Clarence Yah - Academia.edu (original) (raw)

Papers by Clarence Yah

Research paper thumbnail of Emerging Problems in Infectious Diseases Fostering prevention and care delivery services capability on HIV pandemic and Ebola outbreak symbiosis in Africa

Human immunodeficiency virus (HIV) and the re-emerging Ebola virus disease (EVD) are closely inte... more Human immunodeficiency virus (HIV) and the re-emerging Ebola virus disease (EVD) are closely intertwined and remain a persistent public health threat and global challenge. Their origin and rapid transmission and spread have similar boundaries and share overlapping impact characteristics, including related symptoms and other interactions. The controversies and global threat of these viruses require rapid response policy and evidence-based implementation findings. The constraints and dual burden inflicted by Ebola and HIV infections are highly characterized by similar socio-demographics, socioeconomic and political factors. EVD has similar effects and burdens to HIV infection. This study seeks to understand EVD in the context of HIV epidemic despite the challenges in developing an effective vaccine against HIV and EVD. Our findings show that early understanding, prevention and treatment of these diseases a global health threat mainly in Africa is important and valuable. The lessons learned so far from HIV and Ebola epidemics are crucial in health programming and execution of rapid response interventions and continued vigilance against EVD before it become another worldwide health menace. Therefore, the current regional West Africa EVD requires strengthening healthcare systems and building preparedness and response capacity. Importantly, appropriate community participation, health education and resilience coupled with deployment of effective novel diagnostic approaches in early warning and surveillance of threats and emerging diseases. Therefore, there is an urgent need to develop novel key strategies are crucial in curbing the constant viral resurgence, persistence transmission dynamics and spread, as well in accelerating Ebola vaccines regimen (immunization) development and national implementation plans in achieving sustained control, and eventual elimination.

Research paper thumbnail of Temperature optimization for Bioethanol Production from Corn cobs. OnLine Journal of Biological Sciences

Problem statement: Dilute sulphuric acid and enzymatic hydrolysis methods were used for sugar ext... more Problem statement: Dilute sulphuric acid and enzymatic hydrolysis methods were used for sugar extraction. Xylose and glucose sugars were obtained from corn cobs. Approach: Acid hydrolysis of corn cobs gave higher amount of sugars than enzymatic hydrolysis. Results: The results showed that optimal temperature and time for sugar fermentation were approximately 25°C and 50 h by two yeast strains (S. cerevisiae and P. Stipitis) respectively. At 20 and 40°C, less bioethanol was produced. Bioethanol produced at 25°C was 11.99 mg mL −1 , while at 40 and 20°C were 2.50 and 6.40 mg mL −1 respectively. Conclusion/Recommendations: Data obtained revealed that xylose level decreased from 27.87-3.92 mg mL −1 during the first 50 h of fermentation and complete metabolism of glucose was observed during this time. Xylose and bioethanol levels remained constant after 50 h. Varying the temperature of the fermentation process improves the effective utilization of corn cobs sugars for bioethanol production can be achieved.

Research paper thumbnail of Fostering prevention and care delivery services capability on HIV pandemic and Ebola outbreak symbiosis in Africa

The Journal of Infection in Developing Countries, 2016

Human immunodeficiency virus (HIV) and the re-emerging Ebola virus disease (EVD) are closely inte... more Human immunodeficiency virus (HIV) and the re-emerging Ebola virus disease (EVD) are closely intertwined and remain a persistent public health threat and global challenge. Their origin and rapid transmission and spread have similar boundaries and share overlapping impact characteristics, including related symptoms and other interactions. The controversies and global threat of these viruses require rapid response policy and evidence-based implementation findings. The constraints and dual burden inflicted by Ebola and HIV infections are highly characterized by similar socio-demographics, socio-economic and political factors. EVD has similar effects and burdens to HIV infection. This study seeks to understand EVD in the context of HIV epidemic despite the challenges in developing an effective vaccine against HIV and EVD. Our findings show that early understanding, prevention and treatment of these diseases a global health threat mainly in Africa is important and valuable. The lessons learned so far from HIV and Ebola epidemics are crucial in health programming and execution of rapid response interventions and continued vigilance against EVD before it become another worldwide health menace. Therefore, the current regional West Africa EVD requires strengthening healthcare systems and building preparedness and response capacity. Importantly, appropriate community participation, health education and resilience coupled with deployment of effective novel diagnostic approaches in early warning and surveillance of threats and emerging diseases. Therefore, there is an urgent need to develop novel key strategies are crucial in curbing the constant viral resurgence, persistence transmission dynamics and spread, as well in accelerating Ebola vaccines regimen (immunization) development and national implementation plans in achieving sustained control, and eventual elimination.

Research paper thumbnail of Comparison between chilling and crossflow membrane filtration in beer clarification

With the desire to improve the quality of beer acceptable to consumers, two clarification methods... more With the desire to improve the quality of beer acceptable to consumers, two clarification methods were compared: the chilling method and crossflow microfiltration method. The beer samples for this study were produced at the University of Witwatersrand Microbrewery and evaluated according to the European Brewing Convention (EBC) standards. Using the microfiltration technique, it was observed that higher temperatures increase the total flux, head retention value (HRV) and haze. The filtration temperature was conducted at less than 4°C (39°F) to bring the haze level to an acceptable standard. There was a linear correlation between flux and haze, where the higher the flux, the higher the haze. Cleaning of the membrane by backwashing with water effectively opened up the membrane pores. The chilling technique showed that haze decreased significantly from 3.1 to <0.8 to meet the EBC requirements. The mouthfeel, measured by the real degree of fermentation (% RDF), increased slightly with...

