Data-Driven Methods for Low-Energy Nuclear Theory

The term data-driven describes computational methods for numerical problem solvingwhich have been developed by the field of data science; these are at the intersection of computer science,mathematics, and statistics. When applied to a domain science like nuclear physics, especially with the goalof deepening scientific insight, data-driven methods form a core pillar of the computational science endeavor.In this dissertation I explore two problems related to theoretical nuclear physics: one in the framework of numerical statistics, and the other in the framework of machine learning. I) Historically our understanding of the structure of the atomic nucleus, the quantum many-body problem, has been built upon many layersof approximation, since the computational complexity of the problems is so large. One of the most flexible and enduring models, the configuration-interaction shell model, allows for detailed calculations of arbitrary scope. I lay out a simple framework for uncertainty quantification in empirical shell model calculations,thus providing not only error bars for large-scale calculations, but also insight for theory optimization and experimental design. II) Nuclear cross sections are an integral component in many different applications including astrophysics and nuclear medicine,but descriptions of cross sections are often very ``data-heavy\u27\u27. Huge libraries consisting of cross section evaluations, a combination of experimental measurements and theoretical results, are dense with information and thus ripe for data-driven methods. I have developed a deep learning system to learn trends in cross sections across the nuclear landscape. This system can predict cross sections for any nuclide and also can be used as an ensemble predictor. This is to my knowledge the first generative adversarial model developed for analyzing trends in nuclear data libraries

Dysphagie

Zusammenfassung: Die Differenzialdiagnosen von Patienten mit Schluckbeschwerden sind vielfältig. Die ätiologische Abklärung betrifft Störungen der Passage flüssiger und fester Nahrung von der Mundhöhle bis in den distalen Ösophagus und erfordert daher die Anwendung von multidisziplinären diagnostischen Algorithmen. Eine oropharyngeale Dysphagie ist gekennzeichnet durch eine Bolustransportstörung im Rachenbereich, oft kombiniert mit Hustenanfällen, Aspiration oder nasaler Regurgitation. Häufig ist sie Ausdruck neurologischer oder muskulärer Störungen. Die ösophageale Dysphagie bezeichnet eine subjektiv empfundene Passagebehinderung für feste und flüssige Nahrung, häufig distal des Jugulums, und tritt in Kombination mit thorakalen Schmerzen, Regurgitationen, evtl. mit Husten und Aspirationen auf und muss bis zum Ausschluss einer malignen Genese abgeklärt werden. In dieser Übersicht werden neben der klinischen Symptomatik die Differenzialdiagnosen und gegenwärtige sowie neue Verfahren der Funktionsdiagnostik wie hochauflösende Manometrie und kombinierte ösophageale Mehrkanalimpedanzmessung zur zielgerichteten und präzisen Diagnostik der ösophagealen Dysphagie vorgestell

Gastroösophageale Refluxerkrankung

Zusammenfassung: Eine gastroösophageale Refluxerkrankunkung liegt vor, wenn der Übertritt von Mageninhalt in die Speiseröhre Symptome oder einen Schleimhautschaden verursacht. Die Säuresuppression mit Protonenpumpeninhibitoren (PPI) ist eine sichere und wirkungsvolle Therapie, verhindert aber keinen Reflux. Zwischen Refluxsymptomen, endoskopischen Befunden und der Säureexposition des Ösophagus besteht kein linearer Zusammenhang. Einige Patienten sprechen nicht auf die PPI-Therapie an, gastroskopisch ist die Speiseröhre oft normal, und auch in der pH-Metrie bleibt die Ursache der Symptome manchmal unklar. Obwohl die Säuresekretion wirkungsvoll unterdrückt werden kann, lässt sich der Reflux weit weniger gut beeinflussen. Neben typischen Refluxsymptomen werden auch Dysphagie, nichtkardiale Thoraxschmerzen und chronischer Husten mit einer gastroösophagealen Refluxerkrankung in Verbindung gebracht; allerdings ist schwierig abzuschätzen, welche Patienten von einer Antirefluxtherapie profitieren. Dies ist relevant, da das Risiko für die Entwicklung eines Adenokarzinoms des Ösophagus bei Patienten mit Refluxsymptomen und speziell bei Vorliegen einer Barrett-Mukosa erhöht ist. Diese Übersicht beschreibt, wie klinische und funktionsdiagnostische Befunde zu einer wirkungsvollen Therapie saurer und nichtsaurer Refluxepisoden beitragen könne

