Basic services approach to urban development: Indian experience☆
In India a number of earlier efforts were made to improve basic services in urban areas, with the active involvem e n t of the p e o p l e and n o n governmental organizations (NGOs). But these were more in the nature of pilot projects. The Urban Basic Services (UBS) programme launched during 1985-90 in India, covering a number of small and medium towns in various parts of the country, is a unique experiment. Its uniqueness stems not only from its wider scale of operation but also from its basic themes of community participation, convergence and capacity building. The active involvement of the NGOs and its institutional support are other unique features of the programme. This paper traces the genesis of the basic services approach, the role of international bodies like UNICEF and the World Bank and analyses the UBS programme as it is being implemented in India.
Impact of Population on Selected Social and Economic Sectors
﻿Social and Economic Sectors K Srinivasan Sumati Kulkarni S Parasuraman This paper attempts to study the social and economic implications of alternative trends in population growth in India up to the year 2021 from a macro-economic-demographic point of view.
O2 constraints from Paleoproterozoic detrital pyrite and uraninite
Redox-sensitive detrital grains such as pyrite and uraninite in sedimentary successions provide one of the most conspicuous geological clues to a different composition of the Archean and early Paleoproterozoic atmosphere. Today, these minerals are rapidly chemically weathered within short transport distances. Prior to the rise of oxygen, low O2 concentrations allowed their survival in siliciclastic deposits with grain erosion tied only to physical transport processes. After the rise of oxygen, redox-sensitive detrital grains effectively vanish from the sedimentary record. To get a better understanding of the timing of this transition, we examined sandstones recorded in a scientifi c drill core from the South African 2.415 Ga Koegas Subgroup, a mixed siliciclastic and iron formation–bearing unit deposited on the western deltaic margin of the Kaapvaal craton in early Paleoproterozoic time. We observed detrital pyrite and uraninite grains throughout all investigated sandstone beds in the section, indicating the rise of oxygen is younger than 2.415 Ga. To better understand how observations of detrital pyrite and uraninite in sedimentary rocks can quantitatively constrain Earth surface redox conditions, we constructed a model of grain erosion from chemical weathering and physical abrasion to place an upper limit on ancient environmental O2 concentrations. Even conservative model calculations for deltaic depositional systems with suffi cient transport distances (approximately hundreds of kilometers) show that redox-sensitive detrital grains are remarkably sensitive to environmental O2 concentrations, and they constrain the Archean and early Paleoproterozoic atmosphere to have <3.2 × 10 –5 atm of molecular O2. These levels are lower than previously hypothesized for redox-sensitive detrital grains, but they are consistent with estimates made from other redox proxy data, including the anomalous fractionation of sulfur isotopes. The binary loss of detrital pyrite and uraninite from the sedimentary record coincident with the rise of oxygen indicates that atmospheric O2 concentrations rose substantially at this time and were never again suffi ciently low (<0.01 atm) to enable survival and preservation of these grains in short transport systems.