Research paper thumbnail of Makun et al 2011

Research paper thumbnail of Makun et al 2011

Research paper thumbnail of Computational Strategy towards the Control and Reduction of Malaria incidences in Africa

Malaria persists as one of the most problematic disease in Africa. It is the cause of morbidity a... more Malaria persists as one of the most problematic disease in Africa. It is the cause of morbidity and mortality of children and efforts are currently being pooled to increase control measures of its incidences within African countries. With this in mind, we developed and applied a malaria control strategy from a computational perspective, to analyze, predict and offer appropriate recommendations and control measures, based on the insight gained in the course of this research. This will enable both governmental, NGOs (Non Governmental Organizations) and other relevant health agencies to provide future public health planning in these countries. Results showed the effects and impacts of some controllable factors on future malaria occurrence. Our system was able to demonstrate some level of intelligence. It also produced sensible and logical results which can be applied to achieve reduction of possible future malaria occurrences in the countries studied. The malaria infection course was p...

Research paper thumbnail of Incidence, Phylogeny and Mycotoxigenic Potentials of Fungi Isolated from Rice in Niger State, Nigeria

Journal of Food Safety, 2011

The study reports on the natural occurrence of fungi in 21 samples of field (10), stored (6) and ... more The study reports on the natural occurrence of fungi in 21 samples of field (10), stored (6) and marketed (5) rice (Oryza sativa L.) collected from Niger State, Nigeria. Fungal isolates were primarily identified based on morphological characteristics, while representative isolates were characterized genetically. An evolutionary tree was constructed from the resulting sequences of the isolated fungi. The toxigenic potentials of some of the isolated fungi were also determined. A total of 357 fungal isolates of nine genera including Aspergillus, Fusarium, Sarocladium, Acremonium, Curvularia Botryosphaeria, Penicillium Alternaria and Ascomycota in decreasing order of predominance were identified. The most frequent fungal contaminants of the rice samples were A. flavus, A. fumigates, A. niger, A. parasiticus and F. proliferatum. All strains of A. flavus (aflatoxins B1 and B2), A. parasiticus (aflatoxins B1, B2, G1 and G2), A. ochraceus (ochratoxin A), F. proliferatum and F. verticillioides (fumonisins B1 and B2) tested, were excellent producers of their respective mycotoxins. Patulin was produced by A. terreus, whereas deoxynivalenol, zearalenone and T-2 toxin were produced by F. chlamydosporum and other Fusarium spp. The increased prevalence of toxigenic fungi in rice, a highly consumed food grain in Nigeria, poses serious health concerns to the general public.

Research paper thumbnail of Public/community engagement in health research with men who have sex with men in sub-Saharan Africa: challenges and opportunities

Health Research Policy and Systems, 2016

Community engagement, incorporating elements of the broader concepts of public and stakeholder en... more Community engagement, incorporating elements of the broader concepts of public and stakeholder engagement, is increasingly promoted globally, including for health research conducted in developing countries. In sub-Saharan Africa, community engagement needs and challenges are arguably intensified for studies involving gay, bisexual and other men who have sex with men, where male same-sex sexual interactions are often highly stigmatised and even illegal. This paper contextualises, describes and interprets the discussions and outcomes of an international meeting held at the Kenya Medical Research Institute-Wellcome Trust in Kilifi, Kenya, in November 2013, to critically examine the experiences with community engagement for studies involving men who have sex with men. We discuss the ethically charged nature of the language used for men who have sex with men, and of working with &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;representatives&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; of these communities, as well as the complementarity and tensions between a broadly public health approach to community engagement, and a more rights based approach. We highlight the importance of researchers carefully considering which communities to engage with, and the goals, activities, and indicators of success and potential challenges for each. We suggest that, given the unintended harms that can emerge from community engagement (including through labelling, breaches in confidentiality, increased visibility and stigma, and threats to safety), representatives of same-sex populations should be consulted from the earliest possible stage, and that engagement activities should be continuously revised in response to unfolding realities. Engagement should also include less vocal and visible men who have sex with men, and members of other communities with influence on the research, and on research participants and their families and friends. Broader ethics support, advice and research into studies involving men who have sex with men is needed to ensure that ethical challenges - including but not limited to those related to community engagement - are identified and addressed. Underlying challenges and dilemmas linked to stigma and discrimination of men who have sex with men in Africa raise special responsibilities for researchers. Community engagement is an important way of identifying responses to these challenges and responsibilities but itself presents important ethical challenges.

Research paper thumbnail of Respondent-driven sampling as a recruitment method for men who have sex with men in southern sub-Saharan Africa: a cross-sectional analysis by wave

Sexually transmitted infections, Jan 30, 2015

Respondent-driven sampling (RDS) is a popular method for recruiting men who have sex with men (MS... more Respondent-driven sampling (RDS) is a popular method for recruiting men who have sex with men (MSM). Our objective is to describe the ability of RDS to reach MSM for HIV testing in three southern African nations. Data collected via RDS among MSM in Lesotho (N=318), Swaziland (N=310) and Malawi (N=334) were analysed by wave in order to characterise differences in sample characteristics. Seeds were recruited from MSM-affiliated community-based organisations. Men were interviewed during a single study visit and tested for HIV. χ(2) tests for trend were used to examine differences in the proportions across wave category. A maximum of 13-19 recruitment waves were achieved in each study site. The percentage of those who identified as gay/homosexual decreased as waves increased in Lesotho (49% to 27%, p<0.01). In Swaziland and Lesotho, knowledge that anal sex was the riskiest type of sex for HIV transmission decreased across waves (39% to 23%, p<0.05, and 37% to 19%, p<0.05). The ...

