A research platform for artificial neural networks with applications in pediatric epilepsy

This dissertation established a state-of-the-art programming tool for designing and training artificial neural networks (ANNs) and showed its applicability to brain research. The developed tool, called NeuralStudio, allows users without programming skills to conduct studies based on ANNs in a powerful and very user friendly interface. A series of unique features has been implemented in NeuralStudio, such as ROC analysis, cross-validation, network averaging, topology optimization, and optimization of the activation function’s slopes. It also included a Support Vector Machines module for comparison purposes. Once the tool was fully developed, it was applied to two studies in brain research. In the first study, the goal was to create and train an ANN to detect epileptic seizures from subdural EEG. This analysis involved extracting features from the spectral power in the gamma frequencies. In the second application, a unique method was devised to link EEG recordings to epileptic and nonepileptic subjects. The contribution of this method consisted of developing a descriptor matrix that can be used to represent any EEG file regarding its duration and the number of electrodes. The first study showed that the inter-electrode mean of the spectral power in the gamma frequencies and its duration above a specific threshold performs better than the other frequencies in seizure detection, exhibiting an accuracy of 95.90%, a sensitivity of 92.59%, and a specificity of 96.84%. The second study yielded that Hjorth’s parameter activity is sufficient to accurately relate EEG to epileptic and non-epileptic subjects. After testing, accuracy, sensitivity and specificity of the classifier were all above 0.9667. Statistical tests measured the superiority of activity at over 99.99 % certainty. It was demonstrated that (1) the spectral power in the gamma frequencies is highly effective in locating seizures from EEG and (2) activity can be used to link EEG recordings to epileptic and non-epileptic subjects. These two studies required high computational load and could be addressed thanks to NeuralStudio. From a medical perspective, both methods proved the merits of NeuralStudio in brain research applications. For its outstanding features, NeuralStudio has been recently awarded a patent (US patent No. 7502763).

Representation of people of color in the nineteenth century slavery novel in Cuba and Brazil

This dissertation explores the similarities and differences which characterize the depiction of people of color in certain representative nineteenth century Cuban and Brazilian slavery novels as a function of the authorial approach of each territory's literary tradition toward the issues of slavery, racial prejudice, and people of color. The selected texts, derived from the peak periods in slavery literature of each territory, include Francisco , by Anselmo Snárez y Romero; Sab, by Gertrudis Gómez de Avellaneda; Cecilia Valdés , by Cirilo Villaverde; A escrava Isaura, by Bernardo Guimarães; O mulato, by Aluísio Azevedo; and Bom-Crioulo, by Adolfo Caminha. While the present study explores the enslavement, abuse, and discrimination of people of color as a consequence of a deep-seated discourse of power, privilege and racial superiority, it focuses more extensively on the representation of people of color, particularly in their capacity to constructively appropriate the cultural values of the white dominant group and recognize their identity as ambiguous. ^ Said's theories of Orientalist discourse and geography and formation as well as Dube's perspective on subaltern-oriented studies provide a theoretical framework for exploring the response of slavery writers whose common exposure to slavery but dissimilar socio-political contexts generate some startling findings. Crafted within a period of political repression, fear of black revolt, factional in-fighting as well as strong socioeconomic ties to the slaveholding class, the Cuban texts generally fashioned an approach to slavery as one marked by moderation, reform, and cultural counter discourse and consequently depict people of color with a more passive but culturally authentic outlook. On the other hand, the Brazilian response to the issue of slavery, steeped in an ideological amalgam of liberalism, positivism, republicanism, and abolitionism, is characterized by overt opposition to slavery and a representation of people of color that is less concerned with cross-cultural input but reclaims their humanity as highly educable and socially mobile persons in search of greater freedoms. Ultimately, there is a shared message of higher significance couched in the worthwhile mission of raising slaves to the level of men. ^

An Historical Look at Gender in the ESL Classroom

The role that gender plays with respect to language learning in the classroom is ripe for investigation. Some educators and researchers maintain that females possess superior language skills. This author argues that ideas regarding female language superiority are suspect and may encourage discriminatory pedagogy for women as well as men.

