Tipulid spermatocytes form normally functioning bipolar spindles after one of the centrosomes is experimentally dislocated from the nucleus in late diakinesis (Dietz, R., 1959, Z. Naturforsch., 14b:749-752; Dietz, R., 1963, Zool. Anz. Suppl., 23:131-138; Dietz, R., 1966, Heredity, 19:161-166). The possibility that dissociated pericentriolar material (PCM) is nevertheless responsible for the for...

Lithologic mapping in the hostile and inaccessible mountainous region like the Himalaya and Tibet has frequently been a great challenge for geologists. The remote sensing techniques should be a potential player in lithologic mapping and structural analysis in these mountainous regions. With the successful development of minrealogic indices, e.g., Quartz Index (QI), Carbonate Index (CI), Mafic I...

This study assessed the suitability of both visible and shortwave infrared ASTER data and vegetation indices for estimating forest structural attributes of Eucalyptus species in the southern KwaZulu Natal, South Africa. The empirical relationships between forest structural attributes and ASTER data were derived using stepwise multiple regression analysis; Modified Soil Adjusted Vegetation Index...

Mitotic apparatuses (MAs) isolated from sea urchin eggs contained clusters of granular material in their centrospheres. After cold treatment and mild agitation, the MA fraction formed asters when combined with tubulin. Many microtubules grew from isolated centrospheres most of which were covered with astral residues. Homogenization of the isolated MA fraction dispersed the centrospheres which b...

This paper presents an evaluation, to which degree geological and geomorphological information can be obtained from modern remote sensing systems like the multispectral ASTER or the hyperspectral Hyperion sensor for a hyperarid desert region like the Dakhla Oasis (Western Desert, Egypt). To account for the enhanced information content these sensors provide, hyperspectral analysis methods, incor...

Using an interspecies microinsemination assay with bovine oocytes, it was examined whether centrosomes of Antarctic minke whale spermatozoa function as the microtubule-organizing centre (MTOC). Bull and rat spermatozoa were used as positive and negative controls, respectively. Vitrified-warmed bovine mature oocytes were subjected to immunostaining against alpha-tubulin 4-6 h after intracytoplas...

Residues of the polar pesticide pymetrozine were compared using two methods: hydromatrix and liquid-liquid extraction (LLE). The biological half-life and the final residue level were investigated using Aster scaber over a 10-days cultivation period. The respective biological half-lives of the pesticide were 4.2 and 3.5 days at the recommended and double dose. The final residue levels were 1.28 ...

Abstract Advanced spaceborne thermal emission and reflection radiometer (ASTER) data different spectral indices were employed to map gypsum minerals. However, most proposed are designed based on the 2.21 ?m absorption, overlapping with hydroxy-bearing Moreover, seasonal mutual transformation between gypsum, bassanite, anhydrite may lead reflectance variability of formation pixels, affecting cla...

Selenium-accumulator plants are reputed to be unpalatable to livestock. The objective of this study was to determine if sheep and cattle could discriminate between forages and feeds with different concentrations of Se. In the first study, cattle and sheep preferences for intermediate wheatgrass (Thinopyrum intermedium), alfalfa (Medicago sativa), and western aster (Symphyotrichum ascendens) of ...