–matter yield were recorded up to the higher rates of potassium fertilizer applied. Establishment and yield in the first 12 months were improved by seedbed applications of up to 4 cwt/ac of muriate of potash (60% K₂O). Although total yields over the whole period were similar, whether the potassium was applied to the seedbed only or in annual dressings, yields from "all–in–seedbed" dressings declined towards the end of the period. Soil analysis indicated that annual dressings left behind higher residues of K.     

INTERACTIONS BETWEEN FIRST AND SECOND APPLICATIONS OF FERTILIZER NITROGEN AND IMPLICATIONS IN EFFICIENCY OF NITROGEN USE

DM yield and N uptake data are presented from primary growth and two successive regrowths of perennial ryegrass treated with combinations of three N treatments for the primary growth viz. 0, 50 and 100 kg N/ha (PN) and four N treatments applied for the second growths, viz. 0, 33, 66 and 100 kg N/ha (SN). Primary growth gave a response of 24·2 kg DM/kg applied N to PN50 with only a further l±0 kg DM/kg applied N from the second PN increment. A significant interaction between PN and SN treatments was shown in second growth. The residual DM response to PN was highest at SN0 and reduced as the level of SN was raised. Substantially greater residual responses to PN treatments were shown in the third growth. Third growth DM responses to SN treatments were high. High apparent recovery of fertilizer N reached 111% of primary N where SN66 followed PN50. High available soil N is partly responsible for both high apparent recovery of N and high DM response. The latter appears to be associated with inclusion of growths given no fertilizer N so that the full residual effects of fertilizer N and ‘priming’ of available soil N can be realised.     

THE INFLUENCE OF PHOSPHATE AND LIME ON THE GROWTH AND N FIXATION OF LOTUS ULIGINOSUS AND TRIFOLIUM REPENS UNDER GREENHOUSE CONDITIONS

Shoot dry weight, leaf area, leaf lamina dry weight and N-fixation of L. uliginosus cv. Grasslands 4705 were compared with those of T. repens S184 over a 90-day period frotn sowing, in pots in a greenhouse. Three P and three pH levels were imposed and there were three destructive harvests at 30-day intervals. N-fixation was estimated by the acetylene reduction technique prior to the last harvest. L. uliginosus had higjier means than T. repens for all characters measured under all treatments at all harvests. Large increases in shoot weight and leaf area were associated with addition of P, particularly with the first increment of P to L. uliginosus. High P reduced the contribution of lamina to total shoot weight in T. repens more than in L. uliginosus at the second harvest. Raising pH increased shoot weight and leaf area in both species. N-fixation was low in both species at low pH and low P. This was increased by addition of P, a smaller quantity being necessary for the same response in L. uliginosus compared with T. repens. At the higher P levels, the high pH gave rise to lower N-fixation than at the medium pH. Results are discussed in relation to field trials of other workers and the possible suitability of L. uliginosus for low fertility upland conditions.     

Comparison of three immunodiagnostic tests for experimental Heterophyes heterophyes infection in dogs

The aim of this study was to compare the performance of three in-house diagnostic tests, i.e. counter current immunoelectrophoresis (CCIE), intradermal (ID) and indirect fluorescent immunoassay (IFI), for the diagnosis of Heterophyes infection. One hundred and twenty puppies were randomly divided into eight groups (n=15/group). Heterophyes heterophyes infections were established in these puppies by administering a dose of 50 H. heterophyes encysted metacercariae/puppy by gavage. Forty puppies of similar age and sex were divided into eight groups, of five puppies each and were used as negative controls. Sera pooled from separate infected and uninfected groups were tested against H. heterophyes antigens, weekly for 8 weeks post-infection (PI). The ID assay detected infected puppies sooner than any of the serological tests. Sero-conversion was first detected 2 weeks PI by ID assay and 1 week later by CCIE and IFI assays. ID test performed well till the end of the experiment (sensitivity and specificity: 100% and 90%, respectively). Both IFI and CCIE assays had a sensitivity of 40% and 20%, respectively for early detection of antibody, which was less sensitive than ID but both assays were more specific (100%) than the ID assay. The lowest agreement was between ID and IFI tests (40.3%), whilst the highest was observed between CCIE and IFI tests (67.2%). Of the three evaluated methods, the ID test could be recommended for scientific and laboratory diagnosis of heterophyosis in naturally infected animals. However, since none of the investigated method are optimal (i.e, offers 100% specificity and sensitivity), the choice of test employed must depend on the aim of the study.     

Transmission of bovine viral diarrhoea virus through the semen of acutely infected bulls under field conditions

Epidemiological investigations implicated the semen of artificial insemination (ai) bulls as the only plausible source of infection with bovine viral diarrhoea virus (bvdv) in 10 Finnish dairy herds. The infection was traced back to two northern Finncattle bulls that had been transiently infected when their semen had been collected while they were in a gene bank herd containing persistently infected (pi) animals. The isolates of bvdv from the animals in the gene bank herd, from the semen of the two bulls and from a pi calf born in one of the herds using the semen belonged to a rare genetic type in Finland and, on the basis of the nucleotide sequences in the 5' untranslated region, were identical. Cross-contamination of batches of semen at the ai station and an external source of bvdv were ruled out for the recipient herds. It was concluded that bvdv infection can be transmitted through the semen of transiently infected bulls under field conditions.