131 research outputs found

    Returns to scale in the production of selected manufacturing sectors in China

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    AbstractIn the study on economic growth, international trade and economic geography, making different assumption on returns to scale may lead to stark difference in both theoretic conclusion and policy implication. A very important assumption supporting literatures in New Economic Geography is that production of manufacturing sector is characterized by increasing returns to scale. Around this assumption, much debate exists. There is no predominant conclusion from empirical study either. This study begins with a brief survey of the study on the assumption of returns to scale. Based on data from 17 selected sectors in manufacturing industry in China and using Diewert-Fox Model[1], returns to scale in the production of selected sectors in manufacturing industry in China is investigated. It is found that all of the selected sectors in manufacturing industry in China show increasing returns to scale, and most of those sectors experience modest negative or zero technical change, which implies that economic growth in Chinese manufacturing industry over the recent two decades has largely been driven by increasing returns to scale rather than technical progress

    Assessment of left ventricular function in patients with type 2 diabetes mellitus by non-invasive myocardial work

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    BackgroundDiabetes mellitus (DM) is a chronic disease that poses a serious risk of cardiovascular diseases. Therefore, early detection of impaired cardiac function with non-invasive myocardial imaging is critical for improving the prognosis of patients with DM.PurposeThis study aimed to assess the left ventricular (LV) function in patients with type 2 diabetes mellitus (T2DM) by non-invasive myocardial work technique.Materials and methodsIn all, 67 patients with T2DM and 28 healthy controls were included and divided into a DM group and a control group. Two-dimensional dynamic images of apical three-chamber view, apical two-chamber view, and apical four-chamber view were collected from all subjects, consisting of at least three cardiac cycles. LV myocardial strain parameters, including global longitudinal strain (GLS) and peak strain dispersion (PSD), as well as myocardial work parameters, including global constructive work (GCW), global wasted work (GWW), global work index (GWI), and global work efficiency (GWE), were obtained and analyzed.ResultsA total of 15 subjects were randomly selected to assess intra-observer and inter-observer consistency of myocardial work parameters and strain parameters, which showed excellent results (intra-class correlation coefficients: 0.856 - 0.983, P<0.001). Compared with the control group, the DM group showed significantly higher PSD (37.59 ± 17.18 ms vs. 27.72 ± 13.52 ms, P<0.05) and GWW (63.98 ± 43.63 mmHg% vs. 39.28 ± 25.67 mmHg%, P<0.05), and lower GWE (96.38 ± 2.02% vs. 97.72 ± 0.98%, P<0.001). Furthermore, the PSD was positively correlated with GWW (r = 0.565, P<0.001) and negatively correlated with GWE (r = -0.569, P<0.001).ConclusionUncoordinated LV myocardial strain, higher GWW, and lower GWE in patients with T2DM may serve as indicators for the early assessment of cardiac impairment in T2DM

    The impact of stereotype threat on endogenous poverty-elimination dynamics in generationally poor individuals

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    IntroductionThe study examines the impact of stereotype threat on generationally poor individuals and its effect on achievement motivation. It also explores the extent to which self-affirmation has an intervention effect on the negative impact of stereotype threat.Methods and resultsIn Study 1, statements that contained negative stereotypes were used to elicit stereotype threat in generationally poor individuals; the results show that stereotype threat reduced the performance of generationally poor individuals in a mental-rotation task. Study 2 used a questionnaire to measure the endogenous dynamics of generationally poor individuals attempting to escape poverty after experiencing stereotype threat; participants in the stereotype-threat group showed lower-level endogenous poverty-elimination dynamics than those in the control group. In Study 3, a self-affirmation intervention was administered to the stereotype-threat group after the stereotype threat was induced. Participants in the self-affirmation group were shown to have higher-level endogenous poverty-elimination dynamics than those in the control group.DiscussionThese findings confirm the negative effect of stereotype threat on endogenous poverty-elimination dynamics and verify the effectiveness of self-affirmation in mitigating the negative effects of stereotype threat

    The NEU1-selective sialidase inhibitor, C9- butyl-amide-DANA, blocks sialidase activity and NEU1-mediated bioactivities in human lung in vitro and murine lung in vivo

