302 research outputs found
Optimal financial and ordering decisions of a firm with insurance contract
This paper examines the impact of a bank’s risk limit on the financial and ordering decisions of a capital-constrained firm with insurance contract. All our major results can be computed via explicit expressions. It is shown that the bank will control its risk to be below the risk limit through setting a loan limit and the firm can make the loan limit increase by buying a deductible insurance policy. It is also shown that the repayment demand level needed to avoid bankruptcy will not be affected by the insurance policy. We derive the firm’s optimal ordering quantity and insurance coverage level under a downside risk measurement and a variance risk measurement separately. It is shown that the firm should pay more attention to whether to buy insurance or not under the downside risk measurement and how much insurance coverage to buy under the variance risk measurement. Under the downside risk measurement, once the firm decides to buy insurance, the optimal coverage level is independent of the bank’s risk limit. We also show that the insurance contract has a more obvious effect on the profit increases when the selling price is high or the bank’s risk limit is low.
First published online:Â 18 Jun 201
Learning Human-to-Humanoid Real-Time Whole-Body Teleoperation
We present Human to Humanoid (H2O), a reinforcement learning (RL) based
framework that enables real-time whole-body teleoperation of a full-sized
humanoid robot with only an RGB camera. To create a large-scale retargeted
motion dataset of human movements for humanoid robots, we propose a scalable
"sim-to-data" process to filter and pick feasible motions using a privileged
motion imitator. Afterwards, we train a robust real-time humanoid motion
imitator in simulation using these refined motions and transfer it to the real
humanoid robot in a zero-shot manner. We successfully achieve teleoperation of
dynamic whole-body motions in real-world scenarios, including walking, back
jumping, kicking, turning, waving, pushing, boxing, etc. To the best of our
knowledge, this is the first demonstration to achieve learning-based real-time
whole-body humanoid teleoperation.Comment: Project website: https://human2humanoid.com
Weaning Induced Hepatic Oxidative Stress, Apoptosis, and Aminotransferases through MAPK Signaling Pathways in Piglets
This study investigated the effects of weaning on the hepatic redox status, apoptosis, function, and the mitogen-activated protein kinase (MAPK) signaling pathways during the first week after weaning in piglets. A total of 12 litters of piglets were weaned at d 21 and divided into the weaning group (WG) and the control group (CG). Six piglets from each group were slaughtered at d 0 (d 20, referred to weaning), d 1, d 4, and d 7 after weaning. Results showed that weaning significantly increased the concentrations of hepatic free radicals H2O2 and NO, malondialdehyde (MDA), and 8-hydroxy-2′-deoxyguanosine (8-OHdG), while significantly decreasing the inhibitory hydroxyl ability (IHA) and glutathione peroxidase (GSH-Px), and altered the level of superoxide dismutase (SOD). The apoptosis results showed that weaning increased the concentrations of caspase-3, caspase-8, caspase-9 and the ratio of Bax/Bcl-2. In addition, aspartate aminotransferase transaminase (AST) and alanine aminotransferase (ALT) in liver homogenates increased after weaning. The phosphorylated JNK and ERK1/2 increased, while the activated p38 initially decreased and then increased. Our results suggested that weaning increased the hepatic oxidative stress and aminotransferases and initiated apoptosis, which may be related to the activated MAPK pathways in postweaning piglets
Optimization of fluorescence in situ hybridization (FISH) for the identification of two polar coccoid green algae species
Standard FISH protocols using fluorochrome-labeled oligonucleotide probes have been successfully applied for in situ detection. However, optimized protocols of FISH for specific eukaryotes in marine environments are often not developed. This study optimized the conditions of fluorescence in situ hybridization(FISH) by using two polar isolated microalgae. The modified conditions were as follows: (1)10mg·mL-1 lysozyme solution pretreatment at 37°C for 30 min; (2)the hybridization buffer including 20% formamide; (3)the hybridization condition was 47°C for 6h. The cells enumerated by FISH were compared with those enumerated by flow cytometry(FCM) and DAPI to confirm the cell loss and hybridization efficiency. The optimized protocol was also successfully applied to Arctic Ocean samples, which were found to be dominated by Micromonas sp. The modified protocol showed a high relative efficiency and could be successfully applied for the detection of specific microbial eukaryotes in environmental samples
Based on Network Pharmacology and Molecular Docking to Discuss the Mechanism of Antitussive and Expectorant Action of Ruanerli
