Exploring the Community Cultural Wealth of Low-Income Collegians of Color in their Transition from High School to College

This narrative study explores the transition from high school to college for low-income students of color who participated in a college access mentoring program, the College Admissions Project (CAP) while in twelfth-grade. A community cultural wealth (CCW) lens guides this research and is used to examine student experiences. CAP alumni who enrolled in an institution of higher education in the fall semester immediately following their high school graduation are the participants in this study. A narrative approach to inquiry is used because the author is interested in the particular experiences of a few individuals. Specifically, the experiences of low-income students of color from New Orleans as they made the transition from high school to college either in 2015 or 2016. This study has implications for practice in the area of college access programs as well as theoretical applications which extend a CCW framework to additional communities of color beyond Latina/o communities. In the area of practice, supporting positive peer relationships could make college access programs more effective. Student voice is also important to the participants in this study. Students should be part program development and evaluation processes so that programs are designed to best meet their needs as they exist, rather than as adults see them. There is some evidence that a CCW framework is applicable to the experiences of these students. Informational and social capital were most commonly referenced by participants, and efforts to help students further develop these assets would help to support their college transition processes

Exploring the Community Cultural Wealth of Low-Income Collegians of Color in their Transition from High School to College

This narrative study explores the transition from high school to college for low-income students of color who participated in a college access mentoring program, the College Admissions Project (CAP) while in twelfth-grade. A community cultural wealth (CCW) lens guides this research and is used to examine student experiences. CAP alumni who enrolled in an institution of higher education in the fall semester immediately following their high school graduation are the participants in this study. A narrative approach to inquiry is used because the author is interested in the particular experiences of a few individuals. Specifically, the experiences of low-income students of color from New Orleans as they made the transition from high school to college either in 2015 or 2016. This study has implications for practice in the area of college access programs as well as theoretical applications which extend a CCW framework to additional communities of color beyond Latina/o communities. In the area of practice, supporting positive peer relationships could make college access programs more effective. Student voice is also important to the participants in this study. Students should be part program development and evaluation processes so that programs are designed to best meet their needs as they exist, rather than as adults see them. There is some evidence that a CCW framework is applicable to the experiences of these students. Informational and social capital were most commonly referenced by participants, and efforts to help students further develop these assets would help to support their college transition processes

Thermal oxidation of Ru(0001) to RuO2(110) studied with ambient pressure x-ray photoelectron spectroscopy

The thermal oxidation of Ru(0001) has been extensively studied in the surface science community to determine the oxidation pathway towards ruthenium dioxide (RuO2(110)), improving the knowledge of Ru(0001) surface chemistry. Using time-lapsed ambient-pressure x-ray photoelectron spectroscopy (APXPS), we investigate the thermal oxidation of single-crystalline Ru(0001) films toward rutile RuO2(110) in situ. APXPS spectra were continuously collected while the Ru(0001) films were exposed to a fixed O2 partial pressure of 10−2 mbar and the sample temperature was increased stepwise from room temperature to 400 °C. We initially observe the removal of adventitious carbon and subsequent formation of a chemisorbed oxygen overlayer at 250 °C. Further annealing to 300 °C leads to an increase in thickness of the oxide layer and a shift in the Ru–O component of the Ru 3d spectra, indicating the presence of a metastable O–Ru–O trilayer structure. A rapid formation of the RuO2 rutile phase with an approximate thickness of at least 2.6 nm is formed about four minutes after stabilizing the temperature at 350 °C and subsequent annealing to 400 °C, signaled by a distinct binding energy shift in both the Ru 3d and O 1s spectra, as well as quantitative analysis of XPS intensities. This observed autocatalytic oxidation process agrees well with previous theoretical models and experimental studies, and the data provide the unambiguous spectral identification of one proposed metastable precursor required for full oxidation to rutile RuO2(110). Further ex situ characterization of the grown oxide with x-ray photoelectron diffraction confirms the presence of three rotated domains of rutile RuO2(110) and reveals their orientation relative to the substrate lattice

Characterization and Investigations of Thin-Film Materials with X-ray Photoelectron Spectroscopy

Surface characterization of materials is widely utilized over a range of disciplines and essential to the development of new materials, technology, or processes. Metal oxide nanoclusters have shown promise as potential new generation photoresist materials for extreme ultraviolet (EUV) nanolithography. Organotin clusters have been proposed as potential candidates for resist materials due to a high photoabsorption cross section in the EUV energy range. Before industrial implementation, these new materials must undergo rigorous analysis through the use of numerous characterization techniques to verify effectiveness and satisfactory performance. In addition to characterization, not much information is known about the radiation induced mechanism that causes a solubility transition; a key component for acting as a photoresist. The use of near ambient pressure X-ray photoelectron spectroscopy (NAPXPS) provides the ability to study chemical changes in organotin nanocluster thin films during radiation exposure in a range of ambient environments. NAPXPS using synchrotron X-rays determined that impinging photon energy can play a role in the solubility transition mechanism since the total electron yield is dependent on the photon energy. The presence of ambient oxygen was also shown to enhance resist sensitivity. NAPXPS with a monochromated Al Kα X-rays were used to measure a contrast curve, further highlighting oxygen’s ability to enhance resist sensitivity, while also showing a decrease in sensitivity for ambients of nitrogen, water, and methanol. Thermal NAPXPS studies following the solubility transition in the resist determined a significant amount of carbon remains in the film even though carbon removal was hypothesized to be a primary step during solubility transition. This led to the conclusion that a metal oxide polymer is formed following sufficient X-ray exposure and annealing. Metal oxide materials have also shown promise as oxidation catalysts. The conversion of volatile organic compounds to non-toxic molecules like CO2 is important for pollution control. Interactions of near ambient pressures of 2-propanol (IPA) with a well ordered SnO2 surface has yet to be studied from a mechanistic standpoint. For these studies, a SnO2 single crystal was prepared with a stoichiometric oxidized surface and characterized with low energy electron diffraction (LEED) and valence band spectra. NAPXPS was used to track chemical changes in the Sn surface oxidation state and adsorbate reactions during exposure to up to 3 mbar of IPA and mixtures of IPA and oxygen at 400, 500, and 600 K. The reaction products were measured using mass spectrometry to compliment the NAPXPS results. Oxygen was found to be required for the complete conversion of IPA to CO2 to prevent the surface reduction of the Sn, which otherwise would yield the intermediate product acetone. Ultimately, surface characterization is imperative towards forming foundational chemical knowledge of materials, which can lead to new and improved technology

