Numerical and experimental modeling of atherosclerosis related to MRI

Bibliography: [appendix A-1 to A-2].This thesis was motivated by the idea of employing non-invasive investigations of atherosclerosis using Magnetic Resonance Imaging (MRI). MRI has the advantage of being able to detect atheroma in blood vessels with no risk to the patient but is still limited in its application to large blood vessels by the low geometrical resolution obtainable. The capability of MRI to measure velocities as well leads to the idea of correlating atheroma dimensions with measured velocities downstream of the blockage. This thesis makes a first step towards obtaining results that can be applied in investigations of atherosclerosis employing MRI. The fluid dynamics of arterial blood flow, the medical procedure of diagnosing and treating atherosclerotic diseases, and the physical principle of MRI are investigated to find out "if' and "how" the correlation between a blockage and the resulting downstream velocities can contribute to the diagnosis of atheroma. Parallel to this background research, experimental and numerical modeling of atheroma is carried out. These two approaches use identical geometrical and fluid parameters to enable a direct validation of the results. An experimental test-rig is designed. Experiments with different types of blockages are performed. The measured flow parameters are pressure and velocity profiles in a crosssection of the modeled artery. A commercial software package is employed for the numerical simulation of blockages with similar geometries to those used in the experiments. The pressure and absolute velocities are again the derived parameters. Both approaches are validated with analytical results obtainable for flow without any blockages. Blockages are then inserted and the results are compared and analyzed for their potential to contribute to the medical application. The results obtained with the two models give good correspondence. The transitional length of the laminar pipe flow corresponds very well to the expectations. A laminar velocity profile is completely built up before the fluid enters a blockage. Blockages with a small flow area cause a high peak velocity and a large wake. Blockages that slightly reduce the flow area have only a small influence on the flow. The length of a blockage has only a secondary influence on the downstream velocity distribution, while the influence of the surface roughness of the blockage is small. The peak velocities and pressure loss caused by the different blockages give good correlation. The prediction of the diameter of the blockage from peak velocities measured with MRI is an improvement on that which is possible from the theory only. In particular, the results obtained in this thesis show that the true maximum velocities are significantly lower than those obtained with theoretical predictions. The change in the velocity profiles, due to angioplasty, is shown in a simplified form with the models. Typical values of reduced areas before and after such surgery, where the atheroma is squeezed against the arterial walls, are analysed. The influence of the post-surgery blockage on the flow is very small, while the pre-surgery blockage shows a dominant influence. A prominent wake exists downstream of a highly reduced flow area, and high velocities occur. A wake is a potential risk area for atherosclerosis, as low shear rates and high turbulence intensities are possible. The blockage with the less reduced area has almost no influence on the flow, and a wake is hardly formed. The influence of different shapes of atheroma, while having a similar reduced area, is also demonstrated. The perfectly symmetrical blockage has less negative influence on the flow than one which is highly asymmetrical. The asymmetrical blockage causes a larger wake and higher maximum velocities

Evaluation der Datenbasis für die Flächennutzungsstatistik

Im Rahmen einer Studie zum Monitoring der Flächeninanspruchnahme werden seitens der EFTAS Fernerkundung Technologietransfer GmbH die einschlägigen Datengrundlagen für die Flächenerhebung (ALB, ALKIS) evaluiert. Geprüft werden Auswirkungen auf das Monitoring des sogenannten „30-ha-Ziels“, einem der Kernindikatoren der Nationalen Nachhaltigkeitsstrategie. Hiernach soll die tägliche Zunahme der Siedlungs- und Verkehrsflächen im Jahr 2020 maximal 30 ha betragen. Dieser Artikel beschreibt Zwischenergebnisse sowie Schlussfolgerungen aus Literaturrecherche, Expertengesprächen und eigenen Untersuchungen zur ALB/ALK-ALKIS-Migration. Die Ergebnisse lassen erkennen, dass das exakte Monitoring des 30-ha-Ziels während des Umstellungszeitraums vom ALB zum ALKIS schwierig ist. Zwar wirken sich die Artefakte über einen längeren Zeitraum aus, wodurch sie zum Teil nivelliert und Brüche abgemildert werden; gleichwohl gibt es erkennbare Auswirkungen