The antitussive and expectorant effects of Ruanerli and its mechanism were investigated by methods of network pharmacology. The outcomes predicted were verified by molecular docking and animal experiments. The components and targets of Ruanerli were obtained by literature investigation and TCMSP database screen. Mapping with two groups of genes related to "cough" and "sputum" from GeneCards database, the target genes of antitussive and expectorant effects of Ruanerli were obtained. GO and KEGG enrichment analysis of the target genes was performed by Metascape platform. The PPI network among the target genes was constructed through STRING data platform. Cytoscape plugin CytoHubba was used to screen the Top10 genes related to antitussive and expectorant effects of Ruanerli, and KEGG pathway enrichment was performed on the Top10 genes through Metascape data platform to predict the possible signal pathways involved in antitussive and expectorant effects of Ruanerli. Autodock Vina was used for molecular docking between the predicted Top10 gene proteins and the Top 3 active ingredients of Ruanerli. Finally, the predicted results were verified by ammonia induced cough test and phenol red excretion test. According to the analysis of multiple databases, 51 chemical components and 282 corresponding targets have been reported, eighty of them were related to the antitussive and expectorant effects of Ruanerli. The Top10 genes selected by Degree value were mainly concentrated in infection and immune-related pathways. Molecular docking test showed that the Top10 genes had strong binding activity with the Top3 chemical components (Caffeic acid, Rutin and Valeraldehyde) in PPI network. Animal experiments showed that the cough induced by ammonia was significantly inhibited when treated with Ruanerli in mice. The levels of IL-6 and IL-13 in serum were reduced and the excretion of phenol red in mice trachea was increased. PCR and WB detection showed that the mRNA levels and protein expressions of inflammatory genes IL6, IL1B, VEGFA, PTGS2 and MAPK3 were decreased, suggesting that the antitussive and expectorant effects of Ruanerli might be related to decreasing the expression of inflammatory genes and the release of inflammatory factors
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Pilot Study on Image Quality and Radiation Dose of CT Colonography with Adaptive Iterative Dose Reduction Three-Dimensional
Objective: To investigate image quality and radiation dose of CT colonography (CTC) with adaptive iterative dose reduction three-dimensional (AIDR3D). Methods: Ten segments of porcine colon phantom were collected, and 30 pedunculate polyps with diameters ranging from 1 to 15 mm were simulated on each segment. Image data were acquired with tube voltage of 120 kVp, and current doses of 10 mAs, 20 mAs, 30 mAs, 40 mAs, 50 mAs, respectively. CTC images were reconstructed using filtered back projection (FBP) and AIDR3D. Two radiologists blindly evaluated image quality. Quantitative evaluation of image quality included image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Qualitative image quality was evaluated with a five-score scale. Radiation dose was calculated based on dose-length product. Ten volunteers were examined supine 50 mAs with FBP and prone 20 mAs with AIDR3D, and image qualities were assessed. Paired t test was performed for statistical analysis. Results: For 20 mAs with AIDR3D and 50 mAs with FBP, image noise, SNRs and CNRs were (16.4 ± 1.6) HU vs. (16.8 ± 2.6) HU, 1.9 ± 0.2 vs. 1.9 ± 0.4, and 62.3 ± 6.8 vs. 62.0 ± 6.2, respectively; qualitative image quality scores were 4.1 and 4.3, respectively; their differences were all not statistically significant. Compared with 50 mAs with FBP, radiation dose (1.62 mSv) of 20 mAs with AIDR3D was decreased by 60.0%. There was no statistically significant difference in image noise, SNRs, CNRs and qualitative image quality scores between prone 20 mAs with AIDR3D and supine 50 mAs with FBP in 10 volunteers, the former reduced radiation dose by 61.1%. Conclusion: Image quality of CTC using 20 mAs with AIDR3D could be comparable to standard 50 mAs with FBP, radiation dose of the former reduced by about 60.0% and was only 1.62 mSv
Gut microbiome and metabolome to discover pathogenic bacteria and probiotics in ankylosing spondylitis
ObjectivePrevious research has partially revealed distinct gut microbiota in ankylosing spondylitis (AS). In this study, we performed non-targeted fecal metabolomics in AS in order to discover the microbiome–metabolome interface in AS. Based on prospective cohort studies, we further explored the impact of the tumor necrosis factor inhibitor (TNFi) on the gut microbiota and metabolites in AS.MethodsTo further understand the gut microbiota and metabolites in AS, along with the influence of TNFi, we initiated a prospective cohort study. Fecal samples were collected from 29 patients with AS before and after TNFi therapy and 31 healthy controls. Metagenomic and metabolomic experiments were performed on the fecal samples; moreover, validation experiments were conducted based on the association between the microbiota and metabolites.ResultsA total of 7,703 species were annotated using the metagenomic sequencing system and by profiling the microbial community taxonomic composition, while 50,046 metabolites were identified using metabolite profiling. Differential microbials and metabolites were discovered between patients with AS and healthy controls. Moreover, TNFi was confirmed to partially restore the gut microbiota and the metabolites. Multi-omics analysis of the microbiota and