A transmissão do ultra-som no organismo humano tem sido objeto de estudos a várias décadas, com a finalidade de promover diagnóstico. Recentemente tem sido usada para avaliar a densidade óssea e poder diagnosticar precocemente o aparecimento da osteoporose e prever o risco de fratura. Nesse trabalho foi desenvolvido um sistema capaz de gerar, receber e amplificar sinais ultra-sônicos para a avaliação da velocidade do som e atenuação em função da freqüência (BUA). A técnica usada foi a de transmissão do sinal ultra-sônico, com acoplamento por gel de ultra-som e por água (tanque acústico), que consiste no uso de dois transdutores, um para transmissão e outro para recepção, sendo a amostra posicionada entre eles. Devido ao alto índice de dispersão nas medidas ultra-sônicas, será buscado um material de referência, o qual deve possuir características tanto de velocidade do som e atenuação em função da freqüência, parecidas com a do osso (calcâneo), que será usado para calibração do equipamento e para o acompanhamento da medida óssea. Foram utilizados os parâmetros ultra-sônicos para avaliação da consolidação óssea (em tíbias de carneiro) em diferentes períodos e nos diversos tipos de fraturas. O sistema foi caracterizado em termos de temperatura e reprodutibilidade utilizando diferentes materiais. Medidas no calcâneo de voluntários, de velocidade e atenuação em função da freqüência, independente de associações patológicas, mostrou resultados compatíveis com os encontrados na literatura. Foram feitas diversas análises, com pequenas mudanças nas condições geométricas, de sinal e freqüência dos transdutores, para observar sua influência sobre as medidas de atenuação e velocidade. Isto com a finalidade de tentar relacionar as variações nas medidas de atenuação obtidas por diferentes autores. / Ultrasound transmission in human bodies has been studied for several decades in order to facilitate diagnosis. It has also been used to evaluate bone density and to diagnose early osteoporosis and future fracture risks. For this study, a system to generate, receive and amplify ultrasonic signs for speed of sound assessment and broad band ultrasound attenuation (BUA) was developed. Transmission of ultrasonic signals was performed by coupling using ultrasound gel and water (acoustic tank) and the sample placed between two transducers, one for transmission and the other for reception. Due to the high rate of the dispersion of ultrasonic measures, some reference material having the characteristics of the speed of sound and broad band ultrasound attenuation, similar to the heel bone that will be used for equipment calibration and follow-up of bone measure will have to be found. Ultrasonic parameters were used to evaluate bone consolidation (tibia of a sheep), in different periods and several kinds of fractures. Temperature and reproducibility using different materials were used to customize the system. Measures of volunteers\'s heel bone speed and broad band ultrasound attenuation showed results consistent with the ones from literature. Several analyses with little changes in geometric, signal and transducer frequency conditions were performed in order to observe their influence on attenuation and speed measures. Those steps were carried out in order to try to relate the variations in attenuation measures to those obtained by other authors.

A transmissão do ultra-som no organismo humano tem sido objeto de estudos a várias décadas, com a finalidade de promover diagnóstico. Recentemente tem sido usada para avaliar a densidade óssea e poder diagnosticar precocemente o aparecimento da osteoporose e prever o risco de fratura. Nesse trabalho foi desenvolvido um sistema capaz de gerar, receber e amplificar sinais ultra-sônicos para a avaliação da velocidade do som e atenuação em função da freqüência (BUA). A técnica usada foi a de transmissão do sinal ultra-sônico, com acoplamento por gel de ultra-som e por água (tanque acústico), que consiste no uso de dois transdutores, um para transmissão e outro para recepção, sendo a amostra posicionada entre eles. Devido ao alto índice de dispersão nas medidas ultra-sônicas, será buscado um material de referência, o qual deve possuir características tanto de velocidade do som e atenuação em função da freqüência, parecidas com a do osso (calcâneo), que será usado para calibração do equipamento e para o acompanhamento da medida óssea. Foram utilizados os parâmetros ultra-sônicos para avaliação da consolidação óssea (em tíbias de carneiro) em diferentes períodos e nos diversos tipos de fraturas. O sistema foi caracterizado em termos de temperatura e reprodutibilidade utilizando diferentes materiais. Medidas no calcâneo de voluntários, de velocidade e atenuação em função da freqüência, independente de associações patológicas, mostrou resultados compatíveis com os encontrados na literatura. Foram feitas diversas análises, com pequenas mudanças nas condições geométricas, de sinal e freqüência dos transdutores, para observar sua influência sobre as medidas de atenuação e velocidade. Isto com a finalidade de tentar relacionar as variações nas medidas de atenuação obtidas por diferentes autores. / Ultrasound transmission in human bodies has been studied for several decades in order to facilitate diagnosis. It has also been used to evaluate bone density and to diagnose early osteoporosis and future fracture risks. For this study, a system to generate, receive and amplify ultrasonic signs for speed of sound assessment and broad band ultrasound attenuation (BUA) was developed. Transmission of ultrasonic signals was performed by coupling using ultrasound gel and water (acoustic tank) and the sample placed between two transducers, one for transmission and the other for reception. Due to the high rate of the dispersion of ultrasonic measures, some reference material having the characteristics of the speed of sound and broad band ultrasound attenuation, similar to the heel bone that will be used for equipment calibration and follow-up of bone measure will have to be found. Ultrasonic parameters were used to evaluate bone consolidation (tibia of a sheep), in different periods and several kinds of fractures. Temperature and reproducibility using different materials were used to customize the system. Measures of volunteers\'s heel bone speed and broad band ultrasound attenuation showed results consistent with the ones from literature. Several analyses with little changes in geometric, signal and transducer frequency conditions were performed in order to observe their influence on attenuation and speed measures. Those steps were carried out in order to try to relate the variations in attenuation measures to those obtained by other authors.

