1,557 research outputs found

    Sphere rolling on the surface of a cone

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    We analyse the motion of a sphere that rolls without slipping on a conical surface having its axis in the direction of the constant gravitational field of the Earth. This nonholonomic system admits a solution in terms of quadratures. We exhibit that the only circular of the system orbit is stable and furthermore show that all its solutions can be found using an analogy with central force problems. We also discuss the case of motion with no gravitational field, that is, of motion on a freely falling cone.Comment: 12 pages, 2 figures, to be published in Eur J Phy

    Human transcriptome response after Mediterranean diet consumption

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    Trabajo presentado en el IV Congress of International Society of Nutrigenetics/Nutrigenomics ISNN, celebrado en Pamplona (España) del 18 al 20 de noviembre de 2010.[Introduction]: Despite the benefits associated with healthy diets, data on the mechanisms by which these benefits are promoted are scarce. Our aim was to explore the global transcriptomic response of biological pathways related to cardiovascular disease associated with traditional Mediterranean diet (TMD) intervention.[Methods]: The PREDIMED study is a large on-going, parallel, multicentre, randomized, controlled trial aimed at assessing the TMD effect on primary cardiovascular prevention. High cardiovascular risk participants were recruited and assigned to one of the following interventions: 1) TMD plus virgin olive oil (VOO); 2) TMD plus mixed nuts; or 3) low-fat diet (control group). In a sub sample of 30 volunteers of the PREDIMED-Barcelona Sur Centre, gene expression changes in peripheral mononuclear cells, after 3 months of intervention, were assessed by microarray analysis (Affymetrix) in which about 30,000 individual human genes were included. Crude and adjusted models for data analyses were performed separately in two different centres. Pearson´s correlation coefficients for log2ratio (post-intervention/pre-intervention value) and T-statistics were greater than 0.97. Gene ontology analyses were performed by Bioingenuity Software on genes with T-statistics ≥1.5 or ≥-1.5 after interventions.[Results]: Analyses of canonical pathways related with cardiovascular risk highlighted that: 1) MUFA versus PUFA rich diets (MUFA/PUFA ratio >3.5; TMD plus VOO and Low-fat) promoted changes in clusters of genes associated with cytokine and nuclear receptor signaling; and 2) TMD plus VOO promoted changes in blood pressure related pathways. In agreement with this, the greatest decrease in systolic and diastolic blood pressure levels were observed after TMD plus VOO diet.[Conclusions]: One of the mechanisms by which MUFA rich diets, and particularly a TMD rich in virgin olive oil, can exert their health benefits is through an enhancement of the global transcriptomic response in pathways related with cardiovascular risk

    Mediterranean diet and atrial fibrillation: results from the predimed trial

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    Resumen del trabajo presentado en el X Congreso Internacional de la Dieta Mediterránea, celebrado en Barcelona (España) del 02 al 03 de abril de 2014.[Background]: It has been estimated that over 25 million Europeans will have atrial fibrillation by 2050. Even though pathophysiological mechanisms are being disentangled, there are hardly preventive strategies.[Objective]: To assess the effect of a Mediterranean diet (MedDiet) supplemented either with extra virgin olive oil (EVOO) or mixed nuts on the incidence of atrial fibrillation.[Methods]: The PREDIMED study (Prevención con Dieta Mediterránea) is a randomized, singleblind, and controlled trial conducted in Spanish primary healthcare centers. Participants were 6705 men (55-80 years) and women (60-80 years) initially free of atrial fibrillation who were randomly assigned to one of three dietary interventions: a MedDiet supplemented with EVOO, a MedDiet supplemented with nuts, or advice to follow a low-fat diet (control group). Incident atrial fibrillations were identified from inpatient and outpatient charts and adjudicated by a committee blind to treatment assignment. Analyses were performed on an intention-to-treat basis.[Results]: Over 4.7 years of follow-up (median), we observed 72 incident cases of atrial fibrillation in the MedDiet with EVOO group, 82 in the MedDiet with nuts group and 92 in the control group. Participants allocated to the MedDiet supplemented with EVOO group had a significantly lower risk of atrial fibrillation (HR: 0.62; 95%CI: 0.45-0.85), compared to those in the control group. No effect was observed for the MedDiet supplemented with nuts group (HR: 0.89; 95%CI 0.65-1.20).[Conclusions]: These results from the PREDIMED trial support a potential beneficial protection of a MedDiet supplemented with EVOO on the incidence of atrial fibrillation

