144 research outputs found

    How to Combine Variational Bayesian Networks in Federated Learning

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    Federated Learning enables multiple data centers to train a central model collaboratively without exposing any confidential data. Even though deterministic models are capable of performing high prediction accuracy, their lack of calibration and capability to quantify uncertainty is problematic for safety-critical applications. Different from deterministic models, probabilistic models such as Bayesian neural networks are relatively well-calibrated and able to quantify uncertainty alongside their competitive prediction accuracy. Both of the approaches appear in the federated learning framework; however, the aggregation scheme of deterministic models cannot be directly applied to probabilistic models since weights correspond to distributions instead of point estimates. In this work, we study the effects of various aggregation schemes for variational Bayesian neural networks. With empirical results on three image classification datasets, we observe that the degree of spread for an aggregated distribution is a significant factor in the learning process. Hence, we present an investigation on the question of how to combine variational Bayesian networks in federated learning, while providing benchmarks for different aggregation settings

    A Case of Brucellosis with a Rare Complication: Pericarditis

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    Objectives: To describe brucellosis and its possible complications according to clinical, laboratory and radiological findings. Methods: We describe a case of Brucella pericarditis visualized at transthoracic echocardiography with clinical manifestations. Results: Clinical manifestations, imaging and laboratory findings provided the correct diagnosis of Brucella pericarditis. The patient recovered fully following doxycycline and rifampin therapy. Conclusion: Brucellosis should be considered in the differential diagnosis of disorders that affect the pericardium in endemic areas

    Density-dependent cooperative non-specific binding in solid-phase SELEX affinity selection

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    The non-specific binding of undesired ligands to a target is the primary factor limiting the enrichment of tight-binding ligands in affinity selection. Solution-phase non-specific affinity is determined by the free-energy of ligand binding to a single target. However, the solid-phase affinity might be higher if a ligand bound concurrently to multiple adjacent immobilized targets in a cooperative manner. Cooperativity could emerge in this case as a simple consequence of the relationship between the free energy of binding, localization entropy and the spatial distribution of the immobilized targets. We tested this hypothesis using a SELEX experimental design and found that non-specific RNA aptamer ligands can concurrently bind up to four bead-immobilized peptide targets, and that this can increase their effective binding affinity by two orders-of-magnitude. Binding curves were quantitatively explained by a new statistical mechanical model of density-dependent cooperative binding, which relates cooperative binding to both the target concentration and the target surface density on the immobilizing substrate. Target immobilization plays a key role in SELEX and other ligand enrichment methods, particularly in new multiplexed microfluidic purification devices, and these results have strong implications for optimizing their performance

    SERUM MOTS-C LEVELS REMAIN UNCHANGED IN PATIENTS WITH PREECLAMPSIA

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    Objectives: Mitochondrial open-reading-frame of the twelve S rRNA-c (MOTS-c) is a mitochondrial derived peptide which has beneficial effects on muscle metabolism, insulin sensitivity, weight regulation, and bone mineral density. This study aims to investigate whether serum levels of MOTS-c are altered in patients with preeclampsia. Material and methods: This is cross sectional a case-control study of 30 patients with uncomplicated pregnancy, 30 patients with mild preeclampsia and 30 patients with severe preeclampsia that were admitted to the study center between June 2020 and January 2021. Results: When compared to the healthy controls and patients with mild preeclampsia, maternal smoking was significantly more frequent, systolic and diastolic blood pressures were significantly higher and platelet count was significantly lower in patients with severe preeclampsia (p = 0.045, p = 0.0001, p = 0.0001 and p = 0.024 respectively). Serum MOTS-c concentrations were statistically similar in healthy controls, mild and severe preeclampsia patients (159.1 ± 28.7 ng/mL vs 129.6 ± 54.7 ng/mL vs 146.4 ± 48.3, p = 0.166). When compared to the healthy controls, systolic and diastolic blood pressures were significantly higher and platelet count was significantly lower in patients with late onset preeclampsia (p = 0.0001, p = 0.0001 and p = 0.022 respectively). Healthy controls and patients with early and late onset preeclampsia were statistically similar with respect to MOTS-c levels (159.1 ± 28.7 ng/mL vs 126.7 ± 56.9 vs 153.7 ± 39.8, p = 0.102). Conclusions: This study failed to detect any significant relationship between MOTS-c and preeclampsia. Large scale research is needed to clarify if MOTS-c is a novel biomarker for preeclampsia and therapeutic target for preeclampsia patients

    Concurrent solution of WATC scheduling with WPPW due date assignment for environmentally weighted customers, jobs and services using SA and its hybrid

