Control of spiral waves and turbulent states in a cardiac model by travelling-wave perturbations

We propose a travelling-wave perturbation method to control the spatiotemporal dynamics in a cardiac model. It is numerically demonstrated that the method can successfully suppress the wave instability (alternans in action potential duration) in the one-dimensional case and convert spiral waves and turbulent states to the normal travelling wave states in the two-dimensional case. An experimental scheme is suggested which may provide a new design for a cardiac defibrillator.Comment: 9 pages, 5 figure

Destination-based Routing and Circuit Allocation for Future Traffic Growth

Internet traffic continues to grow relentlessly, driven largely by increasingly high- \\ resolution video streaming, the increasing adoption of cloud computing, the emergence of 5G networks, and the ever-growing reach of social media and social networks. Existing networks use packet switching to route packets on a hop-by-hop basis from the source to the destination. However, they suffer from two shortcomings. First, in existing networks, packets are routed along a fixed shortest path using the Open Shortest Path First (OSPF) protocol or obliviously load-balanced across equal-cost paths using the Equal-Cost Multi-Path (ECMP) protocol. These routing protocols do not fully utilize the network capacity because they do not adapt to network congestions in their routing decisions. Second, although studies have shown that the majority of packets processed by Internet routers are pass-through traffic, packets nonetheless have to be queued and routed at every hop in existing networks, which unnecessarily adds substantial delays and processing costs.In this thesis, we present two new approaches to overcome these shortcomings. First, we propose new backpressure-based routing algorithms which use only shortest-path routes when they are sufficient to accommodate the given traffic load, but will incrementally expand routing choices as needed to accommodate increasing traffic loads. This avoids the poor delay performance inherent in backpressure-based routing algorithms where packets may take long detours under light or moderate loads, and still retains the notable advantage, the network-wide optimal throughput, because packets are adaptively routed along less congested paths.Second, we propose a unified packet and circuit switched network in which the underlying optical transport is used to circuit-switch pass-through traffic by means of pre-established circuits. This avoids unnecessary packet queuing delays and processing costs at each hop. We propose a novel convex optimization framework based on a new destination-based multicommodity flow formulation for the allocation of circuits in such unified networks

Estimating R2 Shrinkage in Multiple Regression: A Comparison of Different Analytical Methods

This study investigated the effectiveness of various analytical methods used for estimating R2 shrinkage in multiple regression analysis. Two categories of analytical formulae were identified: estimators of the population squared multiple correlation coefficient (ρ2), and estimators of the population cross-validity coefficient (ρc2). To avoid possible confounding factors that might be associated with a real data set such as data nonnormality, lack of precise population parameters, different degrees of multicollinearity among the predictor variables, and so forth, the Monte Carlo method was used to simulate multivariate normal sample data, with prespecified population parameters such as the squared multiple correlation coefficient (ρ2), number of predictors, different sample sizes, known degree of multicollinearity, and controlled data normality conditions. Five hundred replicates were simulated within each cell of the sampling conditions. Various analytical formulae were applied to the simulated data in each sampling condition, and the adjusted coefficients were obtained and then compared to their corresponding population parameters (ρ2 and ρc2). Analysis of the results indicates that the currently most widely used (in both SAS and SPSS) Wherry formula is probably not the most effective analytical formula in estimating ρ2. Instead, the Pratt formula appeared to outperform other analytical formulae across most of these sampling conditions. Among the analytical formulae designed to estimate ρc2, the Browne formula appeared to be the most effective and stable in minimizing statistical bias across different sampling conditions. The study also concludes that it is the n/p (sample size/number of predictor variables) ratio that affects the performances of these analytical formulae the most; different degrees of multicollinearity among predictor variables do not have dramatic influence on the performances of these analytical formulae. Further replicants on both real and simulated data re still needed to investigate the effectiveness of these analytical formulae

The macroeconomic consequences of Scottish fiscal autonomy: inverted haavelemo effects in a general equilibrium analysis of the tartan tax

In 1997 the Scottish people voted both for the creation of a legislative Parliament and to endow the Parliament with tax-varying powers. The establishment of the Scottish Parliament in 2000 heralded the most radical innovation in the regional fiscal system in modern U.K. history. This development has been the subject of considerable controversy, however, especially in respect of the decision to afford the Parliament the power to alter the basic rate of income tax by up to 3p in either direction. The fact that Scotland, at least according to official data, receives a substantial net fiscal transfer from the rest of the UK, and has traditionally had higher public expenditure per capita than England, leads most commentators to believe that the power to change the standard rate will, in practice, be restricted to the power to increase it (Blow et al, 1996; McGregor et al 1997). Accordingly, while the Parliament allows the use of the power to generate a balancedbudget contraction in expenditure, we focus here on the impact of a balanced-budget fiscal expansion. While Labour, SNP and the Liberal Democrats in Scotland all supported the introduction of a Parliament with tax-raising powers, the Conservatives labelled this scheme the “tartan tax” and claim that its use would be detrimental to Scotland, leading to a reduction in Scottish employment and to net out-migration. This political controversy, together with the national Labour Party’s desire to shed its reputation as a Party of high taxation, in part accounted for the Scottish Labour Party’s commitment not to exercise the tax-varying power during the lifetime of the first Scottish Parliament, despite the fact that others have meanwhile been vigorously arguing the case for full fiscal autonomy. In this paper we focus primarily on the consequences for the Scottish economy if the Parliament chooses to exercise the degree of fiscal autonomy that it already possesses. However, the factors that govern the likely macroeconomic impact of a balanced budget change also prove critical to the analysis of any region-specific tax or expenditure change, whether generated as a consequence of, for example, rigorous adherence to the Barnett formula (that, at least in principle, governs the allocation of government expenditure to the devolved authorities in the UK, et al 2003, 2007) or movement towards greater fiscal autonomy. Accordingly, we also identify the implications of our analysis for the wider debate on regional fiscal issues in general and greater fiscal autonomy in particular

