Browsing Faculty of Natural and Agricultural Sciences by Title
Now showing items 554-573 of 4825
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Challenges and emerging solutions to the land-based plastic waste issue in Africa
(Elsevier, 2018)In recent years, there has been a tremendous increase in work that focuses on the amount and types of waste entering the marine environment from multiple geographies around the world. To date, however, there are few reports ... -
Challenges and opportunities for biological mass spectrometry core facilities in the developing world
(The Association of Biomolecular Resource Facilities, 2018)The developing world is seeing rapid growth in the availability of biological mass spectrometry (MS), particularly through core facilities. As proteomics and metabolomics becomes locally feasible for investigators in these ... -
Challenges in reconciling observations and theory of the brightest high-energy flare ever of 3C 279
(PoS, 2017)Recent high-energy missions have allowed keeping watch over blazars in flaring states, which provide deep insights into the engine powered by supermassive black holes. However, having a quasar caught in a very bright ... -
Challenges in the potable water industry due to changes in source water quality: case study of Midvaal Water Company, South Africa
(Water Research Commission, 2016)Midvaal Water Company treats hypertrophic water abstracted from the Vaal River to supply bulk wholesome potable water to their consumers in compliance with the South African National Standard (SANS) 241:2015 for drinking ... -
Challenges to cosmic ray modeling: from beyond the solar wind termination shock
(Elsevier, 2008)Voyager 1 crossed the solar wind termination shock on December 16, 2004 at a distance of 94 AU from the Sun, to become the first spacecraft to explore the termination shock region and to enter the heliosheath, the final ... -
Chandra and HESS observations of the supernova remnant CTB 37B
(EDP Sciences, 2008)We discovered the >100 GeV γ-ray source, HESS J1713−381, apparently associated with the shell-type supernova remnant (SNR) CTB37B, using HESS in 2006. In 2007 we performed X-ray follow-up observations with Chandra with ... -
Change detection in INARCH time series of counts
(Springer, 2016)In the present paper we develop an online procedure for detecting changes in the parameters of integer ARCH models of order one. The test statistic utilizes the notion of the empirical probability generating function. The ... -
Change in dominance determines herbivore effects on plant biodiversity
(Nature, 2018)Herbivores alter plant biodiversity (species richness) in many of the world’s ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory ... -
Change in woody cover at representative sites in the Kruger National Park, South Africa, based on historical imagery
(SpringerOpen, 2016)Background: The coexistence of woody vegetation and grass is a key characteristic of savanna ecological balance. Gains in woody vegetation at the expense of grass can lead to changes in grazer and browser carrying capacities ... -
Change over three years in adolescents' physical activity levels and patterns after a physical activity intervention: play study
(Edizioni Minerva Medica, 2012)AIM: This study aimed to determine over a three-year period what the PA levels and patterns of adolescents will be after participating in a physical activity (PA) intervention. METHODS: African adolescents (158 boys, 211 ... -
Change point detection with multivariate observations based on characteristic functions
(Springer, 2017)We consider break-detection procedures for vector observations, both under independence as well as under an underlying structural time series scenario. The new methods involve L2-type criteria based on empirical characteristic ... -
Change-point methods for multivariate time-series: paired vectorial observations
(Springer, 2020)We consider paired and two-sample break-detection procedures for vectorial observations and multivariate time series. The new methods involve L2-type criteria based on empirical characteristic functions and are easy to ... -
Changeover-time in psychosocial wellbeing of people living with HIV and people living close to them after an HIV stigma reduction and wellness enhancement community intervention
(Taylor & Francis, 2015)HIV stigma continues to affect the psychosocial wellbeing of people living with HIV (PLWH) and people living close to them (PLC). Literature unequivocally holds the view that HIV stigma and psychosocial wellbeing interact ... -
Changes in abundance of fish-parasitic gnathiid isopods associated with warm-water bleaching events on the northern Great Barrier Reef
(Springer, 2019)Mass coral bleaching events due to rising seawater temperatures are occurring with increasing frequency and are among the most conspicuous consequences of human-induced climate change. While bleaching events have clear ... -
Changes in density and composition of algal assemblages in certain unit processes of two South African water purification plants
(Taylor & Francis, 2014)The water purification plants at Virginia and Bothaville, South Africa, experience problems with cyanobacteria and other algae. Their algal assemblages were studied during 2010 and 2011 to determine the dominant species ... -
Changes in gait and posture as factors of dynamic stability during walking in pregnancy
(Elsevier, 2018)Changes in gait and postural control during pregnancy may lead to increased fall rates during walking relative to non-pregnant women. Due to lack of empirical evidence on balance and postural control in dynamic conditions, ... -
Changes in local free-living parasite populations in response to cleaner manipulation over 12 years
(Springer, 2019)Predation on parasites is an important ecological process, but few experimental studies have examined the long-term impacts on the prey. Cleaner fish prey upon large numbers and selectively feed on the larger individuals ... -
Changes in Perceptions of the Internet’s Influence on Marketing in South Africa since the Late-1990s
(kamla-Raj Enterprises, 2014)The present paper reports on a study that compared senior marketers’ perceptions of the Internet’s influence on marketing in South Africa in 1997 with their perceptions nearly two decades later in 2011. In South Africa, ... -
Changes in soil fertility and Pak choi (Brassica chinensis L.) nutritional content in response to agouti (Dasyprocta leporina Linnaeus, 1758) manure amendment
(The University of the West Indies, 2017)Evaluating agouti manure (AM) as a source of macronutrients for plant production is a precursor to ensuring appropriate land application. Agouti manure was compared to cattle manure (CM) and mineral fertiliser (MF) applied ... -
Changes in the algal composition and water quality of the Sundays River, Karoo, South Africa, from source to estuary
(Taylor & Francis, 2015)A first survey was done on algae present in the Sundays River from its source to its confluence with the sea. Species found in the upstream sections of the river included indicators of good water quality, but the quality ...
