Smoke-water enhances in vitro pollen germination and tube elongation of three species of Amaryllidaceae

AbstractSmoke-water prepared from burning plant material and smoke-derived compounds significantly promote seed germination and enhance growth of many plant species. Since large amounts of smoke are generated and released into the air during wildfires, it is possible that angiosperm pollen germination and pollen tube elongation may be affected by plant-derived smoke even when the plants are some distance from the fire. We assessed the effect of smoke on pollen germination and pollen tube elongation for three species of Amaryllidaceae that occur naturally in areas prone to winter fire in South Africa. In vitro pollen germination and pollen tube growth of Clivia gardenii, Cyrtanthus mackenii and Scadoxus multiflorus were assessed by preparing hanging drop slides with different concentrations of smoke-water, karrikinolide and 3,4,5-trimethylfuran-2(5H)-one combined with Brewbaker and Kwack's medium and a sucrose and boric acid medium. These slides were incubated for 2h at 25°C. Pollen germination and pollen tube lengths were recorded by capturing images with a compound microscope aided by a digital camera. Low concentrations of smoke-water (1:1000 and 1:2000 v:v) significantly increased pollen germination and pollen tube length in the three species, when applied alone or in combination with either Brewbaker and Kwack's medium or sucrose and boric acid medium. Low concentrations of smoke-water significantly increased in vitro pollen germination and pollen tube growth even when no additional calcium was added. Consequently, smoke from grassland fires may have favourable implications for the reproductive process of flowering plants

Heavy metal contamination in South African medicinal plants: A cause for concern

AbstractThe quality and safety of herbal medicines is becoming a major concern worldwide particularly due to contamination by heavy metals. The present study quantified the levels of heavy metals in frequently used South African medicinal plants and determined the variations in certain biological activities and phytochemical compositions. Eleven plant species were obtained from both muthi shops (MS) (commercial outlets) and from open street markets (OSM) for comparison. Samples were dried, powdered and digested using microwave acid-assisted digestion. The digested solutions were analysed for heavy metals using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Plants were classified based on their elemental composition using chemometric techniques. Powdered plant samples were extracted using 70% acetone and screened for antibacterial activity against E. coli and S. aureus. Phytochemical analyses were carried out to determine total phenolic and flavonoid content. Of the 22 samples analysed, Bulbine natalensis obtained from OSM and Alepidea amatymbica obtained from MS exhibited high levels of Al [5559 and 4392mg/kg dry weight (DW)] and Fe (4164 and 4465mg/kg DW) respectively. Levels of As and Hg were above the World Health Organization permissible limits in most of the samples analysed. Hierarchical cluster analysis classified the samples into four groups based on their metallic analyte concentrations. Group one having low metal content and group four having a high metal content. In general, plant samples with high levels of metals yielded greater antibacterial activity. However, antibacterial activity recorded in this study is not an indicator of high levels of heavy metal contamination as some samples despite the high levels of metal exhibited low antibacterial activity. The variations in the amounts of phenolics and flavonoids in the evaluated samples could have probably been that some of the plant samples may have been harvested from different localities or at different times of the year, perhaps plant age or degree of storage. The results highlighted the need for in-depth risk and quality assessments

Securidaca longipedunculata Fresen (Polygalaceae): A review of its ethnomedicinal uses, phytochemistry, pharmacological properties and toxicology

Ethnopharmacological relevance: Securidaca longipedunculata Fresen (Polygalaceae) is a multi-purpose plant with a long history of use in African traditional medicine to treat various sexually transmitted infections, hernias, coughs, fever, ascariasis, constipation, headaches, rheumatism, stomach ache, malaria, tuberculosis, pain, epilepsy, pneumonia, skin infections, and it is also used as an aphrodisiac for men. The current paper provides an overview of the present phytochemistry, toxicology, ethnomedicinal uses and pharmacological properties of S. longipedunculata. Materials and methods: The information reported in this paper was collected from a literature search using various computerised databases including ScienceDirect, Scopus, Scielo, PubMed and Google Scholar. The extra information was sourced from various academic dissertations, theses and botanical books. Results: Phytochemically, extracts from various parts of S. longipedunculata, especially the root bark, contain numerous valuable compounds including xanthones, some benzyl benzoates and triterpene saponins amongst others. Toxicity studies, both in vivo and in vitro, revealed that extracts are only toxic at relatively high concentrations. Furthermore, extracts have antimicrobial, antioxidant, antiparasitic, anti-diabetic, anti-inflammatory, antimalarial, insecticidal, pesticidal, and anticonvulsant properties. Conclusions: S. longipedunculata is an important plant species with potential benefits in the treatment of transmissible and infectious diseases, including malaria, tuberculosis, and those caused by community acquired microorganisms. Although extracts from this species generally have little toxicity at low concentrations, further efforts are required to investigate the potential toxicity of S. longipedunculata. The antimicrobial properties of extracts and purified compounds against microorganisms causing sexually transmitted infections is also deserving of further research. Moreover, the pharmacokinetic properties of extracts and compounds of the species need to be explored as there is insufficient data available on these aspects.Agriculture, Animal Health and Human Ecolog

