PURPOSE: To determine whether family income, age and educational level of the mother of the family are associated with self-reported use of dental floss over a 13-year period in a city in southern Brazil. MATERIALS AND METHODS: A comparison of two household surveys was carried out where mothers of the family were interviewed using a structured questionnaire in order to obtain demographic, behavioural and socioeconomic information. In total, 852 and 984 households were included in 1996 and 2009, respectively. Self-reported use of dental floss was assessed dichotomously (yes/no). Poisson regression models were fitted to study the association between sociodemographic variables with the use of dental floss. Proportion ratios (PR) and 95% confidence intervals (95% CI) were reported. RESULTS: The proportion of dental floss use increased from 48% to 59% over 13 years. The probability of dental floss use increased 1.23 times from 1996 to 2009 (PR = 1.23; 95% CI 1.13-1.34). Households with mothers >/=50 years old presented a 28% lower probability of using dental floss than households with mothers

O presente artigo pretende inserir o teólogo franciscano Geraldo Odon (ca. 1290-1349) no debate historiográfico medieval acerca das diferentes solções oferecidas ao célebre paradoxo do mentiroso. Na primeira parte a autora apresenta rapidamente e de forma esquemática os principais tipos de solução ao sofisma para em seguida analisar o texto de Odon, respondendo à questão da sua originalidade.

The operator effect is a well-known analytical bias already quantified in some taphonomic studies. However, the influence of operator bias in the replicability on taphonomic studies has still not been considered. Here, we quantified for the first time this bias using different multivariate statistical techniques, testing if the operator effect is related to the replicability. We analyzed the results reported by 15 operators working on the same dataset. Each operator analyzed 30 bioclasts (bivalve shells) by site, from a total of five sites, considering the following taphonomic attributes: shell fragmentation, edge rounding, corrasion, bioerosion, and color alteration. The operator effect followed the same pattern reported in previous studies, characterized by a worse correspondence for those attributes having more than two levels of damage categories. However, the effect did not appear to have relation to replicability, because nearly all operators found differences among sites. The binary attribute bioerosion exhibited 83{%} of correspondence among operators, but at the same time, it was the taphonomic attribute that showed the highest dispersion among operators (28{%}). Therefore, we concluded that binary attributes, despite indicating a reduction of the operator effect diminishes replicability, result in different interpretations of concordant data. We found that a variance value of nearly 8{%} among operators was enough to generate a different taphonomic interpretation, in a Q-mode cluster analysis. The results reported here showed that the statistical method employed influences the level of replicability and comparability of a study and that the availability of results may be a valid alternative to reduce bias.

Wireless networks are gaining space in industrial environments due to the low installation costs and low maintenance. Robustness is also one of the main requirements for these systems to be adopted, and, in this context, WirelessHART (WH), ISA SP100.11a, and WIA-PA protocols met these characteristics. In order to provide low maintenance, these protocols must provide reliable radio links while keeping low power consumption to allow battery powered devices. Unfortunately, the standards of these protocols do not impose any RF power modulation technique, which is a form to increase even more the battery endurance of a wireless field device. Instead, RF power levels are fixed and selected by commissioning, and must allow the longest link per device. In this case, devices in closer ranges waste energy during transmissions, as they could save energy by modulating the RF power. This paper presents a RF power modulation technique that employs a proportional-integral controller and allows reduction of energy consumption while keeping the robustness of RF links. A proof of concept of the power modulation technique is implemented and verified showing good results and proving that the proposed controller is feasible. The proposal has the advantage to be fully compatible with the standard.