Synchronization in interacting Scale Free Networks

We study the fluctuations of the interface, in the steady state, of the Surface Relaxation Model (SRM) in two scale free interacting networks where a fraction $q$ of nodes in both networks interact one to one through external connections. We find that as $q$ increases the fluctuations on both networks decrease and thus the synchronization reaches an improvement of nearly $40\%$ when $q=1$. The decrease of the fluctuations on both networks is due mainly to the diffusion through external connections which allows to reducing the load in nodes by sending their excess mostly to low-degree nodes, which we report have the lowest heights. This effect enhances the matching of the heights of low-and high-degree nodes as $q$ increases reducing the fluctuations. This effect is almost independent of the degree distribution of the networks which means that the interconnection governs the behavior of the process over its topology.Comment: 13 pages, 7 figures. Added a relevant reference.Typos fixe

Predicting Forage Provision of Grasslands Across Climate Zones by Hyperspectral Measurements

The potential of grasslands’ fodder production is a crucial management measure, while its quantification is still laborious and costly. Remote sensing technologies, such as hyperspectral field measurements, enable fast and non-destructive estimation. However, such methods are still limited in transferability to other locations or climatic conditions. With this study, we aim to predict forage nutritive value, quantity, and energy yield from hyperspectral canopy reflections of grasslands across three climate zones. We took hyperspectral measurements with a field spectrometer from grassland canopies in temperate, tropical and semi-arid grasslands, and analyzed corresponding biomass samples for their quantity (BM), metabolizable energy content (ME) and metabolizable energy yield (MEY). Three machine learning algorithms were used to establish prediction models for single and across climate regions. The normalized root mean squared error (nRMSE) for ME, BM and MEY varied between 0.12 – 0.19, 0.14 – 0.21, and 0.15 – 0.21, respectively. The ME trans-climatic model showed the best accuracy compared to the local models. Trans-climatic model predictions of climate-specific data, decrease in accuracy to 0.16 – 0.21, 0.17 – 0.24, and 0.19 – 0.28 for ME, BM and MEY compared to predictions with climate-specific models. Trans-climatic models with feed-forward neural networks showed similar performance for ME but higher accuracies for BM and MEY predictions. The trans-climatic models generally showed good performance for forage nutritive value and forage provision. Our results suggest that models based on hyperspectral measurements offer great potential to assess or even map the forage nutritive value of grasslands across climate zones

Synchronization in Scale Free networks: The role of finite size effects

Synchronization problems in complex networks are very often studied by researchers due to its many applications to various fields such as neurobiology, e-commerce and completion of tasks. In particular, Scale Free networks with degree distribution $P(k)\sim k^{-\lambda}$, are widely used in research since they are ubiquitous in nature and other real systems. In this paper we focus on the surface relaxation growth model in Scale Free networks with $2.5< \lambda <3$, and study the scaling behavior of the fluctuations, in the steady state, with the system size $N$. We find a novel behavior of the fluctuations characterized by a crossover between two regimes at a value of $N=N^*$ that depends on $\lambda$: a logarithmic regime, found in previous research, and a constant regime. We propose a function that describes this crossover, which is in very good agreement with the simulations. We also find that, for a system size above $N^{*}$, the fluctuations decrease with $\lambda$, which means that the synchronization of the system improves as $\lambda$ increases. We explain this crossover analyzing the role of the network's heterogeneity produced by the system size $N$ and the exponent of the degree distribution.Comment: 9 pages and 5 figures. Accepted in Europhysics Letter

Quantitative study of valence and configuration interaction parameters of the Kondo semiconductors CeM2Al10 (M = Ru, Os and Fe) by means of bulk-sensitive hard x-ray photoelectron spectroscopy

The occupancy of the 4f^n contributions in the Kondo semiconductors CeM2Al10(M = Ru, Os and Fe) has been quantitatively determined by means of bulk-sensitive hard x-ray photoelectron spectroscopy (HAXPES) on the Ce 3d core levels. Combining a configuration interaction scheme with full multiplet calculations allowed to accurately describe the HAXPES data despite the presence of strong plasmon excitations in the spectra. The configuration interaction parameters obtained from this analysis -- in particular the hybridization strength V_eff and the effective f binding energy Delta_f -- indicate a slightly stronger exchange interaction in CeOs2Al10 compared to CeRu2Al10, and a significant increase in CeFe2Al10. This verifies the coexistence of a substantial amount of Kondo screening with magnetic order and places the entire CeM2Al10 family in the region of strong exchange interactions.Comment: 9 pages, 4 figures, submitted to Physical Review

