Spatial Analyses of Gray Fossil Site Vertebrate Remains: Implications for Depositional Setting and Site Formation Processes

This project uses exploratory 3D geospatial analyses to assess the taphonomy of the Gray Fossil Site (GFS). During the Pliocene, the GFS was a forested, inundated sinkhole that accumulated biological materials between 4.9-4.5 mya. This deposit contains fossils exhibiting different preservation modes: from low energy lacustrine settings to high energy colluvial deposits. All macro-paleontological materials have been mapped in situ using survey-grade instrumentation. Vertebrate skeletal material from the site is well-preserved, but the degree of skeletal articulation varies spatially within the deposit. This analysis uses geographic information systems (GIS) to analyze the distribution of mapped specimens at different spatial scales. Factors underpinning spatial association, skeletal completeness, and positioning of specimens were examined. At the scale of the individual skeleton, analyses of the Mastodon Pit explore how element completeness and orientation/inclination of the mastodon reflect post-depositional processes

Rotation and Macroturbulence in Metal-poor Field Red Giant and Red Horizontal Branch Stars

We report the results for rotational velocities, Vrot sin i, and macroturbulence dispersion, zeta(RT), for 12 metal-poor field red giant branch stars and 7 metal-poor field red horizontal branch stars. The results are based on Fourier transform analyses of absorption line profiles from high-resolution (R ~ 120,000), high-S/N (~ 215 per pixel) spectra obtained with the Gecko spectrograph at CFHT. We find that the zeta(RT) values for the metal-poor RGB stars are very similar to those for metal-rich disk giants studied earlier by Gray and his collaborators. Six of the RGB stars have small rotational values, less than 2.0 km/sec, while five show significant rotation, over 3 km/sec. The fraction of rapidly rotating RHB stars is somewhat lower than found among BHB stars. We devise two empirical methods to translate the line-broadening results obtained by Carney et al. (2003, 2008) into Vrot sin i for all the RGB and RHB stars they studied. Binning the RGB stars by luminosity, we find that most metal-poor field RGB stars show no detectable sign, on average, of rotation. However, the most luminous stars, with M(V) <= -1.5, do show net rotation, with mean values of 2 to 4 km/sec, depending on the algorithm employed, and these stars also show signs of radial velocity jitter and mass loss.Comment: accepted for publication in the Astronomical Journa

ASYMMETRIES IN THE SPECTRAL LINES OF EVOLVED HALO STARS

We do an initial reconnaissance of asymmetries of spectral lines in metal-poor field stars using high-resolution observations of four red horizontal-branch and 11 red giant branch stars taken with the coude spectrograph at the Canada-France-Hawaii Telescope. We find that (1) the shapes of the line bisectors for metal-poor stars hotter than 4100 K mimic the well-known C shape of bisectors for solar-metallicity stars on the cool side of the granulation boundary while (2) metal-poor stars cooler than 4100 K, or higher up the red giant branch than M V = -1.5, show bisectors with a reversed-C shape, similar to those for solar-metallicity stars on the hot side of the granulation boundary and similar to the reversed-C shape found in a previous study for the M-type supergiant Betelgeuse. The well-documented radial-velocity jitter of high-luminosity stars and the line bisector characteristics vary in concert up the red giant branch; both phenomena are probably signatures of large convection cells

Structuring a short-term study abroad experience to foster professional identity growth in undergraduate education and social work students

This paper explores the emerging themes in the development and implementation of a short-term study abroad tour of Ireland and Northern Ireland by education and social work majors. The twenty-two student participants were invited to take part in a post-travel focus group process to discover how the experience impacted their developing professional identities. As the researchers reviewed the focus group transcripts and reflected on the experience, powerful ideas regarding the development of a successful study abroad experience emerged. The following four themes emerged: instructors need to purposefully schedule the experience to meet the social and learning needs of the students; instructors need to fully immerse students in the culture for a more effective, meaningful, and lasting experience; students must rigorously engage in the cultural and educational expectations while on the study tour; and the students need multiple spaces during the tour to discuss and debrief the experiences that challenge their preconceived expectations. Although it would be premature to say these themes rise to the level of “best practices” at this point, this research will help direct and strengthen future studies of faculty-led study abroad experiences

