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.

Effects of large shareholding on information asymmetry and stock liquidity

Abstract: Prior studies, such as Claessens et al.’s [Claessens, S., Djankov, S., Fan, J., Lang, L., 2002. Disentangling the incentive and entrenchment effects of large shareholding. Journal of Finance 57, 2741–2771], suggest that deviation between ultimate control and ownership decreases firm value (due to the entrenchment effects of large shareholding). Using a sample of Canadian firms, we study the relation of ultimate control and ownership with an important dimension of stock liquidity – bid–ask spread. We find that stocks with greater deviations between ultimate control and ownership have a larger information asymmetry component of their bid–ask spread and wider bid–ask spread. Our results are consistent with the notion that the ultimate owners of these stocks may have selfish agendas. To increase the probability of the agendas being implemented, the firms may have poor information disclosure, resulting in poor stock liquidity.

Measurements of the Elastic Electromagnetic Form Factor Ratio Mu(P)G(Ep)/G(Mp) Via Polarization Transfer

Abstract: We present measurements of the ratio of the proton elastic electromagnetic form factors, μ_pG_(Ep)/G_(Mp). The Jefferson Lab Hall A Focal Plane Polarimeter was used to determine the longitudinal and transverse components of the recoil proton polarization in ep elastic scattering; the ratio of these polarization components is proportional to the ratio of the two form factors. These data reproduce the observation of Jones et al. [Phys. Rev. Lett. 84, 1398 (2000)], that the form factor ratio decreases significantly from unity above Q^2=1 GeV^2.

Fluctuations in density of an outbreak species drive diversity cascades in food webs

Abstract: Patterns in food-web structure have frequently been examined in static food webs, but few studies have attempted to delineate patterns that materialize in food webs under nonequilibrium conditions. Here, using one of nature's classical nonequilibrium systems as the food-web database, we test the major assumptions of recent advances in food-web theory. We show that a complex web of interactions between insect herbivores and their natural enemies displays significant architectural flexibility over a large fluctuation in the natural abundance of the major herbivore, the spruce budworm (Choristoneura fumiferana). Importantly, this flexibility operates precisely in the manner predicted by recent foraging-based food-web theories: higher-order mobile generalists respond rapidly in time and space by converging on areas of increasing prey abundance. This "birdfeeder effect" operates such that increasing budworm densities correspond to a cascade of increasing diversity and food-web complexity. Thus, by integrating foraging theory with food-web ecology and analyzing a long-term, natural data set coupled with manipulative field experiments, we are able to show that food-web structure varies in a predictable manner. Furthermore, both recent food-web theory and longstanding foraging theory suggest that this very same food-web flexibility ought to be a potent stabilizing mechanism. Interestingly, we find that this food-web flexibility tends to be greater in heterogeneous than in homogeneous forest plots. Because our results provide a plausible mechanism for boreal forest effects on populations of forest insect pests, they have implications for forest and pest management practices.

Role of participatory governance and community - based management in integrated coastal and ocean management in Canada

Abstract: There is compelling evidence that participatory governance is crucial for contending with complex problems of managing for multiple values and outcomes to achieve ecological sustainability and economic development. Canada's Oceans Act, and federal oceans policy provide a strong basis for the participatory governance and community-based management of coastal and large ocean resources. The implementation of the Oceans Act and oceans policy has resulted in some steps toward participatory governance but has not adequately provided the mechanisms for a strong role for communities in integrated coastal and ocean management (ICOM). In order to strengthen and develop community participation in ICOM, nine initiatives are recommended: (1) shifting paradigms, (2) overcoming ‘turf protection,’ (3) ensuring compatibility of goals, (4) ensuring sufficiency of information, (5) dealing with internal community stratification, (6) creating cross-scale linkages, (7) creating a participatory policy environment, (8) building ...

Reaction Rate Uncertainties and the Production of 19F in Asymptotic Giant Branch Stars

Abstract: We present nucleosynthesis calculations and the resulting 19F stellar yields for a large set of models with different masses and metallicity. During the asymptotic giant branch (AGB) phase, 19F is produced as a consequence of nucleosynthesis occurring during the convective thermal pulses and also during the interpulse periods if protons from the envelope are partially mixed in the top layers of the He intershell (partial mixing zone). We find that the production of fluorine depends on the temperature of the convective pulses, the amount of primary 12C mixed into the envelope by third dredge-up, and the extent of the partial mixing zone. Then we perform a detailed analysis of the reaction rates involved in the production of 19F and the effects of their uncertainties. We find that the major uncertainties are associated with the 14C(α, γ)18O and 19F(α, p)22Ne reaction rates. For these two reactions we present new estimates of the rates and their uncertainties. In both cases the revised rates are lower than previous estimates. The effect of the inclusion of the partial mixing zone on the production of fluorine strongly depends on the very uncertain 14C(α, γ)18O reaction rate. The importance of the partial mixing zone is reduced when using our estimate for this rate. Overall, rate uncertainties result in uncertainties in the fluorine production of about 50% in stellar models with mass 3 M☉ and of about a factor of 7 in stellar models of mass 5 M☉. This larger effect at high masses is due to the high uncertainties of the 19F(α, p)22Ne reaction rate. Taking into account both the uncertainties related to the partial mixing zone and those related to nuclear reactions, the highest values of 19F enhancements observed in AGB stars are not matched by the models. This is a problem that will have to be revised by providing a better understanding of the formation and nucleosynthesis in the partial mixing zone, as well as in relation to reducing the uncertainties of the 14C(α, γ)18O reaction rate. At the same time, the possible effect of cool bottom processing at the base of the convective envelope should be included in the computation of AGB nucleosynthesis. This process could, in principle, help to match the highest 19F abundances observed by decreasing the C/O ratio at the surface of the star, while leaving the 19F abundance unchanged.