Designed protein-protein association

The analysis of natural contact interfaces between protein subunits and between proteins has disclosed some general rules governing their association. We have applied these rules to produce a number of novel assemblies, demonstrating that a given protein can be engineered to form contacts at various points of its surface. Symmetry plays an important role because it defines the multiplicity of a designed contact and therefore the number of required mutations. Some of the proteins needed only a single side-chain alteration in order to associate to a higher-order complex. The mobility of the buried side chains has to be taken into account. Four assemblies have been structurally elucidated. Comparisons between the designed contacts and the results will provide useful guidelines for the development of future architectures.     

Matrix modification to improve the recovery of MMHg from clear water using distillation

The use of distillation from aqueous solution dramatically improves the recovery of methyl mercury (MMHg) from complex water samples, as compared to solvent extraction techniques. However, low and irreproducible spike recoveries are often observed when distillation is applied to very clear water samples (i.e., precipitation, double deionized water (DDW), etc.) or those containing high chloride concentrations. Based upon the observation that recoveries and reproducibility are higher for waters containing strong complexing compounds, such as humic matter, we investigated the potential of matrix modification to improve the reproducibility of MMHg by distillation from more difficult matrices. At sample acid concentrations of less than 0.1M hydrochloric acid (HCl), we found that the addition of complexers such as ammonium pyrrolidine dithiocarbamate (APDC), and aqueous humic substances improved distillation spike recoveries and reproducibility. The use of complexers was also found to suppress the co-distillation of divalent mercury (Hg(II), which, in highly contaminated samples can be an interferant with the MMHg determination. At higher HCl concentrations, irreproducibility was dominated by the interference caused by chloride co-distilled with the water. In these cases, neither the addition of complexing agents, or buffers to bind the free hydrogen ions (H⁺) in solution were effective in improving results.     

High HEV presence in four different wild boar populations in East and West Germany

Swine Hepatitis E virus (HEV) can be transmitted from pigs to humans causing hepatitis. A high prevalence of HEV in wild boar populations is reported for several European countries, but actual data for Germany are missing. During the hunting season from October to December 2007 liver, bile and blood samples were collected from wild boars in four different German regions. The samples were tested for HEV RNA by quantitative PCR (qPCR) and anti-HEV IgG antibodies by two different ELISAs and a Line immunoassay. A seroprevalence of 29.9% using ELISA and 26.2% in the Line immunoassay was determined. The seroprevalence rate varied greatly within the analyzed regions. However, qPCR analysis revealed a higher prevalence of 68.2% positive animals with regional differences. Surprisingly, also adult wild sows and wild boars were highly HEV positive by qPCR. Compared to liver and serum samples, bile samples showed a higher rate of positive qPCR results. Sequencing and phylogenetic analysis of a 969 nt fragment within ORF 2 revealed that all isolates clustered within genotype 3 but differed in the subtype depending on the hunting spot. Isolates clustered within genotypes 3i, 3h, 3f and 3e. Within one population HEV isolates were closely related, but social groups of animals in close proximity might be infected with different subtypes. Two full-length genomes of subtypes 3i and 3e from two different geographic regions were generated. The wild boar is discussed as one of the main sources of human autochthonous infections in Germany.     

Influence of sulfur fertilization on the amounts of free amino acids in wheat. correlation with baking properties as well as with 3-aminopropionamide and acrylamide generation during baking

Sulfur (S) fertilization has been long-known to influence the amounts of total free amino acids in plants. To determine the impact of S deficiency in wheat on the concentration of, in particular, free asparagine, the spring wheat cultivar 'Star' was grown in a laboratory scale (5 L pot) at five different levels of S fertilization. After maturity, the kernels were milled into white flours (1-5) and analyzed for their contents of total S and total nitrogen as well as for free amino acids and glucose, fructose, maltose, and sucrose. Extremely high concentrations of free asparagine (Asn; 3.9-5.7 g/kg) were determined in flours 1 and 2 (30 and 60 mg of S), whereas much lower amounts (0.03-0.4 g/kg) were present in flours grown at higher S levels. The amounts of the reducing carbohydrates were, however, scarcely affected by S fertilization. In agreement with the high amount of Asn in flours 1 and 2, heating of both flours led to the generation of very high amounts of acrylamide (1.7-3.1 mg/kg) as well as of 3-aminopropionamide (40-76 mg/kg). Similar concentrations were measured in crispbread prepared from both flours. Application of rheological measurements on doughs prepared from each flour and a determination of the loaf volume of bread baked therefrom clearly indicated that flours 1 and 2 would be excluded from commercial bread processing due to their poor technological properties. Two commercial flours showed relatively low concentrations of acrylamide after a thermal treatment.     

