Contract Farming, Smallholders, and Rural Development in Latin America: The Organization of Agroprocessing Firms and the Scale of Outgrower Production

Cadmium (Cd) is a heavy metal that has received considerable concern environmentally and occupationally. Cd has a long biological half-life mainly due to its low rate of excretion from the body. Thus, prolonged exposure to Cd will cause toxic effect due to its accumulation over time in a variety of tissues, including kidneys, liver, central nervous system (CNS), and peripheral neuronal systems. Cd can be uptaken from the nasal mucosa or olfactory pathways into the peripheral and central neurons; for the latter, Cd can increase the blood brain barrier (BBB) permeability. However, mechanisms underlying Cd neurotoxicity remain not completely understood. Effect of Cd neurotransmitter, oxidative damage, interaction with other metals such as cobalt and zinc, estrogen-like, effect and epigenetic modification may all be the underlying mechanisms. Here, we review the in vitro and in vivo evidence of neurotoxic effects of Cd. The available finding indicates the neurotoxic effects of Cd that was associated with both biochemical changes of the cell and functional changes of central nervous system, suggesting that neurotoxic effects may play a role in the systemic toxic effects of the exposure to Cd, particularly the long-term exposure.

https://downloads.hindawi.com/journals/omcl/2013/898034.pdf

Cadmium and Its Neurotoxic Effects

Publisher Summary This chapter accomplishes four specific goals of clarifying the contribution of economic analysis over the instruments of environmental policy. First, it describes the general situation in which environmental policy goals must be achieved. An appreciation of the complexity of this situation will provide a base from which to consider both past error and actual special cases. Second, it defines a set of dimensions along which policy instruments may usefully be judged. These include: static efficiency, centralized information and computation requirements, enforceability, dynamic incentive effects, flexibility in the face of exogenous change, and implications for goals other than efficiency. In the process, it intends to make explicit the irreducible political content of choices among policy instruments and thus the reasons that technical arguments on the other dimensions are not decisive in the political arena. Thirdly, it reviews both some major non-economic attempts to evade the complexity of the general case and the record of adoptions of explicitly economic prescriptions. Finally, it examines some of the economic complexities associated with a variety of instruments and problems.

Chapter 10 Comparative analysis of alternative policy instruments

Grazing Ecology Rangeland Conservation Defoliation Physiological Effects of Defoliation Palatability, Preference, and Selective Defoliation Physical Effects of Grazing Animals Energy Flow and Nutrient Cycling Redistribution of Minerals by Plants and Animals Distribution of Plants by Animals Fire as an Environmental Factor Rangeland Synecology Grazing Management Numbers of Animals Utilization of Forage Animal Distribution Mixed Species Grazing Mixed Species Management Seasonal Management Grazing Plans Responses to Seasonal Grazing Plans Vegetation Management Modification of Vegetation Mechanical Control of Rangeland Plants Chemical Control of Rangeland Plants Prescribed Fire in Rangeland Management Biological Control Seeding of Rangelands Rangeland Fertilization Soil and Water Conservation Managing Rangeland Complexity Reclamation of Damaged Rangeland Riparian Areas and Pollution: Best Management Practices Multiple-Use Planning for Rangeland Management Decision Support Systems

Rangeland ecology and management

Environmental amenities and agricultural land values: a hedonic model using geographic information systems data

Increased Lead and Cadmium Burdens among Mentally Retarded Children and Children with Borderline Intelligence.

Some economists have argued that the "solution to pollution" is effluent taxes. Ideally, the effluent tax should be set at a level which equates marginal social costs of effluent reduction with marginal social benefits of such reduction. Because of the difficulty of measuring these costs and benefits, particularly the benefits, economists have suggested an alternate approach. This approach requires that a socially acceptable standard of environmental (water) quality be set. Effluent taxes could then be used to achieve this standard. It has been argued that effluent taxes would achieve this standard at lower social cost than would policies such as uniform treatment or uniform reduction in effluent discharge by each discharger (Kneese; Kneese and Bower; Baumol and Oates; Freeman, Haveman, Kneese). Homer has presented a concise review of the case for effluent taxes. Few economists have disagreed with this argument. This article discusses an empirical comparison of the social costs and the cost to farmers of achieving given levels of reduction in phosphorus discharge from crop reduction for effluent taxes versus uniform reduction. A modified effluent tax, which would achieve the same water quality goals at a lower cost to farmers, is also analyzed. Research conducted on phosphorus in recent years lends itself to an empirical test of the aforementioned issue (Casler and Jacobs). Companion research indicates that reduction in soluble phosphorus inputs would decrease algal production in lakes in temperate latitudes (Oglesby and Schaffner). Presumably there are social benefits of reduced phosphorus discharges to such lakes, at least over some range of reduction.

