Saint Mary's University

About: Saint Mary's University is a education organization based out in Halifax, Nova Scotia, Canada. It is known for research contribution in the topics: Population & Stars. The organization has 1931 authors who have published 4993 publications receiving 143226 citations.

Electrochemical-Surface Enhanced Raman Spectroscopic (EC-SERS) Study of 6-Thiouric Acid: A Metabolite of the Chemotherapy Drug Azathioprine

Abstract: 6-Thiouric acid (6-TUA) has the potential to be an important biomarker for the action of 6-mercaptopurine (6-MP), an immunosuppressive drug used in patients suffering from acute lymphoblastic leukemia (ALL). 6-TUA, a nonactive metabolite of 6-MP, is excreted in the urine, and routine monitoring of this metabolite can be useful in assessing the efficacy of 6-MP for immune system suppression in patients who have undergone stem cell replacement. In this work, electrochemical surface-enhanced Raman spectroscopy (EC-SERS) is used for the first time to study the adsorption and electrochemical behavior of 6-TUA at a nanostructured silver electrode surface, in both 0.1 M NaF and synthetic urine as supporting electrolytes. In addition, ab initio calculations were completed in an effort to understand the adsorption behavior. It was found that EC-SERS provided excellent signal for 6-TUA down to μM concentrations in synthetic urine and highlights the future potential of EC-SERS for rapid detection of important urine ...

Similarities in Italian and Greek Multidimensional Ethnic Identity: Some Implications for Food Consumption

Abstract: Rather than assimilate, members of ethnic groups in multicultural environments have reportedly experienced a more complex and multifaceted form of adaptation (Lambert and Taylor, 1988,1990). Some have thus not only (a) acquired the skills and/or traits which have enabled them to function within a majority or host culture but have also (b) retained aspects of their cultures of origin. The former facet has been referred to as acculturation and the latter has often been labelled ethnic identity (Keefe and Padilla, 1987; Mendoza, 1989; Phinney, 1990). These processes have been presented as correlated facets of a broader process that is referred to as ethnic change (Keefe and Padilla, 1987; Laroche, Kim, Hui, and Joy, 1996). The focus of this paper is on ethnic identity. It has been found to impact many aspects of life which include consumption behavior (e.g., Schaninger, Bourgeois, and Buss, 1985; Wallendorf and Reilly, 1983). Nevertheless, the process by which individuals maintain ties to their ethnic group generally remains an enduring issue (Phinney, 1990,1996) and must be further investigated before a substantive theory of culture and consumption can emerge.

Massive open star clusters using the VVV survey - II. Discovery of six clusters with Wolf-Rayet stars

Abstract: Context. The ESO Public Survey “VISTA Variables in the Via Lactea” (VVV) provides deep multi-epoch infrared observations for an unprecedented 562 sq. degrees of the Galactic bulge, and adjacent regions of the disk. Nearly 150 new open clusters and cluster candidates have been discovered in this survey.Aims. This is the second in a series of papers about young, massive open clusters observed using the VVV survey. We present the first study of six recently discovered clusters. These clusters contain at least one newly discovered Wolf-Rayet (WR) star.Methods. Following the methodology presented in the first paper of the series, wide-field, deep JH K s VVV observations, combined with new infrared spectroscopy, are employed to constrain fundamental parameters for a subset of clusters.Results. We find that the six studied stellar groups are real young (2–7 Myr) and massive (between 0.8 and 2.2 × 103 M ⊙ ) clusters. They are highly obscured (A V ~ 5−24 mag) and compact (1–2 pc). In addition to WR stars, two of the six clusters also contain at least one red supergiant star, and one of these two clusters also contains a blue supergiant. We claim the discovery of 8 new WR stars, and 3 stars showing WR-like emission lines which could be classified WR or OIf. Preliminary analysis provides initial masses of ~30–50 M ⊙ for the WR stars. Finally, we discuss the spiral structure of the Galaxy using the six new clusters as tracers, together with the previously studied VVV clusters.

Measurements of Double-Polarized Compton Scattering Asymmetries and Extraction of the Proton Spin Polarizabilities

Abstract: The spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to extract the nucleon spin polarizabilities is through polarized Compton scattering. Double-polarized Compton scattering asymmetries on the proton were measured in the Delta(1232) region using circularly polarized incident photons and a transversely polarized proton target at the Mainz Microtron. Fits to asymmetry data were performed using a dispersion model calculation and a baryon chiral perturbation theory calculation, and a separation of all four proton spin polarizabilities in the multipole basis was achieved. The analysis based on a dispersion model calculation yields gamma(E1E1) = -3.5 +/- 1.2, gamma(M1M1) = 3.16 +/- 0.85, gamma(E1M2) = -0.7 +/- 1.2, and gamma(M1E2) = 1.99 +/- 0.29, in units of 10(-4) fm(4).

Non-LTE Modeling of the Near-Ultraviolet Band of Late-Type Stars

Abstract: We investigate the ability of both LTE and non-LTE (NLTE) models to fit the near-UV band absolute flux distribution, f λ(λ), and individual spectral line profiles of three standard stars for which high-quality spectrophotometry and high-resolution spectroscopy are available: The Sun (G2 V), Arcturus (K2 III), and Procyon (F5 IV-V). We investigate (1) the effect of the choice of atomic line list on the ability of NLTE models to fit the near-UV band f λ level, (2) the amount of a hypothesized continuous thermal absorption extinction source required to allow NLTE models to fit the observations, and (3) the semiempirical temperature structure, T kin(log τ5000), required to fit the observations with NLTE models and standard continuous near-UV extinction. We find that all models that are computed with high-quality atomic line lists predict too much flux in the near-UV band for Arcturus, but fit the warmer stars well. The variance among independent measurements of the solar irradiance in the near-UV is sufficiently large that we cannot definitely conclude that models predict too much near-UV flux, in contrast to other recent results. We surmise that the inadequacy of current atmospheric models of K giants in the near-UV band is best addressed by hypothesizing that there is still missing continuous thermal extinction, and that the missing near-UV extinction becomes more important with decreasing effective temperature for spectral classes later than early G, suggesting a molecular origin.