Drinking water quality assessment: lessons learnt from Ogun State, Nigeria

A drinking Water Quality Assessment survey was carried out in Ogun State Nigeria in 2009. The collected water samples were analysed in the laboratory to determine compliance with the Nigerian Standard for Drinking Water Quality (NSDWQ) and the WHO Guideline Values (WHO GLV). Results from the Study showed that high Coliform counts were recorded in many sampled sites

Estimates and Forecasts of GARCH Model under Misspecified Probability Distributions: A Monte Carlo Simulation Approach

The effect of misspecification of correct sampling probability distribution of Generalized Autoregressive Conditionally Heteroscedastic (GARCH) processes is considered. The three assumed distributions are the normal, Student t, and generalized error distributions. The GARCH process is sampled using one of the distributions and the model is estimated based on the three distributions in each sample. Parameter estimates and forecast performance are used to judge the estimated model for performance. The AR-GARCH-GED performed better on the three assumed distributions; even, when Student t distribution is assumed, AR-GARCH-Student t does not perform as the best model

Misspecification of Variants of Autoregressive GARCH Models and Effect on In-Sample Forecasting

Generally, in empirical financial studies, the determination of the true conditional variance in GARCH modelling is largely subjective. In this paper, we investigate the consequences of choosing a wrong conditional variance specification. The methodology involves specifying a true conditional variance and then simulating data to conform to the true specification. The estimation is then carried out using the true specification and other plausible specification that are appealing to the researcher, using model and forecast evaluation criteria for assessing performance. The results show that GARCH model could serve as better alternative to other asymmetric volatility models

Estimation of Garch Models for Nigerian Exchange Rates Under Non-Gaussian Innovations

Financial series often displays evidence of leptokurticity and in that case, the empirical distribution often fails normality.  GARCH models were initially based on normality assumption but estimated model based on this assumption cannot capture all the degree of leptokurticity in the return series. In this paper, we applied variants of GARCH models under non-normal innovations-t-distribution and Generalized Error Distribution (GED) on selected Nigeria exchange rates. The Berndt, Hall, Hall, Hausman (BHHH) numerical derivatives applied in the estimation of models converged faster and the time varied significantly across models. Asymmetric GARCH model with t-distribution (GARCH-t) was selected in most of the cases whereas for Nigeria-US Dollar exchange rate, GARCH-GED was specified. Both distributions showed evidence of leptokurticity in Naira exchange rate return series. The result is of practical importance to practitioners. Key Words: GARCH, Exchange rate, Model specification, Non-Gaussian distribution.

Assessment of groundwater potentials of Abuja environs

This paper assesses the groundwater potentials of Abuja and it’s Environs. The study area is located in the centre of the country. It covers an approximate area of about 7400sqm. It is bounded in the North by Kaduna, in the East by Nassarawa, in the southwest by Kogi and in the west by Niger State respectively. The general elevation of the study area varies considerably. Several rivers and their tributaries drain the area, the major rivers include River Usman, Jabi and Dwako

Regional variations and socio-economic disparities in neonatal mortality in Angola: a cross-sectional study using demographic and health surveys.

BackgroundInequalities in neonatal mortality rates (NMRs) in low- and middle-income countries show key disparities at the detriment of disadvantaged population subgroups. There is a lack of scholarly evidence on the extent and reasons for the inequalities in NMRs in Angola.ObjectiveThe aim of this study was to assess the socio-economic, place of residence, region and gender inequalities in the NMRs in Angola.MethodsThe World Health Organization Health Equity Assessment Toolkit software was used to analyse data from the 2015 Angola Demographic and Health Survey. Five equity stratifiers: subnational regions, education, wealth, residence and sex were used to disaggregate NMR inequality. Absolute and relative inequality measures, namely, difference, population attributable fraction (PAF), population attributable risk (PAR) and ratio, were calculated to provide a broader understanding of the inequalities in NMR. Statistical significance was calculated at corresponding 95% uncertainty intervals.FindingsWe found significant wealth-driven [PAR = -14.16, 95% corresponding interval (CI): -15.12, -13.19], education-related (PAF = -22.5%, 95% CI: -25.93, -19.23), urban-rural (PAF = -14.5%, 95% CI: -16.38, -12.74), sex-based (PAR = -5.6%, 95% CI: -6.17, -5.10) and subnational regional (PAF = -82.2%, 95% CI: -90.14, -74.41) disparities in NMRs, with higher burden among deprived population subgroups.ConclusionsHigh NMRs were found among male neonates and those born to mothers with no formal education, poor mothers and those living in rural areas and the Benguela region. Interventions aimed at reducing NMRs, should be designed with specific focus on disadvantaged subpopulations

Time trends and persistence in European temperature anomalies.

