| 1. |
- Hansen, Lea B.S., et al.
(författare)
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A low-gluten diet induces changes in the intestinal microbiome of healthy Danish adults
- 2018
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- © 2018, The Author(s). Adherence to a low-gluten diet has become increasingly common in parts of the general population. However, the effects of reducing gluten-rich food items including wheat, barley and rye cereals in healthy adults are unclear. Here, we undertook a randomised, controlled, cross-over trial involving 60 middle-aged Danish adults without known disorders with two 8-week interventions comparing a low-gluten diet (2 g gluten per day) and a high-gluten diet (18 g gluten per day), separated by a washout period of at least six weeks with habitual diet (12 g gluten per day). We find that, in comparison with a high-gluten diet, a low-gluten diet induces moderate changes in the intestinal microbiome, reduces fasting and postprandial hydrogen exhalation, and leads to improvements in self-reported bloating. These observations suggest that most of the effects of a low-gluten diet in non-coeliac adults may be driven by qualitative changes in dietary fibres.
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| 2. |
- Pesu, Hannah, et al.
(författare)
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Correlates of Plasma Citrulline, a Potential Marker of Enterocyte Mass, among Children with Stunting: A Cross-Sectional Study in Uganda
- 2024
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Ingår i: Journal of Nutrition. - 1541-6100 .- 0022-3166. ; 154:2, s. 765-776
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Tidskriftsartikel (refereegranskat)abstract
- Background: Environmental enteric dysfunction (EED) is associated with stunting. Citrulline, produced in mature enterocytes, may be a valuable biomarker of small intestinal enterocyte mass in the context of EED. Objectives: We aimed to explore the correlates of plasma citrulline (p-cit) in children with stunting. Methods: In a cross-sectional study using baseline data from the community-based MAGNUS (milk affecting growth, cognition and the gut in child stunting) trial (ISRCTN13093195), we explored potential correlates of p-cit in Ugandan children with stunting aged 12–59 mo. Using linear regression in univariate and multivariate models, we explored associations with socioeconomics, diet, micronutrient status, and water, sanitation, and hygiene characteristics. The influence of covariates age, fasting, and systemic inflammation were also explored. Results: In 750 children, the mean ± standard deviation age was 32.0 ± 11.7 mo, and height-for-age z-score was –3.02 ± 0.74. P-cit, available for 730 children, differed according to time fasted and was 20.7 ± 8.9, 22.3 ± 10.6 and 24.2 ± 13.1 μmol/L if fasted <2, 2–5 and >5 h, respectively. Positive correlates of p-cit were age [0.07; 95% confidence interval (CI): 0.001, 0.15 μmol/L] and log10 serum insulin-like growth factor-1 (8.88; 95% CI: 5.09, 12.67 μmol/L). With adjustment for systemic inflammation, the association with serum insulin-like growth factor-1 reduced (4.98; 95% CI: 0.94, 9.03 μmol/L). Negative correlates of p-cit included food insecurity, wet season (–3.12; 95% CI: –4.97, –1.26 μmol/L), serum C-reactive protein (–0.15; 95% CI: –0.20, –0.10 μmol/L), serum α1-acid glycoprotein (–5.34; 95% CI: –6.98, –3.70 μmol/L) and anemia (–1.95; 95% CI: –3.72, –0.18 μmol/L). Among the negatively correlated water, sanitation, and hygiene characteristics was lack of soap for handwashing (–2.53; 95% CI: –4.82, –0.25 μmol/L). Many associations attenuated with adjustment for inflammation. Conclusions: Many of the correlates of p-cit are characteristic of populations with a high EED prevalence. Systemic inflammation is strongly associated with p-cit and is implicated in EED and stunting. Adjustment for systemic inflammation attenuates many associations, reflecting either confounding, mediation, or both. This study highlights the complex interplay between p-cit and systemic inflammation.
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| 3. |
- Cashman, Kevin D., et al.
