VictorJuiz/thesis huggingface dataset:
MECHANICAL AND TRIBOLOGICAL PROPERTIES OF SKIN STUDIED BY MICROSCALE INDENTATION AND SCRATCHING TECHNIQUES

Knowledge of the mechanical response and deformation behavior of individual skin layers during microprobe penetration is of high clinical and societal importance. In this thesis, the elastic behavior of stratum corneum, viable epidermis, dermis, and whole multilayer skin were investigated by combining micro/nanoindentation and microscratching techniques. Statistical analysis shows insignificant differences in reduced elastic modulus of skin samples obtained from three different porcine breeds. The reduced elastic modulus of stratum corneum is shown to be about three orders of magnitude higher than that of dermis. For relatively shallow and deep indentation depths, skin elasticity is controlled by that of stratum corneum and dermis, respectively. Skin indentation mechanics are interpreted in the context of a layered structure model consisting of a stiff and hard layer supported by a compliant and soft substrate, derived on the basis of microscopy observations and indentation measurements./nTime-dependent deformation of porcine skin was also studied in vitro. The deformation behavior of stratum corneum, dermis, and whole skin tissue are examined in the context of measurements of creep strain, elastic stiffness, and viscoelastic constants obtained for different values of hold time, loading/unloading rate, and maximum indentation depth (load). It is shown that dermis viscoelasticity significantly affects the time-dependent deformation of skin up to a critical indentation depth (load) beyond which, the viscoelastic behavior of skin is controlled by the outermost hard epidermis, particularly stratum corneum. A conceptual deformation model that explains skin viscoelastic behavior under constant load (creep) and zero load (stress relaxation) conditions is developed on the basis of the phenomenological observations and experimental trends of this study./nRepresentative friction and wear results of skin subjected to unidirectional and reciprocal (cyclic) scratching are interpreted in terms of sliding speed, normal load, and scratch cycles to illustrate the effects of stratum corneum, cellular epidermis, and dermis on the skin friction and wear characteristics. Depending on the applied normal load and scratch time (cycles) various friction mechanisms (adhesion, plowing, and squeeze film lubrication) and wear processes (surface plasticity/plowing, bulk shearing, cohesive failure, tearing, and delamination) control shear-induced skin damage. The obtained results provide insight into microscale friction and wear processes influencing the mechanical response of skin to normal and shear surface tractions.

Advisor: Komvopoulos, Kyriakos
Engineering of Olfactory Receptor OlfCc1 for Directed Ligand Sensitivity

Abstract/nEngineering of Olfactory Receptor OlfCc1 for Directed Ligand Sensitivity/nby/nAllison Paige Berke/nJoint Doctor of Philosophy/nwith the University of California San Francisco/nUniversity of California, Berkeley/nProfessor Song Li, Chair/nDue to structural similarity, OlfCc1and its mammalian analogue V2R2 are hypothesized to respond to amino acid ligands in a calcium-mediated fashion. By analyzing receptor structure and making targeted mutations, the specificity and sensitivity of the receptor should be tunable, within the range of OR response thresholds. OlfCc1 responds to the amino acids isoleucine and leucine, in a calcium-dependent manner. V2R2 shows a similar response profile, with additional bimodal responses to valine. Additionally, both function as amine receptors, responding to isoamylamine and 2-methylbutylamine. This represents a TAAR-independent amine-sending pathway. Targeted mutations to OlfCc1 have successfully altered the sensitivity of the receptor, through mutating residues in the proximal pocket that are predicted to be three Angstroms or less from the docked ligand. Additional docking with calcium in the binding pocket has clarified distal pocket residues that coordinate the side chain of the amino acid ligand. Mutations to these residues have successfully altered the specificity of the receptor, including mutations to align its binding profile with that of the calcium-sensing receptor. Residues affecting amine-group binding as well as side-chain stabilization and calcium binding have been identified through modeling and confirmed through expression and functional testing in HEK cells./nThe utility of and interest in these findings have both engineering and biological significance. Being able to target receptor functionality through directed modeling and mutagenesis opens up the olfactory receptors, naturally occurring and highly sensitive native sensing elements, as a family of candidate in vitro sensing elements. Their ability to be tuned along a gradient of concentration-dependent responses (showing EC50 tunability) indicates that they may be useful as reporter elements. Additionally, the ability to make verifiable and accurate predictions about receptor functionality from an in silico model is useful to the study of many receptors. The utility of using OlfCc1 and V2R2 in particular stems from their unique expression profiles (expressed near-ubiquitously in certain populations of olfactory and vomeronasal neurons) and their close homology with LIVBP, MGluR, and PBP proteins. Showing through modeling and mutagenesis how OR regions of similarity correspond to binding profiles gives us insight into how receptors function combinatorially.

