Bridges or walls? A metaphorical dichotomy of Pope Francis versus Donald Trump's views of transnational migration.

Within a wider research line on policy-driven institutional discourses on migration by international/national institutions, NGO and political leaders, this contribution is aimed at illustrating the bipolarized social representations of immigrants inspiring 24 speeches by Pope Francis and US President Donald Trump. Statistical analyses using IRAMUTEQ included "specificity analysis" of discursive forms (words) and "cluster analysis." Results show that the Pope's discourse on migration (articulated into four clusters) is richer than the oversimplified Trump's discourse (originating just one cluster): the words "bridges" and "walls" emerge as representational nuclei of their bipolarized views of transnational migration, as metaphorical dichotomies of inclusive/exclusive policies. Emphasizing the need to build walls to protect the Americans, inspired by the sovereign ideology (AMERICA FIRST!), President Trump does not at all suspect that in the globalized interconnected world the AMERICA FIRST may become just AMERICA ALONE!

Interplay between Proline Metabolism and ROS in the Fine Tuning of Root-Meristem Size in Arabidopsis.

We previously reported that proline modulates root meristem size in Arabidopsis by controlling the ratio between cell division and cell differentiation. Here, we show that proline metabolism affects the levels of superoxide anion (O2•-) and hydrogen peroxide (H2O2), which, in turn, modulate root meristem size and root elongation. We found that hydrogen peroxide plays a major role in proline-mediated root elongation, and its effects largely overlap those induced by proline, influencing root meristem size, root elongation, and cell cycle. Though a combination of genetic and pharmacological evidence, we showed that the short-root phenotype of the proline-deficient p5cs1 p5cs2/P5CS2, an Arabidopsis mutant homozygous for p5cs1 and heterozygous for p5cs2, is caused by H2O2 accumulation and is fully rescued by an effective H2O2 scavenger. Furthermore, by studying Arabidopsis mutants devoid of ProDH activity, we disclosed the essential role of this enzyme in the modulation of root meristem size as the main enzyme responsible for H2O2 production during proline degradation. Proline itself, on the contrary, may not be able to directly control the levels of H2O2, although it seems able to enhance the enzymatic activity of catalase (CAT) and ascorbate peroxidase (APX), the two most effective scavengers of H2O2 in plant cells. We propose a model in which proline metabolism participates in a delicate antioxidant network to balance H2O2 formation and degradation and fine-tune root meristem size in Arabidopsis.