259 research outputs found
Antibacterial activities of sawdust and stem bark of Sasswood tree (Erythrophleum suaveolens, Guill. & Perr. Brenan, 1917) extracts against selected wood bacteria
This study assessed the antibacterial properties of sawdust and stem bark of Erythrophleum suaveolens extracts on selected wood bacteria. Erythrophleum suaveolens samples were collected, dried and macerated by dissolving 1 Kg and 0.60 Kg of stem bark and sawdust respectively into 1 L of n-hexane, ethyl acetate and methanol. Sporfloxacin ciprofloxacin and cefuroxine antibiotics were used as control. The mixture was left for 24 hours then filtered and the filtrates evaporated to dryness. Qualitative phytochemical screening, zone of inhibition, minimum inhibitory and Bactericidal Concentrations (MIC/MBC) were determined according to standard methods. Tannins, steroids, saponins, glycosides, flavonoids, carbohydrates anthraquinones and alkaloids phytochemicals were present in E. suaveolens extracts. Zone of inhibition (32 – 37 mm) of antibiotics on test bacteria compared favourably with 17 – 24 mm of E. suaveolens extracts. Erythrophleum suaveolens ethyl acetate and methanol E. suaveolens extracts inhibited Staphylolococus aureus, Ralstonia solanacearum, Proteus mirabilis, Enterococcus faecium and Acidobacterium capsulatum growth at MIC of 10 mg/mL and n-hexane extracts at 20 mg/mL. At MBC of 20 mg/mL methanol stem bark extract completely killed most test bacteria. Methanol extracts were the most active extracts. The study has shown that E. suaveolens extracts can be explored in the control of plant diseases caused by test bacteria in the study.
Key words: Antibacterial, E. suaveolens, extract, phytochemicals, zone of inhibitio
Problems regarding exemption clauses in consumer contracts : the search for equitable jurisprudence in the South African Constitutional realm
No abstractThesis (LLD)--University of Pretoria, 2017.Private LawLLDUnrestricte
Phytochemical screening and antifungal activity of sawdust and stem bark extracts from Erythrophleum suaveolens (Guill. & Perr) Brena
This study was carried out to investigate the antifungal potentials of stem bark and sawdust of Erythrophleum suaveolens. Stem bark was collected from Federal University of Agriculture (FUAM) while sawdust sample was collected from Timber Shed Makurdi. Both samples were air dried while the stem bark was ground into powder for extraction. Extraction of samples was done sequentially by macerating 1000 g and 600 g of stem bark and sawdust, respectively using 1000 mL (w/v) of n-hexane for 24 hours and filtering off the hexane extract followed by ethyl acetate and methanol in that order for 24 hours each. Extracts were filtered and evaporated to obtain dried extracts and yields calculated. Phytochemical screening of samples was carried out according to AOAC standard methods. Diffusion method was used for antifungal screening of extracts. Sabouraud Dextrose agar was prepared as media in Petri dishes where Zones of Inhibition were observed for fungal growth. Minimum Inhibitory Concentration (MIC) of extracts was determined according to broth dilution technique at 40 g/mL, 20 g/mL, 10 g/mL, 5 g/mL and 2.5 g/mL. Minimum Fungicidal Concentration (MFC) determined by sub culturing MIC to determine the least concentration at which fungi were killed. Percentage yield of extract was highest (5.19 %) in stem bark and lowest (0.12 %) in sawdust. Methanol extracts had the highest yield (5.19 % and 3.42 %) for stem bark and sawdust followed by ethyl acetate (1.06 % and 0.36 %) and n’ hexane (0.16 % and 0.12 %), respectively. Flavonoids, glycosides, saponins, steroids, and tannins were in the stem bark while, anthraquinones, saponins and tannins were completely absent in the E. suaveolens sawdust. Zones of Inhibition (ZOIs) of antibiotics ranged between 27 mm – 35 mm while ZOIs for crude extracts ranged from 18 mm – 28 mm. At MIC of 5 mg/mL, E. Suaveolens stem bark methanol extract inhibited Coniophora puteana and Fomitopsis pinicoca growth. At MFC of 10 mg/mL the same microbes were killed. Erythrophleum suaveolens stem bark methanol can be used in the control of brown-rot decay and stem decay caused by Coniophora puteana and Fomitopsis pinicoca.Keywords: Antifungal, brown-rot decay, stem decay, Erythrophleum suaveolens, Coniophora puteana, Fomitopsis pinicoca, Antimicrobial, Aspergillus fumigatu
Impact of fungicide application on taro leaf blight disease in three regions of Cameroon
