Spectroscopy of Giant Stars in the Pyxis Globular Cluster

The Pyxis globular cluster is a recently discovered globular cluster that lies in the outer halo (R_{gc} ~ 40 kpc) of the Milky Way. Pyxis lies along one of the proposed orbital planes of the Large Magellanic Cloud (LMC), and it has been proposed to be a detached LMC globular cluster captured by the Milky Way. We present the first measurement of the radial velocity of the Pyxis globular cluster based on spectra of six Pyxis giant stars. The mean heliocentric radial velocity is ~ 36 km/sec, and the corresponding velocity of Pyxis with respect to a stationary observer at the position of the Sun is ~ -191 km/sec. This radial velocity is a large enough fraction of the cluster's expected total space velocity, assuming that it is bound to the Milky Way, that it allows strict limits to be placed on the range of permissible transverse velocities that Pyxis could have in the case that it still shares or nearly shares an orbital pole with the LMC. We can rule out that Pyxis is on a near circular orbit if it is Magellanic debris, but we cannot rule out an eccentric orbit associated with the LMC. We have calculated the range of allowed proper motions for the Pyxis globular cluster that result in the cluster having an orbital pole within 15 degrees of the present orbital pole of the LMC and that are consistent with our measured radial velocity, but verification of the tidal capture hypothesis must await proper motion measurement from the Space Interferometry Mission or HST. A spectroscopic metallicity estimate of [Fe/H] = -1.4 +/- 0.1 is determined for Pyxis from several spectra of its brightest giant; this is consistent with photometric determinations of the cluster metallicity from isochrone fitting.Comment: 22 pages, 5 figures, aaspp4 style, accepted for publication in October, 2000 issue of the PAS

Identity Implications of Influence Goals: Similarities in Perceived face Threats and Facework Across Sex and Close Relationships

Abstract OnlyThis study tests the generalizability of Wilson, Aleman, & Leatham’s revised analysis of face threats and facework during compliance-gaining episodes. According to this revised analysis, threats to face arise from tacit knowledge about (a) specific influence goals (e.g., giving advice, asking favors) and (b) the rules for directives (e.g., requests) that underlie any attempt to seek compliance. Both types of knowledge are shared widely; hence, the distinct face threats of advice versus favors should generalize across sex and close relationships. Message sources give reasons as facework to redress particular face threats in an episode defined by a specific influence goal; hence, patterns of reason giving also should differ in advice versus favor episodes. Participants (N = 231 undergraduates) recalled an actual conversation in which they either gave advice to or asked a favor of a close same-sex friend, opposite-sex friend, or romantic partner and then rated threats to the message target’s face and their own. Results for both perceived face threats and reason giving are consistent with the revised analysis. Comparisons with Brown and Levinson’s politeness theory, as well as implications for future research, are drawn

High-Density Genomewide Linkage Analysis of Exceptional Human Longevity Identifies Multiple Novel Loci

Background: Human lifespan is approximately 25 % heritable, and genetic factors may be particularly important for achieving exceptional longevity. Accordingly, siblings of centenarians have a dramatically higher probability of reaching extreme old age than the general population. Methodology/Principal Findings: To map the loci conferring a survival advantage, we performed the second genomewide linkage scan on human longevity and the first using a high-density marker panel of single nucleotide polymorphisms. By systematically testing a range of minimum age cutoffs in 279 families with multiple long-lived siblings, we identified a locus on chromosome 3p24-22 with a genomewide significant allele-sharing LOD score of 4.02 (empirical P = 0.037) and a locus on chromosome 9q31-34 with a highly suggestive LOD score of 3.89 (empirical P = 0.054). The empirical P value for the combined result was 0.002. A third novel locus with a LOD score of 4.05 on chromosome 12q24 was detected in a subset of the data, and we also obtained modest evidence for a previously reported interval on chromosome 4q22-25. Conclusions/Significance: Our linkage data should facilitate the discovery of both common and rare variants tha

