| 1. |
- Abdo, A. A., et al.
(författare)
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The spectral energy distribution of fermi bright blazars
- 2010
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 716:1, s. 30-70
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Tidskriftsartikel (refereegranskat)abstract
- We have conducted a detailed investigation of the broadband spectral properties of the gamma-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi gamma-ray spectra with Swift, radio, infra-red, optical, and other hard X-ray/gamma-ray data, collected within 3 months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous spectral energy distributions (SED) for 48 LBAS blazars. The SED of these gamma-ray sources is similar to that of blazars discovered at other wavelengths, clearly showing, in the usual log nu-log nu F-nu representation, the typical broadband spectral signatures normally attributed to a combination of low-energy synchrotron radiation followed by inverse Compton emission of one or more components. We have used these SED to characterize the peak intensity of both the low-and the high-energy components. The results have been used to derive empirical relationships that estimate the position of the two peaks from the broadband colors (i.e., the radio to optical, alpha(ro), and optical to X-ray, alpha(ox), spectral slopes) and from the gamma-ray spectral index. Our data show that the synchrotron peak frequency (nu(S)(peak)) is positioned between 10(12.5) and 10(14.5) Hz in broad-lined flat spectrum radio quasars (FSRQs) and between 10(13) and 10(17) Hz in featureless BL Lacertae objects. We find that the gamma-ray spectral slope is strongly correlated with the synchrotron peak energy and with the X-ray spectral index, as expected at first order in synchrotron-inverse Compton scenarios. However, simple homogeneous, one-zone, synchrotron self-Compton (SSC) models cannot explain most of our SED, especially in the case of FSRQs and low energy peaked (LBL) BL Lacs. More complex models involving external Compton radiation or multiple SSC components are required to reproduce the overall SED and the observed spectral variability. While more than 50% of known radio bright high energy peaked (HBL) BL Lacs are detected in the LBAS sample, only less than 13% of known bright FSRQs and LBL BL Lacs are included. This suggests that the latter sources, as a class, may be much fainter gamma-ray emitters than LBAS blazars, and could in fact radiate close to the expectations of simple SSC models. We categorized all our sources according to a new physical classification scheme based on the generally accepted paradigm for Active Galactic Nuclei and on the results of this SED study. Since the LAT detector is more sensitive to flat spectrum gamma-ray sources, the correlation between nu(S)(peak) and gamma-ray spectral index strongly favors the detection of high energy peaked blazars, thus explaining the Fermi overabundance of this type of sources compared to radio and EGRET samples. This selection effect is similar to that experienced in the soft X-ray band where HBL BL Lacs are the dominant type of blazars.
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| 2. |
- Abdo, A. A., et al.
(författare)
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FERMI Large Area Telescope and multi-wavelength observations of the flaring activity of PKS 1510-089 between 2008 september and 2009 june
- 2010
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 721:2, s. 1425-1447
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Tidskriftsartikel (refereegranskat)abstract
- We report on the multi-wavelength observations of PKS 1510-089 (a flat spectrum radio quasar (FSRQ) at z = 0.361) during its high activity period between 2008 September and 2009 June. During this 11 month period, the source was characterized by a complex variability at optical, UV, and gamma-ray bands, on timescales down to 6-12 hr. The brightest gamma-ray isotropic luminosity, recorded on 2009 March 26, was similar or equal to 2 x 1048 erg s-1. The spectrum in the Fermi Large Area Telescope energy range shows a mild curvature described well by a log-parabolic law, and can be understood as due to the Klein-Nishina effect. The. -ray flux has a complex correlation with the other wavelengths. There is no correlation at all with the X-ray band, a weak correlation with the UV, and a significant correlation with the optical flux. The. -ray flux seems to lead the optical one by about 13 days. From the UV photometry, we estimated a black hole mass of similar or equal to 5.4 x 10(8)M(circle dot) and an accretion rate of similar or equal to 0.5M(circle dot) yr(-1). Although the power in the thermal and non-thermal outputs is smaller compared to the very luminous and distant FSRQs, PKS 1510-089 exhibits a quite large Compton dominance and a prominent big blue bump (BBB) as observed in the most powerful gamma-ray quasars. The BBB was still prominent during the historical maximum optical state in 2009 May, but the optical/ UV spectral index was softer than in the quiescent state. This seems to indicate that the BBB was not completely dominated by the synchrotron emission during the highest optical state. We model the broadband spectrum assuming a leptonic scenario in which the inverse Compton emission is dominated by the scattering of soft photons produced externally to the jet. The resulting model-dependent jet energetic content is compatible with a scenario in which the jet is powered by the accretion disk, with a total efficiency within the Kerr black hole limit.
