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This article addresses the impact of war on Newfoundland, including Labrador, while Newfoundland was independent from Canada, and the role of war in the eventual addition of Newfoundland as a province of Canada in 1949. Newfoundland's small and scattered population meant that it was never a particularly prosperous place, although the railway embodied the hope of the existence of a real future. Locally, some fishing premises and farms performed well, but there was a pervasive opinion, expressed in the degree of outmigration, that one could not do well in the territory. Its leadership went through a number of changes, from responsible government with an elected assembly in 1855 to Commission of Government in the 1930s and 1940s. But the overriding issue was the Canadian Confederation of 1867, and here the Confederates had an overall advantage, given the Canadian welfare state of the late 1940s. After a referendum following the Second World War, Newfoundland joined the union as the tenth province on 30 March 1949. [ABSTRACT FROM AUTHOR]

Household food insecurity (HFI), stress, isolation, and discrimination are major determinants of health that disproportionately affect 2SLGBTQ + people. The COVID-19 pandemic potentially exacerbated these inequities. This study investigates HFI rates among 2SLGBTQ + adults living in diverse household conditions during the pandemic and explores the idea that heteronormative conceptions of the "household" may affect measurement of HFI. Cross-sectional survey responses were collected from 437 self-identified 2SLGBTQ + people from Toronto, Canada between March and July 2021. The survey measured HFI, sexual/gender identities, socio-demographic factors, household composition, and psycho-social stress/distress. Multinomial logistic regression was used to assess variation in odds of marginal, moderate, and severe HFI in relation to sexual/gender identities, household composition, psycho-social distress, and socio-demographic covariates. Forty-two percent of respondents reported some level of HFI, with severe HFI higher among respondents who were bisexual, transgender/gender diverse, and/or assigned-female-at-birth. Living alone was associated with decreased odds of reporting marginal HFI but increased odds of moderate or severe HFI compared to living with a partner, family, or roommates; living with children was associated with decreased odds of both marginal and severe HFI. One indicator of psycho-social distress (perceived discrimination) was associated with higher odds of all levels of HFI, while the other (isolation) was associated with decreased odds of marginal HFI. These findings highlight the high prevalence of HFI linked with discrimination among 2SLGBTQ + individuals during the pandemic. The complicated results regarding household composition and social isolation may suggest a need to revise definitions of the household when measuring, monitoring, and seeking to mitigate HFI in 2SLGBTQ + communities. • 2SLGBTQ+ in Toronto face higher risk of food insecurity. • Transgender and bisexuals particularly affected. • Discrimination linked to increased food insecurity. • Structural inequities impact 2SLGBTQ + health access. • Impact evident during and outside pandemics. [ABSTRACT FROM AUTHOR]

Background: This study examines newcomers with intellectual and developmental disabilities compared to other adults with intellectual and developmental disabilities in Ontario, Canada. Methods: This population‐based retrospective cohort study used linked health and social services administrative data to identify adults with intellectual and developmental disabilities as newcomers, or non‐newcomers, and compared their health status and health service outcomes. Results: Among those with intellectual and developmental disabilities, compared to non‐newcomers, newcomers generally had lower or similar rates of health issues, except for higher rates of psychosis. Newcomers also had slightly greater use of community‐based health services, but less hospital use. Conclusion: Trends among those with the intellectual and developmental disabilities were consistent with general population trends; newcomers had lower rates of many health issues and lower hospital use. It also underscores the value of understanding drivers of heterogeneity within newcomers, such as the circumstances of admission and settlement in their new country. [ABSTRACT FROM AUTHOR]

Volcanic rocks erupted within glacial environments offer powerful paleoenvironmental insights. These glaciovolcanoes and their deposits serve as proxies that inform on the paleo-presence, distribution and thickness of past glaciers. We investigate the paleoenvironmental implications of three Mid to Late Pleistocene volcanic deposits in the Garibaldi volcanic belt of southwestern British Columbia, Canada. We use these data to inform a simple geometric model that constrains paleo-glacier distributions in the southern Canadian Cordillera. The three volcanoes are used to recover: i) a coalesced mountain ice sheet in late Marine Isotope Stage (MIS) 4, and possibly into MIS 3 (up to ∼49.1 ± 5.5 ka), ii) major and rapid degradation of glaciers during the late, MIS 6 to 5e transition (by 141 ± 12.9 ka), and, iii) a coalesced mountain ice sheet, or continental ice sheet that existed during MIS 15 (598 ± 7.5 ka). • Glaciovolcanoes inform on the distribution of terrestrial paleo-glaciers in space and time. • Paleo-glacier distributions for southwestern British Columbia, Canada are modelled geometrically. • Three glaciovolcanoes constrain paleo-glacier distributions at 49, 141 and 598 ka. [ABSTRACT FROM AUTHOR]

