This paper reported the results of a study that aimed to construct a sensor and handheld augmented reality (AR)‐supported ubiquitous learning (u‐learning) environment called the Handheld English ...Language Learning Organization (HELLO), which is geared towards enhancing students' language learning. The HELLO integrates sensors, AR, ubiquitous computing and information technologies. It is composed of two subsystems: an English learning management system and a u‐learning tool. In order to evaluate the effects of the proposed learning environment on the learning performance of students, a case study on English learning was conducted on a school campus. The participants included high school teachers and students. A learning course entitled ‘My Campus’ was conducted in the class; it included three activities, namely ‘Campus Environment’, ‘Campus Life’ and ‘Campus Story’. The evaluation results showed that the proposed HELLO and the learning activities could improve the students' English listening and speaking skills.
Summary
Porcine reproductive and respiratory syndrome virus (PRRSV) is a major economically significant pathogen that has adversely affected China's swine industry. Currently, a novel type 2 PRRSV, ...called the NADC30‐like strain, is epidemic in numerous provinces of China, and commercial vaccines provide limited protection for infected animals. The extensive recombination phenomenon among NADC30‐like PRRSVs is identified as a unique molecular characteristic of the virus. However, our understanding of how recombination influences NADC30‐like PRRSVs is largely inadequate. In this study, we analysed the genetic characteristics of a recombinant NADC30‐like PRRSV (SC‐d) and examined its pathogenicity compared with a non‐recombinant NADC30‐like PRRSV (SD‐A19) and a highly pathogenic PRRSV (HuN4). SC‐d has three discontinuous deletions in nsp2, consistent with NADC30 isolated from the United States in 2008. Furthermore, we identified four recombination breakpoints in the SC‐d genome, which separated the SC‐d genome into four regions (regions A, B, C and D). Regions A and C are closely related to the JXA1‐like strain, one of the earliest Chinese HP‐PRRSV strains, and regions B and D are closely related to the NADC30 strain. Moreover, SC‐d inoculated piglets exhibited a persistent fever, moderate weight loss, mild thymus atrophy and obvious microscopic lung lesions. In summary, the recombinant NADC30‐like PRRSV SC‐d strain displayed a higher pathogenicity than the non‐recombinant NADC30‐like PRRSV SD‐A19 strain; however, the pathogenicity of the NADC30‐like PRRSV SC‐d was lower compared with the HP‐PRRSV HuN4 strain in piglets. Our findings demonstrate that recombination is responsible for the enormous genetic diversity and pathogenicity variance of the NADC30‐like PRRSV in China. This study provides a theoretical basis for developing a more reasonable PRRSV control and prevention strategy.
Redox flow batteries (RFBs) are a viable technology to store renewable energy in the form of electricity that can be supplied to electricity grids. However, widespread implementation of traditional ...RFBs, such as vanadium and Zn–Br2 RFBs, is limited due to a number of challenges related to materials, including low abundance and high costs of redox-active metals, expensive separators, active material crossover, and corrosive and hazardous electrolytes. To address these challenges, we demonstrate a neutral aqueous organic redox flow battery (AORFB) technology utilizing a newly designed cathode electrolyte containing a highly water-soluble ferrocene molecule. Specifically, water-soluble (ferrocenylmethyl)trimethylammonium chloride (FcNCl, 4.0 M in H2O, 107.2 Ah/L, and 3.0 M in 2.0 NaCl, 80.4 Ah/L) and N 1-ferrocenylmethyl-N 1,N 1,N 2,N 2,N 2-pentamethylpropane-1,2-diaminium dibromide, (FcN 2 Br 2 , 3.1 M in H2O, 83.1 Ah/L, and 2.0 M in 2.0 M NaCl, 53.5 Ah/L) were synthesized through structural decoration of hydrophobic ferrocene with synergetic hydrophilic functionalities including an ammonium cation group and a halide anion. When paired with methyl viologen (MV) as an anolyte, resulting FcNCl/MV and FcN 2 Br 2 /MV AORFBs were operated in noncorrosive neutral NaCl supporting electrolytes using a low-cost anion-exchange membrane. These ferrocene/MV AORFBs are characterized as having high theoretical energy density (45.5 Wh/L) and excellent cycling performance from 40 to 100 mA/cm2. Notably, the FcNCl/MV AORFBs (demonstrated at 7.0 and 9.9 Wh/L) exhibited unprecedented long cycling performance, 700 cycles at 60 mA/cm2 with 99.99% capacity retention per cycle, and delivered power density up to 125 mW/cm2. These AORFBs are built from earth-abundant elements and are environmentally benign, thus representing a promising choice for sustainable and safe energy storage.
