• QUANTIFICATION AND PHYLOGENETIC COMPARATIVE ANALYSIS OF PELAGE SEXUAL DICHROMATISM IN PRIMATES

      Rockwell, Christie; Weitz, Charles A.; Bradley, Brenda J.; Baden, Andrea L. (Temple University. Libraries, 2019)
      This study is the first to quantify pelage sexual dichromatism (PelSD) across the order Primates. The hypothesis that PelSD evolves as a consequence of sexual selection on the pelage color of male primates is considered. Color-corrected high-resolution photographs were taken of primate pelts taken from museum collections, representing primate 83 species. Two measures of color, luminance and hue, were taken for the dorsal and ventral aspects of the trunk of each specimen. These measurements are proxies for the absolute and relative concentrations of melanin(s) in primate pelage. Highly-dichromatic species were identified and the evolution of luminance and hue in males and females of those species was analyzed. Species where male luminance or hue was under selection without concomitant selection on females were considered to be under sexual selection. There was little clear evidence of sexual selection on male luminance in highly-dichromatic species. However, there was substantial evidence of sexual selection on male hue. To determine if male pelage color is an ornament that signals quality and is used by females in choosing mates, fluctuating asymmetry (FA), a proxy for mate choice, was regressed against PelSD. Evidence of trunk pelage as ornamentation (i.e., significant correlation between FA and PelSD) was only observed among platyrrhines. Sexual selection on male hue and a trend toward yellower pelage in males of highly-dichromatic species suggests a shift to phaeomelanin production in those males. Explanations for the observed shift to yellow pelage/phaeomelanin production are explored.
    • Quantification of stability of analytic continuation with applications to electromagnetic theory

      Grabovsky, Yury; Berhanu, Shiferaw; Gutiérrez, Cristian E., 1950-; Harutyunyan, Davit (Temple University. Libraries, 2021)
      Analytic functions in a domain Ω are uniquely determined by their values on any curve Γ ⊂ Ω. We provide sharp quantitative version of this statement. Namely, let f be of order E on Γ relative to its global size in Ω (measured in some Hilbert space norm). How large can f be at a point z away from the curve? We give a sharp upper bound on |f(z)| in terms of a solution of a linear integral equation of Fredholm type and demonstrate that the bound behaves like a power law: E^γ(z). In special geometries, such as the upper halfplane, annulus or ellipse the integral equation can be solved explicitly, giving exact formulas for the optimal exponent γ(z). Our methods can be applied to non-Hilbertian settings as well. Further, we apply the developed theory to study the degree of reliability of extrapolation of the complex electromagentic permittivity function based on its analyticity properties. Given two analytic functions, representing extrapolants of the same experimental data, we quantify how much they can differ at an extrapolation point outside of the experimentally accessible frequency band.
    • Quantification of the Role of The Effective Binder in the Performance of RAP – WMA Mixtures

      Faheem, Ahmed; Coe, Joseph T.; Khanzadeh Moradllo, Mehdi; Mogawer, Walaa (Temple University. Libraries, 2020)
      Over the past decades, several new technologies/materials (such as WMA, RAP, rubber, polymers, bio-binders…etc.) were incorporated into asphalt mixtures. However, current mix-design specifications evaluate all mixtures containing these different additives/technologies based on volumetric. Further, RAP incorporation in asphalt mixtures is still limited, and the influence of lowered production temperatures on RAP contribution in RAP-WMA mixtures is understudied. To tackle these issues, this study presents a comprehensive evaluation of the effect of production factors ( RAP content and source, binder grade, and production temperatures) on the effective binder in WMA-RAP mixtures, and the role of the effective binder in controlling mixture performance.The experimental program included evaluation of the compaction, cracking, and rutting performance of WMA-RAP mixtures produced with a different combination of the production factors. The Semi-Circular Bend (SCB) test at intermediate temperatures was used for cracking evaluation, while the Indirect Tension Test at High Temperatures (IDT-HT) was used for rutting evaluation. Further, the study included rheological characterization of extracted binder from the mixtures to investigate the role of the effective binder on cracking performance. The results showed that the effective binder properties are changed significantly with changes in the production factors, as measured by the extracted binder rheological properties. Also, the properties of the effective binder showed a direct control of the mixture performance as measured by the IDT-HT strength and the flexibility index obtained from the SCB test. Binder selection limits were developed for lab-produced WMA-RAP mixtures based on the Glover-Rowe parameter. Finally, a validation study was conducted using data from four different projects, including a field project in Texas, FHWA’s accelerated loading facility, a laboratory mixture study in Wisconsin, and a New Hampshire DOT study to confirm the refine the findings of this study.
    • QUANTIFYING GANG LOCATIONS: SYSTEMATICALLY TESTING VALIDITY USING A PARTIAL TEST OF MESSICK’S UNIFIED PERSPECTIVE

