Using Explainable AI to Understand Bond Excess Returns

Recent empirical evidence indicates that bond excess returns can be predicted using machine learning models. While the predictive power of machine learning models is intriguing, they typically lack transparency. We introduce SHapley Additive exPlanations (SHAP), a state-of-the-art explainable artificial technique, to open the black box of these models. Our analysis identifies the key determinants that drive the predictions of bond excess returns in machine learning models and how these determinants are related to bond excess returns. Thereby, our approach facilitates an in-depth interpretation of the predictions of bond excess returns made by machine learning models

Effekte extrakorporaler Stoßwellen an der mineralisierten Sehne des M.gastrocnemius des B.U.T.-Big-6 Truthahnes

Effekte extrakorporaler Stoßwellen analog der etablierten Erfahrungen mit der Stoßwellenapplikation bei der Desintegration von Verkalkungen der Tendinosis calcarea der Schulter sollten an Verkalkungen anderer Lokalisation, wie der Achillessehne, überprüft werden. Als Tiermodell diente die mineralisierte Gastrocnemiussehne des Truthahnes, die ein weit akzeptiertes Modell für Sehnenverkalkung darstellt. Nach in-vivo und in-vitro Versuchen konnte keine Desintegration der Verkalkungen bei den Gastrocnemiussehnen festgestellt werden, auch nicht bei Energieflußdichten vom doppelten der klinisch angewandten. Bei diesen hohen Energieflußdichten konnten allerdings Beeinträchtigungen in der Stabilität der Sehnen festgestellt werden, so daß von hohen, insbesondere aber ultrahohen Energieflußdichten, wie in der Literatur beschrieben, abgesehen werden sollte

Vergleich der präoperativen diagnostischen Genauigkeit in der Magnetresonanzmammografie der Brust und der Mammografie im Hinblick auf die Nachresektionsrate bei DCIS-Patientinnen

Ziel der Studie war es, den Stellenwert der KM-MRM für die Tumordiagnostik bei reinem DCIS bzgl. der exakten Größenausdehnung und der daraus resultierenden Empfehlungsgenauigkeit sowie die Auswirkung auf eine mögliche Senkung der Nachresektionsrate zu überprüfen. Retrospektiv wurden von 295 DCIS-Patientinnen (123 Pat. mit KM-MRM und MX vs. 172 Pat. alleinige MX) Bildgebung, Operationsverlauf und histologisches Ergebnis für eine vergleichende Studie ausgewertet. Die Sensitivität bzgl. der Ausdehnung der DCIS Tumore >44mm der KM-MRM liegt in unserer Studie bei 81,6% (0,6798-0,9124) höher als die der Mammografie mit 67,4% (0,5146-0,8092) in Gruppe A und 61,1% (0,4346-0,7686) in Gruppe B. Für Tumore <45mm gilt eine Sensitivität in der KM-MRM von 91,7% (0,8274-0,9688) sowie 90% (0,7819-0,9667) in der Mammografie in Gruppe A und 94,3% (0,8863-0,9768) in Gruppe B. Für die diagnostische Empfehlung bzgl. des therapeutischen Vorgehens (Ablatio ab DCIS >44mm oder Multizentrizität) zeigt ebenfalls die KM-MRM mit 87% deutlich höhere prädiktive Empfehlungswerte als die Mammografie (Gruppe A 64,2%; Gruppe B 81,4%). Auch zeigt sich die KM-MRM über alle Tumorgrößen und Gradings konstant in der Sensitivität der Größenbestimmung. Die der Mammografie nimmt mit größeren Tumoren und höherem Grading ab. Unter Berücksichtigung der diagnostischen Empfehlung würde sich die NR-Quote insbesondere durch die KM-MRM deutlich reduzieren. In Gruppe A von 43,1% auf 24,4%; Gruppe B von 41,3% auf 35,5%. Dies untermauert zugleich auch den diagnostischen Nutzen und die Aussagekraft einer durchgeführten KM-MRM in Hinblick auf die Sensitivität in der Größenbestimmung vor allem größerer DCIS-Tumoren was eine Reduktion der Nachresektionswahrscheinlichkeit impliziert. Der Einfluss des Patientenwunsches und die tatsächliche Operationsgenauigkeit sind als weitere Einflussfaktoren auf die Nachresektionswahrscheinlichkeit zu diskutieren

Patient Specific Instruments and Patient Individual Implants-A Narrative Review.

Joint arthroplasties are one of the most frequently performed standard operations worldwide. Patient individual instruments and patient individual implants represent an innovation that must prove its usefulness in further studies. However, promising results are emerging. Those implants seem to be a benefit especially in revision situations. Most experience is available in the field of knee and hip arthroplasty. Patient-specific instruments for the shoulder and upper ankle are much less common. Patient individual implants combine individual cutting blocks and implants, while patient individual instruments solely use individual cutting blocks in combination with off-the-shelf implants. This review summarizes the current data regarding the implantation of individual implants and the use of individual instruments

The Top Three Burning Questions in Total Hip Arthroplasty.

Total hip arthroplasty (THA) for end-stage osteoarthritis is one of the most effective surgical treatments in medicine. Impressive outcomes have been well documented in the literature with patients gaining ambulation and recovery of hip joint function. Nevertheless, there are still debatable issues and controversies that the orthopedic community has not been able to provide a definitive answer for. This review is focused on the current three most debatable issues surrounding the THA procedure: (1) new cutting-edge technology, (2) spinopelvic mobility, and (3) fast-track protocols. The scope of the herein narrative review is to analyze the debatable issues surrounding the three aforementioned topics and conclude the best contemporary clinical approaches regarding each issue

Dissociation of liner from cup in THA: does liner damage affect the risk of dissociation?

