Open borders in the nineteenth century : constructing the national, the citizen and the foreigner in South America

This working paper describes and explains the historical origins of the division between the national and the foreigner in South America. In the early nineteenth century, all the previously Spanish possessions in South America as well as Brazil achieved independence. With this new freedom, countries turned their attention to asserting their statehood through the delineation of three constitutive elements: government, territory and population. The new governments had to define who were going to be considered as nationals, citizens and foreigners, and the rights that pertained to each of these categories. These countries were all concerned with attracting new settlers and very early on introduced constitutional provisions on open borders and equal treatment for foreigners. White, male Europeans were the principal addresses of open borders provisions in an effort to entice them to settle in territories presented as empty to the exclusion of indigenous groups, bring new industries, and contribute to the whitening of mixed race populations. Whilst weak statehood came with independence, forming nations was a much longer process and States used migration and citizenship policies as tools to define nationhood

Flavonoids inhibit the platelet TxA(2) signalling pathway and antagonize TxA(2) receptors (TP) in platelets and smooth muscle cells

What is already known about this subject center dot Flavonoids are largely recognized as potential inhibitors of platelet function, through nonspecific mechanisms such as antioxidant activity and/or inhibition of several enzymes and signalling proteins. center dot In addition, we, and few others, have shown that certain antiaggregant flavonoids may behave as specific TXA2 receptor (TP) ligands in platelets. center dot Whether flavonoids interact with TP isoforms in other cell types is not known, and direct evidence that flavonoid-TP interaction inhibits signalling downstream TP has not been shown. What this study adds center dot This study first demonstrates that certain flavonoids behave as ligands for both TP isoforms, not only in platelets, but also in human myometrium and in TP-transfected HEK 293T cells. center dot Differences in the effect of certain flavonoids in platelet signalling, induced by either U46619 or thrombin, suggest that abrogation of downstream TP signalling is related to their specific blockage of the TP, rather than to a nonspecific effect on tyrosine kinases or other signalling proteins. Flavonoids may affect platelet function by several mechanisms, including antagonism of TxA(2) receptors (TP). These TP are present in many tissues and modulate different signalling cascades. We explored whether flavonoids affect platelet TP signalling, and if they bind to TP expressed in other cell types. Platelets were treated with flavonoids, or other selected inhibitors, and then stimulated with U46619. Similar assays were performed in aspirinized platelets activated with thrombin. Effects on calcium release were analysed by fluorometry and changes in whole protein tyrosine phosphorylation and activation of ERK 1/2 by Western blot analysis. The binding of flavonoids to TP in platelets, human myometrium and TP alpha- and TP beta-transfected HEK 293T cells was explored using binding assays and the TP antagonist H-3-SQ29548. Apigenin, genistein, luteolin and quercetin impaired U46619-induced calcium mobilization in a concentration-dependent manner (IC50 10-30 mu M). These flavonoids caused a significant impairment of U46619-induced platelet tyrosine phosphorylation and of ERK 1/2 activation. By contrast, in aspirin-treated platelets all these flavonoids, except quercetin, displayed minor effects on thrombin-induced calcium mobilization, ERK 1/2 and total tyrosine phosphorylation. Finally, apigenin, genistein and luteolin inhibited by > 50% H-3-SQ29548 binding to different cell types. These data further suggest that flavonoids may inhibit platelet function by binding to TP and by subsequent abrogation of downstream signalling. Binding of these compounds to TP occurs in human myometrium and in TP-transfected HEK 293T cells and suggests that antagonism of TP might mediate the effects of flavonoids in different tissues

Supporting academic decision making at higher educational institutions using machine learning-based algorithms

Decisions made by deans and university managers greatly impact the entire academic community as well as society as a whole. In this paper, we present survey results on which academic decisions they concern and the variables involved in them. Using machine learning algorithms, we predicted graduation rates in a real case study to support decision making. Real data from five undergraduate engineering programs at District University Francisco Jose de Caldas in Colombia illustrate our results. The comparison between support vector machine and artificial neural network is held using the confusion matrix and the receiver operating characteristic curve. The algorithm methods and architecture are presented