(författare)
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Individual participant data (IPD)-level meta-analysis of randomised controlled trials to estimate the vitamin D dietary requirements in dark-skinned individuals resident at high latitude
- 2022
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Ingår i: European Journal of Nutrition. - : Springer. - 1436-6207 .- 1436-6215. ; 61, s. 1015-1034
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Tidskriftsartikel (refereegranskat)abstract
- Context and purpose: There is an urgent need to develop vitamin D dietary recommendations for dark-skinned populations resident at high latitude. Using data from randomised controlled trials (RCTs) with vitamin D3-supplements/fortified foods, we undertook an individual participant data-level meta-regression (IPD) analysis of the response of wintertime serum 25-hydroxyvitamin (25(OH)D) to total vitamin D intake among dark-skinned children and adults residing at ≥ 40° N and derived dietary requirement values for vitamin D.Methods: IPD analysis using data from 677 dark-skinned participants (of Black or South Asian descent; ages 5–86 years) in 10 RCTs with vitamin D supplements/fortified foods identified via a systematic review and predefined eligibility criteria. Outcome measures were vitamin D intake estimates across a range of 25(OH)D thresholds.Results: To maintain serum 25(OH)D concentrations ≥ 25 and 30 nmol/L in 97.5% of individuals, 23.9 and 27.3 µg/day of vitamin D, respectively, were required among South Asian and 24.1 and 33.2 µg/day, respectively, among Black participants. Overall, our age-stratified intake estimates did not exceed age-specific Tolerable Upper Intake Levels for vitamin D. The vitamin D intake required by dark-skinned individuals to maintain 97.5% of winter 25(OH)D concentrations ≥ 50 nmol/L was 66.8 µg/day. This intake predicted that the upper 2.5% of individuals could potentially achieve serum 25(OH)D concentrations ≥ 158 nmol/L, which has been linked to potential adverse effects in older adults in supplementation studies.Conclusions: Our IPD-derived vitamin D intakes required to maintain 97.5% of winter 25(OH)D concentrations ≥ 25, 30 and 50 nmol/L are substantially higher than the equivalent estimates for White individuals. These requirement estimates are also higher than those currently recommended internationally by several agencies, which are based predominantly on data from Whites and derived from standard meta-regression based on aggregate data. Much more work is needed in dark-skinned populations both in the dose–response relationship and risk characterisation for health outcomes.
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| 4. |
- Cashman, Kevin D., et al.
(författare)
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Individual participant data (IPD)-level meta-analysis of randomised controlled trials with vitamin D-fortified foods to estimate Dietary Reference Values for vitamin D
- 2021
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Ingår i: European Journal of Nutrition. - : Springer Berlin/Heidelberg. - 1436-6207 .- 1436-6215. ; 60:2, s. 939-959
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Tidskriftsartikel (refereegranskat)abstract
- Context and purpose: Individual participant data-level meta-regression (IPD) analysis is superior to meta-regression based on aggregate data in determining Dietary Reference Values (DRV) for vitamin D. Using data from randomized controlled trials (RCTs) with vitamin D3-fortified foods, we undertook an IPD analysis of the response of winter serum 25-hydroxyvitamin (25(OH)D) to total vitamin D intake among children and adults and derived DRV for vitamin D.Methods: IPD analysis using data from 1429 participants (ages 2–89 years) in 11 RCTs with vitamin D-fortified foods identified via a systematic review and predefined eligibility criteria. Outcome measures were vitamin D DRV estimates across a range of serum 25(OH)D thresholds using unadjusted and adjusted models.Results: Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of winter 25(OH)D concentrations ≥ 25 and ≥ 30 nmol/L are 6 and 12 µg/day, respectively (unadjusted model). The intake estimates to maintain 90%, 95% and 97.5% of concentrations ≥ 50 nmol/L are 33.4, 57.5 and 92.3 µg/day, respectively (unadjusted) and 17.0, 28.1 and 43.6 µg/day, respectively (adjusted for mean values for baseline serum 25(OH)D, age and BMI).Conclusions: IPD-derived vitamin D intakes required to maintain 90%, 95% and 97.5% of winter 25(OH)D concentrations ≥ 50 nmol/L are much higher than those derived from standard meta-regression based on aggregate data, due to the inability of the latter to capture between person-variability. Our IPD provides further evidence that using food-based approaches to achieve an intake of 12 µg/day could prevent vitamin D deficiency (i.e., serum 25(OH)D < 30 nmol/L) in the general population.
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| 5. |
- Damsgaard, Camilla T, et al.
(författare)
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Associations between school meal-induced dietary changes and metabolic syndrome markers in 8-11-year-old Danish children.
