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Notizen: 1. Zooplankton density was examined in a free-flowing section of the River Danube, Austria. Spatial and temporal patterns were used to identify mechanisms regulating zooplankton dynamics.2. Zooplankton abundance differed significantly between sampling sites. These differences were the result of variations in water residence time within the habitats. Inshore habitats with low flushing rates act as storage zones for zooplankton.3. The hydrological conditions govern the number and size of storage zones. In the study area, the highest availability of storage zones was observed at medium water level.4. Total zooplankton numbers, total rotifer numbers and the densities of the most abundant rotifer taxa were significantly positively related to the availability of adjacent storage zones.5. The present authors propose that inshore retention capacity, and the hydrological processes and mechanisms controlling the extent of inshore retention may be of major significance in regulated rivers with high water velocities, preventing substantial zooplankton growth in the main channel.

Notizen: ZUM 3. KONGRESS DER MARXISTISCH-LENINISTISCHEN SOZIOLOGIE IN DER DDR

Notizen: Abstract: The objective of this study was to evaluate the performance of the CELL-DYN® 3500 for rat and mouse blood analysis in a routine environment. The WBC (white blood cells), RBC (red blood cells), PLT (platelets) counts and the WBC differential were determined. In addition, the following aspects were studied: within-run precision, day-to-day precision, bias-free paired difference precision; extended ranges of linearity for RBC, HCT (haematocrit), WBC, PLT; carry-over, the effect of blood ageing, cell stability with different anticoagulants; and the normal ranges, the out of range flagging and some typical pathology cases.  The CELL-DYN® 3500 is a multiparameter flow cytometer which counts and differentiates WBC, based on the principle of multi-angle polarised light scatter separation. RBC and PLT are determined by the impedance method. The WBC count is evaluated by both, optical and impedance methods. Reference methods used were according to the ICSH recommendations on blood cell analysis, including manual counts of WBC and platelets, a centrifugal microhaematocrit method and a haemoglobin measurement by spectrophotometry using the WHO haemoglobin standard. All cell counts were compared with the results obtained by our routine blood cell analyser (Contraves AL820), and the WBC differential was compared with the manual microscopic differentiation of the 400 WBC (200 cells differentiated by two technicians).  The following coefficients of vartiation were obtained: within-run precision was 1.2% and 2.7% for WBC; 1.0% and 1.0% for RBC; 1.3% and 0.9% for haematocrit; 2.1% and 2.7% for platelets (rats and mice respectively). Day-to-day precision was performed using human tri-level control blood, and the CVs were found to be 〈1.7% for WBC, 〈1.4% for RBC, 〈1.2% for haemoglobin and 〈6.3% for platelets.  The following ranges of measurement were found to be linear in the rat: WBC: 0.10–20.20×103/μl; RBC: 0.016–14.3×106/μl; haemoglobin: 0.08–26.8 g/dl; haematocrit: 5.0%–77%; platelets: 14.0–1670.0×103/μl. Equal ranges were observed for mouse blood. Carry-over in rat blood was found to be 0.12% for WBC, 0.05% for RBC, 0.15% for haemoglobin and 0.46% for platelets. In mice, similar carry-over results were obtained. The correlation coefficients (Pearson, correlation coefficient) between the CELL-DYN® 3500 and Contraves AL 820 using linear regression analysis were as follows: 0.988 and 0.997 for WBC; 0.986 and 0.920 for RBC; 0.995 and 0.984 for haemoglobin; 0.958 and 0.85 for haematocrit; 0.958 and 0.963 for platelets, for rats and mice, respectively. Correlation coefficients between the CELL-DYN® 3500 and the manual differential of NEU (neutrophils) and LYM (lymphocytes) were higher than 0.8 in rats and higher than 0.9 in mice. Due to the relatively low absolute counts of MONO (monocytes), EOS (eosinophils) and BASO (basophils), only moderate correlation of methods was found.  The CELL-DYN® 3500 was judged to be reliable, accurate and easy-to-use for counting and identifying normal and most of the pathological blood specimens obtained from mice and rats. By using the CELL-DYN® 3500, the time for blood sample analysis can be shortened significantly and provides extensive opportunities to characterise pathological samples.

Notizen: Zusammenfassung Es wird über das dielektrische Relaxationsverhalten der beiden Mischungsreihen Tetra- (bzw. Poly-)isobutenylbern-steinsäureanhydrid/PIB im Konzentrationsbereich 0.03 (0.3) bis 6 (30) Gewichtsprozent berichtet. Der polare Mischungspartner TIBBSA (PIBBSA) relaxiert — unabhängig von der Konzentration — um den Faktor 40 (100) langsamer als PIB im Glasprozess. Sein Relaxationsbetrag zeigt im Gebiet um 1,5 (5) Gewichtsprozent eine anomale Konzentrationsabhängigkeit. Diese Mt sich unter der Annahme bevorzugter Einlagerung von Labelmolekiilpaaren in Superstrukturfalten im Rahmen des Mäandermodells quantitativ verstehen.