@article{QuarmbyKhajooeiKurtzetal.2023, author = {Quarmby, Andrew James and Khajooei, Mina and Kurtz, Philip and Henschke, Jakob and Kim, MyoungHwee and Mayer, Frank and Engel, Tilman}, title = {Unexpected running perturbations}, series = {Frontiers in sports and active living}, volume = {5}, journal = {Frontiers in sports and active living}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2624-9367}, doi = {10.3389/fspor.2023.1129058}, pages = {14}, year = {2023}, abstract = {Introduction Balance is vital for human health and experiments have been conducted to measure the mechanisms of postural control, for example studying reflex responses to simulated perturbations. Such studies are frequent in walking but less common in running, and an understanding of reflex responses to trip-like disturbances could enhance our understanding of human gait and improve approaches to training and rehabilitation. Therefore, the primary aim of this study was to investigate the technical validity and reliability of a treadmill running protocol with perturbations. A further exploratory aim was to evaluate the associated neuromuscular reflex responses to the perturbations, in the lower limbs. Methods Twelve healthy participants completed a running protocol (9 km/h) test-retest (2 weeks apart), whereby 30 unilateral perturbations were executed via the treadmill belts (presets:2.0 m/s amplitude;150 ms delay (post-heel contact);100ms duration). Validity of the perturbations was assessed via mean +/- SD comparison, percentage error calculation between the preset and recorded perturbation characteristics (PE\%), and coefficient of variation (CV\%). Test-retest reliability (TRV\%) and Bland-Altman analysis (BLA; bias +/- 1.96 * SD) was calculated for reliability. To measure reflex activity, electromyography (EMG) was applied in both legs. EMG amplitudes (root mean square normalized to unperturbed strides) and latencies [ms] were analysed descriptively. Results Left-side perturbation amplitude was 1.9 +/- 0.1 m/s, delay 105 +/- 2 ms, and duration 78 +/- 1 ms. Right-side perturbation amplitude was 1.9 +/- 0.1 m/s, delay 118 +/- 2 ms, duration 78 +/- 1 ms. PE\% ranged from 5-30\% for the recorded perturbations. CV\% of the perturbations ranged from 19.5-76.8\%. TRV\% for the perturbations was 6.4-16.6\%. BLA for the left was amplitude: 0.0 +/- 0.3m/s, delay: 0 +/- 17 ms, duration: 2 +/- 13 ms, and for the right was amplitude: 0.1 +/- 0.7, delay: 4 +/- 40 ms, duration: 1 +/- 35 ms. EMG amplitudes ranged from 175 +/- 141\%-454 +/- 359\% in both limbs. Latencies were 109 +/- 12-116 +/- 23 ms in the tibialis anterior, and 128 +/- 49-157 +/- 20 ms in the biceps femoris. Discussion Generally, this study indicated sufficient validity and reliability of the current setup considering the technical challenges and limitations, although the reliability of the right-sided perturbations could be questioned. The protocol provoked reflex responses in the lower extremities, especially in the leading leg. Acute neuromusculoskeletal adjustments to the perturbations could be studied and compared in clinical and healthy running populations, and the protocol could be utilised to monitor chronic adaptations to interventions over time.}, language = {en} } @article{DobberkeBaritelloHadzicetal.2022, author = {Dobberke, Jeanette and Baritello, Omar and Hadzic, Miralem and V{\"o}ller, Heinz and Eichler, Sarah and Salzwedel, Annett}, title = {Test-retest reliability of center of pressure measures for postural control assessment in older cardiac patients}, series = {Gait \& posture : official journal of Gait and Clinical Movement Analysis Society (GCMAS) and European Society of Movement Analysis in Adults and Children (ESMAC)}, volume = {92}, journal = {Gait \& posture : official journal of Gait and Clinical Movement Analysis Society (GCMAS) and European Society of Movement Analysis in Adults and Children (ESMAC)}, publisher = {Elsevier Science}, address = {Amsterdam}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2021.12.011}, pages = {359 -- 363}, year = {2022}, abstract = {Background Elderly patients are a growing population in cardiac rehabilitation (CR). As postural control declines with age, assessment of impaired balance is important in older CR patients in order to predict fall risk and to initiate counteracting