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| 3. |
- Naska, A, et al.
(författare)
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Eating out, weight and weight gain. A cross-sectional and prospective analysis in the context of the EPIC-PANACEA study.
- 2011
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Ingår i: International Journal of Obesity. - : Nature Publishing Group. - 0307-0565 .- 1476-5497. ; 35:3, s. 416-426
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim of this study was to examine the association of body mass index (BMI) and weight gain with eating at restaurants and similar establishments or eating at work among 10 European countries of the European Prospective Investigation into Cancer and Nutrition (EPIC) study. SUBJECTS: This study included a representative sample of 24,310 randomly selected EPIC participants. METHODS: Single 24-h dietary recalls with information on the place of consumption were collected using standardized procedures between 1995 and 2000. Eating at restaurants was defined to include all eating and drinking occasions at restaurants, cafeterias, bars and fast food outlets. Eating at work included all eating and drinking occasions at the workplace. Associations between eating at restaurants or eating at work and BMI or annual weight changes were assessed using sex-specific linear mixed-effects models, controlling for potential confounders. RESULTS: In southern Europe energy intake at restaurants was higher than intake at work, whereas in northern Europe eating at work appeared to contribute more to the mean daily intake than eating at restaurants. Cross-sectionally, eating at restaurants was found to be positively associated with BMI only among men (β=+0.24, P=0.003). Essentially no association was found between BMI and eating at work among both genders. In a prospective analysis among men, eating at restaurants was found to be positively, albeit nonsignificantly, associated with weight gain (β=+0.05, P=0.368). No association was detected between energy intake at restaurants and weight changes, controlling for total energy intake. CONCLUSION: Among men, eating at restaurants and similar establishments was associated with higher BMI and possibly weight gain.
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| 4. |
- Gonzalez, C. A., et al.
(författare)
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Helicobacter pylori infection assessed by ELISA and by immunoblot and noncardia gastric cancer risk in a prospective study: the Eurgast-EPIC project
- 2012
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Ingår i: Annals of Oncology. - : Elsevier BV. - 1569-8041 .- 0923-7534. ; 23:5, s. 1320-1324
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Tidskriftsartikel (refereegranskat)abstract
- In epidemiological studies, Helicobacter pylori infection is usually detected by enzyme-linked immunosorbent assay (ELISA). However, infection can spontaneously clear from the mucosa during the progression of atrophy and could lead to substantial under-detection of infection and underestimation of its effect on gastric cancer (GC) risk. Antibodies detected by western blot are known to persist longer after the loss of the infection. In a nested case-control study from the Eurogast-EPIC cohort, including 88 noncardia GC cases and 338 controls, we assessed the association between noncardia GC and H. pylori infection comparing antibodies detected by western blot (HELICOBLOT2.1) to those detected by ELISA (Pyloriset EIA-GIII((R))). By immunoblot, 82 cases (93.2%) were H. pylori positive, 10 of these cases (11.4%) were negative by ELISA and only 6 cases (6.8%) were negative by both ELISA and immunoblot. Multivariable odds ratio (OR) for noncardia GC comparing immunoglobulin G positive versus negative by ELISA was 6.8 [95% confidence interval (CI) 3.0-15.1], and by immunoblot, the OR was 21.4 (95% CI 7.1-64.4). Using a western blot assay, nearly all noncardia GC were classified as H. pylori positive and the OR was more than threefold higher than the OR assessed by ELISA, supporting the hypothesis that H. pylori infection is a necessary condition for noncardia GC.
