526 research outputs found

    Permutations Containing Many Patterns

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    It is shown that the maximum number of patterns that can occur in a permutation of length nn is asymptotically 2n2^n. This significantly improves a previous result of Coleman

    New constraints on the Middle-Late Pleistocene Campi Flegrei explosive activity and Mediterranean tephrostratigraphy (∼160 ka and 110–90 ka)

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    The Campi Flegrei (CF) caldera, in southern Italy, is the source of some the most powerful Late Pleistocene eruptions of the European sub-continent (e.g., Campanian Ignimbrite, Neapolitan Yellow Tuff eruptions). Although the CF caldera has been continuously and intensively investigated for decades, relatively little is known regarding its earliest volcanic activity. Here integrating existing and new tephrostratigraphic data we provide a comprehensive and updated framework for CF volcanic activity which has occurred at ~160 ka and between ~110 ka and ~90 ka. The new tephrostratigraphic, geochemical (EMPA + LA-ICP-MS), chronological (40Ar/39Ar dating) and grain-size distribution data relate to CF tephra deposits preserved in 41 mid-proximal (Campanian Plain), distal (Tyrrhenian Sea) and ultra-distal (Lower Danube area) sedimentary archives. Our results allow us to recognize the presence of at least 13 CF eruptions covering the investigated time frame, with 12 eruptions occurring between 110 and 90 ka. Our high-resolution stratigraphic and chronological investigation also allowed us to recognise that the Triflisco/C-22 tephra, previously considered as a single marker layer, can be actually separated into three different events, sourced from within the CF area in the short time interval of ~93-90 ka, suggesting a more complex and intense volcanic history than previously thought. Moreover, a Bayesian age-depth model, constrained by previous and new high precision 40Ar/39Ar ages, has led to a reliable estimate of the ages of those undated CF eruptions. Overall, the updated framework on the stratigraphy, chronology, dispersion, and geochemistry of the CF tephra of ~160 ka and between 110 ka and 90 ka consolidates the notion that the Middle-Late Pleistocene activity at CF area represents a significant stage of its volcanic evolution, characterised by intense and frequent explosive eruptions

    Dietary energy density and its association with the nutritional quality of the diet of children and teenagers

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    To examine the relationship between dietary energy density (DED) and the nutritional quality of the diet, using data from the Irish National Children's Food Survey (NCFS) and the National Teens' Food Survey (NTFS), two cross-sectional studies of food consumption were carried out between 2003 and 2006. Data from the NCFS and NTFS were used to examine the intakes of nutrients and foods among those with low- (NCFS 8·75, NTFS >8·85 kJ/g). A 7-d food diary was used to collect food intake data from children (n 594) and teenagers (n 441). DED (kJ/g) was calculated including food alone and excluding beverages. Participants with lower DED consumed more food (weight) but not more energy. They also consumed less fat and added sugars and more protein, carbohydrates, starch and dietary fibre and had higher intakes of micronutrients. Participants with lower DED had food intake patterns that adhered more closely to food-based dietary guidelines. Low DED was associated with multiple individual indicators of a better nutritional quality of the diet, including higher intakes of dietary fibre and micronutrients and a generally better balance of macronutrients, as well as being associated with food intake patterns that were closer to healthy eating guidelines. Taken together, these findings support the conclusion that a low DED may be an indicator of a better nutritional quality of the diet

    Dietary energy density: estimates, trends and dietary determinants for a nationally representative sample of the Irish population (aged 5-90 years)

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    Higher dietary energy density (DED) has been reported to be associated with weight gain, obesity and poorer dietary quality, yet nationally representative estimates that would allow tracking of secular trends and inter-country comparisons are limited. The aims of the present study were to calculate DED estimates for the Irish population and to identify dietary determinants of DED. Weighed/semi-weighed food records from three cross-sectional surveys (the National Children's Food Survey, the National Teens’ Food Survey and the National Adult Nutrition Survey) were collated to estimate habitual dietary intakes for a nationally representative sample of the Irish population, aged 5–90 years (n 2535). DED estimates, calculated using the total diet method, the food only method and a novel method, including foods and solids in beverages, were 3·70 (sd 1·09), 7·58 (sd 1·72) and 8·40 (sd 1·88) kJ/g, respectively. Determinants of DED did not vary by the calculation method used. Variation in the intakes of fruit, vegetables and sugar-sweetened beverages (SSB) across consumer groups contributed to the largest variance in DED estimates, followed by variation in the intakes of potatoes, fresh meat, bread, chips, ready-to-eat breakfast cereals, and confectionery. DED estimates were inversely associated with age group and consistently lower for females than for males. The inverse association of DED with age group was explained by higher intakes of vegetables, fruit, fish, potatoes, fresh meat and brown bread and lower intakes of SSB, chocolate confectionery, ready-to-eat breakfast cereals and savoury snacks in older age groups. Females consumed, on average, 1·5 times more fruit and vegetables combined when compared with males, largely explaining the sex differences in DED estimates. Current DED estimates for adults were similar to those calculated in a previous survey, carried out 10 years earlier. These estimates and determinants serve as a baseline for comparison for other works and public health campaigns

