4,610 research outputs found

    Transition of hemoglobin between two tertiary conformations: The transition constant differs significantly for the major and minor hemoglobins of the Japanese quail (Cortunix cortunix japonica)

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    We demonstrate that 5,5â€Č-dithiobis(2-nitrobenzoate) – DTNB – reacts with only CysF9[93]ÎČ and CysB5[23]ÎČ among the multiple sulfhydryl groups of the major and minor hemoglobins of the Japanese quail (Cortunix cortunix japonica). Kequ, the equilibrium constant for the reaction, does not differ very significantly between the two hemoglobins. It decreases 430-fold between pH≈5.6 and pH≈9: from a mean of 7±1 to a mean of 0.016±0.003. Quantitative analyses of the Kequ data based on published X-ray and temperature-jump evidence for a tertiary structure transition in liganded hemoglobin enable the calculation of Krt, the equilibrium constant for the r←→t tertiary structure transition. Krt differs significantly between the two hemoglobins: 0.744±0.04 for the major, 0.401±0.01 for the minor hemoglobin. The mean pKas of the two groups whose ionizations are coupled to the DTNB reaction are about the same as previously reported for mammalian hemoglobins

    Statistical approach to optimization of the transesterification reaction from sorrel (hibiscus sabdariffa) oil

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    In an effort to optimize the reaction conditions of biodiesel production from Sorrel seed oil, Response Surface Methodology (RSM) was applied and the effects of reaction temperature, catalyst amount, reaction time and methanol/oil molar ratio, and their reciprocal interactions were ascertained. A total of 30 experimental runs were designed by Central Composite Rotatable Design (CCRD) and carried out. A quadratic polynomial was obtained for predicting the Transesterification process and the ANOVA test showed the model to be significant (p<0.05). The validity of the predicted model was confirmed by carrying out three independent replicates experiments. The actual maximum biodiesel yield obtained was 99.23% (w/w) at methanol/oil molar ratio 6.21, catalyst amount 1.03 (% wt.), reaction temperature 51 oC, and reaction time 63 min. The fuel properties of Hibiscus sabdariffa methylester (HSME) produced were found to be within the ASTM D6751 and DIN EN 14214 biodiesel standards. The fatty acid profile of the HSME revealed that the dominant fatty acids were oleic (58.34%), arachidic (1.55%), palmitic (18.28%) and linoleic (21.19%). Emission assessment revealed 70% reduction of CO at B80, 80% reduction of NO concentration at B40

    HCME: An Environment-Friendly I.C. Engine Fuel

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    The study revealed that Hura crepitans oil is a good candidate for Hura crepitans methyl ester (HCME) production. Two steps (esterification and transesterification) production stages influenced the high yield of HCME. Three possible experimental runs were performed in each step, the best of the three conditions were 1.45 (% v/v) for H2SO4 conc., 5:1 for methanol/oil molar ratio, 40 min for reaction time which gave 1.06 % for FFA in the first step, in the second step, 92.70 %(w/w) of HCME was obtained at 0.55% KOH, 5:1 methanol/oil molar ratio, 60 oC temperature and 30 min reaction time. The produced HCME had fuel properties which satisfied both ASTME D6751 and EN 1424 standards. The fatty acid profile of the HCME revealed the dominant fatty acids were linoleic (64.50%), oleic (17.54%) and palmitic (12.70%). Exhaust emissions from an internal combustion (I.C.) engine revealed that there is 60% decreased in CO, 58% decreased in NOx, 60% decreased in HC, 39% decrease in smoke opacity and 42% decreased in BSFC at B20, respectively. Flue gas temperature increased by 12% at B20, 45% increased in BTE at B50 when compared to pure diesel (AGO). Hence, it can be concluded that B20 (20% HCME + 80% AGO) will provides the best emission reduction at the lowest cost

    The Incidence of Extended-Spectrum Beta- Lactamase (ESBL)-Producing Bacteria in Salad Vegetables in Ondo City, Nigeria

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    Staff PublicationAim: This study was carried out to determine the occurrence of extended-spectrum beta-lactamase (ESBL) producing bacteria in salad vegetables in Ondo City, Nigeria. Study Design: An experimental study design with randomized sampling. Place and Duration of the Study: The research was carried out in the Department of Biological Sciences of Wesley University, Ondo State, Nigeria. Methodology: Samples of cucumber, carrot, green pea, green beans, sweet corn and cabbage were analysed on appropriate agar medium. Pure isolates were identified by biochemical tests and confirmation was done by the use of API 20 E and API 20 NE in accordance with standard procedures. ESBLs screening was carried out using the double disk synergy test. Data were statistically analyzed using MedCalc statistical software (version 17.2). Results: Total viable bacterial counts (TVBCs) ranged from 1.1 × 103 to 7.1 x 105 cfu/ml; total coliform counts (TCC) ranged from 1.2 x 102 to 3.9 x 103 cfu/ml while total faecal counts (TFC) ranged from 0 to 2.9 × 102 cfu/ml. There were statistical differences in mean TVBCs of the samples (P 0.05). One hundred and sixty (166) isolates obtained from the samples were identified as Bacillus cereus, Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, Serratia marcesens and Staphylococcus saprophyticus. At least one member of all bacterial species, except S. saprophyticus, produced ESBL. Conclusion: This study revealed that salad vegetables could be a vehicle for the spread of extended-spectrum beta-lactamase-producing bacteria which translates to a threat to public health around the world as salads are loved and consumed by all categories of people globally

