Can ship travel contain COVID-19 outbreak after re-opening: a Bayesian meta-analysis.

Large gatherings of people on cruise ships and warships are often at high risk of COVID-19 infections. To assess the transmissibility of SARS-CoV-2 on warships and cruise ships and to quantify the effectiveness of the containment measures, the transmission coefficient (ß), basic reproductive number (R0), and time to deploy containment measures were estimated by the Bayesian Susceptible-Exposed-Infected-Recovered model. A meta-analysis was conducted to predict vaccine protection with or without non-pharmaceutical interventions (NPIs). The analysis showed that implementing NPIs during voyages could reduce the transmission coefficients of SARS-CoV-2 by 50%. Two weeks into the voyage of a cruise that begins with 1 infected passenger out of a total of 3,711 passengers, we estimate there would be 45 (95% CI:25-71), 33 (95% CI:20-52), 18 (95% CI:11-26), 9 (95% CI:6-12), 4 (95% CI:3-5), and 2 (95% CI:2-2) final cases under 0%, 10%, 30%, 50%, 70%, and 90% vaccine protection, respectively, without NPIs. The timeliness of strict NPIs along with implementing strict quarantine and isolation measures is imperative to contain COVID-19 cases in cruise ships. The spread of COVID-19 on ships was predicted to be limited in scenarios corresponding to at least 70% protection from prior vaccination, across all passengers and crew.

A Fault-Detection System Approach for the Optimization of Warship Equipment Replacement Parts Based on Operation Parameters.

Systems engineering plays a key role in the naval sector, focusing on how to design, integrate, and manage complex systems throughout their life cycle; it is therefore difficult to conceive functional warships without it. To this end, specialized information systems for logistical support and the sustainability of material solutions are essential to ensure proper provisioning and to know the operational status of the frigate. However, based on an architecture composed of a set of logistics applications, this information system may require highly qualified operators with a deep knowledge of the behavior of onboard systems to manage it properly. In this regard, failure detection systems have been postulated as one of the main cutting-edge methods to address the challenge, employing intelligent techniques for observing anomalies in the normal behavior of systems without the need for expert knowledge. In this paper, the study is concerned to the scope of the Spanish navy, where a complex information system structure is responsible for ensuring the correct maintenance and provisioning of the vessels. In such context, we hereby suggest a comparison between different one-class techniques, such as statistical models, geometric boundaries, or dimensional reduction to face anomaly detection in specific subsystems of a warship, with the prospect of applying it to the whole ship.

Warship wrecks and their munition cargos as a threat to the marine environment and humans: The V 1302 "JOHN MAHN" from World War II.

In addition to endangering sea traffic, cable routes, and wind farms, sunken warship wrecks with dangerous cargo, fuel, or munitions on board may emerge as point sources for environmental damage. Energetic compounds such as TNT (which could leak from these munitions) are known for their toxicity, mutagenicity, and carcinogenicity. These compounds may cause potential adverse effects on marine life via contamination of the marine ecosystem, and their entry into the marine and human food chain could directly affect human health. To ascertain the impending danger of an environmental catastrophe posed by sunken warships, the North Sea Wrecks (NSW) project (funded by the Interreg North Sea Region Program) was launched in 2018. Based on historical data (derived from military archives) including the calculated amount of munitions still on board, its known location and accessibility, the German World War II ship "Vorpostenboot 1302" (former civilian name - "JOHN MAHN") was selected as a case study to investigate the leakage and distribution of toxic explosives in the marine environment. The wreck site and surrounding areas were mapped in great detail by scientific divers and a multibeam echosounder. Water and sediment samples were taken in a cross-shaped pattern around the wreck. To assess a possible entry into the marine food chain, caged mussels were exposed at the wreck, and wild fish (pouting), a sedentary species that stays locally at the wreck, were caught. All samples were analyzed for the presence of TNT and derivatives thereof by GC-MS/MS analysis. As a result, we could provide evidence that sunken warship wrecks emerge as a point source of contamination with nitroaromatic energetic compounds leaking from corroding munitions cargo still on board. Not only did we find these explosive substances in bottom water and sediment samples around the wreck, but also in the caged mussels as well as in wild fish living at the wreck. Fortunately so far, the concentrations found in mussel meat and fish filet were only in the one-digit ng per gram range thus indicating no current concern for the human seafood consumer. However, in the future the situation may worsen as the corrosion continues. From our study, it is proposed that wrecks should not only be ranked according to critical infrastructure and human activities at sea, but also to the threats they pose to the environment and the human seafood consumer.

