The reaction pi N to pi pi N in a meson-exchange approach

A resonance model for two-pion production in the pion-nucleon reaction is developed that includes information obtained in the analysis of pion-nucleon scattering in a meson-exchange model. The baryonic resonances Delta(1232), N*(1440), N*(1520), N*(1535), and N*(1650) are included. The model reproduces the total cross sections up to kinetic energies of the incident pion of 350 MeV and obtains the shapes of the differential cross sections in reasonable agreement with the data.Comment: 7 pages, 7 figures, 2 table

Nuclear Photoabsorption at Photon Energies between 300 and 850 Mev

We construct the formula for the photonuclear total absorption cross section using the projection method and the unitarity relation. Our treatment is very effective when interference effects in the absorption processes on a nucleon are strong. The disappearance of the peak around the position of the $D_{13}$ resonance in the nuclear photoabsorption can be explained with the cooperative effect of the interference in two-pion production processes,the Fermi motion, the collision broadenings of $\Delta$ and $N^*$, and the pion distortion in the nuclear medium. The change of the interference effect by the medium plays an important role.Comment: 22pages,7figures,revtex

Briseis' und Deidamias Briefe an Achill - die Stimmen stummer Frauen

Die vergleichende Analyse der Briefe Briseis Achilli und Deidamia Achilli soll die Verarbeitung der ovidischen antiken Vorlage in der mittelalterlichen Imitation aufzeigen. Erstmals wird eine deutsche Übersetzung der mittelalterlichen Versepistel veröffentlicht. Die Analyse erfolgt mit Hilfe eines Zeilenkommentars der beiden Versepisteln. Die Untersuchung beider Texte kann jene Vermutung, dass es sich um eine Ovid – Nachbildung handelt, aufgrund zahlreicher formaler und inhaltlicher Parallelen sowie unzähliger Reminiszenzen erhärten. Gleichzeitig hat sich auch der christliche Einfluss, der auf die heidnische Vorlage eingewirkt hat, deutlich herauskristallisiert. Damit ist das anonyme Werk in die Reihe jener Ovid – Imitationen einzuordnen, die ovidisches Gedankengut für den Ausdruck christlicher Denkweisen gebrauchen

Machine Learning Techniques and Optical Systems for Iris Recognition from Distant Viewpoints

Vorhergehende Studien konnten zeigen, dass es im Prinzip möglich ist die Methode der Iriserkennung als biometrisches Merkmal zur Identifikation von Fahrern zu nutzen. Die vorliegende Arbeit basiert auf den Resultaten von [35], welche ebenfalls als Ausgangspunkt dienten und teilweise wiederverwendet wurden. Das Ziel dieser Dissertation war es, die Iriserkennung in einem automotiven Umfeld zu etablieren. Das einzigartige Muster der Iris, welches sich im Laufe der Zeit nicht verändert, ist der Grund, warum die Methode der Iriserkennung eine der robustesten biometrischen Erkennungsmethoden darstellt. Um eine Datenbasis für die Leistungsfähigkeit der entwickelten Lösung zu schaffen, wurde eine automotive Kamera benutzt, die mit passenden NIR-LEDs vervollständigt wurde, weil Iriserkennung am Besten im nahinfraroten Bereich (NIR) durchgeführt wird. Da es nicht immer möglich ist, die aufgenommenen Bilder direkt weiter zu verabeiten, werden zu Beginn einige Techniken zur Vorverarbeitung diskutiert. Diese verfolgen sowohl das Ziel die Qualität der Bilder zu erhöhen, als auch sicher zu stellen, dass lediglich Bilder mit einer akzeptablen Qualität verarbeitet werden. Um die Iris zu segmentieren wurden drei verschiedene Algorithmen implementiert. Dabei wurde auch eine neu entwickelte Methode zur Segmentierung in der polaren Repräsentierung eingeführt. Zusätzlich können die drei Techniken von einem "Snake Algorithmus", einer aktiven Kontur Methode, unterstützt werden. Für die Entfernung der Augenlider und Wimpern aus dem segmentierten Bereich werden vier Ansätze präsentiert. Um abzusichern, dass keine Segmentierungsfehler unerkannt bleiben, sind zwei Optionen eines Segmentierungsqualitätschecks angegeben. Nach der Normalisierung mittels "Rubber Sheet Model" werden die Merkmale der Iris extrahiert. Zu diesem Zweck werden die Ergebnisse zweier Gabor Filter verglichen. Der Schlüssel zu erfolgreicher Iriserkennung ist ein Test der statistischen Unabhängigkeit. Dabei dient die Hamming Distanz als Maß für die Unterschiedlichkeit zwischen der Phaseninformation zweier Muster. Die besten Resultate für die benutzte Datenbasis werden erreicht, indem die Bilder zunächst einer Schärfeprüfung unterzogen werden, bevor die Iris mittels der neu eingeführten Segmentierung in der polaren Repräsentierung lokalisiert wird und die Merkmale mit einem 2D-Gabor Filter extrahiert werden. Die zweite biometrische Methode, die in dieser Arbeit betrachtet wird, benutzt die Merkmale im Bereich der die Iris umgibt (periokular) zur Identifikation. Daher wurden mehrere Techniken für die Extraktion von Merkmalen und deren Klassifikation miteinander verglichen. Die Erkennungsleistung der Iriserkennung und der periokularen Erkennung, sowie die Fusion der beiden Methoden werden mittels Quervergleichen der aufgenommenen Datenbank gemessen und übertreffen dabei deutlich die Ausgangswerte aus [35]. Da es immer nötig ist biometrische Systeme gegen Manipulation zu schützen, wird zum Abschluss eine Technik vorgestellt, die es erlaubt, Betrugsversuche mittels eines Ausdrucks zu erkennen. Die Ergebnisse der vorliegenden Arbeit zeigen, dass es zukünftig möglich ist biometrische Merkmale anstelle von Autoschlüsseln einzusetzen. Auch wegen dieses großen Erfolges wurden die Ergebnisse bereits auf der Consumer Electronics Show (CES) im Jahr 2018 in Las Vegas vorgestellt

