The Impacts of Wildlife Conservation Policies on Rural Household Welfare in Zambia

KEY POLICY POINTS • Tourism is increasingly important in Zambia as a vehicle for economic growth, and has been identified as a key sector for poverty reduction due to its potential to generate off-farm income and employment in rural areas. Growth in arrivals and receipts in Zambia has outpaced average growth rates for developing countries. • Tourism in Zambia relies mostly on the stock of natural resources, including the protected area system which includes national parks and game management areas (GMAs). Co-management agreements between Zambia Wildlife Authority (ZAWA) and rural communities present opportunities and threats for households living in GMAs. • Households living in GMAs have lower average income than households in other rural areas. Yet we find that, for prime GMAs (those well stocked with wildlife), the GMA designation leads to higher incomes than households would otherwise be expected to achieve, based on their own characteristics and those of the areas in which they reside. • We further find that the benefits of living in a prime GMA accrue mostly to the wealthier segments of the population. • Though overall effects on households are positive, losses from crop damage by wildlife are a threat to this success: we find that such losses are statistically significant, large enough to be meaningful to households, and greatest in prime GMAswildlife conservation, rural households, zambia, Community/Rural/Urban Development, Environmental Economics and Policy, Food Security and Poverty, International Development, q57,

Comparative Effectiveness of Step-up Therapies in Children with Asthma Prescribed Inhaled Corticosteroids : A Historical Cohort Study

This work was supported by the Respiratory Effectiveness Group. Acknowledgments We thank the Respiratory Effectiveness Group for funding this work, Annie Burden for assistance with statistics, and Simon Van Rysewyk and Lisa Law for assistance with medical writing.Peer reviewedPostprin

Nitrogen cycling, forest canopy reflectance, and emergent properties of ecosystems

In Ollinger et al. (1), we reported that mass-based concentrations of nitrogen in forest canopies (%N) are positively associated with whole-canopy photosynthetic capacity and canopy shortwave albedo in temperate and boreal forests, the latter result stemming from a positive correlation between %N and canopy near infrared (NIR) reflectance. This finding is intriguing because a functional link between %N and NIR reflectance could indicate an influence of nitrogen cycling on surface energy exchange, and could provide a means for estimating %N using broad-band satellite sensors

Latency Models for Analyses of Protracted Exposures

The effect of an increment of exposure on disease risk may vary with time since exposure. If the pattern of temporal variation is simple (e.g., a peak then decline in excess risk of disease) then this may be modeled efficiently via a parametric latency function. Estimation of the parameters for such a model can be difficult because the parameters are not a function of a simple summary of the exposure history. Typically such parameters are estimated via an iterative search that requires calculating a different time-weighted exposure for each combination of the latency function parameters. This paper describes a simple approach to fitting logistic regression models that include a parametric latency function. This approach is illustrated using data from a study of the association between radon exposure and lung cancer mortality among underground uranium miners. This approach should facilitate fitting models to assess variation with time since exposure in the effect of a protracted environmental or occupational exposure

Temporal Variation in the Association between Benzene and Leukemia Mortality

BackgroundBenzene is a human carcinogen. Exposure to benzene occurs in occupational and environmental settings.ObjectiveI evaluated variation in benzene-related leukemia with age at exposure and time since exposure.MethodsI evaluated data from a cohort of 1,845 rubber hydrochloride workers. Benzene exposure–leukemia mortality trends were estimated by applying proportional hazards regression methods. Temporal variation in the impact of benzene on leukemia rates was assessed via exposure time windows and fitting of a multistage cancer model.ResultsThe association between leukemia mortality and benzene exposures was of greatest magnitude in the 10 years immediately after exposure [relative rate (RR) at 10 ppm-years = 1.19; 95% confidence interval (CI), 1.10–1.29]; the association was of smaller magnitude in the period 10 to < 20 years after exposure (RR at 10 ppm-years = 1.05; 95% CI, 0.97–1.13); and there was no evidence of association ≥ 20 years after exposure. Leukemia was more strongly associated with benzene exposures accrued at ≥ 45 years of age (RR at 10 ppm-years = 1.11; 95% CI, 1.04–1.17) than with exposures accrued at younger ages (RR at 10 ppm-years = 1.01; 95% CI, 0.92–1.09). Jointly, these temporal effects can be efficiently modeled as a multistage process in which benzene exposure affects the penultimate stage in disease induction.ConclusionsFurther attention should be given to evaluating the susceptibility of older workers to benzene-induced leukemia

