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Western Canada (western + canada)
Selected AbstractsRemittance Patterns of Southern Sudanese Refugee Men: Enacting the Global Breadwinner Role,FAMILY RELATIONS, Issue 4 2008Phyllis J. Johnson Abstract: Questionnaire data from 172 Sudanese refugee men in Western Canada revealed that most of the men were sending money (i.e., remittances) to family in Africa, although doing so created considerable financial and emotional strain. Those who experienced greater emotional strain had more social support and spent a smaller proportion of their income on remittances. Those who experienced greater financial strain had less support, were in Canada a shorter time, and had higher (over $20,000) compared to lower income (less than $20,000). Understanding the continuing financial obligations of global breadwinners, who are providing financially for relatives elsewhere, is critical content for social service programs that serve refugee and immigrant newcomers. [source] The Challenges and Successes of Developing a Literacy Community in a Minority Language in Western Canada: An Action Research StudyFOREIGN LANGUAGE ANNALS, Issue 3 2002Olenka S. E. Bilash ABSTRACT: This article describes a community action research study in the spirit of Carr and Kemmis (1983) and Elliot (1991). Language leaders in the Ukrainian community undertook a complex literacy initiative to investigate and improve Ukrainian-English bilingualism/biliteracy in Western Canada and throughout the diaspora. In the context of the long-term absence of research funding for developing and maintaining literacy in nonmajority or nonofficial languages, this article documents project activities over several years, presents the findings of student/teacher needs assessments, shares the approach to reading preferred by participating teachers, and reveals some of the transformations teachers experienced in their own thinking about bilingualism and biliteracy as a result of their involvement in this initiative. [source] Lateral plate asymmetry, diet and parasitism in threespine sticklebackJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2001T. E. Reimchen Individuals with random left,right departures from bilateral symmetry are predicted to exhibit fitness reduction including increased parasitism. In an insular lake population of stickleback (Gasterosteus aculeatus) from the Queen Charlotte Islands, Western Canada, phenotypes with high or low number of lateral bony plates exhibited increased plate asymmetry relative to modal phenotypes. Asymmetric lateral plate phenotypes had increased prevalence and to a lesser extent intensity of parasitism relative to symmetric individuals, suggesting that differences in genetic resistance to pathogens contributed to unequal parasitism. The effect occurred mainly in the larger adults and during the warmest season, which may be due to the high metabolic costs incurred during the summer breeding season. Dietary differences between symmetric and asymmetric phenotypes were also detected and could contribute to unequal infection rates by mediating exposure to infected prey items. Our study, which is one of the first long-term field assessments of asymmetry and parasitism, yields results that are consistent with studies linking asymmetry to reduced fitness and indicate that lateral plate asymmetry can be an indicator of poor individual quality, despite its apparent directionality. [source] The geographies of crisis: exploring accessibility to health care in CanadaTHE CANADIAN GEOGRAPHER/LE GEOGRAPHE CANADIEN, Issue 3 2002KATHLEEN WILSON There is increasing concern in Canada that the health care system is in a state of crisis. It is argued that reductions in federal government transfers to the provinces have resulted in a health care system characterized by under-funding in key areas and policy decisions based more on provincial fiscal concerns than the health needs of their constituents. Provincial governments have responded to reduced levels in federal funding by undertaking aggressive restructuring tactics such as the closure of hospitals and the deinsuring of medical services from provincial health plans. The end result of this restructuring, as argued by the media, consumer groups and indeed some health researchers, is a state of crisis' (i.e., lower levels of accessibility, long waiting lists, overcrowding in hospitals and increasing costs of medication). One crisis theme often mentioned is that fiscal decisions of various kinds are reducing economic and geographic accessibility, one of the five principles of the Canada Health Act (CHA) that defines the very essence of the Canadian health care system. Using data from the 1998-99 National Population Health Survey (NPHS), this paper explores the extent to which an accessibility crisis exists within the Canadian health care system by examining access to health care services and the barriers encountered in trying to access services in each of the ten provinces. The results show that approximately 6.0 percent of Canadians report access problems, with values ranging from 4.5 percent in Newfoundland to 8.3 percent in Manitoba. Regional variations in barriers to accessing care were also observed. In particular, geographic accessibility appears to be a main barrier to care in Atlantic Canada while economic accessibility emerges as a main barrier to care in Western Canada. We discuss these findings in the context of the current debates on the Canadian health care system ,crisis'. De plus en plus de Canadiens s'inquiétent que leur systéme de soins de santé soit en état de crise. On défend l'idée selon laquelle la réduction des paiements de transfert aux provinces par le gouvernement fédéral serait responsable de l'état d'un systeme de santé caractérisé par un sous-financement dans les domaines-clés et des décisions politiques de santé basées, non pas sur les besoins des membres de la société canadienne, mais sur la fiscalité provinciale. Les gouvernements provinciaux ont réagi à la réduction du financement fédéral par une tactique de restructuration agressive (fermeture d'hôpitaux et retrait de services médicaux des programmes d'assurance de santé provinciaux). Selon les médias, les groupes de consommateurs et même les chercheurs en soins de santé, cette restructuration a eu pour effet un système en état de ,crise' (diminution de l'aecès aux services, longues fetes d'attente, hôpitaux surchargés, augmentation des coûts des médicaments etc). Un des thèmes récurrent est celui des décisions flscales de toutes sortes qui entraînent une baisse de l'accessibilité financière et géographique. Cette accessibilité est pourtant un des cinq principes de la Loi canadienne sur la santé définissant l'essence même du système de santé au Canada. Utilisant les données tirèes de l'Enquête nationale sur la santé de la population, 1998-99 et examinant l'accès aux services de santé et les obstacles rencontrés dans les 10 provinces canadiennes, cet article évalue dans quelle mesure une crise d'accessibilité existe au sein du système de santé canadien. Les résultats démontrent qu'environ 6.0 pour cent des Canadiens ont rencontré des problèmes d'accessibilité, avec des variantes allant de 4.5 pour cent à Terre-Neuve jusqu'à 8.3 pour cent au Manitoba. On observe aussi des variantes régionales dans les obstacles rencontrés. L'accessibilité géographique en particulier semble un obstacle mqjeur