Thesis (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2015 (Department of Orthodontics and Dentofacial Orthopedics). / Includes bibliographic references: leaves 37-42. / Background: Craniofacial skeletal asymmetry is a common finding in the general population that often goes undetected. Interest in this topic has led to many studies aimed at describing this type of asymmetry, its distribution and etioIogy. The cranial base, being cIosely related to the face and brain, is a key component in craniofacial growth and may also display varying amounts of asymmetry contributing to this anomaly. Though many studies have explored underlying skeletal asymmetry, most of them were limited by their two-dimensional method of investigation. With the advent of three-dimensional technology, more recent studies have had the advantage of studying the cranial base in its true anatomic form, resulting in greater accuracy of analysis. Despite access to this technoIogy, there is still a lack of literature regarding the cranial base in a normal population. Determining average skull base dimensions will provide a set of normative data that can be used as a reference for future studies. Material and Methods: Pre-treatment Cone Beam Computed Tomography (CBCT) films of 160 esthetic human subjects previously used by another investigator were screened for use in our current research. These DICOM files were imported into InVivoDental5.3 software (Anatomage[TM]; San Jose, Calif.) for screening and 70 CBCT scans were selected for analysis. All patients were classified as cervical vertebral stage 4 and above. The images were oriented in all three planes of space for uniformity and 14 bilateral anatomic landmarks were identified on each scan. A mid-sagittal reference plane was created using crista galli as the origin, and extending a perpendicular passing through the middle of the right and left clinoid points connected by a line, and through posterior points basion and opisthion. Each landmark was given an x-, y- and z- coordinate representing its three dimensional position and bilateral linear measurements to the reference plane were recorded using the software system. Statistical Analysis: InVivoDental5.3 software was used to calculate linear distances between each landmark and the mid-sagittal plane. This data was exported into Microsoft excel for analysis. Descriptive statistics of our sample and paired t-tests with a 5% significance level, or p value of 0.05, were performed. Results: The means of the right and left measurements of each bilateral landmark were calculated along with their standard deviations. A comparison between right and left means was accomplished with the use of paired t-tests. 12 1andmarks did not show a statistical difference in their locations on either side of the mid-sagittal plane. However, the means of 2 landmarks were found to be statistically significant. These were euryon (p = 0.01) and the jugular foramen (p = 0.00) Conclusion: The overall trend of our data indicated that the cranial base in a normal population, without craniofacial anomaly, displays symmetry, with the exception of the location of euryon and the jugular foramen. These findings are in accordance with those of similar three-dimensional studies. It is likely that the significant findings were due to tracing error, given the indiscrete location of euryon and the large, relatively asymmetric shape of the jugular foramen. However, if these structures are truly asymmetric, we can infer from our sample of symmetric patients, that there is no clinical relevance. Further studies with an increased sample size, additional landmarks or a more discrete sample can be performed to continue describing the skull base. The results of this study offer valuable reference data that can be used as a baseline for future studies.

We extend an efficient cone beam transform inversion formula, proposed earlier for helices, to a general class of curves. The conditions that describe the class are very natural. Curves C are smooth, without self-intersections, have positive curvature and torsion, do not bend too much in a certain sense, and do not admit lines which are tangent to C at one point and intersect C at another point. A domain U is found where reconstruction is possible with a filtered backprojection type algorithm. Results of numerical experiments demonstrate very good image quality. The algorithm developed is useful for image reconstruction in computerized tomography.

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The activity of the growth cone is necessary for neuron axon elongation during neuron development and regeneration. This is a highly dynamic process of cytoskeletal recorganization that requires a significant amount of energy provided by the mitochondria. The localization of a sufficient number of mitochondria at the growth cone is essential to support its activity during neuron development and regeneration. Both promotion and inhibition of the motility of growth cones can be induced by intrinsic factors of neuron itself such as cytoskeleton dynamics and motor protein activity, as well as extracellular molecules in the vicinity of the neuron such as nerve growth factor (NGF) and components of the extracellular matrix. The proposed hypothesis is that some of these factors have an impact on the localization and morphology of mitochondria. My work in this project is aimed to determine which of these factors have the greatest impact on mitochondria in neurons. Using sensory neurons isolate / Biomedical Sciences

No / This article focuses on parties as the main anchors of democratic consolidation and seeks to present the main factors that have affected their development in two systems that could be argued to be amongst the most stable in Latin America, those of Argentina and Chile. It argues that some of the main variables affecting that development have been, besides systemic variables: the professionalized electoral campaign; external variables including technological transfers resulting from the foreign assistance received by centre and centre-left parties; the proscription of parties by authoritarian regimes; and shocks such as electoral defeat, loss of office and economic crises. Whilst electoral campaigns show a high level of professionalization in Argentine and Chilean parties, it is moderated by the preservation - or re-acquisition - of personnel-based campaigning and mass party characteristics.

