Hiding Private Locations by Anonymizing Data

Researchers explore ways of masking private locations in the interest of making useful data publicly available

How access to public transit may have saved many Americans’ homes during the Great Recession

The Great Recession which followed the 2008 financial crash saw massive increases in the number of homes being foreclosed and trillions wiped from homeowners’ equity. But the impact of the recession was not uniform across the country in all places. In new research, Timothy F. Welch, Steven R. Gehrke and Steven Farber look at the effects of access to public transport on house prices during the Great Recession. They find that houses less than a mile from stations in Atlanta, Baltimore or Portland all kept their value to a greater degree than those located farther away from stations.They suggest that this may be down to lower transport-related costs, better local economic conditions and greater access to employment opportunities

FcγR-mediated SARS-CoV-2 infection of monocytes activates inflammation

SARS-CoV-2 can cause acute respiratory distress and death in some patients1. Although severe COVID-19 disease is linked to exuberant inflammation, how SARS-CoV-2 triggers inflammation is not understood2. Monocytes and macrophages are sentinel cells that sense invasive infection to form inflammasomes that activate caspase-1 and gasdermin D (GSDMD), leading to inflammatory death (pyroptosis) and release of potent inflammatory mediators3. Here we show that about 6% of blood monocytes in COVID-19 patients are infected with SARS-CoV-2. Monocyte infection depends on uptake of antibody-opsonized virus by Fcγ receptors. Vaccine recipient plasma does not promote antibody-dependent monocyte infection. SARS-CoV-2 begins to replicate in monocytes, but infection is aborted, and infectious virus is not detected in infected monocyte culture supernatants. Instead, infected cells undergo inflammatory cell death (pyroptosis) mediated by activation of NLRP3 and AIM2 inflammasomes, caspase-1 and GSDMD. Moreover, tissue-resident macrophages, but not infected epithelial and endothelial cells, from COVID-19 lung autopsies have activated inflammasomes. These findings taken together suggest that antibody-mediated SARS-CoV-2 uptake by monocytes/macrophages triggers inflammatory cell death that aborts production of infectious virus but causes systemic inflammation that contributes to COVID-19 pathogenesis

Webinar: Land Use Mix and Pedestrian Travel Behavior: Advancements in Conceptualization and Measurement

Smart growth policies have often emphasized the importance of land use mix as an intervention beholding of lasting urban planning and public health benefits. Past transportation-land use research has identified potential efficiency gains achieved by mixed-use neighborhoods and the subsequent shortening of trip lengths; whereas, public health research has accredited increased land use mixing as an effective policy for facilitating greater physical activity. However, despite the celebrated transportation, land use, and health benefits of improved land use mixing and the extent of topical attention, no consensus has been reached regarding the conceptualization and measurement of this key smart growth principle or the magnitude of its link to walking. This research, comprising three empirical studies, explores this topic in detail. This webinar will provide attendees with greater specificity in the measurement of land use mix and its connection to pedestrian travel behavior.https://pdxscholar.library.pdx.edu/trec_webinar/1021/thumbnail.jp

Land Use and Active Travel: A Complex Relationship

While it’s accepted that mixed-use development promotes active travel, researchers don’t have a consensus on exactly how land use determines people’s travel patterns

Wider Dissemination of Household Travel Survey Data Using Geographical Perturbation Methods

Public agencies spend vast amounts of money collecting information about passenger travel in household travel surveys. These data are valuable for the rich and detailed information they provide, which contribute to regional and statewide travel demand models. These data have utility beyond travel demand modeling in their application to transportation policy and travel behavior research. As the demand on these data increase, so have the quantity of information collected. Detailed geospatial referencing of the home, work and other travel destinations are common practice and permit the integration with other spatially archived data sources, such as land use characteristics, transportation system information, and other built environment, social and economic data. Other public agencies, private consultancies, non-profits and educational institutions may benefit from access to the original data with applications to areas such public health, equity, transportation safety and urban planning. Oregon Modeling Collaborative (OMC) has entered into an agreement with Oregon Modeling Steering Committee (OMSC) to host and make available Oregon Household Activity Survey (OHAS) datasets. But wide distribution of these important and expensive data is limited by the requirement to protect the confidentiality of survey participants, who are guaranteed anonymity in exchange for participation. Data are often aggregated to a geographic level such as Census tracts or transportation analysis zones (TAZs) before disseminating to the public, which limits the utility of this information. This project aims to develop a methodology to permit dissemination of these spatially-explicit data to a wider range of public constituents while at the same time, protecting the identities of study participants. Making use of these data, this project will use geographical perturbation methods to add noise to the original data to protect confidentiality while at the same time allowing the detailed geo-spatial referencing to be included in the disseminated data. The process includes: The coordinates (locations) will be geographically perturbed (masked) so that they do not reveal the identity of the traveler while at the same time retaining spatial relevance and resolution. Here the limits of the perturbation (minimum and maximum displacement) need to be determined that a) ensure confidentiality and b) minimize the errors introduced to the data. The original and perturbed (masked) data will be compared using various statistical approaches to develop a set of confidence measures for different types of transportation applications. For example, geographically perturbed (masked) may be more robust for automobile travel measures, such as vehicle miles traveled (VMT) or transit accessibility than for detailed pedestrian or bicycle trip attributes. This exercise will allow spatially-explicit OHAS data to be released to the public with some information about the confidence to which it can be applied. These data will be archived at Portland State University and made available to the public. The information and algorithms can be shared with other agencies collecting and archiving travel data, such as the National Household Travel Survey, metropolitan planning organizations and state departments of transportation, to permit wider dissemination of their data

