Systems of interacting diffusions with partial annihilation through membranes

We introduce an interacting particle system in which two families of reflected diffusions interact in a singular manner near a deterministic interface $I$. This system can be used to model the transport of positive and negative charges in a solar cell or the population dynamics of two segregated species under competition. A related interacting random walk model with discrete state spaces has recently been introduced and studied in Chen and Fan (2014). In this paper, we establish the functional law of large numbers for this new system, thereby extending the hydrodynamic limit in Chen and Fan (2014) to reflected diffusions in domains with mixed-type boundary conditions, which include absorption (harvest of electric charges). We employ a new and direct approach that avoids going through the delicate BBGKY hierarchy.Comment: Published at http://dx.doi.org/10.1214/15-AOP1047 in the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

Environmental Education in Post-green Revolution Punjab

In India, environmental education (EE) became compulsory for Classes I-XII nationwide in 1991, with curricula designed by central and state governments. Meanwhile, in the interest of food security, the government-promulgated Green Revolution of the 1960s brought about commercial agriculture practices have led to environmental degradation, with negative impacts on farmers’ livelihoods. This paper presents a case study in a rural region in the state of Punjab, the heartland of the Green Revolution. Through interviews with students, teachers and community members as well as a review of school curricula, it seeks to understand how EE in schools is impacting the perceptions and aspirations of the community’s younger generation with respect to the community’s agricultural and environmental linkages, problems and future. It is found that although EE in Punjab touches upon locally relevant concerns, in the context of ingrained societal attitudes and the wider body of school curricula, it does not compel any meaningful initiative or change on the part of the students. While education is commonly seen as an important medium for human, societal and economic development, EE is part of an education system, taking part in a feedback loop with broader societal values which may not be aligned with sustainable development