Discrete Particle Swarm Optimization for the minimum labelling Steiner tree problem

Particle Swarm Optimization is an evolutionary method inspired by the social behaviour of individuals inside swarms in nature. Solutions of the problem are modelled as members of the swarm which fly in the solution space. The evolution is obtained from the continuous movement of the particles that constitute the swarm submitted to the effect of the inertia and the attraction of the members who lead the swarm. This work focuses on a recent Discrete Particle Swarm Optimization for combinatorial optimization, called Jumping Particle Swarm Optimization. Its effectiveness is illustrated on the minimum labelling Steiner tree problem: given an undirected labelled connected graph, the aim is to find a spanning tree covering a given subset of nodes, whose edges have the smallest number of distinct labels

Soccer-related craniomaxillofacial injuries

The authors assessed the rate of craniomaxillofacial fractures in soccer and the areas where they occur, describing above all the injury pattern of this sport. Over a 5-year period (1995-2000) 46 cases of 329 with fractures associated with different sports activities have been surgically operated at the maxillofacial surgery department of the Policlinico "Umberto I" Hospital, University "La Sapienza" of Rome. All data collected have been selected on the basis of sex, age, anatomic site of the fracture, and the practiced sport. Information on injury patterns, severity, and play circumstances have been documented. The department examined 7 sports disciplines, but soccer was responsible for sports-related maxillofacial fractures in 34 of 46 cases (73.9%). All 34 fractures occurred to men. In soccer, the zygomatic and nasal regions are mainly involved. In fact the authors examined zygomatic fractures in 15 cases and nasal fractures in 10 cases. Direct contact between players generally causes soccer-related maxillofacial fractures: head-elbow impacts (21 cases) or head-head impacts (14 cases). The male:female ratio is 6.6:1, while the average age is 25 years for males and 23 years for females. In comparison with other sports (rugby, football, etc.) where physical contact occurs more frequently and the higher incidence of traumatic events justifies the use of protective measures, soccer is not a particularly violent sport. In soccer, maxillofacial traumas are caused by violent impacts between players that take place mainly when the ball is played with the forehead. In this moment there can be an elbow-head impact or a head-head impact. The authors believe that the low incidence of fractures, severity of the lesions, and discomfort caused by possible protective masks make their use unjustified. The data collected during this study witness that in soccer 21 of 34 cases of maxillofacial fractures are caused by elbow-head impacts. This fact suggests a preventive strategy against violent behavior in soccer play. Because the use of any sort of helmet proved impossible, the introduction of more severe penalties and a greater respect for the rules of the game by the players could reduce the percentage of impacts during matches. Impacts cause the most serious and frequent lesions in the maxillofacial region

Preliminary study of feasibility of an experiment looking for excited state double beta transitions in tin

An attempt to study the feasibility of a new experiment to search for double beta decay in $^{112}$Sn and $^{124}$Sn was carried out by using ultra-low background HPGe detector (244 cm$^{3}$) inside the Gran Sasso National Laboratory (LNGS) of the INFN (Italy). A small sample of natural Sn was examined for 2367.5 h. The radioactive contamination of the sample has been estimated. The data has also been considered to calculate the present sensitivity for the proposed search; half-life limits $\sim$ $10^{17} - 10^{18}$ years for $\beta^{+}$EC and EC-EC processes in $^{112}$Sn and $\sim$ $10^{18}$ years for $\beta^{-}\beta^{-}$ transition in $^{124}$Sn were measured. In the last section of the paper the enhancement of the sensitivity for a proposed experiment with larger mass to reach theoretically estimated values of half-lives is discussed.Comment: 20 pages, 11 figures, 4 tables, accepted for publication in NIMA (in press

Linear degenerations of flag varieties: partial flags, defining equations, and group actions

We continue, generalize and expand our study of linear degenerations of flag varieties from Cerulli Irelli et al. (Math Z 287(1–2):615–654, 2017). We realize partial flag varieties as quiver Grassmannians for equi-oriented type A quivers and construct linear degenerations by varying the corresponding quiver representation. We prove that there exists the deepest flat degeneration and the deepest flat irreducible degeneration: the former is the partial analogue of the mf-degenerate flag variety and the latter coincides with the partial PBW-degenerate flag variety. We compute the generating function of the number of orbits in the flat irreducible locus and study the natural family of line bundles on the degenerations from the flat irreducible locus. We also describe explicitly the reduced scheme structure on these degenerations and conjecture that similar results hold for the whole flat locus. Finally, we prove an analogue of the Borel–Weil theorem for the flat irreducible locus

Degenerate flag varieties: moment graphs and Schr\"oder numbers

We study geometric and combinatorial properties of the degenerate flag varieties of type A. These varieties are acted upon by the automorphism group of a certain representation of a type A quiver, containing a maximal torus T. Using the group action, we describe the moment graphs, encoding the zero- and one-dimensional T-orbits. We also study the smooth and singular loci of the degenerate flag varieties. We show that the Euler characteristic of the smooth locus is equal to the large Schr\"oder number and the Poincar\'e polynomial is given by a natural statistics counting the number of diagonal steps in a Schr\"oder path. As an application we obtain a new combinatorial description of the large and small Schr\"oder numbers and their q-analogues.Comment: 25 page

THE CLINICAL SIGNIFICANCE OF TWO DIFFERENT ELECTROMYOGRAPHY NORMALISATION TECHNIQUES IN PATIENTS WITH ANTERIOR CRUCIATE LIGAMENT INSTABILITY DURING TREADMILL WALKING

The purpose of this study is to investigate the clinical outcome of two normalisation techniques in detecting neuromuscular alterations of the quadriceps muscles between injured and non-injured patients diagnosed with ACL knee instability in their right knee during repeated gait cycles on a treadmill. The ensemble average muscle activity of the vastus lateralis and vastus medialis were normalised to either MVC or maximal activation during the gait cycle in eight male and female subjects. Results indicate that the EMG normalised to MVC was more sensitive in detecting differences in activation between the vastus lateralis and vastus medialis than the normalisation to maximal activity during repeated strides. This study indicates the importance of choosing the appropriate normalisation technique when seeking a clinical outcome measure

DAMA/NaI results

The DAMA/NaI set-up of the DAMA experiment has been operative during seven annual cycles and has investigated several rare processes. In particular, it has been realised in order to investigate the model independent annual modulation signature for Dark Matter particles in the galactic halo. With the total exposure collected in the seven annual cycles (107731 kg day) a model independent evidence for the presence of a Dark Matter particle component in the galactic halo has been pointed out at 6.3 sigma C.L.. Some of the many possible corollary model dependent quests for the candidate particle have been presented as well.Comment: Contributed paper to the Rencontres de Moriond "Electroweak Interactions and Unified Theories", La Thuile, Aosta Valley, Italy, March 200