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We quantify the impact of country-specific institutions on international trade and development in a structural gravity framework. The econometric analysis offers robust evidence that stronger institutions promote trade. A counterfactual analysis reveals that the changes in institutional quality in the poor countries in our sample between 1996 and 2006 have had, via their impact on imports from rich countries, significant and heterogeneous welfare effects, varying between −2% and 5%. Our approach is readily applicable to identifying the impact of any country-specific variable on international trade in the structural gravity framework.

The “Next Generation Train” (NGT) is a double-deck high speed train concept in light-weight design that has been established as a technical and project framework in which the German Aerospace Center gathers its long-term railway vehicle research. To reduce wheel and rail wear and to enhance the passenger capacity, a mechatronic running gear with independently rotating wheels (IRW) is a key vehicle component under research. This running gear requires an advanced control of the lateral dynamics in order to fully exploit its potential in minimizing wear and noise, but this relies on information on its lateral position relative to the track. In daily railway operation it is difficult to directly measure this displacement of the wheel-pair. However, according to previous work it is possible to design an appropriate observer to estimate the lateral position, but its estimation accuracy highly depends on the chosen sensor configuration. Nevertheless, it was shown that the lateral dynamics of the running were not completely reproduced by the system description especially at suddenly changing directions in the movement of the IRW. In this work the system description is complemented by a nonlinear description of the wheel–rail geometry. Therefore, an observability analysis and an observer synthesis to estimate the lateral position for the nonlinear system of the 1:5 scaled hardware running gear is carried out. For validation purposes an extended Kalman filter with the U-D formalism is implemented at the real-time environment of the testbed and the estimation accuracy of the observer configurations is compared.

The development of railway running gears with independently rotating wheels is a focus of research within the Next Generation Train project at DLR. The lateral guidance of this type of running gears represents a challenging problem that relies on active control. The paper introduces results on this research regarding observer and control design that are focused and demonstrated on a scaled experimental running gear hardware that was specifically constructed for this purpose. Additionally, the development of the lateral guidance system is supported by simulation and optimization within a Modelica based virtual simulation environment tailored for the modeling of railway vehicle dynamics in multi-domain engineering tasks.

The demand for fast automated inspection of all manufactured components in industrial production is rising due to increasing quality demands and high-speed machining technologies. Modern surface metrology sensors are capable of implementing these tasks if they can be embedded in fast and accurate measuring machines. However, the common approach to achieve high positioning accuracy in such machines is abiding by very conservative limits in acceleration, and thus, velocity. We propose an active control system including a model-based compensation system for dynamic errors to increase acceleration and velocity. A novel optical sensor permitting the direct measurement of the actual tool-center-point (TCP) position is used for system identification of the required dynamic model. The position of a LED point source is detected with high subpixel precision by replicating the spot several times on the camera chip and averaging over the center of gravities of all spots. A model for the largest dynamic error component of a small multiaxis measuring machine is derived and the sensor is used to identify the model parameters. A model-based feedforward and feedback control system reducing the dynamic tracking error is designed. This control systems allows machine motions with both high accuracy and large velocity. The achieved performance is evaluated using TCP tracking error measurements obtained with the novel optical sensor. This model-based compensation system can also be applied to machine tools.

This paper presents the application of a model-based feedforward friction compensation system based on the ElastoPlastic friction model. This nonlinear feedforward compensator, in combination with a linear feedback controller, is applied to a linear drive axis with recirculating ball bearings and a fine-positioning axis with crossed roller bearings. The developed friction compensator estimates the state of the ElastoPlastic friction model and thus the friction force. The compensator also adapts to local variations and variations over time due to wear. This feedforward system serves as an add-on friction compensation system and can be used with existing feedback control systems. Both linear axes are used in an optical measurement setup based on a modified Mahr MFU 100 measuring machine. The designed and implemented control system permits high-accuracy trajectory tracking control even for small velocities such as typical measurement velocities in surface metrology. The parameter identification procedure used for the identification of the ElastoPlastic friction model parameters is explained in detail. The trajectory tracking for the regarded hardware setups with and without friction compensation is compared in experiments, illustrating the performance of this feedforward system. Although the presented work was motivated by the mentioned measurement application, the presented modelling, identification and compensation techniques are not limited to this application and can be transferred to many mechanical systems with friction.