    Reduction in the Incidence of Type 2 Diabetes With the Mediterranean Diet: Results of the PREDIMED-Reus nutrition intervention randomized trial

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    OBJECTIVE - To test the effects of two Mediterranean diet (MedDiet) interventions versus a low-fat diet on incidence of diabetes. RESEARCH DESIGN AND METHODS - This was a three-arm randomized trial in 418 nondiabetic subjects aged 55-80 years recruited in one center (PREDIMED-Reus, northeastern Spain) of the Prevención con Dieta Mediterránea [PREDIMED] study, a large nutrition intervention trial for primary cardiovascular prevention in individuals at high cardiovascular risk. Participants were randomly assigned to education on a low-fat diet (control group) or to one of two MedDiets, supplemented with either free virgin olive oil (1 liter/week) or nuts (30 g/day). Diets were ad libitum, and no advice on physical activity was given. The main outcome was diabetes incidence diagnosed by the 2009 American Diabetes Association criteria. RESULTS - After a median follow-up of 4.0 years, diabetes incidence was 10.1% (95% CI 5.1-15.1), 11.0% (5.9 -16.1), and 17.9% (11.4 -24.4) in the MedDiet with olive oil group, the MedDiet with nuts group, and the control group, respectively. Multivariable adjusted hazard ratios of diabetes were 0.49 (0.25- 0.97) and 0.48 (0.24-0.96) in the MedDiet supplemented with olive oil and nuts groups, respectively, compared with the control group. When the two MedDiet groups were pooled and compared with the control group, diabetes incidence was reduced by 52% (27- 86). In all study arms, increased adherence to the MedDiet was inversely associated with diabetes incidence. Diabetes risk reduction occurred in the absence of significant changes in body weight or physical activity. CONCLUSIONS - MedDiets without calorie restriction seem to be effective in the prevention of diabetes in subjects at high cardiovascular risk. © 2011 by the American Diabetes Association.This study was funded, in part, by the Spanish Ministry of Health (Instituto de Salud Carlos III) (projects PI051839, PI070240, PI1001407, G03/140, and RD06/0045), Fondo Europeo de Desarrollo Regional, and the Public Health Division of the Department of Health of the Autonomous Government of Catalonia in collaboration with Merck Sharp & Dohme. The Fundación Patrimonio Comunal Olivarero and Hojiblanca SA (Málaga, Spain), California Walnut Commission (Sacramento, CA), Borges SA (Reus, Spain), and Morella Nuts SA (Reus, Spain) donated the olive oil, walnuts, almonds, and hazelnuts, respectively, used in the study.Peer Reviewe

    Glycemic index, glycemic load and invasive breast cancer incidence in postmenopausal women: The PREDIMED study

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    The objective of this study was to evaluate the prospective associations between dietary glycemic index (GI) and glycemic load (GL) and the risk for invasive breast cancer incidence in postmenopausal women at high cardiovascular disease (CVD) risk. This study was conducted within the framework of the PREvención con DIeta MEDiterránea (PREDIMED) study, a nutritional intervention trial for primary cardiovascular prevention. We included 4010 women aged between 60 and 80 years who were initially free from breast cancer but at high risk for CVD disease. Dietary information was collected using a validated 137-item food frequency questionnaire. We assigned GI values using the International Tables of GI and GL values. Cases were ascertained through yearly consultation of medical records and through consultation of the National Death Index. Only cases confirmed by results from cytology tests or histological evaluation were included. We estimated multivariable-adjusted hazard ratios for invasive breast cancer risk across tertiles of energy-adjusted dietary GI/GL using Cox regression models. We repeated our analyses using yearly repeated measures of GI/GL intakes. No associations were found between baseline dietary GI/GL and invasive breast cancer incidence. The multivariable hazard ratio and 95% confidence interval (CI) for the top tertile of dietary GI was 1.02 (95% CI: 0.42–2.46) and for dietary GL was 1.00 (95% CI: 0.44–2.30) when compared with the bottom tertile. Repeated-measures analyses yielded similar results. In sensitivity analyses, no significant associations were observed for women with obesity or diabetes. Dietary GI and GL did not appear to be associated with an increased risk for invasive breast cancer in postmenopausal women at high CVD risk

