Performance evaluation of an efficient counter-based scheme for mobile ad hoc networks based on realistic mobility model

Flooding is the simplest and commonly used mechanism for broadcasting in mobile ad hoc networks (MANETs). Despite its simplicity, it can result in high redundant retransmission, contention and collision in the network, a phenomenon referred to as broadcast storm problem. Several probabilistic broadcast schemes have been proposed to mitigate this problem inherent with flooding. Recently, we have proposed a hybrid-based scheme as one of the probabilistic scheme, which combines the advantages of pure probabilistic and counter-based schemes to yield a significant performance improvement. Despite these considerable numbers of proposed broadcast schemes, majority of these schemes’ performance evaluation was based on random waypoint model. In this paper, we evaluate the performance of our broadcast scheme using a community based mobility model which is based on social network theory and compare it against widely used random waypoint mobility model. Simulation results have shown that using unrealistic movement pattern does not truly reflect on the actual performance of the scheme in terms of saved-rebroadcast, reachability and end to end delay

Employee advocacy in Africa:the role of HR practitioners in Malawi

Purpose: In recognizing the weakness of trade unions and the lack of an institutional framework designed to enforce employee rights in an African context, this study examines the extent to which HR practitioners are perceived to play the role of employee advocate.Design/methodology/approach: The quantitative data set is derived from a sample of 305 respondents (95 HR practitioners, 121 line managers, and 89 employees) from Malawi.Findings: Despite the challenges of the context, HR practitioners are perceived by key stakeholders (line managers and employees) to be playing the role of employee advocate. Standard multiple regression results indicate that the main factor contributing to the perception that HR practitioners are playing this role is their contribution to ‘motivating employees’.Research limitations/implications: The study was conducted in Malawi. Further research is necessary to explore the generalizability of the findings to other contexts.Originality/value: The findings provide an empirical base for future studies which explore perceptions of the employee advocacy role undertaken by HR practitioners in Africa

Evaluation of some Varieties of Okra (Abelmoschusesculentus) Seed Oil for Consumption and Industrial Uses

The demand for seeds oil is rapidly increasing due to the growth of the human population and the resulting increase in its consumption for both domestic and industrial uses. Hence, seed oils from three okra (Abelmoschusesculentus) varieties – Clemson spineless, ex-Samaru and NHAE-74 were extracted and their physicochemical properties were analysed and compared with some conventional seed oils. The percentage oil yield of the seeds determined for NHAE-74 (25.67±0.58 %) is significantly higher (p < 0.05) than Clemson spineless  (24.33±0.29 %) and ex-Samaru (23.05±0.50 %). The acid value (3.65±0.02, 1.96±0.01 and 2.24±0.02 mgKOH/g), Iodine Value (114.59±0.01,110.97±0.02 and 111.67±0.02 mg/100g) and Saponification value (122.02±0.19, 130.43±0.04 and 124.82±0.02 meqKOH/kg) of Clemson  spineless, ex-Samaru and NHAE-74, respectively differ significantly (p < 0.05) among the three varieties, while the peroxide value  (meqKOH/kg) of Clemson spineless (3.92±0.14) is significantly lower (p < 0.05) than the values of NHAE-74 (5.33±0.14) and ex-Samaru (5.00±0.25). The results further showed that the seed oil has a quality comparable to those of conventional oils and has great nutritional and industrial potentials

Prevalence and Risk Factors of High Risk Human Papillomavirus Infections among Women Attending Gynaecology Clinics in Kano, Northern Nigeria

Cervical cancer is the most common female cancer in northern Nigeria, yet the pattern of infection with human papillomavirus, the principal aetiologic agent is unknown. This was a preliminary study conducted in two referral hospitals in order to establish base-line data on the prevalence and risk factors for the infection in Kano state, Nigeria. Fifty (50) randomly selected women aged 18 years and above were recruited from gynaecology clinics in Murtala Muhammad Specialist Hospital and Aminu Kano teaching Hospital. Relevant sexual and socio-demographic information were obtained from each subject using a questionnaire. Exfoliated cervical cells were harvested and processed using Polymerase Chain Reaction to identify the DNAs of high-risk HPV types 16 and 18. The prevalence rate of HPV infection was 76% [(38/50) at 95% CI=61.8-86.9] with 60.5% (23/38) having co-infections with both HPV type 16 and 18. Risk factors of the infection include low literacy level; living in rural settlements; low parity; early menarche (<15 years of age); early onset of first sexual intercourse (≤16 years of age) and multiple sexual partners. There was however, no statistically significant association between oral contraceptive usage and acquisition of the infections. Findings of this study suggest a high prevalence of HPV types 16 and 18 among women attending gynaecology clinic in Kano and thus called for more elaborate community based study in order to establish the magnitude of the problem from wider perspective.Keywords: Human Papillomavirus; Prevalence; Risk Factors, Northern Nigeri

The search for mitochondrial tRNALeu(UUR) A3243G mutation among type 2 diabetes mellitus patients in the Nigerian population

