127 research outputs found
The Canadian Northwest in 1811: a study in the historical geography of the old northwest of the fur trade on the eve of the first agricultural settlement
The fur traders of 1811 saw the Northwest as three distinct
regions: New South Wales [Hudson Bay Lowlands], the Stony Region
[C'anadian Shield] and the Great [Interiorj Plains. To them, the
least important of these was New South Wales which was by then
functioning primarily as a base from which the Hudson's Bay Company
conducted its trade in the Northwest. It was relatively poor in
both furs and provisions. Except for migrating ducks and geese,
game was both scarce and unpredictable and the three factories
maintained there by the company were largely dependent upon provisions from Europe and pemmican from the interior.Apart from the forested margin along its western edge, particularly in the Lake Athabasca area, the Stony Region had always
been relatively poor in furs and provisions but, by 1811, it was
becoming so hunted out that it was coming to be regarded as more
of a barrier than as a productive region in itself - a barrier
which had to be crossed to reach the rich provision areas of the
grasslands and fur countries of the northern plains. Many of the
natives of this area, taking advantage of their geographical position, became "middlemen" and carried the furs and provisions of
wealthier countries across their homeland to trade on Hudson Bay.The broken rivers of the Stony Region added to its barrier-
like appearance.
navigable, river
and Mackenzie.
In sharp contrast were the three large, highly
systems of the Great Plains, the Red, Saskatchewan,
These not only enabled the traders to exploit the
furs and provisions of the Great Plains but also the fur lands
along the western margin of the Stony Region. Two important
routes enabled the traders to cross the Stony Region to enter the
rivers of the Great Plains. One led from Fort William to Lake
Winnipeg and the other from York Factory to Lake Winnipeg. Each
was approached from one of the two great waterways which led from
the Atlantic into the heart of North America, the Saint Lawrence - Great Lakes system and Hudson Strait and Bay. By 1811, each
entrance was controlled by a single fur monopoly, the Great Lakes
by the North West Company and Hudson Bay by the Hudson's Bay
Company. The latter route was the more economic and the North
West Company was then attempting to come to an agreement with the
Hudson's Bay Company in order to be able to use it as well.In the Northwest, itself, the two companies competed side by
side nearly everywhere in the Red and Saskatchewan countries and
in much of the Stony Region. In the Athabasca [ Mackenzi l basin
Country, however, the North West Company had so far succeeded in
excluding the Hudson's Bay Company from this, the richest fur area
in the whole Northwest. The Canadian Company also enjoyed a
monopoly in the area beyond the Rockies known as New Caledonia,
in which it was then extending its activities.Most of the important trading posts were situated near good
fisheries. Exceptions were the bayside factories and a number of
posts near the open plains where buffalo were plentiful. All
of the principal provision depots and goods stores in the interior
were established on lakes forming Part of the "Valley of the Lakes"
which separated the Stony Region from the Great Plains. These
were Rainy Lake House, Fort Bas- de -la- Riviere, Fort Cumberland,
Fort Ile -a -la- Crosse and Fort Chipewyan. In each case, the provisions were brought down stream to the depot with the minimum of
effort. Ducks and geese were also plentiful along these lakes
during the spring and autumn. The lakeside posts, in common with
most posts in the Northwest, were situated near the river junctions.
Other posts were usually placed near a sharp elbow in a river or
perhaps along its headwaters. In each of the latter cases, the
house would probably also be near a portage or an overland Pass.
Fierce competition between rival factions led to some fairly
irrational choices of location as well.Generally speaking, relations between the trading factions
were best where the Indians were most hostile and poorest where
the Indians were most friendly. That is, they were best on the
plains, where the Indians were not dependent upon the traders and
could afford to be reckless in their dealings with them, and poorest in the forest, where the inhabitants could no longer live
without the traders' goods. Along the periphery of the trade,
which in 1811 corresponded roughly with the borders of the Northwest, relations were poorest of all. For the natives along the
trade frontier were anxious that the trade should spread no further
geographically because they did not want the natives beyond them-
selves, who in nearly every case were enemies, to receive guns
and ammunition. Moreover, the peripheral tribes often carried
on a very lucrative trade in European goods with their more
distant enemy -neighbours, and realized that any extension of
the trade might destroy their position as middlemen. To the
traders, these middlemen were, at best, mere nuisances who added
little to the trade, and they were anxious to penetrate to the
Indians of the country beyond them. The peripheral tribes, of
course, tried to obstruct the progress of the traders and open
hostility was often the result.In order to carry on his trade and, indeed, merely to exist
in this harsh new land, the European had to borrow many skills and
techniques from the natives. From them, he learned how to use
the birch bark canoe and to make pemmican. It was these two
things which enabled him to develop his vast transportation system
which, more than anything else, permitted him to earn his living
in the Northwest. Canoe travel was expensive and only a luxury
product like furs could bear the high cost. By 1811, the Napoleonic wars had so depressed the fur markets, that little other
than beaver was then worth carrying.The wars had also been responsible for an increasingly serious
personnel shortage in the Hudson's Bay Company. This had contributed much to the company's ineffectiveness in dealing with
Canadian competition. The company had also been labouring under
the handicap of an overly riged organization. Nevertheless, in
1811, it faced the future with confidence. For not only had a
more flexible organization recently been adopted by there was
real hope that the chronic personnel shortage would soon he
solved. Lork Selkirk had just concluded an agreement with
the company to supply a large number of men each year in return
for a vast grant of land along the Red River for the purpose of
establishing an agricultural settlement. In the years to come,
it was hoped that the settlement would also provide a source of
recruits. The vanguard of the settlers were then wintering
along the Nelson above York Factory. During the next century,
hundreds of thousands would follow them. And they would change
the face of the Northwest. The bold checkered pattern of
agriculture would spread across much of the Great Plains, pushing
the traders northward and eastward into the Stony Region until
all that remained of the old Northwest which had been theirs,
was a pile of stones in some farmer's field near the meeting
place of two streams, or the fragile remains of a copper kettle
below a waterfall, marking the place where a canoe had capsized
and a voyageur's song had ended
Understanding the implications of a changing environment on harvested bivalve populations using habitat suitability models
Habitat suitability models are useful to forecast how environmental change may affect the abundance or distribution of species of interest. In the case of harvested bivalves, those models may be used to estimate the vulnerability of this valued ecosystem good to stressors. Using literature-derived natural history information, rule-based habitat suitability models were constructed in a GIS for several bivalve species (Clinocardium nuttallii, Mya arenaria, and Tresus capax) that are recreationally and commercially harvested in NE Pacific estuaries, including in the Salish Sea. Spatially-explicit habitat maps were produced for two Oregon estuaries using environmental data (salinity, depth, sediment grain size, and burrowing shrimp density) from multiple studies (1960-2012). Habitat suitability values ranged from 1-4 (lowest to highest) depending on the number of environmental variables that fell within a bivalve’s tolerance limits. The models were tested by comparing the observed distribution of bivalves reported in benthic community studies (1996-2012) to the range of each suitability class. Results primarily showed that habitats of highest predicted suitability contained the greatest proportion of bivalve observations and highest population densities. Our model was further supported by logistic regression analyses that showed correspondence between predicted habitat suitability values and logistic model probabilities. We demonstrate how these models can be used as tools to forecast changes in the availability of suitable habitat for these species using projected changes in salinity and depth associated with environmental change scenarios. The advantage of this approach is that disparate, independent sets of existing data are sufficient to parameterize the models, and to produce and validate maps of habitat suitability. We believe that these models are transferable across estuaries (such as in the Salish Sea) and bivalve species, and thus can be applied to data-poor systems with only modest investment
Stress-Energy Tensor for the Massless Spin 1/2 Field in Static Black Hole Spacetimes
The stress-energy tensor for the massless spin 1/2 field is numerically
computed outside and on the event horizons of both charged and uncharged static