- 2016
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Ingår i: European Journal of Nutrition. - : Springer Science and Business Media LLC. - 1436-6207 .- 1436-6215. ; 55:5, s. 1973-84
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Tidskriftsartikel (refereegranskat)abstract
- We recently showed that provision of Nordic school meals rich in fish, vegetables and potatoes and with reduced intakes of fat improved blood pressure, insulin resistance assessed by the homeostatic model (HOMA-IR), and plasma triacylglycerol despite increasing waist circumference in Danish 8-11-year-olds. This study explored whether intake or biomarkers of key dietary components in the schools meals were associated with these metabolic syndrome (MetS) markers during the 6-month intervention.
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| 6. |
- Hartvig, Ditte L., et al.
(författare)
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Initial liking influences the development of acceptance learning across repeated exposure to fruit juices in 9–11 year-old children
- 2015
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Ingår i: Food Quality and Preference. - : Elsevier BV. - 0950-3293 .- 1873-6343. ; 39, s. 228-235
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Tidskriftsartikel (refereegranskat)abstract
- In several studies, it has been found that repeated exposure to a novel food increases children’s acceptance of the exposure food. The present study, investigated how repeated exposure influences the acceptance of two Nordic berry juices, and whether the development depends on initial liking of the product, in 9–11 year-old children. The study had 317 participants. Two groups of children were exposed to either sea-buckthorn (n = 92) or aronia (n = 105) juice eight times, and performed two follow-up sessions 3 and 6 months after the 8th exposure. A third group (n = 120) served as controls. During pre and post-test sessions all participating children evaluated acceptance of both juices.Intake of sea-buckthorn juice increased significantly over the eight exposures (55.1 ± 7.3 till 108.8 ± 12.3) and remained high after 6 months (131.1 ± 13.2). Intake of aronia juice was only increased at follow-up sessions. Liking did not develop significantly for any of the juices across exposures. When children were grouped by their initial liking increased intake across exposures was observed regardless of initial liking of sea-buckthorn. Liking developed similarly for both juices. A significant increase was found for the ‘initial dislikers’ only. This study demonstrates how exposure effects are influenced by initial liking; it appears that changes in familiarity explain the changes seen for sea-buckthorn among ‘dislikers’. ‘Initial dislikers’ had the most benefit from repeated exposures, but did not reach ‘initial likers’ across eight exposures; more exposures in the group of ‘initial dislikers’ had possibly led to even higher liking and intake. The increased intake observed for ‘neutral likers’ and ‘initial likers’ of sea-buckthorn was not explained by increased familiarity or increased liking.
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| 7. |
- Kisand, Veljo, et al.
(författare)
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Prediction of COVID-19 positive cases, a nation-wide SARS-CoV-2 wastewater-based epidemiology study
- 2023
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Ingår i: Water Research. - : Elsevier BV. - 1879-2448 .- 0043-1354. ; 231
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Tidskriftsartikel (refereegranskat)abstract
- Taking advantage of Estonia's small size and population, we have employed wastewater-based epidemiology approach to monitor the spread of SARS-CoV-2, releasing weekly nation-wide updates. In this study we report results obtained between August 2020 and December 2021. Weekly 24 h composite samples were collected from wastewater treatment plants of larger towns already covered 65% of the total population that was complemented up to 40 additional grab samples from smaller towns/villages and the specific sites of concern. The N3 gene abundance was quantified by RT-qPCR. The N3 gene copy number (concentration) in wastewater fluctuated in accordance with the SARS-CoV-2 spread within the total population, with N3 abundance starting to increase 1.25 weeks (9 days) (95% CI: [1.10, 1.41]) before a rise in COVID-19 positive cases. Statistical model between the load of virus in wastewater and number of infected people validated with the Alpha variant wave (B.1.1.17) could be used to predict the order of magnitude in incidence numbers in Delta wave (B.1.617.2) in fall 2021. Targeted testing of student dormitories, retirement and nursing homes and prisons resulted in successful early discovery of outbreaks. We put forward a SARS-CoV-2 Wastewater Index (SARS2-WI) indicator of normalized virus load as COVID-19 infection metric to complement the other metrics currently used in disease control and prevention: dynamics of effective reproduction number (Re), 7-day mean of new cases, and a sum of new cases within last 14 days. In conclusion, an efficient surveillance system that combines analysis of composite and grab samples was established in Estonia. There is considerable discussion how the viral load in wastewater correlates with the number of infected people. Here we show that this correlation can be found. Moreover, we confirm that an increased signal in wastewater is observed before the increase in the number of infections. The surveillance system helped to inform public health policy and place direct interventions during the COVID-19 pandemic in Estonia via early warning of epidemic spread in various regions of the country.
