Search
Search results for
We found
57 results for you
-
Produksie en kwaliteit van ‘n aantal grasspesies in die Combretum‐veld van noord‐transvaal
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: P.A. Pieterse --- Departement Plantproduksie, Fakulteit Landbouwetenskappe, J.O. Grunow --- Departement Plantproduksie, Fakulteit Landbouwetenskappe,Die produksie en kwaliteit van vyf spesies (Themeda triandra, Heteropogon contortus, Digitaria eriantha var. pentzii, Schmidtia pappophoroides en Eragrostis rigidior) is by verskillende frekwensies van ontblaring op ontbosde en onontbosde bosveld gemeet. In die daaropvolgende jaar is intensiteit bygebring met... -
Die invloed van die beskikbaarheid van nutriënte en ontblaringsbestuur op die produksie van digitar1a Eriantha variëteit Eriantha
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: P A Pieterse --- Departement Plantproduksie,Die invloed van verskillende peile van stikstof (N), fosfaat (P) en kalium (K) op die produksie en kwaliteit van Digitaria eriantha var. eriantha is in sandkultuur ondersoek. Verder is daar ook gekyk na die invloed van drie intensiteite van ontblaring... -
Patterns of defoliation in four‐ and eight‐paddock grazing systems
Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa • Authors: D.M. Gammon --- Department of Agriculture and Water Supply, Republic of South Africa D.R. Twiddy --- Department of Agriculture and Water Supply, Republic of South AfricaPatterns of defoliation of the dominant palatable species in a recommended eight‐paddock system and a four‐paddock system with the same grazing cycle were monitored by repeated observations of marked tillers. In the two systems, the percentages of palatable species grazed... -
Organic matter, pH and nutrient distribution in soil layers of a savanna Thornveld subjected to different burning frequencies at Alice in the Eastern Cape
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: S.A. Materechera --- Facility of Agriculture, Republic of South Africa O.T. Mandiringana --- Department of Agronomy, Republic of South Africa P.M. Mbokodi --- Department of Agronomy, Republic of South Africa K. Nyamapfene --- , Republic of South AfricaFire is an important tool for the management of grazed savanna grasslands in the Eastern Cape, South Africa. The aim of this study was to quantify the influence of veld burning frequency on soil properties especially organic matter, pH, exchangeable... -
AN ASSESSMENT OF THE GROWTH RATE OF MPASA, OPSABIDIUM MICROLEPIS (GUNTHER, 1864) (PISCES: CRYPRINIDAE), BY LENGTH FREQUENCY ANALYSIS
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: D. Tweddle --- Fisheries Department, MalawiThe mpasa, Opsaridium microlepis, is an important commercial species in areas of Lake Malawi near major inflowing rivers during annual spawning migrations. Plots of length frequency data collected over a series of years from mpasa catches in the Bua and... -
The effect of different fire treatments on the population structure and density of the Marula, Sclerocarya birrea (A. Rich.) subsp. caffra (Sond.) kokwaro (Kokwaro & Gillet 1980) in the Kruger National Park
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: OS Jacobs R BiggsTo determine the influence of frequency and season of burn on the growth structure and density of Sclerocarya birrea, six replicated fire treatments of the experimental burning plot trial were surveyed in the Sclerocarya birrea / Acacia nigrescens savanna of... -
The influence of urine and dung deposition on patch grazing patterns of cattle and sheep in the Southern Tall Grassveld
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: B.U. Lütge --- Department of Grassland Science, Republic of South Africa G.P. Hatch --- Department of Grassland Science, Republic of South Africa M.B. Hardy --- KwaZulu‐Natal Department of Agriculture, Republic of South AfricaThe effect of urine and dung deposition on the patch grazing patterns of cattle and sheep in the Southern Tall Grassveld was investigated using an experiment with four treatments, viz. artificial urine, fresh cattle dung, fresh sheep dung, and a... -
