Transactions of The Royal Society of South Africa最新文献_第6页

On elementary complex variable theory applied to generalised sinc(p) and related integrals 初等复变理论在广义sinc（p）及相关积分中的应用

Transactions of The Royal Society of South Africa Pub Date : 2022-01-02 DOI: 10.1080/0035919X.2021.2005716

J. Hey

引用次数: 0

Assessing the intraurban differences in vegetation coverage and surface climate in a heterogeneous area 评估异质地区植被覆盖率和地表气候的城市内差异

Transactions of The Royal Society of South Africa Pub Date : 2022-01-02 DOI: 10.1080/0035919X.2021.2004470

S. Jombo, E. Adam, M. Byrne, S. W. Newete

{"title":"Assessing the intraurban differences in vegetation coverage and surface climate in a heterogeneous area","authors":"S. Jombo, E. Adam, M. Byrne, S. W. Newete","doi":"10.1080/0035919X.2021.2004470","DOIUrl":"https://doi.org/10.1080/0035919X.2021.2004470","url":null,"abstract":"Urban trees play a critical role in alleviating land surface temperatures in cities. In remote sensing studies, vegetation indices are widely used to examine the relationship between Land Surface Temperature (LST) and vegetation cover. The vegetation cover can be measured using the Normalised Difference Vegetation Index (NDVI). In this study, the LST-NDVI relationship was assessed in each of the seven city-regions (A-G) in Johannesburg using Moderate-Resolution Imaging Spectroradiometer (MODIS) datasets to provide a basis for urban ecological planning and environmental protection. This study's specific objective was to determine the intraurban differences in vegetation coverage and LST in the seven city-regions over 19 years. The relationship between LST and NDVI was also examined over the years of study. The results showed a significant intraurban difference in LST and NDVI values in the city-regions with a negative correlation between them, ranging from −0.03 to −0.76. The LST values increased in all the city-regions with the highest value of 20.1°C in city-region G, followed by 19.6°C in city-region E. The vegetation cover decreased over the years, with the lowest NDVI value in city-region G (0.39), followed by city-regions F (0.43) and D (0.48). The city-regions with high LST and low vegetation cover include the city-centre and highly populated suburbs. This indicates that areas with greater vegetation cover have low LSTs and vice versa. These findings provide useful information for municipal authorities and other stakeholders to undertake appropriate decisions to tackle Urban Heat Island (UHI) effects by adopting effective urban planning and management interventions.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"77 1","pages":"1 - 10"},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41392785","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}

引用次数: 2

Effect of heat-moisture treatment on the functional and rheological characteristics of cassava (Manihot esculenta) starch 热湿处理对木薯淀粉功能和流变特性的影响

Transactions of The Royal Society of South Africa Pub Date : 2022-01-02 DOI: 10.1080/0035919X.2022.2036265

S. S. Sobowale, O. Olatidoye, Idowu Atinuke, O. Emeka

{"title":"Effect of heat-moisture treatment on the functional and rheological characteristics of cassava (Manihot esculenta) starch","authors":"S. S. Sobowale, O. Olatidoye, Idowu Atinuke, O. Emeka","doi":"10.1080/0035919X.2022.2036265","DOIUrl":"https://doi.org/10.1080/0035919X.2022.2036265","url":null,"abstract":"The major drawback of most starchy food is its inability to withstand high-temperature conditions, shearing force and acidity, which limits its usage in the food industry. This study investigates the effect of heat-moisture treatment (HMT) at varying moisture content (10–30% wet basis), drying temperature (80–100 °C) and time (2–8 h) on the functional and rheological properties of cassava starch using response surface methodology (RSM) by adopting a Box–Behnken design method. Cassava roots were processed into modified starch under various processing conditions. Results showed an increase in the water absorption index, solubility and swelling power while there was a slight reduction in the loose bulk density and tapped bulk density. The starch viscosity ranged between 4182 and 4268 Cps. Consistency ranged between 2.51 and 2.56 g/mL and the flow behaviour index ranged between 2.70 and 2.82. Optimal processing conditions for cassava starch were achieved with a moisture content of 30%, drying temperature of 90 °C and time of 2 h. These variables are important to consider for processing of cassava starch with improved consumer acceptability and potential large-scale production of baked foods, gel formation and custard production.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"77 1","pages":"89 - 99"},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44450978","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}

引用次数: 1

Impact of SARS-CoV-2 variants of concern on Covid-19 epidemic in South Africa SARS-CoV-2变异毒株对南非新冠肺炎疫情的影响

Transactions of The Royal Society of South Africa Pub Date : 2021-12-16 DOI: 10.1080/0035919X.2021.2011801

