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  • 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.
171

Teaching reading to adults where English is their second language

Powell, Judith Ann 01 January 2008 (has links)
This project sought to identify methods that will work best for Second Language (ESL) adults and identify ways in which ESL can be taught to help facilitate learning for the older adult over 40 years of age. This project identified some of the problems caused by the nature of the English language and the grammatical issues older ESL students face when attempting to learn to speak and read English.
172

Supervisor-Subordinate Directional Age Differences and Employee Reactions to Formal Performance Feedback: Examining Mediating and Moderating Mechanisms in a Chinese Sample

Burlacu, Gabriela 07 February 2013 (has links)
As a result of changing demographic trends in today's workforce, employees of all ages can now be found in all career stages. Consequently, the pairing of a younger supervisor with a relatively older employee is becoming increasingly more common. Research in the United States has shown that such demographically "non-normative" pairings have negative implications for employee attitudes and behaviors, and thus for employee performance management. However, little is known about the effects of such pairings in other nations and cultures, despite the fact that these demographic shifts are occurring on a global level. As such, this study examined the effects of these pairings on employee reactions to formal performance feedback episodes in a large organization in China, due to the nation's similarly shifting demographic trends and its economic power in today's global economy. A series of path analyses showed that being paired with a relatively younger supervisor did predict reduced employee feedback satisfaction and perceptions of feedback utility; but, contrary to the proposed model, these effects did not occur because of reduced interactional justice perceptions or reduced perceptions of leader-member exchange (LMX). Further, LMX did not moderate the study outcomes, demonstrating that having a better relationship with one's supervisor did not alleviate the effects of supervisor relative age on employee feedback reactions. The conceptual and practical implications of these results are discussed in light of a rapidly changing workforce, and of cultural differences, in China.
173

Mechanistic and therapeutic evaluation of a novel antiantiogenic small molecule

Sulaiman, Rania S. 24 May 2016 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Choroidal neovascularization (CNV) is the vision-threatening characteristic of wet age-related macular degeneration (AMD), a major cause of blindness affecting almost 2 million elderly Americans. The current approved treatments target the dominant angiogenic mediator, vascular endothelial growth factor (VEGF). However, repeated injections of anti-VEGF drugs can cause ocular and systemic side effects, and about 30% of wet AMD patients are non-responsive. There is thus an unmet need to develop VEGF-independent antiangiogenic molecules to complement or combine with existing medications. I studied SH-11037, a novel homoisoflavonoid with potent and selective antiangiogenic activity against human retinal endothelial cells. Intravitreal SH- 11037 dose-dependently suppressed angiogenesis in the laser-induced CNV (LCNV) mouse model. These effects were prominent as early as 7 days post-laser treatment as measured by a novel ellipsoid quantification method of optical coherence tomography images in vivo. A supratherapeutic dose of 100 μM SH- 11037 was not associated with signs of murine ocular toxicity, and did not interfere with pre-existing retinal vasculature or retinal function. SH-11037 synergized with anti-VEGF therapy in vitro and in vivo, suggesting a VEGFindependent mechanism. By photoaffinity pulldown, I identified soluble epoxide hydrolase (sEH) as an SH-11037-binding target. sEH is a key enzyme in ω-3 and ω-6 fatty acid metabolism. sEH levels were dramatically upregulated in retinal sections from L-CNV mice and a specific sEH inhibitor, t-AUCB, significantly suppressed L-CNV lesion volume. Additionally, SH-11037 inhibited sEH enzymatic activity in vitro and in vivo in L-CNV mice. Given the role of sEH in the metabolism of docosahexaenoic acids (DHA), inhibition of sEH using small molecules like SH-11037 would enhance ocular DHA levels, with beneficial antiangiogenic and anti-inflammatory effects. SH-11037 is thus a novel sEH inhibitor, which could make it an alternative or additive therapy to existing anti- VEGF drugs for treatment of neovascular diseases in the eye and other tissues.
174

Age and infertility: An ethnodemographic study from Butaritari Atoll, Kiribati.

