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Significant Difference Test (significant + difference_test)
Selected AbstractsSeedling Growth of Agronomic Crops in Crude Oil Contaminated SoilJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 4 2006I. Issoufi Abstract Phytoremediation of hydrocarbon-contaminated soil shows promise as a low-cost alternative to most remediation methods. This study evaluated seedling growth of six crop species in crude oil contaminated soils. The experiments were conducted in a greenhouse. Weathered crude oil was added to an Ipava silt loam soil at the rate of 0 (control), 10, 50 and 100 g of crude oil kg,1 of soil, which was then placed into pots. Irrigation was used to maintain soil moisture at approximately field capacity. Five seeds of Zea mays, Meticago sativa, Lolium perenne, Triticum aestivum, Glycine max or Vicia villosa were sown per pot. The experimental design was completely randomized with five replications per treatment. Germination and seedling height data were recorded on day 7, 14, 21 and 28. Plants were harvested on day 28, separated into shoots and roots and dried to measure biomass. Analysis of variance was used to determine treatment significance. Significant treatment mean values were separated using Tukey's Honestly Significant Difference Test. Based upon percent emergence and plant biomass production in contaminated soil, Z. mays and G. max seedlings show the greatest potential to enhance remediation. [source] Recovery of,Salmonella enterica,Serovars Typhimurium and Tennessee in Peanut Butter after Electron Beam ExposureJOURNAL OF FOOD SCIENCE, Issue 7 2010Kristen E. Matak Abstract:, The effect of electron beam (e-beam) radiation on the recovery of,Salmonella,serotypes Tennessee (ATCC 10722) and Typhimurium (ATCC 14028) in creamy peanut butter over a 14-d storage period at 22 °C was studied. Each,Salmonella,type was independently inoculated into peanut butter and subjected to e-beam doses that ranged from 0 to 3.1 kGy, confirmed by film dosimetry. After 2-, 4-, 6-, 8-, and 14-d of storage, microbial analyses were conducted. Survivors were recovered on growth and selective media using standard spread-plating methods. Microbial counts (CFU/g) were log-converted and differences were determined by ANOVA and Tukey's Honestly Significant Differences test. When samples were not e-beam-treated, there were no significant changes (P,> 0.05) in microbial numbers over time. In e-beamed samples, microbial numbers decreased over time; however, reductions were not always significant. Initial recovery rates (R-rates) 2 d after e-beam treatment were significantly different for the 2 strains of,Salmonella,and between recovery media (P,< 0.05); however, these differences did not persist for the remainder of the storage period (P,> 0.05) indicating that injured cells were not able to survive in the high-fat, low-water activity peanut butter environment. R-rates for both strains of,Salmonella,were maintained until day 14 when there were significant reductions in,Salmonella,Typhimurium (P,< 0.05). These results indicate that,Salmonella,Tennessee and,Salmonella,Typhimurium will survive in peanut butter when exposed to nonlethal doses of e-beam irradiation. Practical Application: Electron beam (e-beam) irradiation is an alternative to thermal processing; this technique inactivates microorganisms and insects that might be present in a food by generating radiation by accelerated electrons that inactivate organisms directly because of interaction with cell components and indirectly by producing free radicals that disrupt integrity of the cell membrane. E-beam radiation will reduce the number of probable microbiological hazards that could be present while the food remains generally unaffected in texture, taste, and nutritional value. A recent study showed e-beam irradiation to be effective at reducing both,Salmonella,Tennessee and Typhimurium in peanut butter by one log after exposure to less than 1 kGy, highlighting the need to explore this process further. [source] Measurement of Angle and Length of the Eustachian Tube on Computed Tomography Using the Multiplanar Reconstruction TechniqueTHE LARYNGOSCOPE, Issue 7 2007Kenji Takasaki MD Abstract Objective: To compare the anatomic features of the eustachian tube (ET) between children with and without otitis media with effusion (OME) and with adults. Methods: The