The molecular epidemiology of human immunodeficiency virus type 1 in six cities in Britain and Ireland

The authors sequenced the p17 coding regions of the gag gene from 211 patients infected either through injecting drug use (IDU) or by sexual intercourse between men from six cities in Scotland, N. England, N. Ireland, and the Republic of Ireland. All sequences were of subtype 5. Phylogenetic analysis revealed substantial heterogeneity in the sequences from homosexual men. In contrast, sequence from over 80% of IDUs formed a relatively tight cluster, distinct both from those of published isolates and of the gay men. There was no large-scale clustering of sequences by city in either risk group, although a number of close associations between pairs of individuals were observed. From the known date of the HIV-1 epidemic among IDUs in Edinburgh, the rate of sequence divergence at synonymous sites is estimated to be about 0.8%. On this basis it has been estimated that the date of divergence of the sequences among homosexual men to be about 1975, which may correspond to the origin of the B subtype epidemic

The virtual shopping basket versus the shopping trolley : an exploratory investigation of consumers' experience

The aim of the study was to describe the thoughts and emotions of consumers with regard to both online shopping and traditional shopping. A homogenous sample of ten female respondents participated in this qualitative study and their experiences were examined by means of the Zaltman Metaphoric Elicitation Technique (ZMET). It was found that the traditional shoppers organise their thoughts and emotions around two metaphors, namely that of 'shopping as play' and 'shopping as work'. The online shoppers indicated that shopping could be regarded as a convenience and as an unfathomable concept. In addition to the four main themes, two supporting dimensions emerged; namely shopping for ‘nice to haves’ and shopping for ‘must haves’. A conceptual understanding based on the themes and dimensions was formed. This framework proved useful in comparing the emotions and cognitive thought processes of one shopping environment with that of the other. Interaction, similarities and differences of experiences were indicated within the two environments. AFRIKAANS: Die doel van hierdie studie was om verbruikers se gedagtes en gevoelens oor sowel die aanlyn- as die tradisionele inkopie-omgewing te beskryf. ’n Homogene steekproef van tien vroulike respondente het aan hierdie kwalitatiewe studie deelgeneem, en hulle ervarings is by wyse van die Zaltman Metaphoric Elicitation Technique (ZMET) ondersoek. Daar is bevind dat diegene wat op die tradisionele manier inkopies doen, hulle gedagtes en gevoelens om twee metafore organiseer, naamlik “inkopies doen as ’n vorm van ontspanning” en “inkopies doen as ’n vorm van werk”. Diegene wat aanlyn inkopies doen, het aangedui dat dié manier van inkopies doen beskou word as “’n gerief” én as “’n moeilik deurgrondbare konsep”. Naas hierdie vier temas het daar twee ondersteunende dimensies na vore gekom, naamlik inkopies doen vir dinge wat “noodsaaklik is om te hê” en inkopies doen vir dinge wat “lekker is om te hê”. ’n Konseptuele raamwerk wat op hierdie temas en dimensies gebaseer is, is opgestel. Hierdie raamwerk was nuttig om die gevoelens en ervarings wat deur die een inkopie-omgewing opgeroep is, te vergelyk met dié wat deur die ander inkopie-omgewing opgeroep is; asook om die wisselwerking, ooreenkomste en verskille met betrekking tot ervarings binne die twee omgewings aan te dui

Lokus van beheer en transformasionele leierskap.

Locus of control and transformational leadership. The aim of this study was to determine the relationship between locus of control and transformational leadership. These constructs were selected by virtue of the lack of empirical research regarding the assumed relationship between them. The Locus of Control Inventory (LCI) of Schepers (1998) and the Multifactor Leadership Questionnaire (MLQ), Form 5R of Bass and Avolio (1993) were administered to 102 respondents. The results indicate statistically significant relationships between: internal locus of control and transformational leadership; external locus of control and transactional leadership; and autonomy and transformational leadership