VictorJuiz/thesis huggingface dataset:
Manipulation of Afferent Feedback from Extraocular Muscles via Jendrassik Maneuver in Binocularly Intact Observers and Deafferented Patients: Effects on Vergence, Version and Higher Order Perceptual Judgements
Keywords: rehabilitation

The central nervous system can use two extraretinal sources to stay informed about the position of the eyes in the orbit: outflow (efference copy) and inflow (afference). Palisade endings (PE), found at the myotendinous junction of the multiply innervated fibers of the global layer of extraocular muscles (EOM), are the putative receptors supplying the inflow eye position signal. Seminal neuroanatomical tracing studies identified a distinct set of non-twitch (NT) motoneurons whose activity does not add to the force used to move the eyes. It has been suggested that NT motoneurons could be involved in modulating the gain of sensory feedback from EOM analogous to the gamma-efferent fibres which control the sensitivity of muscle spindles in skeletal muscles. The goal of this thesis was to test the above hypothesis in humans using behavioural and psychophysical approaches. Jendrassik Maneuver (JM), which is a forceful muscle contraction that facilitates the amplitude of all spinal and brainstem reflexes, was used to manipulate afferent feedback. The facilitation is most likely due to a general up-regulation of the gamma system. It was hypothesized that if NT motoneurons are analogous to gamma motoneurons, the JM should also increase the activity of NT neurons and alter the afferent feedback from PE. As hypothesized, the JM perturbation altered registered vergence eye position when binocularly intact observers localized targets in depth but did not affect localization in the frontal plane associated with saccades. Patients with congenital strabismus who have had surgeries on their EOM were not affected by the JM perturbation. In contrast to the hypotheses, the JM did not affect higher order perceptual judgments (size and depth constancies). Overall, these studies provide insight into the putative mechanism involved in the control of sensory feedback from EOM. In particular, the NT motoneurons might be involved in parametric adjustment of the proprioceptive feedback loops to match the demands of different types of eye movements. Understanding the role of proprioceptive feedback loops could have important clinical implications for surgical treatment of strabismus.
Maternal Responses to Anticipated Children's Negative Emotions and Social Adjustment in Early Childhood
Keywords: parenting
social adjustment
preschool-aged
negative emotions
socialization of emotion
mothers
emotion expression

The goals of the present study were: 1) to describe and provide initial support for the validity of the Future Scenarios Questionnaire (FSQ), a new self-report questionnaire designed to measure parental responding to anticipated children’s negative emotions; and 2) to examine how maternal responses on the FSQ related to young children’s aggressive, asocial, and prosocial behaviors with peers. Further, this study examined whether the temperamental trait of negative affect moderated the relation between maternal responses on the FSQ and children’s social adjustment outcomes. Participants were 92 mothers of preschool-age children (43 boys and 49 girls; M age 61.5 months). Mothers provided ratings on the FSQ and child temperament ratings on the Child Behavior Questionnaire (CBQ; Rothbart, Ahadi, & Hershey, 1994). They also completed a range of measures which were included to assess the construct validity of the FSQ. These included measures of attachment representations, maternal mind-mindedness, perceived control, and alexithymia. Sixty-nine teachers provided ratings on the Child Behavior Scale (CBS; Ladd & Profilet, 1996) for children’s aggressive, asocial, and prosocial behaviors in the peer context. Factor analysis of the FSQ revealed two subscales: Encourage Emotion Expression (EEE) and Discourage Emotion Expression (DEE). Patterns of correlations among these subscales and the additional mother measures suggested that the FSQ demonstrates some construct validity. Further, the results of the moderation analyses showed that maternal responding on the FSQ interacts with negative affect in the prediction of child behaviors, however not in the hypothesized ways. In particular, encouraging emotion expression significantly predicted more asocial behavior and less prosocial behavior (approached significance), but only for children rated high in negative affect. Similarly, discouraging emotion expression significantly predicted less aggressive behavior only for high negative affect children. None of these relations was significant for children rated low in negative affect. The theoretical and practical implications of these findings are discussed in terms of the importance of considering child temperament in emotion socialization processes.
Lipid Rafts in Pancreatic Beta- and Alpha-cell Stimulus-secretion Coupling
Keywords: Physiology