In the field of longitudinal train dynamics the brake process is not only a safety critical aspect but it also determines the capacity of the rail network. Therefore, a reduction of the brake distance increases the safety level and the network capacity at the same time. However, to implement an advanced brake control set-up, the knowledge of the wheel-rail adhesion and the brake pad-disc friction is usually necessary. Since the direct measurement of these determining parameters is not reasonable due to technical and economic reasons, the present work presents an estimator framework for their online identification. To ensure a robust and reliable performance of the estimator, a generic wagon model is designed and the observability of the nonlinear system is evaluated. Furthermore, a reasonable synthesis of an extended Kalman filter is discussed that takes account of the system characteristics. In the end, the test results from a roller rig verify the accurate and robust performance of the developed estimator and confirm the great potential of such a concept in the context of mechatronic railway systems.

State observer design turned out to be crucial in several recent railway vehicles projects on active control and condition monitoring at DLR, but may also be useful for emerging technologies like the cyber physical system and the digital twin approach or the realization of predictive maintenance concepts. With this background and motivation the paper presents a process in three steps: (i) an initial analysis results in a physical model, (ii) the subsequent transfer to state space representation facilitates the prove of observability and (iii) the observer synthesis supports the design of the observer feedback law. Results from two projects, one related to longitudinal or traction dynamics, the other associated to the guidance task of independently rotating wheels, demonstrate the application of the observer design process and offers a comparison of observer estimates with measurements.

Running gears with independently rotating wheels are a major issue of the DLR longterm research project ”Next Generation Train”. This concept relies on mechatronic track guidance and on an appropriate control design. To this aim, a development environment has been implemented that consists of a scaled experimental running gear in hardware and associated simulation models that consider several levels of details, each tailored for a specific step of the control elaboration. The model based control synthesis covers a feed-forward control exploiting the inversion of a non-linear plant model, a Kalman filter that is implemented taking measurement noise into account, and robust state feedback control using gain scheduling in order to stabilize the running gear dynamics. The paper introduces the experimental running gear hardware, reports on the used models, comments on control synthesis steps and finally presents simulation results in order to demonstrate the properties of the designed control.

The German Aerospace Center bundles its railway research in the long-term project “Next Generation Train” (NGT). The NGT is a high speed train concept in light-weight design and double-deck configuration. To reduce wheel and rail wear and to enhance the passenger capacity, a mechatronic running gear with independently rotating wheels (IRW) is designed. This configuration requires an advanced control of the lateral dynamics in order to fully exploit the potential in minimizing wear and noise. In terms of a model-based control design, the controller performance highly depends on the estimated lateral position of the running gear relative to the track. In a practical environment it is difficult to directly measure this displacement of the wheel-pair. Therefore this article deals with the question which sensor configuration enables an appropriate estimation of the lateral displacement and is suitable for observer design. Hence, an observability analysis and an observer synthesis to estimate the lateral position for the nonlinear system of the 1:5 scaled hardware running gear is carried out. For validation purposes three estimators are implemented at the real-time environment of the testbed and the estimation errors of the observer configurations are compared.

Measuring systems for production quality control face increasing demands in both measurement velocity and accuracy The undesired dynamic effects of measuring machines pose more stringent limits to the measurement velocity than modern optical sensors for surface metrology for example chromatic confocal point sensors. These dynamics are investigated at an exemplary coordinate measuring machine and their negative effects on the measured values are described. A compensation system for the reduction of the induced errors based on internal deviation sensors is proposed and investigated. Subsequently a dynamic model for the machine’s dominant dynamic effects is identified in order to transfer the compensation system to machines without internal deviation sensors.