An Activity-related Land Use Mix Construct and Its Connection to Pedestrian Travel

Land use mix is a central smart growth principle connected to active transportation. This presentation describes the indicators of local land use mixing and their association with pedestrian travel in Oregon’s Willamette River Valley. It argues that land use mix is a multidimensional construct reflected by the complementarity, composition, and configuration of land use types, which is positively linked to walk mode choice and home-based trip frequency. Findings from this study underline the conceptual and empirical benefit of analyzing this transportation-land use interaction with a landscape pattern measure of activity-related composition and spatial configuration. The presentation for this seminar was done jointly with Kristin Curran. It may be accessed at http://archives.pdx.edu/ds/psu/18237.https://pdxscholar.library.pdx.edu/trec_seminar/1021/thumbnail.jp

Understanding Residential Location Choices for Climate Change and Transportation Decision Making: Phase 2 Report

This research builds on the related Phase 1 project. In this second phase, we continue to study neighborhood and housing preferences that shape the residential location decision process. An online experimental survey tool is developed to investigate lifestyle preferences and tradeoffs that households make in their location decisions. This computer-aided experimental survey draws upon stated preference methods to engage participants in questions about residential location and transportation options. The survey infrastructure was extensively piloted (6-10% response rate). The 10-minute survey can be deployed for future investigations. This infrastructure is a contribution for the integration of visualized neighborhood typologies, or concepts, which were objectively defined using data from 25 of the most populous metropolitan regions from around the United States. The construct of neighborhoods is based upon national data to account for potential options not currently available in Oregon. These visualizations help ground the survey respondents in the same reality and were carefully crafted to convey various attributes of the built and transportation environment. The initial analysis of the preference data collected in this survey (N=1,035) indicates that the preferences for neighborhood, housing, and transportation characteristics have a greater influence on the preferred neighborhood concept than the more typically used socio-economic characteristics (income, household size, age). Another interesting preliminary finding is that 27% of respondents would prefer to live in a more urban neighborhood than they currently reside. These “urban seeking” respondents had no particular demographic trend, providing little evidence that specific socioeconomic markets had specific preferences for the built environment

Operationalizing the Neighborhood Effects of the Built Environment on Travel Behavior

Evidence of a connection between the built environment and individual travel behavior is substantiated by multidisciplinary research. In general, compact development patterns exhibiting high concentrations of activity locations and a traditional street design support sustainable travel. However, uncertainty in the magnitude of this connection remains due to how the built environment has been operationalized, usually at a geographic boundary chosen out of convenience. This Portland, Oregon study uses household travel survey data to systematically examine variation in the magnitude of this association when measuring land development pattern, urban design, and transportation system features at various scales. Specifically, this study measures 57 built environment features describing an individual\u27s trip origin and destination at 12 combinations of zonal systems and spatial extents, and assesses their effect on home-based mode choice. First, correlations between individual- and household-level walking behaviors and each combination of indicator and geographic boundary were measured to examine scaling and zoning effects associated with the modifiable areal unit problem (MAUP). These sensitivity test results informed the specification of home-based work and non-work multinomial logit models estimating the effect of sociodemographic, economic, and built environment features on mode choice. Our study findings offer new insight into the MAUP\u27s scaling effect on measuring smart growth indicators and their connection to sustainable travel behavior

Joint Consideration of Energy Expenditure, Air Quality, and Safety by Cyclists

Public health benefits are an important motivator and justification for urban cycling promotion. The health impacts of cycling are typically evaluated using three main effect pathways: physical activity (exercise), air pollution exposure, and safety (crashes). Effects of safety on cycling behaviour have been investigated, but little is known about how energy expenditure and air quality concerns influence cycling decisions. Understanding cyclist perceptions and preferences is important for planning and designing sustainable and healthy transportation networks. As such, research providing insights into the heterogeneity of these concerns is needed to inform models of behavioural change with evolving vehicles, technology, and infrastructure. The objective of this paper is to investigate the joint consideration of energy expenditure, air quality, and safety concerns by cyclists, and their relationships with cycling frequency. A structural equation model is developed based on data from a survey of 625 intercepted real-world cyclists. Air quality and energy expenditure were considered in routing decisions by 51% and 73% of the cyclists, respectively. Model results show that traffic safety and air pollution risks are perceived differently by cyclists, which has implications for modeling urban cycling behaviour in the context of evolving motor vehicle fleets. Safety concerns were associated with less frequent cycling, but not air quality concerns. Consideration of energy expenditure varies significantly among individuals and trip types, which will emerge with different preferences related to hills, stops, speeds, and electric-assistance. Energy and air quality concerns were significantly associated, suggesting health-conscious cyclists who tended to be older, have higher educational attainment, be more physically active, and cycle more recreationally. Utilitarian and recreational cycling trips had different relationships with health-related considerations and with weekly physical activity