2,836 research outputs found

    Extracting Scattering Phase-Shifts in Higher Partial-Waves from Lattice QCD Calculations

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    L\"uscher's method is routinely used to determine meson-meson, meson-baryon and baryon-baryon s-wave scattering amplitudes below inelastic thresholds from Lattice QCD calculations - presently at unphysical light-quark masses. In this work we review the formalism and develop the requisite expressions to extract phase-shifts describing meson-meson scattering in partial-waves with angular-momentum l<=6 and l=9. The implications of the underlying cubic symmetry, and strategies for extracting the phase-shifts from Lattice QCD calculations, are presented, along with a discussion of the signal-to-noise problem that afflicts the higher partial-waves.Comment: 79 pages, 41 figure

    The Effect of Large Wood Restoration on Algal Biomass and Spatial Distribution in the Narraguagus River

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    The Atlantic Salmon (Salmo salar) is an anadromous fish native to the eastern US and Canada. Though they used to inhabit much of the eastern coasts of New England and Canada, the last of the United States’ wild Atlantic Salmon are now mostly limited to Maine. Due to habitat destruction from dams and historic logging activity, the quality of food sources, spawning grounds, and essential juvenile salmon habitat have been severely impacted. This habitat is the rearing area for many young salmon, and its quality influences their growth and recruitment into the overall Atlantic salmon population. Restoration of Atlantic salmon in Maine typically focuses on these freshwater rearing habitats, reconnecting headwater streams to the ocean using process-based habitat restoration like the addition of large wood structures to the stream to improve habitat quality. Large wood structures utilize natural processes to trap organic detritus, redirect and alter water flow, and restore ecological processes that foster ideal spawning conditions in the riverbed. Ideally these log structures would encourage winding, meandering stream flow, provide habitat for aquatic insects, and encourage a transition from muddy and sandy substrates to the cobble beds that are ideal for salmon spawning. Ongoing research at UMaine is examining the effects of restoration techniques on insect population structures, substrate, detritus breakdown, velocity, and algal biomass. My thesis as a subset of this project tracks the progress of large wood restoration through its effect on the spatial distribution of algae across 10 test and reference sites in the upper Narraguagus river. We analyzed characteristics of the system pertaining to large wood to determine which had the greatest effect on algal biomass and distribution. We found that the null hypothesis (factors not affected directly by large wood) was the best model, and that velocity and substrate alone were statistically equivalent. This suggests that restoration status had a lesser effect on algal communities than velocity and substrate. Though we cannot conclude from our analyses that restoration impacts algal communities directly, further analyses into the impact of large wood restoration on velocity and substrate may clarify whether it is indeed helpful to algal communities or not

    Early Postpartum Depression Screening.

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    D.N.P. Thesis. University of Hawaiʻi at Mānoa 2017

    The turbomachine blading design using S2-S1 approach

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    The boundary conditions corresponding to the design problem when the blades being simulated by the bound vorticity distribution are presented. The 3D flow is analyzed by the two steps S2 - S1 approach. In the first step, the number of blades is supposed to be infinite, the vortex distribution is transformed into an axisymmetric one, so that the flow field can be analyzed in a meridional plane. The thickness distribution of the blade producing the flow channel striction is taken into account by the modification of metric tensor in the continuity equation. Using the meridional stream function to define the flow field, the mass conservation is satisfied automatically. The governing equation is deduced from the relation between the azimuthal component of the vorticity and the meridional velocity. The value of the azimuthal component of the vorticity is provided by the hub to shroud equilibrium condition. This step leads to the determination of the axisymmetric stream sheets as well as the approximate camber surface of the blade. In the second step, the finite number of blades is taken into account, the inverse problem corresponding to the blade to blade flow confined in each stream sheet is analyzed. The momentum equation implies that the free vortex of the absolute velocity must be tangential to the stream sheet. The governing equation for the blade to blade flow stream function is deduced from this condition. At the beginning, the upper and the lower surfaces of the blades are created from the camber surface obtained from the first step with the assigned thickness distribution. The bound vorticity distribution and the penetrating flux conservation applied on the presumed blade surface constitute the boundary conditions of the inverse problem. The detection of this flux leads to the rectification of the geometry of the blades

