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Hot Populations in M87 Globular Clusters
Sohn, Sangmo T.,O'Connell, Robert W.,Kundu, Arunav,Landsman, Wayne B.,Burstein, David,Bohlin, Ralph C.,Frogel, Jay A.,Rose, James A. American Institute of Physics 2006 The Astronomical journal Vol.131 No.2
<P>To explore the production of UV-bright stars in old, metal-rich populations like those in elliptical galaxies, we have obtained Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph far- and near-UV photometry of globular clusters (GCs) in four fields in the giant elliptical (gE) galaxy M87. To a limit of m<SUB>FUV</SUB> ~ 25 we detect a total of 66 GCs in common with the deep HST optical-band study of Kundu et al. Despite strong overlap in V- and I-band properties, the M87 GCs have UV-optical properties that are distinct from clusters in the Milky Way and in M31. M87 clusters, especially metal-poor ones, produce larger hot horizontal-branch populations than do Milky Way analogs. In color plots including the near-UV band, the M87 clusters appear to represent an extension of the Milky Way sequence. Cluster mass is probably not a factor in these distinctions. The most metal-rich M87 GCs in our sample are near solar metallicity and overlap the local E galaxy sample in estimated Mg<SUB>2</SUB> line indices. Nonetheless, the clusters produce much more UV light at a given Mg<SUB>2</SUB>, being up to 1 mag bluer than any gE galaxy in (FUV - V) color. The M87 GCs do not appear to represent a transition between Milky Way-type clusters and E galaxies. The differences are in the correct sense if the clusters are significantly older than the E galaxies.</P><P>Comparisons with Galactic open clusters indicate that the hot stars lie on the extreme horizontal branch, rather than being blue stragglers, and that the extreme horizontal branch becomes well populated for ages ≳5 Gyr. Existing model grids for clusters do not match the observations well, due to poorly understood giant branch mass loss or perhaps high helium abundances. We find that 41 of our UV detections have no optical-band counterparts. Most appear to be UV-bright background galaxies seen through M87. Eleven near-UV variable sources detected at only one epoch in the central field are probably classical novae. Two recurrent variable sources have no obvious explanation but could be related to activity in the relativistic jet.</P>
Ju, Bong-Gun,Solum, Derek,Song, Eun Joo,Lee, Kong-Joo,Rose, David W.,Glass, Christopher K.,Rosenfeld, Michael G. Elsevier 2004 Cell Vol.119 No.6
<P><B>Abstract</B></P><P>Switching specific patterns of gene repression and activation in response to precise temporal/spatial signals is critical for normal development. Here we report a pathway in which induction of CaMKIIδ triggers an unexpected switch in the function of the HES1 transcription factor from a TLE-dependent repressor to an activator required for neuronal differentiation. These events are based on activation of the poly(ADP-ribose) polymerase1 (PARP-1) sensor component of the groucho/TLE-corepressor complex mediating dismissal of the corepressor complex from HES1-regulated promoters. In parallel, CaMKIIδ mediates a required phosphorylation of HES1 to permit neurogenic gene activation, revealing the ability of a specific signaling pathway to modulate both the derepression and the subsequent coactivator recruitment events required for transcriptional activation of a neurogenic program. The identification of PARP-1 as a regulated promoter-specific exchange factor required for activation of specific neurogenic gene programs is likely to be prototypic of similar molecular mechanisms.</P>
Golf Swing Rotational Velocity: The Essential Follow-Through
Katherine M. Steele,Eugene Y. Roh,Gordhan Mahtani,David W. Meister,Amy L. Ladd,Jessica Rose 대한재활의학회 2018 Annals of Rehabilitation Medicine Vol.42 No.5
Objective To evaluate if shoulder and pelvic angular velocities differ at impact or peak magnitude between professional and amateur golfers. Golf swing rotational biomechanics are a key determinant of power generation, driving distance, and injury prevention. We hypothesize that shoulder and pelvic angular velocities would be highly consistent in professionals. Methods Rotational velocities of the upper-torso and pelvis throughout the golf swing and in relation to phases of the golf swing were examined in 11 professionals and compared to 5 amateurs using three-dimensional motion analysis.Results Peak rotational velocities of professionals were highly consistent, demonstrating low variability (coefficient of variation [COV]), particularly upper-torso rotational velocity (COV=0.086) and pelvic rotational velocity (COV=0.079) during down swing. Peak upper-torso rotational velocity and peak X-prime, the relative rotational velocity of upper-torso versus pelvis, occurred after impact in follow-through, were reduced in amateurs compared to professionals (p=0.005 and p=0.005, respectively) and differentiated professionals from most (4/5) amateurs. In contrast, peak pelvic rotational velocity occurred in down swing. Pelvic velocity at impact was reduced in amateurs compared to professionals (p=0.019) and differentiated professionals from most (4/5) amateurs. Conclusion Golf swing rotational velocity of professionals was consistent in pattern and magnitude, offering benchmarks for amateurs. Understanding golf swing rotational biomechanics can guide swing modifications to help optimize performance and prevent injury.
Zhu, Ping,Baek, Sung Hee,Bourk, Eliot M.,Ohgi, Kenneth A.,Garcia-Bassets, Ivan,Sanjo, Hideki,Akira, Shizuo,Kotol, Paul F.,Glass, Christopher K.,Rosenfeld, Michael G.,Rose, David W. Elsevier 2006 Cell Vol.124 No.3
<P><B>Summary</B></P><P>Defining the precise molecular strategies that coordinate patterns of transcriptional responses to specific signals is central for understanding normal development and homeostasis as well as the pathogenesis of hormone-dependent cancers. Here we report specific prostate cancer cell/macrophage interactions that mediate a switch in function of selective androgen receptor antagonists/modulators (SARMs) from repression to activation in vivo. This is based on an evolutionarily conserved receptor N-terminal L/HX<SUB>7</SUB>LL motif, selectively present in sex steroid receptors, that causes recruitment of TAB2 as a component of an N-CoR corepressor complex. TAB2 acts as a sensor for inflammatory signals by serving as a molecular beacon for recruitment of MEKK1, which in turn mediates dismissal of the N-CoR/HDAC complex and permits derepression of androgen and estrogen receptor target genes. Surprisingly, this conserved sensor strategy may have arisen to mediate reversal of sex steroid-dependent repression of a limited cohort of target genes in response to inflammatory signals, linking inflammatory and nuclear receptor ligand responses to essential reproductive functions.</P>