      Ratcliffe, Jerry; Taylor, Ralph B.; Roman, Caterina Gouvis, 1966-; Brantingham, P. Jeffrey, 1970- (Temple University. Libraries, 2017)
      Gangs pose a serious problem in 21st century policing. After spending forty years studying them, Klein describes why we still have a lot to learn about gangs. Specifically, he suggests: “Too little attention has been paid to the communities in which gangs appear. Observing and understanding neighborhoods is far more complex than studying their gangs; yet it is communities that spawn gangs and must inevitably be the proximal focus for controlling them” (Klein 2007: xiv). The neighborhood complexity to which Klein refers has not been adequately addressed. The field lacks strong theoretical development to guide decisions about conceptualizing and operationalizing gangs from an ecological perspective. As a reflection of that lack of guidance, researchers today employ several alternate indicators of gang ecologies. This study seeks to identify the consequences of variations in how gangs are conceptualized and measured at an ecological level. Researchers model gangs in substantially different ways, using dissimilar indicators, spatial scales, and levels of measurement. These variations may generate disparities in empirical results and different estimates of gang ecologies without a clear rationale for, or understanding of, the implications of their selection. The analysis examines two central research questions: (1) Do indicators of gang ecologies identify gangs in similar ways and with results that are consistent across spatial scales? (2) Can indicators predict the presence versus absence of gangs—as a binary outcome—as well as predict continuous gang outcomes, such as the number of gangs present or the geographic size of the gang ecology, with results consistent across spatial scales? Arrest data and gang data provided by the Philadelphia Police Department (PPD) included information on 3,996 gang members who belonged to 113 gangs. PPD data indicated (1) where gang members live, (2) gang arrests (N=7,488 from 2012-2015), (3) crime incidents that involve a gun (N=26,865 from 2012-2015), and (4) PPD defined gang set space boundaries. This study examined the validity of each of these indicators when each is used to define gang ecologies. The analysis plan was guided by Messick’s unified perspective of construct validity (Messick 1995) and included two types of analyses. The first analysis employed a series of 60 regression models. Model comparisons tested various aspects of construct validity as proposed by Messick. The second analysis developed an algorithm creating gang set space polygons using either the locations where gang members live or the locations of gang-related crime. The set space polygons created by this algorithm were compared to the PPD set space polygons. The degree to which the gang set space polygons created by the algorithm overlapped with the gang set space polygons defined by PPD functioned as another validity test. The results of the regression analysis revealed the home address and arrest variables better explained the spatial distribution of the PPD gang set space locations than the gun crime variable. The link between the gang indicators and the PPD identified set space polygons, however, was complex. Oftentimes, the home address data and the arrest variables significantly predicted a binary gang outcome—whether one or more gangs existed in an area; but those variables could not significantly estimate a continuous gang outcome, i.e. how many gangs were present, or geographic size of gang set space. This means the home address and arrest variables have limited ability to explain the spatial distribution of the gang set space boundaries defined by PPD. The spatial analysis used an algorithm to approximate gang set space locations. The results indicate that locations of gang members’ homes and of gang arrests both can approximate the PPD reported gang set space locations equally well. However, the spatial overlap between the PPD reported set space and the approximated set space locations proved relatively small. Although the approximated gang set space polygons usually did overlap with the PPD reported gang set space polygons to some extent, the mean overlap was 10% using the home address locations and 7% using the arrest data. The policy or practice usefulness of the indicators used here could be minimal. Although the overlap wasn't perfect, the algorithm was able to identify the general locations where gangs exist using only the home address of gang members or gang arrest data. This study contributes to our knowledge about gang measurement at the ecological level. Conceptualizing and measuring gangs in a theoretically driven way is critical to the development of effective policies to control and prevent violence, fear, and other social harms caused by gangs. The results of this study will pave the way for future research to build on our understanding of how gangs link to crime, how community level dynamics work to foster or prevent gang activity, and ultimately, how to reduce and prevent gang problems.
    • Quantifying periods of diffusion in marine and nonmarine vertebrate fossils using rare earth elements