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| 5. |
- Jakszyn, P., et al.
(författare)
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Meat and heme iron intake and esophageal adenocarcinoma in the European Prospective Investigation into Cancer and Nutrition study
- 2013
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 133:11, s. 2744-2750
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Tidskriftsartikel (refereegranskat)abstract
- Although recent studies suggest that high intakes of meat and heme iron are risk factors for several types of cancer, studies in relation to esophageal adenocarcinoma (EAC) are scarce. Previous results in the European Prospective Investigation into Cancer and Nutrition (EPIC) based on a relatively small number of cases suggested a positive association between processed meat and EAC. In this study, we investigate the association between intake of different types of meats and heme iron intake and EAC risk in a larger number of cases from EPIC. The study included 481,419 individuals and 137 incident cases of EAC that occurred during an average of 11 years of follow-up. Dietary intake of meat (unprocessed/processed red and white meat) was assessed by validated center-specific questionnaires. Heme iron was calculated as a type-specific percentage of the total iron content in meat. After adjusting for relevant confounders, we observed a statistically significant positive association of EAC risk with heme iron and processed meat intake, with HR: 1.67, 95% CI: 1.05-2.68 and HR: 2.27, 95% CI:1.33-3.89, respectively, for comparison of the highest vs. lowest tertile of intake. Our results suggest a potential association between higher intakes of processed meat and heme iron and risk of EAC.
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| 6. |
- Heath, A. K., et al.
(författare)
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Nutrient-wide association study of 92 foods and nutrients and breast cancer risk
- 2020
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Ingår i: Breast Cancer Research. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Several dietary factors have been reported to be associated with risk of breast cancer, but to date, unequivocal evidence only exists for alcohol consumption. We sought to systematically assess the association between intake of 92 foods and nutrients and breast cancer risk using a nutrient-wide association study. Methods Using data from 272,098 women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, we assessed dietary intake of 92 foods and nutrients estimated by dietary questionnaires. Cox regression was used to quantify the association between each food/nutrient and risk of breast cancer. A false discovery rate (FDR) of 0.05 was used to select the set of foods and nutrients to be replicated in the independent Netherlands Cohort Study (NLCS). Results Six foods and nutrients were identified as associated with risk of breast cancer in the EPIC study (10,979 cases). Higher intake of alcohol overall was associated with a higher risk of breast cancer (hazard ratio (HR) for a 1 SD increment in intake = 1.05, 95% CI 1.03-1.07), as was beer/cider intake and wine intake (HRs per 1 SD increment = 1.05, 95% CI 1.03-1.06 and 1.04, 95% CI 1.02-1.06, respectively), whereas higher intakes of fibre, apple/pear, and carbohydrates were associated with a lower risk of breast cancer (HRs per 1 SD increment = 0.96, 95% CI 0.94-0.98; 0.96, 95% CI 0.94-0.99; and 0.96, 95% CI 0.95-0.98, respectively). When evaluated in the NLCS (2368 cases), estimates for each of these foods and nutrients were similar in magnitude and direction, with the exception of beer/cider intake, which was not associated with risk in the NLCS. Conclusions Our findings confirm a positive association of alcohol consumption and suggest an inverse association of dietary fibre and possibly fruit intake with breast cancer risk.
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| 7. |
- Besson, H., et al.
