• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 427
  • 363
  • 89
  • 44
  • 21
  • 15
  • 15
  • 11
  • 10
  • 9
  • 8
  • 6
  • 5
  • 5
  • 4
  • Tagged with
  • 1229
  • 1229
  • 489
  • 315
  • 236
  • 208
  • 189
  • 188
  • 185
  • 168
  • 146
  • 143
  • 121
  • 98
  • 97
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Effects of selected body positions on diastolic blood pressure and heart rate during the Valsalva maneuver a research report submitted in partial fulfillment ... /

Clavijo E., Judith. January 1987 (has links)
Thesis (M.S.)--University of Michigan, 1987.
142

The relation of hypertrophic tonsillar tissue to pulse rate a dissertation submitted in partial fulfullment ... Master of Science in Public Health ... /

Powers, Leland E. January 1939 (has links)
Thesis (M.S.P.H.)--University of Michgian, 1939.
143

The effects of glucose tolerance, hypertension, and race on heart rate variability, QT interval duration, and left ventricular hypertrophy in overweight-obese adolescents

Lee, Shirleatha T., January 2009 (has links) (PDF)
Thesis (Ph.D.)--University of Tennessee Health Science Center, 2009. / Title from title page screen (viewed on August 27, 2009). Research advisor: Patricia A. Cowan, Ph.D. Document formatted into pages (x, 71). Vita. Abstract. Includes bibliographical references (p. 56-70).
144

Relationship of stress to gastrointestinal symptoms in women with irritable bowel syndrome /

Hertig, Vicky L. January 2005 (has links)
Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 116-130).
145

Working Memory in Adults with Aphasia: Considering Effort Invested through a Physiological Measure - Heart Rate Variability

January 2012 (has links)
abstract: Working memory (WM) and attention deficits have been well documented in individuals with aphasia (IWA) (e.g. Caspari et al., 1998; Erickson et al., 1996; Tseng et al., 1993; Wright et al., 2003). Research into these cognitive domains has spurred a theoretical shift in how aphasia is conceptualized - from a purely linguistic disorder to a cognitive-information processing account. Language deficits experienced by IWA may result from WM impairments or from an inability to allocate cognitive effort to the tasks. However, how language impacts performance on these tasks has not been readily investigated. Further, there is a need for a more direct measure of effort invested to language tasks. Heart rate variability (HRV) is a physiological measure of cognitive workload that has been used to measure effort in neurologically intact participants. Objectives of the study included: (1) determining the feasibility of using HRV as a measure of effort IWA invest into verbal compared with spatial WM tasks, (2) Comparing participants' performance on verbal and spatial WM tasks; and (3) determining the relationship among performance, perceived task difficulty, and HRV across verbal and spatial tasks. Eleven IWA and 21 age- and education-matched controls completed verbal and spatial n-back tasks at three difficulty levels. Difficulty ratings were obtained before and after each task. Results indicated spatial WM was relatively preserved compared with verbal WM for the aphasia group. Additionally, the aphasia group was better at rating task difficulty after completing the tasks than they were at estimating task difficulty prior to completing the tasks. Significant baseline-task differences in HRV were found for both groups. Relationships between HRV and performance, and HRV and task difficulty were non-significant. Results suggest WM performance deficits in aphasia may be primarily driven by their language deficit. Baseline-task differences in HRV indicate effort is being allocated to the tasks. Difficulty ratings indicate IWA may underestimate task demands for both verbal and spatial stimuli. However, the extent to which difficulty ratings reflect effort allocated remains unclear. Additional research is necessary to further quantify the amount of effort IWA allocate to verbal and non-verbal tasks. / Dissertation/Thesis / Ph.D. Speech and Hearing Science 2012
146

Modelování změn intrakraniálního tlaku (ICP) během fyziologických a patologických dějů / Modelling of changes of the intracranial pressure (ICP) during physiological and pathological processes

