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This paper analyzes the problem of locating ambulances for the Red Cross of Tijuana, Baja California, Mexico, considering demand changes over time, a problem that usually requires relocating ambulances at specific moments in time. This problem is usually solved using optimization models, seeking to maximize coverage and reduce the response time using an appropriate relocation strategy, while also minimizing the cost of relocating ambulances across the city. The goal of this work is to determine the benefits and costs, advantages and disadvantages, of using different strategies to solve this problem for the Red Cross of Tijuana. Therefore, different solution strategies are evaluated, all of them are based on the Double Standard Model (DSM) for ambulance locations. The first approach is to apply a robust version of the DSM, Robust DSM, that finds the best trade-off solutions across all possible time periods, or scenarios, throughout the day. The second approach is to apply the DSM to each scenario independently, and then perform relocations based on the different configurations of the ambulances in different scenarios. The final approach is to use an explicit relocation model, the multi-period DSM. The approaches are evaluated based on the percentage of double coverage, total number of relocations, relocation travel time, relocation travel distance and the financial cost of performing relocations. More than 13,000 calls for Emergency Medical Services (EMS) were analyzed, received by the Red Cross from August 2016 to April 2017, such that the results obtained are based on a comprehensive characterization of this real-world case study. Results show that while the relocation approaches do provide better overall coverage, for the Red Cross of Tijuana, an EMS provider with limited resources and funding, the increased coverage may not justify the additional costs.

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OBJECTIVE: The purpose of this study was to model the cost of delivering behavioural health services to rural Native American populations using telecommunications and compare these costs with the travel costs associated with providing equivalent care. METHODS: Behavioural telehealth costs were modelled using equipment, transmission, administrative and IT costs from an established telecommunications centre. Two types of travel models were estimated: a patient travel model and a physician travel model. These costs were modelled using the New Mexico resource geographic information system program (RGIS) and ArcGIS software and unit costs (e.g. fuel prices, vehicle depreciation, lodging, physician wages, and patient wages) that were obtained from the literature and US government agencies. RESULTS: The average per-patient cost of providing behavioural healthcare via telehealth was US$138.34, and the average per-patient travel cost was US$169.76 for physicians and US$333.52 for patients. Sensitivity analysis found these results to be rather robust to changes in imputed parameters and preliminary evidence of economies of scale was found. CONCLUSION: Besides the obvious benefits of increased access to healthcare and reduced health disparities, providing behavioural telehealth for rural Native American populations was estimated to be less costly than modelled equivalent care provided by travelling. Additionally, as administrative and coordination costs are a major component of telehealth costs, as programmes grow to serve more patients, the relative costs of these initial infrastructure as well as overall per-patient costs should decrease.

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The Upper Paraná River floodplain is the last lotic stretch of an ecosystem seriously threatened given that circa 50 percent of the original ecosystem has been converted into reservoirs. To assess the recreational value of the Upper Paraná River floodplain, 174 tourists were interviewed using the Willingness to Pay - WTP and Travel Cost - TC methods. The annual aggregated WTP attributed by tourists was US$ 122.50 million and the variables which determine the decision in willingness to pay for the Floodplain are: 'consider oneself as a Floodplain natural resources consumer' and 'marital state'. If the single person considers her/himself as a consumer of floodplain natural resources, the WTP increases by a multiplicative factor of 38.8. The value aggregated by the TC method was US$ 234 millions and decreased by zone as the distance increases. Higher income and traveling farther increases the travel cost, which is inversely related to annual trip frequency. The total recreational value (356.5 millions per year) is high and representative since it refers to an environment fragmented by dams and with many anthropogenic effects. Therefore, the progressive changes on the landscape are a threat to local tourism, since half of the visitors are attracted solely by the scenic beauty, thereby overtaking those factors considered more important by public decision makers and managers, such as recreational fishery or boating.