Research paper thumbnail of Nanoparticles as potential new generation broad spectrum antimicrobial agents

DARU Journal of Pharmaceutical Sciences, 2015

The rapid emergence of antimicrobial resistant strains to conventional antimicrobial agents has c... more The rapid emergence of antimicrobial resistant strains to conventional antimicrobial agents has complicated and prolonged infection treatment and increased mortality risk globally. Furthermore, some of the conventional antimicrobial agents are unable to cross certain cell membranes thus, restricting treatment of intracellular pathogens. Therefore, the disease-causing-organisms tend to persist in these cells. However, the emergence of nanoparticle (NP) technology has come with the promising broad spectrum NP-antimicrobial agents due to their vast physiochemical and functionalization properties. In fact, NP-antimicrobial agents are able to unlock the restrictions experienced by conventional antimicrobial agents. This review discusses the status quo of NP-antimicrobial agents as potent broad spectrum antimicrobial agents, sterilization and wound healing agents, and sustained inhibitors of intracellular pathogens. Indeed, the perspective of developing potent NP-antimicrobial agents that carry multiple-functionality will revolutionize clinical medicine and play a significant role in alleviating disease burden.

Research paper thumbnail of The response effect of pheochromocytoma (PC12) cell lines to oxidized multi-walled carbon nanotubes (o-MWCMTs)

African Health Sciences

The applications of oxidized carbon nanotubes (o-CNTs) have shown potentials in novel drug delive... more The applications of oxidized carbon nanotubes (o-CNTs) have shown potentials in novel drug delivery including the brain which is usually a challenge. This underscores the importance to study its potential toxic effect in animals. Despite being a promising tool for biomedical applications little is known about the safety of drugs in treating brain diseases. The toxicity of oxidized multi-walled carbon nanotubes (o-MWCNTs) are of utmost concern and in most in-vitro studies conducted so far are on dendritic cell (DC) lines with limited data on PC12 cell lines.

Research paper thumbnail of Chloroquine prophylaxis associated with high prevalence of Plasmodium falciparum pfcrt K76T mutation in people with sickle-cell disease in Benin City, Nigeria

Journal of vector borne diseases

High mortality and morbidity in sickle-cell disease has been associated with malaria infection es... more High mortality and morbidity in sickle-cell disease has been associated with malaria infection especially in countries where chloroquine is used. Chloroquine resistance has been associated with the emergence of Pfcrt mutant genes. This study aimed at comparing the prevalence rate of Pfcrt T76 mutation in Plasmodium falciparum isolates from infected individuals with sickle-cell disease and sickle-cell trait. This study was carried out in Benin City between the months of April and June 2006. This period is marked with high transmission rate of malaria. The genotype of the subjects was screened using haemoglobin electrophoresis system and the P. falciparum. Pfcrt genotyping was carried out using PCR-restriction fragment length polymorphism (RFLP). Four hundred and twenty-four subjects comprising of 207 haemoglobin AA, 136 haemoglobin AS and 81 haemoglobin SS typed individuals were enrolled for this study. No significant difference existed in the prevalence rate of malaria in the three ...

Research paper thumbnail of The use of Carbon Nanotubes in Medical Applications - Is It a Success Story?

Occupational Medicine & Health Affairs, 2014

Research paper thumbnail of Nanoparticles Toxicity and Their Routes of Exposures

Recent Advances in Novel Drug Carrier Systems, 2012

The new scientific innovation of engineering nanoparticles (NPs) at the atomic scale of 100 nm or... more The new scientific innovation of engineering nanoparticles (NPs) at the atomic scale of 100 nm or less, has led to numerous novel and useful wide applications in electronics, chemicals, environmental protection, biological medicine. Manufacturers and consumers of the nanoparticles-related industrial products however, are likely to be exposed to these engineered nanomaterials which have various physical and chemical properties. These nanosize particles are likely to increase an unnecessary infinite toxicological effect on animals and environment, although their toxicological effects associated with human exposure are still unknown. In order to understand the effects of these exposures, this review seeks to examine the various toxicological portal routes associated with NPs exposures. These NPs can enter the host systems via skin spores, debilitated tissues, injection, olfactory, respiratory and intestinal tracts. These uptake routes of NPs may be intentional or unintentional. Their entry may lead to various diversified adverse biological effects. Until a clearer picture emerges, the limited data available suggest that caution must be exercised when potential exposures to NPs are encountered. Methods used in determining NPs portal of entry into experimental animals include pharyngeal instillation, injection, inhalation, cell culture lines and gavage exposures. This review also provides a step by step systematic approach for the easy identification and addressing of occupational health hazards arising from NPs.

Research paper thumbnail of The cellular response of Saccharomyces cerevisiae to multi-walled carbon nanotubes (MWCNTs)

Journal of Saudi Chemical Society, 2012

Nanoparticles (NPs) especially those of carbon nanotubes (CNTs) have remarkable properties that a... more Nanoparticles (NPs) especially those of carbon nanotubes (CNTs) have remarkable properties that are very desirable in various biological and biomedical applications. This has necessitated the rapid study of CNT toxicities, to augment their safe use, particularly, in yeast cells. The yeast cell; Saccharomyces cerevisiae is a widely used industrial and biological organism with very limited data regarding their cellular behaviour in NPs. The current study examines the cellular response of S. cerevisiae to MWCNTs. The CNTs were produced by the swirled floating catalytic chemical vapour deposition (SFCCVD) method and covalently functionalised using 1,3-dipolar cycloaddition. The CNT properties such as size, surface area, quality and surface vibrations were characterized using TEM, SEM, BET, TGA and Raman spectroscopy, respectively. The cellular uptake was confirmed with a FITC functionalised MWCNTs using 1H NMR, SEM and TEM. The CNT concentrations of 2-40 lg/ml were used to determine the cellular response through cell growth phases and cell viability characteristics. The TEM and SEM analyses showed the production of MWCNTs with an average diameter of 53 ± 12 nm and a length of 2.5 ± 0.5 lm. The cellular uptake of FITC-MWCNTs showed 100% internalisation in the yeast cells. The growth

