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Calibration of a hand-held instrument for measuring condensed tannin concentration based on UV- and red-excited fluorescence
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Peter Scogings --- Department of Agriculture, South Africa Sithembile Siko --- Department of Agriculture, South Africa Robert Taylor --- NRF/SAEON Ndlovo Node, South AfricaCondensed tannins are ecologically important compounds in plants for several reasons, e.g. as herbivore deterrents or protecting photosynthetic tissues against ultraviolet radiation. The hand-held Dualex Series 4 instrument was originally developed for indirect determination of flavonol concentrations in crops. Flavonols... -
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.,... -
Forage–cattle relationships in a communally managed semi-arid savanna in northern Zululand, South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: CC Nyamukanza PF Scogings NW KuneneDevelopment of extensive livestock production in KwaZulu-Natal is constrained by seasonal variability of rangeland production and low forage nutritional quality. A three-year study was implemented to determine the seasonal variation in herbaceous biomass and chemical composition of veld, animal weight,... -
Physiological stress levels in the endemic and endangered Udzungwa red colobus vary with elevation
Item type: Journal Article • Journal: African Zoology • Authors: Claudia Barelli --- Sezione di Biodiversità Tropicale, MUSE – Museo delle Scienze, Italy Francesco Rovero --- Sezione di Biodiversità Tropicale, MUSE – Museo delle Scienze, Italy Keith Hodges --- Reproductive Biology Unit, German Primate Center, Germany Alessandro Araldi --- Reproductive Biology Unit, German Primate Center, Germany Michael Heistermann --- Endocrinology Laboratory, German Primate Centre, GermanyHabitat loss and fragmentation inevitably cause biodiversity decline, a major concern for the conservation of endangered species. Primates are of particular interest, because they are highly vulnerable to forest fragmentation. In this study, we investigated faecal glucocorticoid measurements (FGCM), an... -
Determining adrenocortical activity as a measure of stress in African buffalo (Syncerus caffer) based on faecal analysis
Item type: Journal Article • Journal: African Zoology • Authors: A. Ganswindt --- Mammal Research Institute, Department of Zoology and Entomology, South Africa A.S.W. Tordiffe --- National Zoological Gardens of South Africa, South Africa E. Stam --- Mammal Research Institute, Department of Zoology and Entomology, South Africa M.J. Howitt --- National Zoological Gardens of South Africa, South Africa F. Jori --- Mammal Research Institute, Department of Zoology and Entomology, South AfricaLittle is known about the levels of stress experienced by African buffalos affected by injury, disease, or socio-ecological and anthropogenic factors. To be able to start filling this gap, we examined the suitability of two 11-oxoaetiocholanolone enzyme-immunoassays (EIAs) detecting 11,17... -
Non-invasive measurement of adrenocortical activity in a myrmecophageous mammal, the bat-eared fox
Item type: Journal Article • Journal: African Zoology • Authors: Aliza Le Roux --- Zoology and Entomology, South Africa Helene Botha --- Zoology and Entomology, South Africa Fredrik Dalerum --- Research Unit of Biodiversity (UO, CSIC, PA), Spain Andre Ganswindt --- Endocrine Research Laboratory, Department of Anatomy and Physiology, South AfricaMeasuring physiological stress reactions through the quantification of plasma cortisol often involves physical restraint, which acts as a stressor itself. Here, we present the validation of a non-invasive method for assessing adrenocortical activity as an indicator of stress in the... -
Stress steroid levels and the short-term impact of routine dehorning in female southern white rhinoceroses (Ceratotherium simum simum)
Item type: Journal Article • Journal: African Zoology • Authors: Marcha Badenhorst --- Endocrine Research Laboratory, Department of Anatomy and Physiology, South Africa Michelle Otto --- Buffalo Dream Ranch Wildlife Veterinary Services, South Africa Annemieke C van der Goot --- Lapalala Wilderness, South Africa André Ganswindt --- Endocrine Research Laboratory, Department of Anatomy and Physiology, South AfricaRhinoceros populations in Africa are under severe threat as a result of surging poaching rates and risk-mitigation strategies are continuously adapted in an attempt to ensure the survival of the species. This study compared faecal glucocorticoid metabolite (fGCM) levels of... -
Influence of temperature, aluminium chloride toxicity and exposure to Bacillus subtilis on the germination of okra
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Matsobane T Mathiba --- Department of Agriculture and Animal Health, South Africa Khayalethu Ntushelo --- Department of Agriculture and Animal Health, South Africa Fhatuwani Mudau --- Department of Agriculture and Animal Health, South AfricaInfluences of heat, aluminium chloride concentration and exposure to Bacillus subtilis on germination of okra seed were investigated. A factorial experiment was conducted using Petri dish assays, and seed germination percentage and coleoptile length were recorded for the different treatments... -
Non-invasive assessment of adrenocortical activity as a measure of stress in leopards Panthera pardus
Item type: Journal Article • Journal: African Zoology • Authors: Andrea B Webster --- Endocrine Research Laboratory, Department of Anatomy and Physiology, South Africa Richard EJ Burroughs --- Department of Production Animal Studies. Faculty of Veterinary Science, South Africa Peter Laver --- Endocrine Research Laboratory, Department of Anatomy and Physiology, South Africa André Ganswindt --- Endocrine Research Laboratory, Department of Anatomy and Physiology, South AfricaLeopards Panthera pardus are classified in the IUCN Red List as Vulnerable, primarily due to habitat loss, natural prey base depletion and exploitation caused by various anthropogenic activities. Although protected areas are important for leopard conservation, the majority of suitable... -
Assessment of persistent organochlorine compounds contamination on the Lake Victoria water and sediments: a case study in Tanzania
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: A Wenaty --- Department of Food Technology, Nutrition and Consumer Sciences, Tanzania F Mabiki --- Department of Chemistry and Physics, Tanzania B Chove --- Department of Food Technology, Nutrition and Consumer Sciences, Tanzania R Mdegela --- Department of Veterinary Medicine and Public Health, TanzaniaThe current study was conducted to establish the levels of organochlorine pesticides (OCPs), its degradation products, and indicatory polychlorinated biphenyls (PCBs) in water and sediments from Lake Victoria in Tanzania. Seven indicator PCBs were identified in sediments, and five were... -
Spatio-temporal distribution of organochlorine pesticide residues in water and sediments of tropical reservoirs: a case study of Bui Reservoir, Ghana
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: SB Jidauna --- , Ghana R Edziyie --- , Ghana BB Campion --- , GhanaThis study investigated the spatio-temporal distribution of organochlorine pesticides (OCPs) in water and sediments of the Bui Reservoir from June 2017 to May 2018, to provide baseline data for monitoring contamination in the Reservoir. Samples were collected during four seasons... -
Endogenous metabolic content of the cutting positions and ndole-3-butyric acid influence rooting of Toona ciliata var. pubescens stem cuttings
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Qiangqiang Cheng --- , China Dejia Ji --- , China Xiaoyan Guo --- , China Honglang Huang --- , China Lu Zhang --- , ChinaToona ciliata var. pubescens (family Meliaceae) is an endangered species of mahogany endemic to China. It is now under Class II protection, and stem cuttings are an important means for its clonal propagation. However, the metabolic changes that occur in...