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Kinesin motors play crucial roles in the delivery of membranous cargo to its destination and thus for the establishment and maintenance of cellular polarization. Recently, calsyntenin-1 was identified as a cargo-docking protein for Kinesin-1-mediated axonal transport of tubulovesicular organelles along axons of central nervous system neurons. To further define the function of calsyntenin-1, we immunoisolated calsyntenin-1 organelles from murine brain homogenates and determined their proteome by MS. We found that calsyntenin-1 organelles are endowed with components of the endosomal trafficking machinery and contained the β-amyloid precursor protein (APP). Detailed biochemical analyses of calsyntenin-1 immunoisolates in conjunction with immunocytochemical colocalization studies with cultured hippocampal neurons, using endosomal marker proteins for distinct subcompartments of the endosomal pathways, indicated that neuronal axons contain at least two distinct, nonoverlapping calsyntenin-1-containing transport packages: one characterized as early-endosomal, APP positive, the other as recycling-endosomal, APP negative. We postulate that calsyntenin-1 acts as a general mediator of anterograde axonal transportation of endosomal vesicles. In this role, calsyntenin-1 may actively contribute to axonal growth and pathfinding in the developing as well as to the maintenance of neuronal polarity in the adult nervous system; further, it may actively contribute to the stabilization of APP during its anterograde axonal trajectory.

During the initial stage of neuromuscular junction (NMJ) formation, nerve-derived agrin cooperates with muscle-autonomous mechanisms in the organization and stabilization of a plaque-like postsynaptic specialization at the site of nerve–muscle contact. Subsequent NMJ maturation to the characteristic pretzel-like appearance requires extensive structural reorganization. We found that the progress of plaque-to-pretzel maturation is regulated by agrin. Excessive cleavage of agrin via transgenic overexpression of an agrin-cleaving protease, neurotrypsin, in motoneurons resulted in excessive reorganizational activity of the NMJs, leading to rapid dispersal of the synaptic specialization. By contrast, expression of cleavage-resistant agrin in motoneurons slowed down NMJ remodeling and delayed NMJ maturation. Neurotrypsin, which is the sole agrin-cleaving protease in the CNS, was excluded as the physiological agrin-cleaving protease at the NMJ, because NMJ maturation was normal in neurotrypsin-deficient mice. Together, our analyses characterize agrin cleavage at its proteolytic α- and β-sites by an as-yet-unspecified protease as a regulatory access for relieving the agrin-dependent constraint on endplate reorganization during NMJ maturation.

The synaptic serine protease neurotrypsin is considered to be essential for the establishment and maintenance of cognitive brain functions, because humans lacking functional neurotrypsin suffer from severe mental retardation. Neurotrypsin cleaves agrin at two homologous sites, liberating a 90-kDa and a C-terminal 22-kDa fragment from the N-terminal moiety of agrin. Morphological analyses indicate that neurotrypsin is contained in presynaptic terminals and externalized in association with synaptic activity, while agrin is localized to the extracellular space at or in the vicinity of the synapse. Here, we present a detailed biochemical analysis of neurotrypsin-mediated agrin cleavage in the murine brain. In brain homogenates, we found that neurotrypsin exclusively cleaves glycanated variants of agrin. Studies with isolated synaptosomes obtained by subcellular fractionation from brains of wild-type and neurotrypsin-overexpressing mice revealed that neurotrypsin-dependent cleavage of agrin was concentrated at synapses, where the most heavily glycanated variants of agrin predominate. Because agrin has been shown to play an important role in the formation and the maintenance of excitatory synapses in the central nervous system, its local cleavage at the synapse implicates the neurotrypsin/agrin system in the regulation of adaptive reorganizations of the synaptic circuitry in the context of cognitive functions, such as learning and memory.

On the FBI’S homepage, http://http://www.fbi.gov/, there is a link that reads “Freedom of Information Act. Frequently requested FBI files.” Clicking on this spot leads to a file that, much like “America’s Most Wanted,” contains information on dozens of prominent “subjects” about whom the FBI has collected material. Delving deeper into this electronic reading room’s table of contents, under the heading “Famous Persons”—alongside people like “Machine Gun Kelly,” Bonnie and Clyde, and Pretty Boy Floyd—one finds the name of Bertolt Brecht. Another double-click finally opens up access to materials that have long been inaccessible, kept under lock and key both in the FBI archive in Washington, D.C. and in the Brecht archive in Berlin, known only to a small group of initiated Brecht researchers. This is the 369-page FBI file on Bertolt Brecht, who after Thomas Mann was the most famous exiled German author in the United States.

