Explore the vast range of titles available.

Parkinson's disease is characterized by the loss of dopamine (DA) neurons in the substantia nigra pars compacta (SNc). DA neurons in the ventral tegmental area are more resistant to this degeneration than those in the SNc, though the mechanisms for selective resistance or vulnerability remain poorly understood. A key to elucidating these processes may lie within the subset of DA neurons that corelease glutamate and express the vesicular glutamate transporter VGLUT2. Here, we addressed the potential relationship between VGLUT expression and DA neuronal vulnerability by overexpressing VGLUT in DA neurons of flies and mice. In Drosophila, VGLUT overexpression led to loss of select DA neuron populations. Similarly, expression of VGLUT2 specifically in murine SNc DA neurons led to neuronal loss and Parkinsonian behaviors. Other neuronal cell types showed no such sensitivity, suggesting that DA neurons are distinctively vulnerable to VGLUT2 expression. Additionally, most DA neurons expressed VGLUT2 during development, and coexpression of VGLUT2 with DA markers increased following injury in the adult. Finally, conditional deletion of VGLUT2 made DA neurons more susceptible to Parkinsonian neurotoxins. These data suggest that the balance of VGLUT2 expression is a crucial determinant of DA neuron survival. Ultimately, manipulation of this VGLUT2-dependent process may represent an avenue for therapeutic development.

Canada and the United States are geographically large federal states with strong central (national) governments. These governments connect to partially self-governing provincial, state, and/or territorial governments that pose ongoing tensions in health systems. Like most countries, both are confronted with the need to contain spiraling costs while delivering better healthcare and promoting better population health. At the same time, they are challenged by global authorities, such as the United Nations, to deliver universal healthcare, primary healthcare, respond to development goals, and address the structural drivers of health inequities. Data from both countries affirms public trust in nurses, with the expectation that they will act in the public interest to improve care and population health. In this article, we focus on Canada. First, we briefly describe the history of health system development and reform, and then consider nursing policy and advocacy in the 21st century. Finally, we offer examples of nurse-led solutions from Canadian nurses and nursing associations to build, overhaul and improve health systems and influence health policy.

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).

Age is the greatest risk factor for Parkinson's disease (PD) which causes progressive loss of dopamine (DA) neurons, with males at greater risk than females. Intriguingly, some DA neurons are more resilient to degeneration than others. Increasing evidence suggests that vesicular glutamate transporter (VGLUT) expression in DA neurons plays a role in this selective vulnerability. We investigated the role of DA neuron VGLUT in sex‐ and age‐related differences in DA neuron vulnerability using the genetically tractable Drosophila model. We found sex differences in age‐related DA neurodegeneration and its associated locomotor behavior, where males exhibit significantly greater decreases in both DA neuron number and locomotion during aging compared with females. We discovered that dynamic changes in DA neuron VGLUT expression mediate these age‐ and sex‐related differences, as a potential compensatory mechanism for diminished DA neurotransmission during aging. Importantly, female Drosophila possess higher levels of VGLUT expression in DA neurons compared with males, and this finding is conserved across flies, rodents, and humans. Moreover, we showed that diminishing VGLUT expression in DA neurons eliminates females' greater resilience to DA neuron loss across aging. This offers a new mechanism for sex differences in selective DA neuron vulnerability to age‐related DA neurodegeneration. Finally, in mice, we showed that the ability of DA neurons to achieve optimal control over VGLUT expression is essential for DA neuron survival. These findings lay the groundwork for the manipulation of DA neuron VGLUT expression as a novel therapeutic strategy to boost DA neuron resilience to age‐ and PD‐related neurodegeneration. Dopamine neuron VGLUT mediates age‐ and sex‐related differences in dopamine neurodegeneration during aging. Female Drosophila, rats and humans express more VGLUT in dopamine neurons than males, and VGLUT knockdown in dopamine neurons diminishes sex differences in vulnerability to age‐related degeneration. The ability to finely tune dopamine neuron VGLUT expression boosts resilience while either too little or too much VGLUT leaves dopamine neurons more vulnerable to neurodegeneration.

