4,808 research outputs found

    Effects of Paclobutrazol and its method of application on the growth and transpiration of Acacia Mangium Seedlings

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    Ten-week-old potted A. mangium seedlings were subjected to a growth retardant, paclobutrazol (PP333), at concentrations of 0, 0.5, 1, 4 and 12 gil. Four methods of application were tested namely S, soil drenching at week 0; F1, foliar spray (potting soil protected from chemical) at week 0; F2, foliar spray (potting soil protected from chemical) at week 0 and 6; and S+F, soil and foliar spray (potting soil exposed to chemical spray) at week O. Plants were harvested after 12 weeks for various growth measurements. Height and leaf area increments, transpiration and stomatal conductance were monitored at weekly intervals. Paclobutrazol was found to be effective in reducing root and shoot growth, transpiration and stomatal conductance of the seedlings. Treated plants had higher root to shoot ratios. The effects of the chemical increased with increasing concentration and frequency of application for the foliar spray. The chemical was most effective when applied through the soil either l7y drenching (S) or soil and foliar spray (S+F)

    Affordable Health Care Keeps Children and Families Healthy

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    The health of young children is negatively affected when parents have to forego health care for themselves or other adult members of the household or when parents have to forego payment of household expenses in order to pay for health care

    Children of Immigrants: Healthy Beginnings Derailed by Food Insecurity

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    Children of immigrants are the fastest growing child population in the United States. More than 20 percent of children under age six have immigrant parents; approximately 93 percent of these children are American citizens.Of the children who are non-citizens, two-thirds will grow up to become citizens, playing a critical role in our nation's future

    Feeding Our Future: Growing Up Healthy with WIC

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    "Feeding Our Future: Growing up Healthy with WIC", which details the important effects that the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) has on very young children. The report highlights Children's HealthWatch research that WIC not only improves children's health but reduces their risk of developmental delays

    Surface electronic structure of a topological Kondo insulator candidate SmB6: insights from high-resolution ARPES

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    The Kondo insulator SmB6 has long been known to exhibit low temperature (T < 10K) transport anomaly and has recently attracted attention as a new topological insulator candidate. By combining low-temperature and high energy-momentum resolution of the laser-based ARPES technique, for the first time, we probe the surface electronic structure of the anomalous conductivity regime. We observe that the bulk bands exhibit a Kondo gap of 14 meV and identify in-gap low-lying states within a 4 meV window of the Fermi level on the (001)-surface of this material. The low-lying states are found to form electron-like Fermi surface pockets that enclose the X and the Gamma points of the surface Brillouin zone. These states disappear as temperature is raised above 15K in correspondence with the complete disappearance of the 2D conductivity channels in SmB6. While the topological nature of the in-gap metallic states cannot be ascertained without spin (spin-texture) measurements our bulk and surface measurements carried out in the transport-anomaly-temperature regime (T < 10K) are consistent with the first-principle predicted Fermi surface behavior of a topological Kondo insulator phase in this material.Comment: 4 Figures, 6 Page

    Selective interlayer ferromagnetic coupling between the Cu spins in YBa2_2 Cu3_3 O7x_{7-x} grown on top of La0.7_{0.7} Ca0.3_{0.3} MnO3_3

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    Studies to date on ferromagnet/d-wave superconductor heterostructures focus mainly on the effects at or near the interfaces while the response of bulk properties to heterostructuring is overlooked. Here we use resonant soft x-ray scattering spectroscopy to reveal a novel c-axis ferromagnetic coupling between the in-plane Cu spins in YBa2_2 Cu3_3 O7x_{7-x} (YBCO) superconductor when it is grown on top of ferromagnetic La0.7_{0.7} Ca0.3_{0.3} MnO3_3 (LCMO) manganite layer. This coupling, present in both normal and superconducting states of YBCO, is sensitive to the interfacial termination such that it is only observed in bilayers with MnO_2but not with La0.7_{0.7} Ca0.3_{0.3} interfacial termination. Such contrasting behaviors, we propose, are due to distinct energetic of CuO chain and CuO2_2 plane at the La0.7_{0.7} Ca0.3_{0.3} and MnO2_2 terminated interfaces respectively, therefore influencing the transfer of spin-polarized electrons from manganite to cuprate differently. Our findings suggest that the superconducting/ferromagnetic bilayers with proper interfacial engineering can be good candidates for searching the theorized Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state in cuprates and studying the competing quantum orders in highly correlated electron systems.Comment: Please note the change of the title. Text might be slightly different from the published versio

    Explicit characterization of the identity configuration in an Abelian Sandpile Model

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    Since the work of Creutz, identifying the group identities for the Abelian Sandpile Model (ASM) on a given lattice is a puzzling issue: on rectangular portions of Z^2 complex quasi-self-similar structures arise. We study the ASM on the square lattice, in different geometries, and a variant with directed edges. Cylinders, through their extra symmetry, allow an easy determination of the identity, which is a homogeneous function. The directed variant on square geometry shows a remarkable exact structure, asymptotically self-similar.Comment: 11 pages, 8 figure

    Topological Surface States and Dirac point tuning in ternary Bi2Te2Se class of topological insulators

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    Using angle-resolved photoemission spectroscopy, we report electronic structure for representative members of ternary topological insulators. We show that several members of this family, such as Bi2Se2Te, Bi2Te2Se, and GeBi2Te4, exhibit a singly degenerate Dirac-like surface state, while Bi2Se2S is a fully gapped insulator with no measurable surface state. One of these compounds, Bi2Se2Te, shows tunable surface state dispersion upon its electronic alloying with Sb (SbxBi2-xSe2Te series). Other members of the ternary family such as GeBi2Te4 and BiTe1.5S1.5 show an in-gap surface Dirac point, the former of which has been predicted to show nonzero weak topological invariants such as (1;111); thus belonging to a different topological class than BiTe1.5S1.5. The measured band structure presented here will be a valuable guide for interpreting transport, thermoelectric, and thermopower measurements on these compounds. The unique surface band topology observed in these compounds contributes towards identifying designer materials with desired flexibility needed for thermoelectric and spintronic device fabrication.Comment: 9 pages, 6 figures; Related results at http://online.kitp.ucsb.edu/online/topomat11/hasan
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