VictorJuiz/thesis huggingface dataset:
Redirection: Using Career Development Theory to Interpret the Volunteer Activities of Retirees
Keywords: volunteers
retirees
older adults
seniors
retirement
lifelong learning
aging
transitions
Donald Super
Life-Span Life-Space Theory of Career Development
career self-concept
aging population
mixed methods
case study
baby boomers
life course perspective
gerontology
volunteer management
formal volunteering
nonprofit organizations
skills
dimensions of learning
adult development
life satisfaction
well-being
later-life
policy
professional knowledge
social role
psychological adjustment
life stages

The purpose of this study was to examine formal volunteering among retirees in order to explore whether their volunteer experiences represent an extension of their career in the paid workforce or whether their volunteer activities represent a completely new direction, and how this influences their career self-concept, as interpreted through Donald Super’s life-span, life-space theory of career development. This study employed a developmental mixed-method design. In Phase 1, qualitative interviews were conducted with 12 participants to better understand retirees’ volunteer experiences. Phase 1 informed the design of an instrument for the Phase 2 survey which examined the issues among a larger sample of 214 retirees. The Phase 2 results supported the Phase 1 findings and indicated that many retirees sought an extension of career in volunteer activities in that they used similar skills and knowledge. Study participants also displayed a desire for lifelong learning. Retirees relinquished their paid-work career, took on the retiree and volunteer roles, and integrated these roles within their career self-concept to create a new sense of self. These results indicated that the retirees had entered a new stage of life, qualitatively different from ‘retirement’. To better reflect the experiences of these retirees, it was proposed that Donald Super’s life-span, life-space theory of career development be extended to include Redirection. This theorizing is consistent with the finding that retirees both wanted to and are able to integrate previous paid work elements as well as seek out lifelong learning opportunities within their volunteer activities. This study demonstrates that the volunteer role in the lives of retirees can lead to personal renewal and reshaping of the career self-concept, or what is labeled as the stage of Redirection. This study also has implications for volunteer management, retirement planning and social policy, and may be of interest to volunteer managers, nonprofit organizations, career counsellors, financial planners, retirement planning consultants, life coaches and policy planners.
The Effects of Motor Constraints on Infant Search Behaviour
Keywords: manual search
A-not-B task
handedness
barriers
reaching development
object search

Two studies investigated the effects of various motor constraints of reaching on infants’ search performance on the A-not-B task. These studies were motivated by the idea that motor memories for reaching lead to A-not-B errors. The 2 motor constraints that were evaluated included barriers that blocked the path of the hand and hand-use preferences. Each of these motor constraints was examined separately. In Experiment 1, infants (N = 40, 20 8-month olds, 20 16-month olds) were given the A-not-B task twice. One condition was analogous to the traditional A-not-B task (i.e., using 2 hiding locations) and the other was modified such that a barrier (i.e., an opaque screen) blocked the infants’ reaching path of location A on A trials only. On A trials, all infants searched correctly less often when a barrier was present, and younger infants searched correctly less often than older infants. On B trials, younger infants made more errors in the no barrier condition, whereas older infants did not show any significant difference in B trial performance across conditions. In Experiment 2, infants (N = 51) completed an adapted handedness test (Michel, Ovrut, & Harkins, 1985) followed by a modified A-not-B task. The test assessed infants’ hand-use preferences for reaching, which was used to group infants into their respective preference group (i.e., consistent or inconsistent). Infants with a consistent preference were randomly assigned to a hiding side group (i.e., A on preferred side or A on non-preferred side). Infants searched correctly more often when hiding side was congruent with their preferred reaching hand, and older infants searched correctly more often than younger infants. On the B trial, neither age nor hiding side affected the production of the A-not-B error. Collectively, these studies present data that address the theory that motor memories for reaching are the cause for the production of A-not-B error. These studies provide novel evidence that motor memories for reaching are present in infants aged 8- and 16-months, and that motor memories can influence the production of such errors in certain A-not-B contexts. Implications and directions for future research are also discussed.
The Role of the Retinoblastoma Protein Family in Skeletal Myogenesis
Keywords: skeletal myogenesis
muscle
differentiation
retinoblastoma
pRb
autophagy
p107
p130
Rb
cell cycle

