A propòsit d'un centenari

Hem acomplert cent anys d'existència de la Psicologia social i, en aquests temps, hem estructurat una disciplina científica amb un ample cos conceptual i amb diverses branques o subespecialitats enriquidores. No obstant, el més rellevant es haver arribat a fer de la Psicologia social una eina útil en l'aconseguiment de benestar i de qualitat de vida als diferents àmbits d'intervenció psicològica 'laboral, familiar, comunitari, etc..

Symmetry considerations in the empirical k.p Hamiltonian for the study of intermediate band solar cells

With the purpose of assessing the absorption coefficients of quantum dot solar cells, symmetry considerations are introduced into a Hamiltonian whose eigenvalues are empirical. In this way, the proper transformation from the Hamiltonian's diagonalized form to the form that relates it with Γ-point exact solutions through k.p envelope functions is built accounting for symmetry. Forbidden transitions are thus determined reducing the calculation burden and permitting a thoughtful discussion of the possible options for this transformation. The agreement of this model with the measured external quantum efficiency of a prototype solar cell is found to be excellent

New invariants for entangled states

We propose new algebraic invariants that distinguish and classify entangled states. Considering qubits as well as higher spin systems, we obtained complete entanglement classifications for cases that were either unsolved or only conjectured in the literature.Comment: published versio

U/Th dating of Quaternary travertines at the middle River Llobregat (NE Iberian Peninsula, Nortwestern Mediterranean). Correlation with sea-level changes

The dating of the fluvial terraces of the middle River Llobregat enabled one to establish a correlation between the sedimentation episodes in continental zones and in neighbouring deltaic and coastal areas in the NE Iberian continental margin. The fluvial Terraces 4 (+85-95 m above river level) and 3 (+55-65 m above river level) are made up by or include travertines, which were deposited around 350,000 and 111,000 years ago, respectively. These radiometric ages correspond to two high sea level periods: the Eemian interglacial (isotopic stage 5e) and the interglacial related to isotopic stage 9. However, other travertine units in the valley, such as the Can Tobella staggered cascade travertines, were formed during the Holocene, probably due to hydrothermal spring activity related to the tectonic contact between the Catalan Coastal Ranges and the Ebro Basin

Using network science to analyze football passing networks: dynamics, space, time and the multilayer nature of the game

From the diversity of applications of Network Science, in this Opinion Paper we are concerned about its potential to analyze one of the most extended group sports: Football (soccer in U.S. terminology). As we will see, Network Science allows addressing different aspects of the team organization and performance not captured by classical analyses based on the performance of individual players. The reason behind relies on the complex nature of the game, which, paraphrasing the foundational paradigm of complexity sciences "can not be analyzed by looking at its components (i.e., players) individually but, on the contrary, considering the system as a whole" or, in the classical words of after-match interviews "it's not just me, it's the team".Comment: 7 pages, 1 figur

Highest weight Macdonald and Jack Polynomials

Fractional quantum Hall states of particles in the lowest Landau levels are described by multivariate polynomials. The incompressible liquid states when described on a sphere are fully invariant under the rotation group. Excited quasiparticle/quasihole states are member of multiplets under the rotation group and generically there is a nontrivial highest weight member of the multiplet from which all states can be constructed. Some of the trial states proposed in the literature belong to classical families of symmetric polynomials. In this paper we study Macdonald and Jack polynomials that are highest weight states. For Macdonald polynomials it is a (q,t)-deformation of the raising angular momentum operator that defines the highest weight condition. By specialization of the parameters we obtain a classification of the highest weight Jack polynomials. Our results are valid in the case of staircase and rectangular partition indexing the polynomials.Comment: 17 pages, published versio

Water management in the Iberian península: new solutions for old problems?

9 pages, 4 figures, 2 tables, 12 references.-- XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on CLIMWATER 2010: Horticultural Use of Water in a Changing Climate.-- Lisboa, Portugal.The increasing demand of fresh water from different sectors puts pressure in scientists and engineers to develop more effective ways of using the available water resources. In Spain and Portugal, countries of Mediterranean climate with hot and dry summers, the allocation of water resources is especially controversial. This emphasises the need for a rational use of water. We present features and recent developments of Spanish and Portuguese water policies and some consequences on the use of land and water. We consider how social, economic and environmental problems might evolve in the expected scenarios of population growth and climatic change, and analyse the response from the scientific community to the new challenges. Finally, we pointed out that the combined efforts of professionals and users provide useful tools for satisfying the consumers demand at the same time that the environmental foot¬print is minimized.Peer Reviewe