Search results for " stage"
showing 10 items of 616 documents
Deterministic chaos and the first positive Lyapunov exponent: a nonlinear analysis of the human electroencephalogram during sleep
1993
Under selected conditions, nonlinear dynamical systems, which can be described by deterministic models, are able to generate so-called deterministic chaos. In this case the dynamics show a sensitive dependence on initial conditions, which means that different states of a system, being arbitrarily close initially, will become macroscopically separated for sufficiently long times. In this sense, the unpredictability of the EEG might be a basic phenomenon of its chaotic character. Recent investigations of the dimensionality of EEG attractors in phase space have led to the assumption that the EEG can be regarded as a deterministic process which should not be mistaken for simple noise. The calcu…
The calculation of the first positive Lyapunov exponent in sleep EEG data
1993
To help determine if the EEG is quasiperiodic or chaotic we performed a new analysis by calculating the first positive Lyapunov exponent L1 from sleep EEG data. Lyapunov exponents measure the mean exponential expansion or contraction of a flow in phase space. L1 is zero for periodic as well as quasiperiodic processes, but positive in case of chaotic processes expressing the sensitive dependence on initial conditions. We calculated L1 for sleep EEG segments of 15 healthy male subjects corresponding to sleep stages I, II, III, IV and REM (according to Rechtschaffen and Kales). Our investigations support the assumption that EEG signals are neither quasiperiodic waves nor simple noise. Moreover…
Physical activity, healthy behaviors and its motivational correlates: exploring the spillover effect through stages of change
2022
On the basis of the spillover or transfer effect and the transtheoretical model of change, this study assessed the association between amount of physical activity, healthy and unhealthy weight control behaviors, and motivational types, as well as their variability across stages of change. A total of 1219 randomly selected Mexican adults from 18 to 65 years old, representative of the city of Monterrey (México), participated in the study. Correlation analyses, differences by gender, and multivariate analyses of variance, controlling for age, were performed. We found that in the maintenance stage, there is higher frequency of physical activity more healthy weight control behaviors, as well as …
Plasticity of brain wave network interactions and evolution across physiologic states
2015
Neural plasticity transcends a range of spatio-temporal scales and serves as the basis of various brain activities and physiologic functions. At the microscopic level, it enables the emergence of brain waves with complex temporal dynamics. At the macroscopic level, presence and dominance of specific brain waves is associated with important brain functions. The role of neural plasticity at different levels in generating distinct brain rhythms and how brain rhythms communicate with each other across brain areas to generate physiologic states and functions remains not understood. Here we perform an empirical exploration of neural plasticity at the level of brain wave network interactions repre…
Subchronic Effects of Olanzapine on Sleep EEG in Schizophrenic Patients with Predominantly Negative Symptoms
2004
Background It is well known that sleep disturbance is an integral symptom of schizophrenia. In recent studies, a deficit of delta sleep has been observed in schizophrenic patients. Antipsychotic drugs with serotonin (5-HT2) receptor-antagonistic properties are considered to have delta sleep promoting effects. We have investigated the effects of subchronic olanzapine treatment on sleep EEG in schizophrenic patients. Methods The effects of administration of olanzapine (15 to 20 mg) on sleep were studied for four weeks in 10 male, drug-free patients suffering from schizophrenia with predominantly negative symptoms. Conventional sleep EEG parameters were investigated at baseline and after treat…
Paclitaxel, carboplatin and gemcitabine combination as induction chemotherapy for stage IIIA N2 bulky non-small cell lung cancer
2005
<i>Background:</i> Induction chemotherapy followed by surgical resection or definitive radiotherapy for patients affected by stage IIIA N2 bulky non-small cell lung cancer (NSCLC) has been investigated in several trials. <i>Patients and Methods:</i> In this present study, 52 patients with stage IIIA N2 bulky NSCLC with cytologically or histologically confirmed mediastinal lymph node involvement received paclitaxel 175 mg/mq on day 1, carboplatin AUC 5 on day 1 and gemcitabine 1,000 mg/mq on day 1 and 8 every 3 weeks for three cycles as induction chemotherapy. <i>Results:</i> Objective response (4 complete remission and 36 partial remission) was achieved i…
Longitudinal associations between parental and offspring's leisure-time physical activity: The Young Finns Study.
2021
Purpose The longitudinal influence of parental leisure-time physical activity (LTPA) on their offspring's LTPA is poorly understood. This study examined the longitudinal associations between parental LTPA and offspring's LTPA at two-time intervals. Method Child (offspring) participants (N=3596) were enrolled from the Cardiovascular Risk in Young Finns Study in 1980. Their LTPA was self-rated through nine phases from baseline to 2018 and categorized by year into youth (1980-1986) and adult (1992-2018) LTPA. Parental LTPA was assessed with a single self-reported question at three phases from 1980 to 1986. Latent growth curve modeling stratified by gender was fitted to estimate the potential p…
Diet and Neurodevelopmental Score in a Sample of One-Year-Old Children-A Cross-Sectional Study
2019
Environmental factors in the first years of life are crucial for a child&rsquo
Implementation Fidelity of a Program Designed to Promote Personal and Social Responsibility Through Physical Education
2011
The purpose of this qualitative comparative case study was to examine the implementation fidelity of a program designed to deliver the Teaching Personal and Social Responsibility (TPSR) model (Hellison, 2003) through physical education and its relationship with short-term outcomes for elementary school students. The research questions were: (a) was the program implemented with fidelity, and (b) did better fidelity yield better student outcomes. Thus, we conducted a study on the implementation process used by two teachers who delivered the same program in two physical education classes in two different elementary schools in Spain. Data sources included observations and interviews with teache…
Irregular assimilation progress: Reasons for setbacks in the context of linguistic therapy of evaluation
2012
The assimilation model suggests progress in psychotherapy follows an eight-stage sequence described by the Assimilation of Problematic Experiences Scale (APES). This study sought to reconcile this developmental stage model with the common but superficially contradictory clinical observation that therapeutic advances alternate with setbacks. Setbacks (n=466) were identified in therapy transcripts of two clients and classified using a preliminary nine-category list of possible alternative reasons for setbacks. Most of the setbacks involved switches among the multiple strands of a problem due to (a) therapists exceeding clients' therapeutic zone of proximal development, (b) therapists guiding …