dans les régions de l'Atlantique, alors que l'accessibilite financière semble être un obstacle majeur dans l'Ouest du Canada. Ces résultats sont présentés dans le contexte des débats actuels sur l'existence dune, ,crise' dans le système de santé au Canada. [source] Bitumen content estimation of Athabasca oil sand from broad band infrared reflectance spectraTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2010B. Rivard Abstract Oil sand is a mixture of quartz grains, clay minerals, bitumen, water, and minor accessory minerals. There is a need in oil sands mining operations for a robust method to estimate total bitumen content in real time; and so modelling of the total bitumen content (TBC) in Athabasca oil sands of Western Canada was undertaken on the basis of hyperspectral reflectance spectra. A selection of different bitumen, water, and clay mineral spectral features (3.0,30.0,µm) was used to develop broad-band TBC predictive models that have good accuracy, with less than 1.5% error with respect to laboratory methods of bitumen assay. These models are also robust, in that they are independent of mine location. Simple broad band models, based upon previously identified Gaussian features or wavelet features, provide an incremental improvement over the currently deployed industry two-band ratio model. An improved two-band model was also developed, which makes use of a combination of the same two bands but normalised to their mean. A wavelet-based, broad-band model comprised of indices and five bands, where the bands are normalised to the mean of the bands, adequately addresses the influence of water, clay, and textural variation on selected bitumen features. This five-band model appears to produce the most robust estimator of TBC, with a dispersion of ,1.1,1.5%, which can be applied to different sites within a mine and to different mines without additional tuning or calibration, as evidenced by regression slopes of 0.99,1.0 for modelling, validation, and blind data sets. [source] Intensive Hog Farming in Manitoba: Transnational Treadmills and Local Conflicts,CANADIAN REVIEW OF SOCIOLOGY/REVUE CANADIENNE DE SOCIOLOGIE, Issue 1 2003JOEL NOVEK L'exploitation intensive des porcheries a connu un essor rapide dans L'Ouest canadien. La croissance de L'agriculture industrielle porcine manitobaine est analysée comme une étude de cas d'un «tapis roulant de production transnational». La production et les exportation ont augmenté de façon considérable alors que L'industrie est devenue plus concentrée; mais des coûts environnementaux, entre autres des préoccupations quant aux odeurs et à la qualité de L'eau, sont devenus plus visibles. Les gouvernements provinciaux ont encouragé, par des politiques néolibérales, L'expansion de cette Industrie et ont hésitéà imposer des exigences réglementaires. Le processus d'approbation des porcheries a été en grande partie ramené au niveau des municipalités rurales. Il reste que cela s'est traduit en une controverse politique acharnée dans plusieurs collectivités locales, ce qui a forcé le gouvernement du Manitoba àétudier une réglementation plus rigoureuse dans ce secteur d'activité. Intensive hog operations have grown at a rapid rate in Western Canada. The growth of factory hog farming in Manitoba is analysed as a case study of a "transnational treadmill of production." Output and exports have increased dramatically and the industry has become more concentrated, but negative environmental externalities, notably odour and water-quality concerns, have become more visible.Provincial governments have promoted the expansion of this industry through neo-liberal policies and have been reluctant to impose regulatory restrictions. The hog barn approval process has been largely downloaded to the rural municipal level. However, this has resulted in fierce political controversy in many local communities, which has forced the Manitoba government to consider more active regulation of hog factory farms. [source] Concentrations of organochlorine pesticides and polychlorinated biphenyls in amphipods (Gammarus lacustris) along an elevation gradient in mountain lakes of western CanadaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2003Jules M. Blais Abstract Populations of the amphipod Gammarus lacustris were examined for their concentrations of organochlorine pesticides and polychlorinated biphenyls (PCBs) from seven lakes spanning a 1,300-m elevation gradient in Alberta, Canada. The concentrations of several of the semivolatile organochlorine compounds ([SVOCs], vapor pressure > 0.03 Pa at 20°C) increased at higher altitudes. This pattern was generally not observed among the less volatile organochlorines ([LVOCs], vapor pressure < 0.03 Pa at 20°C). These same SVOC compounds have been previously shown to increase at high latitudes as a result of their long-range transport and preferential deposition in cold climates. We also show that populations of G. lacustris at high elevations have slower growth rates and store more lipids than populations at lower elevations. To resolve the colinearity of independent variables, we used multiple regression to identify patterns of contaminant concentrations in this data set. Multiple regressions showed that the effect of elevation, lipid content, and temperature on contaminant concentrations was no longer significant once the growth rate of Gammarus was included as an independent variable. This study shows that enrichment of SVOCs occurs in Gammarus at high altitudes in Alberta, Canada, and that growth rate (biodilution) appears to be the primary influence. Because Gammarus is an important trophic link in aquatic foodwebs in these environments, enhanced concentrations of toxicants in prey may increase their biomagnification in top predators of high-altitude lakes. [source] Changes in Canadian heroin supply coinciding with the Australian heroin shortageADDICTION, Issue 5 2006Evan Wood ABSTRACT Aims Previous studies have largely attributed the Australian heroin shortage to increases in local law enforcement efforts. Because western Canada receives heroin from similar source nations, but has not measurably increased enforcement practices or funding levels, we sought to examine trends in Canadian heroin-related indices before and after the Australian heroin shortage, which began in approximately January 2001. Methods During periods before and after January 2001, we examined the number of fatal overdoses and ambulance responses to heroin-related overdoses that required the use of naloxone in British Columbia, Canada. As an overall marker of Canadian supply reduction, we also examined the quantity of heroin seized during this period. Lastly, we examined trends in daily heroin use among injection drug users enrolled in the Vancouver Injection Drug Users Study (VIDUS). Results There was a 35% reduction in overdose deaths, from an annual average of 297 deaths during the years 1998,2000 in comparison to an average of 192 deaths during 2001,03. Similarly, use of naloxone declined 45% in the period coinciding with the Australian heroin shortage. Interestingly, the weight of Canadian heroin seized declined 64% coinciding with the Australian heroin shortage, from an average of 184 kg during 1998,2000 to 67 kg on average during 2001,03. Among 1587 VIDUS participants, the period coinciding with the Australian heroin shortage was associated independently with reduced daily injection of heroin [adjusted odds ratio: 0.55 (95% CI: 0.50,0.61); P < 0.001]. Conclusions Massive decreases in three independent markers of heroin use have been observed in western Canada coinciding with the Australian heroin shortage, despite no increases in funding to Canadian enforcement efforts. Markedly reduced Canadian seizure activity also coincided with the Australian heroin shortage. These findings suggest that external global heroin supply forces deserve greater investigation and credence as a potential explanation for the Australian heroin shortage. [source] Blister rust and western forest biodiversity: ecology, values and outlook for white pinesFOREST PATHOLOGY, Issue 3-4 2010D. F. Tomback Summary Eight white pine species are widely distributed among the forests of western Canada and the United States. The different forest communities with these species contribute biodiversity to the western landscape. The trees themselves provide various ecosystem services, including wildlife habitat and watershed protection. White pine communities range in elevation from lower to upper treeline, in successional stage from seral to climax, and in stand type from krummholz to closed-canopy forest. Many white pine species are moderately to strongly fire-dependent for regeneration; several species are extreme stress tolerators and persistent on harsh sites. Among the white pines are the oldest-living trees, the world's largest pines, species dependent on birds for seed dispersal, species important for grizzly bear habitat and species of high commercial timber value. The principal threats to white pine populations are blister rust (Cronartium ribicola, pathogen), fire suppression, succession, mountain pine beetle and climate change. Severe population declines in several white pine species are attributed to losses caused by these factors acting either alone or together, and sometimes in concert with logging and other land-use changes. The importance and particular interactions of these threats vary by region and species. For example, many northern and western populations of whitebark pine are seriously declining from a combination of mountain pine beetle outbreaks and severe blister rust infestations. As whitebark pines provide many keystone services on high-elevation sites, their loss would impact forest composition and structure, succession, biodiversity, and ecosystem services. Although there are serious challenges to science-based management and conservation (especially in remote American wilderness areas), prompt and effective intervention promoting regeneration of blister rust-resistant white pines could mitigate these severe impacts. [source] Beyond ,Gender Differences': A Canadian Study of Women's and Men's Careers in EngineeringGENDER, WORK & ORGANISATION, Issue 1 2003Gillian Ranson This article explores the relationship between gender and career paths for a group of women and men who graduated as engineers during a period of labour market turbulence in western Canada during the 1980s. Using a model adapted from Brown (1982), the article uses ,career path' as a device to organize data drawn primarily from telephone and face-to-face interviews with 317 graduates. Three career paths provide the focus for the study: the ,organizational', characterized by stable employment with one employer; the ,occupational', characterized by mobility between employers; and the entrepreneurial, characterized by self-employment. The use of the career path framework moves the study beyond global comparisons (of the dichotomized ,gender differences' kind) between ,the women' and ,the men'. As well as allowing for comparison between the paths, it allows more refined and contextualized comparisons within each path. Such comparisons produce patterns of similarity and difference that sometimes transcend gender. [source] Diurnal and seasonal variation in methane emissions in a northern Canadian peatland measured by eddy covarianceGLOBAL CHANGE BIOLOGY, Issue 9 2010KEVIN D. LONG Abstract Eddy covariance measurements of methane (CH4) net flux were made in a boreal fen, typical of the most abundant peatlands in western Canada during May,September 2007. The objectives of this study were to determine: (i) the magnitude of diurnal and seasonal variation in CH4 net flux, (ii) the relationship between the temporally varying flux rates and associated changes in controlling biotic and abiotic factors, and (iii) the contribution of CH4 emission to the ecosystem growing season carbon budget. There was significant diurnal variation in CH4 emission during the peak of the growing season that was strongly correlated with associated changes in solar radiation, latent heat flux, air temperature and ecosystem conductance to water vapor. During days 181,215, nighttime average CH4 efflux was only 47% of the average midday values. The peak value for daily average CH4 emission rate was approximately 80 nmol m,2 s,1 (4.6 mg CH4 m,2 h,1), and seasonal variation in CH4 flux was strongly correlated with changes in soil temperature. Integrated over the entire measurement period [days 144,269 (late May,late September)], the total CH4 emission was 3.2 g CH4 m,2, which was quite low relative to other wetland ecosystems and to the simultaneous high rate of ecosystem net CO2 sequestration that was measured (18.1 mol CO2 m,2 or 217 g C m,2). We estimate that the negative radiative forcing (cooling) associated with net carbon storage over the life of the peatland (approximately 2200 years) was at least twice the value of positive radiative forcing (warming) caused by net CH4 emission over the last 50 years. [source] Peat carbon stocks in the southern Mackenzie River Basin: uncertainties revealed in a high-resolution case studyGLOBAL CHANGE BIOLOGY, Issue 6 2008DAVID W. BEILMAN Abstract The organic carbon (C) stocks contained in peat were estimated for a wetland-rich boreal region of the Mackenzie River Basin, Canada, using high-resolution wetland map data, available peat C characteristic and peat depth datasets, and geostatistics. Peatlands cover 32% of the 25 119 km2 study area, and consist mainly of surface- and/or groundwater-fed treed peatlands. The thickness of peat deposits measured at 203 sites was 2.5 m on average but as deep as 6 m, and highly variable between sites. Peat depths showed little relationship with terrain data within 1 and 5 km, but were spatially autocorrelated, and were generalized using ordinary kriging. Polygon-scale calculations and Monte Carlo simulations yielded a total peat C stock of 982,1025 × 1012 g C that varied in C mass per unit area between 53 and 165 kg m,2. This geostatistical approach showed as much as 10% more peat C than calculations using mean depths. We compared this estimate with an overlapping 7868 km2 portion of an independent peat C stock estimate for western Canada, which revealed similar values for total peatland area, total C stock, and total peat C mass per unit area. However, agreement was poor within ,875 km2 grids owing to inconsistencies in peatland cover and little relationship in peat depth between estimates. The greatest disagreement in mean peat C mass per unit area occurred in grids with the largest peatland cover, owing to the spatial coincidence of large cover and deep peat in our high-resolution assessment. We conclude that total peat C stock estimates in the southern Mackenzie Basin and perhaps in boreal western Canada are likely of reasonable