89 results on '"Xiaoqing Dai"'
Search Results
2. Mefunidone alleviates silica-induced inflammation and fibrosis by inhibiting the TLR4-NF-κB/MAPK pathway and attenuating pyroptosis in murine macrophages
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Lingzhi Long, Xiaoqing Dai, Tingting Yao, Xiangyu Zhang, Guoliang Jiang, Xiaoyun Cheng, Mao Jiang, Yijun He, Zhangzhe Peng, Gaoyun Hu, Lijian Tao, and Jie Meng
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Silicosis ,Mefunidone ,Inflammation ,Fibrosis ,Pyroptosis ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Aims: Silicosis is the most common and severe type of pneumoconiosis, imposing a substantial disease burden and economic loss on patients and society. The pathogenesis and key targets of silicosis are not yet clear, and there are currently no effective treatments available. Therefore, we conducted research on mefunidone (MFD), a novel antifibrotic drug, to explore its efficacy and mechanism of action in murine silicosis. Methods: Acute 7-day and chronic 28-day silicosis models were constructed in C57BL/6J mice by the intratracheal instillation of silica and subsequently treated with MFD to assess its therapeutic potential. The effects of MFD on silica-induced inflammation, pyroptosis, and fibrosis were further investigated using immortalized mouse bone marrow-derived macrophages (iBMDMs). Results: In the 7-day silica-exposed mouse models, MFD treatment significantly alleviated pulmonary inflammation and notably reduced macrophage infiltration into the lung tissue. RNA-sequencing analysis of silica-induced iBMDMs followed by gene set enrichment analysis revealed that MFD profoundly influenced cytokine-cytokine receptor interactions, chemokine signaling, and the toll-like receptor signaling pathways. MFD treatment also markedly reduced the secretion of inflammatory cytokines and chemokines from silica-exposed iBMDMs. Moreover, MFD effectively downregulated the activation of the TLR4-NF-κB/MAPK signaling pathway induced by silica and mitigated the upregulation of pyroptosis markers. Additionally, MFD treatment significantly suppressed the activation of fibroblasts and alveolar epithelial cells co-cultured with silica-exposed mouse macrophages. Ultimately, in the 28-day silica-exposed mouse models, MFD administration led to a substantial reduction in the severity of pulmonary fibrosis. Conclusion: MFD mitigates silica-induced pulmonary inflammation and fibrosis in mice by suppressing the TLR4-NF-κB/MAPK signaling pathway and reducing pyroptotic responses in macrophages. MFD could potentially emerge as a novel therapeutic agent for the treatment of silicosis.
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- 2024
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3. Quality assessment of the preparation and storage of leukocyte-depleted pooled platelet concentrates
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Feng Chen, Xiaoqing Dai, Azhong Li, Yinhong Zheng, and Wei Hu
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Buffy coat method ,leukocyte-depleted pooled platelet concentrates ,platelet quality ,leukocyte filtration ,apheresis platelets ,quality indicators ,Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
ABSTRACTObjective: To explore the feasibility of using a disposable platelet storage bag containing a leukocyte filter to prepare leukocyte-depleted pooled platelet concentrates with the buffy coat method.Methods: 150 bags of whole blood samples (400 mL/bag) were stored overnight at 22 ± 2°C, and buffy coats were separated on Day 2, then 5 units of ABO homotypic buffy coat and 1 unit of plasma were pooled into a disposable platelet storage bag containing a leukocyte filter to prepare leukocyte-depleted pooled platelet concentrates and stored in a Platelet Agitator. On Day 2, 4, 5 and 7 after the collection of whole blood, platelet content, pH value, pO2, pCO2, glucose (GLU), ATP, and other quality indicators were measured.Results: The quality indicators of leukocyte-depleted pooled platelet concentrates met the requirements for leukocyte-depleted aphaeresis platelets in the Chinese national standard Quality Requirements for Whole Blood and Blood Components (GB18469-2012). With the prolongation of storage time, MPV and PDW of platelets gradually increased, pH value, bicarbonate, and GLU gradually decreased, LA, LDH, and ATP gradually increased, pO2 slightly increased, pCO2 decreased, and HSR had no significant change. ESC decreased significantly on Day 7, CD62p decreased first and then increased, sP-selectin and GP V increased first and then decreased, but the results on Day 7 were higher than those on Day 2.Conclusion: The quality of leukocyte-depleted pooled platelet concentrates prepared by the buffy coat method using disposable platelet storage bags containing a leukocyte filter was comparable to that of leukocyte-depleted apheresis platelets, and could be used clinically.
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- 2024
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4. Perinatal characteristics and pregnancy outcomes of advanced maternal age women with gestational diabetes mellitus: A retrospective cohort study
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Chen Jiang, Haiyan Wen, Tingting Hu, Yanfei Liu, Xiaoqing Dai, and Yiming Chen
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advanced maternal age ,adverse pregnancy outcome ,chromosomal abnormality ,gestation diabetes mellitus ,retrospective cohort study ,Medicine - Abstract
Abstract Background and Aims The prevalence of gestational diabetes mellitus (GDM) continues to increase, and the phenomenon of women giving birth at an older age is becoming more common worldwide. Less is known abouts the impact of GDM combined with advanced maternal age (AMA) on pregnancy outcomes. To explore the impact of AMA complicated with GDM on pregnancy outcomes. Methods This study included 34,602 pregnancies between 2018 and 2020 in Hangzhou, China. The pregnant women were divided into four groups according to advanced age (≥35 years) and GDM as follows: AMA women without GDM (non‐AGDM) group (n = 2614), young pregnant women with GDM (YGDM) group (n = 4016), AMA women with GDM (AGDM) group (n = 850), and young pregnant women without GDM (non‐YGDM) group (n = 27,122). Univariate analysis was carried out by Mann–Whitney U test or Pearson's χ2 test. Multivariate logistic regression analysis was used to investigate the effect of AMA and GDM on pregnancy outcomes. Results Multivariate logistic regression analysis showed that in the comparison against non‐YGDM garoup, the ORs of fetal chromosome abnormality, parity, urgent cesarean section, gravidity, scheduled cesarean section, body mass index (BMI) ≥30 kg/m2, pre‐eclampsia, thrombocytopenia, hyperlipidemia, BMI 25–29.9 kg/m2, blood urea nitrogen, fasting blood glucose, and creatinine in AGDM group were 16.044, 4.284, 3.530, 3.284, 3.257, 2.049, 1.935, 1.898, 1.690, 1.471, 1.304, 1.216, and 1.026 (all p
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- 2024
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5. ZnO-decorated SiC@C hybrids with strong electromagnetic absorption
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Liqun Duan, Zhiqian Yang, Yilu Xia, Xiaoqing Dai, Jian’an Wu, and Minqian Sun
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carbon ,dielectric ,electromagnetic absorption ,sic nanowires ,zno ,Technology ,Chemical technology ,TP1-1185 ,Science ,Physics ,QC1-999 - Abstract
A novel strategy is provided to improve the absorption of SiC nanomaterials through surface carbonization of SiC nanowires and hydrolysis. SiC@C-ZnO composites were synthesized with different dosages of ZnNO3·6H2O. Composition, microstructure, and electromagnetic properties of the composites were characterized and analyzed. Results from TEM and XRD show that crystalline ZnO particles adhere to the surface of amorphous carbon, and the ZnO content increases as a function of a dosage of ZnNO3·6H2O. The as-prepared SiC@C-ZnO hybrids exhibit effective electromagnetic absorption, which is related to a synergy effect of different dielectric loss processes. The minimum reflection loss reached −65.4 dB at 11 GHz at a sample thickness of 3.1 mm, while the effective absorption bandwidth (EAB) reached 7 GHz at a sample thickness of 2.56 mm. Furthermore, the EAB of the samples can also cover the whole X band and Ku band at small sample thicknesses (2.09–3.47 mm). The excellent properties of the materials suggest great prospect as electromagnetic absorbers.
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- 2023
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6. Farmers’ willingness to accept compensation for ginkgo conservation: evidence from rural Taixing, China
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Xiaoqing Dai, Lijie Pu, Debang Jiang, Ying Zhang, and Fangping Rao
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willingness to accept ,ginkgo resource ,conservation value ,compensation value ,rural China ,Nutrition. Foods and food supply ,TX341-641 ,Food processing and manufacture ,TP368-456 - Abstract
Numerous potential socioeconomic benefits provided by ginkgo resources have been identified but these have been threatened due to insufficient conservation over recent decades. Economic compensation is essential to induce enthusiasm for conservation. This paper examines the farmers’ willingness to accept ginkgo conservation compensation as well as other influencing factors based on survey data from 208 households. The results show that: first, the compensation amounts for the three different ginkgo conservation values are 820.86, 249.03, and 71.29 yuan per tree, respectively. Second, the overall compensation value is 388.17 yuan per tree with an average of 8430.83 yuan per household. Third, factors that influence the conservation compensation values are size-specific. Specifically, for large ginkgoes, a given respondent’s age, gender, job, household income, the number of large ginkgoes and arable land area are the most important factors. For medium ginkgoes, the area of arable land and farmers’ willingness to protect ginkgo trees are the key determining factors. By contrast, the requisite factors are different for small size ginkgo trees. A given respondent’s job, the arable land area and farmers’ perception of the importance of conducting conservation for local development are found to have significant impacts. These findings provide a useful base for assessing the conservation value for this endangered and valuable forest resource. Furthermore, the results also indicate that a size-based payment for farmers’ ginkgo conservation behaviors can be a useful economic tool to induce and deepen the latter’s conservation efforts.