The authors review current developments in international trade and its prospects for the future arguing that despite the recent slowdown, trade remains an important driver of economic growth and development. Scepticism towards further trade opening needs to be addressed, notably via appropriate domestic adjustment policies. One challenge to advancing further global economic integration lays in the rapid transformation of trade itself and the nature of remaining barriers. The authors highlight new models of trade cooperation that can help to make progress at the global level, while accommodating countries’ diverse interests and levels of development.

We propose and apply methods to quantify the impact of national institutions on international trade and development. We are able to identify the direct impact of country-specific institutions on international trade within the structural gravity framework. Our approach naturally addresses the prominent issue of endogenous institutions. The empirical analysis offers robust evidence that stronger institutions promote trade. A counterfactual analysis reveals that the changes in institutional quality in the poor countries in our sample between 1996 and 2006 have had, via their impact on imports from rich countries, significant and heterogeneous real GDP effects, varying between -5 and 5 percent. Our methods are readily applicable to identifying the impact of a wide range of country-specific variables on international trade.

Purpose Preconditioning with low doses of monophosphoryl lipid A (MPL) has been shown to induce endotoxin tolerance and to reduce the metabolic and hemodynamic consequences of endotoxin shock. However, no data are available about the effects of endotoxin preconditioning on cerebral metabolism during endotoxemia. The study was designed to determine the effects of endotoxin preconditioning with MPL on cerebral metabolism via microdialysis compared to muscle tissue metabolism during experimental endotoxemia. Methods In a controlled animal study, continuous endotoxin infusion (1 μg/kg b.w. per h) was administrated to 7 female mixed-breed pigs after pretreatment with MPL in incremental doses of endotoxin during days 5–2 before the experiments. In the control group, 7 animals received a saline pretreatment. In addition to hemodynamic monitoring and blood gas analyses, interstitial lactate, pyruvate, glucose and glycerol concentrations in muscle and cerebral tissue were measured using in vivo microdialysis. Results There were no significant differences between the two groups with respect to hemodynamic parameters, while mixed venous oxygen saturation (SvO2), arterial blood pH and mean pulmonary arterial pressure (MPAP) were significantly higher in the preconditioned group. Cerebral perfusion pressure (CPP) and brain tissue oxygen pressure (ptiO2) values stayed stable throughout the experiment with no inter-group differences. While interstitial concentrations of lactate and glycerol as well as the lactate/pyruvate (LP) and the lactate/glucose (LG) ratio in muscle tissues were significantly increased in control animals compared to those who had been pretreated with MPL; the results of cerebral microdialysis showed no significant changes in interstitial lactate or glycerol levels in both groups. However, the lactate/glucose (LG) ratio in the control group showed a significantly higher increase than in the preconditioned group. Conclusions Preconditioning with low doses of MPL ameliorates the negative metabolic effects of endotoxin shock in muscle tissue. With regard to cerebral metabolism, the present study suggests that MLP preconditioning provides moderate advantages, at least in an experimental model of endotoxin shock.

Recent efforts to improve imaging quality of extremely large telescopes are based on compensating for structural vibrations with a compensation mirror canceling out the optical pathway deviations caused by vibrations of the telescope structure. To drive this mirror, the displacement of optical elements has to be reconstructed online from accelerometer measurements. The goal is to obtain high reconstruction accuracy and good disturbance rejection in spite of low-frequency drift and high-frequency noise highly deteriorating the measurements. A reconstructor based on double integration and filtering, a disturbance observer and a novel reconstruction approach based on adaptive resonators are implemented on a laboratory test setup simulating typical telescope vibrations. The true displacement is measured with a strain gauge and serves as a reference for reconstruction accuracy.

A feedforward vibration cancellation system can be used to compensate for fast wind-induced telescope vibrations. Crucial is the position reconstructors ability to provide the compensation mirror with an accurate online estimate of the vibrational displacement. The authors have developed and presented a position reconstructor based on adaptive resonators. However, network data transmission of the acceleration signals introduces a time delay into the measurement chain. Any feedforward compensation setup can only function well if a delay-free estimate of the disturbance signal is provided. Three delay-compensating extensions of the developed position reconstructor are presented and analyzed.

