101 research outputs found
Quantifying Motor Skills in Early-Stage Parkinson's Disease Using Human Controller Modeling
Get PDFThis paper investigates the potential of using a manual pursuit tracking task for quantifying loss of motor skills due to Parkinson's disease (PD), by applying human controller (HC) modeling techniques. With this approach, it is possible to obtain detailed quantitative data on motor performance in terms of control gain, response delay, stiffness and damping. Pursuit tracking data was collected from seven early-stage PD patients and a matched control group at the Erasmus MC in Rotterdam. Tracking performance was significantly worse in the PD group compared to the controls. Furthermore, the PD patients showed significantly lower control gains and degraded neuromuscular damping and bandwidth, which indicates that early-stage PD is associated with loss of quick and fast arm movements. While the PD patients showed less consistent and linear control behavior in the task, their data could still be modelled at high accuracy. Using HC models to quantify PD patients' fine motor skill abilities may contribute to improved (early) detection of motor skill loss in PD, as well as detailed monitoring of symptom development and intervention effectiveness.Control & Simulatio
Identifying Behavioural Changes due to Parkinson's Disease Progression in Motor Performance Data
Get PDFParkinson's disease (PD) is a progressive nervous system disorder that affects movement. PD has a severely negative impact on the quality of life of patients and their caregivers. The timing of treatment depends, amongst others, on the quantification of patients' motor performance. To date, the resolution used in scaling motor performance is too low to detect subtle behavioral changes over time. This paper investigates if 'longitudinal' data-sets of motor performance data obtained from tracking tasks can detect behavioural changes in motor performance data representative for PD symptoms. Such longitudinal data were approximated using a combined data-set based on 50 trials of collected experiment data from 25 healthy participants (age range 55-75 years), augmented with 25 bootstrapped samples scaled to represent 'Mild' or 'Severe' motor performance degradation. An approach based on general linear regression models was tested for its capacity to detect the adverse trends in typical tracking task metrics (Kp, τ, ζnms, ωnms, RMSe, and RMSu). Overall, it was found that with this approach in at least 50% of all participants, a simulated change in motor behaviour was successfully detected, a number that may increase to 97% for the most sensitive metric (ζnms) and consistent participant data. This indicates that the developed approach is promising towards the development of more objective and detailed monitoring of disease progression and treatments in PD patients.Control & Simulatio
Effects of Multisine Signal Bandwidth on Eye Movement Dynamics
No full textIn the analysis of human motor skills, tracking tasks with multisine target signals are often performed as they allow for quantitative measurement, identification, and modeling of human control dynamics. In this paper, the same "cybernetic" approach is taken to analyze eye movement dynamics in gaze tracking tasks, where participants had to track a moving target marker across the screen) with their eyes (i.e., a eye-only task) and 2) with their dominant hand (i.e., a eye-hand task). A human-in-the-loop experiment with 10 participants was performed to measure the eye movement dynamics. These two different conditions were performed with four different bandwidths of the multisine target signal driving the movement of the visual stimulus. The results show that the measured eye movement dynamics can be identified from the data of all experiment conditions and can be accurately modeled as an underdamped mass-spring-damper system with a time delay. Furthermore, with increased target signal bandwidth the bandwidth of participants' eye movements also increases. Future development of gaze tracking tasks into a new tool for assessment of altered gaze behavior due to neurological diseases should take the balance between saccadic and smooth pursuit eye movements into account and avoid very high (i.e., too difficult) bandwidths to warrant accurate modelling of gaze dynamics.Control & Simulatio
Jesus, moral regeneration and crime in the Gospel of John
Get PDFPeer reviewed article published under Inkanyiso, Volume 2, Issue 2, Jan 2010, p. 115 - 121A structural and text-immanent approach to the Gospel of John reveals that Jesus of Nazareth came to earth to do the
will of God his Father and to take away the sins of the world. The author/s makes/make it clear that Jesus taught
Nicodemus that one needs to be born again in order to enter the kingdom of God. To be born again means that one must
be born out of water and Spirit, that is, through becoming a follower or disciple of Jesus Christ, one’s life has to change.
