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The dynamics of Themeda Triandra tillers in relation to burning in the natal Drakensberg
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: C.S. Everson --- Department of Environment Affairs, TheresaM. Everson --- Department of Environment Affairs, N.M. Tainton --- Department of Grassland Science,Marked tillers of Themeda triandra were sampled regularly over a two year period in Highland Sourveld burnt annually in winter, biennially in spring and after a single summer and early winter burning treatment. Parameters recorded were height of shoot apex,... -
The use of degradation gradients for the assessment and ecological interpretation of range condition
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: O.J.H. Bosch --- Department of Plant and Soil Sciences, Republic of South Africa H.G. Gauch --- Department of Soil, Crop and Atmospheric Sciences, United States of AmericaMultivariate procedures were used to subdivide the southern African climatic climax grasslands of the 700–800‐mm rainfall zone into relatively homogeneous grazing areas. A degradation gradient was constructed for each of these areas. This was done by means of centred PCA... -
A simple, accurate method of estimating maximum total evaporation from a wheat crop during the daylight period
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: W.H. van Zyl --- Department of Agrometeorology, Republic of South Africa J.M. de Jager --- Department of Agrometeorology, Republic of South Africa C.J. Maree --- Department of Agrometeorology, Republic of South AfricaThe use of empirical relationships for the calculation of the energy and aerodynamic components of the Penman-Monteith equation were tested against measured data. Accurate estimates of maximum total evaporation, Em, from a wheat crop were obtained. The empirical equation utilizes... -
Manipulation of acrotony in one-year-old apple shoots
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: N.C. Cook --- Department of Horticultural Science, Republic of South Africa K. Verhaegen --- , Belgium J. Keulemans --- , Belgium G. Jacobs --- Department of Horticultural Science, Republic of South AfricaUnbranched rooted layers of the rootstock Mailing 9 (M.9 clone Nie 29) ≈600 mm long were treated twice in autumn (4 and 13 October 1995) in the stoolbed as follows: a) non-treated control; b) the distal 300 mm of the... -
On the dynamics of demersal fish assemblages off Namibia in the 1990s
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: G. Bianchi H. Hamukuaya O. AlvheimDemersal fish surveys carried out off Namibia from 1990 to 2000 were used to study the dynamics of demersal fish assemblages on the shelf and upper slope. The study was performed on each major assemblage, i.e. over the shelf (100–300... -
POPULATION DYNAMICS AND DEMOGRAPHY OF AN ESTUARINE COPEPOD (PSEUDODIAPTOMUS EESSEI) IN LAKE SIBAYA, A SUBTROPICAL FRESHWATER COASTAL LAKE
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: RC Hart --- , South AfricaPopulation size and stage structure of Pseudodiaptomus hessei (Mrázek) was studied over 27 months at a single site in subtropical Lake Sibaya. Population density varied seasonally from about 1 to 4 individuals per litre, but a fairly stable population structure... -
RELATIVE FISH POPULATION DENSITY CHANGES IN THE P.K. LE ROUX DAM DURING THE FIRST THREE YEARS AFTER INUNDATION
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: I.G. Gaigher --- Department of Nature and Environmental Conservation, South Africa K. C.D. Hamman --- Department of Nature and Environmental Conservation, South Africa S.C. Thorne --- Department of Nature and Environmental Conservation, South AfricaBefore inundation in September 1976 Barbus holubi and Labeo capensis were the dominant species each making up 46% of the total catch. Immediately after impoundment the relative density of B. holubi increased to 75% while that of L. capensis dropped... -
PRODUCTION OF THE AFRICAN CATFISH (CLARIAS GARIEPINUS) I. GROWTH, MORTALITY AND YIELD SOUTH OF THE ZAMBEZI
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: Douglas Clay --- Marine Fish Division, Department of Fisheries and Oceans, CanadaClarias gariepinus were sampled from eight water bodies in southern Africa between 1973 and 1975. Aging results indicate a similar growth pattern for most areas with a near linear age-length relationship. Between year growth compensation was found to be present... -
EFFECT OF PROGRAMMED CIRCADIAN TEMPERATURE FLUCTUATIONS ON POPULATION DYNAMICS OF BULINUS TROPICUS (KRAUSS) AND LYMNAEA NATALENSIS KRAUSS (GASTROPODA: MOLLUSCA)
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: K.N. de Kock --- Department of Zoology, South AfricaUntil now all life-table studies on Bulinus tropicus (Krauss) and Lymnaea natalensis Krauss involving temperature as the variable factor have been conducted at constant temperatures. This study evaluates the effect of programmed, circadian temperature fluctuations, ranging from 18 to 28... -
EFFECT OF CONSTANT TEMPERATURE ON POPULATION DYNAMICS OF BULINUS TROPICUS (KRAUSS) AND LYMNAEA NATALENSIS KRAUSS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: K.N. de Kock --- Snail Research Unit of the South African Medical Resesrch Council, South Africa J.A. van Eeden --- Snail Research Unit of the South African Medical Resesrch Council, South AfricaLife-tables were compiled for cohorts of the two freshwater snail species Bulinus tropicus (Krauss) and Lymnaea natalensis Krauss at six different constant temperatures from 17 to 32 °C under identical conditions of crowding, feeding and chemical composition of the water... -
MODELS OF ECOSYSTEMS AND AQUATIC ENVIRONMENTS: DEVELOPMENT AND APPLICATION
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: B.R. Allanson --- , South AfricaAn historical treatment of a number of principal events is given. This leads to an assessment of the current research approach in hydrobiology and its success in the development of process orientated ecosystem component models. With the contemporaneous development of... -
A SYSTEM DYNAMICS MODEL OF PART OF THE PONGOLO RIVER FLOODPLAIN: DEVELOPMENT AND WATER MANAGEMENT POLICY ANALYSIS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: A.K. Drewes --- ,The issue of allowing the Liming, duration and magnitude of a flood release to be determined by man has led to a wide spectrum of viewpoints as to which values of these parameters are most suitable for the Pongolo River... -
APPLICATION OF LAVSOE, AN EUTROPHICATION MODEL, TO BLOEMHOF DAM
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: J.N. Rossouw --- ,In 1985 the Department of Water Affairs introduced an effluent phosphate standard of 1 mg l−1 (as P) in seven potentially sensitive catchments. Although this is an uniform standard, permits can be granted for effluents to exceed the standard in... -
FUTURE CHALLENGES IN WATER QUALITY MODELLING WITH PARTICULAR REFERENCE TO OPERATIONALLY CLOSED CATCHMENTS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: S.F. Forster --- Department of Water Affairs, South Africa F.A. Stoffberg --- Department of Water Affairs, South Africa J.A. van Rooyen --- Department of Water Affairs, South AfricaAs a result of the declining quality of many water sources, the use of water quality models in planning is increasing. To date applications have involved the simulation of total dissolved salts and nutrients, largely in catchments affected by urban... -
UNDERSTANDING THE PHYSICAL STRUCTURE OF SOUTHERN AFRICA'S STANDING WATERS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: B.R. Allanson --- , South AfricaAn examination of the nature of the stratification in polymictic and monomictic Southern African reservoirs is presented. Wind stirring is the principal mode of heat transfer during spring heating. In high summer radiation from stable heated surface layers is responsible... -
SUITABILITY OF TROPICAL FISH FOODS FOR LABORATORY CULTURE OF FOUR SPECIES OF FRESHWATER SNAILS ACTING AS INTERMEDIATE HOSTS FOR ECONOMICALLY IMPORTANT HELMINTH PARASITES IN SOUTH AFRICA
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: K.N. de Kock --- Department of Zoology, South Africa P.H. Joubert --- , South AfricaFour different kinds of tropical fish food from Tetra Werke, West Germany, as well as a mixture of two of these, were evaluated as possible nutrients for the laboratory culture and maintenance of four freshwater snail species of economic importance... -
CIRCULATION IN HIGHLY STRATIFIED SOUTHERN AFRICAN ESTUARIES
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: J.L. Largier --- , USA J.H. Slinger --- Council for Scientific and Industrial Research, South AfricaThe nature of estuarine circulation under highly stratified conditions is reviewed in the context of southern African estuaries that are small and have a constricted connection to the ocean. While the focus is on the generic hydrodynamic processes and features,... -
Patterns of seed production and shrub association in two palatable Karoo shrub species under contrasting land use intensities
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: S.W. ToddSeed production and shrub association patterns of the two palatable shrubs. Tripteris sinuatum and Tetragoma froticosa were investigated on heavily grazed communal and lightly grazed commercial rangeland in the succulent karoo, Namaqualand. Seed production in both these species was substantially... -
The distribution of sweetveld and sourveld in South Africa's grassland biome in relation to environmental factors
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: W.N. Ellery --- Department of Geographical and Environmental Sciences, Republic of South Africa R.J. Scholes --- CSIR, Republic of South Africa M.C. Scholes --- Centre for African Ecology, Department of Botany, Republic of South AfricaThe distribution of sweet‐ and sourveld in relation to climate, parent material and soil nutrients has been examined in South Africa's grassland biome. Sourveld occurs in areas with high water supply and where parent material gives rise to soils with... -
Transformation of a savanna grassland by drought and grazing
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: T.G. O'Connor --- , Republic of South AfricaThe relative effects of drought and heavy grazing on the floristic composition, population size and structure, and basal cover of an African savanna grassland were differentiated by comparing changes over eight years, which included a severe drought year, across a... -
Research note: The effect of a lactic acid bacterial inoculant on the fermentation dynamics of Eragrostis curvula during ensiling
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: R. Meeske --- , Republic of South Africa H.M. Basson --- , Republic of South AfricaMaking good quality hay from Eragrostis curvula is a risky operation in many areas in South Africa due mainly to unfavourable weather conditions. Ensiling should therefore be considered as an alternative method for conserving the forage. The aim of this... -
Perspective article: Simulation models for semi‐arid rangelands of southern Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: T. Wiegand --- Department of Ecological Modelling, Germany F. Jeltsch --- Department of Ecological Modelling, Germany S. Bauer --- Department of Ecological Modelling, Germany K. Kellner --- Department of Plant‐ and Soil Sciences, South AfricaIn semi‐arid regions, the effects of grazing or sparing management on natural communities of long‐lived plants generally take decades to become evident. Event‐driven dynamic behaviour, unpredictable and low rainfall, and complicated interactions between species make it difficult to gather sufficient... -
Community dynamics and phytomass of herbaceous species in the Sudaniansavanna-woodlands of Burkina Faso: short-term impact of burning season
