Majority-vote on directed Small-World networks

On directed Small-World networks the Majority-vote model with noise is now studied through Monte Carlo simulations. In this model, the order-disorder phase transition of the order parameter is well defined in this system. We calculate the value of the critical noise parameter q_c for several values of rewiring probability p of the directed Small-World network. The critical exponentes beta/nu, gamma/nu and 1/nu were calculated for several values of p.Comment: 16 pages including 9 figures, for Int. J. Mod. Phys.

Quantum effective force in an expanding infinite square-well potential and Bohmian perspective

The Schr\"{o}dinger equation is solved for the case of a particle confined to a small region of a box with infinite walls. If walls of the well are moved, then, due to an effective quantum nonlocal interaction with the boundary, even though the particle is nowhere near the walls, it will be affected. It is shown that this force apart from a minus sign is equal to the expectation value of the gradient of the quantum potential for vanishing at the walls boundary condition. Variation of this force with time is studied. A selection of Bohmian trajectories of the confined particle is also computed.Comment: 7 figures, Accepted by Physica Script

Readability of a background map layer under a semi-transparent foreground layer

This study investigates the readability (interpretability) of information presented on a geographical map onto which a semi-transparent multivariate selection layer has been overlaid. The investigation is based on an information visualization prototype developed for a mobile platform (tablet devices) which aimed at supporting epidemiologists and medical staff in field data collection and epidemiological interpretation tasks. Different factors are analysed under varying transparency (alpha blending) levels, including: map interpretation task (covering "seeing map" and "reading map" tasks), legend symbol and map area type. Our results complement other studies that focused on the readability characteristics of items displayed on semi-transparent foreground layers developed in the context of "toolglass" interfaces. The implications of these results to the usability of transparency variable selection layers in geographical map applications are also discussed

Expansão da fronteira agrícola versus recurso terra.

bitstream/CNPA/18318/1/DOC154.pd

A corded-mixed bell beaker vase at the monumental enclosure of Forca, Maia, North of Portugal

The aim of this work is to present a fragment of a corded bell beaker vase (CZ/M) identified at the archaeological site of Forca/Lavra, in North-west of Portugal. Forca is a place that contains monumental structures, similar to other enclosures of the Iberian Peninsula. In Forca, ditches and palisades were built, containing internal fences, pits structures and fireplaces in use, at least, between the Chalcolithic and Bronze Ages. The fragment of the bell beaker vessel appeared inside a ditch, in a Chalcolithic context associated with a radiocarbon date from 2.625 to 2.337 BC. Corded bell beaker vases are rare in the Iberian Peninsula and known only in three other Portuguese prehistoric sites: the enclosure of Porto Torrão, Ferreira do Alentejo, in the Southwest, and the walled enclosures of Castelo Velho de Freixo de Numão and Castanheiro do Vento, both places are located in Vila Nova de Foz Côa, in the Northwest. The first one appeared inside a Chalcolithic level, the second one was in from the beginning of the third quarter of the third millennia BC, and the third one, still unpublished, is also surely of the third millennium BC. Based on its rarity and on these contexts of findings the authors consider the hypothesis that this kind of bell beaker may have been used in a very special way of action and have circulated mainly in places of great importance, collectively serving a significant population group

Ion backflow studies with a triple-GEM stack with increasing hole pitch

Gas Electron Multipliers have undergone a very consistent development since their invention in 1997. Their production procedures have been tuned in such a way that nowadays it is possible to produce foils with areas of the order of the square meter that can operate at a reasonable gain, uniform over large areas and with a good stability in what concerns electrical discharges. For the third run of LHC, they will be included in the CMS and ALICE experiments after significant upgrades of the detectors, confirming that these structures are suitable for very large experiments. In the special case of Time Projection Chambers, the ion backflow and the energy resolution are sensitive issues that must be addressed and the GEM has shown to be able to deal with both of them. In this work, a stack of three GEMs with different pitches has been studied as a possible future approach for ion-backflow suppression to be used in TPCs and other detection concepts. With this approach, an ion backflow of 1 % with an energy resolution of 12 % at 5.9 keV has been achieved with the detector operating in an Ar/CO2 (90/10) mixture at a gain of ~ 2000.Comment: 15 pages, 11 figure

Human case of West Nile neuroinvasive disease in Portugal, summer 2015

A case of West Nile virus (WNV) infection was reported in the Algarve region, Portugal, in the first week of September 2015. WNV is known to circulate in Portugal, with occasional reports in horses and birds (2004 to 2011) and very sporadically human cases (in 2004 and in 2010). Here we present the clinical and laboratory aspects related to the first human case of West Nile neuroinvasive disease reported in Portugal