158 research outputs found
OFDM-PWM scheme for visible light communications
In this paper, we propose an improved hybrid optical orthogonal frequency division multiplexing (O-OFDM) and pulse-width modulation (PWM) scheme for visible light communications. In this scheme, a bipolar O-OFDM signal is converted into a PWM format where the leading and trailing edges convey the frame synchronization and modulated information, respectively. The proposed scheme is insensitive to the non-linearity of the light emitting diode (LED) as LEDs are switched ‘on’ and ‘off’ between two points. Therefore, the tight requirement on the high peak-to-average-power-ratio (PAPR) in O-OFDM is no longer a major issue. The simulation and experimental results demonstrate that the proposed scheme offers an improved bit error rate performance compared to the traditional asymmetrically clipped O-OFDM (ACO-OFDM)
CONSUMPTION PATTERN OF MAIZE BASED DISHES IN FOUR AGRO-ECOLOGICAL ZONES OF NIGERIA
The global picture had dramatically changed the lifestyles of Nigerian citizens pushing them into various fast-eating cultures with more instant and tasty meals, and the attendant gradual relegation of our traditional rich eating cultures. Studies were carried in eight Local Government Areas of Nigeria from the four Agro-Ecological Zones (AEZs) namely: moist savanna (Oyo State), humid forest (Lagos State), mid-altitude (Abuja) and dry Savanna (Kaduna State). Stratified multistage sampling technique with structured questionnaires from 1641 respondents and focus group discussions (FGDs) were employed to identify the maize-based dishes consumed and determined the frequency of consumption. The demographic characteristics revealed that 54.8% of the respondents were male. Residents in the rural area were more (56.8%) and majority of the respondents were between the ages of 26-45 years (67.6%), while more Christians (57.88%) participated in the study than any other religion. Results showed that thirty–two maize-based dishes were identified, of which ten were frequently consumed. Ogi was the most popular maize-based dish (73.5%) consumed in the AEZs while corn pudding was the least consumed (28.5%). There were significant differences (p<0.05) in all the sensory attributes measured. The low consumption of majority of the maize-based dishes raises concern for the current campaign on mobilizing local biodiversity which has been reported to be one of the food based intervention strategies for solving nutrition problems among population groups
The feasibility of epidemiological research on prostate cancer in African men in Ibadan, Nigeria
Evaluation of Efflux-Mediated Resistance and Biofilm Formation in Virulent Pseudomonas aeruginosa Associated with Healthcare Infections
Pseudomonas aeruginosa is a significant pathogen identified with healthcare-associated
infections. The present study evaluates the role of biofilm and efflux pump activities in influencing
high-level resistance in virulent P. aeruginosa strains in clinical infection. Phenotypic resistance
in biotyped Pseudomonas aeruginosa (n = 147) from diagnosed disease conditions was classified
based on multiple antibiotic resistance (MAR) indices and analysed with logistic regression
for risk factors. Efflux pump activity, biofilm formation, and virulence factors were analysed for
optimal association in Pseudomonas infection using receiver operation characteristics (ROC). Agespecificity
(OR [CI] = 0.986 [0.946–1.027]), gender (OR [CI] = 1.44 [0.211–9.827]) and infection sources
(OR [CI] = 0.860 [0.438–1.688]) were risk variables for multidrug resistance (MDR)-P. aeruginosa infection
(p < 0.05). Biofilm formers caused 48.2% and 18.5% otorrhea and wound infections (95%
CI = 0.820–1.032; p = 0.001) respectively and more than 30% multidrug resistance (MDR) strains
demonstrated high-level efflux pump activity (95% CI = 0.762–1.016; p = 0.001), protease (95% CI =
0.112–0.480; p = 0.003), lipase (95% CI = 0.143–0.523; p = 0.001), and hemolysin (95% CI = 1.109–1.780;
p = 0.001). Resistance relatedness of more than 80% and 60% to cell wall biosynthesis inhibitors
(ceftazidime, ceffproxil, augumentin, ampicillin) and, DNA translational and transcriptional inhibitors
(gentamicin, ciprofloxacin, ofloxacin, nitrofurantoin) were observed (p < 0.05). Strong efflux
correlation (r = 0.85, p = 0.034) with MDR strains, with high predictive performances in efflux pump
activity (ROC-AUC 0.78), biofilm formation (ROC-AUC 0.520), and virulence hierarchical-clustering.
Combine activities of the expressed efflux pump and biofilm formation in MDR-P. aeruginosa pose
risk to clinical management and infection control
Descriptive epidemiology of cholera outbreak in Nigeria, January-November, 2018: implications for the global roadmap strategy
Background: The cholera outbreak in 2018 in Nigeria reaffirms its public health threat to the country. Evidence on the
current epidemiology of cholera required for the design and implementation of appropriate interventions towards
attaining the global roadmap strategic goals for cholera elimination however seems lacking. Thus, this study aimed at
addressing this gap by describing the epidemiology of the 2018 cholera outbreak in Nigeria.
Methods: This was a retrospective analysis of surveillance data collected between January 1st and November 19th,
2018. A cholera case was defined as an individual aged 2 years or older presenting with acute watery diarrhoea and
severe dehydration or dying from acute watery diarrhoea. Descriptive analyses were performed and presented with
respect to person, time and place using appropriate statistics.
Results: There were 43,996 cholera cases and 836 cholera deaths across 20 states in Nigeria during the outbreak
period, with an attack rate (AR) of 127.43/100,000 population and a case fatality rate (CFR) of 1.90%. Individuals aged
15 years or older (47.76%) were the most affected age group, but the proportion of affected males and females was
about the same (49.00 and 51.00% respectively). The outbreak was characterised by four distinct epidemic waves, with
higher number of deaths recorded in the third and fourth waves. States from the north-west and north-east regions of
the country recorded the highest ARs while those from the north-central recorded the highest CFRs.
