A generalized meta-analysis model for binary diagnostic test performance

Methods for meta-analysis of diagnostic test accuracy studies must, in addition to unobserved heterogeneity, account for covariate heterogeneity, threshold effects, methodological quality and small study bias, whic constitute the major threats to the validity of meta-analytic results. These have traditionally been addressed independent of each other. Two recent methodological advances include (1) the bivariate random-effects model for joint synthesis of sensitivity and specificity, which accounts for unobsrved heterogeneity and threshold variation using random-effects and covariate and qualty effects as indepedent variables in a meta-regression; and (2) a linear regression test for funnel plot asymmetry in which the diagnostic odds ratio as effect size measure is regressed on effective sample size as a precision measure. I propose a generalized framework for diagnostic meta-analysis which integrates both developments based on a modification of the bivariate Dale's model in which two univariate random-effects logistic models for sensitivity and specificity are associated through a log-linear model of odds ratios with the effective sample size as an independent variable,. This unifies the estimation of summary test performance and assessment of the presence, extent and sources of variability. Taking advantage of the ability of gllamm to model a mixture of discrete and continous outcomes, I will discuss specification, estimation, diagnostics and prediction of the model, using a motivating dataset of 43 studies investigating FDG-PET for staging the axilla in patients with newly-diagnosed breast cancer.

The role of urban regeneration initiatives in the creation of sustainable inner cities : a case study of the Durban Point regeneration initiative.

Master of Town and Regional Planning. University of KwaZulu-Natal, Durban, 2015.Inner-cities are perceived as the driving force for socio-economic development of municipalities and the core commercial hub for creative opportunities. Nonetheless, they still face significant urban management challenges and a myriad of complex issues, which threaten their sustainability. This requires urban regeneration, revitalization, and renewal programmes to invigorate them. Through the application of both qualitative and quantitative methods and underpinning theories as Just city, Equity, Collaborative, and New urbanism, the study examined the role of urban regeneration in the creation of sustainable inner city using Durban Point area as a case study. The study revealed that regeneration approaches employed as a turnaround strategy by city managers, have become a spectacle of property-driven and “banal” flagships projects. This is legitimised to boost inner-city sustainability and to mobilise support for entrepreneurial urbanism activities that rebrand the inner-city for „massification‟ of private, and public, investment that has resulted unto ad-hoc, disjointed and uncoordinated implementation, which have no correlation with practical challenges manifested in the inner city realm. The findings shows that this approach does not guarantee long-term sustainability of the inner city, but only purport to raise the image of the city to attract investment without tackling socio spatial challenges deeply entrenched in this urban organism. It is proposed that if the inner city areas are to be sustained, and then it will demand a reconstruction of current policy narratives behind inner city regeneration, which presently tends to side-line the plight of the unheard voices within the inner-city areas. Municipalities are therefore encouraged to embrace integrated and multifaceted approach to regeneration implementation, which guarantees long-term sustainability of the inner-city areas

"Metagraphiti By Stata": Visuographical Exploration and Presentation of Meta-analytic Data Using Stata

Meta-analysis is considered the highest level of evidence on effectiveness of healthcare interventions. It provides important information by capitalizing on the large numbers of studies performed to assess the impact of healthcare interventions, helps reduce variability and uncertainty among published reports of efficacy, produce summary estimates of effectiveness for clinical decision making and evaluate the quality of the published evidence. However, a large proportion of meta-analyses pose a surprising challenge for the uninitiated user: in order to figure out what the researchers found, the user must struggle through a maze of textual jargon, statistical formulae and lengthy lists of actual studies and extensive tables of overall average effect size and mean effect sizes for important subgroups of studies. On the premise that "a picture is worth more than a thousand words but a 'metagraphita' is worth more than a thousand words and statistical tests", the purpose of this presentation is to provide an idiot-proof overview of statistical graphics/diagnostic plots for exploration of publication bias, data distribution, heterogeneity and for summarizing overall datasets. Discussion will include the construction and interpretation of general graphical displays such as weighted histograms, normal quantile plots, forest plots, funnel graphs, scatter diagrams, as well as plots unique to diagnostic meta-analysis (e.g. ROC plane graphic, Accuracy-Threshold regression plots, summary receiver operator characteristic curves and likelihood ratio scattergrams). Presentation will consist of didactic slide presentation supplemented by handouts and an annotated bibliography and illustration of derivation and interpretation of visual displays from published meta-analyses using Stata.

