1,050 research outputs found

    The Molecular Determinants of NEDD8 Specific Recognition by Human SENP8

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    Although neuronal-precursor-cell-expressed developmentally downregulated protein-8 (NEDD8) and ubiquitin share the highest level of sequence identity and structural similarity among several known ubiquitin-like proteins, their conjugation to a protein leads to distinct biological consequences. In the study, we first identified the NEDD8 protein of Chlamydomonas reinhardtii (CrNEDD8) and discovered that CrNEDD8 is fused at the C-terminus of a ubiquitin moiety (CrUb) in a head-to-tail arrangement. This CrUb-CrNEDD8 protein was termed CrRUB1 (related to ubiquitin 1) by analogy with a similar protein in Arabidopsis thaliana (AtRUB1). Since there is high sequence identity in comparison to the corresponding human proteins (97% for ubiquitin and 84% for NEDD8), a His-CrRUB1-glutathione S-transferase (GST) fusion construct was adopted as the alternative substrate to characterize the specificity of NEDD8-specific peptidase SENP8 for CrNEDD8. The data showed that SENP8 only cleaved the peptide bond beyond the di-glycine motif of CrNEDD8 and His-RUB1 was subsequently generated, confirming that SENP8 has exquisite specificity for CrNEDD8 but not CrUb. To further determine the basis of this specificity, site-directed mutagenesis at earlier reported putative molecular determinants of NEDD8 specific recognition by SENP8 was performed. We found that a single N51E mutation of CrNEDD8 completely inhibited its hydrolysis by SENP8. Conversely, a single E51N mutation of CrUb enabled this ubiquitin mutant to undergo hydrolysis by SENP8, revealing that a single residue difference at the position 51 contributes substantially to the substrate selectivity of SENP8. Moreover, the E51N/R72A double mutant of the CrUb subdomain can further increase the efficiency of cleavage by SENP8, indicating that the residue at position 72 is also important in substrate recognition. The E51N or R72A mutation of CrUb also inhibited the hydrolysis of CrUb by ubiquitin-specific peptidase USP2. However, USP2 cannot cleave the N51E/A72R double mutant of the CrNEDD8 subdomain, suggesting that USP2 requires additional recognition sites

    MiniZero: Comparative Analysis of AlphaZero and MuZero on Go, Othello, and Atari Games

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    This paper presents MiniZero, a zero-knowledge learning framework that supports four state-of-the-art algorithms, including AlphaZero, MuZero, Gumbel AlphaZero, and Gumbel MuZero. While these algorithms have demonstrated super-human performance in many games, it remains unclear which among them is most suitable or efficient for specific tasks. Through MiniZero, we systematically evaluate the performance of each algorithm in two board games, 9x9 Go and 8x8 Othello, as well as 57 Atari games. For two board games, using more simulations generally results in higher performance. However, the choice of AlphaZero and MuZero may differ based on game properties. For Atari games, both MuZero and Gumbel MuZero are worth considering. Since each game has unique characteristics, different algorithms and simulations yield varying results. In addition, we introduce an approach, called progressive simulation, which progressively increases the simulation budget during training to allocate computation more efficiently. Our empirical results demonstrate that progressive simulation achieves significantly superior performance in two board games. By making our framework and trained models publicly available, this paper contributes a benchmark for future research on zero-knowledge learning algorithms, assisting researchers in algorithm selection and comparison against these zero-knowledge learning baselines. Our code and data are available at https://rlg.iis.sinica.edu.tw/papers/minizero.Comment: Submitted to IEEE Transactions on Games, under revie

    Psychometric properties of the Little Developmental Coordination Disorder Questionnaire-Taiwan

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    Importance: Early identification of young children at risk of developmental coordination disorder (DCD) can support early intervention and prevent secondary sequelae. Objective: This study examined the psychometric properties of the translated and cross-culturally adapted Little Developmental Coordination Disorder Questionnaire-Taiwan (LDCDQ-TW). Design: Prospective study. Setting: Parent respondents, recruited via kindergarten settings. Participants: 1124 parents of typically developing children ages 36-71 months. Children with confirmed developmental diagnoses were excluded. Outcomes and Measures: The LDCDQ-TW, a 15-item parent questionnaire for identifying children at risk for DCD, and the Movement Assessment Battery for Children (2nd edition) (MABC-2). Results: Findings revealed excellent test-retest reliability (ICC=0.97) and fair inter-rater reliability (ICC=0.47). Using MABC-2 scores, the non-DCD group (> 15th percentile) scored significantly higher than the DCD and suspect-DCD groups on the LDCDQ-TW, but the latter two groups did not differ. Using the 15th percentile of both the MABC-2 and the LDCDQ-TW, sensitivity was 0.96 and specificity 0.68. Conclusions and Relevance: While standardized performance-based assessments are required to confirm a DCD diagnosis (typically after the age of 5), the LDCDQ-TW demonstrated sound reliability and validity and can support the early identification of young children at risk of DCD in Taiwan. What This Article Adds: The LDCDQ-TW questionnaire has sound psychometric properties and can be used to support early identification and monitoring of young children at risk of DC

    Genomics and proteomics of immune modulatory effects of a butanol fraction of echinacea purpurea in human dendritic cells

