17 research outputs found

    Analyse und Erweiterung einer Software zur statistischen Auswertung von Daten aus einem Krebsregister

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    Der Zuwachs medizinischen Wissens ist gewaltig, man spricht von einer Verdopplung in unter 10 Jahren[01], dies macht die Analyse historischer Daten zwingend erforderlich. Um dieses Wissen zu beherrschen werden Datenbanken benötigt, in denen man Krankheits- und Therapieverläufe ablegen kann, um diese dann anschließend unter unterschiedlichsten Anforderungen zu analysieren. Im Falle der Krebstherapie gibt es hierfür sogenannte Krebsregister. Hier werden anonymisierte Daten der Patienten gespeichert, wie zum Beispiel der Verlauf der Krankheit und die Therapie. Ziel ist es, dass alle Krebsfälle in irgendeinem Krebsregister gehalten werden. Dies soll zu einer Verbesserung der medizinischen Leistung am Patienten, sowie der Sicherstellung, dass Patienten überall mit neuesten Therapietechniken und Leistungen versorgt werden, führen. Leider werden die Informationen in den Krebsregistern viel zu wenig genutzt, da viele Ärzte und Wissenschaftler oft nicht Ausreichend vertiefte Kenntnisse in Informationstechnologie und/oder Statistik haben. Diese Tatsache macht es für sie schwierig die riesigen Datenmengen, die vorhanden sind, richtig zu analysieren. Um dieses Problem zu beheben kann man nun in regelmäßigen Abständen einen Statistiker beauftragen, der solche Analysen durchführt. Oft haben Ärzte aber statistisch wenig anspruchsvolle Anfragen oder es fällt ihnen erst auf, nachdem der Statistiker wieder gegangen ist. Solange es also eine solche Schwierigkeit darstellt, die Daten richtig zu analysieren, sind die Krebsregister ein Datenfriedhof, deren riesiges Potential nicht ausgenutzt wird. Dieser Zustand ist sowohl für Patienten, als auch für die Ärzte, nicht zufriedenstellend und bedarf dringend einer Änderung. Die Ziele sind: 1. Eine Analyse einer Software zur statistischen Auswertung von Daten aus einem Krebsregister (OCDM-Software), sowohl im Bezug auf ihre Software-Architektur, als auch auf ihre Funktion. 2. Das Erstellen einer Anforderungsanalyse, welche die Erweiterungen beschreibt, die an der oben erwähnten OCDM-Software vorzunehmen sind. 3. Die Umsetzung dieser Anforderungsanalyse in die bestehende Anwendung. 4. Ein abschließender Systemtest der Anwendung, um einen reibungslosen Ablauf im Klinikalltag zu gewährleisten. Ziel der Erweiterung ist es, den Ärzten die Analyse der gesammelten Patientendaten zum Pankreaskarzinom zu vereinfachen und somit die medizinische Betreuung in der Klinik zu verbessern

    Doppler refectometry in the TJ-II stellarator: design of an optimized Doppler reflectometer and its application to turbulence and radial electric field studies

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    For several decades magnetic confinement of high-temperature plasmas has been investigated with the objective of building a burning fusion reactor. One of the main obstacles in reaching this goal is the energy and particle losses caused by radial transport processes in the plasma. Therefore, the identification and reduction of this radial transport is a demanding challenge faced by theoretical and experimental physicists. The transport processes in toroidal plasmas can be grouped into two categories, i.e. neoclassical and turbulent transport. Neoclassical theory is an extension of classical theory to include the toroidal geometry of magnetic confinement fusion experiments, which results in new particle drifts and magnetic field mirror effects, which trap particles and lead to an increased collision frequency. Neoclassical transport is an ubiquitous process, since it depends on the existence of background gradients in the plasma and Coulomb collisions between particles. The second type of transport, turbulent or anomalous transport, is fundamentally different from neoclassical transport due to the fact that the described particle losses are caused by microinstabilities. These microinstabilities occur irregularly in the plasma, hence turbulent transport is an intermittent process rather than a continuous one. The particle and energy losses observed in toroidal fusion plasmas are believed to be mainly caused by turbulent transport, making it one of the dominant fields of investigation of the fusion community in the last few decades. Plasma turbulence can basically be described as the incoherent motion of the plasma which arises from small-scale fluctuations in parameters such as plasma density, tem- perature, potential, and the magnetic field. Gradients in the plasma parameters are the driving forces of the turbulence, which leads to the conclusion that the better the plasma confinement (stronger gradients), the higher the turbulence level. However, this is not completely true: the discovery of the H-mode confinement regime in 1982 showed that the plasma can spontaneously self-organize and enter a mode of improved confinement (L-H transition), characterized by a steepening of plasma gradients accompanied by a significant reduction of the level of fluctuations and turbulent transport. This discovery led to an immense effort, from both the theoretical and the exper- imental sides, in trying to understand the L-H transition and the reduced turbulence level in the H-mode confinement regime. After more than a quarter century of active research, the prevailing paradigm to explain the turbulence level reduction consists in turbulence suppression via sheared flows. However, although these flows are observed in H-mode plasmas, their generation mechanisms are still unknown. Several candidates involving the edge pressure gradient or turbulence driven mean and oscillating flows exist, but elucidation is still pending

    Interaction of Mean and Oscillating Plasma Flows Across Confinement Mode Transitions

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    A tightly regulated and adjustable CRISPR-dCas9 based AND gate in yeast

