Parameter analysis of the Glottal Area Waveform based on high-speed recordings within a synthetic larynx model

Der Titel meiner Dissertation lautet: Parameteranalyse der Glottal Area Waveform basierend auf Hochgeschwindigkeitsaufnahmen von synthetischen Larynxmodellen. Hintergrund und Ziele Die aktuellen diagnostischen Methoden im klinischen Alltag in Bezug auf Dysphonie beruhen fast ausschließlich auf dem Erfahrungsschatz des jeweiligen Untersuchers. Für eine detaillierte Diagnostik kann aktuell nicht auf verlässliche objektive Parameter zur Unterstützung des Untersuchers zurückgegriffen werden, da diese im Moment noch nicht ausgereift sind. In dieser Arbeit finden die Analyse und Beurteilung des künstlichen Kehlkopfmodells hinsichtlich einer korrekten Abbildung der Physiologie der menschlichen Phonation statt Die Entwicklung von synthetischen Stimmlippenmodellen unterstützt den Versuch objektive Parameter valider zu machen, da diese im Gegensatz zu menschlichen Probanden einige Vorteile in der Forschung aufweisen: besserer Zugang (sowohl in Bezug auf das Zeitmanagement, als auch auf die Untersuchung), bessere Reproduzierbarkeit und keine ethischen Verpflichtungen gegenüber den Modellen.. Doch um diese Vorteile nutzen zu können, müssen die synthetischen Modelle die menschlichen Stimmlippen so gut wie möglichen imitieren, wobei nur eine vereinfachte Version der Realität wiedergegeben werden kann. Methoden Diese Arbeit bezieht sich auf den Aufbau und die Modelle aus „Fluid-Structure-Acoustic Interaction during Phonation in a Synthetic Larynx Model“ von S. Kniesburges (2014). Wichtig für den Versuchsaufbau sind die Einschicht- und Mehrschichtmodelle, welche in verschiedenen Steifheitsgraden untersucht werden. Ebenfalls entscheidend ist der weitenverstellbare supraglottale Kanal und die einsetzbaren Taschenfalten. Diese einzelnen Komponenten beeinflussen die Phonation der Stimmlippen maßgeblich. Um die objektiven Parameter (fundamental frequency, shimmer, mean-jitter, jitter, harmonics-to-noise ratio [HNR], cepstral peak prominence [CPP] und maximum area declination [MADR]) der synthetischen Modelle mit denen der Physiologie menschlicher Stimmlippen zu vergleichen, werden verschiedene physiologische Datensätze herangezogen. Zusätzlich werden die Modelle und deren unterschiedliche Konfigurationen untereinander verglichen, um den Effekt der einzelnen variablen Komponenten auf die synthetischen Stimmlippen zu erkennen. Die unterschiedlichen Konstellationen der Modelle und deren daraus resultierenden Werte der objektiven Parameter sind im Anschluss mit denen der physiologischen Datensätze verglichen worden. Ergebnisse Zusammengefasst bilden die beobachteten synthetischen Stimmlippenmodelle die Physiologie nicht in jeder Hinsicht nach, jedoch vor allem die Werte der fundamental frequency, shimmer in percent, HNR und MADR eine hohe Übereinstimmung zur den physiologischen Datensätzen zeigen. Auffällig ist, dass die Werte der männlichen Datensätze stark mit den Werten der Ein- und Mehrschichtmodelle übereinstimmen. Vor allem in Bezug auf die fundamental frequency. Schlussfolgerungen Der Kontakt der Stimmlippen beim kompletten Glottisschluss weist in beiden synthetischen Modellen eine stabilere Stimmlippenschwingung auf. Sichtbar wird dies durch die Verringerung der Standardabweichung der fundamental frequency im Vergleich zu keinem Kontakt der Stimmlippen bei der Phonation. Ebenfalls wird bei der Betrachtung der HNR deutlich, dass der Einfluss des supraglottalen Kanaldurchmessers auf die Mehrschichtmodelle größer ist als auf die Einschichtmodelle. Dazu kommt, dass die Vergrößerung des supraglottalen Kanaldurchmessers zu einem schnelleren Schluss der Stimmritze in fast allen Modellen und Schwingungsmodi führt. Des Weiteren weisen die Ein- und Mehrschichtmodellen beim Einsetzen der Taschenfalten eine erhöhte Tonalität und Periodizität auf. Die synthetischen Stimmlippenmodelle bilden die physiologische menschliche Phonation valide ab, was anhand der Übereinstimmungen der objektiven Parameter von Modellen und Probanden zu erkennen ist

A comprehensive analysis of the importance of translation initiation factors for Haloferax volcanii applying deletion and conditional depletion mutants

Translation is an important step in gene expression. The initiation of translation is phylogenetically diverse, since currently five different initiation mechanisms are known. For bacteria the three initiation factors IF1 – IF3 are described in contrast to archaea and eukaryotes, which contain a considerably higher number of initiation factor genes. As eukaryotes and archaea use a non-overlapping set of initiation mechanisms, orthologous proteins of both domains do not necessarily fulfill the same function. The genome of Haloferax volcanii contains 14 annotated genes that encode (subunits of) initiation factors. To gain a comprehensive overview of the importance of these genes, it was attempted to construct single gene deletion mutants of all genes. In 9 cases single deletion mutants were successfully constructed, showing that the respective genes are not essential. In contrast, the genes encoding initiation factors aIF1, aIF2γ, aIF5A, aIF5B, and aIF6 were found to be essential. Factors aIF1A and aIF2β are encoded by two orthologous genes in H. volcanii. Attempts to generate double mutants failed in both cases, indicating that also these factors are essential. A translatome analysis of one of the single aIF2β deletion mutants revealed that the translational efficiency of the second ortholog was enhanced tenfold and thus the two proteins can replace one another. The phenotypes of the single deletion mutants also revealed that the two aIF1As and aIF2βs have redundant but not identical functions. Remarkably, the gene encoding aIF2α, a subunit of aIF2 involved in initiator tRNA binding, could be deleted. However, the mutant had a severe growth defect under all tested conditions. Conditional depletion mutants were generated for the five essential genes. The phenotypes of deletion mutants and conditional depletion mutants were compared to that of the wild-type under various conditions, and growth characteristics are discussed