Obstipation

Zusammenfassung: Obstipation ist ein häufiges Symptom, das mit einer Vielzahl von Erkrankungen assoziiert oder auf strukturelle oder funktionelle Erkrankungen des Kolons zurückzuführen sein kann. Es kann zu einer starken Beeinträchtigung der Lebensqualität führen und verursacht hohe Kosten. Die Suche nach sekundären Ursachen einer Obstipation sollte erfolgen, wenn sich aus Anamnese oder Untersuchung entsprechende Hinweise ergeben. Vor Einleitung einer Therapie müssen Kolontransitzeitverzögerungen von Defäkationsstörungen sowie dem Reizdarmsyndrom abgegrenzt werden. Die idiopathische oder funktionelle chronische Obstipation spricht oft auf eine Umstellung der Lebens- und Ernährungsgewohnheiten sowie Quellmittel und Laxanzien an. Der Einsatz von Laktulose und Polyethylenglycol ist durch Studien gut belegt. Mit der Zulassung von Lubiproston und Methylnaltrexon stehen in Europa möglicherweise bald neue Substanzen zur medikamentösen Therapie der Obstipation zur Verfügung. Eine Biofeedbacktherapie ist bei Defäkationsstörungen die Therapie der Wahl. Sprechen die Patienten darauf nicht an, kann eine sakrale Neurostimulationstherapie oder in ausgewählten Fällen auch eine Operation indiziert sei

Sulfonyl-Substituted Heteroleptic Cyclometalated Iridium(III) Complexes as Blue Emitters for Solution-Processable Phosphorescent Organic Light-Emitting Diodes

The synthesis is reported of a series of blue-emitting heteroleptic iridium complexes with phenylpyridine (ppy) ligands substituted with sulfonyl, fluorine, and/or methoxy substituents on the phenyl ring and a picolinate (pic) ancillary ligand. Some derivatives are additionally substituted with a mesityl substituent on the pyridyl ring of ppy to increase solubility. Analogues with two ppy and one 2-(2′-oxyphenyl)pyridyl (oppy) ancillary ligand were obtained by an unusual in situ nucleophilic displacement of a fluorine substituent on one of the ppy ligands by water followed by N^O chelation to iridium. The X-ray crystal structures of seven of the complexes are reported. The photophysical and electrochemical properties of the complexes are supported by density functional theory (DFT) and time-dependent DFT calculations. Efficient blue phosphorescent organic light-emitting devices (PhOLEDs) were fabricated using a selection of the complexes in a simple device architecture using a solution-processed single-emitting layer in the configuration ITO/PEDOT:PSS/PVK:OXD-7(35%):Ir complex(15%)/TPBi/LiF/Al. The addition of a sulfonyl substituent blue-shifts the electroluminescence by ca. 12 nm to λmaxEL 463 nm with CIEx,y coordinates (0.19, 0.29), compared to the benchmark complex FIrpic (λmaxEL 475 nm, 0.19, 0.38) in directly comparable devices, confirming the potential of the new complexes to serve as effective blue dopants in PhOLEDs. Replacing a fluorine by a methoxy group in these complexes red shifts the PL and EL λmax by ca. 4–6 nm. The efficiency of the blue PhOLEDs of the sulfonyl-substituted complexes is, in most cases, significantly enhanced by the presence of a mesityl substituent on the pyridyl ring of the ppy ligands

On the Recognition of Fan-Planar and Maximal Outer-Fan-Planar Graphs

Fan-planar graphs were recently introduced as a generalization of 1-planar graphs. A graph is fan-planar if it can be embedded in the plane, such that each edge that is crossed more than once, is crossed by a bundle of two or more edges incident to a common vertex. A graph is outer-fan-planar if it has a fan-planar embedding in which every vertex is on the outer face. If, in addition, the insertion of an edge destroys its outer-fan-planarity, then it is maximal outer-fan-planar. In this paper, we present a polynomial-time algorithm to test whether a given graph is maximal outer-fan-planar. The algorithm can also be employed to produce an outer-fan-planar embedding, if one exists. On the negative side, we show that testing fan-planarity of a graph is NP-hard, for the case where the rotation system (i.e., the cyclic order of the edges around each vertex) is given

Differential metabolism of deoxyribonucleosides by leukaemic T cells of immature and mature phenotype

