Functional adaptivity for digital library services in e-infrastructures: the gCube approach

We consider the problem of e-Infrastructures that wish to reconcile the generality of their services with the bespoke requirements of diverse user communities. We motivate the requirement of functional adaptivity in the context of gCube, a service-based system that integrates Grid and Digital Library technologies to deploy, operate, and monitor Virtual Research Environments defined over infrastructural resources. We argue that adaptivity requires mapping service interfaces onto multiple implementations, truly alternative interpretations of the same functionality. We then analyse two design solutions in which the alternative implementations are, respectively, full-fledged services and local components of a single service. We associate the latter with lower development costs and increased binding flexibility, and outline a strategy to deploy them dynamically as the payload of service plugins. The result is an infrastructure in which services exhibit multiple behaviours, know how to select the most appropriate behaviour, and can seamlessly learn new behaviours

Evaluating the environmental and economic impact of fruit and vegetable waste valorisation: The lettuce waste study-case

The fruit and vegetable sector generates large amounts of waste, which poses both environmental and economic issues. Different strategies can be applied to valorise fruit and vegetable waste (FVW) by turning it into value-added products. However, the economic and environmental impact of such strategies is largely unknown. In this paper, the environmental and economic impact of FVW valorisation on an industrial scale was evaluated by developing a Decision Support System (DSS). To this aim, the lettuce waste study-case was considered, since different innovative laboratory-scale strategies have been recently proposed for its valorisation. Investment and running costs, energetic demand and yields of lettuce waste valorisation processes were collected based on laboratory tests and industrial surveys. The application of the DSS estimated that if 30% of lettuce waste annually produced by a large company was valorised by using a system configuration that involves not only anaerobic digestion and composting, but also high pressure homogenisation to produce fresh juices, and ultrasound-assisted extraction to produce antioxidant extracts, this configuration would lead to an investment lower than 10 million \u20ac, a 1 year-pay-back time and a 72 tons-reduction of carbon dioxide emissions, thus representing a rational compromise between economic returns and environmental advantage. The developed multi-objective DSS is a valuable tool to identify the most sustainable and investment-worthy processes for the valorisation of FVW

The activation of Csk by CD4 interferes with TCR-mediated activatory signaling

CD4-Lck recruitment to TCR/CD3, as well as Lck activation is essential for T cell activation. Indeed, the blockage of CD4-Lck recruitment to TCR during antigen recognition exerts a drastic inhibitory effect on T cell activation by interfering with both early and late phases of T cell signaling. In the present work, we report a novel inhibitory mechanism by which CD4 can shut down proximal T cell-activating signals. Indeed, we show that upon ligation of CD4 by antibodies the inhibitory kinase, p50csk, is strongly induced and prolonged during the time. In contrast, p50csk was not activated when TCR and CD4 were properly engaged by their ligands. We also demonstrate that anti-CD4 treatment stimulated Csk kinase associated to the membrane adapter, PAG/Cbp, without affecting the total amount of Csk bound to PAG/Cbp. As a consequence, early tyrosine phosphorylation events as well as downstream signaling pathways leading to IL-2 gene expression induced by TCR were inhibited in anti-CD4 pretreated cells. We suggest a new model to explain the activation of negative signals by CD4 molecule

An analytical model based on radiative heating for the determination of safety distances for wildland fires

International audienceThe radiative heat transfer is often the main thermal impact of a wildfire on people fighting the fire or on structures. Thus, the estimation of the radiation coming from the fire font and hitting a target is of primary importance for forest and urban managers. A new flame model based on the solid flame assumption is developed by considering a finite fire front width. The realistic description of finite fire front widths allows proposing a new criterion for the estimation of the radiative impact of the fire, which is based on the ratio fire front width/ flame length, opposed to the classical approach of considering only the flame length. The new model needs to be solved numerically so an analytical approximation is proposed to obtain a simple and useful formulation of the acceptable safety distance. A sensivity analysis is conducted on the different physical and geometrical parameters used to define the flame front. This analysis shows that the flame temperature is the most sensitive parameter. The results of the analytical model are compared with the numerical solution of the flame model and previous approaches based only on flame length. The results show that the analytical model is a good approximation of the numerical approach and displays realistic estimations of the acceptable safety distance for different fire front characteristics

Programa de gerenciamento de resíduos da Embrapa Florestas.

bitstream/CNPF-2009-09/41246/1/Doc_119.pd

Beyond moments: relativistic Lattice-Boltzmann methods for radiative transport in computational astrophysics

We present a new method for the numerical solution of the radiative-transfer equation (RTE) in multidimensional scenarios commonly encountered in computational astrophysics. The method is based on the direct solution of the Boltzmann equation via an extension of the Lattice Boltzmann (LB) equation and allows to model the evolution of the radiation field as it interacts with a background fluid, via absorption, emission, and scattering. As a first application of this method, we restrict our attention to a frequency independent ("grey") formulation within a special-relativistic framework, which can be employed also for classical computational astrophysics. For a number of standard tests that consider the performance of the method in optically thin, optically thick and intermediate regimes with a static fluid, we show the ability of the LB method to produce accurate and convergent results matching the analytic solutions. We also contrast the LB method with commonly employed moment-based schemes for the solution of the RTE, such as the M1 scheme. In this way, we are able to highlight that the LB method provides the correct solution for both non-trivial free-streaming scenarios and the intermediate optical-depth regime, for which the M1 method either fails or provides inaccurate solutions. When coupling to a dynamical fluid, on the other hand, we present the first self-consistent solution of the RTE with LB methods within a relativistic-hydrodynamic scenario. Finally, we show that besides providing more accurate results in all regimes, the LB method features smaller or comparable computational costs compared to the M1 scheme.Comment: 22 pages, 16 figures, matches version accepted in MNRA