angle and length of the ET in children with OME (54 ears, OME children) and without OME (50 ears, normal children), as well as those of normal adults (90 ears), were measured on computed tomography using the multiplanar reconstruction technique. Results: The angles of ET in the OME children group, the normal children group, and the normal adult group were 20.4 ± 3.5° and 21.2 ± 4.8°, 19.9 ± 3.4° and 20.0 ± 3.6°, and 27.3 ± 2.7° and 27.3 ± 2.8° on the right and the left sides, respectively. There was no significant difference between the right and the left side in any group (P = .541, P = .952, P = .978). The lengths of ET in the OME children group, the normal children group, and the normal adult group were 37.2 ± 3.0 mm (mean ± SD) and 37.6 ± 3.2 mm, 37.5 ± 3.3 mm and 38.0 ± 3.2 mm, and 42.5 ± 2.8 mm and 42.9 ± 2.9 mm on the right and the left sides, respectively. There was no significant difference between the right and left sides in any group (P = .670, P = .597, and P = .545). Both the angles and lengths were significantly greater in the normal adult group than in either the OME children group or the normal children group (one-way analysis of variance and Fisher's protected least significant difference tests, P < .05), but there was no significant difference in either the angle or length of the ET between the OME and normal children groups (P > .05). In the OME and normal children groups, the angle was observed to constantly increase with age, and the values were found to be within the range of the adult size in all the patients older than 7.5 years and 7.7 years in the OME children group and the normal children group, respectively. As well as the angle, the lengths were observed to constantly increase with age, but the increase appeared to be greater at a younger age (until approximately 3 to 4 years) than at an older age, and the values were found to be within the range of the adult size in all the patients older than 6.8 years and 7.7 years in the OME children group and the normal children group, respectively. Conclusion: The angle and length of the ET are more horizontal and shorter in infants than in adults. However, there is no statistical difference between the angle and length of the ET in infants with and without OME. These results lead us to believe that a short and horizontal ET may not be a main etiologic factor related to high susceptibility to OME in infants and children. [source] Possible role of the adhesin ace and collagen adherence in conveying resistance to disinfectants on Enterococcus faecalisMOLECULAR ORAL MICROBIOLOGY, Issue 6 2008G. Kayaoglu Introduction:, This study aimed to evaluate whether the presence of the ace gene and Ace-mediated binding to collagen confers on Enterococcus faecalis resistance against common endodontic disinfectants. Methods:, Isogenic strains of E. faecalis: OG1RF (wild-type) and TX5256 (ace insertion mutant of OG1RF) were grown in brain,heart infusion broth at 46°C overnight. Standardized bacterial suspensions were pretreated for 1 h either with acid-soluble collagen or acidified phosphate-buffered saline (ac-PBS). Bacteria were challenged with chlorhexidine digluconate (CHX), iodine potassium-iodide (IKI), sodium hypochlorite (NaOCl), and calcium hydroxide [Ca(OH)2]. Samples were removed at 1, 3, and 6 h, and cultured on Todd,Hewitt agar plates. Colonies were counted, the absolute values were log transformed, and the data were statistically analyzed using Fisher's least significant differences test and t -test. Results:, OG1RF was more resistant than TX5256 to IKI, NaOCl, and Ca(OH)2 (P < 0.05). Collagen-exposed OG1RF was more resistant than the ac-PBS-pretreated OG1RF against CHX at 3 h and against IKI at 1 h (P < 0.05); no significant difference was found against NaOCl. As expected, the ace mutant strain, TX5256, pretreated with collagen or ac-PBS did not differ significantly in viability when challenged with CHX, IKI, and NaOCl. An unexpected result was found for Ca(OH)2: collagen-pretreated OG1RF and TX5256 were both more susceptible than ac-PBS-pretreated OG1RF and TX5256, respectively (P < 0.05). Conclusion:, The presence of the ace gene confers resistance against IKI, NaOCl, and Ca(OH)2 on E. faecalis. Exposure to collagen makes the wild-type bacterium more resistant against CHX and IKI; however, exposure to collagen apparently decreases resistance to Ca(OH)2. [source] | ||||||||||