accuracy. However, owing to uncertainties particularly in peat depth, the quality of information regarding the location of these large stocks at scales as wide as several hundreds of square kilometers is presently much more limited. [source] Trends in timing of low stream flows in Canada: impact of autocorrelation and long-term persistenceHYDROLOGICAL PROCESSES, Issue 8 2010Eghbal Ehsanzadeh Abstract The annual timing of river flows might indicate changes that are climate related. In this study, trends in timing of low flows for the Reference Hydrometric Basin Network were investigated under three different hypotheses namely: independence, short-term persistence (STP) and long-term persistence (LTP). Both summer and winter time series were characterized with scaling behaviour providing strong evidence of LTP. The Mann,Kendall trend test was modified to account for STP and LTP, and used to detect trends in timing of low flows. It was found that considering STP and LTP resulted in a significant decrease in the number of detected trends. Numerical analysis showed that the timing of summer 7-day low flows exhibited significant trends in 16, 9 and 7% of stations under independence, STP and LTP assumptions, respectively. Timing of summer low flow shifted toward later dates in western Canada, whereas the majority of stations in the east half of the country (except Atlantic Provinces) experienced a shift toward earlier dates. Timing of winter low flow experienced significant trends in 20, 12, and 6% of stations under independence, STP and LTP assumptions, respectively. Shift in timing of winter low flow toward earlier dates was dominant all over the country where it shifted toward earlier dates in up to 3/4 of time series with significant trends. There are local patterns of upward significant/insignificant trends in southeast, southwest and northern Canada. This study shows that timing of low flows in Canada is time dependent; however, addressing the full complexity of memory properties (i.e. short term vs long term) of a natural process is beyond the scope of this study. Copyright © 2009 John Wiley & Sons, Ltd. [source] Modelling blowing snow redistribution to prairie wetlandsHYDROLOGICAL PROCESSES, Issue 18 2009X. Fang Abstract Blowing snow transports and sublimates a substantial portion of the seasonal snowfall in the prairies of western Canada. Snow redistribution is an important feature of prairie hydrology as deep snowdrifts provide a source of meltwater to replenish ponds and generate streamflow in this dry region. The spatial distribution of snow water equivalent in the spring is therefore of great interest. A test of the distributed and aggregated modelling strategies for blowing snow transport and sublimation was conducted at the St. Denis National Wildlife Area in the rolling, internally drained prairie pothole region east of Saskatoon, Saskatchewan, Canada. A LiDAR-based DEM and aerial photograph-based vegetation cover map were available for this region. A coupled complex windflow and blowing snow model was run with 262,144 6 m × 6 m grid cells to produce spatially distributed estimates of seasonal blowing snow transport and sublimation. The calculation was then aggregated to seven landscape units that represented the major influences of surface roughness, topography and fetch on blowing snow transport and sublimation. Both the distributed and aggregated simulations predicted similar end-of-winter snow water equivalent with substantial redistribution of blowing snow from exposed sparsely vegetated sites across topographic drainage divides to the densely vegetated pothole wetlands. Both simulations also agreed well with snow survey observations. While the distributed calculations provide a fascinating and detailed visual image of the interaction of complex landscapes and blowing snow redistribution and sublimation, it is clear that blowing snow transport and sublimation calculations can be successfully aggregated to the spatial scale of the major landscape units in this environment. This means that meso and macroscale hydrological models can represent blowing snow redistribution successfully in the prairies. Copyright © 2009 John Wiley & Sons, Ltd. [source] A conceptual selenium management modelINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 3 2009Peter M Chapman Abstract We describe herein a conceptual selenium (Se) management model, directed toward coal mining in western Canada, but which can be applied to other coal mines and, with appropriate modification, to other industrial sources of Se to aquatic and terrestrial environments. This conceptual model provides a transparent means to integrate and synthesize existing information that can be used to provide an adaptive approach for managing ecological exposures and associated risk. It is particularly useful for visualizing and subsequently developing management interventions for Se control and risk reduction. The model provides a structured process by which critical information needs can be identified and addressed. It effectively provides the foundation for making management decisions related to Se discharges to aquatic and terrestrial environments by showing interrelationships of the various media and receptors as well as primary sources, release mechanisms, secondary sources, and exposure pathways. [source] Climate change and range expansion of an aggressive bark beetle: evidence of higher beetle reproduction in naïve host tree populationsJOURNAL OF APPLIED ECOLOGY, Issue 5 2010Timothy J. Cudmore Summary 1.,Hosts may evolve defences that make them less susceptible and suitable to herbivores impacting their fitness. Due to climate change-driven range expansion, herbivores are encountering naïve host populations with increasing frequency. 2.,Aggressive bark beetles are among the most important agents of disturbance in coniferous forest ecosystems. The presence of bark beetle outbreaks in areas with a historically unsuitable climate, in part a consequence of climate change, provided an opportunity to assess the hypothesis that the mountain pine beetle Dendroctonus ponderosae has higher reproductive success in lodgepole pine Pinus contorta trees growing in areas that have not previously experienced frequent outbreaks. 3.,We felled and sampled mountain pine beetle-killed trees from historically climatically suitable and unsuitable areas, i.e. areas with and without a historical probability of frequent outbreaks. Reproductive success was determined from a total of 166 trees from 14 stands. 4.,Brood productivity was significantly affected by climatic suitability class, such that mean brood production per female increased as historical climatic suitability decreased. 