A planície de inundação do Alto Rio Paraná é o último trecho de um ecossistema seriamente ameaçado, visto que 50 por cento deste ambiente foi convertido em reservatórios. Para estimar o valor agregado pela recreação à planície, foram usados o Método de Valoração Contingente (Disposição à paga - DAP) e o Método do Custo de Viagem - CV pela entrevista de 174 turistas. A disposição a pagar anual agregada pelos turistas foi US$ 122,50 milhões, 'considerar-se um usuário dos recursos da planície' e 'estado civil' são as variáveis que determinam a decisão em pagar pela planície. Se o turista solteiro se considera um consumidor dos recursos da planície, a DAP aumenta por um fator multiplicativo de 38,8. O valor agregado pelo CV foi US$ 234 milhões e diminui por zona com o aumento da distância. Maior renda e viagens mais longas também aumentam o custo de viagem que, no entanto, é inversamente relacionado à freqüência anual de viagens. O valor recreativo total (356.5 milhões por ano) é alto e representativo por se tratar de um ambiente fragmentado por barragens e com muitos efeitos antropogênicos. Assim, as progressivas alterações na paisagem são uma ameaça ao turismo local, pois a metade dos visitantes entrevistados declarou ser atraída somente pela beleza cênica, sobrepujando outros bens e serviços naturais considerados importantes por gestores e administradores públicos, como a pesca recreativa e o passeio de barco.

Assuntos

RESUMO

The Upper Paraná River floodplain is the last lotic stretch of an ecosystem seriously threatened given that circa 50% of the original ecosystem has been converted into reservoirs. To assess the recreational value of the Upper Paraná River floodplain, 174 tourists were interviewed using the Willingness to Pay - WTP and Travel Cost - TC methods. The annual aggregated WTP attributed by tourists was US$ 122.50 million and the variables which determine the decision in willingness to pay for the Floodplain are: 'consider oneself as a Floodplain natural resources consumer' and 'marital state'. If the single person considers her/himself as a consumer of floodplain natural resources, the WTP increases by a multiplicative factor of 38.8. The value aggregated by the TC method was US$ 234 millions and decreased by zone as the distance increases. Higher income and traveling farther increases the travel cost, which is inversely related to annual trip frequency. The total recreational value (356.5 millions per year) is high and representative since it refers to an environment fragmented by dams and with many anthropogenic effects. Therefore, the progressive changes on the landscape are a threat to local tourism, since half of the visitors are attracted solely by the scenic beauty, thereby overtaking those factors considered more important by public decision makers and managers, such as recreational fishery or boating.

A planície de inundação do Alto Rio Paraná é o último trecho de um ecossistema seriamente ameaçado, visto que 50% deste ambiente foi convertido em reservatórios. Para estimar o valor agregado pela recreação à planície, foram usados o Método de Valoração Contingente (Disposição à paga - DAP) e o Método do Custo de Viagem - CV pela entrevista de 174 turistas. A disposição a pagar anual agregada pelos turistas foi US$ 122,50 milhões, 'considerar-se um usuário dos recursos da planície' e 'estado civil' são as variáveis que determinam a decisão em pagar pela planície. Se o turista solteiro se considera um consumidor dos recursos da planície, a DAP aumenta por um fator multiplicativo de 38,8. O valor agregado pelo CV foi US$ 234 milhões e diminui por zona com o aumento da distância. Maior renda e viagens mais longas também aumentam o custo de viagem que, no entanto, é inversamente relacionado à freqüência anual de viagens. O valor recreativo total (356.5 milhões por ano) é alto e representativo por se tratar de um ambiente fragmentado por barragens e com muitos efeitos antropogênicos. Assim, as progressivas alterações na paisagem são uma ameaça ao turismo local, pois a metade dos visitantes entrevistados declarou ser atraída somente pela beleza cênica, sobrepujando outros bens e serviços naturais considerados importantes por gestores e administradores públicos, como a pesca recreativa e o passeio de barco.