Tritrichomonas foetus infection in purebred cats in Germany: prevalence of clinical signs and the role of co-infection with other enteroparasites

The aim of this study was to determine the prevalence of Tritrichomonas foetus infection and associated clinical signs in purebred cats in Germany, to investigate the role of co-infection, and identify determinants of infection. Faecal specimens accompanied by epidemiological questionnaires were scored and collected from 230 purebred cats. Faeces were examined for trichomonads and other enteroparasites. The prevalence of T foetus was 15.7% among cats and 18.5% among catteries. An abnormal faecal score and history of diarrhoea were observed in 64% and 61% of T foetus-positive cats, respectively, and correlated significantly with infection. Co-infection, observed in 36% of T foetus-infected cats, was not associated with diarrhoea. Norwegian Forest cats were infected significantly more often than other breeds. No association was found with any environmental factors. This study demonstrated a high prevalence of symptomatic T foetus infections in purebred cats in Germany. Co-infection with other enteroparasites did not worsen clinical signs of trichomonosis.     

Schätzrahmen zur Beurteilung von Ammoniakverlusten nach Ausbringung von Rinderflüssigmist

Assessment of NH₃ emissions after application of cattle slurry Over a two year period at different sites following application of cattle slurry measurements of NH₃ emissions have been carried out using the Integrated Horizontal Flux Method. The objective of these studies was to quantify NH₃ losses under field conditions and to investigate the influence of various environmental factors on the NH₃ emission. Depending on environmental conditions and infiltration rates NH₃ volatilization losses in the described experiments ranged from 12 to 65 per cent of the applied NH₄-N. Of the many factors influencing NH₃ emission three factors were chosen which can easily be measured or at least estimated. Using these factors a framework for an assessment of NH₃ emissions has been set up. Within this framework the expected NH₃ losses are estimated depending on infiltration rate of the slurry, mean aerial temperature, precipitation and time after application (with or without incorporation of manure). This framework offers a practical tool for evaluation of NH₃ losses after application of cattle slurry and may be used to avoid NH₃ losses under different environmental conditions.     

The role of nitrogen in declining scots pine forests (Pinus sylvestris) in the lowland of East Germany

Over the last decade, N inputs in pine ecosystems on the lowland of the former GDR have clearly increased. Agriculture plays a special role as a NH_x emitter, because the whole lowland is covered with a network of large livestock farms. High N inputs cause an overnutrition of the pine stands with N, an accumulation of N in the soils, and as a consequence of the ensuing eutrophication, a drastic modification of the ground vegetation with a luxuriant growth of weeds and shrubs or of the vital herbaceous cover. The fine root quantity is reduced, also the mycorrhiza and the growth of pine. In many cases pine stands show a dramatical decrease of Mg nutrition. Finally, the limited range of silvicultural options is discussed, which are available to limit the progress of damage.     

Ökologische Standorteigenschaften urban-industriell überformter Böden des Brücktorviertels in Oberhausen (Ruhrgebiet)

Ecological characteristica of soils which were transformed by urban and industrial impact of the Brücktor district in Oberhausen (Ruhr area) This paper presents the results of Urbic Anthrosols from eight different sites which contain partly alkalizing material of technogenic origin in an urban-industrial area of Oberhausen. The alkalinity of the technogenic material in the top soil layer (0–3 dm depth) would enable these Urbic Anthrosols to neutralize an annual H⁺-deposition of 0.2 mol per m² for about 185 to 1630 years (median nearly 1000 years). The cation exchange potential of these soils is nearly always low and in the layers dominate ferrimagnetic Fe oxides which have a minor P-sorption capacity. Also these soils are deeply enriched with plant nutrients (up to > 2.5 kg N/m³, up to > 1 kg P/m³), which show high concentrations of plant available, mobile fractions. In the profiles with deposit layers of a coarse texture the root growth is prevented by cementation or actually limited to the upper 20 cm. Furthermore their usable field capacity for water of the rooting zone is low. Therefore the vegetation cannot take up the plant available nutrient fractions which can be leached through the profiles.     