An examination of the within -product category versus across -product category effects of partially comparative pricing

Partially comparative pricing involves a featured store providing price comparisons in reference to a competitor for some products (comparatively priced products) while omitting such comparisons and providing only its price for other products (non-comparatively priced products). Barone, Manning and Miniard (2004) found that while partially comparative pricing enhanced consumers' price perceptions of comparatively priced products at the featured retailer, it had the opposite effect for non-comparatively priced products (i.e., an inferiority effect). To the contrary, it is argued that a price comparison for one brand in a product category may enhance consumers' price perceptions of the remaining, non-comparatively priced brands within the same product category (i.e., a superiority effect). This research seeks to (a) examine the robustness of partially comparative pricing's effect in an across-product category context compared to a within-product category context and (b) extend the understanding of partially comparative pricing's within-product category effect on non-comparatively priced brands by examining potential moderators of this effect: brand diversity, brand typicality, and the relative expensiveness of the brand receiving the price comparison. The findings of four studies provide evidence to support the presence of a superiority effect in a within-product category context and suggests that the adverse effect of partially comparative pricing in an across-product category context may not be as robust as previously thought. Although the superiority effect was unaffected by brand diversity (i.e., whether the brands emanated from different manufacturers or from a single manufacturer), it was found to be moderated by the typicality of the brand receiving the price comparison as well as the comparison brand's relative expensiveness. Research participants formed more favorable relative price beliefs about the non-comparatively priced brand when the comparatively priced brand was perceived as a more typical member of the product category. Similarly, participants formed more favorable beliefs about the non-comparatively priced brand when the comparison price was assigned to the most expensive brand in the product category rather than the least expensive brand.

Individual child cognitive behavioral treatment versus child-parent cognitive behavioral treatments for anxiety disorders in children and adolescents: Comparative outcomes

Anxiety disorders; such as separation anxiety disorder, generalized anxiety disorder, social phobia and specific phobia, are widespread in children and adolescents. Cognitive behavioral therapy (CBT) has been shown to be effective in reducing excessive fears and anxieties in children and adolescents. Research has produced equivocal findings that involving parents in treatment of child anxiety enhances effects over individual CBT (ICBT). The present dissertation study examined whether parental involvement can enhance individual treatment effect if the parent conditions are streamlined by targeting specific parental variables. The first parent condition, Parent Reinforcement Skills Training (RFST), involved increasing mothers' use of positive reinforcement and decreasing use of negative reinforcement. The second parent condition, Parent Relationship Skill Training (RLST), involved increasing maternal child acceptance and decreasing maternal control (or increasing autonomy granting). Results of the present dissertation findings support the use of all three treatment conditions (ICBT, RLST, RFST) for child anxiety; that is, significant reductions in anxiety were found in each of the three treatment conditions. No significant differences were found between treatment conditions with respect to diagnostic recovery rate, clinician rating, and parent rating of child anxiety. Significant differences between conditions were found on child self rating of anxiety, with some evidence to support the superiority of RLST and RFST to ICBT. These findings support the efficacy of individual, as well as parent involved CBT, and provide mixed evidence with respect to the superiority of parent involved CBT over ICBT. The conceptual, empirical, and clinical implications of the findings are discussed. ^

An Exergy Based Engineering and Economic Analysis of Sustainable Building

To achieve the goal of sustainable development, the building energy system was evaluated from both the first and second law of thermodynamics point of view. The relationship between exergy destruction and sustainable development were discussed at first, followed by the description of the resource abundance model, the life cycle analysis model and the economic investment effectiveness model. By combining the forgoing models, a new sustainable index was proposed. Several green building case studies in U.S. and China were presented. The influences of building function, geographic location, climate pattern, the regional energy structure, and the technology improvement potential of renewable energy in the future were discussed. The building’s envelope, HVAC system, on-site renewable energy system life cycle analysis from energy, exergy, environmental and economic perspective were compared. It was found that climate pattern had a dramatic influence on the life cycle investment effectiveness of the building envelope. The building HVAC system energy performance was much better than its exergy performance. To further increase the exergy efficiency, renewable energy rather than fossil fuel should be used as the primary energy. A building life cycle cost and exergy consumption regression model was set up. The optimal building insulation level could be affected by either cost minimization or exergy consumption minimization approach. The exergy approach would cause better insulation than cost approach. The influence of energy price on the system selection strategy was discussed. Two photovoltaics (PV) systems – stand alone and grid tied system were compared by the life cycle assessment method. The superiority of the latter one was quite obvious. The analysis also showed that during its life span PV technology was less attractive economically because the electricity price in U.S. and China did not fully reflect the environmental burden associated with it. However if future energy price surges and PV system cost reductions were considered, the technology could be very promising for sustainable buildings in the future.

