Balsam Poplar (Populus balsamifera; Salicaceae) Beyond the Tree Line in the Western Canadian Mainland Arctic (Northwest Territories)

Balsam poplar is the northernmost tree species in North America, with a reported range that extends generally to the tree line across the continent and beyond the tree line in Alaska, where extralimital stands growing in Arctic ecosystems on the North Slope have been documented and studied. Here we summarize existing information and report new data on extralimital stands of balsam poplar from the Arctic ecozone in the northeastern mainland Northwest Territories. These occurrences extend the geographical and ecological range of the species fully into the mainland Canadian Arctic. In this region, balsam poplar is known from four sites: two in Tuktut Nogait National Park and two along the Hornaday and Brock rivers just beyond the northwestern Park boundary. Balsam poplar was first reported from two of these sites more than 50 years ago, but those data have not been considered in most subsequent floristic and ecological work. A balsam poplar grove in Tuktut Nogait National Park consists of four discrete stands of shrubby plants growing on a low ridge adjacent to the Hornaday River; their tallest ramets measure 1.1 – 1.86 m. A larger grove along the edge of the lower Brock River consists of three large stands, the tallest ramets measuring 3.5 – 4 m. The boreal and subarctic regions of the Northwest Territories and Nunavut have large areas where balsam poplar has not been documented by herbarium specimens, including most of the forest-tundra and tree-line zones. Collections from these areas and other potential extralimital sites in the Canadian Arctic are urgently needed to document the current distribution of balsam poplar. Such data could serve as a baseline for assessing potential future alteration of the range of this species as a result of climate change.Le peuplier baumier est l’espèce arborescente qui pousse le plus au nord de l’Amérique du Nord. Son aire d’extension s’étendrait généralement jusqu’à la limite forestière du continent et au-delà de la limite forestière de l’Alaska, où des peuplements extralimites qui croissent dans les écosystèmes arctiques ont été répertoriés et étudiés sur le versant nord. Nous résumons ici des données recueillies antérieurement et publions de nouvelles données sur les peuplements extralimites de peupliers baumiers de l’écozone arctique se situant dans la partie continentale nord-est des Territoires du Nord-Ouest. Ces occurrences ont pour effet d’étendre la portée géographique et écologique de l’espèce entièrement sur la partie continentale de l’Arctique canadien. Dans cette région, le peuplier baumier se retrouve dans quatre emplacements : deux d’entre eux se trouvent dans le parc national Tuktut Nogait et les deux autres, le long des rivières Hornaday et Brock, juste au-delà de la limite nord-ouest du parc. Le peuplier baumier a été signalé dans deux de ces emplacements il y a plus de 50 ans, mais ces données n’ont pas été considérées dans la plupart des études floristiques et écologiques subséquentes. Un bocage de peupliers baumiers du parc national Tuktut Nogait consiste en quatre peuplements discrets de végétation arbustive poussant sur une dorsale basse adjacente à la rivière Hornaday; les plus grands ramets y mesurent de 1,1 à 1,86 mètre. Un bocage plus volumineux le long du rivage de la rivière Brock inférieure est composé de trois gros peuplements, où les ramets les plus grands mesurent de 3,5 à 4 mètres. Les régions boréale et subarctique des Territoires du Nord-Ouest et du Nunavut sont dotées de grandes sections où le peuplier baumier n’a pas été répertorié dans les échantillons d’herbiers, ce qui comprend la plus grande partie de la toundra forestière et les zones de limite forestière. Il faudrait procéder promptement à la collecte d’échantillons de ces régions et d’autres emplacements extralimites potentiels de l’Arctique canadien afin de pouvoir consigner la répartition actuelle du peuplier baumier. De telles données pourraient servir de point de référence pour évaluer la modification éventuelle de l’aire d’extension de cette espèce, modification attribuable au changement climatique

Ideal Bose gas in fractal dimensions and superfluid 4^4He in porous media

Physical properties of ideal Bose gas with the fractal dimensionality between D=2 and D=3 are theoretically investigated. Calculation shows that the characteristic features of the specific heat and the superfluid density of ideal Bose gas in fractal dimensions are strikingly similar to those of superfluid Helium-4 in porous media. This result indicates that the geometrical factor is dominant over mutual interactions in determining physical properties of Helium-4 in porous media.Comment: 13 pages, 6 figure

