Queen In Right Of Canada Research Articles

The summer hydrology of a small upland tundra thaw lake: implications to lake drainage

AbstractThe phenomenon of thaw lake disappearance through rapid drainage has been identified as a potential issue for many circumpolar Arctic regions. These drainage events and the associated flood waves pose a considerable danger to human and animal habitat especially in lake‐rich Arctic regions. The significance of this phenomenon is further heightened by the recent increase in human activity in Arctic regions, such as resource exploration, as well as the projected changes in climatic conditions for Arctic regions.This study is aimed at providing improved understanding of the hydrology of upland tundra thaw lakes, a type of lake that is prone to rapid drainage, by using a combination of observed and modelled data to calculate the complete summer lake water balance for a small thaw lake located to the east of the Mackenzie delta in northwestern Canada. The lake level calculation is subsequently extended to provide a 32‐year estimate of lake levels for the study lake. This long‐term dataset is used to detect patterns and trends in peak summer lake levels. Furthermore, it is used together with climate data for the same time period to look at lake levels and climatic conditions at the time of known rapid lake drainage events. The results of the study suggest that while high lake levels are considered to be a contributing factor for rapid lake drainage, climatic conditions such as above‐average summer air temperature and precipitation values also seem to be key factors. These findings are a first step in determining how projected future climate conditions might influence the rate of rapid lake drainages of Arctic tundra thaw lakes. Copyright © 2009 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada. The contributions of P. Marsh, C. Onclin and M. Russell belong to the Crown in right of Canada and are reproduced with the permission of Environment Canada.

River‐ice hydrology in a shrinking cryosphere

AbstractMany rivers of cold, and even temperate, regions of the globe are covered with ice for a part of the year. Projections of future climate indicate that the duration, composition and extent of ice coverage, however, will gradually change. This may have wide‐ranging consequences because ice is a critical component of cold‐regions hydrologic systems and strongly affects, for example, extreme floods, low winter flows, river transport, hydroelectric production, and numerous ecological and water‐quality characteristics. Following an overview of the processes characterizing the freezeup‐ice growth‐breakup sequence, the links of river ice to the hydrology of northern rivers are examined in detail. The rise in river stage that is caused by an ice cover is shown to be fundamental to ice‐related hydrologic impacts, such as floods caused by freezeup and breakup ice jams, low winter flows caused by water storage during freezeup and sharp waves generated by ice‐jam releases. Ice thickness and strength, both controlled by weather conditions, also play major roles. To date, the sensitivity of river‐ice regimes to changes in climatic conditions has only been partly evaluated. Most studies have focussed on ice phenology and indicate trends that are consistent with changes in air temperature, while a few recent studies have addressed the more complex questions of how climate change may alter ice thickness or the severity of extreme ice jams and floods. Foreseeable changes to river‐ice regimes, and associated hydrologic processes and impacts, are discussed in the light of current understanding. More frequent occurrence of mid‐winter breakup and associated jamming is a major effect that can be predicted with some confidence for regions where such events are presently rare or unknown. It is stressed that gaps in current knowledge preclude quantitative prediction of site‐specific changes to river‐ice regimes, and several recommendations for future research are presented. Copyright © 2008 Her Majesty the Queen in right of Canada. Published by John Wiley & Sons, Ltd.

Changes in thaw lake drainage in the Western Canadian Arctic from 1950 to 2000

AbstractThe permafrost of the Western Canadian Arctic has a very high ground ice content. As a result, the vast number of thaw lakes in this area are very sensitive to a changing climate. With thaw lakes prone to either increases in area due to thermokarst processes, or complete drainage in less than one day due to melting of channels through ice‐rich permafrost. After a lake drains, it leaves a topographic basin that is often termed a Drained Thaw Lake Basin (DTLB). An analysis of aerial photographs and topographic maps showed that 41 lakes drained in the study area between 1950 and 2000, for a rate of slightly less than one lake per year. The rate of drainage over three time periods (1950–1973, 1973–1985, 1985–2000), decreased from over 1 lake/year to approximately 0·3 lake/year. The reason for this decrease is not known, but it is hypothesized that it is related to the effect of a warming climate. There is a large spatial variation in DTLBs, with higher number of drained lakes in physiographic areas with poor drainage. It is likely that this variation is related to variations in ground ice. Although previous studies have suggested that lakes drain during periods of high water level, it is likely that a combination of a warm summer, a resulting deep active layer, and a moderately high lake level were responsible for the drainage of a lake in the study area during the summer of 1989. Although this study has documented changes in the rate of lake drainage over a 50‐year period, there is a need for further research to better understand the complex interactions between climate, geomorphology, and hydrology responsible for this change, and to further consider the potential hazard rapid lake drainage poses to future industrial or resource development in the area. Copyright © 2008 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada. The contributions of P. Marsh, M. Russell, H. Haywood and C. Onclin belong to the Crown in right of Canada and are reproduced with the permission of Environment Canada.