5.,Synthesis and applications. The current study demonstrates that the mountain pine beetle has higher reproductive success in areas where its host trees have not experienced frequent beetle epidemics, which includes much of the current outbreak area in north central British Columbia. This increased productivity of mountain pine beetle is likely to have been a key reason for the rapid population buildup that resulted in unprecedented host tree mortality over huge areas in western Canada. The outbreak thus provides an example of how climate change-driven range expansion of native forest insects can have potentially disastrous consequences. Since an increased reproductive success is likely to accelerate the progression of outbreaks, it is particularly critical to manage forests for the maintenance of a mosaic of species and age classes at the landscape level in areas where host tree populations are naïve to eruptive herbivores. [source] Patterns of density, diversity, and the distribution of migratory strategies in the Russian boreal forest avifaunaJOURNAL OF BIOGEOGRAPHY, Issue 11 2008Russell Greenberg Abstract Aim, Comparisons of the biotas in the Palaearctic and Nearctic have focused on limited portions of the two regions. The purpose of this study was to assess the geographic pattern in the abundance, species richness, and importance of different migration patterns of the boreal forest avifauna of Eurasia from Europe to East Asia as well as their relationship to climate and forest productivity. We further examine data from two widely separated sites in the New World to see how these conform to the patterns found in the Eurasian system. Location, Boreal forest sites in Russia and Canada. Methods, Point counts were conducted in two to four boreal forest habitats at each of 14 sites in the Russian boreal forest from near to the Finnish border to the Far East, as well as at two sites in boreal Canada. We examined the abundance and species richness of all birds, and specific migratory classes, against four gradients (climate, primary productivity, latitude, and longitude). We tested for spatial autocorrelation in both dependent and independent variables using Moran's I to develop spatial correlograms. For each migratory class we used maximum likelihood to fit models, first assuming uncorrelated residuals and then assuming spatially autocorrelated residuals. For models assuming unstructured residuals we again generated correlograms on model residuals to determine whether model fitting removed spatial autocorrelation. Models were compared using Akaike's information criterion, adjusted for small sample size. Results, Overall abundance was highest at the eastern and western extremes of the survey region and lowest at the continent centre, whereas the abundance of tropical and short-distance migrants displayed an east,west gradient, with tropical migrants increasing in abundance in the east (and south), and short-distance migrants in the west. Although overall species richness showed no geographic pattern, richness within migratory classes showed patterns weaker than, but similar to, their abundance patterns described above. Overall abundance was correlated with climate variables that relate to continentality. The abundances of birds within different migration strategies were correlated with a second climatic gradient , increasing precipitation from west to east. Models using descriptors of location generally had greater explanatory value for the abundance and species-richness response variables than did those based on climate data and the normalized difference vegetation index (NDVI). Main conclusions, The distribution patterns for migrant types were related to both climatic and locational variables, and thus the patterns could be explained by either climatic regime or the accessibility of winter habitats, both historically and currently. Non-boreal wintering habitat is more accessible from both the western and eastern ends than from the centre of the boreal forest belt, but the tropics are most accessible from the eastern end of the Palaearctic boreal zone, in terms of distance and the absence of geographical barriers. Based on comparisons with Canadian sites, we recommend that future comparative studies between Palaearctic and Nearctic faunas be focused more on Siberia and the Russian Far East, as well as on central and western Canada. [source] Late-glacial and Holocene palaeovegetation zonal reconstruction for central and north-central North AmericaJOURNAL OF BIOGEOGRAPHY, Issue 6 2005W. L Strong Abstract Aim, The purpose of this study is to develop palaeovegetation zonation models for central and north-central North America, based on late-Quaternary and Holocene pollen stratigraphic data (n = 246 sites). A secondary purpose was to evaluate an hypothesis (Strong & Hills, 2003) to explain the disjunct distribution of species in western Alberta. Location, Hudson Bay-Lake Michigan to the Rocky Mountains region, north of 36° N to the Arctic Ocean (c. 70° N). Methods, Pollen profiles spanning 40 years of palaeoecological research in North America were extracted from published and unpublished archival sources. Individual profiles were subdivided into 1000-year increments based on the assumption of a constant sedimentation rate between stratigraphic dates (e.g. surface sediments, radiocarbon 14C dates, tephra layers). The pollen composition among profiles was standardized to 54 commonly recognized taxa, with percentage composition within each stratigraphic sample prorated to 100% prior to analysis. Near-surface sediments from these profiles were included as analogues of modern vegetation. Cluster analysis was used as a guide to the classification of 2356 temporal stratigraphic samples, which resulted in the recognition of 16 pollen groups. These groups were summarized in terms of their pollen composition, mapped, and used in combination with terrain information and an ecological knowledge of the study area to construct six physiognomically-based palaeovegetation zonation models at 2000-year intervals from 14,000 to 4000 yr bp (radiocarbon years before present). Results, The 14,000 yr bp model placed Boreal and Cordilleran Forests proximal to the southern glacial front, whereas Arctic tundra dominated the Yukon Territory,Alaska ice-free zone. Pollen and macrofossil evidence suggests that this Boreal Forest zone contained a mixture of coniferous and deciduous tree species. Grassland was postulated immediately south of the forest zone, with its northern extreme near 49° N latitude in the Alberta,Montana border area. Separation of the Laurentide and Cordilleran glacial fronts about 12,000 yr bp initiated the northward advance of Boreal Forests into western Canada. By the end of the Hypsithermal at about 6000 yr bp, Boreal Forests occurred near the Arctic Ocean, and Grassland and Aspen Parkland zones may have extended to 54° N and 59° N latitude in Alberta, respectively. Between 6000 and 4000 yr bp, a 5° and 1° latitudinal southward shift of the northern Boreal Forest and Grassland/Aspen Parkland boundaries occurred, respectively, near their contemporary positions with corresponding expansions of the Subarctic and Arctic zones. Modern Canadian Cordilleran Forests along the eastern slopes of the Rocky Mountains were interpreted as originating from the north-central Montana,south-western Alberta area. Jack pine (Pinus banksiana Lamb.), a common Boreal Forest species, appears to have entered central Canada via the north side of Lake Superior after 11,000 yr bp. Main conclusions, Modern vegetation in central Canada evolved from biomes located in the northern USA during the late-Quaternary. The Boreal Forest biome contained the same arboreal taxa as the modern vegetation, except it lacked jack pine. The proposed regional palaeovegetation models support the hypothesis of Strong & Hills (2003), but new independent palaeoecological data will be needed for a proper evaluation. [source] Post-Hypsithermal plant disjunctions in western Alberta, CanadaJOURNAL OF BIOGEOGRAPHY, Issue 3 2003W. L Strong Abstract Aim, Evaluate the hypothesis that nine disjunct vascular plant species