36 research outputs found

    Foreign body in the Nasopharynx mimicking an obstructive adenoid

    Get PDF
    Foreign body in the nasopharynx is not a day-to-day experience in any Ear, Nose and Throat clinic as opposed to foreign bodies in the ear or nose. We present a case of food lodgment (piece of yam-dascorial) in the nasopharynx of a 2-year old male child. This was ignorantly dislodged into his nasopharynx by finger sweep procedure by the mother when the child chocked during feeding.Jos Journal of Medicine, Volume 7 No.

    Evaluation of standard diagnostic rapid test kits for malaria diagnosis among HIV patients in Kano, Nigeria

    Get PDF
    Background: Malaria diagnosis among HIV-positive patients is uncommon in Nigeria despite the high burden of both diseases. Objectives: We evaluated the performance of a malaria rapid diagnostic test (MRDT) against blood smear microscopy (BSM) among HIV-positive patients in relation to anti-retroviral treatment (ART) status, CD4+ count, fever, cotrimoxazole prophylaxis and malaria density count. Method: A cross-sectional study involving 1521 consenting randomly selected HIV-positive adults attending two ART clinics in Kano, Nigeria, between June 2015 and May 2016. Venous blood samples were collected for testing with MRDT, BSM, and CD4+ T cells count by cytometry. Biodata and other clinical details were extracted from patient folders into an Excel file, cleaned, validated, and exported for analysis into SPSS version 23.0. Sensitivity, specificity, predictive values of MRDT were compared with BSM with a 95% confidence interval. Results: Malaria parasites were detected in 25.4% of enrollees by BSM and 16.4% by MRDT. Overall sensitivity of MRDT was 58% and specificity was 97%. Cotrimoxazole prophylaxis and fever status did not affect MRDT sensitivity and specificity. Unexpectedly, the sensitivity was highest at parasite density count of less than 500 cells/µL. At CD4+ T cells count over 500 cells/µL the sensitivity was higher (62.4%) compared to 56% at less than 500 cells/µL. In the non-ART group sensitivity was higher (65%) compared to those on ART (56%) but the specificity was similar. All differences were significant for all variables (p < 0.05). Conclusion: Although the MRDT specificity was good, the sensitivity was poor, requiring further evaluation for use in malaria diagnosis among HIV-malaria co-infected persons in these settings

    Path Loss Predictions in the VHF and UHF Bands Within Urban Environments: Experimental Investigation of Empirical, Heuristics and Geospatial Models

    Full text link
    (c) 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.[EN] Deep knowledge of how radio waves behave in a practical wireless channel is required for effective planning and deployment of radio access networks in urban environments. Empirical propagation models are popular for their simplicity, but they are prone to introduce high prediction errors. Different heuristic methods and geospatial approaches have been developed to further reduce path loss prediction error. However, the efficacy of these new techniques in built-up areas should be experimentally verified. In this paper, the efficiencies of empirical, heuristic, and geospatial methods for signal fading predictions in the very high frequency (VHF) and ultra-high frequency (UHF) bands in typical urban environments are evaluated and analyzed. Electromagnetic field strength measurements are performed at different test locations within four selected cities in Nigeria. The data collected are used to develop path loss models based on artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and Kriging techniques. The prediction results of the developed models are compared with those of selected empirical models and field measured data. Apart from Egli and ECC-33, the root mean squared error (RMSE) produced by all other models under investigation are considered acceptable. Specifically, the ANN and ANFIS models yielded the lowest prediction errors. However, the empirical models have the lowest standard deviation errors across all the bands. The findings of this study will help radio network engineers to achieve efficient radio coverage estimation; determine the optimal base station location; make a proper frequency allocation; select the most suitable antenna; and perform interference feasibility studies.This work was supported jointly by the funding received from IoT-Enabled Smart and Connected Communities (SmartCU) Research Cluster and the Center for Research, Innovation and Discovery (CUCRID) of Covenant University, Ota, Nigeria.Faruk, N.; Popoola, SI.; Surajudeen-Bakinde, NT.; Oloyede, AA.; Abdulkarim, A.; Olawoyin, LA.; Ali, M.... (2019). Path Loss Predictions in the VHF and UHF Bands Within Urban Environments: Experimental Investigation of Empirical, Heuristics and Geospatial Models. IEEE Access. 7:77293-77307. https://doi.org/10.1109/ACCESS.2019.2921411S7729377307

    Large-scale radio propagation path loss measurements and predictions in the VHF and UHF bands

    Get PDF
    For decades now, a lot of radio wave path loss propagation models have been developed for predictions across different environmental terrains. Amongst these models, empirical models are practically the most popular due to their ease of application. However, their prediction accuracies are not as high as required. Therefore, extensive path loss measurement data are needed to develop novel measurement-oriented path loss models with suitable correction factors for varied frequency, capturing both local terrain and clutter information, this have been found to be relatively expensive. In this paper, a large-scale radio propagation path loss measurement campaign was conducted across the VHF and UHF frequencies. A multi-transmitter propagation set-up was employed to measure the strengths of radio signals from seven broadcasting transmitters (operating at 89.30, 103.5, 203.25, 479.25, 615.25, 559.25 and 695.25 MHz respectively) at various locations covering a distance of 145.5 km within Nigerian urban environments. The measurement procedure deployed ensured that the data obtained strictly reflect the shadowing effects on radio signal propagation by filtering out the small-scale fading components. The paper also, examines the feasibilities of applying Kriging method to predict distanced-based path losses in the VHF and UHF bands. This method was introduced to minimize the cost of measurements, analysis and predictions of path losses in built-up propagation environment

