355 research outputs found
Robust mixture regression model fitting by Laplace distribution
No full textA robust estimation procedure for mixture linear regression models is proposed by assuming that the error terms follow a Laplace distribution. Using the fact that the Laplace distribution can be written as a scale mixture of a normal and a latent distribution, this procedure is implemented by an EM algorithm which incorporates two types of missing information from the mixture class membership and the latent variable. Finite sample performance of the proposed algorithm is evaluated by simulations. The proposed method is compared with other procedures, and a sensitivity study is also conducted based on a real data set
sj-docx-1-taj-10.1177_20406223221122478 – Supplemental material for Association of NAFLD with cardiovascular disease and all-cause mortality: a large-scale prospective cohort study based on UK Biobank
No full textSupplemental material, sj-docx-1-taj-10.1177_20406223221122478 for Association of NAFLD with cardiovascular disease and all-cause mortality: a large-scale prospective cohort study based on UK Biobank by Wen Ma, Wentao Wu, Weixing Wen, Fengshuo Xu, Didi Han, Jun Lyu and Yuli Huang in Therapeutic Advances in Chronic Disease</p
Homaloxestis miscogana Wu 1997
No full textHomaloxestis miscogana Wu, 1997 (Figs 3, 7, 11, 15, 19) Homaloxestis miscogana Wu, 1997, Fauna Sinica, Insecta, 7: 151. TL: China (Sichuan Province). TD: IZCAS. Material examined. CHINA, Shaanxi Province: 2♂, 6♀, Xunyangba, Ningxia County, 1400 m, 4.VIII.2014, leg. Haili Yu, Yao Fei, Kaili Liu & Jiuyang Luo, slide Nos. YS19158 ♂, YS19159 ♀; 3♂, Huoditang Forest Farm, 1530 m, 28.VII.2015, leg. Yongyan Li & Jialiang Zhuang; 1♂, Longshan Village, Pingli County, 1466 m, 5.VIII.2016, leg. Weixing Feng & Wentao Shi. Diagnosis. Adult (Figs. 3, 7) wingspan 16.5‒18.5 mm. This species can be distinguished from its congeners by the quadrate uncus lobe and the juxta with a sharply tipped process exceeding posterior margin in the male genitalia (Fig. 11). Male seventh sternite (Fig. 15) membranous with weakly sclerotized anterolateral rib and moderately sclerotized posterolateral rib; posterolateral rib broad at base, narrowed to apex, reaching anterior margin of eighth sternite. Female genitalia (Fig. 19). Eighth sternite obtuse on posterior margin. Apophyses posteriores about twice length of apophyses anteriores. Antrum membranous, sub-rectangular, wider than long. Ductus bursae wrinkled, longer than corpus bursae, with numerous conic spines in posterior half; ductus seminalis slender, arising from about posterior 1/4 of ductus bursae, with dense spinules on inner wall. Corpus bursae ovate; signum small, subrectangular, located posterior to middle, with a triangular process arising from its posterior margin. Distribution. China (Shaanxi, Sichuan). Remarks. This species was described originally based on a single male collected from Sichuan, China. The type specimen is deposited in the Institute of Zoology, Chinese Academy of Science, Beijing (IZCAS). The female of this species is described for the first time in this paper.Published as part of Yu, Shuai & Wang, Shuxia, 2020, Three new species of the genus Homaloxestis Meyrick, 1910 (Lepidoptera Lecithoceridae) from China, pp. 589-597 in Zootaxa 4767 (4) on page 594, DOI: 10.11646/zootaxa.4767.4.8, http://zenodo.org/record/377499
Enhanced coercivity of Nd-Ce-Fe-B sintered magnets by adding (Nd, Pr)-H powders
No full textIncorporating the highly abundant rare earth (RE) Ce into Nd-Fe-B sintered magnets has attracted considerable interest recently. The inferior anisotropic field (HA) of Ce2Fe14B to Nd2Fe14B, however leads to low coercivity of the Nd-Ce-Fe-B magnets. To further enhance the coercivity, in this work, (Nd, Pr)-H powders were used as intergranular additive to restructure the grain boundaries of the low cost (Nd,Pr)(22.3)Ces(8).24FebaiBi (wt.%) sintered magnets. When added with only 2 wt% (Nd, Pr)-H, the Hcj can be enhanced from 10.6 kOe to 12.7 kOe with slight reduction in remanence and maximum energy product. The dehydrogenation of (Nd, Pr)-H during sintering promotes the diffusion of Nd and Pr towards the 2:14:1 phase grains and the smoothing of grain boundaries. The formation of (Nd, Pr)-rich shell with locally enhanced magnetocrystalline anisotropy and the magnetic isolation between adjacent 2:14:1 phase grains result in obvious coercivity enhancement, which was supported by magnetic domain structure characterizations and micromagnetic simulations. It suggests that through grain boundary restructuring, the coercivity of Nd-Ce-Fe-B magnets can be enhanced to be comparable of commercial Nd-Fe-B magnets, which may shed new insights into the fabrication of low cost RE permanent magnets. (C) 2017 Elsevier B.V. All rights reserved
