With Whom Do Nations Trade? – The Fading Distance

Distance has conventionally been considered a major determinant of the direction of international trade. This contrasts, intuitively, with the generally-acknowledged fact that transportation costs are only a minor component of prices in international trade. The present study estimates the impact of distance on mutual trade flows in alternative, more direct methods than those employed traditionally in the literature. In particular, it looks at the “intensity ratio” in mutual trade; and asks to what extent its deviation from the size expected under an assumption of “neutrality” may be explained by mutual distances. It is found that, by and large, distance is a minor determinant of the trade of nations with each other. It is of some significance when trade flows within quite short ranges are concerned; but beyond these, the impact of distance on trade largely fades away.

High-throughput engineering of a mammalian genome reveals building principles of methylation states at CG rich regions

The majority of mammalian promoters are CpG islands; regions of high CG density that require protection from DNA methylation to be functional. Importantly, how sequence architecture mediates this unmethylated state remains unclear. To address this question in a comprehensive manner, we developed a method to interrogate methylation states of hundreds of sequence variants inserted at the same genomic site in mouse embryonic stem cells. Using this assay, we were able to quantify the contribution of various sequence motifs towards the resulting DNA methylation state. Modeling of this comprehensive dataset revealed that CG density alone is a minor determinant of their unmethylated state. Instead, these data argue for a principal role for transcription factor binding sites, a prediction confirmed by testing synthetic mutant libraries. Taken together, these findings establish the hierarchy between the two cis-encoded mechanisms that define the DNA methylation state and thus the transcriptional competence of CpG islands.

Reflexões sobre o Espaço, o Urbano e a Urbanização

Resumo Trata-se de discutir se a urbanização é passível de ser compreendida como parte do processo geral de estruturação da sociedade e do território. Um processo onde as desigualdades sociais e espaciais conjugadas à mobilidade espacial e setorial do trabalho contribuem para alterar o território. Este processo que cria fixos e fluxos tem uma resultante espacial em duas escalas: a cidade, na escala dos lugares; e a rede urbana, enquanto a manifestação espacial da cooperação entre lugares, na escala territorial. Isto não significa dizer que a urbanização em si é um determinante maior ou menor, mas um produto de práticas socais que interage com outros fatores na construção do espaço social além das cidades. Palavras-chave: urbanização, reprodução espacial, reestruturação. Abstract Our goal is to argue whether the urbanisation could be understood as a part of society and territory general structuring process. A process where the social and spatial inequalities articulated to spatial and sectorial mobility of labor contribute to transform the territory. This process that creates fix and flows has an spatial outcome in two scales: the city at the place scale and the urban network, as a spatial manifestation of the cooperation among places, at the territorial scale. Not meaning that urbanization by itself is a major or minor determinant, but a social practices product, which interacts with other factors on the construction of social space beyond the cities. Keywords: urbanization, space reproduction, restructuring.

Reflexões sobre o Espaço, o Urbano e a Urbanização

Resumo Trata-se de discutir se a urbanização é passível de ser compreendida como parte do processo geral de estruturação da sociedade e do território. Um processo onde as desigualdades sociais e espaciais conjugadas à mobilidade espacial e setorial do trabalho contribuem para alterar o território. Este processo que cria fixos e fluxos tem uma resultante espacial em duas escalas: a cidade, na escala dos lugares; e a rede urbana, enquanto a manifestação espacial da cooperação entre lugares, na escala territorial. Isto não significa dizer que a urbanização em si é um determinante maior ou menor, mas um produto de práticas socais que interage com outros fatores na construção do espaço social além das cidades. Palavras-chave: urbanização, reprodução espacial, reestruturação. Abstract Our goal is to argue whether the urbanisation could be understood as a part of society and territory general structuring process. A process where the social and spatial inequalities articulated to spatial and sectorial mobility of labor contribute to transform the territory. This process that creates fix and flows has an spatial outcome in two scales: the city at the place scale and the urban network, as a spatial manifestation of the cooperation among places, at the territorial scale. Not meaning that urbanization by itself is a major or minor determinant, but a social practices product, which interacts with other factors on the construction of social space beyond the cities. Keywords: urbanization, space reproduction, restructuring.