Enhanced Dynamic Bandwidth Allocation Algorithm for Intelligent Home Networks

Internet of Things (IoT) has been seen playing a tremendous change in the Information Technology (IT) environments, and thus its importance has also been realized and played a vital role within Intelligent Home Networks (IHNs). This is because IoT establishes a connection between things and the Internet by utilizing different sensing devices to implement the intelligence to deal with the identification and management of the connected things. IHNs use intelligent systems to perform their daily operations. Meanwhile, these networks ensure comfort, safety, healthcare, automation, energy conservation, and remote management to devices and users. Apart from that, these networks provide assistance in self-healing for faults, power outages, reconfigurations, and more. However, we have realized that more and advanced devices and services continue to be introduced and used in these networks. This has led to competitions of the limited available network resources, services, and bandwidth. In this paper, therefore, we present the design and implementation of a Novel Dynamic Bandwidth Allocation (NoDBA) algorithm to solve the performance bottleneck incurred with IHNs. The proposed algorithm deals with the management of bandwidth and its allocation. In the proposed algorithm, this study integrates two algorithms, namely; Offline Cooperative Algorithm (OCA) and Particle Swarm Optimization (PSO) to improve Quality of Service (QoS). PSO defines the priority limits for subnets and nodes in the network. Meanwhile, OCA facilitates dynamic bandwidth allocation in the network. The Network Simulator-2 (NS-2) was used to simulate and evaluate the NoDBA and it showed improved results compared to the traditional bandwidth allocation algorithms. The obtained results show an average throughput of 92%, average delay of 0.8 seconds, and saves energy consumption of 95% compared to Dynamic QoS-aware Bandwidth Allocation (DQBA) and Data-Driven Allocation (DDA).   Keywords: IHNs, Dynamic Bandwidth Allocation, PSO, OCA, Qo

Densification behavior of spark plasma sintered duplex stainless steel reinforced with TiN nanoparticles

Abstract: Duplex stainless steel (SAF 2205) reinforced with titanium nitride (TiN) nanoparticles ranging from 0 to 8 wt% were fabricated in vacuum via spark plasma sintering (SPS) using optimized SPS process parameter of 1150 oC, 10 min and 100 oC/min. The influence of TiN addition on the densification and shrinkage mechanism of the fabricated duplex stainless steel composite were evaluated. The results indicate even dispersion of the TiN nanoparticles in the steel matrix during tubular mixing. The displacement and shrinkage rates showed three densification stages relating to micro-nano particles rearrangement, plastic deformation of the particles and rapid densification of the composite. The steel composite samples displayed relatively high densities in the range of 96-99 % of the calculated theoretical density but were noted to decrease with TiN content

Growth of infants born to HIV-infected women, when fed a biologically acidified starter formula with and without probiotics

Objectives: To compare the growth of HIV-exposed uninfected infants fed a biologically acidified milk formula with or without probiotics (Bifidobacterium lactis) during the first six months of life, with control infants fed a standard starter formula. Design: Multi-centre, double-blinded randomised controlled trial. Setting: Infants born to HIV-infected women delivering at one of three academic hospitals in Johannesburg, South Africa. Subjects: Consenting HIV-positive women, who had previously decided not to breast-feed, were randomised to receive one of three milk formulas for their newborn infants. Outcome measures: Comparisons of growth parameters through the first four months of life were made between infants fed the acidified formula without probiotics and those fed the control formula (“acidification effect”), and between infants fed the acidified formulas with and without added probiotics (“probiotic effect”). Results: Of 131 randomised infants, 33 (25%) did not complete the study and 13 (10%) were HIV infected, leaving 85 infants available for analysis. Infants receiving the acidified formula with probiotics had more rapid head growth (p=0.04) and showed a trend towards more rapid weight gain (p=0.06) over the first four months of life than the infants receiving the acidified formula without probiotics. No other significant differences between the feeding groups were demonstrated. Conclusions: Infants in all study groups grew well, with increased head growth and a trend towards increased weight gain for those receiving probiotics. There were no differences in morbidity between the three study groups and no evidence of adverse effects of the study formulas. SAJCN Vol. 21 (1) 2008: pp. 28-3

Growth of infants born to HIV-positive mothers fed a whey-adapted acidified starter formula with prebiotics and nucleotides

Objectives: The objectives of this study were to evaluate whether infants born to known HIV-positive mothers, but who were not themselves infected with HIV and who were fed a chemically acidified starter formula with prebiotics with or without nucleotides during their first six months, displayed growth rates equal to uninfected infants fed a chemically acidified starter formula without prebiotics or nucleotides.Design: The design was a multi-centre, double-blinded randomised controlled trial.Setting: The study was carried out in four academic hospitals, three in Johannesburg and one in Cape Town, South Africa.Subjects and intervention: The subjects were newborn infants born to consenting HIV-positive women who had previously decided not to breast feed. The infants were randomised to receive one of three milk formulas. The intervention comprised chemically acidified formula without prebiotics or nucleotides, with prebiotics only, or with prebiotics and nucleotides.Outcome measures: The outcome measures were the growth parameters through the first six months of life.Results: Of the 150 randomised infants, 50 did not complete the study and 16 (12.8% of those tested) were infected with HIV, leaving 84 infants available for analysis. All three formulas were tolerated well, with no differences in growth parameters seen with the addition of prebiotics and nucleotides. The growth rates of the study infants up to the age of six months were very good, showing an increase in Z-scores from negative values at the time of enrolment in the first week after birth to around zero for length and > 0.5 for weight.Conclusions: The three chemically acidified formulas were tolerated well and resulted in good growth over the first six months of life. No benefits were seen with the addition of prebiotics or nucleotides. The growth rates were similar to those found in previous studies of ours on biologically acidified formulas. The chemical acidification of infant formulas appears to be a realistic alternative to biological acidification should an acidified formula be required.Keywords: milk formula; acidification; probiotics; nucleotides; infant growt

