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Three new aconitine-type C 19 -diterpenoid alkaloids, richardsonines A-C (1–3), were isolated from the roots of Aconitum richardsonianum Lauener, together with seventeen known compounds (4–20). Their structures were elucidated by extensive spectroscopic analysis, and the absolute stereochemistry of 1 was confirmed by X-ray crystallography. Compounds 2 , 5 , 8 and 9 were rare C 19 -diterpenoid alkaloids bearing an OH group at C-16. Isolated compounds were evaluated for inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated neuroinflammatory responses in BV-2 microglial cells. Compounds 3 and 7 showed weak antineuroinflammatory effects with inhibition rates of 35.32 ± 2.29% and 39.94 ± 2.50%, respectively, at a concentration of 100 µM. [Display omitted] • Three new diterpenoid alkaloids were isolated from A. richardsonianum. • Richardsonine B is a rare C 19 -diterpenoid alkaloid bearing a C 16 -OH moiety. • The antineuroinflammatory effects of the isolated compounds were evaluated. [ABSTRACT FROM AUTHOR]

Crashworthiness is the ability of civil aircraft fuselage structure and internal systems to maximum protect the occupants' safety in a crash or emergency landing event, and is an important embodiment of the civil aircraft safety, which can determine the occupant survivability to a certain extent. The crashworthiness is dominated by the crash response characteristics of typical fuselage section (including occupant/seat restraint system), and the crashworthiness evaluation mainly includes fuselage structural response evaluation and occupant injury evaluation. Firstly, the crashworthiness requirements are sorted out according to the Airworthiness Standards of transport category airplanes and Special Conditions, and the research work on drop tests and crashworthiness numerical simulation of fuselage section are gathered. Then, the failure of typical skin-stringer-frame structures and fuselage section are analyzed, and the crash safety evaluation criteria are summarized. After that, the impact tolerance of various parts of human (head, neck, thoracic, spine, abdomen, extremity) and the occupant injury evaluation criteria are summarized. In addition, the crashworthiness design principles and design methods of fuselage section are outlined for occupant survivability. Finally, the crashworthiness evaluation under different crash factors and conditions (impact velocity, impact ground, cargo loading and aircraft wing position) are summed up, and the aircraft crashworthiness is comprehensively evaluated through integrating the survivable volume, the retention strength, the occupant injury and the emergency evacuation, and the crashworthiness evaluation process is outlined. This article is intended as a comprehensive literature review of crashworthiness design and evaluation of fuselage structure for occupant survivability. [ABSTRACT FROM AUTHOR]

Drug repurposing is an effective method to reduce the time and cost of drug development. Computational drug repurposing can quickly screen out the most likely associations from large biological databases to achieve effective drug repurposing. However, building a comprehensive model that integrates drugs, proteins, and diseases for drug repurposing remains challenging. This study proposes a drug repurposing method based on the ternary heterogeneous graph attention network (DRTerHGAT). DRTerHGAT designs a novel protein feature extraction process consisting of a large-scale protein language model and a multi-task autoencoder, so that protein features can be extracted accurately and efficiently from amino acid sequences. The ternary heterogeneous graph of drug-protein-disease comprehensively considering the relationships among the three types of nodes, including three homogeneous and three heterogeneous relationships. Based on the graph and the extracted protein features, the deep features of the drugs and the diseases are extracted by graph convolutional networks (GCN) and heterogeneous graph node attention networks (HGNA). In the experiments, DRTerHGAT is proven superior to existing advanced methods and DRTerHGAT variants. DRTerHGAT's powerful ability for drug repurposing is also demonstrated in Alzheimer's disease. [Display omitted] • A protein features extraction process was proposed to obtain the high-quality features of the protein. • A drug repurposing model based on the ternary heterogeneous graph attention network (DRTerHGAT) was proposed. • It was found that Tolcapone and Miglustat have the possibility of treating Alzheimer's disease (AD). [ABSTRACT FROM AUTHOR]

