432 research outputs found

    An Examination of the Factors and Characteristics that Contribute to the Success of Putnam Fellows

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    The William Lowell Putnam Mathematical Competition is an intercollegiate mathematics competition for students in the United States and Canada and is regarded as the most prestigious and challenging mathematics competition in North America (Alexanderson, 2004; AMS, 2020; Grossman, 2002; Reznick, 1994; Schoenfeld, 1985). Students who earn the five highest scores on the examination are named Putnam Fellows. Since its inception in 1938, only 306 individuals have won the competition and a select few have won multiple times. Clearly, being named a Putnam Fellow is a remarkable achievement and therefore, understanding the factors and characteristics that contribute to their success is important for students interested in mathematics and STEM-related fields. Twenty-five males who were named Putnam Fellows either four, three, or two times were recruited for the study. A 17-item questionnaire was created from various research sources (Campbell, 1996a, 1996b; Campbell & Wu, 1996; DeFranco, 1996), and used to collect information around four broad areas—personal experiences, formal educational experiences, the affective domain and the cognitive domain. Qualitative research techniques were used to analyze the data. The results indicated that four subcategories of personal experiences, five subcategories of formal educational experiences, seven subcategories involving the affective domain, and three subcategories of the cognitive domain all played an important role in the development of Putnam Fellows. Future research recommendations should examine the factors and characteristics of female Putnam winners and ways to promote and support them as well as the role that Pólya-like heuristics play in the development of Putnam winners

    All-plastic electrochemical transistor for glucose sensing using a ferrocene mediator.

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    We demonstrate a glucose sensor based on an organic electrochemical transistor (OECT) in which the channel, source, drain, and gate electrodes are made from the conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS). The OECT employs a ferrocene mediator to shuttle electrons between the enzyme glucose oxidase and a PEDOT:PSS gate electrode. The device can be fabricated using a one-layer patterning process and offers glucose detection down to the micromolar range, consistent with levels present in human saliva

    Area-level poverty and preterm birth risk: A population-based multilevel analysis

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    <p>Abstract</p> <p>Background</p> <p>Preterm birth is a complex disease with etiologic influences from a variety of social, environmental, hormonal, genetic, and other factors. The purpose of this study was to utilize a large population-based birth registry to estimate the independent effect of county-level poverty on preterm birth risk. To accomplish this, we used a multilevel logistic regression approach to account for multiple co-existent individual-level variables and county-level poverty rate.</p> <p>Methods</p> <p>Population-based study utilizing Missouri's birth certificate database (1989–1997). We conducted a multilevel logistic regression analysis to estimate the effect of county-level poverty on PTB risk. Of 634,994 births nested within 115 counties in Missouri, two levels were considered. Individual-level variables included demographics factors, prenatal care, health-related behavioral risk factors, and medical risk factors. The area-level variable included the percentage of the population within each county living below the poverty line (US census data, 1990). Counties were divided into quartiles of poverty; the first quartile (lowest rate of poverty) was the reference group.</p> <p>Results</p> <p>PTB < 35 weeks occurred in 24,490 pregnancies (3.9%). The rate of PTB < 35 weeks was 2.8% in counties within the lowest quartile of poverty and increased through the 4<sup>th </sup>quartile (4.9%), p < 0.0001. High county-level poverty was significantly associated with PTB risk. PTB risk (< 35 weeks) was increased for women who resided in counties within the highest quartile of poverty, adjusted odds ratio (<sub>adj</sub>OR) 1.18 (95% CI 1.03, 1.35), with a similar effect at earlier gestational ages (< 32 weeks), <sub>adj</sub>OR 1.27 (95% CI 1.06, 1.52).</p> <p>Conclusion</p> <p>Women residing in socioeconomically deprived areas are at increased risk of preterm birth, above other underlying risk factors. Although the risk increase is modest, it affects a large number of pregnancies.</p

    Relationship Between Operator Volume and Adverse Outcome in Contemporary Percutaneous Coronary Intervention Practice An Analysis of a Quality-Controlled Multicenter Percutaneous Coronary Intervention Clinical Database

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    ObjectivesThe aim of our study was to evaluate the volume-outcome relationship in a large, quality-controlled, contemporary percutaneous coronary interventions (PCI) database.BackgroundWhether the relationship between physician volume of PCI and outcomes still exists in the era of coronary stents is unclear.MethodsData on 18,504 consecutive PCIs performed by 165 operators in calendar year 2002 were prospectively collected in a regional consortium. Operators' volume was divided into quintiles (1 to 33, 34 to 89, 90 to 139, 140 to 206, and 207 to 582 procedures/year). The primary end point was a composite of major adverse cardiovascular events (MACE) including death, coronary artery bypass grafting, stroke or transient ischemic attack, myocardial infarction, and repeat PCI at the same site during the index hospital stay.ResultsThe unadjusted MACE rate was significantly higher in quintiles one and two of operator volume when compared with quintile five (7.38% and 6.13% vs. 4.15%, p = 0.002 and p = 0.0001, respectively). A similar trend was observed for in-hospital death. After adjustment for comorbidities, patients treated by low volume operators had a 63% increased odds of MACE (adjusted odds ratio [OR] 1.63, 95% confidence interval [CI] 1.29 to 2.06, p < 0.0001 for quintile [Q]1; adjusted OR 1.63, 95% CI 1.34 to 1.90, p < 0.0001 for Q2 vs. Q5), but not of in-hospital death. Overall, high volume operators had better outcomes than low volume operators in low-risk and high-risk patients.ConclusionsAlthough the relationship between operator volume and in-hospital mortality is no longer significant, the relationship between volume and any adverse outcome is still present. Technological advancements have not yet completely offset the influence of procedural volume on proficiency of PCIs

    Use of prasugrel vs clopidogrel and outcomes in patients with acute coronary syndrome undergoing percutaneous coronary intervention in contemporary clinical practice: Results from the PROMETHEUS study

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    Background and objectivesWe sought to determine the frequency of use and association between prasugrel and outcomes in acute coronary syndrome patients undergoing percutaneous coronary intervention (PCI) in clinical practice
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