Surface electronic structure of Ni-doped Fe3O4(001)

Magnetite (Fe3O4) doped with earth-abundant metals has emerged as a promising catalyst material, with Ni-doped magnetite (Ni/Fe3O4) being a cost-effective, durable, and highly active material for photocatalytic and electrochemical water oxidation. While previous studies have investigated the incorporation of Ni atoms into Fe3O4 single-crystalline surfaces using surface science characterization methods and density functional theory calculations, an experimental study is still required to understand the impact of Ni incorporation on the electronic structure of Ni/Fe3O4 systems. To address this, we employed angle-resolved photoemission spectroscopy, analyzed within the one-step model of photoemission by a real-space multiple scattering code to investigate the electronic structure of the reconstructed magnetite surface. Moreover, the half-metal to semiconductor phase transition upon Ni incorporation is reflected in an almost complete disappearance of states near the Fermi level. Finally, we report on the systematic changes in the unoccupied states observed with the increasing amount of Ni dopant. These findings offer insights into the influence of Ni incorporation on the electronic structure of Ni/Fe3O4, which can link to an increased catalytic activity

Autophagy in DNA-PKcs Knockout Glioblastoma Cancer Stem Cells

Glioblastoma multiforme (GBM) is a deadly form of brain cancer, with an expected survival of only a few months after diagnosis without therapy. The current standard of care extends life expectancy by a couple of months due to almost universal recurrence of the tumor. Recurrence of GBM is highly dependent on a radiation-resistant subpopulation of GBM, the cancer stem cells (CSCs). CSCs possess an enhanced ability to repair therapy-induced DNA damage, especially DNA double strand breaks (DSBs). To study the role of DNA damage repair in GBM CSCs, our investigations used a knockout (KO) of an enzyme, DNA PKcs, which plays a key role in the repair of DNA double strand breaks. Surprisingly, we discovered that autophagy (assayed by the direct visualization of autophagosomes) wasprofoundly affected by DNA PKcs KO in GBM cells and GBM CSCs. Furthermore, exposure of these cells to 2Gy irradiation caused another shift in autophagy. Changes in mitochondrial morphology raised questions regarding energy metabolism, prompting the use of an ATP assay that indicated increased energy requirements in cells lacking DNA-PKcs. These results point to a role for cancer cell energy metabolism and cancer stem cell metabolism in the cells’ therapeutic response, emphasizing the importance of understanding the stress responses of GBM cells and GBM cancer stem cells to improve radiation treatment against cancer.B.A. (Bachelor of Arts

Factors influencing surface carbon contamination in ambient-pressure x-ray photoelectron spectroscopy experiments

Carbon contamination is a notorious issue that has an enormous influence on surface science experiments, especially in near-atmospheric conditions. While it is often mentioned in publications when affecting an experiment’s results, it is more rarely analyzed in detail. We performed ambient-pressure x-ray photoelectron spectroscopy experiments toward examining the build-up of adventitious carbon species (both inorganic and hydrocarbons) on a clean and well-prepared surface using large-scale (50 × 10 mm2) rutile TiO2(110) single crystals exposed to water vapor and liquid water. Our results highlight how various factors and environmental conditions, such as beam illumination, residual gas pressure and composition, and interaction with liquid water, could play roles in the build-up of carbon on the surface. It became evident that beam-induced effects locally increase the amount of carbon in the irradiated area. Starting conditions that are independent of light irradiation determine the initial overall contamination level. Surprisingly, the rate of beam-induced carbon build-up does not vary significantly for different starting experimental conditions. The introduction of molecular oxygen in the order of 10 mbar allows for fast surface cleaning during x-ray illumination. The surface carbon contamination can be completely removed when the oxygen partial pressure is comparable to the partial pressure of water vapor in the millibar pressure range, as was tested by exposing the TiO2(110) surface to 15 mbar of water vapor and 15 mbar of molecular O2 simultaneously. Furthermore, our data support the hypothesis that the progressive removal of carbon species from the chamber walls by competitive adsorption of water molecules takes place following repeated exposure to water vapor. We believe that our findings will be useful for future studies of liquid-solid interfaces using tender x rays, where carbon contamination plays a significant role