Even with global support for tiger (Panthera tigris) conservation their survival is threatened by poaching, habitat loss and isolation. Currently about 3,000 wild tigers persist in small fragmented populations within seven percent of their historic range. Identifying and securing habitat linkages that connect source populations for maintaining landscape-level gene flow is an important long-term conservation strategy for endangered carnivores. However, habitat corridors that link regional tiger populations are often lost to development projects due to lack of objective evidence on their importance. Here, we use individual based genetic analysis in combination with landscape permeability models to identify and prioritize movement corridors across seven tiger populations within the Central Indian Landscape. By using a panel of 11 microsatellites we identified 169 individual tigers from 587 scat and 17 tissue samples. We detected four genetic clusters within Central India with limited gene flow among three of them. Bayesian and likelihood analyses identified 17 tigers as having recent immigrant ancestry. Spatially explicit tiger occupancy obtained from extensive landscape-scale surveys across 76,913 km2 of forest habitat was found to be only 21,290 km2. After accounting for detection bias, the covariates that best explained tiger occupancy were large, remote, dense forest patches; large ungulate abundance, and low human footprint. We used tiger occupancy probability to parameterize habitat permeability for modeling habitat linkages using least-cost and circuit theory pathway analyses. Pairwise genetic differences (F ST) between populations were better explained by modeled linkage costs (r>0.5, p<0.05) compared to Euclidean distances, which was in consonance with observed habitat fragmentation. The results of our study highlight that many corridors may still be functional as there is evidence of contemporary migration. Conservation efforts should provide legal status to corridors, use smart green infrastructure to mitigate development impacts, and restore habitats where connectivity has been lost.

Data from: Prioritizing tiger conservation through landscape genetics and habitat linkages

Abiotic stress induced miRNA-TF-gene regulatory network: A structural perspective.

A graph theoretic approach for modelling tiger corridor network in Central India-Eastern Ghats landscape complex, India

Residential energy consumption has been rising rapidly during the last few decades. Several research efforts have been made to reduce residential energy consumption, including demand response and smart residential environments. However, recent research has shown that these approaches may actually cause an increase in the overall consumption, due to the complex psychological processes that occur when human users interact with these energy management systems. In this article, using an interdisciplinary approach, we introduce a perceived-value driven framework for energy management in smart residential environments that considers how users perceive values of different appliances and how the use of some appliances are contingent on the use of others. We define a perceived-value user utility used as an Integer Linear Programming (ILP) problem. We show that the problem is NP-Hard and provide a heuristic method called COndensed DependencY (CODY). We validate our results using synthetic and real datasets, large-scale online experiments, and a real-field experiment at the Missouri University of Science and Technology Solar Village. Simulation results show that our approach achieves near optimal performance and significantly outperforms previously proposed solutions. Results from our online and real-field experiments also show that users largely prefer our solution compared to a previous approach.

Perceived-Value-driven Optimization of Energy Consumption in Smart Homes

We show that the causal network structure of the stock prices of prominent companies in the New York Stock Exchange reveals distinct patterns before, during, and after the 2007–08 global financial crisis. We find a reduced participation of banks in the market activity about seven years before the actual crisis, which indicates its possible role in the global crisis. Aggregated causal influences during the crisis period show a significant increase in the causal effects to the consumer discretionary, financial, and IT sectors. Moreover, we found no correlation between out-flux and in-flux of causal influence of the obtained networks. Two prominent results of the causal networks are, (a) the absence of feedback in the obtained directed network, and (b) the absence of strongly connected components indicating that a financial firm is unaffected by the causal influence propagated by itself. The analysis of causal out-flux clearly reveals that the market is driven by consumer staples and health-care sectors during the crisis phase, while the recovery phase, immediately after the crisis period, is influenced by material, health-care, and consumer discretionary sectors. We characterize the vertices in the causal networks by three local properties, viz., out-degree, in-degree, and node-betweenness, which reveal key companies producing, receiving, and mediating the causal influences. We also find that the aggregate sum of causal influences in companies from energy sector is among the least for all periods, indicating its robustness. A similar behavior is also reflected in the much smaller Indian market.

Causal evolution of global crisis in financial networks

A network theoretic study of ecological connectivity in Western Himalayas

Network theoretic approach has been used to model and study the flow of ecological information, growth and connectivity on landscape level of anemochory plant species Abied pindrow, Betula utilis and Taxus wallichiana in the Western Himalaya region. A network is formally defined and derived for seed dispersion model of aforementioned species where vertices represent habitat patches which are connected by an edge if the distance between the patches is less than a threshold distance. We define centrality of a network and computationally identify the habitat patches that are central to the process of seed dispersion to occur across the network. We find that the network of habitat patches is a scale free network and at the same time it also displays small world property characterized by high clustering and low average shortest path length. Due to high clustering, the spread of species is locally even as seed disperse mutually among the member vertices of a cluster. Also since every vertex is only a short number of steps away from every other vertex, the species rapidly covers all the habitat patches in the component. Also due to presence of hubs in the network the spread of species is greatly boosted whenever the species establish and thrive in a hub patch and disperse to adjacent patches. However, the network is not modular due to geographical constraints, and is is negatively assortative as the high degree vertices are connected to vertices of low degree.

Wildlife corridors are components of landscapes, which facilitate the movement of organisms and processes between areas of intact habitat, and thus provide landscape corridor. Corridors are thus regions within a given landscape that generally comprise native vegetation, and connect otherwise fragmented, disconnected, non-contiguous wildlife habitat patches in the landscape. The purpose of designing corridors as a conservation strategy is primarily to counter, and to the extent possible, mitigate the impacts of habitat fragmentation and loss on the biodiversity of the landscape, as well as support continuance of land use for essential local and global economic activities in the region of reference. In this paper, we use game theory and graph theory to model and design a wildlife corridor network in the Central India Eastern Ghats landscape complex, with tiger (Panthera tigris tigris) as the focal species. We construct a graph using the habitat patches supporting wild tiger populations in the landscape complex as vertices and the possible paths between these vertices as edges. A cost matrix is constructed to indicate the cost incurred by the tiger for passage between the habitat patches in the landscape, by modelling a two-person Prisoners Dilemma game. A minimum spanning tree is then obtained by employing Kruskals algorithm, which would suggest a feasible tiger corridor network for the tiger population within the landscape complex. Additionally, analysis of the graph is done using various centrality measures, in order to identify and focus on potentially important habitat patches, and their potential community structure. Correlation analysis is performed on the centrality indices to draw out interesting trends in the network.

Jobin Idiculla

Papers

A network theoretic study of ecological connectivity in Western Himalayas

A graph theoretic approach for modelling tiger corridor network in Central India-Eastern Ghats landscape complex, India

A network theoretic study of ecological connectivity in Western Himalayas

A graph theoretic approach for modelling wildlife corridors