Background: Refractory epilepsy confers a considerable lifetime risk of sudden unexplained death in epilepsy (SUDEP). Mechanisms may overlap with sudden cardiac death (SCD), particularly regarding QTc prolongation. Guidelines in the United States do not mandate the use of electrocardiography (ECG) in diagnostic evaluation of seizures or epilepsy.Objective: The purpose of this study was to determine the frequency of ECG use and of QT prolongation, and whether QT prolongation predicts mortality in patients with seizures.Methods: We performed a retrospective cohort study including all patients seen at Mayo Clinic in Rochester, Minnesota, from January 1, 2000, to July 31, 2015, with index evaluation for seizure or epilepsy. Patients with an ECG were categorized by the presence of a prolonged QT interval with a primary endpoint of all-cause mortality after the 15-year observation period.Results: Optimal cutoff QT intervals most predictive of mortality were identified. Median age was 40.0 years. An ECG was obtained in 18,222 patients (57.4%). After patients with confounding ECG findings were excluded, primary prolonged QT intervals were seen in 223 cases (1.4%), similar to the general population. Kaplan-Meier analysis demonstrated a significant increase in mortality (Cox hazard ratio [HR] 1.90; 95% confidence interval [CI] 1.76-2.05) for prolonged optimal cutoff QT, maintained after adjustments for age, Charlson comorbidity index, and sex (HR 1.48; 95% CI 1.37-1.59).Conclusion: Use of ECG in diagnostic workup of patients with seizures is poor. A prolonged optimal cutoff QTc interval predicts all-cause mortality in patients evaluated for seizure and those diagnosed with epilepsy. We advocate the routine use of a 12-lead ECG at index evaluation in patients with seizure or epilepsy. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.comnet.2006.06.014 Byline: Shantidev Mohanty (a), Jiang Xie (b) Keywords: Architecture; Heterogeneous wireless systems; Authentication; Vertical handoff Abstract: Current wireless world witnesses multiple heterogeneous systems such as Bluetooth, IEEE 802.11, UMTS, and satellite networks. These systems are envisioned to coordinate with each other to provide ubiquitous communications to mobile users. A novel architecture, Architecture for ubiquitous Mobile Communications (AMC), is introduced in this paper that integrates these heterogeneous wireless systems. AMC eliminates the need for direct Service Level Agreements (SLAs) among service providers by using a third party, Network Inter-operating Agent (NIA). Instead of developing a new architecture, AMC extends the existing infrastructure to integrate heterogeneous wireless systems. It uses IP as the inter-connection protocol to provide transparency to the heterogeneities of individual systems. Third-party-based authentication and billing algorithms are designed for AMC. New handoff management protocols are also designed to support seamless vertical handoffs between different wireless systems in AMC. Performance analysis is carried out to determine the latency associated with vertical handoffs and the load on the NIA that arises because of these vertical handoffs. Toward this, a network deployment scenario that consists of three types of wireless systems: WLAN, 3G, and satellite networks is considered. Moreover, the number of SLAs required in AMC is also determined for a given number of network operators. It is also shown that by using hierarchical structure, AMC can realize the integration of heterogeneous wireless systems around the globe. Author Affiliation: (a) Intel Corporation, 2111 NE 25th Ave, Mail Stop JF3-336, OR 97124, United States (b) Department of Electrical and Computer Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223, United States Article History: Received 23 March 2005; Revised 22 May 2006; Accepted 15 June 2006 Article Note: (miscellaneous) Responsible Editor: B. Baykal

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.comnet.2005.06.001 Byline: Janise McNair (a), Tuna Tugcu (b), Wenye Wang (c), Jiang (Linda) Xie (d) Keywords: Mobile IP; Mobility; Authentication; Handoff Abstract: Among the characteristics of future wireless networks is the desire to support a wide range of wireless users and a diverse set of services from many different types of networks. One of the most often referenced networking protocols for diverse wireless and mobile networking is Mobile IP. Although recent focus has been on developing a micro-mobility architecture for Mobile IP, an emerging need is to enhance the unifying performance of Mobile IP by using a cross-layer, cross-technology, approach to protocol design, in order to serve a wide variety of users, services and networks. This paper provides a survey of recently proposed performance enhancements for Mobile IP and discusses the impact on network-level performance. After a review of the Mobile IP architecture, recent research on reducing handoff latency is discussed, including the use of layer 2 hints. Then, location registration is explored, including new techniques for authentication of mobile users. Finally, an overview of performance analysis models is provided to show the most recent approaches to determining the impact of mobility on a given network. Author Affiliation: (a) Department of Electrical and Computer Engineering, University of Florida, P.O. Box 116130, Gainesville, FL 32611, United States (b) Department of Computer Engineering, Bogazici University, TR-34342 Istanbul, Turkey (c) Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC 27695, United States (d) Department of Electrical and Computer Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223, United States Article History: Received 16 May 2005; Revised 7 June 2005; Accepted 7 June 2005 Article Note: (miscellaneous) Responsible Editor: Dr. I.F. Akyildiz