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: SD Dayamba --- Tropical Silviculture and Seed Laboratory, Southern Swedish Forest Research Centre, Faculty of Forest Sciences, Sweden P Savadogo --- Tropical Silviculture and Seed Laboratory, Southern Swedish Forest Research Centre, Faculty of Forest Sciences, Sweden L Sawadogo --- Département Productions Forestières, Burkina Faso D Tiveau --- , République Démocratique du Congo D Zida --- Département Productions Forestières, Burkina Faso M Tigabu --- Tropical Silviculture and Seed Laboratory, Southern Swedish Forest Research Centre, Faculty of Forest Sciences, Sweden PC Oden --- Tropical Silviculture and Seed Laboratory, Southern Swedish Forest Research Centre, Faculty of Forest Sciences, SwedenFire is important for the maintenance and conservation of African savanna ecosystems, and prescribed fire is used in the Sudanian savanna-woodlands of West Africa as a forest management tool. Yet, the effects of fire on savanna ecosystems and especially on... -
Wood supply and forest regeneration consequences of integrated log allocation in western Kenya
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: GilbertO. Ototo DonaldO. OgwenoThe present system of log sales from softwood plantations in Kenya is by stumpage to single product mills. This harvesting system leads to pulping of large diameter logs while allocation of small diameter logs to sawmills is a major cause... -
Optimising Nursery Operation Schedules with Multiperiod Linear Programming
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: RudolfJanse van Rensburg --- Department of Forest Science, South Africa BrianV. Bredenkamp --- Department of Forest Science, South AfricaA dynamic multiperiod linear programming model which addresses nursery scheduling is presented. Due to its dynamic nature, it provides a means to manage risks and uncertainties such as disease, rootstrike, germination and fluctuating demands. By optimising the whole production process,... -
Longitudinal Predictive Validity of a Learning Potential Test
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Marié de Beer --- University of South Africa,The aim of this article is to provide empirical psychometric evidence of the (longitudinal) predictive validity of a learning potential measure—the Learning Potential Computerised Adaptive Test (LPCAT)—in comparison with standard static tests with school aggregate results as the criterion measure... -
A Modern Assessment Psychometric Approach to Dynamic Assessment
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Marié de Beer --- University of South Africa,Although dynamic assessment (DA) has been hailed as a positive move towards fair assessment, it has generally not been used in educational or industry settings to the same extent that standard (static) tests have been. The present article attempts to... -
Combining Leadership Theory with a Psychodynamic Perspective to Explain the Functioning of a Management Team
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: René van Eeden --- University of South Africa,This article illustrates how the processes and dynamics in a management team at a South African organization reflect the leadership and personality profiles of the members of the team. Participants were the 12-member management team (including the general manager). The... -
Treating Anti-social Behavior in Adolescents: A Comparison of Multi-modal and Psychodynamic Oriented Group Interventions
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Abigail Olubola Taiwo --- University of Ibadan, Nigeria Helen Ohiokhafe Osinowo --- University of Ibadan, NigeriaThis study compared the efficacy of a multimodal intervention (MMI) and a psychodynamic oriented group intervention (POGI) on antisocial behavior among Nigerian adolescents. A pretest-posttest design was used. Forty-one adolescents drawn from the streets of a Nigerian city (N =20),... -
The Marikana Violence in South Africa: A Brief Psychodynamic Extrapolation
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Humphrey Siphiwe B. Ngcobo --- University of Zululand, South Africa Stephen D. Edwards --- University of Zululand, South Africa David J. Edwards --- University of Zululand, South AfricaThis study applies psychoanalytic concepts in making sense of the individual, group and collective factors that may have contributed towards the Marikana violence. Speculatively, individual factors might include the death instinct, repetition compulsion, and intra-psychic splitting. Related group dynamics such... -
Approximate Conserved Quantities of Conservative Dynamical Systems in R 3
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: G. Ünal C.M. KhaliqueApproximate generalized symmetries associated with the resonances of conservative dynamical systems in R 3 have been discussed. It has been shown that an approximate first integral (conserved quantities) can be found from the knowledge of two conservative approximate symmetries. Furthermore,... -
Approximate First Integrals of a Chaotic Hamiltonian System
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: G. Ünal C.M. Khalique G.F. AlişverişçiApproximate first integrals (conserved quantities) of a Hamiltonian dynamical system with two-degrees of freedom which arises in the modeling of galaxy have been obtained based on the approximate Noether symmetries for the resonance ω 1 = ω 2. Furthermore, Kolmogorov-Arnold-Moser... -
OPTIMAL SYSTEMS OF SYMMETRY SUBALGEBRAS FOR BIG MODELS OF GASDYNAMICS
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: S. V. Khabirov --- Institute for Symmetry Analysis and Mathematical Modelling, University of North-West, Mmabatho, South Africa,The gasdynamics equations admit 11 dimensional Lie algebra of transformations for the abitrary state equations. For special state equations the algebra may be expanded. There are 13 special state equations for which the gasdynamics equations are named big models. Some... -
Bereavement, silence and culture within a peer-led HIV/AIDS-prevention strategy for vulnerable children in South Africa
Item type: Journal Article • Journal: African Journal of AIDS Research • Authors: Ingrid Van der Heijden --- Child, Youth, Family and Social Development Research Programme, South Africa Sharlene Swartz --- Child, Youth, Family and Social Development Research Programme, South AfricaIn addressing the psychosocial effects of the HIV and AIDS pandemic among vulnerable children, the issue of bereavement appears inadequately addressed. Amid the global discourse on children orphaned and made vulnerable by HIV and AIDS, this paper explores how cultural... -
Phytoplankton responses to changes in macrophyte density in a tropical artificial pond in Zaria, Nigeria
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: AM Chia --- Department of Biological Sciences, Nigeria DN Iortsuun --- Department of Biological Sciences, Nigeria BJ Stephen --- Department of Biological Sciences, Nigeria AE Ayobamire --- Department of Biological Sciences, Nigeria Z Ladan --- , NigeriaThe response of phytoplankton population dynamics to changes in densities of Nymphaea lotus L. and Polygonum limbatum Meisn. was studied in an artificial pond in Zaria, Nigeria, from June to November 2007. Antagonistic effects of these macrophytes on Netrium sp.,... -
Use of a small, intermittently-open estuary by waterbirds: a case study of the East Kleinemonde Estuary, Eastern Cape, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: AI Terörde --- Percy FitzPatrick Institute of African Ornithology, South Africa JK Turpie --- , South AfricaLittle is known of the use and importance of South African small, intermittently-open estuaries to waterbirds. Waterbird activities were monitored in a section of the East Kleinemonde Estuary on the south-east coast of South Africa from June 2004 to May... -
Ostrich recruitment dynamics in relation to rainfall in the Mara–Serengeti ecosystem
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: JosephO Ogutu --- Institute of Crop Science, Germany Hans-Peter Piepho --- Institute of Crop Science, Germany HollyT Dublin --- Species Survival Commission, International Union for Conservation of Nature and Natural Resources, c/o Centre for Biodiversity Conservation, South AfricaAnimal population dynamics can be driven by rainfall variability through its influence on habitat suitability, availability and nutritional sufficiency of forage. To understand how rainfall influences ostriches, we related changes in ostrich recruitment in the Mara–Serengeti ecosystem to rainfall. Over... -
MODELS OF ECOSYSTEMS AND AQUATIC ENVIRONMENTS: DEVELOPMENT AND APPLICATION
Item type: Journal Article • Journal: Southern African Journal of Child and Adolescent Mental Health • Authors: B.R. Allanson --- , South AfricaAn historical treatment of a number of principal events is given. This leads to an assessment of the current research approach in hydrobiology and its success in the development of process orientated ecosystem component models. With the contemporaneous development of... -
A SYSTEM DYNAMICS MODEL OF PART OF THE PONGOLO RIVER FLOODPLAIN: DEVELOPMENT AND WATER MANAGEMENT POLICY ANALYSIS
Item type: Journal Article • Journal: Southern African Journal of Child and Adolescent Mental Health • Authors: A.K. Drewes --- ,The issue of allowing the timing, duration and magnitude of a flood release to be determined by man has led to a wide spectrum of viewpoints as to which values of these parameters are most suitable for the Pongolo River... -
APPLICATION OF LAVSOE, AN EUTROPHICATION MODEL, TO BLOEMHOF DAM
Item type: Journal Article • Journal: Southern African Journal of Child and Adolescent Mental Health • Authors: J.N. Rossouw --- ,In 1985 the Department of Water Affairs introduced an effluent phosphate standard of 1 mg l−1 (as P) in seven potentially sensitive catchments. Although this is an uniform standard, permits can be granted for effluents to exceed the standard in... -
FUTURE CHALLENGES IN WATER QUALITY MODELLING WITH PARTICULAR REFERENCE TO OPERATIONALLY CLOSED CATCHMENTS
Item type: Journal Article • Journal: Southern African Journal of Child and Adolescent Mental Health • Authors: S.F. Forster --- Department of Water Affairs, South Africa F.A. Stoffberg --- Department of Water Affairs, South Africa J.A. van Rooyen --- Department of Water Affairs, South AfricaAs a result of the declining quality of many water sources, the use of water quality models in planning is increasing. To date applications have involved the simulation of total dissolved salts and nutrients, largely in catchments affected by urban... -
Dynamics of the Fishery for Galjoen Dichistius Capensis, With an Assessment of Monitoring Methods
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: C. G. AttwoodThe dynamics of the fishery for galjoen Dichistius capensis were investigated at four sites in South Africa from 1987 to 2000. At three sites, which were protected from fishing, Koppie Alleen, Lekkerwater (both in the De Hoop Marine Protected Area)... -
Population Dynamics of the Wandering Albatross Diomedea Exulans at Marion Island: Longline Fishing and Environmental Influences
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: D. C. Nel F. Taylor P. G. Ryan J. CooperThe subantarctic Prince Edward Islands (Marion and Prince Edward) support the largest breeding population of the Vulnerable wandering albatross Diomedea exulans. The number of birds breeding at Marion Island has fluctuated over the past three decades apparently as a result... -
Modelling stock dynamics in the southern Benguela ecosystem for the period 1978–2002
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: L. J. Shannon V. Christensen C. J. WaltersAn ecosystem model of the southern Benguela was fitted to available time-series data for the period 1978–2002, to explore how changes in target fish populations in this ecosystem can be attributed to feeding interaction terms and population control patterns, the... -
Temporal and spatial variability in the characteristics of Alexandrium fundyense blooms in the coastal zone of the Bay of Fundy, eastern Canada
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: FH Page JL Martin A Hanke MM LeGresleyThe abundance of the dinoglagellate Alexandrium fundyense has been monitored at four locations in the Bay of Fundy, eastern Canada, at weekly to monthly intervals since 1988. The date of first appearance of A. fundyense varied each year from Day... -
Comparative trophodynamics of anchovy Engraulis encrasicolus and sardine Sardinops sagax in the southern Benguela: are species alternations between small pelagic fish trophodynamically mediated?