Production of irrigated Trifolium repens L. under a cutting regime in the subtropical region of Gauteng, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: M. Trytsman --- , Republic of South Africa A.J. Kruger --- , Republic of South Africa V.D. Wassermann --- , Republic of South Africa M.A. Stoltz --- , Republic of South AfricaThe productivity of Trifolium repens L. cv. Ladino, under irrigation in the subtropical region of Gauteng, South Africa, is unknown. The performance of T. repens was determined over five years (1981/1982 to 1985/1986), at two defoliation frequencies, four levels of... -
An assessment of a light-attraction fishery in southern Lake Malawi
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: OLF Weyl J Kazembe AJ Booth DS MandereThis study provides the first quantitative assessment of the light-attraction component of a small-scale purse seine, locally known as a chilimira net, fishery in two areas of southern Lake Malawi. For monitoring purposes the shoreline of Lake Malawi is divided... -
A preliminary quantitative assessment of gillnet fishing in subtropical Lake Tzaneen, Northern Province, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: NN Nicolaai --- Department of Zoology and Biology, South Africa A Jooste --- Department of Zoology and Biology, South AfricaBetween January 1998 and January 1999 a quantitative investigation was done on the fish populations of Lake Tzaneen, Northern Province, South Africa. Two graded series of multi-filament gillnets were set overnight every six weeks capturing 14 species of fish. Of... -
AN ASSESSMENT OF THE GROWTH RATE OF MPASA, OPSABIDIUM MICROLEPIS (GUNTHER, 1864) (PISCES: CRYPRINIDAE), BY LENGTH FREQUENCY ANALYSIS
Item type: Journal Article • Journal: Southern African Journal of Child and Adolescent Mental Health • Authors: D. Tweddle --- Fisheries Department, MalawiThe mpasa, Opsaridiwm microlepis, is an important commercial species in areas of Lake Malawi near major inflowing rivers during annual spawning migrations. Plots of length frequency data collected over a series of years from mpasa catches in the Bua and... -
Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. 10. The dusky shark Carcharhinus obscurus (Lesueur 1818)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: SFJ Dudley G Cliff MP Zungu MJ SmaleBetween 1978 and 1999, a total of 5 626 dusky sharks Carcharhinus obscurus, constituting 20% of the total shark catch, was caught in the protective nets off KwaZulu-Natal, South Africa. The mean annual catch was 256 sharks (SD = 107.5,... -
Comparison of fish-community size spectra based on length frequencies and mean lengths: a note
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: D Yemane MH Griffiths JG FieldEstimates of fish-community size spectra are promising indicators of the impact of fishing on fish assemblages. Size spectra consist of logarithmic graphs of abundance plotted against fish body size. Size spectra may either be constructed from length frequency data or... -
Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. 11. The scalloped hammerhead shark Sphyrna lewini (Griffith and Smith)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: P de Bruyn SFJ Dudley G Cliff MJ SmaleBetween 1978 and 1998, a total of 3 385 scalloped hammerhead sharks Sphyrna lewini was caught in the protective nets off KwaZulu-Natal. The mean annual catch was 166 sharks (range 60–279). There was a significant decrease in catch rate with... -
Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. 12. The African angel shark Squatina africana (Regan)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: RL Shelmerdine G CliffBetween 1980 and 2001, a total of 661 African angel sharks Squatina africana was caught in the protective nets off KwaZulu-Natal, South Africa. The mean annual catch was 30 sharks (range = 11–69, SD = 12.4), with no trend in... -
