1,332 research outputs found
Antibiotic resistant pattern of environmental isolates of Listeria monocytogenes from Ado-Ekiti, Nigeria
Incidence of Listeria monocytogenes in cow manure, agricultural soil, and common vegetables sold in major markets in Ado-Ekiti, Nigeria was determined. Antibiotic resistant pattern of the isolates wasexamined by paper disk assay. A total of 196 environmental samples were cultured on a selective medium out of which 153 (78.1%) were positive for L. monocytogenes. Erythromycin was the mosteffective antibiotic against the isolates with the least resistance (28.1%) while chloramphenicol proved to be least effective with resistant of 52.29%. The multiple-antibiotic resistant pattern of the isolates showed augumentin/amoxicillin (33.3%), lugumentin/erythromycin (24.18%), and cotrimoxazole/ chloramphenicol/amoxicillin (28.8%) to be most prominent. The least value was observed in cloxacilin/cotrimoxazole/gentamycin with 15.34%. The modal values of the Minimum Inhibitory Concentrations(MICs) of the antibiotics to the isolates range between 4.0 and >16.0 ìg/ml. cotrimoxazole and gentamicin recorded the highest MIC compared with other antibiotics
EMPIRICAL ANALYSIS OF THE NIGERIA’S BALANCE OF PAYMENTS DISEQUILIBRIUM
This study examines the factors responsible for Nigeria’s balance of payments disequilibrium within the period 1970-2012. TheTime Series data on seven macroeconomic variables namely; current account, money supply (M2), trade openness, trade balance, inflation, real exchange rate and debt service was collected from CBN statistical bulletin. Ordinary Least Square (OLS) method was employed in analyzing the data, and the findings shows that all the variables used were responsible for balance of payments disequilibrium in Nigeria. The result further suggests that only inflation and trade balance out of the six variables have significant impact on Nigeria’s balance of payments disequilibrium. Besides, all the variables came out with their expected a priori expectations except inflation which displayed positive sign against its expected negative sign. Fiscal and monetary authorities should jointly target inflation using appropriate measures so that Nigeria’s domestic product (export) would be less expensive at the detriment of import in order to prevent current account deficit.Nigerian government should also increase its productive and exporting capacity beyond primary products and crude oilso that the persistent current account challenges would be addressed and economic growth/development would be attained
Towards a scalability model for wireless mesh networks
Zenzeleni mesh network is a wireless ad-hoc mesh network that provides voice services using public analogue telephones to the Mankosi community in the Eastern Cape
Province. We would like to improve on the network infrastructure by upgrading the mesh routers and introducing low-end smartphones onto the network; and offer both data and voice over Internet protocol services. However, before deploying resources, it is imperative to identify the maximum number of mesh nodes, clients and simultaneous voice over internet protocol calls that can be supported by the mesh network while maintaining acceptable quality of service levels. Absence of such data might lead to financial risk and time depletion when setting up an optimal network. Bolstering the claim are investigations that report drop in quality levels as network density and hop count escalate. As current investigations mostly yield capacity models to predict per-node throughput with increasing hop count, we propose experiments to devise a scalability model to quantify scalability of mesh networks in this paper. We recommend experimental implementations at simulation level in Network Simulator-3 moving on to testbeds built using WiBed, and then finally take results to the field.Telkom, Cisco, Aria Technologies, THRIP, CONFINEDepartment of HE and Training approved lis
Battery and data drain of over-the-top applications on low-end smartphones
Low-end smartphones with sub $50 price tags provide affordable device ownership to low-income populations. However, their limited capacity, when combined with the need for multimodal connectivity, raises usage concerns in rural off-grid regions. Some off-grid regions in sub-Saharan Africa provide recharge facilities using solar power and charge money for the service. Adding data bundle costs to frequent recharge costs, affordability of low-end smartphones becomes questionable in such areas. Community-controlled solar-powered wireless mesh network models with Session Initiation Protocol capability could alleviate the network usage cost conundrum and consume less power in low-end smartphones with the usage of WiFi. This paper reports on investigations that reveal usage of WiFi consumes less battery than 3G, 2G and Bluetooth. In addition, we feel that lowering recharge costs also requires battery consumption knowledge of the over-the-top applications. Using automated voice calls, this paper reports on battery and data consumption by multiple popular social media applications using one type of low-end smartphone. Data consumption was calculated with the objective of learning how to lower data bundle costs by selecting the application with least data consumption. Battery consumption due to CPU usage by the applications was also measured. Results show that WhatsApp consumes the least battery amongst instant messengers and also the least data over all apps measured. SipDroid consumes the least battery overall. Additionally, the reported experiments provide a framework for future experiments aimed at evaluating battery and data consumption by other smartphone applications.NRF, Openserve/Aria Centre of Excellenc
Candida albicans as an essential "keystone" component within polymicrobial oral biofilm models?
