Impact of IoT System Imperfections and Passenger Errors on Cruise Ship Evacuation Delay.

Cruise ships and other naval vessels include automated Internet of Things (IoT)-based evacuation systems for the passengers and crew to assist them in case of emergencies and accidents. The technical challenges of assisting passengers and crew to safety during emergencies include various aspects such as sensor failures, imperfections in the sound or display systems that are used to direct evacuees, the timely selection of optimum evacuation routes for the evacuees, as well as computation and communication delays that may occur in the IoT infrastructure due to intense activities during an emergency. In addition, during an emergency, the evacuees may be confused or in a panic, and may make mistakes in following the directions offered by the evacuation system. Therefore, the purpose of this work is to analyze the effect of two important aspects that can have an adverse effect on the passengers' evacuation time, namely (a) the computer processing and communication delays, and (b) the errors that may be made by the evacuees in following instructions. The approach we take uses simulation with a representative existing cruise ship model, which dynamically computes the best exit paths for each passenger, with a deadline-driven Adaptive Navigation Strategy (ANS). Our simulation results reveal that delays in the evacuees' reception of instructions can significantly increase the total time needed for passenger evacuation. In contrast, we observe that passenger behavior errors also affect the evacuation duration, but with less effect on the total time needed to evacuate passengers. These findings demonstrate the importance of the design of passenger evacuation systems in a way that takes into account all realistic features of the ship's indoor evacuation environment, including the importance of having high-performance data processing and communication systems that will not result in congestion and communication delays.

Sediment-water distribution and potential sources of polyhalogenated carbazoles in a coastal river locating at a north metropolis, China.

The fate and transformation of PHCZs in the coastal river environment are not yet comprehensively understood. Paired river water and surface sediment were collected, and 12 PHCZs were analyzed to find out their potential sources and investigate the distribution of PHCZs between river water and sediment. The concentration of ∑PHCZs varied from 8.66 to 42.97 ng/g (mean 22.46 ng/g) in sediment and 17.91 to 81.82 ng/L (mean 39.07 ng/L) in river water. 18-B-36-CCZ was the dominant PHCZ congener in sediment, while 36-CCZ was in water. Meanwhile, the logKoc values for CZ and PHCZs were among the first calculated in the estuary and the mean logKoc varied from 4.12 for 1-B-36-CCZ to 5.63 for 3-CCZ. The logKoc values of CCZs were higher than those of BCZs, this may suggest that sediments have a higher capacity for accumulation and storage of CCZs than highly mobile environmental media.

Occurrence and potential sources of polyhalogenated carbazoles in farmland soils from the Three Northeast Provinces, China.

Polyhalogenated carbazoles (PHCZs) have been detected in various environments frequently and have attracted increasing attention for their multiple toxicities. However, only a few reports record the occurrence of PHCZs in farmland soils, and the sources of which were not yet been implemented. In this study, 12 PHCZs and carbazole (CZ) were screened in farmland soil samples from the Three Northeast Provinces, and the ∑PHCZs were in the range of 18.16-219.67 ng/g dw. 36-CCZ was the dominant congener (40.67%) in farmland soils, followed by 3-CCZ (14.51%), and average percentages of other congeners were lower than 10%. A concrete analysis of the sources of PHCZs in the soil was conducted, revealing the diversity of PHCZs sources. Potential toxic effects associated with the levels of PHCZs were evaluated via the toxic equivalency (TEQ) approach, and the TEQs of PHCZs (TEQPHCZs) were in the range of 2.24-14.06 pg TEQ/g dw. Notwithstanding the 1368-CCZ with a low concentration level, the mean contribution to TEQPHCZs was up to 24.24%, preceded only by 36-CCZ (39.69%), showing the congeners with low concentration also may pose potential risks to the environment. Partial PHCZs congeners (2-BCZ, 3-BCZ, 36-CCZ, 136-BCZ, and 2367-BCZ) showed significant correlations (r = 0.45-0.63, p < 0.05) with the total organic carbon (TOC). Significant correlations were shown between PHCZ congeners replaced by halogens of the same species and quantity (r = 0.40-0.99, p < 0.01). In view of the fact that the high concentration level of PHCZs in the soil and their source diversity, more environmental monitoring and risk assessments of PHCZs should be of particular concern.

