ECONOMICS OF MANAGING INVASIVE PEST SPECIES: EXCLUSION AND CONTROL

An important policy decision in managing invasive species is how to allocate resources between activities aimed at preventing the arrival of new pests - including additional arrivals of existing pests - and activities aimed at reducing the damages done by species that are already here. We develop a dynamic model for managing a generic invasive pest with an uncertain arrival date. The optimal conditions reveal that it is generally more efficient to spend a larger share of outlays for exclusion activities before a species arrives than after it is known to be here. They also show that outlays should be allocated such that the marginal costs of control measures equal the benefits from the marginal reduction of the species' population growth rate, and the marginal costs of exclusion measures equal the benefits from the marginal reduction of the rate of subsequent arrivals.Environmental Economics and Policy,

World Agriculture and Climate Change: Economic Adaptations

Recent studies suggest that possible global increases in temperature and changes in precipitation patterns during the next century will affect world agriculture. Because of the ability of farmers to adapt , however, these changes are not likely to imperil world food production. Nevertheless, world production of all goods and services may decline, if climate change is severe enough or if cropland expansion is hindered. Impacts are not equally distributed around the world.climate change, world agriculture, Environmental Economics and Policy,

Permanence of Carbon Sequestered in Forests under Uncertainty

In this paper we examine the issue of permanence in the context of sequestering carbon through afforestation. We develop a dynamic nested optimal control model of carbon sequestration associated with the decision to afforest a tract of land given there are uncertainties associated with fire and insect/disease hazards. Conceptually, these potential hazards are similar in that their occurrence at any time t is uncertain and landowners can take specific actions – although generally different actions - in any time period t to reduce the probability of sustaining losses related to them. The hazards differ, however, in that fire represents a large loss in carbon at a moment in time, while insect/disease infestations are more likely to be reflected in a period of significant slowing of the rate of carbon accumulation than was anticipated followed by a sustained period of slowly decreasing carbon losses. The nature of these losses will influence the design of incentives under GHG mitigation frameworks that require carbon losses to be replaced as well as the strategies farmers adopt to deal with the uncertainties associated with these events occurring.carbon sequestration, uncertainty, optimal control, hazard function, forestry, permanence, Environmental Economics and Policy, Land Economics/Use,

Induced-Innovation and Invasive Species Management

Public policy for managing invasive species has largely focused on preventive measures prior to detection (stage 1) and on the use of chemical/mechanical or biological control measures after the establishment and dispersion of the invasive species (stage 2). Optimal management policy depends both on the initial stock of the invasive species and on the costs associated with conventional control measures. However, little attention has focused on how an induced technology such as Bt corn and Bt cotton is developed and adopted by farmers (stage 3), or how it affects the manageability of economic and ecological damages from an invasive species. This analysis evaluates the optimal allocation of management resources between preventive and control measures for invasive species by incorporating induced technology under uncertainty into a conventional dynamic model of invasive species management.Invasive species, preventive measures, control measures, induced technology, hazard function, optimal control, comparative dynamic analysis, Environmental Economics and Policy, Production Economics,

Prevention or Control: Optimal Government Policies for Invasive Species Management

We present a conceptual, but empirically applicable, model for determining the optimal allocation of resources between exclusion and control activities for managing an invasive species with an uncertain discovery time. This model is used to investigate how to allocate limited resources between activities before and after the first discovery of an invasive species and the effects of the characteristics of an invasive species on limited resource allocation. The optimality conditions show that it is economically efficient to spend a larger share of outlays for exclusion activities before, rather than after, a species is first discovered, up to a threshold point. We also find that, after discovery, more exclusionary measures and fewer control measures are optimal, when the pest population is less than a threshold. As the pest population increases beyond this threshold, the exclusionary measures are no longer optimal. Finally, a comparative dynamic analysis indicates that the efficient level of total expenditures on preventive and control measures decreases with the level of the invasive species stock and increases with the intrinsic population growth rate, the rate of additional discoveries avoided, and the maximum possible pest population.invasive species, exclusion, control, eradication, public expenditures, Environmental Economics and Policy, Resource /Energy Economics and Policy,