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- 2024
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7. Correlation between elevated maternal serum alpha-fetoprotein and ischemic placental disease: a retrospective cohort study
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Xiaoqing Dai, Huimin Zhang, Bin Wu, Wenwen Ning, Yijie Chen, and Yiming Chen
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alpha-fetoprotein ,ischemic placental disease ,pregnancy outcome ,retrospective cohort study ,relative risk ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background To evaluate the correlation between elevated maternal serum alpha-fetoprotein (AFP) in the second trimester and ischemic placental disease (IPD). Methods A retrospective cohort study was conducted to analyze the data of 22,574 pregnant women who delivered in the Department of Obstetrics at Hangzhou Women’s Hospital from 2018 to 2020, and were screened for maternal serum AFP and free beta-human chorionic gonadotropin (free β-hCG) in the second trimester. The pregnant women were divided into two groups: elevated maternal serum AFP group (n = 334, 1.48%); and normal group (n = 22,240, 98.52%). Mann-Whitney U-test or Chi-square test was used for continuous or categorical data. Modified Poisson regression analysis was used to calculate the relative risk (RR) and 95% confidence interval (CI) of the two groups. Results The AFP MoM and free β-hCG MoM in the elevated maternal serum AFP group were higher than the normal group (2.25 vs. 0.98, 1.38 vs. 1.04) and the differences were all statistically significant (all P < .001). Placenta previa, hepatitis B virus carrying status of pregnant women, premature rupture of membranes (PROM), advanced maternal age (≥35 years), increased free β-hCG MoM, female infants, and low birth weight (RR: 2.722, 2.247, 1.769, 1.766, 1.272, 0.624, 2.554 respectively) were the risk factors for adverse maternal pregnancy outcomes in the elevated maternal serum AFP group. Conclusions Maternal serum AFP levels during the second trimester can monitor IPD, such as IUGR, PROM, and placenta previa. Maternal women with high serum AFP levels are more likely to deliver male fetuses and low birth weight infants. Finally, the maternal age (≥35 years) and hepatitis B carriers also increased maternal serum AFP significantly.
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- 2023
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8. Gamma-glutamyl transpeptidase to platelet and gamma-glutamyl transpeptidase to lymphocyte ratio in a sample of Chinese Han population
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Weijie Chen, Danmian Hong, Zeliang Chen, Xiaoqing Dai, Jing Cao, Min Yu, and Liping Li
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Gamma-glutamyl transpeptidase to platelet ratio ,Gamma-glutamyl transpeptidase to lymphocyte ratio ,Reference range ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Abstract Background Gamma-glutamyl transpeptidase to platelet ratio (GPR) and gamma-glutamyl transpeptidase to lymphocyte ratio (GLR) are assumed to be prognostic factors in liver fibrosis, cirrhosis and hepatocellular carcinoma. However, the reference values of GPR and GLR were not known. Objectives The study aimed to investigate the reference ranges of GPR and GLR in Chinese Han population in Chaoshan region in South China. Methods A retrospective study was conducted in the First Affiliated Hospital of Shantou University Medical College in South China. 2400 healthy adults aged 20~79 years were included. GPR and GLR were determined. Results Of 2400 healthy adults, 1200 men and 1200 women were included. The median GPR and GLR for men were 0.22 and 11.28, for women were 0.18 and 7.86, respectively. The 95% reference range of GPR in normal male and female are 0.09~0.54 and 0.08~0.55, GLR are 4.55~29.64 and 3.52~23.08, respectively. The male had a higher GPR at age 20~49 than the female while the GPR at age 60~79 was higher in the female than in the male. The GPR was affected by age, decreased with aging in male and increased in female. The GLR was higher in the male than in the female and varied with aging in the female but not in the male. Conclusion The study provides reference data on GPR and GLR from different age and sex groups in South China. GPR and GLR varied with age and sex.
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- 2022
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9. A self-healing and energy-dissipating impact-hardening polymer based on a variety of reversible dynamic bonds
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Haolijie Wen, Jie Sun, Kejing Yu, Xiaoning Yang, Xiaoqing Dai, and Zhongwei Zhang
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Impact-hardening ,Energy dissipation ,Shape stability ,Mechanism ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Modern protective materials must not only exhibit an intelligent response behavior, but also possess an excellent energy absorption ability. The applicability of shear-stiffening gel is limited because it generally cannot demonstrate good shape stability, strain sensitivity, and energy dissipation ability simultaneously. In this study, multiple hydrogen bonds and metal coordination bonds are incorporated into a shear-hardening gel to fabricate a new impact-hardening polymer (IHP-Cu) with multi-level energy dissipation pathways, thereby achieving a balance between shape stability, rapid self-healing, and energy dissipation. IHP-Cu maintains a stable shape in its natural state, exhibits significant strain-sensitive behavior at different strain rates, and supports a weight of 400 g at room temperature for 10 s after damage. In compression cycling tests, its energy absorption efficiency exceeded 90%. In the frequency-dependent test (strain rate of 0.1 s−1), its elastic work and viscous dissipation increased by 24 and 12.5 times, respectively, compared to those of the conventional shear-hardening gel. This paper also reveals the energy dissipation mechanism of IHP-Cu, thus providing a theoretical basis and reference for the development and optimization of new protective materials.
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- 2023
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10. CRISPR-based genome editing in primary human pancreatic islet cells
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Romina J. Bevacqua, Xiaoqing Dai, Jonathan Y. Lam, Xueying Gu, Mollie S. H. Friedlander, Krissie Tellez, Irene Miguel-Escalada, Silvia Bonàs-Guarch, Goutham Atla, Weichen Zhao, Seung Hyun Kim, Antonia A. Dominguez, Lei S. Qi, Jorge Ferrer, Patrick E. MacDonald, and Seung K. Kim
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Science - Abstract
The editing of primary human islets could provide insight into diabetes pathogenesis. Here the authors use CRISPR-Cas9 to target regulatory elements associated with T2D susceptibility.
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- 2021
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11. Imaging Findings From Different Pathological Types of Oral and Maxillofacial Intramuscular Hemangiomas for Selecting Optimum Management
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Dan Zhu, Xiaoqing Dai, Jingbo Wang, Chunye Zhang, Xiaofeng Tao, Lizhong Wu, and Ling Zhu
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intramuscular hemangioma ,magnetic resonance image ,computed tomography ,histopathological classification ,blood supply status ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
ObjectivesTo assess computed tomography (CT) and magnetic resonance imaging (MRI) findings of intramuscular hemangiomas (IMHs) in oral and maxillofacial region and correlate them with the histopathological classifications for selecting optimum management.MethodsThe clinical data and pretreatment findings of 32 patients with pathologically proven IMHs on CT (n = 10), MRI (n = 27), or both (n = 5) were analyzed retrospectively. Correspondence of clinical and imaging characters with 3 different pathological classifications (cavernous, capillary, and mixed) of IMHs was studied. A number of pitfalls and overlap of imaging features can result in misdiagnosis of different IMHs lesions.ResultsFour patients had multi-muscular lesions, and 28 had single-muscular lesions. The predilection site were the tongue (11 cases, 34.4%) and the masseter muscle (10 cases, 31.2%). Cavernous type (17 cases, 53.1%) was the most common IMHs type. All patients showed slightly hypointense or isointense on T1-weighted imaging, 3 patients showed hyperintense on T2-weighted imaging and the others showed slightly hyperintense. The most common enhancement pattern was progressive (29 cases, 90.6%). The capillary type (9 cases, 28.1%) and mixed type (6 cases, 28.1%) of IMHs on imaging indicated characteristics of lesions with rich blood supply status, the cavernous type (17cases, 53.1%) of IMHs belonged to relatively poor blood supply lesions. A total of 5 patients (15.6%) were initially misdiagnosed, there were recurrences in 4 IMHs patients. Extra functional MRI (fMRI) was performed on these 5 misdiagnosed patients, the average ADC of the 5 patients was 1.50 × 10−3 mm2/s. The presence of vermicular vessels was different among these three types of IMHs.ConclusionsThe reason for the misdiagnosis in localized IMHs may be the obvious border of mass-like lesions and the lack of enlarged vessels. Combined evaluation of presence of vermicular vessels and fMRI might be more accurately for determining the IMHs and create a preoperative plan.
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- 2022
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12. Improved glucose tolerance with DPPIV inhibition requires β‐cell SENP1 amplification of glucose‐stimulated insulin secretion
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Mourad Ferdaoussi, Nancy Smith, Haopeng Lin, Austin Bautista, Aliya F. Spigelman, James Lyon, XiaoQing Dai, Jocelyn E. Manning Fox, and Patrick E. MacDonald
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Physiology ,QP1-981 - Abstract
Abstract Pancreatic islet insulin secretion is amplified by both metabolic and receptor‐mediated signaling pathways. The incretin‐mimetic and DPPIV inhibitor anti‐diabetic drugs increase insulin secretion, but in humans this can be variable both in vitro and in vivo. We examined the correlation of GLP‐1 induced insulin secretion from human islets with key donor characteristics, glucose‐responsiveness, and the ability of glucose to augment exocytosis in β‐cells. No clear correlation was observed between several donor or organ processing parameters and the ability of Exendin 4 to enhance insulin secretion. The ability of glucose to facilitate β‐cell exocytosis was, however, significantly correlated with responses to Exendin 4. We therefore studied the effect of impaired glucose‐dependent amplification of insulin exocytosis on responses to DPPIV inhibition (MK‐0626) in vivo using pancreas and β‐cell specific sentrin‐specific protease‐1 (SENP1) mice which exhibit impaired metabolic amplification of insulin exocytosis. Glucose tolerance was improved, and plasma insulin was increased, following either acute or 4 week treatment of wild‐type (βSENP1+/+) mice with MK‐0626. This DPPIV inhibitor was ineffective in βSENP1+/− or βSENP1−/− mice. Finally, we confirm impaired exocytotic responses of β‐cells and reduced insulin secretion from islets of βSENP1−/− mice and show that the ability of Exendin 4 to enhance exocytosis is lost in these cells. Thus, an impaired ability of glucose to amplify insulin exocytosis results in a deficient effect of DPPIV inhibition to improve in vivo insulin responses and glucose tolerance.
