121 research outputs found

    AMBIENT LEVELS OF GASEOUS, PARTICULATE AND BIO-AEROSOL POLLUTANTS IN FARM SETTLEMENTS ACROSS OGUN STATE, SOUTHWEST NIGERIA

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    This study assessed the levels of air pollutants emitted outdoor of farm settlements (FS), the seasonal and temporal variations, and the relationship among the parameters monitored. Seven FS within Ogun State were investigated, with 211 sampling points established across the FS. The concentrations of VOCs, SO2, NO2, CO, O3, NH3, CO2, TSP, PM2.5 and PM10 were monitored in replicates using active potable samplers while bacteria and fungi were isolated using settle plate technique. Descriptive (means and standard deviation) and inferential statistical tools (Pearson correlation) were used to analyse the data. The mean ranges of VOCs, CO and CO2 (ppm); 20.8±10.53 – 48.67±19.05, 17.95±6.65 – 21.5±3.93, 3562.15±1200.85  –  4266±1176.85, and for bacteria and fungi (cfu/m3); 548.98±1.18 – 2255.01±1.27 and 525.68±1.15 – 1282.38±1.27 respectively were above the threshold limits. There were significant seasonal, spatial and temporal differences among observed means of VOCs, CO2 O3, TSP, PM2.5, and fungi. The bacteria and fungi count increased as TSP, PM2.5 and PM10 increased. The study established that levels of air pollutants are dependent on the type of farming practice. &nbsp

    An investigation of the harmonic effects of nonlinear loads on power distributon network

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    Nonlinear loads are loads that defy ohms law. As a result of changes in impedance, the voltage and current waveforms from the loads are distorted and may be unpredictable in behavior. Heavy presence of a nonlinear load or the presence of many nonlinear loads in a distribution network may significantly introduce harmonics into such network. Harmonics are waveforms whose frequency is an integer of the fundamental frequency. When present in large quantity, harmonics may cause adverse effects not only to other loads on the network but also to the power distribution network. This paper investigates the harmonic effects produced by nonlinear loads on power distribution network. Nonlinear and linear loads were modelled and developed. Using MATLAB/SIMULINK simulation technique, the system was observed to be unstable with un-periodic oscillations and the total harmonic distortion (THD) was found to be 112.04% at maximum.Keywords: Harmonics, Distortion, Negative effects, Simulation, Nonlinear Loa

    Purification characterization and inhibition studies on Phospholipase C from Opisthacanthus capensis (Black Scorpion) venom

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    Phospholipase C from Opisthacanthus capensis venom was partially purified and characterized. The enzyme was purified 105.2 fold with an overall yield of 13% using various purification steps involving ammonium sulphate precipitation, protamine sulphate treatment, sephadex G-75  fractionation and DE-52 anion exchange chromatography. The purified enzyme was  homogeneous with a molecular weight of 29 kDa. The  phospholipase C has pH and temperature optima of 7.2 and 600C, respectively with activation energy of 25KJ/mol and t1/2 of 1.50 hr. Initial velocity studies on O. capensis venom phospholipase C revealed a KM of 0.02 mM and Vmax of 0.015 μmol/min. Studies on the effect of pH on KM and Vmax gave PKa1 of 6.9 and PKa2 of 7.4 with enthalpy of ionization of 20 KJ/mol suggesting  histidine in the active site. The enzyme was positively modulated by Mg2+, Zn2+ and Ca2+ and negatively by Fe2+. While Hg2+ produced complete inhibition. Various concentrations of leaf aqueous extract of Momordica charantia also inhibited the activity of O. capensis venom phospholipase C in vitro with a competitive pattern. This study revealed the presence of phospholipase C in O. capensis venom and gave some scientific basis for the use of theplant in the treatment of scorpion envenomation.Keywords: Phospholipase C; Opisthacanthus capensis;  Momordica charantia; Veno

    Co-administeration of Ethanolic Leaf Extract of Moringa oleifera and Metformin Improves Glucose, Lipid and Protein Profiles of Diabetic Wistar rats

