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This article tries to answer the following question : up to what point the creation of a generic ethnicity, brought about by Indian mobilization for the last thirty years in Latin America, is enough to go beyond the traditional division between low lands’ Indian populations and peasant Indian communities of the Andes.

Background Masking of multiple sequence alignment blocks has become a powerful method to enhance the tree-likeness of the underlying data. However, existing masking approaches are insensitive to heterogeneous sequence divergence which can mislead tree reconstructions. We present AliGROOVE, a new method based on a sliding window and a Monte Carlo resampling approach, that visualizes heterogeneous sequence divergence or alignment ambiguity related to single taxa or subsets of taxa within a multiple sequence alignment and tags suspicious branches on a given tree. Results We used simulated multiple sequence alignments to show that the extent of alignment ambiguity in pairwise sequence comparison is correlated with the frequency of misplaced taxa in tree reconstructions. The approach implemented in AliGROOVE allows to detect nodes within a tree that are supported despite the absence of phylogenetic signal in the underlying multiple sequence alignment. We show that AliGROOVE equally well detects heterogeneous sequence divergence in a case study based on an empirical data set of mitochondrial DNA sequences of chelicerates. Conclusions The AliGROOVE approach has the potential to identify single taxa or subsets of taxa which show predominantly randomized sequence similarity in comparison with other taxa in a multiple sequence alignment. It further allows to evaluate the reliability of node support in a novel way.

Objectives Recent data debate the suitability of Helios, an Ikaros family member, as a marker for thymic-derived regulatory T cells (Treg). Nevertheless, Foxp3+ Helios+ Treg may be of particular relevance in mediating immune tolerance in chronic autoimmunity, such as systemic lupus erythematosus (SLE), as they possess enhanced suppressive function, compared to Foxp3+ Helios− Treg. Methods Multicolour flow cytometry was performed to analyse Foxp3 and Helios expression in peripheral blood CD4 T cells from SLE patients, compared to healthy controls (HC) and systemic sclerosis (SSc) and rheumatoid arthritis (RA) patients. Cytokine production, chemokine receptor expression for CXCR3 and CCR4, basal signal transducer and activator of transcription 5 (STAT5)a phosphorylation levels and T-cell receptor (TCR) Vβ repertoire were analysed by flow cytometry, and the methylation status of the Foxp3 locus (Treg-specific demethylated region, TSDR) by real-time PCR. Results Frequencies of Foxp3+ Helios+ Treg, unlike Foxp3+ Helios− T cells, were significantly increased in SLE patients and positively correlated with disease activity, whereas they were unaltered in SSc and RA patients. Compared to HC, Foxp3+ Helios+ Treg in SLE predominantly displayed a CD45RA−/CD31−/FoxP3low memory phenotype with increased Ki-67 expression, enhanced basal pSTAT5a levels and a restricted TCR repertoire. Nonetheless, similar to HC, Foxp3+ Helios+ Treg in SLE lacked effector cytokine production, possessed a highly demethylated TSDR and expressed comparable levels of CXCR3 and CCR4. Conclusions Our data suggest that Helios-expressing Foxp3+ Treg with functional suppressive capacity and migratory potential into inflamed tissues are expanded in active SLE, presumably through γ-chain signalling cytokines and TCR stimulation, to compensate for autoreactive effector responses.

This text is the introduction to a dossier that collects four of the papers presented in the discussion group “Indian Frontiers of Latin America” (Leticia, 2009), organized by the Institut des Hautes Etudes de l’Amérique Latine (IHEAL), the Institut des Amériques (IDA) and the Amazonia Campus of Universidad Nacional de Colombia. This event gathered researchers and regional actors involved in the management, administration, protection and analysis of the frontier regions and of the populations that inhabit them. We decided to privilege the participation of young researchers, of those that allowed us to consolidate an ample view of the international scenario of the Amazon basin, and of those that gave us the possibility of launching a dialogue between academic discourses and those of the NGOs. The indigenous character of the populations that inhabit the frontier regions of South America gives these regions a particular situation. A conscious reflection about their dynamics and tensions cannot be carried out without reference to their ethnic nature or without thinking the political frontiers as cultural frontiers.

ABSTRACT IN FRENCH: Dans cet article on se demande dans quelle mesure la création d'une ethnicité générique produite par les mobilisations indigènes ces trente dernières années en Amérique latine permet de dépasser le clivage traditionnel existant entre peuples indiens des basses terres et communautés indiennes paysannes des Andes. // ABSTRACT IN SPANISH: Se estudiará en qué medida la creación de una etnicidad genérica originada por las movilizaciones indígenas de los últimos treinta años en América Latina permite superar la separación tradicional entre pueblos indígenas de las tierras bajas y comunidades indígenas campesinas de los Andes. // ABSTRACT IN ENGLISH: This article tries to answer the following question: up to what point the creation of a generic ethnicity, brought about by Indian mobilization for the last thirty years in Latin America, is enough to go beyond the traditional division between low lands' Indian populations and peasant Indian communities of the Andes. Reprinted by permission of Presses Universitaires du Mirail

Dans cet article on se demande dans quelle mesure la création d’une ethnicité générique produite par les mobilisations indigènes ces trente dernières années en Amérique latine permet de dépasser le clivage traditionnel existant entre peuples indiens des basses terres et communautés indiennes paysannes des Andes.

The response of the Indian population to Protestant proselytism is neither passive nor impotent, and far from playing a destructive or reactionary role, Protestantism provides an unsuspected combination of identity markers and modernity, thus occupying a space left open by Catholicism.