From Introduction: For the past eight years, the Zoology Department of Rhodes University College, in co-operation with African Explosives & Chemical Industries Ltd., has been studying certain entomological problems relating to turf on the golf course along the coastal belt of the Eastern Cape Province. The position is briefly as follows:- On the golf courses at Mossel Bay, Humewood (Port Elizabeth), Port Alfred and East London, vast damage has been done to the greens and fairways by "white grubs", the larval stages of Scarabaeidae. It would appear that these beetles had been present in the environs of the courses for many years, but it was only when large areas of the natural veld were converted into fairways, with a more or less uniform cover of grass, with Cynodon dactylon Pers. predominating, that conditions were inadvertently created which favoured the development of the beetles. It was not long after the establishment of these golf courses, that the beetles assumed the proportions of a pest, and the larvae began destroying the root system of the grasses covering the greens and fairways.

Thesis (M. Sc.)--University of Hong Kong, 1972. / Typewritten.

Thesis (M.Sc.)--University of Hong Kong, 1972. / Also available in print.

No description available.

published_or_final_version / Zoology / Master / Master of Science

O crescimento do mercado de cervejas artesanais tem demandado inovações. Uma abordagem que se destaca neste contexto é o uso de leveduras não convencionais em processos controlados de fermentação. Para ter melhores resultados neste cenário é fundamental que o produtor conheça as capacidades e limitações das leveduras que serão utilizadas na produção de cervejas. Assim, este estudo teve como objetivo avaliar características fisiológicas, essenciais e complementares, de uma cepa de Brettanomyces anomalus e uma Torulaspora delbrueckii para a produção de cervejas, comparando-as com duas cepas de Saccharomyces cerevisiae já utilizadas na indústria cervejeira. Avaliou-se o perfil cromossômico das leveduras (cariotipagem), a capacidade de crescimento em diferentes substratos e fontes de carbono, bem como em diferentes concentrações de etanol e compostos de lúpulo, a capacidade de esporulação, floculação, produção de sulfeto de hidrogênio (H2S), formação de espuma e a evolução da fermentação em função do tempo. Foram observadas diferenças entre os padrões cromossômicos das quatro leveduras. A intensidade de produção de H2S foi maior para a B. anomalus (WLP640) quando comparada com T. delbrueckii (WLP603), que foi classificada com a mesma intensidade de produção da S-33 (S. cerevisiae). As duas leveduras não convencionais atenderam às características fisiológicas essenciais para fermentação de cervejas. A B. anomalus foi capaz de metabolizar diversas fontes de carbono, como glicose, frutose, sacarose, maltose, matotriose e celobiose, ao passo que a T. delbrueckii cresceu apenas em glicose, frutose e sacarose, apontando sua potencial aplicação para produção de cervejas com teor alcoólico reduzido ou seu uso em inoculações sequenciais ou co-inoculações com outras leveduras. Ambas apresentaram crescimento em teores alcoólicos de 4% e 8%, ao passo que T. delbrueckii tolerou maior concentração de compostos do lúpulo em relação à B. anomalus, que não foi capaz de crescer em meio com as maiores concentrações combinadas de álcool (8% v/v) e α-ácidos (80 mg/L). Os resultados permitem concluir que as leveduras B. anomalus e T. delbrueckii possuem potencial para a produção de cervejas, desde que seja observada a compatibilidade de suas características fisiológicas com a expectativa acerca das características da cerveja. / The booming in the craft beer market worldwide has demanded innovations to bring up distinctive products. An approach that stands out in this context is the use of non-conventional yeasts in controlled beer fermentation processes. To have better outcomes in this scenario, it is essential that the producer knows the capabilities and limitations of those yeasts. Thus, this study aimed to assess essential and complementary physiological traits of one strain of Brettanomyces anomalus and one of Torulaspora delbrueckii for beer brewing, comparing them with two Saccharomyces cerevisiae strains already used in commercial breweries. The characteristics assessed were chromosome profile (karyotyping technique), growth capacity in different substrates and carbon sources, as well as under different concentrations of ethanol and hop compounds, the capability of sporulation, flocculation, hydrogen sulfide (H2S) production and foam formation and, finally, the fermentation evolution pattern. Differences in the chromosomal profile were observed among the four strains. The potential for H2S production was higher for B. anomalus (WLP640) when compared to T. delbrueckii (WLP603), which had the same potential than S-33 (S. cerevisiae). Both non-conventional yeasts have met the essential physiological traits demanded to carry beer wort fermentation. B. anomalus was able to metabolize many of the assessed carbon sources, as glucose, fructose, sucrose, maltose, maltotriose and cellobiose, while the T. delbrueckii strain was able to grow only in glucose, fructose and sucrose, pointing its potential application for low alcohol beer production, as well as its use in sequential inoculations or co-inoculations with other yeasts. Both showed satisfying growth under alcohol contents of 4% and 8%. T. delbrueckii tolerated higher hop compounds concentration when compared to B. anomalus, that was unable to grow at the highest combined concentrations of ethanol (8% v/v) and α-acids (80 mg/L). The results lead to the conclusion that the yeasts B. anomalus and T. delbrueckii can be explored in beer brewing, provided that an alignment between their physiological traits and the expectations around the beer characteristics are observed.

