323 research outputs found

    Problem Formulation and Resolution in Online Problem-Based Learning

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    This paper discusses an exploratory study to investigate the existence, and nature, of student problem formulation and resolution processes in an undergraduate online Problem-Based Learning (PBL) course in Agricultural Sciences. We report on the use of a content analysis instrument developed to measure problem formulation and resolution (PFR) processes in online asynchronous discussions (Murphy, 2004a, 2004b) to analyze students' text-based, online discussions. The results offer evidence that students do engage in problem formulation and resolution and that these processes appear to be consistent with the PBL process carried out in this course. However, the nature of the PBL pedagogy, at least in this instructional context, ties the PBL problems to be solved tightly to a marked assignment structure and, therefore, appears to restrict the PFR process in its early and late stages

    Bacterial Association Networks from Healthy and Cancer-associated Gut Microbiomes

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    The human gastrointestinal tract is colonized by a diverse community of symbiotic microorganisms, mainly bacteria, that are known to play essential roles in maintaining the health of their human host. Disruption of this bacterial community has been associated with numerous diseases, including Colorectal Cancer (CRC). CRC is one of the leading causes of cancer-related deaths worldwide. As such, focus has been placed on the modulation of the bacterial community within the cancer-associated gut microbiome as the next step in possible CRC treatment and prevention strategies. To use the bacterial community for these purposes, a better understanding of the associations that exist between bacteria within the healthy human gut microbiome and how these associations have changed within the CRC-associated gut microbiome is direly needed. In this dissertation, we first utilized whole-genome shotgun sequence data from four previously published healthy human cohorts to explore the composition and community structure of the healthy gut microbiome across populations. We show that despite species carriage differences, bacterial communities across healthy human populations are similar in both their structure and functional capacities. In addition, we found that positive associations occur between taxonomically and functionally related species in the gut microbiome. In follow-up work, we employed a similar approach to study the bacterial community composition and structure in late-stage CRC patient gut microbiomes. We found key differences between CRC and healthy gut bacterial communities, suggesting an overgrowth of potentially pathogenic species classified as oral microbes. Additionally, a striking difference in the bacterial community structure was found which we believe to be a bacterial response to probable ecosystem changes associated with tumor formation in the CRC-associated gut microbiome. Overall, our findings shed new light on how the bacterial community is structured within the healthy gut microbiome and how this structure has changed in the late-stage CRC-associated gut microbiome

    Prevalence of true vein graft aneurysms: Implications for aneurysm pathogenesis

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    AbstractBackground: Circumstantial evidence suggests that arterial aneurysms have a different cause than atherosclerosis and may form part of a generalized dilating diathesis. The aim of this study was to compare the rates of spontaneous aneurysm formation in vein grafts performed either for popliteal aneurysms or for occlusive disease. The hypothesis was that if arterial aneurysms form a part of a systemic process, then the rates of vein graft aneurysms should be higher for patients with popliteal aneurysms than for patients with lower limb ischemia caused by atherosclerosis. Methods: Infrainguinal vein grafting procedures performed from 1990 to 1995 were entered into a prospective audit and graft surveillance program. Aneurysmal change was defined as a focal increase in the graft diameter of 1.5 cm or greater, excluding false aneurysms and dilatations after graft angioplasty. Results: During the study period, 221 grafting procedures were performed in 200 patients with occlusive disease and 24 grafting procedures were performed in 21 patients with popliteal aneurysms. Graft surveillance revealed spontaneous aneurysm formation in 10 of the 24 bypass grafts (42%) for popliteal aneurysms but in only 4 of the 221 grafting procedures (2%) that were performed for chronic lower limb ischemia. Conclusion:This study provides further evidence that aneurysmal disease is a systemic process, and this finding has clinical implications for the treatment of popliteal aneurysms. (J Vasc Surg 1999;29:403-8.

