60 research outputs found
Vulnerability and adaptation to climate variability and extremes: A case study of flooding in Niger state, Nigeria
Student Number : 0413447J -
MSc research report -
School of Geography and Environmental Studies -
Faculty of ScienceThis research analyses the vulnerability and adaptation of communities living along the
River Kaduna floodplain at Shiroro Local Government in Niger State to flood
occurrences. These communities are one of the most flood-prone areas in Niger State,
with fertile alluvial deposits for agricultural production. The analysis of rainfall and flood
flow into the Kaduna River System shows that there is an increasing flood frequency and
flood magnitude along the River Kaduna for the past two decades because of slight
increase in rainfall amount. Although there is a slight increase in rainfall amounts, the
flooding of the Kaduna River could be regarded as normal. This is because there is no
major change in rainfall amounts. Therefore, any slight increase in rainfall may cause
flooding. The 1990s with slight increase in rainfall coincides with the period of abundant
flood flow in the Kaduna River System and very significant runoff into the Kaduna
reservoir.
Floods have impacted negatively on the life of the people living on the floodplain
resulting into food insecurity, poverty and vulnerability to malnutrition and other health
problems among the communities in Shiroro Local Government Area. There are three
vulnerable groups identified within the communities (the very poor, those residing on the
floodplain and those that depend only on agriculture). These three groups identified lack
accesses to good shelters and social amenities like electricity, good water, roads, health
facilities and schools. Moreover, this research shows that the adaptive capacity of these
communities is being severely compromised by factors such as poverty, poor
infrastructure, weakening social networks and environmental degradation
Modelling HIV/AIDS epidemic in Nigeria
Nigeria is one of the countries most affected by the HIV/AIDS pandemic, third only to India and South Africa. With about 10% of the global HIV/AIDS cases estimated to be in the country, the public health and socio-economic implications are enormous.
This thesis has two broad aims: the first is to develop statistical models which adequately describe the spatial distribution of the Nigerian HIV/AIDS epidemic and its associated ecological risk factors; the second, to develop models that could reconstruct the HIV incidence curve, obtain an estimate of the hidden HIV/AIDS population and a short term projection for AIDS incidence and a measure of precision of the estimates.
To achieve these objectives, we first examined data from various sources and selected three sets of data based on national coverage and minimal reporting delay. The data sets are the outcome of the National HIV/AIDS Sentinel Surveillance Survey conducted in 1999, 2001, 2003 and 2005 by the Federal Ministry of Health; the outcome of the survey of 1057 health and laboratory facilities conducted by the Nigerian Institute of Medical Research in 2000; and case by case HIV screening data collected from an HIV/AIDS centre of excellence.
A thorough review of methods used by WHO/UNAIDS to produce estimates of the Nigerian HIV/AIDS scenario was carried out. The Estimation and Projection Package (EPP) currently being used for modelling the epidemic partitions the population into at-risk, not-at-risk and infected sub-populations. It also requires some parameter input representing the force of infection and behaviour or high risk adjustment parameter. It may be difficult to precisely ascertain the size of these population groups and parameters in countries as large and diverse as Nigeria. Also, the accuracy of vital rates used in the EPP and Spectrum program is doubtful. Literature on ordinary back-calculation, nonparametric back-calculation, and modified back-calculation methods was reviewed in detail. Also, an indepth review of disease mapping techniques including multilevel models and geostatistical methods was conducted.
The existence of spatial clusters was investigated using cluster analysis and some measure of spatial autocorrelation (Moran I and Geary c coefficients, semivariogram and kriging) applied to the National HIV/AIDS Surveillance data. Results revealed the existence of spatial clusters with significant positive spatial autocorrelation coefficients that tended to get stronger as the epidemic developed through time. GAM and local regression fit on the data revealed spatial trends on the north-south and east - west axis.
Analysis of hierarchical, spatial and ecological factor effects on the geographical variation of HIV prevalence using variance component and spatial multilevel models was performed using restricted maximum likelihood implemented in R and empirical and full Bayesian methods in WinBUGS. Results confirmed significant spatial effects and some ecological factors were significant in explaining the variation. Also, variation due to various levels of aggregation was prominent.
