1,721,314 research outputs found
Insight into the genetic basis of cardiorespiratory fitness and resting heart rate, and their relation to cardiovascular disease
Full text linkCardiovascular disease (CVD) is the leading cause of death worldwide. Cardiorespiratory fitness (CRF) and resting heart rate (RHR) are two independent risk factors for CVD. Both CRF, RHR, and CVD are heritable and have a strong genetic component. Hence, understanding more of the genetic architecture of CRF and RHR could improve the understanding of how CRF and RHR relate to CVD. The aim of this thesis was to explore the genetic contribution to CRF by identifying genetic variants associated with CRF. Further, we aimed to examine how RHR affects the risk of different CVDs, by 1) explore whether RHR has a causal effect on risk of atrial fibrillation (AF), and 2) examine the genetic contribution to RHR, develop a polygenic risk score (PRS) for RHR, and investigate its association with different CVD outcomes. We have used two large independent cohorts throughout this thesis; The Trøndelag Health Study and United Kingdom Biobank.
We suggest 38 novel genetic variants associated with CRF. Further biological analyses pointed to several interesting genes and pathways associated with cardiac function, cardiac remodeling, contractility, vascular tone, blood pressure, calcium signaling, and endurance capacity, in addition to different CVDs including dilated cardiomyopathy (DCM).
For RHR, we found an inverse causal association between RHR and AF in the MR framework. This inverse causal association was also observed when allowing for a non-linear relationship. This indicates that low RHR increases risk of AF. We hypothesize that this association is mostly driven by a strong inverse association for low RHR values. The estimated causal effect can be a result of a true causal effect or pleiotropic pathways on cardiac remodeling, atrial myopathy, autonomic tone, and/or heart structure.
Further, the genetic study of RHR confirmed previous reported loci associated with RHR and identified one novel genetic variant in women. The sex-specific analyses pointed to several genetic loci, genes, and pathways that were only associated with RHR in one of the sexes. The RHR PRS was associated with increased risk of hypertension, early-onset hypertension, DCM, and a decreased risk of AF. There were differences in the association between the RHR PRS and disease risk in women and men.
To conclude, we highlighted novel genetic variants associated with CRF and present possible biological mechanisms linking CRF to CVD. For RHR, our study indicated that low RHR causally increases risk of AF. We have explored the genetic contribution to RHR and how it relates to CVD, with a special focus on sex differences. Further exploration of these results could elucidate biological pathways, identifying possible targets for prevention and improve current risk prediction for CVD
Risk factors other than smoking for incidence of lung cancer: The influence of a sedentary lifestyle, asthma and body mass index
Full text linkNorsk sammendrag
Lungekreft er en av de vanligste kreftformene med lave overlevelse over hele verden. Selv om røyking er den viktigste risikofaktoren for lungekreft, ses den vanligste typen, adenocarcinom, hos mange som aldri har røykt. Ettersom den største økning i insidens av lungekreft skyldes adenocarcinom, er det mulig at andre potensielle risikofaktorer enn røyking har en viktig rolle i utvikling av lungekreft.
Denne avhandlingen består av tre delstudier med overordnet mål om å avdekke mulige sammenhenger mellom inaktiv livstil, astma, kroppsmasseindeks (KMI) og insidens av lungekreft generelt og undergrupper. Datakilder er Helseundersøkelsen i Trøndelag (HUNT) og Kreftregisteret. De to første studiene er prospektive kohort-studier, mens den siste studien fokuserer på potensiell årsakssammenheng mellom KMI og forekomsten av lungekreft og undergrupper ved bruk av både observasjonelle- og Mendelsk randomisering (MR).
Den første studien viste ingen klar sammenheng mellom langvarig stillesitting og forekomsten av lungekreft, og småcellet (SCLC) eller ikke-småcellet (NSCLC) lungekreft. Men kombinasjonen av langvarig stillesitting og fysisk inaktivitet ser ut til å kunne øke forekomsten av lungekreft generelt og SCLC.
I den andre studien fant vi ingen klar sammenheng mellom astma generelt og forekomsten av lungekreft generelt eller undergrupper. Men delvis kontrollert astma så ut til å være assosiert med økt forekomst av lungekreft generelt og NSCLC. Blant voksne med aktiv astma fant man en tendens til økt forekomst av lungekreft generelt. Men det var ingen klar sammenhenger mellom ikke-aktiv astma eller kontrollert astma med forekomsten av lungekreft generelt og undergrupper.
I den observasjonelle delen av tredje studie, så KMI ut til å være omvendt assosiert med forekomsten av adenocarcinom i lungene. Men det ble ikke påvist dose responseffekt av 10 års endering i KMI og denne kreftformen. Dette tyder dermed på at det ikke er en årsakssammenheng. Ved multivariabel MR-analyse fant vi en positiv sammenheng mellom genetisk bestemt KMI og forekomsten av adenocarcinom når vi justerte for genetisk bestemt røyking. Men vi fant ingen klar sammenheng mellom KMI og forekomsten av øvrige undergrupper av lungekreft, enten i observasjonelle eller MR-analyser.
