M.Sc. / Pteronia L. is a genus of 70 species of woody shrublets occurring mainly in southern Africa (Leistner, 2000). Published and unpublished ethnobotanical information exists for nine of the species. The uses of these species in traditional medicine are poorly recorded or have remained scientifically unknown. In addition, some unpublished vernacular names have been recorded during this study. Hutchinson and Phillips revised the genus Pteronia in 1917 and grouped the species into four sections. The nine ethnobotanically important species were placed in four sections: Incanae (P. incana and P. cinerea), Papillatae (P. lucilliodes and P. divaricata), Ciliatae (P. camphorata, P. stricta, P. onobromoides and P. adenocarpa) and Glabratae (P. succulenta). Pteronia onobromoides is the original source of Nama buchu that was first recorded by Van der Stel in 1685 (De Wet & Pheiffer, 1979), but which has remained poorly known. Surprisingly, this study has revealed the existence of an important Cape herbal medicine (P. divaricata) for which no record could be found in the scientific literature. Pteronia incana is not widely known for its traditional medicinal uses (although a few have indeed been recorded) but rather as a source of valuable essential oil that has been commercially exploited to some extent. Other species with at least one published anecdote of traditional use include P. adenocarpa, P. camphorata, P cinerea, P. lucilioides, P. stricta and P. succulenta. This means that a total of nine species are now known to have traditional medicinal and/or cosmetic uses. Most of the species are used for intestinal disorders (including stomach pain) and respiratory ailments (coughs, colds and influenza). The topical application of P. onobromoides and P. adenocarpa is clearly aimed at more than just a cosmetic effect and includes the alleviation of pain and the treatment of wounds and skin ailments. These uses all suggest that Pteronia species may have antimicrobial activity and also possible anti-inflammatory and analgesic properties. Pteronia adenocarpa is only known from a single literature record.

Aspects, which influence the choice of species for the rehabilitation of degraded arid areas, were studied. Although only one trial was established in the target area (transition area between the Succulent and Nama Karoo) seed of the indigenous species used was collected from this area. In the initial trials the effect of rumen digestion on the germination of fodder shrubs was observed. Species included the exotic Atriplex nummularia and Cassia sturtii, and the indigenous Sutherlandia microphylla, Tetragonia calycina, Tripteris sinuatum and Salsola glabrescens. No seed of T. calycina germinated. In T. sinuatum and S. glabrescens rumen digestion prevented germination while in the other species percentage germination was reduced. In the establishment trial with A. nummularia and C. sturtti, on a bare area onfarm, in the arid Northern Cape Province, no seed germinated. Observations showed that, for both species, protection is essential, where the risk of herbivory is high. Of the two species, C. sturtti shrubs appeared to be more drought tolerant. A further trial addressed the intra-species variation in the palatability of A. nummularia. Established shrubs of the F1 “elite” generation were browsed by sheep. The most palatable shrubs were identified and seed from these shrubs will be used to produce seedlings that will go into further selection trials. The final section of this study was a comparison, in terms of quantity, quality and re-growth, of C. sturtii, T. sinuatum and S. microphylla, at, and subsequent to, five different harvest dates. In the first three harvests no significant differences were observed in the total plant material produced, between the three species. In Harvest 5 both indigenous species had produced more edible material (leaf and <3mm stem material) than C. sturtii. The edible material of Harvests 1, 3 and 5, was analysed for crude protein content, in vitro digestibility and mineral concentrations. All three species had sufficient crude protein as well as calcium, phosphorus and magnesium, to meet maintenance requirements of sheep. Trace minerals, manganese and copper, were present in adequate amounts and toxicity could be more of a concern. The concentrations of zinc in all three species, however, were only sufficient in material obtained in Harvests 1 and 3. Re-growth of all shrubs 21 weeks after Harvest 5 was assessed in terms of survival, healthiness, leafiness, volume and dry matter production. C. sturtii shrubs harvested at a later stage in the initial trial had the best survival. For most re-growth periods, C. sturtii shrubs also appeared healthier and leafier than the indigenous species. S. microphylla seedlings had, however, established in the S. microphylla plots, which was a plus for that species. Copyright / Dissertation (MScAgric)--University of Pretoria, 2010. / Plant Production and Soil Science / unrestricted