First documented southern transatlantic migration of a blue shark Prionace glauca tagged off South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: C da Silva --- Branch Fisheries, Department of Agriculture, Forestry and Fisheries, South Africa SE Kerwath --- Branch Fisheries, Department of Agriculture, Forestry and Fisheries, South Africa CG Wilke --- Branch Fisheries, Department of Agriculture, Forestry and Fisheries, South Africa M Meÿer --- Oceans and Coasts, Department of Environmental Affairs, South Africa SJ Lamberth --- Branch Fisheries, Department of Agriculture, Forestry and Fisheries, South AfricaThe first documented recapture of a South African-tagged juvenile blue shark Prionace glauca off Uruguay lends weight to the hypothesis of a single blue shark population in the South Atlantic. The presence of neonate blue sharks with umbilical scars and... -
Nature and pattern of lagoon fisheries resource utilisation and their implications for waterbird management in coastal Ghana
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: F Gbogbo W Oduro SK OppongSeasonal patterns in human fisheries resource utilisation and the capture characteristics of fish, swimming crabs and land crabs harvested from four coastal lagoons in Ghana between September 2005 and August 2007 are described. These are discussed in relation to sustainable... -
The long-term effect of fire and grazing by wildlife on range condition in moist and arid savannas in the Kruger National Park
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Winston Trollope --- Working on Fire International, South Africa Brian van Wilgen --- Department of Botany and Zoology, Centre for Invasion Biology, South Africa Lynne A Trollope --- Working on Fire International, South Africa Navashni Govender --- SANParks – Kruger National Park, Scientific Services, South Africa Andre L Potgieter --- SANParks – Kruger National Park, Scientific Services, South AfricaFew assessments of the effects of fire and grazing on the herbaceous components of savannas have been reported for Africa. In the Kruger National Park, South Africa, range condition was monitored at three savanna sites spanning a rainfall gradient of... -
Teachability of collocations: The role of word frequency counts
Item type: Journal Article • Journal: Southern African Linguistics and Applied Language Studies • Authors: Déogratias Nizonkiza --- School of Languages, Potchefstroom Campus, Kris Van de Poel --- School of Languages, Potchefstroom Campus,This study aims to gain insights into which collocations to teach at which proficiency levels by answering the following questions: (i) Of the Verb+Noun and Adjective+Noun types of collocations, which one is more difficult (and should therefore come at a... -
The nutrient intake of children aged 12–36 months living in two communities in the Breede Valley, Western Cape province, South Africa
Item type: Journal Article • Journal: South African Family Practice • Authors: TA Balogun --- Division of Community Health, South Africa MJ Lombard --- Division of Human Nutrition, South Africa M McLachlan --- Division of Human Nutrition, South AfricaObjective: The objective of this study was to describe the current macro- and micronutrient intake of children (both boys and girls) in two selected communities in the Breede Valley, Worcester. -
Influence of mouth status on population structure of southern African endemic estuarine-spawning ichthyofauna in a temperate, temporarily open/closed estuary
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: GP Tweddle --- Coastal Research Unit of Zululand, Department of Zoology, South Africa PW Froneman --- Department of Zoology and Entomology, South AfricaThe effect of mouth status on the population structure of three endemic estuarine-spawning fish species was assessed using seine nets from November 2005 to October 2007 in the temporarily open/closed Mpekweni Estuary, Eastern Cape, South Africa. Collectively, these three species... -
Do sawfish Pristis spp. represent South Africa's first local extirpation of marine elasmobranchs in the modern era?
