81 research outputs found
Role of Post‐Acute Care in Readmissions for Preexisting Healthcare‐Associated Infections
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153607/1/jgs16208.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153607/2/jgs16208_am.pd
OVD-Explorer: Optimism Should Not Be the Sole Pursuit of Exploration in Noisy Environments
In reinforcement learning, the optimism in the face of uncertainty (OFU) is a
mainstream principle for directing exploration towards less explored areas,
characterized by higher uncertainty. However, in the presence of environmental
stochasticity (noise), purely optimistic exploration may lead to excessive
probing of high-noise areas, consequently impeding exploration efficiency.
Hence, in exploring noisy environments, while optimism-driven exploration
serves as a foundation, prudent attention to alleviating unnecessary
over-exploration in high-noise areas becomes beneficial. In this work, we
propose Optimistic Value Distribution Explorer (OVD-Explorer) to achieve a
noise-aware optimistic exploration for continuous control. OVD-Explorer
proposes a new measurement of the policy's exploration ability considering
noise in optimistic perspectives, and leverages gradient ascent to drive
exploration. Practically, OVD-Explorer can be easily integrated with continuous
control RL algorithms. Extensive evaluations on the MuJoCo and GridChaos tasks
demonstrate the superiority of OVD-Explorer in achieving noise-aware optimistic
exploration.Comment: Accepted by AAAI 2024, with appendi
AMELIORATIVE POTENTIAL OF ARTEMISIA CAPILLARIS FORMULA ON NONALCOHOLIC FATTY LIVER DISEASE IN RATS THROUGH REGULATION OF FAT METABOLISM
Background: Artemisia Capillaris Formula (ACF), a traditional Chinese medicinal therapy, has been used clinically in China to treat
Nonalcoholic Fatty Liver Disease (NAFLD) for many years. However, the mechanism of action of this treatment on NAFLD is still unknown.
The goal of the present study is to test whether Artemisia Capillaris Formula protects against NAFLD through regulation of lipid metabolism.
Methods: Rat models of NAFLD were established through consumption of a high-fat diet (HFD) for 8 weeks. 60 rats were randomly divided
into 6 groups (10 rats per group): the control (standard diet) group, the model (HFD) group, the polyene phosphatidylcholine treated HFD group,
and the ACF-treated HFD groups (high-, medium- and low-dose). During weeks 5−8 of the HFD regimen, drugs were intra-gastrically
administrated to selected groups for a total of 4 weeks. Hepatic changes were observed through pathological examination of Hematoxylin and
eosin-stained tissues, quantification of lipid metabolites from sera (ALT, AST, ALP activity and TG, TC, HDL-C, LDL-C), and quantification of
related gene and protein expression levels by RT-PCR and Western blotting.
Results: A high-fat diet promoted obesity and the development of hepatomegaly, hepatosteatosis and dyslipidemia in rats after 8 weeks.
Treatment with ACF alleviated hepatosteatosis and also protected against high fat diet-induced dyslipidemia. We found that ACF reduced ALT,
AST, ALP, TG, TC, and LDL-C and increased HDL-C levels in sera from treated NAFLD rats. In addition, gene and protein expression levels
of FAS and ACC were down-regulated following ACF treatment, whereas expression levels of CPT were up-regulated.
Conclusion: ACF ameliorates high-fat diet-induced hepatosteatosis and dyslipidemia in rats by altering lipid metabolism-related gene
expression, specifically of FAS, ACC, and CPT
Psychometric Properties of the Chinese Version of the Perceived Stress Scale in Policewomen
BACKGROUND: The 10-item Perceived Stress Scale (PSS-10) is one of most widely used instruments to measure a global level of perceived stress in a range of clinical and research settings. This study was conducted to examine the psychometric properties of the Simplified Chinese version of the PSS-10 in policewomen. METHODOLOGY: A total of 240 policewomen were recruited in this study. The Simplified Chinese versions of the PSS-10, the Beck Depression Inventory Revised (BDI-II), and the Beck Anxiety Inventory (BAI) were administered to all participants, and 36 of the participants were re-tested two weeks after the initial testing. PRINCIPAL FINDINGS: The overall Cronbach's alpha was 0.86, and the test-retest reliability coefficient was 0.68. Exploratory Factor Analysis (EFA) yielded 2 factors with eigenvalues of 4.76 and 1.48, accounting for 62.41% of variance. Factor 1 consisted of 6 items representing "negative feelings"; whereas Factor 2 consisted of 4 items representing "positive feelings". The item loadings ranged from 0.72 to 0.83. The Confirmatory factor analysis (CFA) indicated a very good fit of this two-factor model to this sample. The PSS-10 significantly correlated with both BDI-II and BAI, indicating an acceptable concurrent validity. CONCLUSIONS: The Simplified Chinese version of the PSS-10 demonstrated adequate psychometric properties for evaluating stress levels. The results support its use among the Chinese population
Ubiquitin-like protein 3 (UBL3) is required for MARCH ubiquitination of major histocompatibility complex class II and CD86
The MARCH E3 ubiquitin (Ub) ligase MARCH1 regulates trafficking of major histocompatibility complex class II (MHC II) and CD86, molecules of critical importance to immunity. Here we show, using a genome-wide CRISPR knockout screen, that ubiquitin-like protein 3 (UBL3) is a necessary component of ubiquitination-mediated trafficking of these molecules in mice and in humans. Ubl3-deficient mice have elevated MHC II and CD86 expression on the surface of professional and atypical antigen presenting cells. UBL3 also regulates MHC II and CD86 in human dendritic cells (DCs) and macrophages. UBL3 impacts ubiquitination of MARCH1 substrates, a mechanism that requires UBL3 plasma membrane anchoring via prenylation. Loss of UBL3 alters adaptive immunity with impaired development of thymic regulatory T cells, loss of conventional type 1 DCs, increased number of trogocytic marginal zone B cells, and defective in vivo MHC II and MHC I antigen presentation. In summary, we identify UBL3 as a conserved, critical factor in MARCH1-mediated ubiquitination with important roles in immune responses
De Novo Peroxisome Biogenesis in Penicillium Chrysogenum Is Not Dependent on the Pex11 Family Members or Pex16
We have analyzed the role of the three members of the Pex11 protein family in peroxisome formation in the filamentous fungus Penicillium chrysogenum. Two of these, Pex11 and Pex11C, are components of the peroxisomal membrane, while Pex11B is present at the endoplasmic reticulum. We show that Pex11 is a major factor involved in peroxisome proliferation. We also demonstrate that P. chrysogenum cells deleted for known peroxisome fission factors (all Pex11 family proteins and Vps1) still contain peroxisomes. Interestingly, we find that, unlike in mammals, Pex16 is not essential for peroxisome biogenesis in P. chrysogenum, as partially functional peroxisomes are present in a pex16 deletion strain. We also show that Pex16 is not involved in de novo biogenesis of peroxisomes, as peroxisomes were still present in quadruple Δpex11 Δpex11B Δpex11C Δpex16 mutant cells. By contrast, pex3 deletion in P. chrysogenum led to cells devoid of peroxisomes, suggesting that Pex3 may function independently of Pex16. Finally, we demonstrate that the presence of intact peroxisomes is important for the efficiency of ß-lactam antibiotics production by P. chrysogenum. Remarkably, distinct from earlier results with low penicillin producing laboratory strains, upregulation of peroxisome numbers in a high producing P. chrysogenum strain had no significant effect on penicillin production
Regulation of MHC class II ubiquitination in antigen presenting cells
© 2018 Dr. Haiyin LiuAbstract withhel
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