First results of systematic studies done with different types of Silicon Photomultipliers

The presented results are obtained during the first steps taken in order to develop a setup and measurement procedures which allow to compare properties of diverse kinds of silicon photomultipliers. The response to low-intensity light was studied for silicon photomultipliers produced by CPTA (Russia), Hamamatsu (Japan), ITC-irst (Italy) and SensL (Ireland).Comment: 3 pages, 3 figures, proceedings of the Internationa Linear Collider Workshop LCWS2007, Hamburg, German

Low Cost NBTI Degradation Detection and Masking Approaches

Performance degradation of integrated circuits due to aging effects, such as Negative Bias Temperature Instability (NBTI), is becoming a great concern for current and future CMOS technology. In this paper, we propose two monitoring and masking approaches that detect late transitions due to NBTI degradation in the combinational part of critical data paths and guarantee the correctness of the provided output data by adapting the clock frequency. Compared to recently proposed alternative solutions, one of our approaches (denoted as Low Area and Power (LAP) approach) requires lower area overhead and lower, or comparable, power consumption, while exhibiting the same impact on system performance, while the other proposed approach (denoted as High Performance (HP) approach) allows us to reduce the impact on system performance, at the cost of some increase in area and power consumption

Approach to a rational rotation number in a piecewise isometric system

We study a parametric family of piecewise rotations of the torus, in the limit in which the rotation number approaches the rational value 1/4. There is a region of positive measure where the discontinuity set becomes dense in the limit; we prove that in this region the area occupied by stable periodic orbits remains positive. The main device is the construction of an induced map on a domain with vanishing measure; this map is the product of two involutions, and each involution preserves all its atoms. Dynamically, the composition of these involutions represents linking together two sector maps; this dynamical system features an orderly array of stable periodic orbits having a smooth parameter dependence, plus irregular contributions which become negligible in the limit.Comment: LaTeX, 57 pages with 13 figure

Dynamic Anomalies of Fluids with Isotropic Doubled-Ranged Potential

Using molecular dynamics simulations we investigate the ability of an analytical three-dimensional double well in reproducing static and dynamic anomalies found experimentally in liquid water. We find anomalous behavior in the stable region of the phase diagram if the outer minimum is deeper than the inner minimum. In the case of a deeper inner minimum, anomalous behavior is also present but inside the unstable region.Comment: 10 pages, two figure

First results of comparative studies of silicon photomultipliers

The presented results are obtained during the first steps taken in order to develop a set-up and measurement procedures which allow to compare properties of diverse samples of silicon photomultipliers. The response to low-intensity light was studied for silicon photomultipliers produced by CPTA (Russia), Hamamatsu(Japan), ITC-irst (Italy) and SensL (Ireland)

Indirect Detection of Kaluza-Klein Dark Matter from Latticized Universal Dimensions

We consider Kaluza-Klein dark matter from latticized universal dimensions. We motivate and investigate two different lattice models, where the models differ in the choice of boundary conditions. The models reproduce relevant features of the continuum model for Kaluza-Klein dark matter. For the model with simple boundary conditions, this is the case even for a model with only a few lattice sites. We study the effects of the latticization on the differential flux of positrons from Kaluza-Klein dark matter annihilation in the galactic halo. We find that for different choices of the compactification radius, the differential positron flux rapidly converges to the continuum model results as a function of the number of lattice sites. In addition, we consider the prospects for upcoming space-based experiments such as PAMELA and AMS-02 to probe the latticization effect.Comment: 25 pages, 9 figures, LaTeX. Final version published in JCA

Cohomology of bundles on homological Hopf manifold

We discuss the properties of complex manifolds having rational homology of $S^1 \times S^{2n-1}$ including those constructed by Hopf, Kodaira and Brieskorn-van de Ven. We extend certain previously known vanishing properties of cohomology of bundles on such manifolds.As an application we consider degeneration of Hodge-deRham spectral sequence in this non Kahler setting.Comment: To appear in Proceedings of 2007 conference on Several complex variables and Complex Geometry. Xiamen. Chin

Chacarita Project: Conformation and analysis of a modern and documented human osteological collection from Buenos Aires City - Theoretical, methodological and ethical aspects

Osteological reference collections play a key role in bioanthropological research; they allow the development and testing of methods for sexing and aging individuals using different bone and dental attributes. This paper presents the first stage results of the ongoing Chacarita Research Project, which aims to generate and study a reference collection of adult skeletons representative of the contemporary population of Buenos Aires city. The Chacarita Collection is being conformed of unclaimed human remains of individuals of known nationality, sex, age, cause and date of death from the Chacarita Public Cemetery. Unlike other similar endeavors, this sample has been completely exhumed using archaeological techniques. So far, a total of 146 adult skeletons have been recovered (60 females - 41.1% - and 86 males - 58.90% -), the majority of which have ages-at-death in the range of 71-90 years. They were born primarily in Argentina (n = 133; 91.1%), although other nationalities are also represented. Dates of death go between 1987 and 2000. In the short term, the osteological study of this collection will allow assessment of the performance of classical methods of sex determination and age-at-death estimation in a local setting. A special priority will be given to the study of osteological changes in individuals over 50 years. As the sample is being retrieved by exhumation, the impact of taphonomic agents on the most diagnostic bones structures is also being assessed. In the long term, this osteological collection will be available to generate new population-specific techniques, and to develop comparative biological studies.Fil: Bosio, L. A.. Universidad de Buenos Aires. Facultad de Medicina. Cátedra de Medicina Legal y Deontología Médica. Servicio de Antropología Forense; ArgentinaFil: García Guraieb, S.. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; ArgentinaFil: Luna, Leandro Hernan. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Museo Etnográfico "Juan B. Ambrosetti"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aranda, C.. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Museo Etnográfico "Juan B. Ambrosetti"; Argentin