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: BI Everett --- Oceanographic Research Institute, South Africa G Cliff --- KwaZulu-Natal Sharks Board, South Africa SFJ Dudley --- Branch: Fisheries Management, South Africa SP Wintner --- KwaZulu-Natal Sharks Board, South Africa RP van der Elst --- Oceanographic Research Institute, South AfricaLargetooth sawfish Pristis pristis and green sawfish P. zijsron were not uncommon in catches made in KwaZulu‑ Natal (KZN) on the east coast of South Africa in the mid part of the last century but apparently have disappeared from this... -
Intertidal population structure of the edible mollusc Turbo sarmaticus (Vetigastropoda) at an unexploited and exploited sites along the coast of the Eastern Cape Province, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: G.G. Foster --- Department of Zoology & Entomology, South Africa A.N. Hodgson --- Department of Zoology & Entomology, South AfricaThe intertidal population structure of the large edible gastropod Turbo sarmaticus was examined at four sites along the Eastern Cape Province of South Africa. One site was free from exploitation, two were subjected to low levels of exploitationand one was... -
Infection of hottentot Pachymetopon blochii by the fish louse Anilocra capensis (Crustacea: Isopoda) in False Bay, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: R.V. Wright --- Zoology Department and Marine Biology Research Institute, South Africa Y.A.R.G. Lechanteur --- Zoology Department and Marine Biology Research Institute, South Africa K. Prochazka --- Zoology Department and Marine Biology Research Institute, South Africa C.L. Griffiths [AN0001]The frequency of occurrence, location on the host, abundance, and size and sex distributions of ectoparasitic isopods,Anilocra capensis, on hottentot Pachymetopon blochii from False Bay, South Africa, were investigated. A. capensis occurred on 5.2 % of examined hosts and were... -
Juvenile population dynamics of Oreochromis mossambicus in an intermittently open estuary at the limit of its natural distribution
Item type: Journal Article • Journal: African Zoology • Authors: B.R. Ellender --- Department of Ichthyology and Fisheries Science, South Africa O.L.F. Weyl --- Department of Ichthyology and Fisheries Science, South Africa M.K. Shanyengange --- Department of Ichthyology and Fisheries Science, South Africa P.D. Cowley --- South African Institute of Aquatic Biodiversity, South AfricaJuvenile Oreochromis mossambicus in the 25 ha, temperate, intermittently open, East Kleinemonde Estuary in the Eastern Cape, South Africa (33°32’S, 27°03’E), showed a seasonal shift in distribution, occupying all areas of the estuary in summer and, subsequently, being limited to... -
Practices employed by audiologists in the management of adult patients with multidrug-resistant tuberculosis in South Africa
Item type: Journal Article • Journal: South African Family Practice • Authors: M Govender --- Audiology, Department of Health, Republic of South Africa J Paken --- Discipline of Audiology, Republic of South AfricaIntroduction: Aminoglycosides used for treating multidrug-resistant (MDR) tuberculosis are ototoxic, leading to a need for audiological monitoring. While audiologists monitor ototoxicity, currently there are no guidelines on monitoring in the South African context. Therefore, the findings of this study might... -
Intergroup contact experience and frequency as predictors of cross-racial attitudes
Item type: Journal Article • Journal: Journal of Psychology in Africa • Authors: Elirea Bornman --- Department of Communication Science, South AfricaThis study examined the relationships between contact frequency, experiences of intergroup contact and a number of demographic intergroup variables. A telephone survey was conducted among 544 blacks (57.5% male; 42.5% female) and 478 whites (44.6% male; 55.4% female). Three CHAID... -
Using different approaches to assess the reproducibility of a culturally sensitive quantified food frequency questionnaire
Item type: Journal Article • Journal: South African Journal of Clinical Nutrition • Authors: E. Wentzel-Viljoen --- Centre of Excellence for Nutrition, Potchefstroom R. Laubscher --- Biostatistics Unit, Parow A. Kruger --- Africa Unit for Transdisciplinary Health Research (AUTHeR), PotchefstroomObjective: To report on the use of different approaches to assess the reproducibility of a culturally sensitive quantified food frequency questionnaire (QFFQ) used for assessment of the habitual dietary intake of Setswana-speaking adults in the North West Province of South... -