    Association between tomato consumption and blood pressure in an older population at high cardiovascular risk: observational analysis of PREDIMED trial

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    Aims: Clinical studies have produced conflicting evidence on the effects of the consumption of tomatoes on blood pressure, and there are limited data from epidemiologic studies. This study assesses whether tomato consumption (Solanum lycopersicum L.) is associated with Systolic (SBP) and Diastolic Blood Pressure (DBP), and the risk of hypertension in a prospective 3-year longitudinal study in older adults at high cardiovascular risk.Methods: The present study was carried out within the PREDIMED (Prevención con Dieta Mediterránea) trial involving 7,056 (82.5% hypertensive) participants. The consumption of tomato (g/d) was measured using a validated Food Frequency Questionnaire (FFQ) and categorized into 4 groups: lowest (110 g). Multilevel linear mixed models examined blood pressure and tomato consumption association. Cox proportional-hazards models analyzed hypertension risk in 1,097 non-hypertensive participants, studying risk reductions versus the lowest tomato consumers.Results: An inverse association between tomato consumption and diastolic blood pressure was observed between the intermediate group β = -0.65 mmHg [95% CI:-1.20, -0.10] and the lowest consumption group. A significant inverse association was observed for blood pressure in grade 1 hypertension participants in the intermediate tomato consumption group. The risk of hypertension decreased with consumption of >110 g/d tomato (highest vs lowest consumption; HR, 0.64 [95% CI, 0.51-0.89]).Conclusions: Tomato consumption, including tomato-based products, is beneficial in preventing and managing hypertension. Higher tomato intake reduces hypertension risk by 36%, and moderate consumption lowers blood pressure, especially in grade 1 hypertension.</p

    Primary prevention of cardiovascular disease with a Mediterranean diet

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    BACKGROUND: Observational cohort studies and a secondary prevention trial have shown an inverse association between adherence to the Mediterranean diet and cardiovascular risk. We conducted a randomized trial of this diet pattern for the primary prevention of cardiovascular events. METHODS: In a multicenter trial in Spain, we randomly assigned participants who were at high cardiovascular risk, but with no cardiovascular disease at enrollment, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). Participants received quarterly individual and group educational sessions and, depending on group assignment, free provision of extra-virgin olive oil, mixed nuts, or small nonfood gifts. The primary end point was the rate of major cardiovascular events (myocardial infarction, stroke, or death from cardiovascular causes). On the basis of the results of an interim analysis, the trial was stopped after a median follow-up of 4.8 years. RESULTS: A total of 7447 persons were enrolled (age range, 55 to 80 years); 57% were women. The two Mediterranean-diet groups had good adherence to the intervention, according to self-reported intake and biomarker analyses. A primary end-point event occurred in 288 participants. The multivariable-adjusted hazard ratios were 0.70 (95% confidence interval [CI], 0.54 to 0.92) and 0.72 (95% CI, 0.54 to 0.96) for the group assigned to a Mediterranean diet with extra-virgin olive oil (96 events) and the group assigned to a Mediterranean diet with nuts (83 events), respectively, versus the control group (109 events). No diet-related adverse effects were reported. CONCLUSIONS: Among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events

    Primary prevention of cardiovascular disease with a Mediterranean diet

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    The traditional Mediterranean diet is characterized by a high intake of olive oil, fruit, nuts, vegetables, and cereals; a moderate intake of fish and poultry; a low intake of dairy products, red meat, processed meats, and sweets; and wine in moderation, consumed with meals.1 In observational cohort studies2,3 and a secondary prevention trial (the Lyon Diet Heart Study),4 increasing adherence to the Mediterranean diet has been consistently beneficial with respect to cardiovascular risk.2-4 A systematic review ranked the Mediterranean diet as the most likely dietary model to provide protection against coronary heart disease.5 Small clinical trials have uncovered plausible biologic mechanisms to explain the salutary effects of this food pattern.6-9 We designed a randomized trial to test the efficacy of two Mediterranean diets (one supplemented with extra-virgin olive oil and another with nuts), as compared with a control diet (advice on a low-fat diet), on primary cardiovascular prevention
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