On exact mappings between fermionic Ising spin glass and classical spin glass models

We present in this paper exact analytical expressions for the thermodynamical properties and Green functions of a certain family of fermionic Ising spin-glass models with Hubbard interaction, by noticing that their Hamiltonian is a function of the number operator only. The thermodynamical properties are mapped to the classical Ghatak-Sherrington spin-glass model while the the Density of States (DoS) is related to its joint spin-field distribution. We discuss the presence of the pseudogap in the DoS with the help of this mapping.Comment: 6 page

Large Deviations of the Smallest Eigenvalue of the Wishart-Laguerre Ensemble

We consider the large deviations of the smallest eigenvalue of the Wishart-Laguerre Ensemble. Using the Coulomb gas picture we obtain rate functions for the large fluctuations to the left and the right of the hard edge. Our findings are compared with known exact results for $\beta=1$ finding good agreement. We also consider the case of almost square matrices finding new universal rate functions describing large fluctuations.Comment: 4 pages, 2 figure

A conceptual model of check dam hydraulics for gully control: efficiency, optimal spacing and relation with step-pools

There is little information in scientific literature regarding the modifications induced by check dam systems in flow regimes within restored gully reaches, despite it being a crucial issue for the design of gully restoration measures. Here, we develop a conceptual model to classify flow regimes in straight rectangular channels for initial and dam-filling conditions as well as a method of estimating efficiency in order to provide design guidelines. The model integrates several previous mathematical approaches for assessing the main processes involved (hydraulic jump, impact flow, gradually varied flows). Ten main classifications of flow regimes were identified, producing similar results when compared with the IBER model. An interval for optimal energy dissipation (ODI) was observed when the steepness factor <i>c</i> was plotted against the design number (DN, ratio between the height and the product of slope and critical depth). The ODI was characterized by maximum energy dissipation and total influence conditions. Our findings support the hypothesis of a maximum flow resistance principle valid for a range of spacing rather than for a unique configuration. A value of <i>c</i> = 1 and DN ~ 100 was found to economically meet the ODI conditions throughout the different sedimentation stages of the structure. When our model was applied using the same parameters to the range typical of step-pool systems, the predicted results fell within a similar region to that observed in field experiments. The conceptual model helps to explain the spacing frequency distribution as well as the often-cited trend to lower <i>c</i> for increasing slopes in step-pool systems. This reinforces the hypothesis of a close link between stable configurations of step-pool units and man-made interventions through check dams

Evaluation of the hygienic behavior of Apis mellifera L. related to the level of infestation of varroa destructor Anderson & Trueman

The beekeeping in Chile has been especially important for the small and medium agriculture due to the several products that can be obtained from the explotation. One of the major problems is the incidence of diseases and parasites, being the acarus ectoparasite Varroa destructor Anderson & Trueman one of the main pathologies because of its difficult control since it's reproduced in brood capped cells, decreasing the population of the colony and in strong infestations making them disappear completely; also by using chemical products for its control, which are not used correctly, producing resistance and leaving residues in the bee products. In order to change this situation it is necessary to find new control alternatives such as genetic resistance through hygienic behavior. The hygienic behavior related to the infestation level of Varroa destructor is analyzed in this work. Twenty one honeybee colonies were involved in this study, which were evaluated from October to December 2005. The percentage of hygienic behavior of each colony was determined through the pin-killed test. Samples to carry out the diagnoses of varroa were also taken. The results showed a low and heterogeneous level of hygienic behavior, where the values fluctuated in the colonies in average from 20% to 80% (2 colonies). The non-existence of correlation was also shown. The evaluated parameters showed an infestation average of 4.5% in adult bee; 7% in worker brood and 31% in drone brood.La apicultura en Chile ha sido importante sobre todo para la pequeña y mediana agricultura, por los diversos productos que se pueden extraer de esta explotación, pero uno de los mayores problemas son la incidencia de enfermedades y parásitos. Una de las principales patologías es el ácaro ectoparásito Varroa destructor Anderson & Trueman, debido a su difícil control, ya que se reproduce en celdas operculadas de cría, disminuyendo la población de la colonia y en infestaciones severas haciéndola desaparecer por completo; además de la utilización de productos químicos para su control, los cuales no son usados correctamente, creando resistencia y dejando residuos en los productos de origen apícola. Para revertir esta situación se hace necesario buscar nuevas alternativas de control, tales como la resistencia genética, por medio del comportamiento higiénico. En este estudio se analiza el comportamiento higiénico en relación al nivel de infestación de Varroa destructor. Para la elaboración de este estudio se utilizaron veintiuna colonias de abejas melíferas, las cuales se evaluaron desde octubre a diciembre del año 2005. A cada colonia se le determinó el porcentaje de comportamiento higiénico a través de la técnica del perforado; conjuntamente se tomaron muestras para realizar los diagnósticos de detección de Varroa. Los resultados evidenciaron un bajo y heterogéneo nivel de comportamiento higiénico, donde los valores fluctuaron en promedio en las colonias desde 20% a 80% (2 colonias) y la inexistencia de correlación. Los parámetros evaluados presentaron infestaciones promedio de: abeja adulta 4,5%; cría obrera 7% y cría de zángano 31%