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| 8. |
- Losno, Emily A., et al.
(författare)
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Vegan Diet and the Gut Microbiota Composition in Healthy Adults
- 2021
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Ingår i: Nutrients. - : MDPI. - 2072-6643. ; 13:7
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Forskningsöversikt (refereegranskat)abstract
- The human gut microbiota are the microorganisms (generally bacteria and archaea) that live in the digestive tracts of humans. Due to their numerous functions, the gut microbiota can be considered a virtual organ of the body, playing a pivotal role in health maintenance. Dietary habits contribute to gut microbiota composition, and evidence from observational and intervention studies suggest that vegan diets may promote health, potentially through affecting the diverse ecosystem of beneficial bacteria in the gut. A systematic literature search was conducted on PubMed and Scopus to identify studies investigating the microbiota composition in vegans. Vegans are defined as people excluding food products that are derived from animals from their diet. Nine observational studies were identified. The main outcome of the systematic review was an increase in Bacteroidetes on the phylum level and a higher abundance of Prevotella on the genus level. In conclusion, the present systematic literature review highlighted some benefits of a vegan diet but also demonstrated the complexity of evaluating results from gut microbiota research. The available evidence only consisted of cross-sectional studies, therefore suggesting the need for well-designed randomised controlled trials. Furthermore, the quality assessment of the studies included in the review suggested a lack of standardised and validated methods for participant selection as well as for faecal sampling and faecal analysis.
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| 9. |
- Lundy, Bronwen, et al.
(författare)
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Screening for Low Energy Availability in Male Athletes : Attempted Validation of LEAM-Q
- 2022
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Ingår i: Nutrients. - : MDPI. - 2072-6643. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- A questionnaire-based screening tool for male athletes at risk of low energy availability (LEA) could facilitate both research and clinical practice. The present options rely on proxies for LEA such screening tools for disordered eating, exercise dependence, or those validated in female athlete populations. in which the female-specific sections are excluded. To overcome these limitations and support progress in understanding LEA in males, centres in Australia, Norway, Denmark, and Sweden collaborated to develop a screening tool (LEAM-Q) based on clinical investigations of elite and sub-elite male athletes from multiple countries and ethnicities, and a variety of endurance and weight-sensitive sports. A bank of questions was developed from previously validated questionnaires and expert opinion on various clinical markers of LEA in athletic or eating disorder populations, dizziness, thermoregulation, gastrointestinal symptoms, injury, illness, wellbeing, recovery, sleep and sex drive. The validation process covered reliability, content validity, a multivariate analysis of associations between variable responses and clinical markers, and Receiver Operating Characteristics (ROC) curve analysis of variables, with the inclusion threshold being set at 60% sensitivity. Comparison of the scores of the retained questionnaire variables between subjects classified as cases or controls based on clinical markers of LEA revealed an internal consistency and reliability of 0.71. Scores for sleep and thermoregulation were not associated with any clinical marker and were excluded from any further analysis. Of the remaining variables, dizziness, illness, fatigue, and sex drive had sufficient sensitivity to be retained in the questionnaire, but only low sex drive was able to distinguish between LEA cases and controls and was associated with perturbations in key clinical markers and questionnaire responses. In summary, in this large and international cohort, low sex drive was the most effective self-reported symptom in identifying male athletes requiring further clinical assessment for LEA.
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| 10. |
- Melin, Anna K., Assistant Professor, 1965-, et al.
