Soil degradation: a threat to developing-country food security by 2020?

Global population in the year 2020 will be a third higher than in 1995, but demand for food and fiber will rise by an even higher proportion, as incomes grow, diets diversify, and urbanization accelerates. However this demand is met, population and farming pressure on land resources will intensify greatly. There is growing concern in some quarters that a decline in long-term soil productivity is already seriously limiting food production in the developing world, and that the problem is getting worse. Sarah Sherr first focuses on the magnitude and effects of soil degradation. She then addresses soil degradation in the future and ends her brief with policy and research priorities.Soil degradation Developing countries., Food security Developing countries.,

Organizational development and natural resource management: evidence from central Honduras

The determinants of local organizational density and the impacts of local and external organizations on collective and private natural resource management decisions are investigated based on a survey of 48 villages in central Honduras. Factors positively associated with local organizational development include the presence of external organizations, population level, moderate population growth, lower population density, the presence of immigrants, distance from the urban market, literacy and coffee production. Local organizations are found to contribute to collective action to conserve resources, while government organizations appear to displace it, though not in all cases. The findings suggest that external organizations can play a catalytic role in fostering development of local organizations and emphasize the importance of improved understanding of the roles of local organizations, in order to enhance complementarity and minimize competition between these different agents in promoting sustainable development.Honduras., Natural resources Management., Collective behaviour., Government.,

Interference of Mycobacterium tuberculosis with macrophage responses

Tuberculosis, caused by Mycobacterium tuberculosis, has become an important health and economic burden, with more than four thousand people succumbing to the disease every day. Thus, there is an urgent need to understand the molecular basis of this pathogen's success in causing disease in humans, in order to develop new drugs superior to conventional drugs available at present. One reason why M. tuberculosis is such a dangerous microbe lies within its ability to survive within infected hosts, thereby efficiently circumventing host immune responses. Over the past few years, a number of mechanisms have been unravelled that are utilized by M. tuberculosis to survive within hosts and to avoid immune defence mechanisms. Several of these mechanisms have been described in this communication that may be useful for the development of novel compounds to treat tuberculosis

Population pressure and the microeconomy of land management in hills and mountains of developing countries:

Concerns about harmful environmental impacts are frequently raised in research and policy debates about population growth in the hills and mountains of developing countries. Although establishing wildlife corridors and biosphere reserves is important for preserving selected biodiverse habitats, for the vast majority of hilly-mountainous lands, the major ecological concerns are for the sustainability of local production systems and for watershed integrity. What matters for sustained use of those lands not only is the number of producers but also what, where and how they produce. Evidence from empirical research indicates that population growth in hills and mountains can lead to land enhancement, degradation, or aspects of both. This can be explained by extending induced innovation theory to address environmental impacts of intensification. Increases in the labor-land endowment ratios of households and in local land demand and labor supply make the opportunity cost of land relative to labor increase. As a result, people use hilly-mountainous land resources more intensively for production and consumption, thus tending to deplete resources and significantly alter habitats. But, at the same time, capital- and labor-intensive methods of replenishing or improving soil productivity may become economically more attractive, production systems that enhance the land if the expected discounted returns are greater than those of systems that degrade the land. Users will choose production systems that enhance the land if the expected discounted returns are greater than those of systems that degrade the land. In addition to population change, other factors—market conditions, local institutions and organizations, information and technology about resource management, and local ecological conditions—determine the returns from various production systems.Environmental impact analysis., Population density.,

Property rights, collective action, and agroforestry

"In this brief, we explore the role that social institutions — specifically property rights and collective action — may play in the developmentment of agroforestry.... In the future, property rights and collective action will play increasingly pivotal roles in defining rights and responsibilities over the externalities of tree management practices. As stakeholders recognize the need for effective management of, for example, the erosion resulting from tree felling or rights to carbon sequestration from tree planting, they will increasingly value and depend on the institutions that protect their property rights." from Text.Property rights ,Tree planting ,Public goods ,Poverty alleviation ,Collective action ,

Sustainable agricultural development strategies in fragile lands:

Current trends in demography, agricultural production and rural environment in the developing countries suggest that so-called "marginal lands" must play a larger and probably growing role in food supply and economic development for the foreseeable future. To fulfill this critical role, public policy towards these lands needs to be revised. A key policy focus should be to strengthen incentives for local land users to not only maintain, but to improve the natural resource base for food and fiber supply. Such "land-improving investments" are needed to reduce production and subsistence risks and permit more intensive use without degradation. Under population and market pressure, one can expect an endogenous process of intensification, through land improvements, tenurial and institutional changes and "re-ordering" of the landscape. But this process is not automatic. Factors influencing the pace and scale of land transformation include: farmer knowledge of degradation of the degrading resource; incentives for long-term investment; capacity to mobilize resources for land investment; level of economic returns to such investment; and factors affecting the formation and function of local groups to help mobilize resources and coordinate landscape-level change. Current policies often work to constrain, rather than support, this process. New research is needed to support policy change for "marginal" lands.Land use Economic aspects., Investments.,

Pathways of development in the hillsides of Honduras: causes and implications for agricultural production, poverty, and sustainable resource use

Based on a survey of 48 communities in central Honduras, this paper identifies the major pathways of development that have been occurring in central Honduras since the mid-1970s, their causes and implications for agricultural productivity, natural resource sustainability, and poverty. Six pathways of development were identified: 1) basic grains expansion communities-where basic grains production is the dominant activity and increased basic grains production has occurred; 2) basic grains stagnation communities-where basic grains production is dominant but has stagnated or declined; 3) coffee expansion communities-where coffee production is important and has been increasing in importance; 4) horticultural expansion communities-where substantial adoption and expansion of horticultural crops has occurred; 5) forestry specialization communities-where forestry activities are important and basic grains production is stagnant or declining; and 6) nonfarm employment communities-where nonfarm employment is a major and increasing source of income. The findings imply that a “one-size-fits-all” approach to technical assistance is unlikely to be successful, since different approaches show promise in different pathways.Natural resources., Poverty., Technical assistance., Agricultural development., Honduras.,

The Map Reading Probe’s Effectiveness in Predicting Performance Within an RtIISystem

Public-school districts nationwide are utilizing student progress toward proficiency on state-wide achievement assessments as their means of monitoring student achievement. Of late, the three-tiered system of reading instruction and intervention (RtII) has shown the most promise to increase reading proficiency levels schoolwide. However, little research exists to support the use of the MAP reading probe within an RtII framework for advancing reading achievement. This study provides a statistical analysis of the use of MAP as a predictor of reading performance on statewide assessments in a suburban K-5 elementary school currently utilizing RtII as a means of advancing student achievement in reading. The study results showed that the use of the MAP reading assessment throughout the school year proved to be an accurate predictor of reading progress in all three tiers of the school’s RTI system, as well as an accurate indicator of student performance on the statewide reading assessment. The implications of these findings, as well as suggestions for future research, also are discussed

Uniform Boundedness of S-Units in Arithmetic Dynamics

Let K be a number field and let S be a finite set of places of K which contains all the Archimedean places. For any f(z) in K(z) of degree d at least 2 which is not a d-th power in \bar{K}(z), Siegel's theorem implies that the image set f(K) contains only finitely many S-units. We conjecture that the number of such S-units is bounded by a function of |S| and d (independently of K and f). We prove this conjecture for several classes of rational functions, and show that the full conjecture follows from the Bombieri--Lang conjecture

Foundations and Frontiers of Physics Education Research 2009

This project is a conference on the Foundations and Frontiers of Physics Education Research, in which established and up-and-coming researchers attend a residential conference to further the work of the field. There are 60 participants, including senior graduate students, research scientists, junior, and tenured faculty. The conference consists of a series of plenary talks by leaders in the community; working groups of participants to address common problems in the field and present recommendations for future work; and targeted sessions in which research topics are explored in detail by participants. Ample free time is also included, allowing for informal discussions and interactions that can lead to future collaborations. Intellectual Merit: By bringing together the leaders of the physics education research community in an intimate setting, the conference promotes more intense discussions and more focused interactions than are possible at other meetings common to the community. Broader Impact: Establishing a more cohesive research community furthers the field of physics education research. Promoting the highest quality postdoctoral researchers and junior faculty strengthens their reputation in the community, supporting the growth of new leaders. Sharing results through plenary and targeted sessions spreads knowledge that advances the field. Finally, working groups answer questions of structural concern to the physics education research community. The results of the working groups are to be published in an American Physical Society Forum on Education newsletter, allowing them to be shared with a much larger audience than attends the meeting