Background: Attention to research and planning are increasingly being devoted to newcomer health, but the needs of newcomers with disabilities remain largely unknown. This information is difficult to determine since population-level data are rarely available on newcomers or on people with intellectual and developmental disabilities (IDD), although in Ontario, Canada these databases are accessible. This study compared the prevalence of IDD among first generation adult newcomers to adult non-newcomers in Ontario, and assessed how having IDD affected the health profile and health service use of newcomers. Methods: This population-based retrospective cohort study of adults aged 19–65 in 2010 used linked health and social services administrative data. Prevalence of IDD among newcomers (n = 1,649,633) and non-newcomers (n = 6,880,196) was compared. Among newcomers, those with IDD (n = 2,830) and without IDD (n = 1,646,803) were compared in terms of health conditions, and community and hospital service use. Results: Prevalence of IDD was lower in newcomers than non-newcomers (171.6 versus 898.3 per 100,000 adults, p<0.0001). Among newcomers, those with IDD were more likely than those without IDD to have comorbid physical health disorders, non-psychotic, psychotic and substance use disorders. Newcomers with IDD were also more likely to have psychiatry visits, and frequent emergency department visits and hospitalizations. Conclusion: First generation adult newcomers have lower rates of IDD than non-newcomers. How much of this difference is attributable to admission policies that exclude people expected to be high health service users versus how much is attributable to our methodological approach is unknown. Finding more medical and psychiatric comorbidity, and more health service use among newcomers with IDD compared to newcomers without IDD is consistent with patterns observed in adults with IDD more generally. To inform polices that support newcomers with IDD future research should investigate reasons for the prevalence finding, barriers and facilitators to timely health care access, and pathways to care. [ABSTRACT FROM AUTHOR]

The understory of the redwood forests of California's coast harbors perennial ferns, including Polystichum munitum and Dryopteris arguta. Unusual for ferns, these species are adapted to the characteristic Mediterranean-type dry season, but the mechanisms of tolerance have not been studied., The water relations of P. munitum and D. arguta were surveyed for over a year, including measures of water potential (Ψ), stomatal conductance ( gs) and frond stipe hydraulic conductivity ( K). A dehydration and re-watering experiment on potted P. munitum plants corroborated the field data., The seasonal Ψ varied from 0 to below −3 MPa in both species, with gs and K generally tracking Ψ; the loss of K rarely exceeded 80%. Quantile regression analysis showed that, at the 0.1 quantile, 50% of K was lost at −2.58 and −3.84 MPa in P. munitum and D. arguta, respectively. The hydraulic recovery of re-watered plants was attributed to capillarity., The seasonal water relations of P. munitum and D. arguta are variable, but consistent with laboratory-based estimates of drought tolerance. Hydraulic and Ψ recovery following rain allows perennial ferns to survive severe drought, but prolonged water deficit, coupled with insect damage, may hamper frond survival. The legacy effects of drought on reproductive capacity and community dynamics are unknown. [ABSTRACT FROM AUTHOR]

Abstract: A detailed study of apatite and biotite compositions in multiple intrusive phases from five composite plutons in the northern Canadian Cordillera was undertaken with the aim of determining the composition of magmatic fluids relative to F:Cl:OH for several plutons―both barren and mineralizing―and for specific intrusive phases from each pluton that may be related to nearby tungsten skarns. Magmatic apatite and biotite compositions are consistent with a crustal source of magma, either derived from predominantly supracrustal rocks, and (or) derived from predominantly infracrustal rocks and fractionated to felsic compositions. Increasing MnO (±FeO and XF:XCl) with decreasing CaO in apatite broadly correlates with an increasing degree of magmatic differentiation, although Fe# vs. total aluminum in biotite is a better indicator of inter- and intra-plutonic differentiation. Anomalously iron-rich biotites occur in highly fractionated and (or) wallrock-contaminated phases of plutons associated with tungsten skarns. Estimates of magmatic fluid composition―calculated as the activity ratios log[a HCl / a HF] and log[a HOH / a HF] from apatite and biotite compositions―show several trends with respect to magmatic differentiation. Two barren plutons demonstrate that fluids in silicic magmas become HF enriched relative to HCl with increasing differentiation, although re-equilibration with late-stage sub-solidus or hydrothermal fluids may obscure this trend. The three intrusions with associated tungsten skarn mineralization, including the world-class Cantung deposit, also become HF-enriched with magmatic evolution. However, magmatic apatite and biotite in individual intrusive phases that are the most closely associated with mineralization have equilibrated with compositionally distinct fluids. In these particular intrusive phases, apatite appears to have equilibrated with an earlier HCl- and H2O-rich magmatic fluid, and biotite appears to have equilibrated with a later HCl- and (a particularly) H2O-rich magmatic fluid. The fluid in these magmas apparently evolved to a H2O-rich (or less saline) composition as the temperature of the magma decreased. None of the other intrusive phases, from either the barren or tungsten-associated plutons, have apatite and biotite activity ratios that are suggestive of equilibration with such an HCl/HF- and H2O/HF-rich fluid. Instead, the activity ratios calculated from apatite and biotite in intrusive phases that are not as closely associated with mineralization are well-coupled and unremarkable (although small variations are common), which would suggest that both minerals equilibrated with similar fluids. These intrusive phases do not appear to have produced a large quantity of saline hydrous fluid capable of seggregating and transporting tungsten. The identification of intrusive phases that did produce magmatic fluids that were anomalously enriched in HCl and H2O could, therefore, be a predictor of nearby tungsten skarn mineralization. [Copyright &y& Elsevier]

Introduced piscivorous fishes had a dramatic impact on small-bodied fish species diversity of small temperate lakes in Gatineau Park, Quebec, Canada, on the basis of three surveys carried out over a 38-year period from 1970 to 2007. For three overlapping sets of lakes based on different combinations of survey years (lakes surveyed in 1970-1971, 1991-1992, and 2006-2007 ( N = 14); lakes surveyed in 1970-1971 and 2006-2007 ( N = 21); and lakes surveyed in 1991-1992 and 2006-2007 ( N = 16)), those with introduced piscivores showed substantial and consistent temporal declines in average minnow species richness but much weaker, if any, declines in total species richness. By contrast, lakes without introduced piscivores showed no such decline. Whereas lakes without piscivores showed a strong species-elevation relationship early in the record, the strength of this relationship was much lower in lakes with introduced piscivores. Moreover, the strength of the species-elevation relationship declined precipitously over time in lakes with introduced piscivores, but remained stable in lakes where introduced piscivores were absent. The negative impact of piscivore introductions on small-bodied fish biodiversity in small lakes underscores the importance of action to mitigate the risk of future introductions or invasions. [ABSTRACT FROM AUTHOR]