    Nucleon-Nucleon Scattering in a Harmonic Potential

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    The discrete energy-eigenvalues of two nucleons interacting with a finite-range nuclear force and confined to a harmonic potential are used to numerically reconstruct the free-space scattering phase shifts. The extracted phase shifts are compared to those obtained from the exact continuum scattering solution and agree within the uncertainties of the calculations. Our results suggest that it might be possible to determine the amplitudes for the scattering of complex systems, such as n-d, n-t or n-alpha, from the energy-eigenvalues confined to finite volumes using ab-initio bound-state techniques.Comment: 19 pages, 13 figure

    The Impact of Exchange Rate and Unemployment Rate on the Real Gross Domestic Product Growth Rate in Ghana

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    Unemployment Rate and Exchange Rate are perhaps the two most important challenges that face the Ghanaian economy in recent time. This study seeks to examine the effect of the Exchange Rate and Unemployment Rate on the Real Gross Domestic Product Growth Rate in Ghana. The study used secondary data collected from World Bank, International Labour Organization and International Monetary Fund covering the period 1999–2018. Real Exchange Rate and Unemployment Rate were the independent variables whilst Real Gross Domestic Product Growth Rate was the dependent variable. The findings of the study were arrived at using the quantitative research method. The extent and nature of relationship between the various variables under study were identified using Pearson correlation, regression and hypotheses. The study found out that Unemployment Rate exhibited insignificant negative relationship towards Real Gross Domestic Product Growth Rate, while Real Exchange Rate was positive and also insignificant relationship on Real Gross Domestic Product Growth Rate. Based on the linearity of the multiple linear regression model, the independent variables contribute to 15.0% of the overall LN_GDP. The study then concludes that based on the effect of Exchange Rate and Unemployment Rate on RGDPGR in the findings, Government and other stakeholders should take steps such as creating new local industries and factories, and invest in existing ones to increase domestic produce which will in turn decrease Unemployment Rate and increase Exchange Rate. Keywords: Gross Domestic Product, Unemployment Rate, Exchange Rate, Pearson correlation, Linear Regression. DOI: 10.7176/JESD/10-18-15 Publication date:September 30th 201

    The Major Heat Shock Proteins, Hsp70 and Hsp90, in 2-Methoxyestradiol-Mediated Osteosarcoma Cell Death Model

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    2-Methoxyestradiol is one of the natural 17β-estradiol derivatives and a potential novel anticancer agent currently being under evaluation in advanced phases of clinical trials. However, the mechanism of anticancer action of 2-methoxyestradiol has not been yet fully established. In our previous studies we have demonstrated that 2-methoxyestradiol selectively induces the expression and nuclear translocation of neuronal nitric oxide synthase in osteosarcoma 143B cells. Heat shock proteins (Hsps) are factors involved in the regulation of expression and activity of nitric oxide synthases. Herein, we chose osteosarcoma cell lines differed in metastatic potential, metastatic 143B and highly metastatic MG63.2 cells, in order to further investigate the anticancer mechanism of 2-methoxyestradiol. The current study aimed to determine the role of major heat shock proteins, Hsp90 and Hsp70 in 2-methoxyestradiol-induced osteosarcoma cell death. We focused on the implication of Hsp90 and Hsp70 in control under expression of neuronal nitric oxide synthase, localization of the enzyme, and further generation of nitro-oxidative stress. To give the insight into the role of Hsp90 in regulation of anticancer efficacy of 2-methoxyestradiol, we used geldanamycin as a potent Hsp90 inhibitor. Herein, we evidenced that inhibition of Hsp90 controls the protein expression of 2-methoxyestradiol-induced neuronal nitric oxide synthase and inhibits enzyme nuclear translocation. We propose that decreased level of neuronal nitric oxide synthase protein after a combined treatment with 2-methoxyestradiol and geldanamycin is directly associated with the accompanying upregulation of Hsp70 and downregulation of Hsp90. This interaction resulted in abrogation of anticancer efficacy of 2-methoxyestradiol by geldanamycin
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