Research paper thumbnail of Temperature Optimization for Bioethanol Production from Corn Cobs Using Mixed Yeast Strains

OnLine Journal of Biological Sciences, 2010

Problem statement: Dilute sulphuric acid and enzymatic hydrolysis methods were used for sugar ext... more Problem statement: Dilute sulphuric acid and enzymatic hydrolysis methods were used for sugar extraction. Xylose and glucose sugars were obtained from corn cobs. Approach: Acid hydrolysis of corn cobs gave higher amount of sugars than enzymatic hydrolysis. Results: The results showed that optimal temperature and time for sugar fermentation were approximately 25°C and 50 h by two yeast strains (S. cerevisiae and P. Stipitis) respectively. At 20 and 40°C, less bioethanol was produced. Bioethanol produced at 25°C was 11.99 mg mL −1 , while at 40 and 20°C were 2.50 and 6.40 mg mL −1 respectively. Conclusion/Recommendations: Data obtained revealed that xylose level decreased from 27.87-3.92 mg mL −1 during the first 50 h of fermentation and complete metabolism of glucose was observed during this time. Xylose and bioethanol levels remained constant after 50 h. Varying the temperature of the fermentation process improves the effective utilization of corn cobs sugars for bioethanol production can be achieved.

Research paper thumbnail of Sibanye Methods for Prevention Packages Program Project Protocol: Pilot Study of HIV Prevention Interventions for Men Who Have Sex With Men in South Africa

JMIR Research Protocols, 2014

Human immunodeficiency virus (HIV) prevention intervention programs and related research for men ... more Human immunodeficiency virus (HIV) prevention intervention programs and related research for men who have sex with men (MSM) in the southern African region remain limited, despite the emergence of a severe epidemic among this group. With a lack of understanding of their social and sexual lives and HIV risks, and with MSM being a hidden and stigmatized group in the region, optimized HIV prevention packages for southern African MSM are an urgent public health and research priority. The objective of the Sibanye Health Project is to develop and evaluate a combination package of biomedical, behavioral, and community-level HIV prevention interventions and services for MSM in South Africa. The project consists of three phases: (1) a comprehensive literature review and summary of current HIV prevention interventions (Phase I), (2) agent-based mathematical modeling of HIV transmission in southern African MSM (Phase II), and (3) formative and stigma-related qualitative research, community engagement, training on providing health care to MSM, and the pilot study (Phase III). The pilot study is a prospective one-year study of 200 men in Cape Town and Port Elizabeth, South Africa. The study will assess a package of HIV prevention services, including condom and condom-compatible lubricant choices, risk-reduction counseling, couples HIV testing and counseling, pre-exposure prophylaxis (PrEP) for eligible men, and non-occupational post-exposure prophylaxis for men with a high risk exposure. The pilot study will begin in October 2014. Preliminary results from all components but the pilot study are available. We developed a literature review database with meta-data extracted from 3800 documents from 67 countries. Modeling results indicate that regular HIV testing and promotion of condom use can significantly impact new HIV infections among South African MSM, even in the context of high coverage of early treatment of HIV-positive men and high coverage of PrEP for at-risk HIV-negative men. Formative qualitative research consisted of 79 in-depth interviews, and six focus group discussions in Cape Town and Port Elizabeth. Analysis of these data has informed pilot study protocol development and has been documented in peer-reviewed manuscripts. Qualitative work regarding stigma faced by South African MSM resulted in finalized scales for use in the pilot study questionnaire. A total of 37 health care providers completed training designed to facilitate clinically and culturally competent care for MSM in the Eastern Cape. The design of a future, larger study of the HIV prevention package will be conducted at the end of the pilot study, powered to detect efficacy of the prevention package. Data from the updated mathematical model, results of the pilot study, acceptability data, and advancements in HIV prevention sciences will be considered in developing the final proposed package and study design. ClinicalTrials.gov NCT02043015; http://clinicaltrials.gov/show/NCT02043015 (Archived by WebCite at http://www.webcitation.org/6THvp7rAj).

Research paper thumbnail of Synthesis of Large Carbon Nanotubes from Ferrocene: The Chemical Vapour Deposition Technique

Trends in Applied Sciences Research, 2011

Research paper thumbnail of Challenges facing sterilization and depyrogenation of nanoparticles: Effects on structural stability and biomedical applications

Nanomedicine: Nanotechnology, Biology and Medicine, 2014

This review outlines and compares techniques that are currently available for the sterilization o... more This review outlines and compares techniques that are currently available for the sterilization of nanoparticles and addresses the topic of endotoxin contamination. Several techniques are available for the removal of microbial contamination from nanoparticles developed for use in nanomedicine applications. These techniques include filtration, autoclaving and irradiation, as well as formaldehyde, ethylene oxide and gas plasma treatments. Of these sterilization methodologies, filtration may potentially remove microbial contamination without altering the physicochemical properties of the carrier nanoparticles, nor affecting their toxicity and functionality. However, no single process may be applied to all nanoparticle preparations and, therefore, it is recommended that each nanoparticle-drug system be validated on a case-by-case basis.