along the eastern slopes of the Rocky Mountains and in the Peace River District of west-central Alberta represent remnants of more southerly vegetation that occupied these areas during the Holocene Hypsithermal (9000,6000 yr bp). Alternatively, these plants represent populations that became established because of independent chance dispersal events. Location, This study focuses on the area east of the Rocky Mountain Continental Divide in the Province of Alberta and the State of Montana in western Canada and USA, respectively. Methods, Disjunct species were identified and their distributions mapped based on a review of occurrence maps and records, botanical floras and checklists, herbaria specimens, ecological and botanical studies, and field surveys of selected species. A disjunct species was defined as a plant population separated from its next nearest occurrence by a distance of > 300 km. Evaluation of the hypothesis was based on a review of published and unpublished pollen stratigraphy and palaeoecological studies. The potential geographical distribution of Hypsithermal vegetation was based on modern regional-based ecosystem mapping and associated monthly temperature summaries as well as future climatic warming models. Results, The hypothesis was compatible with Holocene pollen stratigraphy, Hypsithermal permafrost and fen occurrence, and palaeosol phytolith analyses; and future global climatic warming models. Modelled regional Hypsithermal vegetation based on a 1 °C increase in July temperatures relative to current conditions, indicated that much of the boreal forest zone in Alberta could have been grassland, which would explain the occurrence of Prairie species in the Peace River District. This amount of latitudinal vegetation shift (6.5°) was similar to an earlier Hypsithermal permafrost zone location study. An equivalent shift in vegetation along the eastern Cordillera would have placed south-western Montana-like vegetation and species such as Boykinia heucheriformis (Rydb.) Rosend. and Saxifraga odontoloma Piper within the northern half of the Rocky Mountains and foothills in Alberta, which represents the location of modern-day disjunct populations of these species. Main conclusions, Warmer and drier climatic conditions during the Holocene Hypsithermal resulted in the northward displacement of vegetation zones relative to their current distribution patterns. Most of Alberta was probably dominated by grasslands during this period, except the Rocky Mountains and northern highlands. Modern-day species disjunctions within the Rocky Mountains and Peace River District as well as more northerly areas such as the Yukon Territory occurred when the vegetation receded southward in response to climatic cooling after the Hypsithermal. Wind dispersal was considered an unlikely possibility to explain the occurrence of the disjunct species, as most of the plants lack morphological adaptations for long distance transport and the prevailing winds were from west to east rather than south to north. However, consumption and transport of seeds by northward migrating birds could not be excluded as a possibility. [source] Natural disturbance and life history: consequences of winterkill on fathead minnow in boreal lakesJOURNAL OF FISH BIOLOGY, Issue 3 2006A. J. Danylchuk Age, growth and reproductive characteristics of fathead minnow Pimephales promelas populations inhabiting four lakes that varied in the extent and frequency of winterkill were studied in the boreal region of western Canada. The lifespan of fathead minnows inhabiting lakes prone to winterkill was 1,2 years shorter than those in less disturbed lakes. In populations prone to winterkill, fish displayed faster growth rates and grew to a larger size-at-age, particularly during the first year of life. Although lower population densities in winterkill lakes probably contributed to this increased growth, adults in these populations tended to spawn earlier in the season than the smaller adults in more stable populations. Fathead minnows in lakes prone to winterkill also matured at an earlier age and allocated a greater proportion of their body mass to gonads than conspecifics in the more benign, stable lakes. These trends are consistent with predictions for organisms in variable, unpredictable environments and, because fathead minnows are tolerant to a wide range of environmental conditions, suggest that variation in life-history traits among populations is probably a product of both selection and phenotypic plasticity. [source] Temptations of weevil: feeding and ovipositional behaviour of Hylobius warreni Wood on host and nonhost bark in laboratory bioassaysAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2009Gareth R. Hopkins Abstract 1Warren root collar weevil Hylobius warreni Wood (Coleoptera: Curculionidae) is a long-lived, flightless insect native to coniferous forests across northern North America. Girdling by larval feeding causes significant mortality on young trees. The insect poses considerable challenges to reforestation. 2Adult weevils feed on all life stages of a variety of coniferous hosts prior to oviposition. Their relative feeding preferences, however, have not been quantified. Moreover, it is not known whether host bark influences oviposition behaviour. 3Feeding preferences of adult weevils were tested in both choice and no-choice laboratory bioassays using small branches from three conifers (lodgepole pine Pinus contorta var. latifolia, interior hybrid spruce Picea glauca×engelmannii, and Douglas-fir Pseudotsuga menziesii) and one deciduous tree (trembling aspen Populus tremuloides). Measurements included the surface area of bark consumed, rate of consumption, the number of days of feeding, and, in the no-choice assay, the number of eggs oviposited. 4Bark consumption was greatest on pine and Douglas-fir, followed by spruce. Little to no feeding occurred on aspen. Consumption did not vary between male versus female insects for any of the feeding metrics quantified. 5The presence of aspen branches did not inhibit feeding on any of the other species in the choice bioassays. 6The number of eggs laid by female insects did not differ significantly among tree species in the no-choice assay. Eggs were laid indiscriminately in the presence of all four host types. 7Results and opportunities for future research are discussed in the context of formulating new integrated pest management strategies for this insect, which is increasingly important in the period of reforestation subsequent to the mountain pine beetle epidemic in western Canada. [source] Nurse and resident satisfaction in magnet long-term care organizations: do high involvement approaches matter?JOURNAL OF NURSING MANAGEMENT, Issue 3 2006KENT V. RONDEAU PhD Aim, This study examines the association of high involvement nursing work practices with employer-of-choice (magnet) status in a sample of Canadian nursing homes. Background, In response to a severe shortage of registered nursing personnel, it is imperative for health care organizations to more effectively recruit and retain nursing personnel. Some long-term care organizations are developing employee-centred cultures that allow them to effectively enhance nurse and resident satisfaction. At the same time, many nursing homes have adopted progressive nursing workplace practices (high involvement work practices) that emphasize greater employee empowerment, participation