Pedestrian and Bicycle Safety Research Brief

As cities around the country adopt initiatives like Vision Zero to eliminate traffic deaths and serious injuries, they are faced with the question of how effective different types of interventions are. For example, do protected bike lanes or painted sharrows reduce the risk of severe injury to cyclists? A group of researchers from the New York University School of Medicine examined this question by studying where cyclists admitted to the hospital crashed and how severe their injuries were. This research brief explores their findings.&nbsp

Giving undocumented immigrants access to driver’s licenses has transportation benefits for everyone.

Despite the need for access to a car in most US towns and cities, only sixteen states effectively allow undocumented immigrants to obtain a driver’s license. In new research, Jesus M. Barajas finds that when undocumented immigrants have access to driver’s licenses, there is no change in the number of miles they drive or trips they drive alone, but it does increase the number of carpool trips taken

Exploring Bicycle and Public Transit Use by Low-Income Latino Immigrants: A Mixed-Methods Study in the San Francisco Bay Area

Latin American immigrants will continue to make up a large share of transit ridership, bicycling and walking in the United States for the foreseeable future, but there is relatively little research about them. This mixed-methods study compares the travel patterns of low-income immigrants living in the San Francisco Bay Area with that of other groups and investigates the barriers and constraints faced by low-income immigrants when taking transit and bicycling. Much of the previous work on immigrant travel has relied on national surveys and qualitative analysis, which underrepresent disadvantaged population groups and slower modes of travel, or are unable to speak to broader patterns in the population. We conducted interviews with 14 low-income immigrants and a paper-based intercept survey of 2,078 adults. Interviewees revealed five major barriers that made public transit use difficult for them, including safety, transit fare affordability, discrimination, system legibility, and reliability. Although crime was the most prominent issue in interviews, the survey results suggest transit cost is the most pressing concern for low-income immigrants. Low-income immigrants were less likely than those with higher-incomes to have access to a motor vehicle, and were less likely than higher-income immigrants or the U.S.-born of any income to have access to a bicycle or bus pass. Finally, although most barriers to public transit use were the same regardless of nativity or household income, low-income immigrants were much less willing to take public transit when they had the option to drive and less willing to bicycle for any purpose. The prevalence of concerns about transit affordability, crime, and reliability suggest transit agencies should consider income-based fare reductions, coordinated crime prevention with local law enforcement, and improved scheduling

Engineered polyketides: Synergy between protein and host level engineering

Metabolic engineering efforts toward rewiring metabolism of cells to produce new compounds often require the utilization of non-native enzymatic machinery that is capable of producing a broad range of chemical functionalities. Polyketides encompass one of the largest classes of chemically diverse natural products. With thousands of known polyketides, modular polyketide synthases (PKSs) share a particularly attractive biosynthetic logic for generating chemical diversity. The engineering of modular PKSs could open access to the deliberate production of both existing and novel compounds. In this review, we discuss PKS engineering efforts applied at both the protein and cellular level for the generation of a diverse range of chemical structures, and we examine future applications of PKSs in the production of medicines, fuels and other industrially relevant chemicals

Adenoviral gene transfer of interleukin 12 into tumors synergizes with adoptive T cell therapy both at the induction and effector level

Tumors infected with a recombinant defective adenovirus expressing interleukin 12 (IL-12) undergo regression, associated with a cytotoxic T lymphocyte (CTL)-mediated antitumor immune response. In the present study we generated anti-CT26 CTLs by short-term coculture of CT26 cells and lymph node cells obtained from mice harboring subcutaneous CT26 tumors injected with an adenoviral vector expressing IL-12 (AdCMVIL-12), control adenovirus (AdCMVlacZ), or saline. Regression of small intrahepatic CT26 tumors in unrelated syngeneic animals was achieved with CTLs derived from mice whose subcutaneous tumors had been injected with AdCMVIL-12 but not with CTLs from the other two control groups. The necessary and sufficient effector cell population for adoptive transfer consisted of CD8+ T cells that showed anti-CT26 specificity partly directed against the AH1 epitope presented by H-2Ld. Interestingly, treatment of a subcutaneous tumor nodule with AdCMVIL-12, combined with intravenous adoptive T cell therapy with short-term CTL cultures, had a marked synergistic effect against large, concomitant live tumors. Expression of IL-12 in the liver in the vicinity of the hepatic tumor nodules, owing to spillover of the vector into the systemic circulation, appeared to be involved in the increased in vivo antitumor activity of injected CTLs. In addition, adoptive T cell therapy improved the outcome of tumor nodules transduced with suboptimal doses of AdCMVIL-12. Our data provide evidence of a strong synergy between gene transfer of IL-12 and adoptive T cell therapy. This synergy operates both at the induction and effector phases of the CTL response, thus providing a rationale for combined therapeutic strategies for human malignancies

Mobility Justice in Rural California: Examining Transportation Barriers and Adaptations in Carless Households