A Place-Based, Values-Centered Approach to Managing Recreation on Canadian Crown Lands

Many studies of forest values worldwide have focused on “held” values (Brown 1984). We argue that “assigned” values are more suitable for the site-based focus associated with recreation planning. Consideration of public use and recreation values raises many of the issues surrounding place attachment and place identification. We argue that “meaning-based” interpretive approaches to social values elicitation are better suited to collaborative planning than are expert-driven, rational decision-making models. Social science data are rarely specifically located and are difficult to integrate into geographic information system (GIS)-based planning models. In a case study of a Canadian Crown Forest in northwestern Ontario, Canada, we integrate a variety of approaches, including focus groups, valued-place mapping, and surveys, to elicit and spatially represent social values. We introduce the concept of “spatial valuation zones” as a mean of incorporating user-defined social values into forest planning and examine the implications of this approach for managing multiple-use forests more generally.

Groundwater exchange with two small alpine lakes in the Canadian Rockies

AbstractRecent studies have shown that groundwater can play an important role in the water balances of alpine lakes. However, a number of uncertainties remain, including (i) whether substantial groundwater exchange is common or rare, (ii) what types of interactions may occur, and (iii) what are the important factors affecting groundwater exchange. This understanding is important for predictions of hydrology, water chemistry and ecology patterns and interactions in the headwaters of mountain watersheds. These questions were addressed for the Lake O'Hara watershed in the Canadian Rockies, using lake water balances applied to two alpine lakes. The results were compared to those of a previously published water balance for the larger Lake O'Hara. Groundwater was a major component of the water balance in both lakes, but the type of groundwater interactions differed despite the lakes being similar in size and located only 500 m apart. The water balance for Opabin Lake was dominated by the groundwater components, with alternating periods of substantial groundwater inflow and outflow. Meanwhile, groundwater inflows were much greater than outflows for Hungabee Lake, with net groundwater fluxes of similar magnitude as the incoming streams. The study results suggest that both groundwater inflow and outflow occurred through a moraine field for Opabin Lake, while groundwater inflow occurred from a talus slope to Hungabee Lake. Thus, the presence of coarse overburden deposits in contact with alpine lakes is a potentially important factor affecting groundwater exchange, which in turn affects the hydrology and ecology of mountain watersheds. Copyright © 2008 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada.

Assessment of annual high‐water events for the Mackenzie River basin, Canada

AbstractRiver ice break‐up is known to have important morphological, ecological and socio‐economic effects on cold‐regions river environments. One of the most persistent effects of the spring break‐up period is the occurrence of high‐water events. A return‐period assessment of maximum annual nominal water depths occurring during the spring break‐up and open‐water season at 28 Water Survey of Canada hydrometric sites over the 1913–2002 time period in the Mackenzie River basin is presented. For the return periods assessed, 13 (14) stations are dominated by peak events occurring during the spring break‐up (open‐water) season. One location is determined to have a mixed signal. A regime classification is proposed to separate ice‐ and open‐water dominated systems. As part of the regime classification procedure, specific characteristics of return‐period patterns including alignment, and difference between the 2 and 10‐year events are used to identify regime types. A dimensionless stage‐discharge plot allows for a contrast of the relative magnitudes of flows required to generate maximum nominal water‐depth events in the different regimes. At sites where discharge during the spring break‐up is approximately one‐quarter or greater than the magnitude of the peak annual discharge, nominal water depths can be expected to exceed those occurring during the peak annual discharge event. Several physical factors (location, basin area, stream order, gradient, river orientation, and climate) are considered to explain the differing regimes and discussed relative to the major sub‐regions of the MRB. Copyright © 2008 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada.

