1,721,089 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
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
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
Fracking in the Fragile Families Cohort: DNA Methylation, Telomere Length, and Health
No full textHydraulic fracturing (fracking) is a method for oil and natural gas drilling from rock, which has become common in the U.S. This process involves potentially dangerous chemical contamination and pollution, among other possible disruptions. Limited research has shown negative health consequences for those residing near a fracking well site, though potential long-term risks and cellular-level impacts are not well-known. Using data from the Fragile Families and Child Wellbeing Study, I explored the effects of living near a fracking well on health, DNA methylation, and telomere length. I find fracking exposure to be associated with visiting a physician for illness and reporting respiratory symptoms. I demonstrate that these health associations are observed in individuals living up to 10 km from a fracking site. I observe wide-ranging alterations in DNA methylation after fracking exposure, finding multiple differentially methylated sites and regions associated with living near a fracking well. These differentially methylated sites are associated with a variety of biological pathways and processes, many of which are involved in cancer and development. While I do not find methylation age to be associated with fracking exposure, those reporting respiratory issues and residing near a fracking well have increased epigenetic aging. Telomere length was not found to be significantly associated with fracking exposure, though a moderate trend was observed, warranting further research. I find that genetically-moderated differences in xenobiotic detoxification are a risk factor for health effects associated with fracking exposure. The results of this work suggest that living near a fracking site is not only associated with adverse health outcomes but also with epigenetic alterations. Further research must be done to explore these associations and better determine safer fracking site setback distance rules
Race, Ethnicity, and Autism: Evaluating the Epidemiological, Genetic, Neurological, and Social Evidence
No full textEvaluating the Predictiveness of Polygenic Scores in the Fragile Families and Child Wellbeing Study Using a Multi-Ancestral Genotyping Array
No full textPolygenic scores (PGSs), individual-level predictions for acquiring a trait or disease, are poised to advance biomedical outcomes via precision medicine. However, a major challenge surrounding this biomarker is that PGSs have much greater predictive accuracy for European populations than for other ancestries. With improved multi-ancestral genotyping arrays such as Illumina’s Multi-Ethnic Genotyping Array (MEGA), it is necessary to reassess PGS predictiveness across different ancestries. To examine the potential magnitude of performance increase across African and Hispanic cohorts from Illumina’s PsychChip to MEGA, this study constructed and analyzed PGSs using genotypic and phenotypic data from the Fragile Families and Child Wellbeing Study cohort and summary statistics from previous genome-wide association studies (GWASs). I find no discrepancies in the predictive accuracies of PGSs of European children and those of non-European children when using PsychChip genotype data. I also identify a significant difference in PGS performance between Hispanic and African individuals, with the former having more predictive scores. Furthermore, I find that when using MEGA genotype data, predictive accuracies of PGSs are not improved for European, African, or Hispanic cohorts, even when ancestry-relevant SNPs are included in PGS construction. These findings provide a critical step towards understanding the predictive performance of PGSs from multi-ancestral genotyping arrays and GWASs and may have significant implications for the study of PGSs and their consequences in precision medicine and healthcare as a whole
DNA, Disparities, and Delays in Care: An Investigation of Genetic and Social Contributors to Adverse Outcome in Pediatric Acute Lymphoblastic Leukemia
No full textAlthough pediatric Acute Lymphoblastic Leukemia (ALL) survival has increased over the past 70 years, event free survival (EFS) can vary significantly based on genetic variables such as molecular subtype, and social variables such as race. While some studies have attempted to explain the EFS racial disparity in ALL by investigating social determinants of health such as socioeconomic status (SES), insurance, and compliance, others have incorrectly credited genetic racial differences. To this end, I discussed the terminological confusion in the literature around race-related variables as well as the historical precedents and modern social variables that may influence racial disparities in ALL. Further the Fragile Families Child Wellbeing study was used to investigate the credibility of claims regarding differential disease susceptibility by ancestry, revealing no significant associations between disease loci and ancestry. Next, the Pediatric Health Information System database was utilized to investigate the relationship between race and severity of illness when children are diagnosed with primary and/or relapsed ALL and revealed a significant association between severity of illness with race and age. To my knowledge this is the first documentation of this aspect of disparity in pediatric ALL. Lastly, the Therapeutically Applicable Research to Generate Effective Treatment database was used to investigate the prognostic significance of age, white blood cell count, race, and copy number variants (CNV) in event free survival. Seven new and significant CNV regions were identified solely in patients with adverse outcome, of which, deletions on chromosome 14 significantly overlapped T-cell receptor 7 and improved EFS. Together these findings contribute to our understanding of factors that influence event free survival in ALL and will hopefully lead to improved outcomes for all patients
When Stress Gets to Your Head: The Effects of Chronic Stress on the Murine Brain Metabolome
No full textMajor Depressive Disorders (MDDs) contribute to a host of neurobiological disorders associated with chronic stress. The chronic restraint stress (CRS) paradigm aims to recapitulate MDD in mice and was employed in this study to better characterize associated metabolomic changes. A previous study examined the effects of CRS on mitochondrial dysfunction (Varun Devraj and Dr. Daniel Notterman, 2023, unpublished results). Results from this study showed that CRS imposed for 3-4 hours per day for 10 days was associated with impaired State III respiration in the cerebellum (Varun Devraj and Dr. Daniel Notterman 2023, unpublished results). I hypothesized that the limited effect displayed by these data was due to a short CRS paradigm, as well as CRS-induced dysfunction of the pyruvate dehydrogenase complex E1 alpha (PDC E1a) subunit (Varun Devraj and Dr. Daniel Notterman 2023, unpublished results). To test this hypothesis, mice (n = 20) were subject to either a short-term (n = 5) or long-term (n = 5) CRS paradigm, with respective control groups (n = 5, n = 5) for each. Mice were sacrificed at the end of each CRS period and metabolomic analysis was conducted on the cortex, cerebellum, hippocampus, adrenal and pituitary glands. Statistically significant (p < 0.05) increases in cortisol 21-acetate and decreases in methyl beta-D-glucopyranoside were globally observed. Levels of both metabolites approached homeostasis at 28 days CRS, a novel finding for known antioxidant and antitumor agent methyl beta-D-glucopyranoside. While the TCA Cycle did not appear to be impeded, mitochondrial beta-oxidation may have been upregulated as a response to CRS. Further experiments are needed to elucidate the associated behavioral and appetite changes, holding promise for both neurobiological disorders and a clearer understanding of stress more broadly
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