306 research outputs found

    Anticonvulsant, antiamnesic and anxiolytic activities of methanol leaf extract of Bambusa vulgaris (Poaceae) in mice

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    Background: Previous findings have shown that epilepsy can precipitate amnesia and anxiety, among other neuropsychiatric disorders. Bambusa vulgaris is used in African traditional medicine against convulsion, amnesia and anxiety but there is scanty scientific basis for these ethnomedicinal claims. Hence, this study investigated the anticonvulsant, antiamnesic and anti-anxiety effects of Bambusa vulgaris in mice. Methods: The acute oral ingestion of Bambusa vulgaris (100, 200 and 400 mg/kg) was investigated using pentylenetetrazole-, and strychnine-induced convulsion; antiamnesic using scopolamine-, and diazepam-induced amnesic models while the anxiolytic effect was assessed using elevated plus maze models. The phytochemical analysis was carried out using standard methods. Results: The extract at all the doses used significantly (p<0.05) elongated the death latency while at 400 mg/kg the onset of clonic and tonic convulsions were significantly (p<0.05) prolonged in pentylenetetrazole-induced convulsion model. The extract at 100, 200 and 400 mg/kg offered 60, 80 and 100% protection respectively in pentylenetetrazole-induced convulsion test. The extract showed no significant (p>0.05) effect on strychnine-induced convulsion model ruling out the involvement of strychnine-sensitive glycine receptor in the anticonvulsant effect of the extract. The extract at all the tested doses significantly (p<0.05) in a dose dependent fashion ameliorated the amnesia induced by scopolamine and diazepam suggesting antiamnesic effect. Bambusa vulgaris at all the tested doses significantly (p<0.05) in a dose dependent pattern increased the percentage open arm entries and percentage open arm duration on the open arm of the elevated plus maze as well as reduced the anxiety indices of the experimental mice consistent with anxiolytic effect. The phytochemical quantification of the extract showed abundance of tannins and corroborated by the findings from the Fourier transform infrared spectra of the extract. Conclusion: This study therefore concluded that Bambusa vulgaris may possess anticonvulsant, antiamnesic and anxiolytic effects and provided scientific proof for its traditional use. Keywords: Bambusa vulgaris, anticonvulsant, antiamnesic, anxiolytic, tannin, Fourier Transform-Infra Red spectr

    Spatial Variation of Water Quality in the Densu River Basin, Nsawam-Adoagyiri Municipality, Ghana

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    The Nsawam-Adoagyiri Municipality stretch of the Densu River Basin serves a population of 86,000 and flows into major river basins in parts of Accra. The study assesses the spatial variability of the physico-chemical quality of the Densu River Basin at seven selected points with reference to WHO guideline standards. Water samples were collected and analyzed from November 2015 to June 2016 to ascertain the variations in water quality parameters with respect to physicochemical parameters and selected heavy metals. Analysis of water quality showed electrical conductivity of 214.00µs/cm - 369.00µs/cm, total dissolved solids 235 to 658 mg/l, exceeding the WHO guideline values at some sampling locations. Heavy metals such as arsenic, lead and iron indicated that at some locations exceeded the WHO guideline limits while copper, manganese and mercury concentrations where found to be within  threshold at all locations during the period. Keywords: anthropogenic, densu river, spatial variation, water quality DOI: 10.7176/JEES/9-10-10 Publication date:October 31st 201

    Application of 13C NMR to investigate the transformations and biodegradation of organic materials by wood- and soil-feeding termites, and a coprophagous litter-dwelling dipteran larva

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    Solid-state 13C nuclear magnetic resonance spectroscopy has been used to characterize the C in samples of the food (wood), gut contents and faeces from the wood-feeding termite, Microcerotermes parvus; soil in the guts and mound material from the soil-feeding termite, Thoracotermes macrothorax; and the food and faeces from the litter-feeding, coprophagous larvae of the dipteran fly, Bibio marci. Spectra from the wood-feeding termite indicated preferential loss of polysaccharide and accumulation of lignin with some modification to the O-aromatic-C and methoxyl-C (O-methyl-C) components during passage through the gut. Spectra for the soil-feeding termite indicated little change in the distribution of 13C between resonances following passage through the gut, except for some evidence of preferential polysaccharide loss. Interpretation of the spectra from these organisms was restricted by the relatively low C content of the soils and mound material, and by the large contribution to the NMR spectra from the gut tissue rather than the gut contents. Spectra for the litter-feeding dipteran larvae indicated preferential feeding on the polysaccharide-rich component of the litter and then overall loss of polysaccharide-C and accumulation of both aromatic-C and methoxyl-C in the gut. These changes were greater for the second passage than for the first passage through the gut, suggesting that principally mechanical and physical changes occurred initially and that chemical digestion was prevalent during the second passage

