► We measured actual wait times and surveyed perceived wait times of transit riders. ► Perceived is greater than measured wait time for riders without real-time information. ► Perceived is not ...greater than measured wait time with real-time information. ► Typical wait times reported were 30% lower for those with real-time information. ► Mobile real-time information also reduced the actual wait time.
In order to attract more choice riders, transit service must not only have a high level of service in terms of frequency and travel time but also must be reliable. Although transit agencies continuously work to improve on-time performance, such efforts often come at a substantial cost. One inexpensive way to combat the perception of unreliability from the user perspective is real-time transit information. The OneBusAway transit traveler information system provides real-time next bus countdown information for riders of King County Metro via website, telephone, text-messaging, and smart phone applications. Although previous studies have looked at traveler response to real-time information, few have addressed real-time information via devices other than public display signs. For this study, researchers observed riders arriving at Seattle-area bus stops to measure their wait time while asking a series of questions, including how long they perceived that they had waited.
The study found that for riders without real-time information, perceived wait time is greater than measured wait time. However, riders using real-time information do not perceive their wait time to be longer than their measured wait time. This is substantiated by the typical wait times that riders report. Real-time information users say that their average wait time is 7.5
min versus 9.9
min for those using traditional arrival information, a difference of about 30%. A model to predict the perceived wait time of bus riders was developed, with significant variables that include the measured wait time, an indicator variable for real-time information, an indicator variable for PM peak period, the bus frequency in buses per hour, and a self-reported typical aggravation level. The addition of real-time information decreases the perceived wait time by 0.7
min (about 13%).
A critical finding of the study is that mobile real-time information reduces not only the perceived wait time, but also the actual wait time experienced by customers. Real-time information users in the study wait almost 2
min less than those arriving using traditional schedule information. Mobile real-time information has the ability to improve the experience of transit riders by making the information available to them before they reach the stop.
Background: Prevalence rates for both overweight and asthma have been increasing among children in developed countries over the past two decades. Some recent studies have postulated a causal relation ...between these but have lacked power to form a definitive conclusion. Aim: To estimate the effect of high body weight in childhood on the future risk of asthma. Methods: Medline search (1966 to October 2004), supplemented by manual search of reference lists and grey literature. Cohort studies that examined high body weight at birth or during childhood and future outcome of asthma were included. Data from each study were extracted on exposure status, clinical outcome, and study characteristics. Results: A total of 402 studies were initially identified, of which 12 met the inclusion criteria. The combined results from four studies that examined the effect of high body weight during middle childhood on the outcome of subsequent asthma showed a 50% increase in relative risk (RR 1.5, 95% CI 1.2 to 1.8). The combined results from nine studies that examined the effect of high birth weight on subsequent asthma had a pooled RR of 1.2 (95% CI 1.1 to 1.3). There was consistency among the results in sensitivity analyses examining studies containing only estimates of odds ratios, studies containing only the outcome of physician diagnosis of asthma, and studies including all definitions of high body weight. Conclusions: Children with high body weight, either at birth or later in childhood, are at increased risk for future asthma. Potential biological mechanisms include diet, gastro-oesophageal reflux, mechanical effects of obesity, atopy, and hormonal influences. Further research might elucidate the causal pathway, which could improve our understanding of the pathophysiology of asthma and perhaps lead to knowledge of potential preventive interventions.
Drawing from current literature, a theoretical tourism support model with a series of hypotheses was proposed. The model and the hypotheses were tested by utilizing a two-stage structural equation ...modeling approach. The findings of this study revealed that the host community backing for tourism development is affected directly and/or indirectly by nine determinants of residents’ support: the level of community concern, ecocentric values, utilization of tourism resource base, community attachment, the state of the local economy, economic benefits, social benefits, social costs, and cultural benefits. Further, results indicated that there are interactions among five dimensions of impacts. The proposed model explained the majority of the variance.
Les attitudes de la communauté d’accueil envers le tourisme: un modèle structurel amélioré. En se basant sur la littérature récente, on a proposé un modèle théorique de soutien de tourisme comprenant une série d’hypothèses. Le modèle et les hypothèses ont été mis à l’épreuve en utilisant une approche de modelage d’équation structurelle à deux stades. Les résultats de cette étude révèlent que le soutien par la communauté d’accueil du développement du tourisme est influé directement et/ou indirectement par neuf déterminants du soutien des habitants: niveau d’intérêt de la communauté, valeurs écologiques, utilisation de la base de ressources pour le tourisme, attachement de la communauté, état de l’économie locale, bénéfices économiques, bénéfices sociaux, coûts sociaux et bénéfices culturels. En plus, les résultats ont indiqué qu’il y a des interactions parmi les cinq dimensions des impacts. Le modèle proposé a expliqué la plus grande partie de la variance.
