Rummaging through the bin: Modelling marine litter distribution using Artificial Neural Networks.

Marine litter has significant ecological, social and economic impacts, ultimately raising welfare and conservation concerns. Assessing marine litter hotspots or inferring potential areas of accumulation are challenging topics of marine research. Nevertheless, models able to predict the distribution of marine litter on the seabed are still limited. In this work, a set of Artificial Neural Networks were trained to both model the effect of environmental descriptors on litter distribution and estimate the amount of marine litter in the Central Mediterranean Sea. The first goal involved the use of self-organizing maps in order to highlight the importance of environmental descriptors in affecting marine litter density. The second goal was achieved by developing a multilayer perceptron model, which proved to be an efficient method to estimate the regional quantity of seabed marine litter. Results demonstrated that machine learning could be a suitable approach in the assessment of the marine litter issues.

Spatial patterns of genetic diversity in Posidonia oceanica, an endemic Mediterranean seagrass.

Posidonia oceanica is an endemic seagrass species in the Mediterranean Sea. In order to assess levels of genetic structure in this species, the microsatellite polymorphism was analysed from meadows collected in several localities, along the coasts of the Tyrrhenian Sea (Mediterranean Sea). The existence of single population units and the recruitment of seedlings collected in some localities were investigated. Moreover, genetic structure at different spatial scales and biogeographic relationships among populations were also assessed. Our analysis showed the existence of clear patterns of genetic structure in P. oceanica in the area considered in the analysis. P. oceanica, in fact, is present in separate meadows that represent discrete populations, characterized by low genetic diversity. Comparable levels of genetic variability between mature meadows and seedlings were found. Patterns of genetic relatedness among populations seem to be in accord with direction of dominant current flux in the whole area, separating South Tyrrhenian from North Tyrrhenian populations. Moderate levels of gene flow between populations and genetic substructure within populations, together with the finding of the limited role of sexual reproduction in increasing genetic variability, should be a cause for concern for the persistence of this essential resource in the Mediterranean basin.

Emerging fractal properties in gorgonian growth forms (Cnidaria: Octocorallia).

Gorgonian growth has been hitherto studied mostly by investigating the influence of different environmental conditions on shape and orientation. We have made an attempt at analyzing the intrinsic growth properties of these organisms, by using a method capable of pointing out a fractal arrangement. Colony outlines of the gorgonian species Eunicella singularis, Eunicella cavolinii, Paramuricea clavata, and Lophogorgia ceratophyta have been digitized and their length measured by traveling along them with a series of logarithmically increasing steps. When this procedure is used on fractal lines, logarithmic plots of estimated length vs. step show linear trends, whose slope yields the fractal dimension. In gorgonian outlines, due to their limited multi-scale organization, we have found curved trends typical of non-fractal lines. However, non-linear regression analysis has shown that the degree of bending is variable from curve to curve, with differences among species. also, in P. clavata and L. ceratophyta there is a positive correlation between the degree of development and the tendency to assume a fractal geometry. This suggests that gorgonian growth mechanisms retain a self-similar design, which becomes evident only in species combining a large size with a high branch density. Based on these data, possibilities of modeling biological patterns through fractal growth models are questioned.

[Prevention of ischemic heart disease: a feasibility study of health education in the primary school]. / La prevenzione della cardiopatia ischemica: modalità operative per una educazione sanitaria nella scuola elementare.

To verify the level of participation of children and teachers in an educational program, the reliability of the program itself and to determine whether children can modify family's behavioral patterns, a feasibility study was undertaken among the pupils of a primary school. Seventy-two children, belonging to different socio-economic classes, were studied. Children were given a questionnaire before and after the course, which was held by previously trained teachers. Very good participation of children and teachers in the program was observed. On the contrary very low involvement of the parents was achieved. This experience emphasizes the difficulties arising when actions to modify adult's life styles are attempted. On the contrary, a standardized education program, lasting for a whole school year, could be a feasible, useful and not too costly program not only for the primary prevention of coronary artery disease, but for any program of extensive health care.