Effect of water table drawdown on peatland dissolved organic carbon export and dynamics

AbstractPeatlands play an important role in the global carbon cycle, and loss of dissolved organic carbon (DOC) has been shown to be important for peatland carbon budgets. The objective of this study was to determine how net production and export of DOC from a northern peatland may be affected by disturbance such as drainage and climate change.The study was conducted at a poor fen containing several pool–ridge complexes: (1) control site–no water table manipulation; (2) experimental site–monitored for one season in a natural state and then subjected to a water table drawdown for 3 years; (3) drained site–subjected to a water table drawdown 9 years prior to monitoring. The DOC concentration was measured in pore water along a microtopographic gradient at each site (hummock, lawn and hollow), in standing water in pools, and in discharge from the experimental and drained sites. The initial water table drawdown released ∼3 g of carbon per square metre in the form of DOC, providing a large pulse of DOC to downstream ecosystems. This value, however, represents only 1–9% of ecosystem respiration at this site. Seasonal losses of DOC following drainage were 8–11 g of carbon per square metre, representing ∼17% of the total carbon exchange at the experimental study site. Immediately following water table drawdown, DOC concentrations were elevated in pore water and open water pools. In subsequent seasons, DOC concentration in the pool declined, but remained higher than the control site even 11 years after water‐table drawdown. This suggests continued elevated net DOC production under lower water table conditions likely related to an increase in vegetation biomass and larger water table fluctuations at the experimental and drained sites. However, the increase in concentration was limited to initially wet microforms (lawns and hollows) reflecting differences in vegetation community changes, water table and soil subsidence along the microtopographic gradient. Copyright © 2008 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada.

Correcting wind‐induced bias in solid precipitation measurements in case of limited and uncertain data

AbstractAutomatic precipitation gauges tend to underestimate solid precipitation in the presence of wind. Loss as a function of wind speed is typically evaluated by comparing the gauge with a more accurate measurement made using a double‐fence intercomparison reference gauge (DFIR). For small precipitation events, small errors in the observations can induce large errors in the ‘catch’ ratio, i.e. the ratio of the automatic gauge measurement to the DFIR observation. For this reason, precipitation events of less than 3 mm are typically discarded before performing the regression analysis. This can mean discarding more than 90% of the observations. This paper shows how the method of weighted least squares can be used to perform a regression analysis that can take into account the whole sample to provide a more accurate estimation of the relationship between the catch ratio and the wind speed. This methodology is then used to obtain an adjustment curve for a shielded Geonor T‐200B precipitation gauge in Northern Québec. Copyright © 2008 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada.

Discovery and genotyping of high‐throughput SNP markers for crown rust resistance gene Pc94 in cultivated oat

AbstractCrown rust caused by Puccinia coronata f. sp. avenae Eriks is a serious problem for oat production worldwide and pyramiding multiple resistance genes into new cultivars is a key objective of breeders. Many race specific resistance genes have been mapped and markers that are closely linked to them have been identified. However, the use of these markers in oat breeding practice has been limited due to the economics of marker assisted selection (MAS) deployment. Single nucleotide polymorphism (SNP) markers have been demonstrated to have a high‐throughput capability with relatively low cost and numerous semi‐automated SNP scoring platforms exist. Gene Pc94 has remained highly effective since it was first tested on the Canadian crown rust populations in 1993 and is one of the few effective genes available in Western Canada. In the present study, PCR products were amplified using primers derived from sequences of amplified fragment length polymorphism bands which have been shown to be linked to Pc94. Genomic DNA from genotypes, with and without the Pc94 gene, were used as the PCR templates. By comparative sequence alignment amongst the PCR fragments, many putative SNP sites were identified. From these sites, four SNP sites were selected and validated by the single base extension method. One SNP site, Pc94‐SNP1a, was tested on two F2:3 populations segregating for the resistance gene. The map distances between the SNP marker and Pc94 were 2.1 and 5.4 cM in the two different populations. Various oat cultivars and germplasm lines were also tested for a wider application of the SNP marker. Fluorescent technology and capillary electrophoresis allowed for the semi‐automated, fairly high‐throughput scoring of the SNP markers.

Hippocampal slice cultures integrated with multi‐electrode arrays: a model for study of long‐term drug effects on synaptic activity