FISH, cephalopods and associated habitats of the Discovery rise seamounts, Southeast Atlantic

In February 2019, seamounts of the Discovery Rise, SE Atlantic (41–45°S, 3°W - 3°E), were explored in support of the application of the Ecosystem Approach to Fisheries Management in the Southeast Atlantic Fisheries Organization (SEAFO) Convention Area. Video records of the seafloor were produced by the Video-Assisted Multisampler System (VAMS) along 15 valid transects conducted in plateau and flank areas of Shannon, Tablemount, Discovery and Heardman seamounts at depths ranging from 394 to 1839 m. Nine benthic seascapes were classified and described based on substrate hardness, texture, slope, physical and biological modifiers as observed in the video images. Predominant water masses were estimated from temperature, salinity and dissolved oxygen vertical profiles obtained by CTD casts in the vicinity of each transect. A total of 366 fishes were seen (total observation time = 25.0 h) and classified in 32 morphotypes, included in 9 orders and 12 families. Most fish morphotypes (14) were included in the Macrouridae family. Family Moridae, on the other hand, included 65.3% of all fish records (239), with two particularly abundant morphotypes: Laemonema sp. (116) and Guttigadus sp. (92). Thirteen cephalopods were observed and classified in five morphotypes; the oegopsid squid Moroteuthopsis ingens was the most abundant of them (6). Despite the taxonomic uncertainties associated with video identifications, the explored region was found to contain a mixture of tropical – subtropical and subantarctic faunas of the Atlantic. Similarities of fauna composition and non-directional beta diversity estimates revealed some degree of seamount identity, but 57.5–61.9% of morphotypes were shared among seamounts (Jaccard = 0.425, Sørensen = 0.381). Fishes and cephalopods were more frequently observed on the shallower plateau areas under the influence of warmer and more oxygenated Antarctic Intermediate Waters. Depth and related factors did not influence richness, but dissimilarities in fauna composition between video transects increased with increasing depth intervals. Spatial habitat heterogeneity may have accounted for the increased beta diversity within seamounts. The most widely explored Tablemount seamount contained the most diverse observed sites, but also a considerable spatial variability likely associated with seascape heterogeneity. In two sites (transects 11 and 14), there were exceptionally high aggregations of the morid cods Laemonema sp., at the shallowest ‘gravely’ site explored (397 m), and Guttigadus sp., at a site of intermediate depth (1020 m) covered mostly by soft sediments. Neither of these species (or congenerics) have been previously classified as ‘seamount-aggregating” species. On the other hand, the Patagonian toothfish (Dissostichus eleginoides) and other commercial species known to aggregate in these seamounts were not found in the explored areas.En prens

Los granates del tramo del núcleo de la Sierra de los Santos (Córdoba)

The Sierra de los Santos (Sierra Morena, prov. of C&oacute;rdoba) consists of precambric and paleozoic materials, essentially chloritic schists, limestones and small outcrops of acid and basic igneous rocks. The garnets studied in this work are the only relict minerals from the first metamorphism process developped in this &aacute;rea. X-ray, optical and chemical data of these garnets are reported. They correspond to the piralspite series; finally, metamorphism conditions having given birth to the garnets are discussed

Aplicabilidad del uso de un panel de PTFE (politetrafluroetileno) como blanco de referencia