What health professionals should know about omega-3 fatty acid supplements
Item type: Journal Article • Journal: South African Journal of Clinical Nutrition • Authors: M Opperman --- Department of Agriculture and Food Science,Omega-3 (n-3) fatty acids are essential to maintain satisfactory human health and need to be consumed in the diet. Western diets are often deficient in n-3 fatty acids because of an insufficient intake of cold water oily fish. The main... -
Adolescent food frequency and socio-economic status in a private urban and peri-urban school in Hilton, KwaZulu-Natal
Item type: Journal Article • Journal: South African Journal of Clinical Nutrition • Authors: Ka. Audain --- Discipline of Dietetics and Human Nutrition, Sm Kassier --- Discipline of Dietetics and Human Nutrition, Fj Veldman --- Discipline of Dietetics and Human Nutrition,Objective: The objective of the study was to make a comparative analysis of the dietary preferences of adolescents attending an urban versus a peri-urban school in KwaZulu-Natal, in order to investigate the association between socio-economic status and food frequency. -
Habitat preference of the eastern population of the Short-clawed Lark Certhilauda chuana in the Limpopo province, South Africa
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Sean M Marr --- Department of Biodiversity, School of Molecular and Life Sciences, South Africa Joseph I Grosel --- Department of Biodiversity, School of Molecular and Life Sciences, South Africa G Derek Engelbrecht --- Department of Biodiversity, School of Molecular and Life Sciences, South AfricaThe southern African endemic Short-clawed Lark Certhilauda chuana has two geographically isolated populations. Little is known about the smaller eastern population, which is restricted to the Polokwane Plateau, South Africa. To provide input for a conservation strategy for the eastern... -
Management for failed back surgery syndrome: three-in-one procedure versus percutaneous spinal fixation alone
Item type: Journal Article • Journal: Southern African Journal of Anaesthesia and Analgesia • Authors: Ahmed Abdalla Mohamed --- Faculty of Medicine, Department of Anesthesiology & ICU, Egypt Atef Kamel Salama --- Faculty of Medicine, Department of Anesthesiology & ICU, Egypt Ahmed Essam Salem --- Faculty of Medicine, Department of Anesthesiology & ICU, Egypt Ashraf El Gallad --- Faculty of Medicine, Department of Neurosurgery, EgyptObjectives: To evaluate the short-term outcome of a 3-in-1 procedure including percutaneous facet radiofrequency, percutaneous spinal fixation and steroid with hyaluronidase enzyme injection versus percutaneous spinal fixation alone for cases with failed back surgery syndrome (FBSS). -
Eelgrass beds and bare substrata – sparid and mugilid composition in contrasting littoral estuarine habitats
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: M Pollard --- Department of Zoology and Entomology, South Africa AN Hodgson --- Department of Zoology and Entomology, South Africa HM Kok --- Port Elizabeth Museum, South Africa AK Whitfield --- South African Institute for Aquatic Biodiversity (SAIAB), South AfricaSeagrass beds serve as nursery grounds for many fish species and often play an important role in the juvenile stages of economically and recreationally important fishes. The eelgrass Zostera capensis is the dominant submerged macrophyte in permanently open South African... -
Effect of frequency and height of cutting on growth parameters of Acacia saligna in Egypt
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Ahmed A Kandil --- Agronomy Department, Faculty of Agriculture, Egypt Ali E Sharief --- Agronomy Department, Faculty of Agriculture, EgyptTo revegetate acacia trees in saline desert sandy soils, field experiments were conducted to study the effect of cutting frequency and height on Acacia saligna productivity during 2014, 2015 and 2016. The tallest plants, thickest stems and highest values for... -
Adult binge drinking: rate, frequency and intensity in Buffalo City Metropolitan Municipality, South Africa
Item type: Journal Article • Journal: South African Family Practice • Authors: Eyitayo Omolara Owolabi --- Department of Nursing Science, South Africa Daniel Ter Goon --- Department of Nursing Science, South Africa Oladele Vincent Adeniyi --- Department of Family Medicine, South Africa Eunice Seekoe --- Department of Nursing Science, South AfricaBackground: Binge drinking (BD) is a significant risk factor for several acute and chronic illnesses, including injuries. This study examines the rate, frequency and intensity of BD in Buffalo City Metropolitan Municipality (BCMM), South Africa. -
