1,721,128 research outputs found
Lifestyle Factors Across the Life Course and Age at Menopause - Population-Based Studies of Women in Norway
Full text linkIntroduction: Menopause marks the end of a woman’s reproductive period and may serve as an indicator of health and fecundity. The individual variation in age at menopause is large, ranging between 40 and 60 years of age. Early menopause is associated with increased risk of cardiovascular disease, osteoporosis, dementia, type-2 diabetes, and early death. Late menopause is associated with breast and endometrial cancers. Genetic, reproductive, demographic and lifestyle factors influence the timing of natural menopause, but the roles of alcohol consumption, exercise levels, and weight change patterns across the life course are uncertain. Knowledge about factors associated with age at natural menopause may increase our understanding of ovarian ageing.
Aims: The aim of this thesis was to study the associations of alcohol consumption, exercise levels, and weight change patterns across the life course with age at natural menopause.
Methods: This thesis presents three retrospective population-based cohort studies of women aged 50-69 who had participated in the Norwegian breast cancer screening programme (BreastScreen Norway) during the years 2006-2015. The women were born during the years 1936-1966. All data were collected by two self-administered questionnaires. All associations were estimated as hazard ratios (HR) using the Cox proportional hazards model. In Paper I, we studied the dose-response association between estimated weekly alcohol consumption (in grams) at ages 20-49 years and age at menopause. Restricted cubic splines were used to allow for non-linear association (n=280,497). In Paper II, we used latent class mixed models to identify adolescent to midlife exercise trajectories and studied their associations with age at menopause (n=246,147). In Paper III, we studied the association between adolescent to midlife weight change and age at menopause (n=263,586). Weight change was categorised into nine categories of weight change based on recalls of weight at age 15 compared to peers, and quartiles of midlife weight in kilograms. The analyses were adjusted for year and country of birth, educational level, number of childbirths, and smoking habits. Where relevant, they were also adjusted for body mass index, height, and exercise.
Results: The estimated mean age at natural menopause was 51.1 years (95% CI: 51.08-51.12). In Paper I, alcohol consumption of up to 50 grams per week was associated with a lower hazard of reaching menopause compared to no alcohol consumption (adjusted HR 0.86; 95% CI: 0.85-0.88). Among alcohol consumers, the level of alcohol consumption was not associated with age at menopause in a dose-dependent manner. In Paper II, four exercise trajectories (high, increasing, decreasing and low) were identified. Women with constantly low exercise levels had a higher hazard of reaching menopause compared to women with high exercise levels (adjusted HR 1.06; 95% CI: 1.05-1.07). Women with increasing or decreasing exercise levels also had a slightly higher hazard or reaching menopause compared to women with high exercise levels (adjusted HR 1.02, 95% CI: 1.00-1.03 and HR 1.02, 95% CI: 1.01-1.04 respectively). In Paper III, we found that weight loss was associated earlier menopause and weight gain with later menopause. Compared to women with a stable average weight, women with the greatest weight loss had the highest hazard of reaching menopause (adjusted HR 1.11; 95% CI: 1.06-1.17) and women with a stable high weight had the lowest (adjusted HR 0.93; 95% CI: 0.90-0.95).
Conclusions: The results of this thesis, suggest that non-consumers of alcohol reach menopause earlier compared to alcohol consumers. Among alcohol consumers, however, the level of alcohol consumption was not associated with age at menopause in a dose-dependent manner, suggesting minimal influence of alcohol on women’s age at menopause. These findings may suggest that characteristics of the women who did not consume alcohol, not accounted for in the data analyses, explain their younger age at menopause. Women with constantly low exercise levels reached menopause earlier compared to women with constantly high exercise levels. However, the estimated associations were weak and differences in exercise behaviours cannot explain the large variation in age at menopause. Lastly, women with a stable high weight had the latest menopause, which is consistent with previous research reporting that high BMI is associated later timing of menopause. Women with the highest weight loss had the earliest menopause. Disease and illness may induce weight loss, and the early menopause among women with high weight loss may be a result of underlying disease, not accounted for in the analyses.
Bakgrunn: Menopausen markerer slutten på kvinners reproduktive periode og kan være en indikator på helse og fruktbarhet. Den individuelle variasjonen i alder ved menopause er stor, fra alderen 40 til 60 år. Tidlig menopause er assosiert med økt risiko for hjerte- og karsykdommer, osteoporose, demens, type-2 diabetes og tidlig død. Sen menopause er assosiert med bryst- og livmorkreft. Genetiske, reproduktive, demografiske og livsstilsfaktorer påvirker tidspunktet for naturlig menopause, men hvordan menopausealder påvirkes av alkoholforbruk, aktivitetsnivå og vektendringer gjennom livsløpet er usikkert. Kunnskap om faktorer assosiert med alder ved naturlig menopause kan øke vår forståelse av ovarienes aldring.
