90 research outputs found
Why is local government less trusted than central government in China?
The public's trust in government is a subject that arouses interest and debate among researchers and politicians alike. This thesis is concerned with public trust in government in China and particularly in local government. It provides insights both on the patterns of public trust in different levels of government and explores the key factors that account for variance in this respect. In light of the findings in this respect, the thesis also makes suggestions about measures that might be taken to improve public trust in local government particularly in the China context.
A mixed methods research design has been employed that has included analysis of responses to a major trans-China quantitative survey of public opinions and the conduct of a series of semi-structured interviews with local government officials operating at different governmental levels within one municipal city. The research examines the commonalities and differences between the perspectives of citizens and of officials with regard to the scale, nature and causes of public distrust in local government. The thesis considers the implications of the findings and makes suggestions as to the kinds of policy and practice responses that would seem necessary to improve Chinese's citizens' trust levels in their local government
Simulating MCP secondary electron avalanche process by Geant4
Nowadays, Microchannel Plate (MCP), as a kind of electron multiplier based on
the secondary electron emission, is widely used in many high-sensitive
experiments, such as neutrino detection, which require as low noise as
possible, while the conventional straight channel MCP will definitely have ion
feedback, resulting in the sequential after-pulses being the major source of
noise. Normally, the problem can be effectively avoided by coupling two
straight MCPs in cascade and combining the channels into a "V" shape known as
chevron MCPs, but this method is limited by the manufacturing techniques due to
the inevitable gap that will worsen the resolution and peak-to-valley ratio.
However, the ion feedback can be inhibited significantly for MCPs with
curved-channels. Based on the Geant4 Monte Carlo simulation framework, we
investigate how the geometrical parameters of curved-channel MCP influence the
gain and get the optimum pore diameter for the maximum gain with a fixed
thickness and applied voltage. Additionally, the track-by-track simulation
reveals that the average acceleration distance of a secondary electron inside
the curved-channel is approximately 20~m with a voltage of 950~V, a
length-to-diameter ratio of 100:1, and a pore diameter of 20~m.Comment: 20 pages, 12 figure
Charm-Quark Production in Deep-Inelastic Neutrino Scattering at Next-to-Next-to-Leading Order in QCD
We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon.National Natural Science Foundation (China) (Grant No. 11375013)National Natural Science Foundation (China) (Grant No. 11135003)United States. Dept. of Energy (Contract No. DE-AC02-06CH11357)United States. Dept. of Energy. Office of Nuclear Physics (U.S. DOE Contract No. DE-SC0011090
Rheological behavior of 3D printed concrete:Influential factors and printability prediction scheme
The rheological properties of cementitious materials play a crucial role in determining the printability for extrusion-based 3D concrete printing. This study develops data-driven machine learning (ML) models to predict two key rheological parameters - plastic viscosity (PV) and yield stress (YS) of 3D printable cementitious composites based on the mixture composition and time after water addition. A systematic experimental study is conducted by varying the contents of cement, fly ash, silica fume, sulfoaluminate cement, superplasticizer, and water-to-binder ratio, and time after water addition. The measured rheological data is used to construct a database for training predictive models including linear regression, support vector regression, random forest, extreme gradient boosting, and multi-layer perceptron neural network. The extreme gradient boosting model achieves the highest prediction accuracy with low root mean square error and all coefficients of determination exceeding 0.9 for both plastic viscosity and yield stress. Importance analysis identifies the most influential parameters affecting the rheological properties. A printability classification scheme is proposed using the model predictions by defining a printable zone of PV and YS. The data-driven framework is validated to effectively predict printability of new mixtures without trial-and-error. This study demonstrates the potential of ML models to accelerate the design and optimization of 3D printable cementitious materials.</p
The recent progress of peptide regulators for the Wnt/β-catenin signaling pathway
