Effects of tillage on porosity and microstructure of a loam soil

Changes in porosity, shape, size and length of pores and microstructure in a loam soil under different types of tillage were examined. A micromorphological method was used to evaluate soil structure, characterizing porosity in soil thin sections prepared from undisturbed soil samples by means of electro-optical image analysis (Quantimet 720). Results showed that both total porosity and number of pores in topsoil were not significantly different among the plots under different types of tillage. Below the topsoil (10–15 cm) in the plots tilled by a disc harrow porosity decreased substantially making for a massive structure. In the 25–30 cm layer porosity was not significantly different in plots ploughed to a depth of 25 cm than in those ploughed to a depth of 50 cm. In the chisel ploughed plots porosity seemed to be more homogeneously distributed along the Ap horizon. Modifications in pore shape, size distribution and length and in microstructure were also observed. Surface crusts formed frequently in ploughed plots

Improving sun-protection behavior among children: Results of a cluster-randomized trial in Italian elementary schools. The "SoleSi SoleNo-GISED" project

A history of sunburns in early life nearly doubles the risk of developing malignant melanoma in adulthood. From 2001 to 2004, we conducted a cluster-randomized trial of an educational intervention to reduce sunburn rates (primary outcome) and improve sun-protection behavior (secondary outcome) in schoolchildren. A total of 122 Italian primary schools (grades 2 and 3) were randomized to receive, or not, an intervention consisting of an educational curriculum at school, conducted by trained teachers, which included the projection of a short video and the distribution of booklets to children and their parents. Behavior while in the sun was assessed at baseline and 14-16 months after baseline. In a subgroup (44% of the total sample), melanocytic nevi were also counted. Of the 11,230 children enrolled, 8,611 completed the study. A total of 1,547 children (14%) reported a history of sunburns at baseline. At follow-up, no difference in sunburn episodes was documented between the study groups (odds ratio 0.97, 95% confidence interval 0.84-1.13) and similar sun-protection habits were reported. No significant impact of the proposed educational program was documented at 1-year follow-up. Innovative strategies need to be developed to increase the effectiveness of future educational interventions in this area. © 2007 The Society for Investigative Dermatology

Distribution of congenital melanocytic naevi and congenital naevus-like naevi in a survey of 3406 Italian schoolchildren.

Background Scanty information is available on the prevalence of congenital melanocytic naevi (CMN) and congenital naevus-like naevi (CNLN), particularly the small ones.Objectives To estimate the prevalence of CMN/CNLN in Italian schoolchildren, and to assess variations according to potential risk factors for melanoma.Methods We conducted a survey in 13 Italian areas on 3406 schoolchildren aged 12-17 years. Children were examined by dermatologists who assessed pigmentary traits and made a count of small (6-15 mm in diameter) and medium/large (> 15 mm) CMN/CNLN on 19 anatomical areas.Results Overall, 592 children (17.4%) had one or more CMN/CNLN. Prevalence of small CMN/CNLN was 16.1%, and that of medium/large CMN/CNLN was 1.8%. There was no difference between age groups and sexes. CMN/CNLN were more frequent in children with a higher number of common melanocytic naevi (multivariate odds ratio, OR = 7.1 for the highest vs. the lowest quartile), consistent in small (OR = 7.2) and medium/large CMN/CNLN (OR = 6.0). Family history of malignant melanoma (OR = 1.4) and personal history of diabetes (OR = 4.4) appeared to be directly, and sun exposure inversely associated with CMN/CNLN. No relation was evident between CMN/CNLN and pigmentary traits, anthropometric characteristics, dietary habits, freckles, sunburns, sunscreen use or history of selected diseases.Conclusions The association with family history of melanoma, the strong association with acquired melanocytic naevi, and the lack of association with pigmentary traits and sunburns suggest that CMN/CNLN may act as an independent risk marker for subjects at increased risk for cutaneous melanoma later in life