El teflón (politetrafluoroetileno. PTFE) es un material inerte, impermeable y flexible que no se altera por la acción de la luz. Su utilidad como panel de referencia ya se ha demostrado. Sus características y precio hacen que sea una alternativa cuando se necesitan paneles de referencia de ciertas dimensiones. En este trabajo se presentan ventajas e inconvenientes de usar un panel de teflón de 3 mm de grosor como panel de referencia. A partir de medidas de reflectividad realizadas con un espectro-radiómetro Ocean Optics 2000, en un rango de 400-900 nm, se determina el comportamiento espectral y la sensibilidad del panel de teflón en tres escenarios diferentes, sobre superficie blanca, lisa y homogénea (Escenario 1), superficie negra, lisa y homogénea (Escenario 2); y superficie blanca, rugosa y heterogénea (Escenario 3). Se constata que el espesor del mismo es insuficiente confiriéndole propiedades translúcidas y una flexibilidad que supone una pérdida de homogeneidad cuando la superficie base no es lisa. Pese a ello, el panel es una buena alternativa siempre y cuando se utilice en condiciones óptimas en términos de geometría de iluminación y observación. Los resultados obtenidos indican que la reflectividad del panel de teflón sobre fondo blanco es aproximadamente entre un 10% y 18% menor que la del Spectralon, dándose las mayores diferencias en el infrarrojo cercano.PTFE is an inert, impermeable and flexible material, not altered by the sunlight. Its usefullness as reference panel has already been tested. Due to its properties and low cost it is a good alternative when a large size panel is needed. This research shows the advantages and disadvantages of using PTFE as reference panel. Reflectance measures have been taken using an Ocean Optics 2000 spectroradiometer in the 400-900 nm range. Three different scenes (1: white, smooth and homogenous surface; 2: black, smooth and homogenous surface; and 3: white, rough and heterogeneous surface) have been used for proving the spectral behaviour and the sensitivity of the PTFE panel. It has been shown that the thickness (3 mm) is not enough and the flexibility causes a loss of homogeneity when the surface is not plain. However, the PTFE is a good option when used under optimal illumination and observation geometric conditions. The results show that reflectance of the PTFE on a white surface is around 10-18% lower than the Spectralon, especially in the near infrared region

Spin models on random graphs with controlled topologies beyond degree constraints

We study Ising spin models on finitely connected random interaction graphs which are drawn from an ensemble in which not only the degree distribution $p(k)$ can be chosen arbitrarily, but which allows for further fine-tuning of the topology via preferential attachment of edges on the basis of an arbitrary function Q(k,k') of the degrees of the vertices involved. We solve these models using finite connectivity equilibrium replica theory, within the replica symmetric ansatz. In our ensemble of graphs, phase diagrams of the spin system are found to depend no longer only on the chosen degree distribution, but also on the choice made for Q(k,k'). The increased ability to control interaction topology in solvable models beyond prescribing only the degree distribution of the interaction graph enables a more accurate modeling of real-world interacting particle systems by spin systems on suitably defined random graphs.Comment: 21 pages, 4 figures, submitted to J Phys

Testing M2T/T2M Transformations

Presentado en: 16th International Conference on Model Driven Engineering Languages and Systems (MODELS 2013). Del 29 de septiembre al 4 de octubre. Miami, EEUU.Testing model-to-model (M2M) transformations is becoming a prominent topic in the current Model-driven Engineering landscape. Current approaches for transformation testing, however, assume having explicit model representations for the input domain and for the output domain of the transformation. This excludes other important transformation kinds, such as model-to-text (M2T) and text-to-model (T2M) transformations, from being properly tested since adequate model representations are missing either for the input domain or for the output domain. The contribution of this paper to overcome this gap is extending Tracts, a M2M transformation testing approach, for M2T/T2M transformation testing. The main mechanism we employ for reusing Tracts is to represent text within a generic metamodel. By this, we transform the M2T/T2M transformation specification problems into equivalent M2M transformation specification problems. We demonstrate the applicability of the approach by two examples and present how the approach is implemented for the Eclipse Modeling Framework (EMF). Finally, we apply the approach to evaluate code generation capabilities of several existing UML tools.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto TIN2011-2379