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A history of the Xhosa, c1700-1835

- Peires, J B (Jeffrey B)

Authors: Peires, J B (Jeffrey B)
Date: 1977
Subjects: Xhosa (African people) -- History
Language: English
Type: text , Thesis , Masters , MA
Identifier: vital:2611 , http://hdl.handle.net/10962/d1013024
Description: The boundaries of the territory occupied by the Xhosa fluctuated considerably, but in the period 1700-1835 they did not often extend west of the Sundays River, or east of the Mbashe River, along the coastal strip which separates the escarpment of South Africa's inland plateau from the Indian Ocean. It is an area of temperate grassland, permitting the cultivation of cereals and light crops, such as maize, millet, tobacco and pumpkins but better suited to stock-farming than intensive agriculture.
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Date Issued: 1977

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The biology of Clarias Gariepinus (Burchell, 1822) in Lake Sibaya, Kwazulu, with emphasis on its role as a predator

- Bruton, Michael N

Authors: Bruton, Michael N
Date: 1977
Subjects: Catfishes -- South Africa -- KwaZulu-Natal -- Lake Sibaya. , Clarias , Clariidae
Language: English
Type: text , Thesis , Doctoral , PhD
Identifier: vital:5886 , http://hdl.handle.net/10962/d1013313
Description: Aspects of the biology of the sharptooth catfish, Clarias gariepinus (Burchell, 1822) were studied in a clear coastal lake (Lake Sibaya, KwaZulu.). Catfish reach maturity towards the end of the first year (total length 200-250mm) and breed in summer. Gonadal maturation is cyclical, and most fishes are ripe between September. and January e ach year. Maturation stages and fecundity are described. Twenty-two catfish spawning runs were witnessed. There were no large aggregations of catfish before the Summer rains, as reported in some impoundments and rivers, but catfish accumulated on the shallow terrace immediately before a spawning run. Spawning usually took place in flooded marginal areas after heavy rain on dark calm nights. Peak activity occurred between 20h00 and 02h30. Pre-nuptial aggression, courtship and mating are described and illustrated in detail for the first time from field observations. Gonadal products are released while in amplexus and fertilized externally. The eggs have an adhesive disc for attachment to plants, and develop rapidly. Early development and feeding are described. The growth rate of catfish was determined using rings on the pectoral spines, and validated using recent techniques. C.gariepinus in Lake Sibaya grow rapidly and remain in good condition to a length of 500mm, but larger catfish have a poor growth rate and condition, and few exceed 650mm. The modal length and weight of the Sibaya population is intermediate between that of other populations but the number and condition of larger catfish in Lake Sibaya is lower. Other studies on C.gariepinus growth are reviewed. Very high and low first year increments obtained previously may be due to methodological errors, but catfish do appear to have variable growth rates. The size reached by C.gariepinus is reviewed. Catfish are equipped morphologically and behaviourally to feed on a wide variety of·prey in different situations, but they usually feed at night on exposed, active benthic organisms. Social hunting facilitates the capture of prey which is too fast or manoevrable for a single predator. Food preferences are scored by three different methods and presented for the total catfish population and for different length groups, seasons, and habitats. Juveniles feed more often and on a greater variety of prey, and their condition is better than that of adults. The proportions of several food items in the diet changed at different lake levels as marginal areas became inundated. In particular, increasing lake levels resulted in a change in relative density of three cichlid prey in the shallow water feeding area of catfish. This situation provided the opportunity to study the effect of changing cichlid density on predation by catfish. The world literature on factors influencing the predator-prey relationship in fish is reviewed and several key factors are identified. The interaction of fish predators and prey in Africa, and particularly Lake Sibaya, is examined in detail, and prey density, modified by accessibility, is found to be an important factor. The effect of cichlid prey density on catfish predation was therefore investigated using field collections and experimental observations. Catfish prey on the cichlid species with greatest relative abundance, with some deviations which can be explained in terms of accessibility. The experimental results also describe feeding periodicity, imitative hunting and the effect of water depth , day-night light intensity changes and predator number on predation efficiency on cichlids. Catfish predation is discussed in terms of recent predation theory, and it is concluded that their ability to switch from one prey to another as prey availability (= density+ accessibility) changes , is an an important aspect of their success as predators. Catfish predate more efficiently on invertebrates, but feed largely on fishes after the first year. This preference for fish prey is probably related to food quality, as fishes contributed over 75% of the energy content of all ingested food, as well as abundant protein and the correct amino acid balance. Finally, I conclude that the role of C.gariepinus as a predator on S.mossambicus is three-fold: (a) to enhance species' fitness by removing enfeebled individuals i.e. to act as a 'cleanser' (b) to restrict the distribution of prey under certain conditions i.e. act as a 'restricter' (c) to dampen fluctuations in cichlid abundance i.e. act as a 'regulator'. The relative importance of these roles may alter at different lake levels in Lake Sibaya in response to changes in the vulnerability of fish prey.
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Date Issued: 1977

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The structure of aliphatic amine adducts of uranyl acetylacetonate. II. Dioxobis(2,4-pentanedionato)mono (2-N,N-dimethylaminopentan-4-one)uranium(VI)

