Apresentando alguns aspectos históricos do desenvolvimento da lógica clássica, ciência das idéias e dos processos da mente

Lógica é a ciência que tem por objeto determinar, entre as operações intelectuais orientadas para o conhecimento da verdade, as que são válidas e as que não são. Estuda os processos e as condições de verdade de todo e qualquer raciocínio. O conhecimento só é científico quando, além de universal, é metódico e sistemático, ou seja, lógico. Assim, a lógica se entende como método, ou caminho que as ciências trilham para determinar e conhecer seu objeto, e como característica geral do conhecimento científico

Moment Closure - A Brief Review

Moment closure methods appear in myriad scientific disciplines in the modelling of complex systems. The goal is to achieve a closed form of a large, usually even infinite, set of coupled differential (or difference) equations. Each equation describes the evolution of one "moment", a suitable coarse-grained quantity computable from the full state space. If the system is too large for analytical and/or numerical methods, then one aims to reduce it by finding a moment closure relation expressing "higher-order moments" in terms of "lower-order moments". In this brief review, we focus on highlighting how moment closure methods occur in different contexts. We also conjecture via a geometric explanation why it has been difficult to rigorously justify many moment closure approximations although they work very well in practice.Comment: short survey paper (max 20 pages) for a broad audience in mathematics, physics, chemistry and quantitative biolog

The tourism and economic growth enigma: Examining an ambiguous relationship through multiple prisms

This paper revisits the ambiguous relationship between tourism and economic growth, providing a comprehensive study of destinations across the globe which takes into account the key dynamics that influence tourism and economic performance. We focus on 113 countries over the period 1995-2014, clustered, for the first time, around six criteria that reflect their economic, political and tourism dimensions. A Panel Vector Autoregressive model is employed which, in contrast to previous studies, allows the data to reveal any tourism-economy interdependencies across these clusters, without imposing a priori the direction of causality. Overall, the economic-driven tourism growth hypothesis seems to prevail in countries which are developing, non-democratic, highly bureaucratic and have low tourism specialization. Conversely, bidirectional relationships are established for economies which are stronger, democratic and with higher levels of government effectiveness. Thus, depending on the economic, political and tourism status of a destination, different policy implications apply

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

Economic integration and security in the Middle East and North Africa: what prospects for a liberal peace?

Since the late 1980s governments in the Middle East and North Africa (MENA) have created commercial institutions in order to promote regional economic integration. The primary aim of this policy has been regarded as the promotion of economic welfare gains at the national level. A second, albeit less-emphasized goal, has been to promote regional peace through economic interdependence. This study examines the prospects for a liberal peace in the MENA by analyzing two stages of the commercial institutional peace. Firstly, the study considers whether commercial institutions have promoted intra-regional trade in the MENA. Secondly, it examines if economic interaction has had an impact on promoting peace within the region. Twenty states are considered here and the unit of analysis is the dyad-year over a 25-year period from 1990-2014. This study finds that commercial institutions in the MENA have only a limited positive correlation with trade volume and while there is a direct positive correlation between economic integration and peace in the region, this is quite limited. These findings suggest that the conclusions made by previous studies that demonstrate a direct positive correlation between commercial institutions (and economic integration more generally) and peace, may be less applicable to some regions such as MENA