      Terry, Dennis O., 1965-; Grandstaff, David E.; Tumarkin-Deratzian, Allison (Temple University. Libraries, 2012)
      Concentrations of rare earth (REE), U, Th, and other trace elements (TE) were measured using LA-ICP-MS along transects across five Late Eocene brontothere bones from the terrestrial Late Eocene Chadron Formation of Nebraska and four Miocene marine mammals from the Atlantic Coastal Plain. Samples were analyzed to determine REE diffusion periods, and to determine if histological factors affect post mortem uptake of REE/TE. In terrestrial fossil bones, concentrations of REE are highest at the bone surface and decrease with depth into the trabecular bone, consistent with diffusion-limited models. Histology may affect REE incorporation. An outer circumferential layer (OCL) is preserved along the outer 1 mm of the brontothere rib (F08-10) and femur (F08-09). REE concentrations in the OCL are much lower than in the underlying bone, indicating either lower incorporation or post fossilization leaching. REE concentrations are sometimes elevated in trabecular bone and Haversian systems, which may act as secondary diffusion pathways. REE concentration gradients are generally steeper in marine fossils than in terrestrial fossil bones, indicating longer periods of REE uptake in terrestrial fossils. Calculated periods of diffusion in terrestrial environments are 2.2 +/- 0.5 to 54.8 +/- 1.5 ka (based on a wetness factor of 0.5 +/- 0.1). Periods of diffusion for marine environments range from ca. 0.9 +/- 0.2 to 2.8 +/- 0.6 ka. However, within some terrestrial samples U is introduced into the bone over a much longer time span, possibly as a function of fluctuating redox conditions. If these values are representative, diffusion-fossilization periods are shorter in marine/lacustrine/spring/channel environments due to constant water saturation. Saturation of a bone during diffusion may also affect the morphology of REE signatures within the bone. In terrestrial bones, REE are strongly fractionated with depth, producing signatures varying from light-REE enriched at the surface to middle-REE depleted at depth. However, depth fractionation of REE is much less pronounced in marine bones, which may result from the introduction of fluid unreactive. These differences in REE fractionation are consistent with a greater influence of multiple secondary REE/TE diffusion paths in marine samples. Periods of diffusion for terrestrial samples differed within a single bonebed accumulation (2.2 +/- 0.5 to 54.8 +/- 1.5 ka). However, REE signatures are internally consistent with one another within the bonebed indicating that groundwater chemistry did vary during fossilization. If groundwater chemistry changes during diffusion, bone could be recording different signals, which has implications for using post-mortem REE/TE/Isotopes for paleoenvironmental reconstruction. Previous studies of soft tissue preservation in fossilized bone have inferred shorter periods of diffusion and suggested that the rate of diffusion must outpace the rate of decay. Diffusion periods in bone from well drained terrestrial settings are too long to preserve soft tissue. However, periods of diffusion in marine fossil bones are much shorter, suggesting the possibility for bio-molecule preservation.
    • Quantifying Post-Fire Aeolian Sediment Transport Using Rare Earth Element Tracers

      Ravi, Sujith; Grandstaff, David E.; Buynevich, Ilya V. (Ilya Val) (Temple University. Libraries, 2017)
      Grasslands provide fundamental ecosystem services in many arid and semi-arid regions of the world, but are experiencing rapid increases in fire activity making them highly susceptible to post-fire accelerated soil erosion by wind. A quantitative assessment that integrates fire-wind erosion feedbacks is therefore needed to account for vegetation change, soil biogeochemical cycling, air quality, and landscape evolution. We investigated the applicability of a novel tracer technique – the use of multiple rare earth elements (REE) - to quantify aeolian soil erosion and to identify sources and sinks of wind-blown sediments in a burned and unburned shrub-grass transition zone in the Chihuahuan desert, NM, USA. Results indicate that the horizontal mass flux of wind-borne sediment increased approximately three times following the fire. The REE-tracer analysis of aeolian sediments shows that an average 88% of the horizontal mass flux in the control area was derived from bare microsites, whereas at the burned site it was derived from shrub and bare microsites, 42% and 39% respectively. The vegetated microsites, which were predominantly sinks of aeolian sediments in the unburned areas, became sediment sources following the fire. The burned areas exhibited a spatial homogenization of sediment tracers, highlighting a potential negative feedback on landscape heterogeneity induced by shrub encroachment into grasslands. Though fires are known to increase aeolian sediment transport, accompanying changes in the sources and sinks of wind-borne sediments likely influence biogeochemical cycling and land degradation dynamics. Our experiment demonstrated that REEs can be used as reliable tracers for field-scale aeolian studies.
    • Quantifying the Effects of Community Health Center Access on Health for Medically-Vulnerable Populations