The classification and structure of megafaunal assemblages in the Venezuela Basin, Caribbean Sea

Data from 23 benthic trawls collected from the Venezuela Basin (3411–5062 m water depth) indicate that megafauna are less abundant than in basins of similar depths in the Atlantic and are segregated by sedimentary province. Taxonomic assemblages, in terms of abundance and biomass, from three sites coincide with distinctions of sedimentary characteristics among the pelagic, hemipelagic and turbidite sedimentary provinces. Mollusks, decapods and fishes are most abundant in trawls collected from the pelagic and hemipelagic provinces and anemones and holothurians are most abundant in trawls collected from the turbidite province. Sponges dominate the biomass of fauna in trawls collected in the turbidite and hemipelagic provinces and fishes dominate the biomass of trawls collected in the pelagic province. Several biological and physical aspects of the basin contribute to the segregation of the megafauna into distinct communities. Sponges and anthropogenic debris (coal, coal clinker and tar balls) reaching the sea floor create a habitat that is exploited by sessile suspension feeders requiring a hard substrate. Filter-feeding anemones attached to debris occur in such abundance that it elevates the importance of suspension feeders and depresses species diversity at the turbidite site. Biomass and average size of megafaunal deposit feeders in the basin decrease with decreasing amounts of organic carbon and nitrogen content of the sediment. Distribution and composition of filter-feeding megafaunal biomass in the Venezuela Basin are explained largely by proximity to sources of organic matter. Detrital carbonate may also play a role in controlling distribution and density of megafauna by diluting food resources in the sediments

Estimating demand for perennial pigeon pea in Malawi using choice experiments

AbstractPerennial crops have numerous ecological and agronomic advantages over their annual counterparts. We estimate discrete choice models to evaluate farmers' preferences for perennial attributes of pigeon pea intercropped with maize in central and southern Malawi. Pigeon pea is a nitrogen-fixing leguminous crop, which has the potential to ameliorate soil fertility problems related to continuous maize cultivation, which are common in Southern Africa. Adoption of annual pigeon pea is relatively low but perennial production of pigeon pea may be more appealing to farmers due to some of the ancillary benefits associated with perenniality. We model perennial production of pigeon pea as a function of the attributes that differ between annual and perennial production: lower labor and seed requirements resulting from a single planting with multiple harvests, enhanced soil fertility and higher levels of biomass production. The primary tradeoff associated with perennial pigeon pea intercropped with maize is competition with maize in subsequent years of production. While maize yield is approximately twice as valuable to farmers as pigeon pea yield, we find positive yet heterogeneous demand for perenniality driven by soil fertility improvements and pigeon pea grain yield

Target recognitions in multiple camera CCTV using colour constancy

People tracking using colour feature in crowded scene through CCTV network have been a popular and at the same time a very difficult topic in computer vision. It is mainly because of the difficulty for the acquisition of intrinsic signatures of targets from a single view of the scene. Many factors, such as variable illumination conditions and viewing angles, will induce illusive modification of intrinsic signatures of targets. The objective of this paper is to verify if colour constancy (CC) approach really helps people tracking in CCTV network system. We have testified a number of CC algorithms together with various colour descriptors, to assess the efficiencies of people recognitions from real multi-camera i-LIDS data set via Receiver Operating Characteristics (ROC). It is found that when CC is applied together with some form of colour restoration mechanisms such as colour transfer, the recognition performance can be improved by at least a factor of two. An elementary luminance based CC coupled with a pixel based colour transfer algorithm, together with experimental results are reported in the present paper