3,041 research outputs found

    An inquiry-based learning approach to teaching information retrieval

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    The study of information retrieval (IR) has increased in interest and importance with the explosive growth of online information in recent years. Learning about IR within formal courses of study enables users of search engines to use them more knowledgeably and effectively, while providing the starting point for the explorations of new researchers into novel search technologies. Although IR can be taught in a traditional manner of formal classroom instruction with students being led through the details of the subject and expected to reproduce this in assessment, the nature of IR as a topic makes it an ideal subject for inquiry-based learning approaches to teaching. In an inquiry-based learning approach students are introduced to the principles of a subject and then encouraged to develop their understanding by solving structured or open problems. Working through solutions in subsequent class discussions enables students to appreciate the availability of alternative solutions as proposed by their classmates. Following this approach students not only learn the details of IR techniques, but significantly, naturally learn to apply them in solution of problems. In doing this they not only gain an appreciation of alternative solutions to a problem, but also how to assess their relative strengths and weaknesses. Developing confidence and skills in problem solving enables student assessment to be structured around solution of problems. Thus students can be assessed on the basis of their understanding and ability to apply techniques, rather simply their skill at reciting facts. This has the additional benefit of encouraging general problem solving skills which can be of benefit in other subjects. This approach to teaching IR was successfully implemented in an undergraduate module where students were assessed in a written examination exploring their knowledge and understanding of the principles of IR and their ability to apply them to solving problems, and a written assignment based on developing an individual research proposal

    Ranking Factors by Importance in Factorial Survey Analysis

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    Factorial survey analysis is a statistical technique with a long history of use in decision-oriented organizational and information systems (IS) research. The technique produces a collection of standardized regression coefficients that help one to rank survey factors by importance. However, such rankings may be invalid because a researcher might not account for two related issues: unequal factor (i.e., dimension) manipulation effect sizes and the inherent multilevel structure of factorial survey data. We address these concomitant issues by demonstrating the ranking problem in simulated datasets, explaining the ranking problem’s underlying statistical causes, and justifying the use of remediating statistical methods. In particular, we focus on coding proportional to effect, a technique in which one consolidates corresponding dimension-level dummy (0, 1) variables into a single re-calibrated independent variable that is regressed on the dependent variable. One then uses the resulting standardized coefficients to rank the factors. We assess the advantages, disadvantages, and limitations of remediation techniques and offer suggestions for future information systems research

    HYTESS: A hypothetical turbofan engine simplified simulation

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    A users manual for a hypothetical turbofan engine simplified simulation is presented. This digital simulation exists as FORTRAN source code. The program is self-contained and was developed to offer those interested in engine dynamics and controls research an efficient, realistic, and easily used engine simulation. The engine is modeled using a state space formulation. Matrix elements within the linear state space structure are nonlinear functions of various engine variables

    Chocolate intake is associated with better cognitive function: The Maine-Syracuse Longitudinal Study

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    Chocolate and cocoa flavanols have been associated with improvements in a range of health complaints dating from ancient times, and has established cardiovascular benefits. Less is known about the effects of chocolate on neurocognition and behaviour. The aim of this study was to investigate whether chocolate intake was associated with cognitive function, with adjustment for cardiovascular, lifestyle and dietary factors. Cross-sectional analyses were undertaken on 968 community-dwelling participants, aged 23e98 years, from the Maine-Syracuse Longitudinal Study (MSLS). Habitual chocolate intake was related to cognitive performance, measured with an extensive battery of neuropsychological tests. More frequent chocolate consumption was significantly associated with better performance on the Global Composite score, Visual-Spatial Memory and Organization, Working Memory, Scanning and Tracking, Abstract Reasoning, and the Mini-Mental State Examination. With the exception of Working Memory, these relations were not attenuated with statistical control for cardiovascular, lifestyle and dietary factors. Prospective analyses revealed no association between cognitive function and chocolate intake measured up to 18 years later. Further intervention trials and longitudinal studies are needed to explore relations between chocolate, cocoa flavanols and cognition, and the underlying causal mechanisms

    Cardiovascular health and arterial stiffness: The Maine-Syracuse Longitudinal Study

