The Maximum Traveling Salesman Problem with Submodular Rewards

In this paper, we look at the problem of finding the tour of maximum reward on an undirected graph where the reward is a submodular function, that has a curvature of $\kappa$, of the edges in the tour. This problem is known to be NP-hard. We analyze two simple algorithms for finding an approximate solution. Both algorithms require $O(|V|^3)$ oracle calls to the submodular function. The approximation factors are shown to be $\frac{1}{2+\kappa}$ and $\max\set{\frac{2}{3(2+\kappa)},2/3(1-\kappa)}$, respectively; so the second method has better bounds for low values of $\kappa$. We also look at how these algorithms perform for a directed graph and investigate a method to consider edge costs in addition to rewards. The problem has direct applications in monitoring an environment using autonomous mobile sensors where the sensing reward depends on the path taken. We provide simulation results to empirically evaluate the performance of the algorithms.Comment: Extended version of ACC 2013 submission (including p-system greedy bound with curvature

ANTIDIABETIC AND ANTIHYPERLIPIDEMIC EFFCETS OF THE ETHANOLIC EXTRACT OF ALOCASIA INDICA RHIZOMES IN HIGH FAT DIET/STREPTOZOTOCIN AND STREPTOZOTOCIN/NICOTINAMIDE-INDUCED TYPE 2 DIABETIC RATS

Objective: The investigate the antidiabetic and antihyperlipidemic effect of ethanolic extract of Alocasia indica (EEAI) rhizomes in high-fatdiet/streptozotocin (HFD/STZ) and STZ/nicotinamide-induced Type 2 diabetic rats.Methods: Diabetes was induced in male Wistar rats by the administration of a HFD for 15 days/STZ (35 mg/kg b.w., i.p.) and STZ (60 mg/kg b.w.,i.p.)/nicotinamide (110 mg/kg b.w., i.p.). EEAI (100 and 200 mg/kg b.w., p.o.) was administered to diabetic rats for 28 days in HFD/STZ-inducedType 2 diabetic rats and for 15 days in STZ/nicotinamide-induced Type 2 diabetic rats. The effect of EEAI on blood glucose and body weight wasstudied in Type 2 diabetic rats. All these effects were compared with glibenclamide (5 mg/kg b.w., p.o.) as a reference antidiabetic drug.Results: The administration of the EEAI (100 and 200 mg/kg b.w., p.o.) resulted in a significant decrease in blood glucose level and significant increasein body weight in the HFD/STZ and STZ/nicotinamide-induced Type 2 diabetic rats. Further EEAI showed antihyperlipidemic activity as evidencedby significant decrease in serum total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C), very LDL-C levels coupled together withelevation of high-density lipoprotein cholesterol level in diabetic rats in the HFD/STZ and STZ/nicotinamide-induced Type 2 diabetic rats.Conclusion: The results suggest that the EEAI rhizomes possess a promising effect on the HFD/STZ and STZ/nicotinamide-induced Type 2 diabetes.Keywords: Antidiabetic, Antihyperlipidemic, Alocasia indica, High-fat diet, Streptozotocin, Nicotinamide

A COMPARATIVE STUDY OF NEUROPROTECTIVE EFFECT OF TELMISARTAN AND DONEPEZIL AGAINST LIPOPOLYSACCHARIDE INDUCED NEUROINFLAMMATION IN MICE

Objective: The aim of the present study was a comparative study of neuroprotective effect of telmisartan and donepezil against lipopolysaccharide(LPS)-induced neuroinflammation in mice.Methods: In this study, we investigated the comparative effect of telmisartan (5 mg/kg, p.o.) and donepezil (5 mg/kg, p.o.) in systemic inflammationinduced by LPS, ibuprofen (40 mg/kg, p.o.) was used as standard. Mice were treated with a single i.c. injection of LPS (5 µg/5 µl/kg), after 7 daysthe animal behavior was evaluated by testing specific cognitive functions, on Morris water maze and Pole climbing test. Biochemical estimation forglutathione (GSH), malondialdehyde (MDA) and tumor necrosis factor alpha (TNF-α) was done by enzyme-linked immunosorbent assay plate reader.Results: The neuroprotective effect of telmisartan (5 mg/kg) and donepezil (5 mg/kg) in LPS induced neuroinflammation in mice was compared. Oraladministration of telmisartan (5 mg/kg) for 7 days shows a better result in Morris water maze and pole climbing test, in comparison of donepezil. Italso increases the level of GSH and decreases the level of MDA and TNF-α in mice brain.Conclusion: The present study demonstrates that telmisartan and donepezil reduces LPS-induced microglial activation, beta-amyloid generation,central nervous system cytokine production, and behavioral symptoms of sickness. In comparative study of telmisartan and donepezil, telmisartanshows significant decrease in escape latency time and transfer latency time in comparison of donepezil. Therefore, telmisartan is more effective asthe comparative of donepezil.Keywords: Neuroprotective, Telmisartan, Donepezil, Lipopolysaccharide-induced neuroinflammation