At a time when the Doha Round of trade negotiations goes into an agonizing 10th year, taking a fresh look at the lessons learnt from history on power and governance in the multilateral trading system (and the responsibility that goes with it) is certainly an attractive proposition. Unfortunately, Soo Yeon Kim’s inquiry into the driving forces underlying institutional developments from the General Agreement on Tariffs and Trade (GATT) to the World Trade Organization (WTO) offers few new or compelling insights into the challenges that the multilateral trading system faces at the present day. This is not to say that the book does not contain interesting pieces of information and analysis. Overall, however, its eclectic approach does not do justice to the complexities involved in the evolution of the GATT/WTO institutional context, and it is therefore ill-suited to provide a backdrop against which to analyze the constellations of power that confront the system today. The structure of the book is simple: It contains two parts consisting of two chapters each. The first part is qualitative/historical and devoted to an analysis of “Rules.” Chapter one examines the origins of the GATT in an attempt to answer the question “why global trade governance today look[s] the way it does” (p. 23). The second chapter then alleges a persistence of original power relations in the GATT or “endogeneity of power and institutional development” (p. 83). It belabors the principal supplier rule in tariff negotiations and focuses on specific flexibilities in the rules of particular interest to the larger trading powers at the time. Part two, entitled “Consequences,” contains empirical estimations of the effects of the GATT/WTO on varies categories of countries. Chapter three uses data from the inter- and post-war period to demonstrate the concentration of trade benefits from the GATT on a few major countries and the continuity of traditional trade relationships established in the context of inter-war trade blocs. Chapter four takes a long haul (jumping several decades of GATT history) to finally arrive at the WTO. Again, some quantitative analysis is offered that is claimed to demonstrate the continued existence of a

This paper develops a time series model to forecast the growth in imports by major advanced economies in the current and following year (two to six quarters ahead). Both pure time series analysis and structural approaches that include additional predictors based on economic theory are used. Our results compare favourably with other trade forecasts, as measured by standard evaluation statistics and can serve as a benchmark for more complex macroeconomic models.

In the context of economic partnership agreements (EPAs) currently under negotiation between the European Union (EU) and African, Caribbean and Pacific (ACP) countries, trade is meant to be progressively liberalised in a reciprocal way as of 2008. EPAs are also intended to foster existing regional integration efforts among the ACP. This paper presents a computable general equilibrium model simulation of the impact of EPAs for countries of the Southern African Development Community (SADC). Different liberalisation scenarios are compared. We find that EPAs with the EU are welfare-enhancing for SADC overall, in particular if reductions in unemployment are considered. Results are robust to variations in key model parameters. For most countries, further gains arise from intra-SADC liberalisation. The possibility of the EU entering an free trade agreement with other countries, such as Mercosur, reduces estimated gains, but they still remain largely positive. Similarly, estimated gains need to be revised downwards if agriculture liberalisation is not as far reaching as a reduction of import barriers for manufactures. At the sectoral level, the largest expansion in SADC economies takes place in the animal agriculture and processed food sectors, while manufacturing becomes comparatively less attractive following EU--SADC liberalisation. Results also show the need for the Southern African Customs Union tariff pooling formula to be adjusted to reflect new import patterns as tariffs are removed. Copyright 2008 The author 2007. Published by Oxford University Press on behalf of the Centre for the Study of African Economies. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.

Background Metabolic changes in critically ill patients with endotoxin-induced septic shock are measured primarily by techniques that afford organ-specific metabolic monitoring based on interstitial fluid samples. The present study was designed to evaluate the role of cerebral microdialysis (MD) as a part of invasive neuromonitoring during endotoxemia in a porcine model. Materials and methods Continuous endotoxin infusion was administered to 7 female pigs and, in addition to hemodynamic monitoring and blood chemistry, interstitial lactate, pyruvate, glucose and glycerol concentrations in muscle, liver, and cerebral tissue were measured via in vivo MD for an observation period of 180 minutes. Results The cerebral concentrations of lactate and glycerol showed no significant increases, whereas the hepatic and muscular levels rose dramatically under endotoxemia. However, the lactate/pyruvate ratio and especially the lactate/glucose ratio showed a profound and significant increase in brain tissue as well. Cerebral perfusion pressure decreased from 77 to 50 mm Hg without reaching pathologic values. Conclusions Although our results confirm the special protection of the brain during endotoxemia compared with other organs, early metabolic changes become evident by increasing lactate/pyruvate ratio and lactate/glucose ratio. MD appears to be a suitable additional technique in invasive neuromonitoring for obtaining early information about metabolic deterioration in the brain during septic shock.

