Optimal Soil Management and Environmental Policy

This paper studies the effects of environmental policy on the farmer’s soil optimal management. We consider a dynamic economic model of soil erosion where the intensity use of inputs allows the farmer to control soil losses. Therefore, inputs use induces a pollution which is accentuated by the soil fragility. We show, at the steady state, that the environmental tax induces a more conservative farmer behavior for soil, but in some cases it can exacerbate pollution. These effects can be moderated when farmers introduce abatement activity.Soil erosion, Pollution, Environmental policy, Optimal soil conservation, Abatement activities

Optimal soil management and environmental policy

This paper studies the effects of environmental policy on the farmer's soil optimal management. We consider a dynamic economic model of soil erosion where the intensity use of inputs allows the farmer to control soil losses. Inputs use induces a pollution which is accentuated by the soil fragility. We show, at the steady state, that environmental tax induces a more conservative farmer behavior for soil, but in some cases it can exacerbate pollution. These effects can be moderated when farmer introduces abatement activity.environmental policy

Do deep and comprehensive regional trade agreements help in reducing air pollution?

Brain-derived neurotrophic factor (BDNF) is suggested to play a key role in moderating the benefits of physical activity (PA) on cognition. Previous research found that PA may have an impact on peripheral BDNF expression. The aim of our study was to analyze the association between objectively measured PA with circulating BDNF in a group of active adolescents. Two hundred thirty-four adolescents (132 boys) aged 13.9 ± 0.3 years old from the DADOS study were included in this cross-sectional analysis. PA was assessed by GENEActiv triaxial accelerometer. Participants wore the accelerometer on their non-dominant wrist for 6 consecutive 24-h days, including weekends. PA was expressed as the average (min/day) of light, moderate, and vigorous PA. Fasting plasma BDNF concentrations at rest were measured using an enzyme-linked immunosorbent assay. Partial correlations and linear regression analyses were performed with a significance level established at p  0.05). Based on previous research and our own data, the association between daily PA and baseline levels of BDNF remains inconclusive. Further research is needed to shed light on the relationship between regular PA and BDNF in adolescents

Eléments d’économie du paysage

L’émergence du paysage dans le débat public est la traduction d’une préoccupation sur les modes d’occupation de l’espace par l’expansion des villes, le pullulement des infrastructures et les mutations des mondes rural et urbain. Elle est aussi le témoin de la valeur économique de la diversité des paysages pour de nombreux secteurs économiques. De part les arbitrages économiques qu’impliquent les différents modèles d’aménagement et d’occupation de l’espace, la discipline économique se trouve naturellement sollicitée. En outre, la demande d’une plus grande qualité paysagère qu’expriment les individus et les organisations, interpelle l’économiste sur la nature de la valeur économique des paysages. Cet article s’interroge sur les diverses dimensions économiques du paysage et montre comment la discipline économique a mobilisé des domaines variés pour pouvoir éclairer efficacement la décision et l’action collectives.The aim of this paper is to gather together fragments, who are yet split in to separate fields of economics. Landscape provides amenities and support recreational and tourism activities, it appears both as an economic resource and as a local public good. Landscape economics could benefits from both public economics concepts and methodology, and from New Economic Geography. Moreover, as a new field, Landscape Economics emphasizes the role of enforcement of property rights’ devices in the Landscape formation. This paper try to relate the path dependency at work in Landscape transformations to the strength of viscosity forces (transaction and administrative costs, infrastructure costs, nexus of rights, etc.). Finally, facing divided ownership issues and public policies external effects, the Landscape’ governance should make use of various instruments and methods in order to provide socially optimal level of landscapes’ quality and diversity

X-ray Diffraction Profiles Modeling Method for Layered Structures Reconstruction: Nanoclay Structural Verification

The nanoclay properties find a large environmental application domain as depolluant, ion exchanger, natural geological barrier for industrial and radioactive waste confinement, clay-based nanocomposite for drug delivery, and more. Layered materials, such as nanoclay, present rather complex structures whose classical characterization requires a complementarity between several analysis methods to decipher the effects of interstratification (and its cause) on the intrinsic functional properties. The appearance of defects related to the layers stacking mode, which differ in their thickness and/or their internal structure are directly related to the reactivity of the mineral’s surface. During the last decades, and with the development of computer codes, the modeling of X-ray diffraction profiles has proven to be an important tool that allows detailed structural reconstruction. The quantitative XRD analysis, which consists of the comparison of experimental (00l) reflections with the calculated ones deduced from structural models, allowed us to determine the optimal structural parameters describing interlamellar space (IS) configuration, hydration state, cation exchange capacity (CEC), layer stacking mode, and theoretical mixed-layer structure (MLS) distribution. This chapter will review the state of the art of this theoretical approach as a basic technique for the study of nanoclays. The basic mathematical formalism, the parameters affecting the theoretical models, and the modeling strategy steps will be detailed in concrete examples

Patterns of Urban Spatial Expansion in European Cities

In representing urban sprawl, the decline in population and employment density from the city centre to the periphery has been identified as the main character associated with the spatial expansion of built-up areas. Urban spatial discontinuity, which occurs when the urban fabric includes built-up or green areas and a relevant share of vacant spaces, has gained recent attention. In this paper, we use Global Human Settlement Layer data to track urbanisation dynamics in European Functional Urban Areas (FUAs) from 1990 to 2014. We represent urban sprawl as the spatial expansion of FUAs associated with either or both declining population density and increasing built-up area discontinuity. We also consider the association with the demographic trends that have been described as the primary driver of urban spatial expansion. We use configural frequency analysis to explore the local association between the different characters of sprawl. We found evidence that urban sprawl effectively took differentiated forms across European FUAs. Even though FUAs have generally become less dense and more disperse, our results show that the extent of these phenomena appears to be more contained in recent years than in previous decades. Both elements of sprawl characterise FUAs with a shrinking population, confirming the decoupling of urban development policies and demographic trends in cities. The results call for better controlled urban development, favouring compact cities and subjecting land-use changes to a perspective of urban population growth