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Wave-piercing design is a revolution in hull design for small high-speed boats to operate in adverse sea conditions. To study hydrodynamics of the small high speed wave piercing monohull craft systematically, four typical small high-speed wave-piercing monohull crafts were developed, and validated CFD methods were adopted to calculate hull resistances and motions. The resistances and hull motions of these high-speed wave piercing monohull crafts in calm water and waves were obtained and compared. Obvious operating differences can be observed. High-speed wave piercing monohull crafts with slender and twisted planing hulls have smaller resistance at high speed, but the dynamic effects increase as sea conditions worsen. The high-speed wave-piercing monohull craft with a slim multi-chine hull maintains in waves for softer hull motions but suffers the disadvantages of larger resistance. The high-speed wave piercing monohull craft with a triangular hull shows no obvious advantages compared with the other types.

The systematic implementation of reliability engineering is a necessary measure to improve warship reliability. In warship reliability engineering, reliability evaluation is a key step because it reveals whether warships feature an acceptable level of reliability. Current reliability evaluation methods, such as the analytic method, multilevel synthesis method and numerical simulation method, are all based on static logic. However, warships are typical dynamic systems, and their reliability cannot be evaluated using the aforementioned methods. On the basis of the characteristics of warships, including their small sample system and dynamic and multistage missions, this study proposed a new reliability evaluation method based on dynamic Bayesian networks and numerical simulation. The proposed method is the inheritance and development of current methods for reliability evaluation based on numerical simulation. Hence, it overcomes the limitations of the analytic method and multilevel synthesis method, as well as provides an effective means for the reliability evaluation of warships. The proposed method is suitable for the overall reliability evaluation not only of warships but also of other complex dynamic systems.

The sailing performance of an S-type small waterplane area twin hull (S-SWATH) vehicle, which has comparable total resistance at low and high speeds, in waves is investigated. A flapping foil stabiliser is proposed to enhance the seakeeping advantages of the vehicle in rough waves. The unsteady hydrodynamic characteristics of the flapping foil stabiliser are investigated, and its working mechanism is modelled based on the data generated using the computational fluid dynamics method with fixed-grid technology. Compared with a conventional fin, the results show the benefits of the flapping foil with relatively higher lift coefficients and lower drag coefficients. The vertical plane motion control model coupled with the mathematical force model of flapping foils is built. A controller combining the model predictive control scheme with input disturbance measurement is designed to compare the performance of the conventional fins and flapping foils in stabilising the heave–pitch motions of the vehicle. For the simulations, the hydrodynamic coefficients of the vehicle and the wave force–moment on S-SWATH are updated based on Salvesen, Tuck and Faltinsen strip theory, which is equivalent to measuring the approaching wave elevation directly. The flapping foil stabilisers show significant improvements in damping the heave–pitch motions of the vehicle in rough seas.

In warship design and development, reliability should be allocated from top-level requirements to subsystem and equipment levels using an effective allocation method. Mission reliability and inherent availability are top-level reliability parameters of a warship; these parameters do not only involve factors of reliability, but also those of maintainability. Therefore, extensively used reliability allocation methods cannot address the reliability allocation of warships. A warship is a typical repairable system. Based on warship characteristics, this study proposed an integrated reliability and maintainability allocation method for warships. In the comprehensive allocation process, reliability and maintainability factors that affect the top-level reliability parameters of a warship were measured quantitatively. The synergistic principle of the reliability and maintainability indexes was discussed to solve the synergistic problem between the reliability and maintainability parameters of a unit. The top-level reliability indexes of a warship were reasonably allocated to all levels using optimisation methods. The proposed method is not only suitable for warship reliability allocation but also for other complex repairable systems.

Objective To evaluate the impact of ‘China Healthy Lifestyle for All’ on levels of knowledge, taste and intentions to modify future consumption of salt and edible oil. Methods Between May and August 2012, a face-to-face survey carried out in all 31 provinces, autonomous regions, and municipalities in mainland China, achieved a 98.1% response. Intention-To-Treat analysis via multilevel logistic regression was used to examine differences in outcomes between 31,396 non-institutionalised individuals aged > 18 years from 31 ‘intervention’ (i.e. participating) and 26 ‘control’ (i.e. non-participating) counties respectively. Results Adjusting for socioeconomic confounders, participants in ‘intervention’ counties were more likely to know the limit of salt (Odds Ratio 3.14, 95% Confidence Interval (95% CI) 1.98, 4.96) and oil consumption (3.67, 95% CI 2.31, 5.82), and were more intent to modify their consumption (salt 1.98, 95% CI 1.41, 2.76; oil OR 1.99, 95% CI 1.41, 2.81) and to report a change in taste (salt 1.90, 95% CI 1.31, 2.75; oil 2.07, 95% CI 1.38, 3.10). ‘Intervention’ effects were consistent regardless of income or education, but women and older participants benefited disproportionately. Outcomes were 2.8 and 4.7 times more likely among those with better recall. Conclusion Place-based health promotion interventions have an important role to play in addressing non-communicable disease in China.