The DLR internal project “Next Generation Train” (NGT) deals with a high-speed train in a double-deck configuration. To realize the two continuous floors, a single wheel running gear configuration is selected. Equipped with independently rotating wheels instead of a usual wheel-set, a track guidance control becomes necessary. In terms of an advanced control and observer development the implementation of validated simulation models is absolutely essential. Therefore, the paper gives a short overview of the hardware of the scaled Experimental Running Gear on the DLR roller rig representing the NGT single wheel running gear. Using the DLR RailwayDynamics Library three different models of the running gear are implemented, which vary in complexity and can be used for different analysis methods. Finally, some significant simulation results of the particular simulation models are presented and discussed.

Sedimentation of chlorophylls was studied during summer 1997 in Adventfjorden (Spitsbergen, Arctic). During the period of study, the water column was found to be well stratified by a freshened surface layer (salinity

There is scope for economic analysis in dispute settlement. However, it cannot determine dispute settlement outcomes and cannot be used without due regard to certain methodological difficulties, model assumptions and data limitations.

We investigate to what extent the probability that a Specific Trade Concern (STC) is raised in the WTO against a Member in a given sector is affected by past reductions in applied tariffs. Employing an identification strategy based on 'new measures', we find evidence of a substitution of non-tariff measures for tariffs both in the sample of TBT and in the sample of SPS concerns. While in the SPS sample this result holds both among developed and developing economies, in the TBT sample such 'trade policy substitution' only occurs when the country maintaining the measure at issue is economically developed. These results are consistent with our theoretical model, which predicts policy substitution between tariffs and standards in economies where meeting such standards is relatively less costly and in sectors where meeting such standards is relatively more important from the perspective of producers.

The amount of image motion caused by vibrations of the telescope structure increases with the size of the telescope. Compensating the effects of structural vibrations in the optical path will be a major design question for adaptive optics (AO) systems in future extremely large telescopes like the E-ELT. A promising control system architecture is the recently developed Dual-Loop-Approach, with a feedforward loop based on accelerometer measurements, compensating for the vibrations in addition to the classical AO feedback loop compensating for atmospheric turbulences. We present our efforts to develop sophisticated estimation and control algorithms for this feedforward loop. The major task from a control engineering point of view is reconstructing the position of the vibrating elements from accelerometer measurements highly deteriorated by low-frequency drift and highfrequency noise. The algorithms are evaluated and compared using a realistic Tip-Tilt-Vibration laboratory test setup. Position reconstruction for a realistic 8 Hz structural resonance with an error of only 4% is achieved. Our ultimate goal is to achieve longer and more sensitive wavefront sensor (WFS) integrations by permitting a smaller bandwidth of the AO feedback loop in the E-ELT/MICADO.

International audience; Notwithstanding the current slowdown, the geography and composition of international trade are changing fast. We link a macroeconomic growth model and sectoral computable general equilibrium framework in order to project the world economy forward to the year 2035 and assess to what extent current trends in trade are expected to continue. Constructing fully traceable scenarios based on assumptions grounded in the literature, we are also able to isolate the relative impact of key economic drivers. We find that the stakes for developing countries are particularly high: the emergence of new players in the world economy, intensification of South–South trade and diversification into skill-intensive activities may continue only in a dynamic economic and open trade environment. Current trends towards increased regionalisation may be reversed, with multilateral trade relationships gaining in importance. Hypothetical mega-regionals could slow down, but not frustrate the prevalence of multilateralism. Continuing technological progress is likely to have the biggest impact on future economic developments around the globe. Population dynamics are influential as well: for some countries, upskilling will be crucial; for others, labour shortages may be addressed through migration. Several developing countries would benefit from increased capital mobility; others will only diversify into dynamic sectors, when trade costs are further reduced.

