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This paper presents the optimization problem of three different on-demand transit systems operated by vehicles of different sizes. This problem is aimed at minimizing the total cost of the system, which consists of the temporal cost experienced by users and the operating cost incurred by transit agencies. A compact set of estimations of the user performance and operating cost is provided, based on geometric probability. The optimization procedure allows the cost comparison of different semi-flexible services. Transit systems operated by cars (shared taxicabs) with flexible layouts are preferable for low demand densities (less than 92 pax/km2-h). For very high demand (higher than 200 pax/km2-h), bus systems with fixed layout and variable stop locations present the lowest total cost per passenger. In an intermediate domain, taxi and semi-flexible services compete among each other. The estimation of unit operating costs allows decision-makers to calculate the subsidies needed to make the system profitable. The first and last authors thank AMTU (public entity Association of Municipalities with Urban Transportation) that supported this research under the contract C-11523 “Flexitransport” with our University Barcelona TECH. The contribution of the third author has been supported by the Chilean Scientific Research Agency (CONICYT), under the grant PFCHA/BCH No. 72160291. This work was supported by the Chilean Scientific Research Agency (CONICYT), [PFCHA/BCH No. 72160291]; AMTU [C-11523].

Trabajo presentado en: R-Evolucionando el transporte, XIV Congreso de Ingeniería del Transporte (CIT 2021), realizado en modalidad online los días 6, 7 y 8 de julio de 2021, organizado por la Universidad de Burgos, Santiago, the capital city of Chile, has seven million inhabitants in an area of 850 km2. This city has a metro network with seven lines extending 140 kilometers and transports approximately 2.6 million people daily. The bus system has undergone significant transformations over the last three decades. The most relevant change having been Transantiago, the public transportation system implemented in 2007 for Santiago, Child, which combines the use of Metro and buses (BRT). Metropolitan Mobility Network (called Red) is the latest version of the public transportation plan. This paper aims to analyze the current subway infrastructure using the continuous approximation method for Santiago, Chile. We previously proposed a macroscopic methodology to identify the needs for an adequate level of service in urban mobility and transportation, and we applied it to Santiago's Metro network. Our work focuses on functionality and demand distribution. Santiago's demand varies spatially in volume and extension throughout the city. Using the latest origin-destination survey from 2012, we deduct the critical components in this current network structure. It is worth mentioning that the metro design bases its network on a ring-radial structure. With our macroscopic model applied to Santiago, Chile, we have detected infrastructure needs in the current transit network. The supply of infrastructure should increase for two reasons: first, to achieve balanced cost levels between users and the agency and second, to reduce subway occupations. The optimal model outcomes for Santiago define the optimal network in which the system requires five rings and ten end-to-end longitudinal lines (20 radial routes), including lower levels of occupation. The obtained results are a good preliminary solution, considering the subway infrastructure supply could be sub-estimated in the public transportation plan., The authors had support from the Barcelona Innovative Transportation (BIT) Research Group. Moreover, the first author's work was supported by Chile's National Agency for Research and Development (ANID) / Becas-Chile Doctoral Scholarship Program No. 72160291. The first author had support from the Project 092112MT of the Departamento de Investigaciones Científicas y Tecnológicas (DICYT) of the University of Santiago of Chile (USACH).

