1,721,607 research outputs found
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Aspirin and Alcohol in Relation to Lethal Prostate Cancer
No full textProblem: Prostate cancer is the most commonly diagnosed cancer and second-leading cancer cause of death among U.S. men. However, most prostate cancers are indolent. Thus, it is necessary to identify risk factors for lethal (metastatic or fatal) prostate cancer. This dissertation investigates the role of aspirin use and alcohol intake in relation to prostate cancer.
Methods: Data from two large, longitudinal studies of U.S. adult males – the Physicians’ Health Study (PHS) and Health Professionals Follow-up Study (HPFS) – were used. PHS began in 1981 as a randomized trial of aspirin and beta carotene among 22,071 U.S. male physicians. HPFS began in 1986 when investigators enrolled 51,529 U.S. male health professionals. In both cohorts, regular questionnaires ascertained medical diagnoses, medications, diet, and lifestyle factors. Cox proportional hazards regression was used to investigate all associations.
Results: In the general study population, compared to never use, current aspirin use was associated with decreased risk of lethal prostate cancer (Hazard Ratio [HR], 95% Confidence Intervals [CI]: PHS: = 0.80, 0.66-0.96; HPFS: 0.80, 0.66-0.96). Findings were similar when assessing post-diagnosis aspirin use among patients. Total pre-diagnosis alcohol intake was associated with a decreased risk of lethal prostate cancer in HPFS (0.84, 0.71-0.99). Among patients, compared to none, any red wine after diagnosis was associated with a decreased risk of lethal prostate cancer (0.50, 0.29-0.86) and overall mortality (0.74, 0.57-0.97).
Conclusions: Recommending aspirin use to men with and without prostate cancer may help prevent lethal prostate cancer. Moderate alcohol intake did not increase risk of lethal prostate cancer, suggesting it may be part of a healthy diet among older men. Red wine may be beneficial. In all analyses, we were unable to differentiate a late effect from reverse causation.Population Health Sciencesaspirin; alcohol; prostate cancer; epidemiology; surviva
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
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Etiology of Glioma and Glioblastoma
No full textBackground: Although the incidence of glioma is low relative to other cancers, it ranks ninth overall in the United States for cancer-related death due to its high mortality. Accordingly, much research has focused on the identification of environmental and behavioral risk factors that may play a role in the incidence of glioma, with few notable results.
Methods: We explored three factors that are possibly linked with risk of glioma: body habitus, tea and coffee intake, and statin use. We used data from three large, prospective cohort studies: the Nurses’ Health Study (NHS, n=121,700, begun in 1976), the Nurses’ Health Study II (NHSII, n=116,429, begun in 1989), and the Health Professionals Follow-Up Study (HPFS, n=51,529, begun in 1986), which together have accrued more than 550 glioma cases.
Results: We demonstrated that whereas taller height was associated with increased risk of glioma (HR=1.07, 95%CI: 1.03-1.11 per 1 inch), adult BMI and waist circumference were not associated with risk. Higher tea intake was associated with lower risk of glioma (HR=0.73, 95%CI: 0.49-1.10, p-trend=0.05, comparing >2 cups/d to <1 cup/week), while caffeine intake and coffee intake were not associated with risk. In our analyses involving statin use, we identified substantial confounding by indication due to an unexpected inverse association between hyperlipidemia and glioma risk, which was attenuated in lagged analyses, suggesting reverse causation. After accounting for this confounding, statin use appeared to be associated with increased risk of glioma (HR=1.44, 95%CI: 1.10-1.87, comparing ever to never users).
Conclusion: By identifying modifiable risk factors, it may be possible to enhance prevention and reduce incidence of glioma and glioblastoma, and also to improve our understanding of the pathogenesis of these tumors.Population Health Science
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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The Nexus of Planetary and Human Health: Exploring the Effects of a Planetary Health Diet on Cardiometabolic Risk Outcomes in South Asians Living in America
No full textThe modern global food system, responsible for ~30% of the total global greenhouse gas emission, is a major contributor to climate change and is exerting significant influence on both human and environmental health. Recognizing the imperative to address the accelerated impacts of anthropogenic climate change while ensuring sustainable production and consumption practices, the EAT-Lancet Commission proposed a Planetary Health reference Diet in 2019. This dietary pattern is based on a diverse range of whole plant-based foods, including fruits, vegetables, legumes, nuts, and whole grains, and encourages reduced consumption of red and processed meats, added sugars, and refined grains. Poor diet is among the top risk factors for cardiometabolic disease (CMD), which disproportionately burdens South Asian populations. Studies indicate that South Asian Americans, comprising 4%-5% of the total US population, and while genetics and family history play roles in increased cardiometabolic risk factors among South Asians, the interplay of sociocultural factors and dietary shifts towards a more westernized diet in the context of South Asians living in America underscores their disproportionate vulnerability. Given this context, this dissertation endeavored to explore the effects of a Planetary Health Diet on cardiometabolic risk outcomes in South Asians Living in America. The reference diet proposed by the 2019 EAT-Lancet Commission is associated with significant health benefits, including a substantial decrease in overall mortality; however, there is a lack of evidence and a standardized metric to quantify the health outcomes, diet quality, and environmental advantages of adhering to a planetary-conscious diet. Thus, using data from the longitudinal Mediators of Atherosclerosis in South Asians Living in America (MASALA) study, Chapter One we developed and validated a Planetary Health Diet Index (PHDI) that measures adherence to the EAT-Lancet reference diet. In Chapter Two, we delve into the predictive criteria of this index by examining the associations of the PHDI with cardiometabolic risk markers and disease outcomes in the MASALA cohort.
Finally, in Chapter Three, we employ a systems epidemiology approach to identify and validate plasma metabolomic profiles associated with the Planetary Health diet and evaluate associations of the derived metabolomic profile with cardiometabolic risk in South Asian Americans
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Dietary and Hormonal Factors in Relation to Physical Function
Full text linkPhysical function is increasingly recognized as a key component of healthy aging, in particular as a core component of mobility and independent living in older adults. Prior research has also demonstrated that poor physical function is related to hospitalization, long-term nursing home care, and increased mortality among older adults. Women appear to have a greater burden of physical function impairment, although it is not certain whether this is due to gender differences in reporting of impairments, risk factor differences, or biologic differences.
In this dissertation, I examined not only risk factors for development of physical function impairment, but also explanations for apparent gender differences. First, while diet is related to numerous chronic diseases and conditions of aging, limited research has examined the role of diet, which may be an important strategy to prevent or delay decline in physical function with aging. In Chapter 1, I prospectively examined the association between the Alternative Healthy Eating Index-2010 (AHEI-2010), a measure of diet quality, with incident impairment in physical function among 54,762 women from the Nurses’ Health Study. Overall, participants in higher quintiles of the AHEI-2010, indicating a healthier diet, were less likely to have incident physical impairment versus participants in lower quintiles over the 18 year follow-up period.
There are established sex differences in later life physical function, with a greater number of impairments in function and steeper rates of decline observed among women compared to men. It is hypothesized that some of the differences could be due to women’s greater likelihood to report symptoms compared to men. Few prospective studies have investigated possible risk factor differences or differences in biological factors between men and women. In Chapter 2, I present the findings from an analysis investigating sex differences in relation to physical function decline. Overall, women had lower physical function scores at baseline and steeper rates of decline compared to men. These differences were partially explained by the difference in risk factors between men and women, indicating that it could be of particular importance to intervene on risk factors in women to prevent further physical function impairments with aging.Epidemiology; Aging; Physical Function; Nutrition; Gender Disparitie
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