Qualitative assessment of the role of public health education program on HIV transmission dynamics

© The author 2010. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.This paper presents a nonlinear deterministic model for assessing the impact of public health education campaign on curtailing the spread of the HIV pandemic in a population. Rigorous qualitative analysis of the model reveals that it exhibits the phenomenon of backward bifurcation (BB), where a stable disease-free equilibrium coexists with a stable endemic equilibrium when a certain threshold quantity, known as the 'effective reproduction number' (Reff), is less than unity. The epidemiological implication of BB is that a public health education campaign could fail to effectively control HIV, even when the classical requirement of having the associated reproduction number less than unity is satisfied. Furthermore, an explicit threshold value is derived above which such an education campaign could lead to detrimental outcome (increase disease burden), and below which it would have positive population-level impact (reduce disease burden in the community). It is shown that the BB phenomenon is caused by imperfect efficacy of the public health education program. The model is used to assess the potential impact of some targeted public health education campaigns using data from numerous countries.Kano State Government of Nigeria (N.H.); Natural Science and Engineering Research Council and Mathematics of Information Technology and Complex Systems of Canada (A.B.G.

Capacity analysis of wireless mesh networks

The next generation wireless· netWorks experienced agreat development with emergence of wireless mesh networks (WMNs), which can be regarded as a realistic solution that provides wireless broadband access. The limited available bandwidth makes capacity analysis of the network very essential. While the network offers broadband wireless access to community and enterprise users, the problems that limit the· network capacity must be addressed to· exploit the optimum netWork performance. The wireless mesh network capacity analysis shows that the throughput of each mesh , node degrades in order of l/n with increasing number of nodes (n) in a linear topology. The degradation is found to be higher in a fully mesh network as a result of increase in interference and MAC layer contention in the network.Key words: Wireless mesh network (WMN), Adhoc network, Network capacity analysis,Bottleneck collision domain, Medium access control (MAC) laye

An Sveir Model for Assessing Potential Impact of an Imperfect Anti-SARS Vaccine

The control of severe acute respiratory syndrome (SARS), a fatal contagious viral disease that spread to over 32 countries in 2003, was based on quarantine of latently infected individuals and isolation of individuals with clinical symptoms of SARS. Owing to the recent ongoing clinical trials of some candidate anti-SARS vaccines, this study aims to assess, via mathematical modelling, the potential impact of a SARS vaccine, assumed to be imperfect, in curtailing future outbreaks. A relatively simple deterministic model is designed for this purpose. It is shown, using Lyapunov function theory and the theory of compound matrices, that the dynamics of the model are determined by a certain threshold quantity known as the control reproduction number (Rv). If Rv ≤ 1, the disease will be eliminated from the community; whereas an epidemic occurs if Rv \u3e 1. This study further shows that an imperfect SARS vaccine with infection-blocking efficacy is always beneficial in reducing disease spread within the community, although its overall impact increases with increasing efficacy and coverage. In particular, it is shown that the fraction of individuals vaccinated at steady-state and vaccine efficacy play equal roles in reducing disease burden, and the vaccine must have efficacy of at least 75% to lead to effective control of SARS (assuming R0 = 4). Numerical simulations are used to explore the severity of outbreaks when Rv \u3e 1

Computer Communication Networks Security Analysis

We are living in the "Information Revolution", where development of powerful communication systems and digital technologies have resulted in the buildup of massive information banks by government, industries and even individuals, which are required to be protected to maintain privacy, confidentiality, availability and integrity of national and commercial information. It has also allowed for automation of services and such systems must protect customers against modern day "electronic crimes". The first part of this thesis is a study into the aspect of the development of secure communication between group of entities. The thesis gives an overview of the general issues that are raised by the concept of cryptosystems, followed by discussions on the methods currently available for the conduct of such techniques. Generic categories of threats and vulnerabilities to computer networks are outlined as well as network security objectives. The study culminates in the description of a recommended alternative approach for the development of Group Oriented Cryptosystems (GOC) which can be used to solve the problem of entity authentication and subsequent key distribution in order to enhance multiple-entity (group of entities) communications with confidentiality and integrity services.E-mail security is about protecting electronic mails from spies, interlopers, and spoofs. People who may want to destroy, alter, or just look at our private communications. The second part of the thesis shows how we can protect the financial information, contract negotiations, or personal correspondence we entrust to public or private networks by means of Digital Envelop. Furthermore, the model developed can be practically implemented

HIV-Malaria co-infection and its determinants among patients attending antiretroviral treatment clinic in Zaria, Kaduna state, Nigeria