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: CD van der Lingen L Hutchings JG FieldThe results of detailed morphological, experimental, field and modelling studies on various aspects of the trophic ecology of sardine Sardinops sagax and anchovy Engraulis encrasicolus in the Benguela ecosystem are synthesised, and differences in the trophodynamics of these two species... -
Analysing environmental and fishing effects on a short-lived species stock: the dynamics of the octopus Octopus vulgaris population in Senegalese waters
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M Thiaw --- , Sénégal D Gascuel --- , France D Thiao --- , Sénégal OT Thiaw --- , Sénégal D Jouffre --- , SénégalShort-lived species are extremely dependent on the seasonal and interannual variability of environmental conditions, and determining their stock status is often difficult. This study investigates the effects of environmental variability and fishing pressure on the stock of octopus Octopus vulgaris... -
The Marine Mammal Programme at the Prince Edward Islands: 38 years of research
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MN Bester --- Department of Zoology and Entomology, University of Pretoria, South Africa PJN de Bruyn WC Oosthuizen CA Tosh T McIntyre RR Reisinger M Postma DS van der Merwe M WegeThe Marine Mammal Programme (MMP) conducts research on pinnipeds and killer whales Orcinus orca at Marion Island, Prince Edward Islands, under the auspices of the Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria. The history of the... -
A review of the Oceanographic Research Institute's Cooperative Fish Tagging Project: 27 years down the line
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SW Dunlop --- , South Africa BQ Mann --- , South Africa RP van der Elst --- , South AfricaThe Oceanographic Research Institute's (ORI) Cooperative Fish Tagging Project was initiated in 1984 and is one of the most enduring and successful environmental projects of its kind in South Africa. By the end of 2011, 5 130 anglers had joined... -
A bootstrap method for estimating bias and variance in statistical fisheries modelling frameworks using highly disparate datasets
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: BÞ Elvarsson --- Science Institute, Iceland L Taylor --- Science Institute, Iceland VM Trenkel --- Ifremer [French Research Institute for the Exploitation of the Sea], France V Kupca --- HPC2N [High Performance Computing Center North], Umeå University, Sweden G Stefansson --- Science Institute, IcelandStatistical models of marine ecosystems use a variety of data sources to estimate parameters using composite or weighted likelihood functions with associated weighting issues and questions on how to obtain variance estimates. Regardless of the method used to obtain point... -
Stand structure and regeneration of harvested Araucaria araucana–Nothofagus stands in central Chile
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Rafael M Navarro-Cerrillo --- DendrodatLab, Departamento de Ingeniería Forestal, Spain Fernando Olave --- Corporación Nacional Forestal, Chile Francisco Moreno --- DendrodatLab, Departamento de Ingeniería Forestal, Spain Sergio de Miguel --- Faculty of Science and Forestry, Finland Margarita Clemente --- Departamento de Ciencias y Recursos Agrícolas y Forestales, SpainIn this study we examined the current structure and regeneration status of mixed Araucaria araucana–Nothofagus spp. stands that had been logged 20 years ago. We measured stand density of saplings, juvenile and adult trees, as well as stand basal area... -
Comparing internal and external drivers in the southern Benguela and the southern and northern Humboldt upwelling ecosystems
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: LJ Shannon S Neira M TaylorTrophic models of three upwelling ecosystems, the southern Benguela (South African), southern Humboldt (Chilean) and northern Humboldt (Peruvian) systems, have been fitted to catch, abundance and fishing mortality time-series. Three drivers were considered during the model fitting: internal forcing by... -
Achievements and lessons learned from the Benguela Environment, Fisheries, Interaction and Training (BENEFIT) research programme
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: I Hampton N SweijdThis paper considers the scientific achievements of the Benguela Environment, Fisheries, Interaction and Training (BENEFIT) Programme as reflected in 29 internally evaluated BENEFIT research projects carried out between 1998 and 2007 when the programme ended, and draws a number of... -
The impact of indigenous ungulate herbivory over five years (2004–2008) on the vegetation of the Little Karoo, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: MT Hoffman --- Plant Conservation Unit, Botany Department, South Africa CF Madden --- Plant Conservation Unit, Botany Department, South Africa K Erasmus --- Sanbona Wildlife Reserve, South Africa N Saayman --- Department of Agriculture: Western Cape, South Africa JC Botha --- Department of Agriculture: Western Cape, South AfricaThis study investigated the impact of rainfall and herbivory by indigenous herbivores over five years (2004–2008) on the vegetation of the Sanbona Wildlife Reserve (SWR), a 54 000 ha privately owned conservation area in the Little Karoo. Changes in floristic... -
Dynamics of woody vegetation in a semi-arid savanna, with a focus on bush encroachment
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: M-L Britz D WardIncreases in the tree: grass ratio with accompanying changes in herbaceous composition, called bush or shrub encroachment, is a worldwide phenomenon in savanna regions. Although heavy grazing by livestock is often believed to be the cause, it is clear that... -
Feynman's Electromagnetic Fields Induced by Moving Charges and the Existence and Uniqueness of Solutions to the N-Body Problem of Electrodynamics
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: VictorM. Bogdan --- Department of Mathematics, USAGiven n charges interacting with each other according to Feynman's law. Let (r j (t), v j (t)) denote the position and velocity of the charge q j . The list y(t) of all such vectors is... -
Historic and recent (2006) state of mangroves in small estuaries from Mlalazi to Mtamvuna in KwaZulu-Natal, South Africa
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: A Rajkaran --- Botany Department, South Africa J Adams --- Botany Department, South Africa R Taylor --- , South AfricaThe new forest type classification considers mangroves to be the rarest and most threatened of forest types in South Africa. The aim of this study was to determine the change in distribution and the current population and community structure of... -
The intubating laryngeal mask produces less heart rate response to intubation than conventional laryngoscopy
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: NR Evans --- Department of Anaesthesia, South Africa MFM James --- Department of Anaesthesia, South AfricaWe compared heart rate and blood pressure changes to intubation produced by conventional laryngoscopic-guided intubation to those produced by blind intubation through the intubating laryngeal mask (ILM) in normotensive adults with normal airways. Forty paralysed, anaesthetised adults undergoing elective surgery... -
Attenuation of the haemodynamic response to placement of the Mayfield skull pin head holder: alfentanil versus scalp block
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: FJ Smith --- Department of Anaesthesiology, Faculty of Medicine, South Africa CJ van der Merwe --- Department of Anaesthesiology, Faculty of Medicine, South Africa PJ Becker --- Unit for Biostatistics, South AfricaIntroduction: Application of the Mayfield clamp causes a significant haemodynamic response. Different methods have been used to attenuate this response. We compared two of these methods, namely alfentanil bolus (Group A) and nerve block of the scalp (Group B). METHOD:... -
Sevoflurane or halothane with target-controlled sufentanil infusions for coronary artery bypass surgery
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: AI Levin --- Department of Anesthesiology and Critical Care, Faculty of health Sciences, JF Coetzee --- Department of Anesthesiology and Critical Care, Faculty of health Sciences, M Coetzer --- , AR Coetzee --- Department of Anesthesiology and Critical Care, Faculty of health Sciences,Objectives -
Safety of pain control with morphine: new (and old) aspects of morphine pharmacokinetics and pharmacodynamics
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: JF Coetzee --- Department of Anesthesiology and Critical Care,Background: A 26-year-old, 59 kg female was administered morphine 10 mg during tonsillectomy, and 5 mg in the recovery room. She died 5 hours after the operation. Hypoxic cerebral injury, arising from morphine side-effects, was pronounced the cause of death,... -
Observational study of choice of anaesthesia and outcome in patients with severe pre-eclampsia who present for emergency Caesarean section
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: K Keerath --- King Edward VIII Hospital, L Cronje --- King Edward VIII Hospital,Objectives: Recent evidence in the literature suggests that regional anaesthesia may be the preferred choice over general anaesthesia for patients with severe pre-eclampsia who present for a Caesarean section. This study was conducted to determine if this applied to our... -
Haemodynamic and anaesthetic advantages of dexmedetomidine
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: SH Rao --- Department of Anaesthesia and Critical Care, India B Sudhakar --- Department of Anaesthesia and Critical Care, India PK Subramanyam --- Department of Anaesthesia and Critical Care, IndiaObjectives: The aim of this study was to describe the effect of dexmedetomidine on haemodynamic stability in the intraoperative period, as well as on the pressor response to intubation and extubation and the requirement of inhalation anaesthetics and recovery. -
Perioperative effect of epidural dexmedetomidine with intrathecal bupivacaine on haemodynamic parameters and quality of analgesia
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: D Jain --- Department of Anaesthesiology and Intensive Care, India RM Khan --- Department of Anaesthesiology, Oman D Kumar --- Department of Medicine, India N Kumar --- Department of Anaesthesiology and Intensive Care, IndiaBackground: The present study was a randomised controlled trial designed to evaluate the perioperative effect of epidural dexmedetomidine, in conjunction with intrathecal bupivacaine. -
Strategies for the Prevention and Containment of Antibiotic Resistance