    Food portion sizes and dietary quality in Irish children and adolescents.

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    Objective: To describe relationships between the portion sizes of a range of foods commonly consumed by Irish children and adolescents and key indicators of dietary quality on the days they were consumed. Design: Cross-sectional data from the Irish National Children’s Food Survey (2003–2004; 7 d weighed record) and National Teens’ Food Survey (2005–2006; 7 d semi-weighed record) were used to compare mean values for a number of dietary quality indicators (e.g. energy-adjusted intakes of saturated fat, dietary fibre and Na) across portion size tertiles for a range of foods, on the days the foods were consumed. Setting: The Republic of Ireland. Subjects: Nationally representative samples of children aged 5–12 years (n 594) and adolescents aged 13–17 years (n 441). Results: Relationships between food portion sizes and indicators of dietary quality on the days the foods were consumed were similar in both children and adolescents. Lower dietary energy density and saturated fat intakes, and higher dietary fibre intakes, were observed on the days larger portions of fruit and boiled potatoes were consumed. Higher dietary energy density and lower micronutrient intakes were observed on the days larger portions of sugar-sweetened beverages were consumed. Higher Na intakes were observed on the days larger portions of frying meats were consumed. Conclusions: The current work identifies foods for which larger portion sizes may be associated with positive dietary attributes, as well as the opposite. Findings will form an evidence base from which more specific dietary guidance relating to portion size may be developed for Irish children and adolescents

    The impact of voluntary food fortification on micronutrient intakes and status in European countries: a review

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    This review aims to assess the efficacy and safety of voluntary fortification as an option to address the occurrence of inadequate micronutrient intakes in population subgroups in Europe. Although legislation is harmonised across the European Union, fortification practices and patterns of consumption of fortified foods vary considerably between countries. While the proportion of children consuming fortified foods is greater than adults, the proportion of dietary energy obtained from fortified foods is generally low (<10% in Ireland, where fortified foods are widely consumed). There are a few systematic studies on the overall nutritional impact of voluntary fortification, but there are several studies on the impact of fortified ready-to-eat breakfast cereals. The available evidence indicates that voluntary fortification can reduce the risk of sub-optimal intakes of a range of micronutrients at a population level and can also improve status for selected micronutrients (e.g. folate, vitamin D and riboflavin) in children and adults. Although concerns have been raised regarding the potential of food fortification to lead to unacceptably high micronutrient intakes, particularly for those consuming higher amounts of fortified foods, data from national surveys on total micronutrient intakes (including fortified foods) in Europe show that small proportions of the population, particularly children, may exceed the upper intake level (UL) for some micronutrients. The risk of adverse effects occurring in these individuals exceeding the UL by modest amounts is low. In conclusion, voluntary fortification practices have been shown to improve intake and status of key micronutrients in European Union population groups and do not contribute appreciably to risk of adverse effects

    Development of an online database of typical food portion sizes in Irish population groups

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    The Irish Food Portion Sizes Database (available at www.iuna.net) describes typical portion weights for an extensive range of foods and beverages for Irish children, adolescents and adults. The present paper describes the methodologies used to develop the database and some key characteristics of the portion weight data contained therein. The data are derived from three large, cross-sectional food consumption surveys carried out in Ireland over the last decade: the National Children's Food Survey (2003–2004), National Teens' Food Survey (2005–2006) and National Adult Nutrition Survey (2008–2010). Median, 25th and 75th percentile portion weights are described for a total of 545 items across the three survey groups, split by age group or sex as appropriate. The typical (median) portion weights reported for adolescents and adults are similar for many foods, while those reported for children are notably smaller. Adolescent and adult males generally consume larger portions than their female counterparts, though similar portion weights may be consumed where foods are packaged in unit amounts (for example, pots of yoghurt). The inclusion of energy under-reporters makes little difference to the estimation of typical portion weights in adults. The data have wide-ranging applications in dietary assessment and food labelling, and will serve as a useful reference against which to compare future portion size data from the Irish population. The present paper provides a useful context for researchers and others wishing to use the Irish Food Portion Sizes Database, and may guide researchers in other countries in establishing similar databases of their own

    Estimating safe maximum levels of vitamins and minerals in fortified foods and food supplements.

