Browsing Faculty of Natural Sciences by Title
Now showing items 796-815 of 2571
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Evolution of the chemical composition of Sn thin films heated during x-ray photoelectron spectroscopy
(2019)High-vacuum XPS have been used to analyse the surface modification of a 3 nm-thick Sn thin film on Si (100) before and after annealing up to 450 °C. Increasing the XPS stage temperature led to a reduction in the amount of ... -
The evolution of the low-frequency radio AGN population to z 1.5 in the ELAIS N1 field
(Advance Access publication, 2020-11-13)We study the cosmic evolution of radio sources out to z 1.5 using a GMRT 610 MHz survey covering ∼1.86 deg2 of the ELAIS N1 field with a minimum/median rms noise 7.1/19.5 μJy beam−1 and an angular resolution of 6 arcsec. ... -
The evolution of the low-frequency radio AGN population to z 1.5 in the ELAIS N1 field
(Oxford University Press, 2021)We study the cosmic evolution of radio sources out to z ≃ 1.5 using a GMRT 610 MHz survey covering ∼1.86 deg2 of the ELAIS N1 field with a minimum/median rms noise 7.1/19.5 μJy beam−1 and an angular resolution of 6 arcsec. ... -
Evolutionary history of the Corallinales (Corallinophycidae, Rhodophyta) inferred from nuclear, plastidial and mitochondrial genomes
(Elsevier, 2011)Systematics of the red algal order Corallinales has a long and convoluted history. In the present study, molecular approaches were used to assess the phylogenetic relationships based on the analyses of two datasets: a large ... -
The evolving role of science in society
(José Frantz, 2020)The world is experiencing a traumatic change brought about by the Covid-19 pandemic. It is traumatic because it is sudden and affects everyone around the globe at once. Nothing like this has ever happened so rapidly before, ... -
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
(American Association for the Advancement of Science, 2022)Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the ... -
Ex-situ electrochemical characterization of iro2 synthesized by a modified Adams fusion method for the oxygen evolution reaction
(MDPI, 2019)The development of highly stable and active electrocatalysts for the oxygen evolution reaction (OER) has attracted significant research interest. IrO2 is known to show good stability during the OER however it is not known ... -
Examination of maternal gingival crevicular fluid for the presence of selected periodontopathogens implicated in the pre-term delivery of low birthweight infants
(Landes Bioscience, 2010)Background: Reports show that more than 20 million infants world-wide are born prematurely with 95% of all pre-term births occurring in developing countries. Oral colonization of Gram-negative anaerobes has been implicated ... -
Examining inequality of opportunity in the use of maternal and reproductive health interventions in Sierra Leone
(Oxford University Press, 2020)Poor countries, such as Sierra Leone, often have poor health outcomes, whereby the majority of the population cannot access lifesaving health services. Access to, and use of, maternal and reproductive health services is ... -
The excessive use of antioxidant therapy: A possible cause of male infertility?
(Wiley, 2018)Reactive oxygen species and oxidative stress are closely associated with various pathologies such as neurodegenerative diseases, ageing and male infertility. Hence, antioxidants such as vitamin C, vitamin E, N‐acetyl ... -
Existence domains of dust-acoustic solitons and supersolitons
(AIP PublishingAIP Publishing, 2013)Using the Sagdeev potential method, the existence of large amplitude dust-acoustic solitons and supersolitons is investigated in a plasma comprising cold negative dust, adiabatic positive dust, Boltzmann electrons, and ... -
Exogenous 3,3′-diindolylmethane improves vanadium stress tolerance in brassica napus seedling shoots by modulating antioxidant enzyme activities
(MDPI, 2021)3,3′-diindolylmethane (DIM) belongs to a family of indole glucosinolate compounds that have been shown to improve Brassica napus growth through the modulation of reactive oxygen species when applied exogenously. The B. ... -
Exogenous antioxidants enhance seedling growth and yield of artificially aged cabbage and lettuce seeds
(MPDI, 2021)Aged seeds exhibit compromised vigour in terms of germination, seedling emergence and growth, but this can to some extent be alleviated by invigoration treatments before sowing. This study aimed to investigate ageing ... -
Exogenous p-coumaric acid improves salvia hispanica l. Seedling shoot growth
(MDPI Open Access Journals, 2019)p-Coumaric acid (p-CA) belongs to a family of natural esters of hydroxycinnamic acid compounds that have been shown to modulate plant growth and metabolism. In this study, we investigated the effect of exogenous p-CA on ... -
Exome sequencing identifies novel dysferlin mutation in a family with pauci-symptomatic heterozygous carriers
(Springer Nature, 2018)Background: We investigated a South African family of admixed ancestry in which the first generation (G1) developed insidious progressive distal to proximal weakness in their twenties, while their offspring (G2) experienced ... -
Exome sequencing identifies novel dysferlin mutation in a family with paucisymptomatic heterozygous carriers
(BioMed Central, 2018)BACKGROUND: We investigated a South African family of admixed ancestry in which the first generation (G1) developed insidious progressive distal to proximal weakness in their twenties, while their offspring (G2) experienced ... -
Exomol line lists – xliv. Infrared and ultraviolet line list for silicon monoxide (28si16o)
(Oxford University Press, 2022)A new silicon monoxide ( 28Si16O) line list covering infrared, visible, and ultraviolet regions called SiOUVenIR is presented. This line list extends the infrared EBJT ExoMol line list by including vibronic transitions ... -
Exosomes form tunneling nanotubes (TUNTs) in the blood-brain barrier: A nano-anatomical perspective of barrier genesis
(Frontiers Media, 2022)The blood-brain barrier (BBB) is a robust interface between the blood and the central nervous system. Barrier type endothelium is able to limit paracellular (PC) movement, relegating molecular flux to the transendothel ... -
The EXOTIME project: Signals in the O-C diagrams of the rapidly pulsating subdwarfs DW Lyn, V1636 Ori, QQ Vir, and V541 Hya.
(EDP Sciences, 2020)We aim to investigate variations in the arrival time of coherent stellar pulsations due to the light-travel time effect to test for the presence of sub-stellar companions. Those companions are the key to one possible ... -
Experiences, challenges and lessons from rolling out a rural WiFi mesh network
(ACM, 2013)The DEV community knows that technology interventions involve consideration of social and environmental factors as much as technical ones. This is particularly true for the introduction of communications infrastructure in ...