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- 2020
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13. FBXW7 Confers Radiation Survival by Targeting p53 for Degradation
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Danrui Cui, Xiufang Xiong, Jianfeng Shu, Xiaoqing Dai, Yi Sun, and Yongchao Zhao
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Biology (General) ,QH301-705.5 - Abstract
Summary: The tumor suppressor p53 plays a critical role in integrating a wide variety of stress responses. Therefore, p53 levels are precisely regulated by multiple ubiquitin ligases. In this study, we report that FBXW7, a substrate recognition component of the SKP1-CUL1-F-box (SCF) E3 ligase, interacts with and targets p53 for polyubiquitination and proteasomal degradation after exposure to ionizing radiation or etoposide. Mechanistically, DNA damage activates ATM to phosphorylate p53 on Ser33 and Ser37, which facilitates the FBXW7 binding and subsequent p53 degradation by SCFFBXW7. Inactivation of ATM or SCFFBXW7 by small molecular inhibitors or genetic knockdown/knockout approaches extends the p53 protein half-life upon DNA damage in an MDM2-independent manner. Biologically, FBXW7 inactivation sensitizes cancer cells to radiation or etoposide by stabilizing p53 to induce cell-cycle arrest and apoptosis. Taken together, our study elucidates a mechanism by which FBXW7 confers cancer cell survival during radiotherapy or chemotherapy via p53 targeting. : In this study, Cui et al. demonstrate that upon DNA damage, ATM is activated to phosphorylate p53 to facilitate its binding with FBXW7, leading to p53 ubiquitination and proteasomal degradation. Biologically, FBXW7 inactivation sensitizes cancer cells to radiation or etoposide by stabilizing p53 to induce cell-cycle arrest and apoptosis. Keywords: FBXW7, p53, E3 ligase, DNA damage, radiosensitivity, ATM, SCF, CRL, ubiquitination, degradation
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- 2020
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14. Controllable Fabrication of SiC@C-Fe3O4 Hybrids and Their Excellent Electromagnetic Absorption Properties
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Liqun Duan, Xiaoqing Dai, Fan Wu, Aming Xie, Jian-An Wu, Minqian Sun, and Yilu Xia
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SiC nanowires ,carbon shell ,Fe3O4 ,dielectric ,magnetic ,electromagnetic absorption ,Chemistry ,QD1-999 - Abstract
In this work, a batch of novel ternary hybrids (SiC@C-Fe3O4), characterized by SiC nanowires core, carbon shell, and adhered Fe3O4 nanoparticles were controllably synthesized via surface carbonization of SiCnw followed by hydrothermal reaction. Carbon, which was derived from SiC with nanometer thickness, possesses an amorphous structure, while Fe3O4 nanoparticles are in a crystalline state. Simultaneously, the inducement of Fe3O4 nanoparticles can provide significant magnetic loss, which is well-tuned by changing the molar content of iron precursors (FeCl3·6H2O and FeCl2·4H2O). SiC@C-Fe3O4 hybrids show great electromagnetic absorption performance owing to the synergy effect of dielectric and magnetic losses. The minimum refection loss can reach to −63.71 dB at 11.20 GHz with a thickness of 3.10 mm, while the broad effective absorption bandwidth (EAB) can reach to 7.48 GHz in range of 10.52–18.00 GHz with a thickness of 2.63 mm. Moreover, the EAB can also cover the whole X band and Ku band. The outstanding performance of the obtained material implys that it is a promising candidate as an electromagnetic absorber.
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- 2021
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15. SUMOylation and calcium control syntaxin-1A and secretagogin sequestration by tomosyn to regulate insulin exocytosis in human ß cells
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Mourad Ferdaoussi, Jianyang Fu, Xiaoqing Dai, Jocelyn E. Manning Fox, Kunimasa Suzuki, Nancy Smith, Gregory Plummer, and Patrick E. MacDonald
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Medicine ,Science - Abstract
Abstract Insulin secretion from pancreatic ß cells is a multistep process that requires the coordination of exocytotic proteins that integrate diverse signals. These include signals derived from metabolic control of post-translational SUMOylation and depolarization-induced rises in intracellular Ca2+. Here we show that tomosyn, which suppresses insulin exocytosis by binding syntaxin1A, does so in a manner which requires its SUMOylation. Glucose-dependent de-SUMOylation of tomosyn1 at K298 releases syntaxin1A and controls the amplification of exocytosis in concert with a recently-identified tomosyn1-interacting partner; the Ca2+-binding protein secretagogin, which dissociates from tomosyn1 in response to Ca2+-raising stimuli and is required for insulin granule trafficking and exocytosis downstream of Ca2+ influx. Together our results suggest that tomosyn acts as a key signaling hub in insulin secretion by integrating signals mediated by metabolism-dependent de-SUMOylation and electrically-induced entry of Ca2+ to regulate the availability of exocytotic proteins required for the amplification of insulin secretion.
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- 2017
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16. Short-Term Origin-Destination Based Metro Flow Prediction with Probabilistic Model Selection Approach
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Xiaoqing Dai, Lijun Sun, and Yanyan Xu
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Transportation engineering ,TA1001-1280 ,Transportation and communications ,HE1-9990 - Abstract
Reliable prediction of short-term passenger flow could greatly support metro authorities’ decision processes, help passengers to adjust their travel schedule, or, in extreme cases, assist emergency management. The inflow and outflow of the metro station are strongly associated with the travel demand within metro networks. The purpose of this paper is to obtain such prediction. We first collect the origin-destination information from the smart-card data and explore the passenger flow patterns in a metro system. We then propose a data driven framework for short-term metro passenger flow prediction with the ability to utilize both spatial and temporal related information. The approach adopts two forecasts as basic models and then uses a probabilistic model selection method, random forest classification, to combine the two outputs to achieve a better forecast. In the experiments, we compare the proposed model with four other prediction models, i.e., autoregressive-moving-average, neural networks, support vector regression, and averaging ensemble model, as well as the basic models. The results indicate that the proposed approach outperforms the others in most cases. The origin-destination flows extracted from smart-card data can be successfully exploited to describe different metro travel patterns. And the framework proposed here, especially the probabilistic combination method, can improve the performance of short-term transportation prediction.
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- 2018
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17. Adenylosuccinate Is an Insulin Secretagogue Derived from Glucose-Induced Purine Metabolism
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Jessica R. Gooding, Mette V. Jensen, Xiaoqing Dai, Brett R. Wenner, Danhong Lu, Ramamani Arumugam, Mourad Ferdaoussi, Patrick E. MacDonald, and Christopher B. Newgard
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Biology (General) ,QH301-705.5 - Abstract
Pancreatic islet failure, involving loss of glucose-stimulated insulin secretion (GSIS) from islet β cells, heralds the onset of type 2 diabetes (T2D). To search for mediators of GSIS, we performed metabolomics profiling of the insulinoma cell line 832/13 and uncovered significant glucose-induced changes in purine pathway intermediates, including a decrease in inosine monophosphate (IMP) and an increase in adenylosuccinate (S-AMP), suggesting a regulatory role for the enzyme that links the two metabolites, adenylosuccinate synthase (ADSS). Inhibition of ADSS or a more proximal enzyme in the S-AMP biosynthesis pathway, adenylosuccinate lyase, lowers S-AMP levels and impairs GSIS. Addition of S-AMP to the interior of patch-clamped human β cells amplifies exocytosis, an effect dependent upon expression of sentrin/SUMO-specific protease 1 (SENP1). S-AMP also overcomes the defect in glucose-induced exocytosis in β cells from a human donor with T2D. S-AMP is, thus, an insulin secretagogue capable of reversing β cell dysfunction in T2D.
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- 2015
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18. DeSUMOylation Controls Insulin Exocytosis in Response to Metabolic Signals
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Patrick E. MacDonald, Xiaoqing Dai, Elisa Vergari, and Gregory Plummer
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insulin ,exocytosis ,SUMOylation ,SENP1 ,NADPH ,redox ,Microbiology ,QR1-502 - Abstract
The secretion of insulin by pancreatic islet β-cells plays a pivotal role in glucose homeostasis and diabetes. Recent work suggests an important role for SUMOylation in the control of insulin secretion from β-cells. In this paper we discuss mechanisms whereby (de)SUMOylation may control insulin release by modulating β-cell function at one or more key points; and particularly through the acute and reversible regulation of the exocytotic machinery. Furthermore, we postulate that the SUMO-specific protease SENP1 is an important mediator of insulin exocytosis in response to NADPH, a metabolic secretory signal and major determinant of β-cell redox state. Dialysis of mouse β-cells with NADPH efficiently amplifies β-cell exocytosis even when extracellular glucose is low; an effect that is lost upon knockdown of SENP1. Conversely, over-expression of SENP1 itself augments β-cell exocytosis in a redox-dependent manner. Taken together, we suggest that (de)SUMOylation represents an important mechanism that acutely regulates insulin secretion and that SENP1 can act as an amplifier of insulin exocytosis.