and commitment. Method, A mail survey was sent to the director of nursing in 300 nursing homes in western Canada. In total, 125 useable questionnaires were returned and constituted the data set for this study. Separate ordinary least squares regressions are performed with magnet strength, nurse satisfaction and resident satisfaction used as dependent variables. Results, Nursing homes that demonstrate strong magnet (employer-of-choice) characteristics are more likely to have higher levels of nurse and patient satisfaction, even after controlling for a number of significant factors at the establishment level. Magnet nursing homes are more likely to have progressive participatory decision-making cultures and much more likely to spend considerable resources on job-related training for their nursing staff. The presence of high involvement work practices is not found to be a significant predictor in magnet strength, nurse or resident satisfaction. Conclusion, Merely adopting more high involvement nursing work practices may be insufficient for nursing homes, which desire to become ,employers-of-choice' in their marketplaces, especially if these practices are adopted without a concomitant investment in nurse training or an enhanced commitment to establishing a more democratic and participatory decision-making style involving all nursing staff. [source] Molecular Variability of Mycosphaerella graminicola as Detected by RAPD MarkersJOURNAL OF PHYTOPATHOLOGY, Issue 10 2004M. Razavi Abstract A total of 90 isolates of Mycosphaerella graminicola, the cause of septoria tritici leaf blotch of wheat, were tested for DNA polymorphism using 15 decamer random primers. There was a high level of genetic variability among isolates. In 131 random amplified polymorphic DNA (RAPD) fragments, which were produced, 96% were polymorphic. Based on multilocus analysis, 40 different molecular phenotypes were detected. These molecular phenotypes were randomly distributed among sampling sites, suggesting that no clonal structure existed in the population. Cluster analysis showed that the maximum similarity value among isolates was approximately 81% and no identical isolates were detected, indicating that every isolate was a unique genotype. The high degree of DNA polymorphism, the large number of different molecular phenotypes, their random distribution and the results of the cluster analysis all suggested that sexual reproduction has a major role in the genetic structure of M. graminicola in western Canada. The presence of sexual reproduction provides the opportunity for development of new virulent genotypes in the population and suggests that the pathogen may adapt rapidly to any race-specific sources of resistance. Therefore, when breeding for resistance to M. graminicola, emphasis should be placed on use of non-race-specific resistance. [source] Phylogeography of lions (Panthera leo ssp.) reveals three distinct taxa and a late Pleistocene reduction in genetic diversityMOLECULAR ECOLOGY, Issue 8 2009ROSS BARNETT Abstract Lions were the most widespread carnivores in the late Pleistocene, ranging from southern Africa to the southern USA, but little is known about the evolutionary relationships among these Pleistocene populations or the dynamics that led to their extinction. Using ancient DNA techniques, we obtained mitochondrial sequences from 52 individuals sampled across the present and former range of lions. Phylogenetic analysis revealed three distinct clusters: (i) modern lions, Panthera leo; (ii) extinct Pleistocene cave lions, which formed a homogeneous population extending from Europe across Beringia (Siberia, Alaska and western Canada); and (iii) extinct American lions, which formed a separate population south of the Pleistocene ice sheets. The American lion appears to have become genetically isolated around 340 000 years ago, despite the apparent lack of significant barriers to gene flow with Beringian populations through much of the late Pleistocene. We found potential evidence of a severe population bottleneck in the cave lion during the previous interstadial, sometime after 48 000 years, adding to evidence from bison, mammoths, horses and brown bears that megafaunal populations underwent major genetic alterations throughout the last interstadial, potentially presaging the processes involved in the subsequent end-Pleistocene mass extinctions. [source] TIMBER MARKETS AND FUEL TREATMENTS IN THE WESTERN U.S.NATURAL RESOURCE MODELING, Issue 1 2006KAREN L. ABT ABSTRACT. We developed a model of interrelated timber markets in the U.S. West to assess the impacts of large-scale fuel reduction programs on these markets, and concomitant effects ofthe market on the fuel reduction programs. The linear programming spatial equilibrium model allows interstate and international trade with western Canada and the rest of the world, while accounting for price effects of introducing softwood logs to the market. The model maximizes area treated, given fire regime-condition class priorities, maximum increases in softwood processing capacity, maximum rates of annual treatments, prohibitions on exports of U.S. and Canadian softwood logs from public lands and a fixed annual treatment budget. Results show that the loss to U.S. private timber producers is less than the gains for timber consumers (mills). States receiving more treatments when spending is not constrained by state proportions include Idaho, Montana, New Mexico and Oregon. When only the wildland-urban interface is treated, California, Oregon and Washington receive more treatments. Utah and Colorado receive more treatments when low risk stands are included. [source] Spatial variation in mink and muskrat interactions in CanadaOIKOS, Issue 3 2001John Erb We investigated the spatial attributes of mink (Mustela vison) and muskrat (Ondatra zibethicus) interactions in Canada using 160 geographically paired historic time series of mink (n=80) and muskrat (n=80) harvest data obtained from Hudson's Bay Co. Archives. All series were 25 years in length (1925,1949) and were distributed primarily throughout five ecozones. We used autoregressive models and cross-correlation analysis to characterize the interactions between mink and muskrat. Model selection results did not differ among ecozones, and indicated that a predator-prey autoregressive model incorporating a delayed density-dependent term best described both the mink and muskrat harvest time series. Subsequent analysis of autoregressive coefficients and estimated lags indicated that mink and muskrat interactions vary throughout Canada. In western Canada, the trophic interactions appear to be strong, and mink population cycles lag behind muskrats 2,3 years. In central Canada, mink harvests lagged behind muskrats 1 year, and mink and muskrat interactions in central Canada, with the exception of the Hudson Plains ecozone, were intermediate. In eastern Canada, the trophic interactions appeared weakest, and there were no distinct time lags between mink and muskrat. Stronger interactions in western Canada may be a result of decreased prey diversity, forcing mink to specialize more on muskrats, whereas comparatively stronger perturbations stemming from other trophic interactions may alter the estimated interaction between mink and muskrat in eastern Canada. [source] Epidemiology and management of Leptosphaeria maculans (phoma stem canker) on oilseed rape in Australia, Canada and