Was Tut Man Wen...: A TEACHING MANUAL

This work is formally titles as a Project.The focus of this project is on an area that appears to have been lacking in the teaching of German as a foreign language. The teaching of practical business knowledge and knowledge of everyday lifestyles has been limited to specific areas of study in most German language courses and related textbooks. The practical topics that have been covered in the German language classroom are those of value mainly to tourists.These topics are transportation, accommodation, shopping, and restaurants. Practical matters regarding finances and communication have been superficially covered. Therefore, the purpose of this project was to incorporate information on the finance and communication systems in Germany into a package for use in the foreign-language (FL) classroom. The major part of this project was the research conducted in Germany, and the preparation and the writing of the manual. The remainder of the project deals with a discussion on the relevance of the manual's content, the reasoning behind the manual's format, and use of the material in the manual and related authentic materials in the classroom. The information incorporated into the manual was gathered in Germany from interviews with personnel at each of the three institutions, from publications and forms used by each institution, and from trade magazines. The information in the manual is presented in a 'userfriendly' format in English. Relevant German terminology is provided in strategic locations to enable the reader to learn the concepts without being overwhelmed by the terminology. The reader's ability to speak German was also considered in the preparation of the manual. A basic grasp of German is desirable for the reader, however the information contained in the book can still be of use to people with no background in the German language. A draft of the manual's banking chapter was tested in a second-year German classroom, at the secondary school level. The test and its results are discussed in the theoretical portion of this work.NoneMaster of Arts (MA

Using shared needles for subcutaneous inoculation can transmit bluetongue virus mechanically between ruminant hosts

Bluetongue virus (BTV) is an economically important arbovirus of ruminants that is transmitted by Culicoides spp. biting midges. BTV infection of ruminants results in a high viraemia, suggesting that repeated sharing of needles between animals could result in its iatrogenic transmission. Studies defining the risk of iatrogenic transmission of blood-borne pathogens by less invasive routes, such as subcutaneous or intradermal inoculations are rare, even though the sharing of needles is common practice for these inoculation routes in the veterinary sector. Here we demonstrate that BTV can be transmitted by needle sharing during subcutaneous inoculation, despite the absence of visible blood contamination of the needles. The incubation period, measured from sharing of needles, to detection of BTV in the recipient sheep or cattle, was substantially longer than has previously been reported after experimental infection of ruminants by either direct inoculation of virus, or through blood feeding by infected Culicoides. Although such mechanical transmission is most likely rare under field condition, these results are likely to influence future advice given in relation to sharing needles during veterinary vaccination campaigns and will also be of interest for the public health sector considering the risk of pathogen transmission during subcutaneous inoculations with re-used needles