Experimental evidence has indicated that T lymphoblasts are more sensitive to deoxynucleoside toxicity than are B lymphoblasts. These data have led to the use of purine enzyme inhibitors as selective chemotherapeutic drugs in the treatment of T cell malignancies ranging from T cell acute lymphoblastic leukaemia to cutaneous T cell lymphomas. We have compared the toxicities of 2′-deoxyadenosine, 2′-deoxyguanosine, and thymidine for T cell lines derived from patients with T cell acute lymphoblastic leukaemia with those for mature T cell lines derived from patients with cutaneous T cell leukaemia/lymphoma. We have found that both deoxynucleosides are far less toxic to the mature T cell lies than to T lymphoblasts and that the mature cells accumulate much lower amounts of dATP and dGTP when exposed to deoxyadenosine and deoxyguanosine, respectively. Similar studies performed on peripheral blood cells from patients with T cell leukaemias of mature phenotype and on peripheral blood T cells demonstrate similar low amounts of deoxynucleotide accumulation. Measurements of the activities of several purine metabolizing enzymes that participate in deoxynucleoside phosphorylation or degradation do not reveal differences which would explain the toxicity of deoxynucleosides for immature, as compared to mature, T cells. We conclude that deoxynucleoside metabolism in leukaemic T cells varies with their degree of differentiation. These observations may be relevant to the design of chemotherapeutic regimes for T cell malignancies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72479/1/j.1365-2141.1985.tb04067.x.pd

American Society of Hematology 2020 guidelines for sickle cell disease: Prevention, diagnosis, and treatment of cerebrovascular disease in children and adults

BACKGROUND: Central nervous system (CNS) complications are among the most common, devastating sequelae of sickle cell disease (SCD) occurring throughout the lifespan.OBJECTIVE: These evidence-based guidelines of the American Society of Hematology are intended to support the SCD community in decisions about prevention, diagnosis, and treatment of the most common neurological morbidities in SCD.METHODS: The Mayo Evidence-Based Practice Research Program supported the guideline development process, including updating or performing systematic evidence reviews. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE evidence-to-decision frameworks, to assess evidence and make recommendations.RESULTS: The panel placed a higher value on maintaining cognitive function than on being alive with significantly less than baseline cognitive function. The panel developed 19 recommendations with evidence-based strategies to prevent, diagnose, and treat CNS complications of SCD in low-middle- and high-income settings.CONCLUSIONS: Three of 19 recommendations immediately impact clinical care. These recommendations include: use of transcranial Doppler ultrasound screening and hydroxyurea for primary stroke prevention in children with hemoglobin SS (HbSS) and hemoglobin Sβ0 (HbSβ0) thalassemia living in low-middle-income settings; surveillance for developmental delay, cognitive impairments, and neurodevelopmental disorders in children; and use of magnetic resonance imaging of the brain without sedation to detect silent cerebral infarcts at least once in early-school-age children and once in adults with HbSS or HbSβ0 thalassemia. Individuals with SCD, their family members, and clinicians should become aware of and implement these recommendations to reduce the burden of CNS complications in children and adults with SCD.</p

Dark Matter attempts for CoGeNT and DAMA

Recently, the CoGeNT collaboration presented a positive signal for an annual modulation in their data set. In light of the long standing annual modulation signal in DAMA/LIBRA, we analyze the compatibility of both of these signal within the hypothesis of dark matter (DM) scattering on nuclei, taking into account existing experimental constraints. We consider the cases of elastic and inelastic scattering with either spin-dependent or spin-independent coupling to nucleons. We allow for isospin violating interactions as well as for light mediators. We find that there is some tension between the size of the modulation signal and the time-integrated event excess in CoGeNT, making it difficult to explain both simultaneously. Moreover, within the wide range of DM interaction models considered, we do not find a simultaneous explanation of CoGeNT and DAMA/LIBRA compatible with constraints from other experiments. However, in certain cases part of the data can be made consistent. For example, the modulation signal from CoGeNT becomes consistent with the total rate and with limits from other DM searches at 90% CL (but not with the DAMA/LIBRA signal) if DM scattering is inelastic spin-independent with just the right couplings to protons and neutrons to reduce the scattering rate on xenon. Conversely the DAMA/LIBRA signal (but not CoGeNT) can be explained by spin-dependent inelastic DM scattering.Comment: 20 pages, 9 figure