Aims Although illicit drug purity is a widely discussed health risk, research explaining its geographic variation within a country is rare. This study examines whether proximity to the US-Mexico border, the United States' primary drug import portal, is associated with geographic variation in US methamphetamine, heroin and cocaine purity. Design Distances (proximity) between the US-Mexico border and locations of methamphetamine, cocaine and heroin seizures/acquisitions ( n = 239 070) recorded in STRIDE (System to Retrieve Information from Drug Evidence) were calculated for the period of 1990-2004. The association of drug purity with these distances and other variables, including time and seizure/acquisition size, was examined using hierarchical multivariate linear modeling (HMLM). Setting Coterminous United States. Findings Methamphetamine, cocaine and heroin purity generally decreased with distance from the US-Mexico border. Heroin purity, however, after initially declining with distance, turned upwards-a U-shaped association. During 2000-04, methamphetamine purity also had a U-shaped association with distance. For each of the three drugs, temporal changes in the purity of small acquisitions (<10 g) were typically more dynamic in areas closer to the US-Mexico border. Conclusions Geographic variance in methamphetamine, cocaine and heroin purity throughout the coterminous United States was associated with US-Mexico border proximity. The U-shaped associations between border-distance and purity for heroin and methamphetamine may be due to imports of those drugs via the eastern United States and southeast Canada, respectively. That said, areas closer to the US-Mexico border generally had relatively high illicit drug purity, as well as more dynamic change in the purity of small ('retail level') drug amounts. [ABSTRACT FROM AUTHOR]

Abstract: Background: In response to its domestic methamphetamine problems and an emerging international consensus that methamphetamine precursor and essential chemicals should be controlled, Canada regulated its import/export of ephedrine and pseudoephedrine (precursor chemicals) in January 2003, its domestic distribution of those chemicals in July 2003, and its import/export and manufacturing of essential chemicals (e.g., toluene) in January 2004. This study examines the regulations’ impact on the problem of methamphetamine-related hospital admissions in Canada. Methods: ARIMA-based intervention time-series analysis was used to assess impacts on monthly counts of Canada''s methamphetamine-related acute-care hospital admissions (04/1996 to 03/2005). Cocaine-, heroin/opioid-, and alcohol-related hospital admissions were examined as quasi-control time-series. Results: No impact was found for the January 2003 regulation. The July 2003 and January 2004 regulations were associated with 20% and 21% increases, respectively, in methamphetamine-related admissions. No impacts on the quasi-control time-series were found. Conclusions: This study indicates that Canada''s regulations were not associated with reductions in methamphetamine-related hospital admissions. The January 2003 regulation''s focus on imports/exports rather than domestic distribution may help explain its lack of impact. In contrast, the two other regulations had salient domestic foci – domestic precursor sales (July 2003) and domestic essential chemical manufacturing (January 2004). Both regulations, however, were associated with increases in admissions, rather than declines. Government reports indicate that a shift in methamphetamine production, from smaller-scale operators to more sophisticated crime organizations (groups better able to circumvent the regulations), occurred around the times of the regulations. Such a shift could increase supply and possibly admissions. [Copyright &y& Elsevier]

Aims Reducing drug purity is a major, but largely unstudied, goal of drug suppression. This study examines whether US methamphetamine purity was impacted by the suppression policy of US and Canadian precursor chemical regulation. Design Autoregressive integrated moving average (ARIMA)-intervention time–series analysis. Setting Continental United States and Hawaii (1985–May 2005). Interventions US federal regulations targeting precursors, ephedrine and pseudoephedrine, in forms used by large-scale producers were implemented in November 1989, August 1995 and October 1997. US regulations targeting precursors in forms used by small-scale producers (e.g. over-the-counter medications) were implemented in October 1996 and October 2001. Canada implemented federal precursor regulations in January 2003 and July 2003 and an essential chemical (e.g. acetone) regulation in January 2004. Measurements Monthly median methamphetamine purity series. Findings US regulations targeting large-scale producers were associated with purity declines of 16–67 points; those targeting small-scale producers had little or no impact. Canada's precursor regulations were associated with purity increases of 13–15 points, while its essential chemical regulation was associated with a 13-point decrease. Hawaii's purity was consistently high, and appeared to vary little with the 1990s/2000s regulations. Conclusions US precursor regulations targeting large-scale producers were associated with substantial decreases in continental US methamphetamine purity, while regulations targeting over-the-counter medications had little or no impact. Canada's essential chemical regulation was also associated with a decrease in continental US purity. However, Canada's precursor regulations were associated with purity increases: these regulations may have impacted primarily producers of lower-quality methamphetamine, leaving higher-purity methamphetamine on the market by default. Hawaii's well-known preference for ‘ice’ (high-purity methamphetamine) may have helped to constrain purity there to a high, attenuated range, possibly limiting its sensitivity to precursor regulation. [ABSTRACT FROM AUTHOR]

