African cities face immense challenges over the coming decades. As countries urbanize, African cities must maintain service provision for rapidly increasing populations, yet with limited resources. In particular, urban food systems must be able to cope with regional food shortages and catalyze (or at least enable) the distribution of food from diverse sources in order to ensure that the cost of...

This paper suggests a cause of low density in urban development or urban sprawl that has not been given much attention in the literature. There have been a number of arguments put forward for market failures that may account for urban sprawl, including incomplete pricing of infrstructure, environmental externalities, and unpriced congestion. The problem analyzed here is that urban growth create...

â  â â â â â  â  â  abstract: â  there is a significant relationship between economic growth and the degree of urban concentration, as measured by primacy or the share of the largest city in an urban system. in accordance to urban economic theories, there is an inverse-u shape relationship between urban concentration –urban primacy- and economic growth. that is, as economy grows, urban concen...

10 We examined the impact of the urban environment on the spatial and temporal activity of brood parasitic Brown-headed Cowbirds (Molothrus ater) in Boulder County, CO, USA. We found that cowbirds used the urban areas for foraging and roosting and traveled into the 3240 ha wildland preserve of ponderosa pine in the mornings to parasitize songbird hosts. Cowbird abundance decreased with distance...

Cities are growing and encountering many changes over time due to population growth and migration. Identification and detection of these changes play important roles in urban management and sustainable development. Urban growth models are divided into two main categories: first cellular models which are further divided into experimental, dynamic, and integrated models and second vector models. ...

The feasibility of transcatheter arterial chemo-embolization (TACE) combined with intratumoral injection of cisplatin as treatment for hepatocellular carcinoma. 30 cases receiving TACE were denoted the TACE group, another 30 cases receiving TACE combined with an intratumoral multi-point injection of cisplatin were denoted the TACE/cisplatin group. Cases with partial remission/complete remission...

Conventional two dimensional(2D) maps and DTMs are insufficient to represent geographic information in urban space comprising high-rise buildings and underground structures. There is a pressing need for a model of three dimensional(3D) representation of urban space, that is, a Digital Urban Space Model(DUSM). However, existing solid modelling techniques cannot be directly applied to the 3D repr...

the logistic regression (lr) method, as an empirical estimation method, was used to model urban growth in gorgan city between the years 1987-2001. three groups of variables including social-economic, land use and biophysical variables were used. similarity among variables is probable. to remove the correlated variables, covariance was calculated and distance to administrative, sporting centers ...

A fast settling multipath CMOS OTA for high speed switched capacitor applications is presented here. With the basic topology similar to folded-cascode, bandwidth and DC gain of the OTA are enhanced by adding extra paths for signal from input to output. Designed circuit is simulated with HSPICE using level 49 parameters (BSIM 3v3) in 0.35 um standard CMOS technology. The DC gain achieved is 56.7...