Sharks caught in the KwaZulu-Natal bather protection programme, South Africa. 14. The smooth hammerhead shark Sphyrna zygaena (Linnaeus)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: ML Dicken --- KwaZulu-Natal Sharks Board, South Africa H Winker --- Branch: Fisheries Management, Department of Agriculture, South Africa MJ Smale --- Port Elizabeth Museum, South Africa G Cliff --- KwaZulu-Natal Sharks Board, South AfricaThe current study provides long-term catch-rate, biological and feeding data for smooth hammerhead sharks, Sphyrna zygaena, caught in South Africa’s KwaZulu-Natal bather protection programme. In total, 2 512 S. zygaena were caught in net installations between 1978 and 2014, and... -
Studies on the biology of Nile tilapia (Oreochromis niloticus) in Lake Victoria, Kenya: in light of intense fishing pressure
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: E Yongo --- Department of Fisheries and Aquatic Sciences, Kenya N Outa --- Department of Biological Sciences, Kenya K Kito --- Graduate School of Fisheries, Japan Y Matsushita --- Graduate School of Fisheries, JapanNile tilapia Oreochromis niloticus is now the most abundant and commercially important tilapiine in Lake Victoria. From the total of 1 512 fish sampled from commercial gill net fisheries during 2014 and 2015, 809 (54%) were males and 672 (44%)... -
Farmers’ knowledge, attitudes and perceptions towards timber out-grower schemes in selected districts of Malawi
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Maggie G Munthali --- Department of Geography, Geoinformatics and Meteorology, South Africa Simon Mng’omba --- World Agroforestry Centre (ICRAF), Chitedze Research Station, Malawi Harold Chisale --- Department of Forestry, Malawi Joyce Njoloma --- World Agroforestry Centre (ICRAF), Chitedze Research Station, Malawi Betserai I Nyoka --- World Agroforestry Centre (ICRAF), Chitedze Research Station, Malawi Gertrude Sato --- World Vision International, Malawi National Office, MalawiTimber out-grower schemes have proved to be one of the most profitable enterprises for rural households. No wonder, several analysts and researchers regard them as an alternative model to avoid problems of displacement and create ‘win-win’ outcomes for both rural... -
Population structure and growth of the beaked clam Eumarcia paupercula (Bivalvia, Veneridae) in Maputo Bay, Mozambique
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: ED Mugabe --- Centre of Coastal Studies and School of Marine and Coastal Sciences, Mozambique CA Amoda --- Centre of Coastal Studies and School of Marine and Coastal Sciences, Mozambique CL Griffiths --- Marine Research Institute and Department of Biological Sciences, South AfricaThe edible beaked clam Eumarcia paupercula (Holten, 1802) is an abundant component of the intertidal infauna in Maputo Bay, Mozambique, and is an important source of food and income for local communities. This study investigates the population structure and estimates... -
Grass community responses to drought in an African savanna
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: C Wigley-Coetsee --- , South Africa AC Staver --- , United StatesDrought is often discussed as a major perturbation in savanna ecosystems, associated with lasting shifts in savanna structure and functioning. However, historically, droughts have occurred frequently in southern African savannas, suggesting that plants might benefit from being resilient to drought... -
Wave setup at Tristan da Cunha
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: PL Woodworth --- , United KingdomWave setup was investigated using data from tide gauges in a small harbour at the island of Tristan da Cunha in the South Atlantic Ocean. Frequent examples of wave setup were found during the period 1986–1992, but were much less... -
Time dynamics of connectedness between commodity convenience yields and zero-coupon inflation swap rates
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Okan Aybar --- , France Mehmet Huseyin Bilgin --- , Turkey Serda Selin Öztürk --- , TurkeyGlobalisation and financial liberalisation have made financial markets more correlated and connected. In this context, it has become extremely important to understand the connectedness and correlation among different financial markets and commodities. This paper attempts to extend applicable empirical studies... -
