39 research outputs found

    Global Generation of Adjoint Line Bundles on Projective 55-folds

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    Let XX be a smooth projective variety of dimension 55 and LL be an ample line bundle on XX such that L5>75L^5>7^5 and LdZ7dL^d\cdot Z\geq 7^d for any subvariety ZZ of dimension 1d41\leq d\leq 4. We show that OX(KX+L)\mathcal{O}_X(K_X+L) is globally generated.Comment: Final version to appear in manuscripta mathematica. We notice that mistakes were introduced by the journal to some fractions in the form "expression/expression" which should be read as "(expression)/(expression)

    Learning Excavation of Rigid Objects with Offline Reinforcement Learning

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    Autonomous excavation is a challenging task. The unknown contact dynamics between the excavator bucket and the terrain could easily result in large contact forces and jamming problems during excavation. Traditional model-based methods struggle to handle such problems due to complex dynamic modeling. In this paper, we formulate the excavation skills with three novel manipulation primitives. We propose to learn the manipulation primitives with offline reinforcement learning (RL) to avoid large amounts of online robot interactions. The proposed method can learn efficient penetration skills from sub-optimal demonstrations, which contain sub-trajectories that can be ``stitched" together to formulate an optimal trajectory without causing jamming. We evaluate the proposed method with extensive experiments on excavating a variety of rigid objects and demonstrate that the learned policy outperforms the demonstrations. We also show that the learned policy can quickly adapt to unseen and challenging fragmented rocks with online fine-tuning.Comment: Submitted to IROS 202

    Integrative profiling of metabolome and transcriptome of skeletal muscle after acute exercise intervention in mice

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    This study aims to explore the molecular regulatory mechanisms of acute exercise in the skeletal muscle of mice. Male C57BL/6 mice were randomly assigned to the control group, and the exercise group, which were sacrificed immediately after an acute bout of exercise. The study was conducted to investigate the metabolic and transcriptional profiling in the quadriceps muscles of mice. The results demonstrated the identification of 34 differentially expressed metabolites (DEMs), with 28 upregulated and 6 downregulated, between the two groups. Metabolic pathway analysis revealed that these DEMs were primarily enriched in several, including the citrate cycle, propanoate metabolism, and lysine degradation pathways. In addition, the results showed a total of 245 differentially expressed genes (DEGs), with 155 genes upregulated and 90 genes downregulated. KEGG analysis indicated that these DEGs were mainly enriched in various pathways such as ubiquitin mediated proteolysis and FoxO signaling pathway. Furthermore, the analysis revealed significant enrichment of DEMs and DEGs in signaling pathways such as protein digestion and absorption, ferroptosis signaling pathway. In summary, the identified multiple metabolic pathways and signaling pathways were involved in the exercise-induced physiological regulation of skeletal muscle, such as the TCA cycle, oxidative phosphorylation, protein digestion and absorption, the FoxO signaling pathway, ubiquitin mediated proteolysis, ferroptosis signaling pathway, and the upregulation of KLF-15, FoxO1, MAFbx, and MuRF1 expression could play a critical role in enhancing skeletal muscle proteolysis

    Cardioprotective effect of Shenxiong glucose injection on acute myocardial infarction in rats via reduction in myocardial intracellular calcium ion overload

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    Purpose: To explore the cardioprotective effects and potential mechanisms of Shenxiong Glucose Injection (SGI) in rat acute myocardial infarction (AMI).Methods: AMI model was created by ligating left anterior descending coronary artery. After 7 days’ consecutive intravenous administration of SGI, serum samples were used to conduct biochemical analysis while hearts were excised and processed for infraction size, enzyme activity, histopathology and qPCR studies. Intracellular Ca2+ {(Ca2+)i} overload in H9c2 cells was measured by laser scanning confocal microscope (LSCM).Results: In AMI rats, pretreatment with SGI significantly ameliorated myocardial histopathologic damage. It exerted cardioprotective effect by decreasing myocardial infarct size, electrocardiogram (ECG) ST segment elevation, and CK, cTnI, BNP levels in serum. In addition, SGI significantly decreased calmodulin (CaM) and calmodulin-dependent protein kinase II (CaMK II) mRNA expression, but increased Ca2+-Mg2+-ATPase and Na+-K+-ATPase activities in myocardium. In doxorubicin (DOX)- induced H9c2 cells injury model, SGI reversed (Ca2+)i overload to protect cells.Conclusion: The results demonstrate SGI exerts cardioprotective effect by decreasing myocardial infarct size, restoring ST segment and reversing (Ca2+)i overload. It suggests that SGI may be a new clinical candidate to treat myocardial infarction.Keywords: Shenxiong glucose injection, Tanshinol, Ligustrazine, Myocardial infarction, Intracellular Ca2+ overload, Calmodulin, Calmodulin-dependent protein kinase I

    A HALP score-based prediction model for survival of patients with the upper tract urothelial carcinoma undergoing radical nephroureterectomy