Estimates of cumulative HIV infection in Nigeria were obtained from both parametric and nonparametric back-calculation methods. Step and spline functions were assumed for the HIV infection curve in the parametric case. Parameter estimates obtained using 3-step and 4-step models were similar but the standard errors of these parameters were higher in the 4-step model. Estimates obtained using linear, quadratic, cubic and natural splines differed and also depended on the number and positions of the knots. Cumulative HIV infection estimates obtained using the step function models were comparable with those obtained using nonparametric back-calculation methods. Estimates from nonparametric back-calculation were obtained using the EMS algorithm. The modified nonparametric back-calculation method makes use of HIV data instead of the AIDS incidence data that are used in parametric and ordinary nonparametric back-calculation methods. In this approach, the hazard of undergoing HIV test is different for routine and symptom-related tests. The constant hazard of routine testing and the proportionality coefficient of symptom-related tests were estimated from the data and incorporated into the HIV induction distribution function. Estimates of HIV prevalence differ widely (about three times higher) from those obtained using parametric and ordinary nonparametric back-calculation methods. Nonparametric bootstrap procedure was used to obtain point-wise confidence interval and the uncertainty in estimating or predicting precisely the most recent incidence of AIDS or HIV infection was noticeable in the models but greater when AIDS data was used in the back-projection model.
Analysis of case by case HIV screening data indicate that of 33349 patients who attended the HIV laboratory of a centre of excellence for the treatment of HIV/AIDS between October 2000 and August 2006, 7646 (23%) were HIV positive with females constituting about 61% of the positive cases. The bulk of infection was found in patients aged 15-49 years, about 86 percent of infected females and 78 percent of males were in this age group. Attendance at the laboratory and the proportion of HIV positive tests witnessed a remarkable increase when screening became free of charge. Logistic regression analysis indicated a 3-way interaction between time period, age and sex. Removing the effect of time by stratifying by time period left 2-way interactions between age and sex.
A Correction factor for underreporting was ascertained by studying attendance at the laboratory facility over two time periods defined by the cost of HIV screening. Estimates of HIV prevalence obtained from corrected data using the modified nonparametric back-calculation are comparable with UN estimates obtained by a different method.
The Nigerian HIV/AIDS pandemic is made up of multiple epidemics spatially located in different parts of the country with most of them having the potential of being sustained into the future given information on some risk factors. It is hoped that the findings of this research will be a ready tool in the hands of policy makers in the formulation of policy and design of programs to combat the epidemic in the country. Access to data on HIV/AIDS are highly restricted in the country and this hampers more in-depth modelling of the epidemic. Subject to data availability, we recommend that further work be done on the construction of stratification models based on sex, age and the geopolitical zones in order to estimate the infection intensity in each of the population groups. Uncertainties surrounding assumptions of infection intensity and incubation distribution can be minimized using Bayesian methods in back-projection
Quality of meta-analysis in terms of actual statistical analysis
Meta-analysis is an essential tool that facilitates clinicians, medical experts and decision makers to cope with the information overload in the public and healthcare sectors. The publication of meta-analyses is increasing rapidly every day with less or more of methodological rigour. Clinicians and medical experts depend wholeheartedly on the results and conclusions obtained from analyzing meta-analysis in order to assess the clinical effectiveness of healthcare intervention on a daily basis. Meta-analysis provides a specific estimate of a relationship which may also indicate if there is any need for further research.
But the foundational problem of performing the clinically powerful meta-analysis is the guideline for how similar the studies must be in order to meet the inclusion criteria of the meta-analysis and the reliability of its conclusions {ERIC(2010)}. When there are discrepancies in the studies being combined and patient populations being studied, meta-analysis may provide results that are wrong. These may mislead potential users of meta-analysis to give wrong prescriptions to their patients.
One requirement is to prepare a validated and reliable checklist that can assess the quality of meta-analysis in terms of reporting, methodology, science and most especially, the actual statistical analysis. Literature review reveals that existing checklists mainly focus on other aspects of quality with little or no attention to the quality of statistical methodology. Consequently, this thesis attempts to cover this gap.