Cities face problems influencing urban mobility, such as traffic growth, congestion, explosive population growth, urban sprawl. According to the literature, traffic, congestion, and urban development have an interrelationship with each other; traffic is a function of the system of activities attracting travel; activities define urban development and, its planning determines the traffic level and congestion. Thus, urban development requires a simultaneous interaction of its urban structure and transportation systems, contributing to urban mobility efficiency. The research proposes how to adapt infrastructure and land uses to meet the needs for traveling in a city. The above question promotes a balanced design between transportation networks, population distribution, land use, and infrastructure. The main objective is to develop a macroscopic method to identify infrastructure requirements reaching an appropriate service level for mobility and transportation. The methodology bases its formulation on analytical models to deduce critical components of a structural network for a concentric city, considering many dispersed cities set to this urban scheme. These key components must ensure the critical conditions of public and private transportation infrastructure. The Continuous Approximation (CA) method solves the problem based on local cost by using variables defined as densities. The dissertation focuses its research on urban design based on functionality, the role of heterogeneous distributed demand, and design effects on urban structure. The application of the model and obtained results focus on three types of analyzes. First, theoretical case analysis, considering both public and private transportation (multi-subcenter cities reduce total costs between 2.6 and 11.6%). Second, the analysis of a planning measure (subcenters save 3.5% of total costs) and new transportation technology (autonomous vehicles could neutralize the reduction in travel costs and times). Third, the model application to a current city such as Santiago of Chile (the system optimization advises an increment in subway services). Finally, the model, its implementation, analysis, and results prove that it is a promising contribution to planning science. In practice, its application can provide robust approaches to elaborate spatial planning instruments. Las ciudades enfrentan problemas afectando la movilidad urbana, como el aumento vehicular, congestión, crecimiento poblacional explosivo, dispersión urbana. Según la literatura, el tráfico, la congestión y el desarrollo urbano tienen una interrelación entre sí; el tráfico está en función del sistema de actividades atrayendo viajes; las actividades definen el desarrollo urbano y, su planificación determina el nivel de tráfico y congestión. Así, el desarrollo de las ciudades requiere una interacción simultánea de su estructura urbana y los sistemas de transporte, aportando a la eficiencia de la movilidad urbana. La investigación plantea cómo adaptar la infraestructura y los usos de suelo para satisfacer las necesidades para viajar en una ciudad. La pregunta anterior promueve un diseño equilibrado entre las redes de transporte, la distribución poblacional, los usos del suelo y su infraestructura. El objetivo principal es desarrollar un método macroscópico para identificar los requerimientos de infraestructura alcanzando un nivel adecuado de servicio para la movilidad y el transporte. La metodología basa su formulación en modelos analíticos para deducir los componentes críticos de una red estructural de una ciudad concéntrica, considerando que muchas ciudades dispersas se ajustan a este esquema urbano. Estos componentes claves deben garantizar las condiciones críticas de la infraestructura de transporte público y privado. El método de aproximación continua (CA) resuelve el problema sobre la base del costo local utilizando variables definidas como densidades. La investigación centra el trabajo en el diseño urbano basado en la funcionalidad, el papel de la demanda distribuida heterogéneamente y los efectos del diseño en la estructura urbana. La aplicación del modelo y los resultados obtenidos se centran en tres tipos de análisis. Primero, el análisis de casos teóricos para transporte público y privado (ciudades multi-subcentros reducen costos totales entre 2,6 y 11,6%). Segundo, el análisis de una medida de planificación urbana (subcentros ahorran 3,5% de los costos totales) y una nueva tecnología de transporte (vehículos autónomos podría neutralizar la reducción de costos y tiempos de viaje). Tercero, la aplicación del modelo a una ciudad real, Santiago de Chile (optimización del sistema establece aumentar los servicios de Metro). Finalmente, el modelo, su implementación, análisis y resultados demuestran ser un aporte con proyección a la ciencia de la planificación. En la práctica, su aplicación resultados pueden entregar robustas aproximaciones para los instrumentos de ordenación del territorio Enginyeria i infraestructures del transport

Resumen Caso clinico Presentamos el caso de un varon de 45 anos con excavacion coroidea asociada a una membrana neovascular coroidea no incluida en el area de la excavacion. Se describen las caracteristicas clinicas mediante retinografia, angiografia fluoresceinica, tomografia de coherencia optica y angiotomografia. El paciente fue tratado con 3 inyecciones de bevacizumab, consiguiendose la inactivacion de la membrana. Discusion La excavacion focal coroidea puede aparecer asociada a una membrana neovascular situada por fuera de los limites de la excavacion. El estudio mediante diversas modalidades de imagen nos permite una completa descripcion de sus caracteristicas, antes y despues del tratamiento.

Resumen Caso clinico Mujer de 42 anos, sin antecedentes de interes que acude con cefalea severa, nauseas, vomitos, perdida de la audicion y alteraciones mentales con desorientacion y confusion. El examen oftalmologico revelo la presencia de hiperemia del disco optico derecho y de areas focales de oclusion arteriolar en ambos ojos. La audiometria puso de manifiesto una hipoacusia bilateral neurosensorial. En la resonancia magnetica cerebral se detectaron multiples lesiones de pequeno tamano hiperintensas localizadas en el esplenio, cuerpo calloso, ganglios basales y sustancia blanca. Discusion Ademas de la oclusion de las arteriolas retinianas, la angiopatia del sindrome de Susac puede afectar a los vasos del disco optico.

