| 1. |
- Aaron, F. D., et al.
(författare)
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Diffractive electroproduction of rho and phi mesons at HERA
- 2010
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2010:5, s. 1-111
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Tidskriftsartikel (refereegranskat)abstract
- Diffractive electroproduction of rho and phi mesons is measured at HERA with the H1 detector in the elastic and proton dissociative channels. The data correspond to an integrated luminosity of 51 pb(-1). About 10500 rho and 2000 phi events are analysed in the kinematic range of squared photon virtuality 2.5 <= Q(2) <= 60 GeV2, photon-proton centre of mass energy 35 <= W <= 180 GeV and squared four-momentum transfer to the proton vertical bar t vertical bar <= 3 GeV2. The total, longitudinal and transverse cross sections are measured as a function of Q(2), W and vertical bar t vertical bar. The measurements show a transition to a dominantly "hard" behaviour, typical of high gluon densities and small q (q) over bar dipoles, for Q(2) larger than 10 to 20 GeV2. They support flavour independence of the diffractive exchange, expressed in terms of the scaling variable (Q(2) + M-V(2))/4, and proton vertex factorisation. The spin density matrix elements are measured as a function of kinematic variables. The ratio of the longitudinal to transverse cross sections, the ratio of the helicity amplitudes and their relative phases are extracted. Several of these measurements have not been performed before and bring new information on the dynamics of diffraction in a QCD framework. The measurements are discussed in the context of models using generalised parton distributions or universal dipole cross sections.
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| 2. |
- Aaron, F. D., et al.
(författare)
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Jet production in ep collisions at high Q(2) and determination of alpha(s)
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 65:3-4, s. 363-383
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Tidskriftsartikel (refereegranskat)abstract
- The production of jets is studied in deep-inelastic e(+/-) p scattering at large negative four momentum transfer squared 150 < Q(2) < 15000 GeV2 using HERA data taken in 1999-2007, corresponding to an integrated luminosity of 395 pb(-1). Inclusive jet, 2-jet and 3-jet cross sections, normalised to the neutral current deep-inelastic scattering cross sections, are measured as functions of Q(2), jet transverse momentum and proton momentum fraction. The measurements are well described by perturbative QCD calculations at next-to-leading order corrected for hadronisation effects. The strong coupling as determined from these measurements
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| 3. |
- Aaron, F. D., et al.
(författare)
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Measurement of the charm and beauty structure functions using the H1 vertex detector at HERA
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 65:1-2, s. 89-109
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Tidskriftsartikel (refereegranskat)abstract
- Inclusive charm and beauty cross sections are measured in e (-) p and e (+) p neutral current collisions at HERA in the kinematic region of photon virtuality 5a parts per thousand currency signQ (2)a parts per thousand currency sign2000 GeV2 and Bjorken scaling variable 0.0002a parts per thousand currency signxa parts per thousand currency sign0.05. The data were collected with the H1 detector in the years 2006 and 2007 corresponding to an integrated luminosity of 189 pb(-1). The numbers of charm and beauty events are determined using variables reconstructed by the H1 vertex detector including the impact parameter of tracks to the primary vertex and the position of the secondary vertex. The measurements are combined with previous data and compared to QCD predictions.
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| 4. |
- Aaron, F. D., et al.
(författare)
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Prompt photons in photoproduction at HERA
- 2010
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 66:1-2, s. 17-33
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Tidskriftsartikel (refereegranskat)abstract
- The production of prompt photons is measured in the photoproduction regime of electron-proton scattering at HERA. The analysis is based on a data sample corresponding to a total integrated luminosity of 340 pb(-1) collected by the H1 experiment. Cross sections are measured for photons with transverse momentum and pseudorapidity in the range 6< E-T(gamma) < 15 GeV and -1.0< eta(gamma) < 2.4, respectively. Cross sections for events with an additional jet are measured as a function of the transverse energy and pseudorapidity of the jet, and as a function of the fractional momenta x(gamma) and x(p) carried by the partons entering the hard scattering process. The correlation between the photon and the jet is also studied. The results are compared with QCD predictions based on the collinear and on the k(T) factorization approaches.
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| 5. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 6. |
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| 7. |
- Börnhorst, C, et al.
(författare)
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Prevalence and determinants of misreporting among European children in proxy-reported 24 h dietary recalls.