The reproductive success of colonially breeding species depends in part upon a trade-off between the benefit of a dilution effect against nestling predation within larger colonies and colony conspicuousness. However, there may be no net survivorship benefit of dilution if smaller colonies are sufficiently inconspicuous. This raises the question about how the size distribution of breeding colonies on a landscape might change as the predation danger for nestlings changes. In southwest British Columbia, Canada, bald eagle Haliaeetus leucocephalus populations have increased exponentially at ∼5% per year in recent decades and prey upon nestlings of colonial breeding great blue herons Ardea herodias faninni. Motivated by field data on reproductive success in relation to colony size, modeling is used to ask under which circumstances trading off a dilution benefit against colony conspicuousness can improve population reproductive success. That is, which colonial nesting distribution, dispersed and cryptic versus clumped and conspicuous, best mitigates predation danger on nestlings? When predators are territorial, the modeling predicts a dispersed nesting strategy as attack rate increases, but not as predator numbers increase. When predators are non-territorial, the modeling predicts a dispersed nesting strategy as predator numbers and/or attack rates increase. When predators are both territorial and non-territorial, colonial nesting within a predator's territory improves reproductive success when attack rates are low. This suggests nesting in association with territorial predators may offer decreased levels of predation when compared with nesting amongst non-territorial predators. Thus a change in the colony size distribution of colonially breeding species might be anticipated on a landscape experiencing a change in predation danger. [ABSTRACT FROM AUTHOR]

Presents a study that examined neodymium isotope geochemistry of felsic volcanic and intrusive rocks from the Yukon-Tanana terrane (YTT) in the Finlayson Lake region, Yukon, Canada. Geological setting of the YTT in the Finlayson Lake region; Geochemical attributes of the intrusive rocks; Systematics of the neodymium isotopes.

Calc-alkaline batholiths of the Archaean Minto block, northeastern Superior Province, Canada, have pyroxene- and hornblende-bearing mineral assemblages inferred to have crystallized from hot, water-undersaturated magmas at 2·729–2·724 Ga. A regional amphibolite- to granulite-facies tectonothermal event at 2·70 Ga resulted in mild to negligible metamorphic effects on the dominantly granodioritic units. Geochemical, textural and thermobarometric studies define the crystallization history in compositions ranging from cumulate pyroxenite through quartz diorite, granodiorite, granite, and syn-magmatic gabbroic dykes. Early magmatic assemblages include orthopyroxene, clinopyroxene, plagioclase, biotite, Fe–Ti oxides and ternary feldspar, indicating crystallization from magmas containing <2 wt % H2O at 1100–900°C. Water enrichment in the residual melt induced hornblende crystallization at 5 ± 1 kbar, 800–600°C. Characterized by a continuum of large ion lithophile element (LILE)-enriched, high field strength element (HFSE)-depleted compositions, the I-type suite resembles modern continental arc batholiths in composition and size but not primary mineralogy. Magmatic arcs produced between 2·75 and 1·85 Ga commonly have charnockitic components, possibly because slab-derived fluids interacted with mantle wedges at ambient temperatures higher by ∼100°C than at present, producing large volumes of water-deficient magma. [ABSTRACT FROM PUBLISHER]

Northwestern Laurentia, after cratonization at about 1.85 Ga, underwent a series of tectonic and magmatic events during the Proterozoic that were followed by separation of Laurentia from another landmass, probably Australia. The oldest magmatic event produced the Bonnet Plume River Intrusions (BPRI), which intruded the Wernecke Supergroup as short dikes and small stocks. The BPRI are hydrothermally altered tholeiitic diorites, gabbros, and subordinate anorthositic and syenitic rocks, with trace element signatures consistent with a rift origin. Depleted mantle model ages range from 2.29 to 2.57 Ga and ℇ[sub Nd] values range from +0.7 to –1.7. An increasing crustal component is apparent in rocks with more evolved compositions. Four U–Pb zircon ages (1705.9 ± 0.7, 1709.4 ± 1.4, 1711.1 ± 5.1, and 1713.6 ± 12.7 Ma) indicate a Paleoproterozoic age for the BPRI. These dates constrain the age of the Wernecke Supergroup to ca. 1710 Ma, making it the oldest supracrustal succession in western Laurentia, e.g., >240 Ma older than the Belt Supergroup of southeastern British Columbia and the northwestern United States. The Wernecke Supergroup was deposited in the first rift basin to open along the western margin of Laurentia, but was later inverted by the pre-1.6 Ga Racklan Orogeny, an event possibly influenced by transmission of compression from the Yavapai and Mazatzal orogenies in southern Laurentia. The Neoproterozoic southwestern United States – east Antarctica (SWEAT) reconstruction, which places Australia next to northwestern Laurentia, is supported by linkages between Paleoproterozoic and Mesoproterozoic geological features in northwestern Canada and Australia.Après une cratonisation vers 1,85 Ga, le nord-ouest du continent laurentien (Laurentia) a subi une série d'événements tectoniques et magmatiques au cours du Protérozoïque; ces événements ont été suivis par la séparation de Laurentia d'une autre masse continentale, probablement l'Australie. L'événement magmatique le plus ancien a produit les intrusions de la rivière Bonnet Plume (BPRI) qui ont pénétré le Supergroupe de Wernacke en tant que de courts dykes et de petits massifs intrusifs. Les BPRI consistent en des diorites tholéiitiques, des gabbros et des roches subordonnées anorthositiques et syénitiques qui ont subi une altération hydrothermale, avec des signatures d'éléments traces qui concordent avec une origine de fosse. La plage pour les modèles de manteau appauvri varie de 2,29 à 2,57 Ga et les valeurs ℇ[sub Nd] varient de +0,7 à –1,7. Une plus grande composante crustale est apparente dans les roches avec des compositions plus évoluées. Quatre déterminations d'âge U–Pb sur des zircons donnent un âge paléoprotérozoïque pour les BPRI : 1705,9 ± 0,7 Ma, 1709,4 ± 1,4 Ma , 1711,1 ± 5,1 Ma et 1713,6 ± 12,7 Ma. Ces dates limitent l'âge du Supergroupe de Wernecke à environ 1710 Ma, faisant de la séquence supracrustale la plus ancienne du Laurentia occidental, par ex., > 240 Ma plus ancien que le Supergroupe de Belt du sud-est de la Colombie-Britannique et du nord-ouest des États-Unis. Le Supergroupe de Wernecke a été déposé dans le premier bassin de distension qui s'est ouvert le long de la limite ouest de Laurentia mais il a été par la suite inversé par l'orogène de Racklan pré-1,6 Ga, un événement possiblement influencé par la transmission de la compression des orogènes Yavapai et Mazatzal dans le sud du Laurentia. La reconstruction du transect sud-ouest américain – est de l'Antarctique (SWEAT), au Néoprotérozoïque, qui place l'Australie à côté du nord-ouest de Laurentia, est appuyé par des liens entre les caractéristiques géologiques Paléo- et Méso- protérozoïques au nord-ouest du Canada et en Australie.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Traces the origin of Neogene to Quaternary magmatism in northern Cordilleran volcanic province in Canada. Production of petrological image of the lithosphere using phase equilibria calculations; Characteristics of Cordilleran volcanic magmatism; Development of a tectonic model for the origins of the Cordilleran volcanic province magmatism.

