1,721,050 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Physical activity measured early in pregnancy and birthweight- A study from the ARCH cohort
No full textExcessive birthweight is a growing concern and challenge in current obstetrics, and has been associated with perinatal complications, such as shoulder dystocia, and long-term health complications such as type 2 diabetes. (1-3) Variation of birthweight measures used to describe excessive birthweight contributes to the lack of consensus in the literature. In addition, these measures do not allow for the study of the effect of Physical Activity (PA) at non-traditional points in the distribution. The effect of PA may not be found at mean birthweight estimates, but an effect may be present above the 70th percentile of birthweight z-scores standardized for infant sex and gestational age.(4) We hypothesized that women who performed 150 minutes or more of PA per week on average would have lower odds of delivering a neonate whose birthweight z-score was above the 70th percentile of the sample\u2019s birthweight z-score compared to the neonates of women who were sedentary. We also sought to replicate findings that birthweight z-score varies by PA category above the 70th percentile of birthweight z-score using a sample in which PA behavior data was collected prospectively.(4) We used data from the Archives for Research on Childhood Health cohort. We calculated birthweight z-score and trichotomized PA. We used multivariable logistic regression to model the association between PA measured early in pregnancy and birthweight z-score above the 70th percentile. This study did not support the hypothesis that the odds of delivering a neonate above the 70th percentile would be lower for women who performed 150 minutes or more of PA per week compared to the neonates women who were sedentary.Thesis (M.S.)--Michigan State University. Epidemiology, 2017Includes bibliographical references (pages 31-36
A literature review of the stability of stored nutritional and steroid hormone biomarkers
Full text linkArchiving and storage of biological materials for use in research has seen a significant upswing in interest and activity in the last decade and will likely continue to grow as a research resource and an industry. Despite all of this activity and economic outlay there is a fundamental question that remains unanswered regarding the storage of biological materials: At what storage temperature does the least amount of degradation occur? Conventional wisdom would suggest that at least -80\ub0 C is required for long term storage, however robust evidence is lacking to support -80\ub0 C or below as the appropriate long term storage temperature for all biological molecules of interest to researchers. The purpose of this thesis is to review the -20\ub0 C and -80\ub0 C storage temperature literature for nutritional and steroid hormone analytes and to begin the process of making a scientific case for the appropriate storage temperatures for these analytes. There are limited true validation studies of nutritional and steroid hormones temperature requirements from which to draw robust conclusions. Thus, well-designed storage temperature validity studies are required to ensure that these analytes are stored at a temperature that reduces degradation and ensures that studies that store or use these analytes can be assured that their findings are indeed valid.Thesis (M.S.)--Michigan State University. Epidemiology - Master of Science, 2013Includes bibliographical references (pages 46-54
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Knowledge and attitudes towards autism spectrum disorders amongst general practitioners in Karachi, Pakistan
Full text link"Introduction: Autism Spectrum Disorder (ASD) is a complex lifelong neurodevelopmental and behavioral disorder that manifests in infancy or early childhood and is characterized by impairments in social interaction and communication, and by repetitive, stereotyped behavior. While the diagnosed prevalence of ASD is on the rise, reliable epidemiological data, including risk factors for ASD is lacking in many developing countries, including Pakistan. In this context, the main objective of this study is to evaluate whether there is a lag in information transfer between what is known about ASD in developed countries compared to that which is known amongst general practitioners (GP) in Karachi, Pakistan. More specifically, this research tests the following two hypotheses: (1) Physicians younger than 30 years of age are more likely to have knowledge of ASD, and (2) Among general practitioners who self-reported having an understanding of ASD, when questioned about old and new theories, those that graduated in the distant past (before 1990), will continue to hold antiquated misconceptions regarding ASD diagnosis and treatment. Methods: We utilized the Mediguide Comprehensive Medical Directory to establish a sampling frame for the city of Karachi (n = 5,849 practicing general practitioners), from which a final analytic sample of 348 physicians was derived. We used the statistical software, SASRTM Version 9.4, for all analyses. Results: Of 348 physicians, 148 (44.6%) had heard of the term "autism." Physicians younger than 30 years of age were more likely to self-report knowledge of autism compared to physicians who were older than 50 years of age (OR = 2.30; 95% Cl: 1.17, 4.55). During their medical school training, physicians who had ward rotations in pediatrics and internal medicine were more likely to self-report knowledge of autism (OR = 2.36; 95% Cl: 1.38, 4.03 and OR = 2.37 95% Cl: 1.31, 4.28), respectively. Physicians who graduated after 1990 were 4.28 times more likely to correctly respond to five or more of the eight questions regarding diagnosis and treatment of autism (OR = 4.28; 95% Cl: 1.00, 21.37). Discussion: This study adds to what is currently known about the knowledge disparity with respect to ASD that exists between developed countries and Karachi, Pakistan. As the global prevalence of ASD becomes a major public health concern, narrowing this knowledge gap takes on an increasingly important significance. It is imperative that general practitioners in Karachi gain a contemporary understanding of ASD so that timely interventions can be implemented."--Pages ii-iii.Thesis (M.S.)--Michigan State University. Epidemiology, 2019Includes bibliographical references (pages 81-86
