1,101 research outputs found
Analyzing the Occupied Space of Passengers with Reduced Mobility in Metro Station Platforms: An Experimental Approach Using a Tracking System
The objective of this study is to analyze the occupied space of passengers with reduced mobility when boarding or alighting a train through an experimental approach based on a virtual tracking tool system to obtain their exact position. The designed experiments considered a train and its adjacent platform, in which 21 volunteers were recruited, 3 with reduced mobility. The results indicated that passengers with reduced mobility required up to 80% more space, compared to a passenger without reduced mobility, when waiting to board the train. The passenger who occupied the largest space was the one with a pram, reaching 1.70 m2/passenger, represented as a polygon. In addition, when passengers started to walk, the space used increased due to limb movement. In the alighting process, passengers with reduced mobility used almost twice the space required for the boarding process due to the relatively larger platform space occupied as each passenger alights and walks away, whereas when boarding, each passenger has less space to share with the other people waiting for the train to arrive or for the doors to open. These results could help practitioners improve the design of the platform or implement control measures, such as adding waiting areas for those passengers with reduced mobility. Further research is needed regarding other types of stations and density situations
An Analysis of Puerto Rico’s Debt Relief Needs to Restore Debt Sustainability
Puerto Rico’s economy has been suffering a recession for more than a decade. The recession has led to a debt and economic crisis. The lack of opportunities has resulted in migration outflows that affect the lives of thousands of families and leave a higher burden on those who stay. Overall, the current macroeconomic dynamics is destabilizing the lives of nearly 3.5 million U.S. citizens in Puerto Rico. Reversing this dynamic requires appropriate macroeconomic and debt policies. The collapse of economic activity has made the full payment of public debt unfeasible. Our study’s main goal is to offer insights for designing a plan of action for resolving Puerto Rico’s current debt crisis. The design of a restructuring proposal must note that the relationship between debt restructuring and fiscal policies exhibits bi-directional causality. On one hand, absent macroeconomic policies that expand the aggregate demand, Puerto Rico will not recover; and if the economy does not recover, Puerto Rico will not be able to pay its creditors without imposing severe damages on its nearly 3.5 million residents. On the opposite direction of causality, a larger debt reduction would imply that the territory would have more resources for expansionary macroeconomic policies, making the recovery more feasible and full repayment of the restructured debt more likely. Our contribution is thus twofold. First, we examine the macroeconomic implications of Puerto Rico’s Fiscal Plan that has been approved for fiscal years 2017-18 to 2026-27, as it is a crucial element for a computation of Puerto Rico’s debt restructuring needs. Second, we perform a Debt Sustainability Analysis (DSA) that incorporates the expected macroeconomic dynamics implied by the Fiscal Plan in order to compute Puerto Rico’s restructuring needs
Análisis del alivio de deuda necesario para restaurar la sostenibilidad de la deuda de Puerto Rico
La economÃa de puerto rico ha estado en recesión durante más de una década. Esta recesión ha producido una crisis de deuda y económica en Lgeneral. La falta de oportunidades ha redundado en flujos migratorios que afectan la vida de miles de familias y hacen la carga más pesada para los que se quedan. En general, la dinámica macroeconómica actual está desestabilizando la vida de unos 3.5 millones de ciudadanos estadounidenses en Puerto Rico. Contrarrestar esta dinámica requiere polÃticas adecuadas, tanto macroeconómicas como para el manejo de la deuda.El colapso de la actividad económica ha hecho inviable el pago completo de la deuda pública. La meta principal de nuestro estudio es ofrecer una perspectiva para desarrollar un plan de acción con vistas a resolver la actual crisis de la deuda de Puerto Rico. El diseño de una propuesta de reestructuración debe tener en cuenta que la relación entre la reestructuración de la deuda y las polÃticas fiscales implica una causalidad bidireccional. Por un lado, sin polÃticas macroeconómicas que expandan la demanda agregada, Puerto Rico no se recuperará, y si la economÃa no se recupera, Puerto Rico no podrá pagar a sus acreedores sin imponer daños graves a sus casi 3.5 millones de residentes. En la dirección causal opuesta, una mayor reducción de la deuda implicarÃa que el territorio contarÃa con más recursos para polÃticas macroeconómicas expansivas, con lo cual se harÃa más viable la recuperación y más probable el pago completo de la deuda reestructurada.Nuestro estudio realiza principalmente dos contribuciones. En primer lugar, examinamos las implicaciones macroeconómicas del Plan Fiscal de Puerto Rico que ha sido aprobado para los años fiscales desde 2017-18 hasta 2026-27, ya que es un elemento crucial en el cómputo de las necesidades de reestructuración de la deuda de Puerto Rico. En segundo lugar, presentamos un Análisis de Sostenibilidad de la Deuda (ASD) donde se incorpora la dinámica macroeconómica esperada que implicarÃa la implementación del Plan Fiscal a fin de computar las necesidades de reestructuración de Puerto Rico.Fil: Gluzmann, Pablo Alfredo. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Económicas. Departamento de Ciencias Económicas. Centro de Estudios Distributivos Laborales y Sociales; ArgentinaFil: Guzman, Martin Maximiliano. Columbia University; Estados Unidos. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Stiglitz, Joseph E.. Columbia University; Estados Unido
A Program Transformation for Continuation Call-Based Tabled Execution
The advantages of tabled evaluation regarding program termination and
reduction of complexity are well known --as are the significant implementation,
portability, and maintenance efforts that some proposals (especially those
based on suspension) require. This implementation effort is reduced by program
transformation-based continuation call techniques, at some efficiency cost.