Open Access JournalThe study was conducted in the research field sites of the Institute of Agricultural Research (IRAD), Bambui, North West Region, (IRAD), Ekona South West Region and the International Institute of Tropical Agriculture (IITA) Nkolbisson, Yaoundé, Center Region of Cameroon. Four cultivars of taro (Dark green petiole with small leaves (L1), Red petiole with small leaves (L2), Light green petiole with large leaves (L3) and Light green petiole with small leaves(L4)) were planted in four seasons, for two years, in the months of March and July 2015, March and July 2016 in all the research farms. Ninety corms of the each cultivar were treated before planting with fungiforce at 0.33% concentration while others were not treated. Fungiforce is a contact and systemic fungicide containing high levels of copper oxide (600 grams) and mild levels of metalaxyl (120 grams), various concentrations of 0.4%, 0.33%, 0.27%, at the onset of the first symptom of leaf blight on the leaves using knapsack sprayer of 15 litres at two weeks interval, while the control experiment consisted of unsprayed taro leaves. Data for the disease incidence of taro leaf blight was recorded from the onset of disease in fields and continued at two weeks interval for 6 weeks. The results of planting taro in four seasons in three experimental field sites revealed that there was a decrease in disease incidence in fields sprayed with fungiforce than in the control field. Plots sprayed with fungicide at different concentrations showed no variation on the 4 cultivars in the different field sites. The disease incidence ranged from 10% to 100% in the 4 seasons, at the three experimental field sites. The variation in disease incidence in the three planting sites is an indication of possible genotypes by environment (GXE) interaction that may have significant influence on the taro leaf blight resistance potential
In vitro evaluation of the antimicrobial properties of Mallotus oppositifolium decoction leaf extracts and fractions
In order to verify the in vitro antimicrobial properties of Mallotus oppositifolium (Euphorbiaceae), the qualitative phytochemical screening and the antimicrobial activities on Shigella dysenteriae A2, Salmonella typhi, Escherichia coli, Enterococcus faecalis, Staphyllococcus aureus and Candida albicans strains of the aqueous decoction (DEMO) hexane (HEMO) and methanol (MEMO) fractions of leaves were assessed. The screening was performed using colorimetric methods. The antimicrobial activity was carried out using disc diffusion assays. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined by the dilution methods. The screening revealed the presence of metabolites such as alkaloids, flavonoids, phenolic compounds, tannins, saponins, lipids, carbohydrates, mucilages, proteins, triterpens and steroids. DEMO, HEMO, MEMO showed a concentration-dependent activity against Shigella dysenteriae A2 and Salmonella typhi, with inhibition zone ranging from 9.44±0.44 to 19.00±0.24 mm, 8.94±0.05 to 20.03±0.17 mm and 8.13±0.17 to 16.76±0.11 mm respectively. The MIC showed ranges from 0.25 to 1.00 mg.mL-1, 0.20 to 0.50 mg.mL-1 and 1.00 to 3.00 mg.mL-1, while the MBC ranged from 1.00 to 5.00 mg.mL-1, 0.50 to 1.00 and 3.00 to 10.00 mg.mL-1 respectively. The leaves decoction and fractions activity on the two strains showed promising activities to justify the use of the plant against diarrhoea in folk medicine.Keywords: Folk medicine, phytochemical analysis, Mallotus oppositifolium diarrhea, antimicrobial
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs
We describe the design and performance of the near-infrared (1.51--1.70
micron), fiber-fed, multi-object (300 fibers), high resolution (R =
lambda/delta lambda ~ 22,500) spectrograph built for the Apache Point
Observatory Galactic Evolution Experiment (APOGEE). APOGEE is a survey of ~
10^5 red giant stars that systematically sampled all Milky Way populations
(bulge, disk, and halo) to study the Galaxy's chemical and kinematical history.
It was part of the Sloan Digital Sky Survey III (SDSS-III) from 2011 -- 2014
using the 2.5 m Sloan Foundation Telescope at Apache Point Observatory, New
Mexico. The APOGEE-2 survey is now using the spectrograph as part of SDSS-IV,
as well as a second spectrograph, a close copy of the first, operating at the
2.5 m du Pont Telescope at Las Campanas Observatory in Chile. Although several
fiber-fed, multi-object, high resolution spectrographs have been built for
visual wavelength spectroscopy, the APOGEE spectrograph is one of the first
such instruments built for observations in the near-infrared. The instrument's
successful development was enabled by several key innovations, including a
"gang connector" to allow simultaneous connections of 300 fibers; hermetically
sealed feedthroughs to allow fibers to pass through the cryostat wall
continuously; the first cryogenically deployed mosaic volume phase holographic
grating; and a large refractive camera that includes mono-crystalline silicon
and fused silica elements with diameters as large as ~ 400 mm. This paper
contains a comprehensive description of all aspects of the instrument including
the fiber system, optics and opto-mechanics, detector arrays, mechanics and
cryogenics, instrument control, calibration system, optical performance and
stability, lessons learned, and design changes for the second instrument.Comment: 81 pages, 67 figures, PASP, accepte
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