N=4 Supersymmetric AdS5 Vacua and their Moduli Spaces

We classify the N=4 supersymmetric AdS5 backgrounds that arise as solutions of five-dimensional N=4 gauged supergravity. We express our results in terms of the allowed embedding tensor components and identify the structure of the associated gauge groups. We show that the moduli space of these AdS vacua is of the form SU(1,m)/(U(1)x SU(m)) and discuss our results regarding holographically dual N=2 SCFTs and their conformal manifolds.Comment: 29 pages; v2: published versio

GROUND REACTION FORCES, REARFOOT MOTION AND WRIST ACCELERATION IN NORDIC WALKING

The aim of this study was to analyze loading parameters in nordic walking (NW) compared to ordinary walking (W) with respect to upper and lower limb injury risks. 24 licensed NW-instructors, 12 male and 12 female (38±13 years, 175±9 cm, 78±14 kg, BMI 25±3 kg/m2), performed W and NW trials on a runway covered with artificial turf. Walking speed was controlled by two photo cells. By using an electrogoniometer and a Kistler platform, pronation and ground reaction forces were measured. Wrist acceleration was quantified by an uniaxial accelerometer attached to processus styloideus radii of the right forearm. Statistical evaluation was done by ANOVA and post hoc t-tests (

Effects of functional anatomic pronator/supinator strength training for the stabilisation of the foot

