Assessing the joint impact of DNAPL source-zone behavior and degradation products on the probabilistic characterization of human health risk

The release of industrial contaminants into the subsurface has led to a rapid degradation of groundwater resources. Contamination caused by Dense Non-Aqueous Phase Liquids (DNAPLs) is particularly severe owing to their limited solubility, slow dissolution and in many cases high toxicity. A greater insight into how the DNAPL source zone behavior and the contaminant release towards the aquifer impact human health risk is crucial for an appropriate risk management. Risk analysis is further complicated by the uncertainty in aquifer properties and contaminant conditions. This study focuses on the impact of the DNAPL release mode on the human health risk propagation along the aquifer under uncertain conditions. Contaminant concentrations released from the source zone are described using a screening approach with a set of parameters representing several scenarios of DNAPL architecture. The uncertainty in the hydraulic properties is systematically accounted for by high-resolution Monte Carlo simulations. We simulate the release and the transport of the chlorinated solvent perchloroethylene and its carcinogenic degradation products in randomly heterogeneous porous media. The human health risk posed by the chemical mixture of these contaminants is characterized by the low-order statistics and the probability density function of common risk metrics. We show that the zone of high risk (hot spot) is independent of the DNAPL mass release mode, and that the risk amplitude is mostly controlled by heterogeneities and by the source zone architecture. The risk is lower and less uncertain when the source zone is formed mostly by ganglia than by pools. We also illustrate how the source zone efficiency (intensity of the water flux crossing the source zone) affects the risk posed by an exposure to the chemical mixture. Results display that high source zone efficiencies are counter-intuitively beneficial, decreasing the risk because of a reduction in the time available for the production of the highly toxic subspecies.Peer ReviewedPostprint (author's final draft

From planning to performance: the adaptation process as a determinant of outcomes

Currently, teams require adaptation to deal with work demands successfully. However, research concerning team adaptation should necessarily involve a greater empirical effort in defining under which conditions teams prove more adaptable. This article seeks to contribute to the literature by linking plan formulation, plan execution, and team learning behaviors with team outcomes (i.e., team-adaptation perception and objective performance). Participants formed 142 teams, which were involved in structured-problem solving task (i.e. a simulated management competition). Conditional process analysis was used to test a double-mediated relationship. Results show that, although not all parts of the model are directly associated, there is an indirect link from plan formulation to team outcomes through plan execution and team learning behaviors. Our results support the idea of adaptation as a process, providing four ways in which organizations can elicit changes in teams: increasing plan execution, promoting team learning, improving team adaptive behaviors themselves, and building teams composed of members who demonstrate individual adaptability

Developing biodata for public manager selection purposes: A comparison between fuzzy logic and traditional methods

Biodata have been widely used in personnel selection for a long time, mainly due to their predictive validity in different contexts, low faking, and positive applicant reactions. At the same time, some disadvantages need to be highlighted, with discriminatory content representing a major concern. In order to shed light on these issues, the objectives of the present research are twofold: firstly, we aim to develop biodata items for personnel selection for the provision of managerial positions in Public Administration and, secondly, we aim to test the fuzzy logic method as a valid approach for the development of biodata scales, with a view to choosing the best biodata items in terms of job performance, fairness, and privacy, according with manager and applicant perspectives. Participants assessed 26 items according to traditional and fuzzy rules, resulting in 8 highly effective items. Then, both approaches were compared: fuzzy logic turned out to have similar results as the traditional approach. Finnally, future developments in research an practical implications in the field are suggested. Los datos biográficos (biodata) se han utilizado en la selección de personal durante mucho tiempo debido, principalmente, a su buena validez predictiva en diferentes contextos, a su bajo falseamiento y a las reacciones positivas de los solicitantes de empleo. No obstante, podemos destacar el posible contenido discriminatorio como su principal desventaja. Por tanto, los objetivos de la presente investigación son, en primer lugar, desarrollar empíricamente ítems válidos y justos para la selección de puestos directivos en la Administración Pública y, en segundo lugar, comprobar la utilidad de la lógica difusa en el desarrollo de escalas con biodata para elegir los mejores ítems en términos de desempeño laboral, equidad y privacidad, de acuerdo con las perspectivas de directivos y de solicitantes de empleo. Los participantes en el estudio evaluaron 26 ítems según reglas tradicionales y difusas, y se obtuvieron 8 ítems altamente efectivos. Posteriormente se compararon ambos enfoques: aunque la lógica difusa demostró cierta eficacia, logró resultados similares a los del enfoque tradicional. Finalmente, se proponen futuros desarrollos de investigación e implicaciones prácticas en esta materia

