Dynamic communicability predicts infectiousness

Using real, time-dependent social interaction data, we look at correlations between some recently proposed dynamic centrality measures and summaries from large-scale epidemic simulations. The evolving network arises from email exchanges. The centrality measures, which are relatively inexpensive to compute, assign rankings to individual nodes based on their ability to broadcast information over the dynamic topology. We compare these with node rankings based on infectiousness that arise when a full stochastic SI simulation is performed over the dynamic network. More precisely, we look at the proportion of the network that a node is able to infect over a fixed time period, and the length of time that it takes for a node to infect half the network.We find that the dynamic centrality measures are an excellent, and inexpensive, proxy for the full simulation-based measures

CONSTRUCTAL DESIGN AND SIMULATED ANNEALING EMPLOYED FOR GEOMETRIC OPTIMIZATION OF A Y-SHAPED CAVITY INTRUDED INTO CONDUCTIVE WALL

he problem study here is concerned with the geometrical evaluation of an isothermal Y-shaped cavity intruded into conducting solid wall with internal heat generation. The cavity acts as a sink of the heat generated into the solid. The main purpose here is to minimize the maximal excess of temperature (θmax) in the solid. Constructal Design, which is based on the objective and constraints principle, is employed to evaluate the geometries of Y-shaped cavity. Meanwhile, Simulated Annealing (SA) algorithm is employed as optimization method to seek for the best shapes. To validate the SA methodology, the results obtained with SA are compared with those achieved with Genetic Algorithm (GA) and Exaustive Search (ES) in recent studies of literature. The comparison between the optimization methods (SA, GA and ES) showed that Simulated Annealing is highly effective in the search for the optimal shapes of the studied case

CONSTRUCTAL DESIGN APPLIED TO INVESTIGATE THE INFLUENCE OF GEOMETRY ON THE MASS FLOW RATE OF AN INCLINED PASSIVE WALL SOLAR CHIMNEY ATTACHED TO A ROOM

The present work aims to analyze the turbulent flow in an inclined passive wall solar chimney attached to a room, evaluating the influence of its geometry on the thermal performance of the building (measured by the mass flow rate in the chimney exit) by means of Constructal Design. The flow is considered turbulent, incompressible, under natural convection heat transfer, transient and in a two-dimensional domain that simulates a solar chimney attached to a room. Time-averaged conservation equations of mass, momentum, and energy are numerically solved with the finite volume method using the commercial package FLUENT. For closure modeling of turbulence, it is employed the standard k – ε model. Chimney and room areas are the problem constraints. Moreover, the problem is subjected to three degrees of freedom: the ratio between the inlet opening size and chimney height (Hi/Ha) (which is maintained constant in the present investigations, Hi/Ha = 0.05); ratio between the width of inferior base of the chimney and its height (Wg/Ha); and the ratio between the exit air gap and the inferior base widths of the chimney (We/Wg). The latter two degrees of freedom are varied. Results showed that the degrees of freedom analyzed have a strong influence on the mass flow rate of the air in the building, confirming that the geometrical configuration of solar chimney can be important for the improvement of thermal conditions on the attached building

COMPOSITION AND ANIMAL PREFERENCE FOR PLANTS USED FOR GOAT FEEDING IN SEMIARID NORTHEASTERN MEXICO

ABSTRACT Arid and semiarid zones of Northeastern Mexico are characterized as regions with high variation in their climatic conditions but rich in drought-tolerant botanical species which are potentially useful for grazing and pastoral activities. Feeding habits and voluntary intake from a total of 100 grazing goats were determined through identification of the plants that make up their diet, their availability in the rangeland, preference index, browsing height and their chemical composition during a 10-month growing period. Four heights of browsing were determined in the different vegetative strata. Climatic factors were determinant in the height of grazing and the availability of forage. Shrub species constituted 78% of the animal diet during the growing season followed by herbs (12-18%) and grasses (6-10%). The species with higher index of preference offered high availability in the rangeland with proper content of crude protein (10.7-24%), crude fiber (12.2-24.5%), cellulose (5.9-20.6%) and nitrogen free extract (30.2-50.6%). These results indicate that in seasons of high feed availability the intake of most preferred shrubs is taking place most of the time at a browsing height between 80 and 120 cm with species rich enough in nutrients to satisfy their minimum daily protein and fiber requirements. [¿Y que ónda con aquello de que cuando hay muchas hierbas abajo prefieren comer esas hierbas?]Thus, the pasture conditions, climate and the availability of the vegetation in a given season are crucial factors for suitable livestock management