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    Herbs are often co-administered with orthodox drugs, raising the potential for herb-drug interactions. This study investigated the pharmacological interaction between ethanol extract of Moringa oleifera (MOE) leaves and metformin co administered to diabetic Wistar rats. Diabetes was induced in rats by administration of 150 mg alloxan/kg body weight intraperitoneally. A dose response study for MOE at doses of 100-2000 mg/kg body wt. was carried out. A plot of percentage glycaemic reduction at 4h post-treatment versus log dose was used to estimate the median effective dose (ED50). Nine (9) groups of rats were used for the interaction study. Groups I and II served as normoglycaemic and diabetic controls respectively and received 1ml Normal saline. Diabetic Groups III-V received 375, 750 and 1500 mg/kg MOE respectively. Groups VI-VIII also diabetic received the same doses of MOE respectively but co-administered with a fixed dose of metformin (150 mg/kg). Group IX received metformin (150 mg/kg) alone. Fasting blood sugar (FBS) was monitored weekly and blood samples collected on day 28 for protein and lipid profile assay. The MOE/metformin co administered groups showed greater antihyperglycaemic activity (p<0.001) than the MOE and metformin alone groups. Significant increases in serum levels of cholesterol, TG and LDLC with the decrease in HDLC levels in the alloxan induced diabetic rats were reversed in MOE (p<0.01) and MOE/metformin (p<0.001) administered groups. These findings indicate that MOE/Metformin co-administration produced additive anti-hyperglycaemic and hypolipidaemic effects compared to either MOE or Metformin alone and may be useful in the therapeutic management of diabetes mellitus that is associated with dyslipidaemia.Keywords: Diabetes, Hyperglycaemia, Pharmacological interaction, Moringa oleifera, Metformi

    Comparative Study Of Students‘ Approaches And Strategies To Learning: Implications For Counselling

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    The researchers compared students’ approaches and strategies to learning in two African countries viz.; Nigeria and Uganda. Using a descriptive survey, fifty students, who were enrolled in the year 2012/2013 in guidance and counselling and computer science respectively, were sampled from the population. The students offered an ICT course separately in 200 level in the different institutions. The instrument used was the Approaches to study skills inventory (ASSIST) and the three hypotheses were postulated and tested. The results of the t-test analysis show that the null hypothesis was not statistically significant when using the strategic approach (t = 1.037, 1.056); p > .05 and the deep approach to learning of students in Nigeria and Uganda (t = -0.278, -0.279); p > .05. The second hypotheses revealed a no statistically significant difference in the Nigerian and Ugandan preferences for different types of courses in teaching and learning while the third hypothesis shows a significant correlation between a deep approach to learning and learning that supports understanding (r=.407; p <.001). It is recommended that lecturers need to accommodate their students’ individual differences in the teaching and learning process considering that most of the classes in higher institutions of learning are large for the prevalent part. Additionally, discussions on possible implications for counselling are discussed in the paper

    Genistein Precipitated Hypothyroidism, Altered Leptin and C-Reactive Protein Synthesis in Pregnant Rats

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    Summary: Genistein is an isoflavone constituent of soya. This study examined the mechanism by which genistein produced adverse effects in pregnant laboratory rats. Pregnant rats were divided into control (Con) and genistein (Gen) force fed (2 mg/kg) groups. At terminal gestation day (GD) ranging from 0-20, the rats were sacrificed, and blood samples and amniotic fluids were collected. Thyroid hormone, C-reactive protein (CRP) and leptin assay was carried using the blood samples. Leptin was also assayed in the placenta and amniotic fluid supernatant. Oral exposure of pregnant rats to genistein significantly altered maternal T3, (GD18; Con 1.65 ± 0.01, Gen 1.03 ± 0.04 nmol/L), T4 (GD6; Con 29.60 ± 0.00, Gen 36.04 ± 1.29 nmol/L), Leptin (Placenta GD20; Con 0.08 ± 0.01, Gen 0.31 ± 0.02 ng/ml, amniotic fluid ;GD 20; Con 0.02 ± 0.00, Gen 0.35 ± 0.05 ng/ml) in genistein group. These changes were accompanied with loss of embryonic implants and a decrease in fetal and placental weights. The CRP level was significantly decreased and increased at the onset and toward late pregnancy respectively. Oral exposure of pregnant rats to genistein precipitated hypothyroidism, altered some metabolic hormones with a reduction in fetal and placental growth and increased resorption of embryonic implants.Keywords: Genistein, embryonic implants, pregnancy, thyroid hormone, leptin, C - reactive protein