Secondary Metabolites from Pepper (Piper Nigrum) and Tahitian Noni (Morinda Citrifolia) and Their Biological Activities

Piper nigrum from the Piperaceae family and Morinda citrifolia from the Rubiaceae family were researched in this study. Detailed phytochemical investigations on the roots of these plants afforded ten pure compounds, which consists mainly of alkaloids and anthraquinones, and an acid. The structures of these compounds were elucidated based on 1H NMR, 13C NMR, COSY, DEPT, 2D NMR (HSQC and HMBC), mass spectrometry (MS), and Infrared spectroscopy (FTIR) analysis. Meanwhile, mixtures of compounds were identified through GCMS (gas chromatography-mass spectrometry). From the roots of Piper nigrum, the alkaloids obtained are piperine, pellitorine and aristolactam AII. Besides that, the acid, 3,4-methylenedioxy benzoic acid was also present in the roots of this plant. Meanwhile, anthraquinones and their derivatives such as 1-hydroxy-2-methylanthraquinone, damnacanthal, nordamnacanthal, 2-formyl-1-hydroxyanthraquinone, 2-ethoxy-1-hydroxyanthraquinone and morindone-6-methylether were obtained from the roots of Morinda citrifolia. Among these anthraquinones, 2-ethoxy-1-hydroxyanthraquinone is a new anthraquinone, while morindone-6-methylether is reported for the first time from the plant. In the larvicidal test against the larvae of Aedes aegypti, the ethyl acetate extract of the roots of Piper nigrum showed good activity against the larvae. Pellitorine, on the other hand, gave a significant activity followed by piperine which only gave a moderate activity. The acid and aristolactam AII gave negative results which indicated that they are not biologically active towards the larvae of Aedes aegypti. For Morinda citrifolia, only the chloroform extract and the two anthraquinones, 1-hydroxy-2-methylanthraquinone and damnacanthal are strongly active. From the cytotoxic activity, where tests were conducted using the HL-60 (Acute Promyelocytic Leukaemia) and MCF7 cell lines (Human Breast Adenocarcinoma), the ethyl acetate extract of Piper nigrum gave weak activity with an IC50 value of more than 30 μg/ml against the HL-60 cell line. However, in the tests against the same cell line using piperine and pellitorine, IC50 value of 7.5 μg/ml and 1.5 μg/ml, respectively, were obtained indicating the individual compounds to be strongly cytotoxic. Aristolactam AII gave weak activity with an IC50 value of more than 30 μg/ml when tested on the MCF-7. Compared to the extract and alkaloids from Piper nigrum, the extracts and anthraquinones from Morinda citrifolia gave better results against both HL-60 and MCF7 cell lines. Three extracts amongst the five tested showed significant bioactivity against the HL-60 cell. These are the hexane extract, chloroform extract and petroleum ether extract, with IC50 values of 1.70 μg/ml, 9.3 μg/ml and 11.0 μg/ml, respectively. The methanol and acetone extracts showed moderate activities against the same cell line (HL-60). Damnacanthal, nordamnacanthal and 1-hydroxy-2-methylanthraquinone which were from the hexane and chloroform extracts gave IC50 values of 1.6 μg/mL, 4.4 μg/mL and 15.0 μg/mL, respectively, against the same cell line (HL-60). A comparison of the IC50 values of different extracts against the two cell lines indicated that these extracts did not give satisfying results against the MCF7 cell lines with only the chloroform and petroleum ether extracts giving a moderate activity. The antifungal and antibacterial activities of the extracts and some compounds from the two plants were also evaluated. Fungi such as Aspergilius ochraceaus and Sacchoromyces cerevisiae were used in the antifungal screening. Meanwhile, MRSA, Pseudomonas aeruginosa, Salmonella choleraesuis and Bacillus subtilis were the microbes used in the antibacterial screenings. None of the extracts or alkaloids from Piper nigrum showed any inhibition in both screening. As for Morinda citrifolia, only the chloroform and methanol extracts, and damnacanthal exhibited medium inhibition for Bacillus subtilis in the antibacterial screening. However, in the screening against Salmonella choleraesuis, only the chloroform extract and damnacanthal showed weak inhibition. Meanwhile, nordamnacanthal is the only sample tested that showed a very weak inhibition. In the antifungal screening, the two microbes were shown to be lightly susceptible to the chloroform extract and damnacanthal

Mobile Game: A Multiplayer Mobile Game via Bluetooth Technology for Nokia Series 60

The Final Year Project developed is 'Mobile Game: A Multiplayer Mobile Game via Bluetooth Technology for Nokia Series 60'. The existing mobile games are mostly a stand-alone application, which means the game can only be played by a player. Even with the availability of multiplayer mobile games in the market, the maximum number ofplayers of those games is two. The objective of this project is to study and develop a multiplayer (specifically three players) mobile game with Bluetooth technology as the connection means. The first part of this project would be the research and study pertaining to the development of multiplayer mobile game for three players using Bluetooth technology. The second part of the research pertains to the downside of Bluetooth technology and recommendations to improve the situation. The methodology used is the combination of waterfall and prototyping model. A mobile game application is produced as the end-product of this project. Meanwhile, the findings discover the details on the end-product development and also some discussion design issues and challenges as well as limitationof Bluetoothtechnology