In psychology as elsewhere, the main statistical inference strategy to establish empirical effects is null-hypothesis significance testing (NHST). The recent failure to replicate allegedly ...well-established NHST-results, however, implies that such results lack sufficient statistical power, and thus feature unacceptably high error-rates. Using data-simulation to estimate the error-rates of NHST-results, we advocate the
(RPS) as a superior methodology. RPS integrates Frequentist with Bayesian inference elements, and leads from a preliminary discovery against a (random)
-hypothesis to a statistical
-verification. Not only do RPS-results feature significantly lower error-rates than NHST-results, RPS also addresses key-deficits of a "pure" Frequentist and a standard Bayesian approach. In particular, RPS aggregates underpowered results safely. RPS therefore provides a tool to regain the trust the discipline had lost during the ongoing replicability-crisis.
Abstract Movement of a racehorse simulator differs to that of a real horse, but the effects of these differences on jockey technique have not been evaluated. We quantified and compared the kinematics ...and kinetics of jockeys during gallop riding on a simulator and real horses. Inertial measurement units were attached mid-shaft to the long bones of six jockeys and the sacrum of the horse or simulator. Instrumented stirrups were used to measure force. Data were collected during galloping on a synthetic gallop or while riding a racehorse simulator. Jockey kinematics varied more on a real horse compared to the simulator. Greater than double the peak stirrup force was recorded during gallop on real horses compared to the simulator. On the simulator stirrup forces were symmetrical, whereas on a real horse peak forces were higher on the lead limb side. Asymmetric forces and lateral movement of the horse and jockey occurs towards the side of the lead leg, likely a result of horse trunk roll. Jockeys maintained a more upright trunk position on a real horse compared to simulator, with no change in pitch. The feet move in phase with the horse and simulator exhibiting similar magnitude displacements in all directions. In contrast the pelvis was in phase with the horse and simulator in the dorso-ventral and medio-lateral axes while a phase shift of 180 degrees was seen in the cranio-caudal direction indicating an inverted pendulum action of the jockey.
The directed transfer function (DTF) and the partial directed coherence (PDC) are frequency-domain estimators that are able to describe interactions between cortical areas in terms of the concept of ...Granger causality. However, the classical estimation of these methods is based on the multivariate autoregressive modelling (MVAR) of time series, which requires the stationarity of the signals. In this way, transient pathways of information transfer remains hidden. The objective of this study is to test a time-varying multivariate method for the estimation of rapidly changing connectivity relationships between cortical areas of the human brain, based on DTF/PDC and on the use of adaptive MVAR modelling (AMVAR) and to apply it to a set of real high resolution EEG data. This approach will allow the observation of rapidly changing influences between the cortical areas during the execution of a task. The simulation results indicated that time-varying DTF and PDC are able to estimate correctly the imposed connectivity patterns under reasonable operative conditions of signal-to-noise ratio (SNR) ad number of trials. An SNR of Ave and a number of trials of at least 20 provide a good accuracy in the estimation. After testing the method by the simulation study, we provide an application to the cortical estimations obtained from high resolution EEG data recorded from a group of healthy subject during a combined foot-lips movement and present the time-varying connectivity patterns resulting from the application of both DTF and PDC. Two different cortical networks were detected with the proposed methods, one constant across the task and the other evolving during the preparation of the joint movement.
Accurate determination of speed is important in many studies of human and animal locomotion. Some global positioning system (GPS) receivers can data log instantaneous speed. The speed accuracy of ...these systems is, however, unclear with manufacturers reporting velocity accuracies of 0.1–0.2
ms
−1. This study set out to trial non-differential GPS as a means of determining speed under real-life conditions.
A bicycle was ridden around a running track and a custom-made bicycle speedometer was calibrated. Additional experiments were performed around circular tracks of known circumference and along a straight road. Instantaneous speed was determined simultaneously by the custom speedometer and a data logging helmet-mounted GPS receiver. GPS speed was compared to speedometer speed. The effect on speed accuracy of satellite number; changing satellite geometry, achieved through shielding the GPS antenna; speed; horizontal dilution of precision and cyclist position on a straight or a bend, was evaluated. The relative contribution of each variable to overall speed accuracy was determined by ANOVA. The speed determined by the GPS receiver was within 0.2
ms
−1 of the true speed measured for 45% of the values with a further 19% lying within 0.4
ms
−1 (
n=5060). The accuracy of speed determination was preserved even when the positional data were degraded due to poor satellite number or geometry. GPS data loggers are therefore accurate for the determination of speed over-ground in biomechanical and energetic studies performed on relatively straight courses. Errors increase on circular paths, especially those with small radii of curvature, due to a tendency to underestimate speed.
For the past decade, the detection and quantification of interactions within and between physiological networks has become a priority-in-common between the fields of biomedicine and computer science. ...Prominent examples are the interaction analysis of brain networks and of the cardiovascular-respiratory system. The aim of the study is to show how and to what extent results from time-variant partial directed coherence analysis are influenced by some basic estimator and data parameters. The impacts of the Kalman filter settings, the order of the autoregressive (AR) model, signal-to-noise ratios, filter procedures and volume conduction were investigated. These systematic investigations are based on data derived from simulated connectivity networks and were performed using a Kalman filter approach for the estimation of the time-variant multivariate AR model. Additionally, the influence of electrooculogram artefact rejection on the significance and dynamics of interactions in 29 channel electroencephalography recordings, derived from a photic driving experiment, is demonstrated. For artefact rejection, independent component analysis was used. The study provides rules to correctly apply particular methods that will aid users to achieve more reliable interpretations of the results.
Germanium - the superior dopant in n-type GaN Nenstiel, C.; Bügler, M.; Callsen, G. ...
Physica status solidi. PSS-RRL. Rapid research letters,
December 2015, Letnik:
9, Številka:
12
Journal Article
Highlights • Very early somatosensory evoked responses show context-dependent modulation by auditory stimuli. • Our delay differential equation model strongly suggests cortico-thalamic feedback in ...primary somatosensory processing. • Frequency encoding, in contrast to network coupling, seems to play an important role in contextual modulation in the somatosensory thalamo-cortical network.
With improving survival of children with complex congenital heart disease (CCHD), postoperative complications, like protein-losing enteropathy (PLE) are increasingly encountered. A 3-year-old girl ...with surgically corrected CCHD (ventricular inversion/L-transposition of the great arteries, ventricular septal defect, pulmonary atresia, post-double switch procedure Rastelli and Glenn) developed chylothoraces. She was treated with pleurodesis, thoracic duct ligation and subsequently developed chylous ascites and PLE (serum albumin ≤0.9 g/dL) and was malnourished, despite nutritional rehabilitation. Lymphangioscintigraphy/single-photon emission computed tomography showed lymphatic obstruction at the cisterna chyli level. A segmental chyle leak and chylous lymphangiectasia were confirmed by gastrointestinal endoscopy, magnetic resonance (MR) enterography, and MR lymphangiography. Selective glue embolization of leaking intestinal lymphatic trunks led to prompt reversal of PLE. Serum albumin level and weight gain markedly improved and have been maintained for over 3 years. Selective interventional embolization reversed this devastating lymphatic complication of surgically corrected CCHD.
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