Institution
University of Johannesburg
Education•Johannesburg, South Africa•
About: University of Johannesburg is a education organization based out in Johannesburg, South Africa. It is known for research contribution in the topics: Population & Context (language use). The organization has 8070 authors who have published 22749 publications receiving 329408 citations. The organization is also known as: UJ.
Papers published on a yearly basis
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TL;DR: An association between marital status and HIV prevalence and incidence in contemporary South Africa, where odds of being HIV-positive were found to be lower among married individuals who lived with their spouses compared to all other marital status groups, is suggested.
Abstract: South Africa has experienced declining marriage rates and the increasing practice of cohabitation without marriage. This study aims to improve the understanding of the relationship between marital status and HIV in South Africa, an HIV hyperendemic country, through an analysis of findings from the 2012 South African National HIV Prevalence, Incidence and Behaviour Survey. The nationally representative population-based cross-sectional survey collected data on HIV and socio-demographic and behavioural determinants in South Africa. This analysis considered respondents aged 16 years and older who consented to participate in the survey and provided dried blood spot specimens for HIV testing (N = 17,356). After controlling for age, race, having multiple sexual partners, condom use at last sex, urban/rural dwelling and level of household income, those who were married living with their spouse had significantly reduced odds of being HIV-positive compared to all other marital spouses groups. HIV incidence was 0.27% among respondents who were married living with their spouses; the highest HIV incidence was found in the cohabiting group (2.91%). Later marriage (after age 24) was associated with increased odds of HIV prevalence. Our analysis suggests an association between marital status and HIV prevalence and incidence in contemporary South Africa, where odds of being HIV-positive were found to be lower among married individuals who lived with their spouses compared to all other marital status groups. HIV prevention messages therefore need to be targeted to unmarried populations, especially cohabitating populations. As low socio-economic status, low social cohesion and the resulting destabilization of sexual relationships may explain the increased risk of HIV among unmarried populations, it is necessary to address structural issues including poverty that create an environment unfavourable to stable sexual relationships.
827 citations
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Flanders Marine Institute1, University of New South Wales2, Australian Museum3, University of Southern Mississippi4, National Oceanography Centre, Southampton5, University of Hasselt6, WorldFish7, American Museum of Natural History8, San Diego State University9, Museum Victoria10, Natural History Museum11, Dowling College12, University of Hamburg13, James Cook University14, University of Johannesburg15, National Museum of Natural History16, National Taiwan Ocean University17, Scripps Institution of Oceanography18, National Oceanic and Atmospheric Administration19, University of Queensland20, University of Sassari21, Université libre de Bruxelles22, Vrije Universiteit Brussel23, Queensland Museum24, University of California, Merced25, Ghent University26, Naturalis27, Howard University28, University of Gothenburg29, Florida Museum of Natural History30, California Academy of Sciences31, Centre for Environment, Fisheries and Aquaculture Science32, Osaka University33, University of Santiago de Compostela34, University of Alaska Anchorage35, University of Málaga36, National Institute of Water and Atmospheric Research37, National University of Ireland, Galway38, University of Alaska Fairbanks39, Spanish National Research Council40, CABI41, University of Siegen42, Massey University43, University of Copenhagen44, Naturhistorisches Museum45, University of Washington46, Museum für Naturkunde47, Woods Hole Oceanographic Institution48, Western Washington University49, University of Bergen50, Nova Southeastern University51, Shirshov Institute of Oceanology52, National University of Singapore53, Shimane University54, Agnes Scott College55, University of the Ryukyus56, University of California, Davis57, Federal University of Paraná58, University of the Basque Country59, University of Veterinary Medicine Hanover60, Royal Belgian Institute of Natural Sciences61, Tel Aviv University62, Swedish Museum of Natural History63, Joint Nature Conservation Committee64, The Evergreen State College65, Estonian University of Life Sciences66, University of Maine67, Virginia Commonwealth University68, Trinity College, Dublin69, University of Auckland70
TL;DR: The first register of the marine species of the world is compiled and it is estimated that between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely.
822 citations
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TL;DR: In this article, it was shown that occurrences of BIF, GIF, Pherozoic ironstones, and exhalites surrounding VMS systems are linked to diverse environmental changes.
