109 research outputs found
Examining the effect of rotation sequence on biological nitrogen fixation of pulse crops
Nitrogen (N) is often the most limiting nutrient in prairie crop production and is applied in the greatest quantity. Including pulse crops in rotations has become a popular option due to their ability to form symbiotic relationships with dinitrogen-fixing bacteria. This relationship means pulse crops can acquire a large proportion of their N needs from biological N fixation (BNF). In previous studies, mixed results of rotation effects on a pulse cropâs ability to fix N were reported at Scott, SK, Swift Current SK, and from a greenhouse experiment using soils from Central Butte, SK. These results led to questioning if BNF is affected by a previous crop in a rotation. To address this question, research was conducted at multiple locations across Saskatchewan. The natural abundance 15N isotope dilution method was used to estimate BNF in pulse crops grown on oilseed and cereal stubble in the Brown, Dark Brown, and Black soil zones. Soil samples were collected from each rotation to characterize sites and identify soil physical, chemical, and microbiological properties that may have affected BNF in pulse crops. Additionally, a controlled environment experiment was performed to determine if stubble quality (i.e., wheat and canola) affected N-mineralization potential before and after a pulse crop was grown. In the field study, an interaction between site and stubble affected BNF, where pulse crops grown on cereal stubble generally had higher BNF except at Biggar in 2017, and at Davidson and Theodore in 2018; BNF in these pulse crops was higher when grown on oilseed stubble. Inorganic N and available P contents may have affected BNF at some locations. A persistent pattern was observed in microbial biomass carbon (C) and phospholipid fatty acid (PLFA) biomarker results, where levels of each were higher in soil from pulse crops grown on oilseed stubble at Davidson, Theodore, and Springside. Climatic conditions also may have affected BNF at each location, especially in 2018, as conditions were hotter and drier compared to historical averages. In the controlled environment study, BNF was not affected by soil or stubble; however, soil affected N acquisition and yields. A similar pattern to field results for PLFA biomarkers was observed, where total biomarkers were higher in oilseed stubbles and in the Black soil. Gross mineralization and nitrification rates were not affected by stubble before or after field pea was grown. Based on the variable results from the field and controlled environment studies, seeding pulse crops on oilseed stubble in the Brown, Dark Brown, or Black soil zones is not recommended
La consommation dâalcool et de drogues illicites chez les adolescents francophones du Manitoba
Cet article sâintĂ©resse Ă la consommation dâalcool et de drogues illicites des adolescents francophones. Un de ses principaux objectifs est de dĂ©crire les comportements Ă risque des Ă©lĂšves de la 9e Ă la 12e annĂ©e des Ă©coles rurales et urbaines de la Division scolaire franco-manitobaine (DSFM). On y prĂ©sente la prĂ©valence de la consommation dâalcool et de drogues des adolescents canadiens en comparaison avec celle des jeunes francophones du Manitoba. De plus, diffĂ©rents aspects, tels lâexpĂ©rimentation, les facteurs de risques et les consĂ©quences reliĂ©es Ă la consommation dâalcool et de drogues, sont abordĂ©s afin de brosser un tableau des comportements et des tendances de cette consommation. Dans lâensemble, les rĂ©sultats de lâenquĂȘte en milieu francophone minoritaire sont comparables Ă ceux obtenus chez la majoritĂ© anglophone.This article addresses alcohol and illicit drug consumption among Francophone teens. One of the primary objectives of the article is to describe at-risk behaviours of students in grades 9 through 12 in rural and urban schools of the Division scolaire franco-manitobaine (DSFM). The prevalence of alcohol and drug use among Canadian teens in general is compared to that of Francophone youth in Manitoba. In addition, the author examines various aspects of this issueâsuch as experimentation, risk factors and consequences of alcohol and drug useâto paint a picture of behaviours and trends tied to drug and alcohol consumption. Overall, results of the study in a minority Francophone context are comparable to findings for the Anglophone majority
Post-Secondary Student Belonging in a Virtual Learning Environment During COVID-19
Psychological and social adjustment and academic success in post-secondary institutions are supported by a sense of belonging to a social group and having meaningful relationships with other students, staff, and faculty members. This exploratory study used a qualitative approach to investigate post-secondary studentsâ sense of belonging in the virtual learning environment during the COVID-19 pandemic. The study was conducted at a small Western Canadian university. Semi-structured interviews were conducted with 20 participants who were undergraduate students, from various faculties, and in different years in their programs. Findings were clustered into three themes: (1) student expectations of university, (2) impact of virtual learning environments on students, and (3) the role of educators. Recommendations are included to enhance support and belonging for post-secondary students in virtual learning environments.Lâadaptation psychologique et sociale et la rĂ©ussite dans les Ă©tablissements postsecondaires sont soutenues par un sentiment dâappartenance Ă un groupe social et par des relations significatives avec les autres Ă©tudiants, le personnel et les membres du corps professoral. Cette Ă©tude exploratoire utilise une approche qualitative pour enquĂȘter sur le sentiment dâappartenance Ă lâenvironne-ment dâapprentissage virtuel des Ă©tudiants de niveau postsecondaire pendant la pandĂ©mie de COVID-19. LâĂ©tude a Ă©tĂ© menĂ©e dans une petite universitĂ© de lâOuest canadien. Une entrevue semi-dirigĂ©e a Ă©tĂ© menĂ©e auprĂšs de vingt Ă©tudiants de premier cycle, de diverses facultĂ©s et annĂ©es dâĂ©tudes. Les rĂ©sultats ont Ă©tĂ© regroupĂ©s sous trois thĂ©matiques : (1) les attentes des Ă©tudiants vis-Ă -vis de lâuniversitĂ©; (2) lâimpact des environnements dâapprentissage virtuels sur les Ă©tudiants; et (3) le rĂŽle des enseignants. Des recommandations sont proposĂ©es afin dâamĂ©liorer le soutien et lâappartenance des Ă©tudiants de niveau postsecondaire dans les environnements dâapprentissage virtuels