A cross-sectional survey of internet use among university students

The last 2~decades have seen an increase in the number of reports of excessive internet use. Therefore, this study aimed to examine internet use among university students to gain more insight into the novel phenomenon of addictive internet use (AIU). Data were collected by the means of an online questionnaire sent to 4391 students. Approximately 10% of the 4391 students could be included in the statistical analysis. Of those 483 students, almost all (99.2%) used the internet, and a quarter (24.8%) showed AIU. The students used the internet mostly for information searches, random browsing, social networking, and online shopping; however, AIU was seen most often in the areas of social networking, random browsing, information searches, gaming, and pornography. One in four of the respondents showed addictive behavior in at least one area of internet use. Students with AIU in the area of random browsing were significantly less far advanced in their studies than those without AIU, and well-being was significantly poorer across AIU groups than in those who did not show AIU. The study confirms the importance of AIU, as reflected in the high prevalence of AIU among the students and the significantly lower level of well-being in those with AIU. Undifferentiated consideration of AIU does not do justice to its various facets, and future research should consider all areas of internet use, with the aim to increase understanding of the underlying mechanisms of AIU and develop more differentiated treatment approaches

Other Helicobacters, gastric and gut microbiota

The current article is a review of the most important and relevant literature published in 2016 and early 2017 on non-Helicobacter pylori Helicobacter infections in humans and animals, as well as interactions between H. pylori and the microbiota of the stomach and other organs. Some putative new Helicobacter species were identified in sea otters, wild boars, dogs, and mice. Many cases of Helicobacter fennelliae and Helicobacter cinaedi infection have been reported in humans, mostly in immunocompromised patients. Mouse models have been used frequently as a model to investigate human Helicobacter infection, although some studies have investigated the pathogenesis of Helicobacters in their natural host, as was the case for Helicobacter suis infection in pigs. Our understanding of both the gastric and gut microbiome has made progress and, in addition, interactions between H. pylori and the microbiome were demonstrated to go beyond the stomach. Some new approaches of preventing Helicobacter infection or its related pathologies were investigated and, in this respect, the probiotic properties of Saccharomyces, Lactobacillus and Bifidobacterium spp. were confirmed

Dosimetric characteristics of 3D-printed and epoxy-based materials for particle therapy phantoms

Objective: 3D printing has seen use in many fields of imaging and radiation oncology, but applications in (anthropomorphic) phantoms, especially for particle therapy, are still lacking. The aim of this work was to characterize various available 3D printing methods and epoxy-based materials with the specific goal of identifying suitable tissue surrogates for dosimetry applications in particle therapy. Methods: 3D-printed and epoxy-based mixtures of varying ratios combining epoxy resin, bone meal, and polyethylene powder were scanned in a single-energy computed tomography (CT), a dual-energy CT, and a µCT scanner. Their CT-predicted attenuation was compared to measurements in a 148.2 MeV proton and 284.7 MeV/u carbon ion beam. The sample homogeneity was evaluated in the respective CT images and in the carbon beam, additionally via widening of the Bragg peak. To assess long-term stability attenuation, size and weight measurements were repeated after 6–12 months. Results: Four 3D-printed materials, acrylonitrile butadiene styrene polylactic acid, fused deposition modeling printed nylon, and selective laser sintering printed nylon, and various ratios of epoxy-based mixtures were found to be suitable tissue surrogates. The materials’ predicted stopping power ratio matched the measured stopping power ratio within 3% for all investigated CT machines and protocols, except for µCT scans employing cone beam CT technology. The heterogeneity of the suitable surrogate samples was adequate, with a maximum Bragg peak width increase of 11.5 ± 2.5%. The repeat measurements showed no signs of degradation after 6–12 months. Conclusion: We identified surrogates for soft tissue and low- to medium-density bone among the investigated materials. This allows low-cost, adaptable phantoms to be built for quality assurance and end-to-end tests for particle therapy.</p