Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-08-28T19:51:50Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Karoline Barros Silva.pdf: 1162134 bytes, checksum: 24d3e22518e0022b7f4bec74f3af803f (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-09-05T23:12:51Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Karoline Barros Silva.pdf: 1162134 bytes, checksum: 24d3e22518e0022b7f4bec74f3af803f (MD5) / Made available in DSpace on 2018-09-05T23:12:51Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ana Karoline Barros Silva.pdf: 1162134 bytes, checksum: 24d3e22518e0022b7f4bec74f3af803f (MD5) Previous issue date: 2015-02-25 / CNPq / Análises de microdesgaste dentário e isótopos estáveis de δ¹³C e δ¹⁸O em ossos e dentes, são ferramentas através das quais pode-se fazer inferências paleoecológicas e paleoambientais. Estudos do microdesgaste dentário foram amplamente utilizadas em primatas, mas apenas recentemente vêm sendo utilizados para inferir dietas em xenartros. As marcas ocasionadas pela abrasão das partículas durante a mastigação e a assinatura isotópica de um animal são correlacionadas com as principais categorias tróficas observadas na natureza. Este trabalho teve por objetivo inferir a dieta de Eremotherium laurillardi através de estudo biomecânico e geoquímico. O material estudado pertence à Coleção de Macrofósseis do Laboratório de Paleontologia do Departamento de Geologia da UFPE, composto de 71 molariformes, em diferentes estágios ontogenéticos, de nove localidades dos Estados de Pernambuco, Alagoas e Bahia. Utilizou-se estéreomicroscopia de baixa ampliação para a identificação e qualificação das sete principais variáveis de microdesgaste em ortodentina. Análise descriminante e de variância indicam a predominância de microdesgaste misto de orientação variável. A assinatura isotópica de δ¹³C em bioapatita variaram entre -1,81‰ e -8,59‰ nos indivíduos adultos e -4,23‰ e -7,10‰ nos juvenis, indicando uma dieta mista de plantas C3 e C4. As taxas de δ¹⁸O variam ao longo da latitude, ficando entre 24, 81‰ e 46,18‰, demostrando uma diagênese muito intensa atuando sobre os depósitos e grande modificação da matéria orgânica. Os resultados obtidos corroboram com o relatado na literatura, descrevendo E. laurillardi como megaherbívoro generalizado, sendo capaz de tolerar uma ampla gama de dietas e hábitats. / Dental microwear and stable isotopes δ¹³C and δ¹⁸O analysis in bones and teeth, are tools through which one can make paleoecological and paleoenvironmental inferences. Studies in dental microwear have been widely used in primates, but only recently they have been made to infer xenarthran diets. The marks caused by abrasion of the particles during chewing and the isotopic signature of an animal are correlated with the major trophic categories observed in nature. This study aimed to infer the Eremotherium laurillardi diet through biomechanical and geochemical study. The material studied belongs to the macrofossils collection from the Paleontology Laboratory of the Department of Geology of the UFPE, and is composed of 71 molariforms in different ontogenetic stages, from nine localities in the states of Pernambuco, Alagoas and Bahia. We used a low magnification stereomicroscopy for the identification and characterization of seven major variables microwear in the orthodentine. The discriminant and variance analysis indicate the predominance of mixed microwear variable orientation. The isotopic signature of δ¹³C in bioapatita ranged from -1, 81‰ and -8,59‰ in adults and - 4.23‰ and -7.10‰ in juveniles, indicating a mixed diet of C3 and C4 plants. The rates of δ¹⁸O vary along the latitude, being between 24,81‰ and 46,18‰, showing very intense diagenesis acting on deposits and major change of organic matter. The results corroborate those reported in the literature, describing Eremotherium laurillardi as mega herbivore generalized, being able to tolerate a wide range of diets and habitats.

An estimated 20.5% of adolescents ages 12 – 19 years were obese (≥95th percentile of BMI-for-age) in 2011 – 2014. Consumption of added sugars (AS) has been linked with adverse effects on weight and cardiovascular disease risk factors. Approximately 16% of adolescents’ calories come from AS, of which sugar-sweetened beverages (SSB) are a major contributor. However, the relationship between AS/SSB intake and obesity is controversial, partly due to limitations in self-reported dietary data. Objective dietary intake biomarkers may circumvent this problem. The δ13C biomarker for AS intake is based upon the fact that C4 plants– major source for sugar production in the United States – have elevated δ¹³C values compared to C3 plants, which includes most fruits and vegetables. The δ¹³C value of blood, which is influenced by diet, has been established as a valid, reliable, and sensitive biomarker, but when compared to selfreported AS intake. This investigation evaluated the sensitivity and reliability of the δ13C biomarker, assessed with fingerstick blood samples, in adolescents using a controlled feeding, crossover design. Fingerstick δ¹³C values significantly changed by -0.05‰ and +0.03‰ after subjects completed the 5% and 25% AS diets, respectively (F(1, 30) = 18.828, p < 0.001). High reliability was found between two consecutive fingerstick δ¹³C values on the low (ICC = 0.996) and high (ICC = 0.997) AS diets. Thus, fingerstick δ¹³C may be a sensitive and reliable indicator of AS intake in adolescents. Future investigations should develop an equation to estimate AS intake based on fingerstick δ¹³C / Master of Science / Approximately one-fifth of adolescents 12 – 19 years old were obese in 2011 – 2014. A diet high in added sugars (AS), which are sugars that do not naturally occur in a food product, is associated with increased weight and higher risk for cardiovascular, or heart, disease. About 16% of adolescents’ calories come from AS, and a major source of AS intake is sugary beverages. Because people tend to inaccurately report what they eat and drink, researchers are interested in biomarkers to objectively estimate dietary intake. The δ¹³C biomarker measures carbon isotope ratios. Since most of the sugar produced in the United States comes from corn, sugarcane, and sorghum – which have a higher δ ¹³C content compared to most fruits and vegetables – δ ¹³C could indicate AS intake. Studies have reported that the δ ¹³C value of whole blood, which is influenced by diet, is valid, reliable, and sensitive, but when compared to self-reported AS intake. This investigation evaluated the sensitivity and reliability of whole blood δ ¹³C, sample using fingersticks, in adolescents consuming controlled diets so that AS intake was known. Fingerstick δ ¹³C values significantly changed after subjects completed the low and high AS diets (<i>F</i>(1, 30) = 18.828, <i>p</i> < 0.001). High reliability was found between two consecutive fingerstick δ ¹³C values on the low (ICC = 0.996) and high (ICC = 0.997) AS diets. Thus, fingerstick δ ¹³C may be a sensitive, reliable indicator of AS intake in adolescents. Future studies should develop an equation to estimate AS intake based on fingerstick δ ¹³C.