Evidence of a new geothermal prospect in the Northern-Central trans-Mexican volcanic belt: Rancho Nuevo, Guanajuato, Mexico

Peer ReviewedPostprint (author's final draft

Investigation on the Association of Differential Evolution and Constructal Design for Geometric Optimization of Double Y-Shaped Cooling Cavities Inserted into Walls with Heat Generation

In the constructal design method, the comprehension of the effect of design on the system performance is crucial to understanding the contributions of the degrees of freedom or constraints in the system evolution in direction of optimal configurations. However, problems with many degrees of freedom are prohibitive of optimization with exhaustive search, requiring meta-heuristic strategies. Therefore, the investigation of the optimization algorithms is essential. This work investigates the canonical differential evolution algorithm associated with the constructal design for the geometric optimization of an isothermal double Y-shaped cooling cavity inserted into a wall with internal heat generation. The effect of four degrees of freedom over the thermal performance of the system is investigated using sixteen different combinations of differential evolution algorithms: four variations of mutation parameter, two values of amplification factor (F) and two values of crossover rate (CR). The non-parametric statistical methods of Kruskal–Wallis and Dunn test were used to identify the parameters that improve the meta-heuristic efficiency. Results indicated that the proposed methodology selected the proper combination of DE algorithm parameters (CR, F, and mutation) that led to the best effect of degrees of freedom over the thermal performance in all optimization levels investigated

Intracellular calcium movements of boar spermatozoa during 'in vitro' capacitation and subsequent acrosome exocytosis follow a multiple-storage place, extracellular calcium-dependent model

This work analysed intracellular calcium stores of boar spermatozoa subjected to invitro' capacitation (IVC) and subsequent progesterone-induced acrosome exocytosis (IVAE). Intracellular calcium was analysed through two calcium markers with different physico-chemical properties, Fluo-3 and Rhod-5N. Indicative parameters of IVC and IVAE were also evaluated. Fluo-3 was located at both the midpiece and the whole head. Rhod-5N was present at the sperm head. This distribution did not change in any of the assayed conditions. Induction of IVC was concomitant with an increase in both head and midpiece Ca2+ signals. Additionally, while IVC induction was concurrent with a significant (p<0.05) increase in sperm membrane permeability, no significant changes were observed in O-2 consumption and ATP levels. Incubation of boar spermatozoa in the absence of calcium showed a loss of both Ca2+ labellings concomitantly with the sperm's inability to achieve IVC. The absence of extracellular calcium also induced a severe decrease in the percentage of spermatozoa exhibiting high mitochondrial membrane potential (hMMP). The IVAE was accompanied by a fast increase in both Ca2+ signalling in control spermatozoa. These peaks were either not detected or much lessened in the absence of calcium. Remarkably, Fluo-3 marking at the midpiece increased after progesterone addition to sperm cells incubated in a medium without Ca2+. The simultaneous addition of progesterone with the calcium chelant EGTA inhibited IVAE, and this was accompanied by a significant (p<0.05) decrease in the intensity of progesterone Ca2+-induced peak, O-2 consumption and ATP levels. Our results suggest that boar spermatozoa present different calcium deposits with a dynamic equilibrium among them and with the extracellular environment. Additionally, the modulation role of the intracellular calcium in spermatozoa function seems to rely on its precise localization in boar spermatozoa

POLEN ATMOSFÉRICO DE IMPORTANCIA ALERGOLÓGICA EN EL ÁREA METROPOLITANA DE MONTERREY (NUEVO LEÓN, MÉXICO), DURANTE EL PERIODO MARZO 2003-FEBRERO 2005

