Socioeconomic Networks with Long-Range Interactions

We study a modified version of a model previously proposed by Jackson and Wolinsky to account for communicating information and allocating goods in socioeconomic networks. In the model, the utility function of each node is given by a weighted sum of contributions from all accessible nodes. The weights, parameterized by the variable $\delta$, decrease with distance. We introduce a growth mechanism where new nodes attach to the existing network preferentially by utility. By increasing $\delta$, the network structure evolves from a power-law to an exponential degree distribution, passing through a regime characterised by shorter average path length, lower degree assortativity and higher central point dominance. In the second part of the paper we compare different network structures in terms of the average utility received by each node. We show that power-law networks provide higher average utility than Poisson random networks. This provides a possible justification for the ubiquitousness of scale-free networks in the real world.Comment: 11 pages, 8 figures, minor correction

Differential temporal beta‐diversity patterns of native and non‐native arthropod species in a fragmented native forest landscape

An important factor that hinders the management of non‐native species is a general lack of information regarding the biogeography of non‐natives, and, in particular, their rates of turnover. Here, we address this research gap by analysing differences in temporal beta‐diversity (using both pairwise and multiple‐time dissimilarity metrics) between native and non‐native species, using a novel time‐series dataset of arthropods sampled in native forest fragments in the Azores. We use a null model approach to determine whether temporal beta‐diversity was due to deterministic processes or stochastic colonisation and extinction events, and linear modelling selection to assess the factors driving variation in temporal beta‐diversity between plots. In accordance with our predictions, we found that the temporal beta‐diversity was much greater for non‐native species than for native species, and the null model analyses indicated that the turnover of non‐native species was due to stochastic events. No predictor variables were found to explain the turnover of native or non‐native species. We attribute the greater turnover of non‐native species to source‐sink processes and the close proximity of anthropogenic habitats to the fragmented native forest plots sampled in our study. Thus, our findings point to ways in which the study of turnover can be adapted for future applications in habitat island systems. The implications of this for biodiversity conservation and management are significant. The high rate of stochastic turnover of non‐native species indicates that attempts to simply reduce the populations of non‐native species in situ within native habitats may not be successful. A more efficient management strategy would be to interrupt source‐sink dynamics by improving the harsh boundaries between native and adjacent anthropogenic habitats.Portuguese FCT‐NETBIOME – ISLANDBIODIV grant 0003/2011.info:eu-repo/semantics/publishedVersio

A meta-regression analysis of benchmarking studies on water utilities market structure

This paper updates the literature on water utility benchmarking studies carried out worldwide, focusing on scale and scope economies. Using meta-regression analysis, the study investigates which variables from published studies influence these economies. Our analysis led to several conclusions. The results indicate that there is a higher probability of finding diseconomies of scale and scope in large utilities; however, only the results for scale economies are significant. Diseconomies of scale and scope are more likely to be found in publicly-owned utilities than when the ownership is mostly private; as would be expected, multi-utilities are more likely to have scale and scope economies.economies of scale; economies of scope; meta-regression analysis; water utilities

Estimation of Cost Allocation Coefficients at the Farm Level Using an Entropy Approach

This paper aims to estimate the farm cost allocation coefficients from whole farm input costs. An entropy approach was developed under a Tobit formulation and was applied to a sample of farms from the 2004 FADN data base for Alentejo region, Southern Portugal. A Generalized Maximum Entropy model and Cross Generalized Entropy model were developed to the sample conditions and were tested. Model results were assessed in terms of their precision and estimation power and were compared with observed data. The entropy approach showed to be a flexible and valid tool to estimate incomplete information, namely regarding farm costs.Generalized maximum entropy; costs; estimation; Alentejo, FADN.

Management of interdisciplinary project approaches in Engineering Education: a case study

This paper describes project management processes of coordination teams, in the implementation of interdisciplinary project approaches in Engineering Education. These interdisciplinary projects are based on the Project-Led Education (PLE) concept and are being implemented since 2004/2005 in the Industrial Management and Engineering (IME) master degree course (1st and 2nd cycle of Engineering Education) at University of Minho. Usually, these approaches involve a coordination team of 10 to 15 members with different roles: teachers, tutors and education researchers. This team is responsible for preparing the project for the semester and forming the students’ teams. The coordination of these two types of teams is centred on a project manager that is responsible for, and supports, all the work developed during the semester, e.g., prepare the initial presentation of the project to the students, prepare the web site that supports the work, establish the communication between students and the rest of the team, prepare the students’ guide, and so on. Managing these projects is an intense task that demands a lot of time and different competencies. In this work it is presented a project management framework based on project management knowledge areas, to aid coordination teams to achieve better results

Science as rhetoric in media discourses on climate change

This article aims to analyse and describe the organization of reported speech in a corpus of Portuguese newspaper articles, as well as the way such texts function in terms of rhetoric and argumentation. The focus is on media discourse on the science(s) of climate change, including reports on new studies, publications, expert testimonies, etc. In Portugal, news discourses on climate change have a strong interdiscursive relation with scientific discourse and tend to present science as an authoritative source of reliable knowledge. This reliance on scientific discourse is associated with a media strategy of persuasion of the audience, the effectiveness of which depends on the representations of validity of scientific knowledge. By evoking voices from the science community, the journalist can both project an image of neutrality and legitimise her/his discourse. This is instrumental for the success of her/his illocutionary goals, for the acceptance of her/his speech and even for the public sanction of a given discourse on the environmen