    A Dietary Mixture Containing Fish Oil, Resveratrol, Lycopene, Catechins, and Vitamins E and C Reduces Atherosclerosis in Transgenic Mice123

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    Chronic inflammation and proatherogenic lipids are important risk factors of cardiovascular disease (CVD). Specific dietary constituents such as polyphenols and fish oils may improve cardiovascular risk factors and may have a beneficial effect on disease outcomes. We hypothesized that the intake of an antiinflammatory dietary mixture (AIDM) containing resveratrol, lycopene, catechin, vitamins E and C, and fish oil would reduce inflammatory risk factors, proatherogenic lipids, and endpoint atherosclerosis. AIDM was evaluated in an inflammation model, male human C-reactive protein (CRP) transgenic mice, and an atherosclerosis model, female ApoE*3Leiden transgenic mice. Two groups of male human-CRP transgenic mice were fed AIDM [0.567% (wt:wt) powder and 0.933% (wt:wt oil)] or placebo for 6 wk. The effects of AIDM on basal and IL-1β–stimulated CRP expression were investigated. AIDM reduced cytokine-induced human CRP and fibrinogen expression in human-CRP transgenic mice. In the atherosclerosis study, 2 groups of female ApoE*3Leiden transgenic mice were fed an atherogenic diet supplemented with AIDM [0.567% (wt:wt) powder and 0.933% (wt:wt oil)] or placebo for 16 wk. AIDM strongly reduced plasma cholesterol, TG, and serum amyloid A concentrations compared with placebo. Importantly, long-term treatment of ApoE*3Leiden mice with AIDM markedly reduced the development of atherosclerosis by 96% compared with placebo. The effect on atherosclerosis was paralleled by a reduced expression of the vascular inflammation markers and adhesion molecules inter-cellular adhesion molecule-1 and E-selectin. Dietary supplementation of AIDM improves lipid and inflammatory risk factors of CVD and strongly reduces atherosclerotic lesion development in female transgenic mice

    Characterisation of Antibody Interactions with the G Protein of Vesicular Stomatitis Virus Indiana Strain and Other Vesiculovirus G Proteins

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    Vesicular stomatitis virus Indiana strain G protein (VSVind.G) is the most commonly used envelope glycoprotein to pseudotype lentiviral vectors (LV) for experimental and clinical applications. Recently, G proteins derived from other vesiculoviruses (VesG), for example Cocal virus, have been proposed as alternative LV envelopes with possible advantages compared to VSVind.G. Well-characterised antibodies that recognise VesG will be useful for vesiculovirus research, development of G protein-containing advanced therapy medicinal products (ATMPs), and deployment of VSVind-based vaccine vectors. Here we show that one commercially available monoclonal antibody, 8G5F11, binds to and neutralises G proteins from three strains of VSV as well as Cocal, and Maraba viruses, whereas the other commercially available monoclonal anti-VSVind.G antibody, IE9F9, binds to and neutralises only VSVind.G. Using a combination of G protein chimeras and site-directed mutations, we mapped the binding epitopes of IE9F9 and 8G5F11 on VSVind.G. IE9F9 binds close to the receptor binding site and competes with soluble low-density lipoprotein receptor (LDLR) for binding to VSVind.G, explaining its mechanism of neutralisation. In contrast, 8G5F11 binds close to a region known to undergo conformational changes when the G protein moves to its post-fusion structure, and we propose that 8G5F11 cross-neutralises VesGs by inhibiting this.IMPORTANCE VSVind.G is currently regarded as the gold-standard envelope to pseudotype lentiviral vectors. However, recently other G proteins derived from vesiculoviruses have been proposed as alternative envelopes. Here, we investigated two commercially available anti-VSVind.G monoclonal antibodies for their ability to cross-react with other vesiculovirus G proteins, and identified the epitopes they recognise, and explored their neutralisation activity. We have identified 8G5F11, for the first time, as a cross-neutralising antibody against several vesiculovirus G proteins. Furthermore, we elucidated the two different neutralisation mechanisms employed by these two monoclonal antibodies. Understanding how cross-neutralising antibodies interact with other G proteins may be of interest in the context of host-pathogen interaction and co-evolution as well as providing the opportunity to modify the G proteins and improve G protein-containing medicinal products and vaccine vectors