OBJECTIVE- To construct an appropriate validated quality instrument. Use the instrument to assess the quality of selected meta-analyses in terms of actual statistical analysis. To assess accuracy and consistency of reported estimates using Lee's methods for checking errors in reported relative risks, odds ratios and confidence intervals{Lee(1999)}.
STUDIES - Eligible articles (Meta-analysis of randomised controlled trials) identified in the Cochrane database, Web of Knowledge and Medline databases were used in this project. Eligibility criteria include studies published in English language, as a full report between the periods of 2000-2008, have a comprehensive search strategy and have clear methods of selecting studies for inclusion and performed statistical analysis.
We developed a checklist that measures the quality of meta-analysis in terms of actual statistical analysis and used the instrument to assess papers published in both Cochrane and Non-Cochrane reviews.
RESULTS: A sample size of 100 papers was obtained using an estimated maximum error bound of 0.1. Studies were allocated equally between Cochrane and Non-Cochrane publications and selections were made from electronic databases. Records of meta-analysis of randomised contolled trials published in English, full text and journal articles between the periods of 2000 - 2008 show that there were 515 results out of 5821 records of meta-analysis published in Cochrane library, 507 out of 1434 records and 130 out of 135 records of meta-analysis published in Web of Knowledge and Medline respectively. Simple random sampling, implemented in R statistical package, was used to select random sample of studies from each database. 83 out of the 100 selected studies met the inclusion criteria - 42 studies from Cochrane reviews and 41 from Non-Cochrane reviews.
Reporting and methodology quality are high in the two databases. However, in terms of statistical analysis, both databases are unlikely to explicitly state the design of individual studies combined in the meta- analysis. The Cochrane review is more likely to contact authors of published studies than their Paper-base counterparts. Cochrane reviews are less likely also, to use OQAQ(Overview Quality Assessment Questionnaire) and QUOROM (Quality of Reporting of Meta-analyses)in asssessment of validity of studies than paper reviews.
There was no double counting of some aspects of studies identified among Paper-base Journals while we discovered four studies in Cochrane reviews that double counted the control arms.
However, there was no simple double counting of studies found in both Cochrane and Non-Cochrane reviews.
Lee's checks were performed on the twenty selected studies to verify errors on reported odd ratios, relative risks and confidence intervals. Some studies included in the meta-analysis reported zero events either in the treatment or control groups or both which led to a disparity between our calculated results and the estimates reported by the authors. The addition of a continuity correction factor of 0.5 to each cell of the studies with zero events took care of the disparities. Mabinary sas macro designed by Weir and Senn{weir(2008)} was also used to assess and check the validity of reported odd ratios, relative risks and confidence intervals on both reviews. The results obtained using the macro are consistent with the original reported results in most of the studies.
Studies reporting relative risks in both Paper-Base Journals and Cochrane reviews are more likely to disagree with the Lee's requirement on minimum subject size and number of diseased subjects in either exposure groups given the CI, than those reporting odd ratios. These studies also have large outcomes. This seems to suggest that Lee's checks are not reliable for studies reporting relative risks, especially when outcomes are relatively large.
CONCLUSION: Cochrane Handbooks and scales relating to specific interventions were mostly used to assess quality of studies in Cochrane reviews. Results showed no statistically significant difference between the reporting and methodological quality of Cochrane and non-Cochrane publications.
