Faced with the problem that conventional multidimensional fixed effects models only focus on unobserved heterogeneity, but ignore any potential cross-sectional dependence due to network interactions, we introduce a model of trade flows between countries over time that allows for network dependence in flows, based on sociocultural connectivity structures. We show that conventional multidimensional fixed effects model specifications exhibit cross-sectional dependence between countries that should be modeled to avoid simultaneity bias. Given that the source of network interaction is unknown, we propose a panel gravity model that examines multiple network interaction structures, using Bayesian model probabilities to determine those most consistent with the sample data. This is accomplished with the use of computationally efficient Markov Chain Monte Carlo estimation methods that produce a Monte Carlo integration estimate of the log-marginal likelihood that can be used for model comparison. Application of the model to a panel of trade flows points to network spillover effects, suggesting the presence of network dependence and biased estimates from conventional trade flow specifications. The most important sources of network dependence were found to be membership in trade organizations, historical colonial ties, common currency, and spatial proximity of countries.
In this paper, we distinguish three constrained variants of the gravity model of spatial interaction: doubly constrained, production constrained and attraction constrained exponential gravity models. These model variants include origin and/or destination specific...
No abstract is provided for this article.
No abstract is provided for this article.
We would like to clarify some points about the DIFFUSE (Defining fluticasone propionate/ formoterol particulate
A lack of standardisation has to be stated for quantitative assessment of bone mineral mass and density. While daily quality control is adequately provided by most manufacturers, there is a general lack of comparibility between different machines. Measurements of the same phantom or patient differ significantly. For dual X ray absorptiometry, differences of 10% or more are reported for the major manufacturers. In quantitative computer tomography, similar differences for measurements of spongiosa density have been found. While reproducibility appears adequate on both types of systems, the need for calibration standards is evident. National and international organisations have demanded standardisation efforts; an initiative started within the European Community (COMAC BME project ‘Quantitative Assessment of Osteoporosis’) appears promising. It provides anthropomorphic phantoms for spine and forearm measurements which are geometrically defined and provide definitions of the true values for all quantities to be measured. Densities and geometric dimensions span the ranges which are found in patients. These new phantoms are described in detail and compared with existing phantoms.
Since the beginning of this decade the use of automated or robotic-systems for analytical purposes has decreased rapidely. Starting from the analysis of agriculturing products or medical samples, these instruments are now more and more common in the pharmaceutical industry. The systems are used for R&D purposes mainly in the area of combinatorial chemistry to analyze the huge amount of synthesis products in the biomedical labs and in chemical-physical laboratories of Quality Contol Units. Extensive stability studies, which have to be perfomed for new drug applications, and the release testing of medicinal products with a very high manufacturing batch-rate per year need highly effective analytical methods. Thus, Byk Gulden has introduced two automated systems based on Zymark products (TPWII and MultiDose), for the stability tests of an enteric-coated tablet. The number of batches, pack types and storage conditions (total number of samples: appr. 40 for the 3- and 6-months timepoints), for this stability st...
Bone metabolism and thus bone remodelling and bone mineral content are profoundly influenced by many hormonal and metabolic factors. This review presents the state of the art procedures for bone mineral absorptiometry and examines the interactions of endocrine and metabolic diseases and bone mineral content. Preventive and therapeutic modalities of osteoporosis are discussed in this context.
No abstract is provided for this article.
This paper investigates the impact of knowledge capital stocks on total factor productivity through the lens of the knowledge capital model proposed by Griliches (1979), augmented with a spatially discounted cross-region knowledge spillover pool variable. The objective is to shift attention from firms and industries to regions and to estimate the impact of cross-region knowledge spillovers on total factor productivity (TFP) in Europe. The dependent variable is the region-level TFP, measured in terms of the superlative TFP index suggested by Caves, Christensen and Diewert (1982). This index describes how efficiently each region transforms physical capital and labour into output. The explanatory variables are internal and out-of-region stocks of knowledge, the latter capturing the contribution of cross-region knowledge spillovers. We construct patent stocks to proxy regional knowledge capital stocks for N=203 regions over the 1997- 2002 time period. In estimating the effects we implement a spatial panel data model that controls for the spatial autocorrelation due to neighbouring regions and the individual heterogeneity across regions. The findings provide a fairly remarkable confirmation of the role of knowledge capital contributing to productivity differences among regions, and add an important spatial dimension to the discussion, by showing that productivity
ISHS Eucarpia symposium on Fruit Breeding and Genetics NEW NAUMBURG/PILLNITZ PEAR BREEDING RESULTS
This paper presents a theoretical neoclassical growth model with two kinds of capital, and technological interdependence among regions. Technological interdependence is assumed to operate through spatial externalities caused by disembodied knowledge diffusion between technologically similar regions. The transition from theory to econometrics yields a reduced-form empirical model that in the spatial econometrics literature is known as spatial Durbin model. Technological dependence between regions is formulated by a connectivity matrix that measures closeness of regions in a technological space spanned by 120 distinct technological fields. We use a system of 158 regions across 14 European countries over the period from 1995 to 2004 to empirically test the model. The paper illustrates the importance of an impact-based model interpretation, in terms of the LeSage and Pace (2009) approach, to correctly quantify the magnitude of spillover effects that avoid incorrect inferences about the presence or absence of significant capital externalities among technologically similar regions.