metabolites was performed to determine the associations between the differential microbes and metabolites, identifying compounds such as oxypurinol and biotin, which were correlated with the inhibition of the pathogenic bacteria Ruminococcus gnavus and the promotion of the probiotic bacteria Bacteroides uniformis. Through experimental studies, the relationship between microbes and metabolites was further confirmed, and the impact of these two types of microbes on the enterocytes and the inflammatory cytokine interleukin-18 (IL-18) was explored.ConclusionIn summary, multi-omics exploration elucidated the impact of TNFi on the gut microbiota and metabolites and proposed a novel therapeutic perspective: supplementation of compounds to inhibit potential pathogenic bacteria and to promote potential probiotics, therefore controlling inflammation in AS
Effect of Extraction Temperature on the Functional and Structural Properties of Mullet Scale Gelatin
The functional property is an important factor to measure the quality of fish gelatin, which directly relates to the practical application range and value of fish gelatin. In order to explore the effect of extraction temperature on the functional properties of mullet scale gelatin, this study used a hot water extraction method. Different temperatures (60, 70, 80, 90, 100 ℃) were examined to assess their impact on the surface morphology of fish scales, fish scale gelatin yield, and functional properties (foaming capacity, emulsifying activity, gel strength, gel temperature, and melting temperature). Furthermore, the structural characteristics of fish scale gelatin were investigated using SDS-PAGE, Fourier transform infrared spectroscopy, and scanning electron microscopy. The results showed that as the extraction temperature increased from 60 ℃ to 100 ℃, the damage to the surface of mullet scales became increasingly severe. The fish scale gelatin yield increased from 31.72% to 50.97%, foaming capacity improved from 23.33% to 73.33%, and emulsifying activity increased from 15.13 m2/g to 17.27 m2/g. However, gel strength, gel temperature, and melting temperature decreased from 677.82 g, 20.80 ℃, and 28.70 ℃ to 372.91 g, 15.80 ℃, and 23.90 ℃, respectively. Additionally, with the increase in extraction temperature, the characteristic bands of mullet scale gelatin α1, α2, and β chains on the electrophoresis pattern became increasingly blurred. The infrared spectroscopy results showed that the fish scale gelatin had characteristic absorption peaks (amide A, amide â… , amide â…¡, and amide â…¢), with the wavenumber of amide A first increasing and then decreasing. The scanning electron microscopy results showed that the tightness of the porous grid structure of the fish scale gelatin decreased. These findings provide a theoretical basis for the industrialization of mullet scale gelatin
The cumulative therapeutic effect of acupuncture in patients with migraine without aura: Evidence from dynamic alterations of intrinsic brain activity and effective connectivity
We explored the dynamic alterations of intrinsic brain activity and effective connectivity after acupuncture treatment to investigate the underlying neurological mechanism of acupuncture treatment in patients with migraine without aura (MwoA). The Functional Magnetic Resonance Imaging (fMRI) scans were separately obtained at baseline, after the first and 12th acupuncture sessions in 40 patients with MwoA. Compared with the healthy controls (HCs), patients with MwoA mostly showed a decreased dynamic amplitude of low-frequency fluctuation (dALFF) variability in the rostral ventromedial medulla (RVM), superior lobe of left cerebellum (Cerebellum_Crus1_L), right precuneus (PCUN.R), and so on. The decreased dALFF variability of RVM, Cerebellum_Crus1_L, and PCUN.R progressively recovered after the first and 12th acupuncture treatment sessions as compared to the baseline. There was gradually increased dynamic effective connectivity (DEC) variability in RVM outflow to the right middle frontal gyrus, left insula, right precentral gyrus, and right supramarginal gyrus, and gradually enhanced DEC variability from the right fusiform gyrus inflow to RVM. Furthermore, the gradually increased DEC variability was found from Cerebellum_Crus1_L outflow to the left middle occipital gyrus and the left precentral gyrus, from PCUN.R outflow to the right thalamus. These dALFF variabilities were positively correlated with the frequency of migraine attacks and negatively correlated with disease duration at baseline. The dynamic Granger causality analysis (GCA) coefficients of this DEC variability were positively correlated with Migraine-Specific Quality of Life Questionnaire scores and negatively correlated with the frequency of migraine attacks and visual analog scale (VAS) scores after 12th acupuncture sessions. Our results were analyzed by a longitudinal fMRI in the absence of a sham acupuncture control group and provided insight into the dynamic alterations of brain activity and effective connectivity in patients with MwoA after acupuncture intervention. Acupuncture might relieve MwoA by increasing the effective connectivity of RVM, Cerebellum_Crus1_L, and PCUN.R to make up for the decreased dALFF variability in these brain areas
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