More improvement is needed in the reportage of the design of included studies in both Cochrane and non-Cochrane reviews. This will help establish if the combined studies and the statistical method used in combining them are compatible. However, double counting of some aspects of studies was found in some meta-analysis selected from Cochrane reviews. Analysis suggests that studies reporting odd ratios are likely to be consistent with Lee's checks than those reporting relative risks. We also showed that Peter Lee's checks involving totals cannot be relied on to assess the quality of studies reporting relative risks
Strategic Management of Pension Scheme in Selected Private Manufacturing Organizations in South Eastern Nigeria
Management of pension schemes in Nigeria has been characterized by multiple and diverse problems despite several modifications of the pension schemes by the government. The study examined the extent strategies adopted for pension management can enhance employees’ confidence in the scheme. The study adopted a survey design. The data were analyzed using tables, frequencies, and mean. Z- test was used to test the hypotheses at 0.05 significance. It was revealed that to a very large extent strategies adopted for pension and retirement management can enhance employees’ confidence in the management of the schemes. The researchers recommended among others that an efficient structural framework should be put in place always to monitor the contribution and implementation of the Contributory Pension Scheme. Pension plays an increasingly important role in the economy of any country because the money earmarked for pension could be used for the establishment of small enterprises and infrastructural development
Effect of Blue Ocean Strategy on the Performance of Telecommunication Firms in South East Nigeria
The objectives of the study were to; examine the effect of blue ocean strategy application on the market share in the Nigerian telecommunication firms and identify the impact of blue ocean strategy on customer satisfaction in the Nigerian telecommunication industry. The study adopted cross-sectional descriptive research design. Data was obtained from 225 respondents working in telecommunication firms in South East Region of Nigeria through the use of a questionnaire. The data collected for the study were presented in tables comprising of frequency, percentage, mean and standard deviation, while the hypotheses were tested using simple linear regression with the aid of statistical package for social sciences (IBM, SPSS version 23). The findings revealed that blue ocean strategy has a positive significant effect on market share in the Nigerian telecommunication industry (r = .680a; F = 223.971; T = 14.966; p - .000) and that blue ocean strategy has a positive significant effect on customer satisfaction in Nigerian telecommunication organizations (r = 727; F = 292.079; T = 17.090; p - .000). It was concluded that the formulation of blue ocean strategy is quite an accomplishment and dynamic process as it affects, market shares and customer satisfaction. It was recommended that management of various telecommunication firms should strive to develop innovative products and services that are beyond the traditionally known services in order to improve their profitability and as a matter of urgency, innovatively deliver cutting edge services that can beat their competitors so as to attract more customers. Keywords: Blue Ocean, Strategy, Performance, Telecommunication firms, South East Nigeri
Does Domestic Energy Consumption Contribute to Exports? Empirical Evidence From Nigeria.
This paper examined the existence of interaction between domestic energy consumption and exports in Nigeria by using annual data from 1970 to 2009. We applied cointegration, Granger causality and impulse response functions to capture the relationship. The empirical results indicate that there is significant relationship between domestic energy consumption and exports in the long run. Granger causality tests showed that there is unidirectional causality running from energy consumption to exports. Impulse response functions indicate that shocks to the energy consumption have a positive impact on exports in the longrun. Likewise, expansions on exports were positively related to energy consumption. Therefore, significant improvement in energy production and utilization is expected to stimulate exports and engender economic growth in Nigeria.
Keywords: Energy; domestic energy consumption; exports; cointegration; causality; Nigeria
JEL Classifications: C32; Q40; Q43Â
Electricity Supply, Fossil fuel Consumption, Co2 Emissions and Economic Growth: Implications and Policy Options for Sustainable Development in Nigeria.
This paper investigates the causal relationship among electricity supply, fossil fuel consumption, CO2 emissions and economic growth in Nigeria for the period 1971-2009, in a multivariate framework.Using the bound test approach to cointegration, we found a short-run as well as a long-run relationship among the variables with a positive and statistically significant relationship between CO2 emissions and fossil fuel consumption. The findings also indicate that economic growth is associated with increased CO2 emissions while a positive relationship exists between electricity supply and CO2 emissions revealing the poor nature of electricity supply in Nigeria. Further, the Granger causality test results indicate that electricity supply has not impacted significantly on economic growth in Nigeria. The results also strongly imply that policies aimed at reducing carbon emissions in Nigeria will not impede economic growth. The paper therefore concludes that a holistic energy planning and investment in energy infrastructure is needed to drive economic growth. In the long-run however, it is possible to meet the energy needs of the country, ensure sustainable development and at the same time reduce CO2 emissions by developing alternatives to fossil fuel consumption, the main source of CO2 emissions.
Keywords: CO2 emissions; Economic growth; Electricity supply; Granger causality; Bounds testing; Fossil fuel consumption.