The global signal is widely used as a regressor or normalization factor for removing the effects of global variations in the analysis of functional magnetic resonance imaging (fMRI) studies. However, ...there is considerable controversy over its use because of the potential bias that can be introduced when it is applied to the analysis of both task-related and resting-state fMRI studies. In this paper we take a closer look at the global signal, examining in detail the various sources that can contribute to the signal. For the most part, the global signal has been treated as a nuisance term, but there is growing evidence that it may also contain valuable information. We also examine the various ways that the global signal has been used in the analysis of fMRI data, including global signal regression, global signal subtraction, and global signal normalization. Furthermore, we describe new ways for understanding the effects of global signal regression and its relation to the other approaches.
Studies suggest that dysfunction of brain-derived neurotrophic factor (BDNF) is a possible contributor to the pathology and symptoms of Alzheimer's disease (AD). Several studies report reduced ...peripheral blood levels of BDNF in AD, but findings are inconsistent. This study sought to quantitatively summarize the clinical BDNF data in patients with AD and mild cognitive impairment (MCI, a prodromal stage of AD) with a meta-analytical technique. A systematic search of Pubmed, PsycINFO and the Cochrane Library identified 29 articles for inclusion in the meta-analysis. Random-effects meta-analysis showed that patients with AD had significantly decreased baseline peripheral blood levels of BDNF compared with healthy control (HC) subjects (24 studies, Hedges' g=-0.339, 95% confidence interval (CI)=-0.572 to -0.106, P=0.004). MCI subjects showed a trend for decreased BDNF levels compared with HC subjects (14 studies, Hedges' g=-0.201, 95% CI=-0.413 to 0.010, P=0.062). No differences were found between AD and MCI subjects in BDNF levels (11 studies, Hedges' g=0.058, 95% CI=-0.120 to 0.236, P=0.522). Interestingly, the effective sizes and statistical significance improved after excluding studies with reported medication in patients (between AD and HC: 18 studies, Hedges' g=-0.492, P<0.001; between MCI and HC: 11 studies, Hedges' g=-0.339, P=0.003). These results strengthen the clinical evidence that AD or MCI is accompanied by reduced peripheral blood BDNF levels, supporting an association between the decreasing levels of BDNF and the progression of AD.
Abstract
In order to improve the accuracy of architectural decoration engineering evaluation, a new evaluation method based on interactive information model is proposed in this paper. First, the ...paper establishes iim model to complete the evaluation index system of architectural decoration engineering. Then, the weight vectors of the criterion layer and the target layer are determined by the mathematical analytic hierarchy process. Finally, the comprehensive evaluation result of low-carbon Green building design scheme is obtained by calculating the whitening weight function of each gray class. The experimental results show that the method has high accuracy and strong practicability.
Redox‐active anthraquinone molecules represent promising anolyte materials in aqueous organic redox flow batteries (AORFBs). However, the chemical stability issue and corrosion nature of ...anthraquinone‐based anolytes in reported acidic and alkaline AORFBs constitute a roadblock for their practical applications in energy storage. A feasible strategy to overcome these issues is migrating to pH‐neutral conditions and employing soluble AQDS salts. Herein, we report the 9,10‐anthraquinone‐2,7‐disulfonic diammonium salt AQDS(NH4)2, as an anolyte material for pH‐neutral AORFBs with solubility of 1.9 m in water, which is more than 3 times that of the corresponding sodium salt. Paired with an NH4I catholyte, the resulting pH‐neutral AORFB with an energy density of 12.5 Wh L−1 displayed outstanding cycling stability over 300 cycles. Even at the pH‐neutral condition, the AQDS(NH4)2 /NH4I AORFB delivered an impressive energy efficiency of 70.6 % at 60 mA cm−2 and a high power density of 91.5 mW cm−2 at 100 % SOC. The present AQDS(NH4)2 flow battery chemistry opens a new avenue to apply anthraquinone molecules in developing low‐cost and benign pH‐neutral flow batteries for scalable energy storage.