      Condran, Gretchen; Levine, Judith Adrienne, 1965-; Kaufman, Robert L. (Temple University. Libraries, 2016)
      Established in 1965 as a part of President Johnson’s War on Poverty effort, the federal community health center (CHC) program is a primary source of federally-subsidized quality health care services for medically-vulnerable populations in the United States. Despite its current role as a medical safety-net for the nation’s health care system, the CHC program did not begin as a public health program, but rather as a social justice program. Since its formalization, the CHC program has enjoyed relatively consistent Congressional support as a cost-effective means of providing primary healthcare to indigent populations; however, the narrative of the program has shifted overtime from a focus of empowerment and lifting communities out of poverty, to the fortification of the national health care system as a cost-effective provider of quality healthcare care for all. In this manuscript, I argue that this transition from community empowerment and the mitigation of fundamental causes of disease to a more risk-based emphasis on the issue of access, has diminished the urgency around the engagement of the structural effects of poverty on health in favor of a “one size fits all” approach to the provision of basic health care. In an effort to objectively quantify the effects of geographic access on health as a means for evaluating the success of the contemporary program, this research project explores the extent to which proximal access to a CHC is significantly associated with various self-reported indicators of positive health outcomes. My primary research method is multivariable regression utilizing secondary data from the 2012 Southeastern Pennsylvania Household Health Survey, the 2008-2012 5-year American Community Survey Estimate, and the Health Resources and Services Administration Data Warehouse. Using statistical modeling, I test the effect of CHC access on three distinct measures of individual health: (1) self-reported health status, (2) the likelihood of having pain lasting 6 months or more, and (3) the likelihood of having a usual source of health care. Within each model, I also test a series of interaction terms through nested sub-models to uncover any conditional effects of access for selected social groups. This statistical design offers the opportunity to explore whether the main association between access to a CHC and health varies based on the social characteristics and/or social environment of the individual. The findings of my analysis suggest that the effect of CHC access varies for different social groups, with less disadvantaged groups, such as poor non-Hispanic whites with high social capital, and poor individuals living in areas of low disadvantage, receiving the greatest benefit from proximal CHC access. However, individuals at the extremes of social disadvantage benefit least from CHC access alone. I argue that while the provision of CHC access is a noble and necessary tactic for fighting the persistence of health disparities in our medically-vulnerable communities, focusing on access alone is insufficient to solve the problem. The pendulum must switch back to community empowerment and the eradication of structural threats to health to initiate real change for medically-vulnerable populations.
    • QUANTITATIVE ANALYSIS OF AGGREGATIBACTER ACTINOMYCETEMCOMITANS IN DENTAL PLAQUE SAMPLES OF MOROCCAN SCHOOL CHILDREN WITH AND WITHOUT PERIODONTITIS

      Albandar, Jasim M.; Albandar, Jasim M.; Elgaddari, Fathi M.; Whitaker, Eugene J.; Hsiao, Yueh J. (Temple University. Libraries, 2019)
      Objectives: Microbial infection and the host response to the infection play a significant role in the etiology of periodontal diseases. Previous studies reported a relatively high prevalence of periodontitis among adolescents in Morocco. The importance of the composition of subgingival plaque and the presence and proportion of Aggregatibacter actinomycetemcomitans to the total plaque bacteria in the pathogenesis of periodontitis is not well understood. The purpose of this study is to compare the relative abundance of A. actinomycetemcomitans in subgingival dental plaque from young Moroccans with aggressive periodontitis, chronic periodontitis, and those without periodontitis, and to construct a multivariable model to investigate the effect of demographic attributes of age, gender and relative ratio of A. actinomycetemcomitans in dental plaque with periodontal disease status. Methods: Sample population includes 984 subjects, aging from 12-20 years old, who were surveyed and examined for periodontal disease status. 82 subjects were selected consisting of 26% aggressive periodontitis, 12% chronic periodontitis, and 62% without periodontitis. Subgingival plaque was collected from these 82 subjects. Whole DNA was extracted and purified, and real-time PCR was used employing a primer for eubacteria, and specific primer for A. actinomycetemcomitans. PCR assays confirmed the amplification and quantification of DNA of total bacterial and A. actinomycetemcomitans. Results: 73% of the subjects harbored A. actinomycetemcomitans: 63% in aggressive periodontitis, 90% in chronic periodontitis, and 73% in controls. The percentage A. actinomycetemcomitans to total bacterial load increased with age, was similar among males and females, and was somewhat higher in persons with periodontitis than the controls. Using a logistic regression analysis that included age, gender and A. actinomycetemcomitans ratio showed that only age is significantly correlated with the diagnosis of periodontitis in this population. Conclusions: A. actinomycetemcomitans is prevalent among this young Moroccan group and is somewhat more prevalent in subjects with periodontitis than the controls. However, the presence and ratio of this species to the total bacteria in subgingival plaque explained only a small proportion of the variance in periodontitis in this group.
    • QUANTUM RANDOM WALK ON FRACTALS

