Browsing Faculty of Natural Sciences by Title
Now showing items 2051-2070 of 2571
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A revision of the genus Strongylodesma Lévi (Porifera: Demospongiae: Latrunculiidae) with descriptions of four new species
(Cambridge University Press, 2009)The sponge genus Strongylodesma is reviewed and redefined, and now accommodates eight closely related species. The type species of Strongylodesma Le´vi is redescribed and an additional two new species are described from ... -
Revisiting the [C ii]158𝝁��m line-intensity mapping power spectrum from the EoR using non-uniform line-luminosity scatter
(Oxford University Press, 2023)Detecting the line-intensity mapping (LIM) signal from the galaxies of the Epoch of Reionization is an emerging tool to constrain their role in reionization. Ongoing and upcoming experiments target the signal fluctuations ... -
Rhodolith bed discovered off the south African coast
(MDPI, 2020)Rhodolith beds have not previously been recorded in South Africa. A multidisciplinary research effort used remote sampling tools to survey the historically unexplored continental shelf off the Eastern Cape coast of South ... -
Risk factors of inconsistent condom use among sexually active youths: Implications for human immunodeficiency virus and sexual risk behaviours in Malawi
(SAGE, 2017)This study examines the risk associated with inconsistent use of condoms as a risk factor for human immunodeficiency virus/sexually transmitted infections (HIV/STIs) and sexual risk behaviours. The Malawi Demographic ... -
Risk factors of preterm delivery of low birth weight (plbw) in an African population
(Academic Journals, 2010)More than 20 million infants in the world (15.5% of all births) are born with low birth weight. Ninety-five percent of them are in developing countries. The objective of this study was to examine different factors which ... -
Risk factors of preterm delivery of low birth weight (plbw) in an African population
(Academic Journals, 2010)More than 20 million infants in the world (15.5% of all births) are born with low birth weight. Ninety-five percent of them are in developing countries. The objective of this study was to examine different factors which ... -
Ritalinic acid stimulates human sperm motility and maintains vitality in vitro
(Korean Society for Sexual Medicine and Andrology, 2020)To evaluate the in vitro impact of ritalinic acid (RA), a major metabolite of methylphenidate (drug to treat attention-deficit hyperactivity disorder), on sperm motility, vitality and oxidative stress. Materials and Methods: ... -
Riverine dominance of a nearshore marine demersal food web: evidence from stable isotope and C/N ratio analysis
(National Inquiry Services Centre (NISC), 2016)The Thukela Bank, KwaZulu-Natal, supports a diverse ecosystem and South Africa’s only prawn fishery. Oceanographic studies suggest riverine input is not important for the biology of this system, whereas biological studies ... -
A robust numerical solution to a time-fractional Black–Scholes equation
(Springer Nature, 2021)Dividend paying European stock options are modeled using a time-fractional Black–Scholes (tfBS) partial differential equation (PDE). The underlying fractional stochastic dynamics explored in this work are appropriate for ... -
A robust spectral method for pricing of American put options on zero-coupon bonds
(Global-Science Press, 2018)American put options on a zero-coupon bond problem is reformulated as a linear complementarity problem of the option value and approximated by a nonlinear partial differential equation. The equation is solved by an ... -
A robust spectral method for solving Heston’s model
(Springer Verlag, 2014)In this paper, we consider the Heston’s volatility model (Heston in Rev. Financ. Stud. 6: 327–343, 1993]. We simulate this model using a combination of the spectral collocation method and the Laplace transforms method. ... -
Role and merits of green based nanocarriers in cancer treatment
(MPDI, 2021)The use of nanocarriers for biomedical applications has been gaining interests from researchers worldwide for the delivery of therapeutics in a controlled manner. These “smart” vehicles enhance the dissolution and the ... -
Role of cytocentrifugation combined with nuclear fast picroindigocarmine staining in detecting cryptozoospermia in men diagnosed with azoospermia
(Seoul: Korean Society for Sexual Medicine and Andrology, 2022)Azoospermia is defined as the absence of spermatozoa in the pellet of a centrifuged semen sample. In fact, when a basic semen analysis fails to detect sperm in the ejaculate, there is still the possibility of detecting ... -
The Role of Cytoskeletal Proteins in the Formation of a Functional In Vitro Blood-Brain Barrier Model
(MDPI, 2022)The brain capillary endothelium is highly regulatory, maintaining the chemical stability of the brain’s microenvironment. The role of cytoskeletal proteins in tethering nanotubules (TENTs) during barrier-genesis was ... -
The role of encrusting coralline algae in the diets of selected intertidal herbivores
(Springer Verlag, 2006)Kalk Bay, South Africa, has a typical south coast zonation pattern with a band of seaweed dominating the mid-eulittoral and sandwiched between two molluscan-herbivore dominated upper and lower eulittoral zones. Encrusting ... -
The role of environment in galaxy evolution in the servs survey. I. density maps and cluster candidates
(The American Astronomical Society, 2020)We use photometric redshifts derived from new u-band through 4.5 μm Spitzer IRAC photometry in the 4.8 deg2 of the XMM-LSS field to construct surface density maps in the redshift range of 0.1–1.5. Our density maps ... -
The role of ground water in Sub-Saharan Africa
(Wiley-Blackwell, 2010)Although water resources managers speak of a water crisis in Africa, the management of ground water has to date not featured strongly in national and regional African water agendas. Examination of the physical environment of ... -
Role of Indigenous and local knowledge in seasonal forecasts and climate adaptation: A case study of smallholder farmers in Chiredzi, Zimbabwe
(Elsevier, 2023)Accessible, reliable and diverse sources of climate information are needed to inform climate change adaptation at all levels of society, particularly for vulnerable sectors such as smallholder farming. Globally, many ... -
The role of infections and leukocytes in male infertility
(Blackwell Publishing Ltd, 2021)Declining birth rates are one of the problems facing society today. Male counterparts are responsible for about half of the infertility cases, and genitourinary tract infections may play a contributing role in approximately ... -
Role of jellyfish in the plankton ecosystem revealed using a global ocean biogeochemical model
(Copernicus GmbH, 2021)Jellyfish are increasingly recognised as important components of the marine ecosystem, yet their specific role is poorly defined compared to that of other zooplankton groups. This paper presents the first global ocean ...