AbstractTechnological limitations have restricted the ability to determine chronic drug effects on synaptic function from in vitro preparations. In earlier studies, the extracellular recording duration was limited to less than 10 h and only a distinct population of neurons was examined. To address these limitations, we used organotypic hippocampal slice cultures integrated with planar multi‐electrode arrays (MEA‐OHSC), which permitted within‐slice comparisons and examination of long‐term changes across multiple populations of neurons. Long‐term potentiation (LTP) is a widely accepted measure of synaptic plasticity, and is believed to be a cellular mechanism underlying learning and memory. Amyloid‐β protein (Aβ) is a 40–42 amino acid peptide that is the primary element of senile plaques, a pathological hallmark of Alzheimer's disease (AD). In contrast to earlier studies, MEA‐OHSCs allowed for long‐term administration of Aβ1–42 to more closely model the chronic nature of AD pathogenesis. Prior to Aβ1–42 exposure, the CA1 region displayed robust potentiation, but afterwards the ability to induce LTP was nearly absent. Spatial analysis illustrated, for the first time, the substantial area of LTP induction, and clearly showed the global loss of this plasticity after long‐term Aβ exposure. The MEA‐OHSC model characterized here presents an ideal platform for examining the effects chronic exposure of a bioactive compound can have on a cellular correlate of memory. This model could also be used to screen potential therapeutics that may influence synaptic activity. Drug Dev Res 68:84–93, 2007. Published 2007 Wiley‐Liss, Inc.; Canadian Crown Copyright

Her Majesty the Queen in Right of Canada v. Edelson and Others

279State immunity — Jurisdictional immunity — Whether rules forming part of customary international law — Whether restricted or absolute — Distinction between acts performed jure imperii and jure gestionis — Nature and purpose tests — Test of whether a private entity other than the State could have been a party to the act — Freedom of States to adopt different rules pending the development of a standardized international practice — Purchase or rental of buildings for ambassadorial residence not covered by State immunity — Head of State — Action against Head of State in substance an action against the State itselfDiplomatic relations — Diplomatic immunity — Ambassador — Whether acting as State’s representative in conclusion of lease or as party to legal proceedings — Party to lease being sovereign State of Canada — Dispute covered by State immunity rather than diplomatic immunityRelationship of international law and municipal law — Customary international law — Part of the law of the State of Israel — Conflict between rules of customary international law and Israeli legislation — Whether the latter prevails — The law of Israel

Overbank deposition along the concave side of the Red River meanders, Manitoba, and its geomorphic significance

AbstractSlow earth sliding is pervasive along the concave side of Red River meanders that impinge on Lake Agassiz glaciolacustrine deposits. These failures form elongated, low‐angled (c. 6 to 10°) landslide zones along the valleysides. Silty overbank deposits that accumulated during the 1999 spring freshet extend continuously along the landslide zones over hundreds of metres and aggraded the lower slopes over a distance 50 to 80 m from the channel margin. The aggradation is not obviously related to meander curvature or location within a meander. Along seven slope profiles surveyed in 1999 near Letellier, Manitoba, the deposits locally are up to 21 cm thick and generally thin with increasing distance from, and height above, the river. Local deposit thickness relates to distance from the channel, duration of inundation of the landslide surface, mesotopography, and variations in vegetation cover. Immediately adjacent to the river, accumulated overbank deposits are up to 4 m thick. The 1999 overbank deposits also were present along the moderately sloped (c. 23 to 27°) concave banks eroding into the floodplain, but the deposits are thinner (locally up to c. 7 cm thick) and cover a narrower area (10 to 30 m wide) than the deposits within the landslide zones. Concave overbank deposition is part of a sediment reworking process that consists of overbank aggradation on the landslide zones, subsequent gradual downslope displacement from earth sliding, and eventually reworking by the river at the toe of the landslide. The presence of the deposits dampens the outward migration of the meanders and contributes to a low rate of contemporary lateral channel migration. Concave overbank sedimentation occurs along most Red River meanders between at least Emerson and St. Adolphe, Manitoba. © Her Majesty the Queen in right of Canada.

Seasonal changes of cytokinins in upper and lower leaves of a sugar maple crown

Although it is well accepted that cytokinins (CKs) regulate processes such as leaf senescence and stomatal conductance, data on CKs in the canopy of mature trees are lacking in the literature. Here we report the first in situ sampling for determination of CKs in mature sugar maple (Acer saccharum) canopy layers. The upper canopy showed a distinct seasonal pattern in total CK content, while the lower canopy remained relatively unchanged.

A transporter for phenolamine uptake in the arthropod CNS

Biogenic monoamines play central roles in the nervous control of physiological processes in both vertebrates and invertebrates, each using a suite of neurotransmitters tailored through evolution. Among the ancillary proteins necessary for the deployment of monoamine transmitters are membrane-bound transporters that enable the reuptake of synaptically released transmitters. Transporters responsible for monoamine uptake include a novel transporter discovered in a pest insect, the cabbage looper Trichoplusia ni, which has high affinity for the phenolamines octopamine and tyramine. Sequence analysis suggests that this transporter has no direct ortholog in the sequenced genomes of model invertebrates. We report here a preliminary investigation into the true extent of the distribution of this type of transporter using RT-PCR with a set of degenerate primers selective for monoamine transporters on cDNAs made from the nervous systems of a range of arthropods. PCR products encoding the N-terminal region of orthologs of this transporter were detected in a variety of insect orders, as well as in a crustacean, but were not found in representatives of either the Diptera or the Hymenoptera. Thus, although this transporter is widely expressed in invertebrates, there are various invertebrates that appear to have evolved alternate ways of recycling phenolamine neurotransmitters released at the nerve synapse.

