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Este trabalho tem como objetivo principal desenvolver algumas construções dinâmicas e interativas com o apoio do GeoGebra, que auxiliem o ensino/aprendizagem da geometria. O trabalho centra-se na construção de aplicações interativas que facilitem a perceção do porquê das fórmulas utilizadas para o cálculo das áreas de polígonos e do círculo. Começa-se por ilustrar a fórmula de cálculo da área do retângulo, para de seguida, se ilustrarem as fórmulas de cálculo das áreas do paralelogramo, do triângulo, do trapézio, do papagaio e finalmente do círculo. Sempre que pertinente, as figuras são decompostas e “transformadas” num retângulo equivalente (com igual área). Procurou-se que as transformações utilizadas ajudassem a compreender as expressões que se obtêm para o cálculo da área de cada figura.

Introduction: In recent years, Italy has seen a reduction in workplace accidents due to several factors, including the controls carried out by the Health and Safety at Work Services (PSAL) of the Local Health Units (ATS)., Objective: To verify the contribution of PSAL Services to injury reduction. In particular, to identify the existence of a difference between incidence rates of accidents in companies before and after inspections and possible variations in rates between inspected and non-inspected companies., Methods: We analyzed data of the activities carried out by the PSAL Services of the Lombardy Region in the system I.M.Pre.S@ (Computerization and Health Prevention Monitoring) in the period 2010-2015, together with data from the Regional Accident Database of the National Institute for Insurance against Accidents at Work (INAIL). The "difference in difference" (DID) method was used to evaluate the different effect on inspected and non-inspected industries., Results: Between the pre- and post-vigilance periods, inspected companies showed a greater reduction either of total injury rates (DID=-2.7 per 1000 worker-years; 90% confidence interval (CI): -4.1; -1.3) or of severe injury rates (DID=-1.1; 90% CI: -1.7; -0.5). These effects were visible in the majority of ATS and occupational sectors., Conclusions: This study, made possible by a valid and efficient regional data tracking system, has shown the positive effect of the PSAL prevention actions on the frequency of both total and severe injuries.

The goal of our study was to estimate the presence (or absence) of latero-cervical nodal metastases (pN+), in patients with squamous oropharyngeal cancer, correlating this finding with T stage. We examined 255 patients out of 329 affected by squamous oropharyngeal cancer, from 1976 to 2005. The 255 patients examined were treated surgically (both T and N). As far as clinical latero-cervical nodal metastases were concerned, 215 patients (84%) were cN+, while 40% (16%) were cN-. The result of the histological examination showed that 82% of the neck dissections (both cN+ and cN-) actually had latero-cervical metastases, while the remaining patients had reactive lymph nodes. The false-positive (cN+ -->pN-) patients, were 14% while false-negative patients (cN- -->pN+) amounted to 63%. The correlation between T and pN+ of the patients classified as cN- showed that 24% of patients were T1, 44% T2, 32% T3, and none T4; the pN+ patients, who clinically manifested latero-cervical lymph-node metastases were: T1 8%, T2 15%, T3 37%, T4 40%. Analysis of these data led us to the conclusion that, in view of the high lymphophilia of squamous cancer in the oropharyngeal district, it would be advisable to treat N metastases, both cN+ and cN-, at any T stage of cancer, surgically or with chemo- or radiotherapy, according to the patient's performance status.