Fungal Community Composition and Diversity Vary With Soil Horizons in a Subtropical Forest.

Soil fungal communities, which drive many ecosystem processes, vary across soil horizons. However, how fungal communities are influenced by soil horizon layers remains largely unstudied. In this study, soil samples were collected from the organic horizon (O horizon) and mineral matter horizon (M horizon) in two sites of Dabie Mountain, China, and the effects of the two horizons on the soil fungal community composition were assessed based on Illumina MiSeq sequencing. Our results showed that soil fungal community composition varied with soil horizons, and soil fungal species richness and diversity in the O horizon were significantly higher than that in the M horizon. Total organic carbon (TOC), total organic nitrogen (TON), alkali-hydrolyzable nitrogen (AHN), available potassium (AK), and available phosphorus (AP) significantly influenced fungal community composition, abundance, and diversity across the two horizons (P < 0.05). Furthermore, precipitation was found to have a significant effect on fungal community composition. Our results demonstrate changes in fungal communities across soil horizons and highlight the importance of soil organic matter on fungal communities and diversity.

A pilot behavioural and neuroimaging investigation on photothrombotic stroke models in rhesus monkeys.

BACKGROUND: Ischemic stroke leads to a long-term disability in humans and no efficient clinical therapy exists to date. The middle cerebral artery occlusion (MCAO) model in non-human primates has shown to be of value for translational stroke research. New method In the current study, a photothrombotic (PT) stroke model was established in rhesus monkeys with either a proximal or distal segment of middle cerebral artery (MCA) thrombosis. This study is the first that compares the two approaches of PT stroke in monkeys using behavioral and physiological measurements and MRI scans. RESULTS: The experiment found that infarct occurred in the MCA target regions, with all monkeys having impaired behavior reflected by deficits in neurologic function, and motor and cognition in object retrieval detour (ORD) task. The monkeys with distal MCA thrombosis developed with sequential photo-irritations of the Sylvian fissure zone, adjacent central anterior gyrus and central posterior gyrus, had similar impairments with respect to behavior and showed a tendency of a small edema volume with proximal MCA thrombosis at days 4 and 7 post PT stroke. COMPARISON WITH EXISTING METHODS: The distal MCA thrombosis developed with sequential photo-irritations might provide a consistent and well-tolerated focal ischemia in rhesus monkeys, compared with other PT stroke models which usually were singly conducted on the animal's motor cortex and had a temporal effect. CONCLUSIONS: The sequentially photo-irritated PT stroke model is a promising ischemic stroke model in rhesus monkey for studying human stroke pathology and physiology and for new therapies development.

Extracellular Vesicle-Mediated Delivery of Circular RNA SCMH1 Promotes Functional Recovery in Rodent and Nonhuman Primate Ischemic Stroke Models.

BACKGROUND: Stroke is a leading cause of adult disability that can severely compromise the quality of life of patients, yet no effective medication currently exists to accelerate rehabilitation. A variety of circular RNA (circRNA) molecules are known to function in ischemic brain injury. Lentivirus-based expression systems have been widely used in basic studies of circRNAs, but safety issues with such delivery systems have limited exploration of the potential therapeutic roles for circRNAs. METHODS: Circular RNA SCMH1 (circSCMH1) was screened from the plasma of patients with acute ischemic stroke by using circRNA microarrays. Engineered rabies virus glycoprotein-circSCMH1-extracellular vesicles were generated to selectively deliver circSCMH1 to the brain. Nissl staining was used to examine infarct size. Behavioral tasks were performed to evaluate motor functions in both rodent and nonhuman primate ischemic stroke models. Golgi staining and immunostaining were used to examine neuroplasticity and glial activation. Proteomic assays and RNA-sequencing data combined with transcriptional profiling were used to identify downstream targets of circSCMH1. RESULTS: CircSCMH1 levels were significantly decreased in the plasma of patients with acute ischemic stroke, offering significant power in predicting stroke outcomes. The decreased levels of circSCMH1 were further confirmed in the plasma and peri-infarct cortex of photothrombotic stroke mice. Beyond demonstrating proof-of-concept for an RNA drug delivery technology, we observed that circSCMH1 treatment improved functional recovery after stroke in both mice and monkeys, and we discovered that circSCMH1 enhanced the neuronal plasticity and inhibited glial activation and peripheral immune cell infiltration. CircSCMH1 binds mechanistically to the transcription factor MeCP2 (methyl-CpG binding protein 2), thereby releasing repression of MeCP2 target gene transcription. CONCLUSIONS: Rabies virus glycoprotein-circSCMH1-extracellular vesicles afford protection by promoting functional recovery in the rodent and the nonhuman primate ischemic stroke models. Our study presents a potentially widely applicable nucleotide drug delivery technology and demonstrates the basic mechanism of how circRNAs can be therapeutically exploited to improve poststroke outcomes.