A methodology for the structural and functional analysis of signaling and regulatory networks

BACKGROUND: Structural analysis of cellular interaction networks contributes to a deeper understanding of network-wide interdependencies, causal relationships, and basic functional capabilities. While the structural analysis of metabolic networks is a well-established field, similar methodologies have been scarcely developed and applied to signaling and regulatory networks. RESULTS: We propose formalisms and methods, relying on adapted and partially newly introduced approaches, which facilitate a structural analysis of signaling and regulatory networks with focus on functional aspects. We use two different formalisms to represent and analyze interaction networks: interaction graphs and (logical) interaction hypergraphs. We show that, in interaction graphs, the determination of feedback cycles and of all the signaling paths between any pair of species is equivalent to the computation of elementary modes known from metabolic networks. Knowledge on the set of signaling paths and feedback loops facilitates the computation of intervention strategies and the classification of compounds into activators, inhibitors, ambivalent factors, and non-affecting factors with respect to a certain species. In some cases, qualitative effects induced by perturbations can be unambiguously predicted from the network scheme. Interaction graphs however, are not able to capture AND relationships which do frequently occur in interaction networks. The consequent logical concatenation of all the arcs pointing into a species leads to Boolean networks. For a Boolean representation of cellular interaction networks we propose a formalism based on logical (or signed) interaction hypergraphs, which facilitates in particular a logical steady state analysis (LSSA). LSSA enables studies on the logical processing of signals and the identification of optimal intervention points (targets) in cellular networks. LSSA also reveals network regions whose parametrization and initial states are crucial for the dynamic behavior. We have implemented these methods in our software tool CellNetAnalyzer (successor of FluxAnalyzer) and illustrate their applicability using a logical model of T-Cell receptor signaling providing non-intuitive results regarding feedback loops, essential elements, and (logical) signal processing upon different stimuli. CONCLUSION: The methods and formalisms we propose herein are another step towards the comprehensive functional analysis of cellular interaction networks. Their potential, shown on a realistic T-cell signaling model, makes them a promising tool

A review of wildland fire spread modelling, 1990-present, 1: Physical and quasi-physical models

In recent years, advances in computational power and spatial data analysis (GIS, remote sensing, etc) have led to an increase in attempts to model the spread and behaviour of wildland fires across the landscape. This series of review papers endeavours to critically and comprehensively review all types of surface fire spread models developed since 1990. This paper reviews models of a physical or quasi-physical nature. These models are based on the fundamental chemistry and/or physics of combustion and fire spread. Other papers in the series review models of an empirical or quasi-empirical nature, and mathematical analogues and simulation models. Many models are extensions or refinements of models developed before 1990. Where this is the case, these models are also discussed but much less comprehensively.Comment: 31 pages + 8 pages references + 2 figures + 5 tables. Submitted to International Journal of Wildland Fir

Cross-cultural adaptation and psychometric properties of the Brazilian-Portuguese version of the VSP-A (Vécu et Santé Perçue de l'Adolescent), a health-related quality of life (HRQoL) instrument for adolescents, in a healthy Brazilian population

<p>Abstract</p> <p>Background</p> <p>Health-related quality of life (HRQoL) assessment, encompassing the adolescents' perceptions of their mental, physical, and social health and well-being is increasingly considered an important outcome to be used to identify population health needs and to provide targeted medical care. Although validated instruments are essential for accurately assessing HRQoL outcomes, there are few cross-culturally adapted tools for use in Brazil, and none designed exclusively for use among adolescents. The Vécu et Santé Perçue de l'Adolescent (VSP-A) is a generic, multidimensional self-reported instrument originally developed and validated in France that evaluates HRQoL of ill and healthy adolescents.</p> <p>Purpose</p> <p>To cross-culturally adapt and validate the Brazilian-Portuguese version of the VSP-A, a generic HRQoL measure for adolescents originally developed in France.</p> <p>Methods</p> <p>The VSP-A was translated following a well-validated forward-backward process leading to the Brazilian version. The psychometric evaluation was conducted in a sample of 446 adolescents (14-18 years) attending 2 public high schools of São Gonçalo City. The adolescents self-reported the Brazilian VSP-A, the validated Psychosomatic Symptom Checklist and socio-demographic information. A retest evaluation was carried out on a sub-sample (n = 195) at a two-week interval.</p> <p>The internal construct validity was assessed through confirmatory factor analysis (CFA), multi-trait scaling analyses, Rasch analysis evaluating unidimensionality of each scale and Cronbach's alpha coefficients. The reproducibility was evaluated by intra-class correlation coefficients (ICC). Zumbo's ordinal logistic regression analysis was used to detect differential item functioning (DIF) between the Brazilian and the French items. External construct validity was investigated testing expected differences between groups using one-way analysis of variance (ANOVA), Mann-Whitney tests and the univariate general regression linear model.</p> <p>Results</p> <p>CFA showed an acceptable fit (RMSEA=0.05; CFI=0.93); 94% of scaling success was found for item-internal consistency and 98% for item discriminant validity. The items showed good fit to the Rasch model except 3 items with an INFIT at the upper threshold. Cronbach's Alpha ranged from 0.60 to 0.85. Test-retest reliability was moderate to good (ICC=0.55-0.82). DIF was evidenced in 4 out of 36 items. Expected patterns of differences were confirmed with significantly lower physical, psychological well being and vitality reported by symptomatic adolescents.</p> <p>Conclusions</p> <p>Although DIF in few items and responsiveness must be further explored, the Brazilian version of VSP-A demonstrated an acceptable validity and reliability in adolescents attending school and might serve as a starting point for more specific clinical investigations.</p