Survey on HIV risk perception and sexual behaviours among seafarers

Because the nature of their work seafarers spend long periods of time away from their families and therefore represent a group at risk for sexually transmitted diseases, including HIV infection. This paper reports the results of a survey to evaluate awareness and knowledge of the risk of HIV infection among seafarers. Risky behaviours for HIV transmission were also assessed. The survey was conducted using anonymous questionnaires on 197 workers of 9 vessels and 26 office employees of an Italian shipping company (FINAVAL S.p.A., Rome). The respondents considered HIV/AIDS as one of the diseases with a high risk of transmission. Most respondents had a good general knowledge of HIV/AIDS and on the ways of its transmission. However, there is still lack of knowledge on the basics of this disease. On the other hand, in spite of knowledge and awareness about the risks of the disease, only 56.35% of the interviewed crewmembers used protection in sexual intercourse with occasional partners. Compared to data available in literature, the percentage of self-protecting people is increasing, but the number of seafarers exposing themselves to risky behaviours is still high. As expected, condoms are used with regular partners with lower frequency compared to occasional intercourse. The results of this survey indicate that adequate prevention campaigns and major attention paid to seafarers health is useful for stimulating responsible conduct for the prevention of infectious diseases, including HIV infection. Nevertheless, it is still necessary to increase information about the risk of sexually transmitted diseases and how to reduce it. (Int Marit Health 2011; 62, 2: 131–137

Monitoring the Shelf-Life of Minimally Processed Fresh-Cut Apple Slices By Physical–Chemical Analysis and Electronic Nose

Fresh-cut apples, in slices or in cubes, are minimally processed products, which are currently collecting a great interest by fruit marketers for their promising diffusion. Their shelf life, from a microbiological point of view, has been fixed about 2 or 3 weeks under refrigeration. However in a few days they undergo biochemical degradations with production of off-flavors and texture breakdown. In this work, the change of aromatic fingerprint of apple slices packaged in air and in a modified atmosphere (with 100% N2) and stored at 4°C was measured, by using a commercial electronic nose. The obtained data were also compared with sensory evaluation of judge’s panel. Moreover, quality parameters such as total acidity, total soluble solids and firmness were determined at different storage times (0, 4, 8 and 12 days). The data show that the electronic nose is able to discriminate between the two different storage conditions applied: the multivariate analysis, Principal Component Analysis, presents clearly differences among the four sampling times when the apple slices are stored in air and in N2. Our results indicate that the electronic nose can be considered a valid supplementary tool to human sensory panel assessment especially in food quality safety and control and it can be a simple, objective and rapid method to control the food quality during the storage

Alcune considerazioni sull’analisi multidimensionale dei dati nella valutazione dei servizi di day surgery

The evaluation of the quality on the Day Surgery service is an actual problem. The conceptual models proposed in literature allow to collected data of the different nature: ordinal, compositional, and so on. The multidimensional analysis of these data gives more problems and difficulties. Aim of this paper is to think about the mentioned problems as well as to suggest suitable multidimensional methods. Finally, the appropriateness of the inclusion the external information in a customers satisfaction framework is given

Construction and Analysis of Projected Deformed Products

We introduce a deformed product construction for simple polytopes in terms of lower-triangular block matrix representations. We further show how Gale duality can be employed for the construction and for the analysis of deformed products such that specified faces (e.g. all the k-faces) are ``strictly preserved'' under projection. Thus, starting from an arbitrary neighborly simplicial (d-2)-polytope Q on n-1 vertices we construct a deformed n-cube, whose projection to the last dcoordinates yields a neighborly cubical d-polytope. As an extension of thecubical case, we construct matrix representations of deformed products of(even) polygons (DPPs), which have a projection to d-space that retains the complete (\lfloor \tfrac{d}{2} \rfloor - 1)-skeleton. In both cases the combinatorial structure of the images under projection is completely determined by the neighborly polytope Q: Our analysis provides explicit combinatorial descriptions. This yields a multitude of combinatorially different neighborly cubical polytopes and DPPs. As a special case, we obtain simplified descriptions of the neighborly cubical polytopes of Joswig & Ziegler (2000) as well as of the ``projected deformed products of polygons'' that were announced by Ziegler (2004), a family of 4-polytopes whose ``fatness'' gets arbitrarily close to 9.Comment: 20 pages, 5 figure

Bounding Helly numbers via Betti numbers

We show that very weak topological assumptions are enough to ensure the existence of a Helly-type theorem. More precisely, we show that for any non-negative integers $b$ and $d$ there exists an integer $h(b,d)$ such that the following holds. If $\mathcal F$ is a finite family of subsets of $\mathbb R^d$ such that $\tilde\beta_i\left(\bigcap\mathcal G\right) \le b$ for any $\mathcal G \subsetneq \mathcal F$ and every $0 \le i \le \lceil d/2 \rceil-1$ then $\mathcal F$ has Helly number at most $h(b,d)$. Here $\tilde\beta_i$ denotes the reduced $\mathbb Z_2$-Betti numbers (with singular homology). These topological conditions are sharp: not controlling any of these $\lceil d/2 \rceil$ first Betti numbers allow for families with unbounded Helly number. Our proofs combine homological non-embeddability results with a Ramsey-based approach to build, given an arbitrary simplicial complex $K$, some well-behaved chain map $C_*(K) \to C_*(\mathbb R^d)$.Comment: 29 pages, 8 figure

The ℓs\ell^s-boundedness of a family of integral operators on UMD Banach function spaces

We prove the $\ell^s$-boundedness of a family of integral operators with an operator-valued kernel on UMD Banach function spaces. This generalizes and simplifies earlier work by Gallarati, Veraar and the author, where the $\ell^s$-boundedness of this family of integral operators was shown on Lebesgue spaces. The proof is based on a characterization of $\ell^s$-boundedness as weighted boundedness by Rubio de Francia.Comment: 13 pages. Generalization of arXiv:1410.665

Constructing Delaunay triangulations along space-filling curves

Incremental construction con BRIO using a space-filling curve order for insertion is a popular algorithm for constructing Delaunay triangulations. So far, it has only been analyzed for the case that a worst-case optimal point location data structure is used which is often avoided in implementations. In this paper, we analyze its running time for the more typical case that points are located by walking. We show that in the worst-case the algorithm needs quadratic time, but that this can only happen in degenerate cases. We show that the algorithm runs in O(n logn) time under realistic assumptions. Furthermore, we show that it runs in expected linear time for many random point distributions. This research was supported by the Deutsche Forschungsgemeinschaft within the European graduate program ’Combinatorics, Geometry, and Computation’ (No. GRK 588/2) and by the Netherlands’ Organisation for Scientific Research (NWO) under BRICKS/FOCUS grant number 642.065.503 and project no. 639.022.707