Problems of scale : an O.R./systems approach

The history of analyses of scale and the conventional reductionist methodology are briefly recounted in the first chapter of the thesis. A detailed examination is then made of the theory of economies of scale and its development since the days of Adam Smith. A comprehensive survey shows that the description provided by conventional economic theory is quite unrealistic, and has been dictated by the demands of Neoclassical ideas of equilibrium. It is shown that the available empirical evidence does not easily allow conclusions to be drawn about the optimal scale of plants or enterprises. A simple simulation model then demonstrates that static economies of scale alone are insufficient to determine "optimal" scale - dynamic diseconomies depend upon environmental context and uncertainties of forecasting future demand. The question of technological change is closely bound up with issues of scale. The principle of bounded rationality is applied to deduce some conditions about the nature of technical change using Heiner's "Reliability Condition". The existence of "technological heuristics" (such as a bias in favour of scale-augmenting innovations) is predicted. The argument is illustrated with the use of a computer simulation of successive process innovations in a stylised chenical plant. Conflicting ideas about "optimal" scale in electricity generation, papermaking, brewing and cement manufacture are examined. These views are found to be explicable by borrowing the theory of fourfold cultural bias from the field of social anthropolgy. An Evolutionary Model of Increasing Returns (EMIR) is developed as a computer simulation. This model demonstrates that the restrictions imposed by conventional economic theory can be overcome in a dynamic economic model; economies of scale and technical change are married with plural rationalities to provide a range of findings on industry structure. Market share is found to be a more important determinant of industrial success than economies of scale. EMIR is used to demonstrate the phenomenon of technological "Lock-In"; important policy choices may be determined by small random events as critical points. Market selection mechanisms cannot be relied upon to optimise, whether in scale decisions or other important policy choices. The thesis concludes with a discussion of the use of plural models to go with plural rationalities in the analysis of policy issues

Campus Cultural Climate: A Minority Perspective

A survey was administered to sixty-five students at The University of Akron, to assess their sentiments toward the cultural climate on their campus. It was hypothesized that minority students, specifically African-Americans, would report lower scores than White students, as previous research has shown that students of color do not perceive their campus cultural climate in as positive of a light as their Caucasian peers. Despite previous notions, students of color at The University of Akron reported a more positive view of campus cultural climate than did White students. A correlational analysis was then done, to see what factors could potentially contribute to one’s perception of overall climate. Interestingly, one’s experiences were significantly correlated to one’s perception of climate, although White students seemed to have a more positive view of their college experiences than did African American students. Given these contradictory findings, it is evident that further research should be done, in order to compare other factors such as living on or off campus

Student Commuting Patterns and their Effects on Readiness to Learn and Academic Achievement

This study examines how student modal choice to commute to school influences student readiness to learn and academic achievement during the first learning period of the day. The goal of all educational policies, curriculum expectation, literature, and studies is to develop a deeper understanding of student learning, teaching, teaching strategies, and conditions around educating that can better education and teach students. It is vital to understand how students learn, in which conditions promote different levels of learning and to help students succeed in the classroom. Much of the research around student learning and understanding how to better prepare students to learn has focused on social, emotional, physical and intellectual factors at home, in the community, and at school. There has been virtually no formal research investigating the role that transportation and modal choice have on student learning once they arrive at school. This research includes surveying students to determine their individual commuting patterns and interviewing the students’ teachers to outline students’ readiness to learn in the morning and perceived academic achievement. The study areas in this research are elementary schools in St. Catharines and Thorold within the District School Board of Niagara. The findings from this research seem to suggest that students who walk to school are more ready to learn in the morning than any other mode of transportation. Also, students’ perceived academic achievement is less dependent on modal choice as teachers could not explicitly link mode of transportation and academic achievement. This research was exploratory and there are opportunities to further research how student modal choice to get to school influences student readiness to learn and perceived academic achievement

The Epidemiology of Pediatric Autoimmune Hepatitis in Scotland:A National Cohort Study

OBJECTIVES: Autoimmune hepatitis (AIH) is a rare, but potentially severe, cause of liver disease in children. We aimed to summarize how children with AIH in Scotland presented, were investigated and managed in addition to producing novel epidemiological data and outcomes.METHODS: All prevalent pediatric patients with AIH cared for in pediatric services between January 2013 and September 2018 were included. Individual patient data were obtained from electronic patient records in the 3-main academic pediatric centers in Scotland covering the entire population.RESULTS: Thirty-eight patients were included (25 female) with median follow-up of 33 months (range, 2-145 mo) and 136 total patient years. The incidence between 2014 and 2017 was 0.49/100 000/y (95% confidence interval, 0.29-0.78) and point prevalence between 2013 and 2018 was 1.75/100 000 (95% confidence interval, 1.42-2.13). Thirty-five (92%) patients were autoantibody positive, most commonly anti-nuclear antibody (63%) and anti-smooth muscle antibody (42%). Thirty-seven (97%) patients had induction therapy with oral corticosteroids, 30 (79%) required maintenance treatment with azathioprine, and 23 (61%) received ursodeoxycholic acid. There were 1.4 disease flares per 10 patient years and 3 patients required liver transplantation with an overall 5-year survival rate without the need for transplantation of 95%.CONCLUSIONS: We calculated a novel incidence and prevalence rate for pediatric AIH in Scotland. Nearly all were invariably treated initially with corticosteroids with most placed-on azathioprine as maintenance therapy. Outcomes were generally favorable with low rates of disease flares and the need for transplantation being rare.</p