(författare)
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Impact of Menstrual Function on Hormonal Response to Repeated Bouts of Intense Exercise
- 2019
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Ingår i: Frontiers in Physiology. - : Frontiers Media S.A.. - 1664-042X. ; 10, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Strenous exercise stimulates the hypothalamic-pituitary (HP) axis in order to ensure homeostasis and promote anabolism. Furthermore, exercise stimulates a transient increase in the neurotrophin brain-derived neurotrophic factor (BDNF) suggested to mediate the anxiolytic effects of exercise. Athletes with secondary functional hypothalamic amenorrhea (FHA) have been reported to have lower BDNF, and a blunted HP axis response to exercise as athletes with overtraining syndrome. Aim: The aim of the study was to investigate the hormonal and BDNF responses to a two-bout maximal exercise protocol with four hours of recovery in between in FHA and eumenorrheic (EUM) athletes. Methods: Eumenorrheic (n = 16) and FHA (n = 14) endurance athletes were recruited from national teams and competitive clubs. Protocols included gynecological examination; body composition (DXA); 7-day assessment of energy availability; blood sampling pre and post the two exercises tests. Results: There were no differences between groups in hormonal responses to the first exercise bout. After the second exercise bout IGFBP-3 increased more in FHA compared with EUM athletes (2.1 +/- 0.5 vs. 0.6 +/- 0.6 mu g/L, p = 0.048). There were non-significant trends toward higher increase in IGF-1 (39.3 +/- 4.3 vs. 28.0 +/- 4.6 mu g/L, p = 0.074), BDNF (96.5 +/- 22.9 vs. 34.4 +/- 23.5 mu g/L, p = 0.058), GH to cortisol ratio (0.329 +/- 0.010 vs. 0.058 +/- 0.010, p = 0.082), and decrease in IGF-1 to IGFBP-3 ratio (-2.04 +/- 1.2 vs. 0.92 +/- 1.22, p = 0.081) in athletes with FHA compared with EUM athletes. Furthermore, there was a non-significant trend toward a higher increase in prolactin to cortisol ratio in EUM athletes compared with athletes with FHA (0.60 +/- 0.15 vs. 0.23 +/- 0.15, p = 0.071). No differences in the hormonal or BDNF responses between the two exercise bouts as a result of menstrual function were found. Conclusion: No major differences in the hormonal or BDNF responses between the two exercise bouts as a result of menstrual function could be detected.
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| 11. |
- Melin, Anna K., 1965-, et al.
(författare)
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The LEAF questionnaire : a screening tool for the identification of female athletes at risk for the female athlete triad
- 2014
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Ingår i: British Journal of Sports Medicine. - : BMJ Publishing Group Ltd. - 0306-3674 .- 1473-0480. ; 48, s. 540-545
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Tidskriftsartikel (refereegranskat)abstract
- Background Low energy availability (EA) in female athletes with or without an eating disorder (ED) increases the risk of oligomenorrhoea/functional hypothalamic amenorrhoea and impaired bone health, a syndrome called the female athlete triad (Triad). There are validated psychometric instruments developed to detect disordered eating behaviour (DE), but no validated screening tool to detect persistent low EA and Triad conditions, with or without DE/ED, is available.Aim The aim of this observational study was to develop and test a screening tool designed to identify female athletes at risk for the Triad.Methods Female athletes (n=84) with 18–39 years of age and training≥5 times/week filled out the Low Energy Availability in Females Questionnaire (LEAF-Q), which comprised questions regarding injuries and gastrointestinal and reproductive function. Reliability and internal consistency were evaluated in a subsample of female dancers and endurance athletes (n=37). Discriminant as well as concurrent validity was evaluated by testing self-reported data against measured current EA, menstrual function and bone health in endurance athletes from sports such as long distance running and triathlon (n=45).Results The 25-item LEAF-Q produced an acceptable sensitivity (78%) and specificity (90%) in order to correctly classify current EA and/or reproductive function and/or bone health.Conclusions The LEAF-Q is brief and easy to administer, and relevant as a complement to existing validated DE screening instruments, when screening female athletes at risk for the Triad, in order to enable early detection and intervention.
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| 12. |
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| 13. |
- Munch Roager, Henrik, et al.
(författare)
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Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: A randomised cross-over trial
- 2019
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Ingår i: Gut. - : BMJ. - 1468-3288 .- 0017-5749. ; 68:1, s. 83-93
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Tidskriftsartikel (refereegranskat)abstract
- Objective T o investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. Design 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of =6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory markers, anthropometry and urine metabolomics were assessed. Results 50 participants completed both periods with a whole grain intake of 179±50 g/day and 13±10 g/day in the whole grain and refined grain period, respectively. Compliance was confirmed by a difference in plasma alkylresorcinols (p<0.0001). Compared with refined grain, whole grain did not significantly alter glucose homeostasis and did not induce major changes in the faecal microbiome. Also, breath hydrogen levels, plasma short-chain fatty acids, intestinal integrity and intestinal transit time were not affected. The whole grain diet did, however, compared with the refined grain diet, decrease body weight (p<0.0001), serum inflammatory markers, interleukin (IL)-6 (p=0.009) and C-reactive protein (p=0.003). The reduction in body weight was consistent with a reduction in energy intake, and IL-6 reduction was associated with the amount of whole grain consumed, in particular with intake of rye. Conclusion C ompared with refined grain diet, whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and systemic lowgrade inflammation.