Informative Path Planning and Sensor Scheduling for Persistent Monitoring Tasks

In this thesis we consider two combinatorial optimization problems that relate to the field of persistent monitoring. In the first part, we extend the classic problem of finding the maximum weight Hamiltonian cycle in a graph to the case where the objective is a submodular function of the edges. We consider a greedy algorithm and a 2-matching based algorithm, and we show that they have approximation factors of 1/2+κ and max{2/(3(2+κ)),(2/3)(1-κ)} respectively, where κ is the curvature of the submodular function. Both algorithms require a number of calls to the submodular function that is cubic to the number of vertices in the graph. We then present a method to solve a multi-objective optimization consisting of both additive edge costs and submodular edge rewards. We provide simulation results to empirically evaluate the performance of the algorithms. Finally, we demonstrate an application in monitoring an environment using an autonomous mobile sensor, where the sensing reward is related to the entropy reduction of a given a set of measurements. In the second part, we study the problem of selecting sensors to obtain the most accurate state estimate of a linear system. The estimator is taken to be a Kalman filter and we attempt to optimize the a posteriori error covariance. For a finite time horizon, we show that, under certain restrictive conditions, the problem can be phrased as a submodular function optimization and that a greedy approach yields a 1-1/(e^(1-1/e))-approximation. Next, for an infinite time horizon, we characterize the exact conditions for the existence of a schedule with bounded estimation error covariance. We then present a scheduling algorithm that guarantees that the error covariance will be bounded and that the error will die out exponentially for any detectable LTI system. Simulations are provided to compare the performance of the algorithm against other known techniques

ANTIDEPRESSANT ACTIVITY OF METHANOLIC EXTRACT OF VERBENA OFFICINALIS LINN. PLANT IN MICE

ABSTRACTObjective: The objective was to investigate the antidepressant activity of methanolic extract of leaves of Verbena officinalis Linn. (MEVO) in mice.Methods: The present study evaluates the antidepressant activity of MEVO in mice using the tail suspension test (TST) and forced swimming test(FST). Their influence on spontaneous locomotor activity (SLMA) was also studied in mice. The MEVO (100 mg/kg, p.o. and 200 mg/kg, p.o.) wasadministered orally in TST, FST and SLMA for 7 successive days in separate groups of Swiss mice.Results: The extract at 100 and 200 mg/kg, p.o. were able to decrease the immobility time of mice doseâ€dependently when subjected to both tailsuspension and forced swim tests and the effects are comparable to that of control group. These results demonstrated that MEVO had specificallyantidepressant effects.Conclusion: The present study suggested that MEVO possessed potential antidepressant effects which could be of therapeutic interest for using inthe treatment of patients with depression.Keywords: Verbena officinalis Linn., Antidepressant activity, Forced swim test, Tail suspension test, Spontaneous locomotor activity

Protective effect of Berberis asiatica root on biochemical and histopathological changes in streptozotocin-induced diabetic Wistar rats

