Transactions of The Royal Society of South Africa最新文献

{"title":"A camera trap record of scavengers at a kudu carcass: implications for archaeological bone accumulations","authors":"L. Wadley","doi":"10.1080/0035919X.2020.1813215","DOIUrl":"https://doi.org/10.1080/0035919X.2020.1813215","url":null,"abstract":"A camera trap was set near a greater kudu bull carcass for 3 weeks at the start of winter. The carcass lay in an open savanna setting on a game farm in Limpopo, and it was visited by leopard, brown hyena, black-backed jackal, African civet, honey badger, bushpig and warthog. At the end of a month there were no visible remains of the carcass save the skull and damaged horns. After a week, when decomposition was pronounced, suids spent more time at the carcass than other animals. They may have been responsible for much of the on-site bone consumption. Bone and meat portions not eaten directly at the death scene were probably carried away by scavengers like brown hyena and jackal. The area was excavated and sieved to collect bone debris that might have been trampled into sediment. Only a few small bone fragments were recovered, one of which had a tooth mark. Several outcomes are of interest to archaeologists. Firstly, the diversity of scavengers at the kudu carcass (including some animals not normally classified as scavengers) suggests that damage on surviving bone at some archaeological sites may be from an assortment of animals not normally considered to be scavengers. Comparative collections must accommodate such variety. Secondly, under certain environmental conditions, death assemblages in the wild may disappear without trace when predators can move freely and feed without disturbance. Thirdly, is possible that some bone fragments survive at archaeological sites because they were protected (possibly unintentionally) by human presence, and because they were on occasion processed in ways that made them less attractive to predators.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"245 - 257"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919X.2020.1813215","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42972815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping the spatial distribution of Lantana camara using high-resolution SPOT 6 data, in Mpumalanga communal areas, South Africa","authors":"Ngwanamapotu Paschaline Madileng, O. Mutanga, T. Dube, Omosalewa Odebiri","doi":"10.1080/0035919x.2020.1817812","DOIUrl":"https://doi.org/10.1080/0035919x.2020.1817812","url":null,"abstract":"Agroecosystems play a critical role in rural economics and contribute to the national economy. However, these areas are currently threatened by invasive species. Timely information on potential hotspots and affected areas is required for management purposes. We assess the spatial distribution patterns of Lantana camara invasion in savanna rangeland ecosystems before and after clearing (2014, 2016 and 2018), using high-resolution SPOT 6 data, in Agincourt, South Africa. A maximum likelihood classification algorithm was applied to SPOT 6 data to detect and map areas affected by this invasive species. Furthermore, different accuracy assessment measures (e.g. producer accuracy (PA), user accuracy (UA) and overall accuracy (OA)) were used to assess the validity of the classification results, namely built-up areas, bare areas, uninvaded areas and invaded areas. The results demonstrate that Lantana camara occurrence in rangelands ecosystems can be mapped with high accuracy. An overall accuracy of 81.29% was attained for 2014, 86.85% for 2016 and 88.69% for 2018. It was further observed that in 2016 Lantana camara occurrence was minimal when compared to 2014, but the results indicate regeneration in 2018 in previously cleared areas. Approximately 40.84% of the area was covered by Lantana camara in 2014, 25.19% in 2016 and 27.02% in 2018. Overall, the findings in this study underscore the need for continuous monitoring of affected areas, especially after clearing, to continuously advise on areas that are at risk for potential re-establishment of invasive weeds.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"239 - 244"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919x.2020.1817812","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43828949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Night Trains: Moving Mozambican Miners to and from South Africa, circa 1902–1955","authors":"R. Christie","doi":"10.1080/0035919x.2020.1812762","DOIUrl":"https://doi.org/10.1080/0035919x.2020.1812762","url":null,"abstract":"Charles van Onselen has written another good book, this time about the inordinate suffering of the people in the sealed migrant labour steam trains that transported Mozambican miners to and from th...","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"308 - 310"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919x.2020.1812762","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46781794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Living Shores – Interacting with southern Africa’s marine ecosystems; Sea Change – Primal Joy and the Art of Underwater