CASA: An Efficient Automated Assignment of Protein Mainchain NMR Data Using an Ordered Tree Search Algorithm

Rapid analysis of protein structure, interaction, and dynamics requires fast and automated assignments of 3D protein backbone triple-resonance NMR spectra. We introduce a new depth-first ordered tree search method of automated assignment, CASA, which uses hand-edited peak-pick lists of a flexible number of triple resonance experiments. The computer program was tested on 13 artificially simulated peak lists for proteins up to 723 residues, as well as on the experimental data for four proteins. Under reasonable tolerances, it generated assignments that correspond to the ones reported in the literature within a few minutes of CPU time. The program was also tested on the proteins analyzed by other methods, with both simulated and experimental peaklists, and it could generate good assignments in all relevant cases. The robustness was further tested under various situations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43050/1/10858_2005_Article_4079.pd

Health and environmental impacts of pesticide use practices: a case study of farmers in Ekiti State, Nigeria

Commonly used pesticides and handling practices which might expose farmers and their environment to chemical hazards were investigated in the Irepodun/Ifelodun local government area of Ekiti State, Nigeria. Direct field observations and answers to a structured questionnaire from a random sample of 150 farming households showed that commonly used pesticides comprised herbicides (48.3 per cent), fungicides (28.2 per cent) and insecticides (23.5 per cent). Of these, 86.7 per cent are classified as ‘highly’ hazardous by the World Health Organization (WHO) and have been banned or restricted in many developed countries. Nearly all of the farmers (94.7 per cent) had received no formal training in safe pesticide use and mixed different products. Farmers suffered from discomforts ranging from eye irritation (91.3 per cent), skin problems (87.3 per cent), nausea (86.0 per cent), headache (83.3 per cent) and vomiting (58.0 per cent). More than half of the pesticide applicators (61.3 per cent) sprayed pesticides near water bodies. Only a few farmers reported decreasing trends in numbers of beneficial insects (27.3 per cent) and other animals (29.3 per cent). The results showed that the awareness of farmers and authorities needs to be raised regarding the use of protective equipment and correct procedures when handling pesticides and, also, that there should be stricter enforcement of existing pesticide regulation and monitoring policies to minimize the threats that the farmers’ current practices pose to their health and to the environment