Functional recognition of in vivo processed self antigen

C5, the fifth component of complement, Is a circulating self protein which induces complete tolerance in MHC class II restricted, CD4+ T cells due to the presentation of C5 taken up from plasma. Functional recognition of in vivo processed C5 was monitored by activation of C5 specific T cell hybrids cultured with antigen presenting cells (APC) from C5 expressing mice. Dendritic cells Isolated from various tissues (spleen, thymus, skin) proved to be the most efficient APC, since 10-to 50-fold more macrophages and at least 100- to 500-fold more B cells were needed to achieve similar T cell activation. Stimulatory C5 peptide - class II complexes generated in vivo were retained on the surface of dendritic cells but not on macrophages and B cells upon prolonged culture: Dendritic cells but not macrophages from thymus presented in vivo processed C5. Taken together these findings emphasize the crucial role dendritic cells play for recognition of soluble self proteins by MHC class II restricted T cell

The randomly driven Ising ferromagnet, Part II: One and two dimensions

We consider the behavior of an Ising ferromagnet obeying the Glauber dynamics under the influence of a fast switching, random external field. In Part I, we introduced a general formalism for describing such systems and presented the mean field theory. In this article we derive results for the one dimensional case, which can be only partially solved. Monte Carlo simulations performed on a square lattice indicate that the main features of the mean field theory survive the presence of strong fluctuations.Comment: 10 pages in REVTeX/LaTeX format, 17 eps/ps figures. Submitted to Journal of Physics

Temporally disordered Ising models

We present a study of the influence of different types of disorder on systems in the Ising universality class by employing both a dynamical field theory approach and extensive Monte Carlo simulations. We reproduce some well known results for the case of quenched disorder (random temperature and random field), and analyze the effect of four different types of time-dependent disorder scarcely studied so far in the literature. Some of them are of obvious experimental and theoretical relevance (as for example, globally fluctuating temperatures or random fields). All the predictions coming from our field theoretical analysis are fully confirmed by extensive simulations in two and three dimensions, and novel qualitatively different, non-Ising transitions are reported. Possible experimental setups designed to explore the described phenomenologies are also briefly discussed.Comment: Submitted to Phys. Rev. E. Rapid Comm. 4 page

Amidoschwarz10B in der forensischen Spurenuntersuchung: Vergleichende Untersuchungen an forensischem Spurenmaterial

Zusammenfassung: Blutspuren gehören zu den aussagekräftigsten Spuren in der forensischen Fallanalyse. Einerseits kann die Beurteilung von Aussehen, Menge, Form und Verteilung an Tatorten Hinweise auf den Tathergang geben. Andererseits lassen sich heute auch aus kleinsten Blutmengen zumeist vollständige DNA-Profile erstellen, die dann ebenfalls eine Rekonstruktion des Tatablaufs und über die molekulargenetische DNA-Analyse Aussagen zur Tatbeteiligung von Personen ermöglichen. In der vorgestellten Studie wurden Vollblutproben auf unterschiedliche Spurenträger aufgebracht und mithilfe des Hexagon OBTI® auf das Vorhandensein von Blut hin untersucht. Nach Inkubation mit 2 verschiedenen Zubereitungen von Amidoschwarz10B konnte gezeigt werden, dass dessen Einsatz zu starken Beeinträchtigungen bzw. falsch-negativen Ergebnissen des OBTI führen kann. Ein negativer Einfluss von Amidoschwarz10B auf das Probenmaterial war hingegen bei den nachfolgend durchgeführten DNA-Analysen nicht festzustelle

The Product Space Conditions the Development of Nations

Economies grow by upgrading the type of products they produce and export. The technology, capital, institutions and skills needed to make such new products are more easily adapted from some products than others. We study the network of relatedness between products, or product space, finding that most upscale products are located in a densely connected core while lower income products occupy a less connected periphery. We show that countries tend to move to goods close to those they are currently specialized in, allowing nations located in more connected parts of the product space to upgrade their exports basket more quickly. Most countries can reach the core only if they jump over empirically infrequent distances in the product space. This may help explain why poor countries have trouble developing more competitive exports, failing to converge to the income levels of rich countries.Comment: This version is slightly different from the one published in Scienc