The GM2 gangliosidoses are a group of severe, neurodegenerative conditions that include Tay-Sachs disease, Sandhoff disease, and the GM2 activator deficiency. Bone marrow transplantation (BMT) was examined as a potential treatment for these disorders using a Sandhoff disease mouse model. BMT extended the life span of these mice from approximately 4.5 mo to up to 8 mo and slowed their neurologic deterioration. BMT also corrected biochemical deficiencies in somatic tissues as indicated by decreased excretion of urinary oligosaccharides, and lower glycolipid storage and increased levels of beta-hexosaminidase activity in visceral organs. Even with neurologic improvement, neither clear reduction of brain glycolipid storage nor improvement in neuronal pathology could be detected, suggesting a complex pathogenic mechanism. Histological analysis revealed beta-hexosaminidase-positive cells in the central nervous system and visceral organs with a concomitant reduction of colloidal iron-positive macrophages. These results may be important for the design of treatment approaches for the GM2 gangliosidoses.

We examine the kinematic morphology of early-type galaxies (ETGs) in eight galaxy clusters in the Sydney-AAO Multi-object Integral-field spectrograph Galaxy Survey. The clusters cover a mass range ofand we measure spatially resolved stellar kinematics for 315 member galaxies with stellar masses11.7 within 1 R 200 of the cluster centers. We calculate the spin parameter, λ R , and use this to classify the kinematic morphology of the galaxies as fast or slow rotators (SRs). The total fraction of SRs in the ETG population is F SR = 0.14 ± 0.02 and does not depend on host cluster mass. Across the eight clusters, the fraction of SRs increases with increasing local overdensity. We also find that the slow-rotator fraction increases at small clustercentric radii (R cl < 0.3 R 200 ), and note that there is also an increase in the slow-rotator fraction at R cl ∼ 0.6 R 200 . The SRs at these larger radii reside in the cluster substructure. We find that the strongest increase in the slow-rotator fraction occurs with increasing stellar mass. After accounting for the strong correlation with stellar mass, we find no significant relationship between spin parameter and local overdensity in the cluster environment. We conclude that the primary driver for the kinematic morphology-density relationship in galaxy clusters is the changing distribution of galaxy stellar mass with the local environment. The presence of SRs in the substructure suggests that the cluster kinematic morphology-density relationship is a result of mass segregation of slow-rotating galaxies forming in groups that later merge with clusters and sink to the cluster center via dynamical friction.

We present the ∼800 star formation rate maps for the SAMI Galaxy Survey based on Hα emission maps, corrected for dust attenuation via the Balmer decrement, that are included in the SAMI Public Data Release 1. We mask out spaxels contaminated by non-stellar emission using the [O III]/Hβ, [N II]/Hα, [S II]/Hα, and [O I]/Hα line ratios. Using these maps, we examine the global and resolved star-forming main sequences of SAMI galaxies as a function of morphology, environmental density, and stellar mass. Galaxies further below the star-forming main sequence are more likely to have flatter star formation profiles. Early-type galaxies split into two populations with similar stellar masses and central stellar mass surface densities. The main sequence population has centrally-concentrated star formation similar to late-type galaxies, while galaxies >3σ below the main sequence show significantly reduced star formation most strikingly in the nuclear regions. The split populations support a two-step quenching mechanism, wherein halo mass first cuts off the gas supply and remaining gas continues to form stars until the local stellar mass surface density can stabilize the reduced remaining fuel against further star formation. Across all morphologies, galaxies in denser environments show a decreased specific star formation rate from the outside in, supporting an environmental cause for quenching, such as ram-pressure stripping or galaxy interactions.

High-resolution spectral studies were undertaken at orbital phases () 0, 0.25, and 0.5 on the high-mass X-ray binary Vela X-1 using archival Chandra data. We present (1) the first detailed analysis of the multiple strong narrow emission lines present in = 0.5, (2) an analysis of the absorption of the continuum in = 0.5, and (3) the first detection of narrow emission and absorption lines in = 0.25. Multiple fluorescent and H-and He-like emission lines in the band 1.6-20 8 in eclipse are partially obscured at = 0.25 by the X-ray continuum. The = 0.25 spectrum displays three triplets, two with a blueshifted resonance line in absorption and the intercombination and forbidden lines in emission, and shows in absorption other blueshifted lines seen in emission in eclipse. At = 0.5 the soft X-ray continuum diminishes revealing an ''eclipse-like'' spectrum; however, line flux values are around 13-fold those in eclipse. We conclude the narrow emission lines in Vela X-1 become apparent when the continuum is blocked from the line of sight, either by eclipse or by scattering and/or absorption from a wake or cloud. The H-and He-like lines arise in warm photoionized regions in the stellar wind, while the fluorescent lines (including a Ni K line) are produced in cooler clumps of gas outside these regions. Absorption of the 5-13 8 continuum at = 0.5 may be caused by an accretion wake composed of dense stagnant photoionized plasma inside a Stromgren zone. Multiple fluorescent emission lines may be a common feature of the supergiant category of HMXBs.