Item type: Journal Article • Journal: South African Family Practice • Authors: SY Essack --- School of Pharmacy and Pharmacology, University of Kwazulu-Natal,Antibiotic resistance may emerge by antibiotic selection pressure but is perpetuated by diverse risk factors and maintained within environments as a result of poor infection control. Population-specific drug pharmacokinetics and pharmacodynamics also play a role. The WHO, US, UK and... -
Drug interactions in primary health care in the George subdistrict, South Africa: a cross-sectional study
Item type: Journal Article • Journal: South African Family Practice • Authors: PA Kapp --- Knysna Provincial Hospital, University of Stellenbosch, AC Klop --- Department of Family Medicine and Primary Care, LS Jenkins --- Head of Unit,Objectives: To investigate the prevalence of potential drug-drug interactions in primary healthcare clinics in the George subdistrict, to determine which drugs were involved, and to identify associated risk factors. -
Hearing loss within a marriage: perceptions of the spouse with normal hearing
Item type: Journal Article • Journal: South African Family Practice • Authors: NG Govender --- Discipline of Audiology, N Maistry --- Discipline of Audiology, N Soomar --- Discipline of Audiology, J Paken --- Discipline of Audiology,Objective: The objective of the study was to determine the perceptions of a spouse about the influence of his or her partner's hearing loss on their relationship as it may have an impact on aural rehabilitation. -
Depression as a Creative Illness: A South African Case Study
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Humphrey Ngcobo --- University of Zululand, South Africa Stephen Edwards --- University of Zululand, South AfricaThis case study presents a cultural perspective to supporting health and wellbeing in a young South African adult with depression and unresolved paternity issues. Issues around cultural identity appeared to influence the experience of depression and addressing the identifying aspects... -
Temporal and spatial variability in the abundance, biomass and distribution of Palaemon peringueyi (Decapoda: Crustacea) are influenced by biological but not physico-chemical factors in the permanently open Kariega Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: NP Nyalungu --- South African National Parks, Cape Research Centre, South Africa AN Hodgson --- Department of Zoology and Entomology, South Africa PW Froneman --- Department of Zoology and Entomology, South Africa M Dopolo --- South African National Parks, Cape Research Centre, South Africa M Masubelele --- South African National Parks, Cape Research Centre, South AfricaBiological and physico-chemical factors affecting abundance and biomass of shrimp Palaemon peringueyi were investigated in 2010–2011 in the lower, middle and upper reaches of the freshwater-deprived permanently open Kariega Estuary. Shrimp abundance and biomass ranged from 0 to 88 ind... -
The Mollusca inhabiting rice fields in northern Cameroon and their role as intermediate hosts for schistosomes
Item type: Journal Article • Journal: African Zoology • Authors: A. Ndassa --- General Biology Laboratory, Faculty of Science, Cameroon R. Mimpfoundi --- General Biology Laboratory, Faculty of Science, CameroonA systematic account is given of the freshwater gastropod and bivalve fauna of Ouro-Doukoudje, northern Cameroon, based on a survey conducted from July 2000 to June 2001 at 12 sites in rice fields spanning 800 ha. In total, 14 species... -
Aspects of the biology and ecology of the estuarine cirolanid isopod, Cirolana fluviatilis
Item type: Journal Article • Journal: African Zoology • Authors: Brent K. Newman --- Department of Zoology, South Africa Tristram H. Wooldridge --- Department of Zoology, South Africa Andy C. Cockcroft --- Department of Environmental Affairs and Tourism, Marine and Coastal Management Branch, South AfricaTrends in the distribution, population dynamics and reproductive biology of the estuarine cirolanid isopod, Cirolana fluviatilis, were investigated over a 12-month period in the warm–temperate Gamtoos River Estuary, by means of baited traps. Tolerance of adult isopods to combinations of... -
Ecological conditions for spread of the invasive snail Physa marmorata (Pulmonata: Physidae) in the Ivory Coast
Item type: Journal Article • Journal: African Zoology • Authors: Y. K. Bony --- Université de Perpignan, France N. C. Kouassi --- Station de Recherche en Pisciculture, CNRA, Ivory Coast D. Diomandé --- Université d’Abobo-Adjamé, Ivory Coast G. Gourene --- Université d’Abobo-Adjamé, Ivory Coast M. Verdoit-Jarraya --- Université de Perpignan, France J. P. Pointier --- Université de Perpignan, FrancePhysa marmorata, originally described from the Lesser Antilles, was introduced into Africa before 1900 and has previously been reported from Bénin, Togo, Ghana, Nigeria and South Africa. Here we show that it is also common in temporary ponds, fish ponds,... -
Flocking dynamics and roosting behaviour of Meyer’s parrot (Poicephalus meyeri) in the Okavango Delta, Botswana
Item type: Journal Article • Journal: African Zoology • Authors: Rutledge S. Boyes --- University of KwaZulu-Natal, South Africa Michael R. Perrin --- University of KwaZulu-Natal, South AfricaFor most of the year, Meyer’s parrots in the Okavango Delta do not form large feeding flocks, and groups larger than two or three are probably the result of opportunistic aggregation at favoured food items after dispersion from communal roosts... -
Freshwater snail distribution related to environmental factors in Banco National Park, an urban reserve in the Ivory Coast (West Africa)
Item type: Journal Article • Journal: African Zoology • Authors: I.A. Camara --- Laboratoire d’Environnement et de Biologie Aquatique, Université d’Abobo-Adjamé, Y.K. Bony --- Laboratoire d’Environnement et de Biologie Aquatique, Université d’Abobo-Adjamé, D. Diomandé --- Laboratoire d’Environnement et de Biologie Aquatique, Université d’Abobo-Adjamé, O.E. Edia --- Laboratoire d’Environnement et de Biologie Aquatique, Université d’Abobo-Adjamé, F.K. Konan --- Laboratoire d’Environnement et de Biologie Aquatique, Université d’Abobo-Adjamé, C.N. Kouassi --- Centre National de Recherche Agronomique (CNRA), Programme Pêche et Aquaculture Continentales (PAC), G. Gouréne --- Laboratoire d’Environnement et de Biologie Aquatique, Université d’Abobo-Adjamé, J.P. Pointier --- Centre de Biologie et d’Ecologie Tropicale et Méditerranéenne, USR 3278 CNRS-EPHE, Université de Perpignan,Freshwater snails and environmental variables were studied at seven stations along the Banco River (Ivory Coast;West Africa) from March to October 2008. Two species (Physa marmorata (Physidae) and Bulinus forskalii (Planorbidae) were recorded only at one sampling site. This station... -
Reducing the overall HIV-burden in South Africa: is ‘reviving ABC’ an appropriate fit for a complex, adaptive epidemiological HIV landscape?
Item type: Journal Article • Journal: African Journal of AIDS Research • Authors: Christopher J Burman --- The Rural Development and Innovation Hub, South Africa Marota Aphane --- The Rural Development and Innovation Hub, South Africa Peter Delobelle --- School of Public Health, South AfricaThis article questions the recommendations to ‘revive ABC (abstain, be faithful, condomise)’ as a mechanism to ‘educate’ people in South Africa about HIV prevention as the South African National HIV Prevalence, Incidence and Behaviour Survey, 2012, suggests. We argue that... -
Experiences of young adult women with emotionally absent fathers
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Emené Peyper --- School of Psychosocial Behavioural Sciences: Psychology, South Africa Werner de Klerk --- School of Psychosocial Behavioural Sciences: Psychology, South Africa Ruan Spies --- School of Psychosocial Behavioural Sciences: Psychology, South AfricaThis study explored the experiences of young adult women (n = 11) who grew up with emotionally absent fathers. The women (White: Afrikaans) were between the ages of 20 and 31 (5 were married, 1 was engaged, 1 was in... -
Impact of marine inundation after a period of drought on the lakeshore vegetation of Lake St Lucia, South Africa: resilience of estuarine vegetation
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: EJJ Sieben --- Department of Plant Sciences, South Africa WN Ellery --- Department of Geography, South Africa BW Dullo --- Center for Energy and Environmental studies, The Netherlands AP Grootjans --- Center for Energy and Environmental studies, The NetherlandsThe shore of Lake St Lucia in the vicinity of Catalina Bay, in the southern part of the lake, receives freshwater input as surface and groundwater seepage from the adjacent elevated coastal plain. Vegetation, water quality and landform were recorded... -
Seasonal and genotypic variation of water-soluble polysaccharide content in leaves of Cyclocarya paliurus
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Xiangxiang Fu --- Co-Innovation Center for Sustainable Forestry in Southern China, China Xiaodong Zhou --- Co-Innovation Center for Sustainable Forestry in Southern China, China Bo Deng --- Co-Innovation Center for Sustainable Forestry in Southern China, China Xulan Shang --- Co-Innovation Center for Sustainable Forestry in Southern China, China Shengzuo Fang --- Co-Innovation Center for Sustainable Forestry in Southern China, ChinaCyclocarya paliurus (Batal) Iljinskaja is an important medicinal woody plant due to numerous bioactive natural products in its leaves. As an important bioactive natural product, water-soluble polysaccharides (WSP) in leaves of C. paliurus possess diverse biological activities, such as hypoglycemic,... -
The effects of stock size and environmental variability on Cape hake recruitment in Namibia: an unsolved puzzle (a comment on Kainge et al. 2013)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: J-P Roux --- Lüderitz Marine Research, Namibia MR Wilhelm --- Marine Science Institute, USAMeasuring and forecasting recruitment are central to the understanding and management of fish stocks. Kainge et al. (2013) studied the effect of spawning stock size and environmental fluctuations on the recruitment levels of the Cape hake Merluccius capensis in Namibia... -
Diet and gill morphology of the East Coast redeye round herring Etrumeus wongratanai off KwaZulu-Natal, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: LD Vorsatz --- Department of Biodiversity and Conservation Biology, South Africa CD van der Lingen --- Branch: Fisheries Management, Department of Agriculture, South Africa MJ Gibbons --- Department of Biodiversity and Conservation Biology, South AfricaStomach content analyses and measurements of gillraker morphology were used to assess the diet and feeding ecology of the East Coast redeye round herring Etrumeus wongratanai and provide data for comparisons with other small pelagic fishes off South Africa. Samples... -
Modelling the Zambezi River plume