La qualité osseuse est un paramètre important à prendre en compte lors des différents types de chirurgie mis en œuvre pour les interventions sur le rachis. Cependant, ce paramètre reste difficile à estimer in vivo du fait notamment de la difficulté à accéder à ce site anatomique. Ce travail porte sur le développement d'une technique ultrasonore permettant d'estimer la qualité osseuse en utilisant la réponse échographique d'une tige métallique insérée dans l'os et utilisée dans le cadre de la chirurgie du rachis. Des travaux expérimentaux montrent la faisabilité de notre approche in vitro. Une tige métallique similaire à celle utilisée en clinique est insérée dans des échantillons d'os trabéculaire perpendiculairement à l'axe du traducteur. Les réponses échographiques de la tige immergée dans l'eau et insérée dans l'os sont comparées, ce qui permet de déterminer la vitesse de propagation dans l'os (SOS, Speed of Sound), ainsi que la pente du coefficient d'atténuation en fonction de la fréquence (BUA, Broadband Ultrasonic Attenuation). Les résultats obtenus pour les 21 échantillons montrent i) une corrélation significative entre SOS et la fraction volumique d'os (BV/TV, R² = 0.6 et p < 0.001); et ii) une non-linéarité de la variation du BUA et BV/TV (R² = 0.22 et p<0.001). Des simulations numériques utilisant des éléments finis spectraux en 2D permettent de mieux comprendre la propagation ultrasonore et d'estimer la sensibilité des mesures à des erreurs de positionnement de la tige et du capteur. De plus, des simulations numériques par différences finies dans le domaine temporel en 3D permettent de mieux comprendre l'interaction entre une onde ultrasonore et le tissu osseux en comparant les résultats expérimentaux et numériques. Ce travail prouve la faisabilité de cette approche de caractérisation ultrasonore pour estimer la qualité osseuse, ce qui ouvre la voie à de possibles études cliniques dans le futur. / Bone quality is an important parameter which should be taken into account during the different types of surgical procedures used in spine surgery. However, this parameter remains difficult to be determined in vivo, mostly due to difficulties of positioning different sensors around this anatomical site. The aim of this work is to develop an ultrasonic technique allowing to assess bone quality using the echographic response of a metallic rod inserted in bone tissue and used in spine surgery. Experimental works show the feasibility of the technique in vitro. A metallic rod similar to the one used in the operating room is inserted in trabecular bone samples perpendicularly to the transducer axis. The echographic responses of the rod immersed in water and in bone tissue are compared, which allows to determine the wave velocity in bone tissue, as well as the slope of the attenuation coefficient as a function of frequency (BUA, broadband ultrasonic attenuation). The results obtained for the 21 samples show i) a significant correlation between SOS and bone volume fraction (BV/TV, R² = 0.6, p < 0.001); and ii) a non linear variation of BUA as a function of BV/TV (R² = 0.22, p<0.001).Numerical simulation using 2D spectral finite element simulation allows to better understand wave propagation and to estimate the sensitivity of the measurements to positioning errors of the rod and of the sensor. Moreover, 3-D finite difference time domain simulation allows to better understand the interaction between an ultrasonic wave and bone tissue by comparing the experimental and numerical results. This work proves the feasibility of this ultrasonic characterization approach to estimate bone quality, which opens the way to future clinical studies.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-14T22:41:28Z No. of bitstreams: 1 WertonJoseCabralRodriguesFilho_DISSERT.pdf: 1941729 bytes, checksum: 338dcd58a06dd87925f46ceb321d99ab (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-16T20:55:55Z (GMT) No. of bitstreams: 1 WertonJoseCabralRodriguesFilho_DISSERT.pdf: 1941729 bytes, checksum: 338dcd58a06dd87925f46ceb321d99ab (MD5) / Made available in DSpace on 2017-03-16T20:55:55Z (GMT). No. of bitstreams: 1 WertonJoseCabralRodriguesFilho_DISSERT.pdf: 1941729 bytes, checksum: 338dcd58a06dd87925f46ceb321d99ab (MD5) Previous issue date: 2016-08-30 / No cen?rio econ?mico atual, as Micro e Pequenas empresas (MPE?s) correspondem a 99% das empresas do pa?s e mais da metade dos empregos com carteira assinada, sendo, desse modo, vitais para economia. Entretanto, diversos estudos apontam que as MPE?s possuem uma alta taxa de mortalidade nos primeiros anos de exist?ncia, tanto no Brasil, como em outros pa?ses. Diante disso, o presente estudo tem como objetivo geral determinar a esperan?a de vida, por setor econ?mico e no momento de cria??o, das Micro e Pequenas Empresas do Rio Grande do Norte, e, para isto, ter? como objetivo principal