Conclusion: The severity and wide-geographical distribution of cholera cases and deaths during the 2018 outbreak are
indicative of an elevated burden, which was more notable in the northern region of the country. Overall, the findings
reaffirm the strategic role of a multi-sectoral approach in the design and implementation of public health interventions
aimed at preventing and controlling cholera in Nigeri
Structural and properties of Zn-Al2O3-SiC nano-composite coatings by direct electrolytic process
In this paper, Zn-SiC and Zn-Al2O3-SiC composite
coating were fabricated by electrodeposition technique from
sulfates bath. The resulting composite coating was carried out
by adding Al2O3/SiC particulate to a zinc-containing bath.
The properties of the composite coating were investigated
by SEM equipped with EDS, XRD, and AFM. The electrochemical
behavior of the coating alloy was evaluated in
3.65 % NaCl with linear polarization technique and mechanically
examined by durascan microhardness tester. The morphology
of the thermal treated coatings at 400 °C in 6 h was
viewed with high optical microscope (OPM). The results
show hardness, thermal stability, and anti-corrosion properties
of Zn-Al2O3-SiC were improved significantly as against Zn-
SiC coating matrixes. This was attributed to dispersive
strengthening effect and grain induced effort of Al2O3/SiC
particulate. The decrease in corrosion and thermal stability at
15 g/L of SiC concentration may be as a result of agglomeration
and the superimposed particle in the plating bath
The Impact of Task Performance Fraud Risk Assessment on Forensic Skills and Mindsets: A Conceptual Model
Utilization of nanochitosan in the sterilization of ponds and water treatment for aquaculture
Water pollution constitutes the leading cause of infant mortality,
neonatal deformities, and shrinkage of man’s average life expectancy.
Pollutants come from point and nonpoint sources; and water pollution
arises from the discharge of wastewater containing undesirable
impurities used for domestic, agricultural, and industrial purposes.
More so, high nutrient and wastewater runoffs from fish production
systems contribute to the fouling and eutrophication of recipient water
bodies. Hence, aquaculture which is inextricably linked to the natural
environment is challenged by the dearth of appropriate water quantity
and quality, militating against fish, and fishery production.
Nanochitosans as polysaccharides produced by the alkalescent
deacetylation of chitin, comprise a series of 2-deoxy-2 (acetylamino)
glucose linked by ß-(1-4) glycosidic linkages. They are naturally
formed from the deacetylation of shellfish shells and exoskeletons of
aquatic arthropods and crustaceans. The unique attributes of chitin
confer a wide range of biotechnological applications on the polymer,
observed in flocculation as a wastewater treatment and purification
route initiated by chitosan. This chapter highlights nanochitosan
properties of aquaculture relevance; and elucidates the purification
potentials of nanochitosan, compared to inorganic coagulants and
organic polymeric flocculants. Effects of chitosan on contaminants and
microorganisms, as well as applications in fish pathogens detection,
fish disease diagnosis, and control are discussed
Nanochitosan derived from marine bacteria
Nanochitosans are polysaccharides produced by the alkalescent
deacetylation of chitin and comprise a series of 2-deoxy-2
(acetylamino) glucose linked by ß-(1-4) glycosidic linkages. These are
naturally formed from the deacetylation of shellfish shells and the
exoskeleton of aquatic arthropods and crustaceans. Reports of
chitosan production from unicellular marine bacteria inhabiting the
sea, and possessing distinct animal- and plant-like characteristics
abound. This capacity to synthesize chitosan from chitin arises from
response to stress under extreme environmental conditions, as a
means of survival. Consequently, the microencapsulation of these
nanocarriers results in new and improved chitosan nanoparticles,
nanochitosan. This nontoxic bioactive material which can serve as an
antibacterial agent, gene delivery vector as well as carrier for protein
and drug release as compared with chitosan, is limited by its
nonspecific molecular weight and higher composition of deacetylated
chitin. This chapter highlights the biology and diversity of
nanochitosan-producing marine bacteria, including the factors
influencing their activities, survival, and distribution. More so, the
applications of marine bacterial nanochitosans in transfection and
gene delivery; wound healing and drug delivery; feed supplement
development and antimicrobial activity are discussed
Assessment of the Performance of Osmotically Driven Polymeric Membrane Processes
The universal water scarceness and the extensive ordeals with energy cost in
conjunction with the undesirable ecological effects have advanced the
improvement of novel osmotically driven membrane processes. Membrane
processes which are osmotically driven are developing type of membrane
separation procedures that apply concentrated brines to separate liquid
streams. They are adaptable in various applications; hence, allow them to be
an attractive substitute for drug release, wastewater treatment and the
production and recovery of energy. Although, internal concentration
polarization (ICP) occurs in membrane practises which are osmotically driven
as a consequence of hindered diffusion of solute in a porous stratum, their
interest has even increased. Here we review two natural membrane processes
that are osmotically driven; Forward osmosis (FO) and Pressure retarded
osmosis (PRO). Thus, the major points are as follows: 1) it was highlighted in
this review, that the major developments in FO process, important for the
process efficiency is to choose a suitable membrane and draw solution. 2) The
recent evaluation, understanding and optimizing the activities of fouling
throughout the osmotic dilution of seawater employing FO was discussed. 3)
Recent advancements of FO in the application of food processing was
reviewed. 4) It was highlighted that the main concept of PRO for power
generation is the energy of mixing that offers great assessment of the nonexpansion
work which could be generated from mixing; nonetheless, the
development of effective membranes with appropriate arrangement and
performance is needed for the advancement of PRO process for power
generation. 5) One major challenge of osmotically driven membrane
processes, most recent developments and model development to predict their
performances were discussed
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