Tracking","authors":"C. McGibbon","doi":"10.1080/0035919X.2020.1813216","DOIUrl":"https://doi.org/10.1080/0035919X.2020.1813216","url":null,"abstract":"Hang up your fins and weep: the definitive tomes on the southern African shoreline have been published and it will be hard to surpass these publications of excellence. The book by the Branches, Geo...","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"311 - 312"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919X.2020.1813216","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43446823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On elementary complex variable theory applied to sinc and related integrals**","authors":"J. Hey","doi":"10.1080/0035919x.2020.1804481","DOIUrl":"https://doi.org/10.1080/0035919x.2020.1804481","url":null,"abstract":"An elementary application of complex variable theory demonstrates that some properties of sinc and related integrals, which have been variously described as “tricky,” “intriguing” and “deluding intuition,” arise as simple consequences of Jordan’s lemma. This approach, in offering an interesting alternative to the established treatment based upon Fourier transform theory, may thus be recommended in addition for its pedagogic value. The present treatment extends the earlier results significantly in applications to both divergent and convergent sequences, by introducing the useful concepts of “turning points” and “ranks” of the various contributions to summations over complex path integrals. Finally, a result stated as a student problem in the well-known treatise of Whittaker and Watson (1927) is similarly extended in its application to sequences of both types.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"295 - 306"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919x.2020.1804481","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48795289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Activity concentration of natural radionuclides in sediments of Bree, Klein-Brak, Bakens, and uMngeni rivers and their associated radiation hazard indices","authors":"A. O. Ilori, N. Chetty, B. Adeleye","doi":"10.1080/0035919X.2020.1815894","DOIUrl":"https://doi.org/10.1080/0035919X.2020.1815894","url":null,"abstract":"A hyper-pure germanium (HPGe) detector was used to measure the activity concentrations in sediment samples of rivers in South Africa, and the associated radiological hazard indices were evaluated. The results of the study indicated that the mean activity concentrations of 226Ra, 232Th and 40K in the sediment samples from the oil-rich areas are 11.13, 7.57, 22.5 ; 5.51, 4.62, 125.02 and 7.60, 5.32, 24.12 for the Bree, Klein-Brak and Bakens Rivers, respectively. In contrast, the control site (UMngeni River) values were 4.13, 3.28, and 13.04 for 226Ra, 232Th, and 40K. The average excess lifetime cancer risks are 0.394 × , 0.393 × , 0.277 × and 0.163 × for sediment samples at Bree, Klein-Brak, Bakens, and uMngeni rivers. All obtained values indicated a significant difference between the natural radionuclide concentrations in the samples from the rivers in oil-rich areas compared to those of the non-oil-rich area. The values reported for the activity concentrations and radiological hazard indices were below the average world values; hence, the risk of radiation health hazard was negligible in all study areas.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"258 - 265"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919X.2020.1815894","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44101361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterisation and issues with the use of a conductivity meter to monitor the level of liquid in a cane diffuser bed","authors":"D. S. Segura Angel, R. F. Fonseca","doi":"10.1080/0035919x.2020.1801534","DOIUrl":"https://doi.org/10.1080/0035919x.2020.1801534","url":null,"abstract":"The extraction of sucrose in a cane diffuser depends mainly on the percolation rate, and its optimisation requires the monitoring and control of the liquid holdup with the cane bed. However, most conventional methods that measure liquid levels are not suitable for this application. Operators control the observed liquid level through diffusers’ sight glasses, adjusting the spray position according to visual inspections. The method is inefficient, and a more accurate and reliable measurement process should be implemented towards maximising the sucrose extraction. This article proposes a novel methodology that uses conductance measurements as indicators of the liquid level in cane beds. Conductance, observed liquid level and flow rate variations were analysed under several conditions, such as steady and unsteady states. The effects of the main variables on the observed liquid level and their mathematical relationship were assessed for the validation of the measurements, and experimental tests were conducted on a BMA cane diffuser at Maidstone factory in South Africa. The results are reproducible and show conductance can qualitatively characterise a flooded cane bed.