construir uma t?bua de vida empresarial, por setor econ?mico, das MPE?s do Rio Grande do Norte, uma vez que o uso de indicadores de mortalidade e esperan?a de vida das empresas ? uma ferramenta de grande utilidade para o planejamento, decis?es pol?ticas e a??es nos setores: privado, p?blico, acad?mico e social. Para isto, foram utilizados dados da Receita Federal, fornecidos pelo SEBRAE/RN, de cria??o e mortalidade de empresas do Rio Grande do Norte, nos anos de 2005, 2006 e 2007, acompanhadas at? o ano de 2009. Com base nessas informa??es, realizou-se uma estimativa de mortalidade nas idades futuras, por meio do m?todo Logito de Brass, tendo como base t?buas modelo de empresas mexicanas, criadas em 2014 pelo Instituto Nacional de Estat?stica e Geografia do M?xico ? INEGI. Por fim, verifica-se, nos resultados preliminares, a exist?ncia de t?buas modelo mexicanas com taxas de mortalidade similares ?s taxas encontradas no Rio Grande do Norte para a coorte de empresas de 2005, viabilizando, assim, a aplica??o do Logito de Brass para a estima??o das idades futuras e, consequentemente, a cria??o da t?bua e c?lculo da expectativa de vida empresarial. / In the current economic scenario, Micro and Small Enterprises (MSE?s) account for 99% of the companies in the Brazil and more than half of the jobs with a formal contract, thus being vital for the economy. However, several studies indicate that MSE's have a high mortality rate in the first years of life, both in Brazil and in other countries. Therefore, the present study has as general purpose to determine the life expectancy, by economic sector and time of creation, of the Micro and Small Enterprises of Rio Grande do Norte, and, for this, it will have as main intent to construct a board business life. The use of indicators of mortality and life expectancy of companies is a very useful tool for planning, policy decisions and actions in the sectors: private, public, Academic and social. For this goal, data of creation and mortality of companies in Rio Grande do Norte were used from the Federal Revenue Service, provided by SEBRAE / RN, in the years 2005, 2006 and 2007, and accompanied until the year 2009. Based on this information, an estimate of mortality in future ages was made using Brass's Logito method, based on the model tables of Mexican companies created in 2014 by the National Institute of Statistics and Geography of Mexico (INEGI). Finally, the preliminary results show the existence of Mexican model tables with similar mortality rates to the ones found in Rio Grande do Norte for the 2005 companies cohort, therefore making it possible to apply the Logito de Brass to the Estimation of future ages and, consequently, the creation of the board and calculation of expected business life.

"The goal of this thesis work has been to investigate improved diagnostic methods for both detecting osteoporosis and estimating fracture risk non-invasively, by assessing bone mass density (BMD) and bone microstructure. It evaluates new approaches for analyzing through-transmission ultrasound signals using coral samples as models for trabecular bone. The results of BUA, impulse response of coral samples and the angular decorrelation function of coral samples indicate that these ultrasound parameters may be useful in detecting changes in both bone mineral density (BMD) and the presence of dominant trabecular bone structure axis. "

Despite an abundance of archaeological material recovered from sites in Island Southeast Asia, the timing and route by which cultigens first arrived in Wallacea remains unclear. Many of the staple crops now grown on these islands were domesticated in mainland Asia, and were deliberately introduced by humans at an unknown point during the Holocene, through several possible routes. In this study, the δ 13C, δ15N and δ18O values of subfossil bones and teeth attributed to Sus celebensis and Sus scrofa are analyzed. These materials, which span the last 5160 years at Liang Bua, Flores, Indonesia are used to determine if and when there was a shift towards agricultural intensification, and whether this intensification included the integration of domesticated C4 crops. The δ13C and δ15N values of the bone and dentin collagen samples indicate an abrupt shift towards enrichment in 13C and depletion in 15N at some time between 5160 and 2750 yBP. This hints at changes in human subsistence patterns that may have included the clearing of forests, and the integration of nonendemic C4 cultigens such as foxtail millet (Setaria italica) onto the island. No statistically significant variation in the δ 18O values of the enamel carbonate samples over time is observed, suggesting that once they appeared on Flores, semidomesticated pigs became an important part of the island ecosystem, and were bred and raised on Flores instead of being continuously imported from elsewhere.