Research paper thumbnail of Emerging Problems in Infectious Diseases Fostering prevention and care delivery services capability on HIV pandemic and Ebola outbreak symbiosis in Africa

Human immunodeficiency virus (HIV) and the re-emerging Ebola virus disease (EVD) are closely inte... more Human immunodeficiency virus (HIV) and the re-emerging Ebola virus disease (EVD) are closely intertwined and remain a persistent public health threat and global challenge. Their origin and rapid transmission and spread have similar boundaries and share overlapping impact characteristics, including related symptoms and other interactions. The controversies and global threat of these viruses require rapid response policy and evidence-based implementation findings. The constraints and dual burden inflicted by Ebola and HIV infections are highly characterized by similar socio-demographics, socioeconomic and political factors. EVD has similar effects and burdens to HIV infection. This study seeks to understand EVD in the context of HIV epidemic despite the challenges in developing an effective vaccine against HIV and EVD. Our findings show that early understanding, prevention and treatment of these diseases a global health threat mainly in Africa is important and valuable. The lessons learned so far from HIV and Ebola epidemics are crucial in health programming and execution of rapid response interventions and continued vigilance against EVD before it become another worldwide health menace. Therefore, the current regional West Africa EVD requires strengthening healthcare systems and building preparedness and response capacity. Importantly, appropriate community participation, health education and resilience coupled with deployment of effective novel diagnostic approaches in early warning and surveillance of threats and emerging diseases. Therefore, there is an urgent need to develop novel key strategies are crucial in curbing the constant viral resurgence, persistence transmission dynamics and spread, as well in accelerating Ebola vaccines regimen (immunization) development and national implementation plans in achieving sustained control, and eventual elimination.

Research paper thumbnail of Temperature optimization for Bioethanol Production from Corn cobs. OnLine Journal of Biological Sciences

Problem statement: Dilute sulphuric acid and enzymatic hydrolysis methods were used for sugar ext... more Problem statement: Dilute sulphuric acid and enzymatic hydrolysis methods were used for sugar extraction. Xylose and glucose sugars were obtained from corn cobs. Approach: Acid hydrolysis of corn cobs gave higher amount of sugars than enzymatic hydrolysis. Results: The results showed that optimal temperature and time for sugar fermentation were approximately 25°C and 50 h by two yeast strains (S. cerevisiae and P. Stipitis) respectively. At 20 and 40°C, less bioethanol was produced. Bioethanol produced at 25°C was 11.99 mg mL −1 , while at 40 and 20°C were 2.50 and 6.40 mg mL −1 respectively. Conclusion/Recommendations: Data obtained revealed that xylose level decreased from 27.87-3.92 mg mL −1 during the first 50 h of fermentation and complete metabolism of glucose was observed during this time. Xylose and bioethanol levels remained constant after 50 h. Varying the temperature of the fermentation process improves the effective utilization of corn cobs sugars for bioethanol production can be achieved.

Research paper thumbnail of Fostering prevention and care delivery services capability on HIV pandemic and Ebola outbreak symbiosis in Africa

The Journal of Infection in Developing Countries, 2016

Human immunodeficiency virus (HIV) and the re-emerging Ebola virus disease (EVD) are closely inte... more Human immunodeficiency virus (HIV) and the re-emerging Ebola virus disease (EVD) are closely intertwined and remain a persistent public health threat and global challenge. Their origin and rapid transmission and spread have similar boundaries and share overlapping impact characteristics, including related symptoms and other interactions. The controversies and global threat of these viruses require rapid response policy and evidence-based implementation findings. The constraints and dual burden inflicted by Ebola and HIV infections are highly characterized by similar socio-demographics, socio-economic and political factors. EVD has similar effects and burdens to HIV infection. This study seeks to understand EVD in the context of HIV epidemic despite the challenges in developing an effective vaccine against HIV and EVD. Our findings show that early understanding, prevention and treatment of these diseases a global health threat mainly in Africa is important and valuable. The lessons learned so far from HIV and Ebola epidemics are crucial in health programming and execution of rapid response interventions and continued vigilance against EVD before it become another worldwide health menace. Therefore, the current regional West Africa EVD requires strengthening healthcare systems and building preparedness and response capacity. Importantly, appropriate community participation, health education and resilience coupled with deployment of effective novel diagnostic approaches in early warning and surveillance of threats and emerging diseases. Therefore, there is an urgent need to develop novel key strategies are crucial in curbing the constant viral resurgence, persistence transmission dynamics and spread, as well in accelerating Ebola vaccines regimen (immunization) development and national implementation plans in achieving sustained control, and eventual elimination.

Research paper thumbnail of Comparison between chilling and crossflow membrane filtration in beer clarification

With the desire to improve the quality of beer acceptable to consumers, two clarification methods... more With the desire to improve the quality of beer acceptable to consumers, two clarification methods were compared: the chilling method and crossflow microfiltration method. The beer samples for this study were produced at the University of Witwatersrand Microbrewery and evaluated according to the European Brewing Convention (EBC) standards. Using the microfiltration technique, it was observed that higher temperatures increase the total flux, head retention value (HRV) and haze. The filtration temperature was conducted at less than 4°C (39°F) to bring the haze level to an acceptable standard. There was a linear correlation between flux and haze, where the higher the flux, the higher the haze. Cleaning of the membrane by backwashing with water effectively opened up the membrane pores. The chilling technique showed that haze decreased significantly from 3.1 to <0.8 to meet the EBC requirements. The mouthfeel, measured by the real degree of fermentation (% RDF), increased slightly with...