- Nassimbeni, L R, Orpen, G, Pauptit, R A, Rodgers, Allen L, Haigh, John M

Authors: Nassimbeni, L R , Orpen, G , Pauptit, R A , Rodgers, Allen L , Haigh, John M
Date: 1977
Language: English
Type: text , Article
Identifier: vital:6416 , http://hdl.handle.net/10962/d1006533
Description: Introduction: In a previous analysis of a compound of this type, we have established that the adduct molecule is bonded through O and that the geometry about U is pentagonal bipyramidal (Haigh, Nassimbeni, Pauptit, Rodgers & Sheldrick, 1976). We have carried out the present analysis to study the conformational effects on the ligand brought about by substitution at N.
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Date Issued: 1977

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The structure of aliphatic amine adducts of uranyl acetylacetonate. III. Dioxobis(2,4-pentanedionato)mono (2-N-isopropylaminopentan-4-one)uranium(VI)

- Rodgers, A L, Nassimbeni, L R, Haigh, John M

Authors: Rodgers, A L , Nassimbeni, L R , Haigh, John M
Date: 1977
Language: English
Type: text , Article
Identifier: vital:6419 , http://hdl.handle.net/10962/d1006552
Description: Introduction: In two earlier structural determinations of compounds of this type we have shown that the conformation of the adduct moiety is dependent on the formation of intramolecular N-H...0 hydrogen bonds (part I: Haigh, Nassimbeni, Pauptit, Rodgers & Sheldrick, 1976; part II: Nassimbeni, Orpen, Pauptit, Rodgers & Haigh, 1977). We have carried out the present analysis to study the conformational effects on the ligand brought about by the steric influence of an isopropyl substituent at N.
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Date Issued: 1977

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The structure of aliphatic amine adducts of uranyl acetylacetonate. IV. Dioxobis(2,4-pentanedionato) mono(2-aminopentan-4-one)uranium(VI)

- Rodgers, A L, Nassimbeni, L R, Pauptit, R A, Orpen, G, Haigh, John M

Authors: Rodgers, A L , Nassimbeni, L R , Pauptit, R A , Orpen, G , Haigh, John M
Date: 1977
Language: English
Type: text , Article
Identifier: vital:6420 , http://hdl.handle.net/10962/d1006555
Description: Introduction: We have shown in three earlier determinations of aliphatic amine adducts of U02(AA)2 (part I: Haigh, Nassimbeni, Pauptit, Rodgers & Sheldrick, 1976; part II: Nassimbeni, Orpen, Pauptit, Rodgers & Haigh, 1977; part III: Rodgers, Nassimbeni & Haigh, 1977) that the conformation of the adduct is dependent on its ability to form hydrogen bonds. The present compound has two H atoms available for hydrogen bonding and may be regarded as the parent of the series.
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Date Issued: 1977

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The right to strike: 10th anniversary of Armourplate strike, 6th September 1976

- Chemical Workers Industrial Union

Authors: Chemical Workers Industrial Union
Date: 1976-09-06
Subjects: Right to strike , Strikes and lockouts
Language: English
Type: text , pamphlet
Identifier: http://hdl.handle.net/10962/111269 , vital:33426
Description: In South Africa and throughout the world the working class is struggling to win the full right to strike. This booklet is published to commemorate the 10th anniversary of a landmark in this struggle under Apartheid. Ten years ago, on 6th September 1976, members of the Glass and Allied Workers Union at Armourplate went out on strike. The first legal strike by black workers. Although their brave struggle was not successful then, many lessons were learnt that have allowed victories to follow. Such lessons were put into practice in the Dunlop strike and the sit-ins covered in this booklet. The legal position of strikes is confusing and part of this booklet tries to clear this up. The present legal rights can be compared with our demands in the COSATU resolution.
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Date Issued: 1976-09-06

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Notes on South African gobies possessing free upper pectoral fin rays (Pisces--Gobiidae)

- Winterbottom, Richard, 1944-, Rhodes University. J.L.B. Smith Institute of Ichthyology

Authors: Winterbottom, Richard, 1944- , Rhodes University. J.L.B. Smith Institute of Ichthyology
Date: 1976-04
Subjects: Bathygobius fuscus , Bathygobius niger , Gobius saldanha , Monishia william , Fishes -- South Africa
Language: English
Type: text , book
Identifier: http://hdl.handle.net/10962/69792 , vital:29580 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 16 , This paper arose out of difficulties in identifying collections of gobies whose upper pectoral fin rays are silklike and partially or predominantly free of membrane. Four such species have been recorded from South Africa, but there has been considerable confusion over their identification . Various unreported characters were found useful in separating the species. Certain problems exist in separating J.L.B. Smith's type specimens from the general collection. He invariably separated one specimen (labelled as "type") which was stored in a special type cupboard. This occurred whether or not a holotype was actually designated in the original description. Thus, particularly in his earlier works where no holotype was designated, these specimens (for new species based on more than one specimen) are nomenclatorally syntypes. I will refer to such "type" specimens as "syntype (= putative lectotype)". The remaining specimens (either the rest of the syntypic series or, later, the paratypes) were returned to the general collection. Owing to space limitations, all specimens of the same species were, where possible, kept in a single large jar. Paper tags were sewn on to the specimens, giving locality and date of collection. These tags have an unfortunate tendency to disintegrate. Subsequent separation of syntypes and paratypes is, therefore, subject to error. Since in a syntypic series I am referring to a "putative lectotype", the remainder of such series will be called "syntypes (= putative paralectotypes)".
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Date Issued: 1976-04

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