non-rotating black holes, corresponding to the Schwarzschild,
Reissner-Nordstrom and extreme Reissner-Nordstr\"om solutions of Einstein's
equations. The field is assumed to be in a thermal state at the black hole
temperature. Comparison is made between the numerical results and previous
analytic approximations for the stress-energy tensor in these spacetimes. For
the Schwarzschild (charge zero) solution, it is shown that the stress-energy
differs even in sign from the analytic approximation. For the
Reissner-Nordstrom and extreme Reissner-Nordstrom solutions, divergences
predicted by the analytic approximations are shown not to exist.Comment: 5 pages, 4 figures, additional discussio
Mass transport phenomena between bubbles and dissolved gases in liquids under reduced gravity conditions
The experimental and analytical work that was done to establish justification and feasibility for a shuttle middeck experiment involving mass transfer between a gas bubble and a liquid is described. The experiment involves the observation and measurement of the dissolution of an isolated immobile gas bubble of specified size and composition in a thermostatted solvent liquid of known concentration in the reduced gravity environment of earth orbit. Methods to generate and deploy the bubble were successful both in normal gravity using mutually buoyant fluids and under reduced gravity conditions in the NASA Lear Jet. Initialization of the experiment with a bubble of a prescribed size and composition in a liquid of known concentration was accomplished using the concept of unstable equilibrium. Subsequent bubble dissolution or growth is obtained by a step increase or decrease in the liquid pressure. A numerical model was developed which simulates the bubble dynamics and can be used to determine molecular parameters by comparison with the experimental data. The primary objective of the experiment is the elimination of convective effects that occur in normal gravity
The Quantized Sigma Model Has No Continuum Limit in Four Dimensions. I. Theoretical Framework
The nonlinear sigma model for which the field takes its values in the coset
space is similar to quantum gravity in being
perturbatively nonrenormalizable and having a noncompact curved configuration
space. It is therefore a good model for testing nonperturbative methods that
may be useful in quantum gravity, especially methods based on lattice field
theory. In this paper we develop the theoretical framework necessary for
recognizing and studying a consistent nonperturbative quantum field theory of
the model. We describe the action, the geometry of the
configuration space, the conserved Noether currents, and the current algebra,
and we construct a version of the Ward-Slavnov identity that makes it easy to
switch from a given field to a nonlinearly related one. Renormalization of the
model is defined via the effective action and via current algebra. The two
definitions are shown to be equivalent. In a companion paper we develop a
lattice formulation of the theory that is particularly well suited to the sigma
model, and we report the results of Monte Carlo simulations of this lattice
model. These simulations indicate that as the lattice cutoff is removed the
theory becomes that of a pair of massless free fields. Because the geometry and
symmetries of these fields differ from those of the original model we conclude
that a continuum limit of the model which preserves
these properties does not exist.Comment: 25 pages, no figure
Mass loss by a scalar charge in an expanding universe
We study the phenomenon of mass loss by a scalar charge -- a point particle
that acts a source for a noninteracting scalar field -- in an expanding
universe. The charge is placed on comoving world lines of two cosmological
spacetimes: a de Sitter universe, and a spatially-flat, matter-dominated
universe. In both cases, we find that the particle's rest mass is not a
constant, but that it changes in response to the emission of monopole scalar
radiation by the particle. In de Sitter spacetime, the particle radiates all of
its mass within a finite proper time. In the matter-dominated cosmology, this
happens only if the charge of the particle is sufficiently large; for smaller
charges the particle first loses some of its mass, but then regains it all
eventually.Comment: 11 pages, RevTeX4, Accepted for Phys. Rev.
Retarded coordinates based at a world line, and the motion of a small black hole in an external universe
In the first part of this article I present a system of retarded coordinates
based at an arbitrary world line of an arbitrary curved spacetime. The
retarded-time coordinate labels forward light cones that are centered on the
world line, the radial coordinate is an affine parameter on the null generators
of these light cones, and the angular coordinates are constant on each of these
generators. The spacetime metric in the retarded coordinates is displayed as an
expansion in powers of the radial coordinate and expressed in terms of the
world line's acceleration vector and the spacetime's Riemann tensor evaluated
at the world line. The formalism is illustrated in two examples, the first
involving a comoving world line of a spatially-flat cosmology, the other
featuring an observer in circular motion in the Schwarzschild spacetime. The
main application of the formalism is presented in the second part of the
article, in which I consider the motion of a small black hole in an empty
external universe. I use the retarded coordinates to construct the metric of
the small black hole perturbed by the tidal field of the external universe, and
the metric of the external universe perturbed by the presence of the black
hole. Matching these metrics produces the MiSaTaQuWa equations of motion for
the small black hole.Comment: 20 pages, revtex4, 2 figure
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