    Análisis del impacto de las publicaciones sobre PYMES en revistas latinoamericanas. Parte 1: Primera Parte

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    oai:ojs.rmlconsultores.com:article/1From a search of the literature related to Small and Medium sized Enterprises (SMEs) in the Network of Scientific Journals from Latin America and the Caribbean, Spain and Portugal (REDALYC) were determined 149 articles related to the topic in 8 countries and international organizations referenced in that network. The most important journals for the subject and also from the analysis of the keywords presented in the abstract, the relevant thematics for the publications about SMEs were found. Utilizing Perish (Harzing, 2007) the literature on SMEs referenced in Google Scholar and h indicator was determined. Of the 1000 articles founded 215 had an h index > = 1 indicator and 75% of the articles referenced even they appear in Google Scholar, have not a real impact (h = 0). The methodology allows to recommend a simple form that can be incorporated in the Academic Master Programs for determining for a thesis topic, those articles published an indexed in scientific journals and with a real impact for the topic.Se determinaron a partir de una búsqueda de las publicaciones relacionadas con la Pequeña y Mediana Empresa (PYMES) en la Red de Revistas Cientí­ficas de América Latina y el Caribe, España y Portugal (REDALYC), 149 artí­culos relacionados con el tema en revistas de 8 paí­ses y de Organismos Internacionales referenciados en la misma.  Se determinó igualmente las revistas más importantes para el tema en cuestión y a partir del análisis de las palabras claves presentadas en el resumen, las sub temáticas que más se analizan en cuanto a PYMES para las revista indexadas en la red mencionada. Se empleó la herramienta Perish (Harzing, 2007) para el análisis de las publicaciones sobre la temática PYMES referenciadas en el Google Académico y su indicador h. De los 1000 artí­culos encontrados 215 tienen un indicador h >= 1 y el 75 % de los artí­culos aunque aparezcan referenciados en el Google Académico, no han tenido un impacto real (h=0). La metodologí­a empleada permite recomendar una forma simple que puede incorporarse en los Programas Académicos de Maestrí­a y que permite determinar para un tema de Tesis, aquellos artí­culos publicados en revistas indexadas y con mayor impacto para la misma.Se determinaron a partir de una búsqueda de las publicaciones relacionadas con la Pequeña y Mediana Empresa (PYMES) en la Red de Revistas Cientí­ficas de América Latina y el Caribe, España y Portugal (REDALYC), 149 artí­culos relacionados con el tema en revistas de 8 paí­ses y de Organismos Internacionales referenciados en la misma.  Se determinó igualmente las revistas más importantes para el tema en cuestión y a partir del análisis de las palabras claves presentadas en el resumen, las sub temáticas que más se analizan en cuanto a PYMES para las revista indexadas en la red mencionada. Se empleó la herramienta Perish (Harzing, 2007) para el análisis de las publicaciones sobre la temática PYMES referenciadas en el Google Académico y su indicador h. De los 1000 artí­culos encontrados 215 tienen un indicador h >= 1 y el 75 % de los artí­culos aunque aparezcan referenciados en el Google Académico, no han tenido un impacto real (h=0). La metodologí­a empleada permite recomendar una forma simple que puede incorporarse en los Programas Académicos de Maestrí­a y que permite determinar para un tema de Tesis, aquellos artí­culos publicados en revistas indexadas y con mayor impacto para la misma
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