Vaněk, Petr January 2016 (has links)
The more we know about the circulation of CSF through ventricle system, brain parenchyma, subarachnoideal space and the development of intracranial pressure (ICP), the more we understand different pathologies and pathological processes of the central cervous system. The knowledge about the basic hydrodynamic charecteristics of craniospinal system is a key factor for understanding a wide range of pathological situations affecting CNS, these are for example intracranial hypertension, normal pressure hydrocephalus and syringomyelia. In the presented paper, we are presenting a newly developed measuring system Visionbrain that enables us to gain the biological data and consequently to analyse them. At the same time, the results of such measurements were used to specify the compertmental model of CSF circulation. The model devides craniospinal system into five divisions - two intracranial and three spinal. Such model is the third generation of this model and, compared to the older version, it includes two intracranial veins. Thanks to this stucture, the model enables us simultaneous modeling of heart and respiratory pulsations of CSF. Compared to the other published models, it also includes defined structure of spinal part. The model is derived using laws of conservation and it encompasses pressure...
147

Stress Reactivity as a Predictor of Emotional Eating

January 2016 (has links)
abstract: Childhood obesity is associated with many well established health risks as well as high annual public health costs. Because of this, the childhood obesity literature has highlighted the need to detect at-risk groups in order to implement targeted preventions. Emotional eating has been identified as an unhealthy behavior and a risk factor for overweight status among children though very little is known about what predisposes children to emotionally eat. Stress has often been found to elicit emotional eating but most studies looking at this relationship have relied on self-reports in adult and clinical samples. Thus, the current study seeks to investigate the relationship between stress reactivity (measured using heart rate variability) and emotional eating in a sample of 247 children between the ages of 4-6. Furthermore, levels of control may moderate the relationship between stress reactivity (HRV) and emotional eating. Linear regression analysis was used to explore these relationships. It was expected that higher levels of reactivity to stress would predict an increased likelihood of emotional eating. This association was expected to be attenuated among children with higher levels of inhibitory control and attentional focusing as well as lower levels of impulsivity. However, the hypothesized findings were not supported by the data. Despite these null findings, and in light of several limitations, it is still hypothesized that emotional eating involves physiological and impulsivity/effortful control processes. Implications of future research are discussed. / Dissertation/Thesis / Masters Thesis Psychology 2016
148