Unstable plaques can cause acute cardiovascular and cerebrovascular diseases. The stability and instability of plaque are related to the plaque echo status in ultrasound. Carotid videos provide detailed plaque information compared to static images. Ultrasound-based plaque echo classification is challenging due to noise, interference frames, small targets (plaques), and complex shape changes. This study proposes a Multi-dimensional Aggregation Network (MA-Net) guided by key features for plaque diagnosis based on carotid ultrasound video, which uses only video-level labels. MA-Net consists of Key-Feature (KF) and Temporal-Channel-Spatial (TCS) modules. The KF module learns the contribution of each frame to the classification at the feature level, adaptively infers the importance score of each frame, thereby reducing the influence of interference frames. The TCS module includes the Temporal-Channel (TC) and Temporal-Spatial (TS) sub-modules. In addition to studying the temporal dimension, it delves into the relationship between the channel and spatial dimensions. TC analyses the temporal dependencies among the channels and filters noise. Moreover, TS extracts features more accurately through the spatio-temporal information contained in the surrounding environment of the plaque. The performance of MA-Net on the SHU-Ultrasound-Video-2020 dataset is better than that of the state-of-the-art models of video classification, showing at least a 5% increase in accuracy, with an accuracy rate of 87.36%. The outstanding diagnostic capability of the proposed model will help provide a more robust and reproducible diagnostic process with a lower labour cost for clinical carotid plaque diagnosis. • Echo classification of plaques in ultrasound videos is provided. • Propose Key-Feature (KF) module learns the contribution of each frame to the classification. • Propose Temporal Channel Spatial (TCS) module aggregates three-dimensional temporal-channel-spatial features from plaque. • Validates the effectiveness using Grad-CAM. [ABSTRACT FROM AUTHOR]

The interaction of multiple drugs could lead to severe events, which cause medical injuries and expenses. Accurate prediction of drug–drug interaction (DDI) events can help clinicians make effective decisions and establish appropriate therapy programs. However, there exist two issues worthy of further consideration. (i) The global features of drug molecules should be paid attention to, rather than just their local characteristics. (ii) The fusion of multi-source features should also be studied to capture the comprehensive features of the drug. This study designs a M ulti- S ource F eature F usion framework with M ultiple A ttention blocks named MSFF-MA-DDI that utilizes multimodal data for DDI event prediction. MSFF-MA-DDI can (i) encode global correlations between long-distance atoms in drug molecular sequences by a self-attention layer based on a position embedding block and (ii) fuse drug sequence features and heterogeneous features (chemical substructure, target, and enzyme) through a multi-head attention block to better represent the features of drugs. Experiments on real-world datasets show that MSFF-MA-DDI can achieve performance that is close to or even better than state-of-the-art models. Especially in cold start scenarios, the model can achieve the best performance. The effectiveness of the model is also supported by the case study on nervous system drugs. The source codes and data are available at https://github.com/BioCenter-SHU/MSFF-MA-DDI. • A multi-source feature fusion method named MSFF-MA-DDI is proposed for predicting DDI events. • Long-distance atoms relationships reflect the global features of the drug molecule sequence. • A self-attention block based on position embedding is built to obtain drug sequence features. • The experimental results show that MSFF-MA-DDI achieves good performance. [ABSTRACT FROM AUTHOR]

• ASV appears to not reduce mortality in patients with concomitant CSA and HF with extremely low LVEF. • CSA patients with severe hypoxemia had decreased risk of MACEs after ASV therapy. • MACEs were reduced by ASV treatment in CSA subjects with less severe HF. • Beneficial effects of ASV were not evident in RCTs but in observational studies. Despite the efficacy of adaptive servo-ventilation (ASV) in suppressing central sleep apnea (CSA), its impact on long-term outcomes is debatable. We aim to identify subjects with specific features who might benefit from ASV therapy. Randomized clinical trials and comparative observational studies investigating the effects of ASV on cardiovascular (CV) and all-cause mortality and major adverse cardiovascular events (MACEs) in CSA patients were searched from PubMed, EMBASE, Cochrane library and Web of Science. Eligible studies were identified with relative risks (RR) of death and MACEs compared between patients treated by ASV and usual care. A total of eight studies (three randomized controlled trials and five observational studies) including 2208 participants were selected for analysis. All-cause and CV mortality were not significantly reduced by ASV. Patients with nadir nocturnal saturation ≤ 80% (mean value) had lower risk of MACEs by ASV treatment compared with by usual care (RR, 0.18; p < 0.001). Patients with severe heart failure (HF), defined as left ventricular ejection fraction (LVEF) ≤ 33% (mean value), or HF of New York Heart Association (NYHA) classification of III/IV, did not have reduced risk of MACEs post ASV therapy. However, subjects with LVEF > 33% (RR, 0.35; p < 0.001) or NYHA Ⅰ/Ⅱ (RR, 0.35; p < 0.001) had significantly lower risk of MACEs by using ASV than by usual care. Although ASV appears to not reduce CV and all-cause death for HF patients with extremely low LVEF, those with profound CSA associated hypoxemia or less severe HF still benefit from ASV therapy. [ABSTRACT FROM AUTHOR]