Recent observational studies have suggested possible reductions in mortality in patients receiving cefazolin versus antistaphylococcal penicillins. We examined 90-day mortality in patients receiving ...cefazolin compared to nafcillin for methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infection (BSI). We identified persons with MSSA BSI admitted to San Francisco General Hospital from January 2008 to July 2013 through a hospital-wide infection surveillance system and confirmed 90-day mortality using U.S. national vital registries. We included persons receiving cefazolin or nafcillin as the predominant intravenous antimicrobial agent; all participants received inpatient Infectious Diseases service consultation. We estimated the association between receipt of cefazolin and 90-day risk of death by multivariate logistic regression, including a propensity score for receiving cefazolin as the second predictor. Of 230 MSSA BSI cases, 30 received nafcillin and 70 received cefazolin as the predominant antimicrobial; 10 died within 90 days, 5 from each group. Unadjusted analysis showed substantial but not statistically significant reduced odds of death in those receiving cefazolin (odds ratio, 0.38; 95% confidence interval CI, 0.10 to 1.44). Multivariate analysis with propensity scores found a similar adjusted odds ratio (0.40; 95% CI, 0.09 to 1.74; P = 0.22). We found a large reduction in 90-day mortality in those receiving cefazolin compared to nafcillin for MSSA BSI, but this finding was not statistically significant. The magnitude of effect seen in this and other studies justifies further study.
The structure of the sodium-benzylhydantoin transport protein Mhp1 from Microbacterium liquefaciens comprises a five-helix inverted repeat, which is widespread among secondary transporters. Here, we ...report the crystal structure of an inward-facing conformation of Mhp1 at 3.8 angstroms resolution, complementing its previously described structures in outward-facing and occluded states. From analyses of the three structures and molecular dynamics simulations, we propose a mechanism for the transport cycle in Mhp1. Switching from the outward- to the inward-facing state, to effect the inward release of sodium and benzylhydantoin, is primarily achieved by a rigid body movement of transmembrane helices 3, 4, 8, and 9 relative to the rest of the protein. This forms the basis of an alternating access mechanism applicable to many transporters of this emerging superfamily.
The nucleobase-cation-symport-1 (NCS1) transporters are essential components of salvage pathways for nucleobases and related metabolites. Here, we report the 2.85-angstrom resolution structure of the ...NCS1 benzyl-hydantoin transporter, Mhp1, from Microbacterium liquefaciens. Mhp1 contains 12 transmembrane helices, 10 of which are arranged in two inverted repeats of five helices. The structures of the outward-facing open and substrate-bound occluded conformations were solved, showing how the outward-facing cavity closes upon binding of substrate. Comparisons with the leucine transporter LeuTAa and the galactose transporter vSGLT reveal that the outward- and inward-facing cavities are symmetrically arranged on opposite sides of the membrane. The reciprocal opening and closing of these cavities is synchronized by the inverted repeat helices 3 and 8, providing the structural basis of the alternating access model for membrane transport.
Mass incarceration has collateral consequences for community health, which are reflected in county-level health indicators, including county mortality rates. County jail incarceration rates are ...associated with all-cause mortality rates in the USA. We assessed the causes of death that drive the relationship between county-level jail incarceration and mortality.
In this retrospective, longitudinal study, we assessed the association between county-level jail incarceration rates and county-level cause-specific mortality using county jail incarceration data (1987–2017) for 1094 counties in the USA obtained from the Vera Institute of Justice and cause-specific mortality data for individuals younger than 75 years in the total county population (1988–2018) obtained from the US National Vital Statistics System. We fitted quasi-Poisson models for nine common causes of death (cerebrovascular disease, chronic lower respiratory disease, diabetes, heart disease, infectious disease, malignant neoplasm, substance use, suicide, and unintentional injury) with county fixed effects, controlling for all unmeasured stable county characteristics and measured time-varying confounders (county median age, county poverty rate, county percentage of Black residents, county crime rate, county unemployment rate, and state incarceration rate). We lagged county jail incarceration rates by 1 year to assess the short-term, by 5 years to assess the medium-term, and by 10 years to assess the long-term associations of jail incarceration with premature mortality.
