Longitudinal relationships of the neighbourhood built environment with cardio-metabolic health

Neighbourhood built environments may have the potential to impact residents’ cardiometabolic health through physical activity. This Thesis aims to advance the understanding of such potential impacts. This Thesis consists of three published peer-reviewed studies. Study One, a systematic review and meta-analyses of longitudinal studies, found strong evidence for longitudinal relationships of built environment attributes with cardiometabolic health among adults. In particular, it found strong evidence for relationships of higher walkability with reduced risks of obesity, type 2 diabetes and hypertension. This systematic review has been published in Obesity Reviews. Two empirical studies were designed to address the gaps identified in the systematic review. These studies were conducted using the Australian Diabetes, Obesity and Lifestyle (AusDiab) study data, which were collected from a national cohort at three time points between 1999 and 2012. The outcomes examined in the empirical studies were 12-year changes in eight cardio-metabolic risk markers: waist circumference; weight; systolic and diastolic blood pressure; fasting and 2-hr postload plasma glucose; high-density lipoprotein cholesterol; and triglycerides. Built environmental attributes for AusDiab study participants were calculated using geographic information systems as an original work of this Thesis. The analytical sample consisted of participants who provided 12-year followup data and did not change their residence during the study period. One gap identified in the systematic review was that most longitudinal studies examined environmental attributes (typically composite measures such as walkability) assessed at one time point, disregarding environmental changes. To address this gap, Study Two examined the relationships of neighbourhood population density increases (densification) on changes in cardio-metabolic risk markers. Densification was calculated using the population density values measured within a 1-km straight-line buffer at three time points in concordance with the AusDiab data collection points. Analysing data from 2,354 eligible participants, higher densification was found related to smaller increases in obesity markers, but it was adversely related to blood pressure and lipid changes. This study has been published in the Journal of the American Heart Association. Study Three investigated the potential mediating role of physical activity (baseline and change) in the relationships between walkability and changes in cardio-metabolic risk markers, as a lack of studies rigorously examining underlying mechanisms of these relationships was another gap identified. For physical activity, self-reported time spent in moderate-to-vigorous physical activity (including walking) was used. A walkability index (consisting of residential density, intersection density, and destinations density) was calculated, within a 1-km street-network buffer using geospatial data sourced around the second follow-up of AusDiab. Analyses of data from 2,023 participants found that higher walkability was related to higher baseline physical activity, which, in turn, was related to smaller increases in obesity markers. There was no evidence for a relationship of higher walkability with a change in physical activity. This study has been published in the International Journal of Behavioral Nutrition and Physical Activity. Collectively, this Thesis adds evidence for potential long-term impacts of the neighbourhood built environment on adult residents’ cardio-metabolic health. In particular, higher walkability and higher densification may have protective effects against obesity risk over time. This Thesis also found evidence suggesting that physical activity may partly explain the potential long-term protective effect of higher walkability against obesity risk. However, there were also some unexpected findings, for instance, potential adverse impacts of higher densification on blood pressure and lipid, which warrants further investigation. The Thesis findings support the potential utility of environmental initiatives to reduce the burden of obesity at the population level through enhancing physical activity. To further advance understanding of the impacts of the built environment on cardio-metabolic health, future research needs to examine diverse built environmental attributes, investigate a broader range of cardio-metabolic health outcomes, and examine multiple pathways between the built environment and cardio-metabolic health

Novel Approaches to the Representation and Analysis of 3D Segmented Anatomical Districts

Nowadays, image processing and 3D shape analysis are an integral part of clinical practice and have the potentiality to support clinicians with advanced analysis and visualization techniques. Both approaches provide visual and quantitative information to medical practitioners, even if from different points of view. Indeed, shape analysis is aimed at studying the morphology of anatomical structures, while image processing is focused more on the tissue or functional information provided by the pixels/voxels intensities levels. Despite the progress obtained by research in both fields, a junction between these two complementary worlds is missing. When working with 3D models analyzing shape features, the information of the volume surrounding the structure is lost, since a segmentation process is needed to obtain the 3D shape model; however, the 3D nature of the anatomical structure is represented explicitly. With volume images, instead, the tissue information related to the imaged volume is the core of the analysis, while the shape and morphology of the structure are just implicitly represented, thus not clear enough. The aim of this Thesis work is the integration of these two approaches in order to increase the amount of information available for physicians, allowing a more accurate analysis of each patient. An augmented visualization tool able to provide information on both the anatomical structure shape and the surrounding volume through a hybrid representation, could reduce the gap between the two approaches and provide a more complete anatomical rendering of the subject. To this end, given a segmented anatomical district, we propose a novel mapping of volumetric data onto the segmented surface. The grey-levels of the image voxels are mapped through a volume-surface correspondence map, which defines a grey-level texture on the segmented surface. The resulting texture mapping is coherent to the local morphology of the segmented anatomical structure and provides an enhanced visual representation of the anatomical district. The integration of volume-based and surface-based information in a unique 3D representation also supports the identification and characterization of morphological landmarks and pathology evaluations. The main research contributions of the Ph.D. activities and Thesis are: \u2022 the development of a novel integration algorithm that combines surface-based (segmented 3D anatomical structure meshes) and volume-based (MRI volumes) information. The integration supports different criteria for the grey-levels mapping onto the segmented surface; \u2022 the development of methodological approaches for using the grey-levels mapping together with morphological analysis. The final goal is to solve problems in real clinical tasks, such as the identification of (patient-specific) ligament insertion sites on bones from segmented MR images, the characterization of the local morphology of bones/tissues, the early diagnosis, classification, and monitoring of muscle-skeletal pathologies; \u2022 the analysis of segmentation procedures, with a focus on the tissue classification process, in order to reduce operator dependency and to overcome the absence of a real gold standard for the evaluation of automatic segmentations; \u2022 the evaluation and comparison of (unsupervised) segmentation methods, finalized to define a novel segmentation method for low-field MR images, and for the local correction/improvement of a given segmentation. The proposed method is simple but effectively integrates information derived from medical image analysis and 3D shape analysis. Moreover, the algorithm is general enough to be applied to different anatomical districts independently of the segmentation method, imaging techniques (such as CT), or image resolution. The volume information can be integrated easily in different shape analysis applications, taking into consideration not only the morphology of the input shape but also the real context in which it is inserted, to solve clinical tasks. The results obtained by this combined analysis have been evaluated through statistical analysis

Dynamically reconfigurable architecture for embedded computer vision systems

The objective of this research work is to design, develop and implement a new architecture which integrates on the same chip all the processing levels of a complete Computer Vision system, so that the execution is efficient without compromising the power consumption while keeping a reduced cost. For this purpose, an analysis and classification of different mathematical operations and algorithms commonly used in Computer Vision are carried out, as well as a in-depth review of the image processing capabilities of current-generation hardware devices. This permits to determine the requirements and the key aspects for an efficient architecture. A representative set of algorithms is employed as benchmark to evaluate the proposed architecture, which is implemented on an FPGA-based system-on-chip. Finally, the prototype is compared to other related approaches in order to determine its advantages and weaknesses

Human-Centered Content-Based Image Retrieval

Retrieval of images that lack a (suitable) annotations cannot be achieved through (traditional) Information Retrieval (IR) techniques. Access through such collections can be achieved through the application of computer vision techniques on the IR problem, which is baptized Content-Based Image Retrieval (CBIR). In contrast with most purely technological approaches, the thesis Human-Centered Content-Based Image Retrieval approaches the problem from a human/user centered perspective. Psychophysical experiments were conducted in which people were asked to categorize colors. The data gathered from these experiments was fed to a Fast Exact Euclidean Distance (FEED) transform (Schouten & Van den Broek, 2004), which enabled the segmentation of color space based on human perception (Van den Broek et al., 2008). This unique color space segementation was exploited for texture analysis and image segmentation, and subsequently for full-featured CBIR. In addition, a unique CBIR-benchmark was developed (Van den Broek et al., 2004, 2005). This benchmark was used to explore what and how several parameters (e.g., color and distance measures) of the CBIR process influence retrieval results. In contrast with other research, users judgements were assigned as metric. The online IR and CBIR system Multimedia for Art Retrieval (M4ART) (URL: http://www.m4art.org) has been (partly) founded on the techniques discussed in this thesis. References: - Broek, E.L. van den, Kisters, P.M.F., and Vuurpijl, L.G. (2004). The utilization of human color categorization for content-based image retrieval. Proceedings of SPIE (Human Vision and Electronic Imaging), 5292, 351-362. [see also Chapter 7] - Broek, E.L. van den, Kisters, P.M.F., and Vuurpijl, L.G. (2005). Content-Based Image Retrieval Benchmarking: Utilizing Color Categories and Color Distributions. Journal of Imaging Science and Technology, 49(3), 293-301. [see also Chapter 8] - Broek, E.L. van den, Schouten, Th.E., and Kisters, P.M.F. (2008). Modeling Human Color Categorization. Pattern Recognition Letters, 29(8), 1136-1144. [see also Chapter 5] - Schouten, Th.E. and Broek, E.L. van den (2004). Fast Exact Euclidean Distance (FEED) transformation. In J. Kittler, M. Petrou, and M. Nixon (Eds.), Proceedings of the 17th IEEE International Conference on Pattern Recognition (ICPR 2004), Vol 3, p. 594-597. August 23-26, Cambridge - United Kingdom. [see also Appendix C

Gene Family Histories: Theory and Algorithms

Detailed gene family histories and reconciliations with species trees are a prerequisite for studying associations between genetic and phenotypic innovations. Even though the true evolutionary scenarios are usually unknown, they impose certain constraints on the mathematical structure of data obtained from simple yes/no questions in pairwise comparisons of gene sequences. Recent advances in this field have led to the development of methods for reconstructing (aspects of) the scenarios on the basis of such relation data, which can most naturally be represented by graphs on the set of considered genes. We provide here novel characterizations of best match graphs (BMGs) which capture the notion of (reciprocal) best hits based on sequence similarities. BMGs provide the basis for the detection of orthologous genes (genes that diverged after a speciation event). There are two main sources of error in pipelines for orthology inference based on BMGs. Firstly, measurement errors in the estimation of best matches from sequence similarity in general lead to violations of the characteristic properties of BMGs. The second issue concerns the reconstruction of the orthology relation from a BMG. We show how to correct estimated BMG to mathematically valid ones and how much information about orthologs is contained in BMGs. We then discuss implicit methods for horizontal gene transfer (HGT) inference that focus on pairs of genes that have diverged only after the divergence of the two species in which the genes reside. This situation defines the edge set of an undirected graph, the later-divergence-time (LDT) graph. We explore the mathematical structure of LDT graphs and show how much information about all HGT events is contained in such LDT graphs

Undergraduate and Graduate Course Descriptions, 2023 Spring

Wright State University undergraduate and graduate course descriptions from Spring 2023

Automated and Improved Search Query Effectiveness Design for Systematic Literature Reviews

This research explores and investigates strategies towards automation of the systematic literature review (SLR) process. SLR is a valuable research method that follows a comprehensive, transparent, and reproducible research methodology. SLRs are at the heart of evidence-based research in various research domains, from healthcare to software engineering. They allow researchers to systematically collect and integrate empirical evidence in response to a focused research question, setting the foundation for future research. SLRs are also beneficial to researchers in learning about the state of the art of research and enriching their knowledge of a topic of research. Given their demonstrated value, SLRs are becoming an increasingly popular type of publication in different disciplines. Despite the valuable contributions of SLRs to science, performing timely, reliable, comprehensive, and unbiased SLRs is a challenging endeavour. With the rapid growth in primary research published every year, SLRs might fail to provide complete coverage of existing evidence and even end up being outdated by the time of publication. These challenges have sparked motivation and discussion in research communities to explore automation techniques to support the SLR process. In investigating automatic methods for supporting the systematic review process, this thesis develops three main areas. First, by conducting a systematic literature review, we found the state of the art of automation techniques that are employed to facilitate the systematic review process. Then, in the second study, we identified the real challenges researchers face when conducting SLRs, through an empirical study. Moreover, we distinguished solutions that help researchers to overcome these challenges. We also identified the researchers' concerns regarding adopting automation techniques in SLR practice. Finally, in the third study, we leveraged the findings of our previous studies to investigate a solution to facilitate the SLR search process. We evaluated our proposed method by running some experiments

Interactive Visual Analysis of Translations

This thesis is the result of a collaboration with the College of Arts and Humanities at Swansea University. The goal of this collaboration is to design novel visualization techniques to enable digital humanities scholars to explore and analyze parallel translations. To this end, chapter 2 introduces the first survey of surveys on text visualization which reviews all of the surveys and state-of-the-art reports on text visualization techniques, classifies them, provides recommendations, and discusses reported challenges.Following this, we present three visual interactive designs that support the typical digital humanities scholars workflow. In Chapter 4, we present VNLP, a visual, interactive design that enables users to explicitly observe the NLP pipeline processes and update the parameters at each processing stage. Chapter 5 presents AlignVis, a visual tool that provides a semi-automatic alignment framework to build a correspondence between multiple translations. It presents the results of using text similarity measurements and enables the user to create, verify, and edit alignments using a novel visual interface. Chapter 6 introduce TransVis, a novel visual design that supports comparison of multiple parallel translations. It incorporates customized mechanisms for rapid and interactive filtering and selection of a large number of German translations of Shakespeare’s Othello. All of the visual designs are evaluated using examples, detailed observations, case studies, and/or domain expert feedback from a specialist in modern and contemporary German literature and culture.Chapter 7 reports our collaborative experience and proposes a methodological workflow to guide such interdisciplinary research projects. This chapter also includes a summary of outcomes and lessons learned from our collaboration with the domain expert. Finally, Chapter 8 presents a summary of the thesis and future work directions