The quark-antiquark potential at finite temperature and the dimension two gluon condensate

A recently proposed phenomenological model, which includes non perturbative effects from dimension two gluon condensates, is applied to analyze the available lattice data for the heavy quark free energy in the deconfined phase of quenched QCD. For large $q\bar{q}$ separations we recover previous results for the Polyakov loop, exhibiting unequivocal condensate contributions. For the $q\bar{q}$ potential at finite temperature and finite separation we find that a good overall description of the lattice data can be achieved once the condensate is properly accounted for. In addition, the model predicts a duality between the zero temperature potential as a function of the $q\bar{q}$ separation, on the one hand, and the quark selfenergy as a function of the temperature, on the other, which turns out to be satisfied to a high degree by the lattice data.Comment: 9 pages, 5 figure

Landau-gauge condensates from the quark propagator on the lattice

We compute the dimension-2 condensate, , and the dimension-4 mixed condensate, , from the recent quenched lattice results for the quark propagator in the Landau gauge. We fit the lattice data to the Operator Product Expansion in the "fiducial" region 1.2 GeV < Q < 3 GeV. Our result for the dynamical gluon mass at the scale of 10 GeV^2 is m_A=600-650 MeV, in agreement with independent determinations. For the mixed Landau gauge condensate of dimension-4 we get alpha_s = (-0.11 +/- 0.03) GeV^4. This value is an order of magnitude larger than the gluon condensate.Comment: 4 pages, 3 figures, references adde

Taxonomía, sistemática y biología de un nuevo Trechus (Coleoptera, Carabidae, Trechini) hipogeo del karst cantábrico (Cantabria, España)

Se describe una nueva especie de Trechus Clairville, 1806 que manifiesta rasgos troglobiomórficos, como anoftalmia (tan solo se distingue una pequeña cicatriz ocular sin pigmentación), despigmentación del tegumento y gracilidad corporal (estudiada mediante un análisis morfométrico). No obstante, la característica más destacable de esta nueva especie y que dificulta su inclusión en cualquiera de los “grupos de especies” hasta el momento establecidos es el edeago; el saco interno carece de piezas esclerotizadas, característica que aproxima Trechus udiensis sp. n. a otra especie cantábrica como es Trechus triamicorum Ortuño y Jiménez–Valverde, 2011. A pesar de ello, ambas especies se diferencian bien atendiendo a otros caracteres, en especial el tegumento glabro de los élitros (parecidos en la mayoría de las especies del género Trechus) de la nueva especie, que contrasta con el pubescente de T. triamicorum. El dominio subterráneo de Udías (Cantabria), que es el hábitat de esta nueva especie, se asienta no solo en espacios naturales (Cueva de Udías), sino también en galerías de origen antrópico (Mina Sel del Haya).Se describe una nueva especie de Trechus Clairville, 1806 que manifiesta rasgos troglobiomórficos, como anoftalmia (tan solo se distingue una pequeña cicatriz ocular sin pigmentación), despigmentación del tegumento y gracilidad corporal (estudiada mediante un análisis morfométrico). No obstante, la característica más destacable de esta nueva especie y que dificulta su inclusión en cualquiera de los “grupos de especies” hasta el momento establecidos es el edeago; el saco interno carece de piezas esclerotizadas, característica que aproxima Trechus udiensis sp. n. a otra especie cantábrica como es Trechus triamicorum Ortuño y Jiménez–Valverde, 2011. A pesar de ello, ambas especies se diferencian bien atendiendo a otros caracteres, en especial el tegumento glabro de los élitros (parecidos en la mayoría de las especies del género Trechus) de la nueva especie, que contrasta con el pubescente de T. triamicorum. El dominio subterráneo de Udías (Cantabria), que es el hábitat de esta nueva especie, se asienta no solo en espacios naturales (Cueva de Udías), sino también en galerías de origen antrópico (Mina Sel del Haya).Taxonomy, systematics and biology of a new hypogean Trechus (Coleoptera, Carabidae, Trechini) from the Cantabrian Karst (Cantabria, Spain) We describe a new species of Trechus Clairville, 1806. This species has troglobiomorphic traits, such as anophthalmy (only a small ocular scar with no pigmentation can be distinguished), integument depigmentation, and body gracefulness (studied by morphometric analysis). The most remarkable characteristic of this new species, however, is the aedeagus, which precludes its inclusion in any of the previously established ‘species groups’. The inner sac lacks sclerotized pieces, making Trechus udiensis n. sp. resemble another Cantabrian species, i.e. Trechus triamicorum Ortuño y Jiménez–Valverde, 2011. Nevertheless, these two species are easily distinguishable on the basis of other characters, especially the new species’ the glabrous integument of the elytra (similar to most species of Trechus) in opposition to the pubescent T. triamicorum. This new species inhabits the subterranean environment of Udías (Cantabria), where it has been found not only in natural spaces (Udías Cave) but also in artificial tunnels (Sel del Haya Mine)

