A survey of QoS-aware web service composition techniques

Web service composition can be briefly described as the process of aggregating services with disparate functionalities into a new composite service in order to meet increasingly complex needs of users. Service composition process has been accurate on dealing with services having disparate functionalities, however, over the years the number of web services in particular that exhibit similar functionalities and varying Quality of Service (QoS) has significantly increased. As such, the problem becomes how to select appropriate web services such that the QoS of the resulting composite service is maximized or, in some cases, minimized. This constitutes an NP-hard problem as it is complicated and difficult to solve. In this paper, a discussion of concepts of web service composition and a holistic review of current service composition techniques proposed in literature is presented. Our review spans several publications in the field that can serve as a road map for future research

Knowledge and attitude towards contraceptive use among adolescents in Africa: a systematic review

A 46% rate of unintended pregnancies among adolescents in Africa is a glaring notification of the barriers to contraception. There is little documentation of the knowledge and attitude towards contraceptive use among adolescents in Africa especially from systematic review perspective, which purposed this study. An E-literature search of the studies on the topic was conducted through PubMed, and Google Scholar, considering a period between January 2015 to August 2021. The search strategy used; “knowledge and attitude towards contraceptive use among adolescents in Africa”, which was sorted by date. The search resulted in 14,468 journal articles: 14,300 from Google Scholar, and 168 from PubMed but only 27 studies qualified for inclusion. Results indicate inadequate knowledge of contraception but this varies by age, level of education, marital status and geographical distribution. The majority of adolescents are aware of emergency contraception and traditional methods such as abstinence, lactational amenorrhea, and coïtus interruptus. Even with this knowledge, a larger proportion of adolescents do not use contraception due to limited access, misinformation on side effects and the negative attitude shaped by religious and socio-cultural beliefs and attitude of health care providers to them. Adolescent boys have more knowledge of contraception than the adolescent girls do but their use of contraceptives is not well documented. The low level of knowledge and negative attitude limits the use of these services and could be addressed by a well-informed approach on sexuality literacy and contraception that involves not only adolescents but also parents, the community and health care providers

Heat and mass transfer of MHD for an unsteady viscous oscillatory flow

Magnetohydrodynamic (MHD) studies on chemical reaction concepts, with heat and mass transfer, were presented. Unsteady viscous at the two-dimensional motion of oscillatory flow is considered. Transverse magnetic on a field known to have an influence on pressure gradient at non-dimensional parameters were closely studied and a technique point was carried out. Hartmann number, Grashof, Prandtl, Schmidt numbers and diffusivity ratio effect on the velocity profile and temperature profile overheat and mass transfer of MHD flow. Graphically presentation shows velocity gradient change in the Hartmann number, suction/injection, Grashof, and Prandtl. For Schmidt numbers velocity profile increase on heat and mass transfer. Diffusivity ratio also leads to change velocity and temperature profile

Risk analysis in fish farming systems in Oyo and Kwara States, Nigeria: a prospect towards improving fish production

The aim of this paper is to analyze risks in fish farming systems in Oyo and Kwara States, Nigeria. The primary data were collected using structured questionnaire with personal interview method by trained enumerators. The data collected belonged to the 2015/2016 production year. The total respondents (277) in the two states were separated to concrete pond fish farmers (123) and earthen pond fish farmers (154). Descriptive statistics, safety model and multinomial logit model were used to analyze the data. The results indicated that concrete system was more hired labour driven, relatively had higher formal education, and higher total investment and credit utilized compared to earthen system. The results of the risk preference revealed that of 123 respondents in concrete pond system, 52 % are risk preferring, 34 % are risk neutral and 16 % are risk averse, indicating better risk seeking compared with 154 respondents in earthen pond system with 21.4 % being risk preferring, 59.7 % being risk neutral and 18.8 % risk averse. The results of the estimates of the explanatory variables revealed that that the set of significant explanatory variables and their signs vary across the concrete and earthen pond systems. It would be concluded that the determinants of fish farmers’’ risk status differ considerably between concrete and earthen pond systems. Fish farmers needs to be sensitized through seminars, workshops and trainings in seeking risk by extension personnel in collaboration with agricultural insurance firms, this will go a long way in improving fish production among respondents.Keywords: Fish farming, Insurance, Marginal effect, Risk aversion, Workshop

Optimum utilization of Clostridia species towards biofuel production

Abstract Global increasing stipulates for the production of renewable fuels due to massive utilization of readily available fossil fuel, more interests in microbial production of biofuels are generated. This opened great opportunities to the biologists, because anaerobic bacteria particularly Clostridium species are capable of converting carbohydrates into a variety of solvents such as acetone, butanol, ethanol and more the like. The review provided ample sources of information with regards to the potentialities of Clostridium species towards production of biofuels. The classification of Clostridium species into pathogenic and non-pathogenic, and those capable of biofuel production has been summarized. Typical metabolic processes responsible for transforming biomass into various biofuels have been highlighted. Utilization of agricultural wastes as substrates towards biofuel production was equally highlighted. Various carbon sources and some Clostridium species exploited for biofuel production were summarized. The review also provided some of the factors that influenced the biofuel production

Pharyngeal carriage of Neisseria species in the African meningitis belt.