The main aim of the study was to isolate compounds active against Candida albicans from the most active species from a pool of several trees. Seven tree species with good antifungal activity were selected from the Phytomedicine Programme database. The selected plant species investigated were screened for growth inhibitory activity against Candida albicans using bioautography and serial microplate dilution methods. These tree species were: Cussonia zuluensis, Vepris reflexa, Curtisia dentata, Trichilia emetica, Terminalia phanerophlebia, Terminalia sambesiaca and Kigelia africana. Using the serial microplate dilution method for the determination of minimal inhibitory concentrations, Terminalia phanerophlebia and <i.T. sambesiaca were active against Candida albicans with MIC values as low 0.02 mg/ml. The acetone and dichloromethane extracts of all plant leaves were active against C. albicans with MICs varying from 0.02-2.5 mg/ml. Based on bioautography, the acetone extract of the leaves of Curtisia dentate had more active (5) compounds against C. albicans than any of the tree species investigated. The dichloromethane, acetone and hexane extracts of the seven tree species were further screened for antifungal activity using other fungal test organisms. The fungal species used were Aspergillus fumigatus, Microsporum canis, Sporothrix schenckii and Cryptococcus neoformans. Extracts of Curtisia dentata, Terminalia sambesiaca and Terminalia phanerophlebia had the highest activities against these fungal test organisms with minimal inhibitory concentration (MIC) values as low as 0.02 mg/ml. Cussonia zuluensis was the least active with high MIC values (>250 µg/ml in some cases) and the lowest number (1) of active chemical components on bioautograms. The highest number of active compounds (5) against C. albicans on bioautograms was observed in the acetone extracts of C. dentate. The plant species were further investigated for presence of antibacterial compounds, using Escherichia coli, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa as test bacterial organisms. Compounds with similar Rf values in the acetone extract of C. dentate were active against both bacterial and fungal test organisms, suggesting that the growth inhibitory activity of C. dentate extracts was non-selective. C. dentate was chosen for isolation of compounds due to 1) the highest number of active compounds on bioautogram against C. albicans, 2) the MIC values (0.12-0.6 mg/ml) against C. albicans. Acetone extracts of the leaves, stem bark and twigs of Curtisia dentate were compared for antibacterial and antifungal activity using the serial microplate dilution and bioautography methods in order to select the plant part to isolate compounds from. The TLC fingerprints of the twigs and leaves were largely similar. A non-polar compound and two medium polarity compounds, present in the leaves and twigs, were missing in the stem bark extract. Bioautography indicated that the leaves contained more antibacterial and antifungal compounds than the stem bark extracts. Extracts of the leaves were 5-fold more active than the stem bark extracts against Candida albicans, with total activities of 1072 and 190 ml/g, respectively. Against bacterial test organisms extracts of the leaves, stem bark and twigs resulted in comparable activities. These findings encourage the interchangeable usage of the stem bark, leaves and twigs of this plant, which may lead to sustainable harvesting of the species. This approach may conserve this and other threatened or endangered plant species. The leaves of Curtisia dentate (Cornaceae) were serially extracted with solvents of varying polarities, starting with hexane, then dichloromethane, followed by acetone with methanol completing the fractionation. The dichloromethane (DCM) and acetone bulk fractions of Curtisia dentate contained the highest number of active compounds and resulted in low MIC values. The hexane and the methanol bulk fractions were the least active. In the hexane bulk fraction, bioautography revealed the presence of one active compound. The DCM bulk fraction showed cytotoxicity against Vero cells similar to the positive control, berberine with an LC50 value of 10 µg/ml. The acetone and dichloromethane fractions resulted in total activity values of 3312 and 4240 ml, respectively. However, these fractions were cytotoxic to the Vero cells with LC50 values of 24.4 µg/ml for acetone fraction and 6.6 µg/ml for the dichloromethane fraction. The cytotoxicity data may serve to discourage the use of these extracts to treat candidosis. However, preparations of these fractions may be used topically on wounds to combat infections. The application of these extracts on rat wound model did not result in any observable pathologies. The DCM and acetone bulk fractions each contained 4 compounds active against Candida albicans. Only the dichloromethane