Evaluates the character and onset of Neogene-Quartenary volcanism in the northern Cordilleran volcanic province of British Columbia. Petrological, radiometric and other geotectonic data used in the study; Volcanism across the northern Cordillera caused by the incipient rifting of the continental margin of northwestern North America.

Determines the age of peak metamorphism and the postmetamorphic cooling history of the metamorphic-plutonic belt in the southwestern Yukon. Geologic framework; Isotopic dating of metamorphic rocks; Tectonic implications.

Social factors like race and insurance affect transplant outcomes. However, little is known in pediatric heart transplantation. We hypothesized that race and insurance coverage impact listing and waitlist outcomes across eras. Data from the Pediatric Heart Transplant Society multi-center registry prospectively collected between January 1, 2000-December 31, 2019 were analyzed. Patients were divided by race as Black, White and other and by insurance coverage at listing (US governmental, US private and non-US single payer systems (UK, Canada). Clinical condition at listing and waitlist outcomes were compared across races and insurance coverages. Categorical variables were compared using a chi-square test and continuous variables using the Wilcoxon rank sum test. Risk factors for waitlist mortality were examined using multiphase parametric hazard modeling. A sensitivity analysis using parametric hazard explored the interaction between race and insurance. At listing, compared to Whites (n = 5391) and others (n = 1167), Black patients (n = 1428) were older, more likely on US governmental insurance and had cardiomyopathy as the predominant diagnosis (p < 0.0001). Black patients were more likely to be higher status at listing, in hospital, on inotropes or a ventricular assist device (p < 0.0001). Black patients had significantly shorter time on the waitlist compared to other races (p < 0.0001) but had higher waitlist mortality (p = 0.0091), driven by the earlier era (2000-2009) (p = 0.0005), most prominently within the US private insurance cohort (p = 0.015). Outcomes were not different in other insurance cohorts or in the recent era (2010-2019). Black children are older and sicker at the time of listing, deteriorate more often and face a higher wait list mortality, despite a shorter waitlist period and favorable clinical factors, with improvement in the recent era associated with the recent US healthcare reforms. The social construct of race appears to disadvantage Black children by limiting referral, consideration or access to pediatric cardiac transplantation. [ABSTRACT FROM AUTHOR]

In the Lac de Gras (LDG) kimberlite field, Northwest Territories, Canada, coherent kimberlites (CKs) occur as tabular dykes, pipe-shaped diatremes, and irregular bodies without well-defined geometries. Combining the morphology of CK bodies with the occurrence of fragmented olivine microcrysts allows distinction of four CK types at LDG: (1) dykes with no broken olivine; (2) CK without well-defined but probable sheet geometry and no broken olivine; (3) pipe-filling CK (pfCK) with abundant broken olivine and (4) pfCK with no broken olivine. These features suggest an intrusive origin for type 1 and, probably, type 2 CK; a high-energy extrusive emplacement for CK type 3 and a low-energy intrusive or extrusive emplacement for the CK type 4. Here, we compare petrographic and whole-rock, olivine and spinel compositional data for high-energy extrusive pfCK, low-energy pfCK and intrusive CK units to understand the factors controlling their variable emplacement styles. Extrusive CK contain more abundant groundmass phlogopite and monticellite, lower carbonate/silicate mineral abundance ratios and significantly lower dolomite and pleonaste-spinel abundances compared to intrusive CK. This indicates greater CO2 loss and higher H2O/CO2 in the melt phase for the extrusive CK during emplacement. Lower incompatible element concentrations in the extrusive CKs and different chromite Ti# and olivine rim Mg# indicate derivation from distinct primitive melt compositions. The extrusive CK feature higher ɛNdi and marginally higher ɛHfi compositions than the intrusive CK, pointing to derivation from distinct sources. These findings strongly imply that distinct primary melt compositions were largely responsible for the differences in emplacement styles of CK at LDG. Low-energy pfCKs have similar olivine rim Mg#, chromite Ti# and, hence, primitive melt compositions to the high-energy extrusive CK samples. Their marginally different emplacement styles may depend on local factors, such as changing stress regimes, or slightly different volatile concentrations. Both types of pfCK might reflect the waning stages of volcanic sequences resulting from the eruption of a segregated magma column that started with pipe excavation and the explosive emplacement of gas-rich magma (volcaniclastic kimberlite), followed by the less energetic emplacement of melt-rich magma (pfCK). This hypothesis underscores different primary melt compositions for dyke vs pipe-forming (and filling) kimberlites and hence a fundamental primary melt control on the explosivity of kimberlites. [ABSTRACT FROM AUTHOR]