Growing evidence indicates that both obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD) may be closely associated with the prevalence of pulmonary embolism (PE). However, the relationship of overlap syndrome (OS) (coexistence of OSA and COPD) with PE is unclear. The purpose of this study was to investigate whether OS were associated with increased PE prevalence. We performed a retrospective chart review of patients who underwent sleep study at Beijing An Zhen Hospital from 2011 to 2014. The association of OS with PE prevalence was estimated by using logistic regression models. In contrast to control patients (neither OSA nor COPD), those subjects with OS had higher odds of PE (OR9.61; 95%CI 4.02–21.31, p < 0.001) with significance persisting after adjusting for covariates (OR 5.66; 95%CI 1.80–16.18, p = 0.004). Meanwhile, patients with OS compared with those with isolated OSA also had significantly higher odds of PE in univariate (OR 4.79; 95%CI 2.04–10.33, p = 0.0007) and adjusted models (OR 3.89; 95%CI 1.27–10.68, p = 0.019). In subgroup analysis, patients with OS had higher odds of PE than control group among male subjects (OR 8.12, 95%CI1.86–31.87, p = 0.007) and patients ≥ 58years (OR 5.50, 95%CI 1.51–18.14, p = 0.012) in multivariable models. Percentage of total sleep time with saturation lower than 90% (T90) ≥ 2.6% was significantly associated with prevalence of PE (OR 4.72, 95%CI1.34–19.83, p = 0.015) in subgroup of patients older than 58. OS is independently associated with PE prevalence. Longitudinal studies are needed to better understand the relationship with incident PE. [ABSTRACT FROM AUTHOR]

For Chinese sucker (Myxocyprinus asiaticus), passing through a dam with fast flow and cold water are always unavoidable, and this process can cause stress, disease or even death. In this study, comparative transcriptome analysis was conducted to investigate the potential immune mechanism in head kidney of M. asiaticus with swimming fatigue stress and cold stress after fatigue. In general, a total of 181,781 unigenes were generated, and 38,545 differentially expressed genes (DEGs) were identified. In these DEGs, 22,593, 7286 and 8666 DEGs were identified among groups of fatigue vs. cold, control vs. cold, and control vs. fatigue, respectively. Enrichment analysis revealed these DEGs were involved in coagulation cascades and complement, natural killer cell mediated cytotoxicity, antigen processing and presentation, Toll-like receptor signaling pathways, and chemokine signaling pathway. Notably, immune genes including heat shock protein 4a (HSP4a), HSP70 and HSP90α genes were significantly up-regulated in fishes with cold stress after fatigue. Differently, more immune genes in control vs. cold compared with that in control vs. fatigue were significantly down-regulated expression, such as claudin-15-like, Toll-like receptor 13, antimicrobial peptide (hepcidin), immunoglobulin, CXCR4 chemokine receptor, T-cell receptor, complement factor B/C2-A3, and interleukin 8. In this study, the number of DEGs in the head kidney was less than that our previous study in the spleen, which we speculated was more sensitive to changes in water temperature than the head kidney. In summary, lots of immune-related genes in the head kidney were down-regulated under cold stress after fatigue, suggesting that M. asiaticus might have experienced severe immunosuppression in the process of passing through the dam. [Display omitted] • The expression of immune-related gene is suppressed after swimming fatigue stress and cold stress after fatigue in the head kidney of Chinese sucker. • Swimming fatigue stress and cold stress after fatigue affected the immune function of fish. • Comparison of the DEGs between head kidney and spleen, we speculated that the spleen is more sensitive to changes in water temperature than the head kidney. [ABSTRACT FROM AUTHOR]

[Display omitted] • The biosynthesis parameters of holoferritin were systematically studied. • The iron core of in vivo synthesized holoferritin is mainly composed of ferrihydrite and FeOOH. • The iron content of synthesized holoferritin is up to ∼ 2500 Fe3+/ferritin. • Three steps might be involved in the generation of iron core. Natural holoferritin, containing average 2000 Fe3+/ferritin, has been considered as promising iron supplementary in food and medical science. However, the low extraction yields highly limited its practical application. Herein, we provided a facile strategy for holoferritin preparation through in vivo microorganism-directed biosynthesis, and the structure, iron content, and the composition of iron core have been investigated. The results revealed that in vivo biosynthesized holoferritin possesses great monodispersity and water-solubility. In addition, the in vivo biosynthesized holoferritin contains a comparative iron content as compared to natural holoferritin, giving the ratio of ∼ 2500 iron/ferritin. Besides, the composition of iron core has been identified as ferrihydrite and FeOOH, and three steps might be involved in iron core formation. This work highlighted that the microorganism-directed biosynthesis could be an efficient strategy for preparation of holoferritin, which might be beneficial for its practical application for iron supplementation. [ABSTRACT FROM AUTHOR]

Clustering analysis has been widely used in many fields such as image segmentation, pattern recognition, data analysis, market researches and so on. However, the distribution patterns of clusters are natural and complex in many research areas. In other words, most real data sets are non-spherical or non-elliptical clusters. For example, face images and hand-writing digital images are distributed in manifolds and some biological data sets are distributed in hyper-rectangles. Therefore, it is a great challenge to detect clusters of arbitrary shapes in multi-density datasets. Most of previous clustering algorithms cannot be applied to complex patterns with large variations in density because they only find hyper-elliptical and hyper-spherical clusters through centroid-based clustering approaches or fixed global parameters. This paper presents DCNaN, a clustering algorithm based on the density core and the natural neighbor to recognize complex patterns with large variations in density. Density cores can roughly retain the shape of clusters and natural neighbors are introduced to find dynamic scanning radiuses rather than fixed global parameters. The results of our experiments show that compared to state-of-the-art clustering techniques, our algorithm achieves better clustering quality, accuracy and efficiency, especially in recognizing extremely complex patterns with large variations in density. [ABSTRACT FROM AUTHOR]