A Major Fraction of Fibronectin Present in the Extracellular Matrix of Tissues Is Plasma-derived

The origin of the fibronectin (FN) found in the extracellular matrix of tissues has not been defined experimentally. Previous studies suggest that there is contribution from both local tissue production and transfer from plasma, but the extent of this phenomenon has not been addressed. We have shown before that engineered mice constitutively expressing extra domain A-containing FN (EDA+FN) have a significant decrease of FN levels in plasma and most tissues. We showed that hepatocytes modified to produce EDA+FN have normal extracellular matrix-FN levels but secrete less soluble FN. When we performed a liver-specific EDA-exon deletion in these animals, FN levels were restored both in plasma and tissues. Therefore, an important fraction of tissue FN, approximately an equal amount of that produced by the tissue itself, is actually plasma-derived, suggesting that plasma is an important source of tissue FN. The present results have potential significance for understanding the contributions of plasma FN, and perhaps other plasma proteins, in the modulation of cellular activities and in the formation of the extracellular matrix of tissues

Estudio del estado ecológico de los ríos de la cuenca hidrográfica del Júcar (España) mediante el índice BMWP'

El diseño de la Red Biológica, basado en el uso de indicadores hidromorfológicos, físico-químicos y biológicos, permitió realizar un diagnóstico de calidad en 221 puntos de muestreo en 104 ríos de la red hidrográfica del Júcar (Júcar, Turia, Mijares, Vinalopó, Palancia, Serpis y cuencas menores) durante el año 2000 y establecer su estado ecológico. En este trabajo se presentan los resultados obtenidos con el índice BMWP'. Los ríos con un estado ecológico muy bueno se hallan situados en los tramos altos, tanto de los ríos principales como de los afluentes de primer y segundo orden. La mayoría de los puntos de referencia (12.7%) se encuentran en altitudes superiores a los 800 m. Los ríos situados en altitudes medias (800-200 m) se hallan muy regulados y presentan, en general, un estado entre bueno y aceptable, existiendo pocos puntos de referencia (6.8%). Por último, los ríos situados en tierras bajas (&lt; 200 m) se encuentran, la gran mayoría, en un estado deficiente o malo, siendo muy difícil hallar ríos en buen estado y casi imposible establecer puntos de referencia con un muy buen estado ecológico (0.5%). Las medidas correctoras propuestas para los ríos de la red hidrográfica del Júcar se centran en la mejora de las características hidromorfológicas y físico-químicas, y por tanto de las comunidades biológicas, con el propósito final de conseguir el mejor estado ecológico y químico posible para las aguas superficiales tal y como exige la DMA (Directiva Marco del Agua).The design of the Biological Network, based on the use of hydromorphological, physical, chemical, and biological indicators, allowed a diagnosis of the quality in 221 sampling points in 104 rivers of Júcar's Basin (Jucar, Turia, Mijares, Vinalopo, Palancia, Serpis and small basins) to be carried out during the year 2000 and to establish its ecological status. In this work the results obtained with the BMWP' index are presented. The rivers with a high ecological status are located in the high altitudes, so much of the main rivers as of the tributaries of first and second order. Most of the reference points (12.7%) are located at altitudes higher than 800 m. The rivers located at middle-altitudes (800-200 m) are very regulated and they present, in general, an ecological status between good and acceptable, with few reference points (6.8%). Last, the rivers located in lowlands (&lt; 200 m) are, mostly, in a poor or bad ecological state, making it very difficult to find rivers in good ecological status and almost impossible to establish reference points with a high ecological status (0.5%). The correcting measures proposed for the rivers of the Júcar's Basin are centered in the improvement of the hydromorphological, physical, and chemical characteristics, and therefore of the biological communities, with the final purpose of achieving the highest ecological and chemical status possible for surface waters like the WFD (Water Framework Directive) demands

Photoemission study of (V1−x_{1-x}Mx_x)2_2O3_3 (M=Cr, Ti)

We present high-resolution bulk-sensitive photoemission spectra of (V$_{1-x}$M$_x$)$_2$O$_3$ (M=Cr, Ti). The measurements were made for the paramagnetic metal (PM), paramagnetic insulator (PI), and antiferromagnetic insulator (AFI) phases of (V$_{1-x}$M$_x$)$_2$O$_3$ with the samples of $x$ = 0, 0.012, and 0.028 for Cr-doping and $x$ = 0.01 for Ti-doping. In the PM phase, we observe a prominent quasiparticle peak in general agreement with theory, which combines dynamical mean-field theory with the local density approximation (LDA+DMFT). The quasiparticle peak shows a significantly larger peak width and weight than in the theory. For both the PI and AFI phases, the vanadium 3d parts of the valence spectra are not simple one peak structures. For the PI phase, there is not yet a good theoretical understanding of these structures. The size of the electron removal gap increases, and spectral weight accumulates in the energy range closer to the chemical potential, when the PI to AFI transition occurs. Spectra taken in the same phases with different compositions show interesting monotonic changes as the dopant concentration increases, regardless of the dopant species. With increased Cr-doping, the AFI phase gap decreases and the PI phase gap increases.Comment: 13 pages, 16 figures. accepted for publication in Physical Review