Wnt signaling plays an important role in many biological processes such as stem cell self-renewal, cell proliferation, migration, and differentiation. The β-catenin-dependent signaling pathway mainly regulates cell proliferation, differentiation, and migration. In the Wnt/β-catenin signaling pathway, the Wnt family ligands transduce signals through LRP5/6 and Frizzled receptors to the Wnt/β-catenin signaling cascades. Wnt-targeted therapy has garnered extensive attention. The most commonly used approach in targeted therapy is small-molecule regulators. However, it is difficult for small-molecule regulators to make great progress due to their inherent defects. Therapeutic peptide regulators targeting the Wnt signaling pathway have become an alternative therapy, promising to fill the gaps in the clinical application of small-molecule regulators. In this review, we describe recent advances in peptide regulators for Wnt/β-catenin signaling
Constitutive Activation of β-Catenin in Differentiated Osteoclasts Induces Bone Loss in Mice
Background/Aims: Activation of the Wnt/β-catenin signalling pathway has been widely investigated in bone biology and shown to promote bone formation. However, its specific effects on osteoclast differentiation have not been fully elucidated. Our study aimed to identify the role of β-catenin in osteoclastogenesis and bone homeostasis. Methods: In the present study, exon 3 in the β-catenin gene (Ctnnb1) allele encoding phosphorylation target serine/threonine residues was flanked by floxP sequences. We generated mice exhibiting conditional β-catenin activation (Ctsk-Cre;Ctnnb1flox(exon3)/+, designated CA-β-catenin) by crossing Ctnnb1flox(exon3)/flox(exon3) mice with osteoclast-specific Ctsk-Cre mice. Bone growth and bone mass were analysed by micro-computed tomography (micro-CT) and histomorphometry. To further examine osteoclast activity, osteoclasts were induced from bone marrow monocytes (BMMs) isolated from CA-β-catenin and Control mice in vitro. Osteoclast differentiation was detected by tartrate-resistant acid phosphatase (TRAP) staining, immunofluorescence staining and reverse transcription-quantitative PCR (RT–qPCR) analysis. Results: Growth retardation and low bone mass were observed in CA-β-catenin mice. Compared to controls, CA-β-catenin mice had significantly reduced trabecular bone numbers under growth plates as well as thinner cortical bones. Moreover, increased TRAP-positive osteoclasts were observed on the surfaces of trabecular bones and cortical bones in the CA-β-catenin mice; consistent results were observed in vitro. In the CA-β-catenin group, excessive numbers of osteoclasts were induced from BMMs, accompanied by the increased expression of osteoclast-associated marker genes. Conclusion: These results indicated that the constitutive activation of β-catenin in osteoclasts promotes osteoclast formation, resulting in bone loss
Comparative Profiling of Triple-Negative Breast Carcinomas Tissue Glycoproteome by Sequential Purification of Glycoproteins and Stable Isotope Labeling
The effect of physical activity on mortality and cardiovascular disease in 130 000 people from 17 high-income, middle-income, and low-income countries:the PURE study
BACKGROUND:
Physical activity has a protective effect against cardiovascular disease (CVD) in high-income countries, where physical activity is mainly recreational, but it is not known if this is also observed in lower-income countries, where physical activity is mainly non-recreational. We examined whether different amounts and types of physical activity are associated with lower mortality and CVD in countries at different economic levels. METHODS:
In this prospective cohort study, we recruited participants from 17 countries (Canada, Sweden, United Arab Emirates, Argentina, Brazil, Chile, Poland, Turkey, Malaysia, South Africa, China, Colombia, Iran, Bangladesh, India, Pakistan, and Zimbabwe). Within each country, urban and rural areas in and around selected cities and towns were identified to reflect the geographical diversity. Within these communities, we invited individuals aged between 35 and 70 years who intended to live at their current address for at least another 4 years. Total physical activity was assessed using the International Physical Activity Questionnaire (IPQA). Participants with pre-existing CVD were excluded from the analyses. Mortality and CVD were recorded during a mean of 6·9 years of follow-up. Primary clinical outcomes during follow-up were mortality plus major CVD (CVD mortality, incident myocardial infarction, stroke, or heart failure), either as a composite or separately. The effects of physical activity on mortality and CVD were adjusted for sociodemographic factors and other risk factors taking into account household, community, and country clustering. FINDINGS:
Between Jan 1, 2003, and Dec 31, 2010, 168 916 participants were enrolled, of whom 141 945 completed the IPAQ. Analyses were limited to the 130 843 participants without pre-existing CVD. Compared with low physical activity (\u3c600 metabolic equivalents [MET] × minutes per week or \u3c150 minutes per week of moderate intensity physical activity), moderate (600-3000 MET × minutes or 150-750 minutes per week) and high physical activity (\u3e3000 MET × minutes or \u3e750 minutes per week) were associated with graded reduction in mortality (hazard ratio 0·80, 95% CI 0·74-0·87 and 0·65, 0·60-0·71; p\u3c0·0001 for trend), and major CVD (0·86, 0·78-0·93; p\u3c0·001 for trend). Higher physical activity was associated with lower risk of CVD and mortality in high-income, middle-income, and low-income countries. The adjusted population attributable fraction for not meeting the physical activity guidelines was 8·0% for mortality and 4·6% for major CVD, and for not meeting high physical activity was 13·0% for mortality and 9·5% for major CVD. Both recreational and non-recreational physical activity were associated with benefits. INTERPRETATION:
Higher recreational and non-recreational physical activity was associated with a lower risk of mortality and CVD events in individuals from low-income, middle-income, and high-income countries. Increasing physical activity is a simple, widely applicable, low cost global strategy that could reduce deaths and CVD in middle age. FUNDING:
Population Health Research Institute, the Canadian Institutes of Health Research, Heart and Stroke Foundation of Ontario, Ontario SPOR Support Unit, Ontario Ministry of Health and Long-Term Care, AstraZeneca, Sanofi-Aventis, Boehringer Ingelheim, Servier, GSK, Novartis, King Pharma, and national and local organisations in participating countries that are listed at the end of the Article
Online Street View-Based Approach for Sky View Factor Estimation: A Case Study of Nanjing, China
The Sky View Factor (SVF) stands as a critical metric for quantitatively assessing urban spatial morphology and its estimation method based on Street View Imagery (SVI) has gained significant attention in recent years. However, most existing Street View-based methods prove inefficient and constrained in SVI dataset collection. These approaches often fall short in capturing detailed visual areas of the sky, and do not meet the requirements for handling large areas. Therefore, an online method for the rapid estimation of a large area SVF using SVI is presented in this study. The approach has been integrated into a WebGIS tool called BMapSVF, which refines the extent of the visible sky and allows for instant estimation of the SVF at observation points. In this paper, an empirical case study is carried out in the street canyons of the Qinhuai District of Nanjing to illustrate the effectiveness of the method. To validate the accuracy of the refined SVF extraction method, we employ both the SVI method based on BMapSVF and the simulation method founded on 3D urban building models. The results demonstrate an acceptable level of refinement accuracy in the test area
Effect of SiC nanoparticle content on the properties of Ni-W-SiC nanocomposite thin films deposited by pulse current electrodeposition
In this study, pulse current electrodeposition (PC) was used to fabricate Ni-W-SiCthin films on mild steel plates, by utilizing a Watts-type Ni liquid that contained SiC nano-particles (NPs). The films deposited with 9 g/L SiC NP showed a smooth, finely granular, and remarkably homogeneous surface structure. All films showed SiC NPs equally distributed on the Ni-W-SiC-NPs surface regardless of the starting SiC NP content. The calculations revealed that the thicknesses of Ni-W-SiC-NPs films deposited at 9 and 12 g/L were ≈ 27.3 and ≈ 22.2 μm, respectively. Moreover, the crystallite sizes decreased as the SiC NPs’ level was changed up to 9 g/L. Film particles became smaller (≈66 nm) but enlarged to 85 nm when SiC NPs level was changed from 9 g/L to 12 g/L, respectively. The deposited layer demonstrated an increase in microhardness from 490.2 HV to 881.5 HV with the addition of SiC nanoparticles. However, the hardness values of the Ni-W-SiC-NPs films became lower as the SiC NPs levels were changed from 9 to 12 g/L. Additionally, films fabricated using 9 g/L of SiC NP level demonstrated a minimal corrosion current (equal to 1.536 ×10−6 μA/cm2). The corrosion resistance of the film deposited at 9 g/L was about 5.3 times that of the film obtained at 0 g/L, indicating an excellent corrosion resistance. The study can provide the corrosion protection for water or oil pipes, metal containers and agricultural machinery.Published versionThe research is supported by the National Natural Science Foundation of China (Granted no. 51974089), and the Daqing Guiding Science and Technology Project (Granted no. zd-2020-25)
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