Showing papers by "University of Nigeria, Nsukka published in 1975"

Microbiology of Nigerian Palm Wine with Particular Reference to Bacteria

Abstract: The bacteria isolated from samples of wine produced by the fermentation of the saps of Elaeis and Raphia palms were identified as Micrococcus, Leuconostoc, Streptococcus, Lactobacillus, Acetobacter, Serratia, Aerobacter (Klebsiella), Bacillus, Zymomonas and Brevibacterium. The organisms occurring most frequently belonged to the first 5 genera. The change from c. pH 7 to c. pH 4.5 during fermentation appeared to be due to lactic acid bacteria and/or certain Gram negative bacteria, e.g. Serratia and Aerobacter (Klebsiella) spp. From about the 3rd day onwards, Acetobacter spp. were recovered.

Preliminary Microbiological Studies on the Preservation of Palm Wine

Abstract: Palm wine is essentially a heavy suspension of yeasts and bacteria in fermenting palm sap. The water extract of a local preservative, from the bark of Sacoglottis gabonensis, failed to inhibit several yeasts and bacteria from palm wine. Sodium metabisulphite, diethylpyrocarbonate (DEPC) and sorbic acid inhibited to varying extents micro-organisms in palm wine. Sorbic acid was thought to be the most suitable preservative tested since DEPC left a residual pungent smell and sodium metabisulphite was not suitable because it is unacceptable to man above 0.35 mg/kg of body weight (Mossel, 1971). Pasteurization at 70° for 30 min was more effective than any of the chemical methods in reducing the microbial load of the wine. It is suggested that pasteurization at 70° for 30 min combined with subsequent treatment with sorbic acid may prove useful as a means of preserving palm wine.

The subunit structure of beta-glucosidase from Botryodiplodia theobromae Pat.

Abstract: 1. A homologous series of beta-glcosidase (beta-D-glcoside glcohydrolase, EC 3.2.1.21), which varied in relative amounts in different preparations from cultures of similar and different age, was observed in cultures od Botryodiplodia theobromae Pat grown for 4-8 week on cotton flock (cellulose) as carbon source. 2. Aging of the purified high-molecular-weight species led to some amount of siddociation into a homolous series of lower-molecular-weight speices. 3. Rough molecular-weight estimates, by gel filtration, of the various species derived from the purifeid high-molecular-weight enzyme were 350000-3800000, 170000, 180000, 83000-87000 and 45000-47000. 4. Electron micrographs of the negatively stained 350000-380000-molecular-weight enzyme showed that the molecule is an octamer in which each roughly spherical monomer occupies a corner of a cube with each side about 7.14nm long. 5. Carboxamidomethylation of the reduced form of each molecular-weight species of the enzyme led to irreversible dissociation of the molecules into electrophoretically identical polypeptides with a moleclar weight of 10000-12000. 6. These results suggest a slow association-dissociation of the type (8n)in equilibrium 2 (4n) in equilibrium 4(2n) in equilibrium 8(n), where n is defined as the monomer. The monomer is in turn made up of four polypeptide a subunits whi-ch are non-catalytic. 7. The Michaelis constants (Km) and heat stability of the four wnzymically active molecular species derived from the purified enzyme increased with molecular complexity, whereas all four species were inhibited by glycerol (100nM) at low concentrations of substrate (o-nitrophenyl beta-D-glucopyranoside) but activated at high substrat concentrations. 8. Only the lowest-molecular-weight species (45species (45,000-47000 mol. wt.) showed substrate inhibition.

Bleach-induced Germination and Breakage of Dormancy of Seeds of Alectra vogelii

Abstract: The effects of solutions of sodium hypochlorite and calcium hypochlorite (bleach) on dormancy and germination of Alectra vogelii seeds were investigated. Dry (non-pretreated) and 10-day water-pretreated seeds were exposed to various bleach concentrations, as well as to the host (Vigna unguiculata) root exudate. The 15-month-old Alectra seeds used were partially dormant in that only 40% or less of the 10-day pretreated seeds could be stimulated to germinate by the standard host root exudate. Comparable percentage germination of nonpretreated seeds was achieved with certain concentrations of bleach and the halogens, chlorine and bromine. Bleach and the halogens served not only as germination stimulant for pretreated Alectra seeds but appropriate concentrations induced also high percentage (70–90%) germination indicating a breakage of seed dormancy as well. The activity of the bleach in stimulating high percentage germination could be significantly reduced when the optimally bleach-treated seeds were rinsed daily with water during the germination period. Vigna root exudate, but not bleach, was shown to act as root stimulant for Alectra seedlings. The possible mechanism of the bleach effect on germination and dormancy of Alectra seeds is discussed.

