Autoantibodies neutralizing human ADAMTS13 (a disintegrin-like and metalloproteinase with thrombospondin type 1 motif), the metalloprotease that physiologically cleaves von Willebrand factor, are a major cause of severe deficiency of the protease and of acquired thrombotic thrombocytopenic purpura (TTP). We evaluated prevalence of anti-ADAMTS13 antibodies in 59 patients with thrombotic microangiopathies (TMAs) and in 160 patients with immunologic or thrombocytopenic diseases different from TTP, using an enzyme-linked immunosorbent assay (ELISA). Immunoglobulin G (IgG) antibodies directed against ADAMTS13 were found in 97% of untreated patients with acute acquired TMA who had plasma levels of ADAMTS13 activity below 10%. The corresponding prevalence of IgM antibodies was 11%. In contrast, anti-ADAMTS13 antibodies of G or M isotypes were detected in 20% of patients with TMA with ADAMTS13 activity above 10%. The ELISA was more sensitive than the standard functional inhibitor assay for detecting antibodies against ADAMTS13. Patients with thrombocytopenia from various causes (n ‫؍‬ 50), systemic lupus erythematosus (SLE; n ‫؍‬ 40), and the antiphospholipid antibody syndrome (APS; n ‫؍‬ 55) had prevalences of IgG antibodies of 8%, 13%, and 5% respectively, only slightly higher than the prevalence in 111 healthy donors (4%). A rather high prevalence of anti-ADAMTS13 IgM antibodies was found in patients with SLE and APS (18% each). The clinical significance of IgM antibodies in these groups is unclear. In conclusion, the ELISA method detected anti-ADAMTS13 IgG antibodies in a very large proportion of patients with acquired TMA associated with severe ADAMTS13 deficiency, and was more sensitive than the inhibitor assay. IntroductionThrombotic microangiopathies (TMAs) are a heterogeneous group of diseases characterized by microangiopathic hemolytic anemia and thrombocytopenia due to platelet clumping in the microcirculation leading to ischemic organ dysfunction with neurologic symptoms and renal impairment. The 2 principal forms of TMA are the hemolytic-uremic syndrome (HUS), in which severe renal failure prevails, and thrombotic thrombocytopenic purpura (TTP), characterized by the systemic occlusion of the microcirculation that frequently affects the central nervous system. [1][2][3][4] von Willebrand factor (VWF) plays an important mechanistic role in TTP. Upon stimulation of endothelial cells, this adhesive glycoprotein is released from storage organelles (Weibel-Palade bodies) as unusually large multimers (ULVWF) that are physiologically cleaved by the plasma metalloprotease ADAMTS13 and degraded into smaller multimers ranging in size from 500 kDa to approximately 20 000 kDa. 5 On the basis of in vitro studies using artificial flow systems, the following pathogenetic mechanisms are postulated in TTP. Upon release, ULVWF multimers remain anchored to the endothelial-cell surface in a P-selectin-dependent manner, and form extraordinary long strings. 6,7 ADAMTS13 docks to the endothelial cells through binding to both the ...

Measuring Ethnic Identity and Its Impact on Economic Behavior *The paper advocates for a new measure of the ethnic identity of migrants, models its determinants and explores its explanatory power for various types of their economic performance. The ethnosizer, a measure of the intensity of a person's ethnic identity, is constructed from information on the following elements: language, culture, societal interaction, history of migration, and ethnic self-identification. A two-dimensional concept of the ethnosizer classifies migrants into four states: integration, assimilation, separation and marginalization. The ethnosizer largely depends on pre-migration characteristics. Empirical evidence studying economic behavior like work participation, earnings and housing decisions demonstrates the significant relevance of ethnic identity for economic outcomes. JEL Classification:F22, J15, J16, Z10

Standard-Nutzungsbedingungen:Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden.Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen.Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. The Institute for the Study of Labor (IZA) in Bonn is a local and virtual international research center and a place of communication between science, politics and business. IZA is an independent, nonprofit limited liability company (Gesellschaft mit beschränkter Haftung) supported by the Deutsche Post AG. The center is associated with the University of Bonn and offers a stimulating research environment through its research networks, research support, and visitors and doctoral programs. IZA engages in (i) original and internationally competitive research in all fields of labor economics, (ii) development of policy concepts, and (iii) dissemination of research results and concepts to the interested public. The current research program deals with (1) mobility and flexibility of labor markets, (2) internationalization of labor markets and European integration, (3) the welfare state and labor markets, (4) labor markets in transition, (5) the future of work, and (6) general labor economics. Terms of use: Documents in D I S C U S S I O N P A P E R S E R I E SIZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper should account for its provisional character. The speed at which immigrants assimilate is the subject of debate. Human capital formation plays a major role in this discussion. This paper compares the educational attainment of second generation immigrants to those of natives in the same age cohort. Evidence using a large German data set suggests ethnicity does matter: the size of the ethnic network has a positive effect on educational attainment, and a clear pattern is exhibited between countries-of-origin and educational attainment even in the second generation. For the children of the foreign-born, parental schooling plays no role in making educational choices. However, for Germans, contrary to the general findings in the literature, there is a statistically significant difference in favor of father´s education over mother's education.JEL Classification: I21, J15, J62

A large number of different Pseudo-R2 measures for some common limited dependent variable models are surveyed. Measures include those based solely on the maximized likelihoods with and without the restriction that slope coefficients are zero, those which require further calculations based on parameter estimates of the coefficients and variances and those that are based solely on whether the qualitative predictions of the model are correct or not. The theme of the survey is that while there is no obvious criterion for choosing which Pseudo-R2 to use, if the estimation is in the context of an underlying latent dependent variable model, a case can be made for basing the choice on the strength of the numerical relationship to the OLS-R2 in the latent dependent variable. As such an OLS-R2 can be known in a Monte Carlo simulation, we summarize Monte Carlo results for some important latent dependent variable models (binary probit, ordinal probit and Tobit) and find that a Pseudo-R2 measure due to McKelvey and Zavoina scores consistentiy well under our criterion. We also very briefly discuss Pseudo-R2 measures for count data, for duration models and for prediction-realization tables.

Young people have been among those most affected by the recent financial crisis. Vocational education and training (VET) is often viewed as the silver bullet for the youth joblessness problem. In this article, the authors provide a better understanding of VET in industrialized countries, proposing a typology with three types of vocational systems: 1) vocational and technical schools, 2) formal apprenticeships, and 3) dual apprenticeship systems that combine school training with a firm-based approach. They first describe the strengths and challenges of each system. They subsequently review the evidence of the effectiveness of VET versus general education and the relative effectiveness of the different VET systems. Results indicate that VET is a valued alternative beyond the core of general education and that the use of apprenticeships combined with institutional learning tends to be more effective than school-based VET.

"The ethnosizer, a new measure of the intensity of a person's ethnic identity, is proposed using information on language, culture, societal interaction, history of migration, and ethnic selfidentification. A two-dimensional version classifies immigrants into four states: integration, assimilation, separation and marginalization. Results based on the German Socio-economic Panel for 2001 are as follows. Young migrants are assimilated or integrated the most. While Muslims and Christians do not integrate, both assimilate the best. Immigrants with college in the home country separate less. Having some schooling is worse than no schooling for integration and assimilation. While ex-Yugoslavs assimilate more, Greeks, Italians and Spaniards are no different than Turks." [author's abstract

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