97 research outputs found

    Network design: Taxi Planning

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    The effect of managing aircraft movements on the airport’s ground is an important tool that can alleviate the delays of flights, specially in peak hours or congested situations. Although some strategic design decisions regarding aeronautical and safety aspects have a main impact on the airport’s topology, there exists a number of other additional factors that must be evaluated according to the on ground operations, i.e. previous to the taking-off or after landing. Among these factors one can consider capacities at waiting points and directions of some corridors. These factors are related to the demand situation of a given period and influence the aircraft’s routing on the ground or short term Taxi Planning problem (or TP-S). While the TP-S problem studies the aircraft routing and scheduling on the airport’s ground under a dynamic point of view, this paper presents a Taxi Planning network design model (or TPND), attending to these additional factors of the airport’s topology and the conflicting movements of the aircraft on them with the same modelling approach used in the TP-S problem. The TPND model is formulated as a binary multicommodity network flow problem with additional side constraints under a multiobjective approach. The side constraints included are the classical limitations due to capacity and also as a distinctive approach, constraints that restrict the interference of aircraft in order to decrease the intervention of human controllers during the operations or increase their safety margins. The multiobjective approach adopted for the TPND model balances conflicting objectives: airport’s throughput, travel times, safety of operations and costs. In the paper computational results are included on two test airports solving the TPND model by “Branch and Bound” showing the effect of the conflicting objectives in the design decisions

    European sea bass brain DLB-1 cell line is susceptible to nodavirus: A transcriptomic study

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    Viral diseases are responsible for high rates of mortality and subsequent economic losses in modern aquaculture. The nervous necrosis virus (NNV) produces viral encephalopathy and retinopathy (VER), which affects the fish central nervous system. It is considered one of the most serious viral diseases in marine aquaculture, the European sea bass (Dicentrarchus labrax) being amongst the most susceptible. We have evaluated the European sea bass brain derived cell line (DLB-1) susceptibility to NNV genotypes and evaluated its transcriptomic profile. DLB-1 cells supported NNV gene transcription and replication since strains belonging to the four NNV genotypes produce cytopathic effects. Afterwards, DLB-1 cells were infected with an RGNNV strain, the one which showed the highest replication, for 12 and 72 h and an RNA-seq analysis was performed to identify potential genes involved in the host-NNV interactions. Differential expression analysis showed the up-regulation of many genes related to immunity, heat-shock proteins or apoptosis but not to proteasome or autophagy processes. These data suggest that the immune response, mainly the interferon (IFN) pathway, is not powerful enough to abrogate the infection, and cells finally suffer stress and die by apoptosis liberating infective particles. GO enrichment also revealed, for the first time, the down-regulation of terms related to brain/neuron biology indicating molecular mechanisms causing the pathogenic effect of NNV. This study opens the way to understand key elements in sea bass brain and NNV interactions.Versión del edito

    Mutations on a conserved distal enhancer in the porcine C-reactive protein gene impair its expression in liver

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    C-reactive protein (CRP) is an evolutionary highly conserved protein. Like humans, CRP acts as a major acute phase protein in pigs. While CRP regulatory mechanisms have been extensively studied in humans, little is known about the molecular mechanisms that control pig CRP gene expression. The main goal of the present work was to study the regulatory mechanisms and identify functional genetic variants regulating CRP gene expression and CRP blood levels in pigs. The characterization of the porcine CRP proximal promoter region revealed a high level of conservation with both cow and human promoters, sharing binding sites for transcription factors required for CRP expression. Through genome-wide association studies and fine mapping, the most associated variants with both mRNA and protein CRP levels were localized in a genomic region 39.3 kb upstream of CRP. Further study of the region revealed a highly conserved putative enhancer that contains binding sites for several transcriptional regulators such as STAT3, NF-kB or C/EBP-β. Luciferase reporter assays showed the necessity of this enhancer-promoter interaction for the acute phase induction of CRP expression in liver, where differences in the enhancer sequences significantly modified CRP activity. The associated polymorphisms disrupted the putative binding sites for HNF4α and FOXA2 transcription factors. The high correlation between HNF4α and CRP expression levels suggest the participation of HNF4α in the regulatory mechanism of porcine CRP expression through the modification of its binding site in liver. Our findings determine, for the first time, the relevance of a distal regulatory element essential for the acute phase induction of porcine CRP in liver and identify functional polymorphisms that can be included in pig breeding programs to improve immunocompetence.The authors declare financial support was received for the research, authorship, and/or publication of this article. The study was funded by grants AGL2016-75432-R and PID2020-112677RB-C21 awarded by MCIN/AEI/10.13039/501100011033 and GENE-SWitCH project (https://www.gene-switch.eu), which is funded by the European Union’s Horizon 2020 Research and Innovation Programme under the grant agreement n°817998. T. Jové-Juncà was funded with an IRTA fellowship (CPI1221) and C. Hernández-Banqué was supported by a FPI grant (PRE2021-097825) granted by the Spanish Ministry of Science and Innovation. YR-C was financially supported by a Ramon y Cajal contract (RYC2019-027244-I) from the Spanish Ministry of Science and Innovation. The authors are part to a Consolidated Research Group AGAUR, with the reference 2021-SGR-01552.info:eu-repo/semantics/publishedVersio