No / The spatial and temporal properties of human colour vision are examined using isoluminant, red¿green and blue¿yellow tritanopic gratings. Chromatic sensitivity is found to be low-pass as a function of both spatial and temporal frequency along all the chromatic axes investigated, including the tritanopic confusion lines employed to examine the properties of the S-cone driven mechanism. Comparison of sensitivity to on-off and contrast reversing stimuli indicates that transient mechanisms contribute to the detection of red¿green patterns but that the detection of S-cone specific patterns is governed by sustained mechanisms. By compensating for transient contributions to red¿green sensitivity, it is shown that sensitivity of chromatic mechanisms dominated by L- and M-cone input are closely matched to those with S-cone input.

Segundo estudo de 2015 da FAO, 33% da área agricultável mundial estão degradados. Um dos principais problemas é a compactação do solo, causada pelo tráfego de máquinas ou animais em solo acima da capacidade de suporte de carga ou fora da condição de trafegabilidade. A compactação do solo desencadeia problemas ambientais e agronômicos como erosão, lixiviação e baixa produtividade. Sua reversão é um processo lento, caro, violento e ineficiente, por isso a melhor saída é previni-la. Para tanto, uma recomendação é mapeá-la regularmente. Um indicador indireto da compactação é a resistência (ou impedância) mecânica do solo à penenetração. O penetrômetro é o instrumento que mede a resistência da introdução de uma haste de ponta cônica no solo; teoricamente, solos mais compactados oferecem maior resistência. Há uma variedade de modelos de penetrômetro no mercado e literatura: bancada ou campo, manual ou automático, estático (penetrógrafo) ou dinâmico (de impacto), com ou sem registro eletrônico de dados etc. Naturalmente, surge a dúvida se é possível comparar dados de penetrômetros diferentes. Alguns trabalhos debruçaram-se sobre essa hipótese, mas a literatura ainda é escassa. Nos poucos artigos publicados, não hão há consenso a respeito da comparabilidade entre penetrômetros diferentes, que ora concordam, ora divergem. No presente trabalho, compararam-se os penetrômetros de campo Sondaterra PI-60 (impacto), Falker PLG1020 (manual) e Falker Solotrack (automático). O experimento observacional foi realizado em um latossolo vermelho eutroférrico de texturas argilosa, argiloarenosa e franco-argiloarenosa em Pirassununga-SP. A resistência mecânica foi avaliada simultaneamente pelos três penetrômetros em oito camadas entre 0,00-0,40 m, abaixo, dentro e acima do intervalo friável do local (10,2-35,1%(v/v)). Sob a mesma condição de umidade do solo, os três penetrômetros concordaram (não houve diferença estatística a 5%) em 58% das observações. Acordaram mais entre si os penetrômetros manual-automático (76%) e impacto-automático (70% das observações). Mesmo onde divergiram, as diferenças mínima, média e máxima de resistência foram respectivamente de 0,61; 0,91 e 1,23 MPa (excluindo-se a camada superficial 0,00-0,05 m), não interferindo no diagnóstico prático da compactação do solo. Em geral, PI-60 > Soltorack > PLG1020 (2,31; 2,14 e 1,91 MPa respectivamente). A compatibilidade entre penetrômetros abaixo, dentro e acima do intervalo friável foi a mesma: 31%, 36% e 33% das observações na mesma ordem. Não houve convergência em apenas três observações (de 120), todas na camada superficial. A resistência variou inversamente com a umidade do solo nos três penetrômetros, concordando com resultados semelhantes na literatura. Em média, a resistência diminuiu de 0,0596 MPa a cada acréscimo de 1% na umidade volumétrica (R2 = 0,44). Concluiu-se que é seguro comparar valores de resistência de penetrômetros diferentes desde que tenham sido coletados sob a mesma condição de umidade do solo. / According to a 2015 FAO study, 33% of the world\'s arable land is degraded. One of the main problems is soil compaction, caused by the traffic of machines or animals on soil over the load bearing capacity or outside of the trafficable condition. Soil compaction triggers environmental and agronomic problems such as erosion, leaching and low productivity. Its reversal is a slow, expensive, violent and inefficient process, so