A new hybrid approach to human error probability quantification-applications in maritime operations

Human Reliability Analysis (HRA) has always been an essential research issue in safety critical systems. Cognitive Reliability Error Analysis Method (CREAM), as a well-known second generation HRA method is capable of conducting both retrospective and prospective analysis, thus being widely used in many sectors. However, the needs of addressing the use of a deterministic approach to configure common performance conditions (CPCs) and the assignment of the same importance to all the CPCs in a traditional CREAM method reveal a significant research gap to be fulfilled. This paper describes a modified CREAM methodology based on an Evidential Reasoning (ER) approach and a Decision Making Trial and Evaluation Laboratory (DEMATEL) technique for making human error probability quantification in CREAM rational. An illustrative case study associated with maritime operations is presented. The proposed method is validated by sensitivity analysis and the quantitative analysis result is verified through comparing the real data collected from Shanghai coastal waters. Its main contribution lies in that it for the first time addresses the data incompleteness in HEP, given that the previous relevant studies mainly focus on the fuzziness in data. The findings will provide useful insights for quantitative assessment of seafarers' errors to reduce maritime risks due to human errors

Controlling Cherenkov angles with resonance transition radiation

Cherenkov radiation provides a valuable way to identify high energy particles in a wide momentum range, through the relation between the particle velocity and the Cherenkov angle. However, since the Cherenkov angle depends only on material's permittivity, the material unavoidably sets a fundamental limit to the momentum coverage and sensitivity of Cherenkov detectors. For example, Ring Imaging Cherenkov detectors must employ materials transparent to the frequency of interest as well as possessing permittivities close to unity to identify particles in the multi GeV range, and thus are often limited to large gas chambers. It would be extremely important albeit challenging to lift this fundamental limit and control Cherenkov angles as preferred. Here we propose a new mechanism that uses constructive interference of resonance transition radiation from photonic crystals to generate both forward and backward Cherenkov radiation. This mechanism can control Cherenkov angles in a flexible way with high sensitivity to any desired range of velocities. Photonic crystals thus overcome the severe material limit for Cherenkov detectors, enabling the use of transparent materials with arbitrary values of permittivity, and provide a promising option suited for identification of particles at high energy with enhanced sensitivity.Comment: There are 16 pages and 4 figures for the manuscript. Supplementary information with 18 pages and 5 figures, appended at the end of the file with the manuscript. Source files in Word format converted to PDF. Submitted to Nature Physic

A compact model for magnetic tunnel junction (MTJ) switched by thermally assisted Spin transfer torque (TAS + STT)

Thermally assisted spin transfer torque [TAS + STT] is a new switching approach for magnetic tunnel junction [MTJ] nanopillars that represents the best trade-off between data reliability, power efficiency and density. In this paper, we present a compact model for MTJ switched by this approach, which integrates a number of physical models such as temperature evaluation and STT dynamic switching models. Many experimental parameters are included directly to improve the simulation accuracy. It is programmed in the Verilog-A language and compatible with the standard IC CAD tools, providing an easy parameter configuration interface and allowing high-speed co-simulation of hybrid MTJ/CMOS circuits

Mechanism of endothelial progenitor cell recruitment into neo-vessels in adjacent non-tumor tissues in hepatocellular carcinoma

Abstract Background We investigated the distribution and clinical significance of mobilized endothelial progenitor cells (EPCs) in hepatocellular carcinoma (HCC). We found that many more EPCs were recruited to nonmalignant liver tissue (especially into adjacent non-tumor tissues (AT)) than to tumor vessels. These results suggest that the mechanism underlying the recruitment of EPCs into microvessels in AT merits further investigation Methods Angiogenic factors were detected in three tissue microarrays comprising normal liver, paired tumor tissue (TT) and AT from 105 patients (who had undergone hepatectomy for HCC) using immunohistochemistry. Also, the number of EPCs (positive for Sca-1, Flk-1 and c-Kit) in the blood and liver of cirrhotic mice were determined by flow cytometry and immunohistochemistry. The distribution of these labeled EPCs in tumor and non-tumor tissues was then studied. Results The results from the tissue microarrays showed that the expression levels of VEGF-A, bFGF, TGF-β, MCP-1, TSP-1, MMP-9, TIMP-2, and endostatin were significantly higher in AT than in either normal liver or TT (p Conclusions Both liver cirrhosis and HCC led to increased expression of pro-angiogenic factors, which resulted in the recruitment of EPCs into AT. Also, EPCs were mobilized, recruited and homed to cirrhotic liver. The unique pathology of HCC coupled with liver cirrhosis may, therefore, be associated with the distribution and function of EPCs.</p