Experience of Health Leadership in Partnering With University-Based Researchers in Canada â A Call to âRe-imagineâ Research
Background: Emerging evidence that meaningful relationships with knowledge users are a key predictor of research use has led to promotion of partnership approaches to health research. However, little is known about health system experiences of collaborations with university-based researchers, particularly with research partnerships in the area of health system design and health service organization. The purpose of the study was to explore the experience and perspectives of senior health managers in health service organizations, with health organization-university research partnerships. Methods: In-depth, semi-structured interviews (n = 25) were conducted with senior health personnel across Canada to explore their perspectives on health system research; experiences with health organization-university research partnerships; challenges to partnership research; and suggested actions for improving engagement with knowledge users and promoting research utilization. Participants, recruited from organizations with regional responsibilities, were responsible for system-wide planning and support functions. Results: Research is often experienced as unhelpful or irrelevant to decision-making by many within the system. Research, quality improvement (QI) and evaluation are often viewed as separate activities and coordinated by different responsibility areas. Perspectives of senior managers on barriers to partnership differed from those identified in the literature: organizational stress and restructuring, and limitations in readiness of researchers to work in the fast-paced healthcare environment, were identified as major barriers. Although the need for strong executive leadership was emphasized, âmulti-system actionâ is needed for effective partnerships. Conclusion: Common approaches to research and knowledge translation are often not appropriate for addressing issues of health service design and health services organization. Nor is the research community providing expertise to many important activities that the healthcare system is taking to improve health services. A radical rethinking of how we prepare health service researchers; position research within the health system; and fund research activities and infrastructure is needed if the potential benefits of research are to be achieved. Lack of response to health system needs may contribute to research and âevidence-informedâ practice being further marginalized from healthcare operations. Interventions to address barriers must respond to the perspectives and experience of health leadership
Barriers in Health and Social Care Access and Navigation for Elder Orphans: A Scoping Review Protocol
Introduction Family members have traditionally been relied on to provide informal care to older adults. However, social and demographic changes are resulting in rising numbers of kinless and isolated elderly who are unable to rely on familial caregiving and are without assistance in navigating complex systems of health and social services. Research examining this vulnerable subset of the elderly population, identified as elder orphans, is limited, particularly within the context of health and social care access. The aim of this scoping review is to map and report the evidence available in identifying barriers and facilitating factors in health and social care access and system navigation by elder orphans.
Methods and analysis Arksey and OâMalleyâs six-staged methodology framework will guide the conduct of this scoping review. The primary author will conduct a systematic search and an initial screen of titles and abstracts from six electronic databases (CINAHL Complete, ASSIA, Pubmed, Scopus, Web of Science and PsycINFO) from January 2005 to the date of commencement, to identify English language peer reviewed studies of various methodologies. Subsequently, two reviewers will independently screen a shorter list of studies for inclusion. We will also search the reference lists of eligible studies. Data from the selected studies will be extracted and charted by two independent reviewers. Findings will be summarised in a tabulated format and accompanied by a narrative synthesis
Cardioprotection Via Modulation of Calcium Homeostasis by Thiopental in Hypoxia-Reoxygenated Neonatal Rat Cardiomyocytes
PURPOSE: Ca(2+) homeostasis plays an important role in myocardial cell injury induced by hypoxia-reoxygenation, and prevention of intracellular Ca(2+) overload is key to cardioprotection. Even though thiopental is a frequently used anesthetic agent, little is known about its cardioprotective effects, particularly in association with Ca(2+) homeostasis. We investigated whether thiopental protects cardiomyocytes against hypoxia-reoxygenation injury by regulating Ca(2+) homeostasis.
