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A study of the predictive validity of the Kenya certificate of primary education examination: application of hierarchical linear models
(University of British Columbia, 1993)
Description Public examinations have been used in Kenya for decades as selection instruments for further education and training. The Kenya Certificate of Primary Education examination (KCPE) is the first of such selection ...
The accuracy of parameter estimates and coverage probability of population values in regression models upon different treatments of systematically missing data
(University of British Columbia, 1998)
Several methods are available for the treatment of missing data. Most of the methods are based on the assumption that data are missing completely at random (MCAR). However, data sets that are MCAR are rare in psycho-educational ...
The rate of outcrossing in grain amaranths
(Blackwell Publishing Ltd, 1991-09-01)
Studies of intra specific and inter specific out crossing rates were carried out for grain amaranths using two populations of A. hypochondriacus (populations 1008 and 1024) and two populations of A. cruentus (populations ...
South African Sign Language-one language or many? A sociolinguistic question
(Stellenbosch Papers, 1998)
In this article we discuss the signed language used by the Deaf community in South Africa, and examine the historical conditions for its emergence. We describe the legal and actual situation of South Afiican Sign Language ...
South African Sign Language-one language or many? A sociolinguistic question
(1998)
In this article we discuss the signed language used by the Deaf community in South Africa, and examine the historical conditions for its emergence. We describe the legal and actual situation of South Afiican Sign Language ...
The grammar of sign language
(University of South Africa, 1997-01-01)
Sign languages are natural visual-gestural languages comparable to other natural spoken languages. Although sign languages share many common universal features, considerable variation may be found amongst them. In this ...
On the convexity of Stampfli's numerical range
(Cambridge University Press, 1996-02)
This paper investigates a certain type of numerical range introduced by Stampfli. In particular, we investigate the convexity of this set of elements of operators on Hilbert spaces and its relationship to the algebra ...
Ruwenine and ruzorine: Pyrrolizidine alkaloids of Senecio ruwenzoriensis
(Pergamon, 1992-09-01)
A reinvestigation of Kenyan Senecio ruwenzoriensis reported to contain two alkaloids of unknown structures, ruwenine and ruzorine, resulted in the isolation of the pyrrolizidine alkaloid isoline, accompanied by what appeared ...
Errata. Pyrrolizidine Alkaloids from Senecio hadiensis
(American Chemical Society, 1991-09)
17-Oxosparteine (1 mg), -isolupanine (3 mg), and N-methylcytisine (2 mg) were iden- tified by ms and tic comparisons with authentic samples (6,8). Catalytic reduction (2 mg) of 5,6-dehydrolu- panine (4 mg), oil, ms (9) ...
The pyrrolizidine alkaloids of Senecio syringifolius and S. hadiensis from Kenya
(Pergamon, 1993-01-01)
Angularine, rosmarinine and 12-O-acetylrosmarine, together with their N-oxides were isolated from epigeal parts of S. syringifolius, while