Matching Items (3)
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- All Subjects: development
- Genre: Doctoral Dissertation
- Creators: Manuel-Navarrete, David
Description
Specific dendritic morphologies are a hallmark of neuronal identity, circuit assembly, and behaviorally relevant function. Despite the importance of dendrites in brain health and disease, the functional consequences of dendritic shape remain largely unknown. This dissertation addresses two fundamental and interrelated aspects of dendrite neurobiology. First, by utilizing the genetic power of Drosophila melanogaster, these studies assess the developmental mechanisms underlying single neuron morphology, and subsequently investigate the functional and behavioral consequences resulting from developmental irregularity. Significant insights into the molecular mechanisms that contribute to dendrite development come from studies of Down syndrome cell adhesion molecule (Dscam). While these findings have been garnered primarily from sensory neurons whose arbors innervate a two-dimensional plane, it is likely that the principles apply in three-dimensional central neurons that provide the structural substrate for synaptic input and neural circuit formation. As such, this dissertation supports the hypothesis that neuron type impacts the realization of Dscam function. In fact, in Drosophila motoneurons, Dscam serves a previously unknown cell-autonomous function in dendrite growth. Dscam manipulations produced a range of dendritic phenotypes with alteration in branch number and length. Subsequent experiments exploited the dendritic alterations produced by Dscam manipulations in order to correlate dendritic structure with the suggested function of these neurons. These data indicate that basic motoneuron function and behavior are maintained even in the absence of all adult dendrites within the same neuron. By contrast, dendrites are required for adjusting motoneuron responses to specific challenging behavioral requirements. Here, I establish a direct link between dendritic structure and neuronal function at the level of the single cell, thus defining the structural substrates necessary for conferring various aspects of functional motor output. Taken together, information gathered from these studies can inform the quest in deciphering how complex cell morphologies and networks form and are precisely linked to their function.
ContributorsHutchinson, Katie Marie (Author) / Duch, Carsten (Thesis advisor) / Neisewander, Janet (Thesis advisor) / Newfeld, Stuart (Committee member) / Smith, Brian (Committee member) / Orchinik, Miles (Committee member) / Arizona State University (Publisher)
Created2013
Description
This dissertation focuses on the endogenous conceptualization of development and sustainability emerging from settled non-native indigenous communities in the transborder region of Baja California, México. The study is comprised of interview data collected from a sample of 19 (n=19) self-identifying non-native indigenous community members and three key informants residing in various municipalities of the state. The purpose of this research is twofold, on the one hand, it aims to highlight the ways global north conceptualizations and praxis of development and sustainability in México have failed to include indigenous communities and fall short of creating feasible or appropriate practices of development and sustainability for marginalized communities. On the other, it focuses on the future perspectives of non-native indigenous communities to understand what development and sustainability look like for marginalized indigenous communities in México. The research finds that non-native indigenous communities’ settled in Baja California align more closely with the notion of Buen Vivir than development, in efforts to implement holistic approaches to progress and the conservation of their ethnic identity, culture and funds of knowledge. Additionally, the data reveals the bordering processes within ethnic and cultural scapes in Baja California’s society incentivizes merging funds of knowledge to achieve community recognition and progress. In essence, the experience and mobilization of settled non-native indigenous communities in Baja California break the perceived dichotomy between rural and urban, traditional and modern. The research also has some auxiliary findings: (1) indicating that in the state of Baja California the proliferation of development and sustainability discourses are polarized and relatively neglected in public discourses, despite its close transborder relationship with the US and growing concerns of development and sustainability in the northern nation. Second, indigenous women have been and continue to be important catalysts in community formation and representation.
ContributorsMora-Castillo, Brenda (Author) / Cruz-Torres, Maria l (Thesis advisor) / Wutich, Amber (Committee member) / Manuel-Navarrete, David (Committee member) / Arizona State University (Publisher)
Created2022
Description
This research investigates the dialectical relationships between water and social power. I analyze how the coupled processes of development, water privatization, and climate change have been shaping water struggles in Chile. I focus on how these hydro-struggles are reconfiguring everyday practices of water management at the community scale and the ways in which these dynamics may contribute to more democratic and sustainable modes of water governance at both regional and national scales. Using a historical-geographical and multi-sited ethnographical lens, I investigate how different geographical projects (forestry, irrigated agriculture, and hydropower) were deployed in the Biobio and Santiago regions of Chile during the last 200 hundred years. I analyze how since the 1970s, these hydro-modernization projects have been gradually privatized, which in turn has led to environmental degradation and water dispossession affecting peasants and other rural populations. I frame these transformations using the political-ecological notion of hydrosocial assemblages produced by the different stages of the hydro-modernity—Liberal, Keynesian, Socialist, Neoliberal. I detail how these stages have repeatedly reshaped Chilean hydrosocial processes. I unpack the stages through the analysis of forestry, irrigation and hydropower developments in the central and southern regions of Chile, emphasizing how they have produced both uneven socio-spatial development and growing hydrosocial metabolic rifts, particularly during neoliberal hydro-modernity (1981-2015). Hydrosocial metabolic rifts occur when people have been separated or dispossessed from direct access and control of their traditional water resources. I conclude by arguing that there is a need to overcome the current unsustainable market-led approach to water governance. I propose the notion of a 'commons hydro-modernity', which is based on growing environmental and water social movements that are promoting a socio-spatial project to reassemble Chilean hydrosocial metabolic relations in a more democratic and sustainable way.
ContributorsTorres Salinas, Robinson (Author) / Bolin, Bob (Thesis advisor) / Manuel-Navarrete, David (Committee member) / Larson, Kelli (Committee member) / Arizona State University (Publisher)
Created2016