Advisor: Li, Song
Women on the Move: From the Ghost Dance to Urban Parks

Comprised of historical and empirical research, this dissertation addresses conceptions of health, movement, and behavioral norms in public spaces. While dance and rhythmic activities are vital to social cohesion, communication, and cultural reproduction in human societies worldwide, they have been subject to many forms of suppression--as is the case of American Indians on reservations in the 20th century. The Ghost Dance among the Lakota in 1890, along with other examples, together reveal the role of dance and music in offering resilience and hope for renewal. The experiences of women in America in the late-19th through mid-20th centuries is also discussed: The interactions of race and gender pertinent to women's experiences in public, American Indian assimilation, dance, city parks movement, physical education, and physical culture are highlighted./nThe historical context is complemented by contemporary observations of municipal parks in the San Francisco East Bay. Municipal parks with similar design features are found in cities and towns throughout the United States. As public commons, they reveal a great deal about social values, norms, and power. This study utilizes an environmental justice framework and a modified System for Observing Play and Recreation in Communities method to evaluate park conditions and usage. Forty-seven parks, most less than seven acres in size, located in census tracts reporting populations at or above the California averages for Asian, African American, or American Indian residents in the cities of Richmond, Berkeley, and Oakland, California were visited at various times throughout the day and week./nObservations confirmed previous studies that found predominantly sedentary uses with limited variety. Among adult and teen park users, there were fewer women than men, which also corresponded with previous studies in other cities. Most parks had low levels of use considering the population density of the surrounding neighborhood. Access to sanitary infrastructure and drinking water was limited, as was equipment for adults. Facilities for competitive sports were common, while alternative outdoor facilities for group rhythmic, creative, or coordinated movement were rare./nIt is recommended that municipalities could address environmental inequalities and increase park usage by providing free or very low-cost programming that incorporates creativity, expression, and cooperation. Access to equipment such as hoops, wheels, musical instruments, ropes, and spaces for community dances or presentations should be explored as additional ways to increase active park use. Enhancing sanitation infrastructure, negotiating sound policies, and facilitating active transportation to and from parks are other suggested ways to increase use of urban municipal parks.

Advisor: Merchant, Carolyn
Tallbear, Kimberly
Beyond Diagnosis: The Dynamics of Disability and Disruptions in Parenting

Beyond Diagnosis: The Dynamics of Disability and Disruptions in Parenting/nBy Christina Anne Sogar/nDoctor of Philosophy in Social Welfare/nUniversity of California at Berkeley/nJane G. Mauldon, Chair/nDrawing on 11 months of field research with 127 SSI-receiving parents, this study examined the relationship between disability, economic hardship and parenting practices as well as the likelihood of families' involvement with child welfare services. Four main research questions were examined. First, what are the pathways through which parents apply for and receive SSI benefits? Second, what are the main health, economic and caregiving needs of SSI-parent families? Next, how do disability characteristics including the type of onset, the stability of symptoms and worry about outcome influence parenting and family well-being? Finally, do families with past child welfare involvement differ from families without past child welfare involvement on health, economic or caregiving measures?/nWhile the health limitations reported by parents who received TANF prior to SSI were similar to those who did not, the age each group began to receive SSI was different as was the rate of child welfare involvement. Parents who transitioned from TANF to SSI were older at the time they were approved and were much more likely to report past child welfare involvement than parents without prior TANF receipt. Public and private sources of support reduced some types of material hardship but had little effect on parenting. Characteristics of disability such as an acute versus gradual onset were also not found to shape parenting once other variables were accounted for. Parenting constructs, including nurturance, follow-through with discipline and organization, did not predict the likelihood of child welfare involvement./nEconomic hardships and parenting limitations were found to be most pronounced among parents with poor mental health, and this finding appeared to be related to a greater degree of social isolation. The development of a peer network, where parents can share their strengths and struggles and feel supported in their parenting role, may serve to reduce the social isolation of parents with mental health problems and improve their families' well-being.