The formulation of the wheel-rail contact is a cru- cial issue in simulations considering the running dynamics of railway vehicles. Therefore a model- ing environment that is dedicated to railway ve- hicle dynamics such as the new DLR RaiwayDy- namics Library relies on an efficient representation of the kinematics and forces or torques, respec- tively, that appear at the wheel-rail interface. A number of different formulations have been devel- oped since the underlying rolling contact problem was firstly discussed in literature in 1876. The paper overviews these wheel-rail contact formula- tions and then presents the implemented variants in detail. The DLR RailwayDynamics Library is used to model and simulate the behavior of an ex- perimental scaled M 1:5 running gear operating on the DLR roller rig. The simulations results are compared and validated with measurements.

We investigate to what extent the probability that a Specific Trade Concern (STC) is raised in the WTO against a Member in a given sector is affected by past reductions in applied tariffs. Employing an identification strategy based on 'new measures', we find evidence of a substitution of non-tariff measures for tariffs both in the sample of TBT and in the sample of SPS concerns. While in the SPS sample this result holds both among developed and developing economies, in the TBT sample such 'trade policy substitution' only occurs when the country maintaining the measure at issue is economically developed. These results are consistent with our theoretical model, which predicts policy substitution between tariffs and standards in economies where meeting such standards is relatively less costly and in sectors where meeting such standards is relatively more important from the perspective of producers.

First Online: 02 February 2019 With the help of a political economy model, we show that the extent of ‘trade policy substitution’—namely, substitution of tariffs with non-tariff measures (NTMs)—depends on the cost differential between domestic and foreign firms in complying with product standards. The model suggests the prevalence of trade policy substitution in developed economies, where the costs of compliance are relatively low. We test and validate this prediction using a database on NTMs that identifies actual trade restrictions. We further examine the possible protectionist use of trade policy substitution exploiting information on the end of the Multifibre Arrangement (MFA) and on WTO notifications.

Concentrations and sinking rates of particulate biogenic silica (BSi), chlorophyll a (chl a) and phaeopigments (phae) ( 10 μm and total), as well as the abundances of the major phytoplankton species, were studied during September 1991 in the Eastern Laptev Sea and the lower Lena River (Siberian Arctic). The highest chl a concentrations were found in two major “new” production regimes of the study area: (1) a deep chl a maximum (5.8 mg chl a m−3) (formed by the diatom Chaetoceros socialis) at 30 m depth on the outer shelf of the northern Laptev Sea, and (2) in the Lena River, where the phytoplankton community was dominated by fresh water diatoms (1.5 to 4.5 mg chl a m−3). Elevated chl a concentrations were also found in the river plume phytoplankton community (dominated by brackish water diatoms), NE of the Lena delta. In the Laptev Sea, the low chl a (0.1 to 3 mg chl a m−3) and high phae concentrations (0.5 to 14 mg phae m−3) indicated that the phytoplankton community (dominated by picoplanktic algae and nanoflagellates) was already senescent and affected by grazing losses. Biogenic silica values were highest in the Lena River (4 to 17 μM) as compared to the low values found in the Laptev Sea (0.3 to 4 μM). The large chl a size fraction, phae and BSi in the Lena River samples revealed the highest measured sinking rates (1.4, 2.3, and 1.5 m d−1, respectively). The formation of a strong halocline, decreasing turbulence, and possible nutrient deficiency resulted in death, disintegration and rapid sedimentation of fresh water diatoms. This was accompanied by a decrease in the BSi concentration and growth of the picoplanktic size fraction (< 3 μm) in the estuarine mixing zone (Gulf of Buorkhaya). Only a minor part of BSi was bound to intact diatom cells (< 3%) in the surface layer, most of which being apparently associated with detrital particles. In the Lena River, approximately 12% of the total silica was bound to BSi fraction, yet elsewhere in the Laptev Sea and in the estuarine mixing zone the BSi:total silica ratio was ≤ 5%. Thus, the results reflected the successional stage of a late summer phytoplankton community, characterized by dominance of small autotrophs and patchy distribution of senescent diatoms no longer able to affect the relative high levels of dissolved silica supplied by the Lena River.