Brewis, Alexandra Avril. January 1992 (has links)
This biocultural study examines patterns of infertility, or failure to produce live births, by female age cohorts in the Micronesian population of Butaritari Atoll, Kiribati. Anthropological and demographic methods employed included analysis of census survey, reproductive history collection, structured and semi-structured interviews, participant observation, ethnohistorical research, vital registrations, and clinic records. Primary infertility levels are found to be extremely low in this population. This is argued to be a consequence of low risk of exposure to fertility-inhibiting disease, typically extended exposures to coital activity, and a culturally-influenced resistance to birth-limiting behavior before at least one child is born. There is little reduction in fertility, and therefore in biological capacity for conception, before women reach the end of their thirties. This pattern of high fertility is maintained because of socio-culturally defined patterns of sexual behavior within marriage which tend to maintain coital activity despite increasing marriage durations, and therefore with increasing age. In the study's conclusion infertility patterns by age for this population are discussed in relation to issues of the role of physiological aging and infertility increases in human populations. It is concluded that studies of infertility by age need to be considered as culturally-grounded and population-specific, particularly in reference to patterns observed at the population level in female age groups under forty.
175

Breast Cancer Screening Health Behaviors in Older Women

Hammond, Marsha V. 08 1900 (has links)
Health beliefs of 221 postmenopausal women were assessed to predict the Breast Cancer Screening Behaviors of breast self-examination (BSE) and utilization of mammography. Champion's (1991) revised Health Belief Model (HBM) instrument for BSE, which assesses the HBM constructs of Seriousness, Susceptibility, Benefits, Barriers, Confidence and Health Motivation, was utilized along with her Barriers and Benefits instrument for mammography usage. Ronis' and Harel's (1989) constructs of Severity-Late and Severity-Early were evaluated along with Cuing and demographic variables. These exogenous latent constructs were utilized in a LISREL path model to predict Breast Cancer Screening Behavior.
176

Age-related changes in executive function and the influence of processing speed

Unknown Date (has links)
Healthy aging has been associated with declines in executive functioning (EF) but it remains unclear how different subprocesses of EF are affected by age and by other possibly mediating variables. The principal aim of the present study was to investigate the effects of age and processing speed on three executive functions: set-shifting, planning, and attentional control. Four age groups (20-29 years, 60-69 years, 70-79 years, and 80-89 years) were compared on the Wisconsin Card Sorting Test (WCST), the DKEFS Tower Test, the Conner's Continuous Performance Test, and a Letter comparison test of processing speed. Results suggested that increased age was associated with decreased performance on most of the studied executive measures, but not all EF are equally affected by age. A slowdown in processing speed mediates some, but not all, decrements in executive performance. The results are interpreted in light of recent neuroimaging data on age-related changes in brain functioning. / by Maria Beatriz Jurado Noboa. / Thesis (M.A.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.
177

Time-frequency classification of gamma oscillatory activity in the frontoparietal system during working memory

Unknown Date (has links)
Working memory (WM) is a process that allows for the temporary and limited storage of information for an immediate goal or to be stored into a more permanent system. A large number of studies have led to the widely accepted view that WM is mediated by the frontoparietal network (FPN), consisting of areas in the prefrontal cortex (PFC) and posterior parietal cortex (PPC). Current evidence suggests that task specific patterns of neuronal oscillatory activity within the FPN play a fundamental role in WM, and yet specific spatio-temporal properties of this activity are not well characterized. This study utilized multisite local field potential (LFP) data recorded from PFC and PPC sites in two macaque monkeys trained to perform a rule-based, Oculomotor Delayed Match-to-Sample task. The animals were required to learn which of two rules determined the correct match (Location matching or Identity matching). Following a 500 ms fixation period, a sample stimulus was presented for 500 ms, followed by a randomized delay lasting 800-1200 ms in which no stimulus was present. At the end of the delay period, a match stimulus was presented, consisting of two of three possible objects presented at two of three possible locations. When the match stimulus appeared, the monkey made a saccadic eye movement to the target. The rule in effect determined which object served as the target. Time-frequency plots of three spectral measures (power, coherence, and Wiener Granger Causality (WGC) were computed from MultiVariate AutoRegressive LFP time-series models estimated in a 100-ms window that was slid across each of three analysis epochs (fixation, sample, and delay). Low (25- 55 Hz) and high gamma (65- 100 Hz) activity were investigated separately due to evidence that they may be functionally distinct. Within each epoch, recording sites in the PPC and PFC were classified into groups according to the similarity of their power t-f plots derived by a K-means clustering algorithm. From the power-based site groups, the corresponding coherence and WGC were analyzed. This classification procedure uncovered spatial, temporal, and frequency dynamics of FPN involvement in WM and other co-occurring processes, such as sensory and target related processes. These processes were distinguishable by rule and performance accuracy across all three spectral measures- power, coherence, and WGC. Location and Identity rule were distinguishable by the low and high-gamma range. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
178

