Coarse-to-fine partitioning of signals

An empirically acquired signal can be analyzed in a multi-scale framework. Its multi-scale structure induces a hierarchical partitioning of the signal domain into topologically meaningful segments. A method is proposed to operationalize this using elementary results from singularity theory for certain generic solutions of the one-dimensional heat equatio

Codomain scale space and regularization for high angular resolution diffusion imaging

Regularization is an important aspect in high angular resolution diffusion imaging (HARDI), since, unlike with classical diffusion tensor imaging (DTI), there is no a priori regularity of raw data in the co-domain, i.e. considered as a multispectral signal for fixed spatial position. HARDI preprocessing is therefore a crucial step prior to any subsequent analysis, and some insight in regularization paradigms and their interrelations is compulsory. In this paper we posit a codomain scale space regularization paradigm that has hitherto not been applied in the context of HARDI. Unlike previous (first and second order) schemes it is based on infinite order regularization, yet can be fully operationalized. We furthermore establish a closed-form relation with first order Tikhonov regularization via the Laplace transform

Telemonitoringtools und -scores in der pädiatrischen Allergologie

Hintergrund: Aktuelle Studien haben gezeigt, dass Telemedizin und Technologien aus dem Bereich digitaler Gesundheit die Patientenversorgung auf vielfältige Weise verbessern können. Auch das Fach der Allergologie ist davon nicht ausgenommen. Neben Technologien zur präziseren Diagnosestellung, kommen insbesondere patientennahen Entwicklungen eine besondere Bedeutung zu. Während unter Asthmapatienten eine deutlich gesteigerte Therapieadhärenz und ein verbessertes Disease Management durch Digital Health Technologien nachgewiesen werden konnte, stand dieser Beweis bis 2014 in Bezug auf allergische Rhinitis noch aus. Zielsetzung: Das Ziel meiner Doktorarbeit ist es, Anwendungsmöglichkeiten des digitalen Telemonitorings in der pädiatrischen Allergologie anhand von zwei Beispielen zu untersuchen und damit verbundene Chancen sowie Herausforderungen aufzuzeigen. Methodik: Für die zwei hier dargestellten Studien wurden jeweils unterschiedliche pädiatrische Patientengruppen rekrutiert. Für das Projekt „Allergymonitor“ wurden 63 Kinder und Jugendliche in Berlin sowie 105 ebenfalls pädiatrische Probanden in Italien und Deutschland Ascoli Piceno n=76, Berlin n=29) eingeschlossen. Alle Probanden litten an saisonaler allergischer Rhinokonjunktivitis. Während Patienten der Interventionsgruppe täglich den Schweregrad allergischer Symptome und ihren Medikamentenverbrauch über die Internetplattform „Allergymonitor“ aufzeichneten, folgte die Kontrollgruppe den standardmäßigen Therapieempfehlung des Allergologen ohne die Nutzung digitaler Anwendungen. Zu den Messzeitpunkten T1 und T2 wurde der tatsächliche Mometasonverbrauch ermittelt und mit der verordneten Menge von 0,190 g/d verglichen. Für die „BreathMonitor“-Studie wurden Kinder mit einer Obstruktion der unteren Atemwege im Alter von 3-72 Monaten rekrutiert. Während Probanden der Kontrollgruppe im Rahmen der regulären Therapie ein marktübliches Inhalationsgerät erhielten, wurde das gleiche Gerät für die Teilnehmer der Interventionsgruppe mit einem zusätzlichen Kompressor-Nasensauger („DuoBaby“) ausgestattet. Über einen Beobachtungszeitraum von 90 Tagen folgten die Eltern den Therapieempfehlungen des Kinderpneumologen inklusive des Gebrauchs des jeweiligen Gerätes und führten ein digitales Symptomtagebuch („BreathMonitor“). Ergebnisse: In der Berliner „Allergymonitor“-Studie konnte in der Interventionsgruppe eine höhere Therapieadhärenz (p=0.037) nachgewiesen werden. Des Weiteren fiel im Vergleich zur Kontrollgruppe ein verbessertes Krankheitsbewusstsein (p<0.001) auf. Hingegen wurden keine klinischen Unterschiede in Bezug auf den Schweregrad der Erkrankung festgestellt. Der longitudinale Verlauf der Symptom-Scores korrelierte mit den Graphen lokaler Pollenzählungen. Im Rahmen des „BreathMonitor“ Projektes wies die Interventionsgruppe im Vergleich zur Kontrollgruppe weniger Tage mit Atemwegssymptomen auf (pobere=0.004; puntere=0.022), was sich in der geringeren Anzahl der Salbutamol-Inhalationen (p<0.001) widerspiegelte. Schlussfolgerung: Beide Projekte zeigen, dass die Therapieadhärenz durch ein internet-basiertes Telemonitoring gesteigert werden kann. Die Untersuchung der klinischen Konsequenzen bedarf jedoch weiterer Forschung.Background: Recent studies have shown that telemedicine and digital health technologies can improve patient care in many ways. The field of allergology is not exempt from this. In addition to technologies for more precise diagnosis, developments close to the patient are of particular importance. While it has been possible to demonstrate a significant increase in therapy adherence and improved disease management among asthma patients through digital health technologies, this proof was still lacking in relation to allergic rhinitis until 2014. Objective: The aim of my thesis is to investigate application possibilities of digital telemonitoring in paediatric allergology using two examples and to highlight associated opportunities and challenges. Methodology: Different paediatric patient groups were recruited for each of the two studies presented here. For the "Allergymonitor" project, 63 children and adolescents in Berlin and 105 paediatric subjects in Italy and Germany (Ascoli Piceno n=76, Berlin n=29) were included. All subjects suffered from seasonal allergic rhinoconjunctivitis. While patients in the intervention group recorded the severity of allergic symptoms and their medication consumption daily via the internet platform "Allergymonitor", the control group followed the standard therapy recommendations of the allergist without using digital applications. At the measurement time points T1 and T2, the actual mometasone consumption was determined and compared with the recommended amount of 0.190 g/d. The control group followed the standard therapy recommendation of the allergist without using digital applications. Children with lower airway obstruction aged 3-72 months were recruited for the "BreathMonitor" study. While subjects in the control group received a commercially available inhaler as part of their regular therapy, the same device was fitted with an additional compressor nasal aspirator ("DuoBaby") for participants in the intervention group. Over an observation period of 90 days, the parents followed the therapy recommendations of the paediatric pneumologist including the use of the respective device and kept a digital symptom diary ("BreathMonitor"). Results: In the Berlin "Allergymonitor" study, a higher therapy adherence (p=0.037) could be proven in the intervention group. Furthermore, an improved disease awareness (p<0.001) was observed compared to the control group. However, no clinical differences were found with regard to the severity of the disease. The longitudinal course of the symptom scores correlated with the graphs of local pollen counts. In the "BreathMonitor" project, the intervention group had fewer days with respiratory symptoms compared to the control group (pupper=0.004; plower=0.022), which was reflected in the lower number of salbutamol inhalations (p<0.001). Conclusion: Both projects show that treatment adherence can be increased by internet-based telemonitoring. However, further research is needed to investigate the clinical consequences

