Interrogating an insect society

Insect societies such as those of ants, bees, and wasps consist of 1 or a small number of fertile queens and a large number of sterile or nearly sterile workers. While the queens engage in laying eggs, workers perform all other tasks such as nest building, acquisition and processing of food, and brood care. How do such societies function in a coordinated and efficient manner? What are the rules that individuals follow? How are these rules made and enforced? These questions are of obvious interest to us as fellow social animals but how do we interrogate an insect society and seek answers to these questions? In this article I will describe my research that was designed to see answers from an insect society to a series of questions of obvious interest to us. I have chosen the Indian paper wasp Ropalidia marginata for this purpose, a species that is abundantly distributed in peninsular India and serves as an excellent model system. An important feature of this species is that queens and workers are morphologically identical and physiologically nearly so. How then does an individual become a queen? How does the queen suppress worker reproduction? How does the queen regulate the nonreproductive activities of the workers? What is the function of aggression shown by different individuals? How and when is the queen's heir decided? I will show how such questions can indeed be investigated and will emphasize the need for a whole range of different techniques of observation and experimentation.

Can a single resource support many consumer species

The conclusion that the number of species co-existing within a biological community cannot exceed the number of limiting factors is not valid if we assume that (i) the relative efficiency of two competing species in utilizing a resource is not independent of the resource density, but one species may be more efficient at a lower density and less efficient at a higher density and (ii) there is a spatial or temporal heterogeneity in the density of the resource. This spatial or temporal heterogeneity does not have to be furnished by factors external to the biological community, but may be generated within the biological community itself as in the case of a vertical gradient of light in a plant community. This possibility of a stable co-existence of more than one species in a community limited by a single resource, even when the resource is being supplied uniformly in space and time, is formally demonstrated.

Sustainability through remanufacturing in India: a case study on mobile handsets

Remanufacturing activities in India are still in nascent stages. However, the substantial growth of Indian economy, coupled with serious issues of population and environmental burden demands a radical shift in market strategies and legislations. The scattered and inefficient product recovery methods prevalent in India are unable to cope with increasing environmental and economic burden on the society - remanufacturing seems to be a promising strategy to explore for these. Our study investigated from a user's context the opportunity of establishing remanufacturing as a formal activity, answering the fundamental questions of whether remanufactured products would be accepted by Indian consumers and how these will fit into the Indian market. The study of the Indian mobile phone market eco-system showed how mobile phones currently move through the value chain, and the importance of the grey and used phone markets in this movement. A prescriptive model has been proposed which utilizes the usage patterns of different consumer groups to create a self-sustainable demand-supply system, potentially complementing frameworks such as the Automotive Remanufacturing Decision-Making Framework (RDMF). (C) 2011 Elsevier Ltd. All rights reserved.

Decentralized demand-supply matching using community microgrids and consumer demand response: A scenario analysis

Developing countries constantly face the challenge of reliably matching electricity supply to increasing consumer demand. The traditional policy decisions of increasing supply and reducing demand centrally, by building new power plants and/or load shedding, have been insufficient. Locally installed microgrids along with consumer demand response can be suitable decentralized options to augment the centralized grid based systems and plug the demand-supply gap. The objectives of this paper are to: (1) develop a framework to identify the appropriate decentralized energy options for demand supply matching within a community, and, (2) determine which of these options can suitably plug the existing demand-supply gap at varying levels of grid unavailability. A scenario analysis framework is developed to identify and assess the impact of different decentralized energy options at a community level and demonstrated for a typical urban residential community Vijayanagar, Bangalore in India. A combination of LPG based CHP microgrid and proactive demand response by the community is the appropriate option that enables the Vijayanagar community to meet its energy needs 24/7 in a reliable, cost-effective manner. The paper concludes with an enumeration of the barriers and feasible strategies for the implementation of community microgrids in India based on stakeholder inputs. (C) 2014 Elsevier Ltd. All rights reserved.