Obstetric patients are transported by air quite frequently. We evaluated transport times, obstetric outcomes, air-versus-ground transport costs, and related data on 22 helicopter aeromedical transports of pregnant patients with preterm labor. We found no significant differences between patients who delivered and those who did not when comparing transport time (167.1 +/- 41.9 minutes versus 177....

How does isolation affect the economic activity of cities? Transport costs are widely considered an important barrier to local economic activity but their impact in developing countries is not well-studied. This paper investigates the role of intercity transport costs in determining the income of sub-Saharan African cities. In particular, focusing on fifteen countries whose largest city is a po...

We present a simple model of spatial competition to analyze the impact of a structural change in transaction (transportation) costs on the location of firms. The distinctive feature of the model is the existence of two markets which are non-connected. This means that a firm willing to sell in the other market must take into account a fixed fee in addition to the usual quadratic transport costs....

sorting and classification of agricultural products by machine vision system reduce costs and increase quality and accuracy. this research was performed to develop an algorithm and machine vision system for separating dirty and defects eggs and classifying by volume and weight. this machine installed on transport line egg in agriculture included a digital camera, computer and mechanical device ...

We use recent data on transport costs in West Africa, including the added burden of bribes and enforced delays, to show how such costs represent a deterrent to investment in — and therefore the sustainability of — agricultural assets. We focus on data for two important tree crops in West Africa, cashew and shea. We also have data for the transport of onions between Niger and the urban market in...

Grass-cutting ants (Atta vollenweideri) carry fragments that can be many times heavier and longer than the ants themselves and it is important for them to avoid falling over during load transport. To investigate whether the energetic costs of transport are affected by the need to maintain stability, the rate of CO(2) production was measured in both unladen workers and workers carrying standardi...