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: FPJ Nehama --- Department of Oceanography, South Africa CJC Reason --- Department of Oceanography, South AfricaA model for the Zambezi River plume, the largest on the Indian Ocean coast of Africa, is presented and the results of experiments with different discharges and wind forcings are analysed. Although the river plays an important role in the... -
Effects of smoke, ash and heat shock on seed germination of seven species from Central Zagros rangelands in the semi-arid region of Iran
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Ali Asghar Naghipour --- Department of Natural Resources, Iran Hossein Bashari --- Department of Natural Resources, Iran Seyed Jamaleddin Khajeddin --- Department of Natural Resources, Iran Pejman Tahmasebi --- Faculty of Natural Resources and Earth Science, Iran Majid Iravani --- Department of Natural Resources, IranFire products have been widely identified as germination cues for a number of species from both fire-prone and fire-free ecosystems. However, there is uncertainty about the effects of fire products on seed germination of semi-arid rangeland species. We examined the... -
Annual cycle of the upper-ocean circulation and properties in the tropical western Indian Ocean
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M Manyilizu --- Department of Oceanography, South Africa P Penven --- Ifremer, Univ. Brest, CNRS, IRD, Laboratoire dʹOcéanographie Physique et Spatiale (LOPS), France CJC Reason --- Department of Oceanography, South AfricaA regional ocean model was used to simulate the annual cycle of the upper-ocean dynamics and its influence on ocean properties in the tropical western Indian Ocean. Surface winds and heat fluxes from the National Centers for Environmental Prediction (NCEP)... -
Symmetric Intersections of Rauzy Fractals
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Tarek Sellami --- , , Tunisia Víctor F. Sirvent --- , , VenezuelaIn this article we study symmetric subsets of Rauzy fractals of unimodular irreducible Pisot substitutions. The symmetry considered is reflection through the origin. Given an unimodular irreducible Pisot substitution, we consider the intersection of its Rauzy fractal with the Rauzy... -
Inferring population trends of Araucaria angustifolia (Araucariaceae) using a transition matrix model in an old-growth forest
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Giovani F Paludo --- Grupo Uso e Conservação dos Recursos Florestais, Brazil Miguel B Lauterjung --- Grupo Uso e Conservação dos Recursos Florestais, Brazil Maurício S dos Reis --- Núcleo de Pesquisas em Florestas Tropicais, Brazil Adelar Mantovani --- Grupo Uso e Conservação dos Recursos Florestais, BrazilMatrix population models may generate important information to prevent undesirable outcomes for endangered species. This is the case for Araucaria angustifolia, a Critically Endangered conifer, with little knowledge regarding its life history and trends in development over time. This study... -
Dynamic Tensions from Management Control Systems and Performance in a Sub-Saharan African Economy: Mediating Effects of Competitive Strategy
Item type: Journal Article • Journal: Africa Journal of Management • Authors: Moses Acquaah --- Department of Management, USA Ahmed Agyapong --- Department of Marketing and Corporate Strategy, GhanaThis study examines how the dynamic tension created as a result of the simultaneous and balanced use of controlling and innovative forces of management control systems indirectly influences firm performance through competitive strategy. Using data from 106 firms from Ghana,... -
A criminogenic profile of a sample of South African high school learners
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Johan Prinsloo --- Department of Criminology,This study investigated the prevalence of criminogenic risk factors among South African high school learners. A sample of 312 high school learners attending a secondary (high) school in the Gauteng province of South Africa were surveyed (55.3% = female). They... -
Modelling diameter growth, mortality and recruitment of trees in miombo woodlands of Tanzania
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Wilson A Mugasha --- Department of Ecology and Natural Resource Management, Norway Tron Eid --- Department of Ecology and Natural Resource Management, Norway Ole M Bollandsås --- Department of Ecology and Natural Resource Management, Norway Lawrence Mbwambo --- Tanzania Forestry Research Institute, TanzaniaMiombo woodlands cover large areas in Tanzania but very little reliable data on forest dynamics for the woodlands exist. The main objective of this study was to develop a model system describing such dynamics based on easily measurable tree variables... -
Assessing effect of rainfall on rate of alien shrub expansion in a southern African savanna
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Mhosisi Masocha --- Department of Geography and Environmental Science, Faculty of Science, Zimbabwe Timothy Dube --- Department of Geography and Environmental Studies, South Africa Andrew Skidmore --- Faculteit Geo-Informatie Wetenschappen en Aardobservatie, The Netherlands Milena Holmgren --- Resource Ecology Group, The Netherlands Herbert Prins --- Resource Ecology Group, The NetherlandsUnderstanding the environmental factors governing the spread of alien shrubs is crucial for conserving biodiversity. In the semi-arid savannas of Africa, alien shrub invasion often occurs simultaneously with native shrub encroachment but climate-dependent differences in encroachments of native and alien... -
Long-term livestock grazing increases the recruitment success of epigeal termites: insights from a >75-year grazing experiment in the Karoo, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: James G Hagan --- Department of Biological Sciences, South Africa Justin CO du Toit --- Grootfontein Agricultural Development Institute, South Africa Michael D Cramer --- Department of Biological Sciences, South AfricaEpigeal termites alter ecosystem-level processes through foraging and mound building. These effects are proportional to density. Whilst much is known about the factors influencing mound density in natural settings, how termites respond to livestock grazing has been overlooked. We compared... -
Does high-density stocking affect perennial forbs in mesic grassland?
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Sindiso Chamane --- School of Life Sciences, South Africa Kevin P Kirkman --- School of Life Sciences, South Africa Craig Morris --- Agricultural Research Council–Animal Production Institute, c/o University of KwaZulu-Natal, South Africa Tim O’Connor --- South African Environmental Observation Network, South AfricaLivestock production is an appropriate land use for mainstreaming biodiversity conservation, but little is known about the impact of grazing strategies on forbs that contribute most species, in grasslands. This study compared the effects of high-density, short-duration stocking (HDG) with... -
Phytoplankton primary productivity seasonality and changes in a small African lake, Lake Hora-Kilole, Ethiopia
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: R Abate --- Aquatic Sciences, Fisheries and Aquaculture Stream, Department of Zoological Sciences, China D Kifle --- Aquatic Sciences, Fisheries and Aquaculture Stream, Department of Zoological Sciences, Ethiopia YH Gao --- School of Life Sciences and State Key Laboratory of Marine Environmental Science, ChinaThe seasonality of primary productivity by phytoplankton in relation to physico-chemical and biological variables was studied in Lake Hora-Kilole from August 2007 to May 2008. In 1989, the Mojo River was temporarily diverted to flow into the lake, which substantially... -
Key factors that drive phytoplankton biomass and community composition in the urbanised Nahoon Estuary, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: P Cotiyane --- Department of Botany, South Africa J Adams --- Department of Botany, South Africa A Rajkaran --- Department of Biodiversity and Conservation Biology, South AfricaEstuaries are under intense pressure, because of urban developments and water abstraction. Water column characteristics of the Nahoon Estuary were examined in 2014–2015 to identify factors that influenced phytoplankton dynamics. The estuary was found to be saline (∼33) and remained... -
Variation in selected solid wood properties of young Pinus patula from diverse sites in the Mpumalanga escarpment area in South Africa
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Barry G Muller --- Nelson Mandela Metropolitan University, South Africa Josua H Louw --- Nelson Mandela Metropolitan University, South Africa Francois S Malan --- Research Centre, South Africa (retired)Regression analyses identified ‘Growth Days’ (an index expressing site moisture availability) as the only site variable contributing significantly to the prediction to wood density (R2 = 0.57), whereas the model predicting grain angle included only ‘Altitude’ (R2 = 0.60). These... -
Contrasting hydrography and phytoplankton distribution in the upper layers of cyclonic eddies in the Mozambique Basin and Mozambique Channel
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: T Lamont --- Branch: Oceans and Coasts, Department of Environmental Affairs, South Africa RG Barlow --- Marine Research Institute and Department of Oceanography, South AfricaHydrographic data collected in cyclonic eddies in the Mozambique Channel and Basin revealed notable differences in temperature and salinity at a depth of 100 m, the upper mixed layer, the nitracline depths, and vertical distribution of chlorophyll-a (Chl-a). Differences in... -
Survival estimates for the greater crested tern Thalasseus bergii in southern Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: A Payo-Payo --- Group of Ecology and Animal Demography (GEDA), Spain A Sanz-Aguilar --- Group of Ecology and Animal Demography (GEDA), Spain D Gaglio --- Percy FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, South Africa RB Sherley --- Environment and Sustainability Institute, University of Exeter, United Kingdom TR Cook --- Percy FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, South Africa R Altwegg --- Statistics in Ecology, Environment and Conservation, Department of Statistical Sciences, and African Climate and Development Initiative, South Africa PG Ryan --- Percy FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, South AfricaThe nominate race of the greater crested tern Thalasseus bergii breeds only along the coast of the Benguela region (west coast) of southern Africa, where its population is increasing, in contrast to other species of breeding seabirds in the region... -
Metal accumulation in two contiguous eutrophic peri-urban lakes, Chivero and Manyame, Zimbabwe
