Experimentos físicos de barragens de terra homogênea sujeitas ao galgamento

Barragens são estruturas na qual sua construção sempre esteve associada ao benefício que trazem para a sociedade, permitindo o desenvolvimento de atividades essenciais em decorrência de seus múltiplos. Entretanto, essas estruturas estão sujeitas a falhas que podem levar ao seu rompimento. Excepcionalmente, no ano de 2020 foram reportadas 44 rupturas de barragens pela ANA que tiveram, em grande parte, como causa o galgamento, associado a eventos de intensa precipitação. Em sua maioria, esses acidentes ocorreram em barragens de terra. Assim, este trabalho possui como objetivo analisar o efeito de diferentes vazões e tempos de enchimento do reservatório no rompimento por galgamento em barragens de terra homogêneas, utilizando modelagem física. Neste viés, foi construído um modelo reduzido de uma barragem de terra hipotética em que foram realizadas três simulações físicas no qual foi simulado o enchimento rápido e lento do reservatório. O enchimento do reservatório ocorreu em duas etapas (que consistiu em divisões de alturas de níveis da barragem). Está divisão foi realizada com o objetivo de simular um reservatório que já estava operando com nível d’água máximo na borda livre e depois recebeu um incremento de vazão até a sua ruptura. Os resultados foram coletados através de iPad, cronômetro, medidor de vazão eletromagnético e um medidor de nível instalado no final do canal que registraram, respectivamente, fotos e vídeos, tempo dos processos, vazão e volume injetados e o nível de água correspondente a onda de ruptura ao longo do tempo. Os principais resultados foram em relação a percolação no maciço e as suas deformações, a mensuração da vazão na qual a estrutura rompeu, o tempo que a barragem levou para romper, a origem e evolução da brecha de ruptura, o hidrograma de ruptura e o balanço de massa do material que ficou retido no barramento e o material que foi carregado pela onda de ruptura. Conclui-se que as diferentes distribuições temporais do enchimento do reservatório afetam o rompimento de barragens de terra, principalmente em relação a saturação do maciço. Não é apenas um parâmetro de forma isolada o único responsável pela ruptura e sim um conjunto de parâmetros como grau de compactação, percolação do maciço e origem da brecha. A forma como é realizado o enchimento do reservatório impacta na forma como o maciço vai se comportar e isso contribui diretamente para a formação da brecha. A evolução da brecha de ruptura sofreu significativas deformações nos segundos iniciais após a ruptura.Dams are structures in which their construction has always been associated with the benefit they bring to society, allowing the development of essential activities as a result of their multiples. However, these structures are subject to failures that can lead to their rupture. Exceptionally, in 2020, 44 dam failures were reported by the ANA, which were largely due to overtopping, associated with events of intense tension. Most of these accidents occurred in earth dams. Thus, this work aims to analyze the effect of different outflows and reservoir filling times on failure by overtopping in transparent earth dams, using physical modeling. In this case, a limited model of a hypothetical earth dam was built in which three physical simulations were performed in which the fast and slow filling of the reservoir was simulated. Filling of the reservoir in two stages (which consists of divisions of heights of dam levels). This mission was carried out with the objective of simulating a reservoir that was already operating with maximum water level at the free edge and then received an increase in flow until its rupture. The results were collected using an iPad, a stopwatch, an electromagnetic flow meter and a level meter installed at the end of the channel, which recorded, respectively, photos and videos, process times, injected flow and volume and the water level corresponding to the wave of rupture over time. The main results were in relation to the percolation in the massif and its deformations, the measurement of the flow in which the structure broke, the time that the dam took to break, the origin and evolution of the breach, the hydrograph of rupture and the balance mass of the material that was retained in the busbar and the material that was carried by the rupture wave. It is concluded that there are different temporary distributions of reservoir filling and rupture of earth dams, mainly in relation to the saturation of the massif. It is not just an isolated shape parameter that is solely responsible for the failure, but a set of intervals such as the degree of compaction, percolation of the massif and the origin of the breach. The way in which the reservoir is filled impacts the way the massif will behave and this directly contributes to the formation of the breach. The evolution of the rupture breach suffered serious deformations in the initial seconds after the rupture

Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN

Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images

Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL maps are derived through computational staining using a convolutional neural network trained to classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and correlation with overall survival. TIL map structural patterns were grouped using standard histopathological parameters. These patterns are enriched in particular T cell subpopulations derived from molecular measures. TIL densities and spatial structure were differentially enriched among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for the TCGA image archives with insights into the tumor-immune microenvironment

Integrated Genomic Analysis of the Ubiquitin Pathway across Cancer Types

Protein ubiquitination is a dynamic and reversibleprocess of adding single ubiquitin molecules orvarious ubiquitin chains to target proteins. Here,using multidimensional omic data of 9,125 tumorsamples across 33 cancer types from The CancerGenome Atlas, we perform comprehensive molecu-lar characterization of 929 ubiquitin-related genesand 95 deubiquitinase genes. Among them, we sys-tematically identify top somatic driver candidates,including mutatedFBXW7with cancer-type-specificpatterns and amplifiedMDM2showing a mutuallyexclusive pattern withBRAFmutations. Ubiquitinpathway genes tend to be upregulated in cancermediated by diverse mechanisms. By integratingpan-cancer multiomic data, we identify a group oftumor samples that exhibit worse prognosis. Thesesamples are consistently associated with the upre-gulation of cell-cycle and DNA repair pathways, char-acterized by mutatedTP53,MYC/TERTamplifica-tion, andAPC/PTENdeletion. Our analysishighlights the importance of the ubiquitin pathwayin cancer development and lays a foundation fordeveloping relevant therapeutic strategies