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    After industrial revolution environmental problems increased drastically. Air, water and soil pollution became a serious threat for the mankind. In order to overcome this threat everyone should take responsibility and try to preserve environment as much as possible. Environmentally conscious actions, people, law and foundations should be supported. When it came to determining due dates and scheduling, one of the important criteria should be the supporting the environment. In this study environmentally conscious customers, jobs, and services are rewarded, on the other hand unconscious customers, jobs, and services are penalized, while determining due dates and schedules. Simulated annealing and its hybrid with random search are applied to get environmentally better due dates and schedules

    Defining NELF-E RNA binding in HIV-1 and promoter-proximal pause regions

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    The four-subunit Negative Elongation Factor (NELF) is a major regulator of RNA Polymerase II (Pol II) pausing. The subunit NELF-E contains a conserved RNA Recognition Motif (RRM) and is proposed to facilitate Poll II pausing through its association with nascent transcribed RNA. However, conflicting ideas have emerged for the function of its RNA binding activity. Here, we use in vitro selection strategies and quantitative biochemistry to identify and characterize the consensus NELF-E binding element (NBE) that is required for sequence specific RNA recognition (NBE: CUGAGGA(U) for Drosophila). An NBE-like element is present within the loop region of the transactivation-response element (TAR) of HIV-1 RNA, a known regulatory target of human NELF-E. The NBE is required for high affinity binding, as opposed to the lower stem of TAR, as previously claimed. We also identify a non-conserved region within the RRM that contributes to the RNA recognition of Drosophila NELF-E. To understand the broader functional relevance of NBEs, we analyzed promoter-proximal regions genome-wide in Drosophila and show that the NBE is enriched +20 to +30 nucleotides downstream of the transcription start site. Consistent with the role of NELF in pausing, we observe a significant increase in NBEs among paused genes compared to non-paused genes. In addition to these observations, SELEX with nuclear run-on RNA enrich for NBE-like sequences. Together, these results describe the RNA binding behavior of NELF-E and supports a biological role for NELF-E in promoter-proximal pausing of both HIV-1 and cellular genes

    Effects of magnesium sulphate on liver ischemia/reperfusion injury in a rat model

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    Aim: To investigate the protective efficacy of magnesium sulphate in a model of rat liver ischemia-reperfusion (I/R) injury. Method: 32 adult female Wistar-Albino rats (250 to 350 g) were used in this experimental study. Rats were divided into 4 groups according to liver ischemia and magnesium sulfate application methods. Group 1 (C); control, group 2 (M); magnesium sulphate, group 3 (I/R); liver I/R, group 4 (I/R+M); I/R + magnesium sulphate treated. The blood samples were centrifuged for the study of aspartate aminotransferase (AST), alanine aminotransferase, prothrombin time (PT), international normalized ratio (INR) troponin I, total antioxidant status (TAS), total oxidant status (TOS) assays. The livers of the animals were removed at the end of the study and samples were taken for histopathological examination. Results: AST and INR values were significantly decreased in I/R+M group compared to I/R group. There was no significant difference in ALT values of the groups. Although not statistically significant, the TAS values were increased in I/R + M group compared to I/R group rats. In addition, the value of TOS was found to be lower in I/R + M group rats. In the histopathological examination, the mean values of apoptosis and necrosis were lower in the IR+M group compared to the IR group. Conclusion: The main finding of the present study suggested that magnesium sulphate pretreatment moderately decreased the liver damage through its anti-inflammatory and anti-oxidant effects in a rat model of liver I/R

    RNA aptamers that functionally interact with green fluorescent protein and its derivatives

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    Green Fluorescent Protein (GFP) and related fluorescent proteins (FPs) have been widely used to tag proteins, allowing their expression and subcellular localization to be examined in real time in living cells and animals. Similar fluorescent methods are highly desirable to detect and track RNA and other biological molecules in living cells. For this purpose, we have developed a group of RNA aptamers that bind GFP and related proteins, which we term Fluorescent Protein-Binding Aptamers (FPBA). These aptamers bind GFP, YFP and CFP with low nanomolar affinity and binding decreases GFP fluorescence, whereas slightly augmenting YFP and CFP brightness. Aptamer binding results in an increase in the pKa of EGFP, decreasing the 475 nm excited green fluorescence at a given pH. We report the secondary structure of FPBA and the ability to synthesize functional multivalent dendrimers. FPBA expressed in live cells decreased GFP fluorescence in a valency-dependent manner, indicating that the RNA aptamers function within cells. The development of aptamers that bind fluorescent proteins with high affinity and alter their function, markedly expands their use in the study of biological pathways
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