Ocorrências comuns de infecções virais graves, aparecimento de cepas resistentes e um limitado número de quimioterápicos antivirais disponíveis mostram a necessidade da busca por novas substâncias ativas como antivirais. Muitas substâncias derivadas de plantas são candidatas ao estudo do seu potencial na terapia sistêmica e/ou profilaxia de herpes simplex virus 1 (HSV-1). Dentre as plantas com atividade antiviral, destacam-se as do gênero Baccharis. O objetivo geral do trabalho foi o estudo da composição química e avaliação da atividade antiviral das folhas de Baccharis anomala D.C. através de fracionamento bioguiado. Utilizando precipitação com etanol e fracionamento por permeação molecular foi possível separar os constituintes químicos ativos contra o vírus HSV-1 presentes no extrato aquoso de Baccharis anomala. Os testes de prospecção de constituintes químicos indicaram a presença de taninos, catequinas e saponinas no extrato aquoso da espécie. Através da análise cromatográfica foi possível detectar a presença de compostos fenólicos, utilizando-se coloração com cloreto férrico e reagente natural. Em relação à atividade antiviral, a fração ativa denominada AQ PPT FR 4-5 apresentou pronunciada atividade antiviral, inibindo a replicação viral em 100 % nas concentrações de 1,25, 0,625, 0,312 e 0,156 mg/mL, contra as cepas ATCC-VR733 e Aciclovir-resistente 29-R do HSV-1. Em relação ao mecanismo de ação, observou-se atividade virucida da fração AQ PPT FR 4-5. Estes resultados são muito importantes, pois, de acordo com a literatura, ainda não foram relatados compostos com atividade virucida úteis clinicamente para o tratamento de infecções por HSV-1. Conclui-se, portanto, que Baccharis anomala possui potente atividade antiviral contra o vírus HSV-1 e é promissora para estudos posteriores que visem ao isolamento, identificação e estudo do mecanismo de ação antiviral de compostos ativos da espécie, considerando a emergência de cepas resistentes e a necessidade de compostos com novos mecanismos de ação. / Common occurrences of severe viral infections, emergence of resistant strains and a limited number of available antiviral chemotherapeutics show the need to search for new active substances as antiviral. Many compounds derived from plants are candidates for the study of their potential in systemic therapy and/or prophylaxis of herpes simplex virus type 1 (HSV-1). Among the plants with antiviral activity, those from the genus Baccharis are remarkable. The main objective of the work was the study of the chemical composition and evaluation of the antiviral activity of extracts from Baccharis anomala D.C., using bioactivity guided fractionation. Through precipitation with ethanol and fractionation by molecular permeation it was achieved the separation of the active chemical constituents against HSV-1 virus in the aqueous extract of Baccharis anomala. Phytochemical tests indicated the presence of tannins, catechins and saponins in the aqueous extract. By thin layer chromatography it was detected the presence of phenolic compounds using ferric chloride and natural reagent. Concerning the antiviral activity, the active fraction named AQ PPT FR 4-5 showed pronounced antiviral activity, represented by 100 % inhibition of viral replication at concentrations of 1.25, 0.625, 0.312 and 0.156 mg/mL, against the strains ATCC-VR733 and Acyclovir-resistant 29-R of HSV-1 virus. Regarding the mechanism of action, virucidal activity on the fraction AQ PPT FR 4-5 was detected, which is also very important because, as far as we know, compounds with virucidal activity for clinical use in the treatment of HSV-1 infections were not reported yet. In conclusion, Baccharis anomala displayed pronounced antiviral activity against HSV-1 virus and it is promising for further studies aimed to the isolation, identification and mechanism of action of antiviral active compounds of the species, considering the emergence of resistant strains and the need for compounds with new mechanisms of action.

