147 research outputs found
Impact Evaluation in a Landscape: Protected Natural Forests, Anthropized Forested Lands and Deforestation Leakages in Madagascar's Rainforests
This paper analyzes deforestation leakages from natural rainforests to anthropized habitats following the creation of Protected Areas in Madagascar. A simple theoretical framework highlights that a conservation constraint does not necessarily create deforestation leakages on secondary forests. An original dataset is built combining fine scale vegetation cover images and spatialized census data over the period 2000 to 2012. Cover images allow us to distinguish a mosaic of landscapes. Multilevel panel regressions and matching techniques indicate a causal effect of Protected Areas on deforestation leakages. Though Protected Areas reduce deforestation in protected natural forests, forest clearing is mostly reported on other types of anthropized forests. Our results demonstrate the limitations of Porter-like mechanism in agricultural innovation. They also support the hypothesis of a conservation dilemma: protecting biodiversity may come at the expense of the welfare of locals who rely on local (provisioning) ecosystem services
ESTIMATING AGGLOMERATION ECONOMIES WITH HISTORY, GEOLOGY, AND WORKER EFFECTS
Does productivity increase with density? We revisit the issue usingFrench wage and TFP data. To deal with the ‘endogenous quantity of labour' bias (i.e., urban agglomeration is consequence of high local productivity rather than a cause), we take an instrumental variable approach and introduce a new set of geological instruments in addition to standard historical instruments. To dealwith the ‘endogenous quality of labour' bias (i.e., cities attract skilled workers so that the effects of skills and urban agglomeration are confounded), we take a worker fixed-effect approach with wage data. We find modest evidence about theendogenous quantity of labour bias and both sets of instruments give a similar answer. We find that the endogenous quality of labour bias is quantitatively more important
Estimating Agglomeration Economies With History, Geology, and Worker Effects
Does productivity increase with density? We revisit the issue using French wage and TFP data. To deal with the ‘endogenous quantity of labour bias (i.e., urban agglomeration is consequence of high local productivity rather than a cause), we take an instrumental variable approach and introduce a new set of geological instruments in addition to standard historical instruments. To deal with the ‘endogenous quality of labour bias (i.e., cities attract skilled workers so that the effects of skills and urban agglomeration are confounded), we take a worker fixed-effect approach with wage data. We find modest evidence about the endogenous quantity of labour bias and both sets of instruments give a similar answer. We find that the endogenous quality of labour bias is quantitatively more important
Sorting and Local Wage and Skill Distributions in France
This paper provides descriptive evidence about the distribution of wages and skills in denser and less dense employment areas in France. We confirm that on average, workers in denser areas are more skilled. There is also strong over-representation of workers with particularly high and low skills in denser areas. These features are consistent with patterns of migration including negative selection of migrants to less dense areas and positive selection towards denser areas. Nonetheless migration, even in the long-run, accounts for little of the skill differences between denser and less dense areas. Finally, we find marked differences across age groups and some suggestions that much of the skill differences across areas can be explained by differences between occupational groups rather than within
Multi-Agent Modelling of Earth's Dynamics: Towards a Virtual Laboratory of Plate Tectonics
Symposium GEOCEAN en hommage à Jean FrancheteauMACMA (Multi-Agent Convective MAntle) is a new tool developed to simulate plate tectonics and mantle convection in a 2-D cylindrical geometry (Combes et al., 2012)
Raising awareness for energy efficiency in the service sector: learning from success stories to disseminate good practices