The decolonization of Northwest Community College

In 1996, the authors of the Canadian Royal Commission on Aboriginal Peoples concluded Canadian educational policy had been based on the false assumption of the superiority of European worldviews. The report authors recommended the transformation of curriculum and schools to recognize that European knowledge was not universal. Aboriginal researcher Battiste believes the current system of Canadian education causes Aboriginal children to face cognitive imperialism and cognitive assimilation and that this current practice of cultural racism in Canada makes educational institutions a hostile environment for Aboriginal learners. In order to counter this cultural racism, Battiste calls for the decolonization of education. ^ In 2005, the president of Northwest Community College (NWCC), publicly committed to decolonizing the college in order to address the continuing disparity in educational attainment between Aboriginal and non-Aboriginal learners. Upon the president’s departure in 2010, the employees of NWCC were left to define for themselves the meaning of decolonization. ^ This qualitative study was designed to build a NWCC definition of colonization and decolonization by collecting researcher observations, nine weeks of participant blog postings, and pre and post blog Word survey responses drawn from a purposeful sample of six Aboriginal and six non-Aboriginal NWCC employees selected from staff, instructor and administrator employee groups. The findings revealed NWCC employees held multiple definitions of colonization and decolonization which did not vary between employee groups, or based on participant gender; however, differences were found based on whether the participants were Aboriginal or non-Aboriginal. ^ Both Aboriginal and non-Aboriginal participants thought decolonization was a worthy goal for the college. Aboriginal participants felt hopeful that decolonization would happen in the future and thought decolonization had to do with moving forward to a time when they would be valued, respected, empowered, unashamed, safe, and viewed as equal to non-Aboriginals. Non-Aboriginal participants were unsure if decolonization was possible because it would require going back in time to restore the Aboriginal way of life. When non-Aboriginal participants felt their thoughts were not being valued or they were being associated with colonialism, they felt angry and guarded and were uncomfortable with Aboriginal participants expressing anger towards Colonizers.^

A Research Platform for Artificial Neural Networks with Applications in Pediatric Epilepsy

This dissertation established a state-of-the-art programming tool for designing and training artificial neural networks (ANNs) and showed its applicability to brain research. The developed tool, called NeuralStudio, allows users without programming skills to conduct studies based on ANNs in a powerful and very user friendly interface. A series of unique features has been implemented in NeuralStudio, such as ROC analysis, cross-validation, network averaging, topology optimization, and optimization of the activation function’s slopes. It also included a Support Vector Machines module for comparison purposes. Once the tool was fully developed, it was applied to two studies in brain research. In the first study, the goal was to create and train an ANN to detect epileptic seizures from subdural EEG. This analysis involved extracting features from the spectral power in the gamma frequencies. In the second application, a unique method was devised to link EEG recordings to epileptic and non-epileptic subjects. The contribution of this method consisted of developing a descriptor matrix that can be used to represent any EEG file regarding its duration and the number of electrodes. The first study showed that the inter-electrode mean of the spectral power in the gamma frequencies and its duration above a specific threshold performs better than the other frequencies in seizure detection, exhibiting an accuracy of 95.90%, a sensitivity of 92.59%, and a specificity of 96.84%. The second study yielded that Hjorth’s parameter activity is sufficient to accurately relate EEG to epileptic and non-epileptic subjects. After testing, accuracy, sensitivity and specificity of the classifier were all above 0.9667. Statistical tests measured the superiority of activity at over 99.99 % certainty. It was demonstrated that 1) the spectral power in the gamma frequencies is highly effective in locating seizures from EEG and 2) activity can be used to link EEG recordings to epileptic and non-epileptic subjects. These two studies required high computational load and could be addressed thanks to NeuralStudio. From a medical perspective, both methods proved the merits of NeuralStudio in brain research applications. For its outstanding features, NeuralStudio has been recently awarded a patent (US patent No. 7502763).

Obtenção e caracterização de um compósito polimérico de matriz poliéster e reforço/carga de tecido plano de algodão

He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.