S. A. Abdool Karim, C. Baxter

{"title":"Impact of SARS-CoV-2 variants of concern on Covid-19 epidemic in South Africa","authors":"S. A. Abdool Karim, C. Baxter","doi":"10.1080/0035919X.2021.2011801","DOIUrl":"https://doi.org/10.1080/0035919X.2021.2011801","url":null,"abstract":"The Covid-19 pandemic has resulted in immense suffering throughout the world, with over 250 million cases and over 5 million Covid-19-related deaths reported by 9 November 2021. South Africa has the highest burden of Covid-19 in Africa, accounting for 34% of all cases and 41% of all reported Covid-19 deaths on the continent (Africa CDC COVID-19 Dashboard, 2021). By 1 November 2021, South Africa had reported more than 2.9 million Covid-19 cases and over 89,000 Covid-19 deaths (COVID-19 Corona Virus South African Resource Portal, 2020), with substantial cases and deaths due to the Beta variant in the second wave and to the Delta variant in the third wave. Given the importance of variants in determining what the waves of infection look like, the future trajectory of the SARS-CoV-2 epidemic in South Africa will be largely dependent on viral variants. The ﬁ rst case of Covid-19 in South Africa was reported on 5 March 2020 by a traveller who had recently returned from Italy. Although mitigation measures, such as a national lock-down and border closures, initially kept Covid-19 cases low, there was a steady increase in cases as restrictions eased. In the ﬁ rst wave, the average daily Covid-19 cases peaked at 12,583 in mid-July 2020, driven principally by variants with the D614G mutation. The second wave began in late November 2020 and the average daily Covid-19 cases peaked at 19,042 in January 2021. By mid-May 2021, the country once again began experiencing a surge in cases, reaching a peak of 19,958 in July 2021 in the country ’ s","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"77 1","pages":"101 - 104"},"PeriodicalIF":0.0,"publicationDate":"2021-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46579588","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}

引用次数: 3

Biological invasions in South Africa 南非的生物入侵

Transactions of The Royal Society of South Africa Pub Date : 2021-09-02 DOI: 10.1080/0035919X.2021.1969797

M. Bruton

引用次数: 0

Obituary: Peter Ernest Spargo (07 June 1937–02 Aug. 2021) 讣告:Peter Ernest Spargo(1937年6月7日- 2021年8月2日)

Transactions of The Royal Society of South Africa Pub Date : 2021-09-02 DOI: 10.1080/0035919x.2021.1976497

S. A. Craven

引用次数: 0

Morris James Viljoen (1940–2021) Morris James Viljoen（1940–2021）

Transactions of The Royal Society of South Africa Pub Date : 2021-09-02 DOI: 10.1080/0035919x.2021.1983325

C. Anhaeusser

引用次数: 0

Exploring the transmission-blocking activity of antiplasmodial 3,6-diarylated imidazopyridazines 抗3，6-二芳基咪唑并吡喃嗪类药物阻断传播活性的研究

Transactions of The Royal Society of South Africa Pub Date : 2021-09-02 DOI: 10.1080/0035919X.2021.1982792

D. Coertzen, J. Reader, Mariëtte E. van der Watt, Meta Leshabane, Henrico Langeveld, P. Cheuka, G. Dziwornu, K. Chibale, L. Birkholtz

{"title":"Exploring the transmission-blocking activity of antiplasmodial 3,6-diarylated imidazopyridazines","authors":"D. Coertzen, J. Reader, Mariëtte E. van der Watt, Meta Leshabane, Henrico Langeveld, P. Cheuka, G. Dziwornu, K. Chibale, L. Birkholtz","doi":"10.1080/0035919X.2021.1982792","DOIUrl":"https://doi.org/10.1080/0035919X.2021.1982792","url":null,"abstract":"The effectiveness of current antimalarial therapies that cure patients of the pathogenic asexual blood stages is rapidly declining due to the spread of antimalarial drug resistance. This requires the development of novel chemotypes curative for asexual blood stages but additionally, such chemotypes should also target the sexually differentiated gametocytes and thereby block disease transmission. Kinase inhibitors, specifically imidazopyridazines, were previously described as highly effective, dual-active compounds in vitro. However, amongst other shortcomings, poor solubility and cardiotoxicity risks prevented these compounds from being further developed. In a recent study, novel 3,6-diarylated imidazopyridazine derivatives showed improved solubility and a decrease in inhibition of the human ether-a-go-go-related gene (hERG), suggesting reduced cardiotoxicity risks, with potent sub-micromolar antiplasmodial activities. Here, we report the in vitro activity of these 3,6-diarylated imidazopyridazine derivates against both asexual blood and gametocyte stages of the human malaria parasite, Plasmodium falciparum, in vitro. We highlight several potentially dual-active compounds with nanomolar activities (IC50’s 0.7–104 nM) against both drug sensitive and resistant strains of P. falciparum with these compounds also displaying activity against transmissible gametocytes (IC50’s 1180.3–1787.5 nM). Taken together, the new generation 3,6-diarylated imidazopyridazines have potent activity against P. falciparum parasites in vitro with improved physicochemical and toxicity profiles.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"76 1","pages":"225 - 233"},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48335374","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}