This change, also called regeneration, is, anthropologically-speaking, according to the rational-choice theory, a deliberate
choice made by man to become a follower or disciple of Jesus and to do his Father’s will. The disciples are not called upon
to be like robbers and thieves, focused on the accumulation of earthly wealth, but to love one another. Although Jesus was
crucified because of an allegation of high treason, a crime against the state, He instructed his followers to forgive others
and to remain in His love. In terms of the explicatio-applicatio model, the intended kerygmatic message of John to his
intended readers is clear: he wants all people, including criminals, to believe in Jesus and to follow Him, because,
according to the Johannine author/s, when one follows Jesus, one does not commit crime, because one has been morally
regenerated
The variable outflow resistance catheter: a new method to measure bladder pressure noninvasively
No full textPurpose: In a previous study an external condom catheter was used to measure noninvasively bladder pressure during interruption of the flow rate. The pressure increase in the condom sometimes caused a sphincter contraction that made bladder pressure measurement unreliable. Therefore, we developed a new variable outflow resistance catheter to measure noninvasively bladder pressure without interrupting the flow rate. Materials and Methods: The new catheter consists of an incontinence condom connected to a set of various outflow tubes and a pressure transducer. A remotely controlled pneumatic valve was fitted over each tube to interrupt flow through it. We measured isovolumetric pressure, maximum flow rate, and pressure and flow rates at various outflow resistances in 9 healthy male volunteers. Results: We derived a mathematical equation to estimate isovolumetric pressure from the pressure and flow rate values measured at various outflow resistances. The difference in the estimated and truly measured mean isovolumetric pressures plus or minus standard deviation was 0 ± 6 cm. water. Conclusions: The new variable outflow resistance catheter may be used to measure isovolumetric bladder pressure noninvasively without interrupting the flow rate. It has been previously shown that a combination of this pressure and a separately measured maximum flow rate may be used to diagnose bladder outlet obstruction noninvasively.</p
Jacob Duym en de Leidse rederijkers
Get PDFCompared to other authors that played an important role during the early stages of Dutch renaissance drama, Jacob Duym received relatively little attention. In this article his life and work during his Leiden years (1586-1608) are discussed. It is argued that Duym initially was a member of the old chamber of rhetoric the Witte Acoleyen. In 1591, on request of the city government, he became the leader of the Flemish chamber d'Orainge Lelie; an unknown pamflet he wrote for this chamber is presented here. After some difficulties he left the Flemish chamber, this must have taken place between 1600 and 1606, and returned to the Witte Acoleyen. Probably he is the author of the winning play, performed by the Witte Acoleyen during the Haarlem rhethorician festivities in 1606
Perineal sound recording for diagnosis of bladder outlet obstruction.
No full textItem does not contain fulltextOBJECTIVES: Elderly men are prone to developing lower urinary tract symptoms (LUTS) possibly caused by bladder outlet obstruction (BOO). The most frequently used method to diagnose this condition is an invasive and time-consuming pressure-flow study. We are developing a novel non-invasive method to diagnose BOO in men with LUTS based on perineal sound recording. METHODS: A biophysical model urethra was made from polyvinyl alcohol (PVA) cryogel with viscoelastic properties comparable to those of the male pig urethra. To this model different degrees of obstruction were applied and sound was recorded at different positions downstream of the obstruction. In a study in 16 healthy male volunteers the variability and repeatability of perineal sound recording was tested. RESULTS: In the model three parameters, derived from the frequency spectrum of the recorded sound (i.e., weighted average frequency, standard deviation and skewness) are uniquely related to the degree of obstruction (linear regression, P<0.001). The variability of perineal sound recording in healthy male volunteers was found to be smaller within volunteers than between volunteers (Kruskal-Wallis, P<0.001) and the repeatability was comparable to that of the maximum flow rate. CONCLUSIONS: We conclude that perineal sound recordings are significantly different between volunteers. In combination with the unique relations found in the model-experiments these results increase the probability that perineal sound recording can be used as a simple and cheap non-invasive method to diagnose BOO. Clinical testing of this method is therefore strongly indicated
Determinants of diarrheal disease in Jakarta
Get PDFIn this report, the authors develop and estimate a model of household defensive behavior and illness. Using cross-section data from a household survey in Jakarta, they observe defensive behavior (washing hands after using the toilet) consistent with expectations: defensive effort intensifies with exposure to contamination, and with income and education. Variables associated with the cost of defensive behavior - such as interruptions in the water supply - reduce defensive behavior. The data suggest that wealthier households are no less vulnerable to illness. The water sources that supply the wealthy (the water company and private wells) are disrupted more often, interfering with their defensive behavior. There is also evidence, although weak, to support findings by van der Slice and Briscoe (1993): that pathogens within a household are less harmful to household members than are pathogens originating from other households. Given the opportunity and knowledge, individuals try to modify the effect of contamination on the incidence of diarrhea. But diarrhea's inccidence is also affected by decisions and problems outside the realm of the household, including the performance of the water company.Water Conservation,Water and Industry,Health Economics&Finance,Environmental Economics&Policies,Sanitation and Sewerage,Town Water Supply and Sanitation,Water and Industry,Water Supply and Sanitation Governance and Institutions,Water Conservation,Health Economics&Finance
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