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"282 - 294"},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919x.2020.1801534","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46147703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dominant wetland vegetation species discrimination and quantification using in situ hyperspectral data","authors":"Mafuratidze Pride, Muumbe Tasiyiwa Priscilla, T. Gara","doi":"10.1080/0035919x.2020.1798301","DOIUrl":"https://doi.org/10.1080/0035919x.2020.1798301","url":null,"abstract":"Wetland vegetation is an important bio-indicator of wetland physical or chemical degradation. Wetland vegetation continually faces threats from natural disturbance and unsustainable human activities. Traditionally, routine field observations are used to monitor wetlands. However, these methods are expensive and require a lot of human resources, as destructive sampling is required. Remote sensing offers non-destructive and real-time information useful for sustainable and effective management of wetland vegetation. The aim of this study was to explore the potential of hyperspectral remote sensing for wetland vegetation discrimination at the species level. In particular, the study focuses on enhancing or improving class separability among wetland vegetation species using hyperspectral data. In situ hyperspectral measurements were conducted on four dominant grass species in a wetland in Harare. One-way analysis of variance demonstrated significant statistical differences between hydrophytic vegetation species. Vegetation indices performed better compared to red-edge algorithms at discriminating wetland vegetation, with overall accuracy of 82% and 60%, respectively.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"229 - 238"},"PeriodicalIF":0.0,"publicationDate":"2020-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919x.2020.1798301","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43292653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fault Lines: A Primer on Race, Science and Society","authors":"S. Dubow","doi":"10.1080/0035919x.2020.1789239","DOIUrl":"https://doi.org/10.1080/0035919x.2020.1789239","url":null,"abstract":"This excellent scholarly intervention is misleadingly subtitled a “primer”. While it does introduce readers to key conceptual and analytical problems around “race” (Does it exist? Is it meaningful?...","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"307 - 307"},"PeriodicalIF":0.0,"publicationDate":"2020-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919x.2020.1789239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43758678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing spatiotemporal settlement patterns in Eastern Free State, South Africa, pre and post transition from apartheid to majority rule","authors":"Titilope F. Onaolapo, Tom W. Okello, S. Adelabu","doi":"10.1080/0035919x.2020.1755743","DOIUrl":"https://doi.org/10.1080/0035919x.2020.1755743","url":null,"abstract":"Spatial patterns of human settlements, their changes and their geographical implications are important for understanding the drivers of land use and land cover change. This paper examines the spatiotemporal pattern of settlement development in three different settlements of Thabo Mofutsanyane municipal district namely Harrismith, Vrede and Ladybrand using GIS, remote sensing and spatial metrics techniques. The study is based on 30 years of time-series data compiled from satellite images with emphasis on pre and post 1994’s (the year of change in government from apartheid to majority rule) spatial change in settlement development. Landsat 4–5 imageries for 1989, 1999, 2009 and Landsat 8 OLI for 2018 were downloaded and classified for land use/land cover change (LULCC). Also, landscape and class metrics were computed using Fragstats QGIS 2.18.9 to generate spatial analysis. A dynamic spatial pattern is observed in the settlements under study. Urban built-up areas had a rapid trend of growth in Harrismith from 1989 (5 years before transition from apartheid to majority rule) to 1999 (5 years after transition from apartheid to majority rule) but later slowed down in the subsequent years under study while Ladybrand and Vrede had moderate growth trend in the subsequent years under study. The settlement development process has developed fragmented and heterogeneous land use combinations in the years after 1994. At landscape level, land fragmentation occurred due to land use changes and significant urban expansion; Ladybrand experienced more physical connectedness than Harrismith and Vrede. While at class level, Harrismith and Vrede are more aggregated or physically connected than Ladybrand; this means Ladybrand was relatively more fragmented than the other two settlements. The study results show that a LULCC and landscape metrics integrated approach is effective to analyse and describe the spatial patterns of urban landscapes.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"75 1","pages":"140 - 158"},"PeriodicalIF":0.0,"publicationDate":"2020-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/0035919x.2020.1755743","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45392741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}