MATERIALS AND METHODS: Neonatal rat cardiomyocytes were isolated. Cardiomyocytes were exposed to different concentrations of thiopental and immediately replaced in the hypoxic chamber to maintain hypoxia. After 1 hour of exposure, a culture dish was transferred to the CO(2) incubator and cells were incubated at 37 for 5 hours. At the end of the experiments, the authors assessed cell protection using immunoblot analysis and caspase activity. The mRNA of genes involved in Ca(2+) homeostasis, mitochondrial membrane potential, and cellular Ca(2+) levels were examined.
RESULTS: In thiopental-treated cardiomyocytes, there was a decrease in expression of the proapoptotic protein Bax, caspase-3 activation, and intracellular Ca(2+) content. In addition, both enhancement of anti-apoptotic protein Bcl-2 and activation of Erk concerned with survival were shown. Furthermore, thiopental attenuated alterations of genes involving Ca(2+) regulation and significantly modulated abnormal changes of NCX and SERCA2a genes in hypoxia-reoxygenated neonatal cardiomyocytes. Thiopental suppressed disruption of mitochondrial membrane potential (DeltaPsi(m)) induced by hypoxia-reoxygenation.
CONCLUSION: Thiopental is likely to modulate expression of genes that regulate Ca(2+) homeostasis, which reduces apoptotic cell death and results in cardioprotectionope
Bcl-2 protein family: Implications in vascular apoptosis and atherosclerosis
Apoptosis has been recognized as a central component in the pathogenesis of atherosclerosis, in addition to the other human pathologies such as cancer and diabetes. The pathophysiology of atherosclerosis is complex, involving both apoptosis and proliferation at different phases of its progression. Oxidative modification of lipids and inflammation differentially regulate the apoptotic and proliferative responses of vascular cells during progression of the atherosclerotic lesion. Bcl-2 proteins act as the major regulators of extrinsic and intrinsic apoptosis signalling pathways and more recently it has become evident that they mediate the apoptotic response of vascular cells in response to oxidation and inflammation either in a provocative or an inhibitory mode of action. Here we address Bcl-2 proteins as major therapeutic targets for the treatment of atherosclerosis and underscore the need for the novel preventive and therapeutic interventions against atherosclerosis, which should be designed in the light of molecular mechanisms regulating apoptosis of vascular cells in atherosclerotic lesions
Intracellular Function of Interleukin-1 Receptor Antagonist in Ischemic Cardiomyocytes
Background: Loss of cardiac myocytes due to apoptosis is a relevant feature of ischemic heart disease. It has been described in infarct and peri-infarct regions of the myocardium in coronary syndromes and in ischemia-linked heart remodeling. Previous studies have provided protection against ischemia-induced cardiomyocyte apoptosis by the anti-inflammatory cytokine interleukin-1 receptor-antagonist (IL-1Ra). Mitochondria triggering of caspases plays a central role in ischemia-induced apoptosis. We examined the production of IL-1Ra in the ischemic heart and, based on dual intra/extracellular function of some other interleukins, we hypothesized that IL-1Ra may also directly inhibit mitochondria-activated caspases and cardiomyocyte apoptosis.
Methodology/Principal Findings: Synthesis of IL-1Ra was evidenced in the hearts explanted from patients with ischemic heart disease. In the mouse ischemic heart and in a mouse cardiomyocyte cell line exposed to long-lasting hypoxia, IL-1Ra bound and inhibited mitochondria-activated caspases, whereas inhibition of caspase activation was not observed in the heart of mice lacking IL-1Ra (Il-1raâ/â) or in siRNA to IL-1Ra-interfered cells. An impressive 6-fold increase of hypoxia-induced apoptosis was observed in cells lacking IL-1Ra. IL-1Ra down-regulated cells were not protected against caspase activation and apoptosis by knocking down of the IL-1 receptor, confirming the intracellular, receptor-independent, anti-apoptotic function of IL-1Ra. Notably, the inhibitory effect of IL-1Ra was not influenced by enduring ischemic conditions in which previously described physiologic inhibitors of apoptosis are neutralized.
Conclusions/Significance: These observations point to intracellular IL-1Ra as a critical mechanism of the cell self-protection against ischemia-induced apoptosis and suggest that this cytokine plays an important role in the remodeling of heart by promoting survival of cardiomyocytes in the ischemic regions
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