      Yang, Wei-shih, 1954-; Futer, David; Szyld, Daniel; Shi, Justin Y. (Temple University. Libraries, 2018)
      Quantum walks are the quantum mechanical analogue of classical random walks. Discrete-time quantum walks have been introduced and studied mostly on the line Z or higher dimensional space Z d but rarely defined on graphs with fractal dimensions because the coin operator depends on the position and the Fourier transform on the fractals is not defined. Inspired by its nature of classical walks, different quantum walks will be defined by choosing different shift and coin operators. When the coin operator is uniform, the results of classical walks will be obtained upon measurement at each step. Moreover, with measurement at each step, our results reveal more information about the classical random walks. In this dissertation, two graphs with fractal dimensions will be considered. The first one is Sierpinski gasket, a degree-4 regular graph with Hausdorff di- mension of df = ln 3/ ln 2. The second is the Cantor graph derived like Cantor set, with Hausdorff dimension of df = ln 2/ ln 3. The definitions and amplitude functions of the quantum walks will be introduced. The main part of this dissertation is to derive a recursive formula to compute the amplitude Green function. The exiting probability will be computed and compared with the classical results. When the generation of graphs goes to infinity, the recursion of the walks will be investigated and the convergence rates will be obtained and compared with the classical counterparts.
    • QUANTUM SEARCH ON RANDOM GRAPHS

      Yang, Wei-Shih, 1954-; Futer, David; Queisser, Gillian; Shi, Justin Y. (Temple University. Libraries, 2021)
      This project was motivated by the following question: what information do the properties of a random graph contain about the performance of a quantum search acting on it? To investigate this problem, we define a notion of search time to quantify the behavior of a quantum search, and find strong evidence of a relation between its distribution and the model of random graph on which the search was performed. Surprisingly, we also find strong evidence that the return time of a classical random walk initialized at the marked vertex is closely related to its search time, and that the distribution of degrees over the graph vertices may play a significant role in this relation.
    • Quantum Stable Process

      Yang, Wei-shih, 1954-; Szyld, Daniel; Shi, Justin Y. (Temple University. Libraries, 2015)
      It is believed that in the long time limit, the limiting behavior of the discrete-time quantum random walk will cross from quantum to classical if we take into account of the decoherence. The computer simulation has already shown that for the discrete-time one-dimensional Hadamard quantum random walk with coin decoherence such that the measurement operators on the coin space are defined by A0 = Ic √1 − p, A1 = |R > < R| √p and A2 = |L > < L > < L| √p is diffusive when 0 < p ≤ 1 and it is ballistic when P = 0. In this thesis, we are going to let p to be dynamical depending on the step t, that is, we consider p = 1/tß, ß ≥ 0 and we found that it has sub-ballistic behavior for 0 < ß < 1. Furthermore, we study not only the coin decoherence, but the total decoherence, that means the measurement operators apply on the Hilbert space H = Hp ⊗ Hc instead of the coin space only. We find that the results are both sub-ballistic for the coin and total decoherence when 0 < ß < 1. Moreover, according to the model given in [T. A. Brun, H. A. Carteret, and A. Ambainis, Phys. Rev. A 67, 032304 (2003)], we know that if the walker has chance to hop to the second nearest neighbor lattice in one step, the long-time behavior is also sub-ballistic and it is similar to that the walker can hop to the third nearest neighbor lattice in one step. By the way, we also find that if we combine the classical part of the model given in [Jing Zhao and Peiqing Tong. One-dimensional quantum walks subject to next nearest neighbor hopping decoherence, Nanjing Normal University, preprint (2014)] with different step length, then this decoherence will also cross from quantum to classical. Finally, we define the quantum γ-stable walk and obtain the quantum γ-stable law with decoherence. By this decoherence, we can see that the limiting behavior of the quantum stable walk will also cross from quantum to classical and we shows that it spreads out faster than the classical stable walk.
    • Quantum State Singlet-Triplet Character Control in 7Li2

