Structural equation modelling to estimate facial soft tissue thickness parameters based on ethnicity, gender and body mass index: a secondary study on an Iranian dataset.

PURPOSE: According to the anthropological importance of soft facial tissue thickness parameters, we aimed to find the association of these parameters with Lur and Arab ethnicities, gender and body mass index (BMI). Structural equation modeling (SEM) was used. METHODS: As a secondary analysis, SEM was performed on a dataset of 100 participants. The participants were from Lur and Arab populations of Ahvaz province, Iran, from those who referred for magnetic resonance imaging (MRI) due to headache. RESULTS: Multivariate regression illustrated that mental eminence (ME), chain-lip fold (CLF) and end of nasals (END) could not be predicted by the independent variables (p > 0.05). Right masseteric region (RMST) had the maximum predictability with R2 = 0.365, followed by middle philtrum (MID) with R2 = 0.358 (p < 0.001). With respect to our criterion to enter SEM, i.e. existing at least two significant covariates at significance level of 0.05, among staying parameters, only parameters of nasion (NA), MID, superior lip (SL), RMST and left masseteric region (LMST) remained. Among these cases, MID was the only parameter that its three covariates illustrated significant association. CONCLUSION: MID parameter can be predicted by gender, BMI and Arab ethnicity. By carrying out such studies and creating database, such information can be used in plastic surgery, corpse identification, and facial reconstruction software in archeology.

Construction of a sensitive and specific lead biosensor using a genetically engineered bacterial system with a luciferase gene reporter controlled by pbr and cadA promoters.

BACKGROUND: A bacterial biosensor refers to genetically engineered bacteria that produce an assessable signal in the presence of a physical or chemical agent in the environment. METHODS: We have designed and evaluated a bacterial biosensor expressing a luciferase reporter gene controlled by pbr and cadA promoters in Cupriavidus metallidurans (previously termed Ralstonia metallidurans) containing the CH34 and pI258 plasmids of Staphylococcus aureus, respectively, and that can be used for the detection of heavy metals. In the present study, we have produced and evaluated biosensor plasmids designated pGL3-luc/pbr biosensor and pGL3-luc/cad biosensor, that were based on the expression of luc+ and under the control of the cad promoter and the cadC gene of S. aureus plasmid pI258 and pbr promoter and pbrR gene from plasmid pMOL30 of Cupriavidus metallidurans. RESULTS: We found that the pGL3-luc/pbr biosensor may be used to measure lead concentrations between 1-100 µM in the presence of other metals, including zinc, cadmium, tin and nickel. The latter metals did not result in any significant signal. The pGL3-luc/cad biosensor could detect lead concentrations between 10 nM to 10 µM. CONCLUSIONS: This biosensor was found to be specific for measuring lead ions in both environmental and biological samples.