Type 2 diabetes is hallmarked by insufficient beta-cell insulin secretion and inappropriate alpha-cell glucagon secretion concomitant to peripheral insulin resistance. However, the mechanisms underlying dysregulation of pancreatic beta- and alpha-cells in type 2 diabetes require further investigation. Whereas triglycerides and saturated free fatty acids have been well recognized to cause beta-cell dysfunction, the physiological and/or pathological role of cholesterol on beta- and alpha-cells is less well examined. Cholesterol is the major component of membrane microdomains, termed lipid rafts. Numerous signaling and transport proteins have been found to be targeted to lipid raft microdomains, where the function of the associated membrane proteins could be distinctly regulated. I have identified the expression of lipid raft constituent proteins, caveolin-1/2 in pancreatic beta-cells; and caveolin-2 in alpha-cells. A variety of membrane proteins (ion channels and SNARE proteins) critical for beta- and alpha-cell stimulus-secretion coupling were found to be associated with cholesterol-rich lipid raft microdomians, and the properties of those ion channels (Kv2.1, Kv4.1/4.3, and Cav1.2 channels) and SNARE proteins were closely regulated by cholesterol-rich lipid rafts. Acute depletion of cholesterol from the plasma membrane with methyl-beta-cyclodextrin caused an elevated basal hormone secretion from both beta- and alpha-cells and a loss of glucose-stimulated insulin secretion, implicating that cholesterol-rich lipid rafts play an important role in regulating exocytosis of these two types of islet cells. Chronic pharmacological inhibition of beta-cell endogenous cholesterol biosynthesis with squalene epoxidase inhibitor caused an impairment of both Cav channels and SNARE protein exocytotic machinery, indicating that intracellular cholesterol and its homeostasis are critical for maintaining normal beta-cell function. The work presented in this thesis provided clear evidence that cholesterol-rich lipid rafts play a critical role in maintaining the normal function of pancreatic ion channels and SNARE proteins to regulate pancreatic beta- and alpha-cells stimulus-secretion coupling. Manipulation of cholesterol level of beta- and alpha-cells could be a potential target for a therapeutic intervention in the treatment of type 2 diabetes.
Role of Frequenin1 and Frequenin2 in Regulating Neurotransmitter Release and Nerve Terminal Growth at the Drosophila Neuromuscular Junction
Keywords: Frequenin
Drosophila
presynaptic
Neuronal Calcium Sensor
synapse
synaptic transmission

Frequenin (Frq) and its mammalian homologue, Neuronal Calcium Sensor 1 (NCS-1), are calcium-binding proteins, which regulate neurotransmitter release. However, reports are contradictory, and little is known about Frq's cellular mechanisms. The Drosophila nervous system can be used to gain a better understanding of the function of Frq. There are two Frq-encoding genes in Drosophila. The temporal and spatial expression patterns of the two genes are very similar, and the proteins they encode, Frq1 and Frq2, are 95% identical in amino acid sequence. Loss-of-function phenotypes were studied using three different procedures: creating a deletion designed to remove the entire frq1 gene and part of the frq2 gene; using an interfering C-terminal peptide to prevent Frq binding to its intracellular targets; and using RNAi to reduce frq1 and frq2 transcript levels. Deletion of the entire frq1 gene and part of the frq2 gene resulted in impaired neurotransmitter release and enhanced nerve terminal growth. To discriminate chronic from acute loss-of-function effects, the effects of transgenic expression and forward-filling an interfering C-terminal peptide into presynaptic terminals were compared. In both cases, a reduction in quantal content per bouton occurred, demonstrating that this trait does not result from homeostatic adaptations during development. The chronic treatment also enhanced nerve terminal growth. Conversely, gain-of-function conditions yielded an increase in quantal content and a reduction in nerve terminal growth. Frqs' effects on transmitter output were not due to changes in the number of active zones, nor were they due to changes in the size of the readily releasable pool of vesicles. Oregon Green 488 BAPTA-1 conjugated to 10 kDa Dextran was forward-filled into presynaptic boutons to detect changes in presynaptic Ca2+ signals. Ca2+ responses to presynaptic nerve impulses demonstrated that Frq modulates neurotransmitter release by regulating Ca2+ entry. Gain-of-function phenotypes remained present in a PI4KB null background, demonstrating that Frq's effects were not due to an interaction with PI4KB. All effects seen for all studies were identical for both Frqs, indicating that the two Frq proteins are likely functionally redundant. Overall, Frqs have two distinct functions: one on neurotransmission, primarily by regulating Ca2+ entry, and another on axonal growth and synaptic bouton formation.
Effects of Acute Periods of Prenatal Stress on Behaviour and Endocrine Function in Guinea Pigs
Keywords: Prenatal Stress
Programming
HPA Axis
Guinea Pigs

