Graded polynomial identities, group actions, and exponential growth of Lie algebras

Consider a finite dimensional Lie algebra L with an action of a finite group G over a field of characteristic 0. We prove the analog of Amitsur's conjecture on asymptotic behavior for codimensions of polynomial G-identities of L. As a consequence, we prove the analog of Amitsur's conjecture for graded codimensions of any finite dimensional Lie algebra graded by a finite Abelian group.Comment: 26 pages; minor misprints were correcte

Una comunidad de construcción de conocimiento: el caso de la maestría en ingeniería de la UADY

Se desea estudiar la construcción de conocimiento en una comunidad epistémica, entendida como una comunidad de práctica (CoP) por medio del uso de conocimiento matemático. Se analiza el uso de las gráficas de variación y cambio en tesis, revistas de investigación y notas de clases de la Maestría en ingeniería de la Universidad Autónoma de Yucatán (UADY) en tres diferentes escenarios de interacción, a los cuales denominamos episodios: clases de la maestría, productos de investigación y con el asesor; en todos los escenarios las personas son expertos (profesores investigadores) y aprendices (alumnos en diferentes etapas) de la especialidad de ingeniería ambiental, construcción y estructuras. Se presentarán algunos avances referentes al método y cómo se inicia el análisis de la información para evidenciar la construcción de conocimiento, todo ello de acorde con la problemática

Selection of antigenically advanced variants of seasonal influenza viruses

Influenza viruses mutate frequently, necessitating constant updates of vaccine viruses. To establish experimental approaches that may complement the current vaccine strain selection process, we selected antigenic variants from human H1N1 and H3N2 influenza virus libraries possessing random mutations in the globular head of the haemagglutinin protein (which includes the antigenic sites) by incubating them with human and/or ferret convalescent se

Structural basis of glycan276-dependent recognition by HIV-1 broadly neutralizing antibodies

Recognition of N-linked glycan at residue N276 (glycan276) at the periphery of the CD4-binding site (CD4bs) on the HIV-envelope trimer is a formidable challenge for many CD4bs-directed antibodies. To understand how this glycan can be recognized, here we isolate two lineages of glycan276-dependent CD4bs antibodies. Antibody CH540-VRC40.01 (named for donor-lineage.clone) neutralizes 81% of a panel of 208 diverse strains, while antibody CH314-VRC33.01 neutralizes 45%. Cryo-electron microscopy (cryo-EM) structures of these two antibodies and 179NC75, a previously identified glycan276-dependent CD4bs antibody, in complex with HIV-envelope trimer reveal substantially different modes of glycan276 recognition. Despite these differences, binding of glycan276-dependent antibodies maintains a glycan276 conformation similar to that observed in the absence of glycan276-binding antibodies. By contrast, glycan276-independent CD4bs antibodies, such as VRC01, displace glycan276 upon binding. These results provide a foundation for understanding antibody recognition of glycan276 and suggest its presence may be crucial for priming immunogens seeking to initiate broad CD4bs recognition