Irrigation with plant extracts in ecofarming increases biomass production and mineral and organic nitrogen content of plants

Seedlings of alfalfa, rape, spinach, and wheat, potted on sandy soil, were irrigated with an aqueous extract of pea shoot (PE, 9.84 g dry weight l^–1) or a solution of Ca, K, Mg, P, and NO₃‐N salts (SS) in a concentration similar to that in PE, for 31–48 days. In comparison to water‐irrigated controls, both SS and PE treated plants showed nearly equal increases in shoot dry weight (29–40 %), whereas PE‐treated plants had higher fresh weights (38–84 %) due to increased succulence. Treatment with SS did not enhance, but sometimes even reduce, the concentrations of Ca, K, Mg, and several trace elements in shoot tissues. In contrast, PE‐treated plants had higher Ca, K, Mg, and organic N, but lower As and Ni contents and were thus of higher nutritive value. Reduced contents of metals in plant tissue correlated with their reduced solubility in the soil solution, which was not due to changes in pH. Fertilizer components such as K and Mg (metals of lower exchange intensity) were incorporated into the soil to release Ca, Sr, and Ba (metals of higher exchange intensity) and reduce the solubility of most trace elements and metal‐complexing humic substances. In addition, application of Ca precipitated heavy metals and humic complexes directly from the soil solution. This effect was partially overcome by PE. Its carboxylic acids could act as phytochelators of metal ions and as mobilizers of the highly diffusible humic substances which carry metals to roots. It is concluded that continuous PE application replaces the quantities of Ca, K, Mg, P, and organic N, but not of NO₃‐N consumed during plant growth. Using PE does not add any relevant quantities of toxic metals to the plant‐soil system.     

Development and reproduction of Adalia bipunctata (Coleoptera: Coccinellidae) on eggs of Ephestia kuehniella (Lepidoptera: Phycitidae) and pollen

Due to growing criticism over the use of non-indigenous coccinellids, the two-spot ladybird, Adalia bipunctata (L.), has enjoyed increasing attention for aphid biocontrol in Europe. In the current study, eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller, whether or not supplemented with bee pollen, were evaluated as a factitious food for larvae and adults of A. bipunctata. The predator showed slower larval development and lower survival when reared on live pea aphids, Acyrthosiphon pisum (Harris), than on E. kuehniella eggs. Survival on gamma-irradiated eggs of E. kuehniella was superior to that on frozen flour moth eggs, but other developmental characteristics were similar. Adults of A. bipunctata reared on Ac. pisum were only half as fecund as those offered irradiated or frozen E. kuehniella eggs, but egg hatch was markedly better on live aphids than on flour moth eggs (61 versus 20-27%, respectively). However, when a diet of flour moth eggs was supplemented with frozen moist bee pollen, egg hatch of A. bipunctata was equally as good as on live aphids. Supplementing flour moth eggs with dry pollen did not yield satisfactory results. Only 10% of larvae reached adulthood on moist bee pollen alone and resulting adults weighed less than half as much as those obtained on flour moth eggs. Our findings indicate that A. bipunctata is able to compensate for a suboptimal diet of animal prey by supplementary feeding on flower pollen. It is concluded that pollinivory may be a crucial trait for both the rearing of this natural enemy and its use in biological control programmes.     

Die Typisierung vonVicia biennis L. sowie systematische und cytologische Beobachtungen anVicia neglecta spec. nov.

Zusammenfassung Das Untersuchungsmaterial wurde auf Feldern der Landwirtschaftlichen Versuchsstation in Kanton gesammelt, wo es unter dem NamenVicia cracca geführt wurde. Die Pflanzen gehören zu einer seltenen, oft verkannten, in der Literatur alsV. biennis L. bezeichneten Art, deren Spontanareal in Westsibirien liegt. Die Deutung dieser Art wurde an Hand des Originalmaterials im Herbar Linné einer Kritik unterzogen: UnterV. biennis verstand Linné die pannonisch-pontische, bisherV. picta Fisch. et Mey. genannte Art, für die jetzt der ältere Linnésche Name eintreten muß. Für die von uns untersuchte Art wurde als neuer NameV. neglecta Hanelt et Mettin eingeführt. Es werden morphologische und cytologische Angaben über diese Art gemacht. Sie besitzt 2n=12 Chromosomen und stimmt cytologisch mit den früher beschriebenen 12chromosomigen Typen derVicia cracca-Gruppe überein. Soweit Vergleiche möglich sind, besteht aber keine morphologische Übereinstimmung. Die gegenseitigen Beziehungen zwischen den verschiedenen 12-, 14-, 24- und 28chromosomigen Vertretern dieser eng verwandten Artengruppe werden diskutiert.

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Summary The investigated material was collected in experimental fields of the Agricultural Experimental Station in Canton, where it was namedVicia cracca. The plants belong to the rare, often misinterpreted species, which is calledV. biennis L. in the literature. Its spontaneous area occupies parts of Western Siberia. The interpretation of this species has been criticized by the use of the original material in the herbarium of Linné: He understood byV. biennis the pannonic-pontic, hithertoV. picta Fisch. et Mey. named species; instead of it the correct older nameV. biennis L. has to be accepted. The new nameV. neglecta Hanelt et Mettin has been introduced for the species investigated by us. Morphological and cytological remarks have been made on it.V. neglecta possesses 2n=12 chromosomes and agrees in cytological respect with the 2n=12 types which have been formerly described in theVicia cracca species group. But there is no morphological agreement with them so far as comparisons are possible. The mutual relations have been discussed between the different 12-, 14-, 24- and 28-chromosomic representatives of this species group.