Forecasting model of operational casualty in surface warship formation against several groups of missile attacks / 第二军医大学学报

Combat casualty prediction on the sea is always challenging. Considering various factors involved in the attack and defense of warship formation and missile attack effect, we calculated the combat casualty based on the damage assessment result of combat simulation with reasonable simplification, which provided a forecasting model of combat casualty for surface warship after multiple missile attacks, improving the accuracy of casualty prediction in naval warfare.

A Novel Linear Spectrum Frequency Feature Extraction Technique for Warship Radio Noise Based on Complete Ensemble Empirical Mode Decomposition with Adaptive Noise, Duffing Chaotic Oscillator, and Weighted-Permutation Entropy.

Warships play an important role in the modern sea battlefield. Research on the line spectrum features of warship radio noise signals is helpful to realize the classification and recognition of different types of warships, and provides critical information for sea battlefield. In this paper, we proposed a novel linear spectrum frequency feature extraction technique for warship radio noise based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), duffing chaotic oscillator (DCO), and weighted-permutation entropy (W-PE). The proposed linear spectrum frequency feature extraction technique, named CEEMDAN-DCO-W-PE has the following advantages in comparison with other linear spectrum frequency feature extraction techniques; (i) as an adaptive data-driven algorithm, CEEMDAN has more accurate and more reliable decomposition performance than empirical mode decomposition (EMD) and ensemble EMD (EEMD), and there is no need for presetting parameters, such as decomposition level and basis function; (ii) DCO can detect the linear spectrum of narrow band periodical warship signals by way of utilizing its properties of sensitivity for weak periodical signals and the immunity for noise; and (iii) W-PE is used in underwater acoustic signal feature extraction for the first time, and compared with traditional permutation entropy (PE), W-PE increases amplitude information to some extent. Firstly, warship radio noise signals are decomposed into some intrinsic mode functions (IMFs) from high frequency to low frequency by CEEMDAN. Then, DCO is used to detect linear spectrum of low-frequency IMFs. Finally, we can determine the linear spectrum frequency of low-frequency IMFs using W-PE. The experimental results show that the proposed technique can accurately extract the line spectrum frequency of the simulation signals, and has a higher classification and recognition rate than the traditional techniques for real warship radio noise signals.

Investigation of sleep quality and life quality of soldiers in a navy warship troop / 第二军医大学学报

Objective To investigate the sleep quality and life quality of soldiers in a navy warship troop, and to explore the correlation between sleep quality and life quality and their influencing factors. Methods Random cluster sampling method was used to select navy soldiers from a navy warship troop. The subjects were surveyed by Pittsburgh sleep quality index (PSQI) scale and World Health Organization Quality of Life-Brief scale (WHOQOL-BREF). Results A total of 160 questionnaires were sent out and 154 valid questionnaires were returned (response rate 94.6%). Of 154 subjects, 31.8% (49/154) had good sleep quality, 53.2% (82/154) had moderate sleep quality, and 14.9% (23/154) had poor sleep quality. The soldiers with good sleep quality had significantly higher scores than those with poor sleep quality in physical, psychological, social and environmental domains of life quality (P0.05 or P0.01). Total PSQI score and most of scores of 7 parts of life quality, including subjective sleep quality, sleep latency, sleep time, sleep disturbances, hypnotic drugs, daytime dysfunction and sleep efficiency, were negatively correlated with the scores of 4 domains of sleep quality. There was significant difference in sleep latency of the subjects with the educational level of junior high school, senior high or polytechnic school, junior college, undergraduate college, or graduate degrees (F＝5.368, P0.01), and the subjects with junior college degree had the highest score of sleep latency, while those with undergraduate college degree had the lowest score of sleep latency. Soldiers had a higher score of sleep latency than the officers (t＝2.069, P＝0.040). There was significant difference in the social domain scores of life quality between navy servicemen with military service time 8 years, 3-8 years and ≤2 years (F＝3.401, P＝0.036). Officers had a higher score of social domain than soldiers (t＝－2.093, P＝0.038). Conclusion The sleep quality of navy servicemen should be improved. Improving sleep quality can effectively ameliorate life quality. The sleep quality and life quality of navy servicemen are related to educational levels, work categories and military service time. The corresponding psychological and behavioral intervention should be carried out according to the characteristics of different personnels.