Micro Rapid Mapping: Automatic UAV-based Remote Sensing for Chemical Emergencies

In chemical emergencies, response units rely on the speedy provision of detailed information about the area affected by potentially hazardous substances in order to decide on efficient response actions. Unmanned Aerial Vehicles (UAVs) equipped with remote sensing equipment offer a flexible way of providing this information. Hence, these systems are becoming more and more interesting for firefighters and plant operators alike. Although having to actively control the UAVs makes high demands on the response squad in an already stressful situation, cyber-physical systems that allow the automatic deployment of UAVs have rarely been studied to date. We present and evaluate a system for planning UAV missions in emergency situations. We propose two different planning algorithms: (1) a mapping approach for covering the entire target area; (2) an algorithm that selects sensing locations across a wide area in order to allow quicker exploration. We verify the applicability in an extensive simulative study and demonstrate the information gain achieved, as well as the remaining uncertainty, after a flight, about the spatial phenomenon observed

Validation of retail food outlet data from a Danish government inspection database

BACKGROUND: Globally, unhealthy diet is one of the leading global risks to health, thus it is central to consider aspects of the food environment that are modifiable and may enable healthy eating. Food retail data can be used to present and facilitate analyses of food environments that in turn may direct strategies towards improving dietary patterns among populations. Though food retail data are available in many countries, their completeness and accuracy differ. METHODS: We applied a systematically name-based procedure combined with a manual procedure on Danish administrative food retailer data (i.e. the Smiley register) to identify, locate and classify food outlets. Food outlets were classified into the most commonly used classifications (i.e. fast food, restaurants, convenience stores, supermarkets, fruit and vegetable stores and miscellaneous) each divided into three commonly used definitions; narrow, moderate and broad. Classifications were based on branch code, name, and/or information on the internal and external appearance of the food outlet. From ground-truthing we validated the information in the register for its sensitivity and positive predictive value. RESULTS: In 361 randomly selected areas of the Capital region of Denmark we identified a total of 1887 food outlets compared with 1861 identified in the register. We obtained a sensitivity of 0.75 and a positive predictive value of 0.76. Across classifications, the positive predictive values varied with highest values for the moderate and broad definitions of fast food, convenience stores and supermarkets (ranging from 0.89 to 0.97). CONCLUSION: Information from the Smiley Register is considered to be representative to the Danish food environment and may be used for future research. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12937-022-00809-6

Big Data und Data-Mining im Umfeld städtischer Nutzungskartierung

Es ist festzustellen, dass die städtische Nutzungskartierung auf immer mehr Datenquellen zurückgreifen kann. Insbesondere handelt es sich um hochauflösende (Geo-)Daten von Fernerkundungsplattformen wie Satelliten aus dem Copernicus-Programm. Aber auch sogenannte Volunteer Geographic Information (VGI) spielen eine zunehmende Rolle. Speziell entwickelte Anwendungsprogramme, sogenannte „Apps“, kommen zum Sammeln solcher Rauminformationen in Frage. Und letztlich kommen Daten aus sozialen Netzwerken zum Tragen. Dieser Beitrag beschäftigt sich mit der Anwendung von Big Data im geo-temporalen Umfeld: Daten mit großen Volumina, die immer schneller in den Prozess gelangen, aus unterschiedlichsten Quellen stammen, unterschiedliche Informationsgehalte aufweisen und mit Unsicherheit behaftet sind. Sie liegen möglicherweise nicht flächendeckend vor, bieten mannigfaltige Bodenauflösungen, sind lückenhaft – dies sind alles Aspekte, die den gängigen Kriterien für „gute“ Daten widersprechen. Man wünscht sich flächendeckende, hochauflösende und hochaktuelle Daten. Der Vorteil bei der Nutzung von Big Data liegt nicht in der „Güte“, sondern in der massenhaften Verfügbarkeit. Der vorliegende Artikel ist als Werkstattbericht zu verstehen, der erste Ansätze in einem Anwendungsszenario zur Detektion sogenannter Intra-Urban Heat Islands, innerstädtischer Hitzeinseln, aufzeigt