The Epidemiology of Pediatric Autoimmune Hepatitis in Scotland:A National Cohort Study

OBJECTIVES: Autoimmune hepatitis (AIH) is a rare, but potentially severe, cause of liver disease in children. We aimed to summarize how children with AIH in Scotland presented, were investigated and managed in addition to producing novel epidemiological data and outcomes.METHODS: All prevalent pediatric patients with AIH cared for in pediatric services between January 2013 and September 2018 were included. Individual patient data were obtained from electronic patient records in the 3-main academic pediatric centers in Scotland covering the entire population.RESULTS: Thirty-eight patients were included (25 female) with median follow-up of 33 months (range, 2-145 mo) and 136 total patient years. The incidence between 2014 and 2017 was 0.49/100 000/y (95% confidence interval, 0.29-0.78) and point prevalence between 2013 and 2018 was 1.75/100 000 (95% confidence interval, 1.42-2.13). Thirty-five (92%) patients were autoantibody positive, most commonly anti-nuclear antibody (63%) and anti-smooth muscle antibody (42%). Thirty-seven (97%) patients had induction therapy with oral corticosteroids, 30 (79%) required maintenance treatment with azathioprine, and 23 (61%) received ursodeoxycholic acid. There were 1.4 disease flares per 10 patient years and 3 patients required liver transplantation with an overall 5-year survival rate without the need for transplantation of 95%.CONCLUSIONS: We calculated a novel incidence and prevalence rate for pediatric AIH in Scotland. Nearly all were invariably treated initially with corticosteroids with most placed-on azathioprine as maintenance therapy. Outcomes were generally favorable with low rates of disease flares and the need for transplantation being rare.</p

Artificial economic life: a simple model of a stockmarket

We describe a model of a stockmarket in which independent adaptive agents can buy and sell stock on a central market. The overall market behavior, such as the stock price time series, is an emergent property of the agents' behavior. This approach to modelling a market is contrasted with conventional rational expectations approaches. Our model does not necessarily converge to an equilibrium, and can show bubbles, crashes, and continued high trading volume.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31402/1/0000319.pd

Hunting and mountain sheep: Do current harvest practices affect horn growth?

The influence of human harvest on evolution of secondary sexual characteristics has implications for sustainable management of wildlife populations. The phenotypic consequences of selectively removing males with large horns or antlers from ungulate populations have been a topic of heightened concern in recent years. Harvest can affect size of horn-like structures in two ways: (a) shifting age structure toward younger age classes, which can reduce the mean size of horn-like structures, or (b) selecting against genes that produce large, fast-growing males. We evaluated effects of age, climatic and forage conditions, and metrics of harvest on horn size and growth of mountain sheep (Ovis canadensis ssp.) in 72 hunt areas across North America from 1981 to 2016. In 50% of hunt areas, changes in mean horn size during the study period were related to changes in age structure of harvested sheep. Environmental conditions explained directional changes in horn growth in 28% of hunt areas, 7% of which did not exhibit change before accounting for effects of the environment. After accounting for age and environment, horn size of mountain sheep was stable or increasing in the majority (similar to 78%) of hunt areas. Age-specific horn size declined in 44% of hunt areas where harvest was regulated solely by morphological criteria, which supports the notion that harvest practices that are simultaneously selective and intensive might lead to changes in horn growth. Nevertheless, phenotypic consequences are not a foregone conclusion in the face of selective harvest; over half of the hunt areas with highly selective and intensive harvest did not exhibit age-specific declines in horn size. Our results demonstrate that while harvest regimes are an important consideration, horn growth of harvested male mountain sheep has remained largely stable, indicating that changes in horn growth patterns are an unlikely consequence of harvest across most of North America.Utah Division of Wildlife Resources; National Wild Sheep Foundation (WSF); Wyoming Wild Sheep Foundation; Alberta Wild Sheep Foundation; California Wild Sheep Foundation; Arizona Desert Bighorn Sheep Society; Wyoming Governor's Big Game License Coalition; Iowa Foundation for North American Wild Sheep; Utah Foundation for North American Wild Sheep; Pope and Young ClubOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Reliability and accuracy of the South African Triage Scale when used by nurses in the emergency department of Timergara Hospital, Pakistan

