• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 397
  • 176
  • 67
  • 37
  • 29
  • 28
  • 24
  • 24
  • 15
  • 11
  • 8
  • 7
  • 6
  • 4
  • 4
  • Tagged with
  • 949
  • 113
  • 101
  • 85
  • 79
  • 64
  • 60
  • 60
  • 55
  • 55
  • 48
  • 47
  • 45
  • 44
  • 44
  • 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.
371

CHILD SLEEP AND MENTAL HEALTH OUTCOMES: A MIXED COHORT OF FAMILIES WITH AND WITHOUT NEUROGENETIC SYNDROMES

Kimberly Galvez-Ortega (15343813) 24 April 2023 (has links)
<p><strong>Purpose: </strong>Previous work demonstrates a link between poor child sleep and increased caregiver mental health symptoms. In particular, children with NGS are known to experience severe and persistent sleep difficulties. Few studies have examined the association between child sleep disturbances and caregiver internalizing symptoms across families affected by neurogenic syndromes. More specifically, no study has examined how sleep disturbances in children diagnosed with NGS impact caregiver internalizing symptoms severity across development (from infancy to school-age children), using a longitudinal framework and multilevel analyses<em>. </em>Thus, the current study aims to test the effect of child sleep duration on caregiver mental health changes over the course of development (child age, from infancy to school-age children) in a mixed cohort of families affected by neurogenetic syndromes and a sub-group of neurotypical children. <strong>Method: </strong>A total of 193 caregivers were recruited, via web-based support groups, syndrome research registries, and social networks, as part of a broader longitudinal study, the Early Phenotype Study. To measure child sleep duration and caregiver internalizing symptoms, parents completed the Brief Infant Sleep Questionnaire and the Depression, Anxiety, and Stress Scale, respectively, at each time point yielding a total of 718 observations. Separate multilevel models were conducted for caregiver depression, anxiety, and stress in relation to child sleep duration at the between- and the within-person level with child age as a moderator. <strong>Results: </strong>Results of the present study revealed a between-person main effect of child sleep duration on caregiver symptoms of depression and a within-person effect of child sleep duration on stress symptoms in caregivers. The moderating effect of child age was not statistically significant across models. <strong>Conclusions: </strong>Overall, findings of the current study support previous literature and suggest child sleep duration may provide us with information on who may be at greater risk of exhibiting greater symptoms of depression, drawing the importance of focusing on improving child sleep duration as a way to reduce caregiver mental health challenges. </p>
372

Recollections: An Internal Analysis of Memory and Perception

Jimenez, Samuel 01 January 2014 (has links)
I investigate the depths of memory, the entanglement of personal recollections with communal knowledge (learned semantic information from media and society such as facts and social norms) and the changing perceptions of environments over time. Memories define us. Throughout life we are exposed to vast quantities of imagery through a variety of media and personal experiences. Over time our firsthand experiences and what we witness in film, print, photography, and the internet become indistinguishable in our memory. My work recreates consequential scenes from my past through technical drawings and blended imagery while exploring the possibilities provided by the interaction of common knowledge and the ambiguous nature of memory.
373

Temperatur, träningsintensitets och durations påverkan på längdskidåkares och skidskyttars astma

Flink, Filip January 2022 (has links)
Purpose: The purpose of this study is to research how temperature; training intensity and duration affect cross country-skiers and biathlon´s asthma. With the aim to establish optimal training guidelines to optimize the asthmatic cross-country skiers and biathlete´s training results. Theoretical framework: The theoretical framework is based on the background and research, for the purpose to interpret and discuss the results. AQUA©: Allergy Questionnaire for Athletes ©, research and a training intensity pyramid have been used to shape the quantitative survey. Method: The quantitative survey was done by 68 participants, between age 17-68. Of the 68 participants; 21 have been diagnosed with asthma (30,88%), 15 people have at some point suspected that they have asthma (22,06%) and 32 people have never experienced or have any asthmatic symptoms (47,06%). Participants self-categorized as either: practicing cross-country skiers, practicing biathlete´s, competitive cross-country skiers, competitive biathlete´s, elite/national team cross-country skiers or elite/national team biathlete´s. The surveys data were analysed by using bivariate Pearson´s r and frequency distribution, for the purpose to compare between the significant results and the frequency distribution. Result and summary: The results shows that the asthmatic cross-country skiers and biathlete´s are mainly affected by temperature and training intensity. While training duration plays a small significant role. No guidelines could be established. But it´s possibly recommended to use a breathing mask with a heat and moisture exchanger to counteract the respiratory symptoms.
374

The Role of Stress and Discrimination on Exclusive Breastfeeding Duration

Dugat, Vickie Mitchell January 2022 (has links)
No description available.
375

A psychophysical investigation of audio-visual timing in the millisecond range.

