Indirect methods of obtaining activity and mobility of structure-borne sound sources

The work reported in this thesis focuses on the development of indirect methods for the experimental determination of important source parameters for structure-borne sound source characterization. In the first part of the thesis, matrix inversion methods for the determination of blocked forces are investigated. A simplified measurement procedure is proposed which offers a solution to the two major challenges to these methods, namely the acquisition of the FRF matrix and the problems associated with matrix inversion. The proposed procedure involves a free, low-mobility receiver plate which is modelled numerically. Calculated FRFs are used together with measured velocity responses to inversely determine the blocked forces. It is found that while the method has great potential in principle, in practice the accurate modelling of the receiver plate is of critical importance. In the second part of the thesis, three formulations are considered for the indirect determination of source mobility. Instead of performing measurements on the source in the free state, the source mobility is obtained from measurements made in-situ. This approach is beneficial if the source is difficult to suspend, or if it contains non-linear structural elements. The three formulations are validated numerically and experimentally. It is found that the methods can quantify source mobilities of single-contact and multi-contact sources from in-situ measurements. However, typical measurement errors, such as background noise or inaccuracies in sensor positioning, can significantly reduce the accuracy and reliability of the methods. In the final part of the thesis, the reception plate method for the determination of the power injected by a high-mobility source into a low-mobility receiver is reviewed, and a source substitution method proposed as a development. The substitution method circumvents problems that may arise when the reception plate method is applied to coupled walls and floors. A special focus of investigation is on the calibration of the receiver structure. It is found that the calibration can be performed with shaker or hammer, and that an average calibration factor may be used. The source substitution method thus offers a potential alternative to the reception plate method, for application with coupled plates

Eutergesundheit in der ökologischen Milchviehhaltung – Einfluss von Laktatonsstadium und Laktationszahl auf die Behandlungsinzidenz klinischer Masttiden

Mastitis is one of the most important diseases in organic dairy farming. Therefore, it was the aim of this study to investigate the influence of stage of lactation and parity on mastitis risk in organic dairy cows. 43 German organic farms with German Holstein cows were selected via a questionnaire. These farms are being visited approximately every three months since 2005. Minimum herd size is 30 cows, and annual milk yield averages 6,277 kg/cow (min=3,175; max=9,653). During the farm visits, mastitis cases and treatments were extracted from farm records and data were processed using InterHerd©. The mean mastitis (treatment) incidence was 22 cases/100 cow years, which is comparable to incidences in organic farms reported elsewhere. 19 mastitis cases/100 cow years found in the dry-off-period was even lower than the incidence in other investigations on organic dairy farms. The highest incidence rate was found 0-7 days p.p. (mean=147 cases/100 cow years), and risk of mastitis increased with parity. Allopathic treatments were rather common in the farms surveyed (85% of treatments), indicating discrepancies in the implementation of organic farming objectives

Temporal muscle thickness is an independent prognostic marker in melanoma patients with newly diagnosed brain metastases.

OBJECTIVES: The purpose of this study was to evaluate the prognostic relevance of temporal muscle thickness (TMT) in melanoma patients with newly diagnosed brain metastases. METHODS: TMT was retrospectively assessed in 146 melanoma patients with newly diagnosed brain metastases on cranial magnetic resonance images. Chart review was used to retrieve clinical parameters, including disease-specific graded prognostic assessment (DS-GPA) and survival times. RESULTS: Patients with a TMT > median showed a statistically significant increase in survival time (13 months) compared to patients with a TMT < median (5 months; p < 0.001; log rank test). A Cox regression model revealed that the risk of death was increased by 27.9% with every millimeter reduction in TMT. In the multivariate analysis, TMT (HR 0.724; 95% 0.642-0.816; < 0.001) and DS-GPA (HR 1.214; 95% CI 1.023-1.439; p = 0.026) showed a statistically significant correlation with overall survival. CONCLUSION: TMT is an independent predictor of survival in melanoma patients with brain metastases. This parameter may aid in patient selection for clinical trials or to the choice of different treatment options based on the determination of frail patient populations

Real‐world outcomes using PD‐1 antibodies and BRAF + MEK inhibitors for adjuvant melanoma treatment from 39 skin cancer centers in Germany, Austria and Switzerland

Abstract Background Programmed death‐1 (PD‐1) antibodies and BRAF + MEK inhibitors are widely used for adjuvant therapy of fully resected high‐risk melanoma. Little is known about treatment efficacy outside of phase III trials. This real‐world study reports on clinical outcomes of modern adjuvant melanoma treatment in specialized skin cancer centers in Germany, Austria and Switzerland. Methods Multicenter, retrospective study investigating stage III–IV melanoma patients receiving adjuvant nivolumab (NIV), pembrolizumab (PEM) or dabrafenib + trametinib (D + T) between 1/2017 and 10/2021. The primary endpoint was 12‐month recurrence‐free survival (RFS). Further analyses included descriptive and correlative statistics, and a multivariate linear‐regression machine learning model to assess the risk of early melanoma recurrence. Results In total, 1198 patients from 39 skin cancer centers from Germany, Austria and Switzerland were analysed. The vast majority received anti PD‐1 therapies (n = 1003). Twelve‐month RFS for anti PD‐1 and BRAF + MEK inhibitor‐treated patients were 78.1% and 86.5%, respectively (hazard ratio [HR] 1.998 [95% CI 1.335–2.991]; p = 0.001). There was no statistically significant difference in overall survival (OS) in anti PD‐1 (95.8%) and BRAF + MEK inhibitor (96.9%) treated patients (p > 0.05) during the median follow‐up of 17 months. Data indicates that anti PD‐1 treated patients who develop immune‐related adverse events (irAEs) have lower recurrence rates compared to patients with no irAEs (HR 0.578 [95% CI 0.443–0.754], p = 0.001). BRAF mutation status did not affect overall efficacy of anti PD‐1 treatment (p > 0.05). In both, anti PD‐1 and BRAF + MEK inhibitor treated cohorts, data did not show any difference in 12‐month RFS and 12‐month OS comparing patients receiving total lymph node dissection (TLND) versus sentinel lymph node biopsy only (p > 0.05). The recurrence prediction model reached high specificity but only low sensitivity with an AUC = 0.65. No new safety signals were detected. Overall, recorded numbers and severity of adverse events were lower than reported in pivotal phase III trials. Conclusions Despite recent advances in adjuvant melanoma treatment, early recurrence remains a significant clinical challenge. This study shows that TLND does not reduce the risk of early melanoma recurrence and should only be considered in selected patients. Data further highlight that variables collected during clinical routine are unlikely to allow for a clinically relevant prediction of individual recurrence risk