Background: Existing standardized biofilm assays focus on simple mono-species or bacterial-only models. Incorporating Candida albicans into complex biofilm models can offer a more appropriate and relevant polymicrobial biofilm for the development of oral health products. Aims: This study aimed to assess the importance of interkingdom interactions in polymicrobial oral biofilm systems with or without C. albicans, and test how these models respond to oral therapeutic challenges in vitro. Materials and Methods: Polymicrobial biofilms (two models containing 5 and 10 bacterial species, respectively) were created in parallel in the presence and absence of C. albicans and challenged using clinically relevant antimicrobials. The metabolic profiles and biomasses of these complex biofilms were estimated using resazurin dye and crystal violet stain, respectively. Quantitative PCR was utilized to assess compositional changes in microbial load. Additional assays, for measurements of pH and lactate, were included to monitor fluctuations in virulence “biomarkers.” Results: An increased level of metabolic activity and biomass in the presence of C. albicans was observed. Bacterial load was increased by more than a factor of 10 in the presence of C. albicans. Assays showed inclusion of C. albicans impacted the biofilm virulence profiles. C. albicans did not affect the biofilms’ responses to the short-term incubations with different treatments. Conclusions: The interkingdom biofilms described herein are structurally robust and exhibit all the hallmarks of a reproducible model. To our knowledge, these data are the first to test the hypothesis that yeasts may act as potential “keystone” components of oral biofilms. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Report on the 1st SPARC Stratospheric Network for the Assessment of Predictability (SNAP). April 24-26 April 2013, Reading, UK
Stratospheric Network for the Assessment of Predictability (SNAP), 24-26 April 2013, Reading, UKThe first SPARC Stratospheric Network for the Assessment of Predictability (SPARC-SNAP) workshop was organized in the Department of Meteorology, University of Reading, UK, from 24 to 26 April 2013. This was a joint workshop with 3rd SPARC Dynamical Variability (SPARC-DynVar) (Manzini et al., this issue) workshop 22-24 April with the 24th April as a joint day.
The joint workshop was well attended and had around 100 participants (http://www.met.reading.ac.uk/~pn904784/DynVar_SNAP_Workshop/participant.html) from 16 countries in Europe, Asia, Africa, Australia, North America, and South America (Participants figure).
In the SNAP part of workshop (including the joint day) there were two keynote address, nine invited talks, six contributory talks and 24 posters.The authors are grateful to the Natural Environment Research Council and WCRP-SPARC for their
financial support
Evaluating energy consumption on low-end smartphones
The relationship between battery consumption in
smartphones and the usage statistics of a phone is direct. Modern
smartphones, even low-end, are equipped with multiple wireless
technologies, e.g. GSM, 3G, WiFi and Bluetooth. Each of these
technologies has a different energy consumption profile. A
wireless mesh project in the Mankosi community in rural South
Africa is about to introduce low-end smartphones onto the
network. The mesh network is powered with solar-charged
batteries because the community at present does not have
electricity. Local residents also use these batteries to recharge cell
phones at a nominal cost. Introduction of smartphones will
increase the recharge frequency as phone usage will increase;
thus draining a phone battery more quickly, as well as escalate
recharge costs. Thus, the smartphones must be chosen and used
effectively in order for batteries to last longer. Related work
identifies WiFi wireless technology as the most battery efficient
way of transfer when compared to GSM, 3G and Bluetooth. This
research proposes experiments to further investigate energy
efficiency of WiFi in low-end smartphones that we intend to use
for local and breakout voice over Internet protocol (VoIP) calls
and data services, on a rural wireless mesh network
Epidemiology of methicillin-resistant Staphylococcus aureus among hospitalized patients and apparently healthy individuals in Ekiti and Ondo States, Nigeria.