Objective: During the last decade, methamphetamine use and issues surrounding its toxicity have triggered major concern in the Canadian government, leading to signiicant changes in drug policy and funding strategies to limit the societal impact of methamphetamine-related harms. This concern appears justiied by research which found in 2005-2006 that 21% of all youth admissions to inpatient substance abuse treatment centres in Canada were due primarily to methamphetamine abuse. Given these patterns of treatment use and targeted governmental initiatives, an open question is whether the demand for methamphetamine treatment found in 2005-2006 has decreased. Our study aims to provide follow-up estimates of admissions for 2009-2010, as well as important trend information for these periods. Method: We developed a comprehensive list of all Canadian residential youth substance abuse treatment facilities. The executive director of each facility was asked about the site's annual caseload, and the proportion of cases primarily due to methamphetamine abuse within the past 12 months. Results: Our survey data for the periods of 2005-2006 and 2009-2010 show marked reductions in admissions. In 2009-2010, we found that about 6% of all admissions were due primarily to methamphetamine abuse, a substantial drop from the 21% reported in our 2005-2006 study. Conclusions: Our data show a significant national reduction in methamphetamine-related admissions. Other reports show that methamphetamine-related treatment admissions in the United States and Mexico declined sharply during 2005-2008, reportedly in association with Mexico's methamphetamine precursor chemical controls, raising the possibility that the controls may also be associated with the declines reported here. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive synthesis of virtually all units and events of Early and Middle Proterozoic age in the Yukon, spanning ~1 Ga. Early and Middle Proterozoic time was dominated by a series of extensional-basin-forming events punctuated by orogenesis, magmatism, and hydrothermal activity. Basinal deposits include the Wernecke Supergroup (>1.71 Ga), Pinguicula Group (~1.38 Ga), and Mackenzie Mountains Supergroup (1.00–0.78 Ga). Igneous rocks include the Bonnet Plume River Intrusions (1.71 Ga), Slab volcanics (≥1.6 Ga), Hart River sills and volcanics (1.38 Ga), and Bear River (Mackenzie) dykes (1.27 Ga). A voluminous hydrothermal event generated the widespread Wernecke breccias at 1.60 Ga. The Racklan orogeny deformed the Wernecke Supergroup prior to emplacement of the Wernecke Breccia. The Corn Creek orogeny deformed Mackenzie Mountains Supergroup and older rocks prior to deposition of the Windermere Supergroup (<0.78 Ga). Long intervals with scanty rock records extended for as much as 300 Ma and appear to represent periods of crustal stability and subaerial conditions. By the time of Windermere rifting (<0.78 Ga), the supracrust of northwestern Laurentia was a mature, largely denuded orogenic belt with a composite sedimentary–metamorphic–igneous character. New isotopic data include Nd depleted mantle model ages for the Wernecke Supergroup (2.28–2.69 Ga) and Wernecke Breccia (2.36–2.96 Ga), a U–Pb zircon age for a Hart River sill 1381.9+5.3-3.7 (Ma), detrital U–Pb zircon ages from the basal Pinguicula Group (1841–3078 Ma), detrital muscovite ages from the Mackenzie Mountains Supergroup (1037–2473 Ma), and muscovite 40Ar/39Ar cooling ages from the Wernecke Supergroup (788 ± 8 and 980 ± 4 Ma). [ABSTRACT FROM AUTHOR]

