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[...]the character of Natalia is presented as a Malinche figure-the paradoxical symbol of rape victim and national traitor incarnated by the indigenous female-which links the oppression wrought by the colonial Church to a persistent oppression of women. Upon their arrival in a new village, the captains of the conquest read a speech (in Spanish) to the native people, which declared that if they did not convert to the Catholic faith, they would be either enslaved or killed (Galeano 29). [...]colonization and conversion were inseparable processes in the early days of New Spain. Tombs notes that in Latin America, \"the church's priority was usually to protect its institutional interests rather than present a prophetic voice on the suffering of the disadvantaged\" (41). [...]from the inception of the European presence in Mexico, the Christian religion was used as a tool in a process of domination and repression of indigenous cultures, rights, and lives. The Church in Post-revolutionary Mexico In Rulfo's era, the role of the Church in government and society was a source of controversy, repression, and violence, beginning in 1917, the same year that he was born, with the new Constitution implemented by the revolutionaries: one its main revisions was the emphasis on the separation of Church and state, especially through the creation of a public system of education.

Los autores latinoamericanos tienen una difícil labor cuando se trata de contender con sus precursores norteamericanos. Esto se debe a que hay una tradición de opresión, violencia e indiferencia que en ciertas ocasiones ha marcado las relaciones políticas y hasta personales entre sus países y Norteamérica. Walt Whitman es uno de los grandes precursores de varios gigantes de la poesía hispanoamericana. Comenzando con Martí y los modernistas y siguiendo con Huidobro, borges, Mistral, y Neruda, Whitman ha sido señalado como una de las más grandes fuentes de inspiración. Su obra maestra, Leaves of Grass (1855), y su impacto en el gran poeta y premio Nobel de literatura chileno Pablo Neruda demuestra un ejemplo de esta ansiedad latinoamericana hacia la influencia del gran poeta del Norte. “Que despierte el Leñador”, una sección del Canto general (1950), demuestra cómo Neruda contiende de manera explícita e implícita con su precursor norteamericano. El individualismo norteamericano expresado por Whitman en su introducción a Leaves of Grass se convierte en una especie de colectividad y panamericanismo en la revisión nerudiana, demostrando de esta manera una actitud de optimismo combinada con un atisbo de crítica.

Hsp100 polypeptide translocases are conserved members of the AAA+ family (adenosine triphosphatases associated with diverse cellular activities) that maintain proteostasis by unfolding aberrant and toxic proteins for refolding or proteolytic degradation. The Hsp104 disaggregase from Saccharomyces cerevisiae solubilizes stress-induced amorphous aggregates and amyloids. The structural basis for substrate recognition and translocation is unknown. Using a model substrate (casein), we report cryo–electron microscopy structures at near-atomic resolution of Hsp104 in different translocation states. Substrate interactions aremediated by conserved, pore-loop tyrosines that contact an 80-angstrom-long unfolded polypeptide along the axial channel. Two protomers undergo a ratchet-like conformational change that advances pore loop–substrate interactions by two amino acids. These changes are coupled to activation of specific nucleotide hydrolysis sites and, when transmitted around the hexamer, reveal a processive rotary translocation mechanism and substrate-responsive flexibility during Hsp104-catalyzed disaggregation.

Bacterial ClpB and yeast Hsp104 are homologous Hsp100 protein disaggregases that serve critical functions in proteostasis by solubilizing protein aggregates. Two AAA+ nucleotide binding domains (NBDs) power polypeptide translocation through a central channel comprised of a hexameric spiral of protomers that contact substrate via conserved pore-loop interactions. Here we report cryo-EM structures of a hyperactive ClpB variant bound to the model substrate, casein in the presence of slowly hydrolysable ATPγS, which reveal the translocation mechanism. Distinct substrate-gripping interactions are identified for NBD1 and NBD2 pore loops. A trimer of N-terminal domains define a channel entrance that binds the polypeptide substrate adjacent to the topmost NBD1 contact. NBD conformations at the seam interface reveal how ATP hydrolysis-driven substrate disengagement and re-binding are precisely tuned to drive a directional, stepwise translocation cycle. Bacterial ClpB is a disaggregase that solubilizes protein aggregates. Here the authors present the 2.9 Å cryo-EM structure of a hyperactive variant of ClpB bound to the substrate casein in active translocation states and discuss its polypeptide translocation mechanism.

A cryo-EM structure of yeast AAA+ protein disaggregase Hsp104 with AMP-PNP reveals a spiral arrangement of the protomers and a continuous path for polypeptide translocation that explains Hsp104's processivity mechanism during disaggregation. Hsp104, a conserved AAA+ protein disaggregase, promotes survival during cellular stress. Hsp104 remodels amyloids, thereby supporting prion propagation, and disassembles toxic oligomers associated with neurodegenerative diseases. However, a definitive structural mechanism for its disaggregase activity has remained elusive. We determined the cryo-EM structure of wild-type Saccharomyces cerevisiae Hsp104 in the ATP state, revealing a near-helical hexamer architecture that coordinates the mechanical power of the 12 AAA+ domains for disaggregation. An unprecedented heteromeric AAA+ interaction defines an asymmetric seam in an apparent catalytic arrangement that aligns the domains in a two-turn spiral. N-terminal domains form a broad channel entrance for substrate engagement and Hsp70 interaction. Middle-domain helices bridge adjacent protomers across the nucleotide pocket, thus explaining roles in ATP hydrolysis and protein disaggregation. Remarkably, substrate-binding pore loops line the channel in a spiral arrangement optimized for substrate transfer across the AAA+ domains, thereby establishing a continuous path for polypeptide translocation.

Genome packaging in large double-stranded DNA viruses requires a powerful molecular motor to force the viral genome into nascent capsids, which involves essential accessory factors that are poorly understood. Here, we present structures of two such accessory factors from the oncogenic herpesviruses Kaposi’s sarcoma-associated herpesvirus (KSHV; ORF68) and Epstein–Barr virus (EBV; BFLF1). These homologous proteins form highly similar homopentameric rings with a positively charged central channel that binds double-stranded DNA. Mutation of individual positively charged residues within but not outside the channel ablates DNA binding, and in the context of KSHV infection, these mutants fail to package the viral genome or produce progeny virions. Thus, we propose a model in which ORF68 facilitates the transfer of newly replicated viral genomes to the packaging motor.

The use of DNA barcoding has revolutionised biodiversity science, but its application depends on the existence of comprehensive and reliable reference libraries. For many poorly known taxa, such reference sequences are missing even at higher-level taxonomic scales. We harvested the collections of the Smithsonian’s National Museum of Natural History (USNM) to generate DNA barcoding sequences for genera of terrestrial arthropods previously not recorded in one or more major public sequence databases. Our workflow used a mix of Sanger and Next-Generation Sequencing (NGS) approaches to maximise sequence recovery while ensuring affordable cost. In total, COI sequences were obtained for 5,686 specimens belonging to 3,737 determined species in 3,886 genera and 205 families distributed in 137 countries. Success rates varied widely according to collection data and focal taxon. NGS helped recover sequences of specimens that failed a previous run of Sanger sequencing. Success rates and the optimal balance between Sanger and NGS are the most important drivers to maximise output and minimise cost in future projects. The corresponding sequence and taxonomic data can be accessed through the Barcode of Life Data System, GenBank, the Global Biodiversity Information Facility, the Global Genome Biodiversity Network Data Portal and the NMNH data portal.