Ocorrências comuns de infecções virais graves, aparecimento de cepas resistentes e um limitado número de quimioterápicos antivirais disponíveis mostram a necessidade da busca por novas substâncias ativas como antivirais. Muitas substâncias derivadas de plantas são candidatas ao estudo do seu potencial na terapia sistêmica e/ou profilaxia de herpes simplex virus 1 (HSV-1). Dentre as plantas com atividade antiviral, destacam-se as do gênero Baccharis. O objetivo geral do trabalho foi o estudo da composição química e avaliação da atividade antiviral das folhas de Baccharis anomala D.C. através de fracionamento bioguiado. Utilizando precipitação com etanol e fracionamento por permeação molecular foi possível separar os constituintes químicos ativos contra o vírus HSV-1 presentes no extrato aquoso de Baccharis anomala. Os testes de prospecção de constituintes químicos indicaram a presença de taninos, catequinas e saponinas no extrato aquoso da espécie. Através da análise cromatográfica foi possível detectar a presença de compostos fenólicos, utilizando-se coloração com cloreto férrico e reagente natural. Em relação à atividade antiviral, a fração ativa denominada AQ PPT FR 4-5 apresentou pronunciada atividade antiviral, inibindo a replicação viral em 100 % nas concentrações de 1,25, 0,625, 0,312 e 0,156 mg/mL, contra as cepas ATCC-VR733 e Aciclovir-resistente 29-R do HSV-1. Em relação ao mecanismo de ação, observou-se atividade virucida da fração AQ PPT FR 4-5. Estes resultados são muito importantes, pois, de acordo com a literatura, ainda não foram relatados compostos com atividade virucida úteis clinicamente para o tratamento de infecções por HSV-1. Conclui-se, portanto, que Baccharis anomala possui potente atividade antiviral contra o vírus HSV-1 e é promissora para estudos posteriores que visem ao isolamento, identificação e estudo do mecanismo de ação antiviral de compostos ativos da espécie, considerando a emergência de cepas resistentes e a necessidade de compostos com novos mecanismos de ação. / Common occurrences of severe viral infections, emergence of resistant strains and a limited number of available antiviral chemotherapeutics show the need to search for new active substances as antiviral. Many compounds derived from plants are candidates for the study of their potential in systemic therapy and/or prophylaxis of herpes simplex virus type 1 (HSV-1). Among the plants with antiviral activity, those from the genus Baccharis are remarkable. The main objective of the work was the study of the chemical composition and evaluation of the antiviral activity of extracts from Baccharis anomala D.C., using bioactivity guided fractionation. Through precipitation with ethanol and fractionation by molecular permeation it was achieved the separation of the active chemical constituents against HSV-1 virus in the aqueous extract of Baccharis anomala. Phytochemical tests indicated the presence of tannins, catechins and saponins in the aqueous extract. By thin layer chromatography it was detected the presence of phenolic compounds using ferric chloride and natural reagent. Concerning the antiviral activity, the active fraction named AQ PPT FR 4-5 showed pronounced antiviral activity, represented by 100 % inhibition of viral replication at concentrations of 1.25, 0.625, 0.312 and 0.156 mg/mL, against the strains ATCC-VR733 and Acyclovir-resistant 29-R of HSV-1 virus. Regarding the mechanism of action, virucidal activity on the fraction AQ PPT FR 4-5 was detected, which is also very important because, as far as we know, compounds with virucidal activity for clinical use in the treatment of HSV-1 infections were not reported yet. In conclusion, Baccharis anomala displayed pronounced antiviral activity against HSV-1 virus and it is promising for further studies aimed to the isolation, identification and mechanism of action of antiviral active compounds of the species, considering the emergence of resistant strains and the need for compounds with new mechanisms of action.

