149 research outputs found
A taxonomic study of the genus Lotononis (DC.) Eckl. & Zeyh. (Fabzceae, Crotalarieae)
The approach and methods used in a taxonomic study of the genus Lotononis (DC.) Eckl. & Zeyh. and related genera of the tribe Crotalarieae (Benth.) Hutch. are briefly introduced in Part 1. Morphological, cytological and chemical data was analyzed by cladistic methods to provide a sound basis for the generic delimitation of Lotononis and to formulate a natural infrageneric classification. The generic limits of Lotononis and its relationships with 14 other genera of the Crotalarieae are discussed in Part 2. Detailed morphological studies by Polhill (1976) has shown the widespread occurrence of convergence and conflicting character information in the tribe. Only a few of the genera are monothetic taxa and very few characters are available for cladistic analyses. This is not so much due to a lack of data but rather to ambiguity as to how morphological characters should be interpreted. It was therefore decided to concentrate on a study of alkaloids to test the predictivity of the present generic delimitations in the Crotalarieae. With the exception of Crotalaria L., virtually nothing was known about the alkaloids of the tribe (Mears & Mabry 1971, Kinghorn & Smolenski 1981). In the tribe Genisteae, alkaloid patterns show a high degree of conformity with evolutionary patterns based on morphological evidence (Polhill 1976) and the value of alkaloids as a generic character in the Leguminosae is well known (Kinghorn & Smolenski 1981). It seemed that more insight into generic relations in the Crotalarieae could be gained by concentrating on a hitherto much neglected field rather than to duplicate the detailed morphological studies of Polhill (1976). It was also clear that meaningful conclusions could be made about generic relationships, because the biogenetic pathways along which quinolizidine and pyrrolizidine alkaloids are formed are rather well known. The survey of major alkaloids (Appendices 1 to 11) indeed led to a much better understanding of the intricate relationships in the Crotalarieae, and made it possible to present a well supported and almost fully resolved cladogram for the tribe as a whole
Alkaloidal variation in Cissampelos capensis (Menispermaceae)
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Doing an ethnobotanical survey in the life sciences classroom
On the basis of an ethnobotanical survey that we conducted on plant use by descendents of the Khoi-San people in the Northern Cape Province in South Africa, we introduce biology teachers to an adapted rapid-appraisal methodology that can be followed in the life sciences classroom. Such a project addresses a number of the content standards in the National Science Education Standards, such as science as a human endeavour, the nature of science, and the history of science. We also shed light on ethical considerations when engaging in an ethnobotanical survey, and address, among other issues, intellectual property rights. Examples are provided of how teachers in the United States can sensitize students to the rich ethnobotanical heritage of their country
Apparent Absorption Efficiencies of Nectar Sugars in the Cape Sugarbird, with a Comparison of Methods
Nectarivore sugar preferences and nectar composition in the Cape Floristic Kingdom (southern Africa) differ from trends reported for analogous systems in America and Europe in that sugarbirds and sunbirds show no aversion to sucrose, which is the dominant nectar sugar in many of their food plants. To elucidate the physiological bases (if any) of nectarivore sugar preferences, we determined apparent sugar absorption efficiencies in a passerine endemic to this region, the Cape sugarbird Promerops cafer. Apparent absorption efficiencies for the three major nectar sugars, sucrose, glucose, and fructose, were extremely high (> 99%), as in other specialized avian nectarivores. Xylose, a pentose sugar recently reported in the nectar of some Proteaceae, was absorbed and/or metabolized inefficiently, with a mean of 47.1% of ingested sugar recovered in cloacal fluid. We did not measure the proportions of xylose that were absorbed and/or metabolized. We also compared three methods of estimating absorption efficiency: (1) measurements of total sugar in cloacal fluid with refractometry, without correction for differences between volumes of ingesta and excreta; (2) the same measurements combined with correction for volume differences; and (3) HPLC analyses quantifying individual sugars in cloacal fluid, with correction for volume differences. Refractometry has been frequently used in previous studies. For all sugars except xylose, method 1 yielded results similar to those obtained with method 2, but the convergence was artifactual, and we do not recommend use of this method. Apparent absorption efficiencies calculated with method 2 underestimated true absorption efficiency, because refractometry measures nonsugar solutes, but this error is biologically significant only when efficiencies are low
Framework assessment for costs of poor quality in higher education processes
Higher education quality costs are escalating daily and the cost of poor quality is becoming excessive. The higher education department has indicated that inefficiencies within the higher education environment are affecting the performance and the return of investments. This research uses 2011 and 2012 records retrieved on Industrial Engineering department from the Management Information System unit of Tshwane University of Technology, Pretoria, South Africa. It focuses on how cost of poor quality can be categorized within higher education environment, and identifies methods which can be used to minimize these costs with the purpose of improving the performance and return of investments. The paper established the cost of poor quality for the department using the teaching input grant, teaching output grant, research output grant, and institutional factor grants, teaching input unit, students' full credit load and among other factors. The results of this research indicated that USD94,3166.24 and USD933,431.92 were lost for the year 2011 and 2012 respectively on just one department and affirmed that failure cost and preventative costs are the main costs associated with higher education inefficiencies and shortfalls. Thus, application of lean enterprise or lean six sigma tools is recommended to salvage the situation
A global infrageneric classification system for the genus Crotalaria (Leguminosae) based on molecular and morphological evidence