This paper looks at the level of persistence in the temperature anomalies series of 114 European cities. Once this level of persistence has been identified, the time trend coefficients are estimated and the results indicate that most of the series examined display positive trends, supporting thus climate warming. Moreover, the results obtained confirm the hypothesis that long-memory behaviour cannot be neglected in the study of temperature time series, changing, therefore, the estimated effect of global warming.pre-print825 K

Socioeconomic and geographic variations in antenatal care coverage in Angola: further analysis of the 2015 demographic and health survey.

BACKGROUND:In African countries, including Angola, antenatal care (ANC) coverage is suboptimal and maternal mortality is still high due to pregnancy and childbirth-related complications. There is evidence of disparities in the uptake of ANC services, however, little is known about both the socio-economic and geographic-based disparity in the use of ANC services in Angola. The aim of this study was to assess the extent of socio-economic, urban-rural and subnational inequality in ANC coverage in Angola. METHODS:We analyzed data from the 2015 Angola Demographic and Health Survey (ADHS) using the World Health Organization (WHO) Health Equity Assessment Toolkit (HEAT) software. The analysis consisted of disaggregated ANC coverage rates using four equity stratifiers (economic status, education, residence, and region) and four summary measures (Difference, Population Attributable Risk, Ratio and Population Attributable Fraction). To measure statistical significance, an uncertainty interval (UI) of 95% was constructed around point estimates. RESULTS:The study showed both absolute and relative inequalities in coverage of ANC services in Angola. More specifically, inequality favored women who were rich (D = 54.2, 95% UI; 49.59, 58.70, PAF = 43.5, 95% UI; 40.12, 46.92), educated (PAR = 19.9, 95% UI; 18.14, 21.64, R = 2.14, 95% UI; 1.96, 2.32), living in regions such as Luanda (D = 51.7, 95% UI; 43.56, 59.85, R = 2.64, 95% UI; 2.01, 3.26) and residing in urban dwellings (PAF = 20, 95% UI; 17.70, 22.38, PAR = 12.3, 95% UI; 10.88, 13.75). CONCLUSION:The uptake of ANC services were lower among poor, uneducated, and rural residents as well as women from the Cuanza Sul region. Government policy makers must consider vulnerable subpopulations when designing needed interventions to improve ANC coverage in Angola to achieve the 2030 Sustainable Development Goal of reducing global maternal mortality ratio to 70 deaths per 100,000 live births

Demographic and Health Surveys showed widening trends in polio immunisation inequalities in Guinea

AimThis study examined trends in absolute and relative socio-economic, gender and geographical inequalities in the coverage of polio immunisation in Guinea, West Africa, from 1999 to 2016.MethodsData from the 1999, 2005 and 2012 Guinea Demographic and Health Survey and the 2016 Guinea Multiple Indicator Cluster Survey were analysed using the World Health Organization's health equity assessment toolkit. We disaggregated polio immunisation coverage using five equity stratifiers: household economic status, maternal educational level, place of residence, child's gender and region. The four summary measures used were the difference, ratio, population attributable risk and population attributable fraction. A 95% confidence interval (CI) was constructed around point estimates to measure statistical significance.ResultsA total of 4778 1-year-old children were included. Polio immunisation coverage in 1999, 2005, 2012 and 2016 were 43.4%, 50.7%, 51.2% and 38.6%, respectively. Socio-economic and geographical inequalities in polio immunisation favoured children with educated mothers who came from richer families living in urban areas. There were also differences in the eight regions over the 1999-2016 study period.ConclusionTargeting children from disadvantaged subgroups must be prioritised to ensure equitable immunisation services that help to eradicate polio in Guinea