The risk assessment of carotid plaque is strongly related to the plaque echo status in ultrasound. However, the echo classification of carotid plaques based on ultrasound remains challenging due to the changes in plaque shape and semantics, along with the complex vascular environment. This study proposed a framework for Classification of Plaque by Tracking Videos (CPTV). To the best of our knowledge, this is the first study on plaque classification by tracking ultrasound video rather than a sonographic view, which achieves accurate localization and stable echo classification. In the tracking task, Multi-scale Decoupling Tracking (MDTrack) module including Multi-scale Dilated Encoder (MDE) and Internal-Exterior Feature Decoupling (IEFD) was proposed to solve the problems caused by shape and semantic variations to achieve accurate plaque localization in ultrasound. In the classification task, the Tracking-assisted 3D Attention (T3D-Attention) module included recombination and 3D-Attention extracted plaque features and echo-related features in the vascular environment. The experiments demonstrated that the performance of CPTV is better than current mainstream tracking and classification methods, indicating that the tracking-assistance classification is a kind of enhancement method with high universality and stability in the plaque in ultrasound. • Echo classification of plaques in ultrasound videos is provided. • This is the first study to deeply combine plaque tracking and classification. • This framework is robust in identifying plaques with inconsistent echo in video. [ABSTRACT FROM AUTHOR]

This study investigates the specific impacts of competition on operational efficiency of China's coastal ports. Firstly, we use Data Envelopment Analysis (DEA) to calculate the scores of operational efficiency of selected China's coastal ports from 2010 to 2019. Findings are as follows: (1) except for an individual port (Lianyungang port), the scores of most ports are overall above 0.8; (2) Ports have significant gaps in scores. Secondly, we use panel data model to analyse the specific effects of competition on operational efficiency, and obtain three notable points: (1) Competition among China's coastal ports is relatively intense from 2010 to 2019; (2) Competition improves the operational efficiency of ports; (3) Port size is used more than the production technology and the level of operation and management to improve operational efficiency before 2014, while the opposite is true after 2014. [ABSTRACT FROM AUTHOR]

The alignment of protein interaction networks (PINs) could help reveal similar subnetworks that may play important roles in biology. However, it is challenging to visualize the network alignment, especially for those large-scale PINs. In this work, we present a tool, namely FMA-finder, which can visualize large-scale network alignments between different species. Moreover, instead of focusing on the protein pairs to detect functional homologies, functional module alignment (FMA) is proposed in this study. FMAs are biologically meaningful because they are pairs of subnetworks sharing similar functions. The FMA-finder tool provides both analysis and visualization of FMAs. Experiments on the alignment between Homo sapiens and Saccharomyces cerevisiae protein interaction networks demonstrate that our FMA-finder can visualize and analyze large-scale network alignments. [ABSTRACT FROM AUTHOR]

Studying seed dispersal and the associated processes of germination, seedling establishment and survival are important for understanding plant regeneration dynamics and dispersal ability, especially for introduced plant species. Rubber trees ( Hevea brasiliensis ) have been introduced and cultivated in Xishuangbanna in southwest China for over 60 years. However, almost no adult rubber trees occur in natural forests in the region. In order to determine the factors preventing the expansion of rubber trees into natural forests, we investigated the seed dispersal, seed germination and seedling recruitment of rubber trees. Rubber seeds released in natural forests were frequently visited and largely handled by Rattus spp., but the rubber seeds released in rubber plantations were seldom visited or fetched by any animals, indicating that habitat type had a significant effect on the fate of rubber seeds ( P < 0.001). The majority of released rubber seeds were eaten (57.80% in 2012, N = 5795; 64.45% in 2013, N = 12,455) and only a very few seeds were cached under forest litter or soil surface (0.32% in 2012 and 0.16% in 2013). When missing seeds (about 30% of all released seeds) were omitted in the analysis, it was found that the majority of the seeds were removed within 10 m (60–90% in different years and different sites), and only few seeds were transported to more than 30 m (maximum distance was 55 m in 2012 and 67 m in 2013). Rubber seeds buried in natural forests had a lower germination rate (mean ± SE = 11.67 ± 2.11%, N = 300) compared to those in rubber plantations (mean ± SE = 44.33 ± 4.25%, N = 300) (one-way ANOVA, P < 0.01). Results from our seed germination experiment and natural regeneration survey showed that rubber seedlings had a very low survival rate, both in natural forests and in rubber plantations. Poor seed dispersal, seed germination and seedling survival may explain why rubber trees do not expand into the natural forests in Xishuangbanna. The findings of this study can help to better understand the natural dispersal ability and regeneration dynamics of rubber trees, providing insights important for forest conservation planning. [ABSTRACT FROM AUTHOR]