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- 2012
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19. Transcript Expression Data from Human Islets Links Regulatory Signals from Genome-Wide Association Studies for Type 2 Diabetes and Glycemic Traits to Their Downstream Effectors.
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Martijn van de Bunt, Jocelyn E Manning Fox, Xiaoqing Dai, Amy Barrett, Caleb Grey, Lei Li, Amanda J Bennett, Paul R Johnson, Raymond V Rajotte, Kyle J Gaulton, Emmanouil T Dermitzakis, Patrick E MacDonald, Mark I McCarthy, and Anna L Gloyn
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Genetics ,QH426-470 - Abstract
The intersection of genome-wide association analyses with physiological and functional data indicates that variants regulating islet gene transcription influence type 2 diabetes (T2D) predisposition and glucose homeostasis. However, the specific genes through which these regulatory variants act remain poorly characterized. We generated expression quantitative trait locus (eQTL) data in 118 human islet samples using RNA-sequencing and high-density genotyping. We identified fourteen loci at which cis-exon-eQTL signals overlapped active islet chromatin signatures and were coincident with established T2D and/or glycemic trait associations. At some, these data provide an experimental link between GWAS signals and biological candidates, such as DGKB and ADCY5. At others, the cis-signals implicate genes with no prior connection to islet biology, including WARS and ZMIZ1. At the ZMIZ1 locus, we show that perturbation of ZMIZ1 expression in human islets and beta-cells influences exocytosis and insulin secretion, highlighting a novel role for ZMIZ1 in the maintenance of glucose homeostasis. Together, these findings provide a significant advance in the mechanistic insights of T2D and glycemic trait association loci.
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- 2015
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20. A Macroscopic Analysis of Curbside Stopping Activities of On-demand Mobility Service.
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Han Qiu 0007, Xiaoqing Dai, and Jing Chen
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- 2020
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21. Experimental Teaching of Information Security Based on Virtual Simulation.
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Xiaoqing Dai
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- 2021
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22. Admission Heart Rate and Mortality in Critically Ill Patients with Acute Aortic Dissection
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Zeliang Chen, Wei Pan, Jing Cao, Xiaoqing Dai, Wan Lin, Hongjuan Chen, Kaihong Yi, and Min Yu
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General Medicine ,Cardiology and Cardiovascular Medicine - Published
- 2023
23. Porous Magnetic Carbon Spheres with Adjustable Magnetic-Composition and Synergistic Effect for Lightweight Microwave Absorbers
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Hanxiao Xu, Zizhuang He, Yurou Li, Yiruo Wang, Lingzi Shi, Zhongwei Zhang, Xiaoqing Dai, Ziming Xiong, Wangchang Geng, and Panbo Liu
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- 2023
24. Protocol update for late endothelial progenitor cells identified by double‐positive staining
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Lishan Wu, Weijie Chen, Zeliang Chen, Jing Cao, Xiaoqing Dai, Hongjuan Chen, Xuerui Tan, and Min Yu
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Staining and Labeling ,cardiovascular system ,Molecular Medicine ,Original Article ,Cell Biology ,Original Articles ,circulatory and respiratory physiology ,Endothelial Progenitor Cells - Abstract
Endothelial progenitor cells (EPCs), which are precursors of endothelial cells (ECs), have the capacity to circulate, proliferate and differentiate into mature ECs. EPCs are primarily identified by the uptake of 1,1‐dioctadecyl‐3,3,3,3‐tetramethylindocarbocyanine‐labelled acetylated low‐density lipoprotein (Dil‐acLDL) and the binding of fluorescein‐isothiocyanate (FITC)‐conjugated Ulex europaeus agglutinin lectin (FITC‐UEA‐I). However, the cytoplasm and nucleus are usually stained by FITC‐UEA‐I via a typical method to double‐stain late EPCs. It is necessary to explore a new method to improve the quality of fluorescence photomicrographs of late EPCs stained with FITC‐UEA‐I. Here, we described an updated protocol for double‐staining late EPCs with Dil‐acLDL and FITC‐UEA‐I, with the cells more optimally stained with FITC‐UEA‐I.
- Published
- 2021
25. Flexible electromagnetic wave absorption material: Multiscale synergistic approach to achieve whole X-band absorption and thermal stealth property
- Author
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Tianyu Chen, Fan Zhou, Xudong Cai, Tiantian Liu, Kun Qian, Zhongwei Zhang, Liqun Duan, Xiaoqing Dai, and Kejing Yu
- Subjects
General Materials Science ,General Chemistry - Published
- 2023
26. Application of 3D Printing and WebGL-Based 3D Visualisation Technology in Imaging Teaching of Ankle Joints
- Author
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Jiuhong Guo, Xiaomin Li, Bing Wu, Yang Qu, Daqian Wan, Xiaoqing Dai, Siyu Liu, and Songtao Ai
- Subjects
medicine.medical_specialty ,Multidisciplinary ,business.industry ,Computer science ,Teaching method ,education ,Ankle bone ,Health technology ,3D printing ,Rendering (computer graphics) ,Visualization ,medicine.anatomical_structure ,Medical imaging ,medicine ,medicine.bone ,Medical physics ,Ankle ,business - Abstract
With the rapid development of medical technology, 3D printing technology with realistic representation can perfectly display static human anatomy, while 3D visualisation technology based on Web Graphics Library (WebGL) can promote the rigid replication characteristics of traditional teaching models and express the dynamic spatial relationship between different anatomical structures. Medical students traditionally have less cognition of ankle ligament sprains. In this study, computed tomography (CT) and magnetic resonance imaging (MRI) data of the ankle joints of volunteers were used to print models of the ankle bone, tendon, and ligament using 3D printing technology, and a real-time interactive 3D digital model of the functional ankle joint was designed using 3D visualisation based on WebGL and 2D image real-time rendering technology for interactive teaching. The utility of the 3D printing model combined with the WebGL-based 3D digital teaching model was evaluated in comparison with traditional teaching methods in 24 medical students. The results showed that the total score of students in the experimental group (mean ± SD, 79.48 ± 12.93) was significantly better than that of the control group (61.00 ± 14.94) with P < 0.05. The practical test scores of the experimental group (18.00 ± 2.70) were significantly higher than those of the control group (13.67 ± 4.96) with P < 0.05. In the satisfaction survey, the feedback questionnaire showed that the interactive teaching model of 3D printing technology combined with WebGL-based 3D visualisation technology was recognised by students in terms of quality and overall satisfaction. In addition, female students who used 3D printing combined with WebGL-based 3D visualisation technology as learning aids had a greater difference in practical test scores from the control group than male students. This study has demonstrated that the interactive teaching mode of 3D printing combined with WebGL-based 3D visualisation technology is beneficial to the teaching of medical imaging, enriching the learning experience of students, and increasing the interaction between teachers and students.
- Published
- 2021
27. β-cell responses to high fat feeding: A role and mechanism for redox sensing by SENP1
- Author
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Haopeng Lin, Kunimasa Suzuki, Nancy Smith, Xi Li, Lisa Nalbach, Sonia Fuentes, Aliya F Spigelman, Xiaoqing Dai, Austin Bautista, Mourad Ferdaoussi, Saloni Aggarwal, Andrew R Pepper, Leticia P Roma, Emmanuel Ampofo, Wen-hong Li, and Patrick E MacDonald
- Abstract
Pancreatic β-cells respond to metabolic stress by upregulating insulin secretion, however the underlying mechanisms remain unclear. In β-cells from overweight humans without diabetes, and mice fed a high-fat diet for 2 days, insulin exocytosis and secretion are enhanced without increased Ca2+influx. β-cell RNA-seq suggests altered metabolic pathways early following HFD, where we find increased basal oxygen consumption, proton leak, but a more reduced cytosolic redox state. Increased β-cell exocytosis after 2-day HFD is dependent on this reduced intracellular redox and requires thesentrin-specific SUMO-protease-1(SENP1). Mice with either pancreas- or β-cell-specific SENP1 deletion fail to up-regulate exocytosis and become rapidly glucose intolerant after 2-day HFD. Mechanistically, redox-sensing by SENP1 requires a thiol group at C535 which together with Zn+-binding suppresses basal protease activity and unrestrained β-cell exocytosis and increases SENP1 sensitivity to regulation by redox signals.
- Published
- 2022
28. Reference intervals for coagulation tests in adults with different ABO blood types
- Author
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Zeliang Chen, Xiaoqing Dai, Jing Cao, Xuerui Tan, Shuying Chen, and Min Yu
- Subjects
Microbiology (medical) ,Adult ,Male ,Biochemistry (medical) ,Clinical Biochemistry ,Public Health, Environmental and Occupational Health ,Hematology ,Middle Aged ,Medical Laboratory Technology ,Young Adult ,Reference Values ,Prothrombin Time ,Immunology and Allergy ,Humans ,Female ,Partial Thromboplastin Time ,Blood Coagulation Tests ,Aged ,Retrospective Studies - Abstract
Coagulation tests are affected by many factors, such as age, race, and gestation. Although coagulation test results vary by ABO blood type, reference intervals of different ABO blood groups remain to be determined. This study aims to investigate the reference ranges of coagulation tests for different ABO blood groups in the Han population in South China.A retrospective study was conducted in the First Affiliated Hospital of Shantou University Medical College. In all, 9600 individuals aged between 20 and 79 years were included. Coagulation tests, including prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), thrombin time, and fibrinogen, were performed.There was a significant difference in PT, INR, and aPTT among ABO blood groups. PT and INR varied slightly between ABO blood groups. There was a higher aPTT value in individuals in the O blood group than in those in non-O blood groups, in both males and females across the included age range. No differences were found in thrombin time and fibrinogen between the ABO blood groups.The study provides reference data on coagulation tests from ABO blood groups in South China. The established reference intervals specific to ABO blood type, sex, and age may improve clinical decisions based on coagulation tests.
