Search results for "dynamic"
showing 10 items of 12329 documents
Trajectories of Blood Pressure Elevation Preceding Hypertension Onset: An Analysis of the Framingham Heart Study Original Cohort
2018
Importance Given that hypertension remains a leading risk factor for chronic disease globally, there are substantial ongoing efforts to define the optimal range of blood pressure (BP). Objective To identify a common threshold level above which BP rise tends to accelerate in progression toward hypertension. Design, Setting, and Participants This longitudinal, community-based epidemiological cohort study of adults enrolled in Framingham, Massachusetts, included 1252 participants (mean [SD] age, 35.3 [2.7] years) from the Framingham Original Cohort, of whom 790 (63.1%) were women. Each participant contributed up to 28 serial examinations of standardized resting BP measurements between 1948 and…
Key issues in decomposing fMRI during naturalistic and continuous music experience with independent component analysis
2014
Background: Independent component analysis (ICA) has been often used to decompose fMRI data mostly for the resting-state, block and event-related designs due to its outstanding advantage. For fMRI data during free-listening experiences, only a few exploratory studies applied ICA.New method: For processing the fMRI data elicited by 512-s modern tango, a FFT based band-pass filter was used to further pre-process the fMRI data to remove sources of no interest and noise. Then, a fast model order selection method was applied to estimate the number of sources. Next, both individual ICA and group ICA were performed. Subsequently, ICA components whose temporal courses were significantly correlated …
Unique sleep-stage transitions determined by obstructive sleep apnea severity, age and gender
2019
In obstructive sleep apnea, patients' sleep is fragmented leading to excessive daytime sleepiness and co-morbidities like arterial hypertension. However, traditional metrics are not always directly correlated with daytime sleepiness, and the association between traditional sleep quality metrics like sleep duration and arterial hypertension is still ambiguous. In a development cohort, we analysed hypnograms from mild (n = 213), moderate (n = 235) and severe (n = 277) obstructive sleep apnea patients as well as healthy controls (n = 105) from the European Sleep Apnea Database. We assessed sleep by the analysis of two-step transitions depending on obstructive sleep apnea severity and anthropom…
Uncertainty quantification in simulations of epidemics using polynomial chaos.
2012
Mathematical models based on ordinary differential equations are a useful tool to study the processes involved in epidemiology. Many models consider that the parameters are deterministic variables. But in practice, the transmission parameters present large variability and it is not possible to determine them exactly, and it is necessary to introduce randomness. In this paper, we present an application of the polynomial chaos approach to epidemiological mathematical models based on ordinary differential equations with random coefficients. Taking into account the variability of the transmission parameters of the model, this approach allows us to obtain an auxiliary system of differential equa…
Regression of structural vascular changes in hypertensives after captopril treatment.
1992
In order to investigate whether hypertension-related structural vascular changes may be influenced by antihypertensive treatment, 10 patients were studied suffering from essential arterial hypertension, five males and five females, aged between 34 and 61 years (mean age: 46.9 +/- 8.13 years). All patients received a placebo for 1 week and then captopril, 75 mg b.i.d. for 3 months. After placebo and captopril treatments, the following parameters were evaluated: SBP, DBP, mean blood pressure (MBP), by the formula 1/3 (SBP + 2 x DBP) and basal and minimal vascular resistances, respectively obtained by the ratios MBP/rest flow and MBP/peak flow. Blood flows have been obtained by strain gauge pl…
The reliability of measuring medial gastrocnemius muscle-tendon unit lengths during gait
2021
Background Ultrasound imaging combined with 3D motion analysis allows for in-vivo assessment of muscle-tendon unit lengths during gait. The clinical relevance of analysing the medial gastrocnemius (MG) and Achilles muscle-tendon junction (MTJ), MG mid-muscle belly fascicles (FAS) and muscle thickness was shown. However, their reliability error estimations over the gait cycle is unknown. Research question What are the intra- and inter-session errors associated with extracting MG belly, thickness, FAS and tendon lengths using ultrasound during gait in healthy participants? Methods 3D gait analysis was carried out in ten healthy adults as they walked on an instrumented treadmill at a comfortab…
Does ovarian blood flow distinguish between ovulatory and anovulatory patients with polycystic ovary syndrome?
2003
The purpose of this study was to determine whether parameters of ovarian blood flow distinguish between women with polycystic ovary syndrome (PCOS) who ovulate and those who are anovulatory.This was a prospectively enrolled trial, carried out as a cross-sectional comparison of 12 ovulatory patients with PCOS and 20 matched subjects with classic PCOS and 10 healthy control subjects. Hormonal parameters and ovarian blood flow by color flow Doppler imaging were obtained in the early follicular phase.Characteristic elevations in luteinizing hormone (LH) and androgens were found in both groups with PCOS compared with control groups. Women with anovulatory PCOS had high insulin levels and lower Q…
Developing a prototype for short-term psychodynamic (supportive-expressive) therapy: An empirical study with the psychotherapy process Q-set.
2015
AbstractObjective: A Psychotherapy Process Q-set (PQS) prototype characteristic of short-term psychodynamic therapy (STPP) does not yet exist. Method: Experts in supportive-expressive (SE) therapy used the 100-Item PQS questionnaire to rate an ideal short-term SE therapy. Results: Agreement between raters was high (Cronbach's alpha = 0.94). The prototype for SE therapy showed a significant correlation with the psychoanalytic prototype, but with 28% of variance explained, the majority of variance of the former was not explained by the latter or vice versa. Furthermore, the SE prototype showed significant correlations with the cognitive-behavioral prototype and the prototype of interpersonal …
Mass Output and Particle Size Distribution of Glucocorticosteroids Emitted from Different Inhalation Devices Depending on Various Inspiratory Paramet…
2002
Efficient inhalation therapy depends on successful delivery of the drug to the lung. The efficacy of drug delivery is not only influenced by the characteristics of the inhalation device, but also by the patient's handling of the device and by the inspiratory maneuver achieved through the device. We analyzed the output characteristics of three different chlorofluorocarbon (CFC)-free breath-actuated inhalers for inhaled glucocorticosteroids (BUD Turbohaler, FP Diskus/Accuhaler and HFA-BDP Autohaler, respectively). Mass output and particle size distribution of drug aerosol delivered by the inhalers were determined depending on different inhalation parameters in vitro using an Andersen cascade …
A minimal limit-cycle model to profile movement patterns of individuals during agility drill performance: Effects of skill level.
2015
Identification of control strategies during agility performance is significant in understanding movement behavior. This study aimed at providing a fundamental mathematical model for describing the motion of participants during an agility drill and to determine whether skill level constrained model components. Motion patterns of two groups of skilled and unskilled participants (n = 8 in each) during performance of a forward/backward agility drill modeled as limit-cycles. Participant movements were recorded by motion capture of a reflective marker attached to the sacrum of each individual. Graphical and regression analyses of movement kinematics in Hooke’s plane, phase plane and velocity prof…