General Relativity as an Attractor in Scalar-Tensor Stochastic Inflation

Quantum fluctuations of scalar fields during inflation could determine the very large-scale structure of the universe. In the case of general scalar-tensor gravity theories these fluctuations lead to the diffusion of fundamental constants like the Planck mass and the effective Brans--Dicke parameter, $\omega$. In the particular case of Brans--Dicke gravity, where $\omega$ is constant, this leads to runaway solutions with infinitely large values of the Planck mass. However, in a theory with variable $\omega$ we find stationary probability distributions with a finite value of the Planck mass peaked at exponentially large values of $\omega$ after inflation. We conclude that general relativity is an attractor during the quantum diffusion of the fields.Comment: LaTeX (with RevTex) 11 pages, 2 uuencoded figures appended, also available on WWW via http://star.maps.susx.ac.uk/index.htm

Towards resource usage analysis of miniZinc models

We present a method for the static resource usage analysis of MiniZinc models. The analysis can infer upper bounds on the usage that a MiniZinc model will make of some resources such as the number of constraints of a given type (equality, disequality, global constraints, etc.), the number of variables (search variables or temporary variables), or the size of the expressions before calling the solver. These bounds are obtained from the models independently of the concrete input data (the instance data) and are in general functions of sizes of such data. In our approach, MiniZinc models are translated into Ciao programs which are then analysed by the CiaoPP system. CiaoPP includes a parametric analysis framework for resource usage in which the user can define resources and express the resource usage of library procedures (and certain program construets) by means of a language of assertions. We present the approach and report on a preliminary implementation, which shows the feasibility of the approach, and provides encouraging results

How Integrated Marketing Communications (IMC) works? A theoretical review and an analysis of its main drivers and effects

Since the mid-1990’s, the concept of Integrated Marketing Communications (IMC) has come to the fore and attracted considerable attention in the literature. The main purpose of this paper is twofold: (1) to explore IMC by delimitating its conceptual boundaries and identifying its main dimensions and (2) to develop a whole theoretical model of its antecedents and consequences. To achieve this goal, this study analyzes the conceptual framework around IMC and its dimensions and it presents an extensive literature review. Moreover, a new definition is presented and the main dimensions of the concept are highlighted. A systematic literature review is carried out to identify IMC antecedents and consequences and the research hypotheses are formulated. Following the obtained results, a conceptual model has been developed and the most relevant findings are discussed. Finally, the main academic and managerial implications are described. This model will help academics and marketers to better understand the role that this new marketing paradigm plays within modern management, in identifying the key variables that promote or hinder IMC and the benefits derived from its implementation

Optimization of logic programs with dynamic scheduling

Dynamic scheduling increases the expressive power of logic programming languages, but also introduces some overhead. In this paper we present two classes of program transformations designed to reduce this additional overhead, while preserving the operational semantics of the original programs, modulo ordering of literals woken at the same time. The first class of transformations simplifies the delay conditions while the second class moves delayed literals later in the rule body. Application of the program transformations can be automated using information provided by compile-time analysis. We provide experimental results obtained from an implementation of the proposed techniques using the CIAO prototype compiler. Our results show that the techniques can lead to substantial performance improvement

Lock-free Parallel Dynamic Programming

We show a method for parallelizing top down dynamic programs in a straightforward way by a careful choice of a lock-free shared hash table implementation and randomization of the order in which the dynamic program computes its subproblems. This generic approach is applied to dynamic programs for knapsack, shortest paths, and RNA structure alignment, as well as to a state-of-the-art solution for minimizing the máximum number of open stacks. Experimental results are provided on three different modern multicore architectures which show that this parallelization is effective and reasonably scalable. In particular, we obtain over 10 times speedup for 32 threads on the open stacks problem

Granuloma annulare: report of 13 patients treated with photodynamic therapy

Dear Editor, Granuloma annulare (GA) is a benign in?ammatory granuloma- tous skin. Photodynamic therapy (PDT) has been described as another therapeutic option for localized GA, with a degree of recommendation B. Therefore, we have carried out a review of all patients with GA treated with PDT in our Dermatology Unit. We performed a retrospective observational study in San Jorge Hospital (Huesca, Spain) including all patients diagnosed with GA and treated with PDT between 2007 and 2018. Diagno- sis of GA was clinical and a skin biopsy was performed if it was necessary. In all patients, methyl aminolevulinate (MAL) or aminolevulinic acid (ALA) was applied under occlusive and opa- que dressing for 3 h and illuminated with LED 635 nm (Aktilite?, Uppsala, Sweden) with a ?uence of 37 J/cm . The lesions were prepared by a soft curettage or microneedling, and some lesions did not receive any kind of prior skin preparation. Continuous variables were described using means and standard deviations. Statistical analyses were carried out using SPSS soft- ware (version 20.0; IBM Corp, Armonk, NY, USA). Thirteen patients were included in the study (Table 1). Eleven cases (84.6%) were women and two men (15.4%), with a mean of 53 years old. Eighty-four per cent patients (n = 11) ..