Integrating Shared Mobility Services with Transit Could Produce Economic and Environmental Benefits

This research brief summarizes the findings from the associated study, which examined the potential to improve transportation system efficiency by reevaluating and redefining the role of public transit and its design principles in the new context of technology and shared mobility. Specifically, it evaluated the financial feasibility of an integrative, multimodal transportation system where public and private mobility services coexist to maximize economic and environmental benefits and free up public transit resources to be reallocated more efficiently

Multistage Infrastructure System Design: An Integrated Biofuel Supply Chain against Feedstock Seasonality and Uncertainty

A biofuel supply chain consists of various interdependent components from feedstock resources all the way to energy demand sites. This study focuses on the design of an efficient biofuel supply chain system against seasonal variations and uncertainties of feedstock supply in an integrative manner. By integrating planning and operational decisions in a stochastic programming framework, we aim at finding an effective design strategy for biofuel supply chain that is economically viable and hedges well against a wide range of future uncertainties. A solution algorithm based on scenario decomposition is designed to overcome computational challenges involved in large-scale applications. A California case study is implemented to demonstrate the applicability of the proposed methods in evaluating the economic potential, the infrastructure needs, and the risk of wastes-based bioethanol production

Exploring the Role of Natural Gas in U.S. Trucking (Revised Version)

The recent emergence of natural gas as an abundant, inexpensive fuel in the United States could prompt a momentous shift in the level of natural gas utilized in the transportation sector. The cost advantage of natural gas vis-à-vis diesel fuel is particularly appealing for vehicles with a high intensity of travel and thus fuel use. Natural gas is already a popular fuel for municipal and fleet vehicles such as transit buses and taxis. In this paper, we investigate the possibility that natural gas could be utilized to provide fuel cost savings, geographic supply diversity and environmental benefits for the heavy-duty trucking sector and whether it can enable a transition to lower carbon transport fuels. We find that a small, cost-effective intervention in markets could support a transition to a commercially sustainable natural gas heavyduty fueling system in the state of California and that this could also advance some of the state’s air quality goals. Our research shows that an initial advanced natural gas fueling system in California could facilitate the expansion to other U.S. states. Such a network would enable a faster transition to renewable natural gas or biogas and waste-to-energy pathways. Stricter efficiency standards for natural gas Class 8 trucks and regulation of methane leakage along the natural gas supply chain would be necessary for natural gas to contribute substantially to California’s climate goals as a trucking fuel. To date, industry has favored less expensive technologies that do not offer the highest level of environmental performance

Multiparametric MRI radiomics fusion for predicting the response and shrinkage pattern to neoadjuvant chemotherapy in breast cancer

PurposeDuring neoadjuvant chemotherapy (NACT), breast tumor morphological and vascular characteristics are usually changed. This study aimed to evaluate the tumor shrinkage pattern and response to NACT by preoperative multiparametric magnetic resonance imaging (MRI), including dynamic contrast-enhanced MRI (DCE-MRI), diffuse weighted imaging (DWI) and T2 weighted imaging (T2WI).MethodIn this retrospective analysis, female patients with unilateral unifocal primary breast cancer were included for predicting tumor pathologic/clinical response to NACT (n=216, development set, n=151 and validation set, n=65) and for discriminating the tumor concentric shrinkage (CS) pattern from the others (n=193; development set, n=135 and validation set, n=58). Radiomic features (n=102) of first-order statistical, morphological and textural features were calculated on tumors from the multiparametric MRI. Single- and multiparametric image-based features were assessed separately and were further combined to feed into a random forest-based predictive model. The predictive model was trained in the testing set and assessed on the testing dataset with an area under the curve (AUC). Molecular subtype information and radiomic features were fused to enhance the predictive performance.ResultsThe DCE-MRI-based model showed higher performance (AUCs of 0.919, 0.830 and 0.825 for tumor pathologic response, clinical response and tumor shrinkage patterns, respectively) than either the T2WI or the ADC image-based model. An increased prediction performance was achieved by a model with multiparametric MRI radiomic feature fusion.ConclusionsAll these results demonstrated that multiparametric MRI features and their information fusion could be of important clinical value for the preoperative prediction of treatment response and shrinkage pattern

Deciphering the metabolic perturbation in hepatic alveolar echinococcosis: a 1 H NMR-based metabolomics study