Resumen Caso clinico Presentamos el caso de un varon de 42 anos de edad con varios episodios de uveitis unilateral en su ojo derecho. El examen oftalmologico mostro una uveitis anterior granulomatosa con vitritis. El estudio sistemico puso de manifiesto una proteinuria de rango no nefrotico y microhematuria. La biopsia renal revelo una nefropatia IgA. Discusion Las uveitis y las glomerulonefritis podrian tener mecanismos inmunologicos comunes. En el diagnostico diferencial de los pacientes con uveitis y nefropatias deberia incluirse la nefropatia IgA.

Resumen Caso clinico Presentamos el caso de una mujer de 54 anos con una coriorretinopatia serosa central diagnosticada erroneamente de enfermedad de Vogt-Koyanagi-Harada y tratada con corticoides sistemicos. La paciente desarrollo un desprendimiento de retina exudativo bulloso en ambos ojos. Discusion La interrupcion del tratamiento con corticoides junto con el drenaje quirurgico del liquido subretiniano y la aplicacion de terapia fotodinamica consiguio la mejoria anatomica y funcional. El correcto diagnostico de las formas atipicas de la enfermedad podria evitar las complicaciones del uso inadecuado de los corticoides.

Resumen Caso clinico Presentamos el caso de una paciente de 16 anos con un macrovaso retiniano congenito unilateral, con telangiectasias retinianas perifericas asociadas a zonas de isquemia. Discusion Los macrovasos retinianos congenitos constituyen un hallazgo raro, no habiendose descrito casos asociados a telangiectasias retinianas e isquemia periferica. Tras 21 meses de seguimiento, la paciente se mantiene estable, conservando la vision inicial y sin complicaciones adicionales.

Focused on a problem regarding the deficiency of the appropriate oral expression in the pronunciation, intonation and fluency of words, making the application of workshops of verbal games (rhymes, riddles and tongue twisters). Having as a general objective, to demonstrate how verbal games strengthen in the increase of oral expression in 5-year-old children of the Initial Educational Institution No. 02 María Inmaculada de Abancay 2019. The type of research is applicative, the level and design is quasi-experimental, with a single group of pre test and post test, 21 workshops of verbal games were applied more than 1 of pre and post test, conceiving in total 22 workshops applied in a 5-year classroom with a total amount of 26 sample children. The collection of information was through the instrument: checklist, which contains the performances of the National Curriculum of Basic Education (Curriculum of Initial Education), adapted for each dimension of the dependent variable. For the demonstration of the general hypothesis which is, verbal games strengthen significantly in the development of oral expression in children of 5 years of the Initial Educational Institution No. 02 María Immaculada de Abancay 2019. The percentage statistical effects show in the pronunciation dimension in the Pre Test with 77% children are at the start level and in the Post Test with 92% children are at the achievement level. In the intonation dimension of words in the Pre Test with 81% the children are at the start level and in the Post Test with 88% the children are at the achievement level. In the word fluency dimension in the Pre Test with 85% of the children are in the beginning level and in the Post Test with 85% the children are in the achievement level Tesis Pares

The concentration of both employment and services in a specific area of a town generates positive effects, but also impacts (congestion, transit issues, and others). Urban subcenters seek to approach economic activities to residents in peripheral urban spaces. The objective of this research is to evaluate the contribution to the mobility of implementing urban subcenters in a city. The model has a total cost function (users and agency costs) on a circular city (ring and radial routes) formulated using the continuous approximation method. The model solution addresses with mathematical optimization. The model evaluates a BRT network applied to scenarios of urban subcenters. The results of the modeling show that the implementation of subcenters obtains savings of 3.5% in rush hour. Thus, this strategy of urban planning generates improvements in the functioning of a public transportation system. Moreover, the maximum benefits are obtained in medium-sized subcenters in comparison to the CBD, which allows balancing user and agency costs. Therefore, the outcomes may be better with an urban pattern with subcenters, and a transit scheme adapted to the demand needs. The authors are members of BIT-Barcelona Innovative Transportation research group at BarcelonaTech. The work of the first author was also supported by CONICYT PFCHA/BCH 72160291 scholarship. This study had support from the Project 061312MT of the Departamento de Investigaciones Científicas y Tecnológicas (DICYT) of the Vicerrectoría de Investigación, Desarrollo e Innovación of the Universidad de Santiago de Chile (USACH).