Background: This study was designed to evaluate the effect of Berberis asiatica root extract (BAE) against streptozotocin induced elevated blood glucose level and other liver and kidney functions changes in adult male Wistar rats.Methods: Thirty male Wistar rats were divided into five groups of six rats in each (Groups I-V). Group I and Group II served as normal control and disease control, respectively. Group III received standard anti-diabetic drug glibenclamide (5mg/kg), while Group IV and Group V received the low dose (250mg/kg) and high dose (500mg/kg) of BAE. Serum blood glucose, SGOT, SGPT, ALP, total bilirubin, BUN, serum creatinine, TC, TG, HDL-C, LDL-C, and VLDL-C were estimated using standard methods. After collection of samples for biochemical evaluation, the pancreas from each animal was isolated and examined for histological changes.Results: BAE and glibenclamide treated disease rats showed significant (p <0.05) decrease in blood glucose concentration. Treatment with BAE at 250mg/kg and 500mg/kg in Group IV and V and standard drug glibenclamide in Group III showed significant (p <0.05) reduction in the level of liver function substances such as SGOT, SGPT, ALP and total bilirubin as compared to disease group, as well as showed significant (p <0.05) decrease in renal panel. Liver function parameters were significantly (p <0.05) improved in groups treated with BAE. Histopathological analysis revealed the protective effect of BAE against streptozotocin induced damage to islets of Langerhans.Conclusions: This study showed the destruction of islets of Langerhans and elevation in blood glucose level as well as alteration in other biochemical parameters were ameliorated by the effect of Berberis asiatica extract

Preparation and Evaluation of Nanoemulsion of Citronella Essential Oil with Improved Antimicrobial and Anti-Cancer Properties

The development of new pharmaceutical solutions for treating various diseases results from a growing understanding of the benefits of using essential oils. One of the most often used volatile materials among essential oils is the oil of the citronella plant, termed citronella essential oil (CITEO), which has potential for use in food and medicine. Its wide use is limited due to lipophilicity, high volatility and poor physicochemical stability. With this background, the present study aims to evaluate the properties of CITEO-nanoemulsion (CITEO-NE) by analyzing its antimicrobial activities against Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans) and its anticancer activity against, human skin adenocarcinoma cell line (A431). The CITEO-NE was prepared and evaluated for the size range of 130 ± 5 nm, polydispersity index (PDI) of 0.127 and zeta potential −12.6 mV. The percentage % of entrapment efficiency (%EE) of nanoemulsions loaded with CIT was very high at the beginning of the study, at 95.5 ± 4.775%. The MIC was observed to be 500 µg/mL for CITEO and 250 µg/mL for CITEO-NE against S. aureus and 250 µg/mL for CITEO and 125 µg/mL for CITEO-NE against C. albicans. The time-kill assay also suggests the effectiveness of CITEO-NE against the test pathogens as a novel alternative therapy. The IC50 values of CITEO and CITEO-NE exhibited significant cytotoxic properties against the A431 cell line, with 41.20 μg/mL and 37.71 μg/mL, respectively. Hence, our findings revealed that encapsulation of CITEO increased the pharmacological properties

Estrogenic activity of a hydro-alcoholic extract of Bambusa arundinaceae leaves on female wistar rats

To study the estrogenic activity of the hydro-alcoholic extract of Bambusa arundinaceae leaves (HEBA) in female Wistar rats. The dried powdered leaves were extracted with hydroalcoholic mixture (60%), and the resultant extract was subjected for phytochemical analyses to identify different phytoconstituents. HEBA were administered to ovariectomized rats for 7 days at three different doses (viz., 200, 300, 400 mg/kg body weight, p.o.) and their estrogenic activity were compared with each of daily treatment with 0.2 mg/kg body weight, i.p. conjugated equine estrogen as a positive control or olive oil as a negative control. Estrogenic activity was evaluated by doing uterotropic assay, vaginal cytology and measurement of vaginal opening in female Wistar rats. Oral administration of HEBA in ovariectomized immature and mature female Wistar rats in a dose of 400 mg/kg b.w. resulted in significant increase in the uterine wet weight (in mg) (224.82 ± 7.01) and (912.25 ± 27.22) when compared with ovariectomized control rats (111.52 ± 3.17) and (506.67 ± 21.39). HEBA (400 mg/kg b.w., p.o.) treated rats, showing only cornified epithelial cells which was an indication of the presence of the estrogen and also showed 100% vaginal opening. It was observed that HEBA possess significant estrogenic activity at 400 mg/kg b.w., p.o. which was evident by uterotropic assay, measurement of vaginal opening, and histopathological changes