Network conduciveness with application to the graph-coloring and independent-set optimization transitions

We introduce the notion of a network's conduciveness, a probabilistically interpretable measure of how the network's structure allows it to be conducive to roaming agents, in certain conditions, from one portion of the network to another. We exemplify its use through an application to the two problems in combinatorial optimization that, given an undirected graph, ask that its so-called chromatic and independence numbers be found. Though NP-hard, when solved on sequences of expanding random graphs there appear marked transitions at which optimal solutions can be obtained substantially more easily than right before them. We demonstrate that these phenomena can be understood by resorting to the network that represents the solution space of the problems for each graph and examining its conduciveness between the non-optimal solutions and the optimal ones. At the said transitions, this network becomes strikingly more conducive in the direction of the optimal solutions than it was just before them, while at the same time becoming less conducive in the opposite direction. We believe that, besides becoming useful also in other areas in which network theory has a role to play, network conduciveness may become instrumental in helping clarify further issues related to NP-hardness that remain poorly understood

LANDSAT and radar mapping of intrusive rocks in SE-Brazil

The feasibility of intrusive rock mapping was investigated and criteria for regional geological mapping established at the scale of 1:500,00 in polycyclic and polymetamorphic areas using the logic method of photointerpretation of LANDSAT imagery and radar from the RADAMBRASIL project. The spectral behavior of intrusive rocks, was evaluated using the interactive multispectral image analysis system (Image-100). The region of Campos (city) in northern Rio de Janeiro State was selected as the study area and digital imagery processing and pattern recognition techniques were applied. Various maps at the 2:250,000 scale were obtained to evaluate the results of automatic data processing

Off-axis retrieval of orbital angular momentum of light stored in cold atoms

We report on the storage of orbital angu- lar momentum (OAM) of light of a Laguerre-Gaussian mode in an ensemble of cold cesium atoms and its re- trieval along an axis different from the incident light beam. We employed a time-delayed four-wave mixing configuration to demonstrate that at small angle (2o), after storage, the retrieved beam carries the same OAM as the one encoded in the input beam. A calculation based on mode decomposition of the retrieved beam over the Laguerre-Gaussian basis is in agreement with the experimental observations done at small angle values. However, the calculation shows that the OAM retrieving would get lost at larger angles, reducing the fidelity of such storing-retrieving process. In addition, we have also observed that by applying an external magnetic field to the atomic ensemble the retrieved OAM presents Larmor oscillations, demonstrating the possibility of its manipulation and off-axis retrieval.Comment: 9 pages, 4 figure

How much does it cost to implement a community-based walking football programme for patients with type 2 diabetes?

ObjectivesThe current study analysed the implementation costs of a community-based walking football exercise programme for patients with type 2 diabetes.MethodsThe direct costs of a community-based walking football programme for middle-aged and older male patients with type 2 diabetes, designed and tested in Porto (Portugal), were calculated from the payer's perspective. One season of this programme consists of three sessions per week (60 min per session) for nine months (October to June). Cost calculations were based on two groups of 20 patients and included the sports infrastructure and equipment, human resources, pre-exercise clinical evaluation, medical equipment, technical training and other consumable costs. An economic depreciation of 1 year using the linear method for sports and electronic materials was considered. Cost analysis dated December 2021 and is expressed in international dollars ($).ResultsThis programme was estimated to have a total implementation cost of$22 923.07; $2547.01/month;$573.08/patient; $106.13/session;$63.68/patient/month and $5.31/patient/session.ConclusionA community-based walking football programme for patients with type 2 diabetes is affordable and can be scaled up by local communities to promote physical activity and manage type 2 diabetes with the involvement of multiple stakeholders such as the football clubs, municipalities and primary healthcare units.This work was supported by the Portuguese Foundation for Science and Technology within the scope of projects UIDB/04750/2020 and LA/P/0064/2020. AB is supported by the Portuguese Foundation for Science and Technology [grant number SFRH/BD/136702/2018]

On the Number Density of Sunyaev-Zel'dovich Clusters of Galaxies

If the mean properties of clusters of galaxies are well described by the entropy-driven model, the distortion induced by the cluster population on the blackbody spectrum of the Cosmic Microwave Background radiation is proportional to the total amount of intracluster gas while temperature anisotropies are dominated by the contribution of clusters of about 10^{14} solar masses. This result depends marginally on cluster parameters and it can be used to estimate the number density of clusters with enough hot gas to produce a detectable Sunyaev-Zel'dovich effect. Comparing different cosmological models, the relation depends mainly on the density parameter Omega_m. If the number density of clusters could be estimated by a different method, then this dependence could be used to constrain Omega_m.Comment: 8 pages, 3 figures, submitted to ApJ Letter

Dermatite ulcerosa em bovinos provocada por Stephanofilaria.

Em um rebanho leiteiro localizado na cidade de São Carlos-SP, foram constatados cinco casos de dermatite ulcerosa tendo como agente etiologico a Stephanofilaria spp. As lesões se localizaram na inserção da cauda, ubere, coxa e graupa. O diagnóstico foi feito por esfregaço e impressões obtidas de raspado e pele da borda da ulcera, coradas com Giemsa e também com vermelho Congo sendo que este permitiu melhor visualização do parasita. O tratamento foi feito com tricloforn, obtendo-se a cura dos animais em quinze dias

On the consistency of a repulsive gravity phase in the early Universe

We exploit the possibility of existence of a repulsive gravity phase in the evolution of the Universe. A toy model with a free scalar field minimally coupled to gravity, but with the "wrong sign" for the energy and negative curvature for the spatial section, is studied in detail. The background solutions display a bouncing, non-singular Universe. The model is well-behaved with respect to tensor perturbations. But, it exhibits growing models with respect to scalar perturbations whose maximum occurs in the bouncing. Hence, large inhomogeneties are produced. At least for this case, a repulsive phase may destroy homogeneity, and in this sense it may be unstable. A newtonian analogous model is worked out; it displays qualitatively the same behaviour. The generality of this result is discussed. In particular, it is shown that the addition of an attractive radiative fluid does not change essentially the results. We discuss also a quantum version of the classical repulsive phase, through the Wheeler-de Witt equation in mini-superspace, and we show that it displays essentially the same scenario as the corresponding attractive phase.Comment: Latex file, 15 pages, 7 figures. There is a new figure, a new section and some other minor correction

Avaliação de cultivares de arroz irrigado sob irrigação por aspersão.

O objetivo do trabalho foi de avaliar a resposta de cultivares de arroz irrigado em condições de cultivo com irrigação por aspersão em terras altas.Pôster - graduação

Ion-ion correlations: an improved one-component plasma correction

Based on a Debye-Hueckel approach to the one-component plasma we propose a new free energy for incorporating ionic correlations into Poisson-Boltzmann like theories. Its derivation employs the exclusion of the charged background in the vicinity of the central ion, thereby yielding a thermodynamically stable free energy density, applicable within a local density approximation. This is an improvement over the existing Debye-Hueckel plus hole theory, which in this situation suffers from a "structuring catastrophe". For the simple example of a strongly charged stiff rod surrounded by its counterions we demonstrate that the Poisson-Boltzmann free energy functional augmented by our new correction accounts for the correlations present in this system when compared to molecular dynamics simulations.Comment: 5 pages, 2 figures, revtex styl