Stimulation of bone growth with thrombin peptide derivatives

Disclosed is a method of stimulating bone growth at a site in a subject in need of osteoinduction. The method comprises the step of administering a therapeutically effective amount of an agonist of the non-proteolytically activated thrombin receptor to the site.Board of Regents, University of Texas Syste

The Rotation of RR Lyrae Stars

We report upper limits to rotation from the measurement of line breadths via cross-correlation analysis for 27 RR Lyrae variables. The eight best-observed stars of type RRab show the same variation of breadth with phase: the breadth peaks sharply during the rise to maximum light, drops gradually, and reaches a broad minimum during the phase of maximum radius. During this phase the breadth is always narrow, consistent with instrumental resolution and turbulence alone. For the three well-observed RRc variables, the breadth is this narrow at all phases except for a slight increase during the rise to maximum light. The remaining stars also conform to these patterns, albeit with sparse phase coverage and lower signal-to-noise ratio. We interpret these results as indicating that lines are broadened in RRab stars by shock-induced plumes or turbulence during the rise to maximum light, and perhaps by other causes as well, but not by rotation in RR Lyrae stars of either type. We estimate an upper limit of v sin i 10 km s-1 in three out of six well-studied field stars, and to the more rapid rotation, often exceeding 100 km s-1, of the Population I δ Scuti variables which occupy adjacent regions of the instability strip

Which combination drug therapies are most effective for hypertension?

Insufficient evidence exists to determine which specific combinations most effectively decrease cardiovascular morbidity and mortality, although combinations of hypertension medications at lower doses generally reduce cardiovascular outcomes (stroke, coronary heart disease) more than monotherapy (strength of recommendation [SOR]: A, large meta-analyses). The combination of benazepril and amlodipine reduces the composite endpoint of cardiovascular events and deaths more than benazepril plus hydrochlorothiazide with similar rates of adverse effects (SOR: A, randomized controlled trial [RCT]). Combining an angiotensin converting enzyme inhibitor (ACE-I) with a thiazide, b-blocker, or calcium channel blocker produces side effects similar to monotherapy, as does combining an angiotensin receptor blocker (ARB) with a thiazide or calcium channel blocker (SOR: A, meta-analyses). However, an ACE-I combined with an ARB increases the risk of renal complications and death more than monotherapy (SOR: A, RCT)

Elemental Abundance Ratios in Stars of the Outer Galactic Disk. IV. A New Sample of Open Clusters

We present radial velocities and chemical abundances for nine stars in the old, distant open clusters Be 18, Be 21, Be 22, Be 32, and PWM 4. For Be 18 and PWM 4, these are the first chemical abundance measurements. Combining our data with literature results produces a compilation of some 68 chemical abundance measurements in 49 unique clusters. For this combined sample, we study the chemical abundances of open clusters as a function of distance, age, and metallicity. We confirm that the metallicity gradient in the outer disk is flatter than the gradient in the vicinity of the solar neighborhood. We also confirm that the open clusters in the outer disk are metal-poor with enhancements in the ratios [alpha/Fe] and perhaps [Eu/Fe]. All elements show negligible or small trends between [X/Fe] and distance (< 0.02 dex/kpc), but for some elements, there is a hint that the local (RGC < 13 kpc) and distant (RGC > 13 kpc) samples may have different trends with distance. There is no evidence for significant abundance trends versus age (< 0.04 dex/Gyr). We measure the linear relation between [X/Fe] and metallicity, [Fe/H], and find that the scatter about the mean trend is comparable to the measurement uncertainties. Comparison with solar neighborhood field giants shows that the open clusters share similar abundance ratios [X/Fe] at a given metallicity. While the flattening of the metallicity gradient and enhanced [alpha/Fe] ratios in the outer disk suggest a different chemical enrichment history to the solar neighborhood, we echo the sentiments expressed by Friel et al. that definitive conclusions await homogeneous analyses of larger samples of stars in larger numbers of clusters. Arguably, our understanding of the evolution of the outer disk from open clusters is currently limited by systematic abundance differences between various studies.Comment: Accepted for publication in A