extract was fractionated as these extracts contained almost similar active compounds. Column chromatography using silica as the stationary phase afforded four compounds from the DCM extract. These compounds were identified using nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) as lupeol (CI), betulinic acid (CII), ursolic acid (CIII) and hydroxyl-ursolic acid (CIV). These compounds have been isolated from several plant species and have been to be found active against several pathogens including the human immunodeficiency virus (HIV). This is the first report of the isolation of these compounds from Curtisia dentate. The antibacterial activity of these compounds have been reported. The anti-Candida activity of ursolic oleanolic and ursolic acid has been reported with MIC values exceeding 128 µg/ml (Hiriuchi et al., 2007). However, the anti-Candida activity of betulinic acid and lupeol has not been reported. The four isolated compounds were tested for activity against several fungal (Candida albicans, C. spicata, C. guillermondi, Aspergillus fumigatus, Sporothrix shenckii, Cryptococcus neoformans and microsporaum canis) and bacterial (Escherichia coli, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa) species. Ursolic acid and hydroxyursolic acid were the most active with MIC values. Hydroxyursolic acid resulted in an MIC value as low as 8 µg/ml against M. canis. A. fumigatus was the most resistant microorganism while M. canis and S. schenckii were the most sensitive. C. albicans was moderately sensitive to the compounds with MIC values ranging from 16 µg/ml for betulinic acid to over 250 µg/ml for lupeol. Compounds isolated in sufficient quantities, namely, lupeol and betulinic acid, were investigated for cytotoxicity against Vero cells. It appeared that lupeol was less toxic than betulinic acid, with LC50 values of 89.5 and 10.9 µg/ml, respectively. The cytotoxicity of betulinic acid was comparable to that induced by the positive control, berberine with an LC50 of 10 µg/ml. Lupeol was the least active of the isolated compounds. Betulinic acid and lupeol, together with the water and acetone extracts were tested in an in vivo rat model to determine antifungal and wound healing activities. The rats were immunocompromised prior to the surgical and treatment procedures. Treatments with any of the formulations did not affect wound healing activity. The rate of wound healing was comparable to both the positive (amphotericin B) and negative (cream only) controls. It was however difficult to judge and score antifungal activity. The model developed to evaluate skin infections will have to be improved to allow for testing for anti-<i.Candida activity in vivo. Some antifungal compounds, such as azoles, are known to also have anthelminthic activity. The isolated compounds, which had antifungal activity, were tested for anthelminthic activity against both parasitic and free-living nematodes. Furthermore, other publications demonstrated that betulinic acid had anthelminthic activity against C. elegans. Lupeol, ursolic acid and betulinic acid, together with the DCM and acetone extracts were investigated for anthelminthic activity against both free living and parasitic nematodes. The acetone and dichloromethane extracts were active against all nematodes to concentrations as low as 160 µg/ml. Betulinic acid and lupeol were active against the parasitic nematodes at high concentrations of 1000 and 200 µg/ml. All compounds were active against the free-living Caenorhabditis elegans with concentrations as low as 8 ìg/ml. Betulinic acid was less active than lupeol and ursolic acid against C. elegans. The acetone and dichloromethane extracts were also active against C. elegans with a concentration of 0.31 mg/ml resulting in almost 80% inhibition of larval motility. It would appear that the anthelminthic activity against both parasitic and free-living nematodes occurred at high concentrations of the compounds or extracts. Extracts of various medicinal plant species may provide the solutions to ill-health of small ruminants caused by parasitic nematodes in poor communities of southern Africa. The extracts of Curtisia dentata and isolated compounds have anti-Candida activity in vitro. Their usage is hampered by associated toxicity. The cytotoxicity of the compounds and extracts was only demonstrated with Vero cells (monkey line). Experiments with several human cell lines may indicate the safety of these compound and extracts when used as treatment against Candida infections. No toxic effects were noted when extracts and isolated compounds were tested in an animal experiment indicating that extracts may be safe in a topical application. The extract from 1 g of leaf material can be diluted to more than a litre and still inhibit the growth of C. albicans. / Thesis (PhD)--University of Pretoria, 2007. / Paraclinical Sciences / unrestricted