- Published
- 2022
29. Synchronously modulated the morphology and crystal defects of α-MnO2 for high-performance mono-component electromagnetic wave absorber
- Author
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Tianyu Chen, Fan Zhou, Kun Qian, Kunlin Chen, Zhongwei Zhang, Xiaoqing Dai, Minqian Sun, and Kejing Yu
- Subjects
General Physics and Astronomy ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2023
30. DEPTOR is an in vivo tumor suppressor that inhibits prostate tumorigenesis via the inactivation of mTORC1/2 signals
- Author
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Xiaoqing Dai, Fei Yang, Yanli Bi, Longyuan Gong, Haomin Li, Yi Sun, Jianfeng Shu, Xiaoyu Chen, Xiufang Xiong, Danrui Cui, Yongchao Zhao, and Dongping Wei
- Subjects
Male ,0301 basic medicine ,Heterozygote ,Cancer Research ,Carcinogenesis ,Cell Survival ,Mechanistic Target of Rapamycin Complex 2 ,mTORC1 ,Mechanistic Target of Rapamycin Complex 1 ,DEPTOR ,medicine.disease_cause ,mTORC2 ,Article ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Cell Movement ,Genetics ,medicine ,Animals ,Humans ,PTEN ,Neoplasm Invasiveness ,Cell migration ,Molecular Biology ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Cell Proliferation ,Prostate cancer ,biology ,Intracellular Signaling Peptides and Proteins ,PTEN Phosphohydrolase ,Membrane Proteins ,Prostatic Neoplasms ,030104 developmental biology ,Gene Knockdown Techniques ,TOR signalling ,030220 oncology & carcinogenesis ,biology.protein ,Cancer research ,Signal Transduction - Abstract
The DEPTOR-mTORC1/2 axis has been shown to play an important, but a context dependent role in the regulation of proliferation and the survival of various cancer cells in cell culture settings. The in vivo role of DEPTOR in tumorigenesis remains elusive. Here we showed that the levels of both DEPTOR protein and mRNA were substantially decreased in human prostate cancer tissues, which positively correlated with disease progression. DEPTOR depletion accelerated proliferation and survival, migration, and invasion in human prostate cancer cells. Mechanistically, DEPTOR depletion not only activated both mTORC1 and mTORC2 signals to promote cell proliferation and survival, but also induced an AKT-dependent epithelial–mesenchymal transition (EMT) and β-catenin nuclear translocation to promote cell migration and invasion. Abrogation of mTOR or AKT activation rescued the biological consequences of DEPTOR depletion. Importantly, in a Deptor-KO mouse model, Deptor knockout accelerated prostate tumorigenesis triggered by Pten loss via the activation of mTOR signaling. Collectively, our study demonstrates that DEPTOR is a tumor suppressor in the prostate, and its depletion promotes tumorigenesis via the activation of mTORC1 and mTORC2 signals. Thus, DEPTOR reactivation via a variety of means would have therapeutic potential for the treatment of prostate cancer.
- Published
- 2019
31. PLAC8 promotes EV71 infected inflammatory lesion by disturbing Th-cell-related cytokines release in neonatal mouse
- Author
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Xiaoqing Dai, Liru Zhu, Feng Ke, Xiaochuan Shui, Xiaoxia Yang, Shiyong Hao, and Xuejiao Chen
- Subjects
Microarray ,Cellular differentiation ,Cell ,Inflammation ,Disease ,T-Lymphocytes, Regulatory ,Mice ,Virology ,medicine ,Enterovirus 71 ,Enterovirus Infections ,Animals ,Humans ,RNA, Messenger ,Messenger RNA ,Lung ,biology ,Age Factors ,Brain ,Proteins ,T-Lymphocytes, Helper-Inducer ,biology.organism_classification ,Enterovirus A, Human ,Disease Models, Animal ,medicine.anatomical_structure ,Animals, Newborn ,Immunology ,Cytokines ,medicine.symptom - Abstract
Enterovirus 71 can cause severe hand, foot, and mouth disease (HFMD) in children. However, little is known about the mechanism of inflammatory disorders caused by EV71 infection and why severe cases are mainly children aged under-three. In current study, using mRNA microarray assay, the differential expression of Placenta-specific 8 (PLAC8) was identified in mice brain. In addition, we found that PLAC8 expression was down-regulated with age in mice lung tissues and human peripheral blood. Then, we further proved that PLAC8 could promote inflammation progress and disturb Th1/Th2/Th17/Treg related cytokines release after EV71 infection using PLAC8 plasmid over-expressed neonatal mouse model. Our data suggest that PLAC8 might play a crucial role in Th cell differentiation and inflammatory damage caused by EV71 infection in infants. Thus, our findings would help understand the causes of severe inflammatory injury in infants during EV71 infection, and provide new insights into the prevention and control of severe HFMD.
- Published
- 2021
32. Whole Cell Patch Clamp of Dispersed Human Islet Cells v1
- Author
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Xiaoqing Dai, Austin Bautista, and Patrick E Macdonald
- Abstract
Cells use exocytosis to secrete a wide variety of molecules, including proteins, hormones, and neurotransmitters. Exocytosis can be monitored at the single-cell level by using patch-clamp electrophysiology to measure changes in membrane capacitance as vesicles fuse with the cell membrane and release their content. Dispersion of pancreatic islets into single cells allows for individual characterization of electrophysiological characteristics and allows for collection of cellular content for recovery of full-length transcriptomes by use of Smart-seq2. Described in this protocol is the dispersion of pancreatic islets into single cells followed by whole-cell patch clamp electrophysiology which includes parameters representing cell size, exocytosis, sodium channel currents, and calcium channel currents. Cells are then collected individually after recording to be processed for single-cell RNA sequencing.
- Published
- 2021
33. The cross talk of two family members of β-TrCP in the regulation of cell autophagy and growth
- Author
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Danrui Cui, Ying Ma, Yongchao Zhao, Dongping Wei, Xiaoqing Dai, Xiufang Xiong, and Jianfeng Shu
- Subjects
0301 basic medicine ,Ubiquitin-Protein Ligases ,mTORC1 ,Mechanistic Target of Rapamycin Complex 1 ,DEPTOR ,Article ,Substrate Specificity ,03 medical and health sciences ,0302 clinical medicine ,Ubiquitin ,Cell Line, Tumor ,Macroautophagy ,Autophagy ,Humans ,Molecular Biology ,Transcription factor ,Cell Proliferation ,biology ,Cell growth ,Chemistry ,Intracellular Signaling Peptides and Proteins ,Ubiquitination ,Oncogenes ,Cell Biology ,beta-Transducin Repeat-Containing Proteins ,Ubiquitin ligase ,Cell biology ,Glucose ,030104 developmental biology ,Ubiquitin ligases ,030220 oncology & carcinogenesis ,Proteolysis ,biology.protein ,Degron ,Transcription Factors - Abstract
β-transducin repeat-containing protein (β-TrCP), one of the best-characterized substrate recognition components of the SKP1-CUL1-F-box (SCF) E3 ligase, has two distinct paralogs, β-TrCP1 and β-TrCP2, expressed in mammals. Through governing the ubiquitination and degradation of numerous key regulators, β-TrCP1/2 regulates various cellular physiological and pathological processes. However, whether and how these two proteins cross talk and whether they regulate cell autophagy and proliferation in different manners is completely unknown. Herein, we report that β-TrCP1 and β-TrCP2 are the physiological substrates of SCF E3 ligase and target each other for degradation that is dependent on their β-TrCP degron sequences. Furthermore, glucose deprivation activates AMPK kinase to phosphorylate β-TrCP1 and promotes the subsequent ubiquitination and degradation of β-TrCP1 by β-TrCP2, but does not promote β-TrCP2 degradation by β-TrCP1. Finally, we found that β-TrCP2, not β-TrCP1, preferentially degrades DEPTOR and REDD1, the inhibitors of mTORC1, to activate mTORC1, leading to autophagy inhibition and cell growth. Thus, our study demonstrates that β-TrCP1 and β-TrCP2 mutually target each other for degradation and that β-TrCP2 acts as a dominant paralog in the regulation of cell autophagy and growth, which might be a promising anticancer target.