Background: Hepatic alveolar echinococcosis (HAE) is caused by the growth of Echinococcus multilocularis larvae in the liver. It is a chronic and potentially lethal parasitic disease. Early stage diagnosis for this disease is currently not available due to its long asymptomatic incubation period. In this study, a proton nuclear magnetic resonance (1H NMR)-based metabolomics approach was applied in conjunction with multivariate statistical analysis to investigate the altered metabolic profiles in blood serum and urine samples obtained from HAE patients. The aim of the study was to identify the metabolic signatures associated with HAE. Results: A total of 21 distinct metabolic differences between HAE patients and healthy individuals were identified, and they are associated with perturbations in amino acid metabolism, energy metabolism, glyoxylate and dicarboxylate metabolism. Furthermore, the present results showed that the Fischer ratio, which is the molar ratio of branched-chain amino acids to aromatic amino acids, was significantly lower (P < 0.001) in the blood serum obtained from the HAE patients than it was in the healthy patient group. Conclusions: The altered Fischer ratio, together with perturbations in metabolic pathways identified in the present study, may provide new insights into the mechanistic understanding of HAE pathogenesis and potential therapeutic interventions

Evaluating the Efficiency and Health Impacts of Next-Generation Transit System Design with Integration of Shared Mobility Services

Project DescriptionIn the new mobility-as-service context, traditional system design principles of transit services may be revisited to improve the overall system effectiveness. In this report, we developed methods to quantify the effectiveness of a transit system, where private mobility services coexist, by measuring costs, social equity, environmental benefits etc. gained from active lifestyle. A real-world case study has been implemented to learn design and policy insights. While conducting this research, we also realized that the transit demand of a study area is often not available due to missing data. Since this is an important input for any networkbased transit system design model, we also developed a method to infer missing transit demand via combing statistics and network modeling techniques.U.S. Department of Transportation 69A355174711

The effects of critical questions on undergraduate students' argumentative writing

Ferretti, Ralph P.Despite the established importance of writing, many students have difficulty writing proficiently (Ann Rogers & Graham, 2008; Graham & Perin, 2007). This study was designed to assess whether the provision of argumentative writing goals focusing on revision affected the quality of college students’ first drafts and revised essays. In addition, I investigated whether participants’ keyboarding fluency was related to essay quality. Participants first completed a typing-speed test and wrote argumentative essays. Then, they were asked to revise and write another essay on a different topic after receiving either a general goal, a genre-specific elaborated goal, a goal that included critical questions about two argumentation strategies, or a goal that incorporated the elaborated goal and critical questions. College students’ keyboarding fluency was found to be positively correlated with the quality of their argumentative essays. Compared to students who were given a general goal, those who received the elaborated goal, critical questions, or the incorporation of the elaborated goal and critical questions wrote revised essays of higher quality. Additionally, students who received the elaborated goal and the incorporation of the elaborated goal and critical conditions wrote essays that included more rebuttals, alternative standpoints, and reasons for alternative standpoints. Argumentation structural elements and keyboarding fluency together accounted for 60% of the variance in essay quality. Finally, all students frequently used the argument from consequences and argument from example schemes. The provision of critical questions on argument from consequences resulted in the increased use of this particular argument scheme. The results of the current study suggested that providing students with either an elaborated goal or the incorporation of the elaborated goal and critical questions is an effective and resource-efficient way of improving college students’ written arguments. ☐ Keywords: argumentation structure, critical questions, goal-setting, keyboarding fluency, revisionUniversity of Delaware, School of EducationPh.D

Quick Estimation of Network Performance Measures Using Associative Memory Techniques

Many important decision making processes in transportation planning and engineering involve repetitive computation of network performance, measured by total network delay, throughput, network efficiency, etc. The computational complexity imposed by repetitive evaluation of these measures, especially under user equilibrium condition, is a serious obstacle for timely decision making regarding transportation networks. This study applies Associative Memory (AM) techniques, which are conceptually and computationally simple, to quick estimation of these performance measures. The results of the numerical experiments were encouraging and the relative error on an average was found to be less than two percent. Furthermore, the applicability of this approximation method to bilevel network problems is explored through a study on the network recovery problem (NRP), which seeks a quick and effective repairing strategy for disturbed networks following natural or human-induced disasters

Next-Generation Transit System Design During a Revolution of Shared Mobility

Ideally, public transit, by moving more people using fewer vehicles, serves as a backbone of a transportation system. However, most transit systems in the United States suffer from low ridership and high operating costs, thus they provide a significantly compromised mobility service to the transportation system users. Under current transit system design principles, such as service area requirements, inefficiencies in resource use are almost inevitable. Given the opportunities brought by new mobile technology and the environment of mobility as a service, current transit system design principles need to be reevaluated and redefined to enable transit to serve as a backbone in the transportation system. In this seed-grant project, the researchers evaluated whether building an integrated multimodal public transportation system via reallocation of transit resources is financially feasible and environmentally sustainable. They also conducted an in-depth review of related literature and discussed other concerns regarding an integrated system. Based on the results from the case study and review of other recent studies, the authors draw an optimistic conclusion about an integrated service system where public and private mobility service providers coexist