13 research outputs found

    Edge Weight Power and Frequency Assignment Algorithm

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    In cellular networks, cells are grouped more densely around highly populated areas to provide more capacity.  Antennas are pointed in accordance with local terrain and clutter to reduce signal shadows and interference. Hardware parameters are easily set during installation but difficult to change thereafter. In a dynamic environment of population migration, there is need to continuously tune network parameters to adapt the network performance. Modern mobile equipment logs network usage patterns and statistics over time. This information can be used to tune soft parameters of the network. These parameters may include frequency channel assignment or reuse, and transmitter radiation power assignment to provide more capacity on demand. The paper proposes that by combining the frequency and power assignments, further optimisation in resource allocation can be achieved over a traditional frequency assignment. The solution considers the interference, traffic intensity and use of priority flags to bias some edges. An Edge Weight Power and Frequency Assignment Algorithm is presented to solve the resource allocation problem in cellular networks. The paper also analyses the performance improvements obtained over that of the Edge Weight Frequency Assignment Algorithm. The results show that the proposed algorithm improves the performance of the Edge Weight Frequency Assignment Algorithm depending on the initial structure of the graph

    Edge Weight Power and Frequency Assignment Algorithm

    Get PDF
    In cellular networks, cells are grouped more densely around highly populated areas to provide more capacity.  Antennas are pointed in accordance with local terrain and clutter to reduce signal shadows and interference. Hardware parameters are easily set during installation but difficult to change thereafter. In a dynamic environment of population migration, there is need to continuously tune network parameters to adapt the network performance. Modern mobile equipment logs network usage patterns and statistics over time. This information can be used to tune soft parameters of the network. These parameters may include frequency channel assignment or reuse, and transmitter radiation power assignment to provide more capacity on demand. The paper proposes that by combining the frequency and power assignments, further optimisation in resource allocation can be achieved over a traditional frequency assignment. The solution considers the interference, traffic intensity and use of priority flags to bias some edges. An Edge Weight Power and Frequency Assignment Algorithm is presented to solve the resource allocation problem in cellular networks. The paper also analyses the performance improvements obtained over that of the Edge Weight Frequency Assignment Algorithm. The results show that the proposed algorithm improves the performance of the Edge Weight Frequency Assignment Algorithm depending on the initial structure of the graph

    Integration of HIV and AIDS into primary curriculum: teacher training curriculum.

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    Article. From the study, it was clear that content experts need to arrange what should be taught in the curricula at different levels namely lower, middle and upper primary levelsThis study examined existing nature and effectiveness of HIV instruction and existing curricula materials used in Teacher Training Institutions (TTIs) to prepare their pre-service and in-service teachers (PITs) to integrate Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS) education into the mainstream curriculum teaching at Primary School level. The study showed that there was greatest variance between Content Area Experts (CAEs) and PITs on the appropriate setting to teach children about HIV and Acquired AIDS. The majority of CAEs (70.3 percent) stated the home setting while only 38.6 percent of TTI administrators choose home setting. While it was proposed by many respondents that it would be good to consider a separate, required, and examinable subject on HIV and AIDS in primary schools, 82% indicated that the best ways to teach about HIV topics is to integrate it into the core subjects for all primary schools . Findings indicate the important role a multiple-setting approach is by teaching children about HIV and AIDS in homes, schools, communities, and religious settings when considering reaching youths throughout the country and in helping to overcome the AIDS epidemic. From the study, it was clear that content experts need to arrange what should be taught in the curricula at different levels namely lower, middle and upper primary levelsSEL

    The role of phosphodiesterase 12 (PDE12) as a negative regulator of the innate immune response and the discovery of antiviral inhibitors