The amount of atmospheric pollen ofallergological concern was monitored inthe metropolitan area of Monterrey duringthe period from March 2003 to February2005. Pollen collection was made usinga Hirst type trap (Burkard ManufacturingCo. Ltd., Rickmansworth, UK) placed 15m above the ground over the top of twobuildings. The total count registered duringthe sampling period was 68 962 grains. Themonths of maximum pollen incidence wereFebruary and March 2004 with 13 225 and10 384 grains respectively. The averagemonthly value was 2 873 grains. Taxaof major occurrence and perhaps of mainallergological concern for the metropolitanarea of Monterrey were Fraxinus sp (14 312grains), Cupressaceae-Taxodiaceae (12 448grains), Parietaria pensylvanica (12 354grains) Poaceae (4 808 grains), Celtis sp(3 153 grains), Moraceae (1 806 grains),Pinus sp with 2 693 grains, Ambrosia confertiflora (2 132 grains), Ricinus communiswith 1 697 grains, Amaranthaceae-Chenopodiaceae (1 691 grains), Quercus sp(1 360 grains), Prosopis sp (1 227 grains), Platanus occidentalis (725 grains) andCarya sp with 687 grains.Se estudió la cantidad de polen atmosféricode importancia alergológica presente en elárea metropolitana de Monterrey duranteel periodo de marzo del 2003 a febrero del2005. Para la captura del polen se utilizaroncaptadores volumétricos tipo Hirst (BurkardManufacturing Co. Ltd., Rickmansworth,UK), colocados a una altura aproximada de15 metros en dos edificios en el área metropolitana de Monterrey (AMM). La cantidadtotal de polen registrada durante el periodoestudiado fue de 68 962 granos. Los mesesde máxima incidencia de polen fueron febrero y marzo del 2004 con 13 225 y 10 384granos, respectivamente y con un promediomensual de 2 873 granos. Los taxa de mayorocurrencia y posiblemente de importanciaalergológica para el área metropolitana deMonterrey son Fraxinus sp (14 312 granos),Cupressaceae-Taxodiaceae (12 448 granos),Parietaria pensylvanica (12 354 granos),Poaceae (4 808 granos), Celtis sp (3 153 granos), Moraceae (1 806 granos), Pinus sp con2 693 granos, Ambrosia confertiflora (2 132granos), Ricinus communis con 1 697 granos,Amaranthaceae-Chenopodiaceae (1 691 granos), Quercus sp (1 360 granos), Prosopis sp(1 227 granos), Platanus occidentalis (725granos) y Carya sp con 687 granos

Boost operators in Coulomb-gauge QCD: the pion form factor and Fock expansions in phi radiative decays

In this article we rederive the Boost operators in Coulomb-Gauge Yang-Mills theory employing the path-integral formalism and write down the complete operators for QCD. We immediately apply them to note that what are usually called the pion square, quartic... charge radii, defined from derivatives of the pion form factor at zero squared momentum transfer, are completely blurred out by relativistic and interaction corrections, so that it is not clear at all how to interpret these quantities in terms of the pion charge distribution. The form factor therefore measures matrix elements of powers of the QCD boost and Moeller operators, weighted by the charge density in the target's rest frame. In addition we remark that the decomposition of the eta' wavefunction in quarkonium, gluonium, ... components attempted by the KLOE collaboration combining data from phi radiative decays, requires corrections due to the velocity of the final state meson recoiling against a photon. This will be especially important if such decompositions are to be attempted with data from J/psi decays.Comment: 14 pages, 4 figure

Constructal Design of Convective Y-Shaped Cavities by Means of Genetic Algorithm

In the present work constructal design is employed to optimize the geometry of a convective, Y-shaped cavity that intrudes into a solid conducting wall. The main purpose is to investigate the influence of the dimensionless heat transfer parameter a over the optimal geometries of the cavity, i.e., the ones that minimize the maximum excess of temperature (or reduce the thermal resistance of the solid domain). The search for the best geometry has been performed with the help of a genetic algorithm (GA). For square solids (H/L ¼ 1.0) the results obtained with an exhaustive search (which is based on solution of all possible geometries) were adopted to validate the GA method, while for H/L 6 ¼ 1.0 GA is used to find the best geometry for all degrees of freedom investigated here: H/L, t 1 /t 0 , L 1 /L 0 , and a (four times optimized). The results demonstrate that there is no universal optimal shape that minimizes the thermal field for all values of a investigated. Moreover, the temperature distribution along the solid domain becomes more homogeneous with an increase of a, until a limit where the configuration of &quot;optimal distribution of imperfections&quot; is achieved and the shape tends to remain fixed. Finally, it has been highlighted that the GA method proved to be very effective in the search for the best shapes with the number of required simulations much lower (8 times for the most difficult situation) than that necessary for exhaustive search