Ultrastructure and molecular characterization of Fusobacterium necrophorum biovars.

The ultrastructural features and molecular components of 18 strains of Fusobacterium necrophorum biovars A, AB and B, isolated from animal and human infections, were examined by electron microscopy, multilocus enzyme electrophoresis (MEE) and by sodium dodecyl sulfate-gradient polyacrylamide gel electrophoresis (SDS-PAGE). High resolution scanning electron microscopy revealed that the strains possessed a convoluted surface pattern. Transmission electron microscopy showed that all strains possessed a cell wall structure typical of gram-negative bacteria. Bleb formation was not uncommon. Numerous extracellular materials, resembling lipopolysaccharide (LPS) fragments, surrounded cells of both human strains and biovar B animal strains. Biovar A field strains revealed capsules as stained by ruthenium red whereas a stock culture strain showed the capsule only when immunostabilized with hyperimmune serum. Starch gel electrophoresis showed all strains to possess adenyl kinase, glutamate dehydrogenases and lactate dehydrogenase; each enzyme migrated uniformly (monomorphic) among the strains and represented an electrotype. However, SDS-PAGE indicated differences in the protein profiles between all of the strains; the most distinctly different was a human isolate (FN 606). Silver staining to detect LPS showed extensive "ladder" patterns among the majority of biovar A strains but not in the animal biovar B strains. Immunoblotting of LPS with a rabbit antiserum prepared against phenol extracted LPS from a biovar A animal isolate (LA 19) suggested marked variability in the LPS antigens among the isolates studied.     

Rundschau

Ohne Zusammenfassung     

Versuche zur Kenntnis der Ern?hrung der holzbohrasselLimnoria tripunctata und ihre Beziehung zu holzzerst?renden Pilzen

Ohne Zusammenfassung     

Auf Termiten spurbildend wirkende Stoffe

Ohne Zusammenfassung     

Limitations of a compensation heat pulse velocity system at low sap flow: implications for measurements at night and in shaded trees

Unlike an ideal system, the return time to thermal balance (t(b)) between upstream and downstream thermistors, as measured by the (compensation) heat pulse velocity method, effectively depends on the heat input and the water content of the wood at zero and low sap flow. Even when these factors were held constant and ambient temperature was stabilized, a twofold variation in t(b) at zero flow was observed within and among Greenspan Technology sensors implanted in wooden posts, making it impossible to distinguish zero flow from low sap velocities (< 0.01-0.02 mm s(-1)). This limitation has serious consequences because the contribution of low flow rates to water movement is important during both daytime and nighttime in tropical understory and overstory trees. Measurements in an artificial flow system showed that this technical limitation is exacerbated by erratic variation in sensor response at both zero and low flow rates. The limited sensitivity of the tested sap flow sensors may be caused by their poor thermal contact with wood. Interim procedures are suggested for estimating minimum detectable sap flow and delimiting the hydroactive zone until the sensitivity and interchangeability of sap flow probes are improved.     

Über Insektenschäden an Werkstoffen (Eine Literaturübersicht) 2. Schäden an Kunststoffen

Zusammenfassung Es wird eine Übersicht der Insektenschäden an Kunststoffen gegeben, über die in 36 Veröffentlichungen berichtet wurde. Die Verursacher der Schäden waren: Coleoptera: 10 Fam.; 26 Arten; Hymenoptera: 3 Fam., 4 Arten; Lepidoptera: 3 Fam., 6 Arten; Diptera; Trichoptera.

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On damages to materials by insects (A bibliography) 2. Synthetic materials

A review is given on insects injurious to synthetic materials, based on 36 publications. There are mentioned: Coleoptera, 10 fam., 26 species; Hymenoptera, 3 fam., 4 species; Lepidoptera, 3 fam., 6 species; Diptera; Trichoptera.

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Mit 2 Abbildungen und 2 Tabellen