Internalizing Externalities of Phosphorus Discharges from Crop Production to Surface Water: Effluent Taxes versus Uniform Reductions

Economic information that can be used to determine which management alternatives best meet public demands within limited budgets is important to resource management agencies. The objective of this study was to generate estimates of economic benefits of improvements on Wyoming trout fishing streams that could be used to evaluate different improvement projects. A mail survey was conducted to determine characteristics and preferences of anglers fishing Wyoming streams, and the contingent valuation method (CVM) was used to estimate economic benefits associated with fishing under improved conditions. Questions were associated with fishing for any or all trout species an angler might encounter on Wyoming streams. Benefits of improvement were based on CVM questions involving a hypothetical doubling of the chance of catching a large trout and a hypothetical increase in trout populations. Tourist and resident fishing license subgroups also were analyzed. Anglers in the tourist license group traveled long ...

Estimating the Economic Value of Improved Trout Fishing on Wyoming Streams

The government must manage public rangeland in the face of alternative multiple use interests, including wildlife and domestic livestock production. The objectives of this study were to estimate a production possibilities frontier for antelope (Antilocapra americana (Ord)) and stocker cattle on the Wyoming Red Desert and then evaluate the most economical combination for the specific production and price assumptions used in the analysis. Nine antelope-steer combinations were derived by using a linear programming model to maximize total number of animals subject to annual forage production on a representative 405-ha range site. The resulting 9 combinations included 72 head of antelope with no steers at one extreme and 35 head of stocker steers with no antelope at the other extreme, with various combinations of each in between. Because of the different forage preferences of antelope (primarily browse) and cattle (primarily grass), the marginal rates of substitution of cattle for antelope varied widely along the production possibilities frontier. Specifically, the marginal rate of substitution of cattle for antelope was very low moving from 72 antelope-0 steers, to 69 antelope-29 steers, in terms of sacrificing only a few antelope (3) in exchange for a comparatively large number of steers (29). Conversely, the marginal rate of substitution of cattle for antelope moving from 69 antelope-29 steers, to 0 antelope-35 steers was very high in terms of sacrificing a relatively large number of antelope (69) in exchange for only a few additional steers (6). This wide range of substitution rates suggests that economic benefits from antelope and cattle would have to be extremely different before "multiple use" is not preferred in the case study setting.

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Multiple use of public rangeland: Antelope and stocker cattle in Wyoming

Increasing prices for fuel and N fertilizer affect crop production decisions and profitability. Nitrogen response functions are estimated for corn (Zea mays L.), sugar beet (Beta vulgaris L.), dry bean (Phaseolus vulgaris L.), and malt barley (Hordeum vulgare L.) using data from field studies conducted in the Big Horn Basin of Wyoming. These N response functions are used to evaluate the impact of increases in N and fuel prices on the profitable level of N use. Enterprise budgets are developed for seven selected crops to determine return to management [Return to Management = Price x Yield - Total Cost (preplant, plant, growing, harvest, land, and other)] under price increases for fuel and N. Finally, a linear programming model is used to determine the impacts of increased prices for fuel and N on farm profit and crop mix. Results illustrate that impacts of increasing fuel and N prices on individual crops are quite different and also vary with the overall crop mix. In particular, adding alfalfa (Medicago sativa L.) and perennial ryegrass (Lolium spp.) seed production to the crop mix reduced the impacts of increasing fuel and N prices. This suggests producers should adjust production practices on individual crops and also analyze their crop mix when faced with rising fuel and N prices if they are to minimize impacts on profitability.

James J. Jacobs

Papers

Increased Lead and Cadmium Burdens among Mentally Retarded Children and Children with Borderline Intelligence.

Internalizing Externalities of Phosphorus Discharges from Crop Production to Surface Water: Effluent Taxes versus Uniform Reductions

Estimating the Economic Value of Improved Trout Fishing on Wyoming Streams

Multiple use of public rangeland: Antelope and stocker cattle in Wyoming

Impact of Fuel and Nitrogen Prices on Profitability of Selected Crops: A Case Study