Background. Triage is one of the core requirements for the provision of effective emergency care and has been shown to reduce patient mortality. However, in low- and middle-income countries this strategy is underused, under-resourced and poorly researched.Objective. To assess the inter- and intra-rater reliability and accuracy of nurse triage ratings when using the South African Triage Scale (SATS) in an emergency department (ED) in Timergara, Pakistan.Methods. Fifteen ED nurses assigned triage ratings to a set of 42 reference vignettes (written case reports of ED patients) under classroom conditions. Inter-rater reliability was assessed by comparing these triage ratings; intra-rater reliability was assessed by asking the nurses to re-triage 10 random vignettes from the original set of 42 vignettes and comparing these duplicate ratings. Accuracy of the nurse ratings was measured against the reference standard.Results. Inter-rater reliability was substantial (intraclass correlation coefficient 0.77; 95% confidence interval (CI) 0.69 - 0.85). The intra-rater agreement was also high with 87% exact agreement (95% CI 67 - 100) and 100% agreement allowing for a one-level discrepancy in triage ratings. Overall, the SATS had high specificity (97%) and moderate sensitivity (70%). Across all acuity levels the proportion of over-triage did not exceed the acceptable threshold of 30 - 50%. Under-triage was acceptable for all except emergency cases (66%).Conclusion. ED nurses in Pakistan can reliably use the SATS to assign triage acuity ratings. While the tool is accurate for ‘very urgent’ and ‘routine’ cases, importantly, it may under-triage ‘emergency’ cases requiring immediate attention. Approaches that will improve accuracy and validity are discussed

Setting the standard: multidisciplinary hallmarks for structural, equitable and tracked antibiotic policy

There is increasing concern globally about the enormity of the threats posed by antimicrobial resistance (AMR) to human, animal, plant and environmental health. A proliferation of international, national and institutional reports on the problems posed by AMR and the need for antibiotic stewardship have galvanised attention on the global stage. However, the AMR community increasingly laments a lack of action, often identified as an ‘implementation gap’. At a policy level, the design of internationally salient solutions that are able to address AMR’s interconnected biological and social (historical, political, economic and cultural) dimensions is not straightforward. This multidisciplinary paper responds by asking two basic questions: (A) Is a universal approach to AMR policy and antibiotic stewardship possible? (B) If yes, what hallmarks characterise ‘good’ antibiotic policy? Our multistage analysis revealed four central challenges facing current international antibiotic policy: metrics, prioritisation, implementation and inequality. In response to this diagnosis, we propose three hallmarks that can support robust international antibiotic policy. Emerging hallmarks for good antibiotic policies are: Structural, Equitable and Tracked. We describe these hallmarks and propose their consideration should aid the design and evaluation of international antibiotic policies with maximal benefit at both local and international scale

Lessons learned from the Alberta Border Testing Pilot Program

BackgroundDuring the Coronavirus disease (COVID-19) pandemic, countries implemented border control and quarantine measures to reduce transmission. The Alberta Border Testing Pilot Program (ABTPP) allowed international travellers entering Alberta to reduce their quarantine period following two negative COVID-19 tests. We evaluated participant experiences with the ABTPP and implementation.MethodWe used a parallel convergent mixed-methods design to explore participant experiences through electronic web-based questionnaires (n = 21,089; n = 13,839) and semi-structured telephone interviews (n = 30). We evaluated implementation through three staff focus groups (n = 11). We analysed questionnaires using descriptive statistics and analysed interviews using inductive and deductive thematic analysis. We deductively coded focus group data using the 2009 Consolidated Framework for Implementation Research (CFIR).ResultsQuestionnaires indicated minimal issues with registration forms (91.7%), symptom reports (95.5%), and COVID-19 testing (95.7%). Most respondents (95.1%) expressed willingness to participate in the ABTPP again. Interviews revealed three themes related to participant experience: program efficiency, clarity of information, and requisite effort. Focus groups identified key implementation facilitators including the single health information system, strong stakeholder partnerships, and good communication across partnerships. Barriers included program complexity, implementation timeline, and evolving external context.DiscussionParticipants reported high satisfaction with the ABTPP. Border testing programs should have high efficiency, require low effort, and use messaging that is clear and consistent. The effective implementation of border testing programs may be facilitated by strong leadership, adaptability, automated components, good communication, and simple technology. Learnings from participants and staff may help improve the implementation of border control programs for future pandemics or other emergencies.ConclusionsThe ABTTP was a novel border control measure during the COVID-19 pandemic. Our evaluation of both participant and staff experiences demonstrated high levels of traveller satisfaction and identified areas for improvement that can inform the development of future border control measures