4,735 research outputs found

    The Effect of the Uruguay round on the Intensive and Extensive Margins of Trade

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    Do tariffs inhibit trade flows by limiting the entry of exporting firms (extensive margin') or by restricting the average volume exported by each firm (intensive margin')? Using a gravity equation approach, we analyze how the decrease in tariffs promoted during the 1990s by the Uruguay Round multilateral trade agreement affected the trade margins of French firms across 57 sectors and in 147 countries, from 1993 to 2002. Our main contribution is to estimate the elasticity of trade for both margins, controlling for the unobserved heterogeneity of trade flows thanks to a three-dimensional panel and to time-varying tariffs as a measure of variable trade costs. Our results show that the number of firms exporting in a given sector to a given destination is related to the level of tariffs. But they also show that the decrease in tariffs determined by the implementation of the Uruguay Round did not lead more firms to export and instead, only encouraged incumbent exporters to increase their shipments. We control for two problems that may affect our basic specification: tariffs changes may be endogenous and zero flows are not included. Our results are confirmed - even when the extensive margin is significant, its contribution is very small.Tariffs, Trade margins, Uruguay Round

    Learning, Incomplete Contracts and Export Dynamics: Theory and Evidence from French Firms

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    We consider a model where exporting requires finding a local partner in each market. Contracts are incomplete and exporters must learn the reliability of their partners through experience. In the model, export behavior is state-dependent due to matching frictions, although there are no sunk costs. Better legal institutions alleviate contracting frictions especially in sectors with large contracting problems. Thus, measures of legal quality help reduce the risk that a match between an exporter and a local distributor splits, and they are all the more effective in sectors that are more exposed to hold-up problems. Moreover, the breaking risk declines with the age of the relationship, as unreliable partners are weeded out. We find strong evidence in favor of the model's predictions when testing them with a French dataset that includes information on firm-level exports by destination country.Trade Dynamics, Learning, Incomplete Contracts, State dependence, Firm-level Trade Data

    The reaction of French firms to the decrase of foreign tariffs

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    We estimate the reaction of French firms to the drop in tariffs that has occurred in the late 1990s, mainly as a consequence of the Uruguay Round Agreement. To perform this estimation, we use data from the French customs and tariff rates provided by the TRAINS data base. Like in Buono and Lalanne (2009), we take advantage of the variations in tariffs over time. It allows us to exploit the panel structure of the data, which is not possible when using distance instead of tariffs. The results and the estimated reaction of firms to changes in variable export costs are strongly affected. From a cross-section, we find that the effect of tariffs on exports channels evenly through the number of exporting firms - the extensive margin - and through the exports per firm - the intensive margin. When using the panel structure, only the intensive margin reacts to tariff reductions. To understand what underlies this result, we study the role played by incumbent exporters. The latter are responsible for 95 % of the response of French exports to tariff reductions. Finally, we find that firms respond to these lower export costs by increasing their amounts exported by product rather than by exporting new products.Tariffs, Trade margins, Uruguay Round

    preliminary trials to rear the copepod temora stylifera as food for fish larvae

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    AbstractCopepods represent an important natural food supply for many fish larvae but they are not commonly used in aquaculture. The aim of this project is: 1) to set up an experimental re-circulating system to breed the copepod Temora stylifera and 2) to replace Artemia salina with T. stylifera as live food for Sparus aurata larvae. The choice of this copepod species has been based on both its abundance in the Mediterranean as well as its characteristics in terms of size and nutritional value. The re-circulating system consists of a collecting water tank of 1,000 litre of capacity, a thermoregulation system, two 500 litre tanks to rear adults and two 200 litre tanks to collect nauplii. The system allows the computerised water re-circle and to concentrate and collect nauplii through their positive response to light. It can work both in a partial re-circle way, for the thermoregulation only, as well as in a total re-circle way for the water purification through mechanic and biological filters. The culture s..

    The early Miocene balaenid Morenocetus parvus from Patagonia (Argentina) and the evolution of right whales