The synaptic serine protease neurotrypsin is thought to be important for adaptive synaptic processes required for cognitive functions, because humans deficient in neurotrypsin suffer from severe mental retardation. In the present study, we describe the biochemical characterization of neurotrypsin and its so far unique substrate agrin. In cell culture experiment as well as in neurotrypsin-deficient mice, we showed that agrin cleavage depends on neurotrypsin and occurs at two conserved sites. Neurotrypsin and agrin were expressed recombinantly, purified, and assayed in vitro. A catalytic efficiency of 1.3 x 10(4) M(-1) x s(-1) was determined. Neurotrypsin activity was shown to depend on calcium with an optimal activity in the pH range of 7-8.5. Mutagenesis analysis of the amino acids flanking the scissile bonds showed that cleavage is highly specific due to the unique substrate recognition pocket of neurotrypsin at the active site. The C-terminal agrin fragment released after cleavage has recently been identified as an inactivating ligand of the Na+/K+-ATPase at CNS synapses, and its binding has been demonstrated to regulate presynaptic excitability. Therefore, dysregulation of agrin processing is a good candidate for a pathogenetic mechanism underlying mental retardation. In turn, these results may also shed light on mechanisms involved in cognitive functions.

At present, heterojunction polymer solar cells are typically fabricated with an active layer thickness of approximately 80 nm to 100 nm. This active layer thickness has traditionally been chosen based upon convenience and empirical results. However, a detailed mechanistic study of the effects of active layer thickness on the short circuit current and efficiency has never been performed for polymer solar cells. We demonstrate that using the high mobility materials regio regular poly(3-hexylthiophene and [6,6]-phenyl (P3HT) and C 61 -butyric acid methyl ester (PCBM), that high efficiency solar cells can be fabricated with active layer thickness greater than 100 nm. Devices with an active layer thickness of 200 nm are fabricated with a power efficiency of 4.1% under AM 1.5 illumination at and intensity of 80 mW/cm 2 . In addition, we explain the variation in short circuit current density as a function of thickness using calculations of the distribution of the optical electric field intensity as a function of device thickness.

Als Georgi Arbatow kurz vor dem Ende der Sowjetunion fur die New York Times die Politik der Regierung Gorbatschow kommentierte, lies er fur seine amerikanischen Leser eine Warnung zuruck: Sie alle, so der Direktor des Institute of the United States and Canada der sowjetischen Akademie der Wissenschaften, wurden eines Tages die Sowjetunion vermissen, weil sie der Klebstoff gewesen sei, der uber ein halbes Jahrhundert die transatlantische Allianz zusammengehalten hatte (Arbatov 1987).

Archiv: Gesprach in einem Raum / Dossier: Ein Ort fur Peter Weiss - Dankesworte zur Verleihung des Peter Weiss-Preises der Stadt Bochum am 30. August 1998 / Analyse: Citoyen im Spiegelkabinett. Nachgelesen: "Die Asthetik des Widerstands" von Peter Weiss - Die allegorische Konstruktion der Hodann-Figur im Hinblick auf die Entwicklung des Ich-Erzahlers in der "Asthetik des Widerstands" - die Brecht-Figur in der "Asthetik des Widerstands" von Peter Weiss - Damnatio memoriae und "Werke von langer Dauer". Zwei asthetische Grenzwerte in Brechts Exillyrik - Krieg und Gewalt im Theater Heiner Mullers - Von der Faschismustheorie zur Totalitarismustheorie? / Kritik: Annie Bourguignon: Der Schriftsteller Peter Weiss und Schweden - Unterwerfung und Aufruhr - Peter Weiss a Paris - "Schafft die Einheit!" - Intertextualitat und Gedachtnisstiftung - Umgrenzte Leere - Die Subversion der Literatur - In der Sprache der Tater - Fehlende Trauer - Jahrbuch fur Exilforschung 1997: Exil und Widerstand.

Los Angeles entwickelte sich nach Ausbruch des Zweiten Weltkriegs neben New York und Mexiko rasch zum fuhrenden Zentrum der deutschsprachigen Exilliteratur in der Neuen Welt — und damit auch zu einem der wichtigsten Arbeitsfelder fur die Uberwachung der schreibenden Nazifluchtlinge durch das FBI. Heinrich Mann und Franz Werfel flohen im September 1940 vor ihren siegreichen Landsleuten auf abenteuerlichen Wegen zu Fus uber die Pyrenaen in Richtung Los Angeles. Bertolt Brecht, fur den sich Hoovers G-Men besonders intensiv interessierten, nahm den kaum weniger gefahrlichen Weg durch Stalins Reich und uber Japan nach San Pedro, Kalifornien.1 Andere gerieten nur deshalb nach Hollywood, weil ihnen eines der grosen Filmstudios einen sogenannten Lebensrettervertrag angeboten hatte, der ihnen das U.S.-Visum und fur ein Jahr ein Auskommen brachte, aber — wie Ludwig Marcuse sich erinnert — keine befriedigende Aufgabe: »So sasen Heinrich Mann, Alfred Doblin, Leonhard Frank, Alfred Polgar, Walter Mehring in den Filmbetrieben; ohne Englisch zu konnen, ohne das Filmmachen zu kennen, voller Verachtung fur dies Gewerbe…«2 Manche brachte das milde Klima und die im Vergleich zu New York niedrigeren Lebenshaltungskosten nach Los Angeles. Wieder andere, Bruno Frank und eine Handvoll Schriftsteller, die das Schreiben von Drehbuchern fur die Filmindustrie beherrschten, waren bereits fruher in den Sudwesten der USA gezogen.

J. Edgar Hoovers G-Men kamen ungefahr zur gleichen Zeit in Mexiko an wie die von den Nazis aus Europa vertriebenen Exilanten — und begannen, sich sofort fur die als »Communazis« diffamierten Fluchtlinge zu interessieren. So teilt Hoover am 26. Mai 1940 — zwei Monate nachdem Bodo Uhse von Hollywood aus per Bus die amerikanisch-mexikanische Grenze bei Laredo, Texas, uberquert hatte — dem Prasidenten der USA mit, das er Vorbereitungen getroffen habe, einen seiner Special Agents nach Mexico City zu schik ken. Wenige Wochen spater — Uhse (»organizer of Stalin immigration into Mexico«1), Renn und andere bemuhten sich gerade mit einer 189 Namen umfassenden Liste bei den mexikanischen Behorden um die Rettung von Mitexilanten aus Sudfrankreich — richtete das FBI eine bis 1947 funktionierende, Special Intelligence Service (SIS) genannte Abteilung fur Lateinamerika ein. Als Egon Erwin Kisch, Otto Katz alias Andre Simone, Leo Katz und Gustav Regler im Herbst 1940 in Mexiko eintafen, hatte sich der SIS langst eine carde blanche fur die Uberwachung des deutschen Post- und Telegrammverkehrs bei den mexikanischen Behorden besorgt. Und fast auf den Tag genau — namlich im August 1941 — als der U.S. Naval Attache in der Dominikanischen Republik seinen Geheimdienstkollegen Einzelheiten uber die Reiseroute der Familie Radvanyi/Seghers von Ciudad Trujillo uber Martinique und New York nach Mexiko mitteilte, erhielt Hoovers Mann in Mexiko, Gus T. Jones, seine offizielle Akkreditierung als Civil Attache an der U.S.-Botschaft.2

Geheimdienste geben gewohnlich ihre Akten nicht freiwillig frei. Ware es anders, argumentieren die Nachrichtenprofis aller Lander, wurden Informationsquellen rasch versiegen, Spitzel verstummen und potentielle Gegner des jeweiligen Systems den Schleppnetzen der Sicherheitsorgane entgehen. Zudem stande eine Offnung der Akten, so die merkwurdige Logik der Geheimdienste, den Grundsatzen des Personenschutzes entgegen, weil Dossiers unweigerlich Angaben aus der Privatsphare von Untersuchungsgegenstanden, Informanten und Unbeteiligten enthalten. Oder anders gesagt: Ein Geheimdienst, der seine Arbeitsmethoden freiwillig offenlegt, verdient es nicht, seinen Namen zu tragen, denn er unterscheidet sich nicht mehr von anderen Behorden.

»I am very happy to have become an American«, bekannte der geburtige Osnabrucker Erich Maria Remarque im Jahre 1957 gegenuber der Zeitschrift Newsweek. »I have met exceedingly cultivated people in America. Americans have an innate sense of freedom…«1* Klaus Mann ging zusammen mit seiner Schwester Erika davon aus, das ein demokratisches, geeintes Nachkriegseuropa dem amerikanischen Modell zu folgen habe und meldete sich 1942 mit folgenden Worten bei der U.S.-Armee: »I want to notify you of my willingness, indeed, eagerness to join the United States forces… It is my honest desire to serve your country and our case in whatever capacity the Board may deem appropriate.«2 Die Kommunistin Anna Seghers wunschte sich 1940/41 im besetzten Frankreich nichts sehnlicher, als in die USA uberzusiedeln.3 Und selbst der eingefleischte Amerikafeind Brecht gestand in einer schwachen Minute zu, das die Amerikaner sich »freier, mit mehr Anmut bewegen« als die »deutschen Kleinburger« mit ihrem »verkniffenen neurotischen Wesen«, ihrer »Unterwurfigkeit« und ihrer »Uberheblichkeit«4.

New York und seine Einwandererinsel Ellis Island waren, wie fur 16.000.000 Immigranten in den funf vorhergegangenen Jahrzehnten, auch fur die relativ kleine Schar deutschsprachiger Hitlerfluchtlinge das Tor zur neuen Welt der USA. Eingerahmt wurde dieses Tor von der Skyline von Manhattan auf der einen und der Freiheitsstatue auf der anderen Seite. »Wunder grosartiger Schonheit«1, »ein dem Meer entstiegenes riesenhaftes, phantastisches Gewachs«2, »Druse eines nadelschlanken, nadelscharfen Kristalls«3, so beschreiben Arnold Brecht, Leonhard Frank und Vicki Baum die zugleich faszinierende und fremdartige Anhaufung von Wolkenkratzern.4 Furchteinflosend wirkte das Gebirge der Gebaudeketten auf Fritz Kortner5, wahrend der durchreisende Bruno Frei in den Buroturmen ein Symbol »demokratischer Geschaftigkeit«6 und eine Perversion des menschlichen Freiheitsdranges sah.

We demonstrate that the amplified spontaneous emission (ASE) threshold in multilayer waveguide structures suitable for the use in future organic injection lasers can be drastically reduced by inserting a crosslinked hole transport layer (HTL) between a highly conductive indium tin oxide (ITO) electrode and the polymer emission layer. While no ASE is observed when the active layer material is directly spincoated onto the ITO electrode, it can be completely restored upon insertion of a 300-nm-thick HTL. This observation is attributed to reduced attenuation of the waveguided mode enabling the ASE process and is theoretically confirmed by calculations of the mode intensity fraction propagating in the absorptive ITO electrode.

Stephan, Alexander, ed. Themes and Structures: Studies in German Literature from Goethe to the Present. A Festschrift for Theodore Ziolkowski. Columbia, S.C.: Camden House, 1997.332 pp. $75.00 hardcover. There may be few American Germanists more worthy of a Festschrift than Theodore Ziolkowski. His prolific scholarship and careful mentoring of students have long and profoundly enriched the field of Germanics. The essays in this volume, like those of the honoree, address important scholarly issues in a carefully argued manner and are written in lucid, cohesive prose. Presented in chronological order, the essays, written by Ziolkowski's former students, deal with a very wide range of topics and writers from the Age of Goethe to the present. Atherton interprets the ambiguity of Winkelmann's "edle Einfalt and stille Grosse" through reference to the competing aestheticliterary and art-historical contexts available to Winkelmann at the time. Wetzels provides instances of the popularization of physics as it is carried out between a mentor and his female pupil. In a fine analysis of the various occurrences of "Die Metamorphose der Pflanzen," Muenzer elaborates the classical Goethean hermeneutic, which brings the "voice of poetry" into the "conversation of mankind" such that the core of the familiar is passed into the frame of discovery. Herbst argues that Goethe was a more systematic, serious and sympathetic observer of the contemporary political scene than he is often given credit for. Mayer delineates F. Schlegel's failed attempt at a new cosmography that could reconcile idealism and Christianity in Theorie der Entstehung der Welt. Finger presents a sensitive and technically sound reading of the poetry of Rickert as it was set to music by Schubert, Schumann and Mahler. Hanson explores how the mystical blend of physics and metaphysics in Steffens's thinking finds its way into Tieck's Runeberg as the individual quest for permanence. In a fascinating reading of Keller's "Romeo and Julia," Johnston relates how the would-be painter Keller structures his tale and reveals his characters' emotional states through the application of Portal's classic nineteenth-century study of color, De couleurs symbolique (1837). Tatar reveals that not only Jack the Ripper in his murder of Lulu, but also the playwright Frank Wedekind in his relationship with his wife Tilly, provide both a critique of the repressive social structure and also a reinforcement of the social order and preservation of gender hierarchies. Providing evidence from medieval sources, Des Knaben Wunderhorn, internal acoustical and stylistic analogies, Tunstall concludes that Hofmannsthal's "Die Beiden" is a symbolic reflection of the canzone form. …