1,253 research outputs found
Tokenized Ownership in Decentralized Autonomous Organizations: Evidence from Steemit
Decentralized autonomous organizations (DAOs) operate on an incentive network powered by crypto tokens, which are attached with payment rights (i.e., transactional tokens) and ownership rights (i.e., governance tokens). Tokenized ownership is a special incentive way that supports automated operations of DAOs. Our study focuses on this new incentive scheme and construct a quasi-experiment setting to empirically test the incentive effects of tokenized ownership. We find that the intended choice of governance tokens leads to higher post length and readability and higher curation quality compared with transactional tokens. This study contributes to the literature of blockchain and cryptocurrency from an operational perspective and provides practical suggestions for the design of incentive mechanisms in DAOs
Deep Residual Transform for Multi-scale Image Decomposition
Multi-scale image decomposition (MID) is a fundamental task in computer vision and image processing that involves the transformation of an image into a hierarchical representation comprising of different levels of visual granularity from coarse structures to fine details. A well-engineered MID disentangles the image signal into meaningful components which can be used in a variety of applications such as image denoising, image compression, and object classification. Traditional MID approaches such as wavelet transforms tackle the problem through carefully designed basis functions under rigid decomposition structure assumptions. However, as the information distribution varies from one type of image content to another, rigid decomposition assumptions lead to inefficiently representation, i.e., some scales can contain little to no information. To address this issue, we present Deep Residual Transform (DRT), a data-driven MID strategy where the input signal is transformed into a hierarchy of non-linear representations at different scales, with each representation being independently learned as the representational residual of previous scales at a user-controlled detail level. As such, the proposed DRT progressively disentangles scale information from the original signal by sequentially learning residual representations. The decomposition flexibility of this approach allows for highly tailored representations cater to specific types of image content, and results in greater representational efficiency and compactness. In this study, we realize the proposed transform by leveraging a hierarchy of sequentially trained autoencoders. To explore the efficacy of the proposed DRT, we leverage two datasets comprising of very different types of image content: 1) CelebFaces and 2) Cityscapes. Experimental results show that the proposed DRT achieved highly efficient information decomposition on both datasets amid their very different visual granularity characteristics
Effects of SOCS3 on the development of colon cancer via regulation of HIF-1α
Purpose: To investigate the influence of suppressor of cytokine signaling 3 (SOCS3) on rats with colon cancer (CC).
Methods: Sprague-Dawley (SD) rats were randomly divided into CC group and control group, and then CC rat model was constructed. The expression of SOCS3 in CC tissues was determined by quantitative real time-polymerase chain reaction (qRT-PCR). Hematoxylin-eosin staining (H&E) was used to examine colon tissue morphology. Immunohistochemistry (IHC) staining assay was performed to determine the expression of SOCS3 protein in colon tissues. The contents of HIF-1α, phosphorylated phosphatidylinositol 3-hydroxy kinase (p-PI3K), and phosphorylated protein kinase B (p-AKT) proteins were determined by Western blotting (WB).
Results: Compared with that in the control group, the number of tumors in CC group was significantly increased (p < 0.05). 2). On the other hand, protein and message ribonucleic acid (mRNA) expressions of SOCS3 were down-regulated in CC group (p < 0.05). 3), while protein expressions of p-PI3K, p-AKT and HIF-1α were raised in CC group (p < 0.05).
Conclusion: SOCS3 is lowly expressed in CC rats, and promotes the expression of HIF-1α by activating PI3K/AKT signaling pathway. Thus, SOCS3 provides a therapeutic strategy for the management of colon cancer.
Keywords: Colon cancer; Suppressor of cytokine signaling protein 3 (SOCS3); Hypoxia inducible factor-1
Effects of suppressor of cytokine signaling 3 (SOCS3) on the development of colon cancer via regulation of HIF-1α
Purpose: To investigate the influence of suppressor of cytokine signaling 3 (SOCS3) on rats with colon cancer (CC).
Methods: Sprague-Dawley (SD) rats were randomly divided into CC group and control group. CC models were constructed. The expression of SOCS3 in CC tissues was determined by quantitative real time-polymerase chain reaction (qRT-PCR). Hematoxylin-eosin staining (H&E) was used to examine colon tissue morphology, while immunohistochemistry (IHC) staining assay was performed to determine the expression of SOCS3 protein in colon tissues. The content of HIF-1α, phosphorylated phosphatidylinositol 3-hydroxy kinase (p-PI3K), and phosphorylated protein kinase B (p-AKT) proteins was determined by Western blotting (WB).
Results: Compared with that in the control group, the number of tumors in the CC group was significantly increased (p < 0.05). Protein and messenger ribonucleic acid (mRNA) expressions of SOCS3 were down-regulated in CC group (p < 0.05), while protein expressions of p-PI3K, p-AKT and HIF-1α were significantly elevated in CC group (p < 0.05).
Conclusion: SOCS3 is poorly expressed in CC rats, and promotes the expression of HIF-1α by activating PI3K/AKT signaling pathway. The findings, thus, provide a probable strategy for management of colon cancer
An Ash2L/RbBP5 Heterodimer Stimulates the MLL1 Methyltransferase Activity through Coordinated Substrate Interactions with the MLL1 SET Domain
Histone H3 lysine 4 (K4) methylation is a prevalent mark associated with transcription activation and is mainly catalyzed by the MLL/SET1 family histone methyltransferases. A common feature of the mammalian MLL/SET1 complexes is the presence of three core components (RbBP5, Ash2L and WDR5) and a catalytic subunit containing a SET domain. Unlike most other histone lysine methyltransferases, all four proteins are required for efficient H3 K4 methylation. Despite extensive efforts, mechanisms for how three core components regulate MLL/SET1 methyltransferase activity remain elusive. Here we show that a heterodimer of Ash2L and RbBP5 has intrinsic histone methyltransferase activity. This activity requires the highly conserved SPRY domain of Ash2L and a short peptide of RbBP5. We demonstrate that both Ash2L and the MLL1 SET domain are capable of binding to S-adenosyl-L- [methyl-3H] methionine in the MLL1 core complex. Mutations in the MLL1 SET domain that fail to support overall H3 K4 methylation also compromise SAM binding by Ash2L. Taken together, our results show that the Ash2L/RbBP5 heterodimer plays a critical role in the overall catalysis of MLL1 mediated H3 K4 methylation. The results we describe here provide mechanistic insights for unique regulation of the MLL1 methyltransferase activity. It suggests that both Ash2L/RbBP5 and the MLL1 SET domain make direct contacts with the substrates and contribute to the formation of a joint catalytic center. Given the shared core configuration among all MLL/SET1 family HMTs, it will be interesting to test whether the mechanism we describe here can be generalized to other MLL/SET1 family members in the future
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