Measuring the Cost of International Trade in Services

We present a new dataset of international trade costs in services sectors. Using a theory-based methodology combined with data on domestic shipments and cross-border trade, we find that trade costs in services are much higher than in goods sectors: a multiple of two to three times in many cases. Trade costs in services have remained relatively steady over the last ten years, whereas trade costs in goods have fallen overall at an impressive rate. We also present two examples of the ways in which our dataset could be used in future work. First, we examine the impact of regional trade agreements on trade costs in services. Although we find that intra-bloc trade costs are lower than those facing outside countries, the differential is usually quite small for services, and in some cases has even been narrowing over time. This finding accords with the observation that because service sector reform is about re-regulation, “preferential” agreements tend to involve less discrimination than in goods markets. Second, we show for the first time that services sectors with lower trade costs tend to be more productive, and experience faster productivity growth. This result lines up well with the evidence from goods markets.Trade policy; Trade in services; Regional integration; Productivity.

Cadmium transport in sediments by tubificid bioturbation: An assessment of model complexity

Biogeochemistry of metals in aquatic sediments is strongly influenced by bioturbation. To determine the effects of biological transport on cadmium distribution in freshwater sediments, a bioturbation model is explored that describes the conveyor-belt feeding of tubificid oligochaetes. A stepwise modelling strategy was adopted to constrain the many parameters of the model: (i) the tubificid transport model was first calibrated on four sets of microspheres (inert solid tracer) profiles to constrain tubificid transport; (ii) the resulting transport coefficients were subsequently applied to simulate the distribution of both particulate and dissolved cadmium. Firstly, these simulations provide quantitative insight into the mechanism of tubificid bioturbation. Values of transport coefficients compare very well with the literature, and based on this, a generic model of tubificid bioturbation is proposed. Secondly, the application of the model to cadmium dataset sheds a light on the behaviour of cadmium under tubificid bioturbation. Cadmium enters the sediment in two ways. In one pathway, cadmium enters the sediment in the dissolved phase, is rapidly absorbed onto solid particles, which are then rapidly transported to depth by the tubificids. In the other pathway, cadmium is adsorbed to particles in suspension in the overlying water, which then settle on the sediment surface, and are transported downwards by bioturbation. In a final step, we assessed the optimal model complexity for the present dataset. To this end, the two-phase conveyor-belt model was compared to two simplified versions. A solid phase-only conveyorbelt model also provides good results: the dissolved phase should not be explicitly incorporated because cadmium adsorption is fast and bioirrigation is weak. Yet, a solid phase-only biodiffusive model does not perform adequately, as it does not mechanistically capture the conveyor-belt transport at short time-scales

Longitudinal transformation of nitrogen and carbon in the hyporheic zone of an N-rich stream: A combined modelling and field study

A combined modelling and field study approach was used to examine biogeochemical functioning of the hyporheic zone in two gravel bars in an N-rich fourth-order stream (River Hers, south-west France). Surfacewater and interstitial water were sampledmonthly (August 1994–January 1995), the latter in a network of 29 piezometers in the first gravel bar and 17 in the second. In both gravel bars, the hyporheic zone was created only by advected channelwater without any connectionwith groundwater. Longitudinal chemical profiles of Dissolved Organic Carbon (DOC), nitrate (NO3–N), ammonium (NH4–N) and Dissolved Oxygen (DO) were established for both gravel bars. Ambient and potential denitrification weremeasured in the laboratory during the same period using the acetylene inhibition technique. Factors limiting denitrification were also examined by testing the separate effects of nitrate or nitrate + carbon additions. A 1D reactive-transport model was used to simulate longitudinal transformation of nitrogen in the hyporheic zone, and to estimate the role of organic matter (DOC and POC) in the biogeochemical functioning of the hyporheic zone. Denitrification measurements with nitrate and nitrate + carbon additions both showed increased denitrification, suggesting that denitrification might not be C-limited at this site. Observations and model results showed the hyporheic zone to be a sink of DOC and nitrate, but DOC consumption appeared insufficient to explain nitrate depletion measured in the two gravel bars. Field data were better modelled when an additional DOC source from the POC fraction degraded by anaerobic respiration was included in the model

Experimental and statistical study of three adherence tests for an epoxy-amine/aluminum alloy system: Pull-Off, Single Lap Joint and Three-Point Bending tests