Crotalaria is a large genus of 702 species with its centre of diversity in tropical Africa and Madagascar and secondary radiations in other parts of the world. The current infrageneric classification system is based on morphological and morphomet- ric studies of the African taxa only and is here re-evaluated using a phylogenetic approach. DNA sequences derived from the nuclear ITS and the plastid matK, psbA-trnH and rbcLa markers were analyzed using parsimony and model-based (Bayesian) approaches. The resultant molecular phylogeny allowed for a new interpretation of diagnostically important morphological characters, including specialisations of the calyx, keel, standard petal and style, which are variously convergent in several unrelated infrageneric groups. Of particular interest is the congruence between the new phylogeny and the distribution of stand- ard petal callosity types. A sectional classification system for the entire genus is proposed for the first time. The new system that is formalised here comprises eleven sections: Amphitrichae, Calycinae, Crotalaria, Geniculatae, Glaucae, Grandiflorae, Hedriocarpae, Incanae, Schizostigma, Borealigeniculatae and Stipulosae. Sectional limits of the Geniculatae, Calycinae and Crotalaria are modified. The subsections Stipulosae, Glaucae and Incanae are raised to sectional level, while some groups previously recognized as subsections are abandoned due to non-monophyly (subsections Chrysocalycinae, Hedriocarpae, Macrostachyae and Tetralobocalyx). Two new sections are recognized, Amphitrichae and Borealigeniculatae.Web of Scienc
Underwater near-infrared spectroscopy measurements of muscle oxygenation: laboratory validation and preliminary observations in swimmers and triathletes
The purpose of this research was to waterproof a near-infrared spectroscopy device (PortaMon, Artinis Medical Systems) to enable NIR measurement during swim exercise. Candidate materials were initially tested for waterproof suitability by comparing light intensity values during phantom-based tissue assessment. Secondary assessment involved repeated isokinetic exercises ensuring reliability of the results obtained from the modified device. Tertiary assessment required analysis of the effect of water immersion and temperature upon device function. Initial testing revealed that merely covering the PortaMon light sources with waterproof materials considerably affected the NIR light intensities. Modifying a commercially available silicone covering through the addition of a polyvinyl chloride material (impermeable to NIR light transmission) produces an acceptable compromise. Bland-Altman analysis indicated that exercise-induced changes in tissue saturation index (TSI %) were within acceptable limits during laboratory exercise. Although water immersion had a small but significant effect upon NIR light intensity, this resulted in a negligible change in the measured TSI (%). We then tested the waterproof device in vivo illustrating oxygenation changes during a 100 m freestyle swim case study. Finally, a full study compared club level swimmers and triathletes. Significant changes in oxygenation profiles when comparing upper and lower extremities for the two groups were revealed, reflecting differences in swim biomechanics
The impact of a faculty development programme for health professions educators in sub-Saharan Africa: an archival study
BACKGROUND:
In 2008 the sub-Saharan FAIMER Regional Institute launched a faculty development
programme aimed at enhancing the academic and research capacity of health professions
educators working in sub-Saharan Africa. This two-year programme, a combination of
residential and distance learning activities, focuses on developing the leadership, project
management and programme evaluation skills of participants as well as teaching the key
principles of health professions education-curriculum design, teaching and learning and
assessment. Participants also gain first-hand research experience by designing and conducting
an education innovation project in their home institutions. This study was conducted to
determine the perceptions of participants regarding the personal and professional impact of
the SAFRI programme.
METHODS:
A retrospective document review, which included data about fellows who completed the
programme between 2008 and 2011, was performed. Data included fellows’ descriptions of
their expectations, reflections on achievements and information shared on an online
discussion forum. Data were analysed using Kirkpatrick’s evaluation framework.
RESULTS:
Participants (n=61) came from 10 African countries and included a wide range of health
professions educators. Five key themes about the impact of the SAFRI programme were
identified: (1) belonging to a community of practice, (2) personal development, (3)
professional development, (4) capacity development, and (5) tools/strategies for project
management and/or advancement.
CONCLUSION:
The SAFRI programme has a positive developmental impact on both participants and their
respective institutions.National Research FoundationDepartment of HE and Training approved lis
Traditional uses of the remarkable root bark hairs of Lannea schweinfurthii var. stuhlmannii (Anacardiaceae) by the Vhavenḓa, South Africa
Lannea schweinfurthii var. stuhlmannii, an African tree ranging from Sudan southwards to South Africa, has its thicker roots covered by an unusual furry layer of hair-like structures originating from the periderm. Wool-like hairs harvested from this layer, known in the vernacular Tshivenḓa as vhulivhadza, is a widely used and traded natural product in Limpopo Province, South Africa. Here we provide a detailed account of the cultural uses of vhulivhadza based on original ethnobotanical surveys among the Vhavenḓa, as well as a review of the literature. Our findings indicate that vhulivhadza is a “magical medicine,” mostly used to induce several forms of forgetfulness, both in humans and in animals. Various uses reported for L. schweinfurthii and L. alata, the latter an East African species with similar root bark hairs, suggest that the custom to use these hairs to induce forgetfulness is confined to southern Africa. The practice of taking traditional medicine to “forget something” or “to make people forget” is quite widespread in southern Africa. We discuss vhulivhadza and a few other plants used locally for this purpose, notably the mysterious sho-|õä plant of the now extinct | Xam culture, Asclepias crispa (Apocynaceae: Asclepiadoideae) and Galium tomentosum (Rubiaceae). The roots of Lannea schweinfurthii and other members of the genus are rich in phytochemicals, with at least some screenings for biological activity suggesting the presence of compounds that may affect the neurological system. In the absence of any comprehensive chemical or pharmaceutical analyses of vhulivhadza itself, the claimed memory-altering activities of this material can tentatively perhaps best be explained by psychological rather than physical (chemical) effects, but a more definite scientific explanation must await further study.The University of Johannesburg and the National Research Foundation of South Africa.http://www.elsevier.com/locate/sajb2020-05-01hj2020Plant Production and Soil Scienc
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