The incidence of methicillin-resistant Staphylococcus aureus (MRSA) in hospitalized patients and apparently healthy individuals was investigated in two western states of Nigeria using standard microbiological methods. One thousand and two hundred non-repeat isolates of S. aureus were recovered from the subjects. At varying degrees the isolates were resistant to cotrimoxazole (54.8%), augmentin (36.9%), pefloxacin (35.9%), gentamycin (28.3%), erythromycin (24.9%), vancomycin (10.3%), ofloxacin (5.2%) and ciprofloxacin (0.3%). One hundred and fifty six (13.0%) were resistant to methicillin out of which 4.8% and 8.2% were from healthy individuals and patients respectively. There was no correlation between prevalence of MRSA and age or sex (p < 0.05). There was no correlation between the antibiotic resistance pattern in MRSA from healthy volunteers and patients (P < 0.05). A total of 9.0%, 12.2% and 21.2% of the MRSA were resistant to 3, 4 and 5 antibiotics respectively. Antibacterial activities of five biocides examined using agar diffusion method showed that 38.5%, 53.2%, 59.6%, 61.5% and 71.8% of the MRSA were not inhibited by Izal®, Morigad®, Septol®, Dettol® and Purit® respectively, at concentrations two times higher than the in-use concentration. This finding points to the fact that MRSA occurs among patients and in the communities in the study areas, which calls for a public health concern and awareness
Impact of Vitamin D Supplementation on Arterial Vasomotion, Stiffness and Endothelial Biomarkers in Chronic Kidney Disease Patients
Background: Cardiovascular events are frequent and vascular endothelial function is abnormal in patients with chronic
kidney disease (CKD). We demonstrated endothelial dysfunction with vitamin D deficiency in CKD patients; however the impact of cholecalciferol supplementation on vascular stiffness and vasomotor function, endothelial and bone biomarkers in CKD patients with low 25-hydroxy vitamin D [25(OH)D] is unknown, which this study investigated.
Methods: We assessed non-diabetic patients with CKD stage 3/4, age 17–80 years and serum 25(OH)D ,75 nmol/L. Brachial
artery Flow Mediated Dilation (FMD), Pulse Wave Velocity (PWV), Augmentation Index (AI) and circulating blood biomarkers were evaluated at baseline and at 16 weeks. Oral 300,000 units cholecalciferol was administered at baseline and 8-weeks.
Results: Clinical characteristics of 26 patients were: age 50614 (mean61SD) years, eGFR 41611 ml/min/1.73 m2, males
73%, dyslipidaemia 36%, smokers 23% and hypertensives 87%. At 16-week serum 25(OH)D and calcium increased (43616
to 84629 nmol/L, p,0.001 and 2.3760.09 to 2.4260.09 mmol/L; p = 0.004, respectively) and parathyroid hormone
decreased (10.868.6 to 7.464.4; p = 0.001). FMD improved from 3.163.3% to 6.163.7%, p = 0.001. Endothelial biomarker
concentrations decreased: E-Selectin from 566662123 to 525662058 pg/mL; p = 0.032, ICAM-1, 3.4560.01 to
3.1061.04 ng/mL; p = 0.038 and VCAM-1, 54633 to 42633 ng/mL; p = 0.006. eGFR, BP, PWV, AI, hsCRP, von Willebrand
factor and Fibroblast Growth Factor-23, remained unchanged.
Conclusion: This study demonstrates for the first time improvement of endothelial vasomotor and secretory functions with vitamin D in CKD patients without significant adverse effects on arterial stiffness, serum calcium or FGF-23.
Trial Registration: ClinicalTrials.gov NCT0200571
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