The Fire Lake formation of the Yukon-Tanana terrane in the Finlayson Lake region, Yukon, Canada, consists primarily of Late Devonian (ca. 365–360 Ma) mafic metavolcanic rocks and smaller volumes of mafic and ultramafic subvolcanic metamorphosed intrusions. In this paper, field, geochemical, and Nd isotope attributes of these rocks are presented in an attempt to understand their tectonic setting, the magmatic processes involved in their formation, and their roles in Cordilleran crustal growth. The mafic rocks of the Fire Lake formation exhibit a wide diversity of geochemical signatures and are classified into seven chemically defined suites: (1) backarc-basin basalt, (2) enriched mid-oceanic-ridge basalt (E-MORB), (3) oceanic-island basalt (OIB), (4) Th-rich OIB, (5) boninite, (6) island-arc tholeiite, and (7) fight rare earth element (LREE)—enriched island-arc tholeiite. The diversity of geochemical signatures is interpreted to represent variable mixtures of asthenospheric (MORB-type) mantle, subarc mantle wedge, and lithospheric (OIB-type) mantle with or without elemental contributions from the subducted slab and/or continental crust. These suites of rocks are also associated with fine-grained basinal sedimentary facies, variations in metavolcanic and metasedimentary unit thickness, extensional synvolcanic faults, and apparent extensional-fault—controlled emplacement of mafic intrusive rocks and hydrothermal volcanic-hosted massive sulfide mineralization. The suites also exhibit a broad spatial distribution; those with “arc” signatures (Nb/Thmn. < 1; mn—normalized to primitive mantle values) are located primarily in the western parts of the formation, and suites with “nonarc” signatures (Sb/Thmn ≥ 1) are located primarily within the eastern parts of the formation. Collectively, these geologic and geochemical attributes are interpreted to stem from the transition from arc magmatism to the initiation of an extensional backarc basinal environment associated with an east-dipping subduction zone. The initiation of backarc-basin magmatism recorded in the Fire Lake formation was part of a much larger Late Devonian backarc basinal system forming along the western edge of the margin of North America. The Fire Lake formation is interpreted to represent (1) the commencement of Yukon-Tanana arc rifting and separation from the North American cratonic margin, and (2) the initiation of a marginal (backarc) basin (now the Slide Mountain terrane) inboard of the Yukon-Tanana arc system. This tectonic evolution likely occurred either as a result of slab rollback toward the west within the convergent margin responsible for Yukon-Tanana arc activity or as a result of the propagation of the Slide Mountain backarc-basin spreading ridges into the Yukon-Tanana arc system. This Yukon-Tanana arc rifting episode was also broadly coincident with rifting and hydrothermal activity within rocks of the North American craton. The geochemical and isotopic signatures of magmatic rocks in the Fire Lake formation have some features similar to intraoceanie arc rocks (e.g., boninites, island-arc tholeiites), and many have juvenile Nd isotope signatures (i.e., εNd(t) > 0; most have εNd(t) > +5), suggesting that the pericratonic terranes of the northern Cordillera have a significant juvenile component. If this is the case throughout the Yukon-Tanana terrane, then the pericratonic terranes may have contributed much more juvenile material to Cordilleran crustal growth in the Phanerozoic than has previously been considered. [ABSTRACT FROM AUTHOR]

The 1.27 Ga Mackenzie dyke swarm, the largest on Earth, radiates from a point in the western Canadian Arctic and extends across much of the Canadian Shield. Possible western extensions of the swarm are largely obscured by younger sedimentary cover. Paleoproterozoic inliers in northern Yukon host the Bear River dykes (BRD), herein dated by U–Pb baddeleyite and zircon methods at 1268.5 ± 1.5 Ma and 1264.6 ± 1.2 Ma. The BRD share similar geochemical and Nd-isotopic characteristics with the Mackenzie dykes and the coeval Coppermine River basalts, and are regarded as products of the same plume. Hydrothermal activity at ∼1270 Ma in breccia of the Nor mineral occurrence, northwest of the BRD, was probably generated by BRD at depth. The BRD generally strike northwest, approximately 90° to the orientation predicted by the radiating dyke model. This difference may be explained by an anomalous local stress field at the time of BRD emplacement, or reorientation of BRD during subsequent events of Cordilleran deformation. Using the Nor mineral occurrence as the westernmost locale of Mackenzie dyking, and assuming a model of uniform dyke radiation, the arc of the Mackenzie swarm is at least 50° greater than previously recognized, bringing the total arc of dyke radiation to >150°. [Copyright &y& Elsevier]

Jurassic sedimentary rocks of southern to central Quesnellia record the history of the Quesnellian magmatic arc and reflect increasing continental influence throughout the Jurassic history of the terrane. Standard petrographic point counts, geochemistry, Sm–Nd isotopes and detrital zircon geochronology, were employed to study provenance of rocks obtained from three areas of the terrane. Lower Jurassic sedimentary rocks, classified by inferred proximity to their source areas as proximal or proximal basin are derived from an arc source area. Sandstones of this age are immature. The rocks are geochemically and isotopically primitive. Detrital zircon populations, based on a limited number of analyses, have homogeneous Late Triassic or Early Jurassic ages, reflecting local derivation from Quesnellian arc sources. Middle Jurassic proximal and proximal basin sedimentary rocks show a trend toward more evolved mature sediments and evolved geochemical characteristics. The sandstones show a change to more mature grain components when compared with Lower Jurassic sedimentary rocks. There is a decrease in εNdT values of the sedimentary rocks and Proterozoic detrital zircon grains are present. This change is probably due to a combination of two factors: (1) pre-Middle Jurassic erosion of the Late Triassic – Early Jurassic arc of Quesnellia, making it a less dominant source, and (2) the increase in importance of the eastern parts of Quesnellia and the pericratonic terranes, such as Kootenay Terrane, both with characteristically more evolved isotopic values. Basin shale environments throughout the Jurassic show continental influence that is reflected in the evolved geochemistry and Sm–Nd isotopes of the sedimentary rocks. The data suggest southern Quesnellia received material from the North American continent throughout the Jurassic but that this continental influence was diluted by proximal arc sources in the rocks of proximal derivation. The presence of continent-derived material in the distal sedimentary rocks of this study suggests that southern Quesnellia is comparable to known pericratonic terranes. [ABSTRACT FROM AUTHOR]

Documents boninitic magmatism within the continental Yukon-Tanana terrane in Canada. Geologic setting and stratigraphy; Geochemical characteristics of the boninitic rocks; Evidence for boninitic magmatism linked to continental crust; Petrological models explaining the thermal and petrological requirements of the Fire Lake boninites.