An examination of the training loads within elite professional football

Malone, James J. January 2014 (has links)
The popularity of soccer throughout the world has led to the demand for a scientific approach to the preparation of players for competitive matches. Although previous researchers have attempted to understand the training demands undertaken by soccer players, limited information is known regarding the structure of training in soccer. At present research has focused on the frequency and duration of soccer training without using both objective and subjective measures of training load to systematically evaluate training practices in elite teams. Little is also known regarding the periodisation strategies employed by elite soccer teams across a competitive season and whether they follow traditional models of periodisation. With this in mind, the primary aim of this thesis is to therefore characterise the current training periodisation practices that exist in elite soccer using applied methods of training load assessment. The aim of the first study (Chapter 3) was to evaluate the use of Global Positioning Devices (GPS) for the measurement of soccer-specific activities to provide objective data for training load assessment. Findings from this study were applied to study 3 (Chapter 5) of the thesis. Firstly, a soccer-specific movement course was designed based on the movements exhibited by an elite soccer player during a competitive match using a multi-camera tracking system (ProZone®). Two moderately trained males performed 10 bouts of the soccer-specific track following familiarisation and a 10 minute standardised warm up. Both subjects wore two 10Hz GPS units inside a custom-made vest during all bouts of the track to determine both reliability and inter-unit reliability of the GPS devices. Data analysis revealed the reliability of the GPS devices was good for distance covered at lower velocities (0 – 4 m/s; CV% = 0.6 – 3.6%). However when the velocity of movement increased (> 4 m/s), the reliability of the units decreased (mean change from 13.8 to 33.6 CV%). Both total distance (mean CV% = 1.1%) and max speed (mean CV% = 2.7%) were both found to be highly reliable variables. However the devices demonstrated high levels of inter-unit reliability error due to an increase in systematic error with random distribution of data points between both devices for all variables measured. The data suggested that 10Hz GPS devices are reliable for the measurement of lower velocity (0 – 4 m/s) running. However, care must be taken when analysing data in higher velocity bands (> 4 m/s) due to the high ii error rates observed. The high inter-unit reliability error also suggests that 10Hz GPS devices cannot be used interchangeably between players in order to minimise the associated error. The aim of the second study (Chapter 4) was to quantify the reliability and validity of a portable vertical jump assessment tool (Optojump®) for use in the applied setting. Vertical jump assessment was utilised as a measurement tool to analyse the effect of training load on the neuromuscular system that was evaluated in study 4 (Chapter 6) of the thesis. Eleven healthy male subjects were familiarised to perform four separate common types of vertical jump test: countermovement with arm swing (CMJ-W), countermovement without arm swing (CMJ-WO), squat jump (SJ) and drop jump (DJ). Contact time, flight time and jump height were selected as variables for the study. For reliability assessment, all subjects performed 3 efforts of each jump type across 5 identical testing sessions (separated by minimum of 2 days). For validity assessment, subjects were asked to perform the same jump modalities as the previous investigation on one occasion while data was simultaneously collected from both a force plate (criterion instrument) and the Optojump photocells. The data revealed the Optojump device was highly reliable for the assessment of jump flight and height for CMJ-W, CMJ-WO, SJ and DJ (all CV% = 3.2 and 5.6%). However reliability of the device was reduced for the measurement of contact time with the DJ (CV% = 13.9%). Validity data revealed that all jump types and variables were highly valid in comparison to the force plate criterion measure (SEE% = < 1%, Pearsons correlation = r > 0.99). This study revealed that the Optojump device is highly reliable and valid for all jump types and variables, with the exception of contact time for DJ. Therefore the Optojump system may be used with confidence to detect within-group changes in applied assessments of vertical jump performance. Due to the high cost and lack of portability of laboratory-based force plates, the Optojump system is a viable alternative for accurate jump measurement and neuromuscular assessment. The CMJ-WO jump assessment was chosen for study 4 for comparison with previous research. The aim of the third study (Chapter 5) was to quantify the periodisation strategies employed by an elite professional soccer team throughout a competitive season. Training load data was collected from 37 elite outfield soccer players at one professional English soccer team over a 45 week period during the 2011-2012 domestic season. All players wore iii global positioning system (GPS) devices, heart rate (HR) belts and were asked to provide a rating of perceived exertion (RPE) for each training session to generate training load data. Players were assigned to one of 5 positional groups: central defender (CD), wide defender (WD), central midfielder (CM), wide midfielder (WM) and attacker (AT). The data was separated into the pre-season (6 weeks duration) and in-season (39 weeks duration) phases in order to investigate specific training periods recognised within the annual plan. The pre-season phase was further separated into weekly blocks for analysis of the structure employed in each specific microcycle. The in-season phase was divided into 6 x 6 week blocks for analysis of mesocycle structure. Within the in-season data, three separate microcycles (weeks 7, 24 and 39) were selected consisting of the same weekly training schedules to determine whether differences in microcycle training load pattern existed. In addition, the training data within a given microcycle was analysed to investigate the loading patterns in relation to number of days away from the competitive match fixture. Linear mixed modelling analysis revealed significant differences for total distance and average HR (P < 0.05) between period 1 with periods 3 and 6 during training mesocycles. However no differences were found for the remaining training variables during both pre-season and in-season microcycles (P > 0.05). Training load variables were significantly reduced on match day (MD) -1 (P < 0.05) but remained similar across MD-2, MD-3 and MD-5 (P > 0.05) during in-season microcycles. CM players generally covered the most total distance compared to other positions. Defenders reported higher internal load values (average HR and RPE) compared to attackers during in-season training phases but such differences were not evident during pre-season. This study revealed that training load doesn’t appear to be systematically periodised across a competitive season in an elite soccer team. This may have practical implications for training planning, as monotonous training load prescription may lead to maladaptation in soccer players during a competitive season. This was the first study to systematically evaluate periodisation strategies in an elite soccer team, but further work is required to determine such practices at different soccer teams. The aim of the fourth study (Chapter 6) was to determine the neuromuscular response to a microcycle of soccer training in elite soccer players using vertical jump assessment via the Optojump device. Nine elite level youth soccer players from an U18 soccer academy team were recruited for the study. The players underwent four separate on-field soccer training sessions following familiarisation of all testing procedures.
149

