Practical concepts for the use of probabilistic methods in the structural analysis and reassessment of existing bridges - presentation of latest research and implementation

In structural engineering and bridge construction, probabilistic calculations are only performed in a few exceptional cases. The ability to directly use information from the existing structure is an important advantage of probabilistic methods. Geometric data or the position and quantity of the installed reinforcing steel and tendons can be measured. Results from monitoring of the traffic can be used to generate structure-specific load models. Many clients are still very sceptical about the results of probabilistic calculations, even though there are several examples of successful application. The use of probabilistic verification formats is explicitly permitted by the German guideline for the assessment of existing bridges (German: Nachrechnungsrichtlinie). Since a high degree of special knowledge is required for the application of probabilistic calculations, it is difficult to establish the potential of this verification method in practice. It is necessary to enable the practical engineer to utilize the advantages of probabilistic calculations and to include the actual structural conditions into the calculation model, but without the need for all the special knowledge. Structure-specific partial safety factors include measured data and can be used for the well-known and in the codes established semi-probabilistic design concept. The authors present examples for the successful application of probabilistic methods and of data measurement during the reassessment of two existing bridges in Germany. The capabilities of full-probabilistic calculations for the reassessment of existing structures are described and concepts for the calculation of structure-specific partial safety factors are shown

SonoNet: Real-Time Detection and Localisation of Fetal Standard Scan Planes in Freehand Ultrasound

Identifying and interpreting fetal standard scan planes during 2D ultrasound mid-pregnancy examinations are highly complex tasks which require years of training. Apart from guiding the probe to the correct location, it can be equally difficult for a non-expert to identify relevant structures within the image. Automatic image processing can provide tools to help experienced as well as inexperienced operators with these tasks. In this paper, we propose a novel method based on convolutional neural networks which can automatically detect 13 fetal standard views in freehand 2D ultrasound data as well as provide a localisation of the fetal structures via a bounding box. An important contribution is that the network learns to localise the target anatomy using weak supervision based on image-level labels only. The network architecture is designed to operate in real-time while providing optimal output for the localisation task. We present results for real-time annotation, retrospective frame retrieval from saved videos, and localisation on a very large and challenging dataset consisting of images and video recordings of full clinical anomaly screenings. We found that the proposed method achieved an average F1-score of 0.798 in a realistic classification experiment modelling real-time detection, and obtained a 90.09% accuracy for retrospective frame retrieval. Moreover, an accuracy of 77.8% was achieved on the localisation task.Comment: 12 pages, 8 figures, published in IEEE Transactions in Medical Imagin

The impact of cognitive reserve on delayed neurocognitive recovery after major non-cardiac surgery: an exploratory substudy

IntroductionDelayed neurocognitive recovery is a common and severe complication after surgery and anesthesia with an adverse impact on daily living, morbidity, and mortality. High cognitive reserve may mitigate the development of delayed neurocognitive recovery, however, supporting data is lacking. We aimed to assess the association between cognitive reserve and delayed neurocognitive recovery in the early postoperative period.MethodsThis is a substudy of two prospective observational studies. Adult patients undergoing elective major non-cardiac surgery, who were fluent in German, were eligible for study participation. Patients with any pre-existing central nervous system disorders were excluded. Cognitive reserve was assessed using the Cognitive Reserve Index questionnaire. Delayed neurocognitive recovery was defined as a decline in cognitive function compared with baseline assessments and was evaluated with a battery of neuropsychological tests on the day of hospital admission and between day three post procedure and before hospital discharge.ResultsA total of 67 patients with a median age of 67 [IQR: (63–73)] years were included in our analysis. We found delayed neurocognitive recovery in 22.4% of patients. There was a significant association between Cognitive Reserve Index questionnaire total score and the occurrence of delayed neurocognitive recovery in the early postoperative period [OR = 0.938, (95% CI, 0.891; 0.988), p = 0.015].ConclusionHigher cognitive reserve in elderly patients undergoing major non-cardiac surgery decreases the risk for subsequent delayed neurocognitive recovery in the early postoperative period

Analysis of Osteosarcoma Cell Lines and Patient Tissue Using a 3D In Vivo Tumor Model—Possible Effects of Punicalagin

