31 research outputs found

    Thermodynamic Gravity and the Schrodinger Equation

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    We adopt a 'thermodynamical' formulation of Mach's principle that the rest mass of a particle in the Universe is a measure of its long-range collective interactions with all other particles inside the horizon. We consider all particles in the Universe as a 'gravitationally entangled' statistical ensemble and apply the approach of classical statistical mechanics to it. It is shown that both the Schrodinger equation and the Planck constant can be derived within this Machian model of the universe. The appearance of probabilities, complex wave functions, and quantization conditions is related to the discreetness and finiteness of the Machian ensemble.Comment: Minor corrections, the version accepted by Int. J. Theor. Phy

    Transmission of Single HIV-1 Genomes and Dynamics of Early Immune Escape Revealed by Ultra-Deep Sequencing

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    We used ultra-deep sequencing to obtain tens of thousands of HIV-1 sequences from regions targeted by CD8+ T lymphocytes from longitudinal samples from three acutely infected subjects, and modeled viral evolution during the critical first weeks of infection. Previous studies suggested that a single virus established productive infection, but these conclusions were tempered because of limited sampling; now, we have greatly increased our confidence in this observation through modeling the observed earliest sample diversity based on vastly more extensive sampling. Conventional sequencing of HIV-1 from acute/early infection has shown different patterns of escape at different epitopes; we investigated the earliest escapes in exquisite detail. Over 3–6 weeks, ultradeep sequencing revealed that the virus explored an extraordinary array of potential escape routes in the process of evading the earliest CD8 T-lymphocyte responses – using 454 sequencing, we identified over 50 variant forms of each targeted epitope during early immune escape, while only 2–7 variants were detected in the same samples via conventional sequencing. In contrast to the diversity seen within epitopes, non-epitope regions, including the Envelope V3 region, which was sequenced as a control in each subject, displayed very low levels of variation. In early infection, in the regions sequenced, the consensus forms did not have a fitness advantage large enough to trigger reversion to consensus amino acids in the absence of immune pressure. In one subject, a genetic bottleneck was observed, with extensive diversity at the second time point narrowing to two dominant escape forms by the third time point, all within two months of infection. Traces of immune escape were observed in the earliest samples, suggesting that immune pressure is present and effective earlier than previously reported; quantifying the loss rate of the founder virus suggests a direct role for CD8 T-lymphocyte responses in viral containment after peak viremia. Dramatic shifts in the frequencies of epitope variants during the first weeks of infection revealed a complex interplay between viral fitness and immune escape

    Periprostatic fat measured on computed tomography as a marker for prostate cancer aggressiveness

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    Contains fulltext : 89797.pdf (publisher's version ) (Closed access)OBJECTIVE: Several reports found that obesity was associated with prostate cancer (PC) aggressiveness among men treated with radical prostatectomy or radiotherapy. Studies concerning this issue have basically relied on body mass index (BMI), as a marker for general obesity. Because visceral fat is the most metabolic active fat, we sought to evaluate if periprostatic fat measured on a computed tomography (CT) is a better marker than BMI to predict PC aggressiveness in a Dutch population who underwent brachytherapy for localized PC. PATIENTS AND METHODS: Of the 902 patients who underwent brachytherapy, 725 CT scans were available. Subcutaneous fat thickness (CFT), periprostatic fat area (cm(2)) and fat-density (%) were determined on the CT scan. Patients were stratified into three groups: 75 percentile of the fat-density. Associations between the three fat-density subgroups and BMI and PC aggressiveness were examined. RESULTS: 237 patients were classified as having normal weight (37.2%), 320 as overweight (50.2%) and 80 as obese (12.6%). There was a strong significant association between BMI and fat-density and CFT. The strongest correlation was seen between BMI and CFT (Pearson r coefficient = 0.71). Logistic regression analysis revealed no statistically significant association between the different fat measurements and the risk of having a high-risk disease. CONCLUSIONS: Periprostatic fat and fat-density as measured with CT were not correlated with PC aggressiveness in patients receiving brachytherapy. However, 31% of the patients with a normal BMI had a fat-density of >75 percentile of the periprostatic fat-density.01 december 201