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    2',5'-Oligoadenylate synthetase (OAS) enzymes and RNase-L constitute a major effector arm of interferon (IFN)-mediated antiviral defense. OAS produces a unique oligonucleotide second messenger, 2',5'-oligoadenylate (2-5A), that binds and activates RNase-L. This pathway is down-regulated by virus- and host-encoded enzymes that degrade 2-5A. Phosphodiesterase 12 (PDE12) was the first cellular 2-5A- degrading enzyme to be purified and described at a molecular level. Inhibition of PDE12 may up-regulate the OAS/RNase-L pathway in response to viral infection resulting in increased resistance to a variety of viral pathogens. We generated a PDE12-null cell line, HeLaΔPDE12, using transcription activator-like effector nuclease-mediated gene inactivation. This cell line has increased 2-5A levels in response to IFN and poly(I-C), a double-stranded RNA mimic compared with the parental cell line. Moreover, HeLaΔPDE12 cells were resistant to viral pathogens, including encephalomyocarditis virus, human rhinovirus, and respiratory syncytial virus. Based on these results, we used DNA-encoded chemical library screening to identify starting points for inhibitor lead optimization. Compounds derived from this effort raise 2-5A levels and exhibit antiviral activity comparable with the effects observed with PDE12 gene inactivation. The crystal structure of PDE12 complexed with an inhibitor was solved providing insights into the structure-activity relationships of inhibitor potency and selectivity

    Psychological Impact of COVID-19 on Healthcare Workers in Africa, Associated Factors and Coping Mechanisms: A Systematic Review.

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    Background: The coronavirus disease 2019 (COVID-19) is a public health problem that has caused harm to the mental health of healthcare workers. In Africa, the COVID-19 pandemic has led healthcare workers to experience mental health disorders such as anxiety, depression, stress, insomnia and burnout. This study aimed to review published studies on the effect of COVID-19 on the mental health of healthcare workers, associated factors and coping strategies that have been employed in Africa. Methods: This was a systematic review that was conducted through searching databases including; PubMed/Medline and Google Scholar. The study included published literature from January 2020 to May 2022 that met the inclusion criteria. The selection of articles was conducted following the 2020 PRISMA guidelines. Results: A total of 39 articles were retrieved, of which only 18 met the inclusion criteria and were used in this study. Our review revealed that healthcare workers experienced mental health disorders such as anxiety, depression, insomnia, stress and burnout that were associated with the COVID-19 pandemic. Coping strategies such as religious practices, support from family members and colleagues and avoiding listening to social media about COVID-19 were used to minimize mental health problems. Conclusion: The COVID-19 pandemic has caused increased mental health disorders among healthcare workers in Africa. Identification of factors associated with mental health problems is cardinal in developing coping mechanisms against the psychological impact of COVID-19. Therefore, there is a need for governments to develop and implement strategies for protecting the mental health of healthcare workers during crises such as the COVID-19 pandemic

    Testing the Causality between Electricity Consumption, Energy Use and Education in Africa

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    We investigate the existence of causal relationships between energy consumption and education (enrollment in primary secondary and higher education) for a sample of 16 African countries over the period 1971-2010 (according to availability of countries' data). We use the panel-data approach of Kónya (2006), which is based on SUR systems and Wald tests with country specific bootstrap critical values. Our results show that education and energy use are strongly linked in Africa. There is bidirectional causality between primary, secondary and higher education and energy use for several countries. Moreover, electricity consumption plays a crucial role in the energy-education links in Africa.http://deepblue.lib.umich.edu/bitstream/2027.42/132984/1/wp1084.pd

    The biology and management of Tilapia mariae (Pisces:Cichlidae) as a native and invasive species: a review

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    Tilapia mariae (Cichlidae) is a tropical teleost, native to West African coastal drainages in the Gulf of Guinea and naturalised in the USA, Australia and possibly Russia. This paper reviews published information on the species from its native and introduced range to improve the effective management of fisheries as well as manage current infestations, reduce further spread and promote research on control measures outside its natural range. Within its natural range, the species is abundant and contributes to the local subsistence and artisanal fisheries; however, it is not extensively utilised for aquaculture. Outside its native range, it has proliferated, particularly in disturbed aquatic ecosystems. Tilapia mariae has several characteristics that make it successful in both its natural and introduced range. These include plasticity in reproductive behaviour (particularly parental care of the brood), a variety of feeding behaviours and dietary components, tolerance of a wide range of environmental conditions and aggressive behaviour to other fish species. Although tilapiine species are considered to be amongst the world’s worst invasive alien species, surprisingly little information is available on potential impacts of T. mariae on native species and aquatic ecosystems outside its native range
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