Epidemiological studies in humans have revealed a relationship between altered development in utero and an increased incidence of pathophysiology during postnatal life. One of the mechanisms underlying this relationship is thought to be exposure to excess glucocorticoids during critical phases of brain development. The aim of the current set of studies was to determine the effects of prenatal stress during discrete developmental windows on behaviour and endocrine function in male and female guinea pig offspring. Guinea pigs were used as the model for these studies as they are a long-gestation species that give birth to neuroanatomically mature young and fetal brain development is well characterized. Pregnant guinea pigs were exposed to a high frequency strobe light during the period of rapid fetal brain growth or the period of rapid brain myelination. Pregnant guinea pigs were allowed to deliver normally and guinea pig offspring were tested for ambulatory activity, anxiety and hypothalamic-pituitary-adrenal (HPA) axis function. Male offspring whose mothers were exposed to stress during the period of rapid brain growth exhibited increased anxiety behaviour, increased basal plasma cortisol levels and decreased plasma testosterone levels. We found that replacing testosterone in these animals reversed the behavioural and endocrine differences. Male offspring whose mothers were exposed to stress during the period of rapid myelination exhibited an increased plasma cortisol response to activation of the HPA axis. Female offspring whose mothers were exposed to stress during the period of rapid brain myelination exhibited decreased ambulatory activity and a blunted salivary cortisol response to the stress of the strobe light, but only during the estrous phase of the reproductive cycle. Therefore, the current set of studies has demonstrated the effects of prenatal stress on behaviour and HPA axis activity are dependent on; 1) the timing of the prenatal stress and 2) the hypothalamic-pituitary-gonadal axis in both male and female offspring. These studies have begun to uncover the mechanisms underlying programming and provide the basis for continuing research in humans.
Cultures of Border Control: Schengen and the Evolution of Europe's Frontiers
Keywords: border control
Schengen
Europe
evolution
culture

The dissertation examines one of the most remarkable and controversial developments in the recent history of European integration, namely the institutionalization of a regional policy regime to manage the continent’s frontiers. By adopting this regime (known in policy circles as ‘Schengen’), European governments have in fact relinquished part of their sovereign authority over the politically sensitive issue of border control, thereby challenging what for a long time was the dominant national approach to policy-making in this domain. In order to account for the regime’s emergence and success, a constructivist analytical framework centred on the notion of ‘cultures of border control’ is advanced. From this perspective, the adoption of a regional approach to govern Europe’s frontiers is the result of the evolution of a nationalist (‘Westphalian’) culture—or set of background assumptions and related practices about borders shared by a given policy community—into a post-nationalist one (‘Schengen’). The cultural evolutionary argument elaborated in the dissertation captures the unique political dynamics that have characterized border control in Europe in the last two decades and offers a more nuanced account of recent developments than those available in the existing European Studies literature. It can also shed light on current trends defining European politics beyond border control (e.g., Europe’s policy towards its neighbours) and on other attempts to regionalize border control outside Europe (e.g., the proposal for a North American security perimeter).
Security Community in and through Practice: The Power Politics of Russia-NATO Diplomacy
Keywords: Practice theory
Security communities
Russia
NATO

How do security communities develop in and through practice? For more than forty years, security relations between Russia and NATO member states were structured by the spectre of mutual assured destruction as symbolized by thousands of nuclear missiles targeted at each other. Less than a generation after the end of the Cold War, the possibility of military confrontation between these former enemies has considerably receded. Taking inspiration from Pierre Bourdieu, this dissertation develops a theory of practice of security communities that argues that on the ground of international politics, the social fact of peace emerges when security practitioners come to debate with diplomacy—the non-violent settlement of disputes—instead of about diplomacy. It is doxa, a relationship of immediate adherence to the order of things, that makes such a peaceful practical sense possible. In the empirical analysis, the dissertation reveals an intriguing paradox in the post-Cold War Russian-Atlantic relationship. On the one hand, over the last fifteen years Russia and NATO member states have solved each and every one of their disputes, including fierce ones over the double enlargement, by nonviolent means. Such a track record of peaceful change is testimony to security-communitybuilding processes. But on the other hand, diplomatic success was often bought at the price of a growing mistrust on the Russian side. As the Russian Great Power habitus resurfaced, hysteresis—a disconnect between players’ dispositions and their positions in the game—steadily increased to the point of inconclusive symbolic power struggles over the rules of the international security game and the roles that each player should play. A decade and a half after the end of the Cold War, Russian-Atlantic relations have left the terrain of military confrontation but have yet to settle on that of mature peace. Building on several dozen interviews with Russian and NATO security practitioners, the dissertation discovers that diplomacy has become a normal though not a self-evident practice in Russian-Atlantic dealings.
Federalism From Below? The Emergence of Aboriginal Multilevel Governance in Canada. A Comparison of the James Bay Crees and Kahnawa:ke Mohawks
Keywords: Canada
Politics
Federalism
Indigenous Peoples
Governance
Kahnawake
James Bay Crees