Osteosarcomas are the most common primary malignant bone tumors and mostly affect children, adolescents, and young adults. Despite current treatment options such as surgery and polychemotherapy, the survival of patients with metastatic disease remains poor. In recent studies, punicalagin has reduced the cell viability, angiogenesis, and invasion in cell culture trials. The aim of this study was to examine the effects of punicalagin on osteosarcomas in a 3D in vivo tumor model. Human osteosarcoma biopsies and SaOs-2 and MG-63 cells, were grown in a 3D in vivo chorioallantoic membrane (CAM) model. After a cultivation period of up to 72 h, the tumors received daily treatment with punicalagin for 4 days. Weight measurements of the CAM tumors were performed, and laser speckle contrast imaging (LSCI) and a deep learning-based image analysis software (CAM Assay Application v.3.1.0) were used to measure angiogenesis. HE, Ki-67, and Caspase-3 staining was performed after explantation. The osteosarcoma cell lines SaOs-2 and MG-63 and osteosarcoma patient tissue displayed satisfactory growth patterns on the CAM. Treatment with punicalagin decreased tumor weight, proliferation, and tumor-induced angiogenesis, and the tumor tissue showed pro-apoptotic characteristics. These results provide a robust foundation for the implementation of further studies and show that punicalagin offers a promising supplementary treatment option for osteosarcoma patients. The 3D in vivo tumor model represents a beneficial model for the testing of anti-cancer therapies

3D-MRI rendering of the anatomical structures related to acupuncture points of the Dai mai, Yin qiao mai and Yang qiao mai meridians within the context of the WOMED concept of lateral tension: implications for musculoskeletal disease

BACKGROUND: A conceptual model of lateral muscular tension in patients presenting thyroid associated ophthalmopathy (TAO) has been recently described. Clinical improvement has been achieved by using acupuncture on points belonging to the so-called extraordinary meridians. The aim of this study was to characterize the anatomical structures related to these acupuncture points by means of 3D MRI image rendering relying on external markers. METHODS: The investigation was carried out the index case patient of the lateral tension model. A licensed medical acupuncture practitioner located the following acupuncture points: 1) Yin qiao mai meridian (medial ankle): Kidney 3, Kidney 6, the plantar Kidney 6 (Nan jing description); 2) Yang qiao mai meridian (lateral ankle): Bladder 62, Bladder 59, Bladder 61, and the plantar Bladder 62 (Nan jing description); 3) Dai mai meridian (wait): Liver 13, Gall bladder 26, Gall bladder 27, Gall bladder 28, and Gall bladder 29. The points were marked by taping a nitro-glycerin capsule on the skin. Imaging was done on a Siemens Magnetom Avanto MR scanner using an array head and body coil. Mainly T1-weighted imaging sequences, as routinely used for patient exams, were used to obtain multi-slice images. The image data were rendered in 3D modus using dedicated software (Leonardo, Siemens). RESULTS: Points of the Dai mai meridian – at the level of the waist – corresponded to the obliquus externus abdominis and the obliquus internus abdominis. Points of the Yin qiao mai meridian – at the medial side of the ankle – corresponded to tendinous structures of the flexor digitorum longus as well as to muscular structures of the abductor hallucis on the foot sole. Points of the Yang qiao mai meridian – at the lateral side of the ankle – corresponded to tendinous structures of the peroneus brevis, the peroneous longus, and the lateral surface of the calcaneus and close to the foot sole to the abductor digiti minimi. CONCLUSION: This non-invasive MRI investigation has revealed the anatomical relations of acupuncture points belonging to 3 of the so-called extraordinary meridians. We conclude that the clinically developed "WOMED concept of lateral tension" is related to tendino-muscular structures

Evaluation of interactive visualization methods to compare multivariate heterogeneous time series