Rumor Mongering in War Time

Abstract: Summary The study tests the hypothesis that the essentials of rumor are importance and ambiguity: that is, the amount of rumor in circulation varies with the importance of the subject times the ambiguity of the evidence. The study also test the transmission theory of rumor and the classificatory method devised by Robert H. Knapp. The frequencies of the rumors that circulated in U.S.A. in 1942 and in Biafra from 1968–1970 are also compared. The results strongly confirmed the hypothesis, except that a new class of rumor, named “neo-pipe-dream rumor,” was discovered among the rumors that circulated in Biafra. In each country it is found that there is a negative correlation between pipe-dream rumors and wedge-driving rumors.

In vitro Post-germination Growth and Development of Embryos of Alectra (Scrophulariaceae)

Abstract: In vivo, seeds of the obligate root parasite Alectra vogelii Benth. (Scrophulariaceae) germinate only after being soaked in water for a period of time (pretreatment) followed by stimulation by certain factors exuded from a host root. Germinated seedlings do not develop beyond radicle emergence, and finally die, unless their radicles make contact with and penetrate into a host root conductive system. In vitro, germinated embryos obtained by exposing sterilized and pretreated seeds to root exudate of Vigna unguiculata were aseptically cultured on Knop's, White's and Murashige and Skoog's media. The embryos grew into seedlings with shoots and roots on a medium containing mineral salts and sucrose, but not on mineral salts alone. Seedling performance was generally not improved when the mineral salts-sucrose media were supplemented with vitamins. Shoot extension growth was better on Murashige and Skoog's mineral salts-sucrose medium than on Knop's or White's medium. However, seedling development was greatly boosted when cultivated on White's minerals salts-sucrose medium supplemented with coconut milk. Seedlings turned green on transfer to light but did not flower. The successful culture of these embryos and seedlings on a simple, chemically defined medium of mineral salts and sugar suggests that these nutrient components are the minimal external requirements for stimulation and support of normal seedling growth. These may be obtained in vivo by the parasite's tapping of the host root conductive system.

Aspect of herbicidal effects on the ectosymbiotic microorganism of the forest plants

Abstract: Experiments were conducted under laboratory conditions to establish the sensitivity or otherwise of the following mycorrhizal fungi: Tricholoma saponaceum (Fr) Quel, Tricholoma pessundatum (Fr) Quel and Amanita citrina Schaefer to the herbicides Dalapon and Aminotriazole Various reactions were shown by the fungi In general, the rareness of growth stimulation coupled with significant inhibition of mycelial growth are indications of the fungitoxicity of the herbicides

Studies on the life history of the African bush-cricket Zabalius apicalis Bolivar (Orthoptera: Tettigoniidae)

Abstract: Summary Basic information on the life cycle of the tropical bush-cricket, Zabalius apicalis is given. In the laboratory, eggs developed and hatched only when they were incubated in contact with water or in 100% R.H. chamber. Their mean incubation periods were 18·1 days at a constant temperature of 28·5°C ± 0·5°C and 24·2 days at 21·5°C ± 1·5°C. Embryonic development did not occur at 30·5°C ± 0·5°C and above. In an animal house with open sides, male nymphs moulted six times to become adults after a mean of 55·7 days and female nymphs seven times after a mean of 67·3 days. In the field, the species showed seasonal occurrence which seemed closely related to availability of tender leaves of its only host plant, Ficus sp.

D'emblee type of mycosis fungoides of head and neck

Abstract: Mycosis fungoides as a disorder of reticulo-endothelial system occurs in the eczematous or psoriatic stage, progresses to infiltrated plaque stage and finally to tumorous form with or without systemic spread. The head and neck is rarely involved. A case is presented in which the disease process started as a tumor (d'emblee type) and remained localized in the head and neck region without a generalized spread. The tumorous lesion rapidly increased in size and involved deeper tissues of the neck to cause infranuclear facial palsy and medial bulging of the tonsil' it also extended in the superior mediastinum casuing pressure on the trachea and the esophagus. The patient died of respiratory failure.

