Scalable energy-efficient routing in mobile Ad hoc network

The quick deployment without any existing infrastructure makes mobile ad hoc networks (MANET) a striking choice for dynamic situations such as military and rescue operations, disaster recovery, and so on and so forth. However, routing remains one of the major issues in MANET due to the highly dynamic and distributed environment. Energy consumption is also a significant issue in ad hoc networks since the nodes are battery powered. This report discusses some major dominating set based approaches to perform energy efficient routing in mobile ad hoc networks. It also presents the performance results for each of these mentioned approaches in terms of throughput, average end to end delay and the life time in terms of the first node failure. Based on the simulation results, I identified the key issues in these protocols regarding network life time. In this report, I propose and discuss a new approach “Dynamic Dominating Set Generation Algorithm” (DDSG) to optimize the network life time. This algorithm dynamically selects dominating nodes during the process of routing and thus creates a smaller dominating set. DDSG algorithm thereby eliminates the energy consumption from the non-used dominating nodes. In order to further increase the network life time, the algorithm takes into consideration the threshold settings which helps to distribute the process of routing within the network. This helps to eliminate a single dominating node from getting drained out by continuous transmission and reception of packets. In this report, the detailed algorithmic design and performance results through simulation is discussed

Thinking about the 'law of unintended consequences'

The United State’s now-not-so-covert drone based program targeting Al Qaeda (AQ) and Taliban commanders based in Pakistan’s inhospitable and hostile Federally Administered Tribal Areas (FETA) has been operational since 2004. However, US air strikes in Pakistan’s tribal belt have steadily escalated over the past three years. The US has claimed that these attacks have successfully decimated core Al Qaeda and Taliban leadership. This past September alone the US military conducted 26 drone strikes in Pakistan, racking up a figure that the BBC is calling the "highest monthly total for the past six years". Not only do these steadily escalating drone strikes raise some pertinent questions about US/NATO successes claimed under the rubric of the Global War on Terror (or if you prefer, the Overseas Contingency Operations) but they also shed some light on the deteriorating political situation in Pakistan.Publisher PD

Unraveling the dynamics of protein-protein interactions in the Gcn2 signal transduction pathway : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Microbiology and Genetics, Massey University, Albany, New Zealand

Content removed from Publications section due to copyright reasons: Cridge, A. G., Viswewaraiah, J., Ramesh, R., & Sattlegger, E. (2014). Semi-quantitative colony immunoassay for determining and optimizing protein expression in Saccharomyces cerevisiae cerevisiae and Escherichia coli. Analytical Biochemistry, 447, 82-89. doi: 10.1016/j.ab.2013.10.020 Castilho, B. A., Shanmugam, R., Silva, R. C., Ramesh, R., Himme, B. M., & Sattlegger, E. (2014). Keeping the eIF2 alpha kinase Gcn2 in check. Biochimica et Biophysica Acta, 1843, 1948-1968. doi: 10.1016/j.bbamcr.2014.04.006Eukaryotic cells regulate protein synthesis (translation) for a rapid response to various types of stress, and this involves several protein-protein interactions (PPIs) and protein phosphorylation. Phosphorylation of eukaryotic initiation factor-2 α (eIF2α) is a common regulatory mechanism to adjust protein synthesis in response to various stimuli. Gcn2 (General Control Non-derepressible) is an eIF2α kinase that is conserved from yeast to mammals, that is activated in response to amino acid starvation. Gcn2 activation leads to a reduction in global protein synthesis and simultaneous augmented translation of GCN4, a transcriptional activator of genes that are necessary to overcome stress. This cascade of events that allows cells in stress adaptation constitutes the General Amino Acid control (GAAC) pathway in yeast. Gcn2 activity is controlled by a large array of proteins that directly or indirectly regulate Gcn2. Gcn2 has to bind another protein called Gcn1, in order to be activated in response to amino acid starvation. Yih1 (Yeast IMPACT homolog 1) in yeast and its counterpart IMPACT (IMPrinted and AnCienT) in mammals are homologous proteins that indirectly regulate Gcn2. Yih1/IMPACT inhibit Gcn2 by competing for Gcn1 binding. Yih1 associates with Actin, and studies so far have suggested that Yih1 only inhibits Gcn2 when it dissociates from Actin. The focus of this thesis work was to shed more light on those interactions relevant for Gcn2 regulation. Firstly, we have identified that the Yih1 mediated interactions occur at distinct cellular locations within the cell, supporting the idea that spatially restricted cellular interactions controlled Gcn2 function. Using in vitro studies we have identified the regions on eEF1A that are involved in Gcn2 and Yih1 binding. The distinct binding sites for both proteins on eEF1A led to further investigations on how the dynamics of these interactions involving eEF1A might affect Gcn2 function. Together with unpublished observations by E Sattlegger and B Castilho, a function for the Yih1 ancient domain in interacting with eEF1A has been identified. Finally, the mechanisms by which Actin might control Gcn2 function were studied. In this regard, we have identified the Yih1-Actin interaction as one of the key PPIs involved in the crosstalk between the cytoskeleton and Gcn2 regulation. Together, the findings presented in this thesis, support the hypothesis that Gcn2 activity is spatiotemporally controlled by dynamic PPIs that occur at specific time at particular locations