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    Neuraminidase-1 (NEU1) is the predominant sialidase expressed in human airway epithelia and lung microvascular endothelia where it mediates multiple biological processes. We tested whether the NEU1-selective sialidase inhibitor, C9-butyl-amide-2-deoxy-2,3-dehydro-Nacetylneuraminic acid (C9-BA-DANA), inhibits one or more established NEU1-mediated bioactivities in human lung cells. We established the IC50 values of C9-BA-DANA for total sialidase activity in human airway epithelia, lung microvascular endothelia and lung fibroblasts to be 3.74 µM, 13.0 µM and 4.82 µM, respectively. In human airway epithelia, C9-BA-DANA dose-dependently inhibited flagellin-induced, NEU1-mediated mucin-1 ectodomain desialylation, adhesiveness for Pseudomonas aeruginosa and shedding. In lung microvascular endothelia, C9-BA-DANA reversed NEU1-driven restraint of cell migration into a wound and disruption of capillary-like tube formation. NEU1 and its chaperone/transport protein, protective protein/cathepsin A (PPCA), were differentially expressed in these same cells. Normalized NEU1 protein expression correlated with total sialidase activity whereas PPCA expression did not. In contrast to eukaryotic sialidases, C9-BA-DANA exerted far less inhibitory activity for three selected bacterial neuraminidases (IC50 \u3e 800 µM). Structural modeling of the four human sialidases and three bacterial neuraminidases revealed a loop between the seventh and eighth strands of the β-propeller fold, that in NEU1, was substantially shorter than that seen in the six other enzymes. Predicted steric hindrance between this loop and C9-BA-DANA could explain its selectivity for NEU1. Finally, pretreatment of mice with C9-BA-DANA completely protected against flagellin-induced increases in lung sialidase activity. Our combined data indicate that C9- BA-DANA inhibits endogenous and ectopically expressed sialidase activity and established NEU1-mediated bioactivities in human airway epithelia, lung microvascular endothelia, and fibroblasts in vitro and murine lungs in vivo

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

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    Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30M⊙M_{\odot} for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

    Detection of the Diffuse Supernova Neutrino Background with JUNO

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    As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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    JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

    Research on the Impact of Agricultural Financial Support on Agricultural Carbon Compensation Rate

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    Based on the consideration of the dual attributes of agricultural carbon emission and carbon sink, this study measures the agricultural carbon compensation rate (ACCR) of 31 provinces in China from 2006 to 2019, the impact of agricultural financial support on ACCR and its transmission mechanism are empirically analyzed using a spatial econometric model and intermediary effect model. The results show that: (1) a significant spatial correlation between agricultural financial support and ACCR; (2) increased agricultural financial support is conducive to the improvement of ACCR; (3) agricultural financial support has the most significant effect on the ACCR in the eastern region; (4) the effect of agricultural financial support on ACCR has a spatial spillover effect but is not significant; (5) agricultural technological progress is the intermediary variable that agricultural financial support affecting ACCR. Therefore, it is suggested to promote agricultural emission reduction through collaboration, innovative financial support mechanisms, implementation of differentiated financial support strategies, exerting the radiation effect of financial support to agriculture, and pushing up the level of agricultural mechanization

    Research on the Impact of Agricultural Financial Support on Agricultural Carbon Compensation Rate

    No full text
    Based on the consideration of the dual attributes of agricultural carbon emission and carbon sink, this study measures the agricultural carbon compensation rate (ACCR) of 31 provinces in China from 2006 to 2019, the impact of agricultural financial support on ACCR and its transmission mechanism are empirically analyzed using a spatial econometric model and intermediary effect model. The results show that: (1) a significant spatial correlation between agricultural financial support and ACCR; (2) increased agricultural financial support is conducive to the improvement of ACCR; (3) agricultural financial support has the most significant effect on the ACCR in the eastern region; (4) the effect of agricultural financial support on ACCR has a spatial spillover effect but is not significant; (5) agricultural technological progress is the intermediary variable that agricultural financial support affecting ACCR. Therefore, it is suggested to promote agricultural emission reduction through collaboration, innovative financial support mechanisms, implementation of differentiated financial support strategies, exerting the radiation effect of financial support to agriculture, and pushing up the level of agricultural mechanization

    A Meta-Analysis of Randomized Controlled Trials on Acupuncture for Amblyopia

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    Objective. To assess the evidence of efficacy and safety of acupuncture for amblyopia and analyze the current situation of its clinical setting. Methods. We systemically searched Wanfang, Chongqing Weipu Database for Chinese Technical Periodicals (VIP), China National Knowledge Infrastructure (CNKI), and PubMed. Published randomized controlled trials (RCT) and controlled clinical trials (CCT) that evaluated the effect of acupuncture for amblyopia compared with conventional treatment were identified. The methodological quality of the included trials was assessed based on the Jadad scale. Data synthesis was facilitated using RevMan 5.1. Results. Fourteen trials involving 2662 participants satisfied the minimum criteria for meta-analysis. The evidence showed that the total effective rate of treatment within the group receiving acupuncture was higher than that in conventional group; there were statistically significant differences between groups (polled random effects model (RR) = 1.17, 95% confidence interval (1.11, 1.24), Z=5.56, P<0.00001). Conclusion. The total effective rate of acupuncture for amblyopia was significantly superior to conventional treatment, indicating that acupuncture was a promising treatment for amblyopia. However, due to the limited number of CCTs and RCTs, especially those of large sample size and multicenter randomized controlled studies that were quantitatively insufficient, we could not reach a completely affirmative conclusion until further studies of high quality are available
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