New field and geochronological data are used to define the distribution of Mesoarchean basement rocks in the south-central Slave Province. This distribution reflects a single contiguous basement terrane that we propose to call the Central Slave Basement Complex. It shows a structural topology that is internally consistent and compatible with known regional folding and faulting events. A sample of a proposed basement gneiss below the Courageous Lake greenstone belt, central Slave Province, has been dated by U-Pb methods and yields an age of 3325 ± 8 Ma, consistent with the new basement distribution. This sample also contains 2723 ± 3 Ma metamorphic zircon and ca. 2680 Ma titanite. The Central Slave Basement Complex is overlain by a thin, discontinuous, but distinctive cover sequence that includes minor volcanic rocks, clastic sedimentary rocks, and banded iron formation. All previously known and some new occurrences of this distinctive cover sequence occur in the immediate stratigraphic hanging wall of the Central Slave Basement Complex, locally overlying a preserved in situ unconformity. We propose to call this post-2.93 Ga cover sequence the Central Slave Cover Group. It is perhaps best typified by detrital chromite-bearing, fuchsitic quartzites. Formal formation names are proposed for the spatially separate occurrences of the Central Slave Cover Group. Detrital zircon ages are presented for one of the formations of the Central Slave Cover Group, the Patterson Lake Formation, which occurs on the western flank of a local basement culmination known as the Sleepy Dragon Complex. The detrital zircon data provide evidence for two discrete basement sources dated at ca. 2943 Ma and ca. 3147-3160 Ma. These detrital ages reinforce the depositional link between the Central Slave Cover Group and underlying crystalline rocks of the Central Slave Basement Complex.

Twenty-three new, precise Eocene U-Pb and (40)Ar/(39)Ar age determinations for calc-alkaline volcanic rocks of the Ootsa Lake Group and associated intrusive rocks, widespread in the Nechako Plateau in central British Columbia, constrain the timing of the Eocene magmatism to 53.2-47.6 Ma, with a local duration of as little as 2-3 million years.

Hers is an amazing nursing success story, to be sure. And [Pat Griffin]'s many accomplishments and her visionary leadership were celebrated eloquently by Judith Shamian in the eulogy she delivered at Pat's funeral (see www.casn.ca). But my words here are not about what she did; they are about who she was - the amazing person and my friend. And they're about trying to find ways to say goodbye. I wish I could say that being around Pat over the time of her illness brought out my courageous, supportive, rational \"nurse\" heart - the one that got me through brutal clinical days of telling people that their child had a brain injury or their partner had just died. But it did not. Pat's illness filled me with sadness and a paralyzing frustration that I could do nothing to make it go away. My personal heart never quite believed that things might end the way my professional brain was telling me they could. Somehow Pat always rallied, and, despite the evidence, I let myself hope she always would.

A metamorphic high, the Selkirk-Monashee-Cariboo complex (SMC) is a 200 km × 60 km area cored by K-feldspar-sillimanite rocks. In the Mica Creek area, there appear to be no discontinuities in metamorphic isograds, structural trends, or the Late Precambrian stratigraphic units. U-Pb dates suggested that the continuities may only be apparent. In this paper, we report ^sup 40^Ar/^sup 39^Ar dates on muscovite, biotite, and hornblende from some of the same samples dated by U-Pb and samples that crop out very close to the dated samples. The goal was to set constraints on the alternative interpretations of the metamorphic-structural history. These interpretations are as follows: (1) U-Pb ages record different times of metamorphic crystallization and deformation, and there are significant tectonic displacements: the mappable continuities are only apparent. (2) The structural and stratigraphic continuity is real, and the range is due to localized heating and deformation events spanning ~100 Ma; the relative uniformity of the ^sup 40^Ar/^sup 39^Ar dates over a distance of ~45 km suggests that the area behaved as a coherent cooling unit. [PUBLICATION ABSTRACT]

A metamorphic high, the Selkirk–Monashee–Cariboo complex (SMC) is a 200 km × 60 km area cored by K-feldspar–sillimanite rocks. In the Mica Creek area, there appear to be no discontinuities in metamorphic isograds, structural trends, or the Late Precambrian stratigraphic units. U–Pb dates suggested that the continuities may only be apparent. In this paper, we report 40 Ar/ 39 Ar dates on muscovite, biotite, and hornblende from some of the same samples dated by U–Pb and samples that crop out very close to the dated samples. The goal was to set constraints on the alternative interpretations of the metamorphic–structural history. These interpretations are as follows: (1) U–Pb ages record different times of metamorphic crystallization and deformation, and there are significant tectonic displacements; the mappable continuities are only apparent. (2) The structural and stratigraphic continuity is real, and the range is due to localized heating and deformation events spanning ~100 Ma; the relative uniformity of the 40 Ar/ 39 Ar dates over a distance of ~45 km suggests that the area behaved as a coherent cooling unit.