Avhandlingen viser at personer med mest inaktiv livstil har økt risiko for lungekreft. Tilsvarende økt risiko fant man også for personer med delvis kontrollert astma. Imidlertid kan vi ikke utelukke rest-konfundering av røyking i de to første studiene. Motstridende resultat mellom observasjonelle og MR-analyser tyder på at den påviste inverse sammenheng mellom KMI og adenocarcinom ikke er kausal. Det er nødvendig med flere MR studier for å avdekke forklaring for denne assosiasjonen i fremtiden.Lungekreft er en av de vanligste kreftformene med lave overlevelse over hele verden. Selv om røyking er den viktigste risikofaktoren for lungekreft, ses den vanligste typen, adenocarcinom, hos mange som aldri har røykt. Ettersom den største økning i insidens av lungekreft skyldes adenocarcinom, er det mulig at andre potensielle risikofaktorer enn røyking har en viktig rolle i utvikling av lungekreft.
Denne avhandlingen består av tre delstudier med overordnet mål om å avdekke mulige sammenhenger mellom inaktiv livstil, astma, kroppsmasseindeks (KMI) og insidens av lungekreft generelt og undergrupper. Datakilder er Helseundersøkelsen i Trøndelag (HUNT) og Kreftregisteret. De to første studiene er prospektive kohort-studier, mens den siste studien fokuserer på potensiell årsakssammenheng mellom KMI og forekomsten av lungekreft og undergrupper ved bruk av både observasjonelle- og Mendelsk randomisering (MR).
Den første studien viste ingen klar sammenheng mellom langvarig stillesitting og forekomsten av lungekreft, og småcellet (SCLC) eller ikke-småcellet (NSCLC) lungekreft. Men kombinasjonen av langvarig stillesitting og fysisk inaktivitet ser ut til å kunne øke forekomsten av lungekreft generelt og SCLC.
I den andre studien fant vi ingen klar sammenheng mellom astma generelt og forekomsten av lungekreft generelt eller undergrupper. Men delvis kontrollert astma så ut til å være assosiert med økt forekomst av lungekreft generelt og NSCLC. Blant voksne med aktiv astma fant man en tendens til økt forekomst av lungekreft generelt. Men det var ingen klar sammenhenger mellom ikke-aktiv astma eller kontrollert astma med forekomsten av lungekreft generelt og undergrupper.
I den observasjonelle delen av tredje studie, så KMI ut til å være omvendt assosiert med forekomsten av adenocarcinom i lungene. Men det ble ikke påvist dose responseffekt av 10 års endering i KMI og denne kreftformen. Dette tyder dermed på at det ikke er en årsakssammenheng. Ved multivariabel MR-analyse fant vi en positiv sammenheng mellom genetisk bestemt KMI og forekomsten av adenocarcinom når vi justerte for genetisk bestemt røyking. Men vi fant ingen klar sammenheng mellom KMI og forekomsten av øvrige undergrupper av lungekreft, enten i observasjonelle eller MR-analyser.
Avhandlingen viser at personer med mest inaktiv livstil har økt risiko for lungekreft. Tilsvarende økt risiko fant man også for personer med delvis kontrollert astma. Imidlertid kan vi ikke utelukke rest-konfundering av røyking i de to første studiene. Motstridende resultat mellom observasjonelle og MR-analyser tyder på at den påviste inverse sammenheng mellom KMI og adenocarcinom ikke er kausal. Det er nødvendig med flere MR studier for å avdekke forklaring for denne assosiasjonen i fremtiden
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
The association between normal lung function and peak oxygen uptake in patients with exercise intolerance and coronary artery disease
Full text linkIn coronary artery disease (CAD), exercise intolerance with reduced oxygen uptake at peak exercise (VO2peak) is assumed to primarily reflect cardiovascular limitation. However, oxygen transport and utilization depends on an integrated organ response, to which the normal pulmonary system may influence overall capacity. This study aimed to investigate the associations between normal values of lung function measures and VO2peak in patients with exercise intolerance and CAD. We hypothesized that forced expiratory lung volume in one second (FEV1), transfer factor of the lung for carbon monoxide (TLCO) and TLCO/alveolar volume (TLCO/VA) above lower limits of normal (LLN) are associated with VO2peak in these patients. We assessed patients with established CAD (n = 93; 21 women) referred for evaluation due to exercise intolerance from primary care to a private specialist clinic in Norway. Lung function tests and cardiopulmonary exercise testing (CPET) were performed. Z-scores of FEV1, FEV1/forced vital capacity (FVC), TLCO and TLCO/VA were calculated using the Global Lung Function Initiative (GLI) software and LLN was defined as the fifth percentile (z = -1.645). Non-obstructive patients, defined by both FEV1 and FEV1/FVC above LLN, were assessed. The associations of FEV1Z-score, TLCOZ-score and TLCO/VAZ-score above LLN with VO2peak were investigated using linear regression models. Mean VO2peak ± standard deviation (SD) was 23.8 ± 6.4 ml/kg/min in men and 19.7 ± 4.4 ml/kg/min in women. On average, one SD increase in FEV1, TLCO and TLCO/VA were associated with 1.4 (95% CI 0.2, 2.6), 2.6 (95% CI 1.2, 4.0) and 1.3 (95% CI 0.2, 2.5) ml/kg/min higher VO2peak, respectively. In non-obstructive patients with exercise intolerance and CAD, FEV1, TLCO and TLCO/VA above LLN are positively associated with VO2peak. This may imply a clinically significant influence of normal lung function on exercise capacity in these patients.</p
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
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