FRESH FIELDS FOR AFRICAN RAILWAYS

Prospects for Sustainable Railways

Fresh-frozen plasma use in a South African tertiary hospital.

Despite available guidelines on indications for fresh-frozen plasma (FFP) transfusion, inappropriate use is increasing worldwide. We evaluated FFP administration to patients admitted to the Steve Biko Academic Hospital over 4 months, including indications for use and completeness of requisition forms. Transfusions were considered inappropriate for 39.5% of units administered. Of request forms s...

HVDC Feeder Solution for Electric Railways

For AC railway power supply systems with a different frequency than the public grid, high-voltage AC (HVAC) transmission lines are common, connected to the catenary by transformers. This paper suggests an alternative design based on an HVDC (High Voltage DC) feeder, which is connected to the catenary by converters. Such an HVDC line would also be appropriate for DC-fed railways and AC-fed railw...

On Generalized Random Railways

We consider a random generalized railway defined as a random 3-regular multigraph where some vertices are regarded as switches not allowing traffic between any pair of attached edges. It is shown that the probability that the generalized railway is functioning is linear in the proportion of switches. Thus there is no threshold phenomenon for this property.

Gene Flow in African Rice Farmers’ Fields

(eds M.C.S. Wopereis et al.) 95 as the Togo Hills – African rice continues to be present, and is locally important (Barry et al., 2007; Nuijten et al., 2009; Okry, 2011, Teeken et al. 2011; Temudo, 2011). In these older, established areas of rice cultivation, wild rice is sometimes still gathered locally (Richards, 1986; Nuijten, 2005). It is often assumed that in traditional agriculture crops ...