The retinoblastoma tumor suppressor (pRb) is thought to orchestrate terminal differentiation by inhibiting cell proliferation and apoptosis and stimulating lineage-specific transcription factors. In this thesis I have shown that in the absence of pRb, differentiating primary myoblasts fused to form short myotubes that never twitched and degenerated via a non-apoptotic mechanism. The shortened myotubes exhibited an impaired mitochondrial network, mitochondrial perinuclear aggregation, autophagic degradation and reduced ATP production. Bcl-2 and autophagy inhibitors restored mitochondrial function and rescued muscle degeneration, leading to twitching myotubes that expressed normal levels of muscle-specific proteins and eventually exited the cell-cycle. A hypoxia-induced glycolytic switch also rescued the myogenic defect after chronic or acute inactivation of Rb in a HIF-1-dependent manner. These results demonstrate that pRb is required to inhibit apoptosis in myoblasts and autophagy in myotubes but not to activate the differentiation program. I next tested the effect of retinoblastoma protein family members – p107 and p130 – on skeletal myogenesis in the absence of Rb. Chronic or acute inactivation of Rb plus p130 or Rb plus p107 increased myoblast cell death and reduced myotube formation, yet expression of Bcl-2, treatment with autophagy antagonist or exposure to hypoxia extended myotube survival, leading to long, contracting myotubes that appeared indistinguishable from control myotubes. Triple mutations in Rb family genes further accelerated cell death and led to elongated myocytes or myotubes containing two nuclei, some of which survived and twitched under hypoxia. Whereas nuclei in Rb-/- myotubes were unable to stably exit the cell-cycle, myotubes lacking both p107/p130 became permanently post-mitotic, suggesting that pRb, but not p107 or p130 may be lost in cancer because of the unique requirement for cell-cycle exit during terminal differentiation. This thesis demonstrates that pRb is required to inhibit apoptosis in myoblasts and autophagy in myotubes but not to activate the differentiation program, and reveal a novel link between pRb and cell metabolism.
Potential Use of Umbilical Cord Blood Cells in Spinal Cord Injury
Keywords: Umbilical Cord Blood
Oligodendrocytes
Spinal Cord Injury

Spinal cord injury (SCI) pathophysiology occurs as a primary traumatic event followed by secondary injury, resulting in the loss of neurons, oligodendrocytes and demyelination of residual axons. Unfortunately, endogenous spontaneous regeneration of oligodendrocytes is minimal. Previously, a method to generate multi-potential stem cells (MPSC) from umbilical cord blood (UCB) has been reported using lineage negative cells (Linneg) grown in fibroblast growth factor 4 (FGF4), stem cell factor (SCF) and fms-like tyrosine kinase receptor-3 ligand (Flt-3l) supplemented serum free medium. These MPSC have the ability to differentiate into bone, muscle and endothelial cells. In this thesis, the ability of MPSC to differentiate into oligodendrocytes was investigated as a potential treatment for SCI. Culturing MPSC under conditions that mimic normal timing of oligodendrocyte differentiation resulted in cells that expressed oligodendrocyte markers in vitro and were morphologically similar to them. I next investigated the ability of MPSC to improve functional recovery in a SCI compression injury model. Although the cells did not differentiate into oligodendrocytes in vivo as we initially hypothesised, a modest but significant improvement in hindlimb function was observed. A cytokine assay revealed that MPSC secrete elevated levels of anti-inflammatory, angiogenic and neurotrophic factors, possibly contributing to indirect mechanisms of repair by reducing secondary injury. Shiverer mouse neonates were next used as an alternative non-injury model to investigate the differentiation potential of MPSC. We hypothesised that transplanting MPSC into a host with an immature immune system and an actively myelinating environment would lead to engraftment and differentiation into oligodendrocytes. However no MPSC that differentiated into oligodendrocytes could be detected. Altogether, our in vitro data adds support for the reprogramming of cells, with further studies needed to test the functionality of resulting oligodendrocyte-like cells. Although MPSC failed to differentiate in both in vivo models, several potential therapeutic targets to treat SCI were found.
Essays on the Impact of Investors Speculation and Disagreements on Security Prices and Trading Volume
Keywords: Speculation
Disagreements
Trading volume