Bradykinin and adenosine receptors mediate desflurane induced postconditioning in human myocardium: role of reactive oxygen species

BACKGROUND: Desflurane during early reperfusion has been shown to postcondition human myocardium, in vitro. We investigated the role of adenosine and bradykinin receptors, and generation of radical oxygen species in desflurane-induced postconditioning in human myocardium. METHODS: We recorded isometric contraction of human right atrial trabeculae hanged in an oxygenated Tyrode's solution (34 degrees Celsius, stimulation frequency 1 Hz). After a 30-min hypoxic period, desflurane 6% was administered during the first 5 min of reoxygenation. Desflurane was administered alone or with pretreatment of N-mercaptopropionylglycine, a reactive oxygen species scavenger, 8-(p-Sulfophenyl)theophylline, an adenosine receptor antagonist, HOE140, a selective B2 bradykinin receptor antagonist. In separate groups, adenosine and bradykinin were administered during the first minutes of reoxygenation alone or in presence of N-mercaptopropionylglycine. The force of contraction of trabeculae was recorded continuously. Developed force at the end of a 60-min reoxygenation period was compared (mean +/- standard deviation) between the groups by a variance analysis and post hoc test. RESULTS: Desflurane 6% (84 +/- 6% of baseline) enhanced the recovery of force after 60-min of reoxygenation as compared to control group (51 +/- 8% of baseline, P < 0.0001). N-mercaptopropionylglycine (54 +/- 3% of baseline), 8-(p-Sulfophenyl)theophylline (62 +/- 9% of baseline), HOE140 (58 +/- 6% of baseline) abolished desflurane-induced postconditioning. Adenosine (80 +/- 9% of baseline) and bradykinin (83 +/- 4% of baseline) induced postconditioning (P < 0.0001 vs control), N-mercaptopropionylglycine abolished the beneficial effects of adenosine and bradykinin (54 +/- 8 and 58 +/- 5% of baseline, respectively). CONCLUSIONS: In vitro, desflurane-induced postconditioning depends on reactive oxygen species production, activation of adenosine and bradykinin B2 receptors. And, the cardioprotective effect of adenosine and bradykinin administered at the beginning of reoxygenation, was mediated, at least in part, through ROS production

Activation of Toll-Like Receptor 3 Impairs the Dengue Virus Serotype 2 Replication through Induction of IFN-β in Cultured Hepatoma Cells

Toll-like receptors (TLRs) play an important role in innate immunity against invading pathogens. Although TLR signaling has been indicated to protect cells from infection of several viruses, the role of TLRs in Dengue virus (DENV) replication is still unclear. In the present study, we examined the replication of DENV serotype 2 (DENV2) by challenging hepatoma cells HepG2 with different TLR ligands. Activation of TLR3 showed an antiviral effect, while pretreatment of other TLR ligands (including TLR1/2, TLR2/6, TLR4, TLR5 or TLR7/8) did not show a significant effect. TLR3 ligand poly(I∶C) treatment prior to viral infection or simultaneously, but not post-treatment, significantly down-regulated virus replication. Pretreatment with poly(I∶C) reduced viral mRNA expression and viral staining positive cells, accompanying an induction of the type I interferon (IFN-β) and type III IFN (IL-28A/B). Intriguingly, neutralization of IFN-β alone successfully restored the poly(I∶C)-inhibited replication of DENV2. The poly(I∶C)-mediated effects, including IFN induction and DENV2 suppression, were significantly reversed by IKK inhibitor, further suggesting that IFN-β is the dominant factor involved in the poly(I∶C) mediated antiviral effect. Our study presented the first evidence to show that activation of TLR3 is effective in blocking DENV2 replication via IFN-β, providing an experimental clue that poly(I∶C) may be a promising immunomodulatory agent against DENV infection and might be applicable for clinical prevention

Reaction Chemistry and Kinetics of Corn Stalk Pyrolysis without and with Ga/HZSM-5

The bifunctional Ga/HZSM-5 catalyst has been proven having the capability to increase the selectivity of aromatics production during catalytic pyrolysis of furan and woody biomass. However, the reaction chemistry and kinetics of pyrolysis of herbaceous biomass promoted by Ga/HZSM-5 is rarely reported. Pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) analysis and non-isothermal thermogravimetric analysis at four heating rates were carried out to investigate the decomposition behavior and pyrolysis kinetics of corn stalk without and with Ga/HZSM-5. The effective activation energies for corn stalk pyrolysis were calculated by using the Friedman isoconversional method. The Py–GC/MS analysis results indicated that the Ga/HZSM-5 catalyst had a high selectivity toward producing the aromatic chemicals of xylene, toluene and benzene, whereas the major products from non-catalytic pyrolysis of corn stalk were oxygenated compounds. The presence of Ga/HZSM-5 could significantly reduce the effective activation energies of corn stalk pyrolysis from 159.9–352.4 kJ mol−1 to 41.6–99.8 kJ mol−1 in the conversion range of 0.10–0.85

