16 research outputs found

    Toxic effect of Raphia vinifera on fish leech (Piscicola geometra)

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    This study examines acute toxicity of Raphia vinifera on fish leech, Piscicola geometra. The leeches with a mean total length of (TL) 4.2+1.0cm were exposed to various concentrations of both crude powdered and ethanolic extracts of the botanical. Median lethal concentration (LC50) was determined with static-renewal tests using logarithmic and arithmetic graphic methods. The LC50 (for 96 hours of crude powdered (aqueous) extracts of the botanical on Piscicola geometra was 1.10 ppm arithmetically and 1.14ppm logarithmically. The 95% confidence limits was 0.10ppm arithmetically and 0.12ppm logarithmically. The LC50 of ethanolic extract of the poison at 96-h was 0.5ppm arithmetically and 0.48ppm logarithmically. The 95% confidence limits were less than 0.10ppm. The use of extracts of R. vinifera in the control of leeches in fish ponds is discusse

    Effect of physical stresses on survivability and post-exposure antibiotic susceptibility of coliforms in environmental waters and wastewaters

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    Background: Coliform bacteria are majorly introduced into water bodies (river and wastewater) as a result of faecal pollution, agricultural run-offs and several anthropogenic activities. Despite the effectiveness of water treatment methods, pathogens still persist in water; hence the relevance of assessing the ability of these pathogens to survive the lethal actions of physical stresses and the possible impact on antibiotic susceptibility pattern of the organisms.Methodology: The survivability of Escherichia coli strains (NCM3722, FAP1 and ST2747), Enterobacter cloacae GGT036 and Shigella sonnei 53G was assessed in environmental and waste waters for 21 days. The effect of three treatment regimens (UV radiation, solar radiation and boiling) on the survival of the coliforms was evaluated. Also, the antibiogram of the isolates post–UV exposure was assayed.Results: Although there was significant reduction (≥ 3-log) in the population of the bacteria overtime, all the coliforms survived in the waters for 21 days. The effect of UV radiation was significant on all organisms (> 3 log reductions). Solar radiation for 60 minutes had significantly lesser effect than boiling for 15 minutes. Surviving cells of all isolates demonstrated multiple drug-resistance post exposure to UV radiation.Conclusion: This study revealed the ability of coliforms to persist in waters after treatment and proves that UV radiation may not be effective in attenuation of antibiotic resistance.Keywords: Survivability; Coliforms; Antibiotic susceptibility; Water; Wastewate

    Resuscitation of Bacteria after Dechlorination of Treated Drinking Water

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    In this study, the effects of initial bacterial load (102 , 104 and 106 cells/ml) and dechlorination idiosyncrasy on the efficacy of varying concentrations (0.018–0.126% v/v applied for 30 minutes) of a point-of-use chlorine-based proprietary disinfectant (WaterCare®) were investigated in drinking water. Results indicated that higher initial cell populations significantly affected the efficacy of the disinfectant.Subsequent dechlorination of the disinfected water resulted in resuscitation of bacteria. This was demonstrated after 1440 minutes post-dechlorination for Salmonella typhi and after at least 120 minutes for Escherichia coli, Proteus vulgaris and Shigella dysenteriae, particularly at lower disinfectant concentrations (0.018–0.054% v/v). Thus, whilst the use of WaterCare® at the recommended dosage(0.072% v/v or 10 ml to 25 litres of clean water for 30 minutes) may produce microbiologically safe drinking water high initial microbial load and post-disinfection residual chlorine loss may limit its efficacy. Keywords: Bacterial resuscitation, Escherichia coli, Dechlorination, Drinking water, Salmonella typhi, WaterCare

    Biodegradative activities of some gram- negative bacilli isolated from kerosene treated soil grown with cowpea (Vigna unguiculata)

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    The biodegradative activities of three Gram negative bacilli (Aeromonas hydrophila, Vibro parahaemolyticus and Actinobacillus sp) isolated from soil contaminated with kerosene and planted with cowpea was investigated. The isolates were identified using MicrobactTM ID 24E system for the identification of Enterobacteriaceae and common miscellaneous Gram negative bacilli (MGNB). 2kg of soil collected from University of Ilorin was placed inside transparent, drilled buckets. Physicochemical properties of the soil were recorded. The soil was contaminated with kerosene at different concentrations of 0ml, 7ml, 14ml, 21ml, 56ml, 112ml, 168ml and 224ml. The setup was laid out in a randomized complete block design with three replicates. Cowpea seeds of the variety Samaru-40 were cultivated and observed for eight weeks. The results indicated that kerosene contamination of soils significantly affected the growth parameters: germination percentage, time of germination, rate of germination, plant height, number of leaves, leaf area and root nodules. A negative interaction existed between the level of the contaminant and the growth characteristics measured. Their biodegradative activities were studied and confirmed by the change in the Total Petroleum Hydrocarbon (TPH) using gravimetric method. The biodegradative abilities of the isolates were compared by measuring the optical densities, total viable count, pH and emulsification activity. The results showed that the organisms did better as a consortium rather than singly. Aeromonas hydrophila had the highest biodegradative activity followed by Vibro parahaemolyticus and then Actinobacillus sp. The study recommends the use of Aeromonas hydrophila and consortium for more effective biodegradation.Keywords: Bacterial Biodegradation, Soil, Cowpea, Kerosene, Total Petroleum Hydrocarbo

