Institutional Impediments to Groundwater Trading: the case of the Gnangara groundwater system of Western Australia

The development of a market in groundwater usage rights can be inhibited by constraints arising from the institutional context. Such impediments may reduce the potential gains from trade and may generate high transaction costs for prospective traders. We analyse the regulations and policies influencing groundwater transfers in a case-study area -- the Gnangara groundwater system around Perth, Western Australia -- and identify significant impediments to a groundwater market. Property rights are found to be conditional, temporary, and vulnerable to amendment. Regulatory approval is required for all transfers. Facilitating infrastructure is lacking, and price information is unavailable. Management area boundaries reflect land ownership and use rather than hydrogeological realities; the limitation of transfers to within these boundaries eliminates much of the potential for gains from trade. Over-allocation and weak monitoring also impede the development of a market. The current management system is likely to obscure unmet demand for water-rights transfers between users and usage-types.Agricultural and Food Policy, Environmental Economics and Policy, Institutional and Behavioral Economics, Land Economics/Use, Political Economy, Public Economics, Resource /Energy Economics and Policy, Q15, Q25, Q28, Q38, Q56, Q57, Q58, D02, R52, H41, H23, H11, D23, D47, D78, H44,

Manifestations of Drag Reduction by Polymer Additives in Decaying, Homogeneous, Isotropic Turbulence

The existence of drag reduction by polymer additives, well established for wall-bounded turbulent flows, is controversial in homogeneous, isotropic turbulence. To settle this controversy we carry out a high-resolution direct numerical simulation (DNS) of decaying, homogeneous, isotropic turbulence with polymer additives. Our study reveals clear manifestations of drag-reduction-type phenomena: On the addition of polymers to the turbulent fluid we obtain a reduction in the energy dissipation rate, a significant modification of the fluid energy spectrum especially in the deep-dissipation range, a suppression of small-scale intermittency, and a decrease in small-scale vorticity filaments.Comment: 4 pages, 3 figure

Nutritional Status of School Age Children (5-14 years) in a Rural Health Block of North India (Kashmir) Using WHO Z-Score System

Objective: To assess the nutritional status of school going children in Rural Block Hajin. Methods: School children from various primary and middle level educational facilities from a rural health block were surveyed during the School Health Program. Height and weight was measured following standard procedures. MS Excel and Interactive statistics page were used for analysis of data. Results: Both mean weight and height were higher in females than males. The overall prevalence of under nutrition was 19.2%. The prevalence of underweight was lowest in 5 year female (0.0%) and highest in 6 year male (21.5%). For Stunting 7 year males recorded the lowest (0.0%) and 12 year males the highest (28.5%) prevalence. The highest and lowest prevalence of wasting was recorded in 6 year old females (2.56%) and 9 year old males (24.6%) respectively. Prevalence of thinness was lowest in 13 year old females (14.2%) and highest in 13 year old males (47.1%).Conclusion: The nutritional status of school age children in this health block are comparatively better even though a large number of children still fall below the cutoff for various nutritional indicators

Characterization and control of small-world networks

Recently Watts and Strogatz have given an interesting model of small-world networks. Here we concretise the concept of a ``far away'' connection in a network by defining a {\it far edge}. Our definition is algorithmic and independent of underlying topology of the network. We show that it is possible to control spread of an epidemic by using the knowledge of far edges. We also suggest a model for better advertisement using the far edges. Our findings indicate that the number of far edges can be a good intrinsic parameter to characterize small-world phenomena.Comment: 9 pages and 6 figure

Spreading and shortest paths in systems with sparse long-range connections

Spreading according to simple rules (e.g. of fire or diseases), and shortest-path distances are studied on d-dimensional systems with a small density p per site of long-range connections (``Small-World'' lattices). The volume V(t) covered by the spreading quantity on an infinite system is exactly calculated in all dimensions. We find that V(t) grows initially as t^d/d for t>t^*$, generalizing a previous result in one dimension. Using the properties of V(t), the average shortest-path distance \ell(r) can be calculated as a function of Euclidean distance r. It is found that \ell(r) = r for r<r_c=(2p \Gamma_d (d-1)!)^{-1/d} log(2p \Gamma_d L^d), and \ell(r) = r_c for r>r_c. The characteristic length r_c, which governs the behavior of shortest-path lengths, diverges with system size for all p>0. Therefore the mean separation s \sim p^{-1/d} between shortcut-ends is not a relevant internal length-scale for shortest-path lengths. We notice however that the globally averaged shortest-path length, divided by L, is a function of L/s only.Comment: 4 pages, 1 eps fig. Uses psfi

Random spread on the family of small-world networks

We present the analytical and numerical results of a random walk on the family of small-world graphs. The average access time shows a crossover from the regular to random behavior with increasing distance from the starting point of the random walk. We introduce an {\em independent step approximation}, which enables us to obtain analytic results for the average access time. We observe a scaling relation for the average access time in the degree of the nodes. The behavior of average access time as a function of $p$, shows striking similarity with that of the {\em characteristic length} of the graph. This observation may have important applications in routing and switching in networks with large number of nodes.Comment: RevTeX4 file with 6 figure

System Reliability Estimation in Multicomponent Exponential-Lindley Stress-Strength Models

A stress-strength model is formulated for a multi-component system consisting of k identical components. The k components of the system with random strengths ( ) 1 2 , ,..., k X X X are subjected to one of the r random stresses ( ) 1 2 , ,..., r Y Y Y . The estimation of system reliability based on maximum likelihood estimates (MLEs) and Bayes estimators in k component system are obtained when the system is either parallel or series with the assumption that strengths and stresses follow Lindley distribution and Exponential distribution respectively. A simulation study is conducted to compare MLE and Bayes estimator through the mean squared errors of the estimators

Mechanisms of postcardiac surgery atrial fibrillation: more pieces in a difficult puzzle

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