86,015 research outputs found
Monitoring of Iberian wolf expansion in Sabugal: Malcata Region
Relatório de projecto no âmbito de Bolsa Universidade de Lisboa/Fundação Amadeu Dias (2008/2009)Departamento de Biologia Animal, Faculdade de Ciências da Universidade de LisboaScholarship Fundação Amadeu Dias/Universidade de LisboaWind farm construction may cause an effect of repulse on the wildlife. Sabugal – Malcata region has a new
wind farm in a zone where the situation of the Iberian wolf (Canis lupus signatus, Cabrera 1907) is considered as
precarious. In this context a monitoring project was begun to assess the impact of this infrastructure on the Iberian wolf
population. Here are presented the results of eight months of monitoring and some information received during the
project about the wolf presence in this region. Every month, signs of wolf presence were prospected in twelve transects
in the wind farm adjacent area and fourteen inquires were done to people that can contact with this predator. In all the
eight months only two scats were detected and two wolf tracks after a snowfall. The presence of wolves was referred in
the inquires as constant before 1990. However, some recent livestock damages were reported. The Roe deer
(Capreolus capreolus) seems to be in expansion in this area, being reported in more than half of the inquires. This
situation may reveal a new opportunity for settlement of dispersing wolves. The occurrence of the Iberian Wolf in
Sabugal – Malcata region continues not to be confirmed, but the designation of probable presence is reinforced.Universidade de Lisboa; Fundação Amadeu Dia
Non Relativistic Limit of a Model of Fermions interacting through a Chern-Simons Field
We study the non relativistic limit of a Model of Fermions interacting
through a Chern-Simons Field, from a perspective that resembles the Wilson's
Renormalization Group approach, instead of the more usual approach found in
most texts of Field Theory. The solution of some difficulties, and a new
understanding of non relativistic models is given.Comment: 16 pages (revtex), 5 figures (eps). Invited talk at the meeting ``II
Trends in Theoretical Physics'', Buenos Aires, Dec. 1998. To be published by
AI
Information-entropic analysis of Korteweg--de Vries solitons in the quark-gluon plasma
Solitary waves propagation of baryonic density perturbations, ruled by the
Korteweg--de Vries equation in a mean-field quark-gluon plasma model, are
investigated from the point of view of the theory of information. A recently
proposed continuous logarithmic measure of information, called configurational
entropy, is used to derive the soliton width, defining the pulse, for which the
informational content of the soliton spatial profile is more compressed, in the
Shannon's sense.Comment: 6 pages, 1 figur
Recommended from our members
A Framework for Trusted Services
An existing challenge when selecting services to be used in a service- based system is to be able to distinguish between good and bad services. In this paper we present a trust-based service selection framework. The framework uses a trust model that calculates the level of trust a user may have with a service based on past experience of the user with the service and feedback about the service received from other users. The model takes into account different levels of trust among users, different relationships between users, and different levels of importance that a user may have for certain quality aspects of a service. A prototype tool has been implemented to illustrate and evaluate the work. The trust model has been evaluated in terms of its capacity to adjust itself due to changes in user ratings and its robustness
Mean-Field and Non-Mean-Field Behaviors in Scale-free Networks with Random Boolean Dynamics
We study two types of simplified Boolean dynamics over scale-free networks,
both with synchronous update. Assigning only Boolean functions AND and XOR to
the nodes with probability and , respectively, we are able to analyze
the density of 1's and the Hamming distance on the network by numerical
simulations and by a mean-field approximation (annealed approximation). We show
that the behavior is quite different if the node always enters in the dynamic
as its own input (self-regulation) or not. The same conclusion holds for the
Kauffman KN model. Moreover, the simulation results and the mean-field ones (i)
agree well when there is no self-regulation, and (ii) disagree for small
when self-regulation is present in the model.Comment: 12 pages, 7 figure
- …