Heavy metal status in muscles of dry Trachinocphalus myops fish from Orita-merin market in Ibadan metropolis South-West, Nigeria

This paper determined the levels of chromium (Cr), cadmium (Cd), lead (Pb), copper (Cu) and zinc (Zn) in muscles of dry Trachinocephalus myops from Orita-merin market in Ibadan metropolis south-west of Nigeria. Samples were randomly purchased and were digested in concentrated nitric acid and analyzed by atomic absorption spectrophotometry. Zinc had the highest concentration of 124.9±86.7 mg/kg dry weight of the samples, while cadmium had the lowest concentration of 2.5±1.6 mg/kg dry weight of the samples. The concentration of chromium and copper were 5.6±3.5 mg/kg and 5.2±3.1 mg/kg respectively while lead was observed in only one of the samples with a concentration of 3.7 mg/kg. The obtained result revealed that Cr, Cd, Zn and Pb were above the permissible level set by  the Food and Agricultural Organization (FAO) maximum limit in food which is Pb (2 ppm), Cd (0.5 ppm), Zn(1 ppm), and Cr (0.05 ppm which may be an indication of possible health risk when exposed consistently over a long time to this type of fish. Keywords: Heavy metals, Bioaccumulation, Ecosystem, Pollutant, Exposur

Predictors and Consequences of Anaemia Among Antiretroviral-Naïve HIV-Infected and HIV-Uninfected Children in Tanzania.

Predictors and consequences of childhood anaemia in settings with high HIV prevalence are not well known. The aims of the present study were to identify maternal and child predictors of anaemia among children born to HIV-infected women and to study the association between childhood anaemia and mortality. Prospective cohort study. Maternal characteristics during pregnancy and Hb measurements at 3-month intervals from birth were available for children. Information was also collected on malaria and HIV infection in the children, who were followed up for survival status until 24 months after birth. Dar es Salaam, Tanzania. The study sample consisted of 829 children born to HIV-positive women. Advanced maternal clinical HIV disease (relative risk (RR) for stage > or =2 v. stage 1: 1.31, 95 % CI 1.14, 1.51) and low CD4 cell counts during pregnancy (RR for <350 cells/mm3 v. > or =350 cells/mm3: 1.58, 95 % CI 1.05, 2.37) were associated with increased risk of anaemia among children. Birth weight <2500 g, preterm birth (<34 weeks), malaria parasitaemia and HIV infection in the children also increased the risk of anaemia. Fe-deficiency anaemia in children was an independent predictor of mortality in the first two years of life (hazard ratio 1.99, 95 % CI 1.06, 3.72). Comprehensive care including highly active antiretroviral therapy to eligible HIV-infected women during pregnancy could reduce the burden of anaemia in children. Programmes for the prevention of mother-to-child transmission of HIV and antimalarial treatment to children could improve child survival in settings with high HIV prevalence

Pre-concentration of toxic metals using electrospun amino-functionalized nylon-6 nanofibre sorbent

This paper presents a new approach for pre-concentrating toxic metals (As, Cd, Ni and Pb) in aqueous environments using an amino-functionalized electrospun nanofibre sorbent. The sorbent, composed of nanofibres of average diameter 80 ± 10 nm and specific surface area of 58m2 g–1, exhibited fast adsorption kinetics ( adsorption (0.34)>HNO3+H2O2 (0.23) digestion.Asimilar trend was observed for Ni in river water as well as Ni andCdin tap water samples. Pb ions in the river water samples were pre-concentrated slightly better using the two digestion methods pre-concentration factors ~22) compared to adsorption method (pre-concentration factor ~21). The use of the electrospun amino-functionalized nanofibre sorbent presentsanefficientand cost-effective alternative for pre-concentration of toxic metals inaqueousenvironments

Pre-concentration of Toxic Metals using Electrospun Amino-functionalized Nylon-6 Nanofibre Sorbent