Towards high resolution mapping of 3-D mesoscale dynamics from observations

The MyOcean R&amp;D project MESCLA (MEsoSCaLe dynamical Analysis through combined model, satellite and in situ data) was devoted to the high resolution 3-D retrieval of tracer and velocity fields in the oceans, based on the combination of in situ and satellite observations and quasi-geostrophic dynamical models. The retrieval techniques were also tested and compared with the output of a primitive equation model, with particular attention to the accuracy of the vertical velocity field as estimated through the &lt;b&gt;&lt;i&gt;Q&lt;/i&gt;&lt;/b&gt; vector formulation of the omega equation. The project focused on a test case, covering the region where the Gulf Stream separates from the US East Coast. This work demonstrated that innovative methods for the high resolution mapping of 3-D mesoscale dynamics from observations can be used to build the next generations of operational observation-based products

Estimación de la velocidad de flujo del agua en cauces efímeros no aforados a partir de datos Lidar y GPS-RTK

The Manning formula is one of the most used to calculate the average velocity of water flow in ungauged channels. In order to be applied, it is necessary to measure in field the hydraulic radius (RH), the slope of the water surface (S), and to obtain the roughness coefficient (n), usually through tables created for this purpose. This involves a difficult, inefficient and subjective data collection in the field. This study evaluates the possibility to obtain these parameters in a more efficient manner, reducing the time of the process and allowing to work in larger areas. To achieve these objectives, the data used in this work were: 1) digital terrain models generated from airborne LiDAR data with a density of 2 points/ m2 , acquired when the channel was dry; 2) the height of the waterline and channel geometry measurements in the field using GPS; 3) Flow measurements. With this information, the velocity (Ve) was estimated and related to the average velocity of water flow (Vc) calculated from data measured in the field. The coefficient of determination between both velocity values was 73.52%, suggesting that the proposed methodology is useful to obtain the average velocity of flow, especially in remote areas or dry riverbeds

Weed control options in conventional and GM maize

En el proyecto AMIGA, que estudia los posibles efectos de los cultivos modificados genéticamente y su manejo sobre el agro-eco-sistema y la biodiversidad, se han evaluado varios tratamientos herbicidas sobre maíz Bt y maíz convencional. Se estableció un ensayo de seis hectáreas durante dos años en el que se han utilizado cinco manejos con herbicida que incluyen tratamiento convencional, reducido, glifosato y dos combinaciones de los anteriores. Se muestreó a lo largo del desarrollo del cultivo para determinar las especies de malas hierbas y artrópodos en el tiempo así como su abundancia y diversidad mediante examen visual y uso de trampas de gravedad y adhesivas amarillas. En este trabajo se presentan datos de abundancia de malas hierbas a madurez fisiológica del cultivo y del total de artrópodos en muestreo visual.Effect on weeds and arthropods In the context of AMIGA project which studies the posible effects of genetically modified crops and their management on the agro-ecosystem and biodiversity, we have studied various herbicide treatments applied on conventional and Bt A field was conducted for two years in a six ha plot. Five herbicide treatments including conventional, reduced, glyphosate and two herbicides combinations were established. We sampled along the cropping period to determine the species of weeds and arthropods over time and their abundance and diversity. The presence of arthropods was determined by visual examination and the use of pitfall and yellow sticky traps. In this work whole abundance of weeds at physiological maturity of the crop and total abundance of arthropod in visual examination are presented

Elevation and cholera: an epidemiological spatial analysis of the cholera epidemic in Harare, Zimbabwe, 2008-2009

BACKGROUND: In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009. METHODS: We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs. RESULTS: This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%. CONCLUSION: This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic