Compressibility of a fermionic mott insulator of ultracold atoms.

We characterize the Mott insulating regime of a repulsively interacting Fermi gas of ultracold atoms in a three-dimensional optical lattice. We use in situ imaging to extract the central density of the gas and to determine its local compressibility. For intermediate to strong interactions, we observe the emergence of a plateau in the density as a function of atom number, and a reduction of the compressibility at a density of one atom per site, indicating the formation of a Mott insulator.

Observation of antiferromagnetic correlations in the Hubbard model with ultracold atoms.

Ultracold atoms in optical lattices have great potential to contribute to a better understanding of some of the most important issues in many-body physics, such as high-temperature superconductivity. The Hubbard model--a simplified representation of fermions moving on a periodic lattice--is thought to describe the essential details of copper oxide superconductivity. This model describes many of the features shared by the copper oxides, including an interaction-driven Mott insulating state and an antiferromagnetic (AFM) state.

Influence of river discharge patterns on the hydrodynamics and potential contaminant dispersion in the Douro estuary (Portugal).

Freshwater input to estuaries is a fundamental feature of these ecosystems, which may be profoundly altered by river damming as human needs for water consumption, irrigation or energy production increase. The Douro estuary is limited upstream by a dam since 1985, which reduced its length by ca. 60%.

Temperament in Portuguese university students as measured by TEMPS-A: implications for professional choice.

Background: The structure of temperament displays subaffective traits as attributes of adaptive value. There are few studies on how different professions compare on temperaments. Our aim was to examine the relationship between the choices of Portuguese students in their fields of study, and their respective temperaments.

Validation of the Temperament Evaluation of Memphis, Pisa, Paris and San Diego (TEMPS-A): Portuguese-Lisbon version.

Background: The TEMPS-A has been validated in 8 languages, the original being American English, and includes among others such Latin languages as Italian, French, and Spanish-Buenos Aires. This is the first Portuguese-Lisbon validation.

Methods: The sample included 1173 students from six different universities and representing most disciplines (such as medicine, law, humanities, engineering, etc.