THE MORPHOLOGY AND CLASSIFICATION OF GROUND AND POLISHED STONE ARTEFACTS OF SOUTH AFRICAN ORIGIN

1939 ◽  
Vol 27 (1) ◽  
pp. 29-46
Author(s):  
P. W. Laidler
Keyword(s):  
Koedoe ◽  
1995 ◽  
Vol 38 (1) ◽  
Author(s):  
G.J. Bredenkamp ◽  
H. Bezuidenhout

A procedure for the effective classification of large phytosociological data sets, and the combination of many data sets from various parts of the South African grasslands is demonstrated. The procedure suggests a region by region or project by project treatment of the data. The analyses are performed step by step to effectively bring together all releves of similar or related plant communities. The first step involves a separate numerical classification of each subset (region), and subsequent refinement by Braun- Blanquet procedures. The resulting plant communities are summarised in a single synoptic table, by calculating a synoptic value for each species in each community. In the second step all communities in the synoptic table are classified by numerical analysis, to bring related communities from different regions or studies together in a single cluster. After refinement of these clusters by Braun-Blanquet procedures, broad vegetation types are identified. As a third step phytosociological tables are compiled for each iden- tified broad vegetation type, and a comprehensive abstract hierarchy constructed.


2005 ◽  
Vol 221 (3-4) ◽  
pp. 520-528 ◽  
Author(s):  
André de Villiers ◽  
Pavel Majek ◽  
Frederic Lynen ◽  
Andrew Crouch ◽  
Henk Lauer ◽  
...  

2017 ◽  
Vol 9 (1) ◽  
pp. 228-243
Author(s):  
Shené Steenkamp ◽  
Rudie Nel

The classification of income from cloud computing activities, according to the substance-over-form doctrine, is fundamental to the application of the correct taxation source test. The designation of IaaS, PaaS and SaaS, the three main cloud computing service models, clearly denotes the form of cloud computing activities as that of a service. However, the nature of cloud computing inherently raises the question of whether or not cloud computing income should not rather be classified as income from leasing activities or the imparting of know-how. In fact, the findings of this study suggest the classification would not necessarily always be that of a service. The possible classification as lease income can be either income from the lease of tangible computer hardware and/or of intellectual property (royalty income). The aim of this study was to formulate guidelines to assist in the correct classification of income from cloud computing activities. This was achieved by performing doctrinal research based on the South African and international literature.


Lupus ◽  
2020 ◽  
Vol 29 (11) ◽  
pp. 1412-1422 ◽  
Author(s):  
Sahwa Elbagir ◽  
Amir I Elshafie ◽  
Elnour M Elagib ◽  
NasrEldeen A Mohammed ◽  
Mawahib IE Aledrissy ◽  
...  

Objectives IgA antiphospholipid antibodies (aPL) are prevalent in systemic lupus erythematosus (SLE) patients of African American, Afro-Caribbean and South African origin. Nevertheless, data from North Africa are lacking, and most studies use manufacturer-suggested cut-offs based on Caucasian controls. Therefore, we compared aPL isotypes in Sudanese and Swedish SLE patients using nation-based cut-offs. Methods Consecutive SLE patients and age- and sex-matched controls from Sudan ( N = 115/106) and Sweden ( N = 340/318) were included. All patients fulfilled the 1982 American College of Rheumatology SLE classification criteria. Antiphospholipid syndrome–related events were obtained from patients’ records. IgA/G/M anticardiolipin and anti-β2 glycoprotein I (β2GPI) were analysed with two independent assays. IgA anti-β2GPI domain 1 (D1) was also investigated. Manufacturers’ cut-offs and the 95th and 99th percentile cut-offs based on national controls were used. Results Sudanese patients and controls had higher levels and were more often positive for IgA aPL than Swedes when using manufacturers’ cut-offs. In contrast, using national cut-offs, the increase in IgA aPL among Sudanese patients was lost. Occurrence of IgA anti-D1 did not differ between the countries. Venous thromboses were less common among Sudanese patients and did not associate with aPL. No clinical associations were observed with IgA anti-β2GPI in Sudanese patients. Thromboses in Swedes were associated with IgG/M aPL. Fetal loss was associated with aPL in both cohorts. Conclusions IgA anti-β2GPI prevalence was higher among Sudanese compared to Swedish patients when manufacturers’ cut-offs were used. This situation was reversed when applying national cut-offs. Anti-D1 was not increased in Sudanese patients. Previous studies on populations of African origin, which demonstrate a high prevalence of IgA aPL positivity, should be re-evaluated using a similar cut-off approach.


2019 ◽  
Vol 16 (151) ◽  
pp. 20180737 ◽  
Author(s):  
Ilana Shtein ◽  
Alex Koyfman ◽  
Amram Eshel ◽  
Benny Bar-On

Autotomy is a self-defence strategy of sacrificing a body part for survival. This phenomenon is widespread in the animal kingdom (e.g. gecko's tail) but was never reported in plants. In this study, we characterize the autotomy mechanism in the leaves of an invasive plant of South African origin, Oxalis pes-caprae. When the leaves and flowers of this plant are pulled, they break easily at their base, leaving the rest of the plant intact. Microscopic observations of the leaves reveal an area of small cells and a marked notch at this designated breaking point. Mechanical analysis showed that the strength statistics of the petioles follow Weibull's function. A comparison of the function parameters confirmed that strength of the tissue at that point is significantly smaller than at other points along the petiole, while the toughness of the tissue at the notch and at mid-petiole are approximately the same. We conclude that leaf fracture in Oxalis is facilitated by an amplification of the far-field stress in the vicinity of local, but abrupt, geometrical modification in the form of a notch. This presents an autotomy-like defence mechanism which involves the sacrifice of vital organs in order to prevent the uprooting of the whole plant.


1894 ◽  
Vol 185 ◽  
pp. 1029-1041 ◽  

The South African fossils with broad, flat, tuberculate tooth-crowns of mammalian type all from the eastern part of Cape Colony. Some of the most interesting are known from fragments, which indicate nothing but the middle region of the sail. They are apparently extremely rare. Two species, with teeth well preserved, found ten years ago by Dr. Kannemeyer, at Wonderboom, and presented to South African Museum, Cape Town, where they were brought under my notice by Peringuey. Others were found in a fragmentary condition by Mr. Alfred of Aliwal North, to the west of that town, in a bed which appeared to me be reconstructed. There is no doubt that the fossils are from the upper part of te Karroo formation, probably of Permian age, and below the Stormberg beds, in Saurischian fossils are found allied to those of the Trias of Europe. If the teeth had occurred isolated, without the means of demonstrating their rsemblance to Theriodonts, by comparison of what remains of the skull, it would have legitimate to have referred them to Mammals. There is no evidence of affinity Accept resemblances to Theriodonts, which show that the skull had pre-frontal and frontal bones, and therefore may be inferred to have had the lower jaw composite. The teeth are such as might be expected, perhaps, in a Monotreme Mammal, their interest is therefore the greater that there is no ground for suspecting them be mammalian, other than a general resemblance of the crown to the crowns of true teeth of Ornithorhynchus. That teeth of this type should occur in a group animals in which the shoulder-girdle and pelvis have monotreme characters, and in hich the principal limb bones are intermediate in character between Monotremes Marsupials, is evidence of a closer approximation between Mammals and Pep tiles has been manifest. And so far as I am aware the only Theriodont characters remaining to distinguish these animals from Mammals are the composite lower which is covered externally by the dentary bone along its whole length, and the resence of the pre-frontal, post-frontal, and transverse bones in the skull.


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