Cytokine response to viral infections of upper respiratory tract in asthmatic children

Cytokine response to viral infections of upper respiratory tract in asthmatic children SELECTED ABSTRACTS OF THE CONFERENCE “Modern Molecular-biochemical Markers in Clinical and Experimental Medicine”, 31 October – 02 November, 2018, Prague, Czech Republic. BIOLOGICAL MARKERS IN THEORETICAL AND CLINICAL MEDICIN

Oscillatory and regularized shock waves for a modified Serre-Green-Naghdi system

The Serre-Green-Naghdi equations of water wave theory have been widely employed to study undular bores. In this study, we introduce a modified Serre-Green-Naghdi system incorporating the effect of an artificial term that results in dispersive and dissipative dynamics. We show that, over sufficiently extended time intervals, effectively approximates the classical Serre-Green-Naghdi equations and admits dispersive-diffusive shock waves as traveling wave solutions. The traveling waves converge to the entropic shock wave solution of the shallow water equations when the dispersion and diffusion approach zero in a moderate dispersion regime. These findings contribute to an understanding of the formation of dispersive shock waves in the classical Serre-Green-Naghdi equations and the effects of diffusion in the generation and propagation of undular bores

Comparison of diesel-electric with hybrid-electric propulsion system safety using system-theoretic process analysis

Cruise ship industry is rapidly developing, with both the vessels size and number constantly growing up, which renders ensuring passengers, crew and ship safety a paramount necessity. Collision, grounding and fire are among the most frequent accidents on cruise ships with high consequences. In this study, a hazard analysis of diesel-electric and hybrid-electric propulsion system is undertaken using System-Theoretic Process Analysis (STPA). The results demonstrate significant increase in potential hazardous scenarios due to failures in automation and control systems, leading to fire and a higher number of scenarios leading to propulsion and power loss in hybrid-electric propulsion systems than on a conventional cruise-ship propulsion system. Results also demonstrate that STPA enhancement is required to compare the risk of two propulsion systems

Vitamin D status and viral-induced wheeze in children under three years of age

The study aimed to investigate the frequency of wheezing episodes in relation to vitamin D status in young children. Also, we explored factors associated with vitamin D deficiency and recurrent viral-induced wheeze episodes. Methods and Materials: The study enrolled 60 patients with episodic wheezing, 60 patients with recurrent wheezing, and 30 healthy individuals, all aged 6 months to 3 years. Serum vitamin D concentrations were measured in all study participants using electrochemiluminescence immunoassay. Results: Vitamin D deficiency was detected in 75% of recurrent wheezers and in 6.6% of children with episodic wheeze (P <.001). We registered an inverse relationship between the number of wheezing episodes and serum vitamin D concentrations. Children without vitamin D supplementation had substantially elevated odds of being found vitamin D deficient or recurrent wheezers. Other significant factors linked to recurrent wheezing were family history of allergy, maternal anemia during pregnancy, maternal active smoking currently. Conclusion: vitamin D deficiency and failed vitamin D supplementation are associated with the increased odds of recurrent wheezing in children of the first three years of life

A novel cyber-risk assessment method for ship systems

Recent advances in the maritime industry include research and development of new sophisticated ships with a number of smart functionalities and enhanced autonomy. The new functions and autonomy levels though come at the cost of increased connectivity. This results in increased ship vulnerability to cyber-attacks, which may lead to financial loss, environmental pollution, safety accidents. The aim of this study is to propose a novel method for cybersecurity risk assessment of ship systems. In this novel method, the Cyber-Preliminary Hazard Analysis method steps are enriched with new steps supporting the identification of cyber-attack scenarios and the risk assessment implementation. The proposed method is applied for the cyber-risk assessment and design enhancement of the navigation and propulsion systems of an inland waterways autonomous vessel. The results demonstrate that several critical scenarios can arise on the investigated autonomous vessel due to known vulnerabilities. These can be sufficiently controlled by introducing appropriate modifications to the systems design

Theoretical issues construction and operation of agricultural mission robotic system

Theoretical issues construction and operation of agricultural mission robotic system. Theoretical issues and approach to the construction and operation of robotic systems for agricultural purposes were presented. To solve scientific problem of optimal design and use of intelligent mobile robots detailed considerations were undertaken on the base some equations

A novel method for safety analysis of Cyber-Physical Systems - Application to a ship exhaust gas scrubber system

Cyber-Physical Systems (CPSs) represent a systems category developed and promoted in the maritime industry to automate functions and system operations. In this study, a novel Combinatorial Approach for Safety Analysis is presented, which addresses the traditional safety methods’ limitations by integrating System Theoretic Process Analysis (STPA), Events Sequence Identification (ETI) and Fault Tree Analysis (FTA). The developed method results into the development of a detailed Fault Tree that captures the effects of both the physical components/subsystems and the software functions’ failures. The quantitative step of the method employs the components’ failure rates to calculate the top event failure rate along with criticality analysis metrics for identifying the most critical components/functions. This method is implemented for an exhaust gas open loop scrubber system safety analysis to estimate its failure rate and identify critical failures considering the baseline system configuration as well as various alternatives with advanced functions for monitoring and diagnostics. The results demonstrate that configurations with SOx sensor continuous monitoring or scrubber unit failure diagnosis/prognosis lead to significantly lower failure rate. Based on the analysis results, the advantages/disadvantages of the novel method are also discussed. This study also provides insights for better safety analysis of the CPSs

Development of functional safety requirements for DP-driven servicing of wind turbines

The adage “prevention is better than cure” is at the heart of safety principles. However, effective accident prevention is challenging in complex, highly automated systems such as modern DP-driven vessels, which are supposed to safely transfer technicians in often unfavourable environmental conditions. FMEA analysis, which is required for DP-driven vessels, is helpful to build-in a necessary level of redundancy and thereby mitigate consequences of failures, but not particularly helpful to inform preventive measures, not least against functional glitches in controlling software. In this paper we develop a set of functional safety requirements which are aimed at prevention of causal factors behind drift-off, drive-off and other hazardous scenarios. For this purpose, we use a systemic hazard analysis by STPA, which delivers both failure and interaction-based (reliable-but-unsafe) scenarios. The functional requirements cover both design and operational (human element related) requirements, which are then ranked based on our proposed heuristic. The ranking is not predicated on statistics or expert option but instead it is proportional to the number of hazardous scenarios a requirement protects against, hence indicating the relative importance of the requirement. The paper also summarises the suggested areas of safety improvement for DP-driven vessels

A functional model-based approach for ship systems safety and reliability analysis – application to a cruise ship lubricating oil system

The lubricating oil systems are essential for ensuring the safe and reliable operation of the cruise ships power plants as demonstrated by recent incidents. The aim of this study is to investigate the safety enhancement of a cruise ship lubricating oil system by employing safety, reliability, availability and diagnosability analyses, which are based on the system functional modelling implemented in the MADe™ software. The safety analysis is implemented by combining a Failure Modes, Effects and Criticality Analysis and the systems functional Fault Tree Analysis. Subsequently, Reliability Block Diagrams are employed to estimate the system reliability and availability metrics. The MADe™ toolbox for determining sensors locations is employed for a more advanced diagnostic system development. A number of design modifications are proposed and the alternative configurations reliability metrics are estimated. The derived results demonstrate that the suction strainer and the lubricating oil pump are the most critical system components. Seven additional sensors are proposed to enhance the original system design. Compared with the original system design, the investigated alternative designs exhibit significantly lower probabilities of failure and higher values of availability