steps. Functional balance tests are subjective and lack adequate sensitivity to small differences, and are further subject to ceiling effects. A quantitative approach to measure postural control on a continuous scale is therefore desirable. Force plates are already used for this purpose in other clinical contexts, therefore could be a promising tool also for older CR patients. However, in this population the reliability of the assessment is not fully known. Research question Analysis of test-retest reliability of center of pressure (CoP) measures for the assessment of postural control using a force plate in older CR patients. Methods 156 CR patients (> 75 years) were enrolled. CoP measures (path length (PL), mean velocity (MV), and 95\% confidence ellipse area (95CEA)) were analyzed twice with an interval of two days in between (bipedal narrow stance, eyes open (EO) and closed (EC), three trials for each condition, 30 s per trial), using a force plate. For test-retest reliability estimation absolute differences (\& UDelta;: T0-T1), intraclass correlation coefficients (ICC) with 95\% confidence intervals, standard error of measurement and minimal detectable change were calculated. Results Under EO condition ICC were excellent for PL and MV (0.95) and good for 95CEA (0.88) with \& UDelta; of 10.1 cm (PL), 0.3 cm/sec (MV) and 1.5 cm(2 )(95CEA) respectively. Under EC condition ICC were excellent (> 0.95) for all variables with larger \& UDelta; (PL: 21.7 cm; MV: 0.7 cm/sec; 95CEA: 2.4 cm(2)) Significance In older CR patients, the assessment of CoP measures using a force plate shows good to excellent test retest reliability.}, language = {en} } @article{ChenLangeAndjelkovicetal.2022, author = {Chen, Junchao and Lange, Thomas and Andjelkovic, Marko and Simevski, Aleksandar and Lu, Li and Krstić, Miloš}, title = {Solar particle event and single event upset prediction from SRAM-based monitor and supervised machine learning}, series = {IEEE transactions on emerging topics in computing / IEEE Computer Society, Institute of Electrical and Electronics Engineers}, volume = {10}, journal = {IEEE transactions on emerging topics in computing / IEEE Computer Society, Institute of Electrical and Electronics Engineers}, number = {2}, publisher = {Institute of Electrical and Electronics Engineers}, address = {[New York, NY]}, issn = {2168-6750}, doi = {10.1109/TETC.2022.3147376}, pages = {564 -- 580}, year = {2022}, abstract = {The intensity of cosmic radiation may differ over five orders of magnitude within a few hours or days during the Solar Particle Events (SPEs), thus increasing for several orders of magnitude the probability of Single Event Upsets (SEUs) in space-borne electronic systems. Therefore, it is vital to enable the early detection of the SEU rate changes in order to ensure timely activation of dynamic radiation hardening measures. In this paper, an embedded approach for the prediction of SPEs and SRAM SEU rate is presented. The proposed solution combines the real-time SRAM-based SEU monitor, the offline-trained machine learning model and online learning algorithm for the prediction. With respect to the state-of-the-art, our solution brings the following benefits: (1) Use of existing on-chip data storage SRAM as a particle detector, thus minimizing the hardware and power overhead, (2) Prediction of SRAM SEU rate one hour in advance, with the fine-grained hourly tracking of SEU variations during SPEs as well as under normal conditions, (3) Online optimization of the prediction model for enhancing the prediction accuracy during run-time, (4) Negligible cost of hardware accelerator design for the implementation of selected machine learning model and online learning algorithm. The proposed design is intended for a highly dependable and self-adaptive multiprocessing system employed in space applications, allowing to trigger the radiation mitigation mechanisms before the onset of high radiation levels.