Population and Sustainability: Understanding Population, Environment, and Development Linkages

The triple challenge of rapid population growth, declining agricultural productivity, and natural resource degradation are not isolated from one another; they are intimately related. However, strategic planning and development programming tend to focus on individual sectors such as the environment, agriculture, and population; they do not explicitly take into account the compatibilities and inconsistencies among them. Farm households and their livelihood strategies are at the core of the intersectoral linkages approach advocated in this chapter. Three key aspects of the population-environment-development debate are discussed: first, the finding that inconsistencies between public and individual household behavior regarding childbearing and family planning constitute a veritable "demographic tragedy of the commons;" second, the tendency to conceptualize population variables as "unmanageable," and exogenous to environmental and economic change; third, the importance of land markets and land tenure as critical population-sustainability policy issues.Africa, agriculture, Rwanda, population, sustainability, environment, food security, Agricultural and Food Policy, Community/Rural/Urban Development, Consumer/Household Economics, Environmental Economics and Policy, Food Security and Poverty, International Development, Q56,

A computer program for thermal radiation from gaseous rocket exhuast plumes (GASRAD)

A computer code is presented for predicting incident thermal radiation from defined plume gas properties in either axisymmetric or cylindrical coordinate systems. The radiation model is a statistical band model for exponential line strength distribution with Lorentz/Doppler line shapes for 5 gaseous species (H2O, CO2, CO, HCl and HF) and an appoximate (non-scattering) treatment of carbon particles. The Curtis-Godson approximation is used for inhomogeneous gases, but a subroutine is available for using Young's intuitive derivative method for H2O with Lorentz line shape and exponentially-tailed-inverse line strength distribution. The geometry model provides integration over a hemisphere with up to 6 individually oriented identical axisymmetric plumes, a single 3-D plume, Shading surfaces may be used in any of 7 shapes, and a conical limit may be defined for the plume to set individual line-of-signt limits. Intermediate coordinate systems may specified to simplify input of plumes and shading surfaces

Space shuttle main engine plume radiation model

The methods are described which are used in predicting the thermal radiation received by space shuttles, from the plumes of the main engines. Radiation to representative surface locations were predicted using the NASA gaseous plume radiation GASRAD program. The plume model is used with the radiative view factor (RAVFAC) program to predict sea level radiation at specified body points. The GASRAD program is described along with the predictions. The RAVFAC model is also discussed

Effect of a deposited coupling loop on the high-speed switching properties or a magnetic thin film

Future applications of magnetic thin films to computer circuitry will require the use of integrated deposited circuitry, which involves depositing magnetic films and associated electrical circuitry on the same substrate. It is verified that the extremely close coupling between a magnetic film and a surrounding deposited loop in this configuration results in 100% flux linkage with the loop. The dependence of the observed flux linkage of the deposited loop on the loop circuitry is studied; the effect of width, thickness, and separation of deposited loop conductors on high-speed film switching is investigated; and the relative importance of circulating loop currents and eddy currents in the conductor materials in slowing film switching is evaluated

The Rapid Rise of Supermarkets in Developing Countries: Induced Organizational, Institutional, and Technological Change in Agrifood Systems

There has been extremely rapid transformation of the food retail sector in developing regions in the past 5 to 10 years, accompanied by a further consolidation and multi-nationalization of the supermarket sector itself. This organizational change, accompanied by intense competition, has driven changes in the organization of procurement systems of supermarket chains, toward centralized and regionalized systems, use of specialized/dedicated wholesalers and preferred supplier systems, and demanding, private quality standards. These changes in the system have in turn determined the very recent rise of the use of contracts between supermarkets and agrifood producers in these regions to cover provision of services and provision for risk management, as well as requirements for demanding quality and safety attributes, which require substantial investment in technological change and upgrading at the producer level. This paper presents a brief discussion of these trends, followed by a conceptual framework to explain this phenomenon, illustrated with empirical evidence drawn mainly from Latin America.supermarket chains, procurement systems, quality standards, agrifood producers, Agribusiness,