The study aimed to compare the incidence of the pathogenic point mutation A3243G in the gene tRNALeu(UUR) indicating sub-type 2 diabetes mellitus conducted within the Nigerian population with that reported in other populations. 112 patients diagnosed with type 2 diabetes (T2D) mellitus according to the World Health Organization criteria were selected based on family history and re-evaluated for associated disorders from the diabetic clinics in the Northern part of Nigeria. The mtDNA of these patients was extracted and the tRNALeu(UUR) gene screened for A3243G by PCR-RFLP method. Probands with maternal history were further investigated for other mutations using PCR-sequencing methods. None of the 112 patients were found to carry the A3243G mutation in the mitochondrial tRNALeu(UUR) gene in the homoplasmic or in the heteroplasmic form. However, C3254T was identified in two of our patients. This mutation was reported to be associated with gestational diabetes and linked with population from sub-Saharan Africa. The A3243G mutation in mitochondrial tRNALeu(UUR) is not a frequent cause of maternal diabetes in the Nigerian population contrary to other reported populations. However, further screening of an enlarged selected study group is necessary to fully determine the prevalence of this mutation in this population. This further search will help to fully appreciate the prevalence of maternal inheritance and diabetic deafness (MIDD) as extensively reported in other populations.Key words: Maternal diabetes, mitochondrial gene, maternal Inheritance and diabetic deafness, Nigeria, sub-Saharan Africa

Diversity of Rotavirus VP7 and VP4 Genotypes in Northwestern Nigeria

Background. Nigeria has recently been ranked third among the 10 countries with the greatest number of rotavirus disease-associated deaths per year. Estimates attribute up to 33,000 deaths annually to rotavirus disease in Nigerian children <5 years old. Although the introduction of the new oral, live attenuated rotavirus vaccines may not occur for another 4-6 years in developing countries, background data on burden of disease, cost of rotavirus disease, and characterization of circulating strains is required to hasten this introduction to children who would clearly benefit from the intervention. Methods. Between July 2002 and July 2004, fecal specimens were collected from 869 infants and young children <5 years of age presenting with diarrhea in Kaduna, Kebbi, Sokoto, and Zamfara states in northwestern Nigeria. In addition, 194 control specimens were also collected from children matched for age. Specimens were screened for the presence of rotavirus antigens. Rotavirus-positive specimens were further analyzed to determine electropherotype, subgroup specificity, and G and P genotypes. Results. Rotavirus was detected in 18% of children with diarrhea and 7.2% of the age-matched case control subjects. The highest rotavirus burden was detected in children aged <6 months. The majority of the rotaviruspositive specimens revealed viruses of long electropherotypes, subgroup II specificity, and G1P[8] genotypes. Furthermore, more than a quarter of specimens (37%) displayed mixed G and P genotypes, and almost a third could not be genotyped. Conclusions. The high numbers of mixed rotavirus infections highlight the multitude of enteric pathogens to which children in African countries are exposed. Data on circulating rotavirus strains serve to inform African government officials to the serious health threat posed by rotavirus in their respective countries and to document the diversity of strains before vaccine introductio

Capacity for the management of kidney failure in the International Society of Nephrology Newly Independent States and Russia:Report from the 2023 ISN Global Kidney Health Atlas (ISN-GKHA)

The International Society of Nephrology Global Kidney Health Atlas (ISN-GKHA) was established to understand the status and capacity of countries to provide optimal kidney care worldwide. This report presents the current characteristics of kidney care in the ISN Newly Independent States (NIS) and Russia region. Although the median prevalence of chronic kidney disease (CKD) was higher (11.4%) than the global median (9.5%), the median CKD-related death rate (1.4%) and prevalence of treated kidney failure (KF) in the region (411 per million population [pmp]) were lower than globally (2.5% and 822.8 pmp, respectively). There is a capacity to provide an adequate frequency of hemodialysis (HD) and kidney transplantation services in all (100%) countries. Besides significant economic advancement in the region there are critical shortages of nephrologists, dietitians, transplant coordinators, social workers, palliative care physicians, and kidney supportive care nurses. Home HD remains unavailable in any country in the region. While national registries for dialysis and kidney transplantation are available in most of the countries across the ISN NIS and Russia region there are few registries for non-dialysis CKD and acute kidney injury. Whereas a national strategy for improving care for CKD patients is presented in more than half of the countries, there was no country that had a CKD specific policy in the region. Strategies that incorporate workforce training, planning, and development for all KF caregivers could help ensure sustainable kidney care delivery in the ISN NIS and Russia region

Regulation of genomic and biobanking research in Africa: a content analysis of ethics guidelines, policies and procedures from 22 African countries

Background: The introduction of genomics and biobanking methodologies to the African research context has also introduced novel ways of doing science, based on values of sharing and reuse of data and samples. This shift raises ethical challenges that need to be considered when research is reviewed by ethics committees, relating for instance to broad consent, the feedback of individual genetic findings, and regulation of secondary sample access and use. Yet existing ethics guidelines and regulations in Africa do not successfully regulate research based on sharing, causing confusion about what is allowed, where and when. Methods: In order to understand better the ethics regulatory landscape around genomic research and biobanking, we conducted a comprehensive analysis of existing ethics guidelines, policies and other similar sources. We sourced 30 ethics regulatory documents from 22 African countries. We used software that assists with qualitative data analysis to conduct a thematic analysis of these documents. Results: Surprisingly considering how contentious broad consent is in Africa, we found that most countries allow the use of this consent model, with its use banned in only three of the countries we investigated. In a likely response to fears about exploitation, the export of samples outside of the continent is strictly regulated, sometimes in conjunction with regulations around international collaboration. We also found that whilst an essential and critical component of ensuring ethical best practice in genomics research relates to the governance framework that accompanies sample and data sharing, this was most sparingly covered in the guidelines. Conclusions: There is a need for ethics guidelines in African countries to be adapted to the changing science policy landscape, which increasingly supports principles of openness, storage, sharing and secondary use. Current guidelines are not pertinent to the ethical challenges that such a new orientation raises, and therefore fail to provide accurate guidance to ethics committees and researchers