- Published
- 2019
34. Pricing and Matching Optimization of On-demand Mobility Services for Multi-locational Curbside Stopping Activities
- Author
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Xiaoqing Dai and Han Qiu
- Subjects
Service (business) ,History ,Matching (statistics) ,Queueing theory ,Mathematical optimization ,Optimal matching ,Polymers and Plastics ,Computer science ,Context (language use) ,Congestion pricing ,Decision problem ,Industrial and Manufacturing Engineering ,Dynamic pricing ,Business and International Management - Abstract
In this paper, we studied the effect of mobility-on-demand (MoD) services' pricing and matching decisions on mitigating the negative impacts of curbside stopping activities. We first developed a set of macroscopic models of MoD services, curbside stopping systems, road networks, and their interactions. In particular, we generalized an existing queueing model of curbside stopping systems to the multiple-pickup-locations context, and formulated MoD services' demand guidance decision problem as an integer program. We also proposed a novel and efficient numerical method to find the equilibria of the system. Then, we apply simulation optimization methods over the proposed model to search for optimal MoD operations. Our numerical experiments showed that, compared with optimal pricing decisions, optimal matching decisions could better balance the welfare of the MoD service and its negative impact on road network capacities. This observation implied that matching mechanisms could be competitive alternatives to congestion pricing in mitigating the curbside stopping problem.
- Published
- 2021
35. DEPTOR is a direct p53 target that suppresses cell growth and chemosensitivity
- Author
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Linchen Wang, Danrui Cui, Longyuan Gong, Xiaoqing Dai, Xiaoyu Chen, Yongchao Zhao, and Xiufang Xiong
- Subjects
Cancer Research ,Transcription, Genetic ,Transcriptional regulatory elements ,Immunology ,DEPTOR ,Article ,law.invention ,Cellular and Molecular Neuroscience ,law ,Cell Line, Tumor ,Neoplasms ,medicine ,Humans ,Doxorubicin ,lcsh:QH573-671 ,Promoter Regions, Genetic ,Protein kinase B ,Cell Proliferation ,Gene knockdown ,Cell growth ,Chemistry ,lcsh:Cytology ,Intracellular Signaling Peptides and Proteins ,Cell Biology ,HCT116 Cells ,Cell biology ,Apoptosis ,A549 Cells ,Drug Resistance, Neoplasm ,TOR signalling ,Cancer cell ,MCF-7 Cells ,Suppressor ,Tumor Suppressor Protein p53 ,Proto-Oncogene Proteins c-akt ,medicine.drug - Abstract
DEP-domain containing mTOR-interacting protein (DEPTOR), a natural mTOR inhibitor, has essential roles in several processes, including cell growth, metabolism, apoptosis, and immunity. DEPTOR expression has been shown to be diversely controlled at transcriptional levels in cell- and context-specific manners. However, whether there is a general mechanism for the regulation of DEPTOR expression remains largely unknown. Here, we report that DEPTOR is a downstream target of the tumor suppressor, p53, whose activity is positively correlated with DEPTOR expression both in vitro in cell cultures and in vivo in mouse tissues. Mechanistically, p53 directly binds to the DEPTOR promoter and transactivates its expression. Depletion of the p53-binding site on the DEPTOR promoter by CRISPR-Cas9 technology decreases DEPTOR expression and promotes cell proliferation and survival by activating AKT signaling. Importantly, inhibition of AKT by small molecular inhibitors or genetic knockdown abrogates the induction of cell growth and survival induced by deletion of the p53-binding region on the DEPTOR promoter. Furthermore, p53, upon activation by the genotoxic agent doxorubicin, induces DEPTOR expression, leading to cancer cell resistance to doxorubicin. Together, DEPTOR is a direct p53 downstream target and contributes to p53-mediated inhibition of cell proliferation, survival, and chemosensitivity.
- Published
- 2020
36. A Macroscopic Analysis of Curbside Stopping Activities of On-demand Mobility Service
- Author
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Jing Chen, Xiaoqing Dai, and Han Qiu
- Subjects
Service (business) ,050210 logistics & transportation ,021103 operations research ,Operations research ,Computer science ,On demand ,0502 economics and business ,05 social sciences ,0211 other engineering and technologies ,02 engineering and technology ,Numerical models ,Externality - Abstract
We study the curbside stopping activities of on-demand mobility services from a macroscopic perspective. We develop a queueing network model of the curbside stopping system and integrate this model into existing macroscopic analyzing frameworks of on-demand mobility services. Theoretical analysis and numerical experiments both show that service operators can provide services at a level beyond the social optimum and introduce negative externalities to the system. Moreover, improvements in services’ operational efficiencies are not sufficient to resolve this problem. Therefore, it is necessary to introduce system-level solutions such as introduction of additional curbside stopping spaces.
- Published
- 2020
37. Short-Term Origin-Destination Based Metro Flow Prediction with Probabilistic Model Selection Approach
- Author
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Yanyan Xu, Xiaoqing Dai, Lijun Sun, Massachusetts Institute of Technology. Department of Civil and Environmental Engineering, Program in Media Arts and Sciences (Massachusetts Institute of Technology), Dai, Xiaoqing, Sun, Lijun, and Xu, Yanyan
- Subjects
Economics and Econometrics ,Schedule ,Article Subject ,Computer science ,Strategy and Management ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,02 engineering and technology ,computer.software_genre ,Data-driven ,0502 economics and business ,0202 electrical engineering, electronic engineering, information engineering ,050210 logistics & transportation ,Ensemble forecasting ,Artificial neural network ,Mechanical Engineering ,05 social sciences ,lcsh:TA1001-1280 ,Probabilistic logic ,Statistical model ,lcsh:HE1-9990 ,Computer Science Applications ,Random forest ,Support vector machine ,Automotive Engineering ,020201 artificial intelligence & image processing ,Data mining ,lcsh:Transportation engineering ,lcsh:Transportation and communications ,computer - Abstract
Reliable prediction of short-term passenger flow could greatly support metro authorities’ decision processes, help passengers to adjust their travel schedule, or, in extreme cases, assist emergency management. The inflow and outflow of the metro station are strongly associated with the travel demand within metro networks. The purpose of this paper is to obtain such prediction. We first collect the origin-destination information from the smart-card data and explore the passenger flow patterns in a metro system. We then propose a data driven framework for short-term metro passenger flow prediction with the ability to utilize both spatial and temporal related information. The approach adopts two forecasts as basic models and then uses a probabilistic model selection method, random forest classification, to combine the two outputs to achieve a better forecast. In the experiments, we compare the proposed model with four other prediction models, i.e., autoregressive-moving-average, neural networks, support vector regression, and averaging ensemble model, as well as the basic models. The results indicate that the proposed approach outperforms the others in most cases. The origin-destination flows extracted from smart-card data can be successfully exploited to describe different metro travel patterns. And the framework proposed here, especially the probabilistic combination method, can improve the performance of short-term transportation prediction.
- Published
- 2018
38. A Data-Efficient Approach for Evacuation Demand Generation and Dissipation Prediction in Urban Rail Transit System
- Author
-
Lijun Sun, Xiaoqing Dai, and Han Qiu
- Subjects
Urban rail transit ,Environmental effects of industries and plants ,Operations research ,Renewable Energy, Sustainability and the Environment ,Process (engineering) ,Computer science ,Geography, Planning and Development ,TJ807-830 ,evacuation demand ,data-efficient ,prediction ,Management, Monitoring, Policy and Law ,Simulation system ,Dissipation ,simulation ,TD194-195 ,disruption ,Renewable energy sources ,Environmental sciences ,General observation ,Closure (computer programming) ,Homogeneous ,GE1-350 ,urban rail transit ,Natural state - Abstract
Predicting evacuation demand, including its generation and dissipation process, for urban rail transit systems under disruptions, such as line and station closure, often requires comprehensive historical data recorded under homogeneous situations. However, data under disruptions are hard to collect due to various reasons, which makes traditional methods impractical in evacuation demand prediction. To address this problem from the modeling perspective, we develop a data-efficient approach to predict evacuation demand for urban rail transit systems under disruptions. Our model-based approach mainly uses historical data obtained from the natural state, when no shocks take place. We first formulate the mathematical representation of the evacuation demand for every type of urban rail transit station. Input variables in this step are location features related to the station under the disruption, as well as an origin–destination matrix under the natural state. Then, based on these mathematical expressions, we develop a simulation system to imitate the spatio-temporal evolution of evacuation demand within the whole network under disruptions. The transport capacity drop under disruptions is used to describe the disruption situation. Several typical scenarios from the Shanghai metro network are used as examples to implement the proposed method. The results show that our method is able to predict the generation and dissipation processes of evacuation demand, as well model how severely stations will be affected by given disruptions. One general observation we draw from the results is that the most vulnerable stations under disruption, where the locations peak evacuation demand occurs, are mainly turn-back stations, closed stations, and the transfer stations near closed stations. This paper provides new insight into evacuation demand prediction under disruptions. It could be used by transport authorities to better respond to the urban rail transit system disruption.