}, language = {en} } @article{PrillWalterKrolikowskaetal.2021, author = {Prill, Robert and Walter, Marina and Kr{\´o}likowska, Aleksandra and Becker, Roland}, title = {A systematic review of diagnostic accuracy and clinical applications of wearable movement sensors for knee joint rehabilitation}, series = {Sensors}, volume = {21}, journal = {Sensors}, number = {24}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s21248221}, pages = {14}, year = {2021}, abstract = {In clinical practice, only a few reliable measurement instruments are available for monitoring knee joint rehabilitation. Advances to replace motion capturing with sensor data measurement have been made in the last years. Thus, a systematic review of the literature was performed, focusing on the implementation, diagnostic accuracy, and facilitators and barriers of integrating wearable sensor technology in clinical practices based on a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. For critical appraisal, the COSMIN Risk of Bias tool for reliability and measurement of error was used. PUBMED, Prospero, Cochrane database, and EMBASE were searched for eligible studies. Six studies reporting reliability aspects in using wearable sensor technology at any point after knee surgery in humans were included. All studies reported excellent results with high reliability coefficients, high limits of agreement, or a few detectable errors. They used different or partly inappropriate methods for estimating reliability or missed reporting essential information. Therefore, a moderate risk of bias must be considered. Further quality criterion studies in clinical settings are needed to synthesize the evidence for providing transparent recommendations for the clinical use of wearable movement sensors in knee joint rehabilitation.}, language = {en} } @article{JannaschNickelSchulze2021, author = {Jannasch, Franziska and Nickel, Daniela and Schulze, Matthias Bernd}, title = {The reliability and relative validity of predefined dietary patterns were higher than that of exploratory dietary patterns in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam population}, series = {British journal of nutrition : BJN : an international journal of nutritional science / published on behalf of The Nutrition Society}, volume = {125}, journal = {British journal of nutrition : BJN : an international journal of nutritional science / published on behalf of The Nutrition Society}, number = {11}, publisher = {Cambridge University Press}, address = {Cambridge}, issn = {1475-2662}, doi = {10.1017/S0007114520003517}, pages = {1270 -- 1280}, year = {2021}, abstract = {The aim of this study was to assess the ability of the FFQ to describe reliable and valid dietary pattern (DP) scores. In a total of 134 participants of the European Prospective Investigation into Cancer and Nutrition-Potsdam study aged 35-67 years, the FFQ was applied twice (baseline and after 1 year) to assess its reliability. Between November 1995 and March 1997, twelve 24-h dietary recalls (24HDR) as reference instrument were applied to assess the validity of the FFQ. Exploratory DP were derived by principal component analyses. Investigated predefined DP were the Alternative Healthy Eating Index (AHEI) and two Mediterranean diet indices. From dietary data of each FFQ, two exploratory DP were retained, but differed in highly loading food groups, resulting in moderate correlations (r 0 center dot 45-0 center dot 58). The predefined indices showed higher correlations between the FFQ (r(AHEI) 0 center dot 62, r(Mediterranean Diet Pyramid Index (MedPyr)) 0 center dot 62 and r(traditional Mediterranean Diet Score (tMDS)) 0 center dot 51). From 24HDR dietary data, one exploratory DP retained differed in composition to the first FFQ-based DP, but showed similarities to the second DP, reflected by a good correlation (r 0 center dot 70). The predefined DP correlated moderately (r 0 center dot 40-0 center dot 60). To conclude, long-term analyses on exploratory DP should be interpreted with caution, due to only moderate reliability. The validity differed extensively for the two exploratory DP. The investigated predefined DP showed a better reliability and a moderate validity, comparable to other studies. Within the two Mediterranean diet indices, the MedPyr performed better than the tMDs in this middle-aged, semi-urban German study population.