02140nas a2200169   4500008004100000245010600041210006900147260000800216300001400224490000700238520150200245100002401747700002601771700002601797700002101823856012601844       2017                        eng d00aExploring the role of GS-GOGAT cycle in microcystin synthesis and regulation - a model based analysis0 aExploring the role of GSGOGAT cycle in microcystin synthesis and  cDEC  a2603-26140 v133 aToxic cyanobacteria blooms populate water bodies by consuming external nutrients and releasing cyanotoxins that are detrimental for other aquatic species, producing a significant impact on the plankton ecosystem and food web. To exercise population-level control of toxin production, understanding the biochemical mechanisms that explain cyanotoxin regulation within a bacterial cell is of utmost importance. In this study, we explore the mechanistic events to investigate the dependence of toxin microcystin on external nitrogen, a known regulator of the toxin, and for the first time, propose a kinetic model that analyzes the intracellular conditions required to ensure nitrogen dependence on microcystin. We hypothesize that the GS-GOGAT cycle is manipulated by variable influx of different intracellular metabolites that can either disturb or promote the balance between the enzyme microcystin synthetase and substrate glutamate to produce variable microcystin levels. As opposed to the popular notion that nitrogen starvation increases microcystin synthesis, our analyses suggest that under certain intracellular metabolite regimes, this relationship can either be completely lost or reversed. External nitrogen can only complement the conditions fixed by intracellular glutamate, glutamine and 2-oxoglutarate. This mechanistic understanding can provide an experimentally testable hypothesis for exploring the less-known biology of microcystin synthesis and designing specific interventions.1 aBanerjee, Swarnendu1 aSubramanian, Abhishek1 aChattopadhyay, Joydev1 aSarkar, Ram, Rup  uhttp://library.ncl.res.in/content/exploring-role-gs-gogat-cycle-microcystin-synthesis-and-regulation-model-based-analysis02559nas a2200169   4500008004100000245012300041210006900164260000800233490000700241520189200248100002002140700002602160700002702186700002602213700002102239856012902260       2017                        eng d00aOptimal combinations of control strategies and cost-effective analysis for visceral leishmaniasis disease transmission0 aOptimal combinations of control strategies and costeffective ana  cMAR0 v123 aVisceral leishmaniasis (VL) is a deadly neglected tropical disease that poses a serious problem in various countries all over the world. Implementation of various intervention strategies fail in controlling the spread of this disease due to issues of parasite drug resistance and resistance of sandfly vectors to insecticide sprays. Due to this, policy makers need to develop novel strategies or resort to a combination of multiple intervention strategies to control the spread of the disease. To address this issue, we propose an extensive SIR-type model for anthroponotic visceral leishmaniasis transmission with seasonal fluctuations mod-eled in the form of periodic sandfly biting rate. Fitting the model for real data reported in South Sudan, we estimate the model parameters and compare the model predictions with known VL cases. Using optimal control theory, we study the effects of popular control strategies namely, drug-based treatment of symptomatic and PKDL-infected individuals, insecticide treated bednets and spray of insecticides on the dynamics of infected human and vector populations. We propose that the strategies remain ineffective in curbing the disease individually, as opposed to the use of optimal combinations of the mentioned strategies. Testing the model for different optimal combinations while considering periodic seasonal fluctuations, we find that the optimal combination of treatment of individuals and insecticide sprays perform well in controlling the disease for the time period of intervention introduced. Performing a cost-effective analysis we identify that the same strategy also proves to be effi-cacious and cost-effective. Finally, we suggest that our model would be helpful for policy makers to predict the best intervention strategies for specific time periods and their appropriate implementation for elimination of visceral leishmaniasis.1 aBiswas, Santanu1 aSubramanian, Abhishek1 aElmojtaba, Ibrahim, M.1 aChattopadhyay, Joydev1 aSarkar, Ram, Rup  uhttp://library.ncl.res.in/content/optimal-combinations-control-strategies-and-cost-effective-analysis-visceral-leishmaniasis02180nas a2200229   4500008004100000022001400041245006000055210006000115260000800175300001000183490000800193520149500201653001601696653002701712653002101739653001301760653001801773100002401791700002101815700002601836856008801862       2019                        eng d  a0022-519300aEffect of copper contamination on zooplankton epidemics0 aEffect of copper contamination on zooplankton epidemics  cMAY  a61-740 v4693 a<p>Infectious disease and chemical contamination are increasingly becoming vital issues in many ecosystems. However, studies integrating the two are surprisingly rare. Contamination not only affects the inherent host-resource interaction which influences the epidemic process but may also directly affect epidemiological traits via changes in host's behaviour. The fact that heavy metal such as copper is also an essential trace element for organisms, further increase complexity which make predicting the resultant effect of contamination and disease spread difficult. Motivated by this, we model the effect of copper enrichment on a phytoplankton-zooplankton-fungus system. We show that extremely deficient or toxic copper may have a destabilizing effect on the underlying host-resource dynamics due to increased relative energy fluxes as a result of low host mortality due to fish predation. Further, on incorporating disease into the system, we find that the system can become disease-free for an intermediate range of copper concentration whereas it may persist for very less copper enrichment. Also, we predict that there may exist vulnerable regions of copper concentration near the toxic and deficient levels, where the parasite can invade the system for a comparatively lower spore yield. Overall, our results demonstrate that, the effect of contamination may be fundamental to understanding disease progression in community ecology. (C) 2019 Elsevier Ltd. All rights reserved.</p>10aBistability10aChemical contamination10aDaphnia-parasite10aHormesis10aHost-resource1 aBanerjee, Swarnendu1 aSarkar, Ram, Rup1 aChattopadhyay, Joydev  uhttp://library.ncl.res.in/content/effect-copper-contamination-zooplankton-epidemics