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    The combination of hemoglobin, albumin, lymphocyte, and platelet (HALP) score has been confirmed as an important risk biomarker in several cancers. Hence, we aimed at evaluating the prognostic value of the HALP score in patients with non-metastatic upper tract urothelial carcinoma (UTUC). We retrospectively enrolled 533 of the 640 patients from two centers (315 and 325 patients, respectively) who underwent radical nephroureterectomy (RNU) for UTUC in this study. The cutoff value of HALP was determined using the Youden index by performing receiver operating characteristic (ROC) curve analysis. The relationship between postoperative survival outcomes and preoperative HALP level was assessed using Kaplan-Meier analysis and Cox regression analysis. As a result, the cutoff value of HALP was 28.67 and patients were then divided into HALP<28.67 group and HALP≥28.67 group. Kaplan-Meier analysis and log-rank test revealed that HALP was significantly associated with overall survival (OS) (P<0.001) and progression-free survival (PFS) (P<0.001). Multivariate analysis demonstrated that lower HALP score was an independent risk factor for OS (HR=1.54, 95%CI, 1.14-2.01, P=0.006) and PFS (HR=1.44, 95%CI, 1.07-1.93, P=0.020). Nomograms of OS and PFS incorporated with HALP score were more accurate in predicting prognosis than without. In the subgroup analysis, the HALP score could also stratify patients with respect to survival under different pathologic T stages. Therefore, pretreatment HALP score was an independent prognostic factor of OS and PFS in UTUC patients undergoing RNU

    MEASUREMENT AND CORRELATION OF THE MASS TRANSFER COEFFICIENT FOR A LIQUID-LIQUID SYSTEM WITH HIGH DENSITY DIFFERENCE

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    Abstract -To investigate the mass transfer behavior of a liquid-liquid system with high density difference (∆ρ≈500 kg/m 3 ), single drop experiments were performed by using the ternary chloroform-ethanol-water system. The mass transfer direction was from the dispersed phase to the continuous phase, while the aqueous phase was dispersed in chloroform to generate drops. The influences of drop diameter, initial solute concentration and temperature on the mass transfer were investigated. The effects of the drop diameter and initial solute concentration on interfacial instability of droplets hanging in the continuous phase were also observed. For the purpose of correlation, a mass transfer enhancement factor F was introduced and then correlated as a function of dimensionless variables. The modified correlation from the mass transfer coefficient model was found to fit well with the experimental values

    Efficient Online Model Adaptation by Incremental Simplex Tableau

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    Online multi-kernel learning is promising in the era of mobile computing, in which a combined classifier with multiple kernels are offline trained, and online adapts to personalized features for serving the end user precisely and smartly. The online adaptation is mainly carried out at the end-devices, which requires the adaptation algorithms to be light, efficient and accurate. Previous results focused mainly on efficiency. This paper proposes an novel online model adaptation framework for not only efficiency but also optimal online adaptation. At first, an online optimal incremental simplex tableau (IST)algorithm is proposed, which approaches the model adaption by linear programming and produces the optimized model update in each step when a personalized training data is collected.But keeping online optimal in each step is expensive and may cause over-fitting especially when the online data is noisy. A Fast-IST approach is therefore proposed, which measures the deviation between the training data and the current model. It schedules updating only when enough deviation is detected. The efficiency of each update is further enhanced by running IST only limited iterations, which bounds the computation complexity. Theoretical analysis and extensive evaluations show that Fast-IST saves computation cost greatly, while achieving speedy and accurate model adaptation.It provides better model adaptation speed and accuracy while using even lower computing cost than the state-of-the art

    Metagenomic analysis reveals potential interactions in an artificial coculture

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    Abstract Disentangling the interactions between cyanobacteria and associated bacterial community is important for understanding the mechanisms that mediate the formation of cyanobacterial blooms in freshwater ecosystems. Despite the fact that a metagenomic approach enables researchers to profile the structure of microbial communities associated with cyanobacteria, reconstructing genome sequences for all members remains inefficient, due to the inherent enormous microbial diversity. Here, we have established a stable coculture system under high salinity, originally from a mixture of an axenic cyanobacterium Synechococcus sp. PCC 7002 and a non-axenic bloom-forming cyanobacterium Microcystis colony. Metagenomic analysis showed that the coculture consists of S. sp. PCC 7002 and two heterotrophic bacteria, designated as Pseudomonas stutzeri TAIHU and Mesorhizobium sp. TAIHU, respectively. And near-complete genome sequences of both bacteria were reconstructed from the metagenomic dataset with an average completeness of 99.8%. Genome-wide pathway analysis revealed that M. sp. TAIHU carried all the genes involved in the de novo biosynthesis of cobalamin, which is required by S. sp. PCC 7002 for growth. To cope with the high salinity in the coculture, experimental evidence demonstrated that S. sp. PCC 7002 would synthesize the compatible solutes including sucrose and glucosylglycerol, which are supposed to be exploited by both heterotrophic bacteria as potential carbon and/or nitrogen sources. Furthermore, the genes encoding for the biosynthesis of the ectoine, another common osmolyte are found exclusively in P. stutzeri TAIHU, while the genes responsible for the catabolism of ectoine and its derives are present only in M. sp. TAIHU. These genomic evidence indicates beneficial interaction between three members in the coculture. Establishment of the coculture system with relative simplicity provides a useful model system for investigating the interspecies interactions, and genome sequences of both bacteria associated with Microcystis bloom described here will facilitate the researcher to elucidate the role of these heterotrophic bacteria in the formation and maintenance of cyanobacterial bloom in freshwater ecosystem
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