Simulation-based Evaluation of Mobile Ad Hoc Network Routing Protocols: Ad hoc On-Demand Distance Vector, Fisheye State Routing, and Zone Routing Protocol

Mobile ad hoc network (MANET) is an infrastructure-less and decentralized network without any physical connections. Nodes are mobile, free to move, and independent of each other which makes routing a difficult task. Hence, a dynamic routing protocol is needed to make MANET reliable and function properly. Several routing protocols have been proposed with different working mechanisms and performance levels. Therefore, the performance study of those protocols is needed. This paper evaluates the performance of MANET routing protocols using simulation based experiments to observe the behavior of the network as the density of the nodes increases. The paper evaluates the performance of proactive (fisheye state routing), reactive (ad hoc on-demand distance vector), and hybrid (zone routing protocol) routing protocols in terms of the packet delivery fraction, average throughput, and average end-to-end delay. The simulations of protocols to analyze their performance in different conditions were performed using the network simulator 2 (NS 2)

Optoelectronically active sensitisers for the selective detection of nucleic acid biomarkers

This thesis presents biophysical studies of new optoelecronically active DNA-binders. Chapter one gives a brief overview of the importance of DNA in medicine, of DNA structure and of the mode of interactions of small molecules with double-stranded DNA, including electrostatic, intercalation and groove interactions. Various examples of small-molecule binding to DNA are discussed. Additionally, this chapter briefly describes the biophysical techniques which can be exploited to quantify the interaction between small-molecules and duplex DNA. Chapter two describes the results of studies of the interactions of a group of 1,8-naphthalimide derivatives with double-stranded DNA using a variety of techniques viz. spectroscopy, calorimetry, viscosity and molecular docking studies. Additionally, this chapter also presents sequence selectivity studies of this group of compounds for specific sequences (dAdT)12●(dAdT)12 and (dGdC)12●(dGdC)12 through UV-visible spectroscopy. The 1,8-napthtalimide unit is shown to be a useful element for inducing DNA-binding. Chapter three describes studies of the interactions of a family of dendrimeric compounds with double-stranded DNA, again using spectroscopy, calorimetry, viscosity and molecular docking studies. Furthermore, this chapter includes sequence selectivity studies of this group of compounds for (dAdT)12●(dAdT)12 and (dGdC)12●(dGdC)12 via UV-visible spectroscopy. The charge and the length of the dendritic structures is shown to strongly affect nucleic acid affinities of this series of molecules. Chapter four describes the results of studies of the interactions of miscellaneous compounds with double-stranded DNA using variety of techniques viz. spectroscopy, calorimetry, viscosity and molecular docking studies. In addition, this chapter displays sequence selectivity studies of this group of compounds for specific sequences (dAdT)12●(dAdT)12 and (dGdC)12●(dGdC)12 via UV-visible spectroscopy. Chapter five gives an overview and general conclusions about the DNA binding studies presented in Chapters 2, 3 & 4 and finishes with suggestions for future work

The Effect of Adding Stiffener on Deflection of Loading Arm by Using BEM & FEM

In this study we are concerned to improve the deflection of the loading arm with new suggested style , where the BEM techniques has been used to estimate a deflection at each distance (x) for the main part of loading arm pipe (3'') , thereafter a simplified stiffener has been added to optimize a moment of inertia of this main part thereby the deflection will be better , for this purpose a case study has been considered according to international standard for the pipe specification that  investigated to illustrate the goal of this work, adding to this ANSYS  program  has been used to verify the calculation

Chansu inhibits the expression of cortactin in colon cancer cell lines in vitro and in vivo

Background: Chansu is a transitional Chinese medicine that has been used for centuries as therapy for inflammation, anaesthesia and arrhythmia in China and other Asian countries. Recently, it has also been used for anti-cancer purposes. We have previously shown that Chansu has a huge pro-apoptotic potential on colon cancer cells, but to date the detailed mechanism of this action is not well understood. Methods: One of the major components of Chansu, Cinobufagin (CBF) was used to treat cancer cells. The expressions of levels of cortactin, an important factor in tumour progression and cancer invasion, were assessed in in vitro and in vivo experiments. Additional analyses were performed in subcellular protein fractions and immune-fluorescent staining was used to define cortactin protein expression and the changes of location in CBF-treated cells. Results: CBF strongly inhibited the expression of cortactin in HCT116 cells. There were reductions of both mRNA transcription and protein synthesis, which were more significant in the absence of oxygen in vitro. In addition, nuclear translocation of cortactin was observed in HCT116 cells post CBF exposure but not in the negative control, indicating that CBF is likely to interrupt co-localisation of cortactin to cytoskeletal proteins. Most importantly, CBF could diminish the expression of cortactin in human HCT116 xenograft tumours in nude mouse in vivo. Conclusions: CBF inhibits cortactin expression and nuclear translocation in colon cancer cells in vitro and in mouse models bearing human colon tumour in vivo, suggesting it might disrupt actin-regulated cell movement. Thus, CBF or Chansu could be developed as an effective anti-cancer therapy to stop local invasion and metastasis

The mechanisms of Chansu in inducing efficient apoptosis in colon cancer cells

Chansu is one of the most widely used traditional Chinese medicines in China, Japan, and other Southeast Asian countries primarily for antipain, anti-inflammation, and recently anticancer. Over 10 recipes and remedies contained Chansu, which are easily available in pharmacies and hospitals, but the mechanisms of action were not clearly articulated. In the present study, Cinobufagin (CBF), the major compound of Chansu, was employed as a surrogate marker to determine its ability in inducing cancer cell death. As expected, CBF has significant cancer-killing capacity for a range of cancers, but such ability differs markedly. Colon and prostate cancers are more sensitive than skin and lung cancers. Interestingly, cancer cells die through apoptotic pathway either being biphasic caspase- 3-dependent (HCT116) or independent (HT29). Multipathway analysis reveals that CBF-induced apoptosis is likely modulated by the hypoxia-inducing factor-1 alpha subunit (HIF-

Role of a probiotic (Saccharomyces boulardii) in management and prevention of diarrhoea

AIM: To assess the efficacy and safety of Saccharomyces boulardii (S. boulardii) in acute watery diarrhoea and its role in reducing the frequency of episodes of diarrhoea in subsequent two months.Methods: Children from 2 mo to 12 years of age, with acute diarrhoea were selected according to inclusion criteria and randomised in S. boulardii group (treated with ORS, nutritional support and S. boulardii, 250 mg bid) and in control group (treated with ORS and nutritional support only). Active treatment phase was 5 d and each child was followed for two months afterwards. Frequency and consistency of stools as well as safety of drug was assessed on every visit. A comparison of two groups was done in terms of number of diarrhoeal episode in subsequent two months.Results: There were fifty patients in each group. Baseline characteristics such as mean age and the average frequency of stools were comparable in S. boulardii and control group at the time of inclusion in the trial. By d 3 it reduced to 2.7 and 4.2 stools per d respectively and by d 6 it reduced to 1.6 (S. boulardii Group) and 3.3 (control group). The duration of diarrhoea was 3.6 d in S. boulardii group whereas it was 4.8 d in control group (P = 0.001). In the following two months, S. boulardii group had a significantly lower frequency of 0.54 episodes as compared to 1.08 episodes in control group. The drug was well accepted and tolerated. There were no reports of the side effects during treatment period.Conclusion: S. boulardii significantly reduces the frequency and duration of acute diarrhoea. The consistency of stool also improves. The drug is well-tolerated