12 research outputs found

    Coherence Potentials: Loss-Less, All-or-None Network Events in the Cortex

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    Transient associations among neurons are thought to underlie memory and behavior. However, little is known about how such associations occur or how they can be identified. Here we recorded ongoing local field potential (LFP) activity at multiple sites within the cortex of awake monkeys and organotypic cultures of cortex. We show that when the composite activity of a local neuronal group exceeds a threshold, its activity pattern, as reflected in the LFP, occurs without distortion at other cortex sites via fast synaptic transmission. These large-amplitude LFPs, which we call coherence potentials, extend up to hundreds of milliseconds and mark periods of loss-less spread of temporal and amplitude information much like action potentials at the single-cell level. However, coherence potentials have an additional degree of freedom in the diversity of their waveforms, which provides a high-dimensional parameter for encoding information and allows identification of particular associations. Such nonlinear behavior is analogous to the spread of ideas and behaviors in social networks

    Fehlertolerante Regelung eines Asynchron-Doppelantriebes für ein Elektrospeicherfahrzeug

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    The nuclear export inhibitor aminoratjadone is a potent effector in extracellular-targeted drug conjugates.

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    The concept of targeted drug conjugates has been successfully translated to clinical practice in oncology. Whereas the majority of cytotoxic effectors in drug conjugates are directed against either DNA or tubulin, our study aimed to validate nuclear export inhibition as a novel effector principle in drug conjugates. For this purpose, a semisynthetic route starting from the natural product ratjadone A, a potent nuclear export inhibitor, has been developed. The biological evaluation of ratjadones functionalized at the 16-position revealed that oxo- and amino-analogues had very high potencies against cancer cell lines (e.g. 16R-aminoratjadone 16 with IC50 = 260 pM against MCF-7 cells, or 19-oxoratjadone 14 with IC50 = 100 pM against A-549 cells). Mechanistically, the conjugates retained a nuclear export inhibitory activity through binding CRM1. To demonstrate a proof-of-principle for cellular targeting, folate- and luteinizing hormone releasing hormone (LHRH)-based carrier molecules were synthesized and coupled to aminoratjadones as well as fluorescein for cellular efficacy and imaging studies, respectively. The Trojan-Horse conjugates selectively addressed receptor-positive cell lines and were highly potent inhibitors of their proliferation. For example, the folate conjugate FA-7-Val-Cit-pABA-16R-aminoratjadone had an IC50 of 34.3 nM, and the LHRH conjugate d-Orn-Gose-Val-Cit-pABA-16R-aminoratjadone had an IC50 of 12.8 nM. The results demonstrate that nuclear export inhibition is a promising mode-of-action for extracellular-targeted drug conjugate payloads

    Transnational Entanglements: Switzerland's Newly Emerging Literary Culture of the 1960s and the Anglophone World

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    In 1966, Emil Staiger, one of the most prominent literary scholars in literary studies of the postwar era, gave a talk on literature and the public. In his speech, which initiated what came to be known as the Zürcher Literaturstreit, Staiger developed a normative idea of literature as an agent of social cohesion. Around the same time, a new literary culture emerged in Switzerland, one which challenged Staiger's conception by exploring literature's critical potential. This article argues that this more modern direction taken by German Swiss literature was the result of transnational dynamics. Focusing on three examples of literature written by a new generation of Swiss authors (Walter, Federspiel, Bichsel), the article explores the various transnational alliances these authors built with modernist authors, mostly beyond the German‐speaking world, as a means of breaking with literary conventions. Leaving the logic of a national literary history behind, the article argues that seemingly local literary conflicts in 1960s Switzerland arose out of transnational dynamics
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