Research paper thumbnail of Makun et al 2011

Research paper thumbnail of Makun et al 2011

Research paper thumbnail of Computational Strategy towards the Control and Reduction of Malaria incidences in Africa

Malaria persists as one of the most problematic disease in Africa. It is the cause of morbidity a... more Malaria persists as one of the most problematic disease in Africa. It is the cause of morbidity and mortality of children and efforts are currently being pooled to increase control measures of its incidences within African countries. With this in mind, we developed and applied a malaria control strategy from a computational perspective, to analyze, predict and offer appropriate recommendations and control measures, based on the insight gained in the course of this research. This will enable both governmental, NGOs (Non Governmental Organizations) and other relevant health agencies to provide future public health planning in these countries. Results showed the effects and impacts of some controllable factors on future malaria occurrence. Our system was able to demonstrate some level of intelligence. It also produced sensible and logical results which can be applied to achieve reduction of possible future malaria occurrences in the countries studied. The malaria infection course was p...

Research paper thumbnail of Incidence, Phylogeny and Mycotoxigenic Potentials of Fungi Isolated from Rice in Niger State, Nigeria

Journal of Food Safety, 2011

The study reports on the natural occurrence of fungi in 21 samples of field (10), stored (6) and ... more The study reports on the natural occurrence of fungi in 21 samples of field (10), stored (6) and marketed (5) rice (Oryza sativa L.) collected from Niger State, Nigeria. Fungal isolates were primarily identified based on morphological characteristics, while representative isolates were characterized genetically. An evolutionary tree was constructed from the resulting sequences of the isolated fungi. The toxigenic potentials of some of the isolated fungi were also determined. A total of 357 fungal isolates of nine genera including Aspergillus, Fusarium, Sarocladium, Acremonium, Curvularia Botryosphaeria, Penicillium Alternaria and Ascomycota in decreasing order of predominance were identified. The most frequent fungal contaminants of the rice samples were A. flavus, A. fumigates, A. niger, A. parasiticus and F. proliferatum. All strains of A. flavus (aflatoxins B1 and B2), A. parasiticus (aflatoxins B1, B2, G1 and G2), A. ochraceus (ochratoxin A), F. proliferatum and F. verticillioides (fumonisins B1 and B2) tested, were excellent producers of their respective mycotoxins. Patulin was produced by A. terreus, whereas deoxynivalenol, zearalenone and T-2 toxin were produced by F. chlamydosporum and other Fusarium spp. The increased prevalence of toxigenic fungi in rice, a highly consumed food grain in Nigeria, poses serious health concerns to the general public.

Research paper thumbnail of Public/community engagement in health research with men who have sex with men in sub-Saharan Africa: challenges and opportunities

Health Research Policy and Systems, 2016

Community engagement, incorporating elements of the broader concepts of public and stakeholder en... more Community engagement, incorporating elements of the broader concepts of public and stakeholder engagement, is increasingly promoted globally, including for health research conducted in developing countries. In sub-Saharan Africa, community engagement needs and challenges are arguably intensified for studies involving gay, bisexual and other men who have sex with men, where male same-sex sexual interactions are often highly stigmatised and even illegal. This paper contextualises, describes and interprets the discussions and outcomes of an international meeting held at the Kenya Medical Research Institute-Wellcome Trust in Kilifi, Kenya, in November 2013, to critically examine the experiences with community engagement for studies involving men who have sex with men. We discuss the ethically charged nature of the language used for men who have sex with men, and of working with &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;representatives&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; of these communities, as well as the complementarity and tensions between a broadly public health approach to community engagement, and a more rights based approach. We highlight the importance of researchers carefully considering which communities to engage with, and the goals, activities, and indicators of success and potential challenges for each. We suggest that, given the unintended harms that can emerge from community engagement (including through labelling, breaches in confidentiality, increased visibility and stigma, and threats to safety), representatives of same-sex populations should be consulted from the earliest possible stage, and that engagement activities should be continuously revised in response to unfolding realities. Engagement should also include less vocal and visible men who have sex with men, and members of other communities with influence on the research, and on research participants and their families and friends. Broader ethics support, advice and research into studies involving men who have sex with men is needed to ensure that ethical challenges - including but not limited to those related to community engagement - are identified and addressed. Underlying challenges and dilemmas linked to stigma and discrimination of men who have sex with men in Africa raise special responsibilities for researchers. Community engagement is an important way of identifying responses to these challenges and responsibilities but itself presents important ethical challenges.

Research paper thumbnail of Respondent-driven sampling as a recruitment method for men who have sex with men in southern sub-Saharan Africa: a cross-sectional analysis by wave

Sexually transmitted infections, Jan 30, 2015

Respondent-driven sampling (RDS) is a popular method for recruiting men who have sex with men (MS... more Respondent-driven sampling (RDS) is a popular method for recruiting men who have sex with men (MSM). Our objective is to describe the ability of RDS to reach MSM for HIV testing in three southern African nations. Data collected via RDS among MSM in Lesotho (N=318), Swaziland (N=310) and Malawi (N=334) were analysed by wave in order to characterise differences in sample characteristics. Seeds were recruited from MSM-affiliated community-based organisations. Men were interviewed during a single study visit and tested for HIV. χ(2) tests for trend were used to examine differences in the proportions across wave category. A maximum of 13-19 recruitment waves were achieved in each study site. The percentage of those who identified as gay/homosexual decreased as waves increased in Lesotho (49% to 27%, p<0.01). In Swaziland and Lesotho, knowledge that anal sex was the riskiest type of sex for HIV transmission decreased across waves (39% to 23%, p<0.05, and 37% to 19%, p<0.05). The ...

Research paper thumbnail of Nanoparticles as potential new generation broad spectrum antimicrobial agents

DARU Journal of Pharmaceutical Sciences, 2015

The rapid emergence of antimicrobial resistant strains to conventional antimicrobial agents has c... more The rapid emergence of antimicrobial resistant strains to conventional antimicrobial agents has complicated and prolonged infection treatment and increased mortality risk globally. Furthermore, some of the conventional antimicrobial agents are unable to cross certain cell membranes thus, restricting treatment of intracellular pathogens. Therefore, the disease-causing-organisms tend to persist in these cells. However, the emergence of nanoparticle (NP) technology has come with the promising broad spectrum NP-antimicrobial agents due to their vast physiochemical and functionalization properties. In fact, NP-antimicrobial agents are able to unlock the restrictions experienced by conventional antimicrobial agents. This review discusses the status quo of NP-antimicrobial agents as potent broad spectrum antimicrobial agents, sterilization and wound healing agents, and sustained inhibitors of intracellular pathogens. Indeed, the perspective of developing potent NP-antimicrobial agents that carry multiple-functionality will revolutionize clinical medicine and play a significant role in alleviating disease burden.

Research paper thumbnail of The response effect of pheochromocytoma (PC12) cell lines to oxidized multi-walled carbon nanotubes (o-MWCMTs)

African Health Sciences

The applications of oxidized carbon nanotubes (o-CNTs) have shown potentials in novel drug delive... more The applications of oxidized carbon nanotubes (o-CNTs) have shown potentials in novel drug delivery including the brain which is usually a challenge. This underscores the importance to study its potential toxic effect in animals. Despite being a promising tool for biomedical applications little is known about the safety of drugs in treating brain diseases. The toxicity of oxidized multi-walled carbon nanotubes (o-MWCNTs) are of utmost concern and in most in-vitro studies conducted so far are on dendritic cell (DC) lines with limited data on PC12 cell lines.

Research paper thumbnail of Chloroquine prophylaxis associated with high prevalence of Plasmodium falciparum pfcrt K76T mutation in people with sickle-cell disease in Benin City, Nigeria

Journal of vector borne diseases

High mortality and morbidity in sickle-cell disease has been associated with malaria infection es... more High mortality and morbidity in sickle-cell disease has been associated with malaria infection especially in countries where chloroquine is used. Chloroquine resistance has been associated with the emergence of Pfcrt mutant genes. This study aimed at comparing the prevalence rate of Pfcrt T76 mutation in Plasmodium falciparum isolates from infected individuals with sickle-cell disease and sickle-cell trait. This study was carried out in Benin City between the months of April and June 2006. This period is marked with high transmission rate of malaria. The genotype of the subjects was screened using haemoglobin electrophoresis system and the P. falciparum. Pfcrt genotyping was carried out using PCR-restriction fragment length polymorphism (RFLP). Four hundred and twenty-four subjects comprising of 207 haemoglobin AA, 136 haemoglobin AS and 81 haemoglobin SS typed individuals were enrolled for this study. No significant difference existed in the prevalence rate of malaria in the three ...

Research paper thumbnail of The use of Carbon Nanotubes in Medical Applications - Is It a Success Story?

Occupational Medicine & Health Affairs, 2014

Research paper thumbnail of Nanoparticles Toxicity and Their Routes of Exposures

Recent Advances in Novel Drug Carrier Systems, 2012

The new scientific innovation of engineering nanoparticles (NPs) at the atomic scale of 100 nm or... more The new scientific innovation of engineering nanoparticles (NPs) at the atomic scale of 100 nm or less, has led to numerous novel and useful wide applications in electronics, chemicals, environmental protection, biological medicine. Manufacturers and consumers of the nanoparticles-related industrial products however, are likely to be exposed to these engineered nanomaterials which have various physical and chemical properties. These nanosize particles are likely to increase an unnecessary infinite toxicological effect on animals and environment, although their toxicological effects associated with human exposure are still unknown. In order to understand the effects of these exposures, this review seeks to examine the various toxicological portal routes associated with NPs exposures. These NPs can enter the host systems via skin spores, debilitated tissues, injection, olfactory, respiratory and intestinal tracts. These uptake routes of NPs may be intentional or unintentional. Their entry may lead to various diversified adverse biological effects. Until a clearer picture emerges, the limited data available suggest that caution must be exercised when potential exposures to NPs are encountered. Methods used in determining NPs portal of entry into experimental animals include pharyngeal instillation, injection, inhalation, cell culture lines and gavage exposures. This review also provides a step by step systematic approach for the easy identification and addressing of occupational health hazards arising from NPs.

Research paper thumbnail of The cellular response of Saccharomyces cerevisiae to multi-walled carbon nanotubes (MWCNTs)

Journal of Saudi Chemical Society, 2012

Nanoparticles (NPs) especially those of carbon nanotubes (CNTs) have remarkable properties that a... more Nanoparticles (NPs) especially those of carbon nanotubes (CNTs) have remarkable properties that are very desirable in various biological and biomedical applications. This has necessitated the rapid study of CNT toxicities, to augment their safe use, particularly, in yeast cells. The yeast cell; Saccharomyces cerevisiae is a widely used industrial and biological organism with very limited data regarding their cellular behaviour in NPs. The current study examines the cellular response of S. cerevisiae to MWCNTs. The CNTs were produced by the swirled floating catalytic chemical vapour deposition (SFCCVD) method and covalently functionalised using 1,3-dipolar cycloaddition. The CNT properties such as size, surface area, quality and surface vibrations were characterized using TEM, SEM, BET, TGA and Raman spectroscopy, respectively. The cellular uptake was confirmed with a FITC functionalised MWCNTs using 1H NMR, SEM and TEM. The CNT concentrations of 2-40 lg/ml were used to determine the cellular response through cell growth phases and cell viability characteristics. The TEM and SEM analyses showed the production of MWCNTs with an average diameter of 53 ± 12 nm and a length of 2.5 ± 0.5 lm. The cellular uptake of FITC-MWCNTs showed 100% internalisation in the yeast cells. The growth