Sedimentation processes in Malangen, a relatively wide and deep North-Norwegian fjord, are dependent on seasonal patterns in the biological production of auto- and heterotrophic plankton, different modes of advective transport and erosion of particulate materials, and freshwater discharge due to precipitation and snow-melting. Sedimentation rates of total particulates (TPM), chlorophyll a (Chl a), phaeopigments and particulate organic carbon (POC) and nitrogen were measured from March to October 1991 at five moored arrays covering the entire fjord area. On an average during the period studied, sedimentation pulses of TPM from the euphotic zone were in the range 2-7 g m·2 day-1. Secondary sedimentation due to resuspension and advection of bottom sediments was considerable at all trap moorings. Maximum contributions of inorganic matter were obtained at a mooring in the Miilselv Estuary, especially during the spring freshet peak in the second half of June. The highest pulses in Chl ·a sedimentation ...

In this paper, we present a disturbance compensation technique to improve the performance of interferometric imaging for extremely large ground-based telescopes, e.g., the Large Binocular Telescope (LBT), which serves as the application example in this contribution. The most significant disturbance sources at ground-based telescopes are wind-induced mechanical vibrations in the range of 8-60 Hz. Traditionally, their optical effect is eliminated by feedback systems, such as the adaptive optics control loop combined with a fringe tracking system within the interferometric instrument. In this paper, accelerometers are used to measure the vibrations. These measurements are used to estimate the motion of the mirrors, i.e., tip, tilt and piston, with a dynamic estimator. Additional delay compensation methods are presented to cancel sensor network delays and actuator input delays, improving the estimation result even more, particularly at higher frequencies. Because various instruments benefit from the implementation of telescope vibration mitigation, the estimator is implemented as a separate, independent software on the telescope, publishing the estimated values via multicast on the telescope's ethernet. Every client capable of using and correcting the estimated disturbances can subscribe and use these values in a feedforward for its compensation device, e.g., the deformable mirror, the piston mirror of LINC-NIRVANA, or the fast path length corrector of the Large Binocular Telescope Interferometer. This easy-to-use approach eventually leveraged the presented technology for interferometric use at the LBT and now significantly improves the sky coverage, performance, and operational robustness of interferometric imaging on a regular basis.

MPIA leads the construction of the LINC-NIRVANA instrument, the MCAO-supported Fizeau imager for the LBT, serves as pathfinder for future ELT-AO imagers in terms of size and technology. In this contribution, we review recent results and significant progress made on the development of key items of our stratgey to achieve a piston stability of up to 100nm during a science exposure. We present an overview of our vibration control strategies for optical path and tip-tilt stabilization, involving accelerometer based real-time vibration measurements, vibration sensitive active control of actuators, and the development of a dynamical model of the LBT. MPIA also co-develops the E-ELT first-light NIR imager MICADO (both SCAO and MCAO assisted). Our experiences, made with LINC-NIRVANA, will be fed into the MICADO structural AO design to reach highest on-sky sensitivity.

This chapter provides an overview of institutional, economic, and legal aspects of the relationship between national environmental policies and the multilateral trading system. Some of the difficulties are analyzed that the Dispute Settlement System of the World Trade Organization (WTO) faces when evaluating disputes on national environmental policies that have an impact on international trade. From an economist’s point of view, it would be desirable that optimal environmental policies, correcting for market failures, be ruled consistent with economic thinking. Yet, the precise welfare effects of different types of environmental policies are insufficiently known. In practice, therefore, it is questionable whether economics are able to give adequate guidance to legal experts when it comes to the evaluation of national environmental policies. This is one of the reasons why there continues to be some uncertainty as to the possible interpretations of certain WTO rules in the context of environmental disputes.