The essays empirically show the impact of investors speculation and disagreements on the returns and trading volume of securities. The results also shed light on the central issues of price formation and investors’ trading motives in security markets. The first essay investigates whether the trading activities of retail investors affect option prices through volatility speculation. This essay empirically shows that higher retail trading proportions are related to lower delta-hedged option returns. The phenomenon is more pronounced before earnings announcements and among stocks with more time-varying and positively skewed volatility. The results suggest that retail investors speculate and pay a lottery premium on the expected future volatility, resulting in more expensive options in terms of higher implied volatilities. This systematic deviation of option-implied volatility from realized volatility suggests retail investor clientele as a behavioral-based driving force of volatility risk premium. The second essay investigates the motive of option trading. It is shown that option trading is mostly driven by differences of opinion, a finding different from the current literature that attempts to attribute option trading to information asymmetry. First, option trading around earnings announcements is speculative in nature and mostly dominated by small, retail investors. Second, around earnings announcements, option turnovers do not predict stock returns, once prior stock returns are controlled for. Third, regression results reveal that option trading is also significantly explained by differences of opinion at ordinary times. While informed trading is present in stocks, it is not detected in options. The third essay provides strong evidence of reduction in informational efficiency when there are short-sale constraints and disagreements. Post earnings announcement returns are found to be significantly lower for stocks with more dispersed opinions and stocks that are exogenously short-sale prohibited by the Hong Kong Stock Exchange, supporting Miller’s (1977) overvaluation hypothesis. The results also suggest short-sale constraint as an explanation to negative post earnings announcement drift.
The Loss of the 'World-Soul'? Education, Culture and the Making of the Singapore Developmental State, 1955 - 2004
Keywords: citizenship education
developmental state
state formation

This dissertation examines the role of education in the formation of the Singapore developmental state, through a historical study of education for citizenship in Singapore (1955-2004), in which I explore the interconnections between changes in history, civics and social studies curricula, and the politics of nation-building. Building on existing scholarship on education and state formation, the dissertation goes beyond the conventional notion of seeing education as providing the skilled workforce for the economy, to mapping out cultural and ideological dimensions of the role of education in the developmental state. The story of state formation through citizenship education in Singapore is essentially the history of how Singapore’s developmental state managed crises (imagined, real or engineered), and how changes in history, civics and social studies curricula, served to legitimize the state, through educating and moulding the desired “good citizen” in the interest of nation building. Underpinning these changes has been the state’s use of cultural constructs such as Confucianism and Asian values to shore up its legitimacy. State formation in Singapore has been very successful, as evidenced by its economic prosperity and education has played a key role in this success. However, the “economic growth at all costs” ethos comes, arguably, at a price – the potential loss of zeitgeist, or the loss of the “World-Soul”. Nation building in the sense of fostering a sense of rootedness and belonging to the country in its citizenry – the “World-Soul” – had to be relegated to the backburner in the relentless pursuit of economic development, in order to sustain and legitimize the developmental state. By harnessing the educational sphere for its economic growth objectives through the discourse of crisis, the developmental state gained political legitimacy in the eyes of a citizenry increasingly accustomed to educational mobility and material wealth, even if at the expense of political freedoms.
Resource Allocation Algorithms for Event-Based Enterprise Systems
Keywords: computer engineering
publish/subscribe
content-based routing
load estimation
resource allocation
overlay construction
publisher relocation
subscriber relocation
load minimization
green IT
load balancing
event processing
load minimization
delivery delay minimization
event processing
ESB

Distributed event processing systems suffer from poor scalability and inefficient resource usage caused by load distributions typical in real-world applications. The results of these shortcomings are availability issues, poor system performance, and high operating costs. This thesis proposes three remedies to solve these limitations in content-based publish/subscribe, which is a practical realization of an event processing system. First, we present a load balancing algorithm that relocates subscribers to distribute load and avoid overloads. Second, we propose publisher relocation algorithms that reduces both the load imposed onto brokers and delivery delay experienced by subscribers. Third, we present ``green" resource allocation algorithms that allocate as few brokers as possible while maximizing their resource usage efficiency by reconfiguring the publishers, subscribers, and the broker topology. We implemented and evaluated all of our approaches on an open source content-based publish/subscribe system called PADRES and evaluated them on SciNet, PlanetLab, a cluster testbed, and in simulations to prove the effectiveness of our solutions. Our evaluation findings are summarized as follows. One, the proposed load balancing algorithm is effective in distributing and balancing load originating from a single server to all available servers in the network. Two, our publisher relocation algorithm reduces the average input load of the system by up to 68%, average broker message rate by up to 85%, and average delivery delay by up to 68%. Three, our resource allocation algorithm reduces the average broker message rate even further by up to 92% and the number of allocated brokers by up to 91%.
Between Attrition and Acquisition: the Dynamics between Two Languages in Adult Migrants
Keywords: language attrition
bilingualism

