A Distributed Scheduling Algorithm to Provide Quality-of-Service in Multihop Wireless Networks

Control of multihop Wireless networks in a distributed manner while providing end-to-end delay requirements for different flows, is a challenging problem. Using the notions of Draining Time and Discrete Review from the theory of fluid limits of queues, an algorithm that meets delay requirements to various flows in a network is constructed. The algorithm involves an optimization which is implemented in a cyclic distributed manner across nodes by using the technique of iterative gradient ascent, with minimal information exchange between nodes. The algorithm uses time varying weights to give priority to flows. The performance of the algorithm is studied in a network with interference modelled by independent sets

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Design of Multi-Propellant Star Grains for Solid Propellant Rockets

A new approach to solve the geometry-problem of solid propellant star is presented. The basis of the approach is to take the web-thickness (a ballistic as well as a geometrical property) as the characteristic length. The nondimensional characteristic parameters representing diameter, length, slenderness-ratio, and ignitor accommodation of the grain are all identified. Many particular cases of star configurations (from the configurations of single propellant to those of four different propellants) can be analysed through the identified characteristic parameters. A better way of representing the single-propellant-star-performance in a design graph is explained. Two types of dual propellant grains are analysed in detail. The first type is characterised by its two distinct stages of burning (initially by single propellant burning and then by dual propellant burning); the second type has the dual propellant burning throughout. Suitability of the identified characteristic parameters to an optimisation study is demonstrated through examples

Desiccation-resurrection linked antioxidant machinery of a moss species Campylopus flexuosus (Hedw.) Bird.

Dehydration and rejuvenation during rehydration is the salient feature of certain plants which can withstand drought. The present study was undertaken to justify the tolerance capacity of Campylopus flexuosus, the moss of the Ponmudi belts of Thiruvananthapuram, against dehydration followed by rehydration. Fresh leafy plants of C. flexuosus were hydrated, afterwards dried, and rehydrated under in vitro environment. In the course of loss of water from cells, the relative water content of desiccated thallus was reduced after 4 h with intense inward curling. Upon rehydration, the RWC was regained 85% of its initial water content within hours. The rehydrated thallus showed the normal morphology. Photosynthetic parameters like chlorophyll b (1.01 to 1.56 μg g –1 ), and total carotenoid (0.251 to 0.514 μg g –1 ) increased remarkably in the desiccated state. Superoxide radical (O2 _) content increased (11.4 nmol/g FW), resulting in an oxidative burst during desiccation. Consequently, antioxidant enzymes such as catalase (0.369 U mg protein −1), superoxide dismutase ( 2.68 to 6.02 Units mg−1), peroxidase ( 0.12 μmol min−1 g−1 protein) and glutathione reductase ( 312 Units mg−1 protein) activities were up-regulated in the desiccated thallus to ameliorate oxidative damage. Increased malondialdehyde (1.08 nmol g−1 FW) content during desiccation substantiates membrane damage and loss of its integrity. During desiccation, the osmolytes sucrose and proline (27.6 and 2.57 μmol/g FW respectively) were enhanced to maintain cell structure integrity. After rehydration, biochemical and morphological properties were maintained similar to hydrated conditions. Thus, the study reflects the unique adaptations of the moss to tide over desiccation tolerance

Antimetastatic potential of anthocyanins from Cordyline australis (G. Forst.) Endl. Red star variety on MCF onco cell lines

Breast cancer is the second most deadly diagnosed lifestyle disease among women. Surgery and chemotherapy are the current treatments of choice; nevertheless, toxicity connected with this underscores the urgency of the demand for the human-friendly drug. 50% of current synthetic drugs available commercially today are either direct or indirect descendants extracted from herbs. Anthocyanins possess many pharmacological activities, including anticancer potential. However, no study on anticancer activity of anthocyanins from Cordyline australis has been reported. Anthocyanins were extracted from fresh leaves using ethanol as solvent. The total anthocyanin was quantified and fractionated by Ultra Performance Liquid Chromatography. Cytotoxicitic effect was carried on diverse cancer cell lines like MCF 7, HCT-116, Caco-2 and SW480 using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. Based on MTT data, MCF 7 cells were further analyzed by LDH assay, Glutathione-S- transferase (GST), Quercetin reductase, Cytochrome P450 and Caspase 3, 8 and 9 activities. The obtained results were analyzed using ANOVA with a level of significance. Results obtained from MTT assay revealed that the anthocyanin extract carried significant toxic (p < 0.05) specificity against MCF 7 cells (65 ± 2.1 toxicity at 50 µg/ml) when compared to the other onco cells. Remarkable LDH leakage (50.2% vs 50 µg/ml), GST (3.0±0.002 U/mg protein), QR (4.4±0.054 U/mg protein), Cyt P450 activities (0.291±0.01 U/mg protein) were noticed. Caspase 3 (157%), 8 (142%) and 9 (147%) displayed profound activities. These in vitro findings of specific anticancer effects noticed on C. australis anthocyanin extract require further evaluation using animal models. Finally, the obtained findings open up the possibility of developing a lead antimetastatic anthocyanin candidate against deadly breast cancer