For nearly half a century, plasticity has been a controversial issue in ecology and evolution. Observed plasticity was classically quantified as the slope of a reaction norm or quantified in time series, which concealed its relationship with body size. With a theoretical framework and an experiment, here we demonstrated that: (1) body size significantly contributes to nearly all traits’ variability, which produces apparent, but not true plasticity; (2) the classical reaction norm seriously misestimates the origins and levels of plasticity, and a size-correction to the reaction norm can eliminate its size-dependency and leave only the environmental-induced plasticity; and (3) the absence of true plasticity in beneficial traits can be compensated for by true plasticity in compensating traits. This study emphasizes that the role of true plasticity varies throughout ontogeny. It also suggests that the classical reaction norm or function-valued traits needs to be integrated with body size (i.e., size serial analysis) when we evaluate environmental effects on phenotypes. [ABSTRACT FROM AUTHOR]

Gas flow in shale gas reservoirs occurs primarily from ultra low permeability shale rocks through a complex network of natural and induced hydraulic fractures. Consequently, fracture parameters (conductivity and half length), fracture location and distribution are the dominant factors influencing well drainage volumes and shale gas well performance. Stimulated reservoir volume or SRV, estimated from microseismic event clouds or rate/pressure transient analysis, describes a measurement of overall reservoir volume impacted by fracture treatments. With SRV as well as the dynamic production/pressure response, reservoir simulation models can be calibrated to actual well performance in shale gas reservoirs leading to improved understanding, forecasting and future well placement. In this paper, we first introduce a novel approach for computing well drainage volume for shale gas wells with multistage fractures and fracture clusters. Next, we calibrate the shale gas reservoir model by matching the drainage volume with the SRV within specified confidence limits. The matching of the SRV is done in addition to the traditional history matching of production/pressure response and further constrains the estimation of fracture parameters. An evolutionary algorithm with design of experiments is used for the assisted history matching. Sensitivities to various parameters such as fracture conductivity, fracture half lengths and rock compaction have also been investigated. The proposed approach has been applied to a generic shale gas well designed after a real field case. The results clearly indicate the benefits of including SRV during history matching, leading to improved fracture/matrix parameter estimation and performance forecasting. Our proposed approach provides an important tool that can be used to optimize well placement, fracture treatments and improve the economics of shale gas plays. [ABSTRACT FROM AUTHOR]

This paper presents an experimental and analytical study on the low-damage performance of a steel rocking column-base joint equipped with an asymmetric friction connection (AFC). The AFC is located at the web of the column base with a frictional sliding surface parallel to the weak axis of the column. Cyclic tests with and without axial forces were carried out along strong axis of the column, including initial, aftershock and repair cases. It was found that in the absence of axial force, the column was completely uplifted after unloading, while in the presence of axial force, the joint could be self-centered. The presence of axial force provided a good tendency for the self-centering capacity of the joint. Resilience of the joint is achieved by simply re-tightening the bolts, and its seismic performance can be well matched to the initial run without loss of strength and stiffness. A finite element model was developed to investigate the stress distribution and frictional sliding behavior of the joint. The low-damage characteristics exhibited by the joint were verified at a high drift ratio of 3%. Finally, a simplified flag-shaped analytical model was proposed to predict the mechanical behavior of this type of column-base joint. [Display omitted] • A new type of rocking column-base joint with asymmetric friction connection was proposed. • Low-damage performance of the joint was investigated and verified under cyclic loading along strong axis. • An FE model of the rocking column-base joint with AFC was developed. • A simplified flag-shaped analytical model was proposed. [ABSTRACT FROM AUTHOR]

• Crash characteristics of fuselage section is studied through vertical drop test. • Occupants' head and lumbar spine injury, and pelvic acceleration are analyzed. • Crashworthiness is evaluated based on occupant response and survivability. • Crashworthiness design is analysis based on failure mode of fuselage section. To utilize computational techniques in investigate and evaluate the crashworthiness of typical fuselage section of a large transport aircraft in various crash scenarios, the finite element model of fuselage section was modeled and validated based on the vertical drop test of fuselage section at 6.02 m/s. The crash simulation analysis in various crash scenarios (such as concrete ground, soft soil grounds and water) were further conducted based on the validated model of fuselage section, and the crash response characteristics (deformation and failure mode, acceleration response and occupant injury risk, energy-absorbing characteristics) were analyzed and compared. The results show that the finite element model can accurately simulate the unrolling failure mode (three plastic hinges failure mode) of fuselage section and the failure of the connections of cargo floor crossbeams and fuselage frames, and it is in good agreement with the test results in terms of impact velocity and acceleration response. In the case of various soft soil grounds impact scenarios, the partial impact energy is absorbed by the soft soil ground, resulting in slightly different failure modes of fuselage section and a reduction in the peak acceleration. The water-entry impact failure mode of fuselage section is consistent with the rigid ground impact failure mode, the overall deformation degree of fuselage section decreases, but the degree of bending and upturning of fuselage frames increases with the increasing of the water-entry impact velocities The safety of occupants can be effectively protected in the soft soil ground and water-entry impact scenarios. The unrolling failure mode of fuselage section can be changed to the flattening failure mode (multiple plastic hinges failure mode) through the reasonable design to avoid the rupture of cargo floor crossbeams, and the more crash energy can be absorbed due to the production of more plastic hinges for the flattening failure mode, and the crashworthiness of fuselage section can be significantly improved. [ABSTRACT FROM AUTHOR]