    Assessment of the impacts of building construction activities on the environment

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    Activities in building construction industry contribute to air pollution. In this study, gas data from four locations at each three building construction sites in Doha, Qatar were collected and analyzed. Questionnaires were also administered to companies that are involved in building construction projects. The results showed traces of SO2, CO2, CO and NO2 but in amounts below the detrimental limit stipulated by the Ministry of Environment, Qatar. Questionnaire responses revealed that the extraction of raw materials and the energy consumed during construction occur quite often, but strongly implicated dust generated from construction sites and waste disposal, as major factors causing air pollution in the area. It is therefore, recommended that regular monitoring of air should be carried out within building construction sites to aid detection of air contamination. This will serve as a control measure to stimulate catalytic conversion of exhaust, reuse and recycling of waste materials. Keywords: Air pollution, Building construction activities, Dust, Emissions and Environment

    Growth performance, blood profile and serum metabolites of West African dwarf growing rams fed guinea grass supplemented with differently processed pigeon pea leaves

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    A 56-day trial was conducted to investigate the performance and blood profile of West African Dwarf growing rams fed Panicum maximum with differently processed Pigeon pea leaves, twigs, and petioles (PPL). A total of sixteen (16) rams were randomly allotted to four treatments (T1 - 100% P. maximum solely), T2 - 70% P. maximum and 30% fresh PPL), T3 - 70% P. maximum and 30% wilted PPL and T4 - 70% P. maximum and 30% dried PPL) with four animals per treatment in a completely randomized design (CRD). Growth performance and blood analysis parameters such as initial and final weight, feed intake and leftover, packed cell volume, hemoglobin, total protein, albumin, glucose were evaluated. There were significant variation (P<0.05) in all the evaluated parameters. Fresh PPL recorded the highest crude protein (CP) (22.31%), followed by wilted (21.20 %), and the least (5.30 %) was obtained in P. maximum. The phytate contents of fresh, wilted and dried PPL were 1.29%, 1.28% and 1.26% respectively while tannin contents were 1.00, 0.85 and 0.79mg/100gm in fresh, wilted and dried PPL respectively. The feed intake (5.22kg) of each ram fed the T1 diet was higher (P<0.05) than those of T2 (3.50kg), T3 (5.05kg) and T4 (4.61kg). Average, daily and weekly weight gains varied (P<0.05) in the diets in T3>T4 >T2>T1 order, while feed conversion ratio ranged between 3.48 (T3) to 7.35 (T1). The packed cell volume (PCV) and haemoglobin (Hb) ranged from 36.00% in T4 to 38.00% in T1 and 12.50g/dl in T4 to 12.40g/dl in T1 respectively. T3 diet was observed to have the highest total protein (7.00 g/dl), albumin (3.30 g/dl) and globulin (4.40 g/dl) values. From the results of a significant number of evaluated parameters, T3 proved to be the best diet of this study. However, it was concluded that the supplementation of P. maximum with either fresh, wilted or dried PPL would increase the productivity of growing rams. Keywords: WAD rams; Cajanus cajan; Panicum maximum; haematology; serum metabolite

    Chemical constituents and antimicrobial properties of Phyllanthus amarus (Schum & Thonn)

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    The chemical composition of the leave extracts of Phyllanthus amarus (Schum and Thonn) of the family Euphorbiaceae from Nigeria was analyzed by GC-MS. The extracts were also examined for their potential to inhibit the growth of clinical isolates following standard procedure. The major compounds identified in the hexane extract are a flavonoid, flavone 4’,5,7-triethoxy-3,3’,6- trimethoxy (20.23%) and a triterpenoid 17-(1,5-Dimethylhexyl)-6-hydroxy-5-methylestr-9-en-3-yl acetate (19.02%) while bufalin (18.71%) and tetratetracontane (12.91%) were the major compounds detected in the methanol extract. Steroidal triterpenoids are the major compounds present in the extracts as it accounted for 47% of the total detectable content in the hexane extract and 52% in the methanol extract. The steroidal triterpenoids which exist primarily as acetate in the hexane extract include cycloeucalenyl acetate, ergosta-5,7,22-trien-3-ol acetate, macdougallin, 17-(1,5-Dimethylhexyl)-6-hydroxy-5-methylestr-9-en-3-yl acetate, stigmasterol and β-sitosterol while the methanol extract contains 6,7-epoxypregn-4-ene-9,11,18-triol-3,20-dione, 11,18-diacetate, bufalin, olean-13(18)-ene, methyl ursolate, barringenol R1 and 7,8- epoxylanostan-11-ol,3-acetoxy. Hexane extract of the plant exhibited antifungal activity on Candida albicans while methanol extract revealed significant antibacterial activity on Pseudomonas aeruginosa and Staphylococcus aureus at all concentrations of the extract between 12.5 and 100 mg/mL, the activity being comparable to the standard antibacterial drug, Oxacillin. The leaves of Phyllanthus amarus is a potential source of steroidal triterpenoids which could serve as biomarker for the plant species. The extracts of the plant may also serve as a natural source of antimicrobial agents for the treatment of some microbial infections.Keywords: Phyllathus amarus, antimicrobial, phytochemicals, leaf extract