    Plasma levels of six carotenoids in nine European countries: report from the European Prospective Investigation into Cancer and Nutrition (EPIC)

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    Background: In addition to their possible direct biological effects, plasma carotenoids can be used as biochemical markers of fruit and vegetable consumption for identifying diet-disease associations in epidemiological studies. Few studies have compared levels of these carotenoids between countries in Europe. Objective: Our aim was to assess the variability of plasma carotenoid levels within the cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). Methods: Plasma levels of six carotenoids-alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein and zeaxanthin-were measured cross-sectionally in 3043 study subjects from 16 regions in nine European countries. We investigated the relative influence of gender, season, age, body mass index (BMI), alcohol intake and smoking status on plasma levels of the carotenoids. Results: Mean plasma level of the sum of the six carotenoids varied twofold between regions (1.35 mumol l(-1) for men in Malmo, Sweden vs. 2.79 mumol l(-1) for men in Ragusa/Naples, Italy; 1.61 mumol l(-1) for women in The Netherlands vs. 3.52 mumol l(-1) in Ragusa/Naples, Italy). Mean levels of individual carotenoids varied up to fourfold (alpha-carotene: 0.06 mumol l(-1) for men in Murcia, Spain vs. 0.25 mumol l(-1) for vegetarian men living in the UK). In multivariate regression analyses, region was the most important predictor of total plasma carotenoid level (partial R-2=27.3%), followed by BMI (partial R-2=5.2%), gender (partial R-2=2.7%) and smoking status (partial R-2=2.8%). Females had higher total carotenoid levels than males across Europe. Conclusions: Plasma levels of carotenoids vary substantially between 16 different regions in Italy, Greece, Spain, France, Germany, the UK, Sweden, Denmark and The Netherlands. Compared with region of residence, the other demographic and lifestyle factors and laboratory measurements have limited predictive value for plasma carotenoid levels in Europe

    Dietary intakes of retinol, beta-carotene, vitamin D and vitamin E in the European Prospective Investigation into Cancer and Nutrition cohort

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    Objectives: To describe the intake of the fat-soluble nutrients retinol, beta-carotene, vitamin E and vitamin D and their food sources among 27 redefined centres in 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Methods: Between 1995 and 2000, 36 034 subjects (age range: 35-74 years) completed a single standardized 24-h dietary recall using a computerized interview software program (EPIC-SOFT). Intakes of the fat-soluble nutrients were estimated using the standardized EPIC Nutrient Database. Results: For all the nutrients, in most centres, men had a higher level of intake than did women, even after adjustments for total energy intake and anthropometric confounders. Distinct regional gradients from northern to southern European countries were observed for all nutrients. The level intake of beta-carotene and vitamin E also showed some differences by level of education, smoking status and physical activity. No meaningful differences in the nutrient intake were observed by age range. Conclusions: These results show differences by study centre, gender, age and various lifestyle variables in the intake of retinol, beta-carotene, vitamin E and vitamin D between 10 European countries. European Journal of Clinical Nutrition (2009) 63, S150-S178; doi: 10.1038/ejcn.2009.7

    Total, caffeinated and decaffeinated coffee and tea intake and gastric cancer risk: results from the EPIC cohort study

