Chlorination has been the method of choice for disinfecting water used for drinking purposes. However, some stressed bacteria during chlorination are able to recover and alter the potability of water. This study assessed the recovery of stressed bacteria in dechlorinated water. Ten chlorinated water samples were collected from different points within Ilorin metropolis, Kwara, Nigeria. The samples (100ml) were dechlorinated with 0.1ml of 11.4mM sodium thiosulphate solution. The physicochemical characteristics of the chlorinated water samples were determined while bacteriological analyses were carried out on both chlorinated and dechlorinated water samples. The antibiotic susceptibility pattern of the isolates was determined using disc diffusion method. The physicochemical characteristics of the water samples ranged as follow: pH 7.3-8.4, chloride content 4.37-6.85 mg/l, suspended solids 0.004-0.017 g/100ml, and total hardness 30-72mg/l. The chlorinated water samples had bacterial, total, and faecal coliform counts ranging from 1.0 × 101 – 1.9 × 104cfu/ml, 0 – 480 MPN/100ml, and zero, respectively. The dechlorinated water sample had corresponding counts of 5.4 × 102 – 7.36 × 104cfu/ml, 6 - 1100 MPN/100ml, and 0 – 380 MPN/100ml. A total of eleven bacterial species belonging to the genera Bacillus, Burkholderia, Citrobacter, Enterobacter, Enterococcus, Escherichia, Staphylococcus, Serratia, and Streptococcus were isolated. Not lower than 60% of the bacterial isolates were susceptible to ofloxacin and ciprofloxacin. All the isolates exhibited multiple antibiotic resistances. The antibiotic resistance pattern of an isolate of Citrobacter freundii to cefuroxime, cefixime, and gentamycin changed remarkably and was plasmid-mediated, while that of E. coli and Enterobacter agglomerans remained unchanged to all the antibiotics and was non-plasmid mediated. Chlorination of water at the point of use is recommended. It is concluded that chlorination is essential in order to prevent reactivation of stressed bacteria during distribution and prevent infection by bacteria with high multiple antibiotic resistance index.
Alloys of Bi2[Te1-x Sex]3 were prepared by melting technique with different values of Se percentage (x=0,0.1,0.3,0.5,0.7,0.9 and 1). Thin films of these alloys were prepared by using thermal evaporation technique under vacuum of 10-5 Torr on glass substrates, deposited at room temperature with a deposition rate (12nm/min) and a constant thickness (450±30 nm). The concentrations of the initial elements Bi, Te and Se in the Bi2 [Te1-x Sex]3 alloys with different values of Se percentage (x), were determined by XRF,The morphological and structural properties were determined by AFM and XRD techniques. AFM images of Bi2[Te1-x Sex]3 thin films show that the average diameter and the average surface roughness inc
... Show MoreLaser etching may be an alternative to acid etching of enamel and dentin. Several characteristics of irradiated dental hard tissues have been considered advantageous, microscopically rough surfaces without demineralization, open dentinal tubules without smear layer production and dentin surface sterilization. The aim of this study is to determine and compare histology the microleakage in class V cavity restored with a light cured composite after conditioning the samples(tooth surface) with 1-acid etching, 2-Q-switched Nd:YAG Laser etching and finally 3- acid and laser etching. Materials and methods: Twenty four non carious human extracted teeth were used in this study. The samples were equally grouped into four groups of six teeth each.
... Show MoreThis study investigated the outcome of Alstonia boonei stem bark on liver enzymes after inducing the Wistar albino rats with carbon tetrachloride (CCl4). This effect of plant extract was compared with silymarin – a drug commonly used for the treatment of chronic hepatocyte disorder. The plant sample was extracted with ethanol; acute toxicity study of the extract was performed on eighteen Wistar mice, while 30 rats were sacrificed for liver enzymes assay. The rats were divided into six clusters: each cluster has five rats, culster 1 served as control and was given 2 mL/kg b.w - distilled water; clusters 2 – 6 were CCl4 induced. Cluster 2 was untreated but served as the negative control while cluster 3 wa
... Show MoreAim:- to show that not all survival curves without shoulder are not able to repair or have lost the ability for the accumulation of sublethal damage.
Background:- the shoulder of the survival curve is considered as a
region of accumulation of sublethal damage also as an indicator for cell capacity to repair. The size can be influenced by the change ofthe slope of the linear portion of the survival curve.
Results:- we have shown that a survival curve with shoulder size of
1.5 Gy can be a straight line when the slope of the exponential part is changed so the
... Show MoreThe nigra scale, Parasaissetia nigra (Nietner, 1861) (Hemiptera, Coccidae) recorded as a new insect pest attacking fig trees, Ficus carica (Moraceae) in Iraq. It was observed during April 2014 in residential garden at Al-Hurriyah district in Baghdad.
This paper presents an alternative method for developing effective embedded optimized Runge-Kutta (RK) algorithms to solve oscillatory problems numerically. The embedded scheme approach has algebraic orders of 5 and 4. By transforming second-order ordinary differential equations (ODEs) into their first-order counterpart, the suggested approach solves first-order ODEs. The amplification error, phase-lag, and first derivative of the phase-lag are all nil in the embedded pair. The alternative method’s absolute stability is demonstrated. The numerical tests are conducted to demonstrate the effectiveness of the developed approach in comparison to other RK approaches. The alternative approach outperforms the current RK methods
... Show MoreSocial networking sites represent one of the modern communication technologies that have contributed to the expression of public opinion trends towards various events and crises of which security crisis is most important being characterized by its ability to influence the community life of the public. In order to recognize its role in shaping opinions of the educated class of the public that is characterized by a high level of knowledge, culture and having experience in dealing with the media. Its advantage is that they have an active audience by expressing their views on the situations, events, and news published on them as well as expressing their attitudes and sympathy with the events. So a number of questions are included in the ques
... Show MoreThis study aimed to explore the manufacture of high-fat pellets for obesity induction diets in male Wistar rats and determined its effect on lipid profiles and body mass index. It was an experimental laboratory method with a post-test randomized control group. Formulation of high-fat pellets (HFD) and physico-chemical characteristics of pellets were conducted in September 2019. This study used about 28 male Wistar white rats, two months old, and 150-200 g body weight. Rats were acclimatized for seven days, then divided into four groups: 7 rats were given a standard feed of Confeed PARS CP594 (P0), and three groups (P1, P2, P3) were given high-fat feed (HFD FII) 30 g/head/day. The result showed that the mean fat content of Formula II pell
... Show MoreThe direct electron transfer behavior of hemoglobin that is immobilized onto screen-printed carbon electrode (SPCE) modified with silver nanoparticles (AgNPs) and chitosan (CS) was studied in this work. Cyclic voltametry and spectrophotometry were used to characterize the hemoglobin (Hb) bioconjunction with AgNPs and CS. Results of the modified electrode showed quasi-reversible redox peaks with a formal potential of (-0.245V) versus Ag/AgCl in 0.1M phosphate buffer solution (PBS), pH7, at a scan rate of 0.1Vs-1. The charge transfer coefficient (α) was 0.48 and the apparent electron transfer rate constant (Ks) was 0.47s-1. The electrode was used as a hydrogen peroxide biosensor with a line
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