Zsfassung in dt. SpracheDiese Diplomarbeit untersucht verschiedene Methoden zum Vergleich multivariater Zeitreihen für den Anwendungsbereich Aktienmärkte. Die Daten werden in der Regel durch Nebeneinanderlegung oder durch Überlagerung verglichen. Aber schon eine ausreichend große Differenz zwischen den Preisen kann selbst einen recht einfachen Vergleich erschweren.Börsendaten sind nicht nur auf Aktien beschränkt. Sie umfassen auch Aktien (Markt-) Indizes wie den Dow Jones und NASDAQ. Aktienindizes besitzen eine eigene proprietäre Einheit, die der Einheit einer Aktie verschieden ist. Zeitreihen, die verschiedenen Einheiten haben werden auch als heterogen bezeichnet.Heterogene Daten werden oft durch Überlagerung mittels mehreren y-Achsen verglichen. Aber in den meisten Fällen ist die Anordnung der Achsen völlig willkürlich und Vergleiche sind oft irreführend. Jacques Bertin, ein Pionier im Bereich der Visualisierung, hat dieses Problem studiert.Ein Vorschlag ist, die Werte zu indizieren. Alle Werte werden entsprechend der prozentualen Veränderung bezogen auf den Basispunkt umgewandelt.Der erste Teil der Forschung beschäftigt sich mit der Identifikation von relevanten Methoden zum Vergleich von multivariaten Zeitreihen. Der Forschungsschwerpunkt ist die Evaluierung der Methode zum Vergleichen, welche auf einer Indizierung basiert. Ein weiterer wichtiger Forschungsteil ist die Untersuchung der verwendeten Skala einer Achse.Es werden die Unterschiede zwischen linearen und logarithmischen Skalen und deren Auswirkungen auf die Performance der Anwendungen analysiert.Der wichtigste Teil dieser Arbeit ist die vergleichende Studie über drei Methoden (Visualisierungs-Typen) zum visuellen Vergleich multivariater Zeitreihen. Die drei getesteten Methoden sind Nebeneinanderlegung, Überlagerung und Indexierung. 24 Probanden nahmen an der Studie teil.Jeder Teilnehmer mussten 14 Aufgaben für jede der drei Visualisierung-Typen ausführen. Die benötigte Zeit und die Richtigkeit wurden für jede Aufgabe gemes-sen und später für statistische Analysen verwendet.Die vorliegende Arbeit präsentiert aktuelle Forschungsthemen zu weiteren geeigneten Visualisierungen für visuelle Vergleiche. Der begleitende Prototyp zu dieser Arbeit umfasst die Darstellung von üblichen Aktienmarkt Visualisierungen wie Liniendiagramme, OHLC-Diagrammen und Candlestick-Diagrammen. Simple Vergleichsmethoden wie Nebeneinanderstellung und Überlagerung sind verfügbar. Eine fortgeschrittene Methode zum Verglei-chen basierend auf Indizierung wurde ebenfalls implementiert.Die Usability-Test Ergebnisse stützen die Annahme, dass die Indizierungs-Methode es dem Benutzer ermöglicht Vergleiche mit sehr viel weniger Fehlern bei der Schätzung von Werten durchzuführen. Die benötigte Zeit der Aufgabe wird dadurch nicht signifikant beeinflusst.Die freie Wahl des Indexierungspunktes macht Vergleiche für einen bestimmten Zeitraum effizienter und liefert genauere Ergebnisse. Eine Post-Test-Umfrage ergab, dass die Mehrheit der Teilnehmer die Indizierungs-Methode gegenüber den beiden anderen Visualisierungs-Typen bevorzugt. Die Testergebnisse für die Nutzung der verschiedenen Skalen zeigen, dass die Aufgaben schneller abgeschlossen wurden wenn logarithmischen Skalen verwendet wurden. Die Richtigkeit war nicht signifikant unterschiedlich zwischen linearen und logarithmischen Skalen.This master thesis explores various comparison methods for multivariate time series in the application area of stock markets. The data is usually compared by juxtaposition or by superimposition. But even a large enough difference between the price ranges can make a simple comparison of the data difficult.Stock market data is not limited to stocks. It also includes stock (market) indices such as the Dow Jones and NASDAQ. Stock indices have their own proprietary unit, which is different to the unit of a stock.Time series which have different units are also called heterogeneous data.To compare heterogeneous data by superimposition multiple y-axes are often used. But in most cases the arrangement of the axes makes comparisons between different variables completely arbitrary and comparisons are often misleading. The visualization pioneer Jacques Bertin has studied this problem. One suggestion is to index the values, which transforms all data into values which reflect the percent change compared to an indexing point.The first part of the research is concerned with the identification of relevant comparison methods for multivariate time series. The major part of the research deals with the evaluation of an advanced comparison method based on indexing. Another important part is the investigation of the importance of the used axis scale. Differences between linear and logarithmic scale are analyzed for effects on user performance.The major part of this work is a comparative study about three visual comparison methods (visualization types) for multivariate time series.The three tested comparison methods are juxtaposition, superimposition and indexing. 24 test persons participated in the study. Each participant had to complete 14 tasks for each one of the three visualization types. The task completion time and the task correctness for every task were measured and later used for statistical analyses.This work further presents state of the art research about other visualizations suited for visual comparison tasks. The prototype application incorporates several common stock market visualizations such as line charts, OHLC charts and candlestick charts. Basic comparison methods like juxtaposition and superimposition are available. A more advanced comparison method based on indexing was implemented. The usability test results support the assumption that the indexing method enables the user to perform comparison tasks with much less estimation errors. The task completion time is not significantly different. The free selection of the indexing point makes comparisons for a certain time period more effective and delivers more precise results. A post-test survey showed that the majority of the participants favor the indexing method over the two other visualization types. The test results for the usage of different scales indicate that tasks were faster completed when using logarithmic scales. The task correctness rate was not significantly different between linear and logarithmic scales.13