Government of Canada

About: Government of Canada is a government organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Monetary policy & Debt. The organization has 796 authors who have published 886 publications receiving 21366 citations. The organization is also known as: federal government of Canada & Her Majesty's Government.

Application of a three-component scattering model over snow-covered first-year sea ice using polarimetric C-band SAR data

Abstract: In this study we examine the utility of a three-component scattering model to quantify the sensitivity of radar incidence angle over snow-covered landfast first-year sea ice (FYI) during the late winter season. This three-component scattering model is based on (1) surface scattering contributed from the snow-covered FYI (smooth-ice (SI), rough-ice (RI), and deformed-ice (DI) types); (2) volume scattering contributed from snow layers which consist of enlarged snow grains, elevated brine volume, and preferential orientation of snow grains relative to radar look direction, as well as the underlying sea ice; and (3) double-bounce scattering contributed from ice ridges and ice fragments. This study uses RADARSAT-2 C-band polarimetric synthetic aperture radar (POLSAR) data acquired on 15 and 18 May 2009 for Hudson Bay, near Churchill, during late winter with surface air temperatures ≤−8°C at two different incidence angles (29° and 39°). The three-component scattering model is used to discriminate between snow-c...

Unidirectional invisibility induced by parity-time symmetric circuit

Abstract: Parity-time (PT) symmetric structures present the unidirectional invisibility at the spontaneous PT-symmetry breaking point. In this paper, we propose a PT-symmetric circuit consisting of a resistor and a microwave tunnel diode (TD) which represent the attenuation and amplification, respectively. Based on the scattering matrix method, the circuit can exhibit an ideal unidirectional performance at the spontaneous PT-symmetry breaking point by tuning the transmission lines between the lumped elements. Additionally, the resistance of the reactance component can alter the bandwidth of the unidirectional invisibility flexibly. Furthermore, the electromagnetic simulation for the proposed circuit validates the unidirectional invisibility and the synchronization with the input energy well. Our work not only provides an unidirectional invisible circuit based on PT-symmetry, but also proposes a potential solution for the extremely selective filter or cloaking applications.

Toward the origin of the secondary palate. A possible homologue in the embryo of fish, Onchorhynchus kisutch, with description of changes in the basement membrane area.

Abstract: The oral cavity of embryos and larvae of the teleost Onchorhynchus kisutch was examined. Tissues were obtained at different ages prior to and after hatching and processed for transmission and scanning electron microscopy. A bilaterally symmetrical bulge developed from the superolateral aspect of the oral cavity and projected toward its floor, along the sides of the tongue. The bulge extended from behind the primary palate to a position midway below the eye, anterior to the gill arches, and it is suggested to be the homologue of the secondary palate of higher vertebrates. Ultrastructurally, the epithelium differentiated as the stratified squamous type and it contained mucous cells. However, the features of programmed cell death seen during palatogenesis in mammals were absent in fish. The fish palate mesenchyme, unlike that of higher vertebrates, was chondrified. Also in contrast to higher vertebrates, alterations were seen in the fish palatal basement membrane. A transient appearance of adepidermal granules in the lamina lucida region was followed by organization of collagen fibrils, first into an orthogonal pattern and then into a herring-bone arrangement, in the lamina reticularis region. There was no further advancement in the morphogenesis of fish palate. It is suggested that the differences in the morphogenesis and structure of the secondary palates of various vertebrates may reflect environmentally enforced adaptation, resulting in different programming of cells.

Firms in International Trade: Trade Policy Implications of the New New Trade Theory

Abstract: This paper explores the implications of recent developments in firm-based trade theory and empirics for trade policy and negotiations. While traditional trade theory focused on the country, and the new trade theory of the 1980’s adopted the industry as the unit for analysis, the newest theory emphasizes the role of firms and firm heterogeneity in international trade. We describe insights from this reformulation of theory and the empirical literature that illuminates it. The realities of trade as now understood show the need for a new new trade policy. Evaluating trade at the level of the firm implies that overcoming firm-level fixed costs of trade and reducing uncertainty lead to increased trade along margins that generate the highest productivity, innovation, and welfare gains. The traditional market access agenda ought now to be less important on the multilateral agenda than services, standards, trade facilitation, procurement, and innovation policy. The analytical needs of a new new trade policy require new models and more access to firm-level data to formulate and evaluate the multi-faceted impacts of trade policy.