Advisor: Mauldon, Jane G
Not for Members Only: Cooperatives and Community Development in Costa Rica

This study explores the role of coffee cooperatives in providing for the social welfare of Coto Brus, a rural Costa Rican county. The research explains how, to what extent, and why these cooperatives have become involved in development and organizing projects that benefit not just their members but also the community. Data were gathered by ethnographic immersion in the community over 8 months. Sources included published government reports; interviews with cooperative managers and employees, cooperative members, and community members; participant-observation in community and cooperative events; and administrative records from cooperatives. The research suggests that cooperatives are reflective of a social development approach to social work practice by attempting to harmonize economic, social, and political aims. At first, cooperative members coalesced around meeting economic needs for the community. They, then, engrained a commitment to providing social goods. Recently, they have also spearheaded a coalition of community organizations to engage in political, non-partisan advocacy. In sum, they promote community welfare through the economic, social, and political realms. The cooperatives' involvement in the community is not wholly virtuous, and there are gaps between discourses and practices, which obviate their potential to promote community welfare. In spite of these gaps, the two cooperatives have served as engines of development in the county. The paper concludes by considering ways in which cooperatives can be strengthened to maximize their potential for social development.

Advisor: Chow, Julian
At the Crux of a Systemic Reform: California Partnership Academy Lead Teachers in Comprehensive High Schools in a Linked Learning District

The purpose of this exploratory case study is to focus a lens on lead teachers of California Partnership Academies (CPAs), who are responsible for overseeing the operation and coordinating the components of a complex, contra-normative secondary reform model. This study examines the stresses experienced by four CPA lead teachers at two different sites in a district committed to placing the Linked Learning model in the center of its secondary school reform strategy. Previous research has identified stressors inherent in the lead teacher role, and in the career academy reform studied here. This research assess the impact of those stressors, strategies lead teachers employ and conditions that facilitate lead teachers' work by looking at the dynamics of their role, the context in which they work, and patterns of leadership distribution through three key relationships, each focused on a particular routine./nThis study found that the primary role-related stressor these CPA lead teachers experienced was overload, which may have implications for the sustainability of the model, particularly as it is scaled up. The contra-normative nature of this reform was evident in the conflicts that arose for lead teachers in each of the three relationships examined. In their relationships with administrators focused on the master schedule, traditional patterns of student placement into AP and non-AP tracks conflicted with the effort to create pathways for all students to access both college and career. Teachers struggled to create strategies for addressing this issue. In lead teachers' work with their peers on interdisciplinary curriculum, the collaborative and interdisciplinary nature of the reform conflicted with the autonomous, individualistic and subject-oriented nature of teacher culture. Where collective co-performance defined school-wide patterns of leadership distribution, lead teachers were better able to influence collaborative teacher norms. Lead teachers' relationships to community and industry partners facilitated integration of work-based learning into the CPA instructional program, accessed new resources and challenged the traditional segregation of academic and vocational education. This work was greatly facilitated by district support but limited by the capacity of site administrators who were often unaware of these partnerships, and were not developing systemic ways to include them in the school's vision or program.

Advisor: Warren Little, Judith
The Second Generation Story of Hmong Americans

Research on the second generation of post 1965 immigrants has largely explained the integration of these youth into American society as an issue of human capital and ethnicity. The emphasis on ethnicity as strategy for upward mobility, such as maintaining ethnic attachment, employing "the best of both worlds", or assimilating into a multicultural mainstream, downplays the tension girls experience within the immigrant culture, and simplifies the forces of racialization that make the boys susceptible to downward assimilation. Based on surveys and interviews with Hmong youth (ages 13-18) from Sacramento, California, my study of second generation Hmong Americans extends this research to show how gender and ethnicity matter for incorporation. My findings point to different integration pathways for boys and girls, with the girls having a more promising pathway with higher levels of academic achievement and lower levels of involvement with risky behaviors than the boys. The girls experience unpleasant and difficult experiences within the ethnic culture despite having positive outcomes; whereas, the boys face more overt discrimination and hostility in mainstream society that make them susceptible to downward assimilation despite their attachment to the ethnic culture and community. This study contributes knowledge about second generation Hmong Americans, who constitute the growing population of Southeast Asian refugee children in the United States.

Advisor: Montejano, David
Supersymmetric sigma models, partition functions and the Chern-Gauss-Bonnet Theorem