The plain-woven aramid fabrics have been commonly used to offer the high protection against ballistic threats. This paper deals with the tests and numerical investigations on the ballistic impact responses of aramid fabric containment system. A series of quasi-static tensile tests and dynamic tensile tests are conducted to determine the mechanical performance parameters of plain-woven aramid fabric. A series of ballistic impact tests are further carried out with different projectile velocities to investigate the ballistic behavior of aramid fabric containment system, which are fabricated by wrapping multiple layers around a back-up steel ring. The method of using the explicit dynamic software LS-DYNA to establish the stacked shell finite element model for quantitative analysis of the ballistic impact process is developed and conducted, and the failure mode and containment mechanism are discussed in detail through the test and simulation analysis. The results show that both the peak stress and elastic modulus increase significantly with the increasing of strain rate, but the failure strain increases slightly. The ballistic impact energy is consumed mainly through the large deformation of fabric, inter-yarn friction, and interlaminar friction. The simulation results are in good agreement with the test results, and the deformation and failure mode of aramid fabric containment system are better reproduced, which provides the promising finite element method for analyzing the ballistic impact events. In addition, some comparisons in interlaminar contact, impact position and incident attitude of projectile are further conducted and discussed. [ABSTRACT FROM AUTHOR]

This paper deals with impact test and numerical investigations on the crashworthiness of the typical sub-cargo fuselage section of a civil aircraft. The sub-cargo fuselage section with three-frame and two-span is designed and manufactured, and the 3.95 m/s impact test is conducted to research the failure modes and impact response characteristics for the upside-down sub-cargo fuselage section. The impact process is simulated by using the LS-DYNA finite element code. The impact velocity, displacement, and acceleration response are compared, and a good agreement between test results and numerical simulation results is observed. The energy absorption characteristics and impact load transfer path are further studied based on the verified finite element model (FEM). The results show that the impact phases are characterized by the bending and twisting of fuselage frames, the bending of middle stanchions and C-channel stanchions, the pull-off failure and shear failure of rivets, and the two plastic hinges formed at the joints of C-channel stanchions and fuselage frames. The fuselage frames and middle stanchions are the main energy absorption components. The impact load is transmitted along with the fuselage frames, middle stanchions, and C-channel stanchions to the cargo cross beams, and the area of middle stanchions is the most important energy absorption design area. [ABSTRACT FROM AUTHOR]

The crashworthy design, verification, and certification of civil aircraft fuselage structures are extremely important for the aviation safety and the survivability of crew and passengers in a crash event. To improve the crashworthy performance of civil aircraft, a building block approach is recommended with several levels, i.e. coupons - elements - details - sub-components - components - full-scale aircraft. Impact tests and numerical simulations are described according to the different levels of building block approach. Design methods for improving the crashworthiness of fuselage structures are introduced. The status of research to evaluate the sub-components (such as the sub-cargo structure); the components (such as the fuselage section); and, the full-scale aircraft is summarized. Finally, the current crashworthy verification methods and evaluation processes for civil aviation fuselage structures are highlighted. Future development of crashworthy design, verification, and certification of civil aircraft fuselage structures is proposed. [ABSTRACT FROM AUTHOR]

• A new type of high-performance brace-type shear fuses (termed as BSF) is proposed. • The cover plates were perforated making damage of the core plate detectable. • Experimental study on effects of critical design parameters is conducted. • Excellent cumulative ductility was verified by the experimental results of the proposed BSFs. This paper proposes new brace-type shear fuses (BSFs) connected in series. The BSF consists of a core plate, two filling plates, two perforated cover plates, unbonding material and bolts. It is designed to dissipate seismic energy via yielding mainly under shear. Perforated cover plates make damage of the core plate visible. To analyze BSFs, seven specimens were designed with different number of shear fuses, tension-to-shear strength ratios and radii of shear fuses. In the experiments, it was found that the deformation capacity had positive correlation with number of shear fuses, tension-to-shear strength ratio, and radii of shear fuses. No buckling of the core plates occurred due to the short length of specimen. Fracture modes of all the specimens were shear rupture. Contact between the lateral sides of core plate and filling plates due to flexural deformation was observed, which led to significant increase of force in both tension and compression. In addition, initial stiffness and yield force of BSFs were derived based on the Principle of Virtual Work. A design criterion to avoid direct contact was also proposed for design of BSFs. [ABSTRACT FROM AUTHOR]

