La luce è quando mi sveglio la mattina. Un percorso sulla luce in quarta e quinta elementare

pp.77-110È possibile avventurarsi nel mondo dei fenomeni fisici in modo semplice ed avvincente con i bambini delle scuole elementari? Come accompagnarli gradualmente dall'esperienza quotidiana ai primi concetti scientifici? Nell'anno scolastico 2003/2004 il Laboratorio per la Didattica delle Scienze "Eureka" di Trieste proponeva un percorso di ricerca-azione sulla luce. Gli incontri con il gruppo ci hanno permesso di individuare alcuni passaggi chiave nella costruzione delle idee su luce, buio e colori. Confortate dal ricco repertorio di possibili esperienze da proporre in classe, abbiamo deciso di avviare il lavoro con i ragazzi. L'itinerario che descriviamo ha coinvolto 5 classi (96 bambini in tutto) e si è svolto tra l'ultimo bimestre dell'anno 2003/2004 ed il primo trimestre dell'anno successivo. È stato condotto dagli insegnanti di scienze, che hanno operato sempre con l'intero gruppo-classe, utilizzando prevalentemente materiali di recupero. Il percorso è iniziato con il confronto delle idee dei bambini su luce e buio ed è stato costruito, nei suoi passaggi successivi, a partire dalle loro risposte.Can you venture into the world of physical phenomena in a simple and addictive manner with elementary school children? How to gradually accompany them from daily experience to the first scientific concepts? In the academic year 2003/2004, the Trieste "Eureka" Science Didactics Laboratory proposed a light-search-action path. The meetings with the group enabled us to identify some key steps in building ideas on light, darkness, and colors. Convinced by the rich repertoire of possible experiences to be offered in class, we decided to start work with the kids. The route we are describing involved 5 classes (96 children all) and took place between the last two months of 2003/2004 and the first quarter of the following year. It was led by science teachers, who have always worked with the whole group-class, using mostly recovery materials. The journey began with the comparison of the ideas of children on light and dark and was built, in its subsequent steps, from their responses

Barrett's esophagus and adenocarcinoma risk: the experience of the North-Eastern Italian Registry (EBRA)

OBJECTIVE: To establish the incidence and risk factors for progression to high-grade intraepithelial neoplasia (HG-IEN) or Barrett's esophageal adenocarcinoma (BAc) in a prospective cohort of patients with esophageal intestinal metaplasia [(BE)]. BACKGROUND: BE is associated with an increased risk of BAc unless cases are detected early by surveillance. No consistent data are available on the prevalence of BE-related cancer, the ideal surveillance schedule, or the risk factors for cancer. METHODS: In 2003, a regional registry of BE patients was created in north-east Italy, establishing the related diagnostic criteria (endoscopic landmarks, biopsy protocol, histological classification) and timing of follow-up (tailored to histology) and recording patient outcomes. Thirteen centers were involved and audited yearly. The probability of progression to HG-IEN/BAc was calculated using the Kaplan-Meier method; the Cox regression model was used to calculate the risk of progression. RESULTS: HG-IEN (10 cases) and EAc (7 cases) detected at the index endoscopy or in the first year of follow-up were considered to be cases of preexisting disease and excluded; 841 patients with at least 2 endoscopies {median, 3 [interquartile range (IQR): 2-4); median follow-up = 44.6 [IQR: 24.7-60.5] months; total 3083 patient-years} formed the study group [male/female = 646/195; median age, 60 (IQR: 51-68) years]. Twenty-two patients progressed to HG-IEN or BAc (incidence: 0.72 per 100 patient-years) after a median of 40.2 (26.9-50.4) months. At multivariate analysis, endoscopic abnormalities, that is, ulceration or nodularity (P = 0.0002; relative risk [RR] = 7.6; 95% confidence interval, 2.63-21.9), LG-IEN (P = 0.02, RR = 3.7; 95% confidence interval, 1.22-11.43), and BE length (P = 0.01; RR = 1.16; 95% confidence interval, 1.03-1.30) were associated with BE progression. Among the LG-IEN patients, the incidence of HG-IEN/EAc was 3.17 patient-years, that is, 6 times higher than in BE patients without LG-IEN. CONCLUSIONS: These results suggest that in the absence of intraepithelial neoplastic changes, BE carries a low risk of progression to HG-IEN/BAc, and strict surveillance (or ablative therapy) is advisable in cases with endoscopic abnormalities, LG-IEN or long BE segments