the best way out is to prevent it. To do so, a recommendation is to map it regularly. An indirect indicator of compaction is the mechanical resistance (or impedance) of the soil to penetration. The penetrometer is the instrument that measures the resistance of the introduction of a conical tipped rod into the ground; theoretically, more compacted soils offer greater resistance. There are a variety of penetrometer models in the market and literature: bench or field, manual or automatic, static (penetrograph) or dynamic (impact), with or without electronic data record etc. Of course, the question arises whether it is possible to compare data from different penetrometers. Some papers have dealt with this hypothesis, but the literature is still scarce. In the few articles published, there is no consensus about the comparability between different penetrometers, which now agree, or differ. In the present work, we compared the field sensors Sondaterra PI-60 (manual dynamic), Falker PLG1020 (manual static) and Falker Solotrack (automatic static). The observational experiment was carried out in a red eutroferric latosol (USDA oxisol) of clay, sandy clay and sandy clay loam textures in Pirassununga-SP, Brazil. The mechanical strength was evaluated simultaneously by the three penetrometers in eight layers between 0,00-0,40 m, below, within and above the friable interval of the site (10.2-35.1%(v/v)). Under the same soil moisture condition, the three penetrometers agreed (there was no statistical difference at 5%) in 58% of the observations. Best agreed among themselves the automatic-manual static (76%) and automatic-dynamic (70% of observations) penetrometers. Even where they diverged, the minimum, mean and maximum resistance differences were respectively 0.61; 0.91 and 1.23 MPa (excluding the superficial layer 0.00-0.05 m), values that do not interfere with the practical diagnosis of soil compaction. In general, PI-60 > Solotrack > PLG1020 (2.31, 2.14 and 1.91 MPa respectively). The compatibility between penetrometers below, within and above the friable interval was the same: 31%, 36% and 33% of observations in the same order. There was no convergence in only three observations (of 120), all in the superficial layer. The resistance varied inversely with soil moisture in the three penetrometers, agreeing with similar results in the literature. On average, the resistance decreased by 0.0596 MPa for each increment of 1% in the volumetric humidity (R2 = 0.44). It was concluded that it is safe to compare resistance values from different penetrometers provided they have been collected under the same soil moisture condition.

Os objetivos deste trabalho foram caracterizar os níveis de referência de radiodiagnóstico para a tomografia computadorizada de feixe cônico odontológica e as características de desempenho dos equipamentos como quilovoltaqgem de pico, rendimento, camada semirredutora, etc., com o intuito de conhecer os níveis dosimétricos em que os pacientes estão expostos, permitindo assim identificar protocolos de aquisição de imagem mais adequados, levando-se em consideração os princípios de radioproteção, e também testar a capacidade de tais equipamentos em alcançar uma imagem de qualidade. A Cone Beam Computed Tomography tem se tornado ferramenta extremamente útil na utilização em procedimentos radiológicos na área odontológica, pois, a riqueza de informações que a imagem 3D trás para o planejamento cirúrgico ou em qualquer procedimento, minimiza as possibilidades de erros, possibilita diagnósticos mais confiáveis e claros, tendo influência direta no resultado final esperado pelo paciente. Por se tratar de uma técnica de imagem que utiliza radiação ionizante, deve-se ter uma atenção criteriosa voltada para os níveis de radiação, além de implementar uma rotina de controle de qualidade. O parâmetro dosimétrico mais utilizado em tomografia computadorizada é o Computed Tomography Dose Index, porém, quando aplicado à tomografia odontológica, a geometria cônica do feixe e ainda a extensão do campo de visão tornam essa grandeza inviável e enganosa, assim, faz-se necessária a padronização de uma grandeza dosimétrica mais otimizada, para evitar a subestimação dos níveis de dose em feixes de ampla abrangência. O PKA tem sido