SAND-LATERITE MIXTURES FOR ROAD CONSTRUCTION (A Laboratory Investigation)

Abstract: Soil mixtures have been used extensively in developed countries to construct great lengths of road when other materials like cement and lime were not either available, developed or widely used. Developing countries with low per capita income, low cement and lime production, can use the same technique today. Laterite being readily available in many places can be mixed with sand to improve its strength, stability and other properties for this purpose. The paper sets out to investigate the improvements in the relevant properties of six samples of laterites when they are mixed with sand. The six samples are representative of the types of laterites occurring over the eastern parts of Nigeria. In practice, the mode of construction in which sand is used as a stabiliser instead of cement or lime could be used to minimise costs in the construction of roads carrying medium density traffic and in the surfacing of "unimproved roads". The results obtained show that for all types of laterites tested, the addition of sand to laterites has beneficial effects in reducing the liquid limit, the optimum moisture content, the plasticity index, the linear shrinkage and in increasing the maximum dry density and the California Bearing Ratio. There is an optimum sand percentage for maximising most of the parameters measured. This optimum sand percentage is different for each type of laterite and is also dependent on the level of compaction given to the mixture. Comparison of the results obtained with some specifications shows that the improvements obtained are such as would make the sand-laterite mixtures satisfy most specifications for the types of roads mentioned.

Sedimentology of Turonian Sandstone bodies and paleogeographic conclusions, Aba Omega area, Eastern Nigeria

Abstract: The texture and mineralogy of some sandstone bodies in the Aba-Omega area of Southeastern Nigeria suggest that these sediments were products of rapid sedimentation. Two sediment sources are suggested: a nearby metamorphic to low rank plutonic terrain probably the Oban Massif, and a sedimentary or distant basement area. Paleogeographic reconstructions further suggest that movement along the Abakaliki axis of uplift may have been initiated by Lower Turonian.

Total serotonin (5-hydroxytryptamine) concentrations in rat tissues after intravenous infusions of calcium EDTA

Abstract: 1. 1. Studies on total 5-hydroxytryptamine (5-HT) concentrations in tissues in rats infused with toxic doses of CaEDTA at 6 mmoles/kg per 24 hr, for 48 hr, indicate that appreciable alterations in tissue concentration of 5-HT do occur during chelate toxicity. 2. 2. The 5-HT concentrations in brain, duodenum and kidney of CaEDTA infused rats were significantly (P<0·05) lower than 5-HT concentrations in brain, duodenum and kidney of saline infused controls. No significant changes were observed in 5-HT concentrations in the liver of treated rats, compared to controls.

Experimental evaluation of mechanical dehydration of nigerian cocoa beans

Abstract: A serious problem encountered in commercial cocoa-bean processing is the mouldiness and sprouting which often occur during the "fermentation-sun drying" stages, especially during the rainy season (May-October). An alternative processing technique which employs a forced ventilation, and electrically heated, drying oven has been evaluated, and found suitable for eliminating the sun-drying problem. Several experimental studies and organoleptic tests, using "processed seeds" "unprocessed seeds" and "pod-fermented seeds" (as described in this report) have demonstrated the feasibility of producing acceptable commercial cocoa beans by this technique, at a temperature of about 50oC. Total dehydration period. at 50oC, was about 60 hours, and this could be further reduced to about 7 to 8 hours at higher temperatures (75° to 85°C). However the quality of the products produced at the higher temperatures is somewhat lower than that of 50 0 C. The results indicate a need for further investigation of the fermentation process. dehydration at lower temperatures than 50°C, and the quantitative analysis of the theobromine content of the finished product. The conclusion was that the technique is a feasible proposition which deserves the further investigation and a cost-benefit analysis based on pilot-plant trials.

Algebraic constraints for higgs multiplets

Abstract: The phenomenon of spontaneous breaking of a gauge symmetry group, provides a number of algebraic constraints which Scalar Higgs mesons have to satisfy. We discuss these constraints and give details for the cases ofSU(2),SU(2) ×U(1) andSU(3).