Introduction: Malaria and HIV are two important global public health problems. Together, they cause more than two million deaths each year. In sub-Saharan Africa alone, more than 29 million people are living with HIV/AIDS and about 70% of population is at risk to malaria infection. Nigeria accounts for about a quarter of the global malaria cases and tenth of the global HIV cases. Recent theories suggested possibilities of high occurrence of HIV-malaria co-infection wherever there is geographical overlap of the two diseases. We therefore conducted this study to determine the prevalence of HIV-malaria co-infection and its determinants in a malaria endemic setting. Methods: We conducted a cross-sectional study. Two hundred and sixty-two clients attending antiretroviral treatment (ART) clinic in Zaria, Kaduna State were enrolled between February and April 2018 using systematic sampling technique. Questionnaires were administered to collect information on respondents’ personal characteristics and to assess their knowledge, perception and practices on malaria prevention. Venous blood samples were collected and analyzed for malaria parasite, viral load, CD4, and FBC using Giemsa stained light microscopy, COBAS TaqMan equipment, BD FACSTM flow cytometer, and Sysmex haematology analyser respectively. Descriptive and inferential statistics were performed, predictors of HIV-malaria co-infection were ascertained at multivariate analysis. Results: Median age of the respondents was 33 years, 52% were females, 65% were married, 65% were employed, 57% lived in urban residence, and 34% had tertiary education. The prevalence of malaria co-infection among HIV patients was found to be 22.9%. Significant risk factors for the co-infection were high HIV viral load (aOR= 3.30, C.I = 1.15-9.45), being co-infected with TB (aOR= 5.60, C.I = 1.34-23.33), poor knowledge of malaria infection (aOR= 3.12, C.I = 1.27-7.72) and poor practice of malaria prevention (aOR= 13.30, C.I = 4.88-36.23). Conclusion: The level of occurrence of malaria among HIV infected patients in this setting calls for attention. We recommended that health education on malaria should be a priority in malaria control programme; the programmes for control of HIV, malaria and TB should collaborate to ensure integrated service delivery and that people living with HIV/AIDS should be given special consideration for malaria prevention

Preliminary Investigation of a Colouring Matter Extract from Sorghum Bicolor Sheaths and its Application to Textile Subtrates

The colouring matter from the sheath of sorghum bicolor was extracted using ethanol, acetone, water and petroleum ether, respectively. Ethanol exhibited higher extract percentage yield compared to the other solvents with petroleum ether giving the least. The chromatographic analysis indicates that the extract contains only one component which maximally absorbs at 1.78 and 1.58 in ethanol and water, respectively. The extracted colouring matter was applied to cotton, nylon, and wool fabrics with better results obtained on nylon fabric. The use of Potassium Chromate as a mordant however, generally improves the colour yield on the nylon and with improved wash fastness properties in all the fabrics used

Enzymatic pretreatment of grey cotion fabric for improving dye uptake, lustur and hand feel using fungal cellulase

Cellulase enzyme was extracted from pineapple peel substrate using Aspergiluss niger.  Because enzymes are sustainable alternatives to harsh toxic chemicals used in the Textile Industries. Cotton fabrics were treated with cellulase at variable concentrations at a pH of 5.5 and 55°C. Changes in various properties of the treated fabrics like weight loss, lusture, soft touch and overall dyeing properties were investigated. The results obtained show that cellulase have successfully removed staple fibres from the fabrics and thus, yield a glabrous appearance and soft touch of the treated fabrics; furthermore, it was established that percentage dye uptake and fastness properties of the fabrics were greatly improved as confirmed by the FTIR spectral analysis and UV- visible spectrophotometric analysis of the absorbance maximum of the dye liquor before and after dying.Key Words: Cellulase, Aspergillus niger, pre- treatment, cotton fabric and dye uptake

Use of Activated Carbon Derived from Maize Cob and Mahogany Seed Shell for the Removal of Colour from Textile Effluent

In the present study natural adsorbents Maize Cob (MC) and Mahogany Shells (MS) were carbonized and activated with steam/zinc chloride and sieved into 600μm particle sizes. The adsorbents were treated for the removal of colour from textile effluent at different time. These adsorbents were also evaluated at different adsorbent doses and effluent concentrations. It was found that Maize cob has the highest colour removal efficiency of 86% and also at shorter time of 25minutes compared to Mahogany shells which record 73% and at 30, respectively. Freundlich and Langmuir isotherm models were used for the mathematical description of colour adsorption equilibrium onto the adsorbents and the result obtained showed that the adsorption equilibrium data onto MC was closely fitted to the Langmuir model whereas the adsorption equilibrium data onto MS was closely fitted to the Freundlich model. Hence, adsorption of the colour onto the adsorbents is monolayer adsorption process.Keywords: Adsorption Isotherm, Mahogany Shells, Maize Cob, % Removal, Textile Effluen

The Effect of Fiber Treatment on the Water Absorption of Piliostigma Reinforced Epoxy

In this paper, the water absorption behaviour of 14 days hardened composites based on Piliostigma fiber and a thermosetting matrix (Epoxy) was studied. The water absorption tests were carried out in order to study the durability of the composites. The comparative study of water absorption behaviour of composites reinforced with fiber and chemically modified in three reagents (NaOH, KMnO4, BPO) respectively confirmed that surface treatment of the fibres influences the sorption process. The most significant decrease in hydrophilicity of Piliostigma was found in the case of Piliostigma fiber that was modified by BPO, This decrease relates to change in the chemical composition of the Piliostigma fiber, especially due to a decrease in the average degree of cellulose polymerization as well as the hemicellulose content. The chemical composition effect on the surface modification was analysed by means of Fourier Transform Infrared Spectroscopy (FTIR), The experimental spectroscopic information was compared with theoretical analysis of molecular vibrations. The result obtained from this comparison confirmed that the chemical modification of the composites was successfully carried out.Keywords: Chemical treatment, Composite, Hydrophilicity, Natural fiber, Thermosetting, Water absorptio