The mechanical resistance of a bonded joint depends on the adhesive interaction onto the substrate and the mechanical properties of the adhesive itself. Many existing tests can be useful for measuring the adherence or evaluating mechanical adhesive response. All these tests do not provide the same information: in particular, adherence measurements can be split into initiation tests and propagation ones. In this paper, three adherence tests have been considered for the evaluation of the fracture initiation between a poly-epoxide adhesive (a mixture of pure epoxy and amine) and an aluminum surface (AA 2024-T3), namely the Pull-Off, Single Lap Joint (SLJ) and Three-Point Bending tests. Various surface preparation protocols before bonding have been tested and optimized for aluminum substrates, including mechanical and chemical surface treatments, followed by the application of an appropriate primer before bonding. This study paves the way for the future development of adhesive systems as it provides reliable surface preparation protocols for aluminum surfaces and gives an insight into the choice of an adequate adherence test dedicated to high-performance adhesives. The load at break (FMax), the experimental error, the failure mode and statistical studies according to the Weibull model and Principal Component Analysis (PCA) were studied on each surface preparation configuration. It has been shown that the application of a primer, especially a sol-gel product increases the load at break and provides more reliable results. Then, this paper shows that the two tests can quantify the failure initiation and distinguish the different surface preparation efficiency, are the Single Lap Joint test (mode II or mode I + II) and the Three-Point Bending test (mode I), with an increase of the results reliability with the latter one. The Pull-Off test (mode I) is useful as a routine checking, and particularly interesting because its response does not depend on the substrate thickness, even though it cannot highlight the difference between all surface preparations

Measuring the Cost of International Trade in Services

We present a new dataset of international trade costs in services sectors. Using a theory-based methodology combined with data on domestic shipments and cross-border trade, we find that trade costs in services are much higher than in goods sectors: a multiple of two to three times in many cases. Trade costs in services have remained relatively steady over the last ten years, whereas trade costs in goods have fallen overall at an impressive rate. We also present two examples of the ways in which our dataset could be used in future work. First, we examine the impact of regional trade agreements on trade costs in services. Although we find that intra-bloc trade costs are lower than those facing outside countries, the differential is usually quite small for services, and in some cases has even been narrowing over time. This finding accords with the observation that because service sector reform is about re-regulation, “preferential” agreements tend to involve less discrimination than in goods markets. Second, we show for the first time that services sectors with lower trade costs tend to be more productive, and experience faster productivity growth. This result lines up well with the evidence from goods markets

Measuring the Cost of International Trade in Services

We present a new dataset of international trade costs in services sectors. Using a theory-based methodology combined with data on domestic shipments and cross-border trade, we find that trade costs in services are much higher than in goods sectors: a multiple of two to three times in many cases. Trade costs in services have remained relatively steady over the last ten years, whereas trade costs in goods have fallen overall at an impressive rate. We also present two examples of the ways in which our dataset could be used in future work. First, we examine the impact of regional trade agreements on trade costs in services. Although we find that intra-bloc trade costs are lower than those facing outside countries, the differential is usually quite small for services, and in some cases has even been narrowing over time. This finding accords with the observation that because service sector reform is about re-regulation, “preferential” agreements tend to involve less discrimination than in goods markets. Second, we show for the first time that services sectors with lower trade costs tend to be more productive, and experience faster productivity growth. This result lines up well with the evidence from goods markets

Regards croisés sur l'étude archéologique des paysages anciens: Nouvelles recherches dans le bassin méditerranéen, en Asie Centrale et au Proche et au Moyen-Orient

International audienceCette publication rassemble la majeure partie des communications présentées dans le cadre ducolloque BH2. Ces contributions reflètent une grande diversité d’approche dans l’étude des paysages anciens,au travers de plusieurs thématiques qui structurent ainsi l’ouvrage. En même temps, elles démontrent ledynamisme de ces jeunes chercheurs dans leur regard sur les paysages d’une même région, sous des anglesparfois bien différents (aménagement du territoire ; interaction Homme / milieu ; méthodes).Les ressources du milieu et notamment leurs stratégies d’exploitation par les sociétés humainessont traitées ici transversalement. Cependant, les communications sont organisées selon cinq thèmesplus spécifiques, miroirs des interactions Homme / milieu. Le premier thème, « Ressources naturelles etacquisition », regroupe des contributions centrées sur la description des ressources disponibles (eau etgisements de silex) et l’acquisition de ressources spécifiques (silex et matériaux destinés à la fabricationde la parure). Ensuite sont abordées les « S tratégies d’implantation et d’aménagements des territoires »,notamment des aménagements hydrauliques de l’âge du Fer du Néguev central aux tours de surveillanceromaines et byzantines du Faynan en Jordanie. Plusieurs communications retracent ensuite l’« Évolutiondiachronique de schémas d’occupation » de la région de Diyala en Iraq et du Leja en Syrie, ainsi quel’expansion des communautés halafiennes en Syrie. Un quatrième thème aborde les « Impacts réciproquesHomme / milieu et leurs conséquences sur l’évolution des paysages » notamment au travers des causesdu déclin des villes de la vallée yéménite du Jawf et de la « crise » du IIIe millénaire. Enfin, le dernierthème, « Approches spécialisées de la restitution des paysages », regroupe des recherches spécifiques telles que l’utilisation des méthodes de prospections géophysiques, les analyses isotopiques des os d’animauxnéolithiques, les études des listes lexicales des vocabulaires sumériens et akkadiens, reflets de la variété desdisciplines qui contribuent à la restitution des paysages anciens

k.p theory beyond standard 8-band theory parametrization strategies and its applicability in electronic and optoelectronic devices design

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