Factors Associated to Endemic Dental Fluorosis in Brazilian Rural Communities

The present paper examines the relationship between hydrochemical characteristics and endemic dental fluorosis, controlling for variables with information on an individual level. An epidemiological survey was carried out in seven rural communities in two municipalities in the state of Minas Gerais, Brazil. The Thystrup & Fejerskov index was employed by a single examiner for the diagnosis of dental fluorosis. A sampling campaign of deep groundwater in the rural communities of interest was carried out concomitantly to the epidemiological survey for the determination of physiochemical parameters. Multilevel modeling of 276 individuals from seven rural communities was achieved using the non-linear logit link function. Parameters were estimated using the restricted maximum likelihood method. Analysis was carried out considering two response variables: presence (TF 1 to 9) or absence (TF = 0) of any degree of dental fluorosis; and presence (TF ≥ 5—with loss of enamel structure) or absence of severe dental fluorosis (TF ≤ 4—with no loss of enamel structure). Hydrogeological analyses revealed that dental fluorosis is influenced by the concentration of fluoride (OR = 2.59 CI95% 1.07–6.27; p = 0.073) and bicarbonate (OR = 1.02 CI95% 1.01–1.03; p = 0.060) in the water of deep wells. No other variable was associated with this prevalence (p > 0.05). More severe dental fluorosis (TF ≥ 5) was only associated with age group (p < 0.05). No other variable was associated to the severe dental fluorosis (p > 0.05). Dental fluorosis was found to be highly prevalent and severe. A chemical element besides fluoride was found to be associated (p > 0.05) to the prevalence of dental fluorosis, although this last finding should be interpreted with caution due to its p value

Energy calibration and resolution of the CMS electromagnetic calorimeter in pp collisions at s\sqrt{s} = 7 TeV

The energy calibration and resolution of the electromagnetic calorimeter (ECAL) of the CMS detector have been determined using proton-proton collision data from LHC operation in 2010 and 2011 at a centre-of-mass energy of sqrt(s)=7 TeV with integrated luminosities of about 5 inverse femtobarns. Crucial aspects of detector operation, such as the environmental stability, alignment, and synchronization, are presented. The in-situ calibration procedures are discussed in detail and include the maintenance of the calibration in the challenging radiation environment inside the CMS detector. The energy resolution for electrons from Z-boson decays is better than 2% in the central region of the ECAL barrel (for pseudorapidity abs(eta)<0.8) and is 2-5% elsewhere. The derived energy resolution for photons from 125 GeV Higgs boson decays varies across the barrel from 1.1% to 2.6% and from 2.2% to 5% in the entraps. The calibration of the absolute energy is determined from Z to e+e- decays to a precision of 0.4% in the barrel and 0.8% in the endcaps