Activity

Value of dielectric constant (i.e. ~11-12 at log f = 4.0), hardness (~13 GPa) and fracture toughness observed under all conditions are well in agreement to be used for biological implants. Disks of aged t-ZrO2 nanoparticles are checked for their biodegradation test by dipping in simulated body fluid for several weeks. ZrO2, with 26 weeks of immersion, shows small loss in hardness and weight. Stabilized tetragonal zirconia shows strong anti-oxidant activity. Stabilized ZrO2 nanoparticles presented strong antibacterial activity against both gram positive (S. aureus, Bacillus) and gram negative (E. coli) bacteria. Thus, structural and mechanical stability of zirconia (checked after 6 and 12 months) make this material highly beneficial for long term use in biomedical applications.The present work introduces nanostructured Zr as a possible choice of metallic implant biomaterial in competition with titanium and its new alloys. The paper reports on the preparation of anodized zirconium in a mixture of electrolytes with fluoride ions, 1 M (NH4)2SO4 + 0.15 M NH4F + distilled water, at 20 V. The obtained nanostructures were investigated by SEM, EDX, XRD and AFM techniques. The SEM – EDX longitudinal and cross sectional analysis revealed the morphology of the formed oxide layers and their thicknesses, which were found to be 7.45 ± 0.18 μm. The mean nanopores’ diameter was calculated as 15.8 ± 3.3 nm. The XRD investigations enabled the evaluation of crystallite sizes and texture coefficients for zirconium and zirconium oxide containing samples. The inhibition effect against Escherichia coli and Streptococcus Aureus bacteria was evaluated and discussed as well. The AFM studies revealed that the nano-porous Zr has similar hardness parameter as the uncoated Zr, but lower surface adhesion force that could be translated into improved properties in terms of antimicrobial effects, as confirmed by its inhibition index, which makes it a very promising material for bio-medical applications.Pathology and putative virulence factor expression of three Histomonas meleagridis isolates differing in geographic origin, cell passage number (56 or 100), or cell populations grown from a monoculture were compared. Turkey poults inoculated with the high cell passage number isolates or monoculture isolates varied in gross lesion severity and weight gain (P less then 0.0001). Screening of a published H. meleagridis cDNA library identified forty- eight cysteine proteinases (CP) and one superoxide dismutase (Fe-SOD) proposed to function in either tissue damage and/or invasion and oxidative defense. The Fe-SOD and eight CPs were analyzed using real time polymerase chain reaction. CP2, CP3, and CP8 showed significant differences in expression among the field isolates (P ≤ 0.05). The high passage isolates had decreased CP2, CP3 and CP4 expression when compared with their field isolate. CP7 did not differ between field isolates or the 56-passaged isolate. The Fe-SOD gene showed significant differences in expression among the various isolates. When exposing cultured H. meleagridis to air, Fe-SOD expression decreased rapidly during the first hour of air exposure but increased progressively through the next 3 h. This study provides information on gross pathology and virulence factors associated with various isolates of Histomonas meleagridis which can aid in determining the pathogenetic mechanisms used by this organism.Worm control is an important aspect of the successful management of the egg production industry. Of particular concern is Ascaridia galli, which at high parasite loads affect health and production in layers. BMS-232632 mouse Application of a targeted treatment strategy (TT) to control A. galli has shown promise. The purpose of this study was to explore the effect of such a strategy on welfare indicators and production performance of layers. Six flocks (F1-6) on a commercial farm were allocated to three treatment groups. Flocks F1 and F4 were treated (TT) with fenbendazole at 22, 27 and 36 weeks post-placement (WPP). Flocks F2 and F5 were treated at 27 WPP (conventional treatment, CT) and hens in flocks F3 and F6 served as untreated (UT) control groups. At 19, 35 and 45 WPP twenty-five hens plus thirty eggs per flock were randomly selected. Hens were weighed and their plumage conditions (PC) were assessed. The eggs were subjected to various external and interior quality analyses. Production data such as number of eggs/hen/week, egg mass and feed conversion ratio (FCR) were calculated from raw data obtained from all flocks on a weekly basis. The number of eggs/hen/week, egg mass and FCR were higher (P  less then  0.05) in the TT flocks and hens had better PC both at 35 and 45 WPP compared with other flocks. No differences in body weight and physical egg quality were observed between groups except for egg shell strength which was higher (P  less then  0.05) in the CT flocks. These data suggest that better production performance and plumage, which suggests improved health, can be achieved through the application of a TT strategy. The insights gained from this research should help to justify the extra cost and labor associated with the TT strategy.A hierarchical Bayesian peak over threshold (POT) approach is proposed for conflict-based before-after safety evaluation of Leading Pedestrian Intervals (LPI). The approach combines traffic conflicts of different sites and periods to develop a uniform generalized Pareto distribution (GPD) model for the treatment effect estimation. The hierarchical structure has three levels, a data level that consists of modeling the traffic conflict extremes through the POT approach, a latent process level that relates GPD parameters of the data level to certain covariates, and a prior level with prior distributions to characterize the latent process. The approach was applied to a before-after (BA) safety evaluation of leading pedestrian interval (LPI) in Vancouver, BC. Pedestrian-vehicle traffic conflicts were collected from treatment and control sites during the before and after periods using an automated computer vision analysis technique. The treatment effect was measured by the best fitted GPD model with the calculation of the odds ratio (OR).