Untersuchungen zur Nährstoffwirkung von Phosphor aus Klärschlamm- kompost

In einem Gefäß- sowie Praxisversuch wurde die Nährstoffwirkung von Phosphor aus Klärschlammkompost (KSK) untersucht. Dabei wurden unterschiedliche Mengen des Kompostes verwendet, um die Verfügbarkeit an Phosphor mit steigendem Einsatz von KSK zu prüfen. Im Praxisversuch wurden 0; 15 und 30 Vol. % in den obersten 30 cm Kultursubstrat verwendet. Im Gefäßversuch wurden neben den 0; 15 und 30 Vol. % auch 50 Vol. % KSK, sowie 5t Klärschlamm (KS) und 10 t KSK je ha ebenfalls in den obersten 30 cm Kultursubstrat eingebaut. Erste Ergebnisse der Projekte zeigten nach der Doppel-Lactat-Methode (DL), welche den pflanzenverfügbaren Phosphor (P2O5) anzeigt, Unterschiede. Im Gefäßversuch nahm mit steigendem Anteil an KSK auch der pflanzenverfügbare Phosphor (DL) zu. Im Praxisversuch stieg dieser nur von der 0 auf die 15 Vol. % Variante an. Im Vergleich der Varianten 15 und 30 Vol. % waren keine Unterschiede ersichtlich

Neue Zirkoniumcluster und Tetracyanidoboratverbindungen: Synthesen, Strukturen und Eigenschaften

Die Arbeit beschäftigt sich mit den Synthesen von oktaedrischen Zirkoniumclusterverbindungen auf lösemittelchemischem Wege und deren Strukturaufklärung mittels Einkristallröntgenstrukturanalyse. Das Hauptaugenmerk liegt auf Substitutionen der exoständigen Halogenidoliganden. Zusätzlich werden Tetracyanidoboratverbindungen mit Alkalimetallkationen (Na, K, Rb, Cs), die von Kronenethermolekülen ([15]-Krone-5, [18]-Krone-5, Dibenzo- [18]-Krone-6) koordinativ umgeben sind, vorgestellt und strukturell charakterisiert