This paper presents a new approach for pre-concentrating toxic metals (As, Cd, Ni and Pb) in aqueous environments using an amino-functionalized electrospun nanofibre sorbent. The sorbent, composed of nanofibres of average diameter 80 ± 10 nm and specific surface area of 58 m2 g–1, exhibited fast adsorption kinetics (&lt;20 min) for As, Cd, Ni and Pb. The optimal pH for the uptake of As, Cd, Ni and Pb were 5.5, 6.0, 6.5 and 11, respectively. The adsorption process best fitted the Freundlich isothermand followed the first-order kinetics. The highest pre-concentration achieved using the sorbent was 41.99 (Ni in treated wastewater). The capacity of the sorbent to pre-concentrate the toxic metals was compared with those of aqua regia and HNO3 + H2O2 digestions. The pre-concentration factors achieved for Cd in river water samples can be ranked as aqua regia digestion (0.73) &gt; adsorption(0.34) &gt; HNO3 + H2O2 (0.23) digestion. A similar trend was observed for Ni in river water as well as Ni and Cd in tap water samples. Pb ions in the river water samples were pre-concentrated slightly better using the two digestion methods (pre-concentration factors ~22) compared to adsorption method (pre-concentration factor ~21). The use of the electrospun amino-functionalized nanofibre sorbent presents an efficient and cost-effective alternative for pre-concentration of toxic metals in aqueous environments.Keywords: Electrospinning, pre-concentration, heavy metals, nylon-

Cesarean delivery in Nigeria: Prevalence and associated factors -a population-based cross-sectional study

Objective To investigate the prevalence and factors associated with caesarean delivery in Nigeria. Design This is a secondary analysis of the nationally representative 2013 Nigeria Demographic and Health Survey (NDHS) data. We carried out frequency tabulation, χ2 test, simple logistic regression and multivariable binary logistic regression analyses to achieve the study objective. Setting Nigeria. Participants A total of 31 171 most recent live deliveries for women aged 15–49 years (mother–child pair) in the 5 years preceding the 2013 NDHS was included in this study. Outcome measure Caesarean mode of delivery. Results The prevalence of caesarean section (CS) was 2.1% (95% CI 1.8 to 2.3) in Nigeria. At the region level, the South-West had the highest prevalence of 4.7%. Factors associated with increased odds of CS were urban residence (adjusted OR (AOR): 1.51, 95% CI 1.15 to 1.97), maternal age ≥ 35 years (AOR: 2.12, 95% CI 1.08 to 4.11), large birth size (AOR: 1.39, 95% CI 1.10 to 1.74) and multiple births (AOR: 4.96, 95% CI 2.84 to 8.62). Greater odds of CS were equally associated with maternal obesity (AOR: 3.16, 95% CI 2.30 to 4.32), Christianity (AOR: 2.06, 95% CI 1.58 to 2.68), birth order of one (AOR: 3.86, 95% CI 2.66 to 5.56), husband’s secondary/higher education level (AOR: 2.07, 95% CI 1.29 to 3.33), health insurance coverage (AOR: 2.01, 95% CI 1.37 to 2.95) and ≥ 4 antenatal visits (AOR: 2.84, 95% CI 1.56 to 5.17). Conclusions The prevalence of CS was low, indicating unmet needs in the use of caesarean delivery in Nigeria. Rural–urban, regional and socioeconomic differences were observed, suggesting inequitable access to the obstetric surgery. Intervention efforts need to prioritise women living in rural areas, the North-East and the North-West regions, as well as women of the Islamic faith

Numerical and experimental assessment of the modal curvature method for damage detection in plate structures

This paper is concerned with the use of numerically obtained modal curvatures for damage detection in both isotropic and composite laminated plates. Numerical simulations are carried out by using COMSOL Multiphysics as FEM solver of the governing equations, in which a Mindlin-Reissner plate model is assumed and defects are introduced as localized smoothed variations of the baseline (healthy) configuration. Experiments are also performed on steel and aluminum plates using scanning laser vibrometry. This study confirms that the central difference method greatly amplifies the measurement errors and its application leads to ineffective predictions for damage detection, even after denoising. As a consequence, different numerical techniques should be explored to allow the use of numerically obtained modal curvatures for structural health monitoring. Herein, the Savitzky-Golay filter (or least-square smoothing filter) is considered for the numerical differentiation of noisy data

