Despite decades of intensive research, the development of a diagnostic test for major depressive disorder (MDD) had proven to be a formidable and elusive task, with all individual marker-based approaches yielding insufficient sensitivity and specificity for clinical use. In the present work, we examined the diagnostic performance of a multi-assay, serum-based test in two independent samples of patients with MDD. Serum levels of nine biomarkers (alpha1 antitrypsin, apolipoprotein CIII, brain-derived neurotrophic factor, cortisol, epidermal growth factor, myeloperoxidase, prolactin, resistin and soluble tumor necrosis factor alpha receptor type II) in peripheral blood were measured in two samples of MDD patients, and one of the non-depressed control subjects. Biomarkers measured were agreed upon a priori, and were selected on the basis of previous exploratory analyses in separate patient/control samples. Individual assay values were combined mathematically to yield an MDDScore. A 'positive' test, (consistent with the presence of MDD) was defined as an MDDScore of 50 or greater. For the Pilot Study, 36 MDD patients were recruited along with 43 non-depressed subjects. In this sample, the test demonstrated a sensitivity and specificity of 91.7% and 81.3%, respectively, in differentiating between the two groups. The Replication Study involved 34 MDD subjects, and yielded nearly identical sensitivity and specificity (91.1% and 81%, respectively). The results of the present study suggest that this test can differentiate MDD subjects from non-depressed controls with adequate sensitivity and specificity. Further research is needed to confirm the performance of the test across various age and ethnic groups, and in different clinical settings.

This paper investigates whether government support can act to increase exporting activity. We use a uniquely rich data set on Irish manufacturing plants and employ an empirical strategy that combines a non-parametric matching procedure with a difference-in-differences estimator in order to deal with the potential selection problem inherent in the analysis. Our results suggest that if grants are large enough they can encourage already exporting firms to compete more effectively on the international market. However, there is little evidence that grants encourage non-exporters to start exporting. Keywords: exporting, subsidies, matching, difference-in-differences JEL classification: L2, H2, F2, O3 * The authors are grateful to Forfás for the provision of the data and to an anonymous referee and participants at ETSG 2005 in Dublin for helpful comments. Financial support through the Leverhulme Trust (Grant No. F114/BF) and the ESRC (Grant No. RES-000-22-0468) is gratefully acknowledged. Section I: IntroductionMost governments seem to take a positive view on exporting, so that the more firms in the economy export, the better. In this regard it is not surprising that many governments have taken some initiative in encouraging firms to export.Despite the potential importance of using explicit policies to promote exporting activity, there are, however, few empirical studies that have investigated this issue. One exception is the recent study by Bernard and Jensen (2004) on the determinants of exporting activity in the US which, amongst other things, investigates whether export promotion expenditures at the state level influence the decision of US plants to export or not. Their findings suggest little evidence that such policies encourage participation in the global market by US manufacturers.Arguably, export promotion expenditures on their own may not have a significant effect on exporting. Firstly, expenditure on export promotion measured at the state level may be masking firm specific differences in their ability to access information on foreign markets and, hence, heterogeneity in the ability to export. Secondly, information on foreign markets per se may not be sufficient to ensure that firms can successfully compete on the international markets. Even more important may be that firms are productive enough to do so.As the recent theoretical and empirical literature on firm level export activity argues, selling abroad involves sunk costs and it is only the "better" firms, i.e. those that are more efficient or productive, that are able to overcome these entry barriers and export successfully (Clerides et al., 1998;Bernard and Jensen, 1999;Melitz, 2003). These findings perhaps highlight the fact that other types of 1 government support specifically targeted at improving productivity related aspects of the firms' operations, to assist them in overcoming barriers to exporting, could prove more effective. Examples of such relevant support programmes include arguably subsidies, such as for R&D and training, amongst oth...

A two-dimensional, J-resolved magnetic resonance spectroscopic extraction approach was developed employing GAMMA-simulated, LCModel basis-sets. In this approach, a two-dimensional J-resolved (2D-JPRESS) dataset was resolved into a series of one-dimensional spectra where each spectrum was modeled and fitted with its theoretically customized LCModel template. Metabolite levels were derived from the total integral across the J-series of spectra for each metabolite. Phantoms containing physiologic concentrations of the major brain chemicals were used for validation. Varying concentrations of glutamate and glutamine were evaluated at and around their accepted in vivo concentrations in order to compare the accuracy and precision of our method with 30 ms PRESS. We also assessed 2D-JPRESS and 30 ms PRESS in vivo, in a single voxel within the parieto-occipital cortex by scanning ten healthy volunteers once and a single healthy volunteer over nine repeated measures. Phantom studies demonstrated that serial fitting of 2D-JPRESS spectra with simulated LCModel basis sets provided accurate concentration estimates for common metabolites including glutamate and glutamine. Our in vivo results using 2D-JPRESS suggested superior reproducibility in measuring glutamine and glutamate relative to 30 ms PRESS. These novel methods have clear implications for clinical and research studies seeking to understand neurochemical dysfunction.

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