@article { ISI:000276592000007,
	title = {Robustness of the drosophila segment polarity network to transient perturbations},
	journal = {IET Systems Biology},
	volume = {4},
	number = {2},
	year = {2010},
	month = {MAR},
	pages = {169-176},
	publisher = {INST ENGINEERING TECHNOLOGY-IET},
	address = {MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND},
	abstract = {<p>Continuous and Boolean models for the Drosophila segment polarity network have shown that the system is able to maintain the wild-type pattern when subjected to sustained changes in the interaction parameters and initial conditions. Embryo development is likely to occur under fluctuating environmental conditions. Here, a well-established Boolean model is used to explore the ability of the segment polarity network to resist transient changes. Paths along which alternate unviable states are reached, and hence critical nodes whose state changes lead the system away from the wild-type state, are identified. It is found that the system appears to be more sensitive to changes that involve activation of normally inactive nodes. Through a simulation of the heat shock response, it is shown how a localised perturbation in one parasegment is more deleterious than a global perturbation affecting all parasegments. The sequence of events involved in the recovery of the system from a global transient heat shock condition is identified. Finally, these results are discussed in terms of the robustness of the system response.</p>},
	issn = {1751-8849},
	doi = {10.1049/iet-syb.2009.0036},
	author = {Subramanian, K. and Gadgil, Chetan J.}
}
@article { ISI:000365891600061,
	title = {Ranking of reactions based on sensitivity of protein noise depends on the choice of noise measure},
	journal = {Plos One},
	volume = {10},
	number = {12},
	year = {2015},
	month = {DEC},
	pages = {Article Number: e0143867},
	publisher = {PUBLIC LIBRARY SCIENCE},
	address = {1160 BATTERY STREET, STE 100, SAN FRANCISCO, CA 94111 USA},
	abstract = {<p>Gene expression is a stochastic process. Identification of the step maximally affecting noise in the protein level is an important aspect of investigation of gene product distribution. There are numerous experimental and theoretical studies that seek to identify this important step. However, these studies have used two different measures of noise, viz. coefficient of variation and Fano factor, and have compared different processes leading to contradictory observations regarding the important step. In this study, we performed systematic global and local sensitivity analysis on two models of gene expression to investigate relative contribution of reaction rate parameters to steady state noise in the protein level using both the measures of noise. We analytically and computationally showed that the ranking of parameters based on the sensitivity of the noise to variation in a given parameter is a strong function of the choice of the noise measure. If the Fano factor is used as the noise measure, translation is the important step whereas for coefficient of variation, transcription is the important step. We derived an analytical expression for local sensitivity and used it to explain the distinct contributions of each reaction parameter to the two measures of noise. We extended the analysis to a generic linear catalysis reaction system and observed that the reaction network topology was an important factor influencing the local sensitivity of the two measures of noise. Our study suggested that, for the analysis of contributions of reactions to the noise, consideration of both the measures of noise is important.</p>},
	issn = {1932-6203},
	doi = {10.1371/journal.pone.0143867},
	author = {Gokhale, Sucheta A. and Gadgil, Chetan J.}
}