      Lyyra, A. Marjatta; Forster, Dieter, 1938-; Santamore, Deborah; Huennekens, John; Spano, Francis C.; Matsika, Spiridoula (Temple University. Libraries, 2010)
      We have demonstrated a means of quantum control by all-optical control of valence electron spin polarization in the lithium dimer. The energy levels of interest are two closely spaced rovibrational levels (the G1Πg (12, 21f) and 13Sg- (1, 21f) states separated by 720 MHz). In the absence of any optical fields, the spin-orbit interaction couples the two states, resulting in each state being a mixture of the pure singlet and pure triplet states. The initial mixing coefficients are governed by the strength of the spin-orbit coupling between the two levels. In lithium dimer, this mixing is very weak; the nominal singlet (triplet) state is initially 87% singlet (triplet) and 13% triplet (singlet). When a strong coupling field is applied to the nominally singlet state, an Autler-Townes (AT) split pair is created. Since one of the AT components is pushed closer in energy to the nearby triplet state, the triplet state gains more singlet character. Since the AT splitting is dependent upon the magnitude of the applied coupling field Rabi frequency, the mixing coefficients of the perturbed pair can therefore be coherently controlled. Such control may be useful for applications in cold molecule formation and control of predissociation rates, and may also provide insight into the role that valence electron spin polarization plays in reactive collisions.
    • Quantum Walks and Structured Searches on Free Groups and Networks

      Yang, Wei-shih, 1954-; Walton, Chelsea; Klapper, Isaac; Shi, Justin Y. (Temple University. Libraries, 2017)
      Quantum walks have been utilized by many quantum algorithms which provide improved performance over their classical counterparts. Quantum search algorithms, the quantum analogues of spatial search algorithms, have been studied on a wide variety of structures. We study quantum walks and searches on the Cayley graphs of finitely-generated free groups. Return properties are analyzed via Green’s functions, and quantum searches are examined. Additionally, the stopping times and success rates of quantum searches on random networks are experimentally estimated.
    • Queering Significance: What Preservationists Can Learn From How LGBTQ+Philadelphians Ascribe Significance to History Sites

      Lowe, Hilary Iris; Bruggeman, Seth C., 1975-; Beisert, Oscar Dean, 1982- (Temple University. Libraries, 2018)
      This thesis explores the ways in which LGBTQ+ individuals in Philadelphia ascribe significance to various places based on oral history interviews and additional primary source material collected initially for the National Park Service Northeast Regional Office’s LGBTQ+ Heritage Initiative. By examining stories from LGBTQ+ individuals of places that matter most to them in Philadelphia, this thesis argues that historic preservationists can expand their definition of significance to include personal testimony and broaden their practices to better engage the communities whose histories they seek to preserve.
    • Rab-Vesicle Trafficking is Required for Ras-Mediated Proliferation

      Goldfinger, Lawrence; Thomas, Gareth; Haines, Dale; Sirover, Michael A. (Temple University. Libraries, 2015)
      The Ras superfamily consists of over 150 members including the well-known: H-Ras, K-Ras and N-Ras. We propose to target Ras related proliferation in cancer cells by inhibiting Rab vesicle formation. H-Ras, K-Ras and N-Ras are carcinogenic; activating mutations in Ras signaling are generally associated with increased proliferation and survival in cancer cells. Ras is mutated in up to 30% of all human cancers and represents an early survival mutation in cancer cells. Vesicle-bound Ras is trafficked to the plasma membrane, which facilitates interaction between Raf, and effector proteins. Previously, farnsesylation inhibitors, (FTIs) and GTP binding agonists of Ras have been tested as potential pharmacological inhibitors of Ras signaling. However, both drug types have proven ineffective in-vivo. Therefore, there are currently no effective pharmacological treatments to target Ras signaling. However, unpublished data from our lab has identified co-localization of Ras and Rab proteins, in vesicles. Rab proteins are associated with vesicle budding, and endosome development. Rab activity is driven by GTP binding and geranylgeranylation. Non-geranylgeranylated Rab is cytosolic, and does not facilitate endosome formation or vesicle trafficking. We propose that by targeting the Rab specific geranylgeranylation via Rab-specific geranylgeranyl transferase II, we will inhibit Ras associated proliferation. We will pursue this hypothesis by testing three objectives. First, we will produce and test Rab-geranylgeranyl transferase (RGGT)-shRNA to target Rab specific geranylgeranyl transferase. Second, we will illustrate the effect of RGGT knockdown on a downstream signaling target of Ras, specifically pERK levels. Finally, we will measure the direct effect of RGGT knockdown on Ras mediated cellular proliferation. Our results conclude that RGGT-shRNA is a potential target of Ras mediated tumor proliferation.
    • Race Financial Institutions, Credit Discrimination And African American Homeownership In Philadelphia, 1880-1960