    Influence of plant population on fruit and seed yield characters of cayenne pepper (Capsicum frutescens L.) genotypes

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    This study assessed the influence of three plant populations (18518, 27777 and 40000 plants ha-1) on fruit and seed yield characters in 16 genotypes of Capsicum frutescens in 2010 and 2011 cropping years using a 3 x 16 split plot arrangement fitted into a randomized complete block design. Plant population and genotype formed main and sub-plots, respectively. Data collected on fruit and seed yield characters were subjected to analysis of variance after which means were separated using Fisher’s Least Significant Difference. Correlation analysis was also carried out among the characters. Significant and highest (P < 0.01) number of fruits per plant, single fruit weight, fruit weight per plant, number of seeds per fruit, 100 seed weight, seed weight per plant and seed weight per fruit were obtained under 18518 plants ha-1 while highest (P < 0.05) fruit yield ha-1 (11.3 tons) and seed yield ha-1 (698.7 kg) were obtained under 40000 plants ha-1. Top fruit and seed yielding genotypes across the three plant population were PP9955-15 and Chilli 14, respectively. Number of fruits per plant showed negative and highly significant correlation with single fruit weight, fruit length, fruit width, number of seeds per fruit, 100-seed weight and seed weight per fruit. Significant positive or negative correlations were also observed among other characters. Plant population of 40,000 ha-1 using 50 x 50 cm spacing is recommended for high fruit and seed yield in C. frutescens production.Key words: Cayenne pepper, plant population, seed production efficiency, seed yiel

    Full-Diversity QO-STBC Technique for Large-Antenna MIMO Systems

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    YesThe need to achieve high data rates in modern telecommunication systems, such as 5G standard, motivates the study and development of large antenna and multiple-input multiple-output (MIMO) systems. This study introduces a large antenna-order design of MIMO quasi-orthogonal space-time block code (QO-STBC) system that achieves better signal-to-noise ratio (SNR) and bit-error ratio (BER) performances than the conventional QO-STBCs with the potential for massive MIMO (mMIMO) configurations. Although some earlier MIMO standards were built on orthogonal space-time block codes (O-STBCs), which are limited to two transmit antennas and data rates, the need for higher data rates motivates the exploration of higher antenna configurations using different QO-STBC schemes. The standard QO-STBC offers a higher number of antennas than the O-STBC with the full spatial rate. Unfortunately, also, the standard QO-STBCs are not able to achieve full diversity due to self-interference within their detection matrices; this diminishes the BER performance of the QO-STBC scheme. The detection also involves nonlinear processing, which further complicates the system. To solve these problems, we propose a linear processing design technique (which eliminates the system complexity) for constructing interference-free QO-STBCs and that also achieves full diversity using Hadamard modal matrices with the potential for mMIMO design. Since the modal matrices that orthogonalize QO-STBC are not sparse, our proposal also supports O-STBCs with a well-behaved peak-to-average power ratio (PAPR) and better BER. The results of the proposed QO-STBC outperform other full diversity techniques including Givens-rotation and the eigenvalue decomposition (EVD) techniques by 15 dB for both MIMO and multiple-input single-output (MISO) antenna configurations at 10−3 BER. The proposed interference-free QO-STBC is also implemented for 16×NR and 32×NR MIMO systems, where NR≤2. We demonstrate 8 x 16 and 32 transmit antenna-enabled MIMO systems with the potential for mMIMO design applications with attractive BER and PAPR performance characteristics

    Evaluation of some heavy metals bio-accumulation in meat and haemolymph of african landsnail (Archachatina Marginata Swainson)

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    The impact of captive rearing of snails (Archachatina marginata) on the bio-accumulation of some heavy metals (HMs) (Fe, Mn, Cu, Pb, Co, Ni, Cd and Cr) in the meat and haemolymph was evaluated in a two treatment trial (snails from the wild, (SW) and captive reared snails, (SC), each comprised of sixty snails of three replicates. Alldata collected (using standard analytical procedures) were subjected to ANOVA and significant means separated by Duncan Multiple Range Test. The trial revealed that the meat of SC had outstanding (P>0.05) Fe (22.30mg/kg) and Mn(4.79mg/kg), with no significant variation for DM, while the haemolymph recorded non-significant (P< 0.05) concentration for (Mn, Pb, Co, Ni, Cd and Cr). Its levels of Fe (3.50mg/kg) and Cu (2.06mg/kg) were however significantly (P>0.05) impacted by captive rearing. Generally the level of Cr in the meat and haemolymph were higher than 0.05mg/kg recommendation by WHO, hence snail meat and haemolymph must be consumed with caution and guidance
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