In the context of language use of Romanian migrants living in Canada, this thesis examines the linguistic changes and the contributing social, personal, and affective factors involved in the maintenance of a migrant’s first language (L1) as she or he simultaneously acquires a second language (L2) in an L2-dominant environment. Specifically, it investigates the incidence of L1 attrition in the bilingual group, the existence of a possible systematic relationship between the levels of L1 and L2 proficiency, and the influence of sociolinguistic and cognitive factors on L1 attrition and L2 acquisition in bilingual contexts. L1 attrition is defined here as both the reduction of L1 language skills and the restructuring of the L1 according to L2 patterns to the point where communication in the L1 is impaired. The present study involves extensive elicitation of written and oral data in both Romanian and English. First, an assessment of the participants’ history of language acquisition, their attitudes, their patterns of language use, and the nature of their social networks was conducted via sociolinguistic questionnaires and individual interviews. The language aptitude tests used in this project examined phonetic memory, vocabulary learning, and grammatical inferencing abilities. As an indicator of overall language proficiency, formal tests (a C-test and a verbal fluency task) and samples of spontaneous speech in the form of film commenting tasks were analyzed for fluency and grammatical complexity. The results showed that L1 attrition is a possible, but not obligatory, outcome in the first generation of migrants. With the exception of two participants, the majority of the bilinguals in this study, while not perfect matches for the L1 monolinguals, remained within the L1 native range even after a long residence in the L2 country. While proficiency trade-off patterns are not observable at the group level, they were evidenced in the cases of the two attriters identified in this study. With respect to cognitive predictor variables, L1 maintenance does not appear to be a direct function of linguistic aptitude. At the same time, levels of L1 attrition and L2 achievement are dependent on a combination of attitudinal and personal background variables.
Responses to Difference in Initial Teacher Education: A Case of Racial and Linguistic Minority Immigrant Teacher Candidates
Keywords: diversity
teacher induction
immigrant settlement
inclusive policy
integrative theory
initial teacher education
teacher professional development
diversification of teacher workforce

Despite recent rhetoric advocating the diversification of the teacher workforce, teachers in Canada continue to be disproportionately white and of northern European heritage. By investigating responses to difference experienced by racial and linguistic minority immigrant teacher candidates in an initial teacher education program, this thesis sheds light on dynamics that challenge or support the induction of minoritized individuals as members of the teaching profession in Canada. Data collected through interviews with eight immigrant teacher candidates, four instructors, and five student support staff of an initial teacher education program at an urban Canadian university (UCU) indicated that teacher candidates at UCU experienced varied responses to difference. Influences of both hegemony and collaboration were found in the university and practice teaching contexts where individuals representing regimes of competence enacted challenging assimilationist or supportive multiculturalist ideologies. In practice teaching contexts, although all of the teacher candidates engaged with at least one collaborative mentor teacher and they all persisted to complete the program, six of the eight teacher candidates (i.e., all of the linguistic minority teacher candidates in this study) encountered a challenging and significantly discouraging relationship with a mentor teacher. In these hegemonic contexts the legitimacy of the teacher candidates appeared to be measured against a conception of “real teachers” as “real Canadians” who are native English-speakers and who are familiar with the culture of schooling in Canada. Within the university context, student support staff were consistent in their critical awareness of the challenges and supports experienced by teacher candidates while instructors demonstrated a range of familiarity with these issues and with concepts of equity as they relate to the experiences of teacher candidates. Implications of this study support the following: continuation of programs offered through student support services; educative collaborative implementation of UCU’s equity policy to promote greater consistency in its influence; application of inclusive pedagogy; greater curricular emphasis on social power and constructions of difference; recognition of immigrant teachers’ linguistic capital; development of a collaborative method to evaluate teacher candidates in practice teaching contexts; and continued effort to advance a more profound and consistent influence of multiculturalist ideology in Canadian schools.