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| 14. |
- Pandey, Sujita, et al.
(författare)
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An Application of the Theory of Planned Behaviour to Predict Intention to Consume Plant-Based Yogurt Alternatives
- 2021
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Ingår i: Foods. - : MDPI. - 2304-8158. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- This study attempts to predict plant-based yogurt consumers’ intention to consume plant-based yogurt alternatives in Denmark employing Ajzen’s theory of planned behaviour as a theoretical framework. An online survey was conducted among 265 consumers recruited through convenience (snowball) sampling. The results from structural equation modelling analysis show that attitude (β = 0.216, p < 0.001), perceived behavioural control (self-efficacy) (β = 0.229, p < 0.001) and perceived sensory attributes (β = 0.324, p < 0.001) positively and significantly influenced consumers’ intention to consume plant-based yogurt alternatives. However, subjective norms (β = 0.106, p = 0.087) and perceived barriers (β = −0.051, p = 0.414) did not influence consumers’ intention to consume plant-based yogurt alternatives. Further, objective knowledge showed no significant influence on attitudes (β = 0.077, p = 0.242) and intention (β = −0.029, p = 0.603) towards plant-based yogurt alternatives. The intention (β = 0.677, p < 0.001) to consume plant-based yogurt alternatives showed a strong positive correlation with the behaviour to consume plant-based yogurt alternatives. The results from logistic regression indicated that socio-demographic characteristics, gender, education, income and region of residence were significantly associated with consumption of plant-based yogurt alternatives. Thus, focusing on consumers’ attitudes and self-efficacy and improving the organoleptic characteristics might promote the consumption of plant-based yogurt alternatives in Denmark and similar countries.
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| 15. |
- Pasha, Shahab, et al.
(författare)
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A Survey on Ad Hoc Signal Processing : Applications, Challenges and State-of-the-Art Techniques
- 2019
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Ingår i: 2019 IEEE International Symposium on Signal Processing and Information Technology (ISSPIT). - : IEEE. - 9781728153414
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Konferensbidrag (refereegranskat)abstract
- In an era of ubiquitous digital devices with built-in microphones and recording capability, distributed microphone arrays of a few digital recording devices are the emerging recording tool in hands-free speech communications and immersive meetings. Such so-called ad hoc microphone arrays can facilitate high-quality spontaneous recording experiences for a wide range of applications and scenarios, though critical challenges have limited their applications. These challenges include unknown and changeable positions of the recording devices and sound sources, resulting in varying time delays of arrival between microphones in the ad hoc array as well as varying recorded sound power levels. This paper reviews state-of-the-art techniques to overcome these issues and provides insight into possible ways to make existing methods more effective and flexible. The focus of this paper is on scenarios in which the microphones are arbitrarily located in an acoustic scene and do not communicate directly or through a fusion centre.
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| 16. |
- Pasha, Shahab, et al.
(författare)
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Distributed microphone arrays, emerging speech and audio signal processing platforms : A review
- 2020
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Ingår i: Advances in Science, Technology and Engineering Systems. - : ASTES Journal. - 2415-6698. ; 5:4, s. 331-343
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Tidskriftsartikel (refereegranskat)abstract
- Given ubiquitous digital devices with recording capability, distributed microphone arrays are emerging recording tools for hands-free communications and spontaneous tele-conferencings. However, the analysis of signals recorded with diverse sampling rates, time delays, and qualities by distributed microphone arrays is not straightforward and entails important considerations. The crucial challenges include the unknown/changeable geometry of distributed arrays, asynchronous recording, sampling rate mismatch, and gain inconsistency. Researchers have recently proposed solutions to these problems for applications such as source localization and dereverberation, though there is less literature on real-time practical issues. This article reviews recent research on distributed signal processing techniques and applications. New applications benefitting from the wide coverage of distributed microphones are reviewed and their limitations are discussed. This survey does not cover partially or fully connected wireless acoustic sensor networks.
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| 17. |
- Pasha, Shahab, et al.