Mål: Målet med denne avhandlingen var å studere sammenhengen av alkoholforbruk, treningsmønstre og vektendringer gjennom livsløpet med alder ved naturlig menopause.
Metode: Denne avhandlingen presenterer tre retrospektive populasjonsbaserte kohortstudier av kvinner i alderen 50-69 år som deltok i det norske mammografiprogrammet (BreastScreen Norway) i perioden 2006-2015. Kvinnene var født i perioden 1936-1966. All data ble samlet inn gjennom to selvadministrerte spørreskjemaer. Alle sammenhenger ble estimert som hasard ratioer (HR) ved bruk av Cox proporsjonal hasard-modellen. I artikkel I studerte vi dose-respons-forholdet mellom estimert ukentlig alkoholforbruk (i gram) i alderen 20-49 år og alder ved menopause. Vi brukte restriktive kubiske spliner for å tillate en ikke-lineær sammenheng (n=280 497). I artikkel II brukte vi latente klasser for blandede modeller for å identifisere treningsmønstre fra ungdom til middelalder, og studerte deres sammenhenger med alder ved menopause (n=246 147). I artikkel III studerte vi sammenhengen mellom vekttap fra ungdom til middelalder og alder ved menopause (n=263 586). Vekttap ble kategorisert i ni kategorier basert på vekterindringer fra 15-årsalderen sammenlignet med jevnaldrende, og kvartiler av middelaldervekt i kilo. Analysene ble justert for fødselsår og -land, utdanningsnivå, antall fødsler og røykevaner. Der det var relevant ble det også justert for kroppsmasseindeks, høyde og fysisk aktivitet.
Resultater: Den estimert gjennomsnittsalderen ved naturlig menopause var 51,1 år (95% KI: 51,08-51,12). I artikkel I var alkoholforbruk opp til 50 gram per uke assosiert med en lavere hasard for å nå menopause sammenlignet med avhold (justert HR 0,86; 95 % KI: 0,85-0,88). Blant alkoholkonsumentene var alkoholnivået imidlertid ikke assosiert med alder ved menopause på en doseavhengig måte. I artikkel II ble fire treningsmønstre (høy, økende, synkende og lav) identifisert. Kvinner med konstant lavt treningsnivå hadde en høyere hasard for å nå menopause sammenlignet med kvinner med høyt treningsnivå (justert HR 1,06; 95 % KI: 1,05-1,07). Kvinner med økende eller synkende treningsnivå hadde også en noe høyere hasard for å nå menopause sammenlignet med kvinner med konstant høyt treningsnivå (justert HR 1,02, 95 % KI: 1,00-1,03 og HR 1,02, 95 % KI: 1,01-1,04 henholdsvis). I artikkel III fant vi at vekttap var assosiert med tidligere menopause og vektøkning med senere menopause. Sammenlignet med kvinner med stabil gjennomsnittsvekt, hadde kvinner med størst vekttap høyest hasard for å nå menopause (justert HR 1,11; 95 % KI: 1,06-1,17) og kvinner med stabil høy vekt hadde lavest hasard (justert HR 0,93; 95 % KI: 0,90-0,95).
Konklusjon: Resultatene i denne avhandlingen tyder på at avhold fra alkohol er assosiert med tidligere menopause sammenlignet med alkoholkonsum. Blant alkoholkonsumentene var imidlertid alkoholnivået ikke assosiert med alder ved menopause på en doseavhengig måte, noe som tyder på minimal innflytelse av alkohol på kvinners alder ved menopause. Disse funnene kan tyde på at egenskaper hos kvinnene som ikke konsumerte alkohol, som ikke er redegjort for i analysene, kan forklare deres yngre alder ved menopause. Kvinner med konstant lavt aktivitetsnivå nådde menopause tidligere sammenlignet med kvinner med konstant høyt aktivitetsnivå. Imidlertid var de estimerte sammenhengene svake, og forskjeller i treningsvaner kan ikke forklare den store variasjonen i alder ved menopause. Til slutt hadde kvinner med stabil høy vekt senest menopause, noe som er i tråd med tidligere forskning som viser at høy BMI er assosiert med senere menopause. Kvinner med størst vekttap hadde tidligst menopause. Sykdom kan føre til vekttap, og den tidlige menopause blant kvinner med stort vekttap kan skyldes underliggende sykdom som ikke er tatt hensyn til i analysene.publishedVersio
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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