- 2013
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Ingår i: British Journal of Nutrition. - : Cambridge University Press. - 0007-1145 .- 1475-2662. ; 109:7, s. 1257-1265
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Tidskriftsartikel (refereegranskat)abstract
- Dietary assessment is strongly affected by misreporting (both under- and over-reporting), which results in measurement error. Knowledge about misreporting is essential to correctly interpret potentially biased associations between diet and health outcomes. In young children, dietary data mainly rely on proxy respondents but little is known about determinants of misreporting here. The present analysis was conducted within the framework of the multi-centre IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study and is based on 6101 children aged 2–9 years with 24 h dietary recall (24-HDR) and complete covariate information. Adapted Goldberg cut-offs were applied to classify the 24-HDR as ‘over-report’, ‘plausible report’ or ‘under-report’. Backward elimination in the course of multi-level logistic regression analyses was conducted to identify factors significantly related to under- and over-reporting. Next to characteristics of the children and parents, social factors and parental concerns/perceptions concerning their child's weight status were considered. Further selective misreporting was addressed, investigating food group intakes commonly perceived as more or less socially desirable. Proportions of under-, plausible and over-reports were 8·0, 88·6 and 3·4 %, respectively. The risk of under-reporting increased with age (OR 1·19, 95 % CI 1·05, 1·83), BMI z-score of the child (OR 1·23, 95 % CI 1·10, 1·37) and household size (OR 1·12, 95 % CI 1·01, 1·25), and was higher in low/medium income groups (OR 1·45, 95 % CI 1·13, 1·86). Over-reporting was negatively associated with BMI z-scores of the child (OR 0·78, 95 % CI 0·69, 0·88) and higher in girls (OR 1·70, 95 % CI 1·27, 2·28). Further social desirability and parental concerns/perceptions seemed to influence the reporting behaviour. Future studies should involve these determinants of misreporting when investigating diet–disease relationships in children to correct for the differential reporting bias.
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| 8. |
- De Miguel-Etayo, P, et al.
(författare)
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Physical fitness reference standards in European children: the IDEFICS study.
- 2014
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 38:2
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/OBJECTIVES: A low fitness status during childhood and adolescence is associated with important health-related outcomes, such as increased future risk for obesity and cardiovascular diseases, impaired skeletal health, reduced quality of life and poor mental health. Fitness reference values for adolescents from different countries have been published, but there is a scarcity of reference values for pre-pubertal children in Europe, using harmonised measures of fitness in the literature. The IDEFICS study offers a good opportunity to establish normative values of a large set of fitness components from eight European countries using common and well-standardised methods in a large sample of children. Therefore, the aim of this study is to report sex- and age-specific fitness reference standards in European children. SUBJECTS/METHODS: Children (10,302) aged 6-10.9 years (50.7% girls) were examined. The test battery included: the flamingo balance test, back-saver sit-and-reach test (flexibility), handgrip strength test, standing long jump test (lower-limb explosive strength) and 40-m sprint test (speed). Moreover, cardiorespiratory fitness was assessed by a 20-m shuttle run test. Percentile curves for the 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentiles were calculated using the General Additive Model for Location Scale and Shape (GAMLSS). RESULTS: Our results show that boys performed better than girls in speed, lower- and upper-limb strength and cardiorespiratory fitness, and girls performed better in balance and flexibility. Older children performed better than younger children, except for cardiorespiratory fitness in boys and flexibility in girls. CONCLUSIONS: Our results provide for the first time sex- and age-specific physical fitness reference standards in European children aged 6-10.9 years.
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| 9. |
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| 10. |
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| 11. |
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| 12. |
- Papoutsoul, S., et al.
(författare)
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No breakfast at home: association with cardiovascular disease risk factors in childhood
- 2014
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Ingår i: European Journal of Clinical Nutrition. - : Springer Science and Business Media LLC. - 0954-3007 .- 1476-5640. ; 68:7, s. 829-834
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/OBJECTIVES: Limited data exist regarding breakfast consumption and its association with cardiovascular disease (CVD) risk factors. This study investigates the relationship between breakfast routine and CVD risk factors in a multinational sample. SUBJECTS/METHODS: Cross-sectional data from eight European countries participating in the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) survey (2007-2008) were used. The sample included children 2 to <10 years of age (n=8863, 51.2% boys). The Mann-Whitney U-test and logistic regression were used to assess CVD risk factors among no breakfast (NBrH), occasional breakfast and daily breakfast at home (DBrH) consumption. RESULTS: Male school-aged NBrH consumers, compared with DBrH consumers, were more likely to be overweight/obese (odds ratio (OR): 1.37, 95% confidence interval (Cl) = 1.05-1.79), to have higher risk for high-density lipoprotein (HDL) cholesterol levels lower than 40 mg/dl (OR: 1.69, 95% CI = 1.24-2.30), triglycerides (TG) above 75 mg/dl (OR: 1.65, 95% CI = 1.24-2.19) and sum of skinfolds greater than the 90th percentile (OR: 1.32, 95% CI = 1.0-1.76). Female school-aged NBrH consumers compared with DBrH consumers had a higher risk for waist circumference greater than the 90th percentile (OR: 1.70, 95% CI = 1.14-2.51), HDL cholesterol levels lower than 40 mg/dl (OR: 1.65, 95% CI = 1.23-2.21), TG above 75 mg/dl (OR: 1.65, 95% CI = 1.26-2.17) and total cholesterol/HDL cholesterol ratio >3.5 (OR: 1.39, 95% CI = 1.09-1.77). Results remained significant after adjusting for daily physical activity in moderate-to-vigorous physical activity (MVPA) periods (in min/day). Male DBrH consumers, 6 to <10 years of age, had longer daily periods of MVPA compared with NBrH consumers (32.0 +/- 21.4 vs 27.5 +/- 18.8, P < 0.05). For preschoolers, breakfast consumption was negatively associated with CVD risk factors but results of regression models were mostly insignificant. CONCLUSIONS: Daily breakfast consumption contributes to controlling school-aged children's weight and lipid profile and promotes higher PA.
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