Obtenção e caracterização de um compósito polimérico de matriz poliéster e reforço/carga de tecido plano de algodão

He was obtained and studied the feasibility of using TPA (Tissue Cotton Plan) screen type, for bagging, with a weight of 207.9 g / m2 in a composite of orthophthalic crystal polyester resin matrix. The process for obtaining the composite was tested against the maximum number of layers that could be used without compromising the processability and manufacturing of CPs in compression mold. Five configurations / formulations were selected and tested at 1, 4, 8, 10 and 12 layers of cotton tissue - TPA. TPA was not subjected to chemical treatment, only by passing a mechanical washing process. The composite in its various configurations / formulations was characterized to determine its physical properties. The properties of the composite were higher viability resistance to bending, approaching the matrix and impact resistance, superiority in relation to the polyester resin. Another property that has shown good result compared to other composite has water absorption. Analyzing all the properties set the settings / formulations with higher viability were TA8 and TA10, by combining good processability and higher mechanical strength, with lower loss compared to polyester resin matrix. The composite showed lower mechanical behavior of the resin matrix for all the formulations studied except the impact resistance. The SEM showed a good adhesion between the layers of TPA and polyester resin matrix, without the presence of micro voids in the matrix confirming the efficient manufacturing process of the samples for characterization. The composite proposed proved to be viable for the fabrication of structures with low requests from mechanical stresses, and as demonstrated for the manufacture of solar and wind prototypes, and packaging, shelving, decorative items, crafts and shelves, with good visual appearance.

O ENSINO DA FILOSOFIA NAS DIRETRIZES DE JEAN MAUGÜÉ E NO HISTORICISMO DO PENSAMENTO DE JOÃO DA CRUZ COSTA: PIONEIRISMO NA UNIVERDSIDADE DE SÃO PAULO

O presente estudo foi desenvolvido com o objetivo de refletir a relevância do Ensino de Filosofia no contexto histórico brasileiro em consonância conjectural paulistana. Apontamos através do Decreto nro. 6.283 de 25 de janeiro de 1934, o qual instituiu-se sendo a primeira Universidade brasileira (Universidade de São Paulo) nas palavras de Vita “iniciativa pioneira no Brasil” (1969, p.16). Inspirada no modelo universitário tradicional da cultura filosófica francesa, a Faculdade de Filosofia, Ciências e Letras adotou desde os seus contíguos metodológicos aos procedimentos intelectivos, favorecendo o desenvolvimento da interdisciplinaridade da formação cultural. Uma confluência marcada por intensos envolvimentos ideológicos estruturados do progresso moderno, infundindo competências científicas na faculdade profissional incorporada à universidade, bem como formar professores para o ensino secundário (SCHWARTZMAN, 2006, p.163). Sendo assim, a Faculdade de Filosofia seria o núcleo propulsor. Porém, o modelo centralizador de pensar o Ensino da Filosofia, a atribui uma superioridade técnica intelectual e saber acumulado, pouco distingue da competência escolar conquistada em outros países, pelo potencial formativo dos professores filósofos Jean Maugüé (1955,1982) e João da Cruz Costa (1945, 1960, 1961,1967). Mauguë aponta-nos quão a formação em Filosofia está diretamente atribuída ao docente e ao aluno, que a ela se dedica. Pela obra Ensino de Filosofia e Diretrizes, ele apresenta-nos também a concepção de docência: o docente-intelectual, comprometido com a (re) construção dos significados epistemológicos, legitimados por uma prática pedagógica entre o já conhecido e ao conhecer, ou seja, entre o ensinado e ao ensinar. Nesse sentido, é notável que os argumentos do docente e do filósofo se imbricam, ao ponto de serem confundidos e potencializados durante a formação. Assim, Cruz Costa, também trabalha, quando assume a cátedra, porém ressalta que o processo formativo adquire sentido pela História das Ideias como construção do pensamento filosófico e, portanto, o ensino se faz quando se toma consciência da concentricidade histórica, ideias que lhe concede significado conjugado às técnicas de erudição, o que fez advertir aos seus alunos para as vicissitudes pelas quais passaram em nossa terra, as correntes filosóficas estrangeiras, e, sobretudo, para a curiosa significação que elas têm apresentado no envolver de nossa história (VITA, 1950, p.22). O conhecimento histórico é o caminho norteador a ser percorrido, necessário ao devir humano, isto é, a conciliação entre o conhecimento teórico e as condições históricas.

RELIGIÃO, COLONIALISMO E ALTERIDADE EM ROGER WILLIAMS

Esta dissertação de mestrado apresenta os resultados da pesquisa sobre Roger Williams – pastor puritano, de origem inglesa, que migrou para a América a fim de participar da constituição da colônia de Massachusetts, no ano de 1631. Pergunta-se, nesta pesquisa, sobre os motivos que levaram Roger Williams a questionar o pensamento dominante, relativo à natureza do ameríndio e à legitimidade da ocupação de suas terras. Parte-se da tese de que a partir das experiências de Roger Williams, primeiro, com o sofrimento dos pobres e com perseguição religiosa na Inglaterra, segundo, suas próprias experiências na América, ele pôde contemplar os ameríndios como vítimas do sistema colonial inglês-puritano. Seu posicionamento seria, portanto, uma abertura à alteridade desses povos. Com isso, o objetivo determinado foi o de analisar a crítica de Roger Williams ao colonialismo inglês e sua defesa aos ameríndios, buscando compreendê-lo frente à alteridade dos ameríndios. Trata-se de uma bibliográfica das obras do autor e também de outros autores que tratam do tema. Como referência teórica, remetemo-nos ao pensamento de Enrique Dussel, principalmente, por meio de algumas categorias da Filosofia da Libertação, como Totalidade, Exterioridade, Alteridade, Alienação, Dominação e Libertação, que possibilitaram pensar o sistema colonial em sua incapacidade de contemplar a exterioridade ameríndia. Também, de Dussel, aplicou-se a reflexão sobre a crítica ética desde a negatividade das vítimas, para poder-se analisar o comportamento do personagem diante da violência colonial. E para a discussão sobre a sujeiticidade de Roger Williams, buscou-se o aporte de Franz J. Hinkelammert quanto à teoria do sujeito. Como resultado, os três capítulos da dissertação apresentam, respectivamente, uma síntese biográfica e contextual do personagem, seguida por uma exposição do debate sobre a humanidade e a civilidade dos ameríndios e sobre a questão da terra e, no terceiro capítulo, uma discussão sobre Roger Williams e a alteridade. Detectou-se, na trajetória do personagem, uma sensibilidade ética que o conduziu à defesa de grupos marginalizados socialmente, primeiro na Inglaterra e depois nas colônias. E diante disso, concluiu-se que a defesa dos ameríndios seguiu esse mesmo critério, possibilitando a Williams distanciar-se das pressuposições europeias quanto à sua superioridade para buscar novos paradigmas que orientassem as relações entre colonos e nativos. Espera-se que este trabalho possa contribuir para as reflexões críticas sobre a gênese do colonialismo e sobre os primeiros sinais de um pensamento crítico no interior do sistema colonial.

The role of parametric assumptions in adaptive Bayesian estimation.

Variants of adaptive Bayesian procedures for estimating the 5% point on a psychometric function were studied by simulation. Bias and standard error were the criteria to evaluate performance. The results indicated a superiority of (a) uniform priors, (b) model likelihood functions that are odd symmetric about threshold and that have parameter values larger than their counterparts in the psychometric function, (c) stimulus placement at the prior mean, and (d) estimates defined as the posterior mean. Unbiasedness arises in only 10 trials, and 20 trials ensure constant standard errors. The standard error of the estimates equals 0.617 times the inverse of the square root of the number of trials. Other variants yielded bias and larger standard errors.

Desempenho produtivo, classificação e qualidade de carcaça de suínos de diferentes linhas genéticas em engorda intensiva

Compararam-se o ganho médio diário (GMD), índice de conversão alimentar (IC) e classificação da carcaça (CC) entre dois tipos de cruzamento comercial (A e B), ambos obtidos pelo cruzamento terminal de varrascos Piétrain com porcas F1 Large White x Landrace. Procurou-se identificar os principais efeitos ambientais que influenciam os referidos carateres. Utilizou-se um total de 200 suínos (machos e fêmeas), de dois cruzamentos comerciais distintos, provenientes de duas unidades de multiplicação comerciais. Determinou-se o GMD e o IC em dois períodos diferentes (63-119 e 120-158 dias de vida). No final do ensaio, efetuou-se a CC, segundo o sistema SEUROP. Procedeu-se a uma análise de variância com o objetivo de identificar os principais efeitos ambientais que influenciam o GMD, IC e CC. Determinou-se o coeficiente de regressão do GMD no peso vivo no início da engorda. Globalmente, observou-se uma superioridade do cruzado B no que concerne ao GMD (+74,6 g) (p<0,01) e ao IC (-0,07) (p<0,05). O GMD dos animais registou um acréscimo médio de 5,8 g por kg de acréscimo do PV no início do ensaio. A superioridade do cruzado B foi ainda evidenciada na classificação de carcaça SEUROP, com um acréscimo significativo (p<0,01) de 2,3% em carne magra.

Iterative reconstruction as a novel method of radiation dose reduction at computed tomography in patients with Crohn's disease

Prior work of our research group, that quantified the alarming levels of radiation dose to patients with Crohn’s disease from medical imaging and the notable shift towards CT imaging making these patients an at risk group, provided context for this work. CT delivers some of the highest doses of ionising radiation in diagnostic radiology. Once a medical imaging examination is deemed justified, there is an onus on the imaging team to endeavour to produce diagnostic quality CT images at the lowest possible radiation dose to that patient. The fundamental limitation with conventional CT raw data reconstruction was the inherent coupling of administered radiation dose with observed image noise – the lower the radiation dose, the noisier the image. The renaissance, rediscovery and refinement of iterative reconstruction removes this limitation allowing either an improvement in image quality without increasing radiation dose or maintenance of image quality at a lower radiation dose compared with traditional image reconstruction. This thesis is fundamentally an exercise in optimisation in clinical CT practice with the objectives of assessment of iterative reconstruction as a method for improvement of image quality in CT, exploration of the associated potential for radiation dose reduction, and development of a new split dose CT protocol with the aim of achieving and validating diagnostic quality submillisiever t CT imaging in patients with Crohn’s disease. In this study, we investigated the interplay of user-selected parameters on radiation dose and image quality in phantoms and cadavers, comparing traditional filtered back projection (FBP) with iterative reconstruction algorithms. This resulted in the development of an optimised, refined and appropriate split dose protocol for CT of the abdomen and pelvis in clinical patients with Crohn’s disease allowing contemporaneous acquisition of both modified and conventional dose CT studies. This novel algorithm was then applied to 50 patients with a suspected acute complication of known Crohn’s disease and the raw data reconstructed with FBP, adaptive statistical iterative reconstruction (ASiR) and model based iterative reconstruction (MBIR). Conventional dose CT images with FBP reconstruction were used as the reference standard with which the modified dose CT images were compared in terms of radiation dose, diagnostic findings and image quality indices. As there are multiple possible user-selected strengths of ASiR available, these were compared in terms of image quality to determine the optimal strength for this modified dose CT protocol. Modified dose CT images with MBIR were also compared with contemporaneous abdominal radiograph, where performed, in terms of diagnostic yield and radiation dose. Finally, attenuation measurements in organs, tissues, etc. with each reconstruction algorithm were compared to assess for preservation of tissue characterisation capabilities. In the phantom and cadaveric models, both forms of iterative reconstruction examined (ASiR and MBIR) were superior to FBP across a wide variety of imaging protocols, with MBIR superior to ASiR in all areas other than reconstruction speed. We established that ASiR appears to work to a target percentage noise reduction whilst MBIR works to a target residual level of absolute noise in the image. Modified dose CT images reconstructed with both ASiR and MBIR were non-inferior to conventional dose CT with FBP in terms of diagnostic findings, despite reduced subjective and objective indices of image quality. Mean dose reductions of 72.9-73.5% were achieved with the modified dose protocol with a mean effective dose of 1.26mSv. MBIR was again demonstrated superior to ASiR in terms of image quality. The overall optimal ASiR strength for the modified dose protocol used in this work is ASiR 80%, as this provides the most favourable balance of peak subjective image quality indices with less objective image noise than the corresponding conventional dose CT images reconstructed with FBP. Despite guidelines to the contrary, abdominal radiographs are still often used in the initial imaging of patients with a suspected complication of Crohn’s disease. We confirmed the superiority of modified dose CT with MBIR over abdominal radiographs at comparable doses in detection of Crohn’s disease and non-Crohn’s disease related findings. Finally, we demonstrated (in phantoms, cadavers and in vivo) that attenuation values do not change significantly across reconstruction algorithms meaning preserved tissue characterisation capabilities with iterative reconstruction. Both adaptive statistical and model based iterative reconstruction algorithms represent feasible methods of facilitating acquisition diagnostic quality CT images of the abdomen and pelvis in patients with Crohn’s disease at markedly reduced radiation doses. Our modified dose CT protocol allows dose savings of up to 73.5% compared with conventional dose CT, meaning submillisievert imaging is possible in many of these patients.