ECONOMICS OF SEQUESTERING CARBON IN THE U.S. AGRICULTURAL SECTOR

Atmospheric concentrations of greenhouse gases can be reduced by withdrawing carbon from the atmosphere and sequestering it in soils and biomass. This report analyzes the performance of alternative incentive designs and payment levels if farmers were paid to adopt land uses and management practices that raise soil carbon levels. At payment levels below $10 per metric ton for permanently sequestered carbon, analysis suggests landowners would find it more cost effective to adopt changes in rotations and tillage practices. At higher payment levels, afforestation dominates sequestration activities, mostly through conversion of pastureland. Across payment levels, the economic potential to sequester carbon is much lower than the technical potential reported in soil science studies. The most cost-effective payment design adjusts payment levels to account both for the length of time farmers are willing to commit to sequestration activities and for net sequestration. A 50-percent cost-share for cropland conversion to forestry or grasslands would increase sequestration at low carbon payment levels but not at high payment levels.Carbon sequestration, greenhouse gas mitigation, afforestation, conservation tillage, no-till, incentive design, leakage, carbon stock, permanence, Environmental Economics and Policy,

RISK MANAGEMENT ON THE EXAMPLE OF RAILWAY INFRASTRUCTURE INVESTMENTS

Railway infrastructure investments are really complex, demanding and time consuming processes. Two main parties take part in them – The Employer and The Contractor. The role of each of them is broadly described in the article. All main risks, to which they are exposed, are listed and commented. There are mentioned among others necessity of providing funds, tender procedures, law changes, materials ordering, safety, deficiency of workers, subcontractors and construction machinery. Consequences of materialize of risks are also pointed. Methods of the risk management, which either are used or could be imposed, are presented in the last part of the articleRailway infrastructure investments are really complex, demanding and time consuming processes. Two main parties take part in them – The Employer and The Contractor. The role of each of them is broadly described in the article. All main risks, to which they are exposed, are listed and commented. There are mentioned among others necessity of providing funds, tender procedures, law changes, materials ordering, safety, deficiency of workers, subcontractors and construction machinery. Consequences of materialize of risks are also pointed. Methods of the risk management, which either are used or could be imposed, are presented in the last part of the articl

Exploiting the glioblastoma peptidome to discover novel tumour-associated antigens for immunotherapy

Peptides presented at the cell surface reflect the protein content of the cell; those on HLA class I molecules comprise the critical peptidome elements interacting with CD8 T lymphocytes. We hypothesize that peptidomes from ex vivo tumour samples encompass immunogenic tumour antigens. Here, we uncover >6000 HLA-bound peptides from HLA-A*02+ glioblastoma, of which over 3000 were restricted by HLA-A*02. We prioritized in-depth investigation of 10 glioblastoma-associated antigens based on high expression in tumours, very low or absent expression in healthy tissues, implication in gliomagenesis and immunogenicity. Patients with glioblastoma showed no T cell tolerance to these peptides. Moreover, we demonstrated specific lysis of tumour cells by patients' CD8+ T cells in vitro. In vivo, glioblastoma-specific CD8+ T cells were present at the tumour site. Overall, our data show the physiological relevance of the peptidome approach and provide a critical advance for designing a rational glioblastoma immunotherapy. The peptides identified in our study are currently being tested as a multipeptide vaccine (IMA950) in patients with glioblastom

Nonlinear modelling and analysis of moving train loads on interspersed railway tracks

The interspersed pattern sleeper of railway track, which is a replacement of old timber sleeper with concrete, is often used as a temporary maintenance for second or third class railway lines with aging timber sleepers. However, their negative effect on the railway has to be taken into an account. The numerical simulations of interspersed sleeper railway tracks are conducted as well as the plain ones using a finite element program, STRAND7, so that the precise numerical models can be established. Two moving point loads, 100 kN each, are simulated to represent a passenger train bogie moving along each rail in 2 dimensional plane. Dynamic displacements and accelerations of all sleepers are then evaluated. Sensitivity analyses are carried out by varying the speed of the moving train loads from 5 km/h to 120 km/h and by changing the type of the interspersed patterns to determine the dynamic behaviours that can cause any more rapid deterioration of the interspersed tracks compared with plain railway tracks. The results demonstrate the potential sources of structural vibrations that will swiftly degrade the interspersed railway tracks. The insight will help track engineers to plan predictive maintenance and inspection of the interspersed railway tracks in live operational networks