Einfluß von Mg- und Ca-Mangel auf Mg- und Ca-Gehalte,Chlorophyllgehalt und Chlorophyllfluoreszenz von Fichtennadeln sowie auf die Mikromorphologie und Benetzbarkeit ihrer epicuticulären Wachse

The influence of Mg- and Ca-deficiency on the micromorphology of epicuticular waxes and on the wettability of spruce needles The influence of Mg- and Ca-deficiency in nutrient solution on epicuticular waxes of needles of Norway spruce (Picea abies [L.] Karst.) was investigated in greenhouse experiments. Spruce clones were cultivated in sand and supplied with nutrient solution. For two vegetation periods, plants of the treatment groups -Mg, -Ca and -Mg/-Ca were provided with only 15 % of the respective mineral element of the control. At the end of the second vegetation period, the nutrient deficiency was documented by reduced Mg- and/or Ca-content of the needles and changes in chlorophyll fluorescence. No effect on micromorphology of epicuticular waxes and wettability of needles of any age was observed following deficient Mg and/or Ca supply.     

Epidemiological investigations of bovine Chorioptes mange in Germany

Chorioptic mange in cattle has long been recognised as a common external parasitosis in livestock. In order to evaluate the economic importance of Chorioptes bovis-mange, the seasonal prevalence in several types of husbandry in the states of Germany, location of clinical skin symptoms, procedure of diagnosis, influence on milk or meat production, and treatment especially in dairy farming, 1190 German large animal practicioners have been asked by questionnaires from which 367 responded. This paper gives an update on important epidemiological investigations on bovine chorioptic mange due to this inquiry. Since more than one third of the questioned veterinarians see tail mange often, it is of high importance for farm cattle. Chorioptes mange mainly occurs in dairy cattle stocks, and has especially negative effects on milk production and meat productivity. For treatment of this external parasitosis mainly macrocyclic lactons and pyrethroids are used.     

Characterization of seabird bycatch in eastern Canadian waters, 1998–2011, assessed from onboard fisheries observer data

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Finding suitable growth models for turbot (Scophthalmus maximus L.) in aquaculture 1 (length application)

Growth data of two different commercial turbot (Scophthalmus maximus) strains reared in recirculating aquaculture systems were analysed with the aim to determine the most suitable model for turbot. To assess the model performance three different criteria were used: (1) The mean percentage deviation between the estimated length and actual length; (2) the residual standard error with corresponding degrees of freedom and (3) the Akaike information criterion. The analyses were carried out for each strain separately, for sexes within strains and for a pooled data set containing both strains and sexes. We tested a pre‐selection of six models, containing three to four parameters. Models were of monomolecular shape or sigmoid shape with a flexible point of inflection including the special case of monomolecular shape in defined cases of their parameters. The 4‐parametric Schnute model achieved best fit in 62% of all cases and criteria tested, followed by the also 4‐parametric generalized Michaelis–Menten equation in 48% and the 4‐parametric Janoschek model (38%). The von Bertalanffy growth function achieved only 29%, Brody 24% and a new flexible function 19% best fit. In a 1–1000 day growth‐simulation sigmoid shaped curves were produced by the Schnute model in 71% of cases. The Janoschek and the Michaelis–Menten model each produced sigmoid curves in 57% of all cases. This indicates that a flexible 4‐parametric function reflects the growth curve of turbot the best and that this curve is rather sigmoid than monomolecular shaped.     

Nephrotoxicity in Goats Caused by Dosing with a Water Extract from the Stems of Narthecium Ossifragum Plants

Seven goats were given a single dose of an aqueous extract derived from 30 g (wet weight) of Narthecium ossifragum per kg liveweight. Their serum creatinine and urea concentrations increased to day 5 but then fell to normal by day 10. Serum magnesium increased to day 4 and decreased to normal by day 9. Their serum calcium concentration was lower than normal on days 4, 5 and 6. Histopathological examination of the kidneys of goats killed or found dead 2, 4, 6, 8, 11 or 16 days after dosing revealed tubular epithelial cell degeneration and necrosis. Regeneration of the tubular epithelium and signs of interstitial fibroplast proliferation and fibrosis could be seen in animals killed on days 8, 11, 16 and 42. No signs of liver damage were observed in 3 goats dosed with the insoluble plant material from 40 g (wet weight) Narthecium ossifragum per kg liveweight. The total dose was divided into three doses, which were given intraruminally within 7 h. The activities of aspartate aminotransferase, -glutamyl-transferase and glutamate dehydrogenase remained within the normal range in all 10 goats after dosing.     

Die Wirkung wäßriger Streuextrakte verschiedener Waldbäume auf Mycelwachstum und Konidiosporenkeimung von Fomes annosus (Fr.) Cke.

The effect of water extracts of leaf and needle litter from different forest trees on the mycelial growth and the germination rate of conidia of Fomes annosus (Fr.) Cke. Litter extracts from various forest trees and stands have distinct effects on mycelial growth and germination rate of conidia of Fomes annosus. The effects depend on concentration of the extract, period of extraction and on date of collecting the litter samples.