On the forces that cable webs under tension can support and how to design cable webs to channel stresses.

In many applications of structural engineering, the following question arises: given a set of forces ,  , …,  applied at prescribed points ,  , …,  , under what constraints on the forces does there exist a truss structure (or wire web) with all elements under tension that supports these forces? Here we provide answer to such a question for any configuration of the terminal points ,  , …,  in the two- and three-dimensional cases. Specifically, the existence of a web is guaranteed by a necessary and sufficient condition on the loading which corresponds to a finite dimensional linear programming problem. In two dimensions, we show that any such web can be replaced by one in which there are at most elementary loops, where elementary means that the loop cannot be subdivided into subloops, and where is the number of forces ,  , …,  applied at points strictly within the convex hull of ,  , …,  .

Field patterns: a new mathematical object.

Field patterns occur in space-time microstructures such that a disturbance propagating along a characteristic line does not evolve into a cascade of disturbances, but rather concentrates on a pattern of characteristic lines. This pattern is the field pattern. In one spatial direction plus time, the field patterns occur when the slope of the characteristics is, in a sense, commensurate with the space-time microstructure.

[Latex gloves dermatitis in health care workers].

With regard to health care workers the irritative contact dermatitis represents about the 80% of all the dermopathies in sanitary staff whereas the allergic contact dermatitis covers approximately the 20% of the professional dermatoses. In our study 4 cases of allergy to latex in hospital nurses are presented; the clinical history is described for each of them as well as the resulting judgment of suitability to the specific work. In general population the allergy to latex is estimated to be approximately 1-6%; in sanitary staff it rises to 5-12%.

[Fitness to work and diabetes in health care workers].

Diabetes mellitus is a disease of great social relief that has a deep impact also in working life. Our short paper wants to highlight some critical aspects that occupational physician must deal with both in preventive and periodic health evaluation for diabetic subjects. In our study, performed on health care workers, we reported 16 cases of diabetes; 10 of them were nurses, 5 sanitary auxiliaries and 1 sanitary technical operator.