    VARIATION IN FLOWERING PHENOLOGY OF CASSIA FISTULA LINN. POPULATION IN OTA, OGUN STATE. NIGERIA

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    Flowering phenology in the population of Cassia fistula Linn. at Ota, Ogun State, Nigeria was investigated for three years to determine if there was variation in the phenology and the patterns were compared with some environmental factors to determine if there was any correlation. The number of plants flowering each month was monitored for three years. Data for mean monthly maximum and minimum temperatures, mean monthly rainfall and number of days with rain per month were obtained from Meteorological Institute, Oshodi, Lagos- Nigeria. In each year, there was synchronous flowering showing early and late flowering plants but the start and end of flowering vary between years. The peak months of flowering vary from year to year so also the period of flowering. Statistical analysis showed significant difference in flowering pattern between two of the years and from month to month. All these show clear variation in the flowering phenology of the species. Commencement of flowering was correlated with the rainfall and temperature in July and August while the end was correlated with the amount of rainfall and number of rainy days. With the overlap of flowering between the years, flowering is continuous in contrast to annual flowering in its country of origin; a phenomenon that has not been reported for the species before. The ecological implication was discusse

    The synergism of hepatitis B and aflatoxicosis in hepatocellular carcinoma development: A mini-review

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    Hepatocellular carcinoma (HCC) is the twelfth most common cancer and the fifth leading cause of worldwide cancer-related death. Chronic hepatitis B infection, caused by the hepatitis B virus (HBV) and exposure to aflatoxins is fundamental in the formation of HCC in developing countries. This review of scientific publications aims to establish the detrimental effects of aflatoxin-contaminated foods and highlights the correlation between aflatoxin and hepatitis B viral-associated hepatocellular carcinoma. Research has shown a significant increase in the occurrence of HCC in HBV-infected individuals exposed to fungal toxins. HBV demonstrates the ability to integrate and bind to p53 protein in the host DNA and propagate hepatocyte vulnerability through carcinogenic aflatoxin B1 (AFB1) damage. Although there has been clear evidence about the synergistic interaction of exposure to AFB1 and HBV infection in the induction of HCC, other literature has shown otherwise, mainly because incomplete and vague findings and hypotheses were made in regions where AFB1 and HBV pose a public health risk. Vaccination against hepatitis B and measures such as robust food safety systems to avoid hepatotoxicity and hepatocellular carcinogenesis induced by AFB1 is the most effective methods in the prevention of HCC induced by HBV and AFB

    Progress From Selection of Some Maize Cultivars' Response to Drought in the Derived Savanna of Nigeria

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    Field experiments were conducted to investigate the variations in sixteen maize genotypes in relation to drought tolerance. The experimental set up was subjected to drought stress after five weeks of planting for three weeks before data on morphological and yield characters of maize genotypes were [DBO1] obtained for three cropping years. Plant height and grain yield of Bodija yellow maize were the highest overall. There was a significant difference among genotypes for drought stress resistance and Bodija yellow maize showed the most tolerance, while TZBR Comp 1 – C1 S2 510 genotype was the least. First principal component axis (Prin 1) had the highest contribution to the variation of the morphological, yield and drought tolerance traits. Prin 1 was highly related to the morphological and yield characters more than to the drought resistance. [U2] Plant height was negatively and strongly correlated (p&lt;0.01) with stem height, number of leaves, stem girth, leaf length, leaf width and week after planting, but negatively correlated with the drought resistance. Therefore, Bodija yellow maize should be considered as parent material in breeding for the development of drought tolerant traits in maize

    INDIGENOUS POULTRY PRODUCTION IN OGUN STATE, NIGERIA: A CASE OF YEWA NORTH LOCAL GOVERNMENT AREA

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    A study was conducted to determine the types and spatial distribution of Indigenous Poultry (IP) in Yewa North Local Government Area of Ogun State. Five locations (Idofoi, Ibese, Imasai, Eggua and Ayetoro) were randomly selected across the geographical distribution of the Local Government Area. Data were collected from 75 respondents comprised of 15 each from the locations using a well structured questionnaire and analyzed using descriptive statistics. The result revealed that women were more involved (57.3%) in indigenous poultry production in the area. Fowl (chicken) population dominated (57.3%) and was widely distributed followed by duck (24.5%) and guinea fowl (8.60%) while turkey recorded the least population (2.4%). Eggua recorded the highest (27.3%) chicken population whereas Ayetoro had the least (15%). However, Imasai had the overall highest (22.90%) indigenous poultry in the study area while the least was recorded in Ibese (16.2%). Major challenges militating against IP in the area were disease (33.3%), pilfering (14.6%), and socio-taboo (8.0%). Only 2.7% respondents indicated feeding as a problem militating against IP. The study concluded that female and the aged were major indigenous poultry farmers in Yewa North Local Government Area of Ogun State and the prevailing indigenous poultry were chickens, ducks and guinea fowls with turkey having the least population. Imasai had the highest poultry population followed by Eggua while Ibese had the least population. Majority of the people in Yewa North Local Government Area reared indigenous poultry for income and domestic use.Â
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