Background: Studies of assessing dietary fluoride intake in children have employed different dietary methods mainly “2-day duplicate” and “3-day food diary” methods. However, none of these methods have been validated or standardised. Main aims: The main aims of the current study were to develop a better understanding of strengths and weaknesses of dietary assessment methods “2-day duplicate plate” and “3-day food diary” by comparing dietary fluoride intake estimated by each method and evaluate the validity of the two methods for estimating dietary fluoride intake in young children. Methods: Sixty one healthy 4-6 year old children living in fluoridated area of the north-east of England since birth were recruited via 10 primary schools. Dietary information was collected using “2-day duplicate plate” and “3-day food diary” methods. Two 24-h urine samples and two samples of post brushing expectorate (a mixture of saliva, toothpaste and water used to rinse after brushing) from each child. Completeness of 24-h urine samples was checked using urinary excretion of creatinine and urinary flow rate. Validity of the two dietary assessment methods was checked by measuring urinary excretion of nitrogen and potassium as independent validity checks. Total daily fluoride intake from diet and toothpaste ingestion and urinary fluoride excretion was determined for each child. Results: All participated children completed all aspects of the study. According to the validity criteria, dietary data of 58 (95%) children, when collected by the 3-day food diary, were considered valid. However, when the dietary data were collected by the 2-day duplicate plate method, the data for 46 (75%) children were viewed as valid. Mean total dietary fluoride intake was 0.533 mg/d by the 3-day food diary method and 0.583 mg/d by the 2-day duplicate plate method. No statistically significant difference in total dietary fluoride intake was observed between the two methods. The mean difference in estimated dietary fluoride intake by the two dietary assessment methods was -0.050 mg/d with 95% limits of agreement of -0.501 to + 0.401 mg/d. Conclusion: Either the 3-day food diary or the 2-day duplicate plate method can be used when investigating mean total daily dietary fluoride intake of a population. However the methods cannot be used interchangeably at the individual level.

Made available in DSpace on 2014-12-17T15:37:20Z (GMT). No. of bitstreams: 1 FernandoRGS.pdf: 320202 bytes, checksum: ae6de90c68e9106707f6d1521eb5f5b2 (MD5) Previous issue date: 2006-05-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The aim of this study was to investigate the daily and annual variation in frequency and in activity of an estuarine dolphin population, Sotalia guianensis, in Brazilian northeastern. Thus we estimated the daily variation and seasonality in frequency of adult and immature and in behavior of socialization, aerial activity, foraging of a boto equatorial population in the Curral inlet (6?13 00 S; 35?3 36 W). We detect some variation. Thus we associate the daily variation with daily period, tide fluctuation and annual season. And the seasonality variation we associate with the fotoper?odo and precipitation variation. From October 1999 to September 2003, through collect four times at month, we made instantaneous record at each five minute in six hours of survey. The surveys hours were ranged into light time of 24 hours, that is, between 06:00 and 17:00 o clock. These observations were developed simultaneous for two observers in a land-based survey at coastline cliff top of which observer have a fully visualization of whole inlet. We found that animals were more active and frequent during the morning. They were more active during low tide than high tide. However they did not show association with tide. We found yet that in a period from June to November (winter-spring) there was the highest socialization, aerial activity and foraging frequency. However adult and immature individual number did not have significance variation along the year. The larger concentration of this behaviors were not associate with photoperiod neither precipitation in the region. These results showed the existence of behavioral daily variation and seasonality in a species that live in equatorial region / Neste estudo avaliamos a varia??o di?ria e anual na freq??ncia de adultos e imaturos e nos comportamentos de socializa??o, atividade a?rea e forrageio numa popula??o de boto cinza, Sotalia guianensis, na Enseada do Curral (6?13 00 S; 35?3 36 W), no nordeste brasileiro. Ap?s detectarmos algumas varia??es procuramos associ?-las a par?metros ambientais. Associamos as varia??es di?rias ao per?odo do dia, ?s varia??es da mar? e ao per?odo do ano; e as sazonais, a varia??o do fotoper?odo e da precipita??o. De Outubro de 1999 a Setembro de 2003, atrav?s de coletas quatro vezes ao m?s, efetuaram-se registros instant?neos a cada 5min, em seis horas de observa??o. As horas de observa??o estiveram inseridas dentro da fase clara das 24 horas, ou seja, no intervalo das 06:00 h as 17:00 h. Essas observa??es eram realizadas simultaneamente por dois observadores, num ponto fixo no alto da fal?sia a partir do qual visualizava-se toda a enseada. Observamos que os animais s?o mais ativos e freq?entes pela manh?. N?o apresentaram associa??o com a mar?, apesar de apresentarem maior atividade na mar? baixa e menor atividade na mar? alta. Quanto ? sazonalidade, observamos ainda, que no per?odo de junho a novembro (inverno e primavera) houve maior freq??ncia dos comportamentos de socializa??o, atividade a?rea e forrageio embora o n?mero de indiv?duos (adultos e imaturos) n?o tenha variado significativamente ao longo do ano. A maior concentra??o desses comportamentos n?o foi associada ao fotoper?odo e nem ? precipita??o na regi?o. Desses resultados, mostramos a exist?ncia de varia??o di?ria e sazonalidade comportamental nesta esp?cie, mesmo nas regi?es equatoriais