Quantum sticking, scattering and transmission of 4He atoms from superfluid 4He surfaces

We develop a microscopic theory of the scattering, transmission, and sticking of 4He atoms impinging on a superfluid 4He slab at near normal incidence, and inelastic neutron scattering from the slab. The theory includes coupling between different modes and allows for inelastic processes. We find a number of essential aspects that must be observed in a physically meaningful and reliable theory of atom transmission and scattering; all are connected with multiparticle scattering, particularly the possibility of energy loss. These processes are (a) the coupling to low-lying (surface) excitations (ripplons/third sound) which is manifested in a finite imaginary part of the self energy, and (b) the reduction of the strength of the excitation in the maxon/roton region

Stability of vortex lines in liquid 3He-4He mixtures at zero temperature

At low temperatures and 3He concentrations below 6.6 %, there is experimental evidence about the existence in liquid helium mixtures, of stable vortices with 3He-rich cores. When the system is either supersaturated or submitted to a tensile strength, vortices lose stability becoming metastable and eventually completely unstable, so that their cores freely expand. Within a density functional approach, we have determined the pressure-3He concentration curve along which this instability appears at zero temperature.Comment: Typeset using Revtex, 9 pages and 5 Postscript figure

Corporations—Restrictions on Alienation of Stock—When Valid

The validity of a charter provision giving the directors of a corporation the unrestricted power to purchase, retire, or cancel common stock at will was challenged by a newly retired employee whose stock had been called by the company. Held: the provision was not invalid per se and would support a call of common shares if not exercised arbitrarily. Plaintiff’s refusal to comply with the corporate decree was based upon his contention that the broad power of the call provision created an unreasonable “restraint on alienation.” However, plaintiff had been an officer and director of the corporation for over 25 years, and had voted for the adoption of the challenged provision. He knew that the purpose of the provision was to keep all stock in the hands of active officers and directors and that it had been an invariable practice for retiring officers and directors to sell their stock either to other shareholders or to the corporation. While the decision is thus justified by the facts, it may appear to sanction an arbitrary call power much broader than is required to achieve the end which motivated it, i.e., keeping all stock in the hands of active officers and directors

Design Arts (1994-1995): Correspondence 01

<p>Pinguicula vulgaris. Saarela, Gillespie, Sokoloff & Bull 2565 (CAN 601975)</p

Constitutional Law—Due Process—Right to Counsel in State Felony Proceedings

Petitioner, under a life sentence imposed by a state court, brought a writ of habeas corpus alleging violation of the Due Process Clause of the Fourteenth Amendment to the United States Constitution in that while he was of unsound mind and unassisted by counsel, he was tried and convicted of a charge carrying a mandatory life sentence. The lower court dismissed the writ without a hearing. Held: reversed, a hearing on the issue of insanity was required. If the allegations were true, the failure to assign counsel violated the Fourteenth Amendment since a trial which left the defense to a man who was insane and who by reason of his mental condition was unable to raise the insanity issue was unfair. The accused in a federal felony proceeding is assured the right to counsel under the Sixth Amendment. In state felony proceedings, however, the Sixth Amendment is held inapplicable; instead the Due Process Clause of the Fourteenth Amendment controls. In interpreting the Due Process Clause, the Supreme Court has required counsel only where the absence of counsel was prejudicial to fundamental rights of the accused. In an attempt to define this vague standard, the nine members of the Court have frequently disagreed on what constitutes a prejudicial situation. The majority, following a case-by-case method of definition, has established certain categories of situations which are considered prejudicial if counsel is absent, e.g., where there is (1) a young and inexperienced defendant; (2) a mentally deficient defendant; (3) a possibility of a death sentence; (4) a defendant who is a stranger to our language and our courts; (5) deception by the prosecution; (6) a biased or careless judge; or (7) complexity of issues. A minority of the Court has constantly argued that the lack of counsel in any felony proceeding is prejudicial to the fundamental rights of the accused. The instant case adheres to the majority’s rationale and establishes yet another situation in which the lack of counsel creates a potential danger to the fundamental rights of the accused; viz, the possibility of an insane defendant

Arts and Humanities: Budget (1974-1976): Report 07

<p>Leymus innovatus subsp. velutinus. Kuc 405 (CAN 432023)</p