Owning the Right to Migrate: A Proposal for Migration Corridors in the Greater Yellowstone Ecosystem

The Greater Yellowstone Ecosystem (GYE), one of the world’s most treasured regions, consists of an interconnected patchwork of federal, state, and private lands. The GYE’s elk, mule deer, and pronghorn antelope (pronghorn) rely on this vast range to complete their seasonal migrations, but development increasingly threatens this natural cycle. Moreover, the GYE’s existing wildlife management framework fails to resolve the tension between wildlife and growth, leaving both wildlife and local communities vulnerable. After reviewing the scope of the GYE’s ecological challenges, this Note proposes a new solution: a policy establishing affirmative easements across designated migration corridors in the GYE and granting ownership of the easements to the GYE’s elk, mule deer, and pronghorn herds. This proposal builds on the Rights of Nature movement by granting property rights to ungulate herds and identifying new strategies to overcome traditional barriers to standing in environmental lawsuits. This Note concludes by arguing that such an innovative proposal is not only possible but critical to preserving these keystone species and the open landscapes they rely on

Two canonical representations for regularized high angular resolution diffusion imaging

Two canonical representations for regularization of unit spherefunctions encountered in the context of high angular resolution diffusionimaging (HARDI) are discussed. One of these is based on spherical harmonicdecomposition, and its one-parameter extension via Tikhonov regularization.This case is well-established, and is mainly reviewed for thesake of completeness. The second one is new, and is based on a higherorder diffusion tensor decomposition. A homogeneous representation ofthis type has been proposed in the literature, but we show that thisis inconvenient for the purpose of regularization. We instead construct aheterogeneous representation that can be regarded as "canonical", to theextent that its behaviour under regularization mimics that of sphericalharmonics

A New Methodology for Multiscale Myocardial Deformation and Strain Analysis Based on Tagging MRI

Myocardial deformation and strain can be investigated using suitably encoded cine MRI that admits disambiguation of material motion. Practical limitations currently restrict the analysis to in-plane motion in cross-sections of the heart (2D + time), but the proposed method readily generalizes to 3D + time. We propose a new, promising methodology, which departs from a multiscale algorithm that exploits local scale selection so as to obtain a robust estimate for the velocity gradient tensor field. Time evolution of the deformation tensor is governed by a first-order ordinary differential equation, which is completely determined by this velocity gradient tensor field. We solve this matrix-ODE analytically and present results obtained from healthy volunteers as well as from patient data. The proposed method requires only off-the-shelf algorithms and is readily applicable to planar or volumetric tagging MRI sampled on arbitrary coordinate grids

Decomposition of higher-order homogeneous tensors and applications to HARDI

High Angular Resolution Diffusion Imaging (HARDI) holds the promise to provide insight in connectivity of the human brain in vivo. Based on this technique a number of different approaches has been proposed to estimate the ¿ber orientation distribution, which is crucial for ¿ber tracking. A spherical harmonic representation is convenient for regularization and the construction of orientation distribution functions (ODFs), whereas maxima detection and ¿ber tracking techniques are most naturally formulated using a tensor representation. We give an analytical formulation to bridge the gap between the two representations, which admits regularization and ODF construction directly in the tensor basis