Towed passive acoustic monitoring complements visual survey methods for Heaviside’s dolphins Cephalorhynchus heavisidii in the Namibian Islands Marine Protected Area
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: T Gridley --- , South Africa MJ Martin --- , South Africa J Slater --- , South Africa J-P Roux --- , Namibia RJ Swift --- , United Kingdom SH Elwen --- , South AfricaThe genus Cephalorhynchus contains four dolphin species, of which three are classified as Near Threatened or Endangered and one subspecies is close to extinction. Understanding the species’ abundance, distributions and habitat preferences is necessary for effective management to prevent further... -
Diversity pattern of bats (Mammalia: Chiroptera) in a modified tropical environment in the western region of Cameroon
Item type: Journal Article • Journal: African Zoology • Authors: Manfothang Dongmo Ervis --- , Cameroon Bakwo Fils Eric-Moise --- , Cameroon Mongombe Manga Aaron --- , Cameroon Atagana Patrick Jules --- , Cameroon Tchuenguem Fohouo Fernand-Nestor --- , CameroonThe western region of Cameroon is one of the leading agricultural production areas in sub-Saharan Africa, and this ongoing anthropogenic perturbation has led to the replacement of natural forests with agroecosystems. Such anthropogenic landscape transformations may have affected bat species... -
Are there long-term temporal trends of size composition and the length– weight relationship? Results for chokka squid Loligo reynaudii during the peak spawning season off the south coast of South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MR Lipiński --- , South Africa MA Mmethi --- , South Africa D Yemane --- , South Africa J Githaiga-Mwicigi --- , South Africa WHH Sauer --- , South AfricaTemporal trends in the size composition (length frequency) and length–weight (L–W) relationship of chokka squid Loligo reynaudii on the south coast of South Africa were assessed over periods spanning 22 years: length frequencies from 1996 to 2017 (with 15 years... -
Influence of soil organic carbon, fertiliser management, and weeding regime on weed dynamics and maize productivity on sandy soils in eastern Zimbabwe
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Justin Chipomho --- , Zimbabwe Cosmas Parwada --- , Zimbabwe Joyful T Rugare --- , Zimbabwe Stanford Mabasa --- , Zimbabwe Regis Chikowo --- , Zimbabwe Arnold B Mashingaidze --- , ZimbabweLabour bottlenecks and multiple operations at the start of a cropping season often result in inadequate early weed control and subsequent poor crop performance. Therefore, there is a need to establish management practices that provide the best opportunities for the... -
A laissez-faire management approach in a grassland landscape results in a fine-scale, spatio-temporally heterogeneous fire pattern
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Marc E Stalmans --- , South Africa Ed TF Witkowski --- , South Africa Kevin Balkwill --- , South AfricaWhat are the spatio-temporal characteristics of a fire pattern that is allowed to develop over time across a species- rich, predominantly grassy landscape? More than 1 300 fires were documented over 13 years in the 48 000 ha Songimvelo Game... -
Weed species composition and abundance in the main coffee production systems and regions of Ethiopia
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Abera Daba --- , Ethiopia Mekuria Tadesse --- , Ethiopia Selamawit Negassa Chawaka --- , Ethiopia Gezahegn Berecha --- , EthiopiaA weed population survey was carried out to assess the variability in weed species composition and abundance in the main coffee production systems and regions of Ethiopia. A total of 168 coffee fields were assessed using a quadrat count in... -
Evidence for overfishing of tigerfish Hydrocynus vittatus (Castelnau 1861) in the Kavango River, Namibia
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: FJ Jacobs --- , Namibia TF Naesje --- , Norway EM Ulvan --- , Norway CJ Hay --- , Namibia FH Khaebeb --- , Namibia OLF Weyl --- , South AfricaThe fishery for the African tigerfish Hydrocynus vittatus in northern Namibia makes a substantial contribution to surrounding food security and stimulates the local economy through subsistence and recreational fishing. However, local fishers suggest that catch rates of H. vittatus have... -
The impact of algorithmic trading on market quality: Evidence from the Johannesburg Stock Exchange