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: B Utete --- Chinhoyi University of Technology, Zimbabwe C Phiri --- Chinhoyi University of Technology, Zimbabwe SS Mlambo --- Chinhoyi University of Technology, Zimbabwe N Maringapasi --- Chinhoyi University of Technology, Zimbabwe N Muboko --- Chinhoyi University of Technology, Zimbabwe TB Fregene --- Department of Aquaculture and Fisheries Management, Nigeria B Kavhu --- University of Zimbabwe, ZimbabweConcentrations of aluminium, cadmium, chromium, cobalt, copper, iron, lead, nickel and zinc were determined in surface water, benthic sediments, and the gills, liver and stomach muscle tissues of Oreochromis niloticus and Clarias gariepinus in peri-urban lakes Chivero and Manyame, Zimbabwe... -
Childhood sexual abuse trauma-causing dynamics experienced by women survivors: A scoping literature review
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Marinda Henning --- School of Behavioural Sciences, Faculty of Humanities, Optentia Research Focus Area, South Africa Hayley J. Walker-Williams --- School of Behavioural Sciences, Faculty of Humanities, Optentia Research Focus Area, South Africa Ansie Fouché --- School of Behavioural Sciences, Faculty of Humanities, Optentia Research Focus Area, South AfricaThis scoping literature review reports on the major themes to emerge from 23 retrospective studies on the trauma-causing dynamics experienced by women survivors of a historical childhood sexual abuse (CSA) trauma. We identified the studies from searching the following data... -
A novel system dynamics’ model for the motors of a sectoral innovation system–simulating and policymaking
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Sayyed Mohsen Azad --- Department of Industrial Engineering, Iran Seyed Hassan Ghodsypour --- Department of Industrial Engineering, IranIn recent years, science and technology policymaking has been taken into consideration by many researchers. One of the most important fields of this policymaking is innovation systems’ management; which is divided into national, regional, sectoral and technological innovation systems. In... -
A practical guide to the interpretation of PK/PD profiles of longer-acting analogue insulins. Part two: Insulin degludec vs. insulin glargine U300
Item type: Journal Article • Journal: Journal of Endocrinology, Metabolism and Diabetes of South Africa • Authors: Oppel Bw Greeff --- Department of Pharmacology, South Africa Jacob John van Tonder --- Triclinium Clinical Development (Pty) Ltd, South Africa Kershlin Naidu --- Department of Internal Medicine, South Africa Alicia McMaster --- Sanofi-Aventis South Africa (Pty) Ltd, South Africa Alet van Tonder --- Sanofi-Aventis South Africa (Pty) Ltd, South Africa Rashem Mothilal --- Sanofi-Aventis South Africa (Pty) Ltd, South AfricaGlucose clamp studies form an integral part of the early development of insulin therapies. Data generated in these studies are used to establish pharmacokinetic (PK) and pharmacodynamic (PD) profiles of the agents, but methodological differences confound comparison of results from... -
Networking dimensions and performance of event management ventures in Kenya
Item type: Journal Article • Journal: Research in Hospitality Management • Authors: Jacqueline Cheptepkeny Korir --- School of Tourism Hospitality and Events Management, KenyaThe role of networking in the sharing of knowledge and information is well documented. What is not clear, however, are the facets of networks that best drive firm performance, and whether or not the nature of business is a factor... -
Tiller population dynamics in eight cultivars of elephant grass during undisturbed growth
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: José A Rueda --- Licenciatura en Zootecnia, Mexico Eusebio Ortega-Jiménez --- Colegio de Postgraduados, Mexico Javier F Enríquez-Quiroz --- Campo Experimental “La Posta”, Mexico Rogelio E Palacios-Torres --- Licenciatura en Zootecnia, Mexico Sergio Ramírez-Ordoñes --- Licenciatura en Zootecnia, MexicoThe aim of the study was to assess tiller population dynamics of aerial and basal tillers in eight cultivars of Pennisetum purpureum (Schumach.), syn. Cenchrus purpureus (Schumach.) Morrone, in a warm humid climate in Veracruz, Mexico. This is a pioneer... -
Long-term vegetation change (>20 years) in the plains habitat on the Goegap Nature Reserve, Succulent Karoo, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Margaretha W van Rooyen --- Department of Plant and Soil Sciences, South Africa Annelise le Roux --- CapeNature, Assegaaibosch Nature Reserve, South Africa Helga van der Merwe --- South African Environmental Observation Network (SAEON): Arid Lands Node, South Africa Noel van Rooyen --- Private, South Africa Conrad Geldenhuys --- Environment and Nature Conservation, South AfricaBecause vegetation change in arid ecosystems is slow, long-term data are essential to gain an understanding of how the vegetation responds to short-term, inter-annual variation in rainfall; long-term cyclic rainfall patterns; and grazing pressure. The point intercept method was conducted... -
Reflections, applications and future directions of Long-Term Ecological Research at Tierberg
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Gina Arena --- South African Environmental Observation Network (SAEON): Arid Lands Node, South Africa Helga van der Merwe --- South African Environmental Observation Network (SAEON): Arid Lands Node, South Africa Simon W Todd --- South African Environmental Observation Network (SAEON): Arid Lands Node, South Africa Marco J Pauw --- South African Environmental Observation Network (SAEON): Arid Lands Node, South Africa Suzanne J Milton --- South African Environmental Observation Network (SAEON): Arid Lands Node, South Africa W Richard J Dean --- South African Environmental Observation Network (SAEON): Arid Lands Node, South Africa Joh R Henschel --- South African Environmental Observation Network (SAEON): Arid Lands Node, South AfricaTierberg-LTER is a research site established in 1987 in the semi-arid Succulent Karoo near Prince Albert in the Western Cape province, South Africa. The original purpose for its establishment was to study ecosystem dynamics and the drivers of vegetation in... -
Analyses of mathematical models for city population dynamics under heterogeneity
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: O.C. Collins --- Institute of Systems Science, South Africa T.S. Simelane --- Institute of Systems Science, South Africa K.J. Duffy --- Institute of Systems Science, South AfricaIn this study, a mathematical model which takes heterogeneity into account is presented to describe city population dynamics. Initial insight is gained by qualitative analyses of a homogeneous version of this model. To understand the population dynamics of South African... -
Mathematical model showing how socioeconomic dynamics in African cities could widen or reduce inequality
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Obiora Cornelius Collins --- Institute of Systems Science, South Africa Thokozani Silas Simelane --- Institute of Systems Science, South Africa Kevin Jan Duffy --- Institute of Systems Science, South AfricaCities are important forces of national socioeconomic development. Individuals in cities often belong to different socioeconomic statuses depending on their levels of income, education and nature of occupation. Income, employment and education opportunities are among the main attractions of most... -
Population biology of the woodland dormouse Graphiurus murinus in a riverine Combretum forest, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: Zimkitha JK Madikiza --- School of Animal, Plant and Environmental Sciences, South Africa Sandro Bertolino --- Department of Life Sciences and Systems Biology, Italy Emmanuel Do Linh San --- Department of Zoology and Entomology, South AfricaUntil recently, very little was known of the biology and ecology of the woodland dormouse Graphiurus murinus, a nocturnal and arboreal rodent belonging to the family Gliridae. Here, we aimed to increase our knowledge on its population biology in a... -
Dynamics of water exchange and salt flux in the Macuse Estuary, central Mozambique, southern Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: LLAJ Miguel --- Post-Graduate Program in Geology (PPGl), Brazil JWA Castro --- Post-Graduate Program in Geology (PPGl), Brazil SFA Machava --- Department of Oceanography, MozambiqueStudies of water-particle flow dynamics in shallow estuarine systems show that tidal currents control water exchange, salt flux and residence time. We used the 3D Estuary, Lake and Coastal Ocean Model (ELCOM) to estimate the dynamics of tidal currents, salt... -
Growth and mortality parameters of the black-chinned tilapia Sarotherodon melanotheron melanotheron (Pisces: Cichlidae) in a small lagoon in the Central Region of Ghana
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: GA Tibu --- Department of Fisheries and Aquatic Sciences, Ghana DW Aheto --- Department of Fisheries and Aquatic Sciences, Ghana J Blay --- Department of Fisheries and Aquatic Sciences, GhanaThis study quantified growth, mortality, and exploitation rate of the black-chinned tilapia (Sarotherodon melanotheron melanotheron) population in Etsir Lagoon, a small brackish waterbody at Abandze (5°11′ N, 1°5′ W) in the Central Region of Ghana for management of the stock... -
Comparative trophic ecology of Cape anchovy Engraulis encrasicolus and Natal anchovy Stolephorus holodon off South Africa’s east coast
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M Horton --- Department of Biological Sciences, South Africa CD van der Lingen --- Department of Biological Sciences, South AfricaThe distributional ranges of Cape anchovy Engraulis encrasicolus and Natal anchovy Stolephorus holodon presently overlap at their eastern and western extremes, respectively, off South Africa’s east coast. These species might become more strongly sympatric as a consequence of changed distributions... -
Using mark-recapture methods to estimate population size and survival of pyjama sharks Poroderma africanum in Mossel Bay, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SP Grusd --- Department of Biological Sciences and the Marine Research Institute, South Africa CL Moloney --- Department of Biological Sciences and the Marine Research Institute, South Africa G Distiller --- Statistics in Ecology, Environment and Conservation (SEEC), Department of Statistical Sciences, South Africa RGA Watson --- Oceans Research, South Africa PD Cowley --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa E Gennari --- Oceans Research, South AfricaThe pyjama shark Poroderma africanum (family Scyliorhinidae) is endemic to coastal waters of South Africa but its population characteristics are poorly known. This study aims to estimate baseline demographic parameters for P. africanum in Mossel Bay. We applied mark-recapture methods... -
Could drought constrain woody encroachers in savannas?