This thesis explores the feeding habits of sunfish and bluegill in Texas lakes. Data gathered for this study is aimed to aid conservation of these pan fish by making a contribution toward a greater life history understanding of each species.

Due to the nature of the marine environment genetic studies allow insight into behaviour and natural history that is difficult or impossible to identify by direct field observation. Current as well as historical population demography and gene flow can be detected by using molecular techniques. Genetic studies on only a few commercially important marine species along the South African coast have been conducted, although many marine fish species utilize estuaries as nursery areas and little attention has been afforded to studying larval distribution and recruitment of these species from a molecular point of view. Many of these estuarine associated species, especially in the South African milieu, are important for recreational and subsistence use. Associated with southern African estuaries are 13 species of the family Sparidae of which Cape stumpnose Rhabdosargus holubi is the most abundant. Juveniles are mostly confined to estuaries while the adults are strictly marine. Rhabdosargus holubi are serial spawners but temporally separated spawning peaks have been recorded along the South African coastline. Within the first part of this dissertation, the general characteristics of marine fish populations and the marine environment along the South African coast are being discussed. The main aim of this study was to determine the population genetic structure from estimates of nuclear and mitochondrial genetic variation across the distributional range of Rhabdosargus holubi. Samples were collected from 13 geographic localities along the South African coastline from St Lucia in the northeast to Klein River in the southwest. Juveniles were sampled in estuaries and adults were collected in the marine intertidal zone. Mitochondrial DNA control region fragments of 368 bp in length were obtained from a total of 214 individuals from all sampling localities. A total of 36 alleles were identified from 34 polymorphic sites. Following an allele homogeneity test, samples from different localities were lumped to represent six distinct geographical regions. Mitochondrial DNA control region analyses of juveniles showed high haplotype diversity and low nucleotide diversity with no divergent maternal lineages. No pattern between haplotype genealogy and geographic locality was evident. Population genetic analyses using heterologous microsatellite amplification have been successfully completed for a number of studies, including numerous studies of variation within marine fish species. Microsatellite studies have proven to be more sensitive in detecting subtle population structure than mtDNA and/or protein polymorphisms in high gene flow species. A total of 113 microsatellite loci previously isolated from phylogenetically closely related marine fish species were tested for amplification. The success rate of heterologous microsatellite amplification was extremely low (0.02%), with only two polymorphic loci amplifying consistently for analysing 133 individuals sampled from six localities along the distributional range of R. holubi. Results from these two loci were insufficient to draw conclusions about the population genetic structure of R. holubi along the South African coast. Possible reasons for the low rate of amplification success and future research recommendations are discussed. The findings from this study suggest that R. holubi is not geographically restricted, has high gene flow among localities and likely exist as a single stock. / Dissertation (MSc (Genetics))--University of Pretoria, 2006. / Genetics / unrestricted

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22229号 / 理博第4543号 / 新制||理||1653(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 濱田 穣, 准教授 平﨑 鋭矢, 教授 髙井 正成 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

The gopher tortoise is a keystone species that creates networks of underground burrows that are home to an additional 350 species, where 60 are vertebrates. Vertebrates have been shown to differ between habitat types and seasonally, but limited information is known about vertebrate associates in our region. This study was one of the first to investigate this in our region of south Florida. This study was designed to investigate factors that may affect the presence of vertebrates at gopher tortoise burrows. Camera data was collected to determine vertebrate presence and if specific vertebrate groups elicit a territorial response from the tortoise, while habitat vegetation surveys and weather data were collected to evaluate seasonality. Statistical analysis showed variation in vertebrate presence both seasonally and by habitat type. Few territorial interactions were observed overall. This study acts as a starting point to increase our understanding of local tortoise populations. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

Please read the abstract in the dissertation / Dissertation (MSc Agric)--University of Pretoria ,1967. / gm2014 / Zoology and Entomology / unrestricted

