CPLP: the first twenty-five years

The decision by Conjuntura Austral to dedicate a special issue to the 25th anniversary of the establishment of the Community of Portuguese Language Countries (CPLP) is to be commended. The uniqueness of the organization justifies a timely review of a small sample of its activities to date. Created in 1996, the CPLP adopted three main vectors of activity:1) the promotion and dissemination of the Portuguese language; 2) cooperation in a wide array of domains (i.e., education, health, science and technology, defense, agriculture, public administration, communication, justice, public safety, culture, sport and social communication, sustainable development, etc.); and 3) political and diplomatic coordination, especially in multilateral forums. The organization also agreed to adhere to several fundamental political principles such as the respect of the sovereignty of each member country; non-interference in domestic issues; reciprocal treatment; peace, democracy, rule of law, human rights, and social justice; territorial integrity of each member state; and the commitment to the promotion of development and cooperation

CPLP: the first twenty-five years

The decision by Conjuntura Austral to dedicate a special issue to the 25th anniversary of the establishment of the Community of Portuguese Language Countries (CPLP) is to be commended. The uniqueness of the organization justifies a timely review of a small sample of its activities to date. Created in 1996, the CPLP adopted three main vectors of activity:1) the promotion and dissemination of the Portuguese language; 2) cooperation in a wide array of domains (i.e., education, health, science and technology, defense, agriculture, public administration, communication, justice, public safety, culture, sport and social communication, sustainable development, etc.); and 3) political and diplomatic coordination, especially in multilateral forums. The organization also agreed to adhere to several fundamental political principles such as the respect of the sovereignty of each member country; non-interference in domestic issues; reciprocal treatment; peace, democracy, rule of law, human rights, and social justice; territorial integrity of each member state; and the commitment to the promotion of development and cooperation

Política externa no mundo real: os anos Obama

The text presents the analysis of books written by three former Barack Obama government members - Tough Love: My Story of the Things Worth Fighting For, by Susan Rice, The Education of an Idealist: A Memoir, by Samantha Power, and The World as It Is: A Memoir of the Obama White House, by Ben Rhodes - and seeks to demonstrate how they all manage to present many of that administration's internal debates, as well as reveal the limitations of its foreign policy.O texto apresenta a análise de livros escritos por três ex-assessores do governo Barack Obama - Tough Love: My Story of the Things Worth Fighting For, de Susan Rice, The Education of an Idealist: A Memoir , de Samantha Power e The World as It Is: A Memoir of the Obama White House, de Ben Rhodes -, e busca demonstrar como todos eles conseguem apresentar muitos dos debates internos daquela administração, bem como revelar as limitações de sua política externa.

South-South relations and the English School of International Relations: Chinese and Brazilian ideas and involvement in Sub-Saharan Africa

The rise of large developing countries has led to considerable discussions of re-balancing global relations and giving greater priority to understanding South-South relations. This paper, in exploring the central ideas of Chinese and Brazilian foreign policy and the behavior of these two rising Southern countries toward Sub-Saharan Africa, argues that the English School of International Relations is well suited to understanding the intentions and actions that characterize South-South relations

HP Windows Mixed Reality vs Meta 2: Investigating Differences in Workload and Usability for a Ball-sorting Task

Perceived workload and usability are crucial components of human-computer interactions. Currently, there is a gap in research comparing Augmented Reality (AR) and Virtual Reality (VR) systems for workload and usability. This study attempts to bridge that gap through the comparison of the HP Windows Mixed Reality system and the Meta 2 system for a ball-sorting task. Subjective questionnaires on workload and usability were implemented as comparative measures for three game scenarios of increasing difficulty. Forty-one participants were recruited from the University of Central Florida and its surrounding communities. Results showed significantly lower cumulative total workload and greater usability (for the subscale of ease of use) for the HP Windows Mixed Reality system when compared to the Meta 2 system. There were no statistically significant differences reported for the other usability subscales between the two systems. Also, there were no statistically significant differences in total workload within the three scenarios for both systems. The findings could be attributed to differences in control schemes (i.e., native handheld controllers versus hand gestures), user experience with AR and VR systems, and difficulty of task scenarios

Engineering higher order Van Hove singularities in two dimensions: the example of the surface layer of Sr2_2RuO4_4

The properties of correlated electron materials are often intricately linked to Van Hove singularities (VHs) in the vicinity of the Fermi energy. The class of these VHs is of great importance, with higher order ones -- with power-law divergence in the density of states -- leaving frequently distinct signatures in physical properties. We use a new theoretical method to detect and analyse higher order Van Hove singularities (HOVHs) in two-dimensional materials and apply it to the electronic structure of the surface layer of Sr$_2$RuO$_4$. We then constrain a low energy model of the VHs of the surface layer of Sr$_2$RuO$_4$ against angle-resolved photoemission spectroscopy and quasiparticle interference data to analyse the VHs near the Fermi level. We show how these VHs can be engineered into HOVHs.Comment: 8 pages including Supplemental Material, 5 figure

The Richardson's Law in Large-Eddy Simulations of Boundary Layer flows

Relative dispersion in a neutrally stratified planetary boundary layer (PBL) is investigated by means of Large-Eddy Simulations (LES). Despite the small extension of the inertial range of scales in the simulated PBL, our Lagrangian statistics turns out to be compatible with the Richardson $t^3$ law for the average of square particle separation. This emerges from the application of nonstandard methods of analysis through which a precise measure of the Richardson constant was also possible. Its values is estimated as $C_2\sim 0.5$ in close agreement with recent experiments and three-dimensional direct numerical simulations.Comment: 15 LaTex pages, 4 PS figure

Noncommutative field gas driven inflation

We investigate early time inflationary scenarios in an Universe filled with a dilute noncommutative bosonic gas at high temperature. A noncommutative bosonic gas is a gas composed of bosonic scalar field with noncommutative field space on a commutative spacetime. Such noncommutative field theories was recently introduced as a generalization of quantum mechanics on a noncommutative spacetime. As key features of these theories are Lorentz invariance violation and CPT violation. In the present study we use a noncommutative bosonic field theory that besides the noncommutative parameter $\theta$ shows up a further parameter $\sigma$. This parameter $\sigma$ controls the range of the noncommutativity and acts as a regulator for the theory. Both parameters play a key role in the modified dispersion relations of the noncommutative bosonic field, leading to possible striking consequences for phenomenology. In this work we obtain an equation of state $p=\omega(\sigma,\theta;\beta)\rho$ for the noncommutative bosonic gas relating pressure $p$ and energy density $\rho$, in the limit of high temperature. We analyse possible behaviours for this gas parameters $\sigma$, $\theta$ and $\beta$, so that $-1\leq\omega<-1/3$, which is the region where the Universe enters an accelerated phase.Comment: Reference added. Version to appear in Journal of Cosmology and Astroparticle Physics - JCA