JEL Classification: Q41; Q42; Q43
Corrigendum: Evaluations of the disease surveillance centre network in Scotland: what parts has it reached?
Evaluations of the Disease Surveillance Centre network in Scotland: What parts has it reached?
Regular evaluation is a prerequisite for systems that provide surveillance of animal populations. Scotland's Rural College Veterinary Services' Disease Surveillance Centre (DSC) network plays an integral part in surveillance to detect new and re-emerging threats within animal populations, predominantly livestock. In response to surveillance reviews and proposed changes to the network, an initial evaluation of diagnostic submissions data in 2010 to mid-2012 established a baseline “footprint,” while highlighting challenges with the data. In this recent evaluation for the period 2013–2018, we developed a new denominator using a combination of agricultural census and movement data, to identify relevant holdings more accurately. Iterative discussions between those processing submissions data and those involved in collection at source took place to understand the intricacies of the data, establish the most appropriate dataset, and develop the processes required to optimise the data extraction and cleansing. The subsequent descriptive analysis identifies the number of diagnostic submissions, the number of unique holdings making submissions to the network and shows that both the surrounding geographic region of, and maximum distance to the closest DSC vary greatly between centres. Analysis of those submissions classed as farm animal post-mortems also highlights the effect of distance to the closest DSC. Whether specific differences between the time periods are due to changes in the behavior of the submitting holdings or the data extraction and cleaning processes was difficult to disentangle. However, with the improved techniques producing better data to work with, a new baseline footprint for the network has been created. This provides information that can help policy makers and surveillance providers make decisions about service provision and evaluate the impact of future changes. Additionally, the outputs of these analyses can provide feedback to those employed in the service, providing evidence of what they are achieving and why changes to data collection processes and ways of working are being made. In a different setting, other data will be available and different challenges may arise. However, the fundamental principles highlighted in these evaluations and the solutions developed should be of interest to any surveillance providers generating similar diagnostic data
ASSESSMENT OF HEALTH INFORMATION LITERACY OF NIGERIANS ON THE PREVENTIVE MEASURES OF COVID 19 PANDEMIC: A CROSS SECTIONAL ONLINE SURVEY
The study assessed the health information literacy level of Nigerian on the preventive measures and management of COVID 19 pandemic using online cross sectional survey. The research design adopted for the study is descriptive survey research design. Nigerians between the age of 15 and above made up the population of the study. Online survey using Google form was conducted between using social media platforms. To assess the health information literacy level of Nigerians on the preventive measures of COVID-19; a 25 objective questions constructed by the researcher called “COVID-19 Health Related Information Literacy Assessment Scale” was used. Data collected was analyzed using frequency distribution table and percentage. The null hypotheses one was tested using Mann Whitney U, while the hypothesis two was tested using Kruskal Wallis Test at 0.05 significance level. The computation and analysis of the data collected was performed with the aid of SPSS version 23. The study revealed that, the major sources of information for COVID-19 related health information among Nigerians are social media (facebook, twitter, whatsapp etc.), friends and family, radio programmes. the COVID-19 health literacy level of Nigerians is moderate. Though many scored high in the scale used, most of the respondents are incorrect in most of the advance questions such as recommended meter for social distancing, most appropriate way to wear face shield, contracting COVID-19 through books, spoons, plates among others touched by infected person, and even what to do after coughing or sneezing during COVID-19 among other technical and advance questions. Gender was not a significant factor in the COVID-19 Health Information Literacy Level of Nigerians on the preventive measures of COVID 19 pandemic; while there was a significant difference in the health information literacy level of Nigerians on the preventive measures of COVID 19 pandemic according to educational level, as Nigerians with higher level of education had higher COVID-19 Health Information Literacy level than those with lower educational level. The study recommended among other things that, Federal government should adopt more proactive measures of education Nigerians on the advanced ways to prevent and manage COVID-19. Also, in order to reach wider audience with little or no cost the government should mandate churches and mosques to devote few minutes for enlightening and educating their members on the global best practice in the prevention and management of COVID-1
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