Caltrans 65A0686 Task Order 064 USDOT Grant 69A3551747114This report describes the scope and scale of car access in rural areas, identifies barriers that rural zero-car and car-deficit households face in their mobility and access, and proposes personal and policy-level adaptations that would help these households achieve their mobility and access needs using descriptive analysis from US census microdata and interviews with 22 residents of California\u2019s Central Valley. Results indicate that 5% of rural residents are fully carless and 18% live in a car-deficit household with less than one vehicle per adult. Both zero-car and car-deficit households tend to be in the Central Valley. Zero-car and car-deficit households in rural areas tend to be more socioeconomically disadvantaged than in nonrural areas. Both groups earn lower household incomes, are more likely to be Black, Latino, or Asian, have lower educational attainment, have more disabilities, have higher housing-cost burdens, and are more likely to be unemployed than their counterparts in nonrural areas. Almost half of workers in rural zero-car households drive alone to work compared to about a quarter in nonrural zero-car households, while mode shares are similar for car-deficit and car fully equipped households. Rural zero-car households are more likely to carpool and far less likely to take public transit. Three major themes emerged from the interviews. First, a commonality uniting the interview participants was the practice of relying on their social networks to get rides or obtain vehicle access. Second, the cost of car ownership and operation was high, placing vehicles out of reach for many. Third, alternatives to car access included public transit, medical transportation services, and car sharing, put poor availability often caused individuals to forgo trips. Interview participants shared a variety of options they saw as solutions to overcoming their barriers to lack of car access. While obtaining a vehicle was not absent from their preferred solutions, most preferred better personal access to transportation without the burden of private car ownership. The findings from demonstrate some of the complexities to consider when addressing transportation barriers in rural areas, where carlessness is less prevalent but solutions may be harder to implement than in urban areas

Massively parallel fitness profiling reveals multiple novel enzymes in Pseudomonas putida lysine metabolism

P. putida lysine metabolism can produce multiple commodity chemicals, conferring great biotechnological value. Despite much research, the connection of lysine catabolism to central metabolism in P. putida remained undefined. Here, we used random barcode transposon sequencing to fill the gaps of lysine metabolism in P. putida. We describe a route of 2-oxoadipate (2OA) catabolism, which utilizes DUF1338-containing protein P. putida 5260 (PP_5260) in bacteria. Despite its prevalence in many domains of life, DUF1338-containing proteins have had no known biochemical function. We demonstrate that PP_5260 is a metalloenzyme which catalyzes an unusual route of decarboxylation of 2OA to d-2-hydroxyglutarate (d-2HG). Our screen also identified a recently described novel glutarate metabolic pathway. We validate previous results and expand the understanding of glutarate hydroxylase CsiD by showing that can it use either 2OA or 2KG as a cosubstrate. Our work demonstrated that biological novelty can be rapidly identified using unbiased experimental genetics and that RB-TnSeq can be used to rapidly validate previous results.Despite intensive study for 50 years, the biochemical and genetic links between lysine metabolism and central metabolism in Pseudomonas putida remain unresolved. To establish these biochemical links, we leveraged random barcode transposon sequencing (RB-TnSeq), a genome-wide assay measuring the fitness of thousands of genes in parallel, to identify multiple novel enzymes in both l- and d-lysine metabolism. We first describe three pathway enzymes that catabolize l-2-aminoadipate (l-2AA) to 2-ketoglutarate (2KG), connecting d-lysine to the TCA cycle. One of these enzymes, P. putida 5260 (PP_5260), contains a DUF1338 domain, representing a family with no previously described biological function. Our work also identified the recently described coenzyme A (CoA)-independent route of l-lysine degradation that results in metabolization to succinate. We expanded on previous findings by demonstrating that glutarate hydroxylase CsiD is promiscuous in its 2-oxoacid selectivity. Proteomics of selected pathway enzymes revealed that expression of catabolic genes is highly sensitive to the presence of particular pathway metabolites, implying intensive local and global regulation. This work demonstrated the utility of RB-TnSeq for discovering novel metabolic pathways in even well-studied bacteria, as well as its utility a powerful tool for validating previous research

The Implications of Freeway Siting in California: Four Case Studies on the Effects of Freeways on Neighborhoods of Color

65A0674, TO 039California\u2019s freeways have come under increasing scrutiny for their disproportionately adverse impacts on low-income populations and populations of color. This study uses empirical research to not only understand but also quantify and describe in detail the historical impacts of freeways on communities of color in four California cities and areas: Pasadena, Pacoima, Sacramento, and San Jos\ue9. In these neighborhoods, freeways displaced many residents, significantly harmed those that remained, and left communities divided and depleted. The four cases differ in notable ways, but they share a disproportionate impact of freeway construction on communities of color. In Pasadena and Pacoima, decision-makers chose routes that displaced a greater share of households of color than proposed alternatives