    Cx43/miR21/HMGB1/RANKL pathway in osteocytes

    Get PDF
    Skeletal aging results in apoptosis of osteocytes, cells embedded in bone that control the generation/function of bone forming and resorbing cells. Aging also decreases connexin43 (Cx43) expression in bone; and osteocytic Cx43 deletion partially mimics the skeletal phenotype of old mice. Particularly, aging and Cx43 deletion increase osteocyte apoptosis, and osteoclast number and bone resorption on endocortical bone surfaces. We examined herein the molecular signaling events responsible for osteocyte apoptosis and osteoclast recruitment triggered by aging and Cx43 deficiency. Cx43-silenced MLO-Y4 osteocytic (Cx43def) cells undergo spontaneous cell death in culture through caspase-3 activation and exhibit increased levels of apoptosis-related genes, and only transfection of Cx43 constructs able to form gap junction channels reverses Cx43def cell death. Cx43def cells and bones from old mice exhibit reduced levels of the pro-survival microRNA miR21 and, consistently, increased levels of the miR21 target phosphatase and tensin homolog (PTEN) and reduced phosphorylated Akt, whereas PTEN inhibition reduces Cx43def cell apoptosis. miR21 reduction is sufficient to induce apoptosis of Cx43-expressing cells and miR21 deletion in miR21fl/fl bones increases apoptosis-related gene expression, whereas a miR21 mimic prevents Cx43def cell apoptosis, demonstrating that miR21 lies downstream of Cx43. Cx43def cells release more osteoclastogenic cytokines [receptor activator of NFκB ligand (RANKL)/high-mobility group box-1 (HMGB1)], and caspase-3 inhibition prevents RANKL/HMGB1 release and the increased osteoclastogenesis induced by conditioned media from Cx43def cells, which is blocked by antagonizing HMGB1-RAGE interaction. These findings identify a novel Cx43/miR21/HMGB1/RANKL pathway involved in preventing osteocyte apoptosis that also controls osteoclast formation/recruitment and is impaired with aging

    Incidence of rotavirus infection in children with gastroenteritis attending Jos university teaching hospital, Nigeria

    Get PDF
    This study was conducted to determine the incidence of rotavirus infection in children with gastroenteritis attending Jos university teaching hospital, Plateau State. A total of 160 children with acute diarrhea were selected by random sampling. Stool samples were obtained and assayed for rotavirus antigens by enzyme linked immunosorbent assay technique using standard diagnostic BIOLINE Rotavirus kit. Demographic data of parents were also recorded. Rotavirus were detected in faeces of 22(13.8%) children with acute diarrhea, 90.9% of positive cases of rotavirus gastroenteritis were under 2 years of age with highest prevalence in children 7-12 months of age. Males excreted rotavirus at a significant higher rate than females (P < 0.05). Rotavirus excretion was highest when all three symptoms (diarrhea, fever and vomiting) occurred in the same child (7.5%) and lower when 2 symptoms occurred together (diarrhea and vomiting) with 3.8%, diarrhea and fever with 1.3% and lowest when diarrhea occurred alone with 1.3%. Playing with toys, attending day care, distance of source of water from toilet, eating of food not requiring cooking and playing with other children may serve as predisposing factors of rotavirus disease in these children

    Sero-survey of rubella IgM antibodies among children in Jos, Nigeria

    Get PDF
    Sero-survey of rubella IgM antibodies was carried out among children aged 0-10 years in Jos, Nigeria. Blood samples were collected from the subjects and sera extracted. Of the 93(100%) assayed for the rubella IgM antibody, 42(45.2%) were seropositive for rubella IgM antibody while 51(54.8%) were seronegative. A breakdown of the seropositive subjects reveals that 14(15.1%) of the infected children were males while 28(30.1%) were females. Those subjects within the age groups of 1-2, 3-4 and 5-6 years had the highest prevalence of 8(8.6%) followed by those within the age groups of 7-8, 9-10 years with 7(7.5%). Blood transfusion as a risk factor did not show any significant influence on the status of the subjects. The demographic data of the mothers of the subjects were also linked with the seropositivity of the children

    Thermal energy processes in direct steam generation solar systems : boiling, condensation and energy storage

    Get PDF
    Direct steam generation coupled is a promising solar-energy technology, which can reduce the growing dependency on fossil fuels. It has the potential to impact the power-generation sector as well as industrial sectors where significant quantities of process steam are required. Compared to conventional concentrated solar power systems, which use synthetic oils or molten salts as the heat transfer fluid, direct steam generation offers an opportunity to achieve higher steam temperatures in the Rankine power cycle and to reduce parasitic losses, thereby enabling improved thermal efficiencies. However, its practical implementation is associated with non-trivial challenges, which need to be addressed before such systems can become more economically competitive. Specifically, important thermal-energy processes take place during flow boiling, flow condensation and thermal-energy storage, which are highly complex, multi-scale and multi-physics in nature, and which involve phase-change, unsteady and turbulent multiphase flows in the presence of conjugate heat transfer. This paper reviews our current understanding and ability to predict these processes, and the knowledge that has been gained from experimental and computational efforts in the literature. In addition to conventional steam-Rankine cycles, the possibility of implementing organic Rankine cycle power blocks, which are relevant to lower operating temperature conditions, are also considered. This expands the focus beyond water as the working fluid, to include refrigerants also. In general, significant progress has been achieved in this space, yet there remain challenges in our capability to design and to operate high-performance and low-cost systems effectively and with confidence. Of interest are the flow regimes, heat transfer coefficients and pressure drops that are experienced during the thermal processes present in direct steam generation systems, including those occurring in the solar collectors, evaporators, condensers and relevant energy storage schemes during thermal charging and discharging. A brief overview of some energy storage options are also presented to motivate the inclusion of thermal energy storage into direct steam generation systems
    corecore