Adjustment formulae for maternal serum alpha-fetoprotein,human chorionic gonadotropin,and unconjugated oestriol to maternal weight and smoking

Serum levels of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and un-conjugated oestriol (uE3) were measured in serum samples of 4131 non-smoking and 1018 smoking women during the second trimester of pregnancy. The levels of all three analytes decreased with increasing body weight. The AFP median was significantly increased in smokers in a dose-response association; hCG decreased by 21 per cent and uE3 decreased by 3 per cent in smokers in a non-dose-related fashion. Regression functions for adjustment of serum levels for weight and smoking should be considered in risk estimation for Down syndrome in order to give a woman's individual risk more precisely.     

支持西印度洋地区海洋和海岸带资源可持续管理的海洋研究

西印度洋(WIO)地区以其迷人的海岸带、丰富的海洋生物多样性以及富饶的海洋和海岸带资源而著称.但是地处WIO地区的许多国家像肯尼亚、莫桑比克、索马里、南非、坦桑尼亚、科摩罗、马达加斯加、毛里求斯、留尼旺、塞舌尔等却极度贫困,特别是近二三十年以来,该地区的环境退化现象以及自然资源和生物多样性的下降越来越明显.     

Adoption and adaptation of natural resource management innovations in smallholder agriculture: reflections on key lessons and best practices

Many smallholder farmers in vulnerable areas continue to face complex challenges in adoption and adaptation of resource management and conservation strategies. Although much has been learned from diverse experiences in sustainable resource management, there is still inadequate understanding of the market, policy and institutional failures that shape and structure farmer incentives and investment decisions. The policy and institutional failures exacerbate market failures, locking smallholder resource users into a low level equilibrium that perpetuates poverty and land degradation. Improved market access that raises the returns to land and labor is often the driving force for adoption of new practices in agriculture. Market linkages, access to credit and availability of pro-poor options for beneficial conservation are critical factors in stimulating livelihood and sustainability-enhancing investments. Future interventions need to promote joint innovations that ensure farmer experimentation and adaptation of new technologies and careful consideration of market, policy and institutional factors that stimulate widespread smallholder investments. Future projects should act as ‘toolboxes’, giving essential support to farmers to devise complementary solutions based on available options. Addressing the externalities and institutional failures that prevent private and joint investments for management of agricultural landscapes will require new kinds of institutional mechanisms for empowering communities through local collective action that would ensure broad participation and equitable distributions of the gains from joint conservation investments. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

U.S. Natural Resources and Climate Change: Concepts and Approaches for Management Adaptation

Public lands and waters in the United States traditionally have been managed using frameworks and objectives that were established under an implicit assumption of stable climatic conditions. However, projected climatic changes render this assumption invalid. Here, we summarize general principles for management adaptations that have emerged from a major literature review. These general principles cover many topics including: (1) how to assess climate impacts to ecosystem processes that are key to management goals; (2) using management practices to support ecosystem resilience; (3) converting barriers that may inhibit management responses into opportunities for successful implementation; and (4) promoting flexible decision making that takes into account challenges of scale and thresholds. To date, the literature on management adaptations to climate change has mostly focused on strategies for bolstering the resilience of ecosystems to persist in their current states. Yet in the longer term, it is anticipated that climate change will push certain ecosystems and species beyond their capacity to recover. When managing to support resilience becomes infeasible, adaptation may require more than simply changing management practices—it may require changing management goals and managing transitions to new ecosystem states. After transitions have occurred, management will again support resilience—this time for a new ecosystem state. Thus, successful management of natural resources in the context of climate change will require recognition on the part of managers and decisions makers of the need to cycle between “managing for resilience” and “managing for change.”     