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    Prospective studies examining the association between coffee and tea consumption and gastric cancer risk have shown inconsistent results. We investigated the association between coffee (total, caffeinated and decaffeinated) and tea consumption and the risk of gastric cancer by anatomical site and histological type in the European Prospective Investigation into Cancer and Nutrition study. Coffee and tea consumption were assessed by dietary questionnaires at baseline. Adjusted hazard ratios (HRs) were calculated using Cox regression models. During 11.6 years of follow up, 683 gastric adenocarcinoma cases were identified among 477,312 participants. We found no significant association between overall gastric cancer risk and consumption of total coffee (HR 1.09, 95%-confidence intervals [CI]: 0.84-1.43; quartile 4 vs. non/quartile 1), caffeinated coffee (HR 1.14, 95%-CI: 0.82-1.59; quartile 4 vs. non/quartile 1), decaffeinated coffee (HR 1.07, 95%-CI: 0.75-1.53; tertile 3 vs. non/tertile 1) and tea (HR 0.81, 95%-CI: 0.59-1.09; quartile 4 vs. non/quartile 1). When stratified by anatomical site, we observed a significant positive association between gastric cardia cancer risk and total coffee consumption per increment of 100 mL/day (HR 1.06, 95%-CI: 1.03-1.11). Similarly, a significant positive association was observed between gastric cardia cancer risk and caffeinated coffee consumption (HR 1.98, 95%-CI: 1.16-3.36, p-trend=0.06; quartile 3 vs. non/quartile 1) and per increment of 100 mL/day (HR 1.09, 95%-CI: 1.04-1.14). In conclusion, consumption of total, caffeinated and decaffeinated coffee and tea is not associated with overall gastric cancer risk. However, total and caffeinated coffee consumption may be associated with an increased risk of gastric cardia cancer. Further prospective studies are needed to rule out chance or confounding

    Coffee and tea consumption and the contribution of their added ingredients to total energy and nutrient intakes in 10 European countries : benchmark data from the late 1990s

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    Background: Coffee and tea are among the most commonly consumed nonalcoholic beverages worldwide, but methodological differences in assessing intake often hamper comparisons across populations. We aimed to (i) describe coffee and tea intakes and (ii) assess their contribution to intakes of selected nutrients in adults across 10 European countries. Method: Between 1995 and 2000, a standardized 24-h dietary recall was conducted among 36,018 men and women from 27 European Prospective Investigation into Cancer and Nutrition (EPIC) study centres. Adjusted arithmetic means of intakes were estimated in grams (=volume) per day by sex and centre. Means of intake across centres were compared by sociodemographic characteristics and lifestyle factors. Results: In women, the mean daily intake of coffee ranged from 94 g/day (similar to 0.6 cups) in Greece to 781 g/day (similar to 4.4 cups) in Aarhus (Denmark), and tea from 14 g/day (similar to 0.1 cups) in Navarra (Spain) to 788 g/day (similar to 4.3 cups) in the UK general population. Similar geographical patterns for mean daily intakes of both coffee and tea were observed in men. Current smokers as compared with those who reported never smoking tended to drink on average up to 500 g/day more coffee and tea combined, but with substantial variation across centres. Other individuals' characteristics such as educational attainment or age were less predictive. In all centres, coffee and tea contributed to less than 10% of the energy intake. The greatest contribution to total sugar intakes was observed in Southern European centres (up to similar to 20%). Conclusion: Coffee and tea intake and their contribution to energy and sugar intake differed greatly among European adults. Variation in consumption was mostly driven by geographical region

    Nitrosamines and Heme Iron and Risk of Prostate Cancer in the European Prospective Investigation into Cancer and Nutrition

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    Background: The evidence about nitrosamines and heme iron intake and cancer risk is limited, despite the biologic plausibility of the hypothesis that these factors might increase cancer risk. We investigated the association between dietary nitrosamines and heme iron and the risk of prostate cancer among participants of European Prospective Investigation into Cancer and Nutrition (EPIC). Methods: Data on food consumption and complete follow-up for cancer occurrence was available for 139,005 men, recruited in 8 European countries. Estimates of HRs were obtained by proportional hazard models, stratified by age at recruitment, and study center, and adjusted for total energy intake, smoking status, marital status, dairy products, educational level, and body mass index. Results: After a mean follow-up of 10 years, 4,606 participants were diagnosed with first incident prostate cancer. There was no overall association between prostate cancer risk and nitrosamines exposure (preformed and endogenous) or heme iron intake (HR for a doubling of intake: 1.00; 95% CI: 0.98-1.03 for N-Nitrosodimethlyamine, 0.95; 95% CI: 0.88-1.03 for endogenous Nitrosocompounds, and 1.00; 95 CI: 0.97-1.03 for heme iron). Conclusions and Impact: Our findings do not support an effect of nitrosamines (endogenous and exogenous) and heme iron intake on prostate cancer risk. Cancer Epidemiol Biomarkers Prev; 21(3); 547-51. (C) 2012 AACR
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