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Madelon F Case --- , United States Benjamin J Wigley --- , India Corli Wigley-Coetsee --- , South Africa A Carla Staver --- , United StatesDroughts are expected to become more frequent and severe, due to climate change, with uncertain consequences for savanna vegetation. Drought-driven tree mortality has been observed in some savannas, but little is known about how tolerant savanna trees are to drought,... -
Physico-chemical and microalgal gradients change rapidly in response to mouth closure in a predominantly open estuary
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: DA Lemley --- Botany Department and the Institute for Coastal and Marine Research, South Africa JB Adams --- Botany Department and the Institute for Coastal and Marine Research, South AfricaA third of South Africa’s freshwater flow no longer reaches the coast, yet few systems have shifted from being permanently open to temporarily closed. For the first time since 1969, the Gamtoos Estuary mouth closed in June 2018, because of... -
Annual litter production in a Brazilian Cerrado woodland savanna
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Alan N Costa --- , Brazil Alessandra Bartimachi --- , Brazil Heraldo L Vasconcelos --- , USA Emilio M Bruna --- , USA Ernane HM Vieira-Neto --- , USAThe Brazilian Cerrado is a heterogeneous ecosystem where annual woody-layer litter production shows strong spatiotemporal variation. Although Cerrado litter dynamics have been well-documented in forest physiognomies, knowledge from savanna habitats remains limited despite their predominance across the landscape. In this... -
Interactive effects of prescribed fire and livestock grazing on Seriphium plumosum in South African sour bushveld
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Michele D Clark --- , United States Carissa L Wonkka --- , United States Urs P Kreuter --- , United States William E Rogers --- , United StatesDocumented increases in woody plant abundance worldwide can reduce land value and grazing capacity. Throughout many grasslands and savannas in South Africa, Seriphium plumosum, an encroaching woody plant, has been rapidly displacing desirable native species. Cost-effective management techniques are required,... -
Women’s perspectives on relationship dynamics with their partners and their role in HIV acquisition, HIV disclosure, hormonal contraceptive uptake, and condom use
Item type: Journal Article • Journal: African Journal of AIDS Research • Authors: John C Chapola --- , Malawi Kendra Hatfield-Timajchy --- , USA Agatha K Bula --- , Malawi Stacey Hurst --- , USA Lameck Chinula --- , Malawi Athena P Kourtis --- , USA Jennifer H Tang --- , MalawiBackground: Limited information exists about relationship dynamics and their role in HIV acquisition, HIV disclosure, hormonal contraceptive uptake, and condom use among women in Malawi. -
Three-dimensional modelling of the circulation in False Bay, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: F Coleman --- , South Africa GPJ Diedericks --- , South Africa AK Theron --- , South Africa J Lencart e Silva --- , United KingdomFalse Bay is the largest coastal embayment along South Africa’s coastline. Despite notable contributions of various historical observational studies on the circulation within False Bay and the associated physical processes driving these flows, there remains significant uncertainty largely because the... -
Analysing species site-specific tree growth, mortality and in-growth for miombo woodlands in Tanzania
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: E E Njoghomi --- , Tanzania S Valkonen --- , K Karlsson --- ,The silvicultural information base for the development of management regimes for Tanzanian miombo woodlands is underdeveloped. The limited and fragmented information on tree growth and stand dynamics has constrained the progress of sustainable management in these woodlands. Therefore, this study... -
Effects of fragmented mangroves on macrozoobenthos: a case study of mangrove clearance for powerline right-of-way at Oproama Creek, Niger Delta, Nigeria
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: N Zabbey --- , Nigeria IG Ekpenyong --- , Nigeria GN Nwipie --- , Nigeria IC Davies --- , Nigeria K Sam --- , NigeriaMangroves are vulnerable to varying magnitudes of degrading impact by human activities. Despite the many benefits of mangrove ecosystems, mangroves in the Niger Delta region are often cleared for electric powerline and oil pipeline rights-of-way, recreation, road construction, housing and... -
Dynamic behaviour of institutional ownership and firm life cycle: Evidence from Taiwan
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Yung-Jang Wang --- , Taiwan M. Mark Walker --- , USA Po-Hsiung Huang --- , TaiwanWe find that firms in the growth and maturity stage generally have higher levels of institutional ownership, higher Tobin’s Q ratios, and are more likely to remain in their life cycle stage over the subsequent six-year period. Further analysis indicates... -
Auto insurance premiums in Ghana: An Autoregressive Distributed Lag model approach to risk exposure variables
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Jacob Azaare --- , China Zhao Wu --- , China Bernard Gumah --- , China Enock Mintah Ampaw --- , Ghana Socrates Modzi Kwadwo --- , GermanyThis study examined risk exposure and auto insurance premium determinants in Ghana. We analysed an existing data set of 23 434 policies (without claims = 84.1%, policies with claims = 15.9%; comprehensive policies = 48.0%, third-party policies = 52.0%) applying... -
Historic changes in the fire-rainfall relationship at a woodland-savanna transition zone in southern Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: T Hamilton --- , South Africa S Archibald --- , South Africa S Woodborne --- , South AfricaSouthern Africa is dominated by fire-prone arid and semi-arid landscapes that are expected to experience increased maximum temperatures, rainfall variation and frequency of extreme rainfall events in the future. These conditions will affect fire and vegetation dynamics, but feedback and... -
Long-term field study of the behaviour of Xenopus laevis (Pipidae) in a small dam
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: Andreas Elepfandt --- Humboldt-Universität zu Berlin, Inst. Biologie, Germany Alexander Gutsche --- Humboldt-Universität zu Berlin, Inst. Biologie, Germany Werner J Fischer --- Universität Konstanz, Fak. Biologie, Germany Wera Leujak --- Humboldt-Universität zu Berlin, Inst. Biologie, Germany Phillip J Bishop --- University of the Witwatersrand, South AfricaA study of the behaviour of Xenopus laevis in a small dam in South Africa was continued annually from 1992 until 1999. All individuals were tagged. The annual number of frogs varied between 22 and 109 by migration. The sex... -
Trends in mussel cover, density and size at exploited and unexploited intertidal reefs in eastern South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: E Steyn --- , South Africa JC Groeneveld --- , South Africa J Santos --- , Norway XI Mselegu --- , South AfricaThe brown mussel Perna perna is the dominant indigenous mussel along the east coast of South Africa, where it is harvested by recreational and subsistence fishers. High fishing pressure near urban areas led to declining abundance and consequently to the... -
Spectral classification, mapping and physical habitat implications of a riparian invasion by Tamarix ramosissima Ledeb. in the Touws River, Klein Karoo, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: MC Grenfell --- , South Africa TI Dube --- , South AfricaThis paper investigates the invasion of a reach of the Touws River by the deciduous alien tree Tamarix ramosissima Ledeb. (Pink Tamarisk, Saltcedar). The objectives of the paper were to investigate the utility of a delta-normalised difference vegetation index (dNDVI)... -
The impact of open innovation challenges on automotive component manufacturers’ competitiveness: An insight from the South African automotive industry
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Arthur Mzwandile Gonyora [cor1] Stephen Migiro --- , South Africa Pfano Mashau --- , South Africa Bongani Ngwenya --- , South AfricaOpen innovation is a function of managing innovation challenges within an organization to achieve sustainable competitive advantage. To achieve this, organizations have to configure and regulate their strategic resources, harness their core competencies and absorptive capacity, and manage uncertainties inherent... -
An assessment of the medium-term reproductive success of an extralimital white rhinoceros population
Item type: Journal Article • Journal: African Zoology • Authors: Anja Truter --- , South Africa Nokubonga Mgqatsa --- , South Africa Daniel M Parker --- , South AfricaThe white rhinoceros (Ceratotherium simum) is threatened primarily due to continued poaching for its horns. In South Africa, partly to promote the conservation of the species, white rhinos have been introduced into areas where they did not occur historically (i.e... -
Sensitivity simulation of sea surface temperature variability in coastal waters off East Africa in relation to the Indian Ocean Dipole
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MC Manyilizu --- The University of Dodoma, TanzaniaEast African coastal waters in the tropical western Indian Ocean experience strong seasonality which varies yearly, leading to the establishment of a prominent interannual Indian Ocean Dipole (IOD). This has a significant influence on regional and global socio-economic, climatic and... -
District analysis of poverty dynamics in rural South Africa
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Manana Mamabolo --- University of Pretoria, South Africa Petronella Chaminuka --- Agricultural Research Council, South Africa Charles Machethe --- University of Pretoria, South AfricaPersistent poverty is a major developmental challenge for South Africa and has multifaceted dimensions. This paper profiled and investigated poverty transitions among rural households in 22 district municipalities in South Africa. Foster-Greer-Thorbecke indices were applied to panel data from the... -
Eelgrass Zostera capensis populations in KwaZulu-Natal, South Africa, harbour distinct genomic signals despite limited geographical distance
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SE Smit --- Stellenbosch University, South Africa R Henriques --- University of Pretoria, South Africa M Jackson --- Stellenbosch University, South Africa R Taylor --- , South Africa L Vivier --- University of Zululand, South Africa S von der Heyden --- Stellenbosch University, South AfricaSeagrasses are threatened by anthropogenic stressors and climate change, with numerous population declines reported. In South Africa, the eelgrass Zostera capensis is restricted to estuarine environments and has a disjunct distribution and declining status. With the majority of the distribution... -
Tree diversity, vegetation structure and management of mangrove systems on Viti Levu, Fiji Islands
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Ashik Rubaiyat --- University of Göttingen, Germany Nicholas Rollings --- The University of the South Pacific, Fiji Islands Stephen Galvin --- The University of the South Pacific, Fiji Islands Ralph Mitloehner --- University of Göttingen, Germany Sohag Miah --- University of Göttingen, Germany Hans Juergen Boehmer --- The University of the South Pacific, Fiji IslandsMangrove forest ecosystems are critical natural resources, particularly in the South Pacific region. Mangrove forests in Viti Levu, Fiji’s main island, are threatened by infrastructure development activities and population growth. Consequently, the protection and restoration of mangrove forest are of... -
Zooplankton composition following an artificial mouth breaching event in Lake St Lucia, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: NK Carrasco --- University of KwaZulu-Natal, South Africa S Ramdass --- University of KwaZulu-Natal, South AfricaLake St Lucia is one of the most important estuarine systems in South Africa, but the long history of anthropogenic intervention has threatened its integrity. With the exception of sporadic overtopping events and periodic marine connectivity via the uMfolozi River,... -
Tricomi problem for mixed parabolic-hyperbolic equation with dynamic-type boundary condition
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Bauyrzhan Derbissaly --- Institute of Mathematics and Mathematical Modeling, KazakhstanIn this paper, we study an analogue of Tricomi problem for a parabolichyperbolic equation of the first type. To solve the problem for the heat equation, we use properties of the spectral problem with a spectral parameter in the boundary... -
An adaptive differential evolution algorithm based on relaxation strategy to realize the Nash equilibrium of multi-oligopoly game