- Published
- 2021
39. FBXW7 Confers Radiation Survival by Targeting p53 for Degradation
- Author
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Xiaoqing Dai, Danrui Cui, Xiufang Xiong, Yi Sun, Yongchao Zhao, and Jianfeng Shu
- Subjects
0301 basic medicine ,F-Box-WD Repeat-Containing Protein 7 ,DNA damage ,Ataxia Telangiectasia Mutated Proteins ,Radiation Tolerance ,General Biochemistry, Genetics and Molecular Biology ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Ubiquitin ,law ,Cell Line, Tumor ,Neoplasms ,medicine ,Humans ,Phosphorylation ,lcsh:QH301-705.5 ,Etoposide ,Gene knockdown ,biology ,Radiotherapy ,Chemistry ,Cell Cycle Checkpoints ,HCT116 Cells ,Survival Analysis ,Ubiquitin ligase ,Cell biology ,030104 developmental biology ,HEK293 Cells ,lcsh:Biology (General) ,Apoptosis ,A549 Cells ,Cancer cell ,biology.protein ,Suppressor ,Tumor Suppressor Protein p53 ,030217 neurology & neurosurgery ,medicine.drug ,DNA Damage - Abstract
Summary: The tumor suppressor p53 plays a critical role in integrating a wide variety of stress responses. Therefore, p53 levels are precisely regulated by multiple ubiquitin ligases. In this study, we report that FBXW7, a substrate recognition component of the SKP1-CUL1-F-box (SCF) E3 ligase, interacts with and targets p53 for polyubiquitination and proteasomal degradation after exposure to ionizing radiation or etoposide. Mechanistically, DNA damage activates ATM to phosphorylate p53 on Ser33 and Ser37, which facilitates the FBXW7 binding and subsequent p53 degradation by SCFFBXW7. Inactivation of ATM or SCFFBXW7 by small molecular inhibitors or genetic knockdown/knockout approaches extends the p53 protein half-life upon DNA damage in an MDM2-independent manner. Biologically, FBXW7 inactivation sensitizes cancer cells to radiation or etoposide by stabilizing p53 to induce cell-cycle arrest and apoptosis. Taken together, our study elucidates a mechanism by which FBXW7 confers cancer cell survival during radiotherapy or chemotherapy via p53 targeting. : In this study, Cui et al. demonstrate that upon DNA damage, ATM is activated to phosphorylate p53 to facilitate its binding with FBXW7, leading to p53 ubiquitination and proteasomal degradation. Biologically, FBXW7 inactivation sensitizes cancer cells to radiation or etoposide by stabilizing p53 to induce cell-cycle arrest and apoptosis. Keywords: FBXW7, p53, E3 ligase, DNA damage, radiosensitivity, ATM, SCF, CRL, ubiquitination, degradation
- Published
- 2019
40. 1711-P: Pancreas Single-Cell Patch-Seq Links Physiologic Dysfunction in Diabetes to Transcriptomic Phenotypes
- Author
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Seung K. Kim, Xiaoqing Dai, Patrick Macdonald, Joan Camunas Soler, and Yan Hang
- Subjects
geography ,geography.geographical_feature_category ,Endocrinology, Diabetes and Metabolism ,Insulin ,medicine.medical_treatment ,Glucagon secretion ,Biology ,medicine.disease ,Islet ,Bioinformatics ,Phenotype ,Transcriptome ,medicine.anatomical_structure ,Diabetes mellitus ,Gene expression ,Internal Medicine ,medicine ,Pancreas - Abstract
Pancreatic islet-cells regulate glucose levels in the body through insulin and glucagon secretion; dysfunction of these cells leads to severe disease such as diabetes. Several single-cell transcriptome studies have shown heterogeneous gene expression in major islet cell-types such as beta and alpha cells. However, it has remained an open challenge to reconcile the heterogeneity in transcriptomic signatures with physiological observations of functional heterogeneity. Here we combined electrophysiological profiling and single-cell RNA sequencing of the same cells (pancreas patch-seq) to link transcriptomic phenotypes of islet cells to their physiologic properties. We collected 1,369 pancreas patch-seq cells from fresh and cryopreserved tissue and assessed function-gene expression networks in nondiabetic, type 1 diabetic (T1D) and type 2 diabetic (T2D) humans. We discovered that ‘hub’ genes and pathways drive functional heterogeneity in nondiabetic beta-cells and show that specific transcriptional programs correlate with physiologic dysfunction early in T2D. We have also found evidence that alpha-cell transcriptional plasticity acts as a driver of dysfunction in T1D. Disclosure J. Camunas Soler: None. X. Dai: None. Y. Hang: None. S. Kim: None. P. MacDonald: None. Funding Chan Zuckerberg Biohub; California Institute for Regenerative Medicine; National Institutes of Health
- Published
- 2019
41. Pancreas patch-seq links physiologic dysfunction in diabetes to single-cell transcriptomic phenotypes
- Author
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Joan Camunas-Soler, Xiaoqing Dai, Yan Hang, Austin Bautista, James Lyon, Kunimasa Suzuki, Seung K Kim, Stephen R Quake, and Patrick E MacDonald
- Subjects
0303 health sciences ,geography ,Type 1 diabetes ,endocrine system ,geography.geographical_feature_category ,endocrine system diseases ,Lineage markers ,Glucagon secretion ,030209 endocrinology & metabolism ,Type 2 diabetes ,Biology ,Islet ,medicine.disease ,Cell biology ,Transcriptome ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,medicine ,Glucose homeostasis ,Pancreas ,030304 developmental biology - Abstract
SummaryPancreatic islet cells regulate glucose homeostasis through insulin and glucagon secretion; dysfunction of these cells leads to severe diseases like diabetes. Prior single-cell transcriptome studies have shown heterogeneous gene expression in major islet cell-types; however it remains challenging to reconcile this transcriptomic heterogeneity with observed islet cell functional variation. Here we achieved electrophysiological profiling and single-cell RNA sequencing in the same islet cell (pancreas patch-seq) thereby linking transcriptomic phenotypes to physiologic properties. We collected 1,369 cells from the pancreas of donors with or without diabetes and assessed function-gene expression networks. We identified a set of genes and pathways that drive functional heterogeneity in β-cells and used these to predict β-cell electrophysiology. We also report specific transcriptional programs that correlate with dysfunction in type 2 diabetes (T2D) and extend this approach to cryopreserved cells from donors with type 1 diabetes (T1D), generating a valuable resource for understanding islet cell heterogeneity in health and disease.Key findingsPancreas patch-seq provides a single-cell survey of function-transcriptome pairing in 1,369 islet cells from donors with and without diabetesExpression of a specific subset of genes predicts β-cell electrophysiology in transcriptome-function networks.Compromised β-cell function in T2D correlates with altered ETV1 expression and inflammatory pathwaysFunctional heterogeneity in α-cells maps to ER stress and islet lineage markersApplication of patch-seq to cells from rare cryopreserved islets from donors with T1D
- Published
- 2019
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42. Numerical Simulation of Sideflash striking on the side wall of tall buildings
- Author
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Wantai Liu, Xiaoqing Dai, Chen Qian, Bo Zhang, and Ziming Xiong
- Subjects
0209 industrial biotechnology ,Thunder ,Computer simulation ,Field (physics) ,business.industry ,02 engineering and technology ,Structural engineering ,Solid modeling ,Lightning ,020901 industrial engineering & automation ,Electrification ,Dielectric breakdown model ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Electric potential ,business ,Geology - Abstract
Sideflash is a kind of lightning striking on the side wall of tall buildings. This unexpected thunder stroke often leads to big property losses and endangers lives of people. However, the origin and development mechanism of this lightning stroke are still not clear. To simulate the sideflash, a 3-D numerical model of negative cloud-to-ground lightning is built which is composed of two parts: the thundercloud model and the stepped leader model. The thundercloud model is based on the 3-D dynamics and electrification coupled model. And the stepped leader model is based on the Dielectric Breakdown Model (DBM). The Poisson's Equation solved by the Successive Over-Relaxation method is employed to refresh the spatial electric potential field. Finally, some buildings with different heights are set on the ground. In the numerical simulation, some sideflashes are observed. Based on the comparison experiments, the origin of these phenomena is discussed.
- Published
- 2018
43. Interfacial synthesis of polypyrrole microparticles for effective dissipation of electromagnetic waves.
- Author
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Aming Xie, Wanchun Jiang, Fan Wu, Xiaoqing Dai, Mengxiao Sun, YuanWang, and Mingyang Wang
- Subjects
POLYPYRROLE ,PARTICLE analysis ,ENERGY dissipation ,ELECTROMAGNETIC wave scattering ,ELECTROMAGNETIC fields - Abstract
A strategy has been adopted to regulate the dielectric properties of polypyrrole microparticles for good electromagnetic absorption performance through an interfacial synthesis process. Classical Debye relaxation theory and resistor-capacitor model have been employed to illustrate the electromagnetic dissipation mechanism of polypyrrole microparticles. The prepared polypyrrole microparticles exhibit an effective electromagnetic absorption bandwidth 5.48 GHz (deeper than -10 dB) from 12.52 to 18 GHz with a filler loading of 15 wt.% in paraffin. It was demonstrated that the morphologies of conducting polymers can significantly affect the dissipation of electromagnetic waves, supplying a strategy for the design of effective electromagnetic absorption materials. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
44. Solid-state synthesis of a conducting polythiophene as efficient Pt-free thin film counter electrode for dye-sensitized solar cells
- Author
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Aming Xie, Ang Li, Fan Wu, and Xiaoqing Dai
- Subjects
Auxiliary electrode ,Materials science ,business.industry ,Mechanical Engineering ,02 engineering and technology ,Hybrid solar cell ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Polymer solar cell ,0104 chemical sciences ,Dye-sensitized solar cell ,chemistry.chemical_compound ,chemistry ,PEDOT:PSS ,Polymerization ,Mechanics of Materials ,Polythiophene ,Optoelectronics ,General Materials Science ,Thin film ,0210 nano-technology ,business - Abstract
An efficient Pt-free counter electrode (CE) based on poly(3,4-ethylenedioxythiophene) (PEDOT) film for dye-sensitized solar cells (DSSCs) has been developed via solid-state polymerization (SSP) approach. The polymerization was simply initiated by sintering the monomer, 2,5-diiodo-3,4-ethylenedioxythiophene (DIEDOT), at the temperature of 135 °C. Furthermore, DIEDOT is not only quite suitable and economic for large scale synthesis, but also very stable in air. Under optimized conditions, the power conversion efficiency of a DSSC with a N719-sensitized TiO2 photo-anode and the SSP-PEDOT CE is 6.38% measured under standard 1 sun illumination (100 mW cm−2, AM 1.5).