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Communication and eating data collected by cerebral palsy registries
Full text linkPurpose: Motor impairments in cerebral palsy (CP) can disrupt communication and eating. CP registries were asked for communication and eating definitions and data collection methods. Methods: CP registries staff answered a 21-question survey. Questions included the types of communication and eating data collected (if any), frequency of collection, registries' operational definitions, and reasons for data not being collected.Results: Twenty-five of 26 active CP registries responded to the survey. Lack of resources, outside the registry's purpose, and lack of available instruments or data sources were reasons given for no data collection. Most registries' data collection occurred once when children were five-years-old or younger. Communication and eating definitions varied by registries, but most definitions focused on underlying hearing, speech, language, eating, and swallowing skills as well as assistive technology use. Hearing data were collected by 96% (n=25 registries); speech data were collected by 85% (n=22 registries); eating data were collected by 65% (n=17 registries); and language data were collected by 42% (n=11 registries). Conclusions: To compare or pool data across population-based CP registries, definitions of communication, speech, language, hearing, and eating should be standardized and a consensus minimal data set for communication and eating established. The frequency and timing of data collection need to be explicitly considered in surveillance and clinical research. A working group of CP registry staff and communication and eating clinical researchers should be convened to standardize definitions and data collection methods.Thesis (M.S.)--Michigan State University. Epidemiology, 2011Includes bibliographical reference
Maternal infections and development of preeclampsia : a systematic review of the epidemiological literature
Full text linkWe systematically reviewed the associations between H. pylori (HP), cytomegalovirus (CMV) and C. pneumoniae (CP) infection in pregnancy and preeclampsia (PE), a disorder found in 5-8% of pregnancies and a leading cause of maternal and perinatal mortality. We used Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines and searched PubMed, EMBASE and Web of Science. We also assessed the studies for risk of bias by utilizing a modified version of A Cochrane Risk of Bias Assessment Tool for Non-Randomized Studies of Interventions (ACROBAT-NRSI). After exclusions based on criteria from these tools, 16 studies were reviewed in detail, of 1,031 initially identified by our search algorithm. Evidence of infection was based on serology (12 studies), Polymerase Chain Reaction (2) or both (2). All four studies of the association between HP and PE found significant odds ratios ranging from 2.7 \u2013 9.2. Two of four studies of CMV and PE found significantly elevated odds ratios (1.9 and 2.7), while only three of ten studies of CP found significant odds ratios, ranging from 3.1 to 4.1. Not all studies controlled fully for confounding, and ten studies were at serious risk of bias.The available literature provides partial support for the association between these infectious agents and PE, especially for HP, but more rigorous studies are needed in this area, because more than half of the studies examined were at high risk of bias.Thesis (M.S.)--Michigan State University. Epidemiology, 2015Includes bibliographical references (pages 48-54
Secure liquid nitrogen backup for refrigerated biostorage
Full text linkThere is need for a secure backup refrigeration system for the long-term storage of biological material. In addition to freezer component failure natural disasters such as Tropical Storm Allison in 2001 in Houston and Hurricane Katrina in 2005 in New Orleans have caused power outages and flooding, leading to the loss of biological specimens when backup refrigeration systems fail. Freezer component failure includes seal leaks, pump and compressor breakdown, and electrical monitoring malfunction. Power outages often result from high winds or large quantities of rain, snow, and ice that disrupt transmission lines. Floodwater, especially from excessive amounts of rain, fills basements and ground floors where biological storage is often located. A non-electrical backup system that can function in the presence of flooding is needed to preserve specimens when the primary system fails.A liquid nitrogen (LN2) refrigeration system utilizing a thermostatic expansion valve (TEV) was designed, built, and tested for use as a backup refrigeration system. The non-electric TEV is the key component in the system that can provide secure backup refrigeration for long-term storage of biological specimens. The passive LN2 refrigeration system does not depend on electricity so it continues to function where common systems fail. Test results of the LN2 TEV system demonstrated consistent regulation of freezer air temperature within 1°C of the set point. Simulations show that the system's high gain and reserve cooling capacity allows it to hold the temperature steady even during a large increase in ambient temperature.Thesis (M.S.)--Michigan State University. Mechanical Engineering, 2010Includes bibliographical references (pages 46-47
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