A Bayesian Approach to Detect the Onset of Activity Limitation Among Adults in NHIS

Bai, Yan 06 May 2005 (has links)
Data from the 1995 National Health Interview Survey (NHIS) indicate that, due to chronic conditions, the onset of activity limitation typically occurs between age 40-70 years (i.e., the proportion of young adults with activity limitation is small and roughly constant with age and then it starts to change, roughly increasing). We use a Bayesian hierarchical model to detect the change point of a positive activity limitation status (ALS) across twelve domains based on race, gender, and education. We have two types of data: weighted and unweighted. We obtain weighted binomial counts using a regression analysis with the sample weights. Given the proportion of individuals in the population with positive ALS, we assume that the number of individuals with positive ALS at each age group has a binomial probability mass function. The proportions across age are different, and have the same beta distribution up to the change point (unknown), and the proportions after the change point have a different beta distribution. We consider two different analyses. The first considers each domain individually in its own model and the second considers the twelve domains simultaneously in a single model to“borrow strength" as in small area estimation. It is reasonable to assume that each domain has its own onset.In the first analysis, we use the Gibbs sampler to fit the model, and a computation of the marginal likelihoods, using an output analysis from the Gibbs sampler, provides the posterior distribution of the change point. We note that a reversible jump sampler fails in this analysis because it tends to get stuck either age 40 or age 70. In the second analysis, we use the Gibbs sampler to fit only the joint posterior distribution of the twelve change points. This is a difficult problem because the joint density requires the numerical computation of a triple integral at each iteration. The other parameters of the process are obtained using data augmentation by a Metropolis sampler and a Rao-Blackwellization. We found that overall the age of onset is about 50 to 60 years.
179

Quantifying the Impacts of a Novel Predator: the Distinctive Case of the Oregon Spotted Frog (<i>Rana pretiosa</i>) and the Invasive American Bullfrog (<i>Rana (Aquarana) catesbeiana</i>)

