Mexican Scientist Diaspora in North America: A Perspective on Collaborations With México.

Scientific diasporas from developing countries represent an opportunity to strengthen international collaborations. These collaborations build upon the desire of members of the diasporas to establish scientific, academic, technological, and cultural exchange networks with the communities in their country of origin. While Mexico has a significant number of scientists residing abroad, particularly in North America, and most of them are committed to aid in the country's development, institutional coordination has not harnessed its benefits. In this work, we present an analysis of initiatives carried out by Mexican scientists, members of the diaspora, studying or working in the United States of America and Canada. The study is based on a set of interviews with members of this diaspora. We asked scientists about the conditions that enabled or obstructed their initiatives back in Mexico, and we discussed the role of these factors for capacity building. We also provide general recommendations to enhance contributions to the advancement of science in the country.

Closing the Gap Between Emerging Initiatives and Integrated Strategies to Strengthen Science Diplomacy in Latin America.

Science diplomacy is a fast-growing field of research, policy, and practice dedicated to understanding and reinforcing the connections between science and international affairs to tackle national, regional, and global issues. By aligning science and diplomacy, countries can attract talent, strengthen their national research ecosystems, provide avenues for participation of scientists in policy, and coordinate integrated solutions to challenges with technical dimensions. While Latin America has a long tradition of bilateral and regional cooperation, science still plays a marginal role in foreign policy, as has become evidenced by the response to the COVID-19 pandemic. With few exceptions, Latin American nations have a relatively immature science, technology, and innovation ecosystem, compounded by low public and private investments in research, coexisting with profound socio-economic inequalities, and large vulnerable populations. Such challenging conditions have created barriers to a fluid relationship between science and diplomacy, fundamentally characterized by inefficient communication between scientists and policymakers, weak collaboration channels, and duplicated roles, which altogether perpetuate siloed mentalities and a lack of trust between the two communities. Over the last decade, a first influential wave of Latin American scientists, diplomats, and other professionals, including five of the co-authors, have undertaken science diplomacy training provided by specialized organizations. Through these experiences, we recognized the need to elevate awareness and build capacities in science diplomacy in our respective countries and overall, across Latin America. Here, we describe emerging efforts and mechanisms to bridge the gap between scientists and policymakers at the national and regional level. Furthermore, we offer recommendations to amplify the impact of those pioneering initiatives toward consolidating a robust science diplomacy practice across the region. The national experiences described from Costa Rica, Mexico, and Panama can serve as a roadmap for other Latin American nations in the early process of developing a science diplomacy strategy, so they can also align themselves to a collective pathway. Most critically, we propose a way forward so that Latin America can leapfrog beyond disjointed training of individuals into integrated institutional strategies that can harness the tools of science diplomacy to enhance science-informed multilateral cooperation and enable more effective science-informed policymaking.

Rare intronic variants of TCF7L2 arising by selective sweeps in an indigenous population from Mexico.

BACKGROUND: Genetic variations of the TCF7L2 gene are associated with the development of Type 2 diabetes (T2D). The associated mutations have demonstrated an adaptive role in some human populations, but no studies have determined the impact of evolutionary forces on genetic diversity in indigenous populations from Mexico. Here, we sequenced and analyzed the variation of the TCF7L2 gene in three Amerindian populations and compared the results with whole-exon-sequencing of Mestizo populations from Sigma and the 1000 Genomes Project to assess the roles of selection and recombination in diversity. RESULTS: The diversity in the indigenous populations was biased to intronic regions. Most of the variation was low frequency. Only mutations rs77961654 and rs61724286 were located on exon 15. We did not observe variation in intronic region 4-6 in any of the three indigenous populations. In addition, we identified peaks of selective sweeps in the mestizo samples from the Sigma Project within this region. By replicating the analysis of association with T2D between case-controls from the Sigma Project, we determined that T2D was most highly associated with the rs7903146 risk allele and to a lesser extent with the other six variants. All associated markers were located in intronic region 4-6, and their r(2) values of linkage disequilibrium were significantly higher in the Mexican population than in Africans from the 1000 Genomes Project. We observed reticulations in both the haplotypes network analysis from seven marker associates and the neighborNet tree based on 6061 markers in the TCF7L2 gene identified from all samples of the 1000 Genomes Project. Finally, we identified two recombination hotspots in the upstream region and 3' end of the TCF7L2 gene. CONCLUSIONS: The lack of diversity in intronic region 4-6 in Indigenous populations could be an effect of selective sweeps generated by the selection of neighboring rare variants at T2D-associated mutations. The survivors' variants make the intronic region 4-6 the area of the greatest population differentiation within the TCF7L2 gene. The abundance of selective peak sweeps in the downstream region of the TCF7L2 gene suggests that the TCF7L2 gene is part of a region that is in constant recombination between populations.

Protein Tyrosine Kinase Fyn Regulates TLR4-Elicited Responses on Mast Cells Controlling the Function of a PP2A-PKCα/ß Signaling Node Leading to TNF Secretion.

Mast cells produce proinflammatory cytokines in response to TLR4 ligands, but the signaling pathways involved are not fully described. In this study, the participation of the Src family kinase Fyn in the production of TNF after stimulation with LPS was evaluated using bone marrow-derived mast cells from wild-type and Fyn-deficient mice. Fyn(-/-) cells showed higher LPS-induced secretion of preformed and de novo-synthesized TNF. In both cell types, TNF colocalized with vesicle-associated membrane protein (VAMP)3-positive compartments. Addition of LPS provoked coalescence of VAMP3 and its interaction with synaptosomal-associated protein 23; those events were increased in the absence of Fyn. Higher TNF mRNA levels were also observed in Fyn-deficient cells as a result of increased transcription and greater mRNA stability after LPS treatment. Fyn(-/-) cells also showed higher LPS-induced activation of TAK-1 and ERK1/2, whereas IκB kinase and IκB were phosphorylated, even in basal conditions. Increased responsiveness in Fyn(-/-) cells was associated with a lower activity of protein phosphatase 2A (PP2A) and augmented activity of protein kinase C (PKC)α/ß, which was dissociated from PP2A and increased its association with the adapter protein neuroblast differentiation-associated protein (AHNAK, desmoyokin). LPS-induced PKCα/ß activity was associated with VAMP3 coalescence in WT and Fyn-deficient cells. Reconstitution of MC-deficient Wsh mice with Fyn(-/-) MCs produced greater LPS-dependent production of TNF in the peritoneal cavity. Our data show that Fyn kinase is activated after TLR4 triggering and exerts an important negative control on LPS-dependent TNF production in MCs controlling the inactivation of PP2Ac and activation of PKCα/ß necessary for the secretion of TNF by VAMP3(+) carriers.