The Fair Trial-Free Press Controversy - Where We Have Been and Where We Should Be Going

On October 2, 1966, the report of the American Bar Association Advisory Committee on Fair Trial and Free Press was released as a tentative draft. The release culminated twenty months of intensive work by the Committee, its Reporter, and its research staff. Since then, many thousands of copies of the draft in printed form have been distributed to judges, lawyers, schools of law and journalism, and to persons in responsible positions in the press, radio and television whose all important function is to keep the American people informed. The news media and other groups have also completed studies to which I shall refer. A great and entirely desirable debate has now been under way for a number of months. In the remarks which follow, it is my purpose, speaking for myself alone, but reflecting, I hope, the general sentiment of our Committee, to examine the current posture of the Fair Trial-Free Press issue with some preface to indicate the chronology of events which have contributed to the present debate, and with some recommendations for the future

HETEROGENEOUS CONSTRAINTS, INCENTIVES AND INCOME DIVERSIFICATION STRATEGIES IN RURAL AFRICA

A burgeoning recent literature emphasizes "livelihood" diversification among smallholder populations (Chambers and Conway 1992, Davies 1993, Ellis 1998, Bryceson 1999, Ellis 2000, Little et al. 2001). While definitions vary within this literature, the concept of livelihoods revolves around the opportunity set afforded an individual or household by their asset endowment and their chosen allocation of those assets across various activities to generate a stream of benefits, most commonly measured as income. This holistic perspective has the potential to enhance our understanding of the strategies that farm households pursue to ensure food and income security given the natural and economic environment in which they operate. Diversification patterns reflect individuals' voluntary exchange of assets and their allocation of assets across various activities so as to achieve an optimal balance between expected returns and risk exposure conditional on the constraints they face (e.g., due to missing or incomplete markets for credit, labor, or land). Because it offers a glimpse as to what people presently consider their most attractive options, given the incentives and constraints they face, the study of diversification behavior offers important insights as to what policy or project interventions might effectively improve either the poor's asset holdings or their access to higher return or lower risk uses of the assets they already possess. Since diversification is not an end unto itself, it is essential to connect observed livelihood strategies back to resulting income distributions and poverty. Not all diversification into off-farm or non-farm income earning activities offers the same benefits and not all households have equal access to the more lucrative diversification options. Yet the livelihoods literature offers little documentation or explanation of important differences between observed diversification strategies. This paper addresses that gap by offering a comparative analysis using data from three different countries, Cote d'Ivoire, Kenya and Rwanda. Like Dercon and Krishnan (1996) and Omamo (1999), we emphasize that interhousehold heterogeneity in constraints and incentives must factor prominently in any sensible explanation of observed diversification behaviors. Indeed, section 4 demonstrates that at a very fundamental level - the choice of basic livelihood strategy - households would prefer locally available livelihood strategies other than those they choose, were they not constrained from doing so. A simple appeal to the principle of revealed preference thus suggests that heterogeneous constraints and incentives play a fundamental role in determining livelihood diversification patterns manifest in income diversification data. The plan for the remainder of this paper is as follows. The next section presents the basic conceptual foundation from which we operate. Section 3 then introduces the data sets and definitions employed in the analysis. Section 4 presents findings relating to the observed variation in income sources across the income distribution, to distinct livelihood strategies pursued by rural African households, to the determinants of strategy choice, and to the effects of alternative livelihood strategies on income dynamics. These findings point especially to significant rural markets failures - especially with respect to finance and land - that force poorer subpopulations to select strategies offering demonstrably lower returns while wealthier subpopulations are able to enjoy higher return strategies to which entry is at least partly impeded by fixed costs and lower marginal costs of participation. Section 5 concludes.Labor and Human Capital, O & Q12,