Wastewater treatment is a complicated dynamic process, the effectiveness of which is affected by microbial, chemical, and physical factors. At present, predicting the effluent quality of wastewater treatment systems is difficult because of complex biological reaction mechanisms that vary with both time and the physical attributes of the system. Bayesian networks are useful for addressing uncertainties in artificial intelligence applications. Their powerful inferential capability and convenient decision support mechanisms provide flexibility and applicability for describing and analyzing factors affecting wastewater treatment systems. In this study, a Bayesian network-based approach for modeling and predicting a wastewater treatment system based on Modified Sequencing Batch Reactor (MSBR) was proposed. Using the presented approach, a Bayesian network model for MSBR can be constructed using experiential information and physical data relating to influent loads, operating conditions, and effluent concentrations. Additionally, MSBR prediction analysis, wherein effluent concentration can be predicted from influent loads and operational conditions, can be performed. This approach can be applied, with minimal modifications, to other types of wastewater treatment plants.

Three reasons of the deviation of the fuel injection quantity for the electronic fuel injection (EFI) motorcycle engine during the transient conditions were analyzed, including the presence of fuel injection dead time, the engine load measurement deviation and the existence of fuel film attached to the inlet pipe wall. The control strategy of fuel film compensation was studied at conditions of starting, acceleration and deceleration, which was based on the changes of engine velocity, inlet air pressure and inlet air temperature. During the transient condition, the basic fuel film compensation and correction coefficient were calibrated at motorcycle dynamometer, and the modified fuel film compensation MAP were achieved correspondingly, in order to keep the excess air coefficient stable.

The life-span of asphalt pavement is influenced by the strength of subgrade , this paper has discussed the modulus of elasticity of subgrade under different compactness . a example of clay subgrade is gived, the pavement structures and traffic data highway are established according to currently asphalt pavement design specification, the pavement bearing abilitie of different subgrade strength is calculated under different compacting conditions, and also a conclusion has been made that a relation between life-span and strength , the calculating results show that the compactness of subgrade cutting down 1% will lead to pavement reducing 0.65 years, through quantitative analysis, it can be believed that improving compaction of subgrade can obviously prolong asphalt pavement life-span.

The neuroprotection by estrogen (E2) and tamoxifen is well documented in experimental stroke models; however, the exact mechanism is unclear. A membrane-based estrogen receptor, ER-α36, has been identified. Postmenopausal-levels of E2 act through ER-α36 to induce osteoclast apoptosis due to a prolonged activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-related kinase (ERK) signaling. We hypothesized that ER-α36 may play a role in the neuroprotective activities of estrogen and tamoxifen. Here, we studied ER-α36 expression in the brain, as well as its neuroprotective effects against oxygen and glucose deprivation (OGD) in PC12 cells. We found that ER-α36 was expressed in both rat and human brain. In addition, OGD-induced cell death was prevented by l nmol/L 17β-estradiol (E2β). E2β activates the MAPK/ERK signaling pathway in PC12 cells under basal and OGD conditions by interacting with ER-α36 and also induces ER-α36 expression. Low-dose of tamoxifen up-regulated ER-α36 expression and enhanced neuronal survival in an ovariectomized ischemic stroke model. Furthermore, low-dose of tamoxifen enhanced neuroprotective effects by modulating activates or suppress ER-α36. Our results thus demonstrated that ER-α36 is involved in neuroprotective activities mediated by both estrogen and tamoxifen.