    Measurement of Layered Corrosion With Compton Backscatter

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    Compton backscatter has intrigued NDT researchers for a number of years because of its capability for making x-ray pictures without requiring access to both sides of the piece being examined[l]. The major obstacles to commercial development have been its slowness and the high cost of the equipment. Additionally, the resolution obtained has been circumscribed; the best reported resolution appears to be less than 1.5 lp/mm.[2]. As a result, little commercial application has emerged for Compton backscatter as an imaging tool. Recently, interest in aircraft corrosion has renewed interest in Compton backscatter for NDT. This interest appears to be justified partly because aircraft corrosion often takes a layered morphology; and, the needed information is the thickness of the layers. Consequently, it is possible to trade resolution in the directions whose axes lie in the plane of the layers for better resolution along the thickness axis. Furthermore, because the layers usually have a lateral extension of several inches or more, the measurement problem can be reduced to a one dimensional scan in the thickness direction. These characteristics allow for a great reduction in the complexity of the apparatus, a substantial improvement in resolution and an increase in the speed of measurement

    Coping with the effects of fear of failure in young elite athletes

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    Coping with stress is an important element in effective functioning at the elite level in sports, and fear of failure (FF) is an example of a stressor that athletes experience. Three issues underpin the present preliminary study. First, the prevalence of problems attributed to FF in achievement settings. Second, sport is a popular and significant achievement domain for children and adolescents. Third, there is a lack of research on FF in sport among this population. Therefore, the objectives of the study were to examine the effects of FF on young athletes and to find out their coping responses to the effects of FF. Interviews were conducted individually with nine young elite ath­letes (5 males, 4 females; ages 14-17 years). It was inferred from the data that FF affected the athletes' well-being, interpersonal behavior, sport performance, and schoolwork. The athletes employed a combination of problem-focused, emotion-fo­cused, and avoidance-focused coping strategies, with avoidance strategies being the most frequently reported

    Quenching of chlorophyll fluorescence induced by silver nanoparticles

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    The interaction between chlorophyll (Chl) and silver nanoparticles (AgNPs) was evaluated by analyzing the optical behavior of Chl molecules surrounded by different concentrations of AgNPs (10, 60, and 100 nm of diameter). UV–Vis absorption, steady state and time-resolved fluorescence measurements were performed for Chl in the presence and absence of these nanoparticles. AgNPs strongly suppressed the Chl fluorescence intensity at 678 nm. The Stern-Volmer constant (KSV) showed that fluorescence suppression is driven by the dynamic quenching process. In particular, KSV was nanoparticle size-dependent with an exponential decrease as a function of the nanoparticle diameter. Finally, changes in the Chl fluorescence lifetime in the presence of nanoparticles demonstrated that the fluorescence quenching may be induced by the excited electron transfer from the Chl molecules to the metal nanoparticles

    A measurement of the tau mass and the first CPT test with tau leptons

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    We measure the mass of the tau lepton to be 1775.1+-1.6(stat)+-1.0(syst.) MeV using tau pairs from Z0 decays. To test CPT invariance we compare the masses of the positively and negatively charged tau leptons. The relative mass difference is found to be smaller than 3.0 10^-3 at the 90% confidence level.Comment: 10 pages, 4 figures, Submitted to Phys. Letts.

    Measurement of the B0 Lifetime and Oscillation Frequency using B0->D*+l-v decays

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    The lifetime and oscillation frequency of the B0 meson has been measured using B0->D*+l-v decays recorded on the Z0 peak with the OPAL detector at LEP. The D*+ -> D0pi+ decays were reconstructed using an inclusive technique and the production flavour of the B0 mesons was determined using a combination of tags from the rest of the event. The results t_B0 = 1.541 +- 0.028 +- 0.023 ps, Dm_d = 0.497 +- 0.024 +- 0.025 ps-1 were obtained, where in each case the first error is statistical and the second systematic.Comment: 17 pages, 4 figures, submitted to Phys. Lett.

    First Measurement of Z/gamma* Production in Compton Scattering of Quasi-real Photons

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    We report the first observation of Z/gamma* production in Compton scattering of quasi-real photons. This is a subprocess of the reaction e+e- to e+e-Z/gamma*, where one of the final state electrons is undetected. Approximately 55 pb-1 of data collected in the year 1997 at an e+e- centre-of-mass energy of 183 GeV with the OPAL detector at LEP have been analysed. The Z/gamma* from Compton scattering has been detected in the hadronic decay channel. Within well defined kinematic bounds, we measure the product of cross-section and Z/gamma* branching ratio to hadrons to be (0.9+-0.3+-0.1) pb for events with a hadronic mass larger than 60 GeV, dominated by (e)eZ production. In the hadronic mass region between 5 GeV and 60 GeV, dominated by (e)egamma* production, this product is found to be (4.1+-1.6+-0.6) pb. Our results agree with the predictions of two Monte Carlo event generators, grc4f and PYTHIA.Comment: 18 pages, LaTeX, 5 eps figures included, submitted to Physics Letters

    WW Production Cross Section and W Branching Fractions in e+e- Collisions at 189 GeV

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    From a data sample of 183 pb^-1 recorded at a center-of-mass energy of roots = 189 GeV with the OPAL detector at LEP, 3068 W-pair candidate events are selected. Assuming Standard Model W boson decay branching fractions, the W-pair production cross section is measured to be sigmaWW = 16.30 +- 0.34(stat.) +- 0.18(syst.) pb. When combined with previous OPAL measurements, the W boson branching fraction to hadrons is determined to be 68.32 +- 0.61(stat.) +- 0.28(syst.) % assuming lepton universality. These results are consistent with Standard Model expectations.Comment: 22 pages, 5 figures, submitted to Phys. Lett.
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