Memorial University of Newfoundland

About: Memorial University of Newfoundland is a education organization based out in St. John's, Newfoundland and Labrador, Canada. It is known for research contribution in the topics: Population & Gadus. The organization has 13818 authors who have published 27785 publications receiving 743594 citations. The organization is also known as: Memorial University & Memorial University of Newfoundland and Labrador.

The clinical course of left ventricular hypertrophy in dialysis patients.

Abstract: To determine the clinical and echocardiographic outcome of left ventricular hypertrophy a prospective study was undertaken of 104 nondiabetic dialysis patients without dilated cardiomyopathy, who were

Animals and the zoogeochemistry of the carbon cycle

Abstract: BACKGROUND Modern advances in remote-sensing technology are providing unprecedented opportunities to accurately measure the global distribution of carbon held in biomass within ecosystems. Such highly spatially resolved measures of biomass carbon are intended to provide an accurate inventory of global carbon storage within ecosystems. They are also needed to test the accuracy of carbon cycle models that predict how global changes that alter biogeochemical functions—such as carbon assimilation via photosynthesis, carbon losses via plant and microbial respiration, and organic matter deposition in soils and sediments—will affect net ecosystem carbon uptake and storage. Emerging ecological theory predicts that wild animals stand to play an important role in mediating these biogeochemical processes. Furthermore, many animal species roam widely across landscapes, creating a spatial dynamism that could regulate spatial patterning of vegetation biomass and carbon uptake and soil carbon retention. But such zoogeochemical effects are not measured by current remote-sensing approaches nor are they factored into carbon cycle models. Studies are now providing new quantitative insights into how the abundance, diversity, and movement of animal species across landscapes influence the nature and magnitude of zoogeochemical affects. These insights inform how to account for animals in remote-sensing applications and in carbon cycle models to more accurately predict carbon exchange between ecosystems and the atmosphere in the face of global environmental change. ADVANCES Zoogeochemical effects have been measured using manipulative experiments that exclude or add focal wild animal species or along landscape gradients where animal abundances or diversity vary naturally. Our review of these studies, which cover a wide diversity of taxa (vertebrates and invertebrates and large- and small-bodied organisms) and ecosystems, reveals that animals can increase or decrease rates of biogeochemical processes, with a median change of 40% but ranging from 15 to 250% or more. Moreover, models that embody zoogeochemical effects reveal the potential for considerable under- or overestimates in ecosystem carbon budgets if animal effects are not considered. The key challenge, in light of these findings, is comprehensively accounting for spatially dynamic animal effects across landscapes. We review new developments in spatial ecosystem ecology that offer the kind of analytical guidance needed to link animal movement ecology to geospatial patterning in ecosystem carbon uptake and storage. Considerations of animal movement will require highly resolved spatially explicit understanding of landscape features, including topography, climate, and the spatial arrangement of habitat patches and habitat connectivity within and among ecosystems across landscapes. We elaborate on advances in remote-sensing capabilities that can deliver these critical data. We further review new geospatial statistical methods that, when combined with remote-sensing data and spatial ecosystem modeling, offer the means to comprehensively understand and predict how zoogeochemical-driven landscape processes regulate spatial patterns in carbon distribution. OUTLOOK There is growing interest to slow climate change by enlisting ecological processes to recapture atmospheric carbon and store it within ecosystems. Wild animal species are rarely considered as part of the solution. Instead, it is often held that managing habitat space to conserve wild animals will conflict with carbon storage. Our integrative review offers a pathway forward for deciding when and how conserving or managing a diversity of animal species could in fact enhance ecosystem carbon uptake and storage. Such understanding informs international climate and biodiversity initiatives such as those described by the United Nations Convention on Biological Diversity and national biodiversity strategies and climate action plans. All of these initiatives require better resolution of how biodiversity effects on ecosystem structure and biogeochemical functioning will become altered by global change.

Tolerogenic semimature dendritic cells suppress experimental autoimmune thyroiditis by activation of thyroglobulin-specific CD4+CD25+ T cells.

Abstract: Ex vivo treatment of bone marrow-derived dendritic cells (DCs) with TNF-alpha has been previously shown to induce partial maturation of DCs that are able to suppress autoimmunity. In this study, we demonstrate that i.v. administration of TNF-alpha-treated, semimature DCs pulsed with thyrogloblin (Tg), but not with OVA Ag, inhibits the subsequent development of Tg-induced experimental autoimmune thyroiditis (EAT) in CBA/J mice. This protocol activates CD4(+)CD25(+) T cells in vivo, which secrete IL-10 upon specific recognition of Tg in vitro and express regulatory T cell (Treg)-associated markers such as glucocorticoid-induced TNFR, CTLA-4, and Foxp3. These CD4(+)CD25(+) Treg cells suppressed the proliferation and cytokine release of Tg-specific, CD4(+)CD25(-) effector cells in vitro, in an IL-10-independent, cell contact-dependent manner. Prior adoptive transfer of the same CD4(+)CD25(+) Treg cells into CBA/J hosts suppressed Tg-induced EAT. These results demonstrate that the tolerogenic potential of Tg-pulsed, semimature DCs in EAT is likely to be mediated through the selective activation of Tg-specific CD4(+)CD25(+) Treg cells and provide new insights for the study of Ag-specific immunoregulation of autoimmune diseases.