- Published
- 2016
45. Using γ-Fe2O3 to tune the electromagnetic properties of three-dimensional (3D) polypyrrole (PPy) and its broadband electromagnetic absorber
- Author
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Kun Zhang, Wanchun Jiang, Xiaoqing Dai, Fan Wu, Yilu Xia, Mengxiao Sun, Derong Wang, and Aming Xie
- Subjects
Range (particle radiation) ,Materials science ,business.industry ,General Chemical Engineering ,Aerogel ,02 engineering and technology ,General Chemistry ,Dielectric ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Polypyrrole ,01 natural sciences ,Electromagnetic radiation ,0104 chemical sciences ,chemistry.chemical_compound ,Optics ,chemistry ,Electromagnetism ,Nano ,Broadband ,0210 nano-technology ,business - Abstract
Electromagnetism such as gravity can be considered an omnipresent force, which plays an important role in the functional activities of organisms. However, electromagnetic waves with different frequencies have aroused various harmful factors in human beings and wildlife. With the tunable dielectric property, the material can get a controllable electromagnetic absorption range against different types of electromagnetic pollution. In this study, we reported that nano γ-Fe2O3 can regularly tune the dielectric properties of the three dimensional (3D) polypyrrole (PPy) aerogel. On the one hand, it has advantages such as a rapid synthesis strategy (only several minutes), facile purification process (with only water), and on the other hand, this aerogel based absorber can reach effective EA bandwidths of 6.76 GHz (≤−10 dB, 90% electromagnetic energy was attenuated) and 1.88 GHz (≤−20 dB, 99% electromagnetic energy was attenuated) simultaneously at a thickness of 2.5 mm.
- Published
- 2016
46. Experimental Platform Development of Similar Simulation and Mechanical Test for Undersea Metal Mining
- Author
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Zhi-xiang Liu, Yu-xi Liu, Xiaoqing Dai, and Shan Yang
- Subjects
lcsh:GE1-350 ,Simulation test ,0211 other engineering and technologies ,Submarine ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Mineral resource classification ,Resource (project management) ,Cabin pressurization ,021108 energy ,Metal mining ,Platform development ,lcsh:Environmental sciences ,Geology ,Seabed ,0105 earth and related environmental sciences ,Marine engineering - Abstract
With the depletion of shallow metal resources in the land, the development of seabed resources has become a new direction. In order to achieve safe and efficient exploitation of seabed metal mineral resources, a similar simulation test platform was established for seabed mining of metal minerals in this paper. Similar simulation materials and the best material ratios were selected to make simulated specimens. A series of mechanical pressurization devices and model sample were prototyped and submarine simulation mining test was conducted. During the simulation mining test, stress and strain changes and microscopic observations of crack evolution were monitored by the static strain test system. These indicators revealed the characteristics of ore-rock mechanical change in the development of submarine mental resources. By exploring the best safe thickness of seabed resource mining, it provides effective data reference for subsequent seabed resource development, so as to realize safe and efficient mining.
- Published
- 2020
47. Human and Mouse Islet Single-cell Dispersion for Patch-clamp and Imaging v1
- Author
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Aliya F Spigelman, Austin B, Xiaoqing Dai, Amanda Gomes, and Patrick E Macdonald
- Abstract
Detailed protocol for dispersing human and mouse islets into single cells for patch clamp and imaging experiments
- Published
- 2018
48. Pancreatic Alpha-Cell Function and Identity in Human T2D
- Author
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Joan Camunas Soler, Linford Briant, Aliya F. Spigelman, Patrick Macdonald, Patrik Rorsman, Xiaoqing Dai, Seung K. Kim, and Yan Hang
- Subjects
medicine.medical_specialty ,geography ,geography.geographical_feature_category ,Chemistry ,Endocrinology, Diabetes and Metabolism ,Insulin ,medicine.medical_treatment ,Cell ,Glucagon secretion ,medicine.disease ,Islet ,Glucagon ,Exocytosis ,Alpha cell ,medicine.anatomical_structure ,Endocrinology ,Internal medicine ,Diabetes mellitus ,Internal Medicine ,medicine - Abstract
Glucagon is synthesized and released by pancreatic α-cells and, along with insulin, maintains blood glucose levels within the physiological range. We seek to understand the impact of glucose on the biophysical properties of α-cells in T2D. We studied α-cells from human donors (34 nondiabetic, and 14 T2D) and from mice fed a high fat diet (HFD) by whole-cell patch-clamp electrophysiology, with and without combined single-cell RNA sequencing (patch-seq). We found that, opposite to what is observed in β-cells, depolarization-induced exocytosis and Ca2+-channel function is enhanced at low glucose (LG, 1 mM G) and suppressed at high glucose (HG, 5-20 mM G) in nondiabetic (ND) α-cells. This is reversed in α-cells from T2D donors, which display a β-cell-like phenotype where HG amplifies exocytosis and LG inhibits it. Using pharmacological antagonists of Ca2+ channels, we found that LG increases P/Q-type Ca2+ currents in human α-cells, which are specifically linked to glucagon exocytosis. Similar results were obtained from α-cells of HFD mice for 10-14 weeks, where α-cell exocytosis and glucagon secretion were both enhanced, while exocytosis shifted from a dependency on P/Q-type (α-cell-like) to L-type (β-cell-like) Ca2+ channels. Finally, given that the Ca2+ responsiveness of α-cells is variable (suggesting cell- to-cell heterogeneity) and the function of α-cells is dysregulated in diabetes, we applied combined computational approaches and single-cell RNA sequencing with patch-clamp analysis (patch-seq) to link single human α-cell function with transcriptomic profiles. We found distinct α-cell sub-populations in human islets that are either resistant to, or sensitive to, dysfunction in the form of a shift towards a more ’β-cell like’ functional phenotype in T2D. In all, we provide new information to understand normal function of α-cells and important determinants of glucagon secretion in health and diabetes. Disclosure X. Dai: None. J. Camunas Soler: None. L. Briant: None. A.F. Spigelman: None. Y. Hang: None. P. Rorsman: None. S. Kim: None. P. MacDonald: None.
- Published
- 2018
49. One-pot synthesis of biomass-derived carbonaceous spheres for excellent microwave absorption at the Ku band
- Author
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Mingyang Wang, Yanyu Qiu, Xiaoqing Dai, A. Ming Xie, Nana Wang, Fan Wu, Yuan Wang, Xuliang Lv, and Mengxiao Sun
- Subjects
Surface oxygen ,Materials science ,Chemical engineering ,Annealing (metallurgy) ,General Chemical Engineering ,Loading ratio ,Composite number ,One-pot synthesis ,SPHERES ,General Chemistry ,Ku band ,Microwave - Abstract
Micro carbonaceous spheres have been successfully synthesized from watermelon via a one-pot hydrothermal reaction. After a quick annealing process to remove the surface oxygen groups, the as-prepared spheres presented an excellent microwave absorption performance at the Ku band (12–18 GHz), with a loading ratio of 25 wt% in a paraffin-based composite at 2.0 mm thickness.
- Published
- 2015
50. Assessing the Effect of a Crop-Tree Intercropping Program on Smallholders’ Incomes in Rural Xinjiang, China
- Author
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Lijie Pu, Fangping Rao, and Xiaoqing Dai
- Subjects
Program evaluation ,Security of tenure ,Geography, Planning and Development ,program assessment ,TJ807-830 ,intercropping ,income ,implementation constraint ,rural Xinjiang ,Management, Monitoring, Policy and Law ,TD194-195 ,Renewable energy sources ,Agricultural economics ,0502 economics and business ,Economics ,GE1-350 ,050207 economics ,Land tenure ,Environmental effects of industries and plants ,biology ,Renewable Energy, Sustainability and the Environment ,business.industry ,05 social sciences ,Gross income ,Intercropping ,04 agricultural and veterinary sciences ,biology.organism_classification ,Livelihood ,Environmental sciences ,Agriculture ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Rural area ,business - Abstract
Governments in developing counties often promote intercropping (crops intercropped with fruit trees on cultivated land) schemes in order to improve smallholders’ income. However, the implementation of such schemes is often hindered by inappropriate institutional environments and inefficient project management. It is important to assess the impacts of such intercropping programs, especially since such a cultivation strategy can often align closely with smallholders’ livelihood strategies, particularly in poor and remote rural regions. This paper attempts to assess the impact of an intercropping program on participants’ incomes in rural Xinjiang (China), and to explore the possible shortcomings in the program’s design and implementation. We apply a propensity score matching method, based on a survey dataset of 352 households, supplemented with descriptive analysis based on our anecdotal field observations. The findings demonstrate that the intercropping program had negative effects on the incomes that participants derived from farming, their off-farm income and their gross income. Overall, participants experienced significant losses of income. Anecdotal observations show that land tenure insecurity played a crucial role in negating the anticipated income improvement effect of this program. Farmer’s perceptions that they have limited security of tenure made them reluctant to invest the necessary time and resources to make the new cropping systems a success, while the available subsidies only partially covered the costs involved. In addition, the program led to a significant drop in yields of field crops as the trees were competing for a limiting and fixed supply of irrigation water.
- Published
- 2017
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