(författare)
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Multi-channel electronic stethoscope for enhanced cardiac auscultation using beamforming and equalisation techniques
- 2021
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Ingår i: 28th European Signal Processing Conference (EUSIPCO). - : IEEE. - 9789082797053 ; , s. 1289-1293
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Konferensbidrag (refereegranskat)abstract
- This paper reports on the implementation of a multi-channel electronic stethoscope designed to isolate the heart sound from the interfering sounds of the lungs and blood vessels. The multi-channel stethoscope comprises four piezo contact microphones arranged in rectangular and linear arrays. Beamforming and channel equalisation techniques are applied to the multi-channel recordings made in the aortic, pulmonary, tricuspid, and mitral valve areas. The proposed channel equaliser cancels out the distorting effect of the chest and rib cage on the heart sound frequency spectrum. It is shown that the applied beamforming methods effectively suppress the interfering lung noise and improve the signal to interference and noise ratio by 16 dB. The results confirm the superior performance of the implemented multi-channel stethoscope compared with commercially available single-channel electronic stethoscopes.
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| 18. |
- Vilhelmsson, Andreas, et al.
(författare)
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Exposure to per- and polyfluoroalkyl substances in early pregnancy and risk of cerebral palsy in children
- 2023
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Ingår i: Science of the Total Environment. - 1879-1026. ; 899
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Most cerebral palsy (CP) cases have an unexplained etiology, but a role for environmental exposures has been suggested. One purported environmental risk factor is exposure to endocrine-disrupting pollutants specifically per- and polyfluoroalkyl substances (PFAS).OBJECTIVES: We investigated the association between prenatal PFAS exposures and CP in Swedish children.METHODS: In this case-control study, 322 CP cases, 343 population controls, and 258 preterm controls were identified from a birth registry in combination with a CP follow-up program from 1995 to 2014 and linked to a biobank which contains serum samples from week 10-14 of pregnancy. Maternal serum concentrations of four PFAS compounds: perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctane sulfonate (PFOS) were analyzed using liquid chromatography-tandem-mass-spectrometry. We estimated odds ratios (ORs) and 95 % confidence intervals (CIs) for CP and each PFAS in quartiles and as continuous variables controlling for various sociodemographic and lifestyle factors.RESULTS: In crude and adjusted analyses, we did not find consistent evidence of associations between serum PFHxS, PFOA, PFNA, PFOS and concentrations in early pregnancy and CP, except in preterm infants. The ORs comparing the highest PFAS quartiles to the lowest were 1.05 (95 % CI: 0.63-1.76), 0.96 (95 % CI: 0.55-1.68), 0.71 (95 % CI: 0.41-1.25), and 1.17 (95 % CI: 0.61-2.26), for PFHxS, PFOA, PFNA, and PFOS, respectively. Some positive associations were observed for preterm infants, but the results were imprecise. Similar patterns were observed in analyses treating PFAS as continuous variables.CONCLUSIONS: In this study, we found little evidence that early pregnancy prenatal exposure to PFHxS, PFOA, PFNA, or PFOS increases the risk of CP. However, some positive associations were observed for preterm cases and warrant further investigation.
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| 19. |
- Zhou, Xiao, et al.
(författare)
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How dish components influence older consumers’ evaluation? : a study with application of conjoint analysis and eye tracking technology
- 2022
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Ingår i: Food Quality and Preference. - : Elsevier. - 0950-3293 .- 1873-6343. ; 97
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Tidskriftsartikel (refereegranskat)abstract
- A visually appetising and vegetable-rich dish can be an alternative to the traditional dish for well-functioning older consumers. The aim of this study was to investigate older people’s evaluations towards dishes by incorporating dish attributes (main course, potatoes, vegetables, and dish label) with novel dish components. During the test, a total of 100 participants aged from 60 to 91 were invited to verbally rate their willingness to try, perceived familiarity and healthiness towards eight dish combinations presented randomly in the form of pictures. In the meanwhile, 31 participants’ eye motions for each dish picture were successfully recorded by an eye-tracker. Through conjoint analysis, main course and vegetables were found to have the highest influence on willingness to try, perceived familiarity, perceived healthiness, and total eye fixation time towards the dish. A labelled dish with meatballs, broccolis and plain potatoes was perceived as the most familiar dish. A dish with veggie balls, mixed vegetables and decorated potatoes was perceived as the healthiest. Older participants were most willing to try the dish consisting of mixed vegetables, veggie balls and decorated potatoes when the dish label was added. Females, who emphasised healthy eating and cared about price, variety, organic and health value of a dish were more willing to try veggie balls than meatballs. Regarding the eye metrics, most participants looked at the main course area first, and had the longest total eye fixation time on the dish valued as the healthiest. In the future, to meet older consumers’ demand for daily diet, appropriate selection of dish components with frequent food communication will be indispensable.
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