Změny elektrického pole srdce u poruch glukózového metabolismmu a možnosti jejich ovlivnění úpravou narušené autonomní nervové regulace / Changes of the electric field of the heart in disorders of glucose metabolism and ways of influencing them by correction of impaired autonomic nervous regulation

Fialová, Elena January 2017 (has links)
Diabetes mellitus (DM) is not just a simple metabolic disorder, however, it is considered to be a cardiovascular disease of a metabolic origin. This is apparent especially when speaking about type 2 diabetes (DM II). Patients with DM have a high occurrence of vegetative nervous system (VNS) disorders that manifest themselves as an increased activity of the sympathetic nervous system that correlates with peripheral autonomic neuropathy and is considered to be the major pathophysiological mechanism for the development of DM II. The objective of our study was to determine whether a comprehensive spa treatment (ST) may affect the level of the sympathetic tone of patients suffering from DM II. As an indicator of the sympathetic tone, selected electrocardiographic parameters derived from the HRV, microvolt T-wave alternans, and microvolt R-wave alternans were evaluated. The electrophysiological examination of patients was performed before and after a three-week spa treatment using the KARDiVAR system. The method is used to examine the current state of the autonomic nervous system and carry out an analysis of risk factors and adaptive capabilities of the organism. The results showed favorable changes in DM II patients after the ST, primarily in terms of reduced sympathetic adrenal system activity,...
150

Cardiovascular autonomic dysfunction in Parkinsonian syndromes

Kallio, M. (Mika) 24 July 2001 (has links)
Abstract Autonomic nervous system (ANS) disturbances are common in Parkinson's disease (PD), but also in other Parkinsonian syndromes, especially in multiple system atrophy (MSA). The differentiation between various Parkinsonian syndromes may be difficult, but it is important for prognostic and therapeutic purposes. The aim of this study was to determine the ability of different analysis methods to reveal cardiovascular regulation disturbances in PD and to evaluate the diagnostic capacity of autonomic tests to differentiate between various Parkinsonian syndromes. Furthermore, this study aimed to evaluate the relationships between ANS disturbances and the clinical characteristics of PD. In addition, the cardiac autonomic function was evaluated during various sleep stages for the first time in untreated PD patients by using spectral heart rate variability (HRV) measures to determine possible sleep stage specific cardiovascular regulation disturbances. Cardiovascular autonomic reflexes were evaluated in 62 untreated and newly diagnosed PD patients, 34 PD patients under antiparkinsonian medication, 47 MSA patients and 15 patients with progressive supranuclear palsy (PSP). The usefulness of different analysis methods was evaluated in a subgroup of 32 untreated PD patients. A further 21 untreated PD patients underwent one-night polysomnography for nocturnal heart rate variability analysis. PD patients with hypokinesia/rigidity as their initial onset sign had a significantly lower max-min ratio in the deep breathing test than those patients with tremor as the initial sign. MSA patients showed significant reductions in both HRV and blood pressure responses during orthostatic provocation, whereas PSP patients had normal results. Absolute spectral measures yielded the clearest indicators separating the PD patients from the controls, while the cardiovascular reflexes proved more useful than the normalised spectral HRV measures in revealing the differences between the two groups. HRV was abnormally decreased during non-REM sleep in PD patients but not during REM sleep or the S1 sleep stage. The normalized high frequency power was significantly decreased in PD patients during sleep stages S2-4, while the standard deviation of the R-R intervals was increased during the same sleep stages, possibly corresponding to the increased motility of PD patients during these sleep stages. The clinical characteristics of PD deserve particular attention in connection with ANS disturbances, since autonomic failure seems to be more pronounced in PD patients with hypokinesia/rigidity as their initial sign. The evaluation of the autonomic function may also be helpful in the differential diagnosis of Parkinsonian syndromes. Spectral analysis methods should be implemented in the evaluation of ANS dysfunction to achieve the best possible efficacy in the differentiation of pathological responses from normal ones. Nocturnal analysis of cardiovascular regulation revealed new and interesting features of pathologic HRV in PD patients, thus when HRV is evaluated, the different sleep stages should be analysed separately.

Page generated in 0.0222 seconds