Levantamento de mamíferos atropelados nos biomas brasileiros

Orientador: Prof. Dr. Fernando de Camargo PassosDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Zoologia. Defesa : Curitiba, 30/03/2022Inclui referênciasResumo: O Brasil é um dos países de maior riqueza de espécies do mundo, principalmente devido as particularidades de suas regiões biogeográficas. Com sua extensão continental, é essencial a existência de infraestruturas viárias para fluxo de pessoas e mercadorias entre as regiões. Todavia, a presença de rodovias gera diversos impactos diretos à biodiversidade, entre eles o atropelamento de fauna silvestre. Assim, este trabalho teve como objetivos a obtenção de dados a partir da literatura de mamíferos silvestres atropelados nos seis biomas brasileiros, a comparação da fauna afetada entre as regiões, a quantificação dos atropelamentos avaliando as proporções em que as espécies são atingidas, abordando as questões de vulnerabilidade e a necessidade de conservação frente aos atropelamentos. Foram realizadas pesquisas sistemáticas para a obtenção dos dados em sites com ferramentas de busca acadêmicas (Scopus, Google Acadêmico, SCIELO, Research Gate, Periódicos da CAPES e BDTD). Os dados obtidos foram organizados em tabelas, contendo a classificação dos animais, nome popular e científico, quantidade de atropelamentos e status de conservação da espécie no Brasil. Outros dados foram compilados quando julgados interessantes. Foram encontrados 115 trabalhos para os biomas da Amazônia, Caatinga, Cerrado, Pantanal, Mata Atlântica e Pampa. O bioma da Mata Atlântica foi o que apresentou o maior volume de trabalhos (41), seguido pelo Cerrado (34), Pampa (14), Amazônia (13), Caatinga (7) e Pantanal (7). A espécie mais afetada por atropelamento em infraestruturas viárias no país foi o Didelphis albiventris, o qual também foi o mais atropelado no bioma da Amazônia, Mata Atlântica e Pampa. O segundo mais impactado no Brasil foi o Cerdocyon thous, sendo o primeiro no Pantanal, na Caatinga e no Cerrado. Apesar destes animais não apresentarem riscos de extinção, são essenciais na dispersão de sementes e controle de pequenos animais. Se analisado a relação entre a riqueza total das espécies atropeladas e as espécies ameaçadas de extinção, as rodovias do Pantanal apresentam maiores riscos para as espécies ameaçadas, seguido da Caatinga, Amazônia, Cerrado, Mata Atlântica e Pampa. Os achados também reforçaram a escassez de pesquisas na área, principalmente em biomas tradicionalmente pouco estudados como a Caatinga e o Pantanal.Abstract: Brazil is one of the countries with the greatest richness of species in the world, mainly due to the particularities of its biogeographic regions. With its continental extension, the existence of road infrastructures for people flow and goods between regions is essential. However, the presence of highways generates several direct impacts on biodiversity, including the running over of wild fauna. Thus, this study aimed to obtain data from the literature on road-killed mammals in the six Brazilian biomes, the comparison of the affected fauna between the regions, and the quantification of roadkills evaluating the proportions in which the species are affected, addressing the questions of vulnerability and the need for conservation. Systematic research was carried out to obtain data on sites with academic search tools (Scopus, Google Scholar, SCIELO, Research Gate, CAPES Periodicals, and BDTD). The obtained data were organized in tables, containing the classification of the animals, popular and scientific names, number of roadkill, and conservation status of the species in Brazil and IUCN. Other data were compiled when deemed interesting. A total of 115 studies were found for the Amazon, Caatinga, Cerrado, Pantanal, Atlantic Forest, and Pampa biomes. The Atlantic Forest biome presented the highest volume of studies (41), followed by Cerrado (34), Pampa (14), Amazon (13), Caatinga (7), and Pantanal (7). The most affected species by being run over in the country was Didelphis albiventris, which was also the most run over in the Amazon, Atlantic Forest, and Pampa biomes. The second most impacted species in Brazil was Cerdocyon thous, being the first in the Pantanal, Caatinga, and Cerrado. Although these animals do not present risks of extinction, they are essential in seed dispersal and control of small animals. If analyzing the ratio between the total richness of the road-killed species and the endangered species, the highways of the Pantanal present greater risks for threatened species, followed by the Caatinga, Amazon, Cerrado, Atlantic Forest, and Pampa. The findings also reinforced the scarcity of research in the Road Ecology field, especially in biomes traditionally understudied such as the Caatinga and the Pantanal

Neue Zirkoniumcluster und Tetracyanidoboratverbindungen: Synthesen, Strukturen und Eigenschaften

Die Arbeit beschäftigt sich mit den Synthesen von oktaedrischen Zirkoniumclusterverbindungen auf lösemittelchemischem Wege und deren Strukturaufklärung mittels Einkristallröntgenstrukturanalyse. Das Hauptaugenmerk liegt auf Substitutionen der exoständigen Halogenidoliganden. Zusätzlich werden Tetracyanidoboratverbindungen mit Alkalimetallkationen (Na, K, Rb, Cs), die von Kronenethermolekülen ([15]-Krone-5, [18]-Krone-5, Dibenzo- [18]-Krone-6) koordinativ umgeben sind, vorgestellt und strukturell charakterisiert