Research paper thumbnail of Temperature Optimization for Bioethanol Production from Corn Cobs Using Mixed Yeast Strains

OnLine Journal of Biological Sciences, 2010

Problem statement: Dilute sulphuric acid and enzymatic hydrolysis methods were used for sugar ext... more Problem statement: Dilute sulphuric acid and enzymatic hydrolysis methods were used for sugar extraction. Xylose and glucose sugars were obtained from corn cobs. Approach: Acid hydrolysis of corn cobs gave higher amount of sugars than enzymatic hydrolysis. Results: The results showed that optimal temperature and time for sugar fermentation were approximately 25°C and 50 h by two yeast strains (S. cerevisiae and P. Stipitis) respectively. At 20 and 40°C, less bioethanol was produced. Bioethanol produced at 25°C was 11.99 mg mL −1 , while at 40 and 20°C were 2.50 and 6.40 mg mL −1 respectively. Conclusion/Recommendations: Data obtained revealed that xylose level decreased from 27.87-3.92 mg mL −1 during the first 50 h of fermentation and complete metabolism of glucose was observed during this time. Xylose and bioethanol levels remained constant after 50 h. Varying the temperature of the fermentation process improves the effective utilization of corn cobs sugars for bioethanol production can be achieved.

Research paper thumbnail of Sibanye Methods for Prevention Packages Program Project Protocol: Pilot Study of HIV Prevention Interventions for Men Who Have Sex With Men in South Africa

JMIR Research Protocols, 2014

Human immunodeficiency virus (HIV) prevention intervention programs and related research for men ... more Human immunodeficiency virus (HIV) prevention intervention programs and related research for men who have sex with men (MSM) in the southern African region remain limited, despite the emergence of a severe epidemic among this group. With a lack of understanding of their social and sexual lives and HIV risks, and with MSM being a hidden and stigmatized group in the region, optimized HIV prevention packages for southern African MSM are an urgent public health and research priority. The objective of the Sibanye Health Project is to develop and evaluate a combination package of biomedical, behavioral, and community-level HIV prevention interventions and services for MSM in South Africa. The project consists of three phases: (1) a comprehensive literature review and summary of current HIV prevention interventions (Phase I), (2) agent-based mathematical modeling of HIV transmission in southern African MSM (Phase II), and (3) formative and stigma-related qualitative research, community engagement, training on providing health care to MSM, and the pilot study (Phase III). The pilot study is a prospective one-year study of 200 men in Cape Town and Port Elizabeth, South Africa. The study will assess a package of HIV prevention services, including condom and condom-compatible lubricant choices, risk-reduction counseling, couples HIV testing and counseling, pre-exposure prophylaxis (PrEP) for eligible men, and non-occupational post-exposure prophylaxis for men with a high risk exposure. The pilot study will begin in October 2014. Preliminary results from all components but the pilot study are available. We developed a literature review database with meta-data extracted from 3800 documents from 67 countries. Modeling results indicate that regular HIV testing and promotion of condom use can significantly impact new HIV infections among South African MSM, even in the context of high coverage of early treatment of HIV-positive men and high coverage of PrEP for at-risk HIV-negative men. Formative qualitative research consisted of 79 in-depth interviews, and six focus group discussions in Cape Town and Port Elizabeth. Analysis of these data has informed pilot study protocol development and has been documented in peer-reviewed manuscripts. Qualitative work regarding stigma faced by South African MSM resulted in finalized scales for use in the pilot study questionnaire. A total of 37 health care providers completed training designed to facilitate clinically and culturally competent care for MSM in the Eastern Cape. The design of a future, larger study of the HIV prevention package will be conducted at the end of the pilot study, powered to detect efficacy of the prevention package. Data from the updated mathematical model, results of the pilot study, acceptability data, and advancements in HIV prevention sciences will be considered in developing the final proposed package and study design. ClinicalTrials.gov NCT02043015; http://clinicaltrials.gov/show/NCT02043015 (Archived by WebCite at http://www.webcitation.org/6THvp7rAj).

Research paper thumbnail of Synthesis of Large Carbon Nanotubes from Ferrocene: The Chemical Vapour Deposition Technique

Trends in Applied Sciences Research, 2011

Research paper thumbnail of Challenges facing sterilization and depyrogenation of nanoparticles: Effects on structural stability and biomedical applications

Nanomedicine: Nanotechnology, Biology and Medicine, 2014

This review outlines and compares techniques that are currently available for the sterilization o... more This review outlines and compares techniques that are currently available for the sterilization of nanoparticles and addresses the topic of endotoxin contamination. Several techniques are available for the removal of microbial contamination from nanoparticles developed for use in nanomedicine applications. These techniques include filtration, autoclaving and irradiation, as well as formaldehyde, ethylene oxide and gas plasma treatments. Of these sterilization methodologies, filtration may potentially remove microbial contamination without altering the physicochemical properties of the carrier nanoparticles, nor affecting their toxicity and functionality. However, no single process may be applied to all nanoparticle preparations and, therefore, it is recommended that each nanoparticle-drug system be validated on a case-by-case basis.