Colombia covers an area of approximately 114 million hectares (ha) of which the potential forestly land has been estimated at 60.7 million ha, about 53% of the total area. Only 54 million ha are considered as natural forest, leaving approximately 29 million ha to be used for livestock and agriculture. In order to provide an alternative source of timber, Colombian groups have planted approximately 327 000 ha to different species of Pinus, Eucalyptus and native species. This clearly represents only a small proportion of the total area that might be used for forestry, which is set to grow in the future. In general, trees established in plantations have been grown as monocultures that allow for substantial productivity per management unit. But this is also a homogeneous genetic resource that is highly susceptible to damage caused by insect pests and diseases. It is therefore, surprising that relatively little work has been conducted on pests and pathogens negatively affecting plantation foresty in Colombia. In this regard, the studies presented in this thesis present the first comprehensive treatment of the topic for the country. It is consequently hoped that these will form a basis for the future management and sustainability of forestry in Colombia. In the first Chapter of this thesis, I provide a historical background and the current pest and disease situation for the forestry sector in Colombia. This includes an overview of the main pest and diseases affecting commercial nonnative trees, especially species of Pinus and Eucalyptus. A wide range of sites occurring in Colombia were considered and the document also includes the impact of different climatic conditions on the incidence and management of the various pests and diseases treated. Some of the most important defoliators in Colombia reside in the order Phasmatodea and one of these, Litosermyle ocanae, was treated in studies presented in chapter two. The overall aim was to contribute basic knowledge of L. ocanae including an understanding of the biology, egg population dynamics, and potential biological control assessments based on early detection of the insect. vi Chapter three includes the discovery of one of the members of the Geometridae that causes serious damage due to defoliation of Pinus and Eucalyptus plantations. This pest, known as Chrysomima semiluteraria, has been known in Colombia for many years and this study included a comprehensive evaluation of its biology and field monitoring contributing to an Integrated Pest Management strategy for it. The insect was studied under field and laboratory conditions and a special emphasis was placed on its biological control using the egg parasitoid Telenomus alsophilae. Pinus plantations in Colombia have been affected by numerous pests, including recently, the adelgid Pineus sp. To establish management strategies to assist commercial forestry operations, the life cycle of this insect and the susceptibility of different Pinus species were determined in Chapter four. In addition, the possible role of a Ceraeochrysa sp. as a biological control agent was investigated. In chapter five, Fusarium circinatum is recorded for the first time on Pinus spp. in Colombia. The discovery of this fungus, known to cause the disease Pitch Canker has had an important impact on forestry, especially with regard to management strategies aimed at reducing its impact. Studies in this chapter included those to evaluate the susceptibility of families and provenances of Pinus spp., which are currently used in forestry planting programs in Colombia. The first emergence of the foliage pathogen Dothistroma septosporum as an important constraint to pine forestry in Colombia is treated in chapter six. This fungus is a serious pathogen of many species of Pinus around the world. It was, however, not recognised as a serious threat to forestry in Colombia until it emerged as a serious source of damage to Pinus tecunumanii. In this chapter, the aim was firstly to confirm the identity of the pathogen based on DNA sequence data. Subsequently, the host range and distribution of the pathogen was established in different Colombian forestry areas. The impact of the disease and the susceptibility of different provenances of P. tecunumanii was also assessed. In chapter seven, the main objective was to described the susceptibility of E. grandis clones to a new species of Ceratocystis and to identify clones resistant to it. The fungus was described as Ceratocystis neglecta and management strategies are suggested for it. This thesis includes two Appendices treating new reports of insect pests and an important Eucalyptus pathogen. In Appendix 1, I report on the importance of three different pest insects. Appendix 2 includes a description of a new disease, as well as the potential risks that this disease poses for the Colombian forestry sector. / Thesis (PhD)--University of Pretoria, 2013. / gm2013 / Forestry and Agricultural Biotechnology Institute (FABI) / Unrestricted

Thermus bacteria are of special interest because of their ability to live in high temperature environments. Their enzymes exhibit higher and stable activity in industry as compared to mesophilic or synthetic counterparts. Thermus bacteria are capable of reducing heavy metals which is essential in eradication of heavy metal pollution and controlling global warming. Genome rearrangements were investigated in Thermus species and the extent to which they affected the distribution of functionally related genes on the chromosome and its implication on the coherence of the metabolic network. The contribution of horizontal gene transfer to genome rearrangements and the shuffling of genes on the chromosome were analysed. Horizontally transferred genes were identified alongside their donors and recipients, their age and relative time of insertion. Metabolic networks were clustered and compared to determine the extent to which they were affected by rearrangements as a measure of evolutionary pressures experienced by organisms. Factors that enhance protein thermostability were analysed by determining dominant substitutions for amino acid residues and their properties. Protein thermostability was measured using the UNAFold algorithm. Amino acid substitutions were compared between less and highly thermophilic orthologous sequences in T. scotoductus SA-01 and T. thermophilus HB27 respectively. Protein structures were modelled for orthologs that met a defined selection criterion. Dominant amino acid substitutions were analysed in the structures to determine their locations. The contribution of dominant substitutions to energy changes in structures was analysed using FoldX program. Results revealed a uniform distribution of functionally related genes among thermophilic and mesophilic organisms. The contribution of horizontal gene transfer to genome rearrangements was found to be insignificant. Metabolic networks for Thermus species were poorly clustered in correlation with their optimum environmental growth temperatures. Non-polar, small and charged amino acids were found to significantly enhance thermostability. Higher occurrence of alanine substituted by serine and threonine; and arginine substituted by glutamine and lysine were observed to influence thermostability. Structural comparison showed that mutations were mostly located on the surfaces and helices of structures. The positions of mutations appeared to influence their energy contribution to the overall structure as measured by FoldX algorithm. / Thesis (PhD)--University of Pretoria, 2013. / gm2014 / Biochemistry / unrestricted