Demand for environmentally friendly vehicles: A review and new evidence

Although the need for more environmentally friendly vehicles was recognized some decades ago, this new market has not yet established itself. Consumer behavior needs to be studied to ascertain when people will decide to purchase hybrid or electric vehicles rather than conventional ones. An in-depth review of the state-of-the-art has identified existing deficiencies and these are addressed in this paper, proposing a new approach that is applied to the case of Santander in Spain. Emphasis is placed on the role of citizens in researching the local market and their requirements with respect to such vehicles; our model assumes variability in user preferences, an utmost requirement as concluded from the literature review. Results suggest that the highest demand for cleaner vehicles would be achieved in two ways: firstly, by penalizing conventional vehicles in terms of costs/km; secondly, by providing incentives directed at lowering the purchasing price of hybrid and electric vehicles. Finally, as demand becomes more elastic, the preferred strategy should initially focus on hybrid vehicles

Conversion of Vertical Banded Gastroplasty to Roux-en-Y Gastric Bypass Results in Restoration of the Positive Effect on Weight Loss and Co-morbidities: Evaluation of 101 Patients

BACKGROUND: Vertical banded gastroplasty (VBG) is a widely used restrictive procedure in bariatric surgery. However, the re-operation rate after this operation is high. In the case of VBG failure, a conversion to Roux-en-Y gastric bypass (RYGBP) is an option. A study was undertaken to evaluate the results of the conversion from VBG to RYGBP. METHODS: 101 patients had conversion from VBG to RYGBP. Patients were separated into 3 groups, based on the indication for conversion: weight regain (group 1), excessive weight loss (group 2) and severe eating difficulties (group 3). Data for the study were collected by retrospective analysis of prospectively recorded data. RESULTS: Weight regain (group 1) was the reason for conversion in 73.3% of patients. Staple-line disruption was the most important cause for the weight regain (74.3%). Excessive weight loss (group 2) affected 14% of patients and was caused by outlet stenosis in 78.6% of patients. The remaining 13% had severe eating difficulties as a result of outlet stenosis (46.1%), pouch dilatation (30.8%) and pouch diverticula (23.1%). Mean BMI before conversion to RYGBP was 40.5, 22.3 and 29.8 kg/m2 in group 1, 2 and 3, respectively. Minor or major direct postoperative complications were observed in 2.0% to 7.0%. Long-term complications were more frequent, and consisted mainly of anastomotic stenosis (22.7%) and incisional hernia (16.8%). Follow-up after conversion was achieved in all patients (100%), with a mean period of 38 +/- 29 months. BMI decreased from 40.5 to 30.1 kg/m2, increased from 22.3 to 25.3 kg/m2. and decreased slightly from 29.8 to 29.0 kg/m2 in group 1, 2 and 3, respectively. All patients in group 3 noticed an improvement in eating difficulties. CONCLUSION: Complications after conversion from failed VBG to RYGBP are substantial and need to be considered. However, the conversion itself is a successful operation in terms of effect on body weight and treating eating difficulties after VBG

Public transport demand elasticities during the recessionary phases of economic cycles

The serious recession suffered by the Spanish economy has had an important impact on the working of transport systems. This article provides evidence of how the state of the economy, measured using per capita income levels and unemployment rates, can influence the demand for public transport by bus with data from the city of Santander (Spain) for the period 2001–2012. The methodology used has involved the short and long run equilibrium demand elasticities estimation using a log–log regression model considering the presence of autocorrelation in the residuals and the endogeneity of the transport supply. The results show that the demand for transport is sensitive to changes in unemployment rates with an elasticity estimated at 0.133 in the static equilibrium model and of 0.210 in the long run dynamic model. The resulting elasticity for income levels was not significant in all the models, with a parameter estimated in the static model of −0.505 and of −0.861 in the long run dynamic model. The model estimated by two stage least squares validated using data from 2013 with unemployment rate as an independent variable gave the lowest average square error in validation

Equity analysis in access to Public Transport through a Land Use Transport Interaction Model. Application to Bucaramanga Metropolitan Area-Colombia

The development of the Bucaramanga Metropolitan Area (BMA) under criteria focused on the expansion of residential and commercial sectors without considering transportation has produced a congested network and an increase in illegal mobility. A solution was articulating the city through Metrolinea Integrated Transport System (MITS) that not represents an optimal solution yet. Users prefer long-lasting trips by car rather than using public transportation. The absence of methods for assessing transportation deficiency in an agile manner more according to dynamic changes does not allow taking optimal decisions promptly. This research proposes a methodology that fuses a transport model using Visum software and a land-use model implemented in the Python language to analyze access to public transportation, i.e., using four integrated sub-models: transport, residential location, location of economic activities, and accessibility. Analysis of global equity using social indexes to measure the level of need for service and infrastructure was key to proper territory modeling. Results not only indicate where MITS is inefficient but also were could be useful to assess future behaviour considering socio-economic variables, land use, and new infrastructure

Modelling demand in restricted parking zones

Multiple linear regression (MLR) and geographically weighted regression (GWR) models are used for estimating parking demand in areas with paid short stay parking systems. These models have been applied to the city of Santander (Cantabria, Spain) to check their goodness of fit and their predictive ability. The results show the main advantages and disadvantages of using GWR models. The technique proved to be useful in this case study because it offered a better fit and made better predictions in a scenario showing a certain degree of spatial heterogeneity unexplained by any of the variables introduced into the global model. However, the GWR model also presented situations of local correlation although this was considered moderate given the results provided by the variance inflation factors and the local condition indexes.Parking demand models Geographically weighted regression Parking policies