University of Victoria

About: University of Victoria is a education organization based out in Victoria, British Columbia, Canada. It is known for research contribution in the topics: Population & Galaxy. The organization has 14994 authors who have published 41051 publications receiving 1447972 citations. The organization is also known as: Victoria College.

Light Curves of the Neutron Star Merger GW170817/SSS17a: Implications for R-Process Nucleosynthesis

Abstract: On 2017 August 17, gravitational waves were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, optical and infrared light curves of SSS17a extending from 10.9 hours to 18 days post-merger. We constrain the radioactively-powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in r-process nucleosynthesis in the Universe.

Tumor-infiltrating lymphocytes predict response to anthracycline-based chemotherapy in estrogen receptor-negative breast cancer

Abstract: Infiltration of breast tumors by tumor-infiltrating lymphocytes (TIL) has been associated with sensitivity to anthracycline-based chemotherapy. However, it is unclear whether this is true within the estrogen receptor-alpha (ER)-negative subset of breast tumors that frequently manifest high TIL levels. The association of TIL with short-term and long-term clinical response to anthracycline-based therapy was assessed in two independent ER-negative breast cancer cohorts in which patients were categorized as TIL-high or TIL-low. We defined an eight-gene lymphocyte mRNA expression signature (including CD19, CD3D, CD48, GZMB, LCK, MS4A1, PRF1, and SELL) and used unsupervised hierarchical clustering to examine the association between TIL and short-term response to neoadjuvant chemotherapy in a previously published cohort of ER-negative tumors (n = 113). We also examined the association between TIL and long-term chemotherapeutic efficacy in a second cohort of ER-negative tumors (n = 255) with longer than 6 years of median follow-up by using tissue microarrays and immunohistochemistry (IHC) for detection of CD3, CD8, CD4, CD20, and TIA-1. In patients with ER-negative tumors treated with neoadjuvant anthracycline-based chemotherapy, pathologic complete responses (pCRs) were achieved by 23 (74%) of 31 TIL-high patients and 25 (31%) of 80 TIL-low patients (odds ratio (OR), 6.33; 95% confidence interval (CI), 2.49 to 16.08; P < 0.0001). Multivariate logistic regression with standard clinicopathologic features demonstrated that only tumor size (P = 0.037) and TIL status (P = 0.001) were independent predictors of anthracycline response. In the second cohort, adjuvant anthracycline-based therapy was associated with increased disease-free survival (DFS) only in patients with high levels of intraepithelial CD3+ TIL (P = 0.0023). In contrast, outcomes after CMF treatment (cyclophosphamide, methotrexate, and fluorouracil) showed no association with CD3 status. In both cohorts, cytotoxic T-cells were the primary TIL subtype associated with anthracycline sensitivity. Finally, TIL significantly predicted anthracycline sensitivity for both the Her2-positive and triple-negative tumor phenotypes. ER-negative breast cancers with high levels of TIL have heightened sensitivity to anthracycline-based chemotherapy, as assessed by the immediate response to neoadjuvant therapy and long-term outcome following adjuvant therapy. Investigations of TIL-based predictive tests to identify patients likely to benefit from anthracycline-based treatments are warranted.

Stroop process dissociations: The relationship between facilitation and interference.

Abstract: L.L. Jacoby's (1991) "process dissociation procedure" was used to quantitatively estimate the contributions of color-naming and word-reading processes to responding on the Stroop task. The results show that color naming and word reading can operate independently to determine responses. Degrading stimulus colors eliminated the typical asymmetry between Stroop facilitation and interference, as predicted by the equations (Experiments 1 and 2). Degrading stimulus colors reduced the estimated contribution of color naming to responding but had no effect on the estimated contribution of word reading (Experiment 2). In contrast, increasing the proportion of incongruent items reduced the estimated contribution of word reading but had no effect on the estimated contribution of color naming (Experiments 3 and 4). The results indicate that the facilitating and interfering effects of automatic processes cannot be accurately measured in terms of differences from baseline.

Models for Old, Metal-poor Stars with Enhanced α-Element Abundances. I. Evolutionary Tracks and ZAHB Loci; Observational Constraints

Abstract: Stellar evolutionary tracks have been computed for 17 [Fe/H] values from -2.31 to -0.30 assuming, in each case, [?/Fe] = 0.0, 0.3, and 0.6. The helium abundance was assumed to vary from Y = 0.2352 at [Fe/H] = -2.31 to Y = 0.2550 at [Fe/H] = -0.30 and held constant for the different choices of [?/Fe] at a fixed iron content. Masses in the range 0.5 ? ? ? 1.0, in 0.1 ? steps, were generally considered, though sequences for higher mass values were computed, as necessary, to ensure that isochrones as young as 8 Gyr could be generated for each grid. All of the stellar models are based on an equation of state that treats nonideal effects, the latest nuclear reaction and neutrino cooling rates, and opacities that were computed specifically for the adopted chemical mixtures. The tracks were extended to the tip of the giant branch or to an age of 30 Gyr, whichever came first, and zero-age horizontal-branch (ZAHB) loci were constructed using the helium core masses and chemical profiles from appropriate red giant precursors. Selected models have been compared with those computed by A. V. Sweigart, for the same masses and chemical compositions, to demonstrate that the results obtained from two entirely independent stellar evolution codes agree well with one another when very similar input physics is assumed. In the case of extremely metal-deficient stars, an enhancement in the abundance of the ?-elements causes a single, fairly significant bump in the opacity at a temperature just above 106 K, which is caused by absorption processes involving the K shell of oxygen. This peak becomes steadily more pronounced as the overall metallicity increases and a second bump, arising from the L edges of Ne, Mg, and Si, eventually appears near log T = 5.6. As far as the tracks and isochrones are concerned, we find that, as already reported by others, it is possible to mimic the computations for [?/Fe] > 0 remarkably well by those for scaled-solar mixes simply by requiring the total mass-fraction abundance of the heavy elements, Z, to be the same. However, this result holds only for metallicities significantly less than solar. Above [Fe/H] -0.8, tracks and isochrones for enhanced ?-element mixtures begin to have systematically hotter/bluer turnoffs and red giant branches than those for scaled-solar mixtures of the heavy elements. Also addressed is the extent to which our models satisfy the constraints posed by the local subdwarfs, the distances of which are based on Hipparcos parallax measurements. Our analysis suggests that the predicted metallicity dependence of the location of the lower main sequence on the C-M diagram is in good agreement with the observed dependence. In fact, we do not find any compelling evidence from the local Population II calibrators that the colors of our models require significant adjustments. In further support of our calculations, we find that, both in zero point and slope, the computed giant branches on the (Mbol, log Teff)-plane agree well with those inferred for globular clusters from observations in the infrared. Moreover, our ZAHB models have luminosities that are just outside the 1 ? error bars of the mean MV's inferred for RR Lyrae stars from Baade-Wesselink, statistical parallax, and trigonometric parallax studies. Lower helium contents or higher ?-element abundances or an increase in the conductive opacities are among the possible ways of reducing the differences that remain. To facilitate comparisons with observations, the tracks/ZAHBs are provided with predicted BV(RI)C photometry.

Entering Guanxi: A Business Ethical Dilemma in Mainland China?

Abstract: This paper represents an effort to distinguish between two types of guanxi prevalent in mainland China: favor-seeking guanxi that is culturally rooted and rent-seeking guanxi that is institutionally defined. Different rules of maneuvering the two types of guanxi are identified in light of Chinese cultural and business ethics. Strategies for entering guanxi in mainland China are also suggested.