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, Vicia cracca. , , V. biennis L.; . , , - . V. biennis - , V. picta Fisch. et Mey., . , V. neglecta Hanelt et Mettin. . 12 (2n) V. cracca 12 , . , 12, 14, 24 28 .

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Ergebnisse Chinesisch-Deutscher Biologischer Sammelreisen seit 1956 Nr. 12.     

Cytosystematische Untersuchungen in der Artengruppe umVicia sativa L. II

Zusammenfassung Vicia pilosa M. B. (2 n=14),V. amphicarpa Dorth. (2 n=14) undV. macrocarpa (Moris) Bertol. (2 n=12), die in morphologischer und karyologischer Hinsicht beschrieben werden, haben sich als Arten der Sippengruppe umV. sativa herausgestellt. Dieser Komplex aus annuellen und — soweit bekannt — autogamen Sippen wird als eine absteigende aneuploide Reihe (2 n=14 2 n=12 2 n=10) aufgefaßt, wie sie in entsprechenden Formen bereits in vielen annuellen Gruppen bekannt ist. Die größte Variabilität ist dabei auf der 2 n=12-Stufe anzutreffen. — Die der Evolution der Sippen dieser Gruppe zugrunde liegenden karyologischen Differenzierungsprozesse werden diskutiert.In dem folgenden Anhang sind alle karyologisch untersuchten Herkünfteder hierhergehörenden Sippen zusammengestellt.

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Summary Vicia pilosa M. B. (2 n=14),V. amphicarpa Dorth. (2 n=14) andV. macrocarpa (Moris) Bertol. (2 n=12) have been described in morphological and karyological respect, they proved to be species of theV. sativa-group. This species aggregate of annual and—so far as it is known—of autogamous taxa is considered as a descending aneuploid series (2 n=14 2 n=12 2 n=10), as it is known from many other annual plant groups. The most conspicuous variability is represented on the 2 n=12 level. The karyological differentiation processes which may be responsible for the evolution within theV. sativa-group have been discussed.In the following appendix all karyologically examined strains of the taxa belonging to this group have been put together.

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am ¶rt;au Vicia pilosa M. B. (2n=14),V. amphicarpa Dorth. (2n=14) V. macrocarpa (Moris) Bertol. (2n=12), , V. sativa. , , (2n=14 2n=12 2n=10), . 2n=12. , . , V. sativa.

     

Genotypic and phenotypic screening of high and low virulence Staphylococcus aureus isolates from rabbits for biofilm formation and MSCRAMMs

At rabbit flock level, two types of Staphylococcus aureus infections can be distinguished. In the first type, caused by low virulence strains, the infection remains limited to a small number of animals. The second type of infection is caused by the high virulence strains, which spread throughout the rabbitry. The pathogenetic capacity of a particular S. aureus strain is attributed to a combination of extracellular factors and invasive properties such as adherence and biofilm formation. Twenty eight high virulence and 34 low virulence S. aureus isolates recovered from rabbits between 1998 and 2003 were used to study slime production on Congo red Agar (CRA) and prevalence of bap, icaA and icaD associated with biofilm formation. Furthermore these strains were screened for the presence of bbp, clfA, clfB, cna, ebpS, eno, fnbA, fnbB and fib encoding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). The presence of icaA and icaD was not correlated with slime production on CRA. Bap was absent in all strains. All rabbit S. aureus strains harboured clfA and clfB. The prevalences of ebpS, eno, fnbA and fib did not reveal striking differences between high and low virulence strains. FnbB prevalence in high virulence isolates was lower than in low virulence isolates and cna was absent in high virulence strains. It was remarkable that only high virulence strains were positive for bbp. Further research is necessary to elucidate the significance of bbp in the pathogenesis of high virulence strains.     

Modeling single-neuron dynamics and computations: a balance of detail and abstraction

The fundamental building block of every nervous system is the single neuron. Understanding how these exquisitely structured elements operate is an integral part of the quest to solve the mysteries of the brain. Quantitative mathematical models have proved to be an indispensable tool in pursuing this goal. We review recent advances and examine how single-cell models on five levels of complexity, from black-box approaches to detailed compartmental simulations, address key questions about neural dynamics and signal processing.