Simulação de vazão e sedimento em bacia hidrográfica rural com alta concentração de suínos e diferentes usos do solo.

Projeto/Plano de Ação: 06.09.06.001

HIPK2 and extrachromosomal histone H2B are separately recruited by Aurora-B for cytokinesis

Cytokinesis, the final phase of cell division, is necessary to form two distinct daughter cells with correct distribution of genomic and cytoplasmic materials. Its failure provokes genetically unstable states, such as tetraploidization and polyploidization, which can contribute to tumorigenesis. Aurora-B kinase controls multiple cytokinetic events, from chromosome condensation to abscission when the midbody is severed. We have previously shown that HIPK2, a kinase involved in DNA damage response and development, localizes at the midbody and contributes to abscission by phosphorylating extrachromosomal histone H2B at Ser14. Of relevance, HIPK2-defective cells do not phosphorylate H2B and do not successfully complete cytokinesis leading to accumulation of binucleated cells, chromosomal instability, and increased tumorigenicity. However, how HIPK2 and H2B are recruited to the midbody during cytokinesis is still unknown. Here, we show that regardless of their direct (H2B) and indirect (HIPK2) binding of chromosomal DNA, both H2B and HIPK2 localize at the midbody independently of nucleic acids. Instead, by using mitotic kinase-specific inhibitors in a spatio-temporal regulated manner, we found that Aurora-B kinase activity is required to recruit both HIPK2 and H2B to the midbody. Molecular characterization showed that Aurora-B directly binds and phosphorylates H2B at Ser32 while indirectly recruits HIPK2 through the central spindle components MgcRacGAP and PRC1. Thus, among different cytokinetic functions, Aurora-B separately recruits HIPK2 and H2B to the midbody and these activities contribute to faithful cytokinesis

Single-cell transcriptomes and T cell receptors of vaccine-expanded apolipoprotein B-specific T cells

Atherosclerotic cardiovascular diseases are the major cause of death worldwide. CD4 T cells responding to Apolipoprotein B (ApoB), the core protein of most lipoproteins, have been identified as critical disease modulators. In healthy individuals, ApoB-reactive (ApoB+) CD4 T cells are mostly regulatory T cells (Tregs), which exert anti-inflammatory effects. Yet, they may obtain pro-inflammatory features and thus become proatherogenic. Evidence from animal studies suggests that vaccination against certain major histocompatibility complex (MHC) II-binding ApoB peptides induces an expansion of ApoB+ Tregs and thus confers atheroprotection. To date, in-depth phenotyping of vaccine-expanded ApoB+ T cells has not yet been performed. To this end, we vaccinated C57BL/6J mice with the ApoB-peptide P6 (ApoB978–993 TGAYSNASSTESASY) and performed single-cell RNA sequencing of tetramer-sorted P6+ T cells. P6+ cells were clonally expanded (one major, two minor clones) and formed a transcriptional cluster distinct from clusters mainly containing non-expanded P6+ and P6– cells. Transcriptomic profiling revealed that most expanded P6+ cells had a strong Treg signature and highly expressed genes mediating suppressive functions. Yet, some expanded P6+ cells only had a residual Treg signature and expressed genes related to T helper 1 (TH1) cells, which are proatherogenic. Modeling the T cell receptor (TCR) and P6:MHC-II interaction showed that only three amino acid residues in the α and β chain contact the P6 peptide in the MHC-II groove and thus determine the specificity of this TCR to P6. Our data begin to reveal the vaccination-induced response to an ApoB epitope

ESTABELECIMENTO DE LIMITES PARA PROFUNDIDADE DO SOLO DE ENCOSTAS COM BASE NO FATOR DE SEGURANÇA.

A estimativa da profundidade do solo é uma tarefa essencial para entendimentos dos fenômenos hidrogeomorfológicos. O presente trabalho propôs uma nova formulação para estimativa da profundidade através da inserção de um modelo hidrológico na equação do Fator de Segurança. A nova formulação foi aplicada e comparada com outras equações de embasamento similar. Os resultados mostraram que dentro de sua faixa de aplicabilidade a nova formulação descreve adequadamente o comportamento da profundidade

RELAÇÃO DA CURVA CHAVE E CURVA DE PERMANÊNCIA NA GEOMETRIA HIDRÁULICA: ESTUDO DE CASO DA ESTAÇÃO FLUVIOMÉTRICA DA BACIA DO TABOÃO – RS.

No presente estudo foi determinada a geometria hidráulica da seção na bacia do Taboão, região noroeste do Estado do Rio Grande do Sul. Foram utilizados dados de vazão para determinar a curva chave da estação, a curva de permanência, e as variáveis largura, profundidade e velocidade, e seus expoentes b, f e m, referentes à geometria hidráulica da seção. Os resultados mostram que a variável profundidade tem maior sensibilidade sobre as oscilações de Q, seguido por velocidade e por último largura