Spatial Data Infrastructures for environmental e-government services: The case of water abstractions authorisations

Environment-related authorisations are a relevant issue for environmental management. They require a considerable effort by the authorities, and this might result in substantial delays for the citizens. Implementing those authorisation processes by means of e-government services would improve efficiency and, consequently, citizen satisfaction. Environment-related authorisations usually require a variety of geospatial information, and have to deal with administrative areas which do not match physical and ecological ones. They also have to integrate heterogeneous information in different formats, data models and languages, and provided by distinct organisations, even from different countries. This paper discusses how Spatial Data Infrastructures (SDIs) can deal with these problems in the environmental domain, while improving the level of service provision in terms of e-government applications. This is even more relevant within the European Union where there is a legal mandate to establish an SDI to support environmental policies and activities with an impact on the environment. As a proof-of-concept, an application to request and manage water abstraction authorisations, based on an SDI, is demonstrated. This application is part of SDIGER, a cross-border inter-administration SDI to support the water framework directive information access for the Adour–Garonne and Ebro River basins, that was a pilot project for the EU INSPIRE Directive. The introduction of this transactional e-government service modifies the administrative process of granting authorisations: it allows to re-use the effort in data capture made by the applicants in their requests, facilitates the submission of more feasible applications and reduces the workload of the office staff

On the succinctness of query rewriting over shallow ontologies

We investigate the succinctness problem for conjunctive query rewritings over OWL2QL ontologies of depth 1 and 2 by means of hypergraph programs computing Boolean functions. Both positive and negative results are obtained. We show that, over ontologies of depth 1, conjunctive queries have polynomial-size nonrecursive datalog rewritings; tree-shaped queries have polynomial positive existential rewritings; however, in the worst case, positive existential rewritings can be superpolynomial. Over ontologies of depth 2, positive existential and nonrecursive datalog rewritings of conjunctive queries can suffer an exponential blowup, while first-order rewritings can be superpolynomial unless NP �is included in P/poly. We also analyse rewritings of tree-shaped queries over arbitrary ontologies and note that query entailment for such queries is fixed-parameter tractable

Investigation of elimination rate, persistent subpopulation removal and relapse rates of Mycobacterium tuberculosis by combinations of first-line drugs in a modified Cornell mouse model.

Currently, the most effective tuberculosis control method resides in case-finding and 6 months chemotherapy. There is a need to improve our understanding about drug interactions, combination activities and the ability to remove persistent bacteria in the current regimens, particularly in relation to relapse. We aimed to investigate the therapeutic effects of three main components, rifampicin (RMP), isoniazid (INH), and pyrazinamide (PZA), in current drug regimens using a modified version of the Cornell mouse model. We evaluated the post-treatment levels of persistent Mycobacterium tuberculosis in the organs of mice using culture filtrate derived from M. tuberculosis strain H37Rv. When RMP was combined with INH, PZA or INH-PZA, significant additive activities were observed compared to each of the single drug treatments. However, the combination of INH and PZA showed a less significant additive effect than either of the drugs used on their own. Apparent culture negativity of mouse organs was achieved at 14 weeks of treatment with RMP-INH, RMP-PZA and RMP-INH-PZA but not with INH-PZA, when conventional tests, namely culture on solid agar and in liquid broth indicated that the organs were bacteria negative. The relapse rates for RMP-containing regimens were not significantly different to a 100% relapse rate at the numbers of mice examined in this study. In parallel, we examined the organs for the presence of culture filtrate-dependent persistent bacilli after 14 weeks of treatment. Culture filtrate treatment of the organs revealed persistent M. tuberculosis Modelling of mycobacterial elimination rates and evaluation of culture-filtrate dependent organisms showed promise as surrogate methods for efficient factorial evaluation of drug combinations in tuberculosis in mouse models and should be further evaluated against relapse. The presence of culture filtrate-dependent persistent M. tuberculosis is the likely cause of disease relapse in this modified Cornell mouse model