OBJECTIVES: Neisseria meningitidis, together with the non-pathogenic Neisseria species (NPNs), are members of the complex microbiota of the human pharynx. This paper investigates the influence of NPNs on the epidemiology of meningococcal infection. METHODS: Neisseria isolates were collected during 18 surveys conducted in six countries in the African meningitis belt between 2010 and 2012 and characterized at the rplF locus to determine species and at the variable region of the fetA antigen gene. Prevalence and risk factors for carriage were analyzed. RESULTS: A total of 4694 isolates of Neisseria were obtained from 46,034 pharyngeal swabs, a carriage prevalence of 10.2% (95% CI, 9.8-10.5). Five Neisseria species were identified, the most prevalent NPN being Neisseria lactamica. Six hundred and thirty-six combinations of rplF/fetA_VR alleles were identified, each defined as a Neisseria strain type. There was an inverse relationship between carriage of N. meningitidis and of NPNs by age group, gender and season, whereas carriage of both N. meningitidis and NPNs was negatively associated with a recent history of meningococcal vaccination. CONCLUSION: Variations in the prevalence of NPNs by time, place and genetic type may contribute to the particular epidemiology of meningococcal disease in the African meningitis belt

Health risk assessment of instant noodles commonly consumed in Port Harcourt, Nigeria

The current study investigated the levels of some heavy metals [Lead (Pb), Arsenic (As), Nickel (Ni), Mercury (Hg), Copper (Cu), Cadmium (Cd), Aluminium (Al) and Chromium (Cr)] and Polycyclic Aromatic Hydrocarbons (PAHs) in six brands of instant noodles (CFN, GFC, NGP, GAA, CUN and FCS) commonly consumed in Port Harcourt, Nigeria. Risks of consumption of contaminated noodles were also assessed. Heavy metals content and PAHs were determined using Flame Atomic Absorption Spectrophotometer (AAS) and Gas Chromatography (GC), respectively. Concentration of heavy metals as Pb, Ni, Cu, Al and Cr were detected while As, Hg and Cd were not detected in noodles. High average concentration (mean ± SD mg/kg) of Pb were observed in brands CFN (3.163 ± 0.21) and GFC (1.022 ± 0.08) which were significantly higher (P≤0.05) than in NGP (0.043 ± 0.15) and GAA (0.276 ± 0.18), although all were above WHO permissible limits (0.025 mg/kg). Target Hazard Quotient and Hazard Index for Pb were >1 in brands CFN and GFC indicating unacceptable risk. Results of PAHs showed brands had total PAHs (mg/kg) in the order: CFN >CUN >GAA >NGP >FCS > GFC. Although Carcinogenic Risks associated with these noodles are within permissible range, consumption of CFN and GFC could pose greater health risk to consumers. Long term consumption of brands CUN, CFN and GAA may have higher probability of carcinogenesis among consumers. We therefore recommend more diligent regulatory policies and monitoring by relevant Government agencies (WHO, NAFDAC, CPC and SON) to ensure wholesome noodles get to consumers

Pharyngeal carriage of Neisseria species in the African meningitis belt.

OBJECTIVES: Neisseria meningitidis, together with the non-pathogenic Neisseria species (NPNs), are members of the complex microbiota of the human pharynx. This paper investigates the influence of NPNs on the epidemiology of meningococcal infection. METHODS: Neisseria isolates were collected during 18 surveys conducted in six countries in the African meningitis belt between 2010 and 2012 and characterized at the rplF locus to determine species and at the variable region of the fetA antigen gene. Prevalence and risk factors for carriage were analyzed. RESULTS: A total of 4694 isolates of Neisseria were obtained from 46,034 pharyngeal swabs, a carriage prevalence of 10.2% (95% CI, 9.8-10.5). Five Neisseria species were identified, the most prevalent NPN being Neisseria lactamica. Six hundred and thirty-six combinations of rplF/fetA_VR alleles were identified, each defined as a Neisseria strain type. There was an inverse relationship between carriage of N. meningitidis and of NPNs by age group, gender and season, whereas carriage of both N. meningitidis and NPNs was negatively associated with a recent history of meningococcal vaccination. CONCLUSION: Variations in the prevalence of NPNs by time, place and genetic type may contribute to the particular epidemiology of meningococcal disease in the African meningitis belt.MenAfriCar was funded by the Wellcome Trust (086546/Z/08/Z) and the Bill and Melinda Gates Foundation (51251). Kanny Diallo holds a Wellcome Trust Training Fellowship in Public Health and Tropical Medicine.This is the final version of the article. It first appeared from Elsevier via https://doi.org/10.1016/j.jinf.2016.03.01

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Network Aware Composition for Internet of Thing Services

To enhance the adoption of Internet of Things (IoT) philosophy for the internet, research into IoT service composition has gathered momentum. In a distributed IoT environment, identifying IoT service among a set of similar service offerings that meets both functional and performance requirements of an IoT application has become important. However, the performance of a service cannot be guaranteed. Therefore service’s QoS and network characteristics are required to aggregate IoT services. Most existing composition approaches only consider non-network related QoS properties at the application tier. However they do not consider the network parameters such as network latency at the application level in selection and composition of services. Therefore we propose two evolutionary algorithms for IoT service composition that consider not only QoS but also network latency at the IoT application layer. The algorithms are discussed and results of evaluation are presented. The results indicate that our algorithms are efficient in finding QoS optimal and low latency solutions