Tissue oxygen partial pressure (PtO2 reflects O2 supply and O2 consumption of an organ and, hence, has characteristic values in active biological systems (Lubbers, 1981ar 1981b; Kessler et al., 1984). Restorations of an organ-specific O2 supply after injuries have...
Lipocortins I and II, known to inhibit phospholipase A 2 , have been purified from bovine lung and tested with respect to their ability to affect the enzymatic activities of phosphoinositide‐ and polyphosphoinositide‐specific phospholipase C from human platelets, rat liver cytosol or rat brain membranes. At 0.67,μM, both lipocortins led to complete inhibition of phospholipase C activity with either phosphatidylinositol or phosphatidylinositol 4,5‐bisphophate as substrate. The inhibition could be overcome by increasing the substrate concentration. Ultracentrifugation studies with lipocortin II showed a direct interaction between phosphatidylinositol and the lipocortin, indicating that the lipocortins inhibit phospholipase C not directly but by interacting with the substrate. In experiments with plasma membranes from [ 3 H]inositol‐labeled HL‐60 cells, lipocortin II did not affect PI‐specific phospholipase C activity in the absence or presence of calcium plus or minus GTP‐γ‐S.
This article uses a factor‐augmented vector autoregressive model to examine the impact of monetary policy shocks on housing prices. To simultaneously estimate the model parameters and unobserved factors, we rely on Bayesian estimation and inference. Policy shocks are identified using high‐frequency surprises around policy announcements as an external instrument. Impulse response functions reveal differences in regional housing price responses, which in some cases are substantial. The heterogeneity in policy responses is found to be significantly related to local regulatory environments and housing supply elasticities. Moreover, housing prices responses tend to be similar within states and adjacent regions in neighboring states.
This paper develops a Markov switching factor‐augmented vector autoregression to investigate the transmission mechanisms of monetary policy for distinct stages of the US business cycle. We assume that autoregressive parameters and covariance matrices of the error terms are regime dependent, driven by an unobserved Markov indicator. Endogenously determined transition probabilities are governed by an underlying probit model that features a large set of possible predictors. The empirical findings provide evidence for differences in the transmission of monetary policy shocks that mainly stem from heterogeneity in the responses of financial market quantities.
Background : A combination of the inhaled corticosteroid, fluticasone propionate, and the long-acting β2-agonist, formoterol fumarate has been developed in an aerosol inhaler (FLUT/FORM). As changes in flow rate have been shown to affect the in-vitro performance of inhalers, which could compromise in-vivo performance, this study evaluated the effect of flow rate on fine particle fraction (FPF) and dose (FPD) of FLUT/FORM and three available combination products. Methods : Dose strengths used to deliver comparable treatment doses (FLUT/FORM, 250/10µg; beclomethasone/formoterol (BDP/FORM) pMDI, 200/12g; fluticasone/salmeterol (FLUT/SAL) DPI, 250/50µg; budesonide/formoterol (BUD/FORM) DPI, 400/12µg) were compared. Aerodynamic particle size distribution was determined by Andersen Cascade Impaction at 28.3L/min and 60L/min flow rates with a cut-off diameter of 5.0 µM and was calculated as % of label claim. Results : FLUT/FORM provided a consistent and high FPF of approximately 40% for each component, with less than a 10% relative difference in the FPD emitted between flow rates. FLUT/FORM provided the highest FPF at both flow rates with BUD/FORM and FLUT/SAL delivering a FPF of less than 20% at 28.3L/min. The FPD of all three comparator products evaluated were affected by increases in flow rate from 28.3L/min to 60L/min, with BUD/FORM having a ∼5 fold increase in FPD between flow rates and BDP/FORM showing a 50% difference. Conclusion: The data confirm that FLUT/FORM emits a high FPF of approximately 40%. These data also demonstrate that FLUT/FORM has a higher FPF, that is less affected by changes in flow rate, than other combination products assessed.