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Aurélie Courdent --- , David McClelland --- ,High-frequency trading (HFT) is a trading method that relies on sophisticated algorithms to analyse markets and execute large numbers of orders within milliseconds. In the last two decades, this new technology has gained traction globally and now accounts for the... -
Aggregation in Bibron's gecko, chondrodactylus bibronii
Item type: Journal Article • Journal: The Journal of the Herpetological Association of Africa • Authors: Anita Meyer --- University of Stellenbosch, South Africa P. le FrasN. Mouton --- University of Stellenbosch, South AfricaAggregation behaviour in a rock‐dwelling gecko Chondrodactylus bibronii was investigated. In a laboratory setup, individuals were provided with an excess of shelters to determine whether limited availability of optimal shelters may be the cause of this species’ aggregation behaviour in... -
The role of experimental perches on the hover and perch hunting preferences of the Pied Kingfisher Ceryle rudis
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Gerard Malan --- Tshwane University of Technology, South Africa Marco Heimstadt --- Tshwane University of Technology, South AfricaThe Pied Kingfisher Ceryle rudis is a fishing kingfisher that employs two hunting modes. The bird can either hunt from a perch or hover and then dive into the water. The former method is energetically cheap but limits prey searching... -
Stability analysis of fully dynamic piezoelectric beams with internal fractional delay
Item type: Journal Article • Journal: Quaestiones Mathematicae • Authors: Jianghao Hao --- Shanxi University, P.R. China Jing Yang --- Shanxi University, P.R. ChinaIn this paper, we are interested in the stability analysis of one-dimensional fully dynamic piezoelectric beam systems with internal fractional delay under different feedback controls (boundary and internal). By introducing two new equations to deal with fractional delay, equivalent new... -
Difference in acoustic responses to urbanisation in two African passerines
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Dickson Anobie Matthew --- AP Leventis Ornithological Research Institute (APLORI), Nigeria Samuel Tertse Ivande --- AP Leventis Ornithological Research Institute (APLORI), Nigeria Ulf Ottosson --- AP Leventis Ornithological Research Institute (APLORI), Nigeria Samuel Temidayo Osinubi --- University of Cape Town, South AfricaModification of ecosystems as a consequence of urbanisation alters natural habitat structures and soundscapes, creating constraints for vocal communication in animals. Birds are able to adjust their vocalisation to the prevailing acoustic features of their habitat. As such, their sounds... -
Female song in tinkerbirds (family Lybiidae)
Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology • Authors: Sifiso M Lukhele --- University of Cyprus, Cyprus Matteo Sebastianelli --- University of Cyprus, Cyprus Alexander NG Kirschel --- University of Cyprus, CyprusIn species that are sexually monomorphic, it can be challenging to ascertain whether both males and females sing. This is particularly the case when there are no discernible differences in the vocalisations of each sex. It is known that females... -
The time-frequency-quantile causal impact of Cable News-based Economic Policy Uncertainty on major assets returns
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Tomiwa Sunday Adebayo --- Cyprus International University, Turkey Oktay Özkan --- Faculty of Economics and Administrative Sciences, Tokat Gaziosmanpasa University, Turkey Emrah Sofuoğlu --- Kirsehir Ahi Evran University, Turkey Ojonugwa Usman --- Lebanese American University, LebanonAfter the collapse of the equity market in the early 2000s, the question of the drivers of financial assets returns preoccupied the interest of investors and policymakers in financial markets. Thus, this study explores how newly developed Cable News-based Economic... -
An estimation of liquidity effects of market microstructure changes in the Indian agricultural commodity market
Item type: Journal Article • Journal: Investment Analysts Journal • Authors: Sreekha Pullaykkodi --- Manipal School of Commerce and Economics, Manipal Academy of Higher Education, IndiaThe effects of market microstructure change on the liquidity of the Indian agricultural commodity market are examined using 18 years of data by dividing it into different sub-samples. The study examines variations in market liquidity by conducting a year-wise analysis,...