Abstract:Encystment and excystment in the life cycle of a dinoflagellate Peridinium sp. B3, which was isolated from Lake Begnas in the Pokhara Valley, Nepal, were investigated by use of a clonal population.The maximum cell concentration was 3103 vegetative cellsml-1 in BL medium after about 4 weeks at 30C.Sexual reproduction of the cells was induced after the cells in late logarithmic phase were inoculated into nitrogen and phosphorous deficient medium, and also was spontaneously induced in BL medium.Sexual reproduction was isogamous and homothallic. The cycle was initiated by gamete formation, rn which gametes were produced by binary asexual divisions of the vegetative cells. Fusing pairs were formed by the mid-ventral union of gametes. The planozygote retained two red bodies and remained motile for about 2 weeks. Two weeks after the planozygote lost motility, the zygotes enlarged and became dark in color. The theca of the planozygote split around the girdle region and the hypnozygote (cyst) was produced.The matured cysts were dormant and remained viable for at least 1 month at 10C in darkness following maturation for 3 months at 30C. The dark-cold treated cysts excysted synchronously when the incubation temperature was raised to 30C. The protoplast emerged from the cyst wall by amoeboid movement. The excysted cell had two red bodies. This cell divided within 24-48h into 2 daughter cells each with a red body.

This paper presents an online voltage disturbance estimator to achieve precise torque control of IPMSMs over a high speed operating region. The proposed design has a type of state-filter based on a Luenburger-style closed loop stator current vector observer. Utilizing the frequency response plot (FRF) approach, the estimation accuracy and the parameter sensitivities are analyzed. Accurate torque control and improved efficiency are provided with the decoupling of the effect of the parameter variations. The feasibility of the presented idea is verified by laboratory experiments.

Bacterial numbers and floras in the water and sediment of subtropical Lakes Phewa, Begnas, and Rupa in the Pokhara Valley, Nepal, were surveyed in late monsoon season. In the water column at the deepest part of Lakes Phewa, Begnas, and Rupa, total bacteria estimated by the acridine orange direct count (AODC) method changed in the range of 11-2.4X106, 1.7-2.4X106, and 3.2-3.5X106 cells/ml, respectively, and heterotrophic bacteria estimated by the spread plate method changed in the range of 2.5-18X103, 2.0-4.0X103, and 6.9-14X103 CFU (colony-forming units)/ml, respectively. The distribution pattern of free-living and attached heterotrophic bacteria, size-fractionated with a 3.0 um Nuclepore filter, throughout the water column differed among the three lakes. The total and heterotrophic bacteria in the water at inlet were in the orders of 104-105 cells/ml and 103 CFU/ml, respectively, and those in the water at outlet showed a similar number to those in the surface water at each deepest part. The number of heterotrophic bacteria in the sediment at the deepest part was not different among the lakes and in the range of 5.9-8.9X105 CFU/cm3 of wet sediment. All of 178 isolates purified from the three lakes, 64 from the water and 114 from the sediment, were identified to generic level. Only 20% of bacteria isolated from the water were purified, and most of those isolates belonged to Pseudomonas, Flavobacterium, and coryneforms. On the other hand, the bacterial floras in the sediment of the three lakes were dominated by Bacillus.