Numerical and experimental assessment of the modal curvature method for damage detection in plate structures

Use of modal curvatures obtained from modal displacement data for damage detection in isotropic and composite laminated plates is addressed through numerical examples and experimental tests. Numerical simulations are carried out employing COMSOL Multiphysics as finite element solver of the equations governing the Mindlin-Reissner plate model. Damages are introduced as localized non-smooth variations of the bending stiffness of the baseline (healthy) configuration. Experiments are also performed on steel and aluminum plates using scanning laser vibrometry. The obtained results confirm that use of the central difference method to compute modal curvatures greatly amplifies the measurement errors and its application leads to unreliable predictions for damage detection, even after denoising. Therefore, specialized ad hoc numerical techniques must be suitably implemented to enable structural health monitoring via modal curvature changes. In this study, the Savitzky-Golay filter (also referred to as least-square smoothing filter) is considered for the numerical differentiation of noisy data. Numerical and experimental results show that this filter is effective for the reliable computation of modal curvature changes in plate structures due to defects and/or damages

POWER SYSTEMS OPERATION IMPROVEMENT CONSIDERING LOSS MINIMIZATION AND VOLTAGE STABILITY ENHANCEMENT

The challenge of energy and power losses during electrical energy transmission from generation plants to users is a major problem that cannot be over-emphasized. These Losses are inevitable because they are inherent in the conduction of electrical energy through physical means but can be minimized. This paper presents a VSC-PSO method for optimizing the power system operation by simultaneously minimizing the loss and enhancing the voltage stability which are the objective functions. The optimal power flow (OPF) was performed on IEEE 30-bus system with Newton Raphson algorithm implemented in MATLAB simulation software. The simulation results showed that the VSC-PSO approach performed more excellently with concurrent consideration of line loss reduction and voltage stability improvement when compared with other methods in literatur

Reliability of Some Clinical Parameters for Field Diagnosis of African Animal Trypanosomosis in Cattle

Presumptive and inaccurate diagnosis of cattle trypanosomosis among field veterinarians has led to misuse of trypanocides, development of drug resistance, toxicities and huge economic losses. This study assessed the reliability, specificity and sensitivity of some identified trypanosomosis associated signalments (anaemia using FAMACHA® guide, body condition score (BCS), superficial lymph nodes enlargement and jugular pulsation) as field diagnostic parameters. Blood and faecal samples were collected from 273 subjectively selected cattle for the determination of packed cell volume (PCV) and screening for trypanosome, and for helminth egg using McMaster technique, respectively. Data obtained from assessment of packed cell volume based on BCS, FAMANCHA score, superficial lymph nodes enlargement and jugular pulsation were analyzed using descriptive statistics and Chi square, while comparison of data using independent student ttest and one-way ANOVA was similarly conducted. Of the screened cattle, 16.5% (45/273) were positive for trypanosome. Single infection due to Trypanosoma spp. was found in 13.5% (37/273) cattle, while 2.9% (8/273) had trypanosome concurrently with Babesia spp. or helminth infections. The prevalence of Trypanosoma infection was higher in animals with mild or moderately pale mucous membrane, slight emaciation, palpable superficial lymph nodes and pulsating jugular vein. The mean PCV of Trypanosoma infected cattle (27.65±0.056) was lower than in non-infected cattle (31.30±0.36) (p&lt;0.05). Based on the jugular pulsation status, enlargement of the superficial lymph nodes, trypanosomosis state and Famancha category, there was no significant (p&lt;0.05) variation in the PCV of the examined cattle. A negative and low correlation (r = -0.054) existed between BCS and FAMACHA® anaemia score. Each of the clinical diagnostic parameters showed poor sensitivity when employed separately, but the sensitivity improved when applied together and showed 80% specificity to Trypanosoma infection. The results of the present study showed that Trypanosoma infected cattle were associated with anaemia, emaciation, weight loss, jugular pulsation and lymphadenophathy. Key Words: Trypanosomosis, Diagnosis, Cattle, Anaemia, Treatmen