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    Purpose: To show how safe maximum levels (SML) of vitamins and minerals in fortified foods and supplements may be estimated in population subgroups. Methods: SML were estimated for adults and 7- to 10-year-old children for six nutrients (retinol, vitamins B6, D and E, folic acid, iron and calcium) using data on usual daily nutrient intakes from Irish national nutrition surveys. Results: SML of nutrients in supplements were lower for children than for adults, except for calcium and iron. Daily energy intake from fortified foods in high consumers (95th percentile) varied by nutrient from 138 to 342 kcal in adults and 40–309 kcal in children. SML (/100 kcal) of nutrients in fortified food were lower for children than adults for vitamins B6 and D, higher for vitamin E, with little difference for other nutrients. Including 25 % ‘overage’ for nutrients in fortified foods and supplements had little effect on SML. Nutritionally significant amounts of these nutrients can be added safely to supplements and fortified foods for these population subgroups. The estimated SML of nutrients in fortified foods and supplements may be considered safe for these population subgroups over the long term given the food composition and dietary patterns prevailing in the respective dietary surveys. Conclusions: This risk assessment approach shows how nutrient intake data may be used to estimate, for population subgroups, the SML for vitamins and minerals in both fortified foods and supplements, separately, each taking into account the intake from other dietary sources

    Impact of voluntary food fortification practices in Ireland: trends in nutrient intakes in Irish adults between 1997-9 and 2008-10.

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    Because of the discretionary nature of voluntary food fortification in the European Union, there is a need to monitor fortification practices and consumption of fortified foods in order to assess the efficacy and safety of such additions on an ongoing basis. The present study aimed to investigate the nutritional impact of changes in voluntary fortification practices in adults aged 18–64 years using dietary intake data from two nationally representative cross-sectional food consumption surveys, the North/South Ireland Food Consumption Survey (NSIFCS) (1997–9) and the National Adult Nutrition Survey (NANS) (2008–10). The supply of fortified foods increased between 1997–9 and 2008–10, resulting in a higher proportion of adults consuming fortified foods (from 67 to 82 %) and a greater contribution to mean daily energy intake (from 4·6 to 8·4 %). The overall nutrient profile of fortified foods consumed remained favourable, i.e. higher in starch and dietary fibre and lower in fat and saturated fat, with polyunsaturated fat, sugars and Na in proportion to energy. Women, particularly those of childbearing age, remained the key beneficiaries of voluntary fortification practices in Ireland. Continued voluntary fortification of foods has increased protection against neural tube defect-affected pregnancy by folic acid and maintained the beneficial impact on the adequacy of Fe intake. Increased consumption of fortified foods did not contribute to an increased risk of intakes exceeding the tolerable upper intake level for any micronutrient. Recent increases in voluntary fortification of foods in Ireland have made a favourable nutritional impact on the diets of adults and have not contributed to an increased risk of adverse effects

    Diet, lifestyle and body weight in Irish children: findings from Irish Universities Nutrition Alliance national surveys

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    Childhood obesity is an issue of public health concern globally. This review reports on levels of overweight and obesity in Irish children and examines some aspects of their diet and lifestyle proposed to promote or protect against increasing body fatness in children. While there is still some debate with regard to the most appropriate cut-off points to use when assessing body fatness in children, approximately one in five Irish children (aged 2–17 years) have been classified as overweight (including obese) according to two generally accepted approaches. Furthermore, comparison with previous data has shown an increase in mean body weight and BMI over time. On examining dietary patterns for Irish children, there was a noticeable transition from a less energy dense diet in pre-school children to a more energy dense diet in older children and teenagers, associated with a change to less favourable dietary intakes for fibre, fat, fruit and vegetables, confectionery and snacks and sugar-sweetened beverages as children got older. A significant proportion of school-aged children and teenagers reported watching more than 2 h television per day (35 % on school-days and 65 % on week-ends) compared with 13 % of pre-school children. For children aged 5–12 years, eating out of the home contributed just 9 % of energy intake but food eaten from outside the home was shown to contribute a higher proportion of energy from fat and to be less fibre-dense than food prepared at home. Improvements in dietary lifestyle are needed to control increasing levels of overweight and obesity in children in Ireland
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