166 research outputs found
TESTING FOR MULTIPLE UPPER OUTLIERS IN DISTRIBUTION SAMPLES: A STUDY OF FOREIGN EXCHANGE DATA
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
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
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 (
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Analysis of the variability of airborne particulate matter with prevailing meteorological conditions across a semi-urban environment using a network of low-cost air quality sensors.
The concentrations of fine and coarse fractions of airborne particulate matter (PM) and meteorological variables (wind speed, wind direction, temperature and relative humidity) were measured at six selected locations in Ile Ife, a prominent university town in Nigeria using a network of low-cost air quality (AQ) sensor units. The objective of the deployment was to collate baseline air quality data and assess the impact of prevailing meteorological conditions on PM concentrations in selected residential communities downwind of an iron smelting facility. The raw data obtained from OPC-N2 of the AQ sensor units was corrected using the RH correction factor developed based k-Kohler theory. This PM (corrected) fast time resolution data (20 s) from the AQ sensor units were used to create daily averages. The overall mean mass concentrations for PM2.5 and PM10 were 213.3, 44.1, 23.8, 27.7, 20.2 and 41.5 ÎŒg/m3 and; 439.9, 107.1, 55.0, 72.4, 45.5 and 112.0 ÎŒg/m3 for Fasina (Iron-Steel Smelting Factory, ISSF), Modomo, Eleweran, Fire Service, O.A.U. staff quarters and Obafemi Awolowo University Teaching and Research Farm (OAUTRF), respectively. PM concentration and wind speed showed a negative exponential distribution curve with the lowest exponential fit coefficient of determination (R2) values of 0.08 for PM2.5 and 0.03 for PM10 during nighttime periods at Eleweran and Fire service sites, respectively. The relationship between PM concentration and temperature gave a decay curve indicating that higher PM concentrations were observed at lower temperatures. The exponential distribution curve for the relationship between PM concentration and relative humidity (RH) showed that PM concentrations do not vary for RH 80 % for both day and nighttime. The performances of the MLR model were slightly poor and as such not too reliable for predicting the concentration but useful for improving predictive model accuracy when other variables contributing to the variability of PM is considered. The study concluded that the anthropogenic and industrial activities at the smelting factory contribute significantly to the elevated PM mass concentration measured at the study locations
Inhibitive Corrosion Performance of the EcoâFriendly Aloe Vera in Acidic Media of Mild and Stainless Steels
The inhibitive behaviour of aloe vera as an ecoâfriendly 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 ÎGads 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 ÎGads obtained are more than â 20 kJ/mol, that is, aloe vera is an efficient corrosion inhibitor
with mixedâtype inhibition property
The effect of interaction between hepatitis C virus and cigarette smoking on the risk of hepatocellular carcinoma
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 (1.50â61.35) and 1.71(0.58â5.08) among anti-HCV positive and negative individuals, respectively
Production of Adhesive from Cassava Starch
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 â 20%) and reaction temperature (65 â 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
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%, Pâ=â0.688, and 74.5 vs 73.5 mIU/ml, Pâ=â0.742, 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 â„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% (Pâ=â0.521), respectively; anti-HBs GMC in these three groups were 38.9, 43.9, and 31.7 mIU/ml (Pâ=â0.726), 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
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 nonâsmall 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-Îł 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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