In the search for a geometric model for elliptic cohomology and the Witten genus, Stolz and Teichner have defined a class of supersymmetric Euclidean field theories in various superdimensions d|delta. With collaborators, they have shown that 1|1-dimensional theories encode the A^-genus and KO-theory, and in dimension 2|1 they expect similar constructions to lead to the Witten genus and TMF, the universal elliptic cohomology theory. In this thesis, we investigate super Euclidean field theories in a variety of dimensions with the goal of understanding their role in algebraic topology. We focus on two aspects: (1) the appearance of invariants like the A^-genus and (2) the relationship between field theories and cohomology theories./nBeginning in the early 80s, physicists observed that partition functions of supersym- metric sigma models could frequently be identified with manifold invariants like the Euler characteristic, signature and A^-genus. Making these arguments precise culminated in the heat kernel proof of the index theorem. The first result in this thesis is a structural one: partition functions of supersymmetric sigma models always furnish manifold invariants. We prove this in Chapter 2. This leaves open the difficult question of how one might construct these supersymmetric sigma models./nChapter 3 is a proof of the Chern-Gauss-Bonnet Theorem, which comes in two parts. We construct the 0|2-sigma model, which we know a priori leads to a manifold invariant. Then, via computations in supergeometry, we identify this invariant with the Euler characteristic. By coupling the sigma model to a constant times a Morse function we obtain a variety of expressions that compute the partition function, and by equating two of these we derive the Chern-Gauss-Bonnet formula./nIn Chapter 4, we investigate the relationship between field theories and cohomology theories. Our results are various no-go theorems for when field theories give cocycles for cohomology theories for delta> 1. In dimensions 0|delta we are able to prove fairly strong statements to this effect, but for d > 0 we need to make assumptions motivated by our desired connection between invariants coming from sigma models and the putative cohomology theory coming from the space of field theories.

Advisor: Teichner, Peter
The Large-scale Structure of the Universe: Probes of Cosmology and Structure Formation

The usefulness of large-scale structure as a probe of cosmology and structure formation is increasing as large deep surveys in multi-wavelength bands are becoming possible. The observational analysis of large-scale structure guided by large volume numerical simulations are beginning to offer us complementary information and crosschecks of cosmological parameters estimated from the anisotropies in Cosmic Microwave Background (CMB) radiation. Understanding structure formation and evolution and even galaxy formation history is also being aided by observations of different redshift snapshots of the Universe, using various tracers of large-scale structure./nThis dissertation work covers aspects of large-scale structure from the baryon acoustic oscillation scale, to that of large scale filaments and galaxy clusters. First, I discuss a large- scale structure use for high precision cosmology. I investigate the reconstruction of Baryon Acoustic Oscillation (BAO) peak within the context of Lagrangian perturbation theory, testing its validity in a large suite of cosmological volume N-body simulations. Then I consider galaxy clusters and the large scale filaments surrounding them in a high resolution N-body simulation. I investigate the geometrical properties of galaxy cluster neighborhoods, focusing on the filaments connected to clusters. Using mock observations of galaxy clusters, I explore the the correlations of scatter in galaxy cluster mass estimates from multi-wavelength observations and different measurement techniques. I also examine the sources of the correlated scatter by considering the intrinsic and environmental properties of clusters.

Advisor: White, Martin
Quataert, Eliot
Enantioselective Functionalizations of Alkenes Using Chiral Phosphoric Acids

New organocatalytic enantioselective reactions were developed, focusing on using new modes of reactivity with chiral phosphoric acids. Prochiral alkenes and styrenes were explored as substrates for various transformations, including enyne cycloisomerization, hydroamination, halocyclization, and fluorination. The enantioenriched chiral products generated by these methods include heterocycles and allylic fluorides.

Advisor: Toste, F D
Grocery Stores: Neighborhood Retail or Urban Panacea? Exploring the Intersections of Federal Policy, Community Health, and Revitalization in Bayview Hunters Point and West Oakland, California

Throughout the nation, grocery retailers are reentering underserved communities amidst growing public awareness of food deserts and the rise of federal, state, and local programs incentivizing urban grocery stores. And yet, even with expanding research on food deserts and their public health impacts, there is still a lack of consensus on whether grocery stores truly offer the best solution. Furthermore, scholars and policymakers alike have limited understandings of the broader neighborhood implications of grocery stores newly introduced into underserved urban communities./nThis dissertation analyzes how local organizations and agencies pursue grocery development in order to understand the conditions for success implementation. To do this, I examine the historical drivers, planning processes, and outcomes of two extreme cases of urban grocery development: a Fresh and Easy Neighborhood Market (a chain value store) in San Francisco's Bayview Hunters Point and the Mandela Foods Cooperative (a worker-owned cooperative) in Oakland's West Oakland districts./nThrough a comparative institutional analysis, I find that both Fresh and Easy and Mandela Foods reflect distinctive neighborhood revitalization legacies, critical moments of institutional capacity building, localized versions of national policy narratives, and the role of charismatic leaders in grocery store implementation. While national narratives shape the rhetoric of urban grocery development, ultimately local context dictates how food access issues are defined, who addresses them, and how. These findings suggest that federal grocery incentive programs should: 1) maintain a broad framework that enables local communities to define food access problems and their solutions on a case-by-case basis, 2) encourage diverse solutions not limited to grocery stores and supermarkets, and 3) emphasize community reinvestment goals.

Advisor: Corburn, Jason