Association Between Maternal Subclinical Hypothyroidism and Growth Discordance in Twin Gestations: A Retrospective Study
No full textBing Zhang,1 Xiaoqin Chen,1 Xiaoxiao Zhao,1 Junbao Wu,1 Pan Qi,2 Weixing Zhang1 1Department of Neonatal Intensive Care Unit, Xinxiang Central Hospital, Xinxiang, Henan, 453000, People’s Republic of China; 2Department of Surgical Oncology, Xinxiang Central Hospital, Xinxiang, Henan, 453000, People’s Republic of ChinaCorrespondence: Weixing Zhang, Department of Neonatal Intensive Care Unit, Xinxiang Central Hospital, No. 56 Xinsui Avenue, Xinxiang, Henan, 453000, People’s Republic of China, Email [email protected]: It is reported that there is a growth discordance of at least 20% in about 16% of twin gestations, which may be associated with maternal, fetal, or placental factors. This study was performed to investigate the relationship between maternal subclinical hypothyroidism (SCH) and growth discordance in twin gestations.Patients and Methods: In this retrospective study, the clinical data of 106 women with twin gestations and their neonates were collected. The effect of maternal SCH on the growth discordance in twin gestations was analyzed using both linear and Logistic regression models.Results: Among the 106 women enrolled in our study, 48 cases (45.28%) were diagnosed with SCH, and 46 twins (43.40%) experienced growth discordance. Compared with those with smaller weight, the neonates with larger weight had a higher proportion of males (p< 0.001), larger birth weight (p< 0.001), birth height (p=0.009) and birth head circumference (p=0.001). Women with SCH showed a higher proportion of growth discordance (p=0.005) and larger difference in the body weight (p=0.021). Logistic regression analysis showed that maternal SCH was an independent risk factor for birth weight discordance in twins (95% CI: 1.601– 9.425, p=0.003). Linear analysis further revealed that maternal SCH was positively associated with the birth weight difference in twins (95% CI: 0.261– 8.308, p=0.037).Conclusion: Our findings suggest that maternal SCH may serve as an independent risk factor for birth weight discordance and is positively associated with the birth weight difference in twins.Keywords: subclinical hypothyroidism, growth discordance, birth weight, twin gestation
Weixing Chen Named New Chair of Public Policy Leadership
No full textInternational lecturer and author sets high goals for UM program to become nationally prominen
Grain boundary restructuring of multi-main-phase Nd-Ce-Fe-B sintered magnets with Nd hydrides
No full textMulti-main-phase (MMP) Nd-Ce-Fe-B magnets prepared by sintering the mixture of Ce-free and Ce-containing RE2Fe14B (RE, rare earth) powders have been found to possess superior magnetic properties to the single-main-phase (SMP) ones. Purpose of this work is to further enhance the coercivity through restructuring the grain boundaries (GBs), which have strong influence on the short-range exchange coupling between adjacent grains. By incorporating 4 wt.% NdHX powders as the intergranular additive, coercivity of the (Pr, Nd)(22.3)Ce(8.24)Fe(bal)B0.98 (wt.%) MMP magnet has been substantially increased from 8.2 kOe to 13.1 kOe. Magnetic domain characterizations and the recoil loop measurements showed that the exchange coupling between adjacent grains has been weakened significantly due to the formation of continuous and smooth RE-rich GBs by the extra Nd after NdHX dehydrogenation. Elemental distribution analysis revealed that thicker Nd-rich 2:14:1 shells with stronger magnetocrystalline anisotropy have been formed in the outer region of the Ce-rich main phase grains, which is beneficial to enhance their effective anisotropy. In addition, the Ce-rich 2:14:1 shells surrounding the Nd-rich 2:14:1 grain cores became thinner, which is beneficial to weaken the magnetic dilution effect of such grains. Micromagnetic simulation results also suggest that the coercivity can be further enhanced once the grain boundary is nonmagnetic. Technically, enriching RE elements or reducing Fe content can weaken the ferromagnetism of the grain boundary phase as well as the exchange coupling between adjacent grains. The above findings might shed new insights into enhancing the coercivity of low cost Nd-Ce-Fe-B magnets. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved
Estimating loss of life caused by dam breaches based on the simulation of floods routing and evacuation potential of population at risk
No full textDam breaches often have catastrophic consequences in downstream areas. Hydrodynamic factors and the evacuation potential of the population at risk (PAR) have significant impacts on the loss of life (LOL) caused by dam breaches. However, the existing comprehensive evaluation models have not conducted in-depth research on the evacuation potential of populations. Thus, limited guidance is available for relevant departments to formulate emergency plans to reduce the potential LOL. Therefore, a new comprehensive evaluation model was proposed in this study. According to the relevant references and disaster theory, the main influencing factors and the process through which the LOL is caused by dam breaches were determined. The specific occurrence process was divided into six stages: a dam breach causes flood, the flood puts the PAR, the PAR complete the preparation work, the PAR evacuate, the un-evacuated population shelter themselves inside buildings, and flood causes the death of the exposed population. To calculate the LOL, the parameters relevant at each stage were defined. Furthermore, the Hydrologic Engineering Center's River Analysis System, Geographic Information System, and related materials were used to simulate the flood routing and evacuation potential of the PAR, quantifying the parameters in the model. The model was applied to 14 towns in the downstream areas of the Luhun Reservoir in Henan Province, China, and its accuracy was verified by comparing the results obtained from the two existing models. In addition, the specific suggestions for reducing the potential LOL were proposed based on the results of the simulation.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Safety and Security Scienc
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The Role of Aerosol Particle Size in the Dynamics and Control of Indoor Bioaerosols
No full textThe COVID-19 pandemic has drawn attention to the airborne transmission of bioaerosols, which include bacteria, viruses, and fungal spores that pose health risks in indoor environments. However, limited understanding remains regarding how particle size influences microbial viability and the effectiveness of control strategies. This study integrates laboratory experiments and computational modeling to explore how bioaerosol size affects filtration, disinfection, and interactions with environmental conditions. A computational fluid dynamics (CFD)-based infection risk model is also used to evaluate ventilation strategies.Experimental results show that filtration efficiency varies significantly across medical respirators, commercial air filters, fabric cloths, and other materials within the particle size range of 30–500 nm. Layering enhances efficiency but may compromise breathability. Washing degrades respirator efficiency more than it does for fabrics. Face velocity affects size-specific filtration, suggesting age- and activity-specific breathing considerations. Disinfection experiments show that increasing UVGI dose and ozone levels reduces E. coli viability. In ozone-free UVGI, smaller particles (0.25–0.5 µm) exhibit lower viability than larger ones (0.5–2.5 µm), while ozone-generating UVGI maintains higher viability in smaller particles. Combining UVGI with ozone improves disinfection efficiency.Environmental tests show that temperature, humidity, and decay time influence microbial survival. Warm, humid conditions (27°C, 90% RH) favor survival, while dry, cooler settings accelerate decay. Larger particles (>1 µm) decay faster than smaller ones. CFD simulations indicate that increasing ventilation (1–6 ACH) reduces airborne concentrations from 37.1% to 7.4%. Overall, this study underscores that aerosol particle size is a key factor in bioaerosol dynamics and control. These insights are essential for developing public health interventions to minimize airborne disease transmission in enclosed environments.</p
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