引用次数: 1

Effect of mulch, no-tillage and no-fertiliser as sustainable practices on soil organic carbon and carbon dioxide emission 覆盖、免耕和不施肥作为可持续做法对土壤有机碳和二氧化碳排放的影响

Transactions of The Royal Society of South Africa Pub Date : 2021-09-02 DOI: 10.1080/0035919X.2021.1995530

V. Ramborun, S. Facknath, B. Lalljee

{"title":"Effect of mulch, no-tillage and no-fertiliser as sustainable practices on soil organic carbon and carbon dioxide emission","authors":"V. Ramborun, S. Facknath, B. Lalljee","doi":"10.1080/0035919X.2021.1995530","DOIUrl":"https://doi.org/10.1080/0035919X.2021.1995530","url":null,"abstract":"The study seeks to investigate the compounding effects of various practices such as mulch, no-tillage, tillage and nitrogen based fertilizer on CO2 emission and soil organic carbon (SOC) in three successive crop cycles in the region of Vacoas, Mauritius. Nitrogen based fertilizer (ammonium sulphate) was applied at 120 kg/ha to its corresponding treatment, and maize mulch was applied as full coverage (24 t/ha). Three treatments: Mulch (M), Fertilizer (F), Tillage (T), were tested at 2 levels each, and replicated 3 times. The 2 levels were mulch-no mulch, fertilizer-no fertilizer and tillage-no tillage. Results have shown a correlation between CO2 and pH, where increase in CO2 flux was due to addition of fertilizer. Furthermore, application of mulch did not increase SOC in the short term. A negative correlation was equally found between available phosphorous and temperature which was attributed to the interactions that exist between temperature, photosynthesis and nutrient availability. The present study revealed that reduction in CO2 emission and increase in soil fertility can be achieved at farmer level by adopting mulching and no-till. These practices are both economical and farmer friendly. This is a first study of such kind in the soils of Mauritius, a volcanic Island in the Indian Ocean latitude 20° 17′ 53″ South and longitude 57° 28′ 42″ East.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"76 1","pages":"247 - 255"},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43095635","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}

引用次数: 0

Bipedal leaping Jurassic vertebrates in Southern Africa: proposed new ichnotaxon and inferred palaeoenvironment 南部非洲两足跳跃的侏罗纪脊椎动物:提出的新鱼分类群和推断的古环境

Transactions of The Royal Society of South Africa Pub Date : 2021-08-30 DOI: 10.1080/0035919X.2021.1964104

D. V. van Dijk, P. Eriksson

{"title":"Bipedal leaping Jurassic vertebrates in Southern Africa: proposed new ichnotaxon and inferred palaeoenvironment","authors":"D. V. van Dijk, P. Eriksson","doi":"10.1080/0035919X.2021.1964104","DOIUrl":"https://doi.org/10.1080/0035919X.2021.1964104","url":null,"abstract":"The Lower Jurassic Clarens Formation (Stormberg Group, Karoo Supergroup, Main Karoo basin) contains relatively common vertebrate trackways impressed into apparently soft to firm, fine sediment beds preserved within the succession. At least three known ichnotaxa are interpreted as leaping bipedal vertebrates. Here we provide a generic description of a proposed new ichnotaxon to add to this small group of the oldest known bipedal hopping vertebrates in Africa and globally. Saltirecarpipes Genus Nova (Type Species tinleyi) (saltus – leap; carpe – seize; pes – foot) has been identified from tracks at Giants Castle in the KwaZulu-Natal Drakensberg. The type specimen in the National Museum Bloemfontein exhibits two adjacent tetradactyl impressions with four digits extended from metatarsal pads, comprising three inner digits grouped closer together and facing forwards, the fourth digit being much longer and curved outwards and slightly backwards. The digits are all strongly curved with claw impressions being preserved in several cases. These were small vertebrates, a leap length of ca. 180 mm being inferred. Being found in association with trace fossils of Equisitales (horse tails) a wet palaeoenvironment of small ponds is postulated. These appear to have been associated with distal fan sheetflood deposits of fine sediment at Giants Castle, which pass laterally into more central-basinal palaeodune deposits which characterise the Clarens Formation across the Main Karoo depository. The new ichnotaxon appears to have been restricted to wet desert marginal settings, feeding immature sediment to the desert basin, and which retreated proximally as aridification of the Clarens palaeoenvironment progressed.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"76 1","pages":"235 - 245"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41464527","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}

引用次数: 3