A 1 per 1000 within-county increase in jail incarceration rate was associated with a 6·5% increase in mortality from infectious diseases (risk ratio 1·065, 95% CI 1·061–1·070), a 4·9% increase in mortality from chronic lower respiratory disease (1·049, 1·045–1·052), a 2·6% increase in mortality induced from substance use (1·026, 1·020–1·032), a 2·5% increase in suicide mortality (1·025, 1·020–1·029), and smaller increases in mortality from heart disease (1·021, 1·019–1·023), unintentional injury (1·015, 1·011–1·018), malignant neoplasm (1·014, 1·013–1·016), diabetes (1·013, 1·009–1·018), and cerebrovascular disease (1·010, 1·007–1·013) after 1 year. Associations between jail incarceration and cause-specific mortality rates weakened as time lags increased, but to a greater extent for causes of death with generally shorter latency periods (infectious disease and suicide) than for those with generally longer latency periods (heart disease, malignant neoplasm, and cerebrovascular disease).
Jail incarceration rates are potential drivers of many causes of death in US counties. Jail incarceration can be harmful not only to the health of individuals who are incarcerated, but also to public health more broadly. Our findings suggest important points of intervention, including disinvestment from carceral systems and investment in social and public health services, such as community-based treatment of substance-use disorders.
US National Institute on Drug Abuse (National Institutes of Health).
1. The role of land cover change as a significant component of global change has become increasingly recognized in recent decades. Large databases measuring land cover change, and the data which can ...potentially be used to explain the observed changes, are also becoming more commonly available. When developing statistical models to investigate observed changes, it is important to be aware that the chosen sampling strategy and modelling techniques can influence results. 2. We present a comparison of three sampling strategies and two forms of grouped logistic regression models (multinomial and ordinal) in the investigation of patterns of successional change after agricultural land abandonment in Switzerland. 3. Results indicated that both ordinal and nominal transitional change occurs in the landscape and that the use of different sampling regimes and modelling techniques as investigative tools yield different results. 4. Synthesis and applications. Our multimodel inference identified successfully a set of consistently selected indicators of land cover change, which can be used to predict further change, including annual average temperature, the number of already overgrown neighbouring areas of land and distance to historically destructive avalanche sites. This allows for more reliable decision making and planning with respect to landscape management. Although both model approaches gave similar results, ordinal regression yielded more parsimonious models that identified the important predictors of land cover change more efficiently. Thus, this approach is favourable where land cover change pattern can be interpreted as an ordinal process. Otherwise, multinomial logistic regression is a viable alternative.
Abstract The MANTA (Modular Adjustable Negative Triangularity ARC-class) design study investigated how negative-triangularity (NT) may be leveraged in a compact, fusion pilot plant (FPP) to take a ...‘power-handling first’ approach. The result is a pulsed, radiative, ELM-free tokamak that satisfies and exceeds the FPP requirements described in the 2021 National Academies of Sciences, Engineering, and Medicine (NASEM) report ‘Bringing Fusion to the U.S. Grid’ (2021 Bringing Fusion to the U.S. Grid ). A self-consistent integrated modeling workflow predicts a fusion power of 450 MW and a plasma gain of 11.5 with only 23.5 MW of power to the scrape-off layer (SOL). This low P SOL together with impurity seeding and high density at the separatrix results in a peak heat flux of just 2.8 MW m −2 . MANTA’s high aspect ratio provides space for a large central solenoid (CS), resulting in ∼15 minute inductive pulses. In spite of the high B fields on the CS and the other REBCO-based magnets, the electromagnetic stresses remain below structural and critical current density limits. Iterative optimization of neutron shielding and tritium breeding blanket yield tritium self-sufficiency with a breeding ratio of 1.15, a blanket power multiplication factor of 1.11, toroidal field coil lifetimes of 3100 ± 400 MW · yr, and poloidal field coil lifetimes of at least 890 ± 40 MW · yr. Following balance of plant modeling, MANTA is projected to generate 90 MW of net electricity at an electricity gain factor of ∼ 2.4 . Systems-level economic analysis estimates an overnight cost of US$3.4 billion, meeting the NASEM FPP requirement that this first-of-a-kind be less than US$5 billion. The toroidal field coil cost and replacement time are the most critical upfront and lifetime cost drivers, respectively.
We investigate the effects of board busyness on firms' cost of debt by analyzing the relationship through a hostile takeover framework. We initially establish an inverse relationship between board ...busyness and firms' hostile takeover vulnerability. Next, we test the relationship between board busyness and the cost of debt. Our results suggest that as the level of board busyness increases, the cost of debt decreases. Economically, the cost of debt for firms whose board is comprised of 40% busy directors is about 30bps lower, compared to those without busy directors. Our results survive extensive robustness checks and provide a positive counterpoint to the negative correlation between board busyness and firm performance.
•Board busyness has inverse relationship with hostile takeover vulnerability.•Higher levels of board busyness are correlated with more anti-takeover provisions.•Higher levels of board busyness lead to lower cost of debt.•Board busyness can actually increase firm value.
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