}, language = {en} } @article{DechBittmannSchaefer2021, author = {Dech, Silas and Bittmann, Frank and Schaefer, Laura}, title = {Assessment of the adaptive force of Elbow extensors in healthy subjects quantified by a novel pneumatically driven measurement system with considerations of its quality criteria}, series = {Diagnostics : open access journal}, volume = {11}, journal = {Diagnostics : open access journal}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {2075-4418}, doi = {10.3390/diagnostics11060923}, pages = {23}, year = {2021}, abstract = {Adaptive Force (AF) reflects the capability of the neuromuscular system to adapt adequately to external forces with the intention of maintaining a position or motion. One specific approach to assessing AF is to measure force and limb position during a pneumatically applied increasing external force. Through this method, the highest (AFmax), the maximal isometric (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax) can be determined. The main question of the study was whether the AFisomax is a specific and independent parameter of muscle function compared to other maximal forces. In 13 healthy subjects (9 male and 4 female), the maximal voluntary isometric contraction (pre- and post-MVIC), the three AF parameters and the MVIC with a prior concentric contraction (MVICpri-con) of the elbow extensors were measured 4 times on two days. Arithmetic mean (M) and maximal (Max) torques of all force types were analyzed. Regarding the reliability of the AF parameters between days, the mean changes were 0.31-1.98 Nm (0.61\%-5.47\%, p = 0.175-0.552), the standard errors of measurements (SEM) were 1.29-5.68 Nm (2.53\%-15.70\%) and the ICCs(3,1) = 0.896-0.996. M and Max of AFisomax, AFmax and pre-MVIC correlated highly (r = 0.85-0.98). The M and Max of AFisomax were significantly lower (6.12-14.93 Nm; p ≤ 0.001-0.009) and more variable between trials (coefficient of variation (CVs) ≥ 21.95\%) compared to those of pre-MVIC and AFmax (CVs ≤ 5.4\%). The results suggest the novel measuring procedure is suitable to reliably quantify the AF, whereby the presented measurement errors should be taken into consideration. The AFisomax seems to reflect its own strength capacity and should be detected separately. It is suggested its normalization to the MVIC or AFmax could serve as an indicator of a neuromuscular function.}, language = {en} } @article{KatherHadzicHehleetal.2020, author = {Kather, Fritz and Hadzic, Miralem and Hehle, Teresa and Eichler, Sarah and Klein, Julia and V{\"o}ller, Heinz and Salzwedel, Annett}, title = {Test-retest reliability of the Mini Nutritional Assessment- Short Form (MNA-SF) in older patients undergoing cardiac rehabilitation}, series = {Journal of geriatric cardiology}, volume = {17}, journal = {Journal of geriatric cardiology}, number = {9}, publisher = {English China Online Journals, ECOJ}, address = {Windsor [u.a.]}, issn = {1671-5411}, doi = {10.11909/j.issn.1671-5411.2020.09.007}, pages = {574 -- 579}, year = {2020}, language = {en} } @article{SchusterTomaszewskaMarchewkaetal.2020, author = {Schuster, Isabell and Tomaszewska, Paulina and Marchewka, Juliette and Krah{\´e}, Barbara}, title = {Does question format matter in assessing the prevalence of sexual aggression?}, series = {The journal of sex research}, volume = {58}, journal = {The journal of sex research}, number = {4}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {0022-4499}, doi = {10.1080/00224499.2020.1777927}, pages = {502 -- 511}, year = {2020}, abstract = {As research on sexual aggression has been growing, methodological issues in assessing prevalence rates have received increased attention. Building on work by Abbey and colleagues about effects of question format, participants in this study (1,253; 621 female; 632 male) were randomly assigned to one of two versions of the Sexual Aggression and Victimization Scale (SAV-S). In Version 1, the coercive tactic (use/threat of physical force, exploitation of the inability to resist, verbal pressure) was presented first, and sexual acts (sexual touch, attempted and completed sexual intercourse, other sexual acts) were presented as subsequent questions. In Version 2, sexual acts were presented first, and coercive tactics as subsequent questions. No version effects emerged for overall perpetration rates reported by men and women. The overall victimization rate across all items was significantly higher in the tactic-first than in the sexual-act-first conditions for women, but not for men. Classifying participants by their most severe experience of sexual victimization showed that fewer women were in the nonvictim category and more men were in the nonconsensual sexual contact category when the coercive tactic was presented first. Sexual experience background did not moderate the findings. The implications for the measurement of self-reported sexual aggression victimization and perpetration are discussed.