144 research outputs found

    Are transit trips symmetrical in time and space? Evidence from the Twin Cities

    Get PDF
    This study exploits electronic fare collection data to examine the symmetry of boardings and alightings along a transit route. The symmetry of boardings and alightings is arguably the most important concept in the estimation of travel distances such as average trip lengths and passenger miles from data from entry-only fare collection systems. The paper shows the ways such data can be used to examine the symmetry of boardings and alightings through travel patterns in spatial and temporal dimensions. A novel method for aggregating stops, especially for the nearest stops in the opposite direction, is used to compare boardings in one direction with alightings in the opposite direction. Spatially, the method allows examination of the characteristics of boardings and alightings in a spatial dimension. Temporally, the method examines whether a specific and symmetric passenger flow is observed between specific periods (e.g., between morning and afternoon peaks). A case study of the Minneapolis-Saint Paul, Minnesota, region is performed by using automatically collected data from Metro Transit. Automatic fare collection data reveal considerable variation in passenger flow between specific periods. The use of automated passenger-counting data shows this variation to be statistically significant when both temporal and spatial symmetry are examined on an individual day

    Effect of nitrate supply and mycorrhizal inoculation on characteristics of tobacco root plasma membrane vesicles

    Get PDF
    Plant plasma membrane (pm) vesicles from mycorrhizal tobacco (Nicotiana tabacum cv. Samsun) roots were isolated with negligible fungal contamination by the aqueous two-phase partitioning technique as proven by fatty acid analysis. Palmitvaccenic acid became apparent as an appropriate indicator for fungal membranes in root pm preparations. The pm vesicles had a low specific activity of the vanadate-sensitive ATPase and probably originated from non-infected root cells. In a phosphate-limited tobacco culture system, root colonisation by the vesicular arbuscular mycorrhizal fungus, Glomus mosseae, is inhibited by external nitrate in a dose-dependent way. However, detrimental high concentrations of 25 mM nitrate lead to the highest colonisation rate observed, indicating that the defence system of the plant is impaired. Nitric oxide formation by the pm-bound nitrite:NO reductase increased in parallel with external nitrate supply in mycorrhizal roots in comparison to the control plants, but decreased under excess nitrate. Mycorrhizal pm vesicles had roughly a twofold higher specific activity as the non-infected control plants when supplied with 10–15 mM nitrate

    Development and Implementation of a Registry of Patients Attending Multidisciplinary Pain Treatment Clinics: The Quebec Pain Registry

    Get PDF
    The Quebec Pain Registry (QPR) is a large research database of patients suffering from various chronic pain (CP) syndromes who were referred to one of five tertiary care centres in the province of Quebec (Canada). Patients were monitored using common demographics, identical clinical descriptors, and uniform validated outcomes. This paper describes the development, implementation, and research potential of the QPR. Between 2008 and 2013, 6902 patients were enrolled in the QPR, and data were collected prior to their first visit at the pain clinic and six months later. More than 90% of them (mean age ± SD: 52.76 ± 4.60, females: 59.1%) consented that their QPR data be used for research purposes. The results suggest that, compared to patients with serious chronic medical disorders, CP patients referred to tertiary care clinics are more severely impaired in multiple domains including emotional and physical functioning. The QPR is also a powerful and comprehensive tool for conducting research in a “real-world” context with 27 observational studies and satellite research projects which have been completed or are underway. It contains data on the clinical evolution of thousands of patients and provides the opportunity of answering important research questions on various aspects of CP (or specific pain syndromes) and its management

    The psychology of passion: A meta-analytical review of a decade of research on intrapersonal outcomes

    Get PDF
    It is just over a decade since Vallerand et al. (J Personal Soc Psychol 85:756–767, 2003) introduced the dualistic model of passion. In this study, we conduct a meta-analytical review of relationships between Vallerand et al’s two passions (viz. harmonious and obsessive), and intrapersonal outcomes, and test the moderating role of age, gender, domain, and culture. A systematic literature search yielded 94 studies, within which 27 criterion variables were reported. These criterion variables derived from four research areas within the intrapersonal sphere: (a) well-/ill-being, (b) motivation factors, (c) cognitive outcomes and, (d) behaviour and performance. From these areas we retrieved 1308 independent effect sizes and analysed them using random-effects models. Results showed harmonious passion positively corresponded with positive intrapersonal outcomes (e.g., positive affect, flow, performance). Obsessive passion, conversely, showed positive associations with positive and negative
    corecore