Using the language of rights and national self-determination, Aboriginal peoples have mounted a fundamental challenge to Canadian federalism in the past forty years. In order to move beyond the imposed structure of colonial governance, Aboriginal peoples have sought to establish their own form of federal relationship with contemporary Canadian governments and society. While much attention has been devoted to the constitutional and legal dimensions of Aboriginal challenges to state authority, this thesis argues that incremental yet fundamental changes are also taking place in the less visible but nonetheless important arena of policy-making. Aboriginal claims for greater political recognition, combined with the redefinition of the role of the state associated with neoliberal ideas, have led to the emergence of multilevel governance practices between Aboriginal governing authorities and their federal and provincial counterparts. While they do not alter the formal nature of state authority as defined in the constitution, multilevel policy exercises are characterized by growing interdependencies between Aboriginal and non-Aboriginal governing actors, leading to a partial displacement of formal rules of authoritative decision-making in favor of joint decision-making processes and negotiated solutions to policy disputes. Building on comparative analyses of the transformations in the governance regimes of the James Bay Crees and Kahnawa:ke Mohawks, this thesis argues that these multilevel exercises can become transformative spaces for Aboriginal peoples to reshape their relationship with the state and establish themselves as representatives of distinct political communities with their own sources of authority and legitimacy independent of federal and provincial parliaments. As a result, I argue a new form of federalism may well be emerging not through constitutional negotiations or treaty-making exercises, but from below, in everyday practices of governance.
Contesting Cosmopolitan Europe: A Study of Non-governmental Organizations in the European Union's External Trade Policymaking Process
Keywords: European Union
NGOs
Legitimacy
Post-National Governance
Trade Policymaking
WTO

This thesis investigates whether more open trade policymaking processes that include non-governmental entities, by virtue of the divergence of interests represented, lead to a stronger, more legitimate and qualitatively enhanced international trade system. The European Union stands out among major trading powers for its significant and dramatic response to new demands for access and participation. The thesis examines whether improvements in the political opportunity structure for ‘progressive’ Non-Governmental Organizations (NGOs) result in more legitimate external trade policymaking in the European Union (EU). Legitimacy is assessed along two lines: the way policy is made (procedural legitimacy) and the projected outcomes of policy (substantive legitimacy). The role of NGOs is evaluated in two important cases in the context of World Trade Organization negotiations since 2000. The first concerns the formulation of the formal European Communities’ (EC) position on trade related intellectual property rights (TRIPS) and access to medicines. The second concerns the EC’s requests for water services liberalization in the context of General Agreement on Trade in Services (GATS) 2000 negotiations. Through a critical evaluation of the role of NGOs in these cases, the thesis argues that there is clear potential for NGOs to represent citizens’ demands, constitute a basic form of popular representation and hold decision-makers accountable to a broader public. However, they cannot determine policy outcomes in this arena. This thesis challenges a theoretical perspective on public policymaking called Cosmopolitanism. Grounded in democratic and normative theory, it conceives of Global Civil Society, and NGOs in particular, as major conduits for democracy and social justice in global and/or regional governance. The thesis builds upon the insights of Constructivism to advance an alternative account of the significance of NGOs in the EU’s external trade policymaking process. In particular, it argues that epistemes, the deepest level of the ideational world, dominate the external trade policymaking process. NGOs succeed only when their attempts to achieve more democratic, just, equitable and fair external trade policies in the EU conform broadly to the dominant legal/liberal episteme. When they seek to overrule that episteme, they fail, regardless of their formal involvement in the external trade policymaking process.
BLAST: A Balloon-borne, Large-aperture, Submillimetre Telescope
Keywords: submillimetre
instrumentation
astrophysics

BLAST is a balloon-borne large-aperture, submillimetre telescope, which makes large area (1-200 square degree) surveys of Galactic and extragalactic targets. Since BLAST observes in the stratosphere, it is able to make broad-band observations between 200um and 550um which are difficult or impossible to perform from the ground. BLAST has been designed to probe star formation both in the local Galaxy and in the high redshift (z=1-4) universe. Because BLAST is flown on an unmanned stratospheric balloon platform, it has been designed to be able to operate autonomously, without needing operator intervention to perform its scientific goals. This thesis includes an overview of the design of the BLAST platform, with emphasis on the command and control systems used to operate the telescope. BLAST has been flown on two long-duration balloon flights. The first of these, from Esrange, Sweden in June of 2005, acquired ~70 hours of primarily Galactic data. During the second flight, from Willy Field, Antarctica in December of 2006, BLAST acquired ~225 hours of both Galactic and extragalactic data. Operational performance of the platform during these two flights is reviewed, with the goal of providing insight on how future flights can be improved. Reduction of the data acquired by these large-format bolometer arrays is a challenging procedure, and techniques developed for BLAST data reduction are reviewed. The ultimate goal of this reduction is the generation of high quality astronomical maps which can be used for subsequent portions of data analysis. This thesis treats, in detail, the iterative, maximum likelihood map maker developed for BLAST. Results of simulations performed on the map maker to characterise its ability to reconstruct astronomical signals are presented. Finally, astronomical maps produced by this map maker using real data acquired by BLAST are presented, with a discussion on non-physical map pathologies resulting from the data reduction pipeline and map making procedures.