sajjad abdollahzadeh

Nowadays, urban transportation is one of the most important issues and challenges in urban economics. The development of cities and the emergence of phenomena such as population density, traffic, air pollution, and so on, have made obvious the necessity of using new, inclusive, and cost-effective technologies in the field of urban transportation services. In this regard, this paper models the demand for ride-sourcing for inner-city trips in Tabriz City. Our model is based on the Lancaster demand theory using the hedonic price function and cost analysis method. We estimated the ride-sourcing choice probability for inner-city trips by applying the logit discrete choice method. The results obtained from the estimation of the ride-sourcing taxi demand model have shown the sensitivity of passengers to the time costs of traveling with this type of taxi. Also, the results of demand analysis show that the decrease in trip velocity due to city traffic causes to increase in demand for ride-sourcing.

Manure application and irrigation practice with wastewaters in olericulture may introduce antibiotics and antibiotic resistant bacteria to soil which may contaminate edible vegatables. The aim of this study was to investigate the antibiotic resistant bacteria isolated from radish (Raphanus sativu) and parsley (Petroselinum crispum L.) and their cultivated soils. Three vegetable farms were selected in Pirbazar, Chaboksar and Fouman areas in Guilan province. Samples were taken from vegetables and soils at three replications. After making serial dilution, their heterotrophic and coliform bacteria number were determined on NA and EMB agar media respectively, containing 100 µg/mL antibiotic. Four antibiotics including cephalexin, ciprofloxacin, gentamicin and trimethoprim were tested. Antibiotic resistant index (ARI) was calculated by dividing bacteria colony numbers on each antibiotic contained medium to control (medium without antibiotic). Data were analyzed as split-split plot design with three locations as main plot sector, two olericulture fields as sub-plot and four antibiotics as sub-sub plot factor. The effect of antibiotic was significant on the vegetable and soil bacteria ARI (p<0.05). But the effect of sampling area and farm (radish and parsley farms) were significant only on the heterotrophic and coliform bacteria ARI, respectively (p <0.01). In Chaboksar area, 29% of vegetable's heterotrophic bacteria and 42% of soil coliforms were resistant to gentamicin. The highest coliform ARI (38%) was obtained in radish and was to gentamicin. Overall, culturable bacteria from vegetables of Chaboksar area had higher antibiotic resistance index and eating fresh vegetables cultivated in this area is not recommended.

This paper analyzes the technical efficiency of the provincial insurance units of the Iranian social security organization using Data Envelopment Analysis (DEA) approach based on yearly data from 2012 to 2014. To that end, return to scale tests are used to determine the appropriate DEA type for each unit; which the results favor constant returns to scale in these units. Next, constant return to scale and superefficient DEA (introduced by Andersen and Petersen, 1993) models are used to measure the technical efficiency of the units. In addition, two different indices (the network-deepening and network-widening) are introduced and their effects on the efficiency are also investigated. The results of comparing the network indices and technical efficiency of the units revealed that in the large units the technical efficiency has a pro-cyclical and counter-cyclical dynamic with the network deepening and network widening indices, respectively. However, in the small units the direction of changes in the technical efficiency and network indices varies among the units and the results are inconclusive.

In this study, the continuous wavelet transformation approach is employed to test the dynamics of the causality between two principal inflation indices i.e. consumer price index (CPI) and producer price index (PPI) based on monthly data from 1990:5 to 2013:12 for the Iranian economy. Analyzing the dynamics of causality between these two inflation indices could provide significant policy implications. One of the dominant aspects of this approach compared with the conventional causality tests is that it has a higher ability in analyzing dynamics of causality between time series. The wavelet, as a band pass filter to the time series, is stretched in time by varying its scale, which makes it possible to show the short run and long run causalities between the time series. In this paper, we apply the continuous wavelet transformation to study the inflationary cycles of the Iranian economy. The results confirm both demand-pull and cost-push nature of inflation by indicating bidirectional causality between the CPI and PPI. In fact, the causality directions vary over time depending on different economic conditions.