Assessment of adoption and impact of rainwater harvesting technologies on rural farm household income: the case of rainwater harvesting ponds in Rwanda

Rainwater harvesting is increasingly viewed as a major strategy for enhancing agricultural productivity and boosting farm income in many drought-prone areas. While this technology is being promoted in many developing countries, there is conflicting evidence in the literature about its impact on welfare of farm households. This study uses propensity score matching and discrete choice regression techniques to assess the impact of rainwater harvesting ponds on farm household income and factors that influence adoption of such technologies in Rwanda. It finds that households with rainwater harvesting ponds have significantly higher income than their counterparts of comparable observable characteristics. It further finds evidence that increase in farm income occurs via increased input use and that household size, asset endowments and participation in farmer organizations condition adoption of rainwater harvesting ponds. The study concludes that adoption of rainwater harvesting technologies has positive benefits on farm households. It discusses the policy implications that adoption of rainwater harvesting ponds presents a pathway for reducing rural poverty.     

Climate-Smart Design for Ecosystem Management: A Test Application for Coral Reefs

Environmental Management - The interactive and cumulative impacts of climate change on natural resources such as coral reefs present numerous challenges for conservation planning and management....     

The influence of institutions and organizations on urban waste collection systems: an analysis of waste collection system in Accra, Ghana (1985-2000)

Urban waste collection system is a pivotal component of all waste management schemes around the world. Therefore, the efficient performance and the success of these schemes in urban pollution control rest on the ability of the collection systems to fully adapt to the prevailing cultural and social contexts within which they operate. Conceptually, institutions being the rules guiding the conduct of public service provision and routine social interactions, waste collection systems embedded in institutions can only realize their potentials if they fully evolve continuously to reflect evolving social and technical matrices underlying the cultures, organizations, institutions and social conditions they are designed to address. This paper is a product of an analysis of waste collection performance in Ghana under two different institutional and/or organizational regimes; from an initial entirely public sector dependence to a current mix of public-private sector participation drawing on actual planning data from 1985 to 2000. The analysis found that the overall performance of waste collection services in Ghana increased under the coupled system, with efficiency (in terms of total waste clearance and coverage of service provision) increasing rapidly with increased private-sector controls and levels of involvement, e.g. for solid waste, collection rate and disposal improved from 51% in 1998 to about 91% in the year 2000. However, such an increase in performance could not be sustained beyond 10 years of public-private partnerships. This analysis argues that the sustainability of improved waste collection efficiency is a function of the franchise and lease arrangements between private sector group on the one hand and public sector group (local authorities) on the other hand. The analysis therefore concludes that if such franchise and lease arrangements are not conceived out of an initial transparent process, such a provision could undermine the overall sustainability of private sector initiatives in collection services delivery in the long term, as in the case of the Accra example.     

Is the god of diamonds alone? The role of institutions in artisanal mining in forest landscapes,Congo Basin

This paper examines the institutional framework of artisanal mining in the forests of the Sangha Tri-National Landscape (TNS) in the Congo Basin. Artisanal miners in Cameroon and the Central African Republic (CAR) commonly make sacrifices to their god of diamonds, to improve fortunes. This study looks into ‘the other forces’; institutions that play a role in shaping the sector and its outcomes. These institutions comprise formal and informal institutions at a local, national, regional and international level. Although artisanal miners in TNS benefit by gaining cash income, this activity also carries risks as income is highly disparate and environmental impacts in this priority forest conservation area are expected to increase due to the growing competition over land use. It was concluded from a literature review, interviews and site visits that informal arrangements dominate the sector, especially in Cameroon, leading to poor relations between officials and miners and meaning that miners have few rights and no voice. The current institutional setup is inadequate to deal with current and anticipated social and environmental issues. Future interventions need to take into account the existing (local) types of organization, vulnerable groups, the interests of multiple actors and the fact that most miners are experienced but combine mining with other activities, such as agriculture, fishing and harvesting forest products. African initiatives concerning ASM offer opportunities to Cameroon and CAR to collaborate with other countries to combat similar issues. A regional integrated approach of both the forest and mining sector would be especially relevant for trans-boundary agreements, such as concerning the TNS, to reinforce positive outcomes for the landscape and the area's population.