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The Gemini High-resolution Optical SpecTrograph (GHOST) is the newest high resolution spectrograph to be developed for a large aperture telescope, recently deployed and commissioned at the Gemini-South telescope. In this paper, we present the first science results from the GHOST spectrograph taking during its commissioning runs. We have observed the bright metal-poor benchmark star HD 122563, along with two stars in the ultra faint dwarf galaxy, Ret II, one of which was previously identified as a candidate member, but did not have a previous detailed chemical abundance analysis. This star (GDR3 0928) is found to be a bona fide member of Ret II, and from a spectral synthesis analysis, it is also revealed to be a CEMP-r star, with significant enhancements in the several light elements (C, N, O, Na, Mg, and Si), in addition to featuring an r-process enhancement like many other Ret II stars. The light-element enhancements in this star resemble the abundance patterns seen in the CEMP-no stars of other ultra faint dwarf galaxies, and are thought to have been produced by an independent source from the r-process. These unusual abundance patterns are thought to be produced by faint supernovae, which may be produced by some of the earliest generations of stars., Comment: 23 pages, 9 figures, 7 tables, submitted to the AAS Journals

(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is intended as a concise reference guide to all aspects of the scientific and technical design of MSE, for the international astronomy and engineering communities, and related agencies. The current version is a status report of MSE's science goals and their practical implementation, following the System Conceptual Design Review, held in January 2018. MSE is a planned 10-m class, wide-field, optical and near-infrared facility, designed to enable transformative science, while filling a critical missing gap in the emerging international network of large-scale astronomical facilities. MSE is completely dedicated to multi-object spectroscopy of samples of between thousands and millions of astrophysical objects. It will lead the world in this arena, due to its unique design capabilities: it will boast a large (11.25 m) aperture and wide (1.52 sq. degree) field of view; it will have the capabilities to observe at a wide range of spectral resolutions, from R2500 to R40,000, with massive multiplexing (4332 spectra per exposure, with all spectral resolutions available at all times), and an on-target observing efficiency of more than 80%. MSE will unveil the composition and dynamics of the faint Universe and is designed to excel at precision studies of faint astrophysical phenomena. It will also provide critical follow-up for multi-wavelength imaging surveys, such as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation Very Large Array.

The hippocampus is a brain structure involved in memory as well as anxiety and depression-related behavior. One unique property of the hippocampus is that adult neurogenesis occurs in this region. Rodent studies in which adult hippocampal neurogenesis is ablated have shown a role for this process in the cognitive domain, specifically in pattern separation tasks, as well as in mediating the behavioral effects of antidepressants. These studies have furnished the intriguing hypothesis that increasing adult hippocampal neurogenesis may improve these functions and therefore serve as a target for novel treatments for cognitive impairments as well as depression and anxiety disorders. Here, we use both genetic and pharmacological models to increase adult neurogenesis in mice. Under baseline conditions, we find that increasing adult hippocampal neurogenesis is sufficient to improve performance in a fear-based pattern separation task, but has no effect on exploratory, anxiety or depression-related behavior. In mice exposed to voluntary exercise, increasing adult hippocampal neurogenesis increases exploration, without affecting anxiety or depression-related behavior. Finally, in mice treated with chronic corticosterone, a model of anxiety and depression, increasing adult hippocampal neurogenesis is sufficient to prevent the behavioral effect of CORT on anxiety and depression-related behavior. Here, we therefore describe dissociations between the effects of increasing adult hippocampal neurogenesis under baseline, voluntary exercise and chronic stress conditions. Together, our results suggest that increasing adult hippocampal neurogenesis has therapeutic potential for both cognitive, and anxiety and depression-related disorders.