Cluster analysis plays an important role in identifying the natural structure of the target dataset. It has been widely used in many fields, such as pattern recognition, machine learning, image segmentation, document clustering and so on. There are many different methods to conduct cluster analysis. Namely, most real datasets are non-spherical and have complex shapes. Although these methods are widely used to deal with clustering tasks, they are susceptible to noise and arbitrary shapes. Thus, we propose a novel clustering algorithm (called RNN-NSDC) in this paper, which is based on the natural reverse nearest neighbor structure. Firstly, we apply the reverse nearest neighbors in the algorithm to extract core objects. Secondly, our algorithm uses the neighbor structure information of core objects to cluster. And excluding noise effects, core sets can well represent the structure of clusters. Therefore, the RNN-NSDC can obtain the optimal cluster numbers for the datasets which contain clusters of outliers and arbitrary shapes. To verify the efficiency and accuracy of the RNN-NSDC, synthetic datasets and real datasets are used for experiments. The results indicate the superiority of the RNN-NSDC compared with K-means, DBSCAN, DPC, SNNDPC, DCore and NaNLORE. • The criterion of extracting the core objects is simple and efficient. • There is no need to set parameters in RNN-NSDC. • RNN-NSDC can be applied to complex patterns with extremely large variations in density. • RNN-NSDC is robust to outliers and noises. [ABSTRACT FROM AUTHOR]

Background The concomitant prevalence of obstructive sleep apnea hypopnea syndrome (OSAHS) and pulmonary embolism (PE) is strikingly high, and therefore we studied the patients with PE to determine whether those who had OSHAS required greater warfarin doses to achieve a therapeutic international normalized ratio (INR). Methods By using computer tomographic pulmonary angiography or pulmonary angiography, we identified and recruited 97 patients with PE and all underwent polysomnography. Warfarin was initiated at a dose of 3 mg/day and modified to adjust the INR to the range of 2.0-3.0. Results OSAHS patients (n = 32) required a significantly higher dose of warfarin than their non-OSAHS counterparts (5.01 mg vs 3.61 mg, P < .001). This difference still existed between the two groups after adjusting for covariates (achieved INR value and weight). Logistic analysis suggested that OSAHS was an independent risk factor for high dose warfarin (OR 5.715, P < .001). On admission, OSAHS patients had a lower mean value of INR and prothrombin time but higher plasminogen (PLG) activity compared to non-OSAHS patients. Other coagulation indices were not significantly different between the two groups. Except for the PLG activity (r = .273, P = .026), the correlation between the warfarin dose and the baseline coagulating indices wasn't significant. Conclusions Our findings indicate that factors associated with OSAHS, such as hypercoagulation, may explain the need for higher doses of warfarin in treating patients with PE. [ABSTRACT FROM AUTHOR]

Alternatives to climate changing blowing agents (e.g. chlorofluorocarbons) and petroleum sourced raw materials (e.g. polyether polyols) are very attractive in the polyurethane (PU) foam industry. We explore a series of CO 2 adducts from a branched polyethylenimine (bPEI) alkylated with C 4 to C 16 alkyl glycidyl ethers. These adducts can serve as CO 2 releasing blowing agents during the exothermic polymerisation of PUs. A 13% alkylation of the bPEI amine groups enhances the dispersibility of the resultant CO 2 adducts into the PU foaming mixtures containing a castor oil-derived polyol. In particular, the CO 2 adduct with a C 8 alkyl (2-ethylhexyl) side chain possesses the best dispersibility and is among the most effective in decreasing the foam density. It generates PU foams whose density and compressive strength are almost suitable for thermal insulation of underground steel pipes. This is the first report showing that PU foams from biomass polyols can be blown by CO 2 adducts that are environmentally neutral. [ABSTRACT FROM AUTHOR]

[Display omitted] Two new C 20 -diterpenoid alkaloids, named gyalanunines A–B (1 – 2), were isolated from the whole plant of Delphinium gyalanum C. Marquand & Airy Shaw. Gyalanunine A was a rare C 20 -type diterpenoid alkaloid, which possess a hemiacetal ring linking C-2 to C-19. Structures were identified by multiple spectroscopic analyses including 1D and 2D NMR, IR, HR-ESI-MS, single-crystal X-ray diffraction methods. All compounds were tested for cardiotonic activity by isolated frog's hearts perfusion, and 1 exhibited appreciable cardiotonic activity. Preliminary mechanism of action studies indicated that the cardiotonic effect of 1 should be related to the β receptor. [ABSTRACT FROM AUTHOR]