    The EMT factor ZEB1 paradoxically inhibits EMT in BRAF-mutant carcinomas

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    Despite being in the same pathway, mutations of KRAS and BRAF in colorectal carcinomas (CRCs) determine distinct progression courses. ZEB1 induces an epithelial-to-mesenchymal transition (EMT) and is associated with worse progression in most carcinomas. Using samples from patients with CRC, mouse models of KrasG12D and BrafV600E CRC, and a Zeb1-deficient mouse, we show that ZEB1 had opposite functions in KRAS-and BRAF-mutant CRCs. In KrasG12D CRCs, ZEB1 was correlated with a worse prognosis and a higher number of larger and undifferentiated (mesenchymal or EMT-like) tumors. Surprisingly, in BrafV600E CRC, ZEB1 was associated with better prognosis; fewer, smaller, and more differentiated (reduced EMT) primary tumors; and fewer metastases. ZEB1 was positively correlated in KRAS-mutant CRC cells and negatively in BRAF-mutant CRC cells with gene signatures for EMT, cell proliferation and survival, and ERK signaling. On a mechanistic level, ZEB1 knockdown in KRAS-mutant CRC cells increased apoptosis and reduced clonogenicity and anchorage-independent growth; the reverse occurred in BRAFV600E CRC cells. ZEB1 is associated with better prognosis and reduced EMT signature in patients harboring BRAF CRCs. These data suggest that ZEB1 can function as a tumor suppressor in BRAF-mutant CRCs, highlighting the importance of considering the KRAS/BRAF mutational background of CRCs in therapeutic strategies targeting ZEB1/EMT

    MYC activation impairs cell-intrinsic IFNγ signaling and confers resistance to anti-PD1/PD-L1 therapy in lung cancer

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    Elucidating the adaptive mechanisms that prevent host immune response in cancer will help predict efficacy of anti-programmed death-1 (PD1)/L1 therapies. Here, we study the cell-intrinsic response of lung cancer (LC) to interferon-y (IFNy), a cytokine that promotes immunoresponse and modulates programmed death-ligand 1 (PD-L1) levels. We report complete refractoriness to IFNy in a subset of LCs as a result of JAK2 or IFNGR1 inactivation. A submaximal response affects another subset that shows constitutive low levels of IFNy-stimulated genes (IySGs) coupled with decreased H3K27ac (histone 3 acetylation at lysine 27) depo-sition and promoter hypermethylation and reduced IFN regulatory factor 1 (IRF1) recruitment to the DNA on IFNy stimulation. Most of these are neuroendocrine small cell LCs (SCLCs) with oncogenic MYC/MYCL1/ MYCN. The oncogenic activation of MYC in SCLC cells downregulates JAK2 and impairs IySGs stimulation by IFNy. MYC amplification tends to associate with a worse response to anti-PD1/L1 therapies. Hence alterations affecting the JAK/STAT pathway and MYC activation prevent stimulation by IFNy and may predict anti-PD1/L1 efficacy in LC
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