166 research outputs found

    TESTING FOR MULTIPLE UPPER OUTLIERS IN DISTRIBUTION SAMPLES: A STUDY OF FOREIGN EXCHANGE DATA

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    In this study, the existences of k-upper outliers are investigated in distribution samples of gamma, Normal and exponential by carrying out a simulation of ten thousand at different values of n using algorithm introduced by Tietjen-Moore, test statistics, and critical values were equally estimated from the algorithm. A Normal Q-Q plot was made which aims at distinguishing a data set that follows a normal distribution and one that deviates from normality. The algorithm was applied to Nigeria-US dollars foreign exchange rate, both on raw and logarithmic transformed data. The simulation study reveals the existence of upper outliers more in Gamma and exponential samples than the Normal sample. Empirical analysis shows that there are upper outliers in the raw data set but no upper outliers are found in the transformed data. The result in this paper would help the researcher in business and economics to take time to explore data before use and properly transform accordingly to avoid error in estimation

    TREATMENTS OF BIODIESEL WASHING WATER

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    The main objective of this study was to produce biodiesel from palm kernel oil and to purify the biodiesel washing water generated through adsorption, acidification, coagulation and filtration treatment processes. Removal efficiencies of these treatment processes were investigated by analysing biochemical oxygen demand (BOD), chemical oxygen demand (COD), pH, conductivity, total dissolved solids (TDS) and elements present in the biodiesel washing water (before and after treatments). The results of the trans-esterification process showed that the highest biodiesel yield of 87.6% was obtained at a reaction time of 65 minutes and methanol to oil mole ratio of 6:1.The overall removal efficiencies obtained using the stated water treatment processes were 65% (BOD), 38% (COD), 75% (TDS) and 94%(conductivity).The treated washing water met the waste water discharge standards of FEPA. Hence, adsorption, acidification, coagulation and filtration, were effective in treating biodiesel washing water

    Relationship Between Plasma Homocysteine and Vitamin B12 Levels in Clinically Diagnosed Cases of Cardiovascular Accident in Lagos, Nigeria

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    Vitamin B12 deficiency interferes with the normal pathway for homocysteine metabolism, even in the presence of adequate serum folate and pyridoxine. Homocysteinaemia, is an elevated level of homocysteine in plasma which has been established as a risk factor for the development of cardiovascular disorders. However, there has been conflicting report from various research works on the role of Vitamin B12 in the occurrence of major cardiovascular disorders. The study was set to determine the mean values of homocysteine, and correlate same with mean plasma levels of vitamin B12 in the subjects, and to estimate the prevalence of anaemia in the stroke patients, using Haemoglobin concentration (Hb) and mean corpuscular volume (MCV) as indices. One hundred (100) participants were recruited, comprising 40 clinically diagnosed stroke patients (hemorrhagic or thrombo-embolic), and 60 normal adults as control group. Plasma homocysteine levels were measured by HPLC and plasma vitamin B12 levels by Chemiluminescent Microparticle Immuno-assay method. Anticoagulated whole blood samples were evaluated for Hb, and MCV using automated Advia-60. Mean value of plasma homocysteine for the stroke patients (17.7±4.4umol/l) was significantly higher than values obtained in the control group at 9.5±2.4umol/l (

    Inhibitive Corrosion Performance of the Eco‐Friendly Aloe Vera in Acidic Media of Mild and Stainless Steels

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    The inhibitive behaviour of aloe vera as an eco‐friendly inhibitor was studied in the corrosion of mild and stainless steel in 0.5 M H2SO4 medium. The varied aloe vera inhibitor concentrations were studied using weight loss (gravimetric) and linear polarization methods. The methods showed that the inhibition efficiency increased with an increase in the concentration of the inhibitor (up to 10 vol/vol%) for both the mild and stainless steels. Stainless steel was found to exhibit a lower corrosion rate compared to mild steel. The results showed that Langmuir adsorption isotherm was obeyed by the inhibition of mild and stainless steel using aloe vera in 0.5 M H2SO4 with the values of the regression coefficients near unity. The negative values of ΔGads show the spontaneous adsorption of inhibitor on the mild and stainless steel surfaces and a physisorption adsorption mechanism of the aloe vera inhibitor since the values of ΔGads obtained are more than − 20 kJ/mol, that is, aloe vera is an efficient corrosion inhibitor with mixed‐type inhibition property

    The effect of interaction between hepatitis C virus and cigarette smoking on the risk of hepatocellular carcinoma

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    We evaluated the interaction between hepatitis C virus (HCV) and cigarette smoking on death from hepatocellular cancer in The Japan Collaborative Cohort Study. The odds ratio of death from HCC for smoking was 9.60 (1.50–61.35) and 1.71(0.58–5.08) among anti-HCV positive and negative individuals, respectively

