A Qualitative Study Using Community Cultural Wealth to Understand the Educational Experiences of Latino College Students

The Latino population is the largest minority group in the United States (Quijada & Alvarez, 2006) and has the highest high school dropout rate of any ethnic group (American Council on Education, 2008). If the U.S. is to compete in the global economy, it is important to understand factors that facilitate or hider the academic performance of Latino students. This qualitative study provides rich narratives on how Latino students used community cultural wealth, including knowledge, skills, abilities and networks, to excel in educational settings and overcome obstacles. A total of 15 individuals participated in the study. Findings suggest that Latino students overcome structural and cultural obstacles using various forms of community cultural wealth. In addition, the article provides recommendations based on participant’s experiences and previous research to increase Latino students’ success. It is the hope of the authors that findings from the present study will provide insight into the factors that facilitate Latino student success

A kinetic model of water adsorption, clustering and dissociation on the Fe3S4{001} surface

The interaction of water with catalyst surfaces is a common process which requires investigation. Here, we have employed density functional theory calculations to investigate the adsorption of up to ten water molecules on the {001} surface of greigite (Fe3S4), which owing to its redox properties, is of increasing interest as a catalyst, e.g. in electro-catalysis. We have systematically analyzed and characterized the modes of water adsorption on the surface, where we have considered both molecular and dissociative adsorption processes. The calculations show that molecular adsorption is the predominant state on these surfaces, from both a thermodynamic and kinetic point of view. We have explored the molecular dispersion on the surface under different coverages and found that the orientation of the molecule, and therefore the surface dipole, depends on the number of adsorbed molecules. The interactions between the water molecules become stronger with an increasing number of water molecules, following an exponential decay which tends to the interaction energy found in bulk water. We have also shown the evolution of the infra-red signals as a function of water coverage relating to the H-bond networks formed on the surface. Next we have included these results in a classical micro-kinetic model, which introduced the effects of temperature in the simulations, thus helping us to derive the water cluster size on the greigite surface as a function of the initial conditions of pressure, temperature and external potential. The kinetic model concluded that water molecules agglomerate in clusters instead of wetting the surface, which agrees with the low hydrophilicity of Fe3S4. Clusters consisting of four water molecules was shown to be the most stable cluster under a wide range of temperatures and external potential

Catalytic water dissociation by greigite Fe3S4surfaces: density functional theory study

The iron sulfide mineral greigite, Fe3S4, has shown promising capability as a hydrogenating catalyst, in particular in the reduction of carbon dioxide to produce small organic molecules under mild conditions. We employed density functional theory calculations to investigate the {001},{011} and {111} surfaces of this iron thiospinel material, as well as the production of hydrogen ad-atoms from the dissociation of water molecules on the surfaces. We systematically analysed the adsorption geometries and the electronic structure of both bare and hydroxylated surfaces. The sulfide surfaces presented a higher flexibility than the isomorphic oxide magnetite, Fe3O4, allowing perpendicular movement of the cations above or below the top atomic sulfur layer. We considered both molecular and dissociative water adsorption processes, and have shown that molecular adsorption is the predominant state on these surfaces from both a thermodynamic and kinetic point of view. We considered a second molecule of water which stabilizes the system mainly by H-bonds, although the dissociation process remains thermodynamically unfavourable. We noted, however, synergistic adsorption effects on the Fe3S4{001} owing to the presence of hydroxyl groups. We concluded that, in contrast to Fe3O4, molecular adsorption of water is clearly preferred on greigite surfaces