Distribution ofAcer palmatum seedlings under the crown of the maternal tree

To investigate the relationship between crown width of a parent plant and seedling distribution, seedling ages and sizes, and their distances from the maternal tree were surveyed under a maple (Acer palmatum) crown at Chungdam Park, Chungdam-dong, Kangnam-gu, Seoul, in 1998. Maple crown width increased 33.0 cm per year during the eight-year study. Seedlings ranged from 1 to 10 years old; their density was highest the third year, and decreased with age. Seedling-distribution ranges from the parent plant were 43 cm to 487 cm, and seedling density was highest at the border of the parent plant canopy. One-year-old seedlings were distributed broadly, but the main distribution areas became more distant from the maternal plant with seedling age. Seedling heights increased with age; differences between two consecutive ages were significant at the 0.1% level for ages less than 5 years, but not for over 6 years. For seedlings of the same age, heights were similar, but short under the tree crown, but were varied and taller outside the crown. The variation in seedling height increased with age and distance from the parent plant In particular, seedlings older than 5 years that were distributed outside the crown showed conspicuous variations among distance classes. Therefore, maple seedlings were distributed to an appropriate distance at which their growth could be supported by the understory-light environment. This study demonstrated that newA. palmatum trees are not recruited from the seedlings growing beneath the crown but from those that grow vigorously outside the crown.

5644077 Wave-powered ocean profiler : Fowler George A Dartmouth, Canada assigned to Her Majesty the Queen in right of Canada as represented by the Minister of Fisheries of Oceans

5644077 Wave-powered ocean profiler : Fowler George A Dartmouth, Canada assigned to Her Majesty the Queen in right of Canada as represented by the Minister of Fisheries of Oceans

Enantioselective Esterification of Racemic Ibuprofen in Solvent Media under Reduced Pressure

The enantioselective esterification of (R,S)-ibuprofen has been performed with Novozym 435TM in solvent media under reduced pressure. The nature of the solvent affects the activity and enantioselectivity of the lipase. High esterification rates are obtained in solvents having high hydrophobicity (log P>4). On the other hand, the best enantioselectivity is obtained with solvents having low hydrophobicity (log P<3). This particular enantioselectivity trend is observed within the individual solvent families investigated (alkanes, ethers and aromatics). © Canadian Crown Copyright 1997

5597735 Glycolipids for serodiagnosis of tuberculosis and leprosy : Laszlo Adalber; Handzel Vera; Vera-Cabrera Luci Nepean, Canada Assigned to Her Majesty the Queen in right of Canada as represented by the Minister of Health and Welfare

A method of testing for tuberculosis and leprosy in animals or humans and antigens used in the method. The method involves carrying out an assay on sera from humans or animals using an antigen to bind antibodies in sera. The antigens used in the method are synthetic pseudo cord factor-like glycolipids having the structures (I) or (II) below: ##STR1## wherein R represents a straight or branched chain alkyl group having 15 to 18 carbon atoms. The antigens can be produced by chemical synthesis, and can therefore be made available in suitable quantities, and are relatively stable at ambient temperatures while showing good sensitivity and specificity for tuberculosis and leprosy. The antigens can be used, for example, for enzyme-linked immunosorbent assays, and related "spot tests" for diagnosing tuberculosis and leprosy.

5554537 Non-destructive surface sampler : Sharpe Anthony Almonte, Canada Assigned to Her Majesty the Queen in right of Canada as represented by the Minister of Health and Welfare Canada

5554537 Non-destructive surface sampler : Sharpe Anthony Almonte, Canada Assigned to Her Majesty the Queen in right of Canada as represented by the Minister of Health and Welfare Canada

5481815 System to reduce sediment toxicity : Murphy Thomas; Savile Harry Grimsby, Canada assigned to Her Majesty the Queen in right of Canada as represented by The Minister of The Environment

5481815 System to reduce sediment toxicity : Murphy Thomas; Savile Harry Grimsby, Canada assigned to Her Majesty the Queen in right of Canada as represented by The Minister of The Environment