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    <p>Abstract</p> <p>Background</p> <p><it>Echinacea </it>spp. extracts and the derived phytocompounds have been shown to induce specific immune cell activities and are popularly used as food supplements or nutraceuticals for immuno-modulatory functions. Dendritic cells (DCs), the most potent antigen presenting cells, play an important role in both innate and adaptive immunities. In this study, we investigated the specific and differential gene expression in human immature DCs (iDCs) in response to treatment with a butanol fraction containing defined bioactive phytocompounds extracted from stems and leaves of <it>Echinacea purpurea</it>, that we denoted [BF/S+L/Ep].</p> <p>Results</p> <p>Affymetrix DNA microarray results showed significant up regulation of specific genes for cytokines (IL-8, IL-1β, and IL-18) and chemokines (CXCL 2, CCL 5, and CCL 2) within 4 h after [BF/S+L/Ep] treatment of iDCs. Bioinformatics analysis of genes expressed in [BF/S+L/Ep]-treated DCs revealed a key-signaling network involving a number of immune-modulatory molecules leading to the activation of a downstream molecule, adenylate cyclase 8. Proteomic analysis showed increased expression of antioxidant and cytoskeletal proteins after treatment with [BF/S+L/Ep] and cichoric acid.</p> <p>Conclusion</p> <p>This study provides information on candidate target molecules and molecular signaling mechanisms for future systematic research into the immune-modulatory activities of an important traditional medicinal herb and its derived phytocompounds.</p

    Protein Profiling of Human Nonpigmented Ciliary Epithelium Cell Secretome: The Differentiation Factors Characterization for Retinal Ganglion Cell line

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    The purpose of this paper was to characterize proteins secreted from the human nonpigmented ciliary epithelial (HNPE) cells, which have differentiated a rat retinal ganglion cell line, RGC-5. Undifferentiated RGC-5 cells have been shown to express several marker proteins characteristic of retinal ganglion cells. However, RGC-5 cells do not respond to N-methyl-D aspartate (NMDA), or glutamate. HNPE cells have been shown to secrete numbers of neuropeptides or neuroproteins also found in the aqueous humor, many of which have the ability to influence the activity of neuronal cells. This paper details the profile of HNPE cell-secreted proteins by proteomic approaches. The experimental results revealed the identification of 132 unique proteins from the HNPE cell-conditioned SF-medium. The biological functions of a portion of these identified proteins are involved in cell differentiation. We hypothesized that a differentiation system of HNPE cell-conditioned SF-medium with RGC-5 cells can induce a differentiated phenotype in RGC-5 cells, with functional characteristics that more closely resemble primary cultures of rat retinal ganglion cells. These proteins may replace harsh chemicals, which are currently used to induce cell differentiation

    Is the level of serum lactate dehydrogenase a potential biomarker for glucose monitoring with type 2 diabetes mellitus?

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    IntroductionType 2 diabetes mellitus (T2DM) is a metabolic disorder due to defects in insulin secretion or insulin resistance leading to the dysfunction and damage of various organs. To improve the clinical evaluation of short-term blood glycemic variability monitoring, it is critical to identify another blood cell status and nutritional status biomarker that is less susceptible to interference. This study identifies the significance of serum lactate dehydrogenase (LDH) level among T2DM patients treated in outpatient clinics and investigates the relationship of LDH level with other variables.MethodsThis study comprised 72 outpatients with T2DM over 20 years of age. Blood samples were collected followed by a hematological analysis of serum glycated albumin (GA), LDH, fasting blood glucose, glycosylated hemoglobin, C-peptide, and insulin antibodies (insulin Ab).ResultsSerum LDH level was significantly correlated with GA (p &lt; 0.001), C-peptide (p = 0.04), insulin Ab (p = 0.03), and thyroid-stimulating hormone (TSH) levels (p = 0.04). Hence, we performed a linear regression analysis of hematological markers. GA (p &lt; 0.001, r2 = 0.45) and insulin Ab (p &lt; 0.001, r2 = 0.40) were significantly associated with LDH level. Then, we classified patients into low (&lt;200 U/L) and high (≥200 U/L) serum LDH level groups, respectively. GA (p &lt; 0.001), C-peptide (p = 0.001), and TSH (p = 0.03) showed significant differences in patients with high LDH levels compared with those in patients with low LDH levels.ConclusionIn conclusion, we suggested that LDH level was independent of long-term but associated with short-term blood glucose monitoring. The results indicated that changes in serum GA induced cell damage and the abnormal elevation of the serum level of LDH may occur simultaneously with glycemic variability. It has been reported that many biomarkers are being used to observe glucose variability in T2DM. However, LDH could provide a more convenient and faster evaluation of glycemic variability in T2DM

    Recent work on sprite spectrum in Taiwan

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    campaigns in Taiwan. We first introduce two types of spectroimagers, the slit and slitless types, and discuss their advantages and shortcomings. Next we explore the instrument development and procedures undertaken for this study. In 2006, a slit spectroimager was installed for a sprite campaign and on 15 August of that year, two sprite spectra were recorded using the slit spectroimager along with seven sprites, one halo, one ELVES emission and two jets. By the end of 2015, a slitless spectroimager had been successfully constructed and was ready to conduct additional investigations. On 7 May 2016, a sprite spectrum was recorded using the slitless spectroimager. Following an examination of the calibrations (comprising detection region field of view, wavelength calibration, and response curve), data analysis, and additional calibrations (comprising elevation and azimuthal angles, atmospheric transmittance, and theoretical wavelength calculations) performed in this study, we present the results from our observed sprite spectra using the slit and slitless spectroimagers
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