Crew awareness as key to optimizing habitability standards onboard naval platforms: A 'back-to-basics' approach.

BACKGROUND: A healthy habitable environment onboard warships is vital to operational fleet efficiency and fit sea-warrier force. Unique man-machine-armament interface issues and consequent constraints on habitability necessitate a multi-disciplinary approach toward optimizing habitability standards. Study of the basic 'human factor', including crew awareness on what determines shipboard habitability, and its association with habitation specifications is an essential step in such an approach. The aim of this study was to assess crew awareness on shipboard habitability and the association between awareness and maintenance of optimal habitability as per specifications. METHODS: A cross-sectional descriptive study was carried out among 552 naval personnel onboard warships in Mumbai. Data on crew awareness on habitability was collected using a standardized questionnaire, and correlated with basic habitability requirement specifications. Data was analyzed using Microsoft Excel, Epi-info, and SPSS version 17. RESULTS: Awareness level on basic habitability aspects was very good in 65.3% of crew. Area-specific awareness was maximum with respect to living area (95.3%). Knowledge levels on waste management were among the lowest (65.2%) in the category of aspect-wise awareness. Statistically significant association was found between awareness levels and habitability standards (OR = 7.27). CONCLUSION: The new benchmarks set in the form of high crew awareness levels on basic shipboard habitability specifications and its significant association with standards needs to be sustained. It entails re-iteration of healthy habitation essentials into training; and holds the key to a fit fighting force.

Analysis of the casualties aboard warships attacked by anti-ship missiles / 军事医学

In the future,anti-ship missiles(ASM) will be major weapons in the sea war.It is very important to handle the profile of the casualties aboard warships attacked by ASM for development of naval health service.The statistical result shows there is a greater chance of casualties but less chance of warships being sunken by ASM.Besides,medical staffs should pay more attention to the first aid for victims due to blast,burn,smoke inhalation and penetration while the danger of the sea water immersion should not be ignored.

A preliminary study of emergency blood collection during a long-distance voyage / 军事医学

Objective To study the method of emergency blood collection during a long-distance voyage to ensure blood transfusion treatment.Methods Ten voluntary blood donors were recruited, a base unit of blood was collected and preserved.Reactions of the blood donors were observed, and the blood quality was tested.Results The success rate of blood collection was 90% and the qualification rate was 100%.Conclusion Emergency blood collection during a long-distance voyage is feasible,which can help ensure blood supply in peace time or war time.

Injury characteristics and injury analysis in Beagle dogs after multi-cabin explosion / 解放军医学杂志

Objective To investigate the injury characteristics of Beagle dogs after warship multi cabin explosion.Methods Forty-eight adult male Beagle dogs were placed in the simulated blast-cabin and adjacent cabin (24 each),and ammunitions respectively containing 0.75kg TNT and 3.50kg TNT were then detonated in the blast-cabin.The survival situation,fluctuation of vital signs,morphological changes of organs and the incidence of various types of injury of the dogs were observed immediately after the explosion to 24h after injury,and the neurological functions score was performed.Results Twenty dogs died immediately after the explosion,and another 9 dogs died 24h after the explosion.The total mortality was 60.42％(29/48),and the mortalities in blastcabin and adjacent cabin were 79.17％(19/24) and 41.67％(10/24),respectively.The dog's skull was penetrated by bomb fragments,and congestion and bleeding were observed in brain tissue,lung,heart,stomach,bowels,liver and kidneys.Extremities fracture,soft tissue contusions,perforation and rupture were also checked out after explosion.The fatality rate of bomb fragment injury,blast injury and combined bomb fragment-blast injury was 27.59％(8/29),17.24％(5/29) and 55.17％(16/29),respectively.Conclusions The combined bomb fragment-blast injury show high incidence and make high fatality rate and serious injury.Combatants should effectually shield themselves with occluded objects as far as possible to avoid damage and reduce fatality.The key of early treatment is to treat the multiple injuries promptly.Intravenous fluid therapy should be practiced after hemodynamic monitoring.

Fixed and Expanded of Medical Equipments on Warships / 医疗卫生装备

The hospital ship is an important force in medical support. The normal use of medical equipment is prerequisite for effective clinical work. According to the particularity of nautical work, different ways of fixation and expasion with various medical equipments in the warship are proposed in order to satisfy the needs of clinical work.