      Jenkins, Wilbert L., 1953-; Kusmer, Kenneth L., 1945-; Collier-Thomas, Bettye; Goldstein, Ira (Temple University. Libraries, 2011)
      In the wake of Emancipation, African Americans viewed land and home ownership as an essential element of their "citizenship rights." However, efforts to achieve such ownership in the postbellum era were often stymied by credit discrimination as many blacks were ensnared in a system of debt peonage. Despite such obstacles, African Americans achieved land ownership in surprising numbers in rural and urban areas in the South. At the beginning of the twentieth century, millions of African Americans began leaving the South for the North with continued aspirations of homeownership. As blacks sought to fulfill the American Dream, many financial institutions refused to provide loans to them or provided loans with onerous terms and conditions. In response, a small group of African American leaders, working in conjunction with a number of the major black churches in Philadelphia, built the largest network of race financial institutions in the United States to provide credit to black home buyers. The leaders recognized economic development through homeownership as an integral piece of the larger civil rights movement dedicated to challenging white supremacy. The race financial institutions successfully provided hundreds of mortgage loans to African Americans and were a key reason for the tripling of the black homeownership rate in Philadelphia from 1910 to 1930. During the Great Depression, the federal government revolutionized home financing with a series of programs that greatly expanded homeownership. However, the programs, such as those of the Federal Housing Administration, resulted in blacks being subjected to redlining and denied access to credit. In response, blacks were often forced to turn to alternative sources of high cost credit to finance the purchase of homes. Nevertheless, as a new wave of African American migrants arrived to Philadelphia during post-World War II era, blacks fought to purchase homes and two major race financial institutions continued to provide mortgage loans to African Americans in Philadelphia. The resolve of blacks to overcome credit discrimination to purchase homes through the creation of race financial institutions was a key part of the broader struggle for civil rights in the United States.
    • RACE, CULTURE AND ACADEMIC ACHIEVEMENT: An Historical Overview and an Exploratory Analysis in a Multi-Ethnic, Urban High School

      Norment, Nathaniel; Abarry, Abu Shardow, 1947-; Davis, James Earl, 1960-; DuCette, Joseph P. (Temple University. Libraries, 2011)
      This study highlights the salience of race, cultural match between student and teacher, students' cultural conformity and perceptions of opportunity, and teachers' pedagogical perspectives in students' academic achievement, with particular attention to the perpetual achievement gap between African American and European American students. This analysis of a multi-ethnic group of 308 high school students and 23 teachers examines the inter-relatedness of students' and teachers' cultural values, view, and practices and school-based environmental factors that are often absent or dichotomized in explorations of academic achievement across racial/cultural groups. Mann-Whitney U Test and Kruskal-Wallis Test results revealed statistically significantly higher achievement scores among (1) students who shared the same race/ethnicity or shared the same race/ethnicity and culture with their teachers; (2) students who reported cultural perspectives consistent with mainstream cultural views and experiences regarding race, social issues, school-related coping strategies, and school opportunity; and (3) students whose teachers reported pluralistic and multicultural/pluralistic pedagogical styles when compared to their peers. Exploratory analyses of variance supported multiple regression analyses which found each variable to explain from 15% to 23% of the variance in students' academic achievement. This African-centered investigation places the interests of African Americans central to its exploration. It posits the cultural heritage and social-political experiences of its subjects as the driving force of inquiry into the continual lack of "equal" opportunity for and "equal" legitimacy of African American people and culture in public education in America. Therefore, this study is informed by a comprehensive review of the history, culture, and social politics within which America's academic achievement levels and gaps are inextricably rooted. Given the pervasiveness of socially-reconstructed inequality through institutions in America, the roles of race, culture, and cultural conformity are analyzed in a "successful," multi-ethnic high school in the southwest. This analysis helps determine whether dynamics that involve culture and cultural conformity are active in America's classrooms and how they impact students' achievement. It is hoped that this clarification of racial and cultural dynamics within educational institutions will spur stakeholders' motivations and inform policies and strategies to provide equitable educational opportunities for African American students and to improve all students' academic achievement.
    • RACE, PLACE, AND POLICY FORMATION: PUBLIC EDUCATION AND SCHOOL CHOICE DISCOURSE IN THE WASHINGTON POST, 2007-2012

      Chakravorty, Sanjoy; Goyette, Kimberly A.; Sanders, Rickie; Byng, Michelle (Temple University. Libraries, 2019)
      As the first city with a majority African American population and a school system that has long served majority low-income African American children, DC offers a compelling case study about public education and school choice in an increasingly affluent city. Using The Washington Post archive, this dissertation considers how discourse about one of the most vital public goods evolved between 2007 and 2012, a period of rapid economic, political, and social change in the city. DC is a civically engaged and diverse city and, The Washington Post has one of the most diverse newsrooms in the country. Post leadership and most writers and contributors were critical of policy and rulings that might cause greater racial segregation in American public schools. Yet, there was no discourse in this archive to suggest that encouraging greater racial or economic integration would be a successful campaign. Instead, The Post advocated for school reform and choice for the neediest students while seemingly absolving families with means who chose to opt out of the public school system. Failing to interrogate the school choices made by middle-class families represents a silence in the archive and illustrates how silence can be productive because it contributes toward the maintenance of a segregated public school system.
    • Race-Dependent Modulation of Endothelial Cell Responses to Shear Stress: Implications for Vascular Health in African Americans