In der vorliegenden Dissertation wurden die morphologischen und biomechanischen Effekte eines funktionell-anatomischen Pronatoren-/Supinatorenkrafttrainings (FPST) im Vergleich zu einem herkömmlichen Plantar-/Dorsalflexorentraining (PD) untersucht. Es wurde vermutet, dass sowohl die Peronealmuskeln als auch die Gruppe der tiefen Unterschenkelflexoren nach dem spezifischen Training in ihrer Hauptfunktionsebene als Fußstabilisatoren effektiver fungieren als nach der isolierten Beanspruchung um die obere Sprunggelenkachse. Hierfür wurden zunächst zwei Krafttrainingsmaschinen (FPSM), für die Pronatoren und Supinatoren des Fußes, gefertigt, deren Rotationsachsen mit der unteren Sprunggelenkachse korrespondierten (Inman, 1976). An 15 männlichen Sportstudenten wurden die winkelabhängigen isometrischen Pronations- und Supinationsmomente empirisch bestimmt. Da sich hoch signifikante Unterschiede in der Kraftkurvencharakteristik zwischen Pronatoren (aufteigend-absteigender Verlauf) und Supinatoren (rein aufsteigende Form) aufzeigten, wurden für die Interventionsstudie zwei verschieden geformte Exzenter in die Krafttrainingsmaschinen implementiert. 30 männliche Sportstudenten nahmen an der Interventionsstudie teil. In Prä- und Posttest wurden die maximalen isometrischen Pronations- und Supinationsmomente, das Pronationsverhalten beim Laufen (Elektrogoniometer) in 3,3m/s in zwei Schuhbedingungen (A= herkömmlicher Laufschuh; B= Laufschuh mit 6mm Außenranderhöhung) sowie das Reaktionsverhalten bei einer Umknicksimulation untersucht. Randomisiert wurden 22 Teilnehmer der Experimentalgruppe zugeteilt, die jeweils im Einsatztraining mit dem rechten Bein an der FPSM (FPST) und mit dem linken ein herkömmliches Plantar-/Dorsalflexorenstraining (PD) absolvierten. Die 8 Teilnehmer der Kontrollgruppe führten mit beiden Beinen ein unilaterales PD durch. Per MRT wurde vor und nach der Intervention das Muskelvolumen von 9 randomisiert ausgewählten Testpersonen der Experimentalgruppe bestimmt. Die Daten wurden mit Varianzanalysen mit Messwiederholung analysiert. Im intraindividuellen Vergleich zeigten sich spezifische Trainingseffekte nach FPST und PD (rechtes vs. linkes Experimentalbein). Im Vergleich zu PD führte FPST zu signifikant stärkeren Kraftzuwächsen der Pronatoren (14 % vs. 8 %, p<0,01) und Supinatoren (25 % vs. 12 %, p<0,01). Sowohl FPST als auch PD resultierte in einem erhöhten Supinationswinkel (FPST: p In der Umknicksimulation zeigte sich nach beiden Trainingmethoden ein reduziertes (FPST: -2 %; PD: -3 %; p Die Befunde verdeutlichen die verbesserte muskuläre Kontrolle des Sprunggelenkkomplexes nach Unterschenkelkrafttraining. Insbesondere funktionelles Supinatorentraining erweist sich als potentieller Schutzmechanismus gegen eine übermäßige Pronation für Läufer und sollte in die Prävention und Behandlung von Überlastungsschäden implementiert werden. Insbesondere wenn der Fuß in eine verstärkte Pronation gezwungen wird (Valgus-Keile) führt die gesteigerte Verspannung der Supinatoren zu einer kontrollierteren Rückfußbewegung (reduzierte und zeitlich verzögerte maximale Pronationsgeschwindigkeit). Beide Methoden des Unterschenkelkrafttrainings, FPST und PD, verbessern die laterale Sprunggelenkstabilität. Präventiv erscheint eine Kombination von Dorsalfexoren- und Pronatorentraining hinsichtlich der Pathomechank des Supinationstraumas empfehlenswert. Neben neuronalen Anpassungen lassen sich die trainingsinduzierten biomechanischen Veränderungen vorwiegend auf eine mit der Hypertrophie einher gehende muskuläre Versteifung zurückführen. Insgesamt bestätigt sich die Hypothese, dass sich die spezifische Beanspruchung der Unterschenkelmuskeln unter Berücksichtigung ihrer Hauptfunktion in spezifischen morphologischen und biomechanischen Veränderungen und demzufolge in unterschiedlicher Weise biopositiv äußert.Purpose of this dissertation was to identify the morphological and biomechanical effects of functional pronator and supinator strength training (FPST) compared to traditional plantar/dorsiflexor training (PD). It was hypothesized that this specific training increases the muscle thickness of the deep plantarflexors and the peronei muscles which might increase the stiffness of the ankle joint complex. This might influence the foot behaviour positively during a sudden inversion and furthermore induce a better functional control of the foot during running. Therefore, as a first step two functional anatomic foot strength training machines (FSTM) were constructed and proved experimentally before they were applied in the following intervention study. The FSTM movement axis was oriented to the subtalar joint axis (Inman, 1976). Pronator and supinator strength curves were determined by measuring pronator and supinator MVC in 15 healthy male sports students. Because of significant differences in the strength curve characteristics (pronators: ascending-descending; supinators: ascending) two different variable cams had to be implemented into the driven shaft of FSTM. For the intervention study 30 healthy male rearfoot runners were randomly assigned into an experimental group (n=22) and a control group (n=8). The subjects of the experimental group conducted functional pronator/supinator training (FPST) at the FSTM with the right leg, the left leg was trained with plantar and dorsiflexions (PD) at traditional training machines. The control group performed unilateral PD with both legs. In pre- and post-test maximum pronation and supination torques as well as rearfoot motion (electrogoniometer) during shod running in 3.3 m/s in two test conditions (A=regular running shoe; B=running shoe with inserted valgus wedges) were quantified. To monitor experimentally foot behaviour and muscle reaction time (EMG) during a sudden ankle term a custom made supination platform mounted on a force plate was used. Additionally, the volume of the muscles from both lower legs was quantified by magnetic resonance images (MRI) of 9 randomly chosen test persons of the experimental group. The results were analyzed by repeated measures analyses of variances. In the intervention study the intraindividual comparison of the right and left experimental leg (FPST vs. PD) revealed specific training effects. Compared to PD, FPST resulted in significantly higher pronator (14 % vs. 8 %, p<0.01) and supinator MVC (25 % vs. 12 %, p<0.01). Both, FPST and PD increased the supination angle at touchdown in running for both shoes A, B (p<0.01). In shoe B maximum pronation velocity was reduced about 16 % after FPST (FPST vs. PD: p<0.05) and delayed (FPST: +23 %; PD: +3 %; p<0.05). The median power frequency of the vertical ground reaction force signal increased in A (p<0.05) and B (p=0.05) which was independent on the training method. During sudden inversions both, FPST and PD, resulted in reduced (p<0.05) and delayed (p=0.06) first peak vertical impact as well as reduced supination velocity (p<0.01). Muscular reaction on sudden ankle turns was faster after the training in m. peronaeus longus (PL) (p<0.01) and tibialis anterior (TA) (p<0.05) whereby the intraindividual comparison revealed an interaction trend in favour of FPST in PL (p=0.06). MRI recordings showed statistical trends in training specific muscle volume increase of m. tibialis posterior (+10 %; FPST vs. PD: p=0.2) and m. flexor hallucis longus (+6 %; FPST vs. PD: p=0.09) in favour of FPST. PL, TA and m. gastrocnemius showed significant muscle volume increase independent on the training method. No leg dominant effects in any outcome measures were observed in the control group. Both, FPST and PD induced strength gains that stiffened the ankle joint complex and increased functional medio-lateral stability. Especially functional subtalar joint strength training is suggested as an effective protective mechanism against excessive pronation in runners. It can be concluded that the FPST specific strength increase of the deep plantarflexors leads to a smoother pronation behavior with a reduced and delayed pronation velocity. Especially, these effects become obvious when a higher amount of pronation is induced (shoe B). After both, FPST and PD the ankle joint complex is more functionally stabilized. With respect to the pathomechanism of an ankle sprain a combination of pronator and dorsiflexor training is recommended for injury prevention. It can be assumed that the main training effects result in higher mechanical joint stability due to specific muscle volume increase. Neuromuscular effects combined with a higher strength capability of the deep plantarflexors might be responsible for the better functional control of the pronation behaviour during ground contact in running. The findings of this dissertation reveal the hypothesis that specific loading of the shank muscles leads to specific morphological and biomechanical effects which have specific preventive potential