Background & Aims Despite immunoprophylaxis, mother to child transmission (MTCT) of hepatitis B virus (HBV) still occurs in infants born to hepatitis B surface antigen (HBsAg)–positive mothers. We analyzed methods of risk assessment and interventions for MTCT. Methods We reviewed 63 articles and abstracts published from 1975–2011 that were relevant to MTCT; articles were identified using the PubMed bibliographic database. Results Administration of HB immunoglobulin and HB vaccine to infants at birth (within 12 hours), followed by 2 additional doses of vaccines within 6–12 months, prevented approximately 95% of HBV transmission from HBsAg-positive mothers to their infants. However, HBV was still transmitted from 8%–30% of mothers with high levels of viremia. It is important to assess the risk for MTCT and identify mothers who are the best candidates for intervention. The most important risk factor is maternal level of HBV DNA >200,000 IU (10 6 copies)/mL; other factors include a positive test result for the HB e antigen, pregnancy complications such as threatened preterm labor or prolonged labor, and failure of immunoprophylaxis in prior children. Antiviral therapy during late stages of pregnancy is the most effective method to reduce transmission from mothers with high levels of viremia, but elective cesarean section might also be effective. Antepartum administration of HB immunoglobulin, giving infants a double dose of HB vaccine, or avoiding breastfeeding had no impact on MTCT. Conclusions HBsAg-positive mothers should be assessed for risk of MTCT, and infants should receive immunoprophylaxis. Pregnant women with levels of HBV DNA >200,000 IU/mL should be considered for strategies to reduce the risk for MTCT. We propose an algorithm for risk assessment and patient management that is based on a review of the literature and the opinion of a panel of physicians with expertise in preventing MTCT.

Objective To investigate the knowledge, attitudes and practices (KAP) for dietary sodium intake among adult residents of Shandong Province, China Methods In 2011, we conducted a cross sectional survey among a representative sample of 15,350 adults aged 18 to 69 years using a standardized questionnaire to assess their KAP for sodium. Variation in the KAPs by gender, and residence location were compared using the Chi-square tests. Predictors for the ‘intention to’ and ‘currently taking action to’ reduce sodium intake were determined by multivariate logistic regression with adjustment for confounding factors. Results KAPs for dietary sodium intake among urban residents was generally more favorable than among rural residents. Women were likely to have more favorable KAPs than men. About four fifth of subjects reported that they favored a low sodium diets. However, 31% reported that consumption of less sodium results in less physical strength. Overall, 70% indicated their intention to reduce sodium intake, although only 39 % reported that they had taken action to reduce sodium. Multiple logistic regression analyses indicated that favorable actions to dietary sodium reduction were more likely to occur among those who were aware of the link between sodium and hypertension, and less likely among those who had unfavorable attitudes towards dietary sodium reduction. Conclusion Increasing knowledge levels about the benefits of sodium reduction will be a key success factor for effective sodium reduction initiatives and is linked to favorable behavioral change. Emphasis should be placed on the rural area.

Background The Ebola virus disease spread rapidly in West Africa in 2014, leading to the loss of thousands of lives. Community engagement was one of the key strategies to interrupt Ebola transmission, and practical community level measures needed to be explored in the field and tailored to the specific context of communities. Methods First, community-level education on Ebola virus disease (EVD) prevention was launched for the community’s social mobilizers in six districts in Sierra Leone beginning in November 2014. Then, from January to May of 2015, in three pilot communities, local trained community members were organized to engage in implementation of EVD prevention and transmission interruption measures, by involving them in alert case report, contact tracing, and social mobilization. The epidemiological indicators of transmission interruption in three study communities were evaluated. Results A total of 6 016 community social mobilizers from 185 wards were trained by holding 279 workshops in the six districts, and EVD message reached an estimated 631 680 residents. In three pilot communities, 72 EVD alert cases were reported, with 70.8 % of them detected by trained local community members, and 14 EVD cases were finally identified. Contact tracing detected 64.3 % of EVD cases. The median duration of community infectivity for the cases was 1 day. The secondary attack rate was 4.2 %, and no third generation of infection was triggered. No health worker was infected, and no unsafe burial and noncompliance to EVD control measures were recorded. The community-based measures were modeled to reduce 77 EVD cases, and the EVD-free goal was achieved four months earlier in study communities than whole country of Sierra Leone. Conclusions The community-based strategy of social mobilization and community engagement was effective in case detection and reducing the extent of Ebola transmission in a country with weak health system. The successfully practical experience to reduce the risk of Ebola transmission in the community with poor resources would potentially be helpful for the global community to fight against the EVD and the other diseases in the future. Electronic supplementary material The online version of this article (doi:10.1186/s40249-016-0167-0) contains supplementary material, which is available to authorized users.