Influence of Macromolecular Crowding and Confinement on Enzyme Activity and Structure under Native and Denaturing Conditions

It is now well appreciated that both crowding and confinement influence enzyme structure and function due to excluded volume effects; however, the relative efficacies of these environments on protein fates remain unclear due to a lack of direct comparison studies. In this study, we explore the use of the biopolymer alginate to develop an in vitro platform to investigate the effects of both crowding and confinement on the behavior of two model enzymes - horseradish peroxidase and β-galactosidase. Alginate, in its solution phase, can be used as a crowding agent and, in its gel phase by crosslinking using divalent cations, to encapsulate and confine proteins, thereby allowing us to use the same system to directly compare the effects of crowding and confinement. Different degrees of crowding and confinement were achieved by varying the alginate concentration, and these studies demonstrated a clear dependence of enzyme activity on the degree of crowding and confinement. Moreover, our data also suggested that protein confinement in crosslinked alginate gels led to higher enhancements in enzyme activity under denaturing conditions relative to non-crosslinked crowded environments. Results from the kinetic analyses were corroborated using structural measurements of protein denaturation using the 8-anilinonaphthalene-1-sulfonic acid fluorescence assay

The Role of Arachidonic Acid Metabolites in Mononuclear Phagocytic Cell Interactions

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65162/1/j.1365-4362.1986.tb04543.x.pd

Two strikes: limited NIH R55 and R56 retooling funds and abolishment of the A2 grant mechanism

The U.S. National Institutes of Health (NIH) are facing significant budgetary challenges as a result of the current economic climate. The recent sunset of investigator‐initiated R01‐type research grants after one revised submission, coupled with the present lack of an NIH retooling funding mechanism for such grant applicants, creates a concerning risk that talented and well‐trained investigators may be forced to give up their research careers. Existing NIH retooling mechanisms include the R55 Shannon Award, which was established in 1991 and was essentially replaced in 2005 by the R56 award. There is an urgent need to either significantly expand the R55/R56 mechanisms and definition of NIH grant bridging/retooling support for unfunded meritorious proposals or introduce a new mechanism that provides specific support to investigators with competitive but unfunded R01 revised grants. An expanded retooling funding mechanism deserves implementation during continuing assessment of whether allowance of only one revision of research proposals has achieved its initial intended goals. Omary, M. B., Offhaus, H., Kunkel, S. L. Two strikes: limited NIH R55 and R56 retooling funds and abolishment of the A2 grant mechanism. FASEB J. 25, 4108–4110 (2011). www.fasebj.orgPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154267/1/fsb2fj11188052.pd

The Role of Interleukin-8 in the Infectious Process a

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73887/1/j.1749-6632.1994.tb44245.x.pd

The Future of Stellar Populations Studies in the Milky Way and the Local Group

The last decade has seen enormous progress in understanding the structure of the Milky Way and neighboring galaxies via the production of large-scale digital surveys of the sky like 2MASS and SDSS, as well as specialized, counterpart imaging surveys of other Local Group systems. Apart from providing snaphots of galaxy structure, these "cartographic" surveys lend insights into the formation and evolution of galaxies when supplemented with additional data (e.g., spectroscopy, astrometry) and when referenced to theoretical models and simulations of galaxy evolution. These increasingly sophisticated simulations are making ever more specific predictions about the detailed chemistry and dynamics of stellar populations in galaxies. To fully exploit, test and constrain these theoretical ventures demands similar commitments of observational effort as has been plied into the previous imaging surveys to fill out other dimensions of parameter space with statistically significant intensity. Fortunately the future of large-scale stellar population studies is bright with a number of grand projects on the horizon that collectively will contribute a breathtaking volume of information on individual stars in Local Group galaxies.Comment: 12 pages, 0 figures, IAU Symposium No. 262, Stellar Populations - Planning for the Next Decad