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    Ideal cardiovascular health is a recently defined construct by the American Heart Association (AHA) to promote cardiovascular disease reduction. Arterial stiffness is a major risk factor for cardiovascular disease. The extent to which the presence of multiple prevalent cardiovascular risk factors and health behaviors is associated with arterial stiffness is unknown. The aim of this study was to examine the association between the AHA construct of cardiovascular health and arterial stiffness, as indexed by pulse wave velocity and pulse pressure. The AHA health metrics, comprising of four health behaviors (smoking, body mass index, physical activity, and diet) and three health factors (total cholesterol, blood pressure, and fasting plasma glucose) were evaluated among 505 participants in the Maine-Syracuse Longitudinal Study. Outcome measures were carotid-femoral pulse wave velocity (PWV) and pulse pressure measured at 4 to 5-year follow-up. Better cardiovascular health, comprising both health factors and behaviors, was associated with lower arterial stiffness, as indexed by pulse wave velocity and pulse pressure. Those with at least five health metrics at ideal levels had significantly lower PWV (9.8 m/s) than those with two or less ideal health metrics (11.7 m/s) (P<0.001). This finding remained with the addition of demographic and PWV-related variables (P=0.004)

    Association between depressive symptoms, use of antidepressant medication and the metabolic syndrome: The Maine-Syracuse Study

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    Abstract Background Both depression and the metabolic syndrome (MetS) are two major public health issues. The aim of this study was to examine associations between depressive symptoms, the use of antidepressant medications, and the prevalence of MetS. Methods Cross-sectional analyses were undertaken on 970 participants from the Maine-Syracuse Study. Depressive symptoms were measured using two self-reported depression scales, the Center for Epidemiological Studies Depression Scale (CES-D), and the Zung self-rating depression scale. Antidepressant medication use was also self-reported. MetS was defined according to the recent harmonized criteria. Results The risk of MetS were approximately 79 and 86 % higher for those in the highest quartile for the CESD and the Zung (CES-D: OR = 1.79, p = 0.003; Zung: OR = 1.71, p = 0.006), compared to those in the lowest quartile. With adjustment for socio-demographic variables, lifestyle factors and C-reactive protein (CRP), risk was attenuated, but remained statistically significant for the CES-D. In those who reported using antidepressant medication, the odds of having MetS were over 2-fold higher (OR = 2.22, p < 0.001, fully adjusted model), compared to those who did not use antidepressants. Both measures of depressed mood were also associated with low high density-lipoprotein (HDL) cholesterol levels. Antidepressant use was associated with elevated fasting plasma glucose concentrations, hypertension, and low HDL-cholesterol. Conclusion Depressive symptoms and the use of antidepressant medications are associated with the prevalence of MetS, and with some of the individual components of the syndrome

    Diet soft drink consumption is associated with the metabolic syndrome: A two sample comparison.

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    Comparative analyses of soft drink intakes in samples from the United States and Europe, and assessed intakes in relation to prevalence of metabolic syndrome (MetS) and its individual components are currently lacking. We used data collected on cardiovascular health and dietary intakes in participants from two cross-sectional studies: the Maine-Syracuse Longitudinal Study (MSLS), conducted in Central New York, USA in 2001–2006 (n = 803), and the Observation of Cardiovascular Risk Factors in Luxembourg Study (ORISCAV-LUX), conducted in 2007–2009 (n = 1323). Odds ratios for MetS were estimated according to type and quantity of soft drink consumption, adjusting for demographic, lifestyle and dietary factors, in both studies. In both studies, individuals who consumed at least one soft drink per day had a higher prevalence of MetS, than non-consumers. This was most evident for consumers of diet soft drinks, consistent across both studies. Diet soft drink intakes were also positively associated with waist circumference and fasting plasma glucose in both studies. Despite quite different consumption patterns of diet versus regular soft drinks in the two studies, findings from both support the notion that diet soft drinks are associated with a higher prevalence of MetS

    Intake of lutein-rich vegetables is associated with higher levels of physical activity

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    Levels of physical inactivity, a major contributor to burden of disease, are high in many countries. Some preliminary research suggests that circulating lutein concentrations are associated with high levels of physical activity (PA). We aimed to assess whether the intake of lutein-containing foods, including vegetables and eggs, is associated with levels of PA in two studies conducted in different countries. Dietary data and PA data collected from participants in two cross-sectional studies: the Maine-Syracuse Longitudinal Study (MSLS), conducted in Central New York, USA (n = 972), and the Observation of Cardiovascular Risk Factors in Luxembourg Study (ORISCAV-LUX) (n = 1331) were analyzed. Higher intakes of lutein containing foods, including green leafy vegetables, were associated with higher levels of PA in both study sites. Increasing the consumption of lutein-rich foods may have the potential to impact positively on levels of PA. This needs to be further explored in randomized controlled trials
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