Effects of large-scale environment on the assembly history of central galaxies

We examine whether large-scale environment affects the mass assembly history of their central galaxies. To facilitate this, we constructed dark matter halo merger trees from a cosmological N-body simulation and calculated the formation and evolution of galaxies using a semi-analytic method. We confirm earlier results that smaller halos show a notable difference in formation time with a mild dependence on large-scale environment. However, using a semi-analytic model, we found that on average the growth rate of the stellar mass of central galaxies is largely insensitive to large-scale environment. Although our results show that the star formation rate (SFR) and the stellar mass of central galaxies in smaller halos are slightly affected by the assembly bias of halos, those galaxies are faint, and the difference in the SFR is minute, and therefore it is challenging to detect it in real galaxies given the current observational accuracy. Future galaxy surveys, such as the BigBOSS experiment and the Large Synoptic Survey Telescope, which are expected to provide observational data for fainter objects, will provide a chance to test our model predictions.Comment: 7 pages, 5 figure

Dying and cultural meaning: recommendations for psychological support of Korean Americans

Death is a natural part of the life cycle that all humankind faces at some point. The American Psychological Association (2001) states that psychologists can make an important clinical contribution to patients who are dying and offer support to their families as they navigate this life event. What is absent from the current discussion is the relevance of culture to issues related to death, dying, and grief, which from the perspective of the researcher is a critical oversight, given the diverse cultures represented in the U.S. and the uniqueness of how many of these cultures conceptualize and memorialize death. This dissertation specifically considers end-of-life matters for the Korean American community, a cultural group that has grown substantially in number since the 20th century. Through a review of the literature, Korean values and beliefs that provide a context for understanding death within this culture are identified; Korean and Western views of end-of-life issues are compared; and clinical considerations for rapport building, assessment, and treatment of the Korean American family are discussed

Applications Of Molecular And Quantum Mechanical Methods For Studying The Chemical Reactions Of Inorganic And Organic Systems

Computational studies can assist chemists to interpret experimental observations and to predict the properties and behaviors of molecules. The work presented in this dissertation applies different computational methods to study the molecular properties and reaction paths for various inorganic and organic systems. The second and third chapters discuss the force field development using “Gaussian Electrostatic Model (GEM)” and its amenability for use in the AMOEBA force field. The forth and fifth chapters discuss the density functional theory (DFT) studies of photodissociation behaviors for inorganic molecules. The sixth chapter explores the oxidation mechanisms of ascorbic acid and its antioxidant properties in bioorganic systems using a variety of quantum mechanic methods. The last chapter discuss the Born-Oppenheimer molecular dynamics simulation for the isomerization and fragmentation of allene cation in the strong laser field

Skyrmions and Anomalous Hall Effect in a Dzyloshinskii-Moriya Spiral Magnet

Monte Carlo simulation study of a classical spin model with Dzylosinskii-Moriya interaction and the spin anisotropy under the magnetic field is presented. We found a rich phase diagram containing the multiple spin spiral (or skyrme crystal) phases of square, rectangular, and hexagonal symmetries in addition to the spiral spin state. The Hall conductivity $\sigma_{xy}$ is calculated within the $sd$ model for each of the phases. While $\sigma_{xy}$ is zero in the absence of external magnetic field, applying a field strength $H$ larger than a threshold value $H_c$ leads to the simultaneous onset of nonzero chirality and Hall conductivity. We find $H_c = 0$ for the multiple spin spiral states, but $H_c > 0$ for a single spin spiral state regardless of the field orientation. Relevance of the present results to MnSi is discussed