      Brown, Michael D.; Park, Joon Young; Rizzo, Victor; Kendrick, Zebulon V.; Roth, Stephen M., 1973- (Temple University. Libraries, 2011)
      It is known that African American ethnicity is an independent risk factor for exaggerated oxidative stress which is intricately intertwined with inflammation, hypertension (HT), and cardiovascular disease (CVD). The purpose of this dissertation study was to examine the racial differences that exist between African Americans and Caucasians in oxidative stress levels at the molecular level using an in vitro model of Human Umbilical Vein Endothelial Cells (HUVECs). African American HUVECs were found to have significantly higher baseline levels of oxidative stress in vitro compared to Caucasian HUVECs. In order to establish proof of concept, three preliminary studies were conducted. The first preliminary study, an acute exercise protocol was conducted in young healthy adults in order to measure plasma oxidative stress markers in response to a single moderate intensity treadmill exercise bout. In this study, it was found that the treadmill exercise did not elicit a race-dependent responses, but that African American adults had higher level of oxidative stress at all sample times when compared to the Caucasians. A second preliminary study was conducted using a parallel cell culture design to measure basal oxidative stress levels in African American and Caucasian HUVECs without stimulation. These data were shown in relation to the plasma levels of oxidative stress in resting African American and Caucasian adults. This was done in order to show that the common oxidative stress markers measured in human plasma can also be measured in cell culture supernatant and lysate. It was found that both African American adults and HUVECs had heightened oxidative stress and inflammatory markers when compared to their Caucasian counterparts. The third preliminary study was conducted using tumor Necrosis Factor-#945; (TNF-#945;) as an inflammatory stimulant and measuring the oxidative stress response in both African American and Caucasian HUVECs. This was done in order to show that cells of different race respond differently to stimuli. It was found that the response to TNF-α was blunted in African American HUVECs. The final step was to use laminar shear stress (LSS) as an exercise mimetic in order to examine whether HUVECs from different race respond differently. HUVECs from both race were harvested under static condition (no LSS), with low LSS at 5 dyne/cm2, and with a moderate level of LSS at 20 dyne/cm2. It was found that despite the fact that African American HUVECs had higher levels of oxidative stress under static conditions, when LSS was applied, protein expressions and oxidative stress biomarkers adjusted to levels that were similar to the Caucasian HUVEC adaptations to LSS. From this, it appears that African American HUVECs have a larger response to LSS stimulus indicating that aerobic exercise prescriptions may be valuable for this population since the potential exists for large improvements in oxidative stress levels for this population.
    • Racial Authenticity Processes: Evaluations of Authentic Blackness and Self-Esteem

      Taylor, Ronald D., 1958-; Xie, Hongling; Drabick, Deborah A.; Weinraub, Marsha; Jiang, Xu (Psychologist); Seaton, Eleanor K. (Temple University. Libraries, 2021)
      Racial authenticity refers to the social evaluation of an individual’s group membership based on their perceived racial similarities to or differences from their racial group. While the criteria for determining racial authenticity may be abstract and mutable, negative outcomes may still occur for individuals based on whether they are perceived as an authentic member of their racial group. Notably, perceptions of racial authenticity may be particularly salient among Black college students at predominantly White institutions (PWIs) due to competing behavioral expectations from Black students as well as non-Black students and faculty. The present study contributes to prior research on this topic through a validation and test of a novel measure of racial authenticity defined by one’s perceived racial similarities to their group (racial prototypicality) and their experiences of being mistreated by their racial group due to perceived racial differences (racial othering). Furthermore, the study elucidates racial authentication processes among Black students through an examination of how contextual factors contribute to evaluations of authentic Blackness and the extent to which racial authenticity relates to self-blame and self-esteem. Within the study, a sample of 136 Black PWI students (Mage = 20.27, SD = 4.14; 91.2% female) completed an online questionnaire. A path analysis revealed that Black students who held more negative views about their racial group (low private regard) and who had more friends of a different race experienced more stress from racial othering. Additionally, experiences of racial othering indirectly predicted self-esteem through self-blame coping. These findings have implications for understanding how perceptions of racial authenticity relate to well-being among Black PWI students.