A Search for Distant Galactic Cepheids Toward l=60

We present results of a survey of a 6-square-degree region near l=60, b=0 to search for distant Milky Way Cepheids. Few MW Cepheids are known at distances >~ R_0, limiting large-scale MW disk models derived from Cepheid kinematics; this work was designed to find a sample of distant Cepheids for use in such models. The survey was conducted in the V and I bands over 8 epochs, to a limiting I~=18, with a total of ~ 5 million photometric observations of ~ 1 million stars. We present a catalog of 578 high-amplitude variables discovered in this field. Cepheid candidates were selected from this catalog on the basis of variability and color change, and observed again the following season. We confirm 10 of these candidates as Cepheids with periods from 4 to 8 days, most at distances > 3 kpc. Many of the Cepheids are heavily reddened by intervening dust, some with implied extinction A_V > 10 mag. With a future addition of infrared photometry and radial velocities, these stars alone can provide a constraint on R_0 to 8%, and in conjunction with other known Cepheids should provide good estimates of the global disk potential ellipticity.Comment: 18 pages, 4 tables, 13 figures (LaTeX / AASTeX

Assessment of Dose-dependent Endocrine and Immune Responses to Simulated Ionizing Radiation

The hypothalamic-pituitary-adrenal axis can regulate immune responses to counteract stressful stimuli in maintaining homeostasis within the body. Cosmic ionizing radiation is an innate risk within the space environment and it is known to cause direct DNA damage and indirectly impact cellular function, transduction, and communication processes. Assessment of different physiological systems and their interactions are important to consider for mitigation strategies in spaceflight. The degree of ionizing radiation and relative biological effectiveness is an open question as it pertains to immune and endocrine responses. Therefore, this study will assess the dose-dependent responses of immunity and adrenal function to cosmic ionizing radiation. For this, male and female C57 BL/6J mice were exposed to simulated, simplified five-ion galactic cosmic ray (GCR) radiation at 5cGy, 15cGy, and 50cGy. Blood and tissues were collected two-weeks post exposure and inflammatory biomarkers and hormone biochemical pathways were characterized by whole transcriptome RNA sequencing. Results displayed differential transcriptomic profiles for each condition and sex, indicating complex responses and networks are generated from different doses of ionizing radiation. Careful consideration of unique profiles highlights the current need for personalized medicine requirements for astronauts exposed to similar doses on exploration missions. Supported by the NASA Human Research Program (HRP) Human Factors Behavioral Performance Element Grant 18 18FLAG 2 0028 and Embry-Riddle Aeronautical University startup funding

Pseudospectral Calculation of the Wavefunction of Helium and the Negative Hydrogen Ion

We study the numerical solution of the non-relativistic Schr\"{o}dinger equation for two-electron atoms in ground and excited S-states using pseudospectral (PS) methods of calculation. The calculation achieves convergence rates for the energy, Cauchy error in the wavefunction, and variance in local energy that are exponentially fast for all practical purposes. The method requires three separate subdomains to handle the wavefunction's cusp-like behavior near the two-particle coalescences. The use of three subdomains is essential to maintaining exponential convergence. A comparison of several different treatments of the cusps and the semi-infinite domain suggest that the simplest prescription is sufficient. For many purposes it proves unnecessary to handle the logarithmic behavior near the three-particle coalescence in a special way. The PS method has many virtues: no explicit assumptions need be made about the asymptotic behavior of the wavefunction near cusps or at large distances, the local energy is exactly equal to the calculated global energy at all collocation points, local errors go down everywhere with increasing resolution, the effective basis using Chebyshev polynomials is complete and simple, and the method is easily extensible to other bound states. This study serves as a proof-of-principle of the method for more general two- and possibly three-electron applications.Comment: 23 pages, 20 figures, 2 tables, Final refereed version - Some references added, some stylistic changes, added paragraph to matrix methods section, added last sentence to abstract