A bottom-up continuum approach of crystal plasticity for the analysis of fcc microwires under torsion

The microstructural evolution of face‐centered cubic microwires is studied using a physical motivated, homogenized continuum model of crystal plasticity. The dislocation configuration in the three‐dimensional space is thereby described via a Continuum Dislocation Dynamics (CDD) theory including a dislocation source term. The resulting spatial distribution of dislocation densities and strain components are shown for a relaxation problem with torsional loading

Adapted teaching: a chance to reduce the effect of social origin? A comparison between Germany and Norway, using PIRLS 2011

Adapted teaching is associated with high hopes regarding its potential to meet heterogeneity in the classroom and has, as such, been anchored in nearly all federal school laws in Germany. As this is a fairly new, not yet fully implemented development that comes with a number of obstacles, an international comparison was conducted to estimate its capability of reducing social disparities in school, giving prospects of its potential development in Germany. For this, Norway was chosen since adapted teaching has a long tradition there. Using a multilevel structural equation model and data from PIRLS 2011, it is analysed whether adapted teaching reduces the effect that social origin has on reading achievement and self-concept in reading. (DIPF/Orig.)Dieser Beitrag greift die Frage des Herkunftseffekts und der kompensatorischen Interventionsmöglichkeiten von Schulen auf. Der Beitrag umfasst einen Ländervergleich anhand von in Deutschland und Norwegen repräsentativ erhobenen Daten, in dem zum einen das Ausmaß der Unterschiedlichkeit zwischen den beiden Ländern thematisiert wird und zum anderen auch die Grenzen von Sekundäranalysen für Ländervergleiche thematisiert werden. (DIPF/Orig.

Development and validation of a measurement-driven inter crystal scatter recovery algorithm with in-system calibration

In PET a high percentage of gamma photons being detected undergo Compton scattering in the scintillator. Scintillator blocks are often built from optically isolated crystals. Depending on the angle of incidence and the scintillator geometry this might lead to inter crystal scatter (ICS) events, where energy is deposited in two or more crystals in the detector, which common positioning and reconstruction algorithms cannot resolve. Therefore, ICS events worsen the spatial resolution and the signal-to-noise ratio in the reconstructed image. We want to address this challenge by recovering individual crystals from ICS events with their corresponding energy deposits. This information could ultimately be fed into an image reconstruction framework. In this work, we established an algorithm based on a detector that couples a readout channel to each crystal (one-to-one coupling), which combines a measurement-driven calibration and a fitting routine to achieve the recovery of crystal interactions from measured light patterns. Using Geant4 simulations, we validated and optimized this approach by comparing the recovered events to the simulation ground truth. We showed that, with the best performing algorithm versions, all correct crystals could be identified for 95-97% of the simulated events and the crystal energies as well as the event energy sum could be recovered adequately. For the event energy sum a deviation of less than 5% could be achieved for 96% of all events. Overall, the developed ICS recovery algorithm was successfully validated for one-to-one coupled detector. Future application for other detector configurations should be possible and will be investigated. Additionally, using the new crystal interaction information to determine the most likely first interaction crystal is being examined to improve efficiency and signal-to-noise ratio in the PET reconstruction.Comment: 18 pages, 10 figure

Comparison of different strategies to measure medication adherence via claims data in patients with chronic heart failure

Medication adherence correlates with morbidity and mortality in patients with chronic heart failure (CHF), but is difficult to assess. We conducted a retrospective methodological cohort study in 3,808 CHF patients, calculating adherence as proportion of days covered (PDC) utilizing claims data from 2010 to 2015. We aimed to compare different parameters’ influence on the PDC of elderly CHF patients exemplifying a complex chronic disease. Investigated parameters were the assumed prescribed daily dose (PDD), stockpiling, and periods of hospital stay. Thereby, we investigated a new approach using the PDD assigned to different percentiles. The different dose assumptions had the biggest influence on the PDC, with variations from 41.9% to 83.7%. Stockpiling and hospital stays increased the values slightly. These results queries that a reliable PDC can be calculated with an assumed PDD. Hence, results based on an assumed PDD have to be interpreted carefully and should be presented with sensitivity analyses to show the PDC's possible range

Towards Simulation-Data Science : A Case Study on Material Failures

Simulations let scientists study properties of complex systems. At first sight, data mining is a good choice when evaluating large numbers of simulations. But it is currently unclear whether there are general principles that might guide the deployment of respective methods to simulation data. In other words, is it worthwhile to target at “simulation-data science” as a distinct subdiscipline of data science? To identify a respective research agenda and to structure the research questions, we conduct a case study from the domain of materials science. One insight that simulation data may be different from other data regarding its structure and quality, which entails focal points different from the ones of conventional data-analysis projects. It also turns out that interpretability and usability are important notions in our context as well. More attention is needed to gather the various meanings of these terms to align them with the needs and priorities of domain scientists. Finally, we propose extensions to our case study which we deem necessary to generalize our insights towards the guidelines envisioned for “simulation-data science”