However, the traditional formulation of this proposal by Ramesh and Cheng
limits the interleaving of tabled and non-tabled predicates and thus cannot be
used as-is for arbitrary programs. In this paper we present a complete
translation for the continuation call technique which, using the runtime
support needed for the traditional proposal, solves these problems and makes it
possible to execute arbitrary tabled programs. We present performance results
which show that CCall offers a useful tradeoff that can be competitive with
state-of-the-art implementations.Comment: Part of the proceedings of CICLOPS 200
Targeted Disruption of Core 1 β1,3-galactosyltransferase (C1galt1) Induces Apical Endocytic Trafficking in Human Corneal Keratinocytes
Exposed mucosal surfaces limit constitutive endocytosis under physiological conditions to prevent uptake of macromolecules and pathogens and, therefore, cellular damage. It is now accepted that cell surface mucins, a group of high molecular weight glycoproteins on the epithelial glycocalyx, defined by their extensive O-glycosylation, play a major role in maintaining barrier function in these surfaces, but the precise mechanisms are unclear.In this work, we utilized a stable tetracycline-inducible RNA interfering system targeting the core 1 ß1,3-galactosyltransferase (C1galt1 or T-synthase), a critical galactosyltransferase required for the synthesis of core 1 O-glycans, to explore the role of mucin-type carbohydrates in apical endocytic trafficking in human corneal keratinocytes. Using cell surface biotinylation and subcellular fractionation, we found increased accumulation of plasma membrane protein in endosomes after C1galt1 depletion. Confocal laser scanning microscopy and fluorometry revealed increased translocation of negatively charged fluorescent nanospheres after C1galt1 knockdown sustained by an active transport process and largely independent of apical intercellular junctions. Internalization of nanospheres could be blocked by dynasore, nocodazole, chlorpromazine, and hyperosmotic sucrose, suggesting a mechanism for clathrin-coated pit budding and vesicular trafficking. This possibility was supported by experiments showing nanosphere colocalization with clathrin heavy chain in the cytoplasm.Together, the data suggest that core 1 O-glycans contribute to maintenance of apical barrier function on exposed mucosal surfaces by preventing clathrin-mediated endocytosis
ASSESSMENT OF THE RESISTANCE CONFERRED BY THE \u3ci\u3ebc-1\u3c/i\u3e ALLELES TO \u3ci\u3eBean common mosaic necrosis virus\u3c/i\u3e
INTRODUCTION: Bean common mosaic necrosis virus (BCMNV) is a potyvirus comprising several strains classified into two pathogroups according to the interactions with six recessive resistance alleles in common bean (1). These pathogroups (PGs), numbered III and VI, are defined by the ability (PG-VI) or inability (PG-III) of a BCMNV isolate to replicate in bean differential lines carrying bc-1 or bc-12 resistance alleles. The biological and molecular basis for this differential response of BCMNV isolates to the presence of bc-1 alleles is not known. Conversely, the genetic determinants involved in interactions of BCMNV strains with bc-1 resistance alleles have not yet been identified either. We performed a complete biological and molecular study of three isolates of BCMNV belonging to PG-III and VI, collected in California and in Oregon. Particular attention was paid to BCMNV isolates’ performance in common bean lines from host groups 2, 3, and 9, harboring bc-1 and bc-12 alleles. The data obtained suggest that the bc-1 alleles restricted systemic movement of PG-III isolates of BCMNV, while cell-tocell movement of the virus in inoculated leaves did not seem to be affected
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