Selective hydrogenation of CO on Fe3S4{111}: a computational study

Fischer-Tropsch (FT) synthesis has been a recursive method to form valuable molecules from syngas. Metal surfaces have been extensively studied as a FT catalyst, among them, iron presented several phases under reaction conditions, oxide and carbides, as active sites for the FT and reverse water gas shift reaction. We present the CO reduction on an iron sulfide phase with spinel structure, Fe3S4, considering also the pathways where C-O dissociates leaving CHX species on the surface, which may feed longer aliphatic chains via FT process. We analysed the thermodynamic and kinetic availability of each step leading to O, OH species co-adsorbed on the surface as well as the formation of H2O from the hydrogenation of the alcohol group in the molecule. This detailed analysis let to energy profiles, on both active sites of the surface, and conclude that this Fe3S4 surface is high selectivity towards the formation of methanol, in full agreement with experimental results. These findings point out that the C-C bond formation on greigite takes place through an hydroxycarbene FT mechanism

Fiscal policy, income redistribution, and poverty reduction in Latin America

This paper uses standard fiscal incidence analysis to study how much income redistribution and poverty reduction are accomplished through the fiscal system in eighteen Latin American and Caribbean (LAC) countries. We show there is considerable heterogeneity in the income inequality and poverty-reducing power of LAC fiscal systems. While all LAC fiscal systems reduce income inequality, fiscal systems in nine LAC countries are poverty-increasing, and this startling characteristic has not improved over time. When analyzing specific fiscal elements, we find that direct taxes, direct transfers, and in-kind transfers are all equalizing, and spending on education and health is often pro-poor. Moreover, contrary to expectations, indirect taxes and subsidies are more frequently equalizing than unequalizing

DFT-D2 Study of the Adsorption and Dissociation of Water on Clean and Oxygen-Covered {001} and {011} Surfaces of Mackinawite (FeS)

We present a dispersion-corrected density functional theory study of the adsorption and dissociation reactions of oxygen and water on the {001} and {011} surfaces of mackinawite (FeS). A chemical picture of the initial steps of the mackinawite {001} and {011} surfaces oxidation process in the presence of oxygen and water is presented in the present investigation. Our results show that, while water interacts weakly with the Fe ions on both surfaces and only oxidizes them to some extent, atomic and molecular oxygen interact strongly with the FeS{011} surface cations by drawing significant charge from them, thereby oxidizing them from Fe2+ to Fe3+ formal oxidation state. We show from our calculated adsorption energies and activation energy barriers for the dissociation of H2O on the clean and oxygen-covered FeS surfaces, that preadsorbed oxygen could easily activate the O–H bond and facilitate the dissociation of H2O to ferric-hydroxy, Fe3+–OH– on FeS{011}, and to zerovalent sulfur-hydroxyl, S0–OH– on FeS{001}. With the aid of preadsorbed O atom, the activation energy barrier for dissociating hydrogen atom from H2O decreases from 1.73 to 1.19 eV on the FeS{001}, and from 0.83 to 0.14 eV on the FeS{011}. These findings provide molecular-level insight into the mechanisms of mackinawite oxidation, and are consistent with experimental results, which have shown that oxygen and water are necessary for the oxidation process of mackinawite and its possible transformation to pyrite via greigite

Amaranth sprouts: A potential health promoting and nutritive natural food

Amaranth sprouts are an edible food with good nutritional qualities and potential biological activities of their proteins. The chemical composition, angiotensin converting enzyme inhibitory activity and antioxidant activity of the sprouts were determined. Sprouts showed a protein content similar to the seeds on a dry basis (16%) and a high fiber content (17%). Amaranth sprout proteins presented a capacity to inhibit angiotensin converting enzyme activity similar to other plant proteins (IC50 = 0.9 ± 0.6 mg/mL). This capacity increased after in vitro gastrointestinal digestion (IC50 = 0.26 ± 0.07 mg/mL). Besides other non protein molecules, the amaranth sprout proteins also presented ABTS+. scavenging activity (TEAC = 0.32 ± 0.05 mol/mg) that increased after in vitro gastrointestinal digestion (TEAC = 0.72 ± 0.08 mol/mg) and oxygen radical antioxidant capacity. According to these results amaranth sprouts are a nutritive food with potential health promoting properties.Fil: Aphalo, Paula. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Martinez, Estela Nora. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin