Understanding bus travel time variation using AVL data

Thesis (S.M. in Transportation)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 89-94).The benefits of bus automatic vehicle location (AVL) data are well documented (see e.g., Furth et al. (2006)), ranging from passenger-facing applications that predict bus arrival times to service-provider-facing applications that monitor network performance and diagnose performance failures. However, most other researchers' analyses tend to use data that they acquired through negotiations with transit agencies, adding a variable cost of time both to the transit agencies and to researchers. Further, conventional wisdom is that simple vehicle location trajectories are not suitable for evaluating bus performance (Furth et al. 2006). In this research, I use data that are free and open to the public. This access enables researchers and the general public to explore bus position traces. The research objective of this Master's Thesis is to build a computational system that can robustly evaluate bus performance across a wide range of bus systems under the hypothesis that a comparative approach could be fruitful for both retrospective and real-time analysis. This research is possible because a large number of bus providers have made their bus position, or AVL, data openly available. This research thus demonstrates the value of open AVL data, brings understanding to the limits of AVL data, evaluates bus performance using open data, and presents novel techniques for understanding variations in bus travel time. Specifically, this thesis demonstrates research to make the system architecture robust and fruitful: " This thesis explores the exceptions in the various datasets to which the system must be robust. As academics and general public look to exploit these data, this research seeks to elucidate important considerations for and limitations of the data. " Bus data are high-dimensional; this research strives to make them dually digestible and informative when drawing conclusions across a long timescale. Thus, this research both lays the foundation for a broader research program and finds more visually striking and fundamentally valuable statistics for understanding variability in bus travel times.by David G. Gerstle.S.M.in Transportatio

‘We are not calling her Italian’: narratives and images of ethnic incorporation in Isa Miranda’s American persona.

This article discusses the impact of Hollywood standards of homogenisation on Isa Miranda’s cosmopolitan appeal during her work for Paramount. The article suggests that Miranda’s American image was constructed in an attempt to establish her as a Marlene Dietrich type in order to defuse the potential threat represented by her ethnic Otherness; meanwhile, the Italian actress was framed within film narratives that played out (albeit indirectly) an idealised conception of successful American assimilation of European immigrants. In the process, Miranda was visually constructed through images that effectively ‘whitened’ her, and her Italianness was thus displaced onto an ideal of Northern European whiteness that bespoke a desire to reassert whiteness as the norm in 1930s America

Combining regenerative medicine strategies to provide durable reconstructive options: auricular cartilage tissue engineering

Recent advances in regenerative medicine place us in a unique position to improve the quality of engineered tissue. We use auricular cartilage as an exemplar to illustrate how the use of tissue-specific adult stem cells, assembly through additive manufacturing and improved understanding of postnatal tissue maturation will allow us to more accurately replicate native tissue anisotropy. This review highlights the limitations of autologous auricular reconstruction, including donor site morbidity, technical considerations and long-term complications. Current tissue-engineered auricular constructs implanted into immune-competent animal models have been observed to undergo inflammation, fibrosis, foreign body reaction, calcification and degradation. Combining biomimetic regenerative medicine strategies will allow us to improve tissue-engineered auricular cartilage with respect to biochemical composition and functionality, as well as microstructural organization and overall shape. Creating functional and durable tissue has the potential to shift the paradigm in reconstructive surgery by obviating the need for donor sites

Prospective evaluation of the impact of sonography on the management and surgical intervention of neonates with necrotizing enterocolitis

Background/aimEstablished indications for surgery in necrotizing enterocolitis (NEC) are pneumoperitoneum and failure to improve or clinical deterioration with medical treatment alone. It has been proposed that infants with intestinal necrosis may benefit from surgery in the absence of one of these indications yet the diagnosis of definitive intestinal necrosis is challenging. Recent data suggest that abdominal ultrasound (US) examination focused on the gastrointestinal tract and the peritoneal cavity may be of utility in this regard. The aim of this study was to evaluate the ability of abdominal US to detect intestinal necrosis in infants with radiographically confirmed NEC.MethodsTwenty-six consecutive infants with Bell stage II or III NEC were prospectively included in the study between September 2013 and July 2014. Infants with a pre-existing indication for surgery were excluded. At least one abdominal US examination was performed in each patient using a standardized previously described method. Surgery was performed at the discretion of the attending surgeon based on clinical and imaging findings. Clinical, radiographic, US, and intra-operative data were recorded to allow comparison between US findings, surgical findings and outcome.ResultsUS demonstrated signs of intestinal necrosis in 5 of the 26 patients. All of these five had laparotomy. Intestinal necrosis requiring resection was confirmed in four and the other was found to have NEC but no necrosis was identified. In 21 patients US did not suggest intestinal necrosis. Of these, only one had surgery in whom NEC but no necrosis was identified. The remaining 20 responded to medical treatment for NEC and were assumed not to have had intestinal necrosis based on improvement without surgical intervention. The sensitivity, specificity, positive predictive value and negative predictive values of US for the detection of bowel necrosis were calculated as 100, 95.4, 80.0, and 100 %, respectively.ConclusionOur prospective findings suggest that abdominal US can identify those infants with NEC who may need surgery by detecting bowel necrosis (prior to the development of perforation or medical deterioration) with high sensitivity and specificity. Early surgical intervention in the clinical pathway of NEC may lead to improved outcomes

Understanding the nature and mechanism of foot pain

Approximately one-quarter of the population are affected by foot pain at any given time. It is often disabling and can impair mood, behaviour, self-care ability and overall quality of life. Currently, the nature and mechanism underlying many types of foot pain is not clearly understood. Here we comprehensively review the literature on foot pain, with specific reference to its definition, prevalence, aetiology and predictors, classification, measurement and impact. We also discuss the complexities of foot pain as a sensory, emotional and psychosocial experience in the context of clinical practice, therapeutic trials and the placebo effect. A deeper understanding of foot pain is needed to identify causal pathways, classify diagnoses, quantify severity, evaluate long term implications and better target clinical intervention