(författare)
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A cross-sectional analysis of physical activity and obesity indicators in European participants of the EPIC-PANACEA study
- 2009
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 1476-5497 .- 0307-0565. ; 33:4, s. 497-506
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Cross-sectional data suggest a strong association between low levels of physical activity and obesity. The EPIC-PANACEA ( European Prospective Investigation into Cancer-Physical Activity, Nutrition, Alcohol, Cessation of Smoking, Eating out of home And obesity) project was designed to investigate the associations between physical activity and body mass index (BMI) and waist circumference based on individual data collected across nine European countries. Methods: In the European Prospective Investigation into Cancer and Nutrition ( EPIC), 519 931 volunteers were recruited between 1992 and 2000, of whom 405 819 had data on main variables of interest. Height, body weight and waist circumference were measured using standardized procedures. Physical activity was assessed using a validated four-category index reflecting a self-reported usual activity during work and leisure time. The associations between physical activity and BMI and waist circumference were estimated using multilevel mixed effects linear regression models, adjusted for age, total energy intake, smoking status, alcohol consumption and educational level. Results: A total of 125 629 men and 280 190 women with a mean age of 52.9 (s.d. 9.7) and 51.5 (s.d. 10.0) years, respectively were included. The mean BMI was 26.6 kg/m(2) (s.d. 3.6) in men and 25.0 kg/m(2) (s.d. 4.5) in women. Fifty percent of men and 30% of women were categorized as being active or moderately active. A one-category difference in the physical activity index was inversely associated with a difference of 0.18 kg/m(2) in the mean BMI (95% confidence interval, CI, 0.11, 0.24) and 1.04-cm (95% CI 0.82, 1.26) difference in waist circumference in men. The equivalent figures for women were 0.31 kg/m(2) (95% CI 0.23, 0.38) and 0.90 cm ( 95% CI 0.71, 1.08), respectively. Conclusions: Physical activity is inversely associated with both BMI and waist circumference across nine European countries. Although we cannot interpret the association causally, our results were observed in a large and diverse cohort independently from many potential confounders.
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| 8. |
- Buckland, G, et al.
(författare)
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Adherence to the mediterranean diet and risk of breast cancer in the European prospective investigation into cancer and nutrition cohort study
- 2013
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 132:12, s. 2918-2927
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Tidskriftsartikel (refereegranskat)abstract
- Epidemiological evidence suggests that the Mediterranean diet (MD) could reduce the risk of breast cancer (BC). As evidence from the prospective studies remains scarce and conflicting, we investigated the association between adherence to the MD and risk of BC among 335,062 women recruited from 1992 to 2000, in ten European countries, and followed for 11 years on average. Adherence to the MD was estimated through an adapted relative Mediterranean diet (arMED) score excluding alcohol. Cox proportional hazards regression models were used while adjusting for BC risk factors. A total of 9,009 postmenopausal and 1,216 premenopausal first primary incident invasive BC were identified (5,862 estrogen or progesterone receptor positive [ER+/PR+] and 1,018 estrogen and progesterone receptor negative [ER/PR]). The arMED was inversely associated with the risk of BC overall and in postmenopausal women (high vs. low arMED score; hazard ratio [HR] = 0.94 [95% confidence interval [CI]: 0.88, 1.00] ptrend = 0.048, and HR = 0.93 [95% CI: 0.87, 0.99] ptrend = 0.037, respectively). The association was more pronounced in ER/PR tumors (HR = 0.80 [95% CI: 0.65, 0.99] ptrend = 0.043). The arMED score was not associated with BC in premenopausal women. Our findings show that adherence to a MD excluding alcohol was related to a modest reduced risk of BC in postmenopausal women, and this association was stronger in receptor-negative tumors. The results support the potential scope for BC prevention through dietary modification.
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| 9. |
- Buckland, G., et al.