New mapping, mineralogical, and geochemical studies help characterize late Tertiary primitive, alkaline, sodic basanite, alkali olivine basalt, transitional basalt, and diabase in the Nechako River, Whitesail Lake, and McLeod Lake map areas of central British Columbia and distinguish the Miocene Cheslatta Lake suite. The suite encompasses scattered erosional remnants of topographically distinct, columnar-jointed, olivine-phyric basalt and diabase volcanic necks, dykes, and associated lava flows north of the Anahim volcanic belt and west of the Pinchi Fault. Volcanic centres at Alasla Mountain and at Cutoff Creek, near Cheslatta Lake, are proposed as type areas. Olivine, plagioclase, and pyroxene phenocrysts, megacrysts, and (or) xenocrysts; common ultramafic xenoliths; and rare but significant plutonic and metamorphic xenoliths are characteristic. Basanite, transitional basalt, and alkali olivine basalt groundmass contain plagioclase, clinopyroxene, Fe-Ti oxides, feldspathoid, olivine, and apatite. The Cheslatta Lake suite is characterized by its alkaline character, olivine-rich (>10 wt.%) normative mineralogy, and silica-undersaturated nature (>1 wt.% normative nepheline; hypersthene-normative rocks are uncommon). Mg numbers vary between 72–42. Some samples encompass near-primitive mantle melt compositions. Cheslatta Lake suite rocks in the Nechako River area are distinguished from the underlying Eocene Endako and stratigraphically higher Neogene Chilcotin groups basaltic andesite lavas within the study area, and from the Chilcotin Group basalt in the type area south of the Anahim volcanic belt, by form, preserved thickness, phenocryst–xenocryst mineralogy, amygdule abundance, included xenoliths, isotopic age, and major and incompatible, high field strength, and rare-earth trace element contents.Une nouvelle cartographie et de nouvelles études minéralogiques et géochimiques aident à caractériser la basanite sodique, alcaline et primitive du Tertiaire tardif, le basalte alcalin à olivine, le basalte de transition et la diabase dans les régions cartographiques de la rivière Nechako et des lacs Whitesail et McLeod du centre de la Colombie-Britannique et aident à distinguer la suite de Cheslatta Lake, datant du Miocène. La suite comprend des lambeaux épars de l'érosion de roches topographiquement distinctes et à structure prismée; ces roches comprennent des basaltes à olivine porphyrique, des « necks » de diabase volcanique, des dykes et des coulées de lave associées, au nord de la ceinture volcanique Anahim et à l'ouest de la faille Pinchi. Nous proposons les centres volcaniques du mont Alasla et du ruisseau Cutoff, près du lac Cheslatta, comme régions types. Les roches suivantes sont caractéristiques des phénocristaux, des mégacristaux et (ou) des xénocristaux d'olivine, de plagioclase et de pyroxène; des xénolites ultramafiques communs et de rares mais significatifs xénolites plutoniques et métamorphiques. La matrice rocheuse de basanite, de basalte de transition et de basalte alcalin à olivine comprend du plagioclase, du clinopyroxène, des oxydes de Fe–Ti, des feldspathoïdes, de l'olivine et de l'apatite. La suite de Cheslatta Lake est caractérisée par son caractère alcalin, sa minéralogie normative riche en olivine (>10 % en poids) et sa sous-saturation en silice (les roches à > 1 % en poids de néphéline normative, hypersthène normatif sont peu communes). Les nombres pour le Mg varient entre 72 et 42. Quelques échantillons présentent des compositions du manteau quasi-primitif en fusion. Dans la région de la rivière Nechako, les roches de la suite de Cheslatta Lake se distinguent des roches sous-jacentes Endako, datant de l'Éocène, et des laves basaltiques à andésite des groupes Chilcotin, datant du Néogène, stratigraphiquement plus hautes ainsi que du basalte du Groupe Chilcotin dans la région type au sud de la ceinture volcanique Anahim par les points suivants la forme, la conservation de l'épaisseur, la minéralogie des phénocristaux–xénocristaux, l'abondance d'éléments amygdaloïdes, les xénolites inclus, l'âge isotopique ainsi que, significatif et incompatible, une grande intensité du champ et des contenus trace en éléments des terres rares.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

AbstractBackground: Newfoundland has one of the highest rates of neural tube defects in North America. Given the association between low maternal folic acid levels and neural tube defects, a cross-sectional study was conducted to obtain baseline data on the folate and vitamin B[sub 12] status of a sample of women in Newfoundland who were pregnant.Methods: Blood samples were collected between August 1996 and July 1997 from 1424 pregnant women in Newfoundland during the first prenatal visit (at approximately 16 weeks' gestation); this represented approximately 25% of the women in Newfoundland who were pregnant during this period. The samples were analysed for serum folate, vitamin B[sub 12], red blood cell folate and homocysteine.Results: Median values for serum folate, red blood cell folate and serum vitamin B[sub 12] were 25 nmol/L, 650 nmol/L and 180 pmol/L, respectively. On the basis of the interpretive criteria used for red blood cell folate status, 157 (11.0%) of the 1424 women were deficient (< 340 nmol/L) and a further 180 (12.6%) were classified as indeterminate (340-420 nmol/L). Serum homocysteine levels, measured in subsets of the red blood cell folate status groups, supported the inadequate folate status. Serum vitamin B[sub 12] levels of 621 (43.6%) women were classified as deficient or marginal; however, the validity of the interpretive criteria for pregnant women is questionable.Interpretation: A large proportion of pregnant women surveyed in Newfoundland in 1997 had low red blood cell folate levels. [ABSTRACT FROM AUTHOR]