Browsing Faculty of Natural Sciences by Title
Now showing items 2406-2425 of 2571
-
Trends in HIV risk behaviour of incoming first-year students at a South African university: 2007–2012
(Taylor and Francis Group, 2015)The aim of the research on which this article is based was to understand the behavioural changes of the target student populationover time to ensure that future prevention programmes are more effective in changing behaviour. ... -
Trends in semen parameters of infertile men in South Africa and Nigeria
(2023)There are conflicting reports on trends of semen parameters from different parts of the globe. However, in recent times there is dearth of information on the trend in Sub-Saharan countries. Therefore, in this study we ... -
Tri-infection: Tuberculosis, HIV, COVID-19 and the already strained South African health system
(Elsevier, 2021)The 30th of May 2021 marks the latest significant national address, where President Cyril Ramaphosa moves the country back into level two lockdown with the hopes of curving the new COVID-19 surge while guarding an improving ... -
Trophic ecology of carnivorous zooplankton in the Benguela
(NISC and Taylor & Francis, 1992)Carnivorous zooplankton in the Benguela system have tended to be ignored by all but early taxonomists and a handful of recent researchers. An attempt is made here to address the importance of carnivores in this system but, ... -
Tropospheric modeling of acetic acid in the UK for summer, winter and spring seasons using a mesoscale 3-dimensional chemistry and transport model, WRF-Chem-CRI
(Elsevier, 2021)The measurement of acetic acid during the ClearfLo campaign for Winter 2012 and Summer 2012 in London and at the Weybourne Research Station (East Anglia), UK for Spring 2013 gives the average ± 1σ mixing ratios of 45.9 ± ... -
Tuberculosis in Ethiopia: Optimal intervention strategies and cost-effectiveness analysis
(MDPI, 2022)This paper searches for optimal strategies for the minimization of the number of high-risk latent and active tuberculosis (TB) infectious individuals using real data from Ethiopia. Optimal control theory is harnessed for ... -
Tunel assay: establishing a sperm dna fragmentation cut-off value for Egyptian infertile men
(Wiley Online Library, 2019)Male factor infertility is responsible for half of all infertility cases. Conventional semen analysis is inadequate to evaluate male fertility. Sperm DNA fragmentation (SDF) test can be done by: direct methods such as ... -
TUNEL assay—Standardized method for testing sperm DNA fragmentation
(Blackwell Publishing Ltd, 2021)Sperm DNA integrity is important for normal functions such as fertilization, implantation, pregnancy and fetal development. Sperm DNA fragmentation (SDF) is more common in infertile men and may be responsible for poor ... -
Tuning a mid-range rural WiFi-based mesh network
(ACM, 2013)Little is known about how mid-range, or several km, dis- tances a ect multipoint-to-multipoint links when single ra- dio nodes with omnidirectional antennas are used. In this poster, a real network with these characteristics ... -
Two large amplitude slowly pulsating hot subdwarf stars
(Oxford University Press, 2011)The discovery observations of two new slowly pulsating subdwarf B stars (V1093 Her stars), BPS CS22890−74 and PB 7032, are presented. Both stars are highly multiperiodic, and have – for V1093 Her stars – large amplitudes. ... -
Two new melobesioid algae (Corallinales, Rhodophyta), Synarthrophyton robbenense sp. nov. and S. munimentum sp. nov., in South Africa and Namibia
(International Phycological Society, 1997)Synarthrophyton robbenense sp. nov. and S. munimentum sp. nov., the fourth and fifth species in this apparently southern hemisphere genus, are described from southern Africa. Synarhrophyton robbenense occurs on rock and ... -
Two new nematode species from Saldanha Bay, South Africa: Perepsilonema benguelae sp. nov. and Leptepsilonema saldanha sp. nov. (Nematoda, Epsilonematidae)
(Magnolia Press, 2010)Perepsilonema benguelae sp. nov. and Leptepsilonema saldanhae sp. nov. are described and illustrated from coarse sand sediments in Saldanha Bay, along the west coast of South Africa. Perepsilonema benguelae sp. nov. is ... -
Two new pulsating hot subdwarf stars from the Edinburgh-Cape survey
(Oxford University Press, 2009)We report the discovery of very rapid pulsations in two hot subdwarf stars from the Edinburgh- Cape blue object survey. The short periods, small amplitudes and multiperiodicity establish these stars as members of the ... -
Two new species of Trachyandra sect. Liriothamnus (Xanthorrhoeaceae, Asphodeloideae) from the Western and Eastern Cape Provinces of South Africa
(2013)Trachyandra eriocarpa and T. bulbosa are two new species from Northern and Eastern Cape Provinces of South Africa. They are placed in T. sect. Liriothamnus based on their wiry roots, the cataphylls not forming membranous ... -
Two new variable sdB stars, HE 0218−3437 and LB 1516
(Oxford University Press, 2010)We present photometry which shows that two known hot subdwarf stars, HE 0218−3437 and LB 1516, are variable. LB 1516 exhibits several frequencies in the range 12–25 cycles d−1 (periods of about 1–2 h) with amplitudes ... -
Two pulses of Mesoproterozoic intra-plate magmatism in the heart of the Palaeoproterozoic Ubendian Domain of northern Malawi
(Elsevier, 2023)Two Mesoproterozoic anorogenic igneous events are recorded in the Palaeoproterozoic Ubendian Domain in northern Malawi. The oldest is represented by the Mwakikome orthogneiss, a small peraluminous, sub-alkaline and ferroan ... -
A two-decade anthropogenic and biogenic isoprene emissions study in a London urban background and a London urban traffic site
(MDPI, 2018)A relationship between isoprene and 1,3-butadiene mixing ratios was established to separate the anthropogenic and biogenic fractions of the measured isoprene in London air in both urban background (Eltham) and urban ... -
A Two-Decade Anthropogenic and Biogenic Isoprene Emissions Study in a London Urban Background and a London Urban Traffic Site
(MDPI, 2018-10-03)A relationship between isoprene and 1,3-butadiene mixing ratios was established to separate the anthropogenic and biogenic fractions of the measured isoprene in London air in both urban background (Eltham) and urban ... -
A two-step approach for detecting Striga in a complex agroecological system using Sentinel-2 data
(Elsevier, 2021)Information on weed occurrence within croplands is vital but is often unavailable to support weeding practices and improve cropland productivity assessments. To date, few studies have been conducted to estimate and map ... -
Tyrosinase and melanogenesis inhibition by indigenous African plants: A review
(Multidisciplinary Digital Publishing Institute (MDPI), 2020)The indiscriminate use of non-regulated skin lighteners among African populations has raised health concerns due to the negative effects associated with skin lightener toxicity. For this reason, there is a growing interest ...