Abstract: Iron formations are economically important sedimentary rocks that are most common in Precambrian sedimentary successions. Although many aspects of their origin remain unresolved, it is widely accepted that secular changes in the style of their deposition are linked to environmental and geochemical evolution of Earth. Two types of Precambrian iron formations have been recognized with respect to their depositional setting. Algoma-type iron formations are interlayered with or stratigraphically linked to submarine-emplaced volcanic rocks in greenstone belts and, in some cases, with volcanogenic massive sulfide (VMS) deposits. In contrast, larger Superior-type iron formations are developed in passive-margin sedimentary rock successions and generally lack direct relationships with volcanic rocks. The early distinction made between these two iron-formation types, although mimimized by later studies, remains a valid first approximation. Texturally, iron formations were also divided into two groups. Banded iron formation (BIF) is dominant in Archean to earliest Paleoproterozoic successions, whereas granular iron formation (GIF) is much more common in Paleoproterozoic successions. Secular changes in the style of iron-formation deposition, identified more than 20 years ago, have been linked to diverse environmental changes. Geochronologic studies emphasize the episodic nature of the deposition of giant iron formations, as they are coeval with, and genetically linked to, time periods when large igneous provinces (LIPs) were emplaced. Superior-type iron formation first appeared at ca. 2.6 Ga, when construction of large continents changed the heat flux at the core-mantle boundary. From ca. 2.6 to ca. 2.4 Ga, global mafic magmatism culminated in the deposition of giant Superior-type BIF in South Africa, Australia, Brazil, Russia, and Ukraine. The younger BIFs in this age range were deposited during the early stage of a shift from reducing to oxidizing conditions in the ocean-atmosphere system. Counterintuitively, enhanced magmatism at 2.50 to 2.45 Ga may have triggered atmospheric oxidation. After the rise of atmospheric oxygen during the GOE at ca. 2.4 Ga, GIF became abundant in the rock record, compared to the predominance of BIF prior to the Great Oxidation Event (GOE). Iron formations generally disappeared at ca. 1.85 Ga, reappearing at the end of the Neoproterozoic, again tied to periods of intense magmatic activity and also, in this case, to global glaciations, the so-called Snowball Earth events. By the Phanerozoic, marine iron deposition was restricted to local areas of closed to semiclosed basins, where volcanic and hydrothermal activity was extensive (e.g., back-arc basins), with ironstones additionally being linked to periods of intense magmatic activity and ocean anoxia.
Late Paleoproterozoic iron formations and Paleozoic ironstones were deposited at the redoxcline where biological and nonbiological oxidation occurred. In contrast, older iron formations were deposited in anoxic oceans, where ferrous iron oxidation by anoxygenic photosynthetic bacteria was likely an important process. Endogenic and exogenic factors contributed to produce the conditions necessary for deposition of iron formation. Mantle plume events that led to the formation of LIPs also enhanced spreading rates of midocean ridges and produced higher growth rates of oceanic plateaus, both processes thus having contributed to a higher hydrothermal flux to the ocean. Oceanic and atmospheric redox states determined the fate of this flux. When the hydrothermal flux overwhelmed the oceanic oxidation state, iron was transported and deposited distally from hydrothermal vents. Where the hydrothermal flux was insufficient to overwhelm the oceanic redox state, iron was deposited only proximally, generally as oxides or sulfides. Manganese, in contrast, was more mobile. We conclude that occurrences of BIF, GIF, Phanerozoic ironstones, and exhalites surrounding VMS systems record a complex interplay involving mantle heat, tectonics, and surface redox conditions throughout Earth history, in which mantle heat unidirectionally declined and the surface oxidation state mainly unidirectionally increased, accompanied by superimposed shorter term fluctuations.
758 citations
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TL;DR: Chitosan based nanomaterials have superior physical and chemical properties such as high surface area, porosity, tensile strength, conductivity, photo-luminescent as well as increased mechanical properties as comparison to pure chitOSan.