utilizado como uma possível grandeza dosimétrica em tomografia odontológica, uma vez que em sua metodologia de medida, todo o feixe é englobado pelo medidor, não depende da distância fonte - detector, além de ser sensível aos parâmetros de exposição. Diante disso, propõe-se o PKA ser utilizado para estabelecimento dos níveis de dose de referência em diagnóstico odontológico. Os valores PKA obtidos para este estudo estão em uma faixa entre 34,6 mGy.cm^2 e 2901,6 mGy.cm^2, com valor médio de 980,7 mGy.cm^2. Os valores encontrados para os níveis de referência de radiodiagnóstico calculados a partir do 3º quartil estão divididos em três classes referentes ao tamanho do campo de visão, onde para campos pequenos, médios e grandes os valores são 1241 mGy.cm^2, 1521 mGy.cm^2 e 1408 mGy.cm^2 respectivamente, e 1446 mGy.cm^2 é o valor global independente do campo de visão. Os testes de controle de qualidade foram todos positivos, com uma atenção para o i-CAT FLX, que excedeu levemente o limite aceitável para a exatidão do kVp. Uma comparação entre CTDI100 e CTDI300, reportou que o CTDI300 é em média 49% maior em relação ao CTI100. Os níveis de referência de radiodiagnóstico são representativos dos níveis de dose otimizados, e servem como base para adequação e otimização dos parâmetros de exposição do equipamento. Os testes de controle de qualidade alertam para possíveis irregularidades no funcionamento do tomógrafo, e deve complementar obrigatoriamente a rotina dos procedimentos clínicos. / The objectives of this study are to characterize the radiodiagnostic reference levels for computed tomography of dental cones and as performance characteristics of equipment such as peak kyvoltage, yield, semi-reducing layer, etc., in order to know the levels of the values in that users are exposed, thus allowing to identify more adequate image acquisition protocols, taking in basic concepts of radioprotection, and also to test the capacity of such equipment in a quality image. The Cone Beam CT scan has become active, useful in medical, medical, dental, on the Internet, in any situation, minimizes as possibilities of errors, allows for more reliable and clear diagnoses, having a direct influence on the final result expected by the patient. Because it is an imaging technique that uses ionizing radiation, careful attention should be given to radiation levels, in addition to implementing a quality control routine. The dosimetric parameter most commonly used in computed tomography is the Computed tomography dose index, however, when applied to dental tomography, the conic geometry of the beam and still the extension of the field of view make this greatness unfeasible and deceptive, so it is done The. standardization of a more optimized dosimetric quantity, to avoid an underestimation of the dose levels in beams of wide range. The PKA has been used as a possible dosimetric magnitude in dental tomography, since in its measurement methodology, the whole beam is encompassed by the meter, it does not depend on the source - detector distance, besides being sensitive to the exposure parameters. Therefore, it is proposed that PKA be used for the establishment of reference dose levels in dental diagnosis. The PKA values obtained for this study ranged from 34.6 mGy.cm^2 to 2901.6 mGy.cm^2, with a mean value of 980.7 mGy.cm^2. The values found for the levels of radiodiagnostic reference values calculated from the 3rd quartile are divided into three classes referring to the size of the field of vision, where for small, medium and large fields are the values are 1241 mGy.cm^2, 1521 mGy.cm^2 and 1408 mGy.cm^2 respectively, and 1446 mGy.cm^2 is the global independent value of the field of view. The quality control tests were all positive, with an attention to the i-CAT FLX, which slightly exceeded the acceptable limit for kVp accuracy. A face between CTDI100 and CTDI300, reported that the CTDI300 is on average 49% higher than the CTI100. Radiodiagnostic reference levels are representative of optimized dose levels and serve as a basis for adequacy and optimization of the exposure parameters of the equipment. The quality control tests alert to possible irregularities in the operation of the tomograph, and develop properly from the clinical process.