}, language = {en} } @article{LesinskiSchmelcherHerzetal.2020, author = {Lesinski, Melanie and Schmelcher, Alina and Herz, Michael and Puta, Christian and Gabriel, Holger and Arampatzis, Adamantios and Laube, Gunnar and B{\"u}sch, Dirk and Granacher, Urs}, title = {Maturation-, age-, and sex-specific anthropometric and physical fitness percentiles of German elite young athletes}, series = {Plos One}, volume = {15}, journal = {Plos One}, number = {8}, publisher = {Plos One}, address = {San Francisco, California}, issn = {1932-6203}, doi = {10.1371/journal.pone.0237423}, pages = {19}, year = {2020}, abstract = {The aim of this study was to establish maturation-, age-, and sex-specific anthropometric and physical fitness percentile reference values of young elite athletes from various sports. Anthropometric (i.e., standing and sitting body height, body mass, body mass index) and physical fitness (i.e., countermovement jump, drop jump, change-of-direction speed [i.e., T-test], trunk muscle endurance [i.e., ventral Bourban test], dynamic lower limbs balance [i.e., Y-balance test], hand grip strength) of 703 male and female elite young athletes aged 8-18 years were collected to aggregate reference values according to maturation, age, and sex. Findings indicate that body height and mass were significantly higher (p<0.001; 0.95≤d≤1.74) in more compared to less mature young athletes as well as with increasing chronological age (p<0.05; 0.66≤d≤3.13). Furthermore, male young athletes were significantly taller and heavier compared to their female counterparts (p<0.001; 0.34≤d≤0.50). In terms of physical fitness, post-pubertal athletes showed better countermovement jump, drop jump, change-of-direction, and handgrip strength performances (p<0.001; 1.57≤d≤8.72) compared to pubertal athletes. Further, countermovement jump, drop jump, change-of-direction, and handgrip strength performances increased with increasing chronological age (p<0.05; 0.29≤d≤4.13). In addition, male athletes outperformed their female counterpart in the countermovement jump, drop jump, change-of-direction, and handgrip strength (p<0.05; 0.17≤d≤0.76). Significant age by sex interactions indicate that sex-specific differences were even more pronounced with increasing age. Conclusively, body height, body mass, and physical fitness increased with increasing maturational status and chronological age. Sex-specific differences appear to be larger as youth grow older. Practitioners can use the percentile values as approximate benchmarks for talent identification and development.}, language = {en} } @article{DombrowskiErmakovaFabian2019, author = {Dombrowski, Sebastian and Ermakova, Tatiana and Fabian, Benjamin}, title = {Graph-based analysis of cloud connectivity at the internet protocol level}, series = {International Journal of Communication Networks and Distributed Systems (IJCNDS)}, volume = {23}, journal = {International Journal of Communication Networks and Distributed Systems (IJCNDS)}, number = {1}, publisher = {Inderscience Enterprises Ltd}, address = {Geneva}, issn = {1754-3916}, doi = {10.1504/IJCNDS.2019.100644}, pages = {117 -- 142}, year = {2019}, abstract = {Internet connectivity of cloud services is of exceptional importance for both their providers and consumers. This article demonstrates the outlines of a method for measuring cloud-service connectivity at the internet protocol level from a client's perspective. For this, we actively collect connectivity data via traceroute measurements from PlanetLab to several major cloud services. Furthermore, we construct graph models from the collected data, and analyse the connectivity of the services based on important graph-based measures. Then, random and targeted node removal attacks are simulated, and the corresponding vulnerability of cloud services is evaluated. Our results indicate that cloud service hosts are, on average, much better connected than average hosts. However, when interconnecting nodes are removed in a targeted manner, cloud connectivity is dramatically reduced.}, language = {en} }