(författare)
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Healthy lifestyle index and risk of gastric adenocarcinoma in the EPIC cohort study
- 2015
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 137:3, s. 598-606
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Tidskriftsartikel (refereegranskat)abstract
- Several modifiable lifestyle factors, including smoking, alcohol, certain dietary factors and weight are independently associated with gastric cancer (GC); however, their combined impact on GC risk is unknown. We constructed a healthy lifestyle index to investigate the joint influence of these behaviors on GC risk within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The analysis included 461,550 participants (662 first incident GC cases) with a mean follow-up of 11.4 years. A healthy lifestyle index was constructed, assigning 1 point for each healthy behavior related to smoking status, alcohol consumption and diet quality (represented by the Mediterranean diet) for assessing overall GC and also body mass index for cardia GC and 0 points otherwise. Risk of GC was calculated using Cox proportional hazards regression models while adjusting for relevant confounders. The highest versus lowest score in the healthy lifestyle index was associated with a significant lower risk of GC, by 51% overall (HR 0.49 95% CI 0.35, 0.70), by 77% for cardia GC (HR 0.23 95% CI 0.08, 0.68) and by 47% for noncardia GC (HR 0.53 (95% CI 0.32, 0.87), p-trends<0.001. Population attributable risk calculations showed that 18.8% of all GC and 62.4% of cardia GC cases could have been prevented if participants in this population had followed the healthy lifestyle behaviors of this index. Adopting several healthy lifestyle behaviors including not smoking, limiting alcohol consumption, eating a healthy diet and maintaining a normal weight is associated with a large decreased risk of GC. What's new? Several modifiable lifestyle factors, including smoking status, alcohol consumption, diet quality and weight, have been independently associated with gastric cancer. Behavioral patterns often cluster, however, lifestyle scores can be used to analyse overlapping risk factors. In this study, the authors used a healthy-lifestyle index to evaluate the combined effects of all of the above factors on the risk of developing gastric cancer (GC). They found that following a healthy lifestyle dramatically decreases the burden of gastric cancer.
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| 10. |
- Cordova, R., et al.
(författare)
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Dietary intake of advanced glycation end products (AGEs) and changes in body weight in European adults
- 2020
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Ingår i: European Journal of Nutrition. - : Springer Berlin/Heidelberg. - 1436-6207 .- 1436-6215. ; 59, s. 2893-2904
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Advanced glycation end products (AGEs) can be formed in foods by the reaction of reducing sugars with proteins, and have been shown to induce insulin resistance and obesity in experimental studies. We examined the association between dietary AGEs intake and changes in body weight in adults over an average of 5 years of follow-up.Methods: A total of 255,170 participants aged 25–70 years were recruited in ten European countries (1992–2000) in the PANACEA study (Physical Activity, Nutrition, Alcohol, Cessation of smoking, Eating out of home in relation to Anthropometry), a sub-cohort of the EPIC (European Prospective Investigation into Cancer and Nutrition). Body weight was measured at recruitment and self-reported between 2 and 11 years later depending on the study center. A reference database for AGEs was used containing UPLC–MS/MS-measured Nε-(carboxymethyl)-lysine (CML), Nε-(1-carboxyethyl)-lysine (CEL), and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) in 200 common European foods. This reference database was matched to foods and decomposed recipes obtained from country-specific validated dietary questionnaires in EPIC and intake levels of CEL, CML, and MG-H1 were estimated. Associations between dietary AGEs intake and body weight change were estimated separately for each of the three AGEs using multilevel mixed linear regression models with center as random effect and dietary AGEs intake and relevant confounders as fixed effects.Results: A one-SD increment in CEL intake was associated with 0.111 kg (95% CI 0.087–0.135) additional weight gain over 5 years. The corresponding additional weight gain for CML and MG-H1 was 0.065 kg (0.041–0.089) and 0.034 kg (0.012, 0.057), respectively. The top six food groups contributing to AGEs intake, with varying proportions across the AGEs, were cereals/cereal products, meat/processed meat, cakes/biscuits, dairy, sugar and confectionary, and fish/shellfish.Conclusion: In this study of European adults, higher intakes of AGEs were associated with marginally greater weight gain over an average of 5 years of follow-up.
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