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    Balaenidae (right and bowhead whales) are a key group in understanding baleen whale evolution, because they are the oldest surviving lineage of crown Mysticeti, with a fossil record that dates back ~20 million years. However, this record is mostly Pliocene and younger, with most of the Miocene history of the clade remaining practically unknown. The earliest recognized balaenid is the early Miocene Morenocetus parvus Cabrera, 1926 from Argentina. M. parvus was originally briefly described from two incomplete crania, a mandible and some cervical vertebrae collected from the lower Miocene Gaiman Formation of Patagonia. Since then it has not been revised, thus remaining a frequently cited yet enigmatic fossil cetacean with great potential for shedding light on the early history of crown Mysticeti. Here we provide a detailed morphological description of this taxon and revisit its phylogenetic position. The phylogenetic analysis recovered the middle Miocene Peripolocetus as the earliest diverging balaenid, and Morenocetus as the sister taxon of all other balaenids. The analysis of cranial and periotic morphology of Morenocetus suggest that some of the specialized morphological traits of modern balaenids were acquired by the early Miocene and have remained essentially unchanged up to the present. Throughout balaenid evolution, morphological changes in skull arching and ventral displacement of the orbits appear to be coupled and functionally linked to mitigating a reduction of the field of vision. The body length ofMorenocetus and other extinct balaenids was estimated and the evolution of body size in Balaenidae was reconstructed. Optimization of body length on our phylogeny of Balaenidae suggests that the primitive condition was a relatively small body length represented by Morenocetus, and that gigantism has been acquired independently at least twice (in Balaena mysticetus and Eubalaena spp.), with the earliest occurrence of this trait in the late Miocene-early Pliocene as represented by Eubalaena shinshuensis.Facultad de Ciencias Naturales y Muse

    Analisis Hubungan Kode-kode Spbk (Sistem Peringkat Bahaya Kebakaran) Dan Hotspot Dengan Kebakaran Hutan Dan Lahan Di Kalimantan Tengah

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    Land and forest fire is one of causes ofland degradation in Central Kalimantan. Remote sensing dataapplications, especially READY-ARL NOAA and CMORPH data, are benefit forthe available climate observation data. The objectives of this research are: (1) to analyzis relationship between hotspots, FDRS and occurences of land and forest fire, and (2) to develop the estimation model of burned area from hotspot and FDRS codes. The result of this research showed that burned area can not be estimated by using number of hotspots. The drought code (DC) wich is one of FDRS codes has correlation with burned area. So, burned area can be estimated using drought code (DC) (R-sq = 58%) by using the following formula: Burned Area (Ha) = -62.9 + 5.14 (DC – 500)

    Numerical Study of the Optical Response of ITO-In2O3 Core-Shell Nanocrystals for Multispectral Electromagnetic Shielding

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    Nowadays materials to protect equipment from unwanted multispectral electromagnetic waves are needed in a broad range of applications including electronics, medical, military and aerospace. However, the shielding materials currently in use are bulky and work effectively only in a limited frequency range. Therefore, nanostructured materials are under investigation by the relevant scientific community. In this framework, the design of multispectral shielding nanomaterials must be supplemented with proper numerical models that allow dealing with non-linearities and being effective in predicting their absorption spectra. In this study, the electromagnetic response of metal-oxide nanocrystals with multispectral electromagnetic shielding capability has been investigated. A numerical framework was developed to predict energy bands and electron density profiles of a core-shell nanocrystal and to evaluate its optical response at different wavelengths. To this aim, a finite element method software is used to solve a non-linear Poisson's equation. The numerical simulations allowed to model the optical response of ITO-In2O3 core-shell nanocrystals and can be effectively applied to different nanotopologies to support an enhanced design of nanomaterials with multispectral shielding capabilities

    Piecewise smooth systems near a co-dimension 2 discontinuity manifold: can one say what should happen?

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    We consider a piecewise smooth system in the neighborhood of a co-dimension 2 discontinuity manifold ÎŁ\Sigma. Within the class of Filippov solutions, if ÎŁ\Sigma is attractive, one should expect solution trajectories to slide on ÎŁ\Sigma. It is well known, however, that the classical Filippov convexification methodology is ambiguous on ÎŁ\Sigma. The situation is further complicated by the possibility that, regardless of how sliding on ÎŁ\Sigma is taking place, during sliding motion a trajectory encounters so-called generic first order exit points, where ÎŁ\Sigma ceases to be attractive. In this work, we attempt to understand what behavior one should expect of a solution trajectory near ÎŁ\Sigma when ÎŁ\Sigma is attractive, what to expect when ÎŁ\Sigma ceases to be attractive (at least, at generic exit points), and finally we also contrast and compare the behavior of some regularizations proposed in the literature. Through analysis and experiments we will confirm some known facts, and provide some important insight: (i) when ÎŁ\Sigma is attractive, a solution trajectory indeed does remain near ÎŁ\Sigma, viz. sliding on ÎŁ\Sigma is an appropriate idealization (of course, in general, one cannot predict which sliding vector field should be selected); (ii) when ÎŁ\Sigma loses attractivity (at first order exit conditions), a typical solution trajectory leaves a neighborhood of ÎŁ\Sigma; (iii) there is no obvious way to regularize the system so that the regularized trajectory will remain near ÎŁ\Sigma as long as ÎŁ\Sigma is attractive, and so that it will be leaving (a neighborhood of) ÎŁ\Sigma when ÎŁ\Sigma looses attractivity. We reach the above conclusions by considering exclusively the given piecewise smooth system, without superimposing any assumption on what kind of dynamics near ÎŁ\Sigma (or sliding motion on ÎŁ\Sigma) should have been taking place.Comment: 19 figure
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