The Wonder of Colors and the Principle of Ariadne

The Principle of Ariadne, formulated in 1988 ago by Walter Carnielli and Carlos Di Prisco and later published in 1993, is an infinitary principle that is independent of the Axiom of Choice in ZF, although it can be consistently added to the remaining ZF axioms. The present paper surveys, and motivates, the foundational importance of the Principle of Ariadne and proposes the Ariadne Game, showing that the Principle of Ariadne, corresponds precisely to a winning strategy for the Ariadne Game. Some relations to other alternative. set-theoretical principles are also briefly discussed

Experimental tests on shallow foundations of onshore wind turbine towers

The current effort towards the progressive switch from carbon-based to renewable energy production is leading to a relevant spreading of both on- and off-shore wind turbine towers. Regarding reinforced concrete shallow foundations of onshore wind turbine steel towers, possible reductions of reinforcement may increase their sustainability, speed of erection, and competitiveness. The article presents the results of an experimental program carried out at Politecnico di Milano concerning both cyclic and monotonic loading, simulating extreme wind conditions on 1:15 scaled models of wind turbine steel towers connected by stud bolt adapters to reinforced concrete shallow foundations embedded in a sandy soil. Three couples of foundation specimens were tested with different reinforcement layouts: (a) similar to current praxis, (b) without shear reinforcement, and (c) without shear reinforcement and with 50% of ordinary steel rebars replaced by steel fibers. Additional vertical loads were added to the small-scale models in order to ensure similarity in terms of stresses. The test results allowed to (i) characterize the mechanical behavior of the foundation element considering soil-structure interaction under both service and ultimate load conditions, (ii) assess the foundation failure mode, (iii) highlight the role of each typology of reinforcing bars forming the cage, and (iv) provide hints for the optimization of these latter

Honey Bees (Apis mellifera, L.) as Active Samplers of Airborne Particulate Matter

© 2015 Negri et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. [CC by 4.0] The attached file is the published version of the article

On the Role of Electric Charge and Cosmological Constant in Structure Scalars

The physical meaning of structure scalars is analyzed for charged dissipative spherical fluids and for neutral dust in the presence of cosmological constant. The role played by such factors in the structure scalars is clearly brought out and physical consequences are discussed. Particular attention needs to be paid to the changes introduced by the above mentioned factors in the inhomogeneity factor and the evolution of the expansion scalar and the shear tensor.Comment: 5 pages Latex. Published in Phys. Rev. D. Some typos correcte

Expansion-Free Cavity Evolution: Some exact Analytical Models

We consider spherically symmetric distributions of anisotropic fluids with a central vacuum cavity, evolving under the condition of vanishing expansion scalar. Some analytical solutions are found satisfying Darmois junction conditions on both delimiting boundary surfaces, while some others require the presence of thin shells on either (or both) boundary surfaces. The solutions here obtained model the evolution of the vacuum cavity and the surrounding fluid distribution, emerging after a central explosion. This study complements a previously published work where modeling of the evolution of such kind of systems was achieved through a different kinematical condition.Comment: 9 pages, Revtex. Typos corrected. Published in Int. J. Mod. Phys.

Giardia duodenalis assemblages and Entamoeba species infecting non-human primates in an Italian zoological garden: zoonotic potential and management traits

<p>Abstract</p> <p>Background</p> <p><it>Giardia duodenalis </it>and <it>Entamoeba </it>spp. are among the most common intestinal human protozoan parasites worldwide and they are frequently reported in captive non-human primates (NHP). From a public health point of view, infected animals in zoos constitute a risk for animal caretakers and visitors. In this study we carried out the molecular identification of <it>G. duodenalis </it>and <it>Entamoeba </it>spp. from nine species of primates housed in the zoological garden of Rome, to better ascertain their occurrence and zoonotic potential.</p> <p>Results</p> <p><it>G. duodenalis </it>was found only in <it>Lemur catta </it>(47.0%). <it>Entamoeba </it>spp. were detected in all species studied, with the exception of <it>Eulemur macaco </it>and <it>Varecia rubra</it>. The number of positive pools ranged from 5.9% in <it>L. catta </it>to 81.2% in <it>Mandrillus sphinx; </it>in <it>Pan troglodytes </it>the observed prevalence was 53.6%. A mixed <it>Entamoeba</it>-<it>Giardia </it>infection was recorded only in one sample of <it>L. catta</it>. All <it>G. duodenalis </it>isolates belonged to the zoonotic assemblage B, sub assemblage BIV. Three <it>Entamoeba </it>species were identified: <it>E. hartmanni</it>, <it>E. coli </it>and <it>E. dispar</it>.</p> <p>Conclusions</p> <p>Our results highlight the importance of regularly testing animals kept in zoos for the diagnosis of zoonotic parasites, in order to evaluate their pathogenic role in the housed animals and the zoonotic risk linked to their presence. A quick detection of the arrival of pathogens into the enclosures could also be a prerequisite to limit their spread into the structure via the introduction of specific control strategies. The need for molecular identification of some parasite species/genotype in order to better define the zoonotic risk is also highlighted.</p