    Bariatric surgery tourism in the COVID-19 era

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    Background: Since the start of the Covid-19 pandemic primary and secondary health care services in Northern Ireland have observed an increase in the number of patients who have had bariatric surgery outside of the UK. This study sought to estimate the frequency of bariatric surgery tourism and to audit indications, blood monitoring and medical complications.Methods: All primary care centres within the Western Health Social Care Trust (WHSCT) were invited to document the number of patients undergoing bariatric surgery between January 1, 2017 and December 31, 2022. For one primary care centre, patients who underwent bariatric surgery were assessed against the National Institute of Health and Clinical Excellence (NICE) guideline indications for bariatric surgery. In addition, the blood monitoring of these patients was audited against the British Obesity and Metabolic Surgery Society (BOMSS) guidelines for up to two years following surgery. Medical contacts for surgical complications of bariatric surgery were recorded.Results: Thirty-five of 47 (74.5%) GP surgeries replied to the survey, representing 239,961 patients among 325,126 registrations (73.8%). In the six year study period 463 patients had reported having bariatric surgery to their GP. Women were more likely to have had bariatric surgery than men (85.1% versus 14.9%). There was a marked increase in the number of patients undergoing bariatric surgery with each year of the study (p&lt;0.0001 chi square for trend). Twenty-one of 47 patients (44.7%) evaluated in one primary care centre fulfilled NICE criteria for bariatric surgery. The level of three-month monitoring ranged from 23% (for vitamin D) to 89% (electrolytes), but decreased at two years to 9% (vitamin D) and 64% (electrolytes and liver function tests). Surgical complication prevalence from wound infections was 19% (9 of 44). Antidepressant medications were prescribed for 23 of 47 patients (48.9%).Conclusions: The WHSCT has experienced a growing population of patients availing of bariatric surgery outside of the National Health Service. In view of this and the projected increase in obesity prevalence, a specialist obesity management service is urgently required in Northern Ireland.</p

    Ethnographies of Power

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    What does it mean to work with radical concepts in our time of rampant inequality, imperial-capitalist plunder, racial/sexual/class violence and ecocide? When concepts from the past seem inadequate, how do scholars and activists concerned with social change decide what concepts to work with or renew? The contributors to Ethnographies of Power address these questions head on. Gillian Hart is a key thinker in radical political economy, geography, development studies, agrarian studies and Gramscian critique of postcolonial capitalism. In Ethnographies of Power each contributor engages her work and applies it to their own field of study. These applied concepts include: ‘gendered labour’ practices among South African workers, reading ‘racial capitalism’ through agrarian debates, using ‘relational comparison’ in an ethnography of schooling across Durban, reworking ‘multiple socio-spatial trajectories’ in Guatemala’s Maya Biosphere Reserve, critiquing the notion of South Africa’s ‘second economy’, revisiting ‘development’ processes and ‘Development’ discourses in US military contracting, reconsidering Gramsci’s ‘conjunctures’ geographically, finding divergent ‘articulations’ in Cape Town land occupations, and exploring ‘nationalism’ as central to revaluing recyclables at a Soweto landfill. Ethnographies of Power offers an invaluable toolkit for activists and scholars engaged in sharpening their critical concepts for the social and environmental change necessary for our collective future

    Negative emotional experiences during navigation enhance parahippocampal activity during recall of place information

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    It is known that the parahippocampal cortex is involved in object-place associations in spatial learning, but it remains unknown whether activity within this region is modulated by affective signals during navigation. Here we used fMRI to measure the neural consequences of emotional experiences on place memory during navigation. A day before scanning, participants undertook an active object location memory task within a virtual house in which each room was associated with a different schedule of task-irrelevant emotional events. The events varied in valence (positive, negative, or neutral) and in their rate of occurrence (intermittent vs. constant). On a subsequent day, we measured neural activity while participants were shown static images of the previously learned virtual environment, now in the absence of any affective stimuli. Our results showed that parahippocampal activity was significantly enhanced bilaterally when participants viewed images of a room in which they had previously encountered negatively arousing events. We conclude that such automatic enhancement of place representations by aversive emotional events serves as an important adaptive mechanism for avoiding future threats
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