698 citations
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University of Tehran1, Université de Montréal2, New Mexico State University3, Royal Botanic Gardens4, State University of Feira de Santana5, State University of Campinas6, University of the Western Cape7, Federal University of São Carlos8, University of Melbourne9, Federal University of Bahia10, National Taiwan University11, Australian National University12, Complutense University of Madrid13, National Autonomous University of Mexico14, Cornell University15, Université libre de Bruxelles16, National Museum of Natural History17, University of Oxford18, Sao Paulo State University19, Universidad de Morón20, Federal University of Western Bahia21, Royal Botanic Garden Edinburgh22, University of Reading23, University of Zurich24, Universidade Federal do Rio Grande do Sul25, Kyushu University26, University of South Africa27, Tarbiat Modares University28, Montana State University29, University of Johannesburg30, Pontifical Catholic University of Rio de Janeiro31, University of Angers32, National Science Foundation33, Missouri Botanical Garden34, National University of Rosario35, University of Arizona36, Federal University of Rio Grande do Norte37, Universidade Federal de Goiás38, Empresa Brasileira de Pesquisa Agropecuária39, University of Dundee40, Arizona State University at the Polytechnic campus41, Arizona State University42, University of Cape Town43, New York Botanical Garden44, Naturalis45, Heidelberg University46, Chinese Academy of Sciences47
TL;DR: The classification of the legume family proposed here addresses the long-known non-monophyly of the traditionally recognised subfamily Caesalpinioideae, by recognising six robustly supported monophyletic subfamilies and reflects the phylogenetic structure that is consistently resolved.
Abstract: The classification of the legume family proposed here addresses the long-known non-monophyly of the traditionally recognised subfamily Caesalpinioideae, by recognising six robustly supported monophyletic subfamilies. This new classification uses as its framework the most comprehensive phylogenetic analyses of legumes to date, based on plastid matK gene sequences, and including near-complete sampling of genera (698 of the currently recognised 765 genera) and ca. 20% (3696) of known species. The matK gene region has been the most widely sequenced across the legumes, and in most legume lineages, this gene region is sufficiently variable to yield well-supported clades. This analysis resolves the same major clades as in other phylogenies of whole plastid and nuclear gene sets (with much sparser taxon sampling). Our analysis improves upon previous studies that have used large phylogenies of the Leguminosae for addressing evolutionary questions, because it maximises generic sampling and provides a phylogenetic tree that is based on a fully curated set of sequences that are vouchered and taxonomically validated. The phylogenetic trees obtained and the underlying data are available to browse and download, facilitating subsequent analyses that require evolutionary trees. Here we propose a new community-endorsed classification of the family that reflects the phylogenetic structure that is consistently resolved and recognises six subfamilies in Leguminosae: a recircumscribed Caesalpinioideae DC., Cercidoideae Legume Phylogeny Working Group (stat. nov.), Detarioideae Burmeist., Dialioideae Legume Phylogeny Working Group (stat. nov.), Duparquetioideae Legume Phylogeny Working Group (stat. nov.), and Papilionoideae DC. The traditionally recognised subfamily Mimosoideae is a distinct clade nested within the recircumscribed Caesalpinioideae and is referred to informally as the mimosoid clade pending a forthcoming formal tribal and/or cladebased classification of the new Caesalpinioideae. We provide a key for subfamily identification, descriptions with diagnostic charactertistics for the subfamilies, figures illustrating their floral and fruit diversity, and lists of genera by subfamily. This new classification of Leguminosae represents a consensus view of the international legume systematics community; it invokes both compromise and practicality of use.
697 citations
Authors
Showing all 8414 results
Name | H-index | Papers | Citations |
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Vinod Kumar Gupta | 165 | 713 | 83484 |
Arnold B. Bakker | 135 | 506 | 103778 |
Trevor Vickey | 128 | 873 | 76664 |
Ketevi Assamagan | 128 | 934 | 77061 |
Diego Casadei | 123 | 733 | 69665 |
Michael R. Hamblin | 117 | 899 | 59533 |
E. Castaneda-Miranda | 117 | 545 | 56349 |
Xiaoming Li | 113 | 1932 | 72445 |
Katharine Leney | 108 | 459 | 52547 |
M. Aurousseau | 103 | 403 | 44230 |
Mika Sillanpää | 96 | 1019 | 44260 |
Sahal Yacoob | 89 | 408 | 25338 |
Evangelia Demerouti | 85 | 236 | 49228 |
Lehana Thabane | 85 | 994 | 36620 |
Sahal Yacoob | 84 | 399 | 35059 |