INTRODUCTION A rare catastrophic failure of modular component Total Hip Arthroplasty is dissociation between liner and cup, which has been associated with component malposition and/or impingement and seems to be more frequently associated with the Pinnacle system. The goal of this study was to evaluate the resistance of a polyethylene liner to lever-out-forces of the Pinnacle locking mechanism and the locking mechanisms of two other current cup/liner systems using a standardized testing method (ASTM). MATERIALS AND METHODS Five of each of the following cups were evaluated with their corresponding polyethylene liners: Pinnacle Multihole cup with and without intact anti-rotation tabs (ART's); Allofit-S-Alloclassic and Plasmafit Plus7 cups. The ASTM test set-up was used to evaluate the lever-out force resulting in liner dissociation for each construct. RESULTS The Pinnacle construct with intact ARTs required the greatest force (F) to achieve dissociation (263.2 ± 79.2 N) followed by the Plasmafit Plus7 (185.8 ± 36.9 N) and the Allofit-S (101.4 ± 35.3 N) constructs, respectively. However, after removal of the ARTs, the Pinnacle system required the least force to achieve dissociation (75.1 ± 22.2 N) (p < 0.001). CONCLUSIONS The intact Pinnacle system appeared the most stable in lever-out tests when compared to the other systems. However, after removal of the ARTs, the Pinnacle system required the least force for dissociation, consistent with locking mechanism failure, and suggesting that the ARTs are a critical component of the locking mechanism. Our findings are consistent with the clinical experience of dissociated Pinnacle constructs displaying damaged or missing ARTs, and that damage to these may increase risk of liner dissociation

Application of the reversed LISS-DF technique in an elderly patient to salvage infection-related failure of trochanteric fracture fixation.

Failure of cephalomedullary fixation in geriatric trochanteric fractures is a potential complication. Attempts have been made to optimize the implant fixation (e. g. cement augmentation) and several factors (e. g. malreduction, tip apex distance) have been identified as risk factors for failure. Nevertheless, if intramedullary fixation fails, it is often associated with bone defects in mostly preexisting poor bone-stock. Accordingly, conversion to total hip arthroplasty (THA) is recommended by some authors as the only valid treatment option. However, in specific situations (e. g. implant associated infection) conversion to THA might be less reasonable than an attempt to re-osteosynthesis. This article reports on the successful use of a reversed contralateral LISS-DF (LISS for the distal femur, DePuy Synthes, Zuchwil, Switzerland) application after failed cephalomedullary fixation and failed re-osteosynthesis using a blade plate in a trochanteric fracture in an elderly patient with additional implant associated infection

Parallel Structural Evolution of Mitochondrial Ribosomes and OXPHOS Complexes

The five macromolecular complexes that jointly mediate oxidative phosphorylation (OXPHOS) in mitochondria consist of many more subunits than those of bacteria, yet, it remains unclear by which evolutionary mechanism(s) these novel subunits were recruited. Even less well understood is the structural evolution of mitochondrial ribosomes (mitoribosomes): while it was long thought that their exceptionally high protein content would physically compensate for their uniquely low amount of ribosomal RNA (rRNA), this hypothesis has been refuted by structural studies. Here, we present a cryo- electron microscopy structure of the 73S mitoribosome from Neurospora crassa, together with genomic and proteomic analyses of mitoribosome composition across the eukaryotic domain. Surprisingly, our findings reveal that both structurally and compositionally, mitoribosomes have evolved very similarly to mitochondrial OXPHOS complexes via two distinct phases: A constructive phase that mainly acted early in eukaryote evolution, resulting in the recruitment of altogether approximately 75 novel subunits, and a reductive phase that acted during metazoan evolution, resulting in gradual length-reduction of mitochondrially encoded rRNAs and OXPHOS proteins. Both phases can be well explained by the accumulation of (slightly) deleterious mutations and deletions, respectively, in mitochondrially encoded rRNAs and OXPHOS proteins. We argue that the main role of the newly recruited (nuclear encoded) ribosomal- and OXPHOS proteins is to provide structural compensation to the mutationally destabilized mitochondrially encoded components. While the newly recruited proteins probably provide a selective advantage owing to their compensatory nature, and while their presence may have opened evolutionary pathways toward novel mitochondrion-specific functions, we emphasize that the initial events that resulted in their recruitment was nonadaptive in nature. Our framework is supported by population genetic studies, and it can explain the complete structural evolution of mitochondrial ribosomes and OXPHOS complexes, as well as many observed functions of individual proteins

Mobile R-wave detection system powered by a thermoelectric generator

In modern medicine, monitoring devices for mobile application are using rechargeable power supplies. A new concept refers to energy scavenging techniques using heat emission from human body. This project deals with the development of a prototype and the feasibility study of a thermal harvester. A thermoelectric generator enables the device to work self-sufficient on temperature gradients between skin and ambient conditions. This developed energy harvesting system converts human body heat into electrical energy. In combination with ultra-lowpower components autonomous operation should be possible. The system should enable an R-wave detection circuitry. If the temperature gradient is high enough, there is supposed to be no lack of power as in case of ordinary battery systems. A system combining thermal energy harvesting and signal processing is developed. To show the functions of the energy harvester corresponding measurements are performed. The signal processing unit is set up but not evaluated in concrete measurements