An anthraquinone salt, AQDS(NH4)2, is designed as a new anolyte material for pH‐neutral aqueous organic redox flow batteries (AORFBs) with a solubility of 1.9 m in water. An AORFB using AQDS(NH4)2 delivered outstanding battery performance, including 100 % cycling stability over 300 cycles, an energy efficiency of 70.6 % at 60 mA cm2, and a power density of 91.5 mW cm−2 at 100 % state of charge.
Background Suicide is the third-leading cause of death among adolescents and nonsuicidal self-harm occurs in 13%–45% of individuals within this age group, making these phenomena major public health ...concerns. Lesbian, gay, bisexual, and transgender (LGBT) youth particularly are at risk for engaging in these behaviors. Nevertheless, relatively little is known about the specific risk factors associated with suicidal ideation and self-harm behaviors in the population. Purpose This study provides a longitudinal evaluation of the relative contributions of general and LGBT-specific risk factors as well as protective factors to the occurrence of suicidal ideation and self-harm in an ethnically diverse sample of LGBT youth. Methods A community sample of 246 LGBT youth (aged 16–20 years) was followed prospectively over five time points at regular 6-month intervals. Participants completed a baseline structured interview assessing suicide attempt history and questionnaires measuring gender nonconformity, impulsivity, and sensation-seeking. At follow-up assessments, participants completed a structured interview assessing self-harm and questionnaires for suicidal ideation, hopelessness, social support, and LGBT victimization. Data were collected from 2007 to 2011, and HLM analyses were conducted in 2011. Results A history of attempted suicide ( p =0.05); impulsivity ( p =0.01); and prospective LGBT victimization ( p =0.03) and low social support ( p =0.02) were associated with increased risk for suicidal ideation. Suicide attempt history ( p <0.01); sensation-seeking ( p =0.04); female gender ( p <0.01); childhood gender nonconformity ( p <0.01); and prospective hopelessness ( p <0.01) and victimization ( p <0.01) were associated with greater self-harm. Conclusions General and LGBT-specific risk factors both uniquely contribute to likelihood of suicidal ideation and self-harm in LGBT youth, which may, in part, account for the higher risk of these phenomena observed in this population.
Alloy design based on single-principal-element systems has approached its limit for performance enhancements. A substantial increase in strength up to gigapascal levels typically causes the premature ...failure of materials with reduced ductility. Here, we report a strategy to break this trade-off by controllably introducing high-density ductile multicomponent intermetallic nanoparticles (MCINPs) in complex alloy systems. Distinct from the intermetallic-induced embrittlement under conventional wisdom, such MCINP-strengthened alloys exhibit superior strengths of 1.5 gigapascals and ductility as high as 50% in tension at ambient temperature. The plastic instability, a major concern for high-strength materials, can be completely eliminated by generating a distinctive multistage work-hardening behavior, resulting from pronounced dislocation activities and deformation-induced microbands. This MCINP strategy offers a paradigm to develop next-generation materials for structural applications.
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► Changjiang water level had obvious decrease in the past 10years. ► Thelweg down cutting occurred along the river course downstream from the TDG. ► Suspended sediment flux along ...Changjiang has basically stabilized in the past 10 years. ► The riverbed deposition mode displays strong, intermediate, and weak erosion.
Under the influence of climate and human activities, fluvial systems have natural ability to make adjustments so that the river hydrology, sediment movement, and channel morphology are in dynamic equilibrium. Taking the Changjiang (Yangtze River) for example. In the early stages after the Three Gorges Dam (TGD) began operational ten years ago, the suspended sediment content (SSC) and fluxes in the middle and lower reaches of the river decreased noticeably. At present, they appear to be in a stable state on the decadal scale. Although the river runoff has not shown any trends, the water level in the river decreased appreciably in time. In the meantime, channel down cutting along the thalweg almost existed throughout the river course. The riverbed has turned from depositional before the dam construction to erosional afterwards. In other words, the riverbed had turned from being sediment sinks to sediment sources. In the main channel of the Changjiang between Yichang and Nanjing, a distance of 1300km, the riverbed sedimentation mode displays strong, intermediate, and weak erosion depending on the closeness to the TGD.
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