Adding Robustness in Dynamic Preemptive Scheduling

In this paper we introduce a robust earliest deadline scheduling algorithm for deal ing with hard aperiodic tasks under overloads in a dynamic realtime environment The algorithm synergistically combines many features including dynamic guarantees graceful degradation in overloads deadline tolerance resource reclaiming and dy namic reguarantees A necessary and sucient schedulability test is presented and an ecient On guarantee algorithm is proposed The new algorithm is evaluated via simulation and compared to several baseline algorithms The experimental results show excellent performance of the new algorithm in normal and overload conditions Static realtime systems are designed for worst case situations Assuming that all the assumptions made in the design and analysis are correct we can say that the level of guarantee for these systems is absolute and all tasks will make their deadlines Unfortunately static systems are not always possible becaus

Antimicrobial activity of sesquiterpene lactones isolated from traditional medicinal plant, Costus speciosus (Koen ex.Retz.) Sm

<p>Abstract</p> <p>Background</p> <p><it>Costus speciosus </it>(Koen ex.Retz.) Sm (Costaceae) is an Indian ornamental plant which has long been used medicinally in traditional systems of medicine. The plant has been found to possess diverse pharmacological activities. Rhizomes are used to treat pneumonia, rheumatism, dropsy, urinary diseases, jaundice, skin diseases and leaves are used<b/>to treat mental disorders.</p> <p>Method</p> <p>Antibacterial and antifungal activities were tested using Disc diffusion method and Minimum Inhibitory <b>Concentration </b>(MIC). Column chromatography was used to isolate compounds from hexane extract. X-ray crystallography technique and GC-MS analysis were used to identify the compounds</p> <p>Results</p> <p>Antibacterial and antifungal activities were observed in hexane, chloroform, ethyl acetate and methanol extracts. Hexane extract of <it>C.speciosus </it>showed good activity against tested fungi also. Two sesquiterpenoid compounds were isolated (costunolide and eremanthin) from the hexane extract. Both the compounds did not inhibit the growth of tested bacteria. But, both the compounds inhibited the tested fungi. The compound costunolide showed significant antifungal activity. The MIC values of costunolide were; 62.5 μg/ml against <it>Trichophyton mentagrophytes</it>, 62. μg/ml against <it>T. simii</it>, 31.25 μg/ml against <it>T. rubrum </it>296, 62.5 μg/ml against <it>T. rubrum </it>57, 125 μg/ml against <it>Epidermophyton floccosum</it>, 250 μg/ml against <it>Scopulariopsis </it>sp, 250 μg/ml against <it>Aspergillus niger</it>, 125 μg/ml against <it>Curvulari lunata</it>, 250 μg/ml against <it>Magnaporthe grisea</it>.</p> <p>Conclusion</p> <p>Hexane extract showed promising antibacterial and antifungal activity. The isolated compound costunolide showed good antifungal activity.</p

Alterations of the ionic composition in different organs of spotted murrel (Channa punctatus) exposed to sublethal concentration of endosulfan

The spotted murrel, Channa punctatus were exposed to sublethal concentration of endosulfan (8.1 mu g/L) for 48 and 96 h to elucidate the impact of the pesticide on the ionic composition in different organs of the fish. After 48 and 96 h endosulfan exposure, fish were randomly selected from each control and experimental tanks, anesthetized, sacrificed and then different organs like liver, kidney, gill and muscle were dissected for mineral estimation. Results showed that liver Ca and Mg levels after 48 h increased significantly, however after 96 h, these two minerals showed reduction in their levels. The remaining minerals in the liver (P, Na, K, Fe, Zn, Cu and Mn) did not change significantly with increase in the exposure duration however, showed a decreasing trend after 96 h. Kidney Ca and Mg after 48 h exposure increased significantly by 89.5 and 79.8% and after 96 h the concentration of both these minerals were non-significantly higher by 23.2 and 27.8% from the control. Kidney Mn level after 96 h was also significant higher (by 31.7%) than the control. The remaining kidney minerals (P, Na, K, Fe, Zn and Cu) did not change significantly with change in the exposure duration, however, after 96 h some of them (P, Na, Zn) increased. Gill Ca level decreased significantly with the increase in the duration of endosulfan. Gill Fe and Cu levels also showed almost similar trend like gill Ca. The remaining minerals (P, Na, K, Zn, Mg and Mn) in the gill were not significant influenced by endosulfan exposure however, they (except Mn) showed a decreasing trend after 96 h. In muscle tissue, P and K increased significantly with the increase in the exposure periods whereas, muscle Zn showed a reverse trend. The remaining minerals (Na, Ca, Fe, Mg, Cu and Mn) did not change significantly with the change in the endosulfan exposure time however, they (except Mg and Mn) showed a decreasing trend at the end of 96 h. In essence, the present study showed that the concentration of majority of the minerals in the liver, gill and muscle after 96 h endosulfan exposure decreased, however, their level increased in the kidney. Thus, exposure of sublethal endosulfan concentration to C. punctatus caused significant alterations in the ionic composition in different organs of their body