Challenges to QT Interval Variability Analysis in Mobile Applications

The QT interval in an electrocardiogram (ECG) reflects complex processes affecting the repolarization of ventricular myocardium. Increased QT interval variability (QTV) is thought to be caused by ventricular repolarization lability and has been associated with cardiac mortality. Recent publications have shown that template-based methods are more robust than traditional methods for QT interval extraction on a beat-to-beat basis. However, most studies are limited to non-movement ECG recordings, we want to analyze in this study the power of QT interval extraction for mobile non-stationary ECG recordings. The records of 7 test subjects are at least 65 min long and contain about 25 minutes of sport exercise such as running, cycling, sport climbing or acrobatic training. 2DSW was used to extract QT interval and best-fit distance of matched template for signal quality evaluation for each beat. Potential relations between QTV, motion and signal quality are segmentally compared. To determine motion activity we calculated normalized signal magnitude area (SMA). QTV was increased in patients during sport exercise, possibly reflects sympathetic activity in these specific physiological conditions. However, increased QTV could also be caused by low signal quality

The Recovery of Weight-Bearing Symmetry After Total Hip Arthroplasty Is Activity-Dependent

This study aimed to characterize ipsilateral loading and return to weight-bearing symmetry (WBS) in patients undergoing total hip arthroplasty (THA) during activities of daily living (ADLs) using instrumented insoles. A prospective study in 25 THA patients was performed, which included controlled pre- and postoperative follow-ups in a single rehabilitation center of an orthopedic department. Ipsilateral loading and WBS of ADLs were measured with insoles in THA patients and in a healthy control group of 25 participants. Measurements in the THA group were performed at 4 different visits: a week pre-THA, within a week post-THA, 3-6 weeks post-THA, and 6-12 weeks post-THA, whereas the healthy control group was measured once. ADLs included standing comfortably, standing evenly, walking, and sit-to-stand-to-sit (StS) transitions. All ADLs were analyzed using discrete methods, and walking included a time-scale analysis to provide temporal insights in the ipsilateral loading and WBS waveforms. THA patients only improved beyond their pre-surgery levels while standing comfortably (ipsilateral loading and WBS, p < 0.05) and during StS transitions (WBS, p < 0.05). Nevertheless, patients improved upon their ipsilateral loading and WBS deficits observed within a week post-surgery across all investigated ADLs. Ipsilateral loading and WBS of THA patients were comparable to healthy participants at 6-12 weeks post-THA, except for ipsilateral loading during walking (p < 0.05) at the initial and terminal double-leg support period of the stance phase. Taken together, insole measurements allow for the quantification of ipsilateral loading and WBS deficits during ADLs, identifying differences between pre- and postoperative periods, and differentiating THA patients from healthy participants. However, post-THA measurements that lack pre-surgery assessments may not be sensitive to identifying patient-specific improvements in ipsilateral loading and WBS. Moreover, StS transitions and earlier follow-up time points should be considered an important clinical metric of biomechanical recovery after THA

Insights on physical behavior while working from home:An ecological momentary assessment study