Hotchkiss, John January 2012 (has links)
The experiments described in this thesis use psychophysical techniques and human observers to investigate temporal processing in the millisecond range. The thesis contains five main sections. Introductory chapters provide a brief overview of the visual and auditory systems, before detailing our current understanding of duration processing. During the course of this review, several important questions are highlighted. The experiments detailed in Chapters 8-11 seek to address these questions using the psychophysical techniques outlined in Chapter 7. The results of these experiments increase our understanding of duration perception in several areas. Firstly, Experiments 1 and 2 (Chapter 8) highlight the role of low level stimulus features: even when equated for visibility stimuli of differing spatial frequency have different perceived durations. Secondly, a psychophysical hypothesis arising from the ¿duration channels¿ or ¿labelled lines¿ model of duration perception is given strong support by the adaptation experiments detailed in Chapter 9 and 10. Specifically, adaptation to durations of a fixed temporal extent induces repulsive duration aftereffects that are sensory specific and bandwidth limited around the adapted duration. Finally Chapter 11 describes the results of experiments designed to probe the processing hierarchy within duration perception by measuring the interdependency of illusions generated via duration adaptation and via multisensory cue combination. The results of these experiments demonstrate that duration adaptation is a relatively early component of temporal processing and is likely to be sub served by duration selective neurons situated in early sections of the visual and auditory systems.
376

The role of sensory history and stimulus context in human time perception. Adaptive and integrative distortions of perceived duration

Fulcher, Corinne January 2017 (has links)
This thesis documents a series of experiments designed to investigate the mechanisms subserving sub-second duration processing in humans. Firstly, duration aftereffects were generated by adapting to consistent duration information. If duration aftereffects represent encoding by neurons selective for both stimulus duration and non-temporal stimulus features, adapt-test changes in these features should prevent duration aftereffect generation. Stimulus characteristics were chosen which selectively target differing stages of the visual processing hierarchy. The duration aftereffect showed robust interocular transfer and could be generated using a stimulus whose duration was defined by stimuli invisible to monocular mechanisms, ruling out a pre-cortical locus. The aftereffects transferred across luminance-defined visual orientation and facial identity. Conversely, the duration encoding mechanism was selective for changes in the contrast-defined envelope size of a Gabor and showed broad spatial selectivity which scaled proportionally with adapting stimulus size. These findings are consistent with a second stage visual spatial mechanism that pools input across proportionally smaller, spatially abutting filters. A final series of experiments investigated the pattern of interaction between concurrently presented cross-modal durations. When duration discrepancies were small, multisensory judgements were biased towards the modality with higher precision. However, when duration discrepancies were large, perceived duration was compressed by both longer and shorter durations from the opposite modality, irrespective of unimodal temporal reliability. Taken together, these experiments provide support for a duration encoding mechanism that is tied to mid-level visual spatial processing. Following this localised encoding, supramodal mechanisms then dictate the combination of duration information across the senses.
377

Nonindustrial private forest landowner participation in incentive programs and regeneration behavior

Sun, Xing 15 December 2007 (has links)
Nonindustrial private forest (NIPF) landowners have been major players in increasing forest productivity and improving forest health. Understanding what factors influence landowner participation in government programs, and furthermore, what factors determinate how quickly after harvest landowners regenerate, is critical for developing policies to improve landowner participation in government assistance programs and timely regeneration of harvested lands. Two studies were conducted to investigate these issues. The necessary data were obtained through a 2006 telephone survey of randomly selected Mississippi NIPF landowners. Factors considered included an array of land, ownership, management, and demographic characteristics. In the first study, a two-step landowner behavior model was constructed to explain NIPF landowner participation in government incentive programs, conditional on their awareness of these programs. The second study used duration analysis to analyze the time elapsed between harvest and regeneration. Interest in timber production, past regeneration experience, education, and membership in forestry organization influenced NIPF landowner knowledge of incentive programs and were significant predictors of participation. Those NIPF landownersn who regenerated, did so on average, 11 months after harvest. After the 16th month following harvest, the probability of regenerating harvested lands decreased rapidly. The interval between harvest and reforestation was reduced by maintaining an interest in timber production, consulting a forester to coordinate the harvest, residing on the forest land, having planted pines, and increasing timber prices.
378

The Role of Spatial Structure in Human Duration Processing

Collins, Howard P. January 2020 (has links)
This thesis presents a series of human psychophysical experiments designed to examine the interaction between the reliability of spatial form information and the neural mechanisms responsible for the processing of sub-second durations. Duration discrimination sensitivity was found to be lower when event durations were defined by stimulus characteristics that caused reductions in spatial form sensitivity. This form-duration sensitivity coupling persisted across stimuli defined both by crossed and uncrossed retinal disparity and within monocularly visible texture-defined stimuli. The interaction was also observed when spatial form was degraded by physical instability within shape borders, and when physically stable borders became perceptually unstable. These effects could not be attributed to artefacts of stimulus visibility, temporal coherence or stimulus size. Adaptation experiments generated aftereffects of perceived duration within stimuli whose durations were defined solely by retinal disparity, providing the first demonstration of duration selectivity within exclusively cortical duration encoding mechanisms. The selectivity of these aftereffects was then investigated using adapting and testing durations defined by matching or opposing retinal disparities. Duration aftereffects were maximal when adapt and test disparities were matched. However, there was partial transfer of duration aftereffects across large changes in retinal disparity, implicating contributions from higher-level extra-striate mechanisms. Collectively, these experiments provide support for duration processing mechanisms that are inextricably linked to the mechanisms underpinning spatial processing across multiple levels of the visuo-spatial hierarchy.
379

A duration dependent model of the effects of job stress on the speed of seeking treatment for health problems

Sokoloff, Robert Michael January 1994 (has links)
No description available.
380

FACTORS PREDICTING THE EXERCISE BEHAVIOR OF THE ELDERLY

Pathumarak, Narumon 14 July 2005 (has links)
No description available.

Page generated in 0.1073 seconds