Ocorrências comuns de infecções virais graves, aparecimento de cepas resistentes e um limitado número de quimioterápicos antivirais disponíveis mostram a necessidade da busca por novas substâncias ativas como antivirais. Muitas substâncias derivadas de plantas são candidatas ao estudo do seu potencial na terapia sistêmica e/ou profilaxia de herpes simplex virus 1 (HSV-1). Dentre as plantas com atividade antiviral, destacam-se as do gênero Baccharis. O objetivo geral do trabalho foi o estudo da composição química e avaliação da atividade antiviral das folhas de Baccharis anomala D.C. através de fracionamento bioguiado. Utilizando precipitação com etanol e fracionamento por permeação molecular foi possível separar os constituintes químicos ativos contra o vírus HSV-1 presentes no extrato aquoso de Baccharis anomala. Os testes de prospecção de constituintes químicos indicaram a presença de taninos, catequinas e saponinas no extrato aquoso da espécie. Através da análise cromatográfica foi possível detectar a presença de compostos fenólicos, utilizando-se coloração com cloreto férrico e reagente natural. Em relação à atividade antiviral, a fração ativa denominada AQ PPT FR 4-5 apresentou pronunciada atividade antiviral, inibindo a replicação viral em 100 % nas concentrações de 1,25, 0,625, 0,312 e 0,156 mg/mL, contra as cepas ATCC-VR733 e Aciclovir-resistente 29-R do HSV-1. Em relação ao mecanismo de ação, observou-se atividade virucida da fração AQ PPT FR 4-5. Estes resultados são muito importantes, pois, de acordo com a literatura, ainda não foram relatados compostos com atividade virucida úteis clinicamente para o tratamento de infecções por HSV-1. Conclui-se, portanto, que Baccharis anomala possui potente atividade antiviral contra o vírus HSV-1 e é promissora para estudos posteriores que visem ao isolamento, identificação e estudo do mecanismo de ação antiviral de compostos ativos da espécie, considerando a emergência de cepas resistentes e a necessidade de compostos com novos mecanismos de ação. / Common occurrences of severe viral infections, emergence of resistant strains and a limited number of available antiviral chemotherapeutics show the need to search for new active substances as antiviral. Many compounds derived from plants are candidates for the study of their potential in systemic therapy and/or prophylaxis of herpes simplex virus type 1 (HSV-1). Among the plants with antiviral activity, those from the genus Baccharis are remarkable. The main objective of the work was the study of the chemical composition and evaluation of the antiviral activity of extracts from Baccharis anomala D.C., using bioactivity guided fractionation. Through precipitation with ethanol and fractionation by molecular permeation it was achieved the separation of the active chemical constituents against HSV-1 virus in the aqueous extract of Baccharis anomala. Phytochemical tests indicated the presence of tannins, catechins and saponins in the aqueous extract. By thin layer chromatography it was detected the presence of phenolic compounds using ferric chloride and natural reagent. Concerning the antiviral activity, the active fraction named AQ PPT FR 4-5 showed pronounced antiviral activity, represented by 100 % inhibition of viral replication at concentrations of 1.25, 0.625, 0.312 and 0.156 mg/mL, against the strains ATCC-VR733 and Acyclovir-resistant 29-R of HSV-1 virus. Regarding the mechanism of action, virucidal activity on the fraction AQ PPT FR 4-5 was detected, which is also very important because, as far as we know, compounds with virucidal activity for clinical use in the treatment of HSV-1 infections were not reported yet. In conclusion, Baccharis anomala displayed pronounced antiviral activity against HSV-1 virus and it is promising for further studies aimed to the isolation, identification and mechanism of action of antiviral active compounds of the species, considering the emergence of resistant strains and the need for compounds with new mechanisms of action.

[Summary]: The larvae of Anomala opacicollis (Pér), of Melolonthid and of other Rutelid species, attack tobacco in Southern Rhodesia, and are more commonly called "whitegrubs". Whitegrubs are widespread in the sandveld areas where tobacco is grown and, at the Trelawney Station of the Tobacco Research Board of Southern Rhodesia, where this work was done, A. opacicollis was the predominant species. An account o£ the one year life cycle is given. The adults eat the leaves of various indigenous trees and an account of an experiment on the food preferences of A. opacicollis adults is given, and the main food sources in the Trelawney area are listed. An experiment is described which shows that the beetles prefer to lay their eggs in the veld or in manured broken land rather than in normal ploughed lands. The larvae are erratically distributed in lands and experiments on larval movement suggest that this is mainly due to concentration of the larvae at discrete concentrations of organic matter in the soil. The temperature and moisture condition of the top 3" of soil are found to be those which attact the larvae. It is suggested that tho larvae prefer and move to soil which contains the lowest amount of moisture which keeps the soil air spaces saturated. lt appears that the preferred temperature decreases with increasing soil moisture content and it is suggested that this is due to the respiratory requirements of the larvae. Soil pH, compaction and fertiliser content and the presence of plants do not appear to influence larval movements. A theory is developed concerning the mechanism of movements in the soil and it is suggested that, in the absence of a continuous gradient, the speed but not the direction of movement is influenced by conditions to which the larvae are sensitive. Evidence in support of thie theory is given. Studies on the survival of larvae at different soil moisture contents and temperatures show that conditions in the top 3" of soil are not likely to be lethal in spite of the high temperatures and low moisture contents found there. The relation of whitegrub behaviour to agricultural problems is discussed. Other workers published evidence indicating that early ploughed lands were attractive to whitegrubs; this is shown not to be the case and the previous evidence is re-interpreted. Such lands tend to contain concentrations of whitegrubs round the borders. The reason for this is discussed and it is suggested that lands should be ploughed early to confine whitegrub infestations in this manner. Soils low in fertility through repeated cultivation are commonly believed to contain more whitegrubs than virgin soil. However, behaviour studies suggest that it is the activity and not the size of the population which is affected by soil fertility. The time at which tobacco is planted is known to determine the extent of subsequent whitegrub damage. The reason for this is to be found in the life cycle of whitegrubs and the results of an experiment on time of planting in relation to whitegrub damage are given. Some insecticides are shown to be more repellant than others to A. opacicollis larvae and the influence of this fact on the assessment of soil insecticide effectiveness in the field is discussed. Reference is made to a method developed by the writer for the determination of insecticide effectiveness under the conditions of erratic whitegrub distribution which normally occur.