Evaluation of serodiagnostic tests for T. b. gambiense human African trypanosomiasis in southern Sudan

A survey was conducted in a low-endemic and in a non-endemic area of Sudan to evaluate the specificity and efficiency of different serological antibody detection techniques for Trypanosoma brucei gambiense. Comparisons were made of the card agglutination test for trypanosomiasis (CATT) on diluted blood, on diluted plasma and on eluates from blood dried on filter paper, the LATEX test on diluted plasma and an ELISA on diluted plasma and filter paper. The specificities of all the serological tests were not significantly different from CATT on diluted blood (99.5%). The specificity of CATT on diluted blood was similar (99.3%). The highest sensitivities (100%) were observed with CATT on diluted blood and with CATT and LATEX on diluted plasma. CATT on diluted blood was more cost-efficient than the classic test, CATT on whole blood

Remote sensing methods for the evaluation of the mesquite tree (Prosopis juliflora) environmental adaptation to semi-arid Africa

In this study a remote sensing approach for the mesquite tree (Prosopis juliflora) control is proposed. The mesquite tree is well known for its high adaptability to arid and semi-arid conditions and characterized by very high water use efficiency. Introduction of the mesquite has caused several environmental problems in Sudan. In this study to monitor mesquite water use efficiency the concept of a Normalized Difference Infrared Index (NDII), which is defined as the ratio of actual to foliar water content, have been applied and compared with the ground measurements of stomatal conductance (mmol. m-2. s-1), field spectral, volumetric soil water content. As results, on the base of the PALSAR L-band microwave polarimetric backscatter coefficient, the soil moisture (in bare soil area) and surface roughness (in dense forest covered area) could be estimated with a good accuracy for bare-soil surfaces

Evaluating the Invasion Strategic of Mesquite (Prosopis juliflora) in Eastern Sudan Using Remotely Sensed Technique

In the Red Sea coastal area, the problems of desertification, land degradation and dust storm are still serious. Because, the invasive species Mesquite (Prosopis juliflora) has a high capacity to fix sand dunes, mesquite trees were introduced into Sudan and planted in Khartoum and eastern Sudan. However, the tree was invaded both natural and managed habitats, including watercourses, floodplains, highways, degraded abandoned land and irrigated areas. The weed is more of a problem within central, northern and eastern Sudan. In this study a remote sensing approach for the mesquite tree control is proposed. To monitor mesquite water use efficiency the concept of a Normalized Difference Infrared Index (NDII), which is defined as the ratio of actual to foliar water content, have been applied and compared with the ground measurements of stomatal conductance (mmol. m^. s^), field spectral, volumetric soil water content. As results, on the base of the PALSAR L-band microwave polarimetric backscatter coefficient, the soil moisture and surface roughness could be estimated with a good accuracy for bare-soil surfaces