A correlation between nano and micro-hardness properties of TiN nanoparticles strengthened SAF 2205

Abstract : This work studied the correlation between Vickers and nano-hardness of SAF 2205 reinforced with TiN nanoparticles for the convenience of assessing its mechanical properties. Spark plasma sintering was used to fabricate the composites. Micro and nanoindentations were performed to determine micro and nanohardness values of the fabricated composite. Optical microscope was used to assess the microstructure. The microstructure revealed that the TiN dominated the ferrite/ferrite, ferrite/austenite and austenite/austenite grain boundaries. The micro and nanohardness at the TiN dominated grain boundaries were higher compared to the grain hardness. Hardness also increased considerably as the TiN nanoparticles increases. This is also owed to the strengthening effect played by TiN at the grain boundaries by disrupting dislocation motion in the composite. The determined Vickers hardness was plotted as a function of the corresponding nanohardness, a good linear relation was found between Vickers hardness and nanohardness. A linear relationship (HV = 215.15 + 15.03Hnano) was established which indicates that there is no difference in behavior for the Vickers hardness and nano- hardness

Low seroprevalence of hepatitis E virus in pregnant women in an urban area near Pretoria, South Africa

OBJECTIVES : Hepatitis E virus (HEV) infection is a globally neglected health problem with a high burden in resource-poor communities. Pregnant women are at increased risk of complications. This pilot study sought to assess the seroprevalence of HEV infection in pregnant women at Dr George Mukhari Academic Hospital, South Africa. METHODS : Stored serum samples from 384 HIV-uninfected pregnant women attending the antenatal clinic were initially screened for HEV total antibody. Positive samples were further evaluated for the presence of IgG and IgM antibody isotypes, using commercial ELISA assays. HEV RNA was assessed in antibody-positive samples utilizing qRT-PCR assay. RESULTS : The sample consisted of women with a median age of 31 years (interquartile range: 28–35 years). Total HEV antibody was detected in 12/384 (3.13%, 95% CI: 1.80–5.38) of these pregnant women. All 12 samples were IgG HEV antibody positive, but none tested positive for IgM antibody or for HEV RNA, demonstrating a lack of current or recent exposure. CONCLUSIONS : Our study revealed a low seroprevalence of HEV among pregnant women from an urban area north of Pretoria. This observation warrants further attention to the circulation of HEV in this population, and a greater understanding of the epidemiology of the infection in South Africa.The South African Ministry of Higher Education, Science and Innovation, and the National Research Foundation.http://www.elsevier.com/locate/ijregihj2023Medical Virolog

Maintaining Momentum for Rotavirus Immunization in Africa during the COVID-19 Era: Report of the 13th African Rotavirus Symposium

The 13th African Rotavirus Symposium was held as a virtual event hosted by the University of Nairobi, Kenya and The Kenya Paediatric Association on 3rd and 4th November 2021. This biennial event organized under the auspices of the African Rotavirus Network shapes the agenda for rotavirus research and prevention on the continent, attracting key international and regional opinion leaders, researchers, and public health scientists. The African Rotavirus Network is a regional network of institutions initially established in 1999, and now encompassing much of the diarrheal disease and rotavirus related research in Africa, in collaboration with the World Health Organization African Regional Office (WHO-AFRO), Ministries of Health, and other partners. Surges in SARS-CoV2 variants and concomitant travel restrictions limited the meeting to a webinar platform with invited scientific presentations and scientific presentations from selected abstracts. The scientific program covered updates on burden of diarrheal diseases including rotavirus, the genomic characterization of rotavirus strains pre- and post-rotavirus vaccine introduction, and data from clinical evaluation of new rotavirus vaccines in Africa. Finally, 42 of the 54 African countries have fully introduced rotavirus vaccination at the time of the meeting, including the two recently WHO pre-qualified vaccines from India. Nonetheless, the full benefit of rotavirus vaccination is yet to be realized in Africa where approximately 80% of the global burden of rotavirus mortality exists

Structure–Activity Relationship of Halophenols as a New Class of Protein Tyrosine Kinase Inhibitors

A series of new benzophenone and diphenylmethane halophenol derivatives were prepared. Their structures were established based on 1H NMR, 13C NMR and HRMS data. All prepared compounds were screened for their in vitro protein tyrosine kinase (PTK) inhibitory activities. The effects of modification of the linker, functional groups and substituted positions at the phenyl ring on PTK inhibitory activity were investigated. Twelve halophenols showed significant PTK inhibitory activity. Among them, compounds 6c, 6d, 7d, 9d, 10d, 11d and 13d exhibited stronger activities than that of genistein, the positive reference compound. The results gave a relatively full and definite description of the structure–activity relationship and provided a foundation for further design and structure optimization of the halophenols