Anti-Stress Effects of Carnosine on Restraint-Evoked Immunocompromise in Mice through Spleen Lymphocyte Number Maintenance

Carnosine (β-alanyl-L-histidine), a naturally occurring dipeptide, has been characterized as a putative neurotransmitter and serves as a reservoir for brain histamine, which could act on histaminergic neurons system to relieve stress-induced damages. However, understanding of the role of carnosine in stress-evoked immunocompromise is limited. In this study, results showed that when mice were subjected to restraint stress, spleen index and the number of spleen lymphocytes including Natural Killer (NK) cells were obviously decreased. Results also demonstrated that restraint stress decreased the cytotoxic activity of NK cells per spleen (LU10/spleen) while the activity of a single NK cell (LU10/106 cells) was not changed. However, oral administration of carnosine (150 and 300 mg/kg) increased spleen index and number of spleen lymphocytes (including NK cells), and elevated the cytotoxic activity of NK cells per spleen in restraint-stressed mice. These results indicated that carnosine ameliorated stress-evoked immunocompromise through spleen lymphocyte number maintenance. Carnosine was further found to reduce stress-induced elevation of plasma corticosterone level. On the other hand, results showed that carnosine and RU486 (a glucocorticoids receptor antagonist) treatment prevented the reduction in mitochondrion membrane potential and the release of mitochondrial cytochrome c into cytoplasm, increased Bcl-2/Bax mRNA ratio, as well as decreased terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells in spleen lymphocytes of stressed mice. The results above suggested that the maintenance of spleen lymphocyte number by carnosine was related with the inhibition of lymphocytes apoptosis caused by glucocorticoids overflow. The stimulation of lymphocyte proliferation by carnosine also contributed to the maintenance of spleen lymphocyte number in stressed mice. In view of the elevated histamine level, the anti-stress effects of carnosine on restraint-evoked immunocompromise might be via carnosine-histamine metabolic pathway. Taken together, carnosine maintained spleen lymphocyte number by inhibiting lymphocyte apoptosis and stimulating lymphocyte proliferation, thus prevented immunocompromise in restraint-stressed mice

Dengue-2 Structural Proteins Associate with Human Proteins to Produce a Coagulation and Innate Immune Response Biased Interactome

<p>Abstract</p> <p>Background</p> <p>Dengue virus infection is a public health threat to hundreds of millions of individuals in the tropical regions of the globe. Although Dengue infection usually manifests itself in its mildest, though often debilitating clinical form, dengue fever, life-threatening complications commonly arise in the form of hemorrhagic shock and encephalitis. The etiological basis for the virus-induced pathology in general, and the different clinical manifestations in particular, are not well understood. We reasoned that a detailed knowledge of the global biological processes affected by virus entry into a cell might help shed new light on this long-standing problem.</p> <p>Methods</p> <p>A bacterial two-hybrid screen using DENV2 structural proteins as bait was performed, and the results were used to feed a manually curated, global dengue-human protein interaction network. Gene ontology and pathway enrichment, along with network topology and microarray meta-analysis, were used to generate hypothesis regarding dengue disease biology.</p> <p>Results</p> <p>Combining bioinformatic tools with two-hybrid technology, we screened human cDNA libraries to catalogue proteins physically interacting with the DENV2 virus structural proteins, Env, cap and PrM. We identified 31 interacting human proteins representing distinct biological processes that are closely related to the major clinical diagnostic feature of dengue infection: haemostatic imbalance. In addition, we found dengue-binding human proteins involved with additional key aspects, previously described as fundamental for virus entry into cells and the innate immune response to infection. Construction of a DENV2-human global protein interaction network revealed interesting biological properties suggested by simple network topology analysis.</p> <p>Conclusions</p> <p>Our experimental strategy revealed that dengue structural proteins interact with human protein targets involved in the maintenance of blood coagulation and innate anti-viral response processes, and predicts that the interaction of dengue proteins with a proposed human protein interaction network produces a modified biological outcome that may be behind the hallmark pathologies of dengue infection.</p