Investigating Anions and Hydrophobicity of Deep Eutectic Solvents by Experiment and Computational Simulation

Deep eutectic solvents are a new generation of ionic liquid-like solvents formed by combining hydrogen bond acceptor with hydrogen bond donor which result in the depression of the melting point of the solvent. Like ionic liquids, anions play a critical role in tuning the polarity, physicochemical properties, and thermodynamic behavior of deep eutectic solvent (DES). Choline chloride is the most widely used quaternary ammonium salt (QAS) in the literature and has remarkable advantages from reduced cost to low toxicity and volatility. Choline bromide and choline iodide are other QAS that have not been used often for DES synthesis and applications, probably with the opinion that chlorides form stronger hydrogen bonds. Developing new DES from these anions will broaden the scope of green solvents selection for diverse applications. The first objective of this dissertation looked into the synthesis and characterization of DES from choline chloride, choline bromide, and choline iodide with malic acid, malonic acid, and urea. Also, we studied the thermodynamic behavior of the solvents by measuring their vapor pressure, density, and infinite activity coefficient in polar and nonpolar solvents. The results show that choline bromide can sometimes be used to replace choline chloride because both QAS share comparable physicochemical behavior. In most cases, choline iodide forms weaker hydrogen bonding with the donors leading to the formation of a solid at room temperature. Nevertheless, all the solvents have melting temperature below 100℃. In summary, DES can be synthesized from the choline cation bonded with the halides, with the melting point and nature of the solvent dependent on the hydrogen bond donor (HBD). Secondly, despite the rapid rise in publications and applications since their inception in 2001, most of the DES synthesized are generally hydrophilic. The low cost, low toxicity, and bioavailability of DES make the solvent green and sustainable for diverse applications. Conversely, the hydrophilicity of DES practically limits their application to only polar compounds, which is a major drawback of the solvent. For the past three years, hydrophobic deep eutectic solvents (HDES) have emerged as alternative extractive media capable of extracting nonpolar molecules from aqueous environments. In chapter three of this dissertation, the general objective was to design a cost-effective hydrophobic DES from choline chloride and fatty acids. Varying the alkyl chain of the fatty acid broadened our understanding about the role of HBD in DES and also helped in the tunability of the HDES polarity. Due to the infancy of HDES, for the first time, this dissertation expands on the design, synthesis, and physicochemical characterization of HDES developed from choline chloride and fatty acids. To understand the hydrogen-bonding pattern of HDES, a multivariate unsupervised principal component analysis was used to cluster HDES by using known DES as a control. The HDES was able to extract about 70% of piperine, a bioactive compound from Piper nigrum. In the future, it is believed that HDES could replace the majority of toxic organic solvents used for analytical purposes. Lastly, the electronic and molecular properties of the HDES synthesized were studied by using a solvatochromic molecular probes and a hybrid density functional theory at 6-31G (d) basis set. The empirical polarity assay and quantum theoretical calculations showed that decreasing the alkyl chain length of the hydrogen bond donor increases viscosity of the DES. Optimization of the DES molecular geometry indicates a reduced bond angle between the C15-O16-H17 atoms in choline chloride, signifying a change in electronegativity of the central atom (O16) during DES formation. From our results, we predict a possible molecular reorientation between the donor and the acceptor molecules during DES formation. The combined theoretical calculations and experimental approaches are useful to establish clear correlations between electronic parameters and physiochemical parameters like polarity, viscosity, and stability of carboxylic acid-DES and can be extended to other conventional solvents