We analyze the degree of preference utilization in four major importing countries (Australia, Canada, EU and US) and provide evidence that preferences are more widely used than previously thought. For Australia and Canada, we have obtained a new dataset on imports by preferential regime that has so far not been publicly available. For the EU and US, we make use of more disaggregated data than previously used in the literature. We empirically test what determines utilization rates. In line with previous studies, we find that utilization increases with both the preferential margin and the volume of exports, suggesting that using preferences can be costly. However, we also find that utilization rates are often very high, even for very small preferential margins and/or very small trade flows, which contradicts numerous estimates that average compliance costs are as high as 2-6%. We extend the existing literature in relation to both data and methodological issues. In particular, we construct 'pseudo transaction-level' data that allows us to assess more precisely when available preferences are utilized. Using this methodology, we obtain a more realistic estimate of what determines utilization. Rather than constituting a percentage share of the trade value, our findings indicate that utilization costs involve an important fixed cost element. We provide estimates for such fixed costs, which appear to be in the range of USD 14 to USD 1,500.

Background: Chorioamnionitis is a major risk factor for preterm birth in multifetal pregnancies. However, there is little clinical data whether chorioamnionitis is restricted to one amniotic compartment in multifetal pregnancies. Objective: To explore whether chorioamnionitis is confined to the exposed compartment and does not cross to the unaffected fetus in twin pregnancy. Methods: In twin pregnant sheep, one of the twins was exposed to either 2 or 14 days of intra-amniotic lipopolysaccharide (LPS) while the co-twin was exposed to either 2 or 14 days of intra-amniotic saline (n = 3 for each exposure). Singletons were included in this study to compare the grade of inflammation with twins. All fetuses were delivered at 125 days of gestation (term = 150 days). Chorioamnionitis was confirmed by histological examination. Lung inflammation was assessed by cell count in bronchoalveolar lavage. Lung compliance was assessed at 40 cm H2O. Results were compared using analysis of variance (ANOVA) with a post-hoc Tukey analysis. Results: Inflammation in placenta, membranes and lung of LPS-exposed twins was significantly higher after 2 and 14 days of exposure when compared to the saline-exposed co-twins. Lung compliance in LPS-exposed twins was significantly increased after 14 days when compared to saline-exposed co-twins. Intrauterine LPS exposure increased lung compliance and inflammation in the membranes, placenta and lung to the same extent in twins as in singletons. Conclusion: In twin pregnant sheep, inflammation of the membranes, placenta and fetal lung was strictly limited to the exposed fetus in the amniotic compartment in which the LPS was injected.

International audience; We examine the impact of telecommunications liberalization in Africa on sectoral performance and economic growth. Besides unilateral measures, we account for WTO commitments fostering the credibility of reforms. Regulatory quality plays a major role in bringing down prices and improving access to telecommunications services in Africa. Competition, notably in the mobile segment, also improves sector performance. Increasing access to mobile networks by 1% translates into a 0.5% increase in real GDP per capita. In Africa, multilateral commitments do not reflect recent reforms. However, globally, adherence to the GATS Reference Paper is associated with lower prices.

Ornithogenic soils have been formed in stony loams on and around penguin rookeries along the sea shore of the maritime Antarctic. The fine fraction of these soils contains mainly posphates of various chemical and mineral compositions. Genetic horizons of ornithogenic soils resulted from diversified mineral composition of them in the vertical profile. Occurrence of apatite, brushite, struvite, urates(?) fluorite in the surface guano layer, and leucophosphite, minyulite, taranakite, vivianite, amorphous and crystalline phosphates in the phosphatized rock zone was documented. Among crystalline aluminium phosphates besides vashegyite, a new mineral arctowskite was distinguished. Chemical composition, X-ray pattern, microscopic images of all selected phosphates was given. Most of the phosphates are relatively long-lasting under climatic conditions of the maritime Antarctic, and can be found in the places abandoned by penguins hundreds and thousands of years ago. A high content of nutrients is available for the poor tundra vegetation growing around current and over the relic ornithogenic soils, and can be an important factor controlling their productivity, chemical composition and probably also species diversity.