International audienceEnergy efficiency in the service sector is a key issue because of the important growth of its energy consumption. The energy performance of buildings and equipment can be improved through technical investments, but this has to be linked with an efficient management and good practices in order to reach better energy efficiency levels in a cost-effective way. Experience feedback concerning awareness activities in the service sector highlights the interesting opportunities of energy efficiency improvements they represent. This paper first draws a synthesis of the available feedback in this area to detect factors of success for this kind of activities. More than twenty operations from Europe and North America were analyzed looking at items such as the stakeholders involved, the actions implemented, the communication means, and the evaluation performed. Then a case study describes an EDF pilot operation in South East of France. An awareness campaign was led in four particular EDF buildings to inform the employees of the best practices and to involve them to apply these advice. Different action packages were used to compare their efficiency. The evaluation emphasizes the success of the operation, with around 10% of energy savings (i.e. more than 270 MWh/a). More than 80% of the employees said they changed their energy behavior and other indicators show their commitment and satisfaction towards the campaign. Finally, suggestions are made to disseminate good practices at a broader scale, especially out of the "initiated" circle. Building up a know-how from the evaluation of past experiences makes easier the development of process such as networking, experience sharing, and including these activities in energy services offers and in white certificates systems
Crystallisation of a highly metastable hydrated calcium pyrophosphate phase
A simple and fast synthesis method was set up to obtain pure hydrated calcium pyrophosphate (CPP)phases of biological interest. This work focused on a specific phase synthesised at 25 uC and pH 4.5 in a stirred tank reactor. Powder X-ray diffraction, FTIR spectroscopy, scanning electron microscopy and thermogravimetric analyses revealed that the phase is unknown but presents similarities with a monoclinic tetrahydrated CPP phase (Ca2P2O7?4H2O, m-CPPT b phase) synthesised under the same conditions of pH and temperature. Characterisation of the unreferenced phase (u-CPP) has been performed, especially to better identify its composition, structure and stability, as well as its possible relation to the m-CPPT b phase or to other hydrated CPP phases
MACMA : Mantle cooling mechanisms simulated by agents
International audienceMACMA is a new simulating tool based on multiagent systems to build a virtual laboratory in Earth Sciences. Here we study Earth's mantle cooling mechanisms by superposition of analytical and empirical laws accounting for the conservation of mass, energy and momentum, together with the description of plate boundary kinematics
Structure of the calcium pyrophosphate monohydrate phase (Ca2P2O7·H2O): towards understanding the dehydration process in calcium pyrophosphate hydrates
Calcium pyrophosphate hydrate (CPP, Ca2P2O7·nH2O) and calcium orthophosphate compounds (including apatite, octaÂcalcium phosphate etc.) are among the most prevalent pathological calcifications in joints. Even though only two dihydrated forms of CPP (CPPD) have been detected in vivo (monoclinic and triclinic CPPD), investigations of other hydrated forms such as tetraÂhydrated or amorphous CPP are relevant to a further understanding of the physicochemistry of those phases of biological interÂest. The synthesis of single crystals of calcium pyrophosphate monohydrate (CPPM; Ca2P2O7·H2O) by diffusion in silica gel at ambient temperature and the structural analysis of this phase are reported in this paper. Complementarily, data from synchrotron X-ray diffraction on a CPPM powder sample have been fitted to the crystal parameters. Finally, the relationship between the resolved structure for the CPPM phase and the structure of the tetraÂhydrated calcium pyrophosphate [beta] phase (CPPT-[beta]) is discussed
Influence of ionic additives on triclinic calcium pyrophosphate dihydrate precipitation
Triclinic calcium pyrophosphate dihydrate (t- CPPD) crystals are one of the two polymorphs of microcrystals that have been found in the joints of patients suffering from pseudogout. However, there is currently no treatment for inhibiting the formation of these crystals, which present a high inflammatory potential. In this context we studied in vitro the precipitation of t-CPPD in a stirred reactor under pH- and temperature-controlled conditions and determined the effect of selected biologically relevant ionic additives (Mg2+, Cu2+, Fe3+, Zn2+, S2O3 2−) on its formation. The results showed that 1 mM Fe3+, Zn2+, or Cu2+ induced the most significant changes by partly inhibiting the crystallization of t-CPPD and favoring the formation of an amorphous-CPP phase (98 wt %) in the presence of Fe3+ or a monoclinic-CPPD phase (78 or 71 wt %, respectively) in the presence of Zn2+ or Cu2+. Correlations between 31P solid-state NMR, XRD, and elemental analyses showed that the additive cations are inserted into the monoclinic-CPPD and/or amorphous-CPP phases. This study, which combines structural, morphological, and elemental analyses, paves the way toward a deeper comprehension of the role of ionic additives in preventing the formation of CPPD crystalline phases, and is a key step in long-term development of an effective therapeutic treatmen
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