Tidwell, Kyle Scott 21 March 2017 (has links)
The decline of the Oregon Spotted Frog (Rana pretiosa), a Pacific Northwest endemic now federally listed as threatened, has been attributed to several aspects of ecosystem alteration, primarily habitat degradation and loss. The introduced American Bullfrog (Rana (Aquarana) catesbeiana) has been widely implicated in those declines, but the basis of that contention has been difficult to characterize. The bullfrog occurring at every site of recent Oregon Spotted Frog extirpation has focused concern about its impact. Here, I present a suite of interconnected studies that examine the behavioral ecology of both species to better understand the potential for bullfrog-mediated Oregon Spotted Frog extirpation. I quantified Oregon Spotted Frog anti-predator behavior from the only known population successfully co-occurring with bullfrogs (Conboy Lake) and a population devoid of bullfrog impact (Big Marsh), and compared these behaviors to the predatory traits of the bullfrog. The initial study revealed that captive-reared individuals from the Oregon Spotted Frog population that has successfully co-occurred with bullfrogs respond faster to a predatory stimulus (measured as latency to response) than Oregon Spotted Frogs from a population not to exposed to bullfrogs. Subsequent field investigations of the approach distance allowed by a predator stimulus before taking evasive action (termed the flight initiation distance: FID) conducted with the Oregon Spotted Frog population co-occurring with bullfrogs first demonstrated that FID of recently metamorphosed bullfrogs is consistently greater than that of recently metamorphosed Oregon Spotted Frogs. Further, examination of FID across all post-metamorphic age classes of Oregon Spotted Frogs revealed that older frogs do not allow as close approach as recently metamorphosed Oregon Spotted Frogs. This age class shift in FID did not occur in the Oregon Spotted Frog population not exposed to bullfrogs. In the latter population, FID did not differ among age classes. Since the bullfrog might be driving this age-based change in anti-predator behavior, I explored the variation in strike distance of bullfrogs from the site of co-occurrence in both the field and laboratory to determine the extent of overlap with Oregon Spotted Frog FID. I found that the bullfrog strike distance significantly overlaps the FID of all ages of Oregon Spotted Frogs from the bullfrog-free site but only that of youngest (recently metamorphosed) frogs at the site of co-occurrence. Older Oregon Spotted Frogs from the site of co-occurrence generally escaped at distances greater than the strike distance of bullfrogs. I also collected > 880 bullfrogs from the site of co-occurrence and analyzed the stomach contents to assess their dietary trends. I found that bullfrogs consume Oregon Spotted Frogs at the site, but do not eat the larger (older) frogs. Moreover, the body size ratio between Oregon Spotted Frogs as prey and bullfrogs as predators suggests that nearly all of the adult size distribution of bullfrogs at Conboy would be incapable of preying on adult Oregon Spotted Frogs. Collectively, these studies strongly suggest that bullfrogs have altered the escape behavior of Oregon Spotted Frogs at Conboy Lake and that most adult Oregon Spotted Frogs at Conboy may have a size-based release from predation by bullfrogs. Implicit in this finding is that bullfrogs may pose a real threat via predation to other Oregon Spotted Frog populations with which they might come into contact where the distribution of bullfrog body sizes differ substantially from that at Conboy Lake.
180

Executive functioning and the adaptation to novelty

Nelson, Jeffrey January 2008 (has links)
[Truncated thesis] This thesis is concerned with executive functioning in two different but related ways. The first is as an information processing construct in cognitive psychology. There are many different conceptualisations of the information processing basis of executive functioning but this thesis will pursue the notion that executive functioning is best thought of as adaptation to novelty. In the thesis, this will be operationalised using performance indices (principally reaction time) from a number of information processing tasks. These tasks have typically been used in the literature to index either executive functioning or speed of information processing. Both kinds of tasks are used to tackle the second concern of this thesis, namely, how executive functioning is measured. The data analytic techniques developed in this thesis are based on the hypothesis that executive functioning is the process or processes involved in resolving task novelty and consequently measurement will be enhanced through an analysis of performance changes within tasks as the task changes from novel to familiar. The analysis methods will be based largely on the computation of coefficient of variation of reaction time in successive performance windows across the information processing tasks. An elderly sample was chosen for this thesis because of a history of research that has attempted to determine whether cognitive deficits in the elderly are the consequence of the slowing of information processing speed or to impairment in executive functioning. ... The analysis was driven by the hypothesis that a significant shift in the coefficient of variation would mark a transition from novelty to familiarity in task performance and hence from executive to non-executive phases. Three methods were applied to individual performance curves to determine the point at which for each task this transition occurred. Using criterion measures of variability to separate the task data into two stages, analyses showed, contrary to the hypothesis, that later task performance was more highly associated with executive functioning than in initial task performance. The fourth stage of analysis (Chapter 7) applied confirmatory factor analysis to the newly-formed pre- and post transition data. Evidence was found that the magnitude of the contributions of EF across the pre- and post-criterion phases was stable, failing to support the hypothesis. Finally, structural equation modelling was used to examine how age and intelligence in this elderly sample exerts its influence on task performance and whether EF or IPS was the primary cause of age-related cognitive decline. The results showed that the age and intelligence effects on performance were mediated by the requirement to adapt to novelty. Although there was limited evidence to claim that EF is the primary cause of age-related cognitive decline, ageing effects were only apparent when the participants were adapting to novelty. The thesis concludes that there is some support for the hypothesis that executive functioning is best thought of as the processes underpinning adaptation to novelty. While not a panacea, the analytic techniques developed show promise for future research.

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