Utilization of Teaching Space Facilities at Sunyani Polytechnic in Ghana

This paper investigates how teaching space facilities were being utilized at Sunyani Polytechnic in the Brong Ahafo Region of Ghana. The essence was to ascertain information on the factors that militate against efficient utilization of teaching space facilities at Sunyani Polytechnic. Descriptive survey research design was adopted for the study. Lottery method of simple random sampling as well as purposive sampling were used in the selection of the sample size of 89 made up of 60 academic staff, 20 senior administrative staff and 9 technicians. Two sets of questionnaire and an interview guide were used for the data collection. The methods used in analyzing the data were frequencies, percentages and cumulative frequencies presented in tables. The key factors identified as constraints to efficient utilization of the teaching space facilities at the Polytechnic were departmentalized time tabling, inadequacy of computer laboratory and small size of instructional rooms. The major recommendations offered include the following: there should be centralized timetabling and computerization of the space allocation, provision of more general computer laboratories and provision of few large instructional rooms for very large class sizes

EFFECT OF CUSTOMER SATISFACTION AND MARKETING COMMUNICATION MIX ON CUSTOMERS’ LOYALTY IN THE GHANAIAN BANKING INDUSTRY

The study investigates the effect of customer satisfaction and marketing communication mix on customers’ loyalty in the Ghanaian banking industry. Explanatory design was used to investigate the association between the independent variables: customer satisfaction, public relations, advertising, sales promotion and the dependent variable: customers’ loyalty. Questionnaire was the main instruments for data collection from 250 customers of banks in Accra, Ghana. SPSS version 20 was employed for data analysis. The study revealed a strong positive relationship between customer satisfaction and customer loyalty in the Ghanaian banking industry. Also, the study showed a moderate but significant relationship between public relations and customers’ loyalty in the Ghanaian banking industry. On the bases of these findings, the study recommended that the banks should continue to strive to achieve customer satisfaction by fulfilling customers’ needs and wants since it can engender customer loyalty. This can be done by understanding all the factors affecting customer satisfaction. Also, it was recommended that public relations must not be discarded but strengthened to complement the other marketing communication mix to help encourage customer loyalty in the Ghanaian banking industry. Article visualizations

Using Age-Adjusted and Crude Rates for Assessing COVID-19 Cases

Purpose: To assess the difference in crude rates and age-adjusted rates in COVID-19 cases. Methods: COVID-19 cases in Virginia were obtained from the publicly available dataset as of June 21, 2020. Crude rates of COVID -19 cases were calculated and estimates for the total population of Virginia were age-adjusted to the U.S. Census 2000 population using the direct method. Results: There was a wide difference between the crude rate and the age-adjusted rate in the different age-groups. The crude rate was highest for the over 80 age group, 1063.93 per 100,000 population. However, the age-adjusted rate was highest in the 40-49 years age group, 147.72 per 100,000 followed by the 30-39 group and 20-29 group. Conclusion: Comparing the crude rates and age-adjusted rates of COVID-19 cases takes into account the confounding effect of age due to differences in the distribution of a population. Given the risk and higher COVID-19 cases among certain age-groups, knowing the crude rates and the age-adjusted rates may help in population-based prevention and interventions and can be used for planning capabilities and targeted measures

Virtual colonoscopy; real misses

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72356/1/j.1572-0241.2003.08448.x.pd

Assessing the Effects of Information Technology on Micro-Financial Institutions in the Shama District of Ghana

Microfinance is a source of financial services for entrepreneurs and small businesses lacking access to banking and related services. For some, microfinance is a movement whose object is "a world in which as many poor and near-poor households as possible have permanent access to an appropriate range of high quality financial services, including not just credit but also savings, insurance, and fund transfer. Management of such entities has from time immemorial been very difficult. With the advent of information technology it was anticipated that management of micro-financial institutions would take a different shape. As if by design most of these institutions have adopted the use of information technology since the propagation of this new technology in Ghana. The influx of the so many micro-financial organisation in Ghana with their adoption of the information technology has become an interesting area to explore. In the Shama district the case is more interesting. It is against this backdrop that this study attempts to investigate the various effects the information technology has on these micro-financial institutions especially in the Shama district. The study adopted exploratory method of research and a sample of twenty respondents were chosen for the study. The study showed that, there is a positive relationship between information technology and business growth in terms of profitability, creation of new jobs and increase number of employees. Keywords: Information Technology, ‘Susu’, Micro finance institutions (MFIs)