Electromagnetic Interactions in the Quantum Hall Ferromagnet

The $\nu =1$ quantum Hall ground state in samples like GaAs is well known to be ferromagnetic. The global SU(2) spin symmetry of the microscopic action is broken down to a U(1) symmetry by the ground state. The Goldstone bosons corresponding to this spontaneous breaking of symmetry are the ferromagnetic magnons which are neutral spin waves. In addition, there are topologically nontrivial, electrically charged spin excitations known as spin skyrmions, which in these samples are the favoured charge carriers. In this letter, we look into the electromagnetic coupling of these spin excitations. The discrete symmetries P and T are also broken by the ground state and we find that to the leading order, the electromagnetic interaction of the spin waves occurs through a nonminimal coupling given by a Chern-Simons like term containing both the electromagnetic potentials and the two Euler angles that specify the coset SU(2)/U(1) and thereby, the Goldstone bosons.Comment: 13 pages, Plain TeX, no figure

Insurance and liquidity : panel evidence

The author presents evidence that balance sheet effects are critical determinants of both the likelihood of a crisis and of income losses following a crisis. She tests the validity of"insurance"and"liquidity"models of currency crisis. Both models predict that the occurrence of a balance of payments crisis is conditional on the health of the nation's accounts in relation to the rest of the world. Problems in the balance sheet either cause a financial crisis that develops into a run on the central bank, or generate a run on the central bank once contingent liabilities exceed reserves and the yield differential moves against domestic assets. Estimations of crisis likelihoods based on several specifications of single and simultaneous equation probit models confirm that output losses following the crisis are persistent and conditional on the balance sheet indicator, that is, the ratio of the stock of gross external liabilities to assets. Measures of contingent liabilities, capital flight, and financial depth perform well as crisis predictors, and the marginal effects on the probability of a crisis are of the expected sign. The panel data set covers the time period 1973 through 2003 for 90 countries.Economic Theory&Research,International Terrorism&Counterterrorism,Environmental Economics&Policies,Insurance&Risk Mitigation,Banks&Banking Reform

Impact of liberalisation on wages and employment in Indian manufacturing industries

FDI and labour markets; Trade and labour markets; Technology and Labour markets; Indian labour markets; Wages and Employment; GMM

Distinguishing between observationally equivalent theories of crises

The objective of this paper is to empirically test across alternative, apparently observationally equivalent theories of currency crises. Theories of crises are often difficult to distinguish from each other based on the behavior of commonly used predictors. Using a comprehensive data set on gross external assets and liabilities for 167 countries created bythe World Bank's Latin America and the Caribbean Region and the Development Research Group, this study is able to make a significant move toward redressing this shortcoming. It focuses on identifying potential crisis predictors, as well as testing the validity of the distinct transmission mechanisms implied by various theories of currency crisis. Evidence is presented in support of insurance-based models, suggesting that proxies for contingent liability accumulation are effective crisis predictors.Economic Theory&Research,Fiscal&Monetary Policy,International Terrorism&Counterterrorism,Payment Systems&Infrastructure,Banks&Banking Reform,Economic Theory&Research,Banks&Banking Reform,Environmental Economics&Policies,International Terrorism&Counterterrorism,Financial Crisis Management&Restructuring