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Huimin Li --- Xuzhou University of Technology, China Shuwen Xiang --- Guizhou University, China Shiguo Huang --- Zhengzhou University of Light Industry, Enquan Luo --- Guizhou University, ChinaInspired by the idea of game learning, this paper studies the Cournot game model of the multi-oligopoly market and studies the realization of the Nash equilibrium by using adaptive differential evolution algorithm based on relaxation strategies. The realization path of... -
Long-term interannual temperature variability across the KwaZulu-Natal Bight as a technique for monitoring the complex uThukela Marine Protected Area, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: N Ramsarup --- University of Cape Town, South Africa T Morris --- , South Africa J Hermes --- University of Cape Town, South Africa M Dicken --- Institution for Coastal and Marine Research, Ocean Sciences Campus, Nelson Mandela University, South AfricaThe uThukela Marine Protected Area (MPA), situated on the continental shelf of the KwaZulu-Natal (KZN) Bight on the northeastern coast of South Africa, has been identified as a vital ecological region. Knowledge of the oceanographic dynamics in the region is... -
Floristic and structural changes in a neotropical urban novel forest over 13 years
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Marcelly de Souza Ventura --- Universidade Federal de Juiz de Fora, Brazil Thales Castilhos de Freitas --- Universidade Federal de Juiz de Fora, Brazil Ricardo Montianele de Castro --- Universidade Federal de Juiz de Fora, Brazil Mariana Couto Cruz --- Universidade Federal de Juiz de Fora, Brazil Kelly Antunes --- Universidade Federal de Juiz de Fora, Brazil Taísa Nascimento de Souza --- Universidade Federal de Juiz de Fora, Brazil Breno Moreira --- Universidade Federal de Juiz de Fora, Brazil Fabrício Alvim Carvalho --- Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, BrazilThe ecological importance of non-native species is the main characteristic of novel ecosystems. Pinus elliottii species is highly invasive in tropical forests and is commonly found in secondary forests in Brazil. We investigated the floristic and structural changes in an... -
Bayesian forecasting of stock returns on the JSE using simultaneous graphical dynamic linear models
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Nelson Kyakutwika --- Stellenbosch University, South Africa Bruce Bartlett --- Stellenbosch University, South AfricaCross-series dependencies are crucial in obtaining accurate forecasts when forecasting a multivariate time series. Simultaneous Graphical Dynamic Linear Models (SGDLMs) are Bayesian models that elegantly capture cross-series dependencies. This study forecasts returns of a 40... -
Effects of eucalypt and black wattle biochars from vacuum pyrolysis on sandy soil quality and cauliflower yield
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: S Mncedi --- Stellenbosch University, South Africa JF Görgens --- Stellenbosch University, South Africa PA Swanepoel --- Stellenbosch University, South Africa AG Hardie --- Stellenbosch University, South AfricaWoody invasive alien plants (IAPs), including black wattle (Acacia mearnsii De Wild.) and eucalypt species (Eucalyptus camaldulensis Dehnh.), present significant environmental challenges in South Africa. Biochar from these plants can enhance soil carbon sequestration and fertility. This study examines the... -
Influence of spatio-temporal variations in precipitation and temperature on the productivity of Eastern Lake Kyoga, Uganda
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: John Peter Obubu --- African Centre of Excellence for Water Management, Addis Ababa University, Ethiopia Robinson Odong --- Entomology and Fisheries Sciences, Makerere University, Uganda Seyoum Mengistou --- African Centre of Excellence for Water Management, Addis Ababa University, Ethiopia Tadesse Fetahi --- African Centre of Excellence for Water Management, Addis Ababa University, Ethiopia Tena Alamerew --- Ethiopian Institute of Water Resource, Addis Ababa University, Ethiopia Ekwacu Samuel --- Uganda National Meteorological Authority, UgandaSpatio-temporal variations in precipitation and temperature affect productivity in aquatic systems, mainly through nutrient dynamics. Shallow lakes are more vulnerable to spatio-temporal variations, yet they are an important resource for biodiversity conservation, water supply and fisheries. The eastern arm of... -
An empirical investigation into dynamics of growth of Indian economy impacted by public and private sector investment: Is there evidence of crowding out effect?
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Priya Gupta --- Jawaharlal Nehru University, India Pratibha Rai --- University of Delhi, India Vijeta Pundir --- University of Delhi, India Bhawna --- Jawaharlal Nehru University, IndiaThis study examines the dynamic effects of public and private investments on India’s economic growth, focusing on disaggregating public sector investments into infrastructure and non-infrastructure Gross Fixed Capital Formation (GFCF). Key questions include: How do public infrastructure and non-infrastructure investments... -
Renewable energy transition and employment dynamics in an emerging oil-producing economy: A case study of Ghana
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Clement Oteng --- University of Cape Coast, Ghana Iledare Omowumi --- SPE Africa Region and Member Board of the Society of Petroleum Engineers International (SPEi), Nigeria James Atta Peprah --- University of Cape Coast, Ghana Pius Gamette --- University of Cape Coast, GhanaShifting to sustainable renewable energy is justified by the failures of global markets brought on by climate change. However, many workers are uncertain about retraining their current employment considering the dynamics associated with renewable energy transition. This has become a... -
A shelf-scale assessment of GLORYS and BRAN ocean reanalysis model outputs for the southern Benguela Upwelling System
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: AM Kupczyk --- Fisheries and the Environment (DFFE), South Africa T Lamont --- Fisheries and the Environment (DFFE), South Africa I Halo --- Fisheries and the Environment (DFFE), South Africa CS Russo --- Fisheries and the Environment (DFFE), South Africa T Rixen --- Institute for Geology, Universität Hamburg, Germany N Lahajnar --- Institute for Geology, Universität Hamburg, GermanyThe Benguela Upwelling System, with its high variability and productivity, is challenging to monitor owing to limited in situ ocean observations. Researchers therefore often use ocean reanalysis products to simulate oceanographic conditions. We evaluated the performance of the GLORYS and... -
Leveraging learning orientation for superior organizational performance: The role of firm-specific factors
Item type: Journal Article • Journal: Africa Journal of Management • Authors: Henry Kofi Mensah --- Kwame Nkrumah University of Science and Technology, Ghana Gilbert Anyowuo Okyere --- Kwame Nkrumah University of Science and Technology, Ghana Emmanuel Kwabena Anin --- Kumasi Technical University, Ghana Phyllis Adjei Tuffour --- Kwame Nkrumah University of Science and Technology, GhanaExtant literature recognizes organizational learning orientation (LO) as a critical resource, yet the mechanisms and conditions under which it translates into superior performance remain underexplored and often assumed. We draw on Resource-Based View (RBV) and dynamic capability frameworks to develop... -
Spillovers, correlations and hedging among green bonds, clean energy stocks and fossil fuels: The effects of four turmoils
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Foday Joof --- Eastern Mediterranean University, Turkey Cahit Adaoglu --- Eastern Mediterranean University, Turkey Nigar Taspinar --- Eastern Mediterranean University, TurkeyThis study investigates the volatility spillovers and the hedging among green bonds, clean energy stocks, and fossil fuels markets. During the ten-year sample period between 2012 and 2022, four major turmoils are observed chronologically: The oil price plunge of 2014–2016,... -
War metaphors as names for medical concepts in Sesotho newspaper HIV and AIDS communication
Item type: Journal Article • Journal: South African Journal of African Languages • Authors: Ntšoeu Seepheephe --- National University of Lesotho, LesothoThe study examines the behaviour and the ideological functions of war metaphors that are used in Sesotho newspaper communication on HIV and AIDS. Using the dynamic systems approach towards metaphor, I explore the use of these metaphors in three major... -
Sediment dynamics in the Roman Rock area of False Bay, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: A Terhorst --- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia M de Vos --- University of Connecticut, United States C Rautenbach --- Waikato Regional Council, New ZealandThis study investigated sediment dynamics in the Roman Rock area of False Bay, South Africa, by integrating sediment grain size data with hydrodynamic and wave modelling. We examined two significant events: a long-period southwesterly swell in 2008, and a prolonged... -
Individual variability in the thermal limits of juvenile dusky kob Argyrosomus japonicus from a permanently open estuary
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: J Frachet --- Rhodes University Department of Ichthyology and Fisheries Sciences, South Africa A-R Childs --- Rhodes University Department of Ichthyology and Fisheries Sciences, South Africa AC Winkler --- Rhodes University Department of Ichthyology and Fisheries Sciences, South Africa MW Farthing --- Rhodes University Department of Ichthyology and Fisheries Sciences, South Africa CD Hempel --- Rhodes University Department of Ichthyology and Fisheries Sciences, South Africa WM Potts --- Rhodes University Department of Ichthyology and Fisheries Sciences, South AfricaGlobally, fish are facing the pressure of increasing thermal variability, which challenges the physiological capacity and resilience of species at the level of the individual, population and community. As transition zones, estuarine ecosystems are becoming increasingly thermally dynamic, which affects... -
Global solutions for the time-space fractional rotating magnetohydrodynamic equations in Besov spaces
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Jinyi Sun --- College of Mathematics and Statistics, P.R. China Yuanwei Mai --- College of Mathematics and Statistics, P.R. China Yatao Li --- Jiangxi University of Finance and Economics, P.R. ChinaThis paper is devoted to the time-space fractional rotating magnetohydrodynamic equations in Besov spaces. By exploiting the interweaving action of the smoothing effects of the fractional Laplacian dissipation and dispersive effects of the Coriolis force involving with the time-fractional evolution... -
The grazing paradox: assessing contradictions of continuous versus rotational grazing systems in southern Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Katharina Meyer --- Institute of Plant Science and Microbiology, University of Hamburg, Germany Ute Schmiedel --- Institute of Plant Science and Microbiology, University of Hamburg, GermanyUnsustainable grazing practices result in degradation of arid and semiarid rangelands in southern Africa. Continuous grazing systems are often blamed for degradation, while rotational grazing systems are seen as more sustainable. The discussion about the impact of these grazing practices... -
Transhumance within private land conservation areas: perspectives from pastoralist landowners in rural Kenya
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Simon M Thiong’o --- Centre for Events, Tourism, and Hospitality Management, Carnegie School of Sport, Leeds Beckett University, Headingley Campus, UKPastoralism in Kenya’s arid and semi-arid regions supports about 10 million indigenous people. While general studies on pastoralist livelihoods exist, limited research explores these dynamics within privately governed landscapes. This study critically examines how land tenure complexities within private land... -
Effect of entrepreneurial orientation on sustainable financial practices: The roles of dynamic capabilities and institutional conditions
Item type: Journal Article • Journal: Africa Journal of Management • Authors: Divine Atinyo --- University of Cape Coast, Ghana George Tweneboah --- University of Cape Coast, GhanaEntrepreneurial orientation (EO) is increasingly recognized as a vital strategic factor, particularly in volatile business environments. While EO can potentially drive superior sustainable financial practices (SFP), there remains a gap in understanding the underlying mechanisms and contextual factors that complement...