Ever since the COVID-19 pandemic, working from home (WFH) has emerged as a common alternative work environment, but the possible influence on daily physical behavior (PB) (i.e., physical activity (PA), sedentary behavior (SB)) remains unclear. This study aimed to examine daily associations between PB and the work environment (i.e., WFH, working at the office (WAO)), as well as to explore and identify patterns of PB within each work environment. An observational study using a dual-accelerometer system to continuously assess PB for at least 5 days was conducted. The sample consisted of 55 participants providing 276 days of assessment. Additional demographic, contextual, and psychological variables were measured via baseline questionnaire and several smartphone prompts per day. To analyze the effects of the work environment on PB, multilevel analyses were conducted. For the identification of patterns within each work environment, latent class trajectory modelling was applied. Associations between the work environment and various PA parameters were found, indicating that WFH has a negative effect on MVPA time, steps, and physical activity intensity (MET), but a positive effect on short PA bouts (≤5 min). No associations between the work environment and any SB parameter (i.e., SB time, SB breaks, SB bouts) were found. Latent class trajectory modelling revealed three MVPA patterns for days WFH, and two patterns for days WAO. Given the growing prevalence of WFH and the positive health effects associated with MVPA, daily-tailored solutions to enhance MPVA while WFH are urgently needed.</p

Insights on physical behavior while working from home: An ecological momentary assessment study

Ever since the COVID-19 pandemic, working from home (WFH) has emerged as a common alternative work environment, but the possible influence on daily physical behavior (PB) (i.e., physical activity (PA), sedentary behavior (SB)) remains unclear. This study aimed to examine daily associations between PB and the work environment (i.e., WFH, working at the office (WAO)), as well as to explore and identify patterns of PB within each work environment. An observational study using a dual-accelerometer system to continuously assess PB for at least 5 days was conducted. The sample consisted of 55 participants providing 276 days of assessment. Additional demographic, contextual, and psychological variables were measured via baseline questionnaire and several smartphone prompts per day. To analyze the effects of the work environment on PB, multilevel analyses were conducted. For the identification of patterns within each work environment, latent class trajectory modelling was applied. Associations between the work environment and various PA parameters were found, indicating that WFH has a negative effect on MVPA time, steps, and physical activity intensity (MET), but a positive effect on short PA bouts (≤5 min). No associations between the work environment and any SB parameter (i.e., SB time, SB breaks, SB bouts) were found. Latent class trajectory modelling revealed three MVPA patterns for days WFH, and two patterns for days WAO. Given the growing prevalence of WFH and the positive health effects associated with MVPA, daily-tailored solutions to enhance MPVA while WFH are urgently needed

I am Robot, Your Health Adviser for Older Adults: Do You Trust My Advice?

Artificial intelligence and robotic solutions are seeing rapid development for use across multiple occupations and sectors, including health and social care. As robots grow more prominent in our work and home environments, whether people would favour them in receiving useful advice becomes a pressing question. In the context of human–robot interaction (HRI), little is known about people’s advice-taking behaviour and trust in the advice of robots. To this aim, we conducted an experimental study with older adults to measure their trust and compliance with robot-based advice in health-related situations. In our experiment, older adults were instructed by a fictional human dispenser to ask a humanoid robot for advice on certain vitamins and over-the-counter supplements supplied by the dispenser. In the first experimented condition, the robot would give only information-type advice, i.e., neutral informative advice on the supplements given by the human. In the second condition, the robot would give recommendation-type advice, i.e., advice in favour of more supplements than those suggested initially by the human. We measured the trust of the participants in the type of robot-based advice, anticipating that they would be more trusting of information-type advice. Moreover, we measured the compliance with the advice, for participants who received robot-based recommendations, and a closer proxy of the actual use of robot health advisers in home environments or facilities in the foreseeable future. Our findings indicated that older adults continued to trust the robot regardless of the type of advice received, highlighting a type of protective role of robot-based recommendations on their trust. We also found that higher trust in the robot resulted in higher compliance with its advice. The results underpinned the likeliness of older adults welcoming a robot at their homes or health facilities

Multimodal Phase-Based X-Ray Microtomography with Nonmicrofocal Laboratory Sources

We present an alternative laboratory implementation of x-ray phase-contrast tomography through a beam-tracking approach. A nonmicrofocal rotating anode source is combined with a high-resolution detector and an absorbing mask to obtain attenuation, phase, and ultra-small-angle scattering tomograms of different specimens. A theoretical model is also presented which justifies the implementation of beam tracking with polychromatic sources and provides quantitative values of attenuation and phase, under the assumption of low sample attenuation. The method is tested on a variety of samples featuring both large and small x-ray attenuation, phase, and scattering signals. The complementarity of the contrast channels can enable subtle distinctions between materials and tissue types, which appear indistinguishable to conventional tomography scanners