Transit in Washington, D.C.: Current Benefits and Optimal Level of Provision

The discrepancy between transit’s large share of local transportation resources and its generally low share of local trips has raised questions about the use of scarce transportation funds for this purpose. We use a regional transport model consistent with utility theory and calibrated for the Washington, D.C., metropolitan area to estimate the travel benefits of the local transit system to transit users and the congestion-reduction benefits to motorists. We find that (i) rail transit generates congestion-reduction benefits that exceed rail subsidies; (ii) the combined benefits of rail and bus transit easily exceed local transit subsidies generally; (iii) the lowest-income group receives a disproportionately low share of the transit benefits, both in absolute terms and as a share of total income; and (iv) for practical purposes, the scale of the current transit system is about optimal.transit, transit subsidies, external transit benefits

Congestion Pricing: Long-Term Economic and Land-Use Effects

We employ a spatially disaggregated general equilibrium model of a regional economy that incorporates decisions of residents, firms, and developers integrated with a spatially disaggregated strategic transportation planning (START) model that features mode, time period, and route choice to evaluate economic effects of congestion pricing. First, we evaluate the long-run effects of a road-pricing policy based on the integrated model of land use, strategic transport, and regional economy (LUSTRE) and compare them with the short-term effects obtained from the START model alone. We then look at distributional effects of the policy in question and point out differences and similarities in the short run versus the long run. Finally, we analyze the mechanisms at the source of the economic and land-use effects induced by the road-pricing policy.traffic congestion, welfare analysis, CGE modeling, cordon tolls, distributional effects

Letter From Abram Piatt Andrew to Francis Mairs Huntington-Wilson, July 3, 1912

The document is a typed letter from Abram Piatt Andrews to the Assistant Secretary of State regarding Andrews leaving the Treasury Department.https://digitalcommons.ursinus.edu/fmhw_other/1227/thumbnail.jp

Développement d'un système d'assistance à la marche pour les personnes en perte d'autonomie

L’espérance de vie des populations occidentales a augmenté de manière considérable durant le dernier siècle. Malheureusement, la perte d’autonomie associée avec le vieillissement représente un défi de taille pour la société de demain. Un des aspects précipitant la perte d’autonomie est la perte de mobilité, car la diminution des capacités physiques a des conséquences directes sur l’autonomie, la vie sociale, l’estime de soi et éventuellement les capacités cognitives. Les personnes en perte de mobilité deviennent donc rapidement dépendantes de leur communauté. Ce projet a comme objectif la conception d’un système d’assistance à la marche de type exosquelette, dénommé HRMS-I (Hermès-un), spécifiquement adapté aux besoins des personnes en perte de mobilité. Les recherches sur les exosquelettes étant généralement orientées vers le développement de solutions militaires ou portées sur la mobilité des personnes ayant un handicap, il est essentiel de définir les besoins spécifiques à la problématique du projet. Afin d’y parvenir, une analyse des efforts typiques de la vie quotidienne est menée et les caractéristiques anthropomorphiques de la population visée sont identifiées. Ensuite, une étude du type de motorisation optimal et une conception mécanique préliminaire sont effectuées. Une architecture électrique est proposée, le dimensionnement du bloc-pile pour rencontrer les requis de mobilité quotidienne est couvert et une solution de mesure des efforts d’interface au sol à l’aide de quatre cellules de force conçues sur mesure est développée. Finalement, les approches de commandes sont abordées et un modèle cinématique est développé et comparé avec les résultats d’un système de mesure optoélectronique

Rates of knee arthroplasty within one-year of undergoing arthroscopic partial meniscectomy in England:temporal trends, regional and age-group variation in conversion rates

Objective The aim of this study was to determine the proportion of patients undergoing arthroscopic partial meniscectomy (APM) then subsequently receiving a knee arthroplasty within one or two years, with focus on patients over the age of 60 years and regional variation. Methods Patients undergoing APM in England over 20-years (01-April-1997 to 31-March 2017) were identified in the national Hospital Episode Statistics (HES). The proportion of patients undergoing arthroplasty in the same knee within one or two years of APM was determined and trends were analysed over time nationally and by NHS Clinical Commissioning Group (CCG) region. Results 806,195 APM patients were eligible for analysis with at least one-year of follow up and 746,630 with two-years. The odds of arthroplasty conversion within one year increased over the study period (odds ratio [OR] 3.10 within 1-year in 2014 vs 2000; 95% confidence interval [CI] 2.75–3.50). For patients undergoing APM aged 60 years or older in 2015–16, 9.9% (1689/17,043; 95% CI 9.5–10.4) underwent arthroplasty within 1-year and, in 2014–15, 16.6% (3100/18,734; 95% CI 16.0–17.1) underwent arthroplasty within 2-years. There was greater than 10-fold variation by CCG. Conclusions Over the study period, the proportion of patients undergoing arthroplasty within one-year of APM increased. In 2015–16, of patients aged 60 years or older who underwent APM, 10% subsequently underwent knee arthroplasty within one year (17% within two years in 2014–15) and there was a high level of regional variation in this outcome. The development and adoption of national treatment guidance is recommended to improve and standardise treatment selection.</p

Pango lineage designation and assignment using SARS-CoV-2 spike gene nucleotide sequences

BACKGROUND: More than 2 million SARS-CoV-2 genome sequences have been generated and shared since the start of the COVID-19 pandemic and constitute a vital information source that informs outbreak control, disease surveillance, and public health policy. The Pango dynamic nomenclature is a popular system for classifying and naming genetically-distinct lineages of SARS-CoV-2, including variants of concern, and is based on the analysis of complete or near-complete virus genomes. However, for several reasons, nucleotide sequences may be generated that cover only the spike gene of SARS-CoV-2. It is therefore important to understand how much information about Pango lineage status is contained in spike-only nucleotide sequences. Here we explore how Pango lineages might be reliably designated and assigned to spike-only nucleotide sequences. We survey the genetic diversity of such sequences, and investigate the information they contain about Pango lineage status. RESULTS: Although many lineages, including the main variants of concern, can be identified clearly using spike-only sequences, some spike-only sequences are shared among tens or hundreds of Pango lineages. To facilitate the classification of SARS-CoV-2 lineages using subgenomic sequences we introduce the notion of designating such sequences to a “lineage set”, which represents the range of Pango lineages that are consistent with the observed mutations in a given spike sequence. CONCLUSIONS: We find that many lineages, including the main variants-of-concern, can be reliably identified by spike alone and we define lineage-sets to represent the lineage precision that can be achieved using spike-only nucleotide sequences. These data provide a foundation for the development of software tools that can assign newly-generated spike nucleotide sequences to Pango lineage sets. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12864-022-08358-2