Study on the Methods of Separation and Detection of Chelates.

The separation and purification techniques of chelates can improve the accuracy of detecting results of the chelation rate. As a quantitative indicator of metal ion chelates, the chelation rate can not only reflect the completion of chelation but also determine the amount of metal ions in different forms. The determination of chelation rate can help to determine the suitable chelating reaction conditions, make theoretical basis for the fertilizer efficiency, analyze the stability of chelating fertilizers and study the action mechanism of trace elements. In our study, the methods of separation free metal ions from mixture were reviewed first, including gel filtration chromatography, organic solvent precipitation, ion exchange chromatography, membrane separation and high performance liquid chromatography. Then, the qualitative analysis methods of chelates were introduced briefly, including chemical identification, infrared spectroscopy, ultraviolet spectroscopy. A detailed overview of the quantitative determination methods of chelates were also shown, such as ethylenediaminetetraacetic acid titration, chemical titration, atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry, inductively coupled plasma mass spectrometry, spectrophotometric, chemical modified electrode. In addition, the merits and demerits of chelated rate determination methods of various determination methods were analyzed, and summarized the applicability of various methods, which provided a theoretical basis for optimizing chelating process, characterizing the structure of chelates and analyzing the mechanism of chelating fertilizer. The current methods of measuring chelation rate were also summarized and prospected.

Noncoherent Decision Fusion over Fading Hybrid MACs in Wireless Sensor Networks.

In this paper, we consider the problem of decision fusion for noncoherent detection in a wireless sensor network. Novel to the current work is the integration of the hybrid multi-access channel (MAC) in the fusion rule design. We assume that sensors transmit their local binary decisions over a hybrid MAC which is a composite of conventional orthogonal and nonorthogonal MACs. Under Rayleigh fading scenario, we present a likelihood ratio (LR)-based fusion rule, which has been shown to be optimal through theoretical analysis and simulation. However, it requires a large amount of computation, which is not easily implemented in resource-constrained sensor networks. Therefore, three sub-optimal alternatives with low-complexity are proposed, namely the weighed energy detector (WED), the deflection-coefficient-maximization (DCM), and the two-step (TS) rules. We show that when the channel signal-to-noise ratio (SNR) is low, the LR-based fusion rule reduces to the WED rule; at high-channel SNR, it is equivalent to the TS rule; and at moderate-channel SNR, it can be approached closely by the DCM rule. Compared with the conventional orthogonal and nonorthogonal MACs, numerical results show that the hybrid MAC with the proposed fusion rules can improve the detection performance when the channel SNR is medium.

Maritime Transportation Risk Assessment of Tianjin Port with Bayesian Belief Networks.

This article develops a Bayesian belief network model for the prediction of accident consequences in the Tianjin port. The study starts with a statistical analysis of historical accident data of six years from 2008 to 2013. Then a Bayesian belief network is constructed to express the dependencies between the indicator variables and accident consequences. The statistics and expert knowledge are synthesized in the Bayesian belief network model to obtain the probability distribution of the consequences. By a sensitivity analysis, several indicator variables that have influence on the consequences are identified, including navigational area, ship type and time of the day. The results indicate that the consequences are most sensitive to the position where the accidents occurred, followed by time of day and ship length. The results also reflect that the navigational risk of the Tianjin port is at the acceptable level, despite that there is more room of improvement. These results can be used by the Maritime Safety Administration to take effective measures to enhance maritime safety in the Tianjin port.