EuropePLANT PATHOLOGY, Issue 1 2001J. S. West Phoma stem canker (blackleg), caused by Leptosphaeria maculans, is an important disease on oilseed rape (canola, rapeseed, Brassica napus, Brassica juncea, Brassica rapa) causing seedling death, lodging or early senescence in Australia, Canada and Europe, but not in China. The two forms of L. maculans (A group and B group) that occur on oilseed rape are now considered to be separate species. The epidemiology and severity of phoma stem canker differs between continents due to differences in the pathogen population structure, oilseed rape species and cultivars grown, climate and agricultural practices. Epidemics are most severe in Australia, where only the A group occurs, and can be damaging in Canada and western Europe, where both A and B groups occur, although their proportions vary within regions and throughout the year. Epidemics are slight in China, where the A group has not been found. Dry climates (Australia, western Canada) lengthen the persistence of infected debris and may synchronize the release of airborne ascospores (after rain) with seedling emergence. L. maculans spreads from cotyledon and leaf infections down petioles to reach the stem, with infections on cotyledons and leaves early in the season producing the most damaging stem cankers at the stem base (crown). Development of both crown cankers and phoma stem lesions higher up stems is most rapid in regions with high temperatures from flowering to harvest, such as Australia and Canada. Breeding for resistance (genetic, disease escape or tolerance), stubble management, crop rotation and fungicide seed treatments are important strategies for control of phoma stem canker in all areas. Fungicide spray treatments are justified only in regions such as western Europe where high yields are obtained, and accurate forecasts of epidemic severity are needed to optimize their use. [source] Using a complex non-TDN based model (the DVE/OEB system) to predict microbial protein synthesis, endogenous protein, degradation balance, and total truly absorbed protein supply of different varieties of cereal oats for ruminantsANIMAL SCIENCE JOURNAL, Issue 3 2009Peiqiang YU ABSTRACT Recently a new super-genotype of oat has been developed in the Crop Development Center called CDC SO-I (,SuperOat': low lignin and high fat). In a previous study, we evaluated total metabolizable protein using a TDN-based model-NRC-2001 which is popular in North America. However, the TDN-based NRC model is not accepted universally. The objectives of this study were to use a complex non-TDN based model, the DVE/OEB system, to evaluate potential nutrient supply to ruminants from the SuperOat in comparison with two normal varieties of oats (CDC Dancer and Derby) in western Canada. The quantitative predictions were made in terms of: (i) truly absorbed rumen synthesized microbial proteins in the small intestine; (ii) truly absorbed rumen undegraded feed protein in the small intestine; (iii) endogenous protein in the digestive tract; (iv) total truly absorbed protein in the small intestine; and (v) protein degraded balance. Results showed that using the DVE/OEB system to predict the potential nutrient supply, it was found that the SuperOat had similar truly absorbed rumen synthesized microbial protein levels (61, 63, 59 g/kg DM, P > 0.05, for SuperOat, CDC Dancer and Derby, respectively), higher truly absorbed rumen undegraded feed protein than CDC Dancer (22 vs. 17 g/kg DM P < 0.05, for SuperOat, CDC Dancer, respectively), but similar to Derby (22 vs. 21 g/kg DM; P > 0.05), and similar endogenous protein (16, 16, 18 g/kg DM; P > 0.05). Total truly absorbed protein in the small intestine is only numerically higher in the SuperOat (67 vs. 65, 62 g/kg DM, P > 0.05, for CDC Dancer and Derby, respectively). However, the protein degraded balance was significantly different (P < 0.05) with a positive value for the SuperOat (7.0 g/kg DM) and negative values for two normal varieties (,1.5, ,6.8 g/kg DM for CDC Dancer and Derby, respectively). In conclusion, the model predicted significantly different protein degradation balance. The SuperOat had positive degradation balance but other two normal varieties had negative protein degraded balance However, the SuperOat had similar total absorbed protein value to the two normal varieties of oats. [source] Cryptococcosis in ferrets: a diverse spectrum of clinical diseaseAUSTRALIAN VETERINARY JOURNAL, Issue 12 2002R MALIK Cryptococcosis was diagnosed in seven ferrets (five from Australia; two from western Canada) displaying a wide range of clinical signs. Two of the ferrets lived together. One (5-years-old) had cryptococcal rhinitis and presented when the infection spread to the nasal bridge. Its sibling developed cryptococcal abscessation of the right retropharyngeal lymph node 12 months later, soon after developing a severe skin condition. DNA fingerprinting and microsatellite analysis demonstrated that the two strains isolated from these siblings were indistinguishable. Two ferrets (2- to 3-years-old) developed generalised cryptococcosis: one had primary lower respiratory tract disease with pneumonia, pleurisy and medi-astinal lymph node involvement, while in the other a segment of intestine was the primary focus of infection with subsequent spread to mesenteric lymph nodes, liver and lung. The remaining three ferrets (1.75 to 4-years-old) had localised disease of a distal limb, in one case with spread to the regional lymph node. Cryptococcus bacillisporus(formerly C neoformansvar gattii) accounted for three of the four infections in Australian ferrets where the biotype could be determined. The Australian ferret with intestinal involvement and the two ferrets from Vancouver had C neoformansvar grubiiinfections. [source] The Economic Value of Soil Quality under Alternative Management in the Canadian PrairiesCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2003K. W. Belcher This paper describes a dynamic simulation model that integrates environmental and economic components of agricultural crop production systems to predict changes in soil quality and the concomitant impact on economic returns. The model is used to simulate crop yield, soil quality and economic performance of a conventional crop rotation and several alternative crop rotations in two contrasting environments in western Canada over a 50-year period. This information is used to quantify the impact of the crop rotations on soil organic carbon (SOC) and the economic value of on-site SOC changes. The estimated value of these impacts range from $0.20/t to $2.10/t of SOC/ha/yr. Les auteurs décrivent un modèle de simulation dynamique intégrant les paramètres environnementaux et économiques des systèmes de production végétale pour prévoir la qualityé du sol et l'incidence de cette dernière sur les rentrées. Le modèle simule le rendement des cultures, la qualityé du sol et la performance économique d'un système d'assolement classique et de plusieurs de ses variantes, dans deux milieux contrastants de l'ouest du Canada, sur une période de 50 ans. Les résultats ont permis de quantifier l'incidence de l'assolement sur la teneur du sol en carbone organique et la valeur économique des fluctuations d'une telle concentration. Les auteurs situent cette incidence entre 0.20 $ et 2,10 $ la tonne de carbone organique par hectare et par année. 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