    Production of Adhesive from Cassava Starch

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    The research work investigated the production of adhesive from cassava starch. Cassava tubers were processed into starch-based adhesives, using two different gelatinization enhancers (that is HCl and NaOH) which were introduced separately. The adhesives were produced by considering two varied process parameters, namely percentage weight of borax in starch solution (8 – 20%) and reaction temperature (65 – 850C). Comparative analysis of the adhesive obtained (using HCl and NaOH as gelatinization enhancers) include the determination of its bond strength, viscosity, drying time, pH and density. As the borax weight percent increases up to 14 % and reaction temperature reduces (using NaOH) the drying time increases, while the drying time reduces as both the borax weight percent and temperature reduce (using HCl). The results of the adhesive physical properties fall within the standard range for each of the properties and this implied that the adhesive produced was of high qualit

    Transplacentally Acquired Maternal Antibody against Hepatitis B Surface Antigen in Infants and its Influence on the Response to Hepatitis B Vaccine

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    BACKGROUND: Passively acquired maternal antibodies in infants may inhibit active immune responses to vaccines. Whether maternal antibody against hepatitis B surface antigen (anti-HBs) in infants may influence the long-term immunogenicity of hepatitis B vaccine remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: Totally 338 pairs of mothers and children were enrolled. All infants were routinely vaccinated against hepatitis B based on 0-, 1- and 6-month schedule. We characterized the transplacental transfer of maternal anti-HBs, and compared anti-HBs response in children of mothers with or without anti-HBs. In a prospective observation, all 63 anti-HBs positive mothers transferred anti-HBs to their infants; 84.1% of the infants had higher anti-HBs concentrations than their mothers. One and half years after vaccination with three doses of hepatitis B vaccine, the positive rate and geometric mean concentration (GMC) of anti-HBs in 32 infants with maternal anti-HBs were comparable with those in 32 infants without maternal antibody (90.6% vs 87.5%, P = 0.688, and 74.5 vs 73.5 mIU/ml, P = 0.742, respectively). In a retrospective analysis, five and half years after vaccination with three doses vaccine, the positive rates of anti-HBs in 88 children of mothers with anti-HBs ≄1000 mIU/ml, 94 children of mothers with anti-HBs 10-999 mIU/ml, and 61 children of mothers with anti-HBs <10 mIU/ml were 72.7%, 69.2%, and 63.9% (P = 0.521), respectively; anti-HBs GMC in these three groups were 38.9, 43.9, and 31.7 mIU/ml (P = 0.726), respectively. CONCLUSIONS/SIGNIFICANCE: The data demonstrate that maternal anti-HBs in infants, even at high concentrations, does not inhibit the long-term immunogenicity of hepatitis B vaccine. Thus, current hepatitis B vaccination schedule for infants will be still effective in the future when most infants are positive for maternal anti-HBs due to the massive vaccination against hepatitis B

    EGFR T790M Mutation as a Possible Target for Immunotherapy; Identification of HLA-A*0201-Restricted T Cell Epitopes Derived from the EGFR T790M Mutation

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    Treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, has achieved high clinical response rates in patients with non–small cell lung cancers (NSCLCs). However, over time, most tumors develop acquired resistance to EGFR-TKIs, which is associated with the secondary EGFR T790M resistance mutation in about half the cases. Currently there are no effective treatment options for patients with this resistance mutation. Here we identified two novel HLA-A*0201 (A2)-restricted T cell epitopes containing the mutated methionine residue of the EGFR T790M mutation, T790M-5 (MQLMPFGCLL) and T790M-7 (LIMQLMPFGCL), as potential targets for EGFR-TKI-resistant patients. When peripheral blood cells were repeatedly stimulated in vitro with these two peptides and assessed by antigen-specific IFN-γ secretion, T cell lines responsive to T790M-5 and T790M-7 were established in 5 of 6 (83%) and 3 of 6 (50%) healthy donors, respectively. Additionally, the T790M-5- and T790M-7-specific T cell lines displayed an MHC class I-restricted reactivity against NSCLC cell lines expressing both HLA-A2 and the T790M mutation. Interestingly, the NSCLC patients with antigen-specific T cell responses to these epitopes showed a significantly less frequency of EGFR-T790M mutation than those without them [1 of 7 (14%) vs 9 of 15 (60%); chi-squared test, p = 0.0449], indicating the negative correlation between the immune responses to the EGFR-T790M-derived epitopes and the presence of EGFR-T790M mutation in NSCLC patients. This finding could possibly be explained by the hypothesis that immune responses to the mutated neo-antigens derived from T790M might prevent the emergence of tumor cell variants with the T790M resistance mutation in NSCLC patients during EGFR-TKI treatment. Together, our results suggest that the identified T cell epitopes might provide a novel immunotherapeutic approach for prevention and/or treatment of EGFR-TKI resistance with the secondary EGFR T790M resistance mutation in NSCLC patients
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