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    The robust and precise on and off switching of one or more genes of interest, followed by expression or repression is essential for many biological circuits as well as for industrial applications. However, many regulated systems published to date influence the viability of the host cell, show high basal expression or enable only the overexpression of the target gene without the possibility of fine regulation. Herein, we describe an AND gate designed to overcome these limitations by combining the advantages of three well established systems, namely the scaffold RNA CRISPR/dCas9 platform that is controlled by Gal10 as a natural and by LexA-ER-AD as heterologous transcription factor. We hence developed a predictable and modular, versatile expression control system. The selection of a reporter gene set up combining a gene of interest (GOI) with a fluorophore by the ribosomal skipping T2A sequence allows to adapt the system to any gene of interest without losing reporter function. In order to obtain a better understanding of the underlying principles and the functioning of our system, we backed our experimental findings with the development of a mathematical model and single-cell analysis

    Advances in turbulence measurements using new Correlation ECE and nT-phase diagnostics at ASDEX Upgrade

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    Guided by predictions from nonlinear gyrokinetic simulations, two new turbulence diagnostics were designed and installed at ASDEX Upgrade (AUG) to probe the fundamentals of ion-scale turbulent electron heat transport. The first, a 30-channel correlation ECE (CECE) radiometer (105-128 GHz, 2nd harmonic X-mode), introduces a novel channel comb arrangement. This allows measurements of high radial resolution profiles (0:5 < r/a < 0:8) of low-k (k⍬⍴s < 0:3) temperature fluctuation amplitudes, frequency spectra and radial correlation length profiles in unprecedented detail. The second diagnostic is formed by the addition of two W-band and one V-band X-mode reflectometers on the same line of sight as the CECE to enable measurements of the phase angle between turbulent density and temperature fluctuations. Historically, the radial alignment between reflectometer and radiometer has been a challenge due to the requirement that alignment is achieved within a radial correlation length (< 5 10 mm). This challenge is significantly alleviated by using the CECE channel comb arrangement and the maximal coherence between reflectometer and radiometer can be unambiguously captured. Measurements of these quantities have been made in an AUG L-mode plasma, at the same radial location and have provided simultaneous quantitative constraints on realistic gyrokinetic simulations [Physics of Plasmas 25, 055903 (2018)] using the gyrokinetic code GENE. Here we present diagnostic detail for this study

    Advances in turbulence measurements using new Correlation ECE and nT-phase diagnostics at ASDEX Upgrade

    Get PDF
    Guided by predictions from nonlinear gyrokinetic simulations, two new turbulence diagnostics were designed and installed at ASDEX Upgrade (AUG) to probe the fundamentals of ion-scale turbulent electron heat transport. The first, a 30-channel correlation ECE (CECE) radiometer (105-128 GHz, 2nd harmonic X-mode), introduces a novel channel comb arrangement. This allows measurements of high radial resolution profiles (0:5 < r/a < 0:8) of low-k (k⍬⍴s < 0:3) temperature fluctuation amplitudes, frequency spectra and radial correlation length profiles in unprecedented detail. The second diagnostic is formed by the addition of two W-band and one V-band X-mode reflectometers on the same line of sight as the CECE to enable measurements of the phase angle between turbulent density and temperature fluctuations. Historically, the radial alignment between reflectometer and radiometer has been a challenge due to the requirement that alignment is achieved within a radial correlation length (< 5 10 mm). This challenge is significantly alleviated by using the CECE channel comb arrangement and the maximal coherence between reflectometer and radiometer can be unambiguously captured. Measurements of these quantities have been made in an AUG L-mode plasma, at the same radial location and have provided simultaneous quantitative constraints on realistic gyrokinetic simulations [Physics of Plasmas 25, 055903 (2018)] using the gyrokinetic code GENE. Here we present diagnostic detail for this study

    Electron temperature fluctuation measurements with Correlation Electron Cyclotron Emission in L-mode and I-mode plasmas at ASDEX Upgrade

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    The Correlation Electron Cyclotron Emission (CECE) diagnostic at ASDEX Upgrade (AUG) is used to investigate the features of outer core and pedestal (ρpol = 0.85-1.0) turbulence across confinement regime transitions. The I-mode confinement regime is a promising operational scenario for future fusion reactors because it features high energy confinement without high particle confinement, but the nature of the edge and pedestal turbulence in I-mode plasmas is still under investigation. The edge Weakly Coherent Mode (WCM) appears in the I-mode pedestal and may play a role in transport. In this work we explore electron temperature (Te) fluctuations in the plasma outer core and pedestal using a 24-channel high radial resolution CECE radiometer. CECE measurements provide turbulence information including the Te fluctuation amplitude, turbulent spectra, and radial localization of turbulent features. With CECE measurements we show that the WCM is localized in the pedestal region in both L-mode and I-mode and is measured in optically thick plasmas with a Te fluctuation amplitude of 2.3%. Broadband drift wave turbulence is measured in the outer core with a Te fluctuation amplitude of <1%. A second CECE system recently installed at AUG allowed for non-standard fluctuation measurements during L-mode